主讲人：K.W. Paik
题目：Micro size solder ACF joints for wearable electronics applications
地点：材料馆后三楼报告厅
时间：2015-7-20, 10:00
持续时间：1个小时
邀请人：黄明亮
Abstract
In the near future, wearable electronic products, such asGoogle glasses, smart watches, andbracelets, will become very important electronic products after the saturation of smartphones, requiring extremely small size, higher performance, multi-functions and great flexibility. For realizing wearable electronic products, there are four core technologies, such as (1) flexible semiconductor, (2) flexible display, (3) flexible battery, and (4) flexible packaging and assembly. Among these four technologies, flexible packaging and assembly technology integrate all the electronic components to realize wearable electronic products. For wearable electronics, all the components interconnection need to be flexible and bendable. Usually, for electrical interconnection, there are three major interconnection methods such as (1) socket connector, (2) solder, and (3)anisotropic conductive films (ACF). Among these three interconnect methods only ACFs, consist of thermosetting resin and conductive particles, are flexible. Therefore, ACFs can provide the solution to replace conventional socket type connectors in wearable electronics such as Google glasses and smart watches by ACF Flex-on-Board (FOB) and Flex-on-flex (FOF) methods.To improve the electrical properties such as contact resistance and current carrying capability and reliability results, KAIST has introduced new solder ACFs with micron size solder particles added into ACFs compared with metal conductor particles in conventional ACFs. When solder ACFs was combined with ultrasonic (US) bonding method, solder ACFs form solder alloy metallurgical joints rather than physical contact based joints of conventional ACFs with metal conductor particles resulting in significantly lower contact resistance and improved current carrying capability and also better reliability performance especially at harsh environment, such as Pressure Cooker Test (PCT). In these solder ACFs, solders are Sn-based Sn-Bi or Sn-Ag-Cu (SAC) alloys depending on the melting temperatures. Sn-Bi and Sn-3.0Ag-0.5Cu (SAC305) solder ACFs can be assembled at 200 oC and 250 oC bonding temperature respectively.
Biography
Kyung W. Paik，韩国科学技术院（KAIST）教授，1979年获韩国首尔大学冶金工程专业学士学位，1981年硕士毕业于韩国科学技术院，1989年博士毕业于美国康奈尔大学材料科学与工程专业。1982年至1985年，作为研究人员就职于韩国科学技术院，负责金键合引线和有色合金等多种材料的开发工作。1989年博士毕业后加入通用电气公司的研发部门，并一直工作到1995年，期间作为高级技术人员参与到用于通用高密度互联（HDI）多芯片组块技术的材料和工艺的研发工作。此后，在1995年他加入KAIST，任材料科学与工程系教授，并在1999年和2005年分别在美国乔治亚理工大学封装研究中心和波特兰州立大学做访问教授。2011年至2013年，任材料科学与工程系研究副主席。Paik教授同时是IEEE-CPMT、IMAPS、SEMI等国际组织的会员，ECTC、IMPACT、EMAP、EPTC等国际电子封装会议的组织者、技术委员、分委会主席和特邀报告人。他组建的纳米封装和互连实验室目前主要的研究领域包括各向异性导电粘合剂（ACAs）材料与工艺、三维硅通孔（3-D TSV）互连材料、钎料以及微机电系统（MEMS）&显示封装技术。至今，Paik教授已经发表了150余篇SCI期刊论文，拥有40项授权和正在申请中的美国专利。