6 Jul
2007
6 Jul
'07
1:10 p.m.
David Griffith wrote:
I haven't heard anyone discuss this yet: what
causes traces on some old
PCBs to wrinkle and not others? My guess is a combination of suboptimal
glue and wide temperature swings.
I've never seen a trace "wrinkle". I have seen the (paint? varnish?
lacquer?) whatever finish
applied over the traces wrinkle. The culprit usually appears to be heat. I
have encountered
circuit boards where the traces will lift off of the board when
desoldering/part removal is
attempted. In some cases heat may have been an issue, in others, I could
see nothing to
blame other than substandard quality. Not surprisingly, boards without
plated through holes
seem to be more at risk.
Bill
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Version: 7.5.476 / Virus Database: 269.10.0/887 - Release Date: 7/5/2007
1:55 PM