Research On High Frequency Copper Clad Laminates

Copper clad laminate(CCL)is a kind of basic materials for the electronics industry,mainly for manufacturing printed circuit boards(PCBs),and it has been widely used in electronic communications and instrumentation.Electric technology is developing toward higher integration,lower power consumption,and higher performance direction,which brings higher requirements on high performance electric materials.This kind of CCLs not only should have excellent process and mechanical properties,but also must have low dielectric constant,low dielectric loss and excellent heat resistance,and thus can meet the requirements of modern information industry.Firstly,the application of styrene maleic anhydride(Styrene maleic anhydride,SMA)in fabricating CCLs based on epoxy resin(EP)is studied in this thesis.The effect of the ratio between styrene(St)to anhydride(MA)in styrene maleic anhydride structure on the manufacturing process and properties of CCLs is investigated.With the same molar number of reaction,the biggerthe proportion of St/MA is,the better dielectric properties are,but cohesiveness,flame retardancy and glass transition temperature(Tg)decrease.The dielectric properties of products are improved with the increase of SMA content.When theSMA content is larger than25%,the dielectric properties of the products do notdecrease with the increase of SMA content,and the glass transition temperature,peel strength,flameretardancy and humidity resistance of CCLs will also decrease.The productswith different accelerators show almost similar performances,but the accelerations have big impact on the process.MPZ can significantly reduce the curing temperature of SMA,and thus is more suitable for the processing technology of CCL and PCB.Secondly,the application of cyanate ester in EP based CCLs was studied.When different CEis used to cure EP resin,the required reaction temperaturesis high,this is basically the same with that of SMA.Because the curedEP forms oxazolidinone heterocyclic structure,the bonding of the cured product is better.CE based CCL has excellent heat resistance.Thirdly,the effects of inorganic fillers,solvents and reinforcing materials on dielectric properties of CCLs were investigated.Spherical or fused silica is preferred filler;polar solvents should be avoided;glass fiber cloth with low dielectric constant is selected.With these optimized conditions,the dielectric properties of products can be significantly improved.According to the conclusion from many investigations,composite hardener is used to develop a kind of CCL products with excellent dielectric properties,comprehensive performance.High-frequency CCLs still maintains table performance after many times of laminated,and meeting the processing requirement of preparing PCB,so the developed CCLs can completely meet the requirements.