HART: A new highly accelerated robustness test for conductive adhesive interconnects

The Highly Accelerated Robustness Test, HART, is an approach that allows the assessment or the robustness of adhesive interconnects at a throughput rate that is 10 times faster than the conventional accelerated humidity test, without going to higher stress levels. The test is based on the physics of a conductive adhesive interconnect. In stead of using the contact resistance drift over time in a static temperature- humidity environment, HART uses the effect of a changing temperature or humidity environment on the contact resistance as a characteristic of the robustness of the interconnect. HART using moisture as stressor is by far the most powerful approach of the two. Both the response and hysteresis in a cyclic humidity environment are proposed as new criteria for the interconnect robustness. Flip chip on flex interconnections with conductive and non-conductive adhesives are used as a carrier. Different contact material combinations and different adhesives are used in this study.