Improving the insulating performance of epoxy resin in humid environments byHTPDMSmodification

Abstract The rapid development of the electronic packaging industry imposes stringent requirements on epoxy resin insulation materials for lower water absorption and higher insulation properties. Here, hydroxy‐terminated polydimethylsiloxane (HTPDMS) was grafted on the molecular chain of the epoxy resin for enhanced waterproof and insulating properties of the epoxy resin. The HTPDMS‐modified epoxy resin specimens were prepared and subjected to water absorption and water absorption insulation performance tests. The experimental results indicated that the water absorption rate of the modified epoxy resin was reduced by 34.2%, resulting in a 25.2% reduction of the dielectric loss, an 11.6% increase of the breakdown strength, and a 98.3% increase of the volume resistivity. The satisfactory performance of the HTPDMS‐modified epoxy resin insulation material is attributed to the low surface energy and flexible SiO bond of the introduced HTPDMS. Simultaneously, the reduction of surface defects is also conducive to the epoxy resin insulation performance. Thus, HTPDMS‐modified epoxy resin insulation materials can maintain excellent insulation properties in humid environments, making them a promising application in the field of electronic packaging.