MIRMAN-MODEL-BASED APPROACH FOR PLATED THROUGH HOLE PAD STRESS PREDICTION

Two selected boundary conditions,an ideal elastic and a plastic case at the corners of plated through hole (PTH) pads and barrels,are considered in Mirman's deflection model of PTH pads. In reality,however,the boundary is usually neither,but some conditions between. Based on Mirman's model,deflection model with common boundary condition is established by altering boundary condition parameter,B,which indicates elastoplasticity degree at the joint of pad and barrel. And stress prediction model is also found for PTH pads. Analytical method and FEA (finite element analysis) method are used to calculate the stress of PTH pads. Results show that B value has great effect on stress value. This effect has no relationship with environment parameters such as temperature,but relates to geometry parameters.