The Effect of Test Conditions on HAST and THB Reliability Testing of Thermal Interface Material, and the Introduction of an Improved Thermal Interface Material

摘要

As the world becomes more and more dependent on electronic devices the reliability of these devices increases inrnimportance. Reliability testing of electronic components has been reduced to a rigorous practice, and it is wellrndefined in the literature [12-15]. Of all the materials utilized by electronic devices, Thermal Interface Materialsrn(TIMs) are particularly important to reliability. Since the TIM enables proper thermal management of the electronicrncomponents, if the TIM fails, the entire device fails.rnThe testing of the individual materials utilized in a specific electronic device represents a particular challenge abovernand beyond that of testing the entire device, and TIMs are no exception. During the development of TIMs, thernactual electronic devices are typically unavailable so the TIM designers must replicate the expected conditions of thernactual electronic device (i.e. surface materials, clamping pressure, and geometry). Furthermore, in most electronicrndevices TIMs are utilized for multiple conditions (e.g. TIM1 for silicon / heat spreader interface, TIM2 for heatrnspreader / heat sink interface), therefore, unique fixtures must be employed for each condition, requiring a separaternreliability test for each condition.rnMost modern TIMs display adequate performance just after assembly, but after reliability testing only the trulyrnreliable TIMs maintain their performance. Furthermore, while a TIM may show excellent reliability performance inrna fixture designed to replicate one condition of the electronic device, it may show marginal to poor reliabilityrnperformance when tested for another condition. This paper will discuss the importance of test conditions during thernTHB and HAST reliability testing of TIMs, and introduce an improved TIM that was designed based upon thesernfindings.