Evaluation of Thermal Deformation Model for BGA Packages Using Moire Interferometry

• Published in: Journal of mechanical science and technology Vol. 18; no. 2; pp. 230 - 239
• Main Authors: Joo, Jinwon, Cho, Seungmin
• Format: Journal Article
• Language: English
• Published: Seoul 대한기계학회 01.02.2004; Springer Nature B.V
• Subjects: Assembly; BGA; Data mining; Finite element method; Mathematical models; Packages; Shear strain; Solders; Springs; Springs (elastic); 기계공학
• ISSN: 1738-494X; 1226-4865; 1976-3824
• DOI: 10.1007/BF03184732

A compact model approach of a network of spring elements for elastic loading is presented for the thermal deformation analysis of BGA package assembly. High-sensitivity moiré interferometry is applied to evaluate and calibrated the model quantitatively. Two ball grid array (BGA) package assemblies are employed for moiré experiments. For a package assembly with a small global bending, the spring model can predict the boundary conditions of the critical solder ball excellently well. For a package assembly with a large global bending, however, the relative displacements determined by spring model agree well with that by experiment after accounting for the rigid-body rotation. The shear strain results of the FEM with the input from the calibrated compact spring model agree reasonably well with the experimental data. The results imply that the combined approach of the compact spring model and the local FE analysis is an effective way to predict strains and stresses and to determine solder damage of the critical solder ball.[PUBLICATION ABSTRACT]