| 摘要 |
The conductors, which are formed on a suspension member of the hard-disc drive suspension is subjected to thermal expansion and shrinkage during the laminating process with a substrate via polyimide binder 3. 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% <paragraph lvl="0"><in-line-formula>DELTA(%)=(l-l0)/l0x100 </in-line-formula>l0: the length of a specimen before heating at 330° C. for 2 hours, and l: the length of a specimen after heating at 330° C. for 2 hours. DELTA(%) is measured in the direction parallel to the rolling direction. Furthermore, the copper alloy foil consists of from 1 to 4.8% of Ni, from 0.2 to 1.4% of Si, the ratio of Ni content relative to the Si content being adjusted to 2 to8, the balance being essentially copper and unavoidable impurities. The tensile strength is 650 MPa or more. The inclusions do not exceeding 10 mum in size and fifty or less inclusions from 5 to 10 mum in size should be limited to fifty or less per mm2 of a cross section of the foil in the direction parallel to the rolling direction.
|
