Patent ID: 7470996

Claim:
A packaging method comprising: providing a substrate that includes a primary bump formed on a surface of a pad, which is in turn formed on a dielectric layer on one side of the substrate, wherein the dielectric layer, the pad and the primary bump are placed adjacent to one another in this order along an imaginary line that is generally perpendicular to the plane of the substrate; the primary bump includes gold as a main component of the primary bump, and the pad includes aluminum as a main component of the pad; providing a semiconductor device that includes a secondary bump formed on one side of the semiconductor device, wherein a size of a distal end contact surface area of the primary bump is larger than a size of a distal end contact surface area of the secondary bump; positioning the substrate and the semiconductor device in such a manner that the distal end contact surface of the primary bump is opposed to and contacts the distal end contact surface of the secondary bump; and ultrasonically bonding the distal end contact surface of the primary bump and the distal end contact surface of the secondary bump together while the primary bump and the secondary bump are urged against each other and are thereby plastically deformed.