Thermal interface materials (TIMs) must reduce interfacial thermal resistance while withstanding stresses such as vibration and humidity. Traditional TIMs cannot meet this requirement. Thermal paste, for example, performs well with micron-level surface matching and precise clamping, but is prone to contamination and increases the difficulty of automated assembly. Ordinary silicone thermal pads sometimes lack the thermal conductivity required for high-TDP modules.
AMEC Thermasol’s WG-BN boron nitride thermal pads meet this requirement. They offer relatively high thermal conductivity while maintaining robustness and repeatability. The boron nitride filler forms a conductive network within a flexible substrate, which transfers heat through phonon and percolation contacts. The resulting interface product reduces temperature differences across gap widths without sacrificing dielectric isolation.
Boron nitride thermal pads typically consist of a polymeric matrix loaded with hexagonal boron nitride (h-BN). The polymer provides elasticity and the h-BN platelets create continuous or semi-continuous thermal pathways. Additives such as adhesion layers or EMI foils can be laminated to the base material for enhanced handling.
One key advantage of boron nitride thermal pads is they are more effective in heat transfer compared to traditional thermal pads. Their dielectric properties are usually superior to metal filled pads and their galvanic neutrality mitigates corrosion risk. While silicone and silicone free thermal pads are more cost effective and more conformable, they lose thermal headroom where larger gaps persist. Below are some application examples highlighting the advantages of boron nitride thermal pads compared to traditional thermal pads:
High Power Processors and GPUs
Server blades, compute accelerators and high-end GPUs generate concentrated heat flux. BN thermal pads provide a compromise between the high performance of thermal paste and the practicality of thermal pads. This is especially important for when electrical insulation is needed or gap heights fluctuate.
Automotive Electronics and Power Modules
Robustness is mandatory for in traction inverters, DC-DC converters and onboard chargers. The WG-BN series offer low compression set and high dielectric strength. This maintains thermal pathways during vibration and thermal cycling, thus reducing field failures.
Telecom and 5G Infrastructure Hardware
Remote radio units and baseband modules operate in harsh environments and require predictable thermal behavior. Boron nitride thermal pads maintain thermal continuity across larger tolerance stacks where traditional thermal pastes would either squeeze out or fail to bridge.
The WG-BN material is ROHS and REACH compliant and is halogen free. In addition to this it meets RBA (Responsible Business Alliance) and ISO/TS 16949 standards.
