关键词: 翘曲变形, 有限元仿真, 热-结构耦合, 热缓冲

Abstract: In order to address the problem of poor soldering of small ceramic substrate PCBAs caused by the warpage deformation of the carrier plate during the placement process, this paper adopts a combination of theoretical analysis and thermal-structural coupling finite element simulation and experimental verification to systematically study the evolution of the three-dimensional temperature field of the carrier plate and its mapping relationship with the structural deformation during the process. The simulation found that when the carrier plate directly contacts the heating table, the non-uniform thermal environment leads to thermal stresses, which triggers warping and deformation and reduced yield of the loaded device. In order to solve this problem and buffer the transient thermal effect, the optimization scheme of adding an insulating pad between the carrier plate and the heating table is proposed. The results show that this scheme can effectively reduce the temperature difference and temperature rise rate, and warpage deformation has been reduced by more than 90%, the warpage deformation has been controlled. The device defect rate has decreased from 6.5% to below 2%, the device yield rate has been effectively improved.

Key words: warpage, finite element simulation, thermal-structural coupling, buffer transient thermal