SRC Forum - Message Replies


Forum: Reliability & Maintainability Questions and Answers

Topic: Reliability & Maintainability Questions and Answers

Topic Posted by: Reliability & Maintainability Forum (src_forum@alionscience.com )
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998

Back to message list Show all replies Topics List About this forum
Original Message:

Posted by: Glen Hanington (ghanington@littlefeet-inc.com )
Organization:Littlefeet, Inc.
Date posted: Wed Feb 21 15:18:03 US/Eastern 2001
Subject: Activation Energy in Arrhenius Equation
Message:
I've seen values of Activation Energy ranging from 0.3eV to 1.2eV in Finn Jensen's book Electronic Component Reliability, the AT&T Reliability Manual uses a value of 0.4eV, and MIL-HDBK-217F2 uses 0.423eV, while some Reliability Engineers use 0.7eV for a value. Without running extensive Life Tests at different temperatures, is there some way to estimate the value of Activation Energy for a system based on the percentage of different types of components used in the system? I want to arrive at an MTBF value for an expensive system using 3 samples and an MTBF goal of 70,000hrs, in as short a time as possible. Any suggestions?


Reply:

Subject: Activation Energy
Reply Posted by: Bruce Dudley (bdudley@alionscience.com )
Organization: Reliability Analysis Center
Date Posted: Thu Feb 22 14:01:49 US/Eastern 2001
Message:
In the IEEE Reliability Transactions, there is a paper called "A Method to Predict an Average Activation Energy for Subassemblies by J.D. Seager and C.D. Fieselman that deals with activation energy super-positioning. This article is in the 1988 December issue, volume 37 number 5.


Reply to this message