Impact Performance of Microvia and Buildup Layer Materials and Its Contribution to Drop Test Failures

This paper introduced a new method to investigate the fracture dynamic response of the PCB materials. Ball impact is used to evaluate the performance of PCB laminate and prepreg materials. Various PCB materials and microvia structures are evaluated which compares halogen free (HF) vs. non-HF, and leadfree compatible vs. non-leadfree compatible, and RCC (resin coated) vs. laser drillable prepreg. It is found that pad cratering including cracking of buildup layer and copper pad delamination are effectively screened out by the impact test. Opportunity or severity of cracking and delamination are dependent to the impact energy and as well as materials of PCB. Materials especially halogen free (HF) and non-filler buildup layers are much more tendency to crack.