Fabrication of 3D Micron T‐Shaped SiC/Silicone Rubber Composites With Nonlinear Conductivity

Polymer‐based electronic packaging materials often suffer from surface charge accumulation and transient overvoltage, creating a need for advanced self‐adaptive dielectrics with nonlinear conductive properties. In this work, a switching DC/AC electric field‐induced self‐assembly method was developed to fabricate three‐dimensional micron T‐shaped silicon carbide/silicone rubber (T‐SiC) composite films with a low filler loading of 2 vol%. By utilizing an electrode–insulator–suspension–electrode system, the SiC fillers were directed to self‐assemble into a unique architecture comprising a SiC‐enriched upper surface connected by chain‐like structures across the film thickness. Electrical measurements demonstrated pronounced nonlinear conduction in the T‐SiC films, with resistance decreasing sharply under high electric fields. Under high‐voltage nanosecond pulses (3 kV, 100 ns), the T‐SiC films exhibited rapid surface charge dissipation, effectively preventing charge accumulation and suppressing voltage escalation. Furthermore, a nondestructive indirect technique combining scanning electron microscopy and image processing was developed to quantify micrometer‐scale surface charge distribution. The SiC‐enriched surface showed negligible charge buildup, whereas the SiC‐sparse surface exhibited localized accumulation. These findings highlight T‐SiC films as promising candidates for high‐reliability electronic packaging materials.