The Conductive Process Of Glass Fiber/Epoxy Resin Microporous Surface

With the rapid development of electronic technology, the layers and the density of PCB are getting higher and higher, thickness to diameter ratio of micro hole which plays the role of interlayer conduction is also more and more big, and this will undoubtedly increase the difficulty of PCB porous conductive treatment. The glass fiber/epoxy resin microporous was conducting treatment with chemical oxidative polymerization in this paper, to obtain a layer of poplypyrrole film which is even and has high conductivity, thermal stability and good adhesion. The concrete research is as follows:Firstly, the optimal process formulation and conditions of polypyrrole film polymerization on the glass fiber/epoxy resin were obtained by single factor experiment, laid the foundation for glass fiber/epoxy resin microporous conductive treatment. The polypyrrole film was characterized by FTIR, SEM and thermal shock tests. The results showed that the obtained polypyrrole film was even and covered completely and has good adhesion under the optimal conditions. The optimal conditions for a high conductivity were described as follows: pyrrole monomer concentration 0.041 mol·L-1, temperature 20 ℃, pH 2.6, polymerization 20 min; the best conductivity of polypyrrole film reached to 9.259 S·m-1.Secondly, the pretreatment method of glass fiber/epoxy resin microporous was studied, and the effect of the KMnO4 concentration, coarsening pH and coarsening time on the resistivity of hole was also investigated. The optimal pretreatment process was determined: KMnO4 concentration 15 g·L-1, coarsening 3 min.Finally, The conductive process of monolayer and multilayer substrate microporous was studied based on the formulation and process of the glass fiber/epoxy resin plane. Each aperture microporous (0=0.8,1.0,1.2 mm) in 1,3,5,7,9,11 layers of the substrate were respectively conductive treatment by the optimal process. The morphology and adhesion of the polypyrrole film on the cell wall was characterized by SEM and thermal shock tests. The results showed that the obtained polypyrrole film was even and covered completely and has good adhesion. The average resistance of single-hole got minimum 1.09 kΩ and showed good conductive performance by the optimal process:pyrrole monomer concentration 0.041 mol·L-1, temperature 20 ℃, pH 2.6, polymeric additive BM-1720%, polymerization 20 min.