JPS5864615A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To improve the reliability of polishing position detection by forming a resistance detecting electrode for detecting a short circuit of a circuit of >=2 kinds of different metallic materials. CONSTITUTION:The short-circuit detection part 71 of a resistance detecting electrode is formed of Al to a 0.5mum film thickness, and the open detection part 72 is formed of permalloy to a 0.1mum film thickness. The resistance detecting electrode is arranged as a substitute for a resistance detecting electrode 23 used on both sides of the conductor coil 22 of a thin-film magnetic head. The short detection part 71 is formed of soft Al, so a short-circuit due to a burr and a shear drop during polishing is never generated; and the open detection part 72 is formed of hard ''Permalloy '' and is thin, so neither burrs nor shear drops are generted, so that an open circuit and a short circuit at a polishing stop position X are detected by resistance detectors 27 and 27', respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thin film magnetic head. The present invention relates to improvements in polishing electrodes, particularly in relation to the depth polishing process during the manufacturing process of thin-film magnetic heads.

A conventional polishing method for the above-mentioned polishing process is to use a thin JIa magnetic head 14 formed by laminating a lower magnetic layer 11, a conductive coil 12, and an upper magnetic layer as shown in FIG. 111J power distribution &
It is known that a tube with a collapsed dimension is obtained by detecting that the tube is cut at one time.

However, as shown in Figure 1, the lower part of the film magnetic head #+

2 - The magnetic layer 1141 is made as a common magnetic layer for all channels in order to avoid complication of the manufacturing process. Furthermore, since the conductive magnetic layer 11 is usually made of a conductive material such as permalloy or sendust, the polishing electrode 15 and the conductive magnetic layer may be short-circuited during polishing due to flashing or wobbling in the above method. There is a drawback that the electrodes are cut off and the nine positions cannot be detected accurately.

As a method for solving the above-mentioned drawbacks, a polishing method that actively utilizes the short-circuit phenomenon has been proposed. This is the second
To explain with reference to Figs. 2 and 3, Figs.
The figure shows a thin film magnetic head composed of an upper magnetic body 21, a conductor coil 22, an insulating layer 24 such as a resistance detection electrode 23.8I01, a conductor layer (lower magnetic layer) 25, and a substrate 26, and the resistance detection Resistance detection devices 27 and 27' are connected between the electrode 23 and the conductor layer 25, and the output 28
is an input to an equilibrium detection device 81, which will be described later. Note that FIG. 3 is a sectional view taken along the YY/Iwao line in FIG. 2.

Further, the Kenmaro target position is indicated by the X-X/edge in FIG. 2, and is set so that one end of the page 3 resistance detection electrode 23 is above and east of the X-Xt edge line.

With this configuration, the polishing stop position X-XI
Since the short-circuit between the resistance detection electrodes 2 and 3 and the conductor layer 25 can be detected by the resistance detection devices 27 and 27', the problem of small drips at the base of the polishing plate has been significantly improved.

On the other hand, during polishing, since the polishing surface has an inclination, the inclination must be detected and the angle corrected. For this purpose, it is necessary to detect the polishing state several times during polishing, and the present inventors proposed a resistance detection electrode having a shape that allows position detection multiple times as shown in FIG.

However, since the resistance detection electrode shown in FIG. 4 is made of soft metals such as M, Cu, and Au that are likely to cause short-circuit phenomena, the line width of the open detection section 43 is made extremely narrower than that of the short-circuit detection section 42, and the thickness is reduced. However, it has the disadvantage of low reliability due to the possibility of staining or sagging.In addition, numeral 41 in FIG. 4 indicates a resistance detection electrode.

The present invention has been developed to eliminate such drawbacks.
64615 (2) In a thin film magnetic head having a resistance detection electrode for detecting a short circuit in a circuit through an insulating layer, the resistance detection electrode is formed of two or more different metals. The thin-film magnetic head is characterized by improving the reliability of polishing position detection by forming the open detection part and the short detection part of the resistance detection electrode from different metals.

Specifically, in the present invention, the resistance detection electrode has a two-layer structure of a short detection part and an open detection part, and the short detection part is A.
j! , Cu, Au, and other soft metals to easily cause short circuits, and the open detection part is
It is characterized by improving the reliability of position detection of the resistance detection electrode by preventing short-circuits by forming it with a hard material such as + or Cr permalloy.

