Study On Preparation Of Epoxy Glass Cloth Copper Clad Laminate By Solvent-free Method

The traditional glass cloth prepreg is mainly consisted of epoxy resin,curing agent,accelerator,diluent,filler and solvent.The preparation of it is rely on the volatilization of solvent during the process.But the conventional preparation not only contaminate the environment,and the residual solvent also affect the properties of prepreg and laminate.Thus there exists the most important task and difficulty currently,which is exploring the technology about the preparation of solvent-free FR-4 epoxy prepreg.In this topic,the epoxy resin and phenolic epoxy resin was adopted for the main resin,dicyandiamide was served as curing agent.And adding into different content of curing accelerant,2-ethyl-4-methyl imidazole and UR300.Eventually the epoxy glass cloth laminate was prepared by using of the method of solvent free.It was from the tests of gelation time(GT)of glue under different schemes and curing accelerant,infrared spectroscopy(FT-IR),differential scanning calorimetry(DSC),and thermogravimetric analysis(TGA)that the dipping process and semi curing process without solvent preparation of epoxy glass cloth prepreg was defined.With this in mind,what we obtained from the experiment was that the dipping technology of prepreg with solvent-free preparation was on the double-roller calender,with the temperature of ruller was 90?;process of semi curing was 130?×15min.Then we prepared the prepreg into a CCLwith the relative parameter was130?×15min+180?×60min.With the comparied of the CCL with solvent method and traditional method,we obtained that the solder resistance,peel strength,dielectric constant and breakdown voltage of copper clad laminate without solvent is higher than the one prepared conventional ly.And the epoxy glass cloth prepreg prepared by non solvent had a higher decomposition temperature(310?)and glass transition temperature(176?),it presented a good heat resistance.Meanwhile,we tested that the solder resistance of CCL prepared by this method was 128 s,the dielectric constant was 5.19,the peel strength was 1.4 N/mm and the breakdown voltage could reach to 48kV/mm.As to the CCL,the performance indicators of non solvent method was better than the traditional solvent method.