Check the following article, you will get a general idea. Basically before
the testing you need to know the dominant failure mechanism of your parts,
acceleration factor, sample size you have, confidence level.

http://rel.intersil.com/docs/rel/calculation_of_semiconductor_failure_rates.pdf

A little calculation, but no calculus.

Kang


>From: "Jason Larson, AScT" <[log in to unmask]>
>Reply-To: "TechNet E-Mail Forum." <[log in to unmask]>,        "Jason Larson,
>AScT" <[log in to unmask]>
>To: [log in to unmask]
>Subject: [TN] Failure analysis
>Date: Wed, 19 Jul 2000 10:54:59 -0700
>
>Good day all,
>
>If the time to failure is known (10 months) how can I develop an internal
>stress test to facilitate a failure in less times (like 3 weeks)
>I don't have a HALT chamber, but two thermal chambers
>
>The stresses that I want to use are
>
>high temp (85 degrees C)
>low temp (-40 degrees C)
>salt water bath
>powered cycle
>
>The module is encapsulated, weight approx. 0.3 Kg,
>
>PS: I don't like calculus!!!
>
>Thanks for your help
>
>Jason Larson
>
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