Bondline thickness effect on fracture and cohesive zone model of sintered nano silver adhesive joints under end notched flexure tests

Bondline thickness effect on fracture behaviors and cohesive zone model (CZM) is an important topic for adhesive joints. In this paper, the fracture and CZM of sintered nano silver adhesive joints are investigated based on end notched flexure (ENF) test. Results show that load versus displacement curves of sintered silver adhesive joints is sensitive to the bondline thickness. With compliance-based beam method (CBBM), the shearing fracture toughness of sintered silver bonded joints heightens with the increase of bondline thickness, which indicates that shearing fracture toughness is highly dependent on bondline thickness. R curves increase steeply for short equivalent crack length and become plateau for long equivalent crack length. The cracking morphology shows that the cracking paths are mainly interfacial and interlayer types. The bilinear CZM is also presented. The bondline thickness effect on CZM parameter is presented and discussed. The CZM given in this paper can be adopted for reliability analysis in power devices.