| 摘要 |
PURPOSE:To perform stable wire bonding by a method wherein fed length of a wire is detected to obtain size of gap between the wire and a spark electrode, and a mechanism to make a spark voltage to be changed according to size thereof is added. CONSTITUTION:Varied quantity of fed length of the wire in relation to the reference point of the wire 4 is obtained by detecting variation of the black level on the phot detecting part 10 of an element 7 of charge coupled device (CCD) using a CCD camera 8 consisting of an optical lens 6, a CCD one dimentional sensor 7, and a signal output circuit. Control of the spark voltage is performed according to a detected signal d obtained by this way. Accordingly a ball having the fixed diameter can be formed at the tip part of wire irrelevant to size of gap, and stable bonding can be performed. |
