摘要 |
The invention relates to a method for forming bump electrodes on an electronic part such as a chip or a substrate. Conventional methods for forming bump electrode had a factor causing high cost, but with the invention, instead of solder balls, low cost solder wires are used, that is, solder wires are cut in a predetermined length, the cut solder wires are vacuum-attracted to the lower face of a pick up head and transferred onto a chip, then the solder pieces transferred are heated to melt, then cooled to solidify and results in forming bump electrodes of hemisphere shape.
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