the use of temperature-humidity accelerated life test

[brucelee]

I will appreciate if you provide me the following inquiring:

When I use Peck's model for estimate the acceleration factor


AF= (AFa/AFn)^3 * exp(Ea/k(1/Tn-1/Ta))

http://www.reliasoftforums.com/cid:image001.gif@01C97FD6.F7EEC8C0
where n=3, Tn=25°C, Ta=60C, Hn=60%, Ha=90%, K=0.000086eV. E=activated energy in eV. The reference condition is 25°C-60%RH.

what is an appropriate parameter n and Ea I shall use for an estimate ?
I understand I should avoid to use an acceleration higher than 20.

bruce lee

[Pantelis]

These parameters are based on the physiscs of the problem. One cannot answer the question as posed, as they are not constants.

[Hilaire Perera]

The JEDEC Publication JEP122D: Failure Mechanisms and Models for Semiconductor Devices provides guidance in the selection of reliability modeling parameters, namely functional form, apparent thermal energy values and parameters sensitivity to different kinds of stresses.

n = Peck RH exponent 2.7 (Experimentally determined for Aluminium corrosion)
Eaa = Apparent activation energy, 0.7 to 0.8 eV (typical for Aluminium corrosion when chlorides are present