Study On Dielectric Of DBA Modified Bismaleimide-cyanate Ester Resin

With the rapid development of microwave communication and microelectronic technology,faster signal transmission speed and higher transmission efficiency are required.The dielectric performance of printed circuit board affects the transmission and loss power of the signal to a great extent.The matrix material with excellent dielectric properties plays an important role in the dielectric performance of PCB.Bismaleimide-cyanate resin is an ideal matrix material with excellent dielectric properties.However,the high curing reaction temperature and the brittleness of the cured product limit the applications of BT resins.Therefore,it is necessary to find an appropriate modifier.Previous studies indicated that DBA is one of the most effective modifiers of BT resins.Previous studies prepared BMI/CE/DBA system prepolymers based on the different mass ratios of CE and BMI/DBA and investigated the effect of these components on the polymerization behaviour and performance of the system.However,the effects of the content of DBA on the crosslinking density of the cured products,the structure of the cured products and the properties of the cured products were not taken into account.In this work,we propose to systematically study the effects of DBA content on the curing reaction and dielectric properties of the modified system.1.The curing behavior of DBA modified BT resin was studied by SEM,DMA,DSC and FTIR tests.The results of the study show that the addition of DBA has a major influence on the curing behavior of the bismaleimide-cyanate ester resin.On the one hand,DBA can catalyze the self-polymerization of CE,and allyl groups of DBA react with the C=C of BMI.In addition,the addition of DBA with flexible groups can help to reduce the crosslinking density of the system and can completely promote the reactions of the system.2.Through the thermal performance test of different proportion systems,the research shows that the initial thermal decomposition temperature of DBA modified BT resin is higher than 400 °C,although the thermodynamic performance of the modified resin is slightly lower than that of BT resin.However,it is still much higher than the actual demand.3.DBA-modified bismaleimide-triazine resins has greater flexural strength,tensile strength and impact strength than pure resin system.However,there is a decresing trend in the flexural modulus and the tensile modulus.4.Through the mechanical properties of different systems,the results shows that DBA modified BT resin compared to BT resins exhibited outstanding resistance to heat and humidity,the water absorption was slightly lower than that of bismaleimide-cyanate resin.5.The dielectric constant and dielectric loss of the cured resin dramatically decreased when DBA was introduced into the bismaleimide-cyanate resins at high frequency.The BT2 modified system showed dielectric constant of 2.91–3.07 and dielectric loss lower than 0.0057 under the testing high frequency range of 1 GHz to 15 GHz.The above studies show that DBA modified BT resin has potential application value in the field of high-frequency printed circuit boards.