The Investigation of Reflow Shape of 95Pb-5Sn Solder Paste

• Main Authors: Steven Yao, 姚啟文
• Other Authors: Kwang-Lung Lin
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/19419079812340533133

碩士 === 國立成功大學 === 材料科學及工程學系 === 87 === Abstract This present work investigated the variation in shape and height of the reflow solder paste. In this experiment, alloy component of solder paste is 95% Pb-5% Sn. Substrate material is nickel-plated copper, and solder pad is defined by poor wetting chromium plating. The atmosphere for reflow is N2:H2 = 9:1. In the case of without loading, the solder shape are affected by substrate solder pad area、solder paste volume and solderability of Cr-plating. Solder thickness is proportional to solder paste volume, but is inversely proportional to solder pad area and solderability of Cr-plating. In the case of loading with Si die, substrate or device solder pad、solder paste volume、wettability of Cr-plating have influence on solder shape. Solder paste volume and poor solderability Cr-plating could increase the solder thickness. Besides, solder thickness variation is affected by substrate or device solder pad area. If substrate solder pad area is larger than that of device, solder thickness is in inverse proportion to substrate pad area. On the other hand, device solder pad area dominates solder thickness variation.