[sdiy] Importance of electrical test at PCB manufacturing?

[Joe Grisso]

On Tue, Oct 6, 2009 at 7:30 AM, Karl Ekdahl <elektrodwarf at yahoo.se> wrote:
> Hi list
>
> How important is it to do an electrical test when manufacturing PCBs? I'm going to do a batch of 30 boards and i'd really like to skip the $140 test fee if it's not necessary..
>

Hi Karl+List,

     I usually don't bother with electrical testing on most of the 2
layer boards I design. I've found that either the boards are spot on,
or they're horrendously screwed up. I've only had the latter happen
once, and it was with an Asian PCB house I didn't bother to qualify in
advance. The rule of thumb I follow is that if it's a 2-layer board
that's bigger than a letter/A4 sheet of paper, I have it electrically
tested. This rule of thumb does not carry over to multilayer boards,
because the possibility of failure is much greater when you have a
sandwich of layers. A mis-drill can short the entire stack out, rather
than the usual 2L concerns - developer being spilled on the films, the
resist not sticking to the PCB and flaking off in the post-exposure
wash, and the like.

Best Regards,

-- 
Joe Grisso
Detachment 3 Engineering