CONTROLLED COLLAPSE REFLOW CHIP JOINING
CONTROLLED COLLAPSE REFLOW CHIP JOINING
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DOI：
10.1147/rd.133.0239
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发表时间：
1969-01-01
影响因子：
1.3
通讯作者：
MILLER, LF
中科院分区：
文献类型：
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作者：
MILLER, LF
半导体器件与衬底的回流焊连接已被证明是一种可靠、有效和易于自动化的技术。刚性铜球在焊料回流期间保持刚性，已成功地用作接触接头的主要元件一段时间。然而，为了将这种接合的能力扩展到更大的器件，例如混合部件中的多晶体管芯片，可以在器件上使用可延展的金属接合焊盘而不是铜球，以减少机械应变并允许多焊盘器件在回流期间与模块焊盘进行适当的接触。本文介绍了一种技术，防止这些焊盘崩溃，并允许大规模生产。被称为“受控塌陷”的方法是基于限制衬底焊盘和芯片接触端子的可焊接区域，使得熔融焊盘和焊盘焊料中的表面张力支撑器件，直到接头固化。其结果是一个坚固的，可测试的连接高可靠性（键合强度30-50克，中试生产产量超过97%，预测故障率-基于实验室测试-大大低于铜球接触）。该工艺在经济上适用于自动化，并在制造和控制公差方面提供了相当大的自由度。
Solder reflow connection of semiconductor devices to substrates has been shown to be a reliable, effective, and readily automated technique. Rigid copper spheres, which remain rigid during solder reflow, have been used successfully for some time as a major element of the contact joint. However, to expand the capability of such joints to larger devices such as multiple-transistor chips in hybrid components, ductile metallic joining pads can be used on the devices instead of the copper spheres to reduce mechanical strains and permit multi-pad devices to make proper contact to module lands during reflow. This paper describes a technique that prevents these solder pads from collapsing and permits large scale production. Termed “controlled collapse,” the method is based on limiting the solderable area of the substrate lands and chip contact terminals so that surface tension in the molten pad and land solder supports the device until the joint solidifies. The result is a sturdy, testable connection of high reliability (bond strength 30–50 gm, pilot-production yields exceeding 97%, predicted failure rate—based on laboratory tests—considerably lower than that of copper ball contacts). The process is economically adaptable to automation and offers considerable latitude in fabrication and control tolerances.