Dream rhymes with meme! Meme->Dream Dream->Meme Coincidence?!? I think not! I mean, it actually, probably, maybe, totally is but I just don't think about it.
Your photo editor person needs to learn to crop properly, so that he supporting visual pics fit inside the box. Or your video editor needs to place the content in the proper priority sequence before compiling. Either way, whoopsie!
By far the most popular PCB material is FR4 which is a combination fibreglass matting and Epoxy resin. The solder mask was originally screen printed but with most boards being done with fine pitch SMT these days resist is almost exclusively photo image-able. Silk screen printing of the legend on PCBs is mostly the process used because it's so quick however if you want legible text on a modern high density board then photo image-able polymers/resins. Phenolic resin PCBs are only used for really cheap things like the PCB's in appliances & radios etc that have low complexity. This is mostly because you can punch the component holes (much faster) rather than drilling them individually. It's been my experience that phenolic PCBs can not be made with reliable plated through-holes so they are made with single sided tracks with through-hole parts on one side and SMT on the other. Epoxy (eg. FR-4) boards can be made with anything from single sided up to 32 or more layers of traces and have extremely reliable through-hole plating.
did you ever notice that glass is also green if you're looking at the edges of most sheet glass and mirror. you can get it in the whole rainbow of colors but it is much more expensive
@J Iceberg even when getting a 2$ china prototype you can choose from like 8 colors (at some also apples fancy matte black^^) so I bet if you have high enough piece count basicly any color is possible
All I was saying was it usually depends on manufacturer, like you said options are available. I work in a competitive analysis group so I see all the latest packages from multiple manufacturers.
I’ve used red to indicate proto/beta as well. Final color depends on the application. My PCBs often ended up black to complement the color scheme of the product. Green is for when you don’t care what the final product looks like.
Very good but as others have said, phenolic paper is little used these days for general PCBs and not at all for multilayer boards. The general go-to material for general use is epoxy-resin-bonded-glass-fibre or epoxy-glass which come in various grade of which the commonest is "FR4". Phenolic paper material is also often supplied as grade FR2 and is used in come ultra low cost and low power consumer applications where fine conductors and are not required and the user environment is benign.
In older (guitar and other) amplifiers the terminal post boards were made of phenolic paper and sometimes, there are issues. Those boards are sometimes a bit hydroscopic and start leaking causing noise and other (worse) issues. Of course, this problem varies with the average conditions the amps have been in for 40-50 years. Seemingly, (and I guess, not surprisingly) these boards usually don't respond to cleaning very well. They also warp sometimes.. For some of the more valuable (guitar) amplifiers there are new, fiberglass aftermarket replacement post boards. For others, the board material and loose posts so one can be "made". Either way, not cheap, medium skill and still hurts the "vintage value" quite a bit. Always surprises me when owners honestly think that electronics should operate trouble free for 40-60 years
Hey I work in a shop that makes different things out of that fiberglass resin material, we mainly use g11 and stuff like that but we do rarely use phenolic and nylon
Yes, I believe the older phenolic boards are only suitable for single sided boards without plated through holes or vias. Might sill exist in some toys and very cheep radios.
Yes, and phenolic board are trash... ever tried to put one in a reflow oven? you better keep your temps just right or the entire room will stink for days
they're great for prototyping though since they're cheap and cutting them not only doesn't make any dangerous fiberglass dust but also doesn't usually need any tools beyond a utility knife. or, if you get the really cheap ones, just a reasonably long thumbnail.
Epoxy fibreglass substrates are the most common, but more exotic materials like teflon and ceramic are used in high performance (high frequency and high temperature) circuit boards. Phenolic materials haven't been used in quality products for a while.
oh and there's metal core (aluminum substrate with a kapton insulating layer) for heat dissipation from high power LEDs. but soldermask on most of those is white
The old phenolic boards were very rarely green. The green ones seen everywhere today are fiberglass, same material as car hoods and boat hulls. There are various different weaves and resin contents but you almost never see phenolic paper boards anymore. They are fiberglass.
Agree, the old board you used to make your own circuit board was brown. Interestingly PC motherboards and other things you buy for self builds or upgrades tend to be black. However this is an product the customer buy so you want it to look quality. Another point is that advanced electronic like computer motherboards tend to have lots of layers with circuits on them, over 20 is not uncommon,
I have seen phenolic paper PCBs with bottom painted green around the solder points, it was more common in 1990's-2000's consumer tech like TV's and radios._
In the US, the fire hydrant color code is a bit more extensive than described here, but that could be an entire video on its own. I went down that rabbit hole a while back, and it was surprising how the cap and body colors can indicate so much.
I too ventured down this rabbit hole 🕳 🐇 to figure out why so many colors besides the typically recognized red. Different water pressures, types of fires, location of pipes beneath the ground. It was indeed complex.
in the 80-9+ i worked at a NELCO circuitboard manufacturing plant in Tempe, Az. start to finnish jobs. ie start with cloth roll of fiberglass, 1 tone each, goes thru 3 story dip and oven roller proscess. later i diped large boards in racks like ? tubs of various hazordous chems for reserch and development. Jello was one secret add to mix to harden copper . i did pull and tear tests on samples. later copper thickness. My ex Son, and her mate work at Microchip still.
I used to work at a circuit board manufacturer. My job was to run the boards through a scrubber to clean. Then, I ran them through a coating of photo imageable solder mask(PSIM) and bake to dry. The next step was exposing everything but the contacts to ultraviolet light to harden the solder mask. Then, another scrubbing machine cleaned the remaining solder mask from the contacts, leaving them exposed.
I work in electronics since 1991. Paper-based PCB's are very seldom today, used only for low-end-electronics like cheap toys or cheapest entertainment devices - sometimes still without soldering mask. Today's standard for PCB's is Glass-Epoxy FR-4 (also called Glass-Epoxy A10), in high-end electronics sometimes the boards are made of a ceramic substrate. In the company I currently work, we equip PCB's with components (SMD as well as THD) for hundreds of clients in different market segments. The PCB's I work with have many different colors, but still about 90% of them are green. Green boards are most comfortable to my eye and make fewest problems (good contrast) in automatic optical testing.
The photo of the sailor doing Micro repair work is a job I had in the navy for a couple of years in the early 80's. Pretty much the same equipment. We not only replaced components but could repair the boards themselves if it got burned or Runs broke. As a joke, Maintance Control brought me a board that had been broken in half and ask me how long it would take to fix. I said give me about a week (and I could have done it). They took it back and never saw it again. 🤣 And being military CB's they were always the classic Green.
Crazy! I've been soldering for decades. I noticed the difference in odor of solder and flux over the years but never realized how much easier green is to see. Cool video!
Depends on the board shop. The Asian cheap ones typically take 2 extra days in theory. However the more expensive prototyping services don't typically take longer.
@@howardbaxter2514 im not familiar with that compnay/brand, but for me seeing a red board always makes me think of ATi. they made my first two accelerators. my friend from highschool was 'green with envy' hyuk hyuk hyuk😆
I'm old enough to remember the many colors of boards that my dad would solder on when he was repairing old TVs and radios, among other things. LOL, I'm even old enough to have watched him replace vacuum tubes in those giant, even older, TVs and radios, in fact!
Simon, you got a couple things wrong or at least not exact this time: Initially monochromatic computer screens usually have been white but green or amber screens were found to be more ergonomic with green becoming the one more widespread. PCBs are made from a couple differrent materials. FR1 and FR2 are the phenolic paper materials. Those are used in low cost mass produced products with lower technical requirements. While a solder mask is not uncommon on them not all use it. FR4 is the most common PCB material today. It is epoxy with glass fibre mats. The material is usually kinda like a very pale greenish to yellowish color. Almost all of them have a solder mask. The solder mask used to be applied in a screen printing process but today it is more common to use a photo structuring process for the solder mask. The mask is either applied in liquid form or as a dry film and then exposed to UV light with the required structure and developed (unused material washed out). The use of dry film results in a higher precision (which is important for small structures) and it simplifies the change between colors. It also has better protection against solder creep (solder creeping under the mask).
I've wanted for a long time to get those chemicals for making PCBs - that strip off the copper or whatever.. I don't really remember much about the process but some of what you said reminded me of that.
@@Blalack77 There are a number of different processes. Iron(III)chloride is the messiest, leaves yellow-brown stains everywhere. Hydrochloric acid with hydrogen peroxide is possibly the fastest but can get dangerous. Ammonium persulfate is quite widespread and safe to use. I used all three, did finally stick with the ammonium persulfate but it has been many years sice I made a PCB myself. The express services have gotten so cheap that it makes no sense anymore.
@@phife1878 Another reason why most PCB production has moved to the dry film, it is no messy. I am in the electronics industry since the mid 1980s and always wanted to understand the production process of the stuff I make :)
I’ve worked with circuit boards for over 40 years and I am absolutely sure they have never been described as “ dark, butterscotch, brown.” They now sound tasty.
I first worked with them in the '60s. I would have said they were mostly 'Outhouse brown', but the shade varied somewhat in the early days. Philco used some that were pink plastic that barely survived wave soldering in their consumer electronics. Use a typical soldering iron of the era and it would melt holes through those boards. Rather than solder mask, early Delco circuit boards looked to have been float soldered, after being dipped in a thick rosin flux, because they never cleaned it off their boards.
How about them Vacuum tube days where all the components are floating in the air like a 3D spider web of capacitors, diodes, and lots of solder joints? The circuit board deserves to be on a list of greatest inventions.
