Browse Prior Art Database

Method to Cause Functional Chips to be Electrically O

IP.com Disclosure Number: IPCOM000051937D
Original Publication Date: 1981-Apr-01
Included in the Prior Art Database: 2005-Feb-11

Publishing Venue

IBM

Related People

Authors:
Drotar, JS Huebner, RT [+details]

Abstract

The MC (metallized ceramic) module package must be routinely stress-tested to insure solder joint integrity. This testing which involves thermal cycling of the MC module is commonly called solder fatigue or is electrical resistance. Historically, a solder joint is considered failed or defective once its initial resistance has increased by 200 milli-ohms. Generally, the resistance is measured by a three-point probe technique. A current probe is placed on one substrate pin and a voltage probe is placed on a second with both pins electrically connected to the chip by substrate lines or electrodes. The current and voltage are then measured at a third pin which is connected to the solder joint of interest.