| 摘要 |
PROBLEM TO BE SOLVED: To suppress degradation of the die bonding property and the wire bonding property caused by the punching by providing a groove of the prescribed depth corresponding to the prescribed thickness in a stripper plate or a die plate to maintain the plate surface condition similar to the condition immediately after the plating. SOLUTION: Two grooves 11 are provided in a lower surface 10A of a striper plate 10. The grooves 11 are formed to the dimension of the Ag plating of a bar. Granules of the Ag plating are not squeezed because of the grooves for escaping the Ag plating during the press, and generation of the distortion in the bar is prevented. The depth of the grooves 11 is, for example, 5μm and the width is 5 mm, and the interval between the grooves is 20 mm. The grooves 11 are optimally worked with the depth of +0-+5μm to the thickness of the Ag plating. Similar grooves may be formed in the die plate. Because only the plate part is not firmly pressed, no local distortion is generated in the bar, and the product after punching becomes flat.
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