@@cdogthehedgehog6923 google image a old vacuum tube amplifier. Scroll till you see whats underneath the chassis of any old tech. Its insane sometimes and I bet a nightmare to diagnose.
Yeah. "Through-hole technology" sounds pretentious, until you realise it isn't the absolute baseline. "Potted circuit" is a term I have heard - like, you build it 'in the air' but then fill it in with some insulating gunk to stop things moving about.
My engineering professor, circa 1978, described tubes as transistors that have a light on so the electrons can see where they're going. A part time job of mine., at a local electronics store, was selling tubes. Customer hands you one, plug it in a tester, light doesn't go on, sell him another. All for $3.65 an hour.
@@cdogthehedgehog6923 you can see that early stuff if you watch this video about adding iPod input to vintage radio amp th-cam.com/video/j8YeJ0T3DpI/w-d-xo.html Later on, they used circuit boards with through-hole components, but before all of the circuits on the board - they used all sorts of little jumper wires. That was called "wire wrap", and here's a video about that: th-cam.com/video/OujuzAUD9pc/w-d-xo.html Later they went to phenolic with traces on one side only, then over time we moved to FR4 - first double sided, then eventually multi-layer.
I love the fact that you're Channel deals with some mainstream things but also some things that I never would have thought to go look up but are very valid questions to my curiosity. I love your random videos that pique the Curiosity I used to have for random things and give such complete and total answers.
LOL I was going to comment on this too, but wanted to see if anyone else heard that too. Even the closed captions showed "human pencil" They must have really chose yellow to differentiate them from simian pencils which are brown and frequently thrown at people at the zoo. Despite them being yellow, I keep losing them.
'The Human Pencil' - now that doesn't have any odd connotations does it? Are there pencils made FOR other beings? Are the pencils primarily made OF human? Hmm...
@@halexvr And then he got away with it in post-production - which I find strange. Is this a tactically salient blooper to get greater engagement around the comment section? ( Glad I paid a visit, anyway. )
Most NYC Taxis are now neon green. They started changing the color a few years ago. Also, our hydrants come in a variety of colors and some residents paint them themselves when they're neglected by the city. In my neighborhood it's common for residents to paint the hydrants (also known as Johnny Pumps) red white abd blue or green, white and red.
The brown phenolic board material is still used on low cost products. But almost anything of quality or high complexity is made of fiberglass epoxy board substrates. The brown phenolic is too prone to cracking if the board gets flexed. I have designed printed circuits since the mid 1970s and I have not done a single one for phenolic substrate material since the first ones I did on a computer in the mid 1980s. About solder masks, I have seen solder masked boards from the 1950s, especially in aviation applications and car radios. While everything you said about green is true, at my two jobs since 2001, I introduced the use of red solder masks for prototypes and pre-production samples. Because we were having prototype boards getting mixed with production. Sometimes when production spoiled one too many boards, they would come into the lab and nick a prototype board so they could fill an order. Our hours did not fully overlap. Or we would send a prototype out to a reviewer and they would "forget" to return it. Then a couple years later it would show up at the service department with an odd fault and someone would make a warranty claim on it. So we switched to red boards for pre-production boards as there was no extra charge for different colours. This stopped production from stealing pre-production boards and forced them to either make more spares or properly rework the spoiled ones. My second last job still used green for production. My last job from 2010 until I retired in 2018 we used green on the standard grade products and blue on our premium product line. Especially where part of the board may be visible on the outside. Our board houses have never charged any extra for colours as solder masks have not been silkscreened on for years. Instead it is usually a photo laminated process and there is no cleaning of machines needed in order to change colours. But yes, for most companies green is more a tradition than anything else. My last batch of 5 prototype boards in 2021 for a project of my own, a Raspberry Pi accessory, from a board house in China were in blue and less than $10 for 5 small boards made with a fully automated system. These were double sided plated through boards with vias of less than 0.5mm and legends printed on both the top and bottom. Then about $20 for shipping. I got then 2 weeks by DHL after sending the gerbers to the vendor. "Gerber" is the universal data format for PCB files, one for each layer with the solder masks and the "silk screen" files as separate layers. It might be an interesting story to tell us how the Gerber format became the worldwide standard for outputting the data from pretty well all PCB design programs right from the beginning of PCB creation software around 1980 to the present day. And the file format has not really changed at all. This is the sort of thing that appears to have been correct right from the start.
On the documentation layer (aka silkscreen layer) with blue paste mask we use yellow for visibility. It works better than white. But with red paste mask while works best for the documentation layer.
When I was making printed-circuit boards at home in the early 1980s, using supplies from Radio Shack, the board wasn't green, but that tan color that Simon mentioned. Now I know why.
@@pacificostudios that's incorrect. Phenolic board remains junky even for someone that makes boards at home. Most do not apply a solder mask to homemade boards. So the color you see is the color of the substrate material. Fiberglass and phenolic substrates are very different looking. And yeah the boards at Rat Shack were the crappy stuff.
@@1pcfred I actually have two battery chargers from Radio Shack 87- 89 the 87 edition is designed to recharge carbon/ zinc (up to 50 times) and still works. The 89 version is for ni/cad also works for ni/hydride. By far the best purchase though of the 7 R-Shat products from the 80s I still have is a universal power supply that is overheat/polarity reversal protected (and granted that I don't have any of the adapter ends which had design flaws, my 10 years old self usually wired into the battery compartment of whatever electronic device I didn't have batteries to. Nowadays the electronics are hyper sensitive and unforgiving and also designed to have a very short lifespan. Best $6.99 deal ever! lol
These days, almost every PCB manufacturer offers a range of colours. I always get mine with a black solder mask because I've had several people tell me that my black boards look far cooler!
At the PCB manufacturer I worked at, who designed and built custom test equipment from the PCB on up to full test systems, we used red PCBs to denote that those boards were required to be built lead free, to adhere to ROHS requirements. It was a nice obvious way to ensure they were not exposed to any lead based processes.
1) Phenolic Resin circuit boards are actually rare these days - they have been largely dropped because they are considered a fire-hazard. These days the FR-4 fiberglass-based circuit board is a lot more common. 2) I had actually not known about the dangers of black and several other colors of solder-mask re: conductivity. I've stayed with green or red for more prosaic reasons - I find black and several other colors make boards harder to work with and/or fix when they have a failure (or there is a mistake in the design that needs a manual bodge to fix) 3) If I had the money to spare, I'd be a Patron or paying subscriber to your channels, Fact Boy - keep up the good work!
I built a lot of paper phenolic boards up until the early 90s. They were were single sided and the holes were punched with no plating in the holes. Connections were made between sides with the components themselves or jumper wires. The backs were usually covered in solder mask to prevent solder shorts and un-necessary drag out from the solder pot. As circuits got smaller, denser and faster multi-layer fiberglass boards with plated holes became the standard. I have used other color masks for prototype boards, but it requires adjustment of the equipment sensors and vision inspection systems. The plant was much happier when we stuck with green.
I have seen red circuit boards as well as green. They always look pretty weird though. The problem with painting things red (like fire hydrants and even stop signs) to have it more visible is that red tends to fade much faster than other colors.
phenolic PCBs usually do not have mask on both sides, so the top is brown. The boards talked about here are usually FR4 which is fiberglass, and has solder mask on both sides which tends to be green traditionally. Most of the PCB stock art shown here is indeed fiberglass.
Another suggestion: In America, why, in some cities, fire trucks are not the classic red in color? When I visited my father years ago in Denver, Colorado, that city's fire trucks were a bright, yellowish green.🤯 I think you sort of answered this in the Bonus Facts: is had to do with the level of desired visibility. Fire trucks come in various colors around the world. BTW, what color are Prague fire trucks Simon?🤔
I have seen red, white, yellow, and green fire trucks. It also helps that the there's a Fire Fighter's convention every year in my area. I think I even saw a blue one, too.
When I was a volunteer fire fighter - something like 40 years ago, I made a rather large grass fire in south-west Houston where a field had been allowed to grow to shoulder high grass. A captain from a Houston Fire station wandered off to find some fire to fight. After a bit we hear this odd sounding FOOMP sound. Said captain came back out of the high grass with his then new red bunker gear now "Yellow Cab yellow". It seems someone had dumped several 55 gallon drums of the "Yellow Cab" paint in this field. The fire surrounded the drums and a few of them cooked off, resulting in a shower of very hot paint on anyone near by. I never did hear if the captain was able to remove the paint or if he just went and got another new set of bunker gear.
As someone who learned computer programming in the 80s (My 1st computer was a TRS-80 from Radio Shack) the old school "green screen" displays are burned into my memory. Since them, I've build PCs from the motherboard up, but I never knew why motherboards were green. You never fail to teach me something new with any of your videos. Keep up the great work!
