Development of Molding Compounds Based on Epoxy Resin/Aromatic Amine/Benzoxazine for High‐Temperature Electronic Packaging Applications

Abstract Heat‐resistant molding of compounds is an indispensable part in encapsulating future electronic power devices. Herein, it is used for polyfunctional epoxy resin (EP) and diamine‐phenol benzoxazine (BOZ) as resin matrix, 4,4'‐diaminodiphenylmethane (DDM) as curing agent, and iron acetylacetonate (Fe(acac) 3 ) as curing accelerator, as well as inorganic fillers and other auxiliaries, to prepare heat‐resistant molding compounds. The curing behavior, processability and thermal performance of the EP/DDM/BOZ (EDB) resin blends containing different contents of DDM, BOZ, and Fe(acac) 3 are first systematically investigated. The EDB molding compounds (MC EDB ) with suitable BOZ content show good processability, and the molding process can be compatible with that of commercial epoxy molding compounds (EMC). With increasing the BOZ content, the glass transition temperature of cured MC EDB is greatly enhanced to a maximum of 261 °C determined by dynamic mechanical analyzer, owing to the hydrogen‐bond interaction generated after polymerization of BOZ increasing the rigidity of network chains. Moreover, the cured MC EDB also exhibits higher thermal decomposition stability, better high‐temperature (200 °C) mechanical properties, and lower water absorption compared to the cured EMC. After high‐temperature (200 °C) aging for 500 h, the cured MC EDB with suitable BOZ content still maintains outstanding performance. This study provides a promising strategy for preparing heat‐resistant electronic packaging molding compounds.