In Situ Measurement of Stress Development in ECA for Die-Attachment of Electronic Devices

In this work, investigations on stress development in electrically conductive adhesives used as a die-attachment technology for electronic devices are presented. Three electrically conductive adhesives and two measurement techniques were used for investigations. A silicon stress chip with NiCr-thin film metallic strain-gauge structures developed in our group is used for determination of stress development during hardening process of the adhesives and under temperature shock cycling. Digital-Image-Correlation method was used for comparison of the results from the test-chip. In these investigations, the in-plane warpage and curvature behavior of an assembled silicon-diode during active and passive heating were measured. Maximum stresses and strains during processing and operation can be located. Consequently it is possible to assess the reliability of electronic devices.