IceRook don’t try to understand. Animal rescuer get lot of them too. It’s hard to imagine been against people who rescue almost dead animals. Now, if it’s a thumbs down for the sponge, then it’s ok. Can’t believe they still using the sponge.
+John Gammell 0:15 What are those scourer pads for? 0:35 Does it matter that the wire isn't completely covered? 0:50 How can the excess solder be removed?
The scour pads are actually brass tip cleaners. They do a very nice job but many defense and aerospace manufacturers will not allow them in their facilities because they are notorious for generating FOD (Foreign Object Debris) primarily solder balls. The wire is snug to the base and post. The lead bend radius is a minimum of 180°, with no violation of minimum electrical clearance. Insulation clearance is within 1 wire diameter. There is wetting of the solder at all points of contact with discernable contour and no depressions at lead to post interface. The wetting does not have to embed the entire lead bend radius. We still have to discern wire contour. The solder fillet meets the IPC Class 3 criteria.
Utkal keshari mohanty I don’t think you use oil, you can wick off solder. I don’t know if a solution that will remove solders without causing defects to the board
Uhm no... 400 degrees F will barely melt the solder, let alone activate the flux on the board properly. I just tested this by setting my soldering iron to 400 F (205 degrees C in my case). The solder just melts, but slowly. If it also has to heat the pad and part, you will lose to much heat and things will not wet at all and the flux won't activate as well and especially the flux is important.
I am something like a beginner on smd soldering and I can't accomplish such a good work with that 1:38 "drag" technique. I use flux but still not that successful. Please drop some advices. Thank you
1. A bigger tip is easier than a small tip (due to larger thermal mass). 2. Don't drag too fast. You want to spend about 1/2 second per pin. 3. Flux evaporates quickly (especially liquid flux). Re-apply flux for every drag attempt. For SMD, the pros use gel flux (e.g. Amtech NC-559 or MG Chemicals 8341) since it lasts longer. 4. Usually, you'll have a solder bridge at the end. If it's big, use solder wick to remove it. If it's small, drag outwards (away from the chip) to correct it (but re-apply flux first!).
@@vasilzhekov9245 For SMD, 600F to 700F (320C to 370C). Also: * Place flux onto the PCB *before* laying the chip down. That way the entire solder pad gets coated with flux. This is especially important when the PCB's solder pads are short (i.e. barely longer than the chip itself) where most of the solder has to go behind the pins. Some chips are harder to drag-solder than others (e.g. PLCC) so it may be a good idea to first practice on easy chips (e.g. SOIC) with large pitch (e.g. 1.27mm) and, more importantly, long solder pads on the PCB.
I've been working in Aerospace for years, but it took me moving up to Engineering a year ago to finally score my owm Metcal setup at home. God I love it so far compared to my old Hakko. But I've always heard good things about Weller, that and they are the best. Used in the industry for decades, before SMT and all that yeah?
There really isn't a manufacturer 'the best' in my opinion: it's more down to personal preference. I started of with a Weller station with adjustable temperature and higher range of tips some 10 years ago as a hobbyist, so the WD1 station with a WP80 and WP65 iron for smaller stuff worked for me. And than I started doing some strong SMD stuff where the smallest gullwing point of my Weller still was huge and could not fit between other components, but also could not handle the huge heat dissipation by a ground plane some of the SMD components were connected to. I was then working as an aviation technician for some time already and had a JBC station at my disposal. And wow... compared to my Weller WP80 or 65, where exchanging the tip meant to unscrew the hollow holder while still hot, let the (ever so) hot tip slide out onto something heat resistant, let another tip fall down into the still hot holder and than screw it back to the iron, the 'place tip with ridge in removal cradle, pull, push iron onto new tip and secure with the holes beneath the removal cradle > done' kind of tip-exchange just made my Weller feel ancient. Paired with the active-tip technology, you can almost do anything with any tip: the station will sense immediately that something is dissipating the heat quickly and it will adjust accordingly. And that's my main thing: Many people say that JBC is the best because of their active tips. And though it could very well be they were the first to come up with this technology, manufacturers like Weller and Ersa aren't stupid and came up with their own active-tip stations (I think Weller calls this Rapid Response Technology). And thus it comes down to what you like. For example: I like the desoldering irons by Weller far better than any of the Pace or JBC's, as Weller has the tip under a 75 degree angle-or-so to the handle, while almost all others are in line with the handle, forcing you to hold the thing with almost your whole hand and having far less control over the movement of the nozzle when desoldering, at least, that's my experience, I didn't like them.