An embodiment of the present invention will be described in detail below with reference to FIGS. 5 to 8.

Figure 5 is a shape diagram of resistance detection 11&, Figure 6 is its z
- It is a sectional view along a z' edge. The lengths of a, y, c, d, e, and f in FIG.
m.

d = 25um, e = 25um, f rm l
The short detection part 71 is M and has a film thickness Q, 5
The open detection portion 72 was formed of permalloy with a film thickness of Q and lum.

If such a two-layered resistance detection electrode is used in place of the resistance detection electrode 23 shown in FIG.
The short detection section 71 is located between A and B and between C and D in the figure.
Since the short-circuit detection part between the and the conductor layer (lower magnetic layer) is formed of soft M, short-circuits may occur due to cracks or sag due to polishing, and the open detection part 72 between B-C and D-X. Since the film is made of hard permalloy and has a thin film thickness, it opens without any cracks or sagging, but at the polishing stop position X, a short circuit is detected again by the resistance detection devices 27 and 27' as shown in Figure 7. be done.

FIG. 8 is a schematic diagram of the Kenmaro device, which includes resistance detection devices 27 and 27', balance detection device 81, angle correction device 82, pressure device 83, thin film magnetic head 84, drive motor 85, belt 86, and grindstone 87. configured.

With such a configuration, the thin film magnetic head 84 is connected to the grinding wheel 8.
The thin film magnetic head 84 can be polished by driving the grinding wheel 87 via a belt 86 with a driving motor 85 while applying appropriate pressure in the direction of the arrow 20 using a pressure device 83.

Therefore, if the resistance detection electrode shown in FIG. 5 is used in place of the resistance detection electrode 23 shown in FIG.
7 and 27', it is detected that the polishing has been balanced, and the pressure of the pressure device 83 in the direction of the arrow 20 is released, and the drive motor 85 is stopped to complete the polishing. If the resistance detection devices 27 and 27/detection outputs do not match, the balance detection device 81 detects the unbalanced state and corrects the angle of the thin film magnetic head 120 using the angle correction device 82 until the detection outputs of both match. When the target position X -X/ is reached, press arrow 2 of the pressure device
The pressure in the 0 direction is released and the drive motor 85 is stopped to complete the polishing.

Therefore, since the thin film magnetic head having the X-pole for resistance detection as described above can correct the angle during polishing, it is possible to balance the tip of the thin film magnetic head very accurately.

In the above embodiment, the short detection section 71 is made of Al and the open detection section 72 is made of permalloy, but this is not necessarily the case; the short detection section 71 is made of Cu or Au.

The open detection part 72 is made of a soft metal such as Ti.

A similar result can be obtained even if it is made of a hard metal such as Cr.

As described above, according to the present invention, when polishing a thin film magnetic head to a predetermined position, the short detection section is
By providing a resistance detection electrode made of a relatively soft metal such as u, Au, etc., and the open detection part made of a relatively hard metal such as permalloy, Ti, or Cr, gap depth processing can be easily performed. It is possible to provide a thin-layer magnetic head having the same characteristics as mass-produced.

[Brief explanation of drawings]

2 and 2 are plan views, FIG. 3 is a sectional view taken along line Y--Y' in FIG. 2, and FIG. 4 is a shape diagram of a conventional resistance detection electrode. Further, FIGS. 5 to 8 show embodiments of the present invention, and FIG. 5 shows the shape of the resistance detection electrode, and FIG. 6 shows the shape of the resistance detection electrode.
7 is a graph showing the change in resistance with respect to the amount of polishing between the resistance detection electrode and the conductor layer (lower magnetic layer), and FIG. 8 is a schematic diagram of the polishing apparatus. 23... Resistance detection electrode, 24... Insulating layer, 25...
...Conductor layer. Agent Patent Attorney Tadashi Akimoto Figure 1 Figure 2 Figure 93 Figure 3 Figure 4 jI5 times

Claims (1)

[Claims] The circuit board is connected via an insulating layer above or below the conductor layer.
What is claimed is: 1. A thin film magnetic head having a rounded resistance detection electrode for detecting resistance, characterized in that the resistance detection electrode is formed of two or more different types of gold maple.