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Nondestructive Dry Junction Testing of Integrated Circuit Modules

IP.com Disclosure Number: IPCOM000087740D
Original Publication Date: 1977-Mar-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Kallmeyer, M: AUTHOR [+3]

Abstract

Nondestructive dry-junction testing after the semiconductor chip has been soldered to the substrate is effected by applying a particular test pattern to the module inputs. Then the rear side of the substrate is alternately and repeatedly heated for about 10 seconds by means of hot air of about 400 degrees K and rapidly cooled by means of liquid CO(2) to about 240 degrees K.

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Nondestructive Dry Junction Testing of Integrated Circuit Modules

Nondestructive dry-junction testing after the semiconductor chip has been soldered to the substrate is effected by applying a particular test pattern to the module inputs. Then the rear side of the substrate is alternately and repeatedly heated for about 10 seconds by means of hot air of about 400 degrees K and rapidly cooled by means of liquid CO(2) to about 240 degrees K.

As a result of the different expansion coefficients of silicon and the substrate material, mechanical stresses occur which open the dry junctions without impairing the intact ones. The opening of the dry junctions interrupts signal paths. These interruptions lead to changes in the output signals which are observed. By repeatedly subjecting the substrates to the temperature cycle described, dry junctions are eliminated.

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