High-toughness, low-constant epoxy/α-ZrP layered composites for advanced antenna packaging

Antenna packaging, which is designed to protect electronic components and ensure long-term stability, often employs epoxy resin (EP) composites because high mechanical strength, low dielectric constant and ease of molding satisfy design requirements, yet the highly cross-linked molecular network which leads to poor fracture toughness. In this work, a lamellar aerogel scaffold with different exfoliation α-ZrP flakes was fabricated by the ultrasonic-assisted exfoliation and subsequent freeze-casting technique. An alternating-layered epoxy/α-ZrP composite was made by infiltrating epoxy resin into the aerogel scaffold. The layered epoxy/α-ZrP composite consists of 99 wt% epoxy, in contrast to the scaffold, which contains 1 wt% α-ZrP. It exhibits outstanding fracture toughness, 1.4 times that of neat epoxy, and demonstrates low dielectric constant due to the anisotropic α-ZrP aerogel scaffold, which can be used for antenna packaging. Further studies reveal the effect of exfoliation time on the dimensions and dispersion of α-ZrP flakes, as well as the mechanical properties of epoxy/α-ZrP composites. The crack propagation path and fracture morphology were observed by Optical Microscopy (OM) and Scanning Electron Microscopy (SEM), based on which the toughening mechanisms of epoxy/α-ZrP layered composites were discussed.