Issue link: https://iconnect007.uberflip.com/i/1460418
20 PCB007 MAGAZINE I MARCH 2022 ers and the products they develop. is has been a primary focus of Aismalibar for some time and the company has accordingly devel- oped a family of new thermal interface mate- rial (TIM) technologies designed specifically for printed circuits. e unique materials the company has developed have thermal conduc- tivities up to 3.2 W/mK (tested according to ASTM D5470) and high electrical insulation properties of up to 6 KV AC. (For comparison, nominal laminate materials have thermal con- ductivities of 0.25 W/mK.) Concept Model for Thermal Management Chain in Power Electronics ermal interface materials are used by design in power electronics modules to facil- itate the transfer and dissipation of the heat generated by the active and passive power components on the printed circuit board by enabling efficient transfer of heat through a cooling chain to a downstream cooling ele- ment, such as a heat spreader or heat pipe and cooling fan. e ultimate objective is to ensure that the maximum component temperature specified by the manufacturer is not reached. In addition to providing high thermal con- ductivity, the TIM must also provide adequate electrical insulation properties; this is espe- cially and increasingly important in high-volt- age environments such as those experienced in modern electric vehicles. e better balanced the compromise between thermal conductiv- ity and electrical insulation capability of the TIM, the higher the performance and reliabil- ity of the entire power electronics module over its service life (Figure 1). Thermal Interface Material Solutions A key recent development, underpinning Aismalibar's new TIM concepts, is a new coat- ing technology referred to by the company as its "air gap filler," which in addition to its excel- lent thermal and electrical insulation proper- ties, the need to employ an oen complex and messy TIM thermal paste application. A key objective of the air gap filler product is to eliminate voids which otherwise can result in "hot spots" at the interface as illustrated in Figure 2. e novel air gap filler material solution being offered is non-adhesive at room temperature for ease of handling and advantageously begins to polymerize at low temperature (~40°C). e material is tack free and thus requires no peel- able liner, avoiding waste and streamlining the Figure 1: Thermal management is commonly achieved by means of a chain of materials beginning at the integrated circuit chip or heat-generating electronic power component or element. Thermal interface materials serve a vital role in facilitating such heat exchange.