Patent ID: 7847417

Claim:
A flip-chip mounting method for flip-chip mounting an electronic element on which an Au bump is provided, the flip-chip mounting method comprising: providing a flip-chip mounting substrate, comprising: a substrate main body, a connecting pad provided on the substrate main body and to which the Au bump provided on the electronic element is flip-chip bonded, and a solder resist on the substrate main body, the solder resist having an opening portion for exposing the connecting pad, wherein an edge portion of the opening portion is partially overlapped with an outer peripheral portion of the connecting pad; providing an electrically conductive bonding material on the connecting pad which is exposed from the opening portion formed in the solder resist of the flip-chip mounting substrate; bonding the Au bump and the connecting pad with the bonding material so that the bonding material secures and electrically connects the Au bump and the connecting pad together and the electronic element is mounted on the flip-chip mounting substrate, said bonding material and bump cooperating to fill the opening portion in the solder resist and cover a surface of the connecting pad; and filling a gap between the electronic element and the flip-chip mounting substrate with an underfill resin while the bump and bonding material cooperate to prevent the underfill resin from flowing into the opening portion.