Thin Double Sided PCBs
This evening I had a chance to try out my thin PCBs on a double sided board. For the first run it actually went pretty darn well.
First, I eye-balled the cut of each side of the board and they wound up being pretty different sizes but both were over-sized. I just used scissors.
Then one at a time I transfered my press-n-peels to each side.
I etched each the of the sides separately.
Then I put the sides on top of one another on a light table. Even though there were now two layers of PCB I could still see the bottom side. This allowed me to align each and every pad perfectly.
One extra thing I did to accomplish that was snip the top side a bit so it was smaller than the bottom side. This allowed for better control while sliding the boards around.
Then I taped the boards together in three places.
Next I took the dremel drill press to the boards. The alignment was perfect. My ability to drill thru the center of the pad was not as good as my ability to align the pads themselves.
Once I had all the holes drilled I seperated the two boards to clean the press-n-peel resist off. I had no trouble re-aligning the cleaned sides and soldering the components in.
Finally I trimmed the boards down so that they were both the same size. The scissors had no more trouble cutting thru two layers of board than they did cutting thru one layer with copper on it.
Below is a picture of the assembled board on the light table. While it is all over in this pic (I forgot to take pictures during the process) you can still see the alignment and imagine how you'd do it.