Patent ID: 6913945

Claim:
A method of mounting a chip by bonding bumps formed on at least one of the chip and a substrate to electrodes formed on the other while interposing a thermosetting underfill agent between the chip and the substrate, said method comprising the steps of: preparing an adhesive as said underfill agent, said adhesive having a first viscosity at a room temperature capable of holding its self shape exhibited when said adhesive is applied, the viscosity of said adhesive being decreased from said first viscosity to a second viscosity accompanying with heating and being maintained substantially at said second viscosity within a predetermined specified temperature range, the viscosity of said adhesive being increased from said second viscosity after a specified time is expired in said specified temperature range and said adhesive being cured accompanying with the increase of the viscosity; applying said underfill agent onto at least one of said substrate and said chip; press-contacting said bumps to said electrodes by approaching and pressing said chip to said substrate while spreading said underfill agent around the bumps and electrodes press-contacted to each other between said chip and said substrate; melting said bumps by heating at a state where said bumps are embedded in said underfill agent to bond the molten bumps to said electrodes; and wet-spreading the molten bumps before said underfill agent is cured.