Thermal Interface Materials (TIMs)

Why do we need Thermal Interface Materials?

Thermal interface materials (TIMs) are often inserted between the surfaces of a contact pair to reduce the thermal contact resistance. Although they typically have lower thermal conductivity than the substrate, they are highly compliant and hence under the application of relatively small contact pressures, deform to conform to the geometry of the adjacent rough surfaces. A part of the low thermal conductivity air present is thus replaced by a higher conductivity material. This leads to a decrease in the constriction of the heat flow lines, and hence, an increase in the contact conductance.

Thermal Interface Materials
Thermal Interface Materials Liv2 Thermal Tape

Conductivity and Compliance:

The two most desirable properties of a Thermal Interface Material are high thermal conductivity and high compliance. Since relatively few homogeneous materials possess both these properties, TIMs are typically composite materials with metallic or ceramic fillers in a polymeric matrix. Typically used fillers such as alumina (Al O ) or boron nitride (BN) are characterized by relatively high thermal conductivity and low compliance. Most matrix materials, e.g., silicone, have low thermal conductivity but high compliance. In view of practical applications, optimal volume fractions and geometric distributions of filler and matrix materials are sought at which the contact conductance assumes a maximum value.

Thermal Interface Materials Liv2 Thermal Tape

Use the toggles below to find out more about the benefits of using TIMs and answers to some Frequently Asked Questions (FAQs):

Benefits of using Thermal Interface Materials

  • Reduce thermal impedance across gaps
  • Replace air with more thermally conductive materials
  • Conform to surface irregularities

To optimise heat transfer across a joint it is necessary that:

  • The surface is as flat as possible
  • Surfaces must be in contact
  • The interface material must fill the voids only

Thermal Interface Materials Frequently Asked Questions

TIMs facilitate the efficient transfer of heat from electronic components to heat sinks or other cooling mechanisms, thereby preventing overheating and ensuring optimal performance, reliability and energy efficiency of electronic devices.

Thermal conductivity measures a material’s ability to conduct heat. Higher thermal conductivity in TIMs results in better heat dissipation, leading to lower operating temperatures for electronic components and improved overall performance.

Factors such as thermal conductivity, hardness, compatibility with substrates and other materials, application method, long-term reliability, and environmental conditions must all be carefully evaluated to choose the most suitable TIM for a given application.

Adhesive TIMs, such as thermal tapes, not only facilitate heat transfer but also provide mechanical attachment between components. Non-adhesive TIMs, on the other hand, focus solely on thermal conductivity and are typically used in applications where separate adhesives or mechanical fasteners are employed.

While some TIMs are designed for single-use applications and require replacement during maintenance or repairs, others, such as certain phase change materials (PCMs), may allow for multiple cycles of use. Factors such as curing properties and material stability influence whether a TIM can be reused effectively.

Extreme temperatures or high levels of humidity can affect the properties of TIMs, potentially compromising their thermal conductivity, adhesion strength, or overall performance. It’s essential to select TIMs that are rated for the specific environmental conditions of the intended application.

Depending on their composition, some TIMs may contain substances that pose health or safety risks, such as volatile organic compounds (VOCs) or hazardous chemicals. Proper handling procedures, including the use of personal protective equipment (PPE) and adherence to manufacturer guidelines, are essential to ensure safety during TIM application.

The optimal thickness of a TIM layer depends on factors such as the roughness of contacting surfaces, pressure exerted on the TIM, and the thermal conductivity of the TIM itself. Thermal resistance calculations, considering these factors, can help determine the ideal thickness for maximizing heat transfer efficiency. Check out our Compression Gap Filler Calculator to work out the compression percentage of our thermal pads.

Yes, T-Global Technology offers custom formulations to meet the unique requirements of specific applications. Bespoke formulas may include adjusting thermal conductivity, viscosity, curing properties, or adding additional features such as flame retardancy or electrical insulation.

Ongoing advancements in TIM technology, including the development of new materials and manufacturing processes, enable engineers and product designers to push the boundaries for improved thermal management, enhanced performance, and increased reliability of electronic devices across various industries.

Thermal Interface Materials

TIMs:

T-Global Technology manufactures a wide range of TIMs, including Thermal Pads, Putties and Tapes. Use the buttons below to browse our full product range where you can compare conductivity, filter by format, request samples or read more about the importance of TIMs in electronics cooling.