Homebrew PCBs

El 03-oct-09, a las 15:27, Lee escribió:
>  For any DIY process, getting the two sides to line up and drilling  
> vias is sufficiently complicated and error prone to reduce the  
> success rate, at least in my experience, to we
> ll below 50%.

Hmm, that seems to be a very high failure rate - I've had a 100%  
success rate with getting the registration right with double sided  
boards, done using toner transfer. My second ever board was double  
sided.

Getting the two sides to line up doesn't need to be hard. The best  
method I've found is print on glossy paper (rather than bits of  
magazine), and hold the two sides face in up to the light. The sun  
through a window makes an excellent light source, but otherwise a  
table lamp works adequately. Get the two sides to line up, then tape  
one end of the paper as a "hinge". Double check the line up after  
making the tape hinge, then place the copper board between the sheets  
and get busy with the iron. I've never had a registration failure -  
the worst board I made still had enough overlap that it was usable.  
The worst I've had is an occasional broken trace - but most the boards  
I make at home these days are sufficiently small that it's not a big  
job to find them.

The good thing about home making a board is you can go from PCB layout  
to a functional circuit in hours - there's no two or three week  
turnaround time that there is when you send a design away.

I'd agree if you're making a large complex board with hundreds of  
traces, you'll save a lot of aggravation by using a PCB manufacturer.  
Or if you want to make several boards of the same design (many PCB  
makers have a fairly stiff price for the first board, but successive  
boards get quite a bit cheaper because there's no more setup to do. I  
needed ten of a recent design, and it was obvious that the correct  
thing to do was just get them made by PCB Cart. Especially as it was 4  
layer :-)