5:35 I believe green is most most distinguishable also because it is in the middle of the colour spectrum. For this reason green has been adopted as the default colour for safety first aid stations. Namely eyewash stations as green is the last colour you can perceive as your vision diminishes. Also. Pet conspiracy theory of mine. This is why aliens are little green men. Witnesses may have been smoking something not friendly to a sharp sense of eyesight haha. Keep up the good work. Feel free the fact check my claims. I’m not an expert nor should you take anyone’s claim as fact. 😉
Love your stuff Simon! (All channels!) And as your self-titled "fact-boy" I thought you might appreciate some more facts. I've been in the printing/publishing industry for over 35 years. When referring to a Pantone colour (in this case the London buses' Pantone 485C) it is important to know from whence the Pantone colour number comes from and what the "C" (or "U") stand for. These numbers reach back to PMS, of the Pantone Mixing System, a recipe guide to mixing various colours of ink for printing. A colour doesn't have either a C or a U behind it (although their swatches do) as the "C" stands for Coated and the "U" stands for Uncoated, referring to the stock, or paper upon which it is printed. The ink itself does not have a C or U. You would get a can of PMS-485, but it would only become 485C once on a printed surface. The London bus paint would be Pantone 485 and would only become 485C once on a coated (in this case the metal surface the bus). The colour of Sonic the Hedgehog's fur is Pantone 286 blue. Sonic's fur itself would be 286-U. I know I'm splitting hairs, but....there you have it. :)
As I was about to comment I observed that quite a few others called out issues such as pcb materials, monitor screen colors and others. Quite a following and knowledgeable at that, you've done well developing such a following.
Oddly enough, no mention of the iconic American School Bus. It never ceases to amaze me how many TH-camrs originating from Europe will go to America and be utterly surprised to see that such a thing exists. Now if only American motorists were aware of a big yellow hunk of metal with some red flashing lights and a red stop sign built in to it!
Ive always looked at those circuit boards since I was a kid and the thought of why theyre green always came to mind but I never bothered to find out. Thanks to you now I know without having to really put in any effort lol. Thanks for the info and the great video! :)
@@gelatobiscuato8121 sadly, he got most of the details in the video wrong, so you didn't learn as much as you thought you did! Lol Read the top comments on the video to see the real facts he didn't research long enough to discover...
I have to agree with white paint on a green background being highly visible. I have to look at circuit boards during the course of my work while troubleshooting. Now if only the manufacturers could install them right side up so they would be even easier to read. Thanks for another great video.
Yikes. No, OLD circuit boards used phenolic paper. Most boards today are fiberglass based (with the fiberglass&epoxy normally being yellowish), although other materials are also popular for high frequency devices - colors for those also vary, but white is common. Circuit board manufacturers HATE the phenolic boards - they degrade in the chemical tanks while being etched, which taints the etch and increases costs.
If you looked at old "high end" stereo boards, they used crappy "brown" phenolic single sided boards, while their contemporary "jelly bean" computer board vendors, used epoxy fiberglass multilayer boards. That conflict I always found funny.
Tech note. The protective mask is on the PCB primarily in order to facilitate heatwave application of tin. The board is basically exposed to molten tin which attaches only at the locations not protected by the mask. Then you take the SMD (surface mounting design) components, put them where they belong any bake the whole thing. The tin melts and solders the components. Of course the mask also protects the copper paths on the PCB, but I think it's a secondary effect.
I’m from East Texas and a lot of the fire hydrant’s in the area are painted to match their local school colors. I think it’s a trend that started within the last 15 to 20 years and I’ve often wondered how safe some of the color combinations are. As in how the heck can those be easily found at night?
Maps and memory, my department had agreements with the city we bordered and after a little while we knew where the hydrants were that were closest to us and some backups as well. It's worse in the winter here in WI when the snow covers them and you have to dig the hydrant out of a snowbank or worse the plowed snow.
I think the "Matrix" color is more of a throw-back to the green phosphorous screens common before CGA/EGA/VGA. Even though I am almost too young to have encountered dummy terminals, I am personally a fan of the amber phosphorous colour. I always thought they were better to look at but were just less popular for some reason.
@@michaelterrell phenolic boards are type FR2, fire retardant modified material. They're commonly found in power supplies, especially ones that are at least a few years old and are not a fire hazard. The board in the Xbox360 control pad is also phenolic paper, and they're also found in all sorts of cheap toys. Large manufacturers across the industry (suppliers and cpntract manufacturers etc) have been rolling down FR2 production and there probably won't be any new FR2 boards made within just a handful years. They're only offering FR4 for new designs which is an epoxy glass fibre. In general, using FR2 with lead-free solder tends to lead to delamination and regret.
@@SianaGearz I've worked on and built circuit boards since the late '60s. FR is the fire rating but I have seen both FR2 and FR4 boards that have caught fire and burnt. One FR$ board that failed destroyed a new $20,000 Telemetry receiver at the place where I worked. It was in the standard burn in process before final alignment. If the chamber's fire suppression had failed, it would have set the building on fire. I currently have over 1200 reels of RHOS SMD components in my home shop to build boards with. I've also used a lot of FR4 cabling for jobsites. I worked as a Broadcast engineer for many years.
@@michaelterrell Yeah i should have said "not usually considered an increased fire hazard" but yeah they can burn. The chemicals work to suppress fire up to a point. FR4 is more inherently resilient, but epoxy too has an ignition point.
The funniest part of these videos is the people attempting to "correct" him before watching the video, and these corrections being mentioned within the video anyways.
A lot of people have already commented on this but: Phenolic paper PCB substrate is still very much used but mainly for very cheap products or for power supply boards. If you open up a generic mobile phone charger you're very likely to find a phenolic PCB there, as well as in the internal power supplies of game consoles, maybe even PC power supplies. I believe this is because power supply circuits tend to use a smaller number of much larger circuit components compared to other things, so single-sided designs with wave soldering are more practical there. Solder mask on phenolic PCBs is also green, it's just that phenolic boards are often single sided and will only have solder mask on the side with copper.
Two questions; 'Sole-der'!? Is that how it's pronounced in the UK? In the US we say sAAh-der, and sAAhdering. Also, 'human' pencils? While I love the idea of species specific pencils, I don't think this is "a thing". 😄
Seems all the English speaking Commonwealth countries pronounce the 'l' in solder. The most pronounced I've heard is Mr. Carlson's lab from Canada. He seems to put an accent on the 'l' and I laugh every time I hear it. OK fact boy, how come you guys pronounce the 'l' in solder?
I have been designing and procuring PCBs for longer than I'd care to admit. Never gave much thought to color being anything but a pure cosmetic choice. In fact, some of the PCB manufacturing firms tout having a free choice of other-than-green colors as simply a distinguishing factor on theirs. It's "cool" to have other colors, though I always found this a frivolous expense, if it's not free. Well done.
Just one note from someone in the industry. Most inspection is done by machine as Simon says, but manual inspection under a microscope is still often necessary when problems arise, and I see someone at a microscope with a board almost every time I go to the production line. But we're making tiny high-density substrates for CPUs rather than large component boards, and I imagine that this sort of manual inspection is not near as frequent for most PCBs. (Plus most of these issues and inspections take place before the solder resist step, anyway)
Phenolic boards are rather rare these days due to their worse fire rating compared to FR4 a board material that is far more common these days. Phenolic is also less thermally stable and therefor decomposes more easily around warm components, or in warm environments in general. Phenolic boards are barely used today. (and this were partly already the case in the 90's) The green color comes from the solder resist added on top, it is to prevent solder from smearing over the board as easily, ie to prevent unintended shorts. Also, in regards to chlorine and bromide, these are practically outlawed. In the EU all electronics products must live up to RHoS, ie, the board must be halogen free unless one's application is on the exception list. (And the Brussels effect makes this more or less a world wide requirement.) In regards to colors indicating stuff. This is a myth, or rather, very few companies actually do this. Red boards aren't indicative of a prototype. And PC components aren't color coded either. Some companies use specific colors on their boards, either for marketing/design reasons. A lot of PCBs in computers these days tends to be black, red, or blue. Though, commodity components like RAM and SSDs tends to stick to green since the increased manufacturing cost of other colors is cost prohibitive in that market. In regards to surface mount vs through hole components. There isn't any line in the sand for one being superior to the other. It depends heavily on the application, through hole components have superior mechanical rigidity, so for connectors it is still heavily used and will remain so. Surface mount however offers much tighter pin spacing. So depending on the job, one will use one or the other, but the typical board tends to have both. Even some components uses both approaches, typically seen on connectors. And a lot of hobby/prototype boards uses surface mount as well these days. It isn't really any harder to work with. This is just my two cents having worked in the electronics industry for a rather long time.
As mentioned in a comment by Guido Körber todays common PCB's use glass-epoxy and the natural color is a light shade of green. In your video at 6:54 you can see the lighter green of the bare board contrasting with the darker green of the solder mask. Look at the upper edge of the PCB near a mounting hole.
I used to go to an after school electronics class where i built circuits and studied these. I was about 10 back then. For those who know, in Romania it was called Palatul Copiilor. I'd also be in karting and IT classes.
This explains why a lot of the enthusiast motherboards that are black are more expensive now. Thanks for that! Who remembers the DFI Lan-party boards back in the early 2000s with the UV plastics that were yellow/green/orange? I miss those days...
------------------ SPOILERS that will save you 14 minutes. ------------------ A circuit board not only has components soldered to it, but also copper circuits printed into the fibre glass core itself. Green is the color of the solder mask layer on top to prevent the printed circuit boards from shorting. It's green because they had to standardize the color to something and it is believed green creates the best contrast for visibility of the components on the board.
@@1pcfred @Paul Frederick You could be right. I was going by this : "It is due to the solder mask, which protects the copper circuits printed on the fibre glass core to prevent short circuits, soldering errors, etc." ------------------ So "copper" "printed on" "fibre glass core" then protected by "solder mask". I was pretty close. ------------------ Look up : ablcircuits & solder mask
I am a SMT operator and make populated PCB boards for some of the leading auto manufacturers and all of the boards we make are fiberglass, not all are green, most, but some are white or blue.
