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AssigneeNippon Mining & Metals Co., Ltd.
InventorsYasuo Tomioka, Tetsuo Maki, Naohiko Era
Estimating the term…
Conductors, which are formed on a suspension member of the hard-disc drive suspension, are subject to thermal expansion and shrinkage during the laminating process with a substrate via a polyimide binder. The tracking width of the suspension member is influenced by the thermal expansion and shrinkage. In order to provide a copper-alloy foil, which can attain improved tracking width, the following ratio of thermal expansion and shrinkage is adjusted in a range of from −0.1 to +0.1% Δ(%)=(l−l0)/l0×100 where l0 the length of a specimen before heating at 330° C. for 2 hours, and l is the length of a specimen after heating at 330° C. for 2 hours. Δ(%) is measured in the direction parallel to the rolling direction.
A copper-alloy foil to be used for a suspension member of a hard-disc drive, consisting, by mass percentage, of from 1 to 4.8% of Ni, from 0.2 to 1.4% of Si, a ratio of Ni content relative to Si content being adjusted to 2 to 8, a balance being essentially copper and unavoidable impurities, having 650 MPa or more of tensile strength, and including inclusions not exceeding 10 μm in size and fifty or less inclusions from 5 to 10 μm in size per mm2 of a cross section of the foil in a direction parallel to a rolling direction, and exhibiting from −0.1 to +0.1% of a following ratio of thermal expansion and shrinkage measured in the direction parallel to the rolling direction and occurring prior and subsequent to heating at 330° C. for 2 hours, corresponding to a heating condition to which the foil is subjected to thermal pressure bonding with polyimide,
A copper-alloy foil to be used for a suspension member of a hard-disc drive, consisting, by mass percentage, of from 1 to 4.8% of Ni, form 0.2 to 1.4% of Si, from 0.005 to 2%, in total, of at least one element selected from the group consisting of Mg, Zn, Sn, Fe, Ti, Zr, Cr, Al, Mn, Ag and Be, a ratio of Ni content relative to Si content being adjusted to 2 to 8, a balance being essentially copper and unavoidable impurities, having 650 MPa or more of tensile strength, and including inclusions not exceeding 10 μm in size and fifty or less inclusions from 5 to 10 mm in size per mm2 of a cross section of the foil in a direction parallel to a rolling direction, and exhibiting from −0.1 to +0.1% of a following ratio of thermal expansion and shrinkage measured in the direction parallel to the rolling direction and occurring prior and subsequent to heating at 330° C. for 2 hours, corresponding to a heating condition, to which the foil is subjected to thermal pressure bonding with polyimide,
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