Arthur T Knackerbracket has processed the following story:
While using a stencil should make solder paste application onto PCBs a simple affair, there are a number of “gotchas” that make it more art than science. Luckily, there are tools you can build, like this 3D-printed vacuum-assist stencil jig, that take a little of the finesse out of the process.
[...] In use, the PCB is placed on the center fixed platform, while the stencil sits atop it. Suction pulls the stencil firmly down onto the PCB and holds it there while the solder paste is applied. Releasing the suction causes the outer section of the platform to spring up vertically, resulting in nice, neat solder-covered pads. [Marius] demonstrates the box in the video below, and shows a number of adapters that would make it work with different sized PCBs.
Link to 5m28s YouTube video.
(Score: -1, Spam) by Anonymous Coward on Sunday December 26 2021, @12:07AM (1 child)
My screaming scrotum compliments my STEAMING PENIS.
(Score: 0, Disagree) by Anonymous Coward on Sunday December 26 2021, @12:52AM
Yeah... It hurts when you're soldering a PCB on your lap and a glob of solder drips down.
(Score: 0, Interesting) by Anonymous Coward on Sunday December 26 2021, @02:42AM
But not wow, not going to make this list https://www.youtube.com/watch?v=DzvUUNsj8JY [youtube.com]
(Score: -1, Spam) by Anonymous Coward on Sunday December 26 2021, @04:17AM
Disgusting penguinesque freaks.
(Score: 5, Funny) by VLM on Sunday December 26 2021, @04:24PM (1 child)
Do people really have trouble with this?
I've had pretty good luck over the years with the ole "fuck it and trust the science of surface tension" just yank it off like a bandaid.
Another strategy I've used is the tape hinge, which works pretty well. Tape down the board, tape down one side of the stencil, floopy it up call it good. There is some sport to not having the stencil bend but its not rocket surgery it'll be fine.
The final strategy I've only used twice is if you're doing microwave RF stuff then you've probably got shield walls or heatsinks or something so trim the stencil so it fits and the other component is holding it in place. Yeah a rational person solders the smd first then solders the shield walls but if you do it backwards assuming you can get the stencil trimmed and aligned it'll fit.
If you're mass producing you have to stencil. If you're LARPing that you mass produce for karma and updoots, you have to stencil. If you're doing digital microcontroller stuff with 144 pins you need to stencil. If you're doing microwave RF and your entire LNA or final PA only has two dozen solder joints, you just use the hand syringe of solder paste, F-ing with the stencil takes longer than doing it by hand.
I believe this is yet another corner of the electronics hobby where ham radio guys who've been doing this since the 80s don't exist according to the shiftless urbanite java programmers trying to learn how to solder. Probably because ham isn't kosher (LOL).
(Score: 4, Informative) by Username on Sunday December 26 2021, @05:33PM
Every known SMT place has a screen printer for this. From $200 ones to $50,000 ones. I'm not sure why the article is framed like this stuff never existed.
(Score: 2) by Username on Sunday December 26 2021, @05:40PM
How is this better than just "3d printing" the paste directly onto the board? Why the middle process.
(Score: 2) by looorg on Monday December 27 2021, @04:53AM
This seems like a bit of an over-engineering to solve a problem. I normally don't use paste or stencils very much but I do acknowledge their usefulness when it comes to soldering many very tiny components. This might be useful if you are doing a lot of these boards. But for me, or I guess the small scale amateur, I don't see much need for this. If I have a stencil I just put it on the pcb, tape it over, apply paste, scrape the paste into all the little holes -- usually with some old plastic card, remove tape, lift stencil, apply components and then heat it up. So this whole jig is replacing the tape part essentially?
Still a lot of quite small components can be soldered by hand just fine (I say this now, perhaps in a decade or so my sight has gone and my hand isn't as steady). Just apply a Rossman-quantity of flux and you get a very similar effect when soldering, components will literally snap into place on the pads just as with a heat-gun when heat and solder is applied. Also I never have to deal with those annoying little solder-balls that the paste is made up out of. They have a nasty tendency sometime to go where they don't belong.