はんだリフロー工程で発生するICのパッケージクラックに関する研究

概要

論文の詳細を見る
Recently, the plastic packages of ICs have been changing from insertion types to surface mounted types. Reflow soldering is used for surface mounted ICs onto printed circuit boards. During the process, packages are heated up above 200'C. If the encapsulant absorbs moisture, package cracking may occur during the reflow soldering. It is known that the cracks are caused by vapor pressure generated inside the packages which causes excessive stress in the plastic. A quantitative explanation of the mechanism of this phenomenon, however, has not been made. In this study, a moisture diffusion analysis in the plastic and deformation and stress analyses of the packages are performed. Also, the properties of the plastic at high temperature are measured and the strength evaluation method is investigated. It is found that the vapor pressure generated inside the package is lower than the saturated vapor pressure and depends on the moisture content distribution of the plastic.
社団法人日本機械学会の論文
1989-02-25