Is this is EDS I must say I have to relearn a lot. EDS is normally a single low engergy, nanosecond event that creates microscopical craters and damages, many a times nearly impossible to decide. In my ears this looks more like kind of electrochemical stuff. GaAs chips are tough, you can operate them at +500 Centigrades P/N transitions before they die! But it's not recommended of course. I recommend an EDAX or other element analysis to see what you have there. If you find reactive elements or compounds it could be the result of a chemical or electrochemical reaction. When did the chips die? How are they mounted? What kind of package? What kind of biasing? What kind of surrounding environment? What power dissipation? How are the chips mounted, p&p'd? Mechanical damages? Is there any Chromium under top gold? Etc. You may need to tell something more about the images. At least for me, because I'm slow thinker.
Ingemar Hernefjord
Ericsson Microwave Systems
-----Original Message-----
From: Stephen R. Gregory [mailto:[log in to unmask]]
Sent: den 6 juni 2001 03:05
To: [log in to unmask]
Subject: Re: [TN] UGLY PHOTOS AND FAILURE ANALYSIS OPINIONS NEEDED
Hey Moonman!
'Kay, all the pictures are up!! Go to:
http://stevezeva.homestead.com/index.html
I think I was a little off when I said 15-minutes...I forget that I don't
have a T1 line at home like I do at work! 56k modems aren't quite as fast as
a T1...plus you don't get bumped off Ti's like you do on AOL
dial-ups...hehehe.
But they're there now, all the pictures are labeled ESD/EOS damage...GREAT
pictures Earl!! Wish I knew enough about this stuff to offer some
input...it'll be a real learning experience to hear from those that do!!!
-Steve Gregory-
<< Folks,
In this message, I ask Steve to tell me his requirements for posting
pictures to his site. The photos show component failure at my new contract
company.
Of primary concern is ESD/EOS failure. Also of concern is excessive thermal
excursions and the inability, possibly to get the heat out. Some reasons for
this conclusion involve coplanarity issues not allowing intimate contact
with the heat sink and the company's requirement of not filling the void
with thermal goop. Too messey they say.
My humble conclusion is the part is too ESD/EOS sensitive for the commercial
assembly operation hired to do the job. Contributing to the many failures is
the the thermal issue.
I appreciate any input from you component failure analysis folks. If you've
seen anything like this before, please let me know.
For now, this issue is secret with respect to the supplier (guess who as a
GaAs amplifier supplier) and the customer for it (my employee). Their
customer is one of the folks involved with, what else, broadband
communications.
The photos will be presented on Steve's site with his permission and
procedures. This might not happen until tomorrow, depending on available
time and resources.
Thanks,
MoonMan >>
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