Design of multiobjective optimal laser ablation parameters of hole opening in package-on-package process

In this paper, the design of the multiobjective optimal parameters of the IC package FCPOPCSP (Flip Chip Package on Package Chip Scale Package) manufacturing process was studied. In the IC package FCPOPCSP manufacturing process, the laser ablation of hole openings is the key process affecting the product yield rate of flip chips in the IC package product. Two hole opening problems related to the opening hole diameter (OHD) and inside hole diameter (IHD) were selected as objective functions. The nominal-the-best optimization problem was examined in the studied quality engineering. A statistical model was provided to study the optimization problem of the laser ablation machine. First, the dual response surface method was used to formulate the statistical model. Three laser ablation machine parameters, namely, laser power, draw step, and step period, were selected as three control factors. The fuzzy multiple performance characteristics index (MPCI) method was used to combine the two objective functions into one integrated index. Lastly, the orthogonal particle swarm optimization (OPSO) method was used to solve the nonlinear statistical problem. The derived optimal solution can provide the optimal parameter settings for laser ablation machines in practical industrial applications. The product yield rate can be improved by adopting the nominal-the-best solution set. The suggested model can be further uploaded to be a cloud model on a cloud server to provide the optimal manufacturing strategy of the manufacturing process in the IC package industry. A smart manufacturing function can be achieved to fulfill the modern Internet of Things and Industry 4.0 applications.