[sdiy]Re: [sdiy] PCB making

[rdrake]

like some other folks, i've had good success with homemade boards based on lazerprint output.  it does take a little practice, but it's not any harder than building and troubleshooting electronics.

for the transfer method, i use press-n-peel blue, transfered with a household iron.  biggest single "secret" is to make sure the copper board is CLEAN CLEAN CLEAN before transfering... i scrub with fine steel wool, then with ajax cleanser, then rinse w/ distilled water, airdry/prewarm the board in a slow oven, and don't touch the surface with your fingers after cleaning.  transfer is usually about 5 minutes w/ as much preassure as i muster.  if there are major holes when you peel back the plastic, just clean off and start over... if there are minor issues, touchup with a sharpie before etching.

for photo, i use presensitized boards.  print onto acetate so the toner side faces the board (sometimes you have to mirror-image when printing)--you don't want any space between the mask and the emulsion, even the thickness of the acetate.  you can touch up pinholes on the emulsion w/ a marker.  sandwich everything so it's totally flat, i use a 1/2 piece of plexiglass on top to weight things down.  exposure is not so finicky, i usually do about 8 minutes under my shop florescents at about 12 inches away, seems fine.  if there are still pinholes, you can still touchup w/ a sharpie.

my first few tries were a little dicey, and i've never tired SMD or doublesided boards... but for simple layouts (i've done a few of ray wilson's design's, frinstance) this is entirely doable by the average sdiy nerd...

bbob

>----- ------- Original Message ------- -----
>To: billbigrig at yahoo.com,
>synth-diy at dropmix.xs4all.nl
>Sent: Wed, 03 Jan 2007 02:32:40
>
>>
>>  I usually just make circuits on pre-made
>>projectboards, but would like to start making PCBs
>
>>again(after 20 years). I read about using the
>printer
>>as a pattern maker. Does this have to be a laser
>>printer