Mitsui Chemicals, Inc.

Naoki Nakazawa

Minehiro Mori

Koji Hirota

Masanao Kobayashi

The present invention relates to a metal laminate which is broadly used for a flexible wiring board or the like and an etching method therefor. In particular, the present invention relates to a metal laminate which includes a layer obtained by laminating a metal layer and an insulating layer, where the insulating layer is subjected to an etching process, wherein, in a surface of the metal layer which is positioned so as to come in contact with the insulating layer, respective concentrations of main metal element and oxygen element constituting the metal layer are measured from the surface of the metal layer towards inside of the metal layer in a time-elapsing manner according to AES (Auger electron spectroscopy) and a value of the thickness of a metal oxide film of the surface of the metal layer measured at a time when atomic concentrations of the main metal element and the oxygen element constituting the metal layer become equal to each other is in a range of at least 0 &#x212b; to less than 50 &#x212b;. According to the present invention, an etching time of polyimide in the polyimide metal laminate can be calculated and a flexure used for a suspension for a hard disc drive having a high productivity can be provided.

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Sodegaura, Japan

Naoki Nakazawa