Analysis of complex packaging model based on BGA

Ball grid array (BGA) has the characters of excellent heat dissipation and high mechanical strength to satisfy with the need of high density packaging of electro produces. However BGA faces some problems of complex viscoplastic deformation, difficult failure test and high repair cost. This paper establishes a complex multichip packaging module with lead-free solder ball SAC305 BGA solder ball based on nonlinear Anand viscoplasticity principle. The simulation results are obtained based on the IPC9701 standard thermal cycling condition. The PCB (printed circle board) warpage law and the positions of the dangerous chip and dangerous solder ball are found. The stain-stress change rule and hysteresis curve are also obtained. The lifetime of complex packaging model is analyzed based on Coffin-Manson equation. Result shows that model reliable working time is 399 hours during the IPC9701 standard thermal cycling environment.