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Reply To: | TechNet E-Mail Forum. |
Date: | Fri, 11 Sep 1998 10:51:04 +1200 |
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Clive:
Yep, sounds strange but I came across the term on a PCB testing facility's
web pages (as part of a series of tests on populated PCB boards). (They didn't reply to my email)
In any case we are concerned with ants/cockroaches blowing up our
high voltage IGBT dpak devices and am looking for anyone with experience/solutions.
Termites in NZ aren't that big or hungry!
We have a great example where an ant has been forever immortalised
when climbing up this dpak device. It used the gate lead as a step for one foot and that centre drain "stub" as a step for another foot. It's frozen dead (not vapourised) and so is the device!
Seems enough charge went through the ant to raise the gate voltage and put the IGBT
into its linear region with consequent overheating and failure.
Potting would be a solution but it is expensive.
Conformal coat doesn't really work, it isn't very rugged,
especially over sharp points.
Perhaps noone really worries too much about this sort of thing but if
anyone has experience in this area it would be great to hear from you.
Bernard Williams
(Electronic Engineer)
_________________________________
Fisher & Paykel
Laundry Division
78 Springs Rd., East Tamaki, Auckland.
PO Box 58-732, Greenmount, Auckland.
Tel: (09) 273-0640 ext.6695.
Fax: (09) 273-0649
Email: [log in to unmask]
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