Disk device

A disk device comprising:

• a first flexible printed circuit board including
• a first insulating layer,
• a second insulating layer covering the first insulating layer,
• a first conductive layer between the first insulating layer and the second insulating layer, the first conductive layer being provided with a plurality of first terminals, the second insulating layer being provided with a plurality of holes through which the plurality of first terminals is exposed;
• and
• a plurality of second flexible printed circuit boards each of which has a magnetic head mounted thereon and includes:
• a first face facing the second insulating layer,
• a second face being opposite the first face, and
• a plurality of second terminals provided on the first face and joined to the plurality of first terminals, respectively, with a conductive bonding material,
• wherein
• the second face of at least one of the plurality of second flexible printed circuit boards includes a first area being lower in lightness than a part of the first flexible printed circuit board, the part where the first conductive layer is covered by the second insulating layer,
• each of the plurality of second flexible printed circuit boards includes a band extending in a first direction along the first face, and
• at least two of the plurality of second flexible printed circuit boards include the bands of different widths in a second direction along the first face and orthogonal to the first direction.

A disk device comprising:

• a first flexible printed circuit board including
• a first insulating layer,
• a second insulating layer covering the first insulating layer,
• a first conductive layer between the first insulating layer and the second insulating layer, the first conductive layer being provided with a plurality of first terminals, the second insulating layer being provided with a plurality of holes through which the plurality of first terminals is exposed;
• and
• a plurality of second flexible printed circuit boards each of which has a magnetic head mounted thereon and includes:
• a first face facing the second insulating layer,
• a second face being opposite the first face, and
• a plurality of second terminals provided on the first face and joined to the plurality of first terminals, respectively, with a conductive bonding material
• wherein
• the second face of at least one of the plurality of second flexible printed circuit boards includes a first area being lower in lightness than a part of the first flexible printed circuit board, the part where the first conductive layer is covered by the second insulating layer,
• the first flexible printed circuit board includes a second conductive layer,
• the first insulating layer is interposed between the first conductive layer and the second conductive layer, and
• the first area is lower in lightness than a part of the first flexible printed circuit board, the part where the second conductive layer is covered by the first insulating layer and the second insulating layer.