Magnetic head, head suspension assembly and magnetic disk apparatus

#The present invention relates to a magnetic head, and a head suspension assembly and a magnetic disk apparatus which use the magnetic head.

#With the trend to a larger capacity and a smaller size of hard disk drives (HDD), heads are required to have a higher sensitivity and a larger output. To meet these requirements, strenuous efforts have been made to improve the characteristics of GMR heads (Giant Magneto-Resistive Head) currently available on the market. On the other hand, intense development is under way for a tunnel magneto-resistive head (TMR head) which can be expected to have a resistance changing ratio twice or more higher than the GMR head.

#Generally, the GMR head differs from the TMR head in the head structure due to a difference in a direction in which a sense current is fed. A head structure adapted to feed a sense current in parallel with a film surface, as in a general GMR head, is referred to as a CIP (Current In Plane) structure, while a head structure adapted to feed a sense current perpendicularly to a film surface, as in the TMR head, is referred to as a CPP (Current Perpendicular to Plane) structure. Since the CPP structure can use a magnetic shield itself as an electrode, it is essentially free from short-circuiting between the magnetic shield and a device (defective insulation) which is a serious problem in reducing a lead gap in the CIP structure. For this reason, the CPP structure is significantly advantageous in providing a higher recording density.

#FIG. 1 is a general perspective view schematically illustrating a magnetic head according to a first embodiment of the present invention;

#FIG. 2 is an enlarged cross-sectional view schematically illustrating a portion of a TMR device and an inductive magnetic transducing device in the magnetic head illustrated in FIG. 1;

#FIG. 3 is a general sectional view taken along a line A-A′ indicated by arrows in FIG. 2;

#In the following, a magnetic head, and a head suspension assembly and a magnetic disk apparatus using the magneto-resistive device according to the present invention will be described with reference to the accompanying drawings.

#First, a magnetic head according to a first embodiment of the present invention will be described with reference FIGS. 1 to 5.

#FIG. 1 is a general perspective view schematically illustrating the magnetic head according to the first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view schematically illustrating a portion of a TMR device 2 and an inductive magnetic transducing device 3 in the magnetic head illustrated in FIG. 1. FIG. 3 is a general sectional view taken along a line A-A′ indicated by arrows in FIG. 2. FIG. 4 is a further enlarged view illustrating around the TMR device 2 in FIG. 2. FIG. 5 is a further enlarged view around the TMR device 2 in FIG. 3. For facilitating the understanding, an X-axis, a Y-axis and a Z-axis, orthogonal to one another, are defined as shown in FIGS. 1 to 5 (the same applies to figures later described). The Z-axis direction indicated by the arrow is referred to as the “+Z-direction” or “+Z-side,” and the opposite direction is referred to as the “−Z-direction” or “−Z-side.” The same is applied to the X-axis direction and Y-axis direction. The X-axis direction is the same as a direction in which a magnetic recording medium is moved. The Z-axis direction is the same as a track width direction of the TMR device 2.