Research On The Effect Of Spherical Silica Micro-powder Modification On The Properties Of Epoxy Plastic Packaging Material

Electronic packaging materials are the key components of electronic packaging technology.With the popularization of micro-electronic packaging structure,the packaging industry has put forward higher requirements for the performance and applicability of electronic packaging materials.As a representative of polymer-based electronic packaging materials,the performance requirements and application scope of epoxy plastic packaging materials are also growing.Spherical silica micropowder is a common inorganic heat-conducting filler for epoxy plastic packaging materials.In order to improve the interface bonding,spherical silicon micro-powder will be surface modified before preparing epoxy plastic sealant.However,the high-temperature spheroidization process of spherical silicon micro-powder in production will cause a large number of hydroxyl groups on its surface to dehydrate and condense,and the active sites on the surface that can be grafted by surface modifiers are greatly reduced,and the surface modification effect is not good,which leads to the decline of the reliability of epoxy plastic packaging material.Therefore,it is necessary to carry out surface pretreatment to enhance the surface modification effect when modifying the surface of spherical silicon micro-powder.In this paper,three processes of silane coupling agent modification,surface etching-silane coupling agent modification and surface coating-silane coupling agent modification were designed to modify spherical silicon powder,and the effects of three modification processes on the properties of spherical silicon powder and epoxy plastic packaging material were studied.The main research contents are as follows:（1）Two silane coupling agents,KH560 and KH570,were used to modify spherical silicon micropowder.The effects of two silane coupling agents with different dosage on the properties of spherical silicon powder and epoxy plastic sealant were studied.When the amount of KH560 and KH570 is 3%of the mass of spherical silica powder,the surface modification effect of spherical silica powder is better.The contact angle is 99.7°and 120.1°,the oil absorption value is 28.3%and 30.4%,and the activation index is 12.7%and 22.2%,respectively.The infrared spectrum and energy spectrum show that there are a few silane coupling agent molecules on the surface of spherical silica powder.The matrix consists of epoxy resin E-44,curing agent methyl hexahydrophthalic anhydride,accelerator 2,4,6-tris（dimethylaminomethyl）phenol and diluent propylene oxide benzyl ether,with the preferred mass ratio of 1:0.817:0.01:0.1,and the mass ratio of spherical silica powder modified by silane coupling agent to the matrix of 1:1.Compared with unmodified epoxy resin,the properties of epoxy resin sealant modified by silane coupling agent are improved to some extent.The viscosity of the slurry decreased by 6.8%and 15.7%respectively,and the flexural strength,impact strength and thermal conductivity of cured samples increased by 13.6%and13.9%,32.1%and 31.9%respectively,and 0.7%and 0.6%respectively.（2）Using 5 mol/L Na OH solution to etch the surface of spherical silicon powder,and then using KH560 and KH570 to modify the etched spherical silicon powder.The optimum time for etching spherical silicon powder with Na OH solution is 12 h.When the amount of KH560 and KH570 is 3%of the mass of spherical silica powder,the surface modification effect of spherical silica powder is better.The contact angle is 117.3°and 126.5°,the oil absorption value is 26.7%and 25.9%,and the activation index is 28.7%and 78.9%,respectively.The infrared spectrum and energy spectrum show that silane coupling agent molecules exist on the surface of spherical silica powder.Compared with direct modification with silane coupling agent,the properties of epoxy plastic sealant modified by surface etching-silane coupling agent are improved more.The viscosity of the slurry decreased by12.8%and 15.2%respectively,and the bending strength,impact strength and thermal conductivity of the cured samples increased by 25.9%and 18.2%,21.6%and 2.5%,11.8%and 6.3%respectively.（3）The surface of spherical silicon powder was coated with metal polyphenol network,and then the coated spherical silicon powder was modified with KH560 and KH570respectively.The optimum proportion of surface coating is:the addition of tannic acid is 1%,and the addition of Fe Cl₃·6H₂O is 0.5%.When the amount of KH560 and KH570 is 3%of the mass of spherical silica powder,the surface modification effect of spherical silica powder is good,the contact angle is 119.3°and 116.9°,the oil absorption value is 32.3%and 33.3%,and the activation index is 27.6%and 23.5%,respectively.The infrared spectrum and energy spectrum show that there are metal polyphenol networks and silane coupling agent molecules on the surface of spherical silica powder.Compared with direct modification with silane coupling agent,the performance of epoxy plastic sealant modified by surface coating-silane coupling agent is slightly improved.The viscosity of the slurry decreased by 23.2%and 12.2%respectively,and the flexural strength,impact strength and thermal conductivity of the cured samples increased by 17.8%and 0.9%,26.1%and 16.5%,8.9% and 3.1% respectively.