Preparation Of Three-layer Flexible Copper Clad Laminate Adhesive

The three-layer flexible copper clad laminate, which is also known as adhesive FCCL, is widely used in the field of telecommunications, computers, automotive electronics, cameras, and instrumentation, due to its characteristics of low cost, light, thin and flexible to achieve light, thin, miniaturization for electronic products. As we all known, the performance of the CCL is greatly affect by the adhesives’features. Among these kinds of adhesives, epoxy resin adhesives are widely used because of their strong bonding, high mechanical strength, chemical resistance, good insulation properties, small curing shrinkage and other features. However, the unmodified epoxy adhesive is brittleness and has low peel strength and poor folding after curing which need to be modified.In this paper, two epoxy resins of different types were mechanical blended. The diaminodiphenylsulfone(DDS) was choosed as curing agent,2-Butanoneand DMF as solvent, carboxyl-terminated nitrile rubber as toughening modification. The bending properties and impact properties of the two adhesives were examined and analysised. Results indicated that when the weight content of CTBN was20wt%, the bending strength of adhensive reached to78.006MPa, the impact properties was28.56KJ/m2, the dielectric loss reached0.031and the permittivity was5.580.Based on the results, the FCCL was prepared by the epoxy resin obtained above.The micro-morphology and structure of FCCL were studied by scanning electronic microscope(SEM) and fourier transform infrared spectrum(FT-IR). Results showed that the terminal carboxyl groups peaks were disappeared at1734cm"1and1710cm"1, the ester group absorptions peaks appears at1740cm"1. This proved that the terminal carboxyl group of the nitrile rubber took place entirely esterification reaction with the epoxy resin. SEM observations also showed that the CTBN microvoids were uniformly dispersed in the epoxy resin glue.The peel strength, folding properties, soldering text and other properties of obtained FCCL were also investigated. Results showed that it had the best overall performance as the equivalent rato of epoxy resin901and epoxy resin6128for2:1, nitrile rubber quality for20wt%, DDS quality for3copies, reaction time for120min. In this case, the peel strength was achieved1.4N/mm, the folding performance testing was up to3512times, the number of wiping was up to300times. The soldering text date was260℃/30s, which were all meet or higher than the industry standard. The performance of the FCCL prepared could be best.the adhesive can be used to prepare the FCCL.