Optimum thermal conductivity of LED lamps heat dissipation materials and requirements
Insulation and heat conduction are a pair of contradictions. Metal is a good heat conductor and at the same time a good conductive material. There is a characteristic, the better the heat conduction, the better the conduction, such as gold and silver. It is not easy to achieve heat conduction and insulation. At present, the problem we are facing is about the heat dissipation of LED lighting fixtures, but the key problem to be solved. The thermal conductive material used in the traditional heat dissipation mode is thermal conductive silicone grease. Silicone grease will be more economical in terms of cost, but it needs to be applied on a large area on the led lamp, which has a big problem and cannot be applied evenly. The contact between the heat-dissipating copper plate and the heat sink or metal bracket lamp, metal shell, to solve the problem of LED lamps, one of the most hanging ways is to use a soft silicone thermal pad, which can be used for large-area bedding and easy to operate. The thinnest It is 0.5mm, the thickness can be selected, 1.0mm, 1.5mm...5mm thickness, the thickest can reach 16mm, the compression modulus is 20%-25%, which can effectively transfer heat to the heat sink. More ways to use .
Thermally conductive silica gel has product technical characteristics such as good thermal conductivity, softness, high compression ratio, surface adhesiveness, which makes the installation conditions easier, and superior weather resistance and high pressure resistance. The heat transfer effect of using hands is obvious, reducing the internal temperature of the device for a long time, greatly improving the service life of the LED lamp, reducing the loss of light and heat energy, reducing the light attenuation to a certain range, and improving the various performances of the LED lamp (such as life, lumens, Use ambient temperature, etc.). LED lighting fixtures use thermally conductive silicone sheets, which is a good choice. Targeted research and development and production of LED thermal silica gel and put it on the market.
What are the requirements for thermal silica gel to achieve the desired effect as a heat dissipation material for LED lamps? First of all, it is necessary to use silica gel as the base material, add different alumina, boron nitride and other powder materials with good insulation and thermal conductivity, according to a certain proportion, through a special process, make the inner molecules of the soft silica gel thermal insulation pad intermolecular The size is packed tightly and tightly to achieve high density, which is conducive to heat transfer between molecules during heat conduction.
Secondly, in order to meet environmental protection requirements, LED lamps must choose high-precision powder additives, which cannot contain harmful substances such as lead and mercury. There are also flame retardant requirements, so there can be no materials containing flammable ingredients such as bromine. Applicable temperature requirements, so the materials used should consider the influence of ambient temperature on their physical properties. Although it has a high density, it must be soft and elastic, and it can fill the gap between the heating element and the radiator element well. The selection of silica gel and the particle size and quantity of the powder should be controlled.