Circuit boards are definately still examined by human eyes for the purpose of repairs. I love this. Perfectly obvious and elegant answer right in front of me all along that I didn't notice
for 5 years i worked for a custom PCB manufucter my job was to run a spray booth spaying the green mask then the boards would go into the heated tunnel machine to dry boards then they go to other room to have the boards to be exposed to a uv lite after a circuit stencil was placed on the boards them it would go into a machine that would wash off all the mask over the the circuits that needed to be exposed
Yellow fire hygernts are used in Canada as well! Just all firetruck that operate on airports are yelow=greenish colour (and for most of you >colour< has a U in it...! And the reason for the yellow firetruck it's easier from a distance to see them!
I've worked for companies that had different color circuit boards. The coolest thing was in one company we were concerned about using circuit board cleaners that were environmentally harmful. We switched to a solution of citric acid which worked great and did not hurt the environment. The pleasant side effect was our manufacturing line smelled like oranges.
We use red to indicate that there's something special about the requirements for the boards. Lead-free requirements, conformal coating, etc. I personally don't like doing anything other than green until the final build is ready to go, works well in the AOI we have since it was designed around green PCBs.
This is the most business related content you’ve ever created. Perhaps this channel will also merge into the Business Brain Blaze multi-verse. I’m here for it.
Most of the old audio equipment from the 50s, 60s and 70s mainly contains brown and yellow PCBs, those were without solder mask, but early PCBs with solder mask are often yellow-ish brown too.
I use to apply it through silkscreen then bake it on the boards, we also eched the traces and glued multi layer boards together, applied the white lettering paint after. These jobs making circuit boards are all gone now, I did this job in 1980.
I have brown circuit Boards too and never gave a thought about them being green, but now... it's basically a Uniform Symbol to have circuitry on green base.
I remember using a Hazeltine 2000 terminal back in the late 70's. Never occurred to me to wonder why the on-screen text was green. 45 years later, now I know.
In the maritimes barns were painted w a mix of cod liver oil and powdered rust. Makes a great preservative for wood, especially when exposed to harsh costal conditions.
Simon, circuit boards are no longer limited to the color green as you mentioned. Interesting logic about use on various color combinations. Only the cheapest PCB's are phenolic paper and only used in very low end electronics. The most common boards are epoxy glass such as generic FR4 or Isola 370HR. The Solder Mask comes in a range of colors. Try Black Boards with gold traces and a clear solder mask. I did this in very high end Audio Equipment. Looks stunning when done right. Today green is the cheapest color. Silk Screen might be colors other then white. Manufacturing lines are designed for quick change. There are certain requirements specified in IPC Guidelines for mil spec Class 3 PCB's used in military applications. For commercial boards anything goes but is primarily cost driven. The problems of acid traps is not longer an issue. My comments are based on 50 years current experience designing PCB's and PCB Assemblies. Besides Rigid PCB's there are Flex and Rigid Flex boards. These are a combination of epoxy glass and brown Kapton films.
The fun thing on the developement of the protective red painting is - this was known for more than 1000 years before xD That's why many traditional half-timbered houses you often see in europe ever had a red color (and its awesome to work with the original recipe, as the quite simple combination of iron oxide and linseed oil is great for workflow, easy to wash off and completely non toxic). Subsurface ship bodys - i revcently learned - are colored by the copper parts in the paint but - the logic between tradition and actual color is the same here.
Circuit boards are still often inspected by human eye. At my work we use automated inspection systems as a processing aid and not as final quality control. Part of the reason behind that is that it’s for implantable medical devices which are class 3 assemblies.
Fire hydrants in the UK are yellow, Barns are frequently black, London buses since privatised some have gone back to pre-nationalisation colours. London black cabs are famous. While traditionally UK telephones were part of the Post Office and thus iconic red boxes in Hull town the telephone company was independent and part of the corporation and thus like the buses the boxes are painted cream.
I worked on old equipment that had brown, yellow, and green boards. the green boards came in two shades - very dark green, and a translucent light green
I have hundreds of pencils around the house, but very few of them are yellow, as I get my pencils for free from all the companies that use them as advertising.
PCB Board is fiberglass, its referred to as G10 or FR4 here in 'Murca. I worked as a toolmaker producing precision parts for wire E.D.M. machines from this material, and I can state definitavely that it was a fiberglass matrix. Also, the green color is not a coating, I have machined thoiusands of parts from this material and I can assure you that it is the same color all the wat through.
3:30 the answer is that the green is a solder mask that protects the circuits from unwanted shorts. and they are green so that you can visually contrast the conductive traces vs the background green
What an obscure subject to cover working in electronic manufacturing I have never thought of why the PCB's I work with are green I have also worked with blue and brown boards but predominantly its green. While this is an obscure topic it is none the less interesting. 👍
Because green is the purest colour and much easier to make than gold. Ask any amateur alchemist. A bright red livery? Makes sense as livers are livery and they are bright red... until you cook them. So the colour yellow is an indicator of a bit of quality wood? Interesting... all my trousers are black, brown, or blue! :-(
When I started work repairing analogue sound equipment in 1974, most of the circuit boards I came across were a light tan colour. occasionally a dark brown, green seemed to come much later.
Just for contrast, red barns aren't (as far as I know) a thing in Germany. Buses (and trams) were a kind of yellowish-beige color scheme when I was young, but since have become more colorful, though my impression is that a lot of them have changed to blue-dominated color schemes. Phone boxes were postal yellow (as that's who run our telephones) but since then, the few remaining have become wall-less ... and the now split-off big phone company has a grey-rose color scheme anyway. Water hydrants ... mostly aren't. Over here, there are flat covers in the road that you pick off, and the water line is below that. Nobody running over hydrants. There are usually square dark-blue signs on nearby houses telling how to find it (so far from the wall, then so far to the right or left) - other colors for electricity, gas, whatever. And Taxis were black when I was young, and now have a sort of dark egg-shell color usually known as "taxi color". (And the taxi sign itself is black on yellow.)
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Dream rhymes with meme!
Meme->Dream
Dream->Meme
Coincidence?!? I think not!
I mean, it actually, probably, maybe, totally is but I just don't think about it.
Video starts at 1:23
Your photo editor person needs to learn to crop properly, so that he supporting visual pics fit inside the box. Or your video editor needs to place the content in the proper priority sequence before compiling. Either way, whoopsie!
By far the most popular PCB material is FR4 which is a combination fibreglass matting and Epoxy resin.
The solder mask was originally screen printed but with most boards being done with fine pitch SMT these days resist is almost exclusively photo image-able.
Silk screen printing of the legend on PCBs is mostly the process used because it's so quick however if you want legible text on a modern high density board then photo image-able polymers/resins.
Phenolic resin PCBs are only used for really cheap things like the PCB's in appliances & radios etc that have low complexity. This is mostly because you can punch the component holes (much faster) rather than drilling them individually. It's been my experience that phenolic PCBs can not be made with reliable plated through-holes so they are made with single sided tracks with through-hole parts on one side and SMT on the other.
Epoxy (eg. FR-4) boards can be made with anything from single sided up to 32 or more layers of traces and have extremely reliable through-hole plating.
did you ever notice that glass is also green if you're looking at the edges of most sheet glass and mirror. you can get it in the whole rainbow of colors but it is much more expensive
Having done a few gigs at Intel, the color codes were: red board: Alpha pass, blue board: Beta pass, green board: release/production spec
I suspect this could be the origin of the colored key cards and their order of use in the original Doom games.
Sudden realizations can be neat.
Apple uses black PCBs as do some other manufacturers. I have also seen red and blue.
@J Iceberg even when getting a 2$ china prototype you can choose from like 8 colors (at some also apples fancy matte black^^) so I bet if you have high enough piece count basicly any color is possible
All I was saying was it usually depends on manufacturer, like you said options are available. I work in a competitive analysis group so I see all the latest packages from multiple manufacturers.
I’ve used red to indicate proto/beta as well. Final color depends on the application. My PCBs often ended up black to complement the color scheme of the product. Green is for when you don’t care what the final product looks like.
Very good but as others have said, phenolic paper is little used these days for general PCBs and not at all for multilayer boards. The general go-to material for general use is epoxy-resin-bonded-glass-fibre or epoxy-glass which come in various grade of which the commonest is "FR4". Phenolic paper material is also often supplied as grade FR2 and is used in come ultra low cost and low power consumer applications where fine conductors and are not required and the user environment is benign.
In older (guitar and other) amplifiers the terminal post boards were made of phenolic paper and sometimes, there are issues. Those boards are sometimes a bit hydroscopic and start leaking causing noise and other (worse) issues. Of course, this problem varies with the average conditions the amps have been in for 40-50 years. Seemingly, (and I guess, not surprisingly) these boards usually don't respond to cleaning very well. They also warp sometimes.. For some of the more valuable (guitar) amplifiers there are new, fiberglass aftermarket replacement post boards. For others, the board material and loose posts so one can be "made". Either way, not cheap, medium skill and still hurts the "vintage value" quite a bit. Always surprises me when owners honestly think that electronics should operate trouble free for 40-60 years
It’s almost as if he’s reading a script and has no idea what he’s talking about…
Hey I work in a shop that makes different things out of that fiberglass resin material, we mainly use g11 and stuff like that but we do rarely use phenolic and nylon
I was just about to comment this lol
Yo his comments are absolutely destroying him, his comment has like 10 likes and this has 145 and every comment is telling him hes wrong😂
For the past few decades at least PCBs have most commonly been made of FR4, which is a fiberglass material.
