Design And Performance Research Of Poly(phenylene Oxide) Based Composites For Printed Circuit Board

Polyphenylene oxide?PPO?resin is widely used in the field of high-end printed circuit board?PCB?due to its excellent performances,and has become an important substrate material for high-frequency and high-speed PCB.However,traditional PPO-based dielectric materials cannot meet the demands of diversification,characterization and multifunction for electronic products and match with the development of system in packaging?SIP?technology.Therefore,it is essential to develop new functional dielectric materials that are compatible with PCB substrate material and manufacture process.In this paper,functional PPO-based composites with magnetic properties,high thermal conductivity and high dielectric properties were constructed and the performances of such PPO-based composites were investigated.?1?The magnetic Ba Fe₁₂O₁₉/PPO composites were constructed by blending of BaFe₁₂O₁₉ particles and PPO polymer matrix.The dispersity of surface modified BaFe₁₂O₁₉(t-BaFe₁₂O₁₉)particles in PPO matrix was evaluated while thermal stability,dielectric properties,magnetic behaviors and flexural performances were characterized to investigate the effects of BaFe₁₂O₁₉ particles on the performance of composites.BaFe₁₂O₁₉/PPO composites were employed as embedded magnetic core to enhance the inductance of spiral copper inductors.Improved dispersity in PPO matrix was found in the composites with t-BaFe₁₂O₁₉ particles.The initial decomposition temperatures of all composites were decreased by the addition of t-BaFe₁₂O₁₉ particles,resulting in the decrease of the thermal stability.The increment of t-BaFe₁₂O₁₉ particles first enhanced and then weakened the flexural strength of the composites.The dielectric constant and dielectric loss of composites increased with increasing t-BaFe₁₂O₁₉ and decreased with increasing frequency,showing a weaken dependence on frequency gradually.The addition of t-BaFe₁₂O₁₉ particles enhanced magnetic properties of the composites.The saturation magnetization increased and the coercive force decreased with increasing t-BaFe₁₂O₁₉ particles.The t-BaFe₁₂O₁₉/PPO magnetic composites as core of spiral copper coil could improve the inductance and quality factor of the inductor.?2?The copper calcium titanate?CCTO?ceramics were prepared by solid-phase synthesis method.Surface functionalized CCTO?t-CCTO?were blended with PPO matrix to fabricate t-CCTO/PPO binary composites with high dielectric constant.The electrical insulation properties and dielectric behavior of the composites were measured to investigate the effects of CCTO particles on the performance of PPO-based composites.The results showed that t-CCTO dispersed more uniformly in the PPO matrix.The AC conductivity of t-CCTO/PPO composites increased with increasing t-CCTO particles and frequency.The dielectric constant and dielectric loss of t-CCTO/PPO composites increased with the increase of t-CCTO content and decreased with increasing frequency.A novel graphene-coated CCTO?g-CCTO?material was prepared by heat treatment and was composited with PPO to prepare g-CCTO/PPO ternary composites.The impact of GE content on the performance of the composite was also studied.It was found that the AC conductivity of g-CCTO/PPO ternary composites increased with increasing GE content and frequency.The AC conductivity of g_0.4-CCTO/PPO composites reached the percolation threshold.The dielectric constant and dielectric loss of g-CCTO/PPO ternary composites increased with increasing GE content in g-CCTO and decreased with increasing frequency.The dependence on frequency increased as the GE content in g-CCTO increased.?3?AlN/PPO and t-AlN/PPO composites with high thermal conductivity were fabricated using AlN and surface functionalized AlN?t-AlN?as fillers.The dielectric properties,thermal conductivity and flexural performance were investigated for the PPO-based composites.It was found that the dielectric constant and dielectric loss of all composites increased with the increase of filler content and decrease with increasing frequency.Compared with AlN/PPO composites,t-Al N/PPO composites exhibited higher dielectric constant and lower dielectric loss.The addition of AlN could significantly enhance the thermal conductivity of PPO resin while surface functionalization of AlN could further increase the thermal conductivity.The thermal conductivities of 50 vol%AlN/PPO and 50 vol%t-Al N/PPO composites were 1.403W·m^-1·K^-1 and 1.827 W·m^-1·K^-1 respectively.The flexural strength decreased with increasing filler content whereas t-AlN displayed an improvement of the flexural properties of the composites.Furthermore,graphene?GE?was employed to fabricate an AlN-GE material.AlN-GE/PPO composite combining thermal and mechanical properties were prepared by blending AlN-GE hybrid ceramics with PPO resin.Dielectric properties,thermal conductivity and flexural performance were evaluated to investigate the effect of GE content on the performance of the composites.An enhancement of dielectric constant,dielectric loss,thermal conductivity and flexural strength of AlN-GE/PPO composites was observed compared to that of AlN/PPO composites at the same mass fraction,and these performances increased with the increase of GE content.The thermal conductivity of the AlN-GE_1.5/PPO composite reached 1.303 W·m^-1·K^-1.?4?CNT/PPO and t-CNT/PPO binary composites with high-thermal conductivity were fabricated by using carbon nanotubes?CNT?and surface functionalized CNT?t-CNT?as fillers.The influence of surface functionalization of CNT on its dispersity in PPO matrix was studied while the thermal stability,electrical insulation properties,dielectric behavior and flexural performance were investigated to estimate the influence of filler content on the performances of the binary composites.It was observed that the t-CNT exhibited improved dispersity in PPO polymer matrix.The glass transition temperature?T_g?of composites gradually decreased with increasing CNT.Compared with CNT/PPO composites,t-CNT/PPO composites displayed smaller decrease of T_g.The composites with low t-CNT content possessed lower conductivity and higher dielectric constant while that with high t-CNT content showed higher conductivity and lower dielectric constant.The t-CNT/PPO composites exhibited higher thermal conductivity.The flexural strength of composites increased first and then decreased with increasing filler content.The t-CNT/PPO composites exhibited higher flexural strength than that of CNT/PPO composites.The CNT-GE/PPO and CNT-GP/PPO ternary composites were constructed by employing GE and graphite?GP?as the second filler based on CNT/PPO composites.The effects of GE and GP content on the properties of the composites were studied and the results showed that the introduction of GE and GP accelerated the reduction rate of T_g.Compared with CNT/PPO composites,GE and CNT generated a synergistic effect on the performance of PPO-based composites,resulting in lower electrical conductivity percolation threshold,higher dielectric constant,thermal conductivity and flexural strength of composites.The enhancement of electrical conductivity,dielectric constant and thermal conductivity was also observed in the ternary composites with GP.However,the addition of GP produced a negative influence on the flexural strength of the composites.