Thermal Interface Materials: Diverse, Essential, and Evolving

Thermal Interface Materials (TIMs) are a diverse and growing market. IDTechEx Research has analysed the market in depth in their report, ‘Thermal Interface Materials 2020-2030: Forecasts, Technologies, Opportunities’, by Dr Khasha Ghaffarzadeh, Research Director at IDTechEx.

The highly granular and finely segmented market forecast from IDTechEx are shown below. The market is growing, and its composition is changing. Naturally, suppliers will have to adjust and reposition their TIM product portfolio to capture these rising markets in electric vehicles, 5G, datacentres, autonomous driving, etc.

Inherently, the TIM market is also fragmented on the technology or solution level. In fact, there is no one-sizes-fits-all product. The radar chart below shows a high-level comparison of some of the common solutions, highlighting the diversity of solutions. The TIM material’s menu resembles a toolkit for thermal engineers who can select the material with the right form factor, thermal conductivity, operating temperature, thickness, etc for their specific needs.

This article highlights some key material development trends. More specifically, approaches to increase the thermal conductivity (in W/mK) of TIMs are considered. This is an important trend because the IDTechEx assessment is that the market, in absolute terms, for high or ultrahigh thermal conductivity TIM materials, will inevitably rise. As such, suppliers will need to develop new solutions to extend their TIM portfolio into the high or ultrahigh thermal conductivity segment or risk being stuck in commoditized low-cost low-margin mature market segments and risk losing out on many emerging trends.

This article is extracted from the comprehensive IDTechEx report on the topic, ‘Thermal Interface Materials 2020-2030: Forecasts, Technologies, Opportunities’. This report provides a highly granular view of the market, breaking IDTechEx forecasts down by 51 sub-segments. The major categories covered include consumer electronics, 4G and 5G, electric vehicle batteries, LEDs, data centres, power electronics, and so on.

Furthermore, the report assesses the existing and emerging TIM technologies including alumina, boron nitride, graphite, vertically aligned graphite, PGS, graphene, carbon nanotube forests, boron nitride nanotubes, and more. This report is a must-read for those interested in the TIM market.

Increasing Thermal Conductivity

Thermal conductivity is a key performance indicator. In general, higher thermal conductivity solutions command a higher per sqm or per Kg price. They are therefore used only where needed.

What is a typical thermal conductivity? The chart below shows the thermal conductivity of various types of thermal interface solutions. They are taken from the standard catalogue of the top TIM suppliers worldwide. As such, they represent typical products on the market today. In general most solutions are <5 W/mK. Some mass production solutions reach 14W/mK and slightly higher.

There are two ways main ways to increase the bulk thermal conductivity: (1) change the type of the filler material and (2) increase filler loading. Both strategies typically lead to higher cost and prices. The former because higher thermally conducting fillers tend to be more expensive and the latter because more filler material will be consumer. Note that the filler loading cannot be freely increased because it increases the hardness, which is not positive since a harder TIM conforms poorly to the surface and thus has higher junction or interfacial resistance. There are innovative approaches to improve this trade-off including techniques to vertically align.