What effect does the oil output rate have on the thermal conductive silicone sheet?

Thermally conductive silicone sheet is one of the thermal interface materials, and it is also a widely used thermally conductive material on the market. The thermally conductive silicone sheet is a gap-filling thermal pad made of silicone resin and added with temperature-resistant and thermally conductive materials. It has the characteristics of high thermal conductivity, low interface thermal resistance, insulation, compressibility, etc., because of its softer hardness, it can realize a smaller thermal resistance under low pressure, and at the same time eliminate the air between the contact surfaces And fully fill the rough surface between the contact surfaces to improve the heat conduction effect of the contact surfaces. Because of the good filling effect of the thermally conductive silicone sheet, it can effectively conduct the heat of the heat source to the shell, and the thermally conductive silicone sheet has good compressibility and elasticity, and can serve as a shock-absorbing pad.

There are many parameters that need to be referred to when purchasing thermal silicone pads to determine whether the product is qualified or not. The oil yield is one of the most important parameters for people to pay attention to. So how is the oil yield of the thermal silicone pad tested? What will the oil output rate affect?

It is a normal phenomenon that the thermal conductive silicone film produces oil, because most of the thermal conductive silicone film production process is to mix silicone oil with thermally conductive, heat-resistant, and insulating materials in a certain proportion, and refine them through specific machines. The finished products are not more or less. There will be some small molecules that are free and not completely mixed. In a long-term heated and pressurized environment, small siloxane molecules will slowly precipitate out. This is the reason why the thermally conductive silicone sheet is oily.

If the oil output rate of the thermally conductive silicone sheet is too high, the small siloxane molecules precipitated may be adsorbed on the surface of the radiator or heat source, or penetrate the circuit board, which will affect the reliability of the device. So how to test the oil output rate of thermal conductive silicone sheet?

First, install the sample of the thermally conductive silicone sheet to be tested on the test clip, put it in the high-temperature test box, and simulate the environment where the thermally conductive silicone sheet is exposed to pressure and heat for a long time when working, take it out after a period of time, and calculate The oil output rate and the oil output rate of the thermally conductive silicone sheet are standard. If the oil output rate is lower than the standard, it is considered qualified, and if it is higher than the standard, people can get the test report from the manufacturer and get the sample by themselves. After that, a real machine test is carried out to determine whether the thermal conductive silicone sheet is qualified.