Effective Visual Criteria for Welded Interconnections

One of the most critical aspects affecting the ultimate reliability of welded interconnections is the lack of meaningful visual criteria for crosswire joints. In recognition of this, Autonetics has undertaken a comprehensive program to establish the correlation between visual characteristics and metallurgical and mechanical properties of specific wire combinations.

Significant numbers of welded interconnections were made using 25 wire combinations and employing welding parameters that would produce cold, typical, and overheated welds. The welded joints were critically examined and classified with regard to useful visual characteristics such as embedment, indentation, filleting, bulging, expulsion, pitting, surface fusion, cracks and voids. Also, metallographic studies were conducted to determine the relationship between internal conditions and joint integrity.