A word from the wise... If you're ordering the stencil from JLCPCB, definitely make sure that to have the stencil cut to the right size.. Otherwise you'll get charged a fortune for shipping because the package ends up very large. Cheers!!
@@sdgelectronics Honestly, I always get my stencils with the framing. Despite the shipping cost, it's _so_ nice to have a rigid frame to hold on to for holding the stencil in place.
Thanks Steve! As I understand it, after the solder paste has flowed, you are supposed to leave the preheater on and turn the temperature all the way down. Then the preheater will slowly cool the board down.
I think that this type of ceramic preheater has a large enough thermal mass that when it's turned off it slowly cools down and so does the board with it, so it's not a too rapid cool down of the board.
@@robertcalkjr.8325 It took about 10 minutes before I could remove the PCB, so I was not too concerned about the thermal stress although it of course did not follow the correct profile.
The board will cool faster than the heater block, in my experience. Most of the boards that I solder on are populated so I don't turn the preheater up too high because I don't want to start melting stuff. I normally turn it up to 180C, which will give me about 175F on the bottom of the board, unless I cover around the board to keep the heat from escaping. The temperature on the preheater is at the ceramic heater block, not the board above it.
Great tutorial, Steve. Those 0201 parts look so small; even viewing this on a bigger 4K screen so I could see them in more detail, still made me wonder how you placed them with such a steady hand! Did you use your home-brew pick-and-place device?
No, I've not got around to finishing that yet, so these were placed by tweezers. Same technique used just where I'm placing the final parts in this video.
Andy Jary Prices look a lot better for microscopes now than when I bought mine a few years ago. I have a twin beam trinocular AmScope, but it is not simul-focal. In the next few months I will upgrade it with a new camera and simul-focal head.
I've never bothered with stencils before but my latest design has loads of identical components.... 100+ resistors, 100+ diodes.... so it might be worth a try... thanks for the video... I wonder if I could preheat on my cooker!
Someone should invent a part placement stencil for large numbers of parts - I have a 300 part this week - that you space above the PCB. Then you just have to drop parts in holes.
That sounds like a grand idea. First, use a solder stencil to put the liquid solder in the correct places. Second, remove the solder stencil. Third place a part placement stencil with a spacer to hold it above the PCB. Fourth, drop the parts through the holes to get them properly aligned. Fifth, remove the parts stencil. Sixth, apply heat. Making the part stencil shouldn't be any more involved than making the solder stencil.
A word from the wise... If you're ordering the stencil from JLCPCB, definitely make sure that to have the stencil cut to the right size.. Otherwise you'll get charged a fortune for shipping because the package ends up very large. Cheers!!
Yep, I did that on my first order 😂
@@sdgelectronics Honestly, I always get my stencils with the framing. Despite the shipping cost, it's _so_ nice to have a rigid frame to hold on to for holding the stencil in place.
D'oh! So that's why I got reamed on shipping charges. Wish I had read your post before I ordered.
Thanks Steve! As I understand it, after the solder paste has flowed, you are supposed to leave the preheater on and turn the temperature all the way down. Then the preheater will slowly cool the board down.
I think that this type of ceramic preheater has a large enough thermal mass that when it's turned off it slowly cools down and so does the board with it, so it's not a too rapid cool down of the board.
I meant for multilayered boards and forgot to mention that. If you just shut this preheater off, it will cool down pretty fast.
@@robertcalkjr.8325 It took about 10 minutes before I could remove the PCB, so I was not too concerned about the thermal stress although it of course did not follow the correct profile.
The board will cool faster than the heater block, in my experience. Most of the boards that I solder on are populated so I don't turn the preheater up too high because I don't want to start melting stuff. I normally turn it up to 180C, which will give me about 175F on the bottom of the board, unless I cover around the board to keep the heat from escaping.
The temperature on the preheater is at the ceramic heater block, not the board above it.
Useful video 👍
Great tutorial, Steve. Those 0201 parts look so small; even viewing this on a bigger 4K screen so I could see them in more detail, still made me wonder how you placed them with such a steady hand! Did you use your home-brew pick-and-place device?
No, I've not got around to finishing that yet, so these were placed by tweezers. Same technique used just where I'm placing the final parts in this video.
You just need a good microscope, Andy.
@@robertcalkjr.8325 - Agreed, Robert! I've been looking at a number of models from AliExpress that seem to be reasonably priced.
@@The.Doctor.Venkman I've got a low(ish) cost one to review which may be useful.
Andy Jary Prices look a lot better for microscopes now than when I bought mine a few years ago. I have a twin beam trinocular AmScope, but it is not simul-focal. In the next few months I will upgrade it with a new camera and simul-focal head.
I've never bothered with stencils before but my latest design has loads of identical components.... 100+ resistors, 100+ diodes.... so it might be worth a try... thanks for the video... I wonder if I could preheat on my cooker!
Cool thanks! 👍 from me.
Someone should invent a part placement stencil for large numbers of parts - I have a 300 part this week - that you space above the PCB. Then you just have to drop parts in holes.
That sounds like a grand idea. First, use a solder stencil to put the liquid solder in the correct places. Second, remove the solder stencil. Third place a part placement stencil with a spacer to hold it above the PCB. Fourth, drop the parts through the holes to get them properly aligned. Fifth, remove the parts stencil. Sixth, apply heat.
Making the part stencil shouldn't be any more involved than making the solder stencil.