A new type of spinel ceramic for CBGA package

Abstract

High thermal conductivity with HITCE are highly required for microwave dielectric ceramics for CBGA electronic packaging applications. In this work, AAl2O4-x wt. % (Li2CO3-Al2O3-SiO2) (A = Zn, Mg) ceramics with spinel structure were synthesized through a conventional solid-state reaction method. The coefficient of thermal expansion of the ceramics are much higher than spinel ceramics because of the addition of Li2CO3-Al2O3-SiO2 additive. Meanwhile, the high thermal conductivity ceramics are also obtained due to the high thermal conductivity of its spinel structure and dense microstructure. Especially, ZnAl2O4-5 wt. % (Li2CO3-Al2O3-SiO2) compound exhibits thermal conductivity of 13.531 W/mK, TCE value of 8.65ⅹ10−6 K−1 (30–490 ℃), dielectric constant of 8.40 and dielectric loss of 4.40ⅹ10−4. And MgAl2O4-10 wt. % (Li2CO3-Al2O3-SiO2) compound exhibits thermal conductivity of 16.8 W/mK, TCE value of 8.9ⅹ10−6 K−1 (30–500 ℃), dielectric constant of 7.89 and dielectric loss of 8.90ⅹ10−3. The excellent thermal and dielectric properties give it a great potential in Ceramic Ball Grid Array electronic packaging applications.