| 摘要 |
PURPOSE:To manufacture a lead frame with an aluminum film, which is less expensive and abounds in corrosion resistance and has excellent hermetic sealing properties, by specifying applied voltage to a substrate and relationship with the surface roughness of the coated surface of the substrate of a wire bonding section, etc. CONSTITUTION:Applied voltage B(KV) to a substrate and the surface roughness R(mum) of a lead frame substrate 2 are controlled simultaneously, thus improving the corrosion resistance of an Al film 6. The Al film formed through an ion plating method under the conditions of 0<=(B-C)<2>/R<=45; (in formula, C represents a constant determined by Al film thickness, the material of the substrate, the holding temperature of the substrate, an ionization method, the degree of vacuum and a film formation temperature, and takes a value to 0.0 from -2.0) has excellent corrosion resistance and resin sealing properties and also has superior productivity. Since there is trouble such as the lowering of productivity, it is preferable that applied voltage B(KV) to the substrate is kept within a range of -2.0<=B<=0. It is desirable that the surface roughness R(mum) of the substrate extends over 0.5 or less, but it is preferable that the surface roughness R(mum) of the substrate is kept within a range of 0.05<=R<=0.5. |
