RE: [SI-LIST] : Plane short

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From: Michael Nudelman (mnudelman@tellium.com)
Date: Mon Apr 30 2001 - 08:25:28 PDT


How about this one:

You have a chemical short that will appear within several days or hours or
even minutes of powering up the board. After powering down it will persist
from minutes to hours and than dissappear. But it will return some times
after you power up again.

This one is a b... to find. It is a chemical reaction occuring with the
"right" combination of soldermask, flux, components profile, pin pitch and
the washing process.

Noone believed me 'till I demonstrated them the effect of it.

Mike.

>>>>>If other boards or raw boards do not have the power-to-ground short,
you
probably have:
* A solder bridge.
* A solder splash.
* A solder ball.
* A component turned from its correct location.
* A component off location by one pin (quad flatpacks with power and ground
pins next to each other can easily
    create a power-ground short this way).

>>>>>

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