[SI-LIST] Re: Failed Tantalum capacitors - package hermeticity compromised

Hi Steve,
We have stopped using Tantalum capacitors for some years now.  When we 
used them in the past, we were using 3X voltage derating for Solid 
Tantalum capacitors, and 2X derating for Low ESR Organic Tantalum 
capacitors.

Regards, 
Ravinder Ajmani
Server PCB Development
Hitachi Global Storage Technologies


Email: Ravinder.Ajmani@xxxxxxxxxxxxxx



"Salkow, Steven" <steven.salkow@xxxxxxxx> 
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[SI-LIST] Failed Tantalum capacitors - package hermeticity compromised






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Recently we have had some tantalum capacitors rated at 16V fail on turn
of in a 12V circuit. While some percentage of low ESR capacitors
experience a high surge infant mortality on first turn on unless
serrated by 50% or more, these capacitor were sent for additional
electrical screening at an independent test house.
 
Just as a precaution we decided to also sample test the lot for package
hermeticity by conducting a bubble test. 25 samples were picked at
random from the lot of 450 and 100% of these failed bubble test.
 
Has anyone had this problem before? Has any had counterfeit capacitors?
 
Steven Salkow
Lockheed IS&S
3130 Zanker Rd, San Jose
Ca. 95134
(408) 473-4058
H: (925) 462-1075
steven.salkow@xxxxxxxx
salkow@xxxxxxxxxxxx
 
 



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