BONDING METHOD TO FLIP CHIP SUBSTRATE

摘要

PURPOSE: To provide a bonding method for positioning a flip chip accurately on a board and bonding it correctly. CONSTITUTION: A flip chip 20 is mounted on a board 22. The flip chip 20 has an active face with a conductive bump. The active face thereof is turned to the face of the board 22 and put on the board 22 in a way that the bump of the flip chip 20 is made in accordance with a bonding pattern of the board 22. An ultrasonic horn 30 is moved down and a flat face thereof is put on the rear face of the flip chip 20. Force is applied by the ultrasonic horn 30 to the rear face of the flip chip 20. The force is applied vertically to the board 22 in a way that sidewise dislocation between the flip chip 2O and the board 22 is made a minimum. During the application of force, the ultrasonic horn 30 is operated so that the ultrasonic energy is transmitted from the flip chip 20 to the board 22 isothermally and the flip chip 20 and the board 22 are subjected to diffusion bonding.