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公开(公告)号:US5075965A
公开(公告)日:1991-12-31
申请号:US608766
申请日:1990-11-05
CPC分类号: H01L24/81 , B23K1/0016 , H05K3/3436 , H01L2224/13111 , H01L2224/16237 , H01L2224/81801 , H01L2924/01006 , H01L2924/01013 , H01L2924/01024 , H01L2924/01029 , H01L2924/01033 , H01L2924/0105 , H01L2924/01075 , H01L2924/01079 , H01L2924/01082 , H01L2924/01087 , H01L2924/01322 , H01L2924/014 , H01L2924/14 , H01L2924/15787 , H01L2924/19041 , H01L2924/19042 , H01L2924/19043 , H05K2201/10992 , H05K2203/0415 , H05K3/3431 , H05K3/3457 , Y02P70/613 , Y10T29/49144
摘要: A controlled collapse chip connect method of joining an IC chip to a microelectronic circuit card. According to the method an inhomogeneous, anisotropic column of solder is deposited from a Pb/Sn alloy onto solder wettable I/O terminals of the I/C chip, without subsequent homogenizing reflow. The solder core has a Pb rich core and an Sn rich cap. The matching footprint of the solder wettable I/O terminals on the microelectronic circuit card is substantially free of deposited solder and presents a protected Cu surface to the solder columns, or, at most a surface of Cu and anti-oxidant. The chip is aligned with the corresponding footprints on the microelectronic circuit card, and the solder is reflowed to bond the chip to the microelectronic circuit card.