Magnetic heads having write coil structures with reduced electrical
resistances for reducing thermal protrusion are disclosed. In one
illustrative example, a magnetic head includes a magnetic yoke; a write
gap layer formed between upper and lower poles of the magnetic yoke; and
a write coil having a plurality of coil layers. Each coil layer of the
write coil extends continuously between the upper and the lower poles
through a plane defined by the write gap layer. Preferably, the write
coil is formed using a damascene process, such that each coil layer is
wider than each coil separating layer. Such a structure provides for a
relatively large amount of coil materials to be used, which reduces the
coil's electrical resistance. This, in turn, reduces the heat generated
by the write coils during operation. Further, either one or both of the
lower and upper poles may include a horizontally laminated structure of
alternating magnetic and non-magnetic dielectric layers to further reduce
heating caused by eddy current losses. Since thermal protrusion is
reduced, the fly height of magnetic head may be made relatively small
with a reduced risk of head-to-disk crashes and disk scratches.