| abstract |
PURPOSE: To bond a lead to a pad arranged on a soft substrate by applying laser energy and ultrasonic energy in combination. n CONSTITUTION: A lead 16 is superposed on respective pads 14 arranged on a soft substrate 10. An X-Y stage 12 positions a lead and a pad to be bonded sequentially at a part directly under a bonding chip 22. When a lead 16 and a pad 14 are fitted tightly each other, the bonding chip 22 is fed with ultrasonic energy from a bonder 18 to reciprocate in the direction shown by an arrow 32, i.e., in parallel with an interface 15. In response to a signal being fed from a synchronization unit 28 to a laser 26, a laser pulse is introduced to the chip 22 through an optical fiber 24 simultaneously with application of ultrasonic energy and the forward end face 23 of the chip 22 is heated. Consequently, a gold plated copper lead 16 is bonded directly to a bare copper pad 14 on the soft substrate 10. n COPYRIGHT: (C)1991,JPO |