Yes, I believe the older phenolic boards are only suitable for single sided boards without plated through holes or vias. Might sill exist in some toys and very cheep radios.
Yes, and phenolic board are trash... ever tried to put one in a reflow oven? you better keep your temps just right or the entire room will stink for days
they're great for prototyping though since they're cheap and cutting them not only doesn't make any dangerous fiberglass dust but also doesn't usually need any tools beyond a utility knife. or, if you get the really cheap ones, just a reasonably long thumbnail.
Epoxy fibreglass substrates are the most common, but more exotic materials like teflon and ceramic are used in high performance (high frequency and high temperature) circuit boards.
Phenolic materials haven't been used in quality products for a while.
oh and there's metal core (aluminum substrate with a kapton insulating layer) for heat dissipation from high power LEDs. but soldermask on most of those is white
The old phenolic boards were very rarely green. The green ones seen everywhere today are fiberglass, same material as car hoods and boat hulls. There are various different weaves and resin contents but you almost never see phenolic paper boards anymore. They are fiberglass.
Agree, the old board you used to make your own circuit board was brown.
Interestingly PC motherboards and other things you buy for self builds or upgrades tend to be black. However this is an product the customer buy so you want it to look quality.
Another point is that advanced electronic like computer motherboards tend to have lots of layers with circuits on them, over 20 is not uncommon,
I was thinking the same thing. I have some phenolic boards for prototyping, but almost all production boards are fiberglass now.
The color you see on PCBs is the solder mask layer.
I have seen phenolic paper PCBs with bottom painted green around the solder points, it was more common in 1990's-2000's consumer tech like TV's and radios._
Most car hoods aren't fiberglass
In the US, the fire hydrant color code is a bit more extensive than described here, but that could be an entire video on its own. I went down that rabbit hole a while back, and it was surprising how the cap and body colors can indicate so much.
I’m fairly certain that Simon has already done a video on that a few years ago.
@@adamcroft80 th-cam.com/video/DPrxO_u6sT8/w-d-xo.html Here's the video showing Simon talking about it.
I too ventured down this rabbit hole 🕳 🐇 to figure out why so many colors besides the typically recognized red. Different water pressures, types of fires, location of pipes beneath the ground. It was indeed complex.
@@BiroZombie knew I wasn’t going mad 😀 Simons done so many videos I get confused as to what he has and hasn’t done lol.
Colour *
in the 80-9+ i worked at a NELCO circuitboard manufacturing plant in Tempe, Az. start to finnish jobs. ie start with cloth roll of fiberglass, 1 tone each, goes thru 3 story dip and oven roller proscess. later i diped large boards in racks like ? tubs of various hazordous chems for reserch and development. Jello was one secret add to mix to harden copper . i did pull and tear tests on samples. later copper thickness. My ex Son, and her mate work at Microchip still.
I used to work at a circuit board manufacturer. My job was to run the boards through a scrubber to clean. Then, I ran them through a coating of photo imageable solder mask(PSIM) and bake to dry. The next step was exposing everything but the contacts to ultraviolet light to harden the solder mask. Then, another scrubbing machine cleaned the remaining solder mask from the contacts, leaving them exposed.
I work in electronics since 1991. Paper-based PCB's are very seldom today, used only for low-end-electronics like cheap toys or cheapest entertainment devices - sometimes still without soldering mask. Today's standard for PCB's is Glass-Epoxy FR-4 (also called Glass-Epoxy A10), in high-end electronics sometimes the boards are made of a ceramic substrate.
In the company I currently work, we equip PCB's with components (SMD as well as THD) for hundreds of clients in different market segments. The PCB's I work with have many different colors, but still about 90% of them are green. Green boards are most comfortable to my eye and make fewest problems (good contrast) in automatic optical testing.
The photo of the sailor doing Micro repair work is a job I had in the navy for a couple of years in the early 80's. Pretty much the same equipment. We not only replaced components but could repair the boards themselves if it got burned or Runs broke. As a joke, Maintance Control brought me a board that had been broken in half and ask me how long it would take to fix. I said give me about a week (and I could have done it). They took it back and never saw it again. 🤣
And being military CB's they were always the classic Green.
As an electronics engineer, THAT was a 'brain itch' that I have had for many years. Well done!
Crazy! I've been soldering for decades. I noticed the difference in odor of solder and flux over the years but never realized how much easier green is to see.
Cool video!
I think it’s worth mentioning most board shops offer an array of colors with no difference in delivery time.
You would be wrong.
It's usually a day or so extra at least for anything not green in experience
Depends on the board shop. The Asian cheap ones typically take 2 extra days in theory. However the more expensive prototyping services don't typically take longer.
Sparkfun tends to sell their boards in red
@@howardbaxter2514 im not familiar with that compnay/brand, but for me seeing a red board always makes me think of ATi. they made my first two accelerators. my friend from highschool was 'green with envy' hyuk hyuk hyuk😆
I'm old enough to remember the many colors of boards that my dad would solder on when he was repairing old TVs and radios, among other things. LOL, I'm even old enough to have watched him replace vacuum tubes in those giant, even older, TVs and radios, in fact!
You should remember tube testers at places that sold tubes
@@LadyAnuB I have three portable tube testers, and several CRT testers from my days i TV repair.
Minor correction at 2:27:
Circuit boards _were_ made of phenolic paper at first, but now they're usually made of a fiberglass composite called FR-4
Simon, you got a couple things wrong or at least not exact this time:
Initially monochromatic computer screens usually have been white but green or amber screens were found to be more ergonomic with green becoming the one more widespread.
PCBs are made from a couple differrent materials. FR1 and FR2 are the phenolic paper materials. Those are used in low cost mass produced products with lower technical requirements. While a solder mask is not uncommon on them not all use it.
FR4 is the most common PCB material today. It is epoxy with glass fibre mats. The material is usually kinda like a very pale greenish to yellowish color. Almost all of them have a solder mask.
The solder mask used to be applied in a screen printing process but today it is more common to use a photo structuring process for the solder mask. The mask is either applied in liquid form or as a dry film and then exposed to UV light with the required structure and developed (unused material washed out). The use of dry film results in a higher precision (which is important for small structures) and it simplifies the change between colors. It also has better protection against solder creep (solder creeping under the mask).
I've wanted for a long time to get those chemicals for making PCBs - that strip off the copper or whatever.. I don't really remember much about the process but some of what you said reminded me of that.
I worked for a circuit board manufacturer and it was my job to coat them green(was a dirty job!). You're right about the process.
@@Blalack77 There are a number of different processes.
Iron(III)chloride is the messiest, leaves yellow-brown stains everywhere.
Hydrochloric acid with hydrogen peroxide is possibly the fastest but can get dangerous.
Ammonium persulfate is quite widespread and safe to use.
I used all three, did finally stick with the ammonium persulfate but it has been many years sice I made a PCB myself. The express services have gotten so cheap that it makes no sense anymore.
@@phife1878 Another reason why most PCB production has moved to the dry film, it is no messy.
I am in the electronics industry since the mid 1980s and always wanted to understand the production process of the stuff I make :)
@@Blalack77 You're lying - you were looking for chemicals to make "PCP" 🤣
I’ve worked with circuit boards for over 40 years and I am absolutely sure they have never been described as “ dark, butterscotch, brown.” They now sound tasty.
If you described a board color as dark butterscotch brown you better be a customer and not a tech, lol.
I first worked with them in the '60s. I would have said they were mostly 'Outhouse brown', but the shade varied somewhat in the early days. Philco used some that were pink plastic that barely survived wave soldering in their consumer electronics. Use a typical soldering iron of the era and it would melt holes through those boards.
Rather than solder mask, early Delco circuit boards looked to have been float soldered, after being dipped in a thick rosin flux, because they never cleaned it off their boards.
How about them Vacuum tube days where all the components are floating in the air like a 3D spider web of capacitors, diodes, and lots of solder joints? The circuit board deserves to be on a list of greatest inventions.
Wait say whaaaaaa can you link a vid of that in action? Sounds awesome
@@cdogthehedgehog6923 google image a old vacuum tube amplifier. Scroll till you see whats underneath the chassis of any old tech. Its insane sometimes and I bet a nightmare to diagnose.
Yeah. "Through-hole technology" sounds pretentious, until you realise it isn't the absolute baseline. "Potted circuit" is a term I have heard - like, you build it 'in the air' but then fill it in with some insulating gunk to stop things moving about.
My engineering professor, circa 1978, described tubes as transistors that have a light on so the electrons can see where they're going.
A part time job of mine., at a local electronics store, was selling tubes. Customer hands you one, plug it in a tester, light doesn't go on, sell him another. All for $3.65 an hour.
@@cdogthehedgehog6923 you can see that early stuff if you watch this video about adding iPod input to vintage radio amp th-cam.com/video/j8YeJ0T3DpI/w-d-xo.html
Later on, they used circuit boards with through-hole components, but before all of the circuits on the board - they used all sorts of little jumper wires. That was called "wire wrap", and here's a video about that: th-cam.com/video/OujuzAUD9pc/w-d-xo.html
Later they went to phenolic with traces on one side only, then over time we moved to FR4 - first double sided, then eventually multi-layer.
