On 1 Jun 2007 at 14:51, Jules Richardson wrote:
Surely it's as much effort whether circuits
repeat or not? Don't you still
have to check all possible interconnects to make sure that you've got
everything traced right, even if a quick visual inspection might make it
appear that there's a lot of repetition?
So, you're saying that it's easier deciphering a PCB with a couple of
544-conductor house-numbered BGAs on it than working through a PCB
with 1000 discretes?
No - I'm saying that surely a 1000 transistor board with circuits that repeat
is no more or less difficult than a 1000 transistor board where nothing
repeats; the level of effort required is largely the same as it's tracing the
interconnects which takes the bulk of the time, and that's got to be done
fully for both boards to guarantee an accurate schematic. (All of which
probably means that the number of PCB layers is irrelevant too - the critical
thing is the number of solder points)
I'm not disputing that doing a 1000 transistor board is easier than something
with BGAs on it... :-)