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Topic: My DIY solder paste stencil (Read 2309 times) previous topic - next topic

John_S

Jan 19, 2013, 02:20 am Last Edit: Jan 19, 2013, 02:23 am by John_S Reason: 1
I've looked for a diy way of making a solder paste stencil online. I couldn't find anything simple. There are lots of examples of using a thin copper plate, then etching away the holes. I thought I'd try something else.

I started with a thin piece of plastic from a food container. It's clear and 0.007" thick. Then I overlaid a printout of the PCB pads, and drilled 1.2mm holes through the template and the plastic. The hard part was keeping the drill from wandering. I also had to "clean up" the plastic holes as there were a lot of burrs.

I tried some 0.8mm holes too. Some worked, others I didn't get clean enough after drilling. I don't know if I can drill holes suitable for a TQFP, but I might have to give it a try. There was some minor smudging which seemed to be worse after the first board when the stencil was clean. I just fixed up the smeared paste with some tweezers before placing the components.

The photos below are of the stencil, the solder paste on the board, and the finished job. The resistors are size 0805.

Not bad for an afternoon of DIY  :smiley-mr-green:

edit: sorry for the huge pictures. On the plus side, you can see the granules in the solder paste!
http://jsrintervalometers.blogspot.ca

Osgeld

I use overhead transparency sheets, and a knife
http://arduino.cc/forum/index.php?action=unread;boards=2,3,4,5,67,6,7,8,9,10,11,66,12,13,15,14,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,86,87,89,1;ALL

John_S

Can you cut out pads for a TQFP with a knife?
http://jsrintervalometers.blogspot.ca

Osgeld

#3
Jan 19, 2013, 05:54 am Last Edit: Jan 19, 2013, 05:57 am by Osgeld Reason: 1
you can try, I just cut a thin slit to go across all the legs on one side, the surface tension of the solder usually pulls it onto the legs and off the solder mask as long as you dont over do it

course the finer the pitch the harder it gets, a 44 is no problem, but you can hand paste those as well, 176? you might have bridges

I never bother unless I have more than a couple boards. I had to do 25 simple rectifier boards the other day at work and that saved a ton of time, as I ran the sheet through the laser printer first and cut out the SMC diode pads as if they were in a panel

little tape, and a putty knife bam 5 done at a time

http://arduino.cc/forum/index.php?action=unread;boards=2,3,4,5,67,6,7,8,9,10,11,66,12,13,15,14,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,86,87,89,1;ALL

LarryD

Quote
I use overhead transparency sheets, and a knife

I have not done this but, how about a HOT very fine tipped soldering to burn a hole?
The way you have it in your schematic isn't the same as how you have it wired up!

Osgeld

edges that are not flat with your material is not your friend
http://arduino.cc/forum/index.php?action=unread;boards=2,3,4,5,67,6,7,8,9,10,11,66,12,13,15,14,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,86,87,89,1;ALL

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