High performance write head for 10 krpm HDD with high data rate recording up to 45 MB/s

Fundamental design considerations of the write head for a hard disk drive with a higher data transfer rate are described. With a shorter yoke, the eddy current damping can be suppressed effectively. The head inductance is also reduced by yoke length reduction so that the rise time of write current can be reduced. To reduce yoke length, we adopted a double layer coil, which enabled us to increase coil winding turns. With half yoke length and the coil turns increase, we successfully reduced the NLTS by about half. The FIB pole trimming at wafer level can make an appropriate pole shape for generating a highly efficient writing field.