[flickr 201021274 ]
OK so boards came in, and there’s 80-100 to be assembled. They’re pretty simple boards: 1 8-pin micro, 3 resistors, 1 capacitor and 2 4-pin header plugs. Since it takes a long time to solder, I designed the board for mass-manufacture: surface mount parts!
Eventually everyone needs to make a lot of PCBs (at home), the best way to do this is to use solder paste and a reflow oven. Since EYEBEAM has a laser cutter I can use it to make a screening stencil and a registration frame. (You can also buy stencils from your 4pcb.com and probably a bunch of other PCB manufacturers) Then it’s super fast to make tons of PCBs. Just silkscreen on solder paste (available at digikey), place the components, and bake!
First, cut out a frame from 1/16″ acrylic the same size as the PCB, this will be the registration frame
[flickr 201022618 ]
The PCB should be a perfect fit
[flickr 201022473 ]
Extract the stencil info. I took the stop layer, viewed it in GC-prevue, printed it to a file (ie. PostScript), then opened it in CorelDraw which is set up to print directly to the lasercutter
[flickr 201023132 ]
Cut it out in 2-3 mil Mylar
[flickr 201021392 ]
Register (align) the screen on the frame and tape it down
[flickr 201022333 ]
Now…use a biz card or something similar as a squeegee. Lay down a bead of tasty solder paste…
OK now you have a board with solder paste dots
[flickr 201020933 ]
Place the components with your tweezers
Repeat 80 times, and put them into the toaster. 200 degrees for 4 minutes, 300 for 2 and then 450 until the paste melts, then 300 for a minute to cooldown.
[flickr 201020786 ]
Yay you are done! now all thats left is the thru hole parts…
[flickr 201021144 ]
Have an amazing project to share? Join the SHOW-AND-TELL every Wednesday night at 7:30pm ET on Google+ Hangouts.
Join us every Wednesday night at 8pm ET for Ask an Engineer!
Learn resistor values with Mho’s Resistance or get the best electronics calculator for engineers “Circuit Playground” – Adafruit’s Apps!
Maker Business — Limor Fried featured in NYC’s HER BIG IDEA!
Wearables — Get concrete solutions
Electronics — Probe Compensation
Biohacking — Dr. Rita Levi-Montalcini was a Centenarian Gonzo Biohacker
Sorry, the comment form is closed at this time.