Wow, look at the size of the solder tip that you used for surface mount part U3, then used the heat gun to remove those shorted ! Do you know how hot is the heat gun? Must be commercial products.
Hi I really appreciate your videos. If I were in the US I would try to attend your training. Unfortunately I can't. In the case of "PLCC 28 J-Lead Hot air soldering with paste", what kind of paste did you use? Is it a kind of paste containing tin? Thanks!
you can put the paste anywhere. The heat from the heatgun will melt it, and it will follow the heat source (a.k.a flow to the IC pin). I used to just put it everywhere
Rom Hunter, CAN, yes, but I expect a video called "Master Soldering" to show best practice, not what works 90% of the time. The solder paste that's placed on the solder mask could run either to the left or right, so you don't have a consistent amount of solder on each pad. This could either lead to shorts or insufficient solder on some pads.
Ron Hunter, I noticed when rewatching the video that the paste was applied both on and between the pads, rather than just between the pads. In this case, yes, it's unlikely that it would produce insufficient solder. If the paste was applied ONLY between the pads because the stencil was misaligned, you could be unlucky and the paste on both sides of a pad could flow the wrong direction. In this case you would rely only on the tinning on the leads, and possibly the tinning on the PCB, and you'd also have no flux, which would almost guarantee a bad connection. I wonder what deal is with that part of the video. If they're using a stencil with half the pitch because they couldn't find the right one, or if this is intentional, somehow.
I would have used a laser cut stencil and a different hot air tip and done them all at one. The one I have to replace is a PIA and is crammed in with so many other parts I have to do that. The special hot air tip was worth it. They're a couple places that offer them for Hakko hot air and rip off hakko clones. It cost more than the knock off chicom one but worth it.
I'm using a 20 year old Pace I rebuilt, a chicom rip off of a Hakko hot air that has lasted longer for 1/100th the price, a 50x used scope and some hand made tools. Pace is almost to the point of stopping support for it as tips are getting hard to get but...20 years means I'll likely keep dealing with them. I'm not a fan of Weller or Hakko, they obsolete stuff too fast. I bought a simple Hakko soldering iron, adjustable temp and they notified me it was obsolete 3 months later. Weller...meh.
unebonnevie nope! Not at all. Go check Hakko’s station which are ones of best. Weller have been for long and still using sponges to clean. Not good at all.
Hey I'm still rockin' my good ol' skool Weller WES-51, with its analog temp dial baby blue housing, actually two of them since 1999... served me well all these years along with Chip-Quick for medium board work ;) Lesson #1 - Use lots of flux!! Lesson #2 - Use lots and lots of flux!! Lesson #99 - Use lots and lots of f*ckin' flux!! :D @Marco Polo < I found that the fine metal Brillo-Pads work best instead of the old sponge tip wipes.
Kevin Bates thank you. I’m certified in J-std-001 modules 1-5 and the space addendum. During training I didn’t tin the leads. Nobody made comments like these, everybody was helpful and I passed all hands on with the support of my trainer and peers in the class. Support people and answer questions respectfully, it promotes higher education. Edit: I didn’t know I was supposed to tin the leads, only after I saw others and asked did I learn. Nobody made me feel stupid.
It always looks very nice and easy in these videos, but it looks like they use some dummy boards that have only traces going nowhere. In a real live enviroment, when a component has a connection to larger ground plane (like an IC GND Pin) it will be alot more hard to solder by hand, because the solder cools off extremly fast because of the big thermal are. Non connected pins are very easy to solder, but GND pins can be very very hard to solder by hand...
Cool station. I've been so pleased with my Hakko FX-951 that I've not felt like I really have anything up. I don't do SMD work, mostly turret point-to-point and through hole PCB.
For drag soldering and solder bridge removal using a Hakko 888D use a flow tip (bevel with a hollowed out section) that's what I use for the same result.
Nah you can make them in a toaster oven if you have good temp control and install slow circulation fan and board holders. That's for simple one sided boards for hobbists but can work well. The big nitrogen inert ovens that do large double sided boards on a conveyor for manufacturing. There are several videos of them on youtube. They put the solder on with a screen printer similar but more precise than a t-shirt screen printer.
