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Constant Bias Potential for Package Stress Tests

IP.com Disclosure Number: IPCOM000101138D
Original Publication Date: 1990-Jul-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Foster, RA: AUTHOR [+3]

Abstract

Disclosed is a method for maintaining constant bias potential on package risk sites over a range of leakage resistance.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Constant Bias Potential for Package Stress Tests

       Disclosed is a method for maintaining constant bias
potential on package risk sites over a range of leakage resistance.

      Risk sites are configurations of adjacent conductors on
electronic packages, such as laminated printed wiring boards.  Such
risk sites are stressed with a bias potential while undergoing
environmental conditioning for package reliability assessment.
Typically, this is done with an arrangement as illustrated in Fig. 1.
The flow of current through the risk site is limited by a series
resistor.  This method has the disadvantage that as the leakage
resistance of the risk site decreases, the circuit acts as a voltage
divider reducing the potential across the risk site.  It is desirable
to maintain the bias potential at a constant voltage stress during
reliability assessments and modeling experiments.

      The method recommended is illustrated in Fig. 2.  A zener diode
maintains the bias potential across the risk site at a relatively
constant potential over a large range of risk site resistance.

      This method is useful in the study of voltage-dependent package
failure mechanisms.