Research on Delamination of Plastic Packaging Device during Reflow Soldering

Abstract

Due to the application of lead-free solders, the quality and reliability of plastic packaging device are influenced by the increase of reflow temperature. In this paper, a low-profile quad flat package (LQFP) is chosen to illustrate the interface deformation during reflow soldering. The stress analysis theory and the finite element analysis (FEM) simulation are introduced in this paper. By means of finite element software, the distribution of hygrostress, thermal stress and the deformation of device on the printed circuit board (PCB) are analyzed and calculated under different temperature. The relationship between delamination length and deformation is given. The simulation results show that the warping phenomenon is found at the apex angle of the device; delamination is easily produced in the interfaces between different materials by thermal stress, and possibly leads to the device failure.