发明授权
- 专利标题: Circuit package having low modulus, conformal mounting pads
- 专利标题(中): 具有低模数,适形安装垫的电路封装
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申请号: US09525379申请日: 2000-03-15
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公开(公告)号: US06399896B1公开(公告)日: 2002-06-04
- 发明人: Frank J. Downes, Jr. , Donald S. Farquhar , Robert M. Japp , William J. Rudik
- 申请人: Frank J. Downes, Jr. , Donald S. Farquhar , Robert M. Japp , William J. Rudik
- 主分类号: H05K116
- IPC分类号: H05K116
摘要:
Reliability of circuit packaging while accommodating larger chips and increased temperature excursions is achieved by use of compliant pads only at the locations of connections between packaging levels, preferably between a laminated chip carrier and a printed circuit board. The invention allows the coefficient of thermal expansion of the chip carrier to be economically well-matched to the CTE of the chip and accommodation of significant differences in CTEs of package materials to be accommodated at a single packaging level. The compliant pads are preferably of low aspect ratio which are not significantly deflected by accelerations and can be formed on a surface or recessed into it. Connections can be made through surface connections and/or plated through holes. Connection enhancements such as solder wettable surfaces or dendritic textures are provided in a conductive metal or alloy layer over a compliant rubber or elastomer layer which may be conductive or non-conductive.
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