Sinteirng At Low Temperature And Performance For Ain-based Composite Substrate Materials

Aluminum nitride is a new type of electronic ceramic which was considered to be a promising integrated circuits and electronic packaging substrate materials for its comprehensive performance. But its strong covalent bond combination, high melting point and low self-diffusivity coefficiently lead to its high cost of sintering, thus limit the industry application.In this thesis, A kind of commercial A1N powder, designed the calcium silicate, CaO-B2O3-ZnO-SiO2(CBZS)glass, B203-MgO-SiO2-ZrO2(BMSZ) glass three series of low-temperature materials, as well as rare-earth sintering assistant Y2O3, were used as raw materials. Conventional sintering method under different temperature was used to prepare the A1N composite materials. The effects of sintering aids on the sintering properties, thermal properties, dielectric properties and mechanical properties were investigated in details.(1) The influence of mono-added CaSiO3powder, Y2O3and CaSiO3co-added powder as sintering auxiliary were systematically researched on the low-temperature sintering of aluminum nitride. Comparing with single addition of CaSiO3, the introduction of Y2O3could use additives of mutual synergy to reduce the sinter temperature. As a result, A1N ceramics with high densification were obtained under low-temperature1625℃. And the highest thermal conductivity of co-added samples was72.57W/(m-K).(2) The influence laws on the amount of BMZS glass addition to BMZS-A1N composite materials was studied. Compact BMSZ/A1N glass-ceramic were pressure less sintered at825℃with the BMSZ glass content of70%. It showed relative low dielectric constant and dielectric loss, was a kind of good low temperature co-fired ceramic.(3) AIN-glass composite substrate materials were successfully synthesized with the additive of CBZS glass. The effect mechanism of CBZS glass soften-point and content change on the composite sinter were studied. Dense CBZS/A1N glass-ceramic was sintered at750℃with CBZS glass content of65wt%. The sample gets the excellent comprehensive properties for thermal conductivity of5.31W/(m-K), dielectric constant of7.45, dielectric loss of0.86×10-3and bending strength of209.04MPa.(4) In order to improve the thermal conductivity of aluminum nitride based ceramic, the CaSiO3-CBZS as sintering aids were added to the low-temperature sintering of A1N. Fixed the CaSiO3adding of2wt%, dense AIN-based ceramic were prepared at1625℃under atmospheric pressure with the CBZS glass content of4wt%, and the highest thermal conductivity was68.68W/(m-K).