The increasing power densities in advanced microelectronics and power electronics impose thermomechanical and dielectric constraints that exceed the performance limits of conventional polymeric printed circuit board (PCB) substrates. Monolithic silicate glasses offer superior dimensional stability and chemical inertness, yet their application is limited by intrinsic brittleness and poor solder wettability. This study bridges the materials gap through the development of a borosilicate glass-hexagonal boron nitride (hBN) nanocomposite architecture. The dispersion of exfoliated two-dimensional (2D) hBN nanosheets within the amorphous matrix yields a multifunctional optimization of performance parameters driven by the unique physicochemical properties of the sp2-hybridized filler. Nanomechanical characterization reveals a fundamental transition from catastrophic brittle cleavage to a defect-tolerant fracture regime; the 1.0 wt % composite exhibits a 3-fold amplification in fracture toughness (KIC), rising from 0.82 to 1.45 MPa·m1/2 via crack deflection and platelet bridging mechanisms. This reinforcement is accompanied by a 13% increase in elastic stiffness (Er ≈ 74 GPa), governed by efficient load transfer to the rigid B–N lattice. Electronically, the hybrid structure demonstrates superior insulation performance, achieving a 100% improvement in DC dielectric breakdown strength (9.2 to 18.4 MV/m) through the suppression of Townsend electron avalanches and enhanced electrical treeing tortuosity. Importantly, the low-polarizability hBN phase reduces the bulk dielectric constant (εr) from 3.83 in the pristine glass to 3.02 in the composite, directly mitigating signal propagation latency and capacitive coupling. Surface chemical analysis further confirms a favorable remodeling of interfacial energetics, evidenced by increased moisture resistance (water contact angle shifting from <10° to ∼83°) and enhanced solderability (Pb60Sn40 contact angle reducing from ∼144° to ∼91.5°). These synergistic improvements establish glass-hBN nanocomposites as a promising platform for next-generation wide-bandgap power electronics and high-frequency packaging.
Geesala et al. (Sat,) studied this question.