Study On The Preparation,characterization And Performance Of Phenylmethyl Silicone Materials For Light Emitting Diodes Encapsulation

Semiconductor lighting technology is one of the advanced technologies which has enormous development prospect in 21 st century.And the light emitting diode(LED)is the core of semiconductor lighting technology.Packaging material which is the key component of LED has important influence on the performance of LED.And organic silicon material has become the research focus of the LED packaging material at home and abroad since it has excellent heat stability,aging resistance,mechanical properties,moisture resistance and light transmittance.At present,there are some gaps between our country and abroad in research and application for high refractive index organic silicon material which is used for LED encapsulation.So it is significant to strengthen basic theory research,improve the problem of raw material and optimize the production process for the development of high refractive index organic silicon material which is used for LED encapsulation.Phenylmethyl silicone oil and MDT phenylmethyl silicone resin which are suitable for LED encapsulation are discussed in this paper.And also they are used to prepare high performance LED packaging material.The paper can be divided into the following four parts:(1)The research progress and present situation of LED packaging material are reviewed briefly.All parts of LED packaging material are discussed in detail.The research goals and technical routes for LED packaging material are discussed subsequently.(2)Hydroxyl terminated polyphenylmethylsiloxane intermediate is synthesized via the hydrolytic condensation reaction of phenylmethyldimethoxysilane.The optimal conditions of synthesizing the hydroxyl terminated polyphenylmethylsiloxane intermediate are as follow:the mass ratio of water and phenylmethyldimethoxy-silane is 4:5;the mass ratio of the CH-01 acidic cation resin catalyst to the whole reactants is 1%;the reaction temperature is70 ?;the reaction time is 2 hours;the quality of the product yield is 71.7%.Then different viscosity and vinyl content of vinylphenylmethyl silicone oil and different viscosity and hydrogen content of hydrophenylmethyl silicone oil are synthesized via the hydroxyl terminated polyphenylmethylsiloxane intermediate.(3)High performance MDT vinylphenylmethyl silicone resin without hydroxyl is synthesized via the phenyltrimethoxysilane,phenylmethyldimethoxysilane,divinyl-1,1,3,3-tetramethydisiloxane and hexamethydisiloxane.There are two steps to synthesize the MDTvinylphenylmethyl silicone resin.The first step is hydrolytic condensation process and the second step is eliminating hydroxyl with alkaline catalyst.High performance MDT hydrophenylmethyl silicone resin without hydroxyl is synthesized via the phenyltrimethoxysilane?hydroxyl terminated polyphenyl-methylsiloxane intermediate and dihydro-1,1,3,3-tetramethydisiloxane.Also there are two steps to synthesize the MDT hydrophenylmethyl silicone resin.The first step is synthesizing polyphenylmethylsiloxane intermediate via hydrolytic condensation reaction and the second step is eliminating hydroxyl with excess dihydro-1,1,3,3-tetramethydisiloxane.(4)LED packaging material is prepared by using those synthesized vinylphenylmethyl silicone oil,hydrophenylmethyl silicone oil,MDT vinylphenyl-methyl silicone resin,MDT hydrophenylmethyl silicone resin and platinum catalyst.The optimal results of LED packaging material are showed as follow: the refractive index is more than 1.53;the light transmittance is more than 90%;the hardness is 74 shore A;the tensile strength is 2.25 MPa;the elongation at break is 27.16%.