In a message dated 12/30/98 6:26:09 AM Pacific Standard Time,
[log in to unmask] writes:
<< Don't be so quick to blame the Designer. We are seeing some Led's that have
the long lead on the Anode! We have started to eliminate the Square pad and
mark the "C" for cathode. Of course now the assembler needs a data sheet.
Fred Pescitelli
Phoenix Designs
1285 Turner Rd.
Lilburn, GA 30047 >>
Hi Fred!
Yeah Fred, you're right (hanging head in shame), I probably was a little
hasty saying that it was the designers fault...it was out of sheer frustration
yesterday. The problem is that I've gotten bit by this problem many times over
the years and it still continues to happen. Most of my experience has been
with contract assemblers, and as one knows, contract companies build boards
for many different companies whose design standards vary between each company.
When we hire manual loading people, we need to teach them how to orient
the components correctly, and one of the guidelines I've taught is that the
long lead, goes into the square pad on the board. But as seen by some of the
responses, this still continues to be a source of confusion depending on how
the board was laid-out, who the LED vendor was etc.,etc. Part of my
frustration comes from the times that we've made this mistake always seem to
be on some sort of networking product...and those boards always are lit up
with LED's like a christmas tree! But that's "Murphys Law", when you make a
mistake like wrong orientation, or say a wrong value resistor or cap, it's
never the 1-per board part, it's always the 20-per!
At the places I've worked at in the past, just like I'll do here, I've
learned which way the LED's go on each board from each different customer and
document it. It's like you always have to get burned once before you can do it
right. It seems that LED's are the only part that this issue comes up on,
every other part has a standard marking and orientation that everybody
follows...
So, please forgive my little tantrum yesterday...I was wrong to blame the
designer for this one.
-Steve Gregory-
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