You still have to use it for some soldering for high reliability and defense contracts depending on when it was made. I've had to build some very odd assemblies due to that. It's usually class 3 but it can be class 3 when the contract was written with no allowance for change unless millions are spent in re-certifying a later technique. One small assembly in a radar would cost more than all the existing radars to change the contract solder specification. Of course the assembly fit in the palm of your hand and cost more than most folk make in a year. It would take me a week to build it as it was 1970s technology. The same part done the size of a quarter with surface mount would cost under 20 bucks but by the time it was certified for use, contract altered etc. forget it. Then there are the really strange ones with "to contract" solder alloys requiring special soldering tools...then someone loses that one sheet with the solder specification when the Navy goes out to get a replacement part made...always fun.
I have soldered for more than 20 years. I solder all sorts of ICs and parts as small as 0201 with hand. 1. Couldn’t this gentleman/lady use a more gigantic tip? That has to be the biggest tip ever (jk). You can’t solder SMDs with that. 2. The hands are toooooooo shaky for soldering. But, to be fair, the final work was clean. So whatever rolls his/her boat.
you solder for 20 years and complain that the tip is too big?!?!? i do all sorts of SMD rework, and operate all the smd machine's at work. and i can tell you one rookie mistake: they always try to use the smallest tip possible, all of these small tips have very poor thermal performance. just use enough flux, and use the tip with the largest contact area, this will make your live 10000 times easier, even with the fine pitch large QFP's, i use a big ass hoof tip with my jbc rework station.
Rik Dingus it depends on how much you pay for the tip. The ones I use have a good thermal conductance. They are heated near the tip itself and not on the shaft. Even if I use a big tip, I use one with a sharp edge. The tip has to be copper. Some Chinese ones are other stuff. I always use high quality items including Weller. And I don’t use “the smallest tip possible” unless I have to (repairs) I use a tip with a suitable size. The tip in this video is bigger than some of the ICs themselves. The boards were not densely packed or the tip could not even fit there. I guess whatever rolls your boat. For for me 1-2mm tip is the max size I’d use on small SMD components (not sinks/connectors/...) and 0.2-0.5mm or so for very local repairing. The tip that I have in most of the times is a sloped tip with a short diameter of 1.2mm
Who can give this a thumbs down, beautiful work
IceRook don’t try to understand. Animal rescuer get lot of them too. It’s hard to imagine been against people who rescue almost dead animals. Now, if it’s a thumbs down for the sponge, then it’s ok. Can’t believe they still using the sponge.
Idiots give this thumbs down
+John Gammell
0:15 What are those scourer pads for? 0:35 Does it matter that the wire isn't completely covered? 0:50 How can the excess solder be removed?
The scour pads are actually brass tip cleaners. They do a very nice job but many defense and aerospace manufacturers will not allow them in their facilities because they are notorious for generating FOD (Foreign Object Debris) primarily solder balls.
The wire is snug to the base and post. The lead bend radius is a minimum of 180°, with no violation of minimum electrical clearance. Insulation clearance is within 1 wire diameter. There is wetting of the solder at all points of contact with discernable contour and no depressions at lead to post interface. The wetting does not have to embed the entire lead bend radius. We still have to discern wire contour. The solder fillet meets the IPC Class 3 criteria.
John Gammell
Can they solder more ram memory on the xbox360 and xboxone to see how much better they do.
Also the PS3
John Gammell
Aryan
What oil you use remove soldier?
Utkal keshari mohanty I don’t think you use oil, you can wick off solder. I don’t know if a solution that will remove solders without causing defects to the board
@@utkalkesharimohanty5841
Baby oil
Lol
Any tutorials on speed soldering from wires onto PCB over and over for speed. ??
1:17 why would you have the solding iron at 600? For a pad that size id have plenty heat at 400
Uhm no... 400 degrees F will barely melt the solder, let alone activate the flux on the board properly. I just tested this by setting my soldering iron to 400 F (205 degrees C in my case). The solder just melts, but slowly. If it also has to heat the pad and part, you will lose to much heat and things will not wet at all and the flux won't activate as well and especially the flux is important.
I am something like a beginner on smd soldering and I can't accomplish such a good work with that 1:38 "drag" technique. I use flux but still not that successful. Please drop some advices.
