Preparation Of AlN Ceramics Substrate With High Thermal Conductivity And Packaging For High-power LED

The purpose is to develop High-power LED in this thesis. At first, inorder to save cost and gain AlN substrate with high thermal conductivity, a lowmelting point oxide of CaMgSi2O6was synthesized as sintering additives.Investigation into variation of sintering properties, thermal performance andmechanical behavior of AlN after adding only CaMgSi2O6and mixed with Y2O3andNano-AlN. Secondly, the silver paste was prepared for AlN metallization. Based inCBS(40%CaO、20%B2O3、40%SiO2) glass-bonded, studied on the impact ofchanging its component content as well as adding BaO, Li2O and ZnO, MgO on Agconductor paste. Last, experiment designed the circuit diagram that was used to AlNceramics substrate and metallizated AlN ceramics by the way of screen printing.AlN ceramics substrate was acted in connect wiht other devices to packagehigh-power LED. Otherwise, investigage some actual questions to be noticed aboutthe temperature of wire bonding; the amount of phosphor glue and practical processoperation during the packaging. Then, experiment measured the substrate’stemperature of working LED to dectect cooling capacity. The main research resultswere described as follows:1.Systematically study on the low-temperature sintering mechanism of AlNceramics after adding CaMgSi2O6, Y2O3and Nano-AlN powders. Investigation intothe performance of AlN, especially the impact of second phase on the thermalconductivity of AlN ceramics after adding sintering aids. Successfully, we gain thebest AlN ceramics with volume density reach at98%of theoretical density andthermal conductivity of112.44W/m·K.2.Study on the influence on softening and infiltration of glass for changing thecomponent composition of CBS glass-bonded as well as adding BaO, Li2O and ZnO,MgO to it. Reach metallization of AlN ceramics by the mechanism of gaintingmechanical connection after cooling of the melten glass. Then, discuss metallizationbonding strength of AlN ceramics with sliver paste which is motified with differentcontent of the glass. Finally, we get the sample with shear strength21.3Mpa. 3.Metallizate AlN ceramics substrate on the basis of circuit which ispre-designed then sinter at850℃to get AlN ceramics with high thermalconductivity. Next, high-power LED is packaged through die bonding, bake forcuring, wire bonding, dispending and so on. Otherwise, some practical problemsalso are investigated in the process of packaging and high-power LED of30W and60W are made at last. Then, measure the substrate’s temperature of working LEDafter5seconds of each in30seconds, to dectect it’s cooling capacity.