Deformation analysis of Multilayer Board in the lamination process

The deformation of core board affects the quality of circuit board, like misalignment, during lamination process of MLB (Multilayer Board). Three main factors causing the deformation are discussed, which are the mismatch of CTE (Coefficient of Thermal Expansion) among different materials, the residual stress in core boards and the special properties of the prepreg. Considering properties changing of the prepreg stage, the model of each stage in lamination process is developed. Then the deformation of core boards in a six-layer MLB is simulated using ANSYS software. Finally, the film compensating factor of 1.15 is determined according to the analysis results, and it is close to the actual factor applied in PCB manufacture process.