塑封分立器金线偏移失效行为分析

Failure Behavior Analysis of Gold Wire Sweep of Plastic-Encapsulated Discrete Device

为研究塑封分立器金线偏移导致金线断路失效问题,通过Moldflow数值模拟对金线偏移进行分析和预测,以金线偏移程度最小为最优目标,对工艺参数进行试验设计(DOE).试验得出金线偏移影响程度为充填时间>模具温度>传递压力.仿真结果得出:金线直径越小,金线偏移程度越大,金线离浇口位置越近,金线偏移程度越大;熔体充填阶段金线剪切应力必须小于剥离应力才不会发生熔体冲断金线现象.在应用最佳工艺参数后,塑封体X线检测结果显示,金线偏移量小,未发生金线冲断现象.

The failure of gold wire break caused by gold wire sweep of plastic-encapsulated discrete device was studied.Gold wire sweep was analyzed and predicted by Moldflow numerical simulation.With the minimum gold wire sweep as the optimal goal,the design of experiment(DOE)of process parameters were carried out.According to DOE experimental design,the influence degree of each factor on gold wire sweep were filling time>mold temperature>transfer pressure.The simulation results show that the smaller the diameter of the gold wire is,the greater the gold wire sweep is,and the closer the gold wire is to the gate location,the greater the gold wire sweep is.In the melt filling stage,the shear stress of the gold wire must be less than the peeling stress to avoid the phenomenon of the gold wire punching.After the application of the optimal process parameters,the X-ray detection shows that the wire sweep is small and no wire punching occurs.