I love the fact that you're Channel deals with some mainstream things but also some things that I never would have thought to go look up but are very valid questions to my curiosity. I love your random videos that pique the Curiosity I used to have for random things and give such complete and total answers.
also the green digital Japanese text in The Matrix is taken from a cookbook which makes it funny to Japanese audiences.
So are we just going to ignore the fact that Simon called it “the human pencil?”
99% sure Simon misread humble xD
I came to the comments to look for this.
LOL I was going to comment on this too, but wanted to see if anyone else heard that too. Even the closed captions showed "human pencil" They must have really chose yellow to differentiate them from simian pencils which are brown and frequently thrown at people at the zoo. Despite them being yellow, I keep losing them.
'The Human Pencil' - now that doesn't have any odd connotations does it? Are there pencils made FOR other beings? Are the pencils primarily made OF human? Hmm...
@@halexvr And then he got away with it in post-production - which I find strange. Is this a tactically salient blooper to get greater engagement around the comment section? ( Glad I paid a visit, anyway. )
Most NYC Taxis are now neon green. They started changing the color a few years ago. Also, our hydrants come in a variety of colors and some residents paint them themselves when they're neglected by the city. In my neighborhood it's common for residents to paint the hydrants (also known as Johnny Pumps) red white abd blue or green, white and red.
if you paint the caps of fire hydrants, you impede firefighters' work. they need to be able to see what flow rate they're getting.
They're not yellow anymore? 😮
The brown phenolic board material is still used on low cost products. But almost anything of quality or high complexity is made of fiberglass epoxy board substrates. The brown phenolic is too prone to cracking if the board gets flexed. I have designed printed circuits since the mid 1970s and I have not done a single one for phenolic substrate material since the first ones I did on a computer in the mid 1980s.
About solder masks, I have seen solder masked boards from the 1950s, especially in aviation applications and car radios.
While everything you said about green is true, at my two jobs since 2001, I introduced the use of red solder masks for prototypes and pre-production samples. Because we were having prototype boards getting mixed with production. Sometimes when production spoiled one too many boards, they would come into the lab and nick a prototype board so they could fill an order. Our hours did not fully overlap. Or we would send a prototype out to a reviewer and they would "forget" to return it. Then a couple years later it would show up at the service department with an odd fault and someone would make a warranty claim on it.
So we switched to red boards for pre-production boards as there was no extra charge for different colours. This stopped production from stealing pre-production boards and forced them to either make more spares or properly rework the spoiled ones.
My second last job still used green for production. My last job from 2010 until I retired in 2018 we used green on the standard grade products and blue on our premium product line. Especially where part of the board may be visible on the outside.
Our board houses have never charged any extra for colours as solder masks have not been silkscreened on for years. Instead it is usually a photo laminated process and there is no cleaning of machines needed in order to change colours. But yes, for most companies green is more a tradition than anything else.
My last batch of 5 prototype boards in 2021 for a project of my own, a Raspberry Pi accessory, from a board house in China were in blue and less than $10 for 5 small boards made with a fully automated system. These were double sided plated through boards with vias of less than 0.5mm and legends printed on both the top and bottom. Then about $20 for shipping. I got then 2 weeks by DHL after sending the gerbers to the vendor. "Gerber" is the universal data format for PCB files, one for each layer with the solder masks and the "silk screen" files as separate layers.
It might be an interesting story to tell us how the Gerber format became the worldwide standard for outputting the data from pretty well all PCB design programs right from the beginning of PCB creation software around 1980 to the present day. And the file format has not really changed at all. This is the sort of thing that appears to have been correct right from the start.
On the documentation layer (aka silkscreen layer) with blue paste mask we use yellow for visibility. It works better than white. But with red paste mask while works best for the documentation layer.
When I was making printed-circuit boards at home in the early 1980s, using supplies from Radio Shack, the board wasn't green, but that tan color that Simon mentioned. Now I know why.
Yeah Rat Shack sold garbage.
@@1pcfred - As Simon says, for the home circuit builder, the color of PC board is inconsequential.
@@pacificostudios that's incorrect. Phenolic board remains junky even for someone that makes boards at home. Most do not apply a solder mask to homemade boards. So the color you see is the color of the substrate material. Fiberglass and phenolic substrates are very different looking. And yeah the boards at Rat Shack were the crappy stuff.
@@1pcfred I actually have two battery chargers from Radio Shack 87- 89 the 87 edition is designed to recharge carbon/ zinc (up to 50 times) and still works. The 89 version is for ni/cad also works for ni/hydride. By far the best purchase though of the 7 R-Shat products from the 80s I still have is a universal power supply that is overheat/polarity reversal protected (and granted that I don't have any of the adapter ends which had design flaws, my 10 years old self usually wired into the battery compartment of whatever electronic device I didn't have batteries to. Nowadays the electronics are hyper sensitive and unforgiving and also designed to have a very short lifespan. Best $6.99 deal ever! lol
These days, almost every PCB manufacturer offers a range of colours. I always get mine with a black solder mask because I've had several people tell me that my black boards look far cooler!
At the PCB manufacturer I worked at, who designed and built custom test equipment from the PCB on up to full test systems, we used red PCBs to denote that those boards were required to be built lead free, to adhere to ROHS requirements. It was a nice obvious way to ensure they were not exposed to any lead based processes.
1) Phenolic Resin circuit boards are actually rare these days - they have been largely dropped because they are considered a fire-hazard. These days the FR-4 fiberglass-based circuit board is a lot more common.
2) I had actually not known about the dangers of black and several other colors of solder-mask re: conductivity. I've stayed with green or red for more prosaic reasons - I find black and several other colors make boards harder to work with and/or fix when they have a failure (or there is a mistake in the design that needs a manual bodge to fix)
3) If I had the money to spare, I'd be a Patron or paying subscriber to your channels, Fact Boy - keep up the good work!
Also they have a little formaldehyde problem! They are also not good for vias or reflow because of their low temperature resistance!
I built a lot of paper phenolic boards up until the early 90s. They were were single sided and the holes were punched with no plating in the holes. Connections were made between sides with the components themselves or jumper wires. The backs were usually covered in solder mask to prevent solder shorts and un-necessary drag out from the solder pot. As circuits got smaller, denser and faster multi-layer fiberglass boards with plated holes became the standard. I have used other color masks for prototype boards, but it requires adjustment of the equipment sensors and vision inspection systems. The plant was much happier when we stuck with green.
I have seen red circuit boards as well as green. They always look pretty weird though.
The problem with painting things red (like fire hydrants and even stop signs) to have it more visible is that red tends to fade much faster than other colors.
phenolic PCBs usually do not have mask on both sides, so the top is brown. The boards talked about here are usually FR4 which is fiberglass, and has solder mask on both sides which tends to be green traditionally. Most of the PCB stock art shown here is indeed fiberglass.
Another suggestion: In America, why, in some cities, fire trucks are not the classic red in color? When I visited my father years ago in Denver, Colorado, that city's fire trucks were a bright, yellowish green.🤯
I think you sort of answered this in the Bonus Facts: is had to do with the level of desired visibility. Fire trucks come in various colors around the world.
BTW, what color are Prague fire trucks Simon?🤔
I too, want Prague answers…
Fire trucks here in Czechia are always red.
I have seen red, white, yellow, and green fire trucks. It also helps that the there's a Fire Fighter's convention every year in my area. I think I even saw a blue one, too.
I know a township in NJ where the fire trucks are white.
The fire trucks in my community are gloss white with gold lettering (:
When I was a volunteer fire fighter - something like 40 years ago, I made a rather large grass fire in south-west Houston where a field had been allowed to grow to shoulder high grass. A captain from a Houston Fire station wandered off to find some fire to fight. After a bit we hear this odd sounding FOOMP sound. Said captain came back out of the high grass with his then new red bunker gear now "Yellow Cab yellow". It seems someone had dumped several 55 gallon drums of the "Yellow Cab" paint in this field. The fire surrounded the drums and a few of them cooked off, resulting in a shower of very hot paint on anyone near by. I never did hear if the captain was able to remove the paint or if he just went and got another new set of bunker gear.
I literally avoided watching another video about this just to hear it here first.
As someone who learned computer programming in the 80s (My 1st computer was a TRS-80 from Radio Shack) the old school "green screen" displays are burned into my memory. Since them, I've build PCs from the motherboard up, but I never knew why motherboards were green. You never fail to teach me something new with any of your videos. Keep up the great work!
Yes but...Trash-80s had black and white screens ;^)
When I was growing up in Baltimore city the fire hydrants were painted like revolutionary soldiers in honor of the bicentennial of the united states
paper phenolic is rarely used for anything but the very cheapest single sided PCBs, almost everything is made with FR4 which is epoxy and fiberglass
5:35 I believe green is most most distinguishable also because it is in the middle of the colour spectrum. For this reason green has been adopted as the default colour for safety first aid stations. Namely eyewash stations as green is the last colour you can perceive as your vision diminishes.
Also. Pet conspiracy theory of mine. This is why aliens are little green men. Witnesses may have been smoking something not friendly to a sharp sense of eyesight haha.
Keep up the good work. Feel free the fact check my claims. I’m not an expert nor should you take anyone’s claim as fact. 😉
Love your stuff Simon! (All channels!)
And as your self-titled "fact-boy" I thought you might appreciate some more facts.
I've been in the printing/publishing industry for over 35 years. When referring to a Pantone colour (in this case the London buses' Pantone 485C) it is important to know from whence the Pantone colour number comes from and what the "C" (or "U") stand for.
