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This is the first time I've done this but I've tried about ten times now:

enter image description here

That particular image is of the pads for an ESP-32. It's not a perfectly representative picture because the bridging isn't always that bad.

I followed this guide and in fact I ordered the stencil from JLCPCB but my results are messier. I think perhaps when the solder gets smooshed through the holes in the stencil it's going underneath the stencil to form the bridges. I've tried clamping the stencil to the board and putting a heavy weight on the stencil but it never comes out right.

Can you lead me to the light please. The LED light of course. ...which I will be able to see after I get this solder paste on the pads properly. Thank you!

EDIT - ended up getting it. Check the comments for more information.

user875234
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    Only squeegee once. The openings in your stencil may also be too large. That said, even what you've pictured may be able to be assembled, you appear to be placing a castellated sub-module which may be able to accept quite a bit of solder. Worst case you could also solder the submodule on this version with an iron and wire solder. – Chris Stratton May 20 '20 at 05:44
  • I have to squeegee several times. To only squeegee once I would have to use a lot more solder and press harder. How hard do you have to press? Do you refrigerate your solder? Do you use a credit card? Do you put solder on lots of different places or in one spot and squeegee the whole board at once? ...It might work as it is? How does that work? The solder gets drawn to the pads and the metal components and so the bridge might go away on its own? – user875234 May 20 '20 at 05:51
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    What solder paste are you using? And how do you hold the PCB and stencil in place when applying the paste? – Jakob Halskov May 20 '20 at 05:51
  • This solder paste https://www.digikey.com/product-detail/en/chip-quik-inc/SMD291AX/SMD291AX-ND/1160002. I tape everything to my desk and then put a couple 2x4's on top of the stencil to make it as flat as possible. Then I put a weight on the 2x4's. I've tried other techniques too but that's how I attempt it when I'm trying the hardest. – user875234 May 20 '20 at 05:54
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    I know it's tempting to squeegee multiple times, but don't do it. It is the precise cause of your problem. Unless you are willing to work with this result (and it may well work) you must only make a single pass. – Chris Stratton May 20 '20 at 06:08
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    @user875234 also, the 2×4's sound more like a problem than a solution. The stencil must, by itself, lie absolutely flat on the PCB. Your stencil is probably much larger than your PCB – so, around the PCB you want to apply the paste to, place other PCBs of the same height, and around these, you can achieve a nice and level surface by using normal paper sheet stacks (don't fold!) so that your stencil lies nice and flat and doesn't bulge. Then, single pass. I use a squeegee that's also just a plastic card, but it's much stiffer than what's in the video. – Marcus Müller May 20 '20 at 06:24
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    Can't relate too much to this because I use only framed stencils in a printing rig, but if you refrigerate the paste, allow it to reach room temperature before printing, and (unlike screen printing) you want the stencil actually in contact with the PCB. Pay attention to the squeegee angle, pressure and speed. More solder paste on the stencil makes it easier to get full coverage. When you clean the stencil pay attention to the smaller holes like 0402 pads. Don't be afraid to scrape the paste off the top, clean the PCB & the bottom of the stencil off and start again if things get smushed. – Spehro Pefhany May 20 '20 at 06:29
  • I found [this](https://www.youtube.com/watch?v=AIiAAxyvRB0) video helpful – Keith Miller May 20 '20 at 07:14
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    FYI I slept on it and tried again first thing in the morning and the results came out a lot better. I used the same equipment. I just used a little more solder. I taped the board and the stencil down but I didn't put anything on top of the stencil to apply pressure. Instead I pushed the stencil down with one hand and on scraped the credit card over top of the stencil with the other. setup - https://i.imgur.com/gSQR236.png results - https://i.imgur.com/C8WJ7MN.png Thanks for your advice! – user875234 May 20 '20 at 14:19
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    @user875234 Good stuff - you should add this as an answer and accept it, that's much useful than leaving it in the comments :) – awjlogan May 20 '20 at 14:24
  • Your stencil openings are also supposed to be ever slightly smaller than the pads – DKNguyen May 20 '20 at 14:25

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