Solder Paste Stencilling - This really sucks! 

I saw your tweet, I thought it looked like a vacuum attachment, then I thought "what do I know". Glad you found a working solution for your problem Seon.

The non-transferring of paste correctly is indeed THE most frustrating part of manual stenciling. Have many bad boards to prove it. So much time is wasted in rework. This is a great project! thanks for sharing.

Impeccable timing. About to tackle this exact issue and can now spend the weekend making a vacuum attachment.

A great tip, *especially* the part about 3D printing alignment jigs! Brilliant to use the vacuum too: I’ve done the same for contact-printing film negatives with extremely fine detail on them, but I’m not sure I would have thought to extend it to solder stencils on my own…

I did something simillar for my one off frameless stencils. I 3d printed an air bed that fits my boards and has a lip the same height as the board around the board edge. I put channels in my boards to allow suction at the middle of the stencil. I use a mini pump for fishtanks, the kind they have for sucking air out of over the back syphon overflow boxes.

Ha I was just playing with a vacuum forming machine for the same thing! Nice solution

Actually really cool idea. I do by the tape flap method with boards around it as a jig. Works alright but this looks good for tighter pitch stuff

okay now that's a cool solution. Not that I've encountered it yet but still pretty cool.

is there any possibility of paste being sucked in by the vacuum and smearing on the PCB

Somewhere I can purchase one of these?

Nice work! I should probably make some videos to about mine :)

Nice, I have worked with vacuum test gear that pulls PCB's down onto the bed of nails and this is a great implementation, The company who made the gear is called ' Wayne Kerr ' no joke, it was named after the actor John Wayne and actress Deborah Kerr as the two guys who founded the company were big fan's ! I look forward to your further refinements....cheers.

Really cool!

Why can't you make an array of neodymium magnets embed into the plastic base so that it will hold the stencil in place without any air gap?

Brilliant Seon, thanks for sharing, gonna think about this for my pasting setup. A milled block would be something I would purchase if available rather than 3D printing one..

My pet hate is watching people spread paste over their stencil like they were painting a wall i.e. going over and over and in various directions.....all the time pushing more and more paste down and under the stencil with each subsequent swipe......aarrgghhh! what a mess. If set up correctly and with a wide enough spreader, then one swipe across the board is all it will need. PS. Have never tried a vacuum table, looks great!

I have been using this method myself the last year six months and it works pretty good, however, it's not perfect. The problem I have is that the vacuum finds it way to the stencil cutouts, which means it will suck out the solder paste from the holes. My solution is frameless and I adjust the vacuum so it's as low as possible without the stencil moving around. I have managed to get some flawless solder paste applications, however, now when I just purchased some new solder paste, the viscosity dramatically decreased and the sucking of solder paste from the cutouts got very apparent. Have you had any experience with this problem? Any solutions?

This is why I go frameless on small boards and use the tape flap. A stencil that is much larger than a board will have a warp. A small stencil will sit completely on the board with no outside pressures from a frame.

Hi, Seon! Excellent setup, thanks for sharing! Do you have some sort of filter to prevent solder paste from getting sucked into the vacuum cleaner, or is it not really a concern because hardly any paste would be sucked in?

But isn't a bit of leakage in the vacuum table a good thing? Bad for the vacuum pressure but non shop vacuums use the suction airflow for cooling the motor...

Been doing this for years; I just assumed it was industry standard. The first engineering company i worked for did screen printing of dials upstairs, so whenever i had to solder paste a board i just went upstairs and just threw it on a vacuum table and stenciled the board, i do like the board jig though.

nice improvement. But why vacuum cannot enter the office in a silent way ...

You definitely don't want vias in pads here!

That's pretty cool. Does the vacuum bleed the paste under the stencil at all?

That is actually Genius

Can you make a mini shed outside your garage to house the vacuum, then run a PVC pipe to your bench? Then say: Alexa, this sucks!

brilliant !

Neoden wants $600-$1000 for that stencil frame holder. Is that right?

Have you spoken to Christo from @Burgduino?! ;)

Nice :-)

This really sucks...

Mother of invention! This is killer for non-framed stencils. Consider a bleeder valve for aligning then close for paste. You just saved hundreds of dollars for makers who are considering stencil printer, now they just need some PLA. I thought your part turntable was clever but this tops it. Well done. Thanks.

wow I always assumed stencil frames were like screenprinting and it pulled it down hard against the pcb, but yeah I suppose they are not flexible enough and wont stretch but bow instead..

Hey Seon -- I have to admire you doing this pioneering exploration and sharing it with us! I'm a little concerned that the suction would suck excess solder paste through the stencil, especially if there are through-holes or slots in or between the boards of the panel. So I'll be interested to hear what you observe in that regard. Also -- might there be a role for magnets to hold down the stencil -- rather like the flex plates for 3D printer beds? I wondered if the magnets would attract the stainless steel stencils, but I tried a couple here and they do seem susceptible to magnets.

I suspect the thumbs down came from a specific pick and place manufacturer that we all know well.

Seems a excellent solution that is most probably a great improvement over the present manual method. Only immediately ppssible issue is sucking paste sideways between stencil and pcb, may remain no issue. Probably mainly at outer boundary or regions of drilled holes of the panel. Especially if any residual burs are left from routing, drilling or V groove , or even micro height lift of stencil from text print/ resist layer. So careful control neede on amount of vaccum versus minimum needed to ensure flat holding effect. Next issue is effect on e vaccum is off and the stencil lifts away due to any bowing or misalign of stencil frame or bowing of pcb, if adhesion of paste is imperfect, to same effect as former non flat stencil, retaining paste in stencil holes.. Though should be no worse than complete lifting of stencil to remove the panel

A top tip working with "vacuum" When you get closer to the final solution, add a pressure sensor to measure what level of vacuum you achieve. Suitable for repeatability and simply do not trust only your eyes and fingers. Cheers.

Well that just sucks! Nice work with the design.

Maybe you can get one of those variable speed vacuums, lower noise if it docent need to run at full speed.

You should get a Yamaha YCP10, does this automaticall. It's a little bigger though. :)

Could see immediately with that overlapping frame that arrangement would flex the stencil in all directions in use, good idea with the vac, but would look to support the frame as well, in fact from the vide it is obvious that the bottom pattern is moving well, none of the arrangement is stiff enough. On the design side why are you going to ever smaller component sizes, design for manufacture just as important as design for functionality, can you really not keep component sizes to a sensible size for self build, why stress your processes more than necessary or are your boards really that densely populated?

seems to me like a vacuum table and a frameless stencil with alignment pins might be a winner here? just pop it on over the pins and you're done. no clue how accurate the manus get those pins tho.

I like this idea Seon. So simple and effective.

Well I want one

Seon, If you make sure the panel has holes or cut outs between the individual boards would the suction on the the stencil be better?

Have you had any thoughts on the "open" nature of the project? Still to be decided?

You still deal with CHINA? -----Ok.

Those panels are stainless steel ... can't you use Magnets? or electro-Magnets? ... no need for such complex machined parts for the vacuuming. Just an idea.