Re: Processor wirh Vdd-Vss Short

"Jim Granville" <no.spam@xxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:4755a30d$1@xxxxxxxxxxxxxxx
Joe G (Home) wrote:

Hi All,

I had a tray of 3v processors back from the boad loader and 20 of about
80 had a dead short between Vdd and Vss (3ohms).

Any idea of what could of caused it?

ESD?

Board loader improper handling?

Vdd Transient on power?

Any ideas and experinces you have to share would be apprecicated

Joe

This is shorted, as measured when mounted, or after careful removal ?

Do a simple graph of the I/V, and see if it looks purely resistive, or
has a semiconductor component.

You can also file/grind the package off the die, (with a little care!),
and may be able to read the supplier ID, and check for energy-release
marks with a microscope.

-jg


Hey Jim,

Thanks for your input,

Boards come back from board loader - first power up the the 3v regulator
starts to shut down (~ 100mA)

V/I curve ===> good idea

I wish I had one of those good USB microscopes!


Regards
Joe


.