Introduction of Hardness of Detailed Thermal Conductive Gasket

Heat conductive gaskets are widely used, such as filling cooling devices, communication hardware, automotive control unit, LED lighting equipment, PDP display screen, etc. In these applications, the thermal conductive gasket will produce certain compression to bridge the gap, in order to achieve good thermal conductivity effect. The hardness of the heat conductive gasket directly reflects the hardness and softness of the heat conductive gasket, and its size will affect the compression performance of the product, which is a very important parameter. Many people have doubts about the hardness when choosing heat conductive gaskets, so the hardness of heat conductive gaskets is introduced in this paper.

1. What is the concept of hardness?

Hardness is an indispensable mechanical property index for various mechanical parts and tools. It is used to characterize the degree of hardness and softness of materials. It refers to the ability of materials to resist local deformation, especially plastic deformation, indentation or scratch.

2. What is the hardness of the heat conductive gasket?

Because different testing methods are stipulated, there are different hardness standards. The mechanical meanings of various hardness standards are different, which can not be directly converted to each other, but can be compared by experiments. Common hardness according to the test methods are: scratch hardness, indentation hardness, rebound hardness. According to the specific hardness name, there are Rockwell hardness, Brinell hardness, Richter hardness, Shaw hardness and so on.

According to the standard ASTM D2240 "Standard Test Method for Rubber Hardness by Hardness Meter", heat conductive gasket uses Shaw hardness to express its hardness. Shao's hardness is measured by Shao's hardness tester, which can be divided into three types: A type, C type and 00 type. The measuring principle is exactly the same. The difference is that the size of the measuring needle, especially the tip diameter, is different. Type 00 is the largest and Type A is the smallest. Shaw A hardness tester is suitable for measuring harder heat conductive gaskets and Shaw 00 hardness tester is suitable for measuring softer heat conductive gaskets.

Shaw hardness belongs to indentation hardness. The test method is to insert Shaw hardness tester into the tested material. The needle on the dial is connected with a needle through a spring. The needle is inserted into the surface of the tested object. The value shown on the dial is the hardness value.