Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE A low-dielectric SiO2/polyimide prepreg composite with enhanced thermal, interfacial, and high-frequency properties for next-generation electronic packaging.


ABSTRACT
A low-dielectric prepreg composite was developed for high-frequency electronic packaging by combining a thermally stable, modified polyimide (PI) matrix with silane-functionalized SiO2 fillers. A radical crosslinking network was constructed using dicumyl peroxide (DCP) as the initiator and triallyl cyanurate (TAC) as the multifunctional crosslinker, enabling covalent interfacial bonding and three-dimensional network formation. FT-IR and DSC analyses confirmed the disappearance of maleimide and allyl double bonds and the formation of SiOSi bonds, indicating complete curing and interfacial reactions. Thermomechanical analysis showed that the SiO2-filled composite exhibited a 30%–35% reduction in thermal expansion coefficient compared to the unfilled sample. A 90° peel test revealed over 30% enhancement in interfacial adhesion due to silane-induced chemical bonding. Dielectric measurements at 10 GHz demonstrated a significantly improved dielectric constant (2.1) and dissipation factor (0.0022) relative to the control. S-parameter analysis further confirmed reduced signal loss and enhanced signal integrity, with return loss below −35 dB and insertion loss near −2.0 dB. These results validate the effectiveness of the proposed PI/SiO2 composite as a multifunctional material platform for next-generation high-speed I/O and RF packaging applications.