These numbers reach back to PMS, of the Pantone Mixing System, a recipe guide to mixing various colours of ink for printing. A colour doesn't have either a C or a U behind it (although their swatches do) as the "C" stands for Coated and the "U" stands for Uncoated, referring to the stock, or paper upon which it is printed.
The ink itself does not have a C or U. You would get a can of PMS-485, but it would only become 485C once on a printed surface.
The London bus paint would be Pantone 485 and would only become 485C once on a coated (in this case the metal surface the bus).
The colour of Sonic the Hedgehog's fur is Pantone 286 blue. Sonic's fur itself would be 286-U.
I know I'm splitting hairs, but....there you have it.
:)
I think the blue boards are easy to see text and errors on too.
As I was about to comment I observed that quite a few others called out issues such as pcb materials, monitor screen colors and others. Quite a following and knowledgeable at that, you've done well developing such a following.
I hear a homer simpson like "doh!" In my mind every time a picture pops up without being cropped properly. I feel the editor's pain.
Oddly enough, no mention of the iconic American School Bus. It never ceases to amaze me how many TH-camrs originating from Europe will go to America and be utterly surprised to see that such a thing exists. Now if only American motorists were aware of a big yellow hunk of metal with some red flashing lights and a red stop sign built in to it!
Many motorists are not even aware of a big red hunk of metal with some red flashing lights and a loud noisemaker built into it!
Ive always looked at those circuit boards since I was a kid and the thought of why theyre green always came to mind but I never bothered to find out. Thanks to you now I know without having to really put in any effort lol. Thanks for the info and the great video! :)
Ditto. I came to say exactly this.
And you couldnt bother to say, so people wouldnt need to watch whole video??
@@NoName-md5zb Nope. That would ruin the purpose of the video 😁
@@gelatobiscuato8121 sadly, he got most of the details in the video wrong, so you didn't learn as much as you thought you did! Lol
Read the top comments on the video to see the real facts he didn't research long enough to discover...
I have to agree with white paint on a green background being highly visible. I have to look at circuit boards during the course of my work while troubleshooting. Now if only the manufacturers could install them right side up so they would be even easier to read. Thanks for another great video.
On the blue boards I use yellow for the markings on the document layer for visibility.
Yikes. No, OLD circuit boards used phenolic paper. Most boards today are fiberglass based (with the fiberglass&epoxy normally being yellowish), although other materials are also popular for high frequency devices - colors for those also vary, but white is common.
Circuit board manufacturers HATE the phenolic boards - they degrade in the chemical tanks while being etched, which taints the etch and increases costs.
He actually mentions this in the video
If you looked at old "high end" stereo boards, they used crappy "brown" phenolic single sided boards, while their contemporary "jelly bean" computer board vendors, used epoxy fiberglass multilayer boards. That conflict I always found funny.
@@awkwardllama0509 within the first 3 minutes, nonetheless.
@@inkzorath7408 right? Looks like somebody didn't watch the video first lol
Tech note. The protective mask is on the PCB primarily in order to facilitate heatwave application of tin. The board is basically exposed to molten tin which attaches only at the locations not protected by the mask. Then you take the SMD (surface mounting design) components, put them where they belong any bake the whole thing. The tin melts and solders the components. Of course the mask also protects the copper paths on the PCB, but I think it's a secondary effect.
I’m from East Texas and a lot of the fire hydrant’s in the area are painted to match their local school colors. I think it’s a trend that started within the last 15 to 20 years and I’ve often wondered how safe some of the color combinations are. As in how the heck can those be easily found at night?
Maps and memory, my department had agreements with the city we bordered and after a little while we knew where the hydrants were that were closest to us and some backups as well. It's worse in the winter here in WI when the snow covers them and you have to dig the hydrant out of a snowbank or worse the plowed snow.
In the past few years, ours got painted silver. They've also got blue reflectors on the road where the hydrants are.
I think the "Matrix" color is more of a throw-back to the green phosphorous screens common before CGA/EGA/VGA. Even though I am almost too young to have encountered dummy terminals, I am personally a fan of the amber phosphorous colour. I always thought they were better to look at but were just less popular for some reason.
Oh noooo- they were hideous! After an hour or two, you'd just want to barf orange...
This is the first time I've seen one of these vids in the first hour. Usually I'm watching year old vids from this channel lol
Same here!
I didn't even notice
Look at us being timely together
Me too 🤣
TH-cam has chosen you; declared you worthy of on-time notifications.
SkipJoy: The feeling of satisfaction you have when you bump the video fwd to skip the ad and nail the landing on the real intro
I'm fairly certain that the "phenolic paper" in modern PCBs is made of glass fibre rather than wood fibre.
I've never seen any that was, and Phenolic boards would burn quite well.
@@michaelterrell phenolic boards are type FR2, fire retardant modified material. They're commonly found in power supplies, especially ones that are at least a few years old and are not a fire hazard. The board in the Xbox360 control pad is also phenolic paper, and they're also found in all sorts of cheap toys.
Large manufacturers across the industry (suppliers and cpntract manufacturers etc) have been rolling down FR2 production and there probably won't be any new FR2 boards made within just a handful years. They're only offering FR4 for new designs which is an epoxy glass fibre. In general, using FR2 with lead-free solder tends to lead to delamination and regret.
@@SianaGearz I've worked on and built circuit boards since the late '60s. FR is the fire rating but I have seen both FR2 and FR4 boards that have caught fire and burnt. One FR$ board that failed destroyed a new $20,000 Telemetry receiver at the place where I worked. It was in the standard burn in process before final alignment. If the chamber's fire suppression had failed, it would have set the building on fire. I currently have over 1200 reels of RHOS SMD components in my home shop to build boards with.
I've also used a lot of FR4 cabling for jobsites. I worked as a Broadcast engineer for many years.
@@michaelterrell Yeah i should have said "not usually considered an increased fire hazard" but yeah they can burn. The chemicals work to suppress fire up to a point. FR4 is more inherently resilient, but epoxy too has an ignition point.
@@SianaGearz At least it isn't as dangerous as Plenum cable in a fire. It is still hard on your lungs.
I like the editor for this video. The blue frame for the stock image is merely a suggestion.
Through hole components are still used today, but they are usually higher power or physically larger
I've seen solder mask in blue, red , and green. In my company, green boards were 63/37, red were SN96, Blue were SN10/HMP.
This is why we love you, Simon. You bring us information that we didn't even know we wanted to hear, which is both interesting and readily accessible.
I can't believe I just watched a 14 minute video about what circuit boards are green... And actually found it genuinely interesting!
Same!
The funniest part of these videos is the people attempting to "correct" him before watching the video, and these corrections being mentioned within the video anyways.
A lot of people have already commented on this but: Phenolic paper PCB substrate is still very much used but mainly for very cheap products or for power supply boards. If you open up a generic mobile phone charger you're very likely to find a phenolic PCB there, as well as in the internal power supplies of game consoles, maybe even PC power supplies. I believe this is because power supply circuits tend to use a smaller number of much larger circuit components compared to other things, so single-sided designs with wave soldering are more practical there.
Solder mask on phenolic PCBs is also green, it's just that phenolic boards are often single sided and will only have solder mask on the side with copper.
Two questions; 'Sole-der'!? Is that how it's pronounced in the UK? In the US we say sAAh-der, and sAAhdering.
Also, 'human' pencils? While I love the idea of species specific pencils, I don't think this is "a thing". 😄
Should have said "writing pencils" as opposed to "eyebrow pencils".
@@stevengordon3271 Or styptic pencils, or nuclear fuel pencils...
Seems all the English speaking Commonwealth countries pronounce the 'l' in solder. The most pronounced I've heard is Mr. Carlson's lab from Canada. He seems to put an accent on the 'l' and I laugh every time I hear it. OK fact boy, how come you guys pronounce the 'l' in solder?
In USAdian English, the L in solder is completely silent, yes. Continental speakers tend to pronounce it to one or another degree of depth.
I have been designing and procuring PCBs for longer than I'd care to admit. Never gave much thought to color being anything but a pure cosmetic choice. In fact, some of the PCB manufacturing firms tout having a free choice of other-than-green colors as simply a distinguishing factor on theirs. It's "cool" to have other colors, though I always found this a frivolous expense, if it's not free. Well done.
I never knew that our British cousins pronounce "solder" phonetically.
Just one note from someone in the industry.
Most inspection is done by machine as Simon says, but manual inspection under a microscope is still often necessary when problems arise, and I see someone at a microscope with a board almost every time I go to the production line.
But we're making tiny high-density substrates for CPUs rather than large component boards, and I imagine that this sort of manual inspection is not near as frequent for most PCBs. (Plus most of these issues and inspections take place before the solder resist step, anyway)
Heheh. I’ve never heard anyone pronounce the “L” in. solder before.
He also pronounces the second“L” in lengthly
It’s the British pronunciation of it
It's so much better than the North American pronunciation. "SAHHHHDDER"
@@Grillpan Or to put it another way, it's the proper way to pronounce it.
I'd never heard it called "sodder" until quite recently (Australian)
What an enjoyable episode! Thank you, Simon.
Phenolic boards are rather rare these days due to their worse fire rating compared to FR4 a board material that is far more common these days. Phenolic is also less thermally stable and therefor decomposes more easily around warm components, or in warm environments in general. Phenolic boards are barely used today. (and this were partly already the case in the 90's)
The green color comes from the solder resist added on top, it is to prevent solder from smearing over the board as easily, ie to prevent unintended shorts.
