Thin PCBs! (Updated 2X)
I picked up some really thin single side copper clad last month at a surplus store on a lark. It was cheap, two or three square feet for $3. Today I decided to etch an adapter board for my ETek EB-85A GPS. Heading down to my basement, I spotted the sheet of copper clad and decided I see if I could cut it with scissors. To my delight it cut quite nicely! This level of control feels empowering to me.
Once I had etched the board I got another surprise: the board was translucent. I could see the traces from the wrong side of the board! This has given me an idea that I hope to explore soon.
One of the troubles with double sided boards is getting the two press-n-peels to align right so that each side's pads and via are actually atop one another. There are a variety of techniques to get good alignment. I've tried a few with reasonable success, but its still a pain. With thin, translucent and easily cut boards however, it occurs to me that I could etch the sides completely separately of one another and then combine then. Since the board is translucent it would be easy to get the holes exactly right.
What's more, since two of these boards are probably still thiner than a regular board, making a three layer board should be a straightforward extension of the two layer technique.
The other thing I really like about these thin boards is that a number of my broken drill bits (I eat PCB bits like candy) are still long enough to go through the board!
I'll update this page as I try more things.
I got five more sheets from American Science and Surplus. However, I found out that I had made a bad assumption when I bought the first sheet. I bought it at a tent sale that looked fairly haphazard. I assumed they were remainders.
After speaking to the guys at the store I discovered that they have over 100 sheets at their warehouse. They told me Chicago branch
already has a good supply in-store as well.
There are a couple of numbers on the sticker of the sheets I just bought:
SZZ99935718P0001 (underneath the bar code)
060818 (off to the side)
neither the numbers nor the 'Copper Sheet 24" x 18 1/2" ' text on the sticker turns up on the website but if you call a store maybe they will mail you some if the store is too far for you to drive to. They are $6 a sheet.
I ran across 5.5" x 6" Scissor Cut SS Copper Clad at Electronic Goldmine. It's not as cheap per a square inch as American Science and Surplus but if they run out of the stuff or you don't have a store handy you have this second option.
In the picture above you can see the traces on the same side as the SMT connector. In the picuture below you can see the trace though the board itself.