Thank you
1. A bigger tip is easier than a small tip (due to larger thermal mass).
2. Don't drag too fast. You want to spend about 1/2 second per pin.
3. Flux evaporates quickly (especially liquid flux). Re-apply flux for every drag attempt. For SMD, the pros use gel flux (e.g. Amtech NC-559 or MG Chemicals 8341) since it lasts longer.
4. Usually, you'll have a solder bridge at the end. If it's big, use solder wick to remove it. If it's small, drag outwards (away from the chip) to correct it (but re-apply flux first!).
@@XFi6 some of these advices are very helpful. Thank you
@@XFi6 required temperature?
@@vasilzhekov9245 For SMD, 600F to 700F (320C to 370C).
Also:
* Place flux onto the PCB *before* laying the chip down. That way the entire solder pad gets coated with flux. This is especially important when the PCB's solder pads are short (i.e. barely longer than the chip itself) where most of the solder has to go behind the pins.
Some chips are harder to drag-solder than others (e.g. PLCC) so it may be a good idea to first practice on easy chips (e.g. SOIC) with large pitch (e.g. 1.27mm) and, more importantly, long solder pads on the PCB.
Hi, JOHN. The website can't open. We want cooperate with you.
I've been working in Aerospace for years, but it took me moving up to Engineering a year ago to finally score my owm Metcal setup at home. God I love it so far compared to my old Hakko.
But I've always heard good things about Weller, that and they are the best. Used in the industry for decades, before SMT and all that yeah?
There really isn't a manufacturer 'the best' in my opinion: it's more down to personal preference. I started of with a Weller station with adjustable temperature and higher range of tips some 10 years ago as a hobbyist, so the WD1 station with a WP80 and WP65 iron for smaller stuff worked for me. And than I started doing some strong SMD stuff where the smallest gullwing point of my Weller still was huge and could not fit between other components, but also could not handle the huge heat dissipation by a ground plane some of the SMD components were connected to.
I was then working as an aviation technician for some time already and had a JBC station at my disposal. And wow... compared to my Weller WP80 or 65, where exchanging the tip meant to unscrew the hollow holder while still hot, let the (ever so) hot tip slide out onto something heat resistant, let another tip fall down into the still hot holder and than screw it back to the iron, the 'place tip with ridge in removal cradle, pull, push iron onto new tip and secure with the holes beneath the removal cradle > done' kind of tip-exchange just made my Weller feel ancient.
Paired with the active-tip technology, you can almost do anything with any tip: the station will sense immediately that something is dissipating the heat quickly and it will adjust accordingly.
And that's my main thing: Many people say that JBC is the best because of their active tips. And though it could very well be they were the first to come up with this technology, manufacturers like Weller and Ersa aren't stupid and came up with their own active-tip stations (I think Weller calls this Rapid Response Technology).
And thus it comes down to what you like.
For example: I like the desoldering irons by Weller far better than any of the Pace or JBC's, as Weller has the tip under a 75 degree angle-or-so to the handle, while almost all others are in line with the handle, forcing you to hold the thing with almost your whole hand and having far less control over the movement of the nozzle when desoldering, at least, that's my experience, I didn't like them.
What's with the joints turning dull after cooling? I always thought this is a criteria of quality for a solder joint?
Lead free solder will appear dull after cooling.
Wow, look at the size of the solder tip that you used for surface mount part U3, then used the heat gun to remove those shorted ! Do you know how hot is the heat gun? Must be commercial products.
If I was beginner would this be the course I need to take? I'm talking ground zero! If anyone can let know that would be great.
This is a certification program. It may take a couple of years to achieve this skill level. Start with bigger components first.
Hi I really appreciate your videos. If I were in the US I would try to attend your training. Unfortunately I can't. In the case of "PLCC 28 J-Lead Hot air soldering with paste", what kind of paste did you use? Is it a kind of paste containing tin? Thanks!
Beautiful ! Thanks a lot for this video !
What kind of pen he had used as his name
Wonderful ! So satisfying to watch !
It´s So satisfying to wach! thank you, by the way, what microscope did you use in this video?
what is this flux pensil?
