1. Field of the Invention
This invention relates in general to magnetic heads and, more particularly, to a thin film magnetic write head.
2. Description of the Prior Art
Thin film magnetic heads are used extensively in data storage devices such as disk drives. One thin film magnetic head design is shown in commonly assigned U.S. Pat. No. 4,878,290. U.S. Pat. No. 5,255,142 also describes a similar thin film magnetic head design. The thin film magnetic heads 2 of this type (see FIG. 1) comprise a magnetic yoke 3 which includes two magnetic layers which are in contact in the back gap region 4, are spaced apart in the central region, and spaced apart a small distance in the pole tip region 5 to form a transducing gap. The magnetic yoke 3 is energized by a flat coil 6 deposited in the space between the two magnetic layers in the central region. The magnetic yoke layers have a substantially constant width in the pole tip region which extends to a flare point 7 at which point the width of the magnetic yoke layers becomes progressively greater and this wider area extends to the back gap region 4.
Thin film magnetic heads of this type have been successfully used in many applications over a period of years. However, in this type of head the gap field continues to increase with increasing write current which makes it unsuitable for some applications which require the write field to be constant for an extended range of write currents.