Dow Corning: Focus on the cooperation between organic silica and new substrates

According to Ji Chunyong, the basic structural unit of silicone is composed of silicon-oxygen chains, and the side chains are connected to other organic groups through silicon atoms. Therefore, in the structure of the silicone product, both the "organic group" and the "inorganic structure" are contained. This special composition and molecular structure make it combine the characteristics of organic matter with the function of inorganic substances, among which the greatest advantage It can relieve more stress.

At present, there are some silicone products on the market, the main chain is still carbon-carbon bonds and the side chains are silicon-oxygen bonds. These products are between silicone and silicon in performance, which may cause product failure during LED package use.

Based on the advantages of high temperature resistance and adjustable refractive index, silicones have been gradually applied in LEDs since 2007, especially in the case of gradually increasing brightness of LED white light. However, silicone has poor gas permeability and oxygen permeability, and water vapor does not easily penetrate from the glue to the surface of the chip during use of the LED package.

According to Ji Chunyong, Dow Corning found through aging tests that methyl silica gel will not appear yellow at 200 ° C, while high refractive index silica gel will start to yellow at 180 ° C, and epoxy resin will start at 150 ° C. Yellowing, so manufacturers must control the temperature better during use.

The reporter learned that at present, domestic manufacturers are more confused about the choice of high refractive index silica gel and low refractive index silica gel.

"The refractive index can increase the refractive index by increasing the proportion of side chain benzene rings. Based on the limitation of heat resistance, the highest refractive index of silica gel products currently used in the industry can reach 1.54." Ji Chunyong revealed that Dow Corning has been tested and found that despite high refraction The rate of silica gel can be made better in gas permeability and oxygen permeability, but the stability of light is worse than that of low refractive index silica gel. The high refractive index silica gel has been tested to decay much more at 150 ° C than the low refractive index silica gel.

“This is also why Japanese products generally prefer low-refractive-index silicone products because they value the life of LED lamps.” Ji Chunyong said that in the future, Dow Corning’s product development focus will be on how to reduce the attenuation of organic silica products at high temperatures. .

Based on the changes in the entire packaging technology system, especially from the previous PPA to the current PCB, the future is likely to develop into EMC materials. Dow Corning has improved its formulation to make the silicone and new substrates better. .

According to Ji Chunyong, the basic structural unit of silicone is composed of silicon-oxygen chains, and the side chains are connected to other organic groups through silicon atoms. Therefore, in the structure of the silicone product, both the "organic group" and the "inorganic structure" are contained. This special composition and molecular structure make it combine the characteristics of organic matter with the function of inorganic substances, among which the greatest advantage It can relieve more stress.

At present, there are some silicone products on the market, the main chain is still carbon-carbon bonds and the side chains are silicon-oxygen bonds. These products are between silicone and silicon in performance, which may cause product failure during LED package use.

Based on the advantages of high temperature resistance and adjustable refractive index, silicones have been gradually applied in LEDs since 2007, especially in the case of gradually increasing brightness of LED white light. However, silicone has poor gas permeability and oxygen permeability, and water vapor does not easily penetrate from the glue to the surface of the chip during use of the LED package.

According to Ji Chunyong, Dow Corning found through aging tests that methyl silica gel will not appear yellow at 200 ° C, while high refractive index silica gel will start to yellow at 180 ° C, and epoxy resin will start at 150 ° C. Yellowing, so manufacturers must control the temperature better during use.

The reporter learned that at present, domestic manufacturers are more confused about the choice of high refractive index silica gel and low refractive index silica gel.

"The refractive index can increase the refractive index by increasing the proportion of side chain benzene rings. Based on the limitation of heat resistance, the highest refractive index of silica gel products currently used in the industry can reach 1.54." Ji Chunyong revealed that Dow Corning has been tested and found that despite high refraction The rate of silica gel can be made better in gas permeability and oxygen permeability, but the stability of light is worse than that of low refractive index silica gel. The high refractive index silica gel has been tested to decay much more at 150 ° C than the low refractive index silica gel.

“This is also why Japanese products generally prefer low-refractive-index silicone products because they value the life of LED lamps.” Ji Chunyong said that in the future, Dow Corning’s product development focus will be on how to reduce the attenuation of organic silica products at high temperatures. .

Based on the changes in the entire packaging technology system, especially from the previous PPA to the current PCB, the future is likely to develop into EMC materials. Dow Corning has improved its formulation to make the silicone and new substrates better. .