Patent ID: 6902101
Filing Date: 2005-06-07
Classification: B23K,H01L

Abstract:
1. A bump bonding method for forming a bump on an IC, comprising: forming a ball at a tip of a wire by melting the wire; moving the ball at a first speed before the ball abuts a pad portion on the IC, and then moving the ball at a second speed, slower than the first speed, until the ball abuts the pad portion; substantially linearly increasing, after the ball abuts the pad portion, a pressing pressure of the ball until the pressing pressure reaches a predetermined value; and forming a metal-to-metal joint by applying ultrasonic vibration while pressing the ball against the pad portion on the IC, and wherein the ultrasonic vibration is applied while the applied pressing pressure is maintained, when the pressing pressure reaches the predetermined value, wherein the ultrasonic vibration has a frequency in a range of 130 to 320 kHz.