摘要 |
An initial ball forming method for wire bonding wire and wire bonding apparatus that uses: a capillary through which a wire is passed; a torch electrode made of a low-melting-point material that contains, for instance, tin; and a direct-current high voltage power supply. When the direct-current high voltage power supply is turned ON, a space discharge occurs between the tip end of the wire and the torch electrode, resulting in that the wire tip end melts and is formed into a ball and that the tin of the torch electrode is also heated to a high temperature and diffused into space, so that ionized plus tin ions are attracted to the tip end of the melted wire, thus causing tin to adhere to the surface of the ball-shaped tip end of the wire, and forming an initial ball that has a low-melting-point coating material adhered to its surface.
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