Nice and need! Helped me to refresh my soldering Skills
1:48 The paste application for that PLCC looks offset from from the pads. Is that intentional or recommended? Looks weird to me.
you can put the paste anywhere. The heat from the heatgun will melt it, and it will follow the heat source (a.k.a flow to the IC pin). I used to just put it everywhere
Rom Hunter, CAN, yes, but I expect a video called "Master Soldering" to show best practice, not what works 90% of the time. The solder paste that's placed on the solder mask could run either to the left or right, so you don't have a consistent amount of solder on each pad. This could either lead to shorts or insufficient solder on some pads.
there will never be the case of insufficient solder, but yeah, I agree with you on the part that this video should show the best practice
Ron Hunter, I noticed when rewatching the video that the paste was applied both on and between the pads, rather than just between the pads. In this case, yes, it's unlikely that it would produce insufficient solder. If the paste was applied ONLY between the pads because the stencil was misaligned, you could be unlucky and the paste on both sides of a pad could flow the wrong direction. In this case you would rely only on the tinning on the leads, and possibly the tinning on the PCB, and you'd also have no flux, which would almost guarantee a bad connection. I wonder what deal is with that part of the video. If they're using a stencil with half the pitch because they couldn't find the right one, or if this is intentional, somehow.
I would have used a laser cut stencil and a different hot air tip and done them all at one. The one I have to replace is a PIA and is crammed in with so many other parts I have to do that. The special hot air tip was worth it. They're a couple places that offer them for Hakko hot air and rip off hakko clones. It cost more than the knock off chicom one but worth it.
I like this kind of video without sh*tty music
What temperature You use to solder.
Awesome video was really something to learn. You want many more videos. (Thanks)
You didn’t wick the gold out of the cup before final soldering
Just kidding, that’s only a nasa standard requirement. Are you showing class 3?
And Mil. Std.
Test
aapne jo pen se liquid diya hai uska kya naam hai
That Weller soldering station probably costs a ton.
I'm using a 20 year old Pace I rebuilt, a chicom rip off of a Hakko hot air that has lasted longer for 1/100th the price, a 50x used scope and some hand made tools. Pace is almost to the point of stopping support for it as tips are getting hard to get but...20 years means I'll likely keep dealing with them. I'm not a fan of Weller or Hakko, they obsolete stuff too fast. I bought a simple Hakko soldering iron, adjustable temp and they notified me it was obsolete 3 months later. Weller...meh.
My Ersa digital 2000 cost me 350 euro. Weller is old school.
unebonnevie nope! Not at all. Go check Hakko’s station which are ones of best. Weller have been for long and still using sponges to clean. Not good at all.
Hey I'm still rockin' my good ol' skool Weller WES-51, with its analog temp dial baby blue housing, actually two of them since 1999... served me well all these years along with Chip-Quick for medium board work ;)
Lesson #1 - Use lots of flux!!
Lesson #2 - Use lots and lots of flux!!
Lesson #99 - Use lots and lots of f*ckin' flux!! :D
@Marco Polo < I found that the fine metal Brillo-Pads work best instead of the old sponge tip wipes.
@@africantwin173 My preferred is the Ersa I-Con 2. I do this shit for a living.
IPC 7711/7721 certified IPC trainer.
I love that work beautiful job
at 0:41! what's that liquid? before the soldering
Flux and he used a Flux Pen it stops oxidization helps the wetting process
Idiot dont know that
Flux
@@gedxxe fuck off, how can a person learn if they're never told? Don't act like you were a solder god the second you picked up an iron
Kevin Bates thank you. I’m certified in J-std-001 modules 1-5 and the space addendum. During training I didn’t tin the leads. Nobody made comments like these, everybody was helpful and I passed all hands on with the support of my trainer and peers in the class. Support people and answer questions respectfully, it promotes higher education.
Edit: I didn’t know I was supposed to tin the leads, only after I saw others and asked did I learn. Nobody made me feel stupid.
Very informative ,Thank you 👍👍👍👍
It always looks very nice and easy in these videos, but it looks like they use some dummy boards that have only traces going nowhere. In a real live enviroment, when a component has a connection to larger ground plane (like an IC GND Pin) it will be alot more hard to solder by hand, because the solder cools off extremly fast because of the big thermal are. Non connected pins are very easy to solder, but GND pins can be very very hard to solder by hand...
You know that you can get the iron hotter to solder in this kind of situations, don't you?
Nice hobby technology knowledge 💡. 💡
Cool station. I've been so pleased with my Hakko FX-951 that I've not felt like I really have anything up. I don't do SMD work, mostly turret point-to-point and through hole PCB.
