Industrial Wafer Ball Attach by Gravity Feeding In Comparison to Competing Technologies
Industry becomes more aware of cost saving and productivity increasing wafer level packaging approaches. With the demand to thinner and more compact package solutions, the WL-CSP is a device type that fulfills many demands from compactness, robustness, good electrical performance, low cost, shock robustness and fast assembly using ship shooters. The paper gives insight into a basic WL-CSP construction with all functional elements used in modem WL-CSP packages. It describes different ways to deposit solder balls (from stencil printing, metal jet, vacuum gang feeding, laser assisted single ball attach to C4NP) on the contact side of a wafer with focus on gravity feeding mechanism. The machine working principle is described and information about wafer diameter and thickness requirements, tooling requirements, typical throughput, the integration in a production flow and the achievable ball attach yield are given.
solder sphere ball attach WL-CSP gravity feeding wafer balling technology.
Wolfgang Reinert
Fraunhofer Institute for Silicon Technology, Itzehoe, Germany
国际会议
Chinas Premier SMT & MPT Event(2007年中国国际表面贴装和微组装技术大会)
上海
英文
170-191
2007-03-22（万方平台首次上网日期，不代表论文的发表时间）