Mechanical Cycling Reliability Testing of Thermal Interface Materials for Semiconductor Test

The most challenging applications for thermal interface materials where durability and thermal performance are both required is found in the semiconductor test and burn-in market. There are a wide range of application requirements given the different types of test sockets, test heads, and test equipment configurations. However, a dominant characteristic is the need for a single TIM, applied to a test device, to contact and release cleanly and without damage to either the TIM or to the device under test (DUT), ideally with the ability to conduct such cycles hundreds and thousands of times before replacement of the TIM is required. This places a significant burden on material design, to achieve substantial durability in harsh usage circumstances, while also providing a high level of thermal performance. A mechanical reliability test program for evaluating durability as well as thermal resistance performance of specialized thermal interface materials (TIMs) has been developed. These specialized TIMs have been developed specifically to meet requirements for semiconductor test and burn-in requirements, which are extreme; cycling with multiple contacts for a single TIM (up to thousands of cycles) is a long-sought development goal for the semiconductor test equipment industry. An automated, servo-driven TIM test stand developed to follow industry-standard test methodology is used to conduct testing under controlled test conditions. Examples of test requirements are given, as well as a description of an automated contact cycling test designed to test per those requirements, with results for a set of newly-developed TIMs explicitly adapted for semiconductor test usage. Four test phases have been developed with increasingly challenging test requirements for durability while also exhibiting excellent thermal performance.