Patent ID: 7903370

Claim:
A thin-film magnetic head comprising: an electromagnetic coil element for writing data including a coil layer which generates a magnetic field by current flowing through the coil layer and a coil-insulating layer which surrounds the coil layer; and an overcoat layer which covers the electromagnetic coil element, a width in a track-width direction of the coil-insulating layer being larger than a width that is a minimum width needed to insulate the whole coil layer, and being at least 46 μm, a length in a direction perpendicular to the track-width direction of the coil-insulating layer being larger than a length that is a minimum length needed to insulate the whole coil layer, and being at least 75 μm, a heat expansion coefficient of the coil-insulating layer being larger than or equal to 30×10 −6 /K, a Young's modulus of the coil-insulating layer being larger than or equal to 1 GPa and smaller than or equal to 4 GPa, and the length of the coil-insulating layer is greater than the width of the coil-insulating layer.