Patent ID: 7951701

Claim:
A method of manufacturing a semiconductor device, comprising the steps of: preparing a semiconductor chip including: a first pad, and a first solder alloy being provided over the first pad and not including Pb; preparing a package substrate including: a second pad being provided over a first surface of the package substrate, and a second solder alloy being provided over the second pad and not including Pb; melting and joining the first and second solder alloys to form a solder bump; providing an under-filling resin between the semiconductor chip and the package substrate; and forming a solder ball on a second surface of the package substrate, which is opposite to the first surface, the solder ball having an elastic modulus larger than those of the first and second solder alloys before the solder ball is physically connected to another substrate, wherein both of the solder ball and the solder bump have Ag, Cu, and Sn, and a mass ratio of Ag in the solder bump is lower than that in the solder ball.