Very nice work.
Please make a video on bga ic
soldring
u got three hands？
For drag soldering and solder bridge removal using a Hakko 888D use a flow tip (bevel with a hollowed out section) that's what I use for the same result.
Keren alat dan metodenya
Bro it's only you soldering distance ic legs
Can i join your company ? And continue degree
What a name liquid for this
B- chanel flux, there’s different kinds. I like anything but organic flux
Awesome video
why do hot air with paste and hot air chip soldering? why cant you do just one or the other? or maybe i just dont see the difference
Amazing I thought machines and lasers did tiny solder work.
Nah you can make them in a toaster oven if you have good temp control and install slow circulation fan and board holders. That's for simple one sided boards for hobbists but can work well. The big nitrogen inert ovens that do large double sided boards on a conveyor for manufacturing. There are several videos of them on youtube. They put the solder on with a screen printer similar but more precise than a t-shirt screen printer.
เป่า และ บักกรี ต้องใช้ สองคน
Very fine projects one can also use super glue
Plus super glue isn't a conductor but just sticks your fingers together
Lol
Contact soldering is bad practice and NOT industry standard since 1980.
You still have to use it for some soldering for high reliability and defense contracts depending on when it was made. I've had to build some very odd assemblies due to that. It's usually class 3 but it can be class 3 when the contract was written with no allowance for change unless millions are spent in re-certifying a later technique. One small assembly in a radar would cost more than all the existing radars to change the contract solder specification. Of course the assembly fit in the palm of your hand and cost more than most folk make in a year. It would take me a week to build it as it was 1970s technology. The same part done the size of a quarter with surface mount would cost under 20 bucks but by the time it was certified for use, contract altered etc. forget it. Then there are the really strange ones with "to contract" solder alloys requiring special soldering tools...then someone loses that one sheet with the solder specification when the Navy goes out to get a replacement part made...always fun.
Like a TIG welding... Perfect ;D.
Nice and neat.
nice work
master work
威乐的焊台真心的买不起
ไลด์ ตะกั่ว ไปรอบ หนี่ง แล้ว ตาม เป่าอีกรอบ
Awesome
perfect
satisfying
I like it
man very good job you remind me wen i was 16 years old lololol
17 now?
pro
i see u puting a lot of liquid
Kanari Mentos its a flux
DAMNNN NASTYY
Hi
liked and subed
Badly... hands are shaking...
This try of job looks hella hard 😫😫😫😫😫😭😭😭🤦♂️🤦♂️🤦♂️
that is so easy ..
On fucking ground pattern, not melt
Dull
Your hands are shaking.
That is essential tremor.I bet he is good at his hand.
I don’t know how steady your hands are, but I’m shaky as well when soldering SMT.
I have soldered for more than 20 years.
I solder all sorts of ICs and parts as small as 0201 with hand. 1. Couldn’t this gentleman/lady use a more gigantic tip? That has to be the biggest tip ever (jk). You can’t solder SMDs with that.
2. The hands are toooooooo shaky for soldering.
But, to be fair, the final work was clean. So whatever rolls his/her boat.
you solder for 20 years and complain that the tip is too big?!?!? i do all sorts of SMD rework, and operate all the smd machine's at work. and i can tell you one rookie mistake: they always try to use the smallest tip possible, all of these small tips have very poor thermal performance. just use enough flux, and use the tip with the largest contact area, this will make your live 10000 times easier, even with the fine pitch large QFP's, i use a big ass hoof tip with my jbc rework station.
Rik Dingus it depends on how much you pay for the tip. The ones I use have a good thermal conductance.
They are heated near the tip itself and not on the shaft.
Even if I use a big tip, I use one with a sharp edge. The tip has to be copper. Some Chinese ones are other stuff. I always use high quality items including Weller.
And I don’t use “the smallest tip possible” unless I have to (repairs)
I use a tip with a suitable size. The tip in this video is bigger than some of the ICs themselves. The boards were not densely packed or the tip could not even fit there.
I guess whatever rolls your boat. For for me 1-2mm tip is the max size I’d use on small SMD components (not sinks/connectors/...) and 0.2-0.5mm or so for very local repairing.
The tip that I have in most of the times is a sloped tip with a short diameter of 1.2mm
FLUX FLUX FLUX XD
Cartoon