| 摘要 |
PROBLEM TO BE SOLVED: To obtain a lead frame having an excellent resin adhesiveness and punchability by providing a layer of a specific intermetallic compound on the surface of a thin plate of an Fe-Ni alloy. SOLUTION: After an ingot is obtained by melting a raw material composed of an Fe-Ni alloy, a plate is manufactured by blooming, hot-rolling, and annealing the ingot at about 1,100 deg.C and the surface of the plate is ground. Then a thin plate is obtained by repeatedly cold rolling and annealing the plate. Then one surface of the thin plate is coated with an Sn plated layer having a thickness of about 1μm by electroplating the surface with Sn by using an electroplating Sn bath. Thereafter, an intermetallic compound composed of Fe5 Sn3 , Fe3 Sn2 , FeSn, and FeSn2 is generated by diffusion-annealing the thin plate coated with the Sn plated layer. Therefore, a lead frame material which is improved in resin adhesiveness and punchability can be obtained.
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