Two Dimensional Materials Modified Epoxy Thermal Conductive Electronic Packaging Adhesive

Epoxy resin is often used as the substrate of electronic packaging adhesive because of its good adhesion,high mechanical properties and excellent dielectric properties.However,the thermal conductivity of epoxy resin is poor and it is difficult to meet the thermal conductivity requirements of electronic packaging adhesive.Therefore,it is necessary to modify the thermal conductivity of epoxy resin.Additive thermal conductivity modification is one of the most effective ways to improve the thermal conductivity of epoxy resin.Boron nitride is a kind of thermal insulation filler,which can give epoxy resin excellent thermal conductivity,but its poor compatibility with epoxy resin,difficult to disperse in epoxy resin,which limits its application in epoxy resin.Graphene has also been widely used in the field of improving thermal conductivity of materials due to its unique two-dimensional structure.However,its excellent electrical conductivity limits the dielectric properties of composites.Based on this,this paper chemically modified boron nitride and graphene,and further applied to the modification of thermal conductivity epoxy resin.The main research contents are as follows:(1)Commercial hexagonal boron nitride is chemically modified by means of high temperature stripping,hydroxyl is introduced to obtain hydroxylated hexagonal boron nitride,and then hydroxylated hexagonal boron nitride is reacted with silane coupling agent KH560 to obtain silane coupling agent KH560 modified boron nitride.Two modified boron nitride were added into the epoxy resin to prepare the composites.The results showed that compared with the pure epoxy resin,the thermal conductivity of the epoxy resin was improved by adding 4wt%hydroxylated hexagonal boron nitride,and the thermal conductivity of the epoxy resin was increased from 0.24 W·m-1·K-1 to 0.63 W·m-1·K-1.The dielectric property becomes better and the dielectric constant decreases to 1.5.The resistance value decreases from 9.17×107 Ω to 6.4×107 Ω,and the insulation performance increases.The bond strength is increased from 7.32 MPa to 7.70 MPa.Compared with the pure epoxy resin,the thermal conductivity of hexagonal boron nitride modified by 4wt%silane coupling agent increased to 0.68 W·m-1·K-1.The dielectric properties are better;The resistance value decreases to 6.7×107 Ω,and the insulation property increases.The bond strength is increased to 7.94 MPa.(2)Using the ethyl orthosilicate hydrolysis method,a layer of silica particles was coated on the surface of graphene to form an insulating layer,which allowed the graphene to play the role of thermal conductivity and electrical insulation.The graphene before and after modification was added into the epoxy resin.The research results showed that compared with the pure epoxy resin,the addition of 4 wt%unmodified graphene can increase the thermal conductivity of epoxy resin from 0.24 W·m-1·K-1 to 0.62 W·m-1·K-1,the thermal conductivity is increased,but the resistance value is reduced to 3.3×107 Ω,and the insulation becomes worse.Compared with the unmodified graphene,the addition of 4 wt%SiO2 coated graphene to the epoxy resin can increase the resistance value to 6.6×107 Ω,and the insulation becomes better,and with the increase of SiO2 content,the resistance value gradually increases to 7.9×107Ω,and the insulation becomes better and better.Compared with the epoxy resin with the addition of unmodified graphene,the dielectric constant of the graphene with the addition of silicon dioxide is gradually reduced to less than 4,and the dielectric property is enhanced.Compared with pure epoxy resin,the bond strength of the composites with the addition of both unmodified graphene and modified graphene increased.