Performance of Durable High-Performance Polymer Composite TIMs Under Accelerated Aging Conditions

Polymer-based thermal interface materials (TIMs), filled with thermally conductive particles for improving thermal performance, are commonly used in electronic devices. A polymer composite TIM would have the desirable attribute of maintaining thermal properties without compromising mechanical compliance and reliability, but thin-film delamination becomes a major concern for composite TIMs as the portion of filler increases. In order to design the desired polymer composite structure, it is vital to understand the adhesion between devices and the film. Various physical properties can influence the failure to adhere, such as bond-line thickness and the Young’s modulus of the materials. In electronic packaging systems, the mismatch in the coefficient of thermal expansion (CTE) is also considered to be a main cause of delamination. Because the CTE value of polymer is over 10 times greater than that of metallic fillers, it is crucial to study thermal effects when designing a polymer composite TIM.