Properties of Various Thermal Interface Materials
What Are Thermal Interface Materials?
Chips in electronic devices can generate a lot of heat during operation, which can damage fragile internal components. But thermal interface materials, or TIMs, can protect them by dissipating the heat and transferring it away from the internal configuration. TIMs are manufactured from a wide range of materials to align with the needs of different electronic devices, and they often sit between the chips and any internal heat-dissipating systems.
Chemical Composition of Thermal Interface Materials
Depending on the unique needs and characteristics of specific electronic devices, manufacturers can choose from a wide range of thermal interface materials with different chemical compositions. Here are the most common options.
Epoxy resins are materials that can be poured and shaped as a liquid before setting or curing into a hardened material with exposure to heat. This process is called thermosetting. Epoxy compounds are made from monomers with two or more epoxide groups. Some of the key benefits of using an epoxy resin as a TIM are:
- Specialized properties based on the unique chemical structure and the specific epoxides in the compound
- Good adhesive strength
- Resistance to chemicals
Polyvinyl Chloride (PVC)
Called polyvinyl chloride, vinyl, or PVC, these compounds are a type of polymer. They are at least 50% chlorine by weight and are primarily made up of vinyl chloride monomers, which polymerize during the fabrication process.
These thermoplastics are defined by the carbonate groups present in their chemical composition. There is a wide variety of different polycarbonate grades or types. Polycarbonate TIMs possess these key characteristics:
- Varying degrees of transparency
- High levels of strength
- Toughness and resistance to physical damage
A popular type of thermoplastic TIM is polypropylene (PP). Manufacturers can fabricate the material from propylene monomers through chain-growth polymerization processes.
Each of these materials—epoxy resins, PVC, polycarbonate, or polypropylene—can be used as thermal interface materials. An experienced TIM manufacturing provider can help advise you on the right fit for your specific project.
Thermal Interface Material Product Applications
TIMs can help protect electronics in a range of consumer, commercial, and industrial systems. When temperatures get too high, whether it’s in small handheld devices or large industrial systems, the parts can overheat, wear through faster, and deliver subpar performance. Some of the applications that most rely on cutting-edge TIM options are telecommunications, aerospace, automotive, gaming, and servers.
Thermal interface materials come in a variety of forms to fit these industrial applications.
TIMs don’t just have to be solid products. They can also be hydrocarbon or silicone thermal greases that contain fillers to optimize their thermal dissipation capabilities. TIM greases help remove microscopic air pockets that hold heat.
Elastomeric pads are very thin but solid TIMs. Each one is approximately 0.25 mm thick and constructed from a woven fiberglass substrate with polymerized silicone rubber and filler additives built in. The silicone rubber and fillers act similarly to greases, while the woven piece gives the pad structure. Assemblers add them as precise, die-cut forms to electronic configurations during production.
Functioning as a heat sink, thermal tapes absorb and disperse heat, but they also have adhesive surfaces to ensure the heat sink stays locked in place in its electronic assembly. This reduces space and hardware requirements for the heat sink. The basic structure of a thermal tape is a structural support matrix such as a foil strip, fiberglass mat, or polyimide film with a pressure-sensitive adhesive coating.
Phase Change Materials
As the name implies, phase change materials have the properties of both liquid greases and structurally solid pads. Since their development in the 1980s and quick rise to popularity throughout the following decade, phase change materials have been used for microprocessors and other precision assemblies where liquid grease poses too much of a complication.
TIMs (Thermal Interface Materials) by Robert McKeown
Choosing the right thermal interface materials can make your electronics last longer with less risk of damage or poor performance. At Robert McKeown, we develop cutting-edge, versatile, and precision TIMs, including TIM thermal pastes, phase change pads, double-sided tapes, and more. Request a quote today to discuss your specific thermal interface material needs.