关键词: 可润湿性, 侧翼QFN, 切割深度, 切割宽度, 爬锡高度

Abstract: In recent years, Quad Flat No-Lead packages (QFN) have gained an increasingly significant market share owing to their superior thermal and electrical performance. Wettable Flanks (WF) QFN, an advanced variant of the conventional QFN, has demonstrated significant potential in automotive assembly inspection owing to its superior wettability. In this study, a simulation method for solder climbing is employed to investigate the impact of varying single-step cutting depths and widths on the solder climbing height of QFN products. This approach can provide an approximation of the soldering effect when these products are mounted onto PCB boards. The results demonstrate that when the cutting depth of the step is ≥0.05 mm and the cutting width is ≥0.02 mm, there is a significant improvement in the wettability of the flanks of QFN products. This enhancement leads to a notable increase in the height of solder climb, thereby improving the subsequent soldering performance.

Key words: wettable, flank QFN, cut depth, cut width, solder climbing height