Why are there bubbles on the surface of the thermal pad?

Heat-dissipating silicone sheet is one of many thermal conductive materials. It is a gap-filled thermal pad made of silicone resin as the base material and added with temperature-resistant and thermally conductive materials. It has high thermal conductivity, low interface thermal resistance, and insulation. Properties such as performance, compressibility, etc., because of its softer hardness, it can realize a smaller thermal resistance under low pressure conditions, while eliminating the air between the contact surfaces and fully filling the rough surfaces between the contact surfaces to improve contact The heat conduction effect of the surface. Because of the good filling effect of the heat-dissipating silicone sheet, it can effectively conduct the heat of the heat source to the shell, and the heat-conducting silicone sheet has good compressibility and elasticity, and can serve as a shock-absorbing pad.

Recently, some customers asked whether some of the heat-dissipating silicone sheets they bought from other manufacturers had air bubbles on the surface, whether it was normal. When they heard the problem, the first response was to reply that this is an abnormal situation, which represents your purchase. The heat-dissipating silicone sheet is unqualified. Why are there bubbles on the surface of "these" heat-dissipating silicone sheet? What is the surface of a normal heat sink silicone sheet?

The surface of the qualified and normal Heat-dissipating silicone sheet is smooth and flat, and there will be no bubbles. Then there are two main reasons for the bubbles on the surface of the heat-dissipating silicone sheet.

First of all, one part of the heat dissipation silicone sheet production process is an exhaust process. After the heat dissipation silicone is placed in the molding mold, a lot of air will inevitably be inhaled at the moment of mold closing, but the air cannot be mixed with the raw materials of the thermal conductive silicone sheet. If the air is not completely eliminated, air bubbles will be generated in the molded heat-dissipating silicone sheet.

Then, vulcanization is used in the production process of heat dissipation silicone sheet. Vulcanization time is one of the steps of heat dissipation silicone sheet molding. The vulcanization time determines whether the heat dissipation silicone sheet is completely vulcanized. If the vulcanization time is too short, the Heat-dissipating silicone sheet will become soft after molding. The surface of the heat-dissipating silicone sheet is prone to air bubbles, so manufacturers have strict control and supervision on the vulcanization time of the production process.

The above reasons further explain that "some" manufacturers have immature technology and imperfect production equipment in this area, which has caused the heat-dissipating silicone sheet to have bubbles on the surface. Of course, this is only the case of "some" manufacturers. A strong and qualified manufacturer can guarantee product quality