Evaluation of Adhesion betwene Glass/Epoxy composite and Copper Foils of Printed Circuit Board using a Fracture-mechanics Approach

摘要

Multilayer printed circuit boards have played an important role in the electronic packaging industry with reduction of package size. A typical multilayer construction consists of several layers of woven glass/epoxy composite substrate and copper foil. One of the most important performances of multilayer printed circuit boards is the adhesion stability. Post-manufacturing processes with thermal shock such as solder masking, solder reflow and wave soldering cause several types of damage, and significantly affect the performance of the package. One is macroscopic delamination that occurs at the interface between the compsoite substrate and the copper foil, or that appears at interlayer in the substrates. Another one is microscopic fracture such as measling and crazing in the substrates. It is necessary for a testing method to enable to evaluate the macroscopic and microscopic damages at the same time. Conventional peeling test is suitable to measure the adhesion strength. However, it is impossible that the macroscopic and microscopic damages and/or the adhesion at substrate/copper interface in core-layer are estimated by the peeling test.