Development Scheme of a Novel Polyimide Matrix System for Multilayer Boards

Following a quick survey of the resin systems commercially available, this paper focuses on the design considerations of high temperature matrices. The report examines in detail the key points of the final target properties of a resin system and, by illustrating some of the transfer mechanisms, how they relate to the matrix reinforcement and the copper environment. Based on this, the construction of a development scheme incorporating the various parameters relating structure, chemistry and properties is presented. In high temperature systems, particular emphasis is placed on fracture toughness and related effects in the case of polyimides, such as copper peel strength, delamination, cracking subsequent to drilling operations or thermal cycling. The conclusion is that the number of controllable matrix parameters is surprisingly small: Tg, CTE, K1c/G1c, modulus and elongation at break, in addition to a few others. Finally, this study shows how all of these data were collectively applied to the practical development of a new Kerimid(™). Further studies are now under way to enhance the importance of additional parameters regarding more complex phenomena such as the drilling operation.