| 摘要 |
PROBLEM TO BE SOLVED: To make an IC chip mountable on an accurate position by preventing the occurrence of positional deviations between a bump formed on an electrode of the IC chip and having a sharpened front end and an electrode of a circuit board immediately after ultrasonic vibrations are imparted to the bump, and, at the same time, to improve the junction reliability between the bump and the electrode of the circuit board, by increasing the diffusion joining area between the bump and the electrode of the circuit board at the time of ultrasonic flip chip mounting the bump on the electrode of the circuit board. SOLUTION: The pressure applied to the bump for pressing the bump against the electrode of the circuit board is increased as time elapses and, in addition, the ultrasonic energy applied to the junction between the bump and electrode is increased after the energy is reduced in the initial stage of juncture. The ultrasonic energy can be increased and decreased by changing the amplitude of the energy. The ultrasonic energy applied to the junction can be changed continuously from 0% to 100% or can be changed to increase in steps. In addition, the energy can be increased gradually throughout a period from an initial stage to the end of the juncture or can be fixed after the energy is increased only during a fixed period of time in the initial stage. COPYRIGHT: (C)2003,JPO
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