Preparation Of High Thermal Conductivity And Insulation Epoxy Molding Compound

According to the current development trend of"high speed,high density,low powerconsumption and low cost"of electronic and electrical integrated circuits on the market,the development requirements of high thermal conductivity,high insulation properties of epoxy plastic sealing materials are proposed.This paper conducts research in terms of epoxy resin molding compound base material formulation,surface treatment of thermally conductive powders,selection and compounding of thermally conductive powder.It is expected to prepare an epoxy plastic compound with thermal conductivity above 2.5 W/?m·K?and good insulation and processing performance.The main research contents of study as follows:?1?O-cresol novolac epoxy resin?NPCN-702?,biphenyl epoxy resin?BNPE-3501LL?,bisphenol A epoxy resin?E-12?are epoxy substrates;novolac 2123,novolac 2402 resin are epoxy curing agent;2,4,6-tris?dimethylaminomethyl?phenol?DMP-30?and 2-methylimidazole?2-MZ?are curing accelerators;their mutual curing is studied.The results show that the curing effect of o-cresol novolac epoxy resin,novolak resin 2402,and DMP-30 curing accelerator is more suitable.The molar ratio of epoxy resin epoxy value to curing agent hydroxyl value is 1:0.8,and the mass fraction of DMP-30 is 0.5wt%.?2?The powders were surface treated with two different coupling agents,?-aminopropyltriethoxysilane and?-?2,3-epoxypropyloxy?propyltrimethoxysilane.The effect of the type and amount of silane coupling agent on surface modification are characterized by infrared spectroscopy?FTIR?and thermogravimetric analysis?TG?.Using modified silicon micropowder to prepare epoxy molding compound,the experimental results of thermal conductivity,volume resistivity and breakdown voltage strength show that the modified effect of KH550 is good and the suitable dosage of KH550 is 0.6wt%.?3?Complexing Silicon powder and SiC whisker.The mass fraction of the filler remains 75%.With the amount of SiC whisker increasing,the thermal conductivity of the plastic encapsulant increases,while the insulation performance decreases;when the mass ratio of silicon powder to SiC whisker is 60:15,the thermal conductivity of the plastic encapsulant reaches 1.28W/?m·K?,which is 22%higher than the single filling of silicon fine powder.?4?Al₂O₃ system.5?m,10?m and 20?m Al₂O₃ are used to prepare plastic encapsulants.With the amount of Al₂O₃ increasing,the thermal conductivity of the plastic encapsulants increases less and the insulation performance decreases.The overall performance of the plastic compound prepared by 10?m Al₂O₃ is better.When the filling mass fraction is 75%,the thermal conductivity of the plastic compound is1.18W/?m·K?and the breakdown voltage strength is 19.6k V/mm.Spherical Si O₂ is used to improve the insulation performance of Al₂O₃ plastics,keeping the total filler mass fraction at 75%,and the mass ratio of 10?m Al₂O₃ to spherical Si O₂ is 67.5:7.5,the thermal conductivity is 1.21W/?m·K?.?5?AlN system.With the amount of AlN increasing,the thermal conductivity of the plastic encapsulant increases by a small amount.When the filling mass fraction is 75%,the thermal conductivity is 1.37W/?m·K?.With 5?m,10?m,20?m BN and AlN compound to improve the thermal conductivity of the plastic compound,the torque increases with the increase of particle size;when the mass ratio of 10?m BN and AlN is15:60,the thermal conductivity is 2.16W/?m·K?,The thermal conductivity increases significantly,the breakdown voltage strength is 29.4k V/mm.The compound of SiC whisker and AlN?BN is used to prepare plastic encapsulants.Due to the rod-like structure of the whisker and the morphology of the flake BN and ellipsoidal AlN,the thermal conductivity is 2.56W/?m·K?,when the mass ratio of AlN:10?m BN:SiC whisker is 55:15:5,reaching the expected target.