厚膜基板金导体玻璃相析出对键合的影响

Effect of Glass Phase Precipitation in Gold Conductor of Thick Film Substrate on Bonding

对比分析了混合集成电路中不同型号浆料制备的基板金导体表面的形貌特点,研究了玻璃相的成分、析出机理及对后续组装键合的影响。结果表明:玻璃相析出现象与浆料种类、浆料的烧结次数有很大的关系。玻璃相的主要组成元素为O、Zn、Al、Si、Pb、Ca。玻璃相阻碍键合过程中Au-Al元素扩散,减少了键合点与金层之间的有效结合面积,不利于键合结合。烧结后析出的玻璃相会降低AlSi丝超声键合的可靠性,严重时会造成电路互连失效。因此,为提高混合集成电路的键合可靠性,在匹配AlSi丝超声键合工艺时,可以将是否析出玻璃相作为浆料型号选择的关键指标,且只能选取烧结后无玻璃相析出的浆料型号制备厚膜基板。

The morphological characteristics of the gold conductor surface of the substrate prepared with different types of paste in the hybrid integrated circuit are compared and analyzed,and the composition of the glass phase,the precipitation mechanism and the effect on subsequent assembly and bonding are studied.The results show that the appearance of glass phase separation has a great relationship with the type of paste and the sintering times of the paste.The main constituent elements of the glass phase are O,Zn,Al,Si,Pb,Ca.The glass phase hinders the diffusion of Au-Al elements during the bonding process,reduces the effective bonding area between the bonding point and the gold layer,and is not conducive to bonding.The glass phase precipitated after sintering will reduce the reliability of AlSi wire ultrasonic bonding,and will cause circuit interconnection failure in severe cases.Therefore,in order to improve the bonding reliability of hybrid integrated circuits,when matching the AlSi wire ultrasonic bonding process,the precipitation of glass phase can be used as the key indicator for the selection of the paste type,and only the paste type without precipitation of the glass phase after sintering can be selected to prepare thick film substrates.