A Comparative Study of Thermal Aging Effect on the Properties of Silicone-Based and Silicone-Free Thermal Gap Filler Materials

Abstract

Thermal conductive gap filler materials are used as thermal interface materials (TIMs) in electronic devices due their numerous advantages, such as higher thermal conductivity, ease of use, and conformity. Silicone is a class of synthetic materials based on a polymeric siloxane backbone which is widely used in thermal gap filler materials. In electronic packages, silicone-based thermal gap filler materials are widely used in industries, whereas silicone-free thermal gap filler materials are emerging as new alternatives for numerous electronics applications. Certainly, characterization of these TIMs is of immense importance since it plays a critical role in heat dissipation and long-term reliability of the electronic packages. Insubstantial studies on the effects of various chemical compounds on the properties of silicone-based and silicone-free TIMs has led to this study, which focuses on the effect of thermal aging on the mechanical, thermal, and dielectric properties of silicone-based and silicone-free TIMs and the chemical compounds that cause the changes in properties of these materials. Characterization techniques such as dynamic mechanical analysis (DMA), thermomechanical analysis (TMA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and broadband dielectric spectroscopy (BbDS) are used to study the mechanical, thermal, and dielectric characteristics of these TIMs, which will guide towards a better understanding of the applicability and reliability of these TIMs. The experiments demonstrate that upon thermal aging at 125 °C, the silicone-free TIM becomes hard, while silicone-based TIM remains viscoelastic, which indicates its wide applicability to higher temperature applications for a long time. Though silicone-based TIM displays better mechanical and thermal properties at elevated temperatures, dielectric properties indicate low conductivity for silicone-free TIM, which makes it a better candidate for silicone-sensitive applications where higher electric insulation is desired.

Study on the Machining Accuracy of Soft Elastic Material Using Cryogenic Dicing

“…In recent years, improving the light output e ciency and high dynamic display performance of devices by introducing functional structures during the LED packaging manufacturing process has become a research hotspot [8]. However, common LED packaging materials such as silicone resin have the drawbacks of high elasticity, low hardness, and poor workability at room temperature, which are important reasons for the di culty in manufacturing microstructures on the LED packaging surface [9], [10]. In traditional processing, soft elastic materials have increasingly serious problems, such as low processing accuracy and poor surface processing quality as the processing size decreases, a signi cant factor hindering the development of micro-LED devices.…”

Viscoelastic behavior of filled silicone elastomers and influence of aging in inert and hermetic environment

“…Kashi et al [21] observed a decrease in both the tensile strength and the elongation at break for silicone rubber after accelerated aging in oil. Regarding the aging conditions specific to high-performance electronics, some previous works exist [22,23], but many subjects are yet to be addressed, specially in the context of aging in hermetic environments.…”