关键词: BTC器件焊点, 焊盘设计, 有限元仿真, 金相试验, 正交设计

Abstract: Two printed circuit board (PCB) pads with different sizes and layouts were designed for Bottom Termination Components (BTC), and corresponding finite element models of BTC solder joints were established. Through finite element simulation and metallographic testing, the effects of pad design schemes and solder joint structural parameters on the stress of BTC solder joints under thermal cycling conditions were analyzed. An orthogonal experimental design was employed to configure nine combinations of solder joint length, width, and height. Stress data obtained from finite element analysis were subjected to analysis of variance (ANOVA) and range analysis. The results indicate that the maximum stress in BTC solder joints based on Pad Type II is lower, demonstrating the superiority of this pad design. Solder joint height has a significant impact on the maximum stress, while solder joint length and width exhibit no significant effects. The order of influence of each factor on solder joint stress is: solder joint height > solder joint width > solder joint length. The optimal combination of structural parameters is a solder joint length of 1.90 mm, width of 0.70 mm, and height of 0.14 mm. After optimization, the maximum stress in critical solder joints was reduced by 1.188 MPa, achieving structural optimization of BTC solder joints.

Key words: BTC device solder joints, pad design, Finite element simulation, metallographic test, Orthogonal design