What are thermal interface materials?

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By Pam Hane | Aug 20, 2019
Thermal conductive pads by Laird

As electronic devices are getting smaller, a major concern that largely looms over engineers and designers is the dissipation of heat. All electronic devices emit heat, which without a proper outlet, could lead to a spike in the internal temperature of the device, ultimately resulting in its failure. Trapped heat in a device can not only damage critical internal components but can also negatively impact the performance of the device. To lower the temperature of the device, it is essential to dissipate the heat from the heat source to a heat sink (air duct or vent). Thanks to thermal interface materials, engineers have one less reason to worry now. Often integrated into devices at varying stages of product development, thermal materials enhance the thermal conduction between two components to facilitate the transfer of heat away from the heat source.

Measured in watt per square meter of surface area for a temperature gradient of one Kelvin for every me­ter thickness (W/m-k), thermal conductivity is the rate at which heat passes through a material. When an integrated circuit (IC) in a device gets hot, a thermal material drives the heat in a vertical direction away from the heat source. W/m-k is the measurement of how fast the heat is transferred from the IC to the heat sink. However, if the thermal material doesn’t intimately marry with the IC, it creates air bubbles. These air bubbles can slow down or disrupt the transfer of heat, known as impedance. A thorough understanding of conductivity and impedance is vital towards selecting the optimal thermal material for any given application.

Thermal management solutions

Fortunately, companies such as 3M, Laird and Bergquist, have opened doors to several thermal management solutions in the form of thermal pads and conductive tapes. Designed in a variety of thermal conductiv­ities and softness grades, these materials flow into the nooks and cran­nies of the heat sink and IC to offer a high degree of “wet out” for more efficient heat transfer. Available in different thicknesses, they also provide excellent gap filling proper­ties in most cases.

Advantages of thermal interface materials

Some of the core advantages of thermal materials include:

  • Enhanced thermal coupling between the heat source and heat sink
  • High conformability to uneven and irregular substrates
  • Quick and easy application

Applications for thermal interface materials

Suited for diverse applications such as handheld electronics, notebook and desktop computers, memory mod­ules, telecommunications hardware, and flat panel displays, thermal materials can significantly enhance the durability and performance of the device.

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