Thermal pad have a wide range of uses, such as: filling cooling devices, communication hardware, automotive control units, LED lighting equipment, PDP displays, etc. In these applications, the thermal pad will produce a certain amount of compression to bridge the gap to achieve good thermal conductivity. The hardness of the thermal pad directly reflects the hardness of the thermal pad, and its size will affect the compression performance of the product, which is a very important parameter. Many people have questions about the hardness when choosing a thermal pad, so I will introduce the hardness of the thermal pad.
1. What is the concept of hardness?
Hardness is a mechanical performance index that various mechanical parts and tools must have. It is used to characterize the hardness of the material and refers to the ability of the material to resist local deformation, especially plastic deformation, indentation or scratches.
2. What is the hardness of the thermal pad? As different test methods are specified, there are different hardness standards. Various hardness standards have different mechanical meanings and cannot be directly converted to each other, but they can be compared through experiments. Common hardness is classified according to the test method: scratch hardness, indentation hardness, rebound hardness. According to the specific hardness name classification: Rockwell hardness, Brinell hardness, Leeb hardness, Shore hardness and so on. According to the standard ASTM D2240 "Standard Test Method for Testing the Hardness of Rubber with a Hardness Tester", the thermal pad uses Shore hardness to express its hardness. The corresponding measuring instrument of Shore hardness is Shore hardness tester, which is mainly divided into three types: Type A, Type C and Type 00. The measurement principle is exactly the same, the difference is that the size of the stylus, especially the tip diameter, is different, type 00 is the largest and type A the smallest. Shore A hardness tester is suitable for measuring harder thermally conductive gaskets; Shore 00 hardness tester is suitable for measuring softer thermally conductive gaskets. Shore hardness belongs to indentation hardness. The test method is to insert the measured material with a Shore hardness tester. The pointer on the dial is connected to a needle through a spring, and the needle is pierced into the surface of the object to be tested. The value displayed on the dial is the hardness. value.