High Performance Copper Clad Laminates Based On Epoxy Resin

Copper clad laminate (CCL) is one kind of laminates moulded through a hot-pressprocess, the reinforcements are immersed into the resin to form prepregs, of which one sideor both sides are covered with a copper foil. CCL is base material of Printed circuits board(PCB). Following the trend to further miniaturization, more functions and moreintelligence of electronic and electrical equipments, High density interconnection (HDI)technology brings micro Via and fine lines into the manufacturing of PCB, and it will bethe major technology for the next generation PCBs. Therefore, the heat resistance andthermal stability of the traditional dicyandiamide (DICY) curing system can not meet therequirements for soldering of lead-free soldering and HDI process. With the developmentof HDI and application of lead free processing, the substrate of CCLs should have higherheat-resistance and reliability.Our investigation reported in this thesis used phenolic novolac resin (PN) thatcontains many phenyl and has good heat-resistance as the curing agent, and bisphenol Anovolac epoxy resin (BNE) and methylenediphenyl diisocyanate modified epoxy resin asthe main resin. The main context of this thesis contains four parts, including the influenceof the resin content on the integrated performances (dielectric performance, moisture andhot performance and thermal stability) of CCL, the rheological properties of epoxy resinsystem, and the effect of softening point of phenolic novolac resin on the properties andprocessing of CCLs, the influence of the SiO2(filler) on the performances and processingof CCLs.Results show that the heat-resistance and reliability of CCLs depend on the curingsystem, the structures of the main resin and filler content. High performance CCLs withhigh reliability and good processing can be achieved through the optimization of main resincomponent and use of SiO2. The optimum compositions of high performance CCLs are: theratio of bisphenol A novolac epoxy resin to methylenediphenyl diisocyanate modified epoxyresin is3:2, and the filler content is20-30%.Thermal aging of epoxy resin-based CCLs was investigated using the accelerated aging and the aging kinetics mode of Arrhenius equation. The long term thermal aging offour typical kinds of epoxy resin-based CCLs (bisphenol A epoxy resin, bisphenol Anovolac epoxy resin, phosphorus modified epoxy, and biphenyl epoxy resin) and theinfluence of long term thermal aging on CCLs were investigated. Results show that thecuring system, the flame retardant and the structure of the main epoxy resin are the keyparameters of determining the thermal aging resistance of CCLs.