| 摘要 |
<p>PURPOSE:To form a ball, which does not damage an silicon chip on joining, by a method wherein a metallic wire is used as the positive side and a discharge electrode as the negative side in an inert gas atmosphere, electricity is discharged between both the metallic wire and the discharge electrode, the ball is shaped at the tip section of the metallic wire and the metallic wire is employed as the negative side and the discharge electrode as the positive side on the latter period of discharge. CONSTITUTION:High voltage is applied between a copper wire 1 and a discharge electrode 2, using the copper wire as the positive side and the discharge electrode as the negative side. Consequently, discharge is generated between the tip section of the copper wire 1 and the discharge electrode 2 and an arc 3 is formed, only the tip section of the copper wire 1 is given heat and said tip section is melted, the melting section of the wire 1 is limited only to the tip section of the wire 1, and the volume of the melting section is increased gradually while a complete globular shape is kept. When the time t1 passes after voltage is applied and the latter period of discharge sets in, the copper wire 1 is employed as the negative side and the discharge electrode 2 as the positive side. Accordingly, the surface of a ball 18 is purified by the cleaning action of the arc 3 on the negative pole side, and the desired ball 18 is formed after the time t2 passes.</p> |
