Preparation And Properties Of Thermal Epoxy/Diamond Composites

Thermal Conduction Polymer Composite Material has not only the outstandingperformance of high polymer resin, but also overcomes the limitation that traditionalpolymer is the poor thermal conductor; thus, to create thermal conductive compositemeans a lot for expending polymer usable range, and the thermal conductivity anddielectric strength of polymer composites is of great significance for both theelectronic component packaging field and computer die bonding field. In this paper,thermal conductive diamond/epoxy resin composite is made by combining4kinds ofdifferent-size inorganic carbon padding with epoxy resin E44. The main hybridapproaches applied include powder blending and hot compaction; meanwhile,applications such as laser detector, differential scanning calorimeter (DSC), dynamicmechanical analyzer (DMA), thermo gravimetric analyzer (TGA), Pull andCompression Machine, and scanning electron microscopes(SEM) are used foranalyzing the influence of diamond size, padding quantity, surface treatment oncomposite’s thermal conductivity, mechanical property, thermodynamic property,thermal stability, and linear expansion, etc.The first part of this paper discusses the changes made to the composite’s curingcondition, mechanical and thermodynamic property after different mass fractions ofdiamond powder are added into epoxy resin. By TGA, conclusion about diamond isequally distributed in composite is made; and through Pull and Compression Machine,conclusion about composite keeps the excellent mechanical property of epoxy resincan be drawn. Since decompose temperature of diamond is above1200℃, the usagetemperature of composite is increased due to diamond participation. Diamond massfraction is a75.4%composite5%weight loss, which equals to a20℃increasecompared to pure resin.The first part of this paper discusses the changes made to the composite’s curingcondition, mechanical and thermodynamic property after different mass fractions ofdiamond powder are added into epoxy resin. By TGA, conclusion about diamond isequally distributed in composite is made; and through Pull and Compression Machine, conclusion about composite keeps the excellent mechanical property of epoxy resincan be drawn. Since decompose temperature of diamond is above1200℃, the usagetemperature of composite is increased due to diamond participation. Diamond massfraction is a75.4%composite5%weight loss, which equals to a20℃increasecompared to pure resin.The second part discusses the conductivity coefficient change after diamondpowder with different sizes and mass fractions are added into epoxy resin. By a laserdetector test and SEM observation, it can be concluded that20micron diamond ismore suitable for thermal conductive chain overlap joint, and thermal conductivecoefficient of20micron diamond powder as composite padding is the highestcompared to diamond powder as padding with other mass fraction and sizes. This isalso verified by electron micrographs. When diamond padding occupies75%of thetotal mass fraction of composite, the thermal conductive coefficient of the compositeis the highest, which can be amount to2.71W/m*k. However, too much diamondpadding would worsen the composite’s thermal conductivity and mechanical property.It’s inferred that this is due to diamond powder can’t be soaked into resin to a toolarge degree.To sum up, diamond/epoxy resin composite has good application prospect in themicroelectronic packaging field.