Drilled solder paste stencils

Guys, if you're like me and find soldering SMDs to be a royal PITA and with the cost of laser cut stencils through the roof, then here's a tip
to drill your own stencils. You'll probably need a CNC drill/mill though. Some after "pasting" and after "baking" shots are at the link below. Just click on slideshow in the upper right hand corner.
http://www.pbase.com/eldata/stencils&page=all
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@hotmail.com wrote:

Very nice. I tried this once on a CNC machine, but instead of drilling, I used a fine drill rod to punch the holes in Lexan sheet. It worked well enough, but your holes and the printed paste look better than mine. How did you finish the holes so nicely? No burrs at all.
-- Joe Legris
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Sanding.....Medium grit then fine.
J.A. Legris wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@hotmail.com writes:

Call me stupid, but I'm missing the key "how to do it" part. Looks like a stencil was cut, and then somhow solder wound up on the boards. How was that done? I'm really curious to see how, since this process looks really good in the pictures, and the best you could say about my SMD soldering is that the solder joints tend to hold... mostly...
--
Joseph J. Pfeiffer, Jr., Ph.D. Phone -- (505) 646-1605
Department of Computer Science FAX -- (505) 646-1002
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
writes:

Looks like once the stencil is cut, you just swipe some paste over it and it deposits through the holes. So I would guess that you lay the stencil over the board and use a small squeegee. This would be almost identical to silk screening.
Cheers!
Sir Charles W. Shults II, K.B.B. Xenotech Research 321-206-1840
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You align the stencil with the board/pads, hold it in place, dab solder paste on the stencil then using either a rubber squeegee or flexible plastic putty knife you ensure all the cutouts (holes in this case) are filled flush with the stencil. Agreed, I could have taken more pictures but just assumed this to be a well publicized no-brainer step. Here are some links (BTW, it doesn't have to be as messy);
http://www.sparkfun.com/tutorial/SMD_Printing/SMD_Printing.htm
http://www.stencilsunlimited.com /
Joe Pfeiffer wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@hotmail.com writes:

Ah ha. Definitely in the "now that I know the answer, it was obvious enough I should have realised it" category.
--
Joseph J. Pfeiffer, Jr., Ph.D. Phone -- (505) 646-1605
Department of Computer Science FAX -- (505) 646-1002
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
But how do you get the pad coordinates so you know where to drill the holes? Is there and easy way to extract it from gerber files? Ringo
Joe Pfeiffer wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I can only speak for Eagle. There is a file "smd-coordinate.ulp" in the ULP folder that ouputs x-y coordinates of SMD pad centers. Since CNC solder paste dispensing machines are still around, I suspect most PCB CAD software provides some means to extract this info.
Ringo wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Cool, I use eagle, so I'll have to give it a try. I currently get Stencils made a Pololu for about $40, but this would be great for times swhen you can't wait a week to get them. Thanks
snipped-for-privacy@hotmail.com wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@hotmail.com wrote:

Awesome work. The stencils always kept me from entering the SMD age, but this may actually be the solution. Thanks for posting this!
What material did you use for the stencil?
Now if I could get my CNC machine to position the parts... . ;-)
Matthias
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Google >"solder paste stencils"<
Matthias Melcher wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@hotmail.com writes:

Having just googled, here's a good site on the subject that I found:
http://www.sparkfun.com/tutorial/SMD_Printing/SMD_Printing.htm
Lots of *really* good information there.
And to think the half-dozen SMD parts I've soldered have all been by hand...
--
Joseph J. Pfeiffer, Jr., Ph.D. Phone -- (505) 646-1605
Department of Computer Science FAX -- (505) 646-1002
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Joe Pfeiffer wrote:

Awesome. I alreaddy decided for my first SMD project. I can finnaly get my FTDI mounted and the USB-to-serial converter going ;-)
(Yes, I know, I can also solder that one by hand)
Matthias
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.