Study On ZnAl₂O₄ Based Thermal Conductive Ceramics

With the rapid development of 5G communication,cloud computing,big data,artificial intelligence and other industries,the demand for high-performance chips is increasing,which poses a new challenge to the research of electronic packaging substrate materials.Especially with the development of miniaturization and integration of electronic equipment,the heat dissipation capacity of electronic packaging substrate is more and more urgent.Microwave ceramic substrate materials with good thermal conductivity can be widely used in the field of electronic packaging.ZnAl₂O₄ ceramic has good thermal conductivity and microwave dielectric properties,which is an excellent candidate material for ceramic substrate.How to further improve its thermal conductivity and dielectric properties has become a focus of current research.In this paper,Zn_1-xMg_xAl₂O₄ ceramics were prepared by using Mg²⁺to replace Zn²⁺in ZnAl₂O₄.The causes of different morphology,density,dielectric properties and thermal conductivity of Zn_1-xMg_xAl₂O₄ ceramics under different substitution amounts were explained.Zn_0.9Mg_0.1Al₂O₄ ceramics with good properties were successfully sintered at 1600?.The specific properties are:dielectric constant 8.35,Q×f 136818GHz,thermal conductivity 18.23 W/?m·K?.According to the characteristic that the longer the ball milling time of Mg Al₂O₄sintering powder is,the greater the degree of cation inversion in Mg Al₂O₄ is.The contrast experiment of ball milling time is set up to verify and explain the promotion effect of cation inversion on quality factor and the reduction of thermal conductivity.At the same time,the best milling time of Zn_0.9Mg_0.1Al₂O₄ ceramics was obtained.Using different mass fraction of TiO₂,Zn_0.9Mg_0.1Al₂O₄ ceramics were sintered at different temperatures,and successfully sintered at 1500?sintering temperature.When TiO₂ doping amount was 2wt%,a new ceramic materia with a dielectric constant of 8.57,Q×f of 180861GHz and thermal conductivity of 19.67 W/?m·K?was developed.The good sintering effect of TiO₂ on Zn_0.9Mg_0.1Al₂O₄ ceramics and the cause of its effect on thermal conductivity optimization were analyzed.It is explained by the solid solution defect reaction equation and the ratio of non-stoichiometric compoundsThrough the comparison and simulation of the substrate heat dissipation capacity of three substrate materials including the newly developed thermally conductive ceramic material,the commonly used medium thermal conductivity LTCC material and the low thermal conductivity material epoxy resin,it was found that the newly developed thermally conductive material can adapt to different Working conditions and a wide range of applications.And the higher the chip's thermal power consumption or the stronger the external convection heat dissipation,the advantage of this ceramic material's thermal conductivity is obvious,which proves that the newly developed ceramic material has good application prospects.