Reprocessable, Creep‐Resistant and Fully Biobased Thermosets for Power Semiconductor Packaging

ABSTRACT Amid rapid advances in third‐generation semiconductors and holistic life‐cycle management, thermoset‐based packaging materials are evolving toward high‐temperature resistance, eco‐friendliness, and reprocessability. However, beyond the pursuit of recyclable carbon, thermosets face a fundamental trade‐off between recyclability and high‐temperature reliability, which poses a significant challenge. Herein, we report a thermally activated mechanically constrained adaptive network, in which side‐group transesterification at nanodomain boundaries enables adaptive reorganization without disrupting the connectivity of the network. This reprocessable network (DHBEP/PF/AE), constructed by tetrafunctional epoxy/phenolic/active ester resins with 100% biomass content, achieves a high T g (181°C) and excellent high‐temperature creep resistance as high as 170°C. Critically, a reprocessable epoxy molding compound is fabricated based on DHBEP/PF/AE, which successfully packages SiC chips via TO‐247 method and passes moisture sensitivity level‐3 test. This work resolves the classic contradiction between recyclability and reliability of dynamic thermosets, providing a solution for the biomass‐based conversion and reuse of vast quantities of semiconductor packaging materials.