1. Field of the Invention
The present invention relates to a method of manufacturing magnetic head slider, and in particular, to a method of manufacturing magnetic head slider formed by cutting out from a block member and applied with surface processing.
2. Related Art
A magnetic head slider used for a hard disk drive is required to fly at a low amplitude above a magnetic disk with high accuracy. To achieve this, an ABS ((Air Bearing Surface) flying surface) in a predetermined shape must be formed on the surface facing the magnetic disk, and this surface must be processed by polishing (lapping) with high accuracy. At the same time, in polishing, the MR height (element length from the ABS) of the magnetic head element exposed on the ABS would be adjusted so as to perform data reading and writing to the magnetic disk. Since the MR height affects the accuracy of reading and writing performance to the magnetic disk, highly accurate adjustment is needed.
For these reasons, polishing of an ABS is an important step when processing a magnetic head slider. Further, the surface opposite to the ABS (back surface) is to be mounted on a suspension constituting a Head Gimbal Assembly (HGA), which affects the flying height above the magnetic disk. Therefore, highly accurate polishing is also required for the back surface.
Conventional method of manufacturing a magnetic head slider includes polishing of ABS and its back surface. First, a bar block, in which magnetic head sliders are aligned in a row, is cut out from a wafer where magnetic head elements of a plurality of magnetic head sliders are formed. Then, in a state where the back surface side with respect to the ABS is fixed to a predetermined jig, the ABS is polished. Next, the back surface is polished with the polished ABS side fixed to a predetermined jig. Then, pattern is formed through steps of etching the ABS, the bar block would then be cut into pieces of magnetic head sliders and the like, whereby a magnetic head slider is manufactured.
However, as hard disk drive has size reduction recently, the size of a magnetic head slider itself has been further miniaturized. Therefore, in the manufacturing process, handling such as fixing a member in a bar-block shape to a jig or the like is getting more difficult. In particular, direct handling of the minute and elongated fragile bar block would induce considerable damages to the magnetic head slider.
In view of the above, there are disclosed methods in which polishing of an ABS is performed before cutting into a bar block, and then cutting into a bar block shape, as shown in the following patent documents. Explanation will be given for these methods.
In a method disclosed in the publication of Japanese Patent Application Laid-open No. 11-316928 (Patent Document 1), first, a wafer block in which magnetic head sliders are aligned in a plurality of rows, that is, a wafer block consisting of plural rows of bar blocks, is cut out, and is mounted on a support plate. Next, ABS of magnetic head sliders positioned at the edge thereof is polished. Then, a tape is used so as to cover the polished ABS, and the bar block is cut out from the wafer block in such a state. Then, the bar block is held with vacuum tweezer and mounted on a jig for polishing the back surface, and the back surface is polished.
Similarly, in a method disclosed in the publication of Japanese Patent Document Laid-open No. 11-328642 (Patent Document 2), first, ABS is polished in a state of a wafer block, and then a bar block is cut out. Then, the bar block is adhered to a work holder with the ABS being the adhered surface, and the back surface is polished.
[Patent Document 1] JP11-316928A
[Patent Document 2] JP11-328642A
However, the conventional examples described above involve the following disadvantages. For instance, in either method, polishing of ABS is performed in a wafer block shape. In such method, although stable polishing of ABS can be realized, magnetic head sliders manufactured from an elongated fragile bar block may be damaged since the bar block is handled directly when the back surface is polished after cutting into a bar block.
More specifically, in Patent Document 1, polished ABS is covered with a taper but since it is mounted on a jig for processing the back surface by vacuum tweezer, it may be damaged or broken at that time. Further, a work to mount it on the jig is caused in the process. In Patent Document 2, on the other hand, polished ABS is adhered to a work holder so as to be protected, but it may be damaged when being adhered to the work holder, and also a work to mount it on the jig is caused in the process, similar to the above-described case. As mentioned above, in manufacturing electronic components required high product accuracy, problems of complication and delay of the manufacturing process are caused, in addition to the product quality's deteriorating. Moreover, an increase in the manufacturing cost is also a problem.