Also, in regards to chlorine and bromide, these are practically outlawed. In the EU all electronics products must live up to RHoS, ie, the board must be halogen free unless one's application is on the exception list. (And the Brussels effect makes this more or less a world wide requirement.)
In regards to colors indicating stuff. This is a myth, or rather, very few companies actually do this.
Red boards aren't indicative of a prototype. And PC components aren't color coded either.
Some companies use specific colors on their boards, either for marketing/design reasons. A lot of PCBs in computers these days tends to be black, red, or blue. Though, commodity components like RAM and SSDs tends to stick to green since the increased manufacturing cost of other colors is cost prohibitive in that market.
In regards to surface mount vs through hole components.
There isn't any line in the sand for one being superior to the other. It depends heavily on the application, through hole components have superior mechanical rigidity, so for connectors it is still heavily used and will remain so. Surface mount however offers much tighter pin spacing. So depending on the job, one will use one or the other, but the typical board tends to have both. Even some components uses both approaches, typically seen on connectors.
And a lot of hobby/prototype boards uses surface mount as well these days. It isn't really any harder to work with.
This is just my two cents having worked in the electronics industry for a rather long time.
As mentioned in a comment by Guido Körber todays common PCB's use glass-epoxy and the natural color is a light shade of green. In your video at 6:54 you can see the lighter green of the bare board contrasting with the darker green of the solder mask. Look at the upper edge of the PCB near a mounting hole.
Gotta say i found it unnerving to hear the “l” in “solder” pronounced (because I am an American and we pronounce “solder” as “soder”
This man is posing the questions I didn’t know I had but that I need an answer to.
Just here to represent BrainBlaze
I used to go to an after school electronics class where i built circuits and studied these. I was about 10 back then. For those who know, in Romania it was called Palatul Copiilor. I'd also be in karting and IT classes.
This explains why a lot of the enthusiast motherboards that are black are more expensive now. Thanks for that!
Who remembers the DFI Lan-party boards back in the early 2000s with the UV plastics that were yellow/green/orange? I miss those days...
------------------ SPOILERS that will save you 14 minutes. ------------------
A circuit board not only has components soldered to it, but also copper circuits printed into the fibre glass core itself.
Green is the color of the solder mask layer on top to prevent the printed circuit boards from shorting.
It's green because they had to standardize the color to something and it is believed green creates the best contrast for visibility of the components on the board.
Copper is not printed onto circuit boards. A copper foil is applied to the whole board. A resist is put on that copper and then etched.
@@1pcfred @Paul Frederick
You could be right.
I was going by this :
"It is due to the solder mask, which protects the copper circuits printed on the fibre glass core to prevent short circuits, soldering errors, etc."
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So "copper" "printed on" "fibre glass core" then protected by "solder mask".
I was pretty close.
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Look up : ablcircuits & solder mask
I am a SMT operator and make populated PCB boards for some of the leading auto manufacturers and all of the boards we make are fiberglass, not all are green, most, but some are white or blue.
Circuit boards are definately still examined by human eyes for the purpose of repairs.
I love this. Perfectly obvious and elegant answer right in front of me all along that I didn't notice
for 5 years i worked for a custom PCB manufucter my job was to run a spray booth spaying the green mask then the boards would go into the heated tunnel machine to dry boards then they go to other room to have the boards to be exposed to a uv lite after a circuit stencil was placed on the boards them it would go into a machine that would wash off all the mask over the the circuits that needed to be exposed
Yellow fire hygernts are used in Canada as well!
Just all firetruck that operate on airports are yelow=greenish colour (and for most of you >colour< has a U in it...! And the reason for the yellow firetruck it's easier from a distance to see them!
I've worked for companies that had different color circuit boards. The coolest thing was in one company we were concerned about using circuit board cleaners that were environmentally harmful. We switched to a solution of citric acid which worked great and did not hurt the environment. The pleasant side effect was our manufacturing line smelled like oranges.
We use red to indicate that there's something special about the requirements for the boards. Lead-free requirements, conformal coating, etc. I personally don't like doing anything other than green until the final build is ready to go, works well in the AOI we have since it was designed around green PCBs.
This is the most business related content you’ve ever created. Perhaps this channel will also merge into the Business Brain Blaze multi-verse. I’m here for it.
Most of the old audio equipment from the 50s, 60s and 70s mainly contains brown and yellow PCBs, those were without solder mask, but early PCBs with solder mask are often yellow-ish brown too.
I use to apply it through silkscreen then bake it on the boards, we also eched the traces and glued multi layer boards together, applied the white lettering paint after. These jobs making circuit boards are all gone now, I did this job in 1980.
I would pay a decent amount of money to know how Simon comes up with so many interesting topics! It’s incredible
I have brown circuit Boards too and never gave a thought about them being green, but now... it's basically a Uniform Symbol to have circuitry on green base.
I remember using a Hazeltine 2000 terminal back in the late 70's. Never occurred to me to wonder why the on-screen text was green. 45 years later, now I know.
The green phosphor had a different persistence from the white which was supposed to reduce eye strain. It was developed for RADAR use during WWII.
In the maritimes barns were painted w a mix of cod liver oil and powdered rust. Makes a great preservative for wood, especially when exposed to harsh costal conditions.
Simon, circuit boards are no longer limited to the color green as you mentioned. Interesting logic about use on various color combinations. Only the cheapest PCB's are phenolic paper and only used in very low end electronics. The most common boards are epoxy glass such as generic FR4 or Isola 370HR. The Solder Mask comes in a range of colors. Try Black Boards with gold traces and a clear solder mask. I did this in very high end Audio Equipment. Looks stunning when done right. Today green is the cheapest color. Silk Screen might be colors other then white. Manufacturing lines are designed for quick change. There are certain requirements specified in IPC Guidelines for mil spec Class 3 PCB's used in military applications. For commercial boards anything goes but is primarily cost driven. The problems of acid traps is not longer an issue. My comments are based on 50 years current experience designing PCB's and PCB Assemblies. Besides Rigid PCB's there are Flex and Rigid Flex boards. These are a combination of epoxy glass and brown Kapton films.
The fun thing on the developement of the protective red painting is - this was known for more than 1000 years before xD
That's why many traditional half-timbered houses you often see in europe ever had a red color (and its awesome to work with the original recipe, as the quite simple combination of iron oxide and linseed oil is great for workflow, easy to wash off and completely non toxic).
Subsurface ship bodys - i revcently learned - are colored by the copper parts in the paint but - the logic between tradition and actual color is the same here.
This is the channel that presents the most interesting and common questions that are in most of the people mind.
Circuit boards are still often inspected by human eye. At my work we use automated inspection systems as a processing aid and not as final quality control. Part of the reason behind that is that it’s for implantable medical devices which are class 3 assemblies.
Fire hydrants in the UK are yellow, Barns are frequently black, London buses since privatised some have gone back to pre-nationalisation colours. London black cabs are famous. While traditionally UK telephones were part of the Post Office and thus iconic red boxes in Hull town the telephone company was independent and part of the corporation and thus like the buses the boxes are painted cream.
I worked on old equipment that had brown, yellow, and green boards. the green boards came in two shades - very dark green, and a translucent light green
I have hundreds of pencils around the house, but very few of them are yellow, as I get my pencils for free from all the companies that use them as advertising.
PCB Board is fiberglass, its referred to as G10 or FR4 here in 'Murca.
I worked as a toolmaker producing precision parts for wire E.D.M. machines from this material, and I can state definitavely that it was a fiberglass matrix.
Also, the green color is not a coating, I have machined thoiusands of parts from this material and I can assure you that it is the same color all the wat through.
3:30 the answer is that the green is a solder mask that protects the circuits from unwanted shorts. and they are green so that you can visually contrast the conductive traces vs the background green
I really like clear soldermask and black legend, or silkscreen. A lot of late 1960s Tektronix boards are like that.
What an obscure subject to cover working in electronic manufacturing I have never thought of why the PCB's I work with are green I have also worked with blue and brown boards but predominantly its green. While this is an obscure topic it is none the less interesting. 👍
Because green is the purest colour and much easier to make than gold. Ask any amateur alchemist.
A bright red livery? Makes sense as livers are livery and they are bright red... until you cook them.
So the colour yellow is an indicator of a bit of quality wood? Interesting... all my trousers are black, brown, or blue! :-(
I love your use of a stock photo of a Navy petty officer soldering. That could have been me once upon a time.
When I started work repairing analogue sound equipment in 1974, most of the circuit boards I came across were a light tan colour. occasionally a dark brown, green seemed to come much later.
Just for contrast, red barns aren't (as far as I know) a thing in Germany. Buses (and trams) were a kind of yellowish-beige color scheme when I was young, but since have become more colorful, though my impression is that a lot of them have changed to blue-dominated color schemes. Phone boxes were postal yellow (as that's who run our telephones) but since then, the few remaining have become wall-less ... and the now split-off big phone company has a grey-rose color scheme anyway. Water hydrants ... mostly aren't. Over here, there are flat covers in the road that you pick off, and the water line is below that. Nobody running over hydrants. There are usually square dark-blue signs on nearby houses telling how to find it (so far from the wall, then so far to the right or left) - other colors for electricity, gas, whatever. And Taxis were black when I was young, and now have a sort of dark egg-shell color usually known as "taxi color". (And the taxi sign itself is black on yellow.)
My dog has a Facebook…his Facebook has an album of fire hydrants…he loved this bit of the video ❤️ thank you