High-Performance Printed Circuit Board Materials Based on Benzoxazine and Epoxy Blend System

Low Dielectric Constant Characteristics of Styrene and Maleimide Anhydride Copolymer with Modification for High Frequency Application of Printed Circuit Board

Recently, due to the intensive and fast progress of the high frequency wireless communication environment, including 5th generation (5G) wireless communication, more robust substrate for printed circuit board (PCB) application, especially with less power consumption, is required. In this study, modified resins based on styrene-maleic anhydride (SMA) copolymer were prepared and evaluated as binder resin to accomplish a low dielectric constant or relative permittivity (ε_r: <3.0) substrate for the PCB application under ultrahigh frequencies (UHF; 1 GHz~9.4 GHz). The low ε_r dielectric characteristics of the modified SMA copolymer could be correlated with effects from the stereo-structure of carbon chains or conformational orientation, where the degree of crystallization was analyzed by X-ray diffraction (XRD) and nuclear magnetic resonance (NMR) spectroscopies. Prepreg films of the low ε_r modified SMA copolymers and their compounds with epoxy resins were also characterized in terms of dielectric loss or dissipation factor (D_f), which have shown more noticeable relation with their stereo-structures as well.

Tribological properties of bismaleimide reinforced with Si-containing benzoxazine monomer

To improve the mechanical and tribological properties of bismaleimide (BMI) resin, a novel Si-containing benzoxazine (Si-BOZ) monomer was synthesized using a solvent process and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane as a silane coupling agent. The novel Si-BOZ monomer was subsequently blended with BMI to prepare Si-BOZ/BMI polymer alloys. Furthermore, the effect of Si-BOZ content on the mechanical, tribological, and thermal properties of Si-BOZ/BMI alloys was investigated. The results revealed that the addition of Si-BOZ to BMI improved the mechanical properties and wear resistance of Si-BOZ/BMI; moreover, the glass transition temperature of cured Si-BOZ/BMI alloys was lower than that of pure BMI resin. These results confirmed that the increase in wear resistance of Si-BOZ/BMI alloys can be attributed to the increase in thermal resistance and improvement in mechanical performance owing to the addition of Si-BOZ.

Achieving a 3D Thermally Conductive while Electrically Insulating Network in Polybenzoxazine with a Novel Hybrid Filler Composed of Boron Nitride and Carbon Nanotubes

To solve the problem of excessive heat accumulation in the electronic packaging field, a novel series of hybrid filler (BN@CNT) with a hierarchical “line-plane” structure was assembled via a condensation reaction between functional boron nitride(f-BN) and acid treated carbon nanotubes (a-CNTs). The reactions with different mass ratios of BN and CNTs and the effect of the obtained hybrid filler on the composites’ thermal conductivity were studied. According to the results, BN@15CNT exhibited better effects on promoting thermal conductivity of polybenzoxazine(PBz) composites which were prepared via ball milling and hot compression. The thermally conductive coefficient value of PBz composites, which were loaded with 25 wt% of BN@15CNT hybrid fillers, reached 0.794 W· m⁻¹· K⁻¹. The coefficient value was improved to 0.865 W· m⁻¹· K⁻¹ with 15 wt% of BN@15CNT and 10 wt% of BN. Although CNTs were adopted, the PBz composites maintained insulation. Dielectric properties and thermal stability of the composites were also studied. In addition, different thermal conduction models were used to manifest the mechanism of BN@CNT hybrid fillers in enhancing thermal conductivity of PBz composites.