混合烧结高散热导电胶的封装应用及性能

Assembly Application and Performance of Hybrid Sintering High Heat Dissipation Conductive Adhesive

为满足中大尺寸背面裸硅芯片的封装应用及其高散热需求,开发了一种新型混合烧结高散热导电胶,该新型导电胶以有机二元酸表面活化的银粉颗粒、丙烯酸树脂和其他有机添加剂为原料混合制备而成。采用新型导电胶将6 mm×6 mm裸硅芯片粘接到方形扁平无引脚封装键合(QFNWB)产品上,并进行了导电胶黏度测量、X射线无损检测、导电胶和芯片粘接的破坏性推力测试、导热系数测试和可靠性试验。研究结果表明,该导电胶触变指数为7.2,烘烤后无明显气孔产生,6 mm×6 mm裸硅芯片粘接的破坏性推力为343 N,导热系数高达15 W/(m·K)。与常规导电胶相比,其导热性能优异,且解决了烧结银导电胶无法应用于中大尺寸背面裸硅芯片的问题,满足产品的高散热和高可靠性要求。

In order to meet the assembly application and high heat dissipation requirements of medium-and large-size backside bare silicon chips,a new type of hybrid sintering high heat dissipation conductive adhesive was developed.The new conductive adhesive was prepared by mixing silver powder particles activated on the surface of organic dibasic acid,acrylic resin and other organic additives.The 6 mm×6 mm bare silicon chip was bonded to quad flat no-lead package wire bond(QFNWB)products by using new conductive adhesive.The viscosity measurement of conductive adhesive,X-ray nondestructive test,broken die shear between the conductive adhesive and the chip bonding,thermal conductivity test and reliability test were carried out.The research results show that its thixotropic index is 7.2 and no obvious voids generated after baking.The broken die shear with 6 mm×6 mm bare silicon chip is 343 N.The thermal conductivity is up to 15 W/(m·K).Compared with conventional conductive adhesives,its thermal conductivity property is excellent.At the same time,it solves the problem that sintering silver conductive adhesive cannot be applied to medium-and large-size backside bare silicon chips and meets the product requirements of high heat dissipation and high reliability.