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Exploring Thermally Conductive Insulators

Jun 25

Thermally Conductive Insulators

The rapid development of electronic devices and printed circuit boards has created a need for special solutions to handle the excess heat generated by those components. Jeffrey Beauchamp, Technical Manager at CMI , Field Application Engineer at CMI Group Italy explain that, “With today’s technological developments bringing smaller and smaller products and components into being, it becomes more difficult to disperse or redirect the excess heat using conventional methods. In some cases, the excessive heat can cause the component to shorten its life or even fail.”

These new technologies and trends have fueled the need for thermal management materials that can help to direct the excess heat to cooling components or to other areas where it can be dissipated. These materials are also required to provide electrical conductivity while preventing the transfer of heat between the conductive parts.

The Power of Thermally Conductive Insulators is inversely proportional to its insulating capability. The higher the thermal conductivity of a material, the more it will be able to transmit energy. For this reason, a high conductivity material is often used in applications such as heat sinks where the purpose is to transfer the excess heat from the product to the surrounding environment.

Conversely, low conductivity materials will be better suited for insulating purposes. A material’s thermal insulating properties depend on its product density and its temperature and pressure conditions. For this reason, the insulating properties of a material are typically reported by using a unit called the r-value which is defined as the product of the material’s insulation value and its product density divided by its permeability.

Other important insulating properties include the material’s specific heat capacity and its density. The specific heat capacity of a material is the amount of energy that it will take to raise the temperature of 1kg of the material by one Kelvin. It is also referred to as the material’s Thermal Mass or Thermal Buffering (Decrement Delay). A material with a high specific heat capacity will have a low conductivity and a high thermal mass.

Polyurethane foams are commonly used insulators in applications that require good electrical conductivity while limiting the transfer of heat from conductive parts to the surrounding environment. These foams are available in closed-cell or open-cell formulas. Closed-cell foams have high-density cells that are filled with a low-conductivity gas to increase their insulating properties. Open-cell foams are less dense and are filled with air to make them softer and more flexible.

CMI Group offers a wide range of electrically conductive insulators for use in various applications. These materials are available in many different thicknesses to meet the needs of your application. We also offer thermal interface materials that are both electrically conductive and thermally insulating. Our thermally conductive adhesive tapes are easy to apply and provide excellent adhesion with PCB’s while providing good contact resistance for maximum reliability. We also have a variety of other thermally conductive and electrically insulated materials including phase change material and graphite foils.


Custom Materials, Inc
16865 Park Circle Drive
Chagrin Falls, Ohio 44023
(440) 543-8284