Patent ID: 9230937
Filing Date: 2016-01-05
CPC Classification: H01L

Claim Text:
1. A method for manufacturing a semiconductor device, comprising a step of bonding a copper wire to a pad disposed over the surface of a semiconductor chip, wherein the step of bonding the copper wire, comprises the steps of: (a) forming an initial ball formed of the copper wire at a tip part of a capillary; (b) landing the initial ball over the pad; (c) applying the initial ball with a load and an ultrasonic wave, and thereby deforming the initial ball to form a press-bonded ball, and electrically coupling the pad with the press-bonded ball; and (d) leading out the copper wire from the capillary, wherein the press-bonded ball has a first portion coupled with the pad, a second portion located over the first portion, and a third portion located over the second portion, and coupled with the copper wire led out in step (d), wherein, in step (c) and step (d), the initial ball is electrically coupled with the pad such that, in cross-sectional view, a thickness of the first portion of the press-bonded ball is 1.25 times or more the thickness of the second portion, the thickness of the first portion of the press-bonded ball is 2/9 or more of the diameter of the press-bonded ball, and the thickness of the third portion of the press-bonded ball is smaller than 1/6 of the diameter of the press-bonded ball, and wherein a divergence angle of an inner chamfer part of the capillary forming the second portion of the press-bonded ball is smaller than 90 degrees.