JPS63261509A - Production of thin film magnetic head - Google Patents

Abstract

PURPOSE:To easily control the grinding value by utilizing a notched part of a prescribed pattern formed previously to a gap member layer forming a magnetic gap of a head in a stage where a rubbing surface is finished with grinding. CONSTITUTION:A gap member layer 3 is formed on a lower magnetic layer 2 provided on a substrate 1 for production of a magnetic gap. In this case, the layer 3 has a triangular notched part 3a in an area sandwiched between the layer 2 and an upper magnetic layer 6. A cutting work is carried out for each head chip and the rubbing surface of a magnetic recording medium is finished with grinding as a worked surface up to a finishing line X-X'. The grinding value of the rubbing surface is controlled by means of the part 3a. Thus it is possible to accurately control the grinding value of the rubbing surface and to obtain the highly accurate gap depth.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing an inductive thin film magnetic head for recording or reproducing information on a magnetic recording medium.

[Prior Art] In recent years, thin film magnetic heads have attracted attention as magnetic heads for high-density magnetic recording, and are used, for example, in floppy disk drive devices, still video devices, etc. that perform high-density recording.

FIG. 5 explains a conventional manufacturing method of such an inductive thin film magnetic head, and is a perspective view of a work-in-progress product in the process of manufacturing a thin film magnetic head.

In the manufacturing process of a conventional thin-film magnetic head, first, a lower magnetic layer 2 made of permalloy or sendust is formed into a predetermined shape by vapor deposition, sputtering, etc. on a substrate made of ferrite, glass, etc., shown by reference numeral 1 in FIG.

Next, on the lower magnetic layer 2 is made of a non-magnetic material such as 5IO2,
A gap material layer 3 constituting a ra% gap is formed.

Next, form the pattern of the electrode coil 4 consisting of Cu, A, etc. Next, cover the electrode coil 4 with S! After forming the insulating layer 5 made of 02 or the like, an upper magnetic layer 6 is further formed thereon. The upper magnetic layer 6 and the lower magnetic layer 2 face each other with the gap material layer 3 in between to form a magnetic circuit.

Next, in order to protect these element patterns, the substrate 1 is
A protective plate is pasted onto these patterns above with an insulating adhesive, and each chip of the head is cut out using a dicing saw or the like to form the shape shown in FIG. In FIG. 6, reference numeral 8 is the above-mentioned insulating adhesive, and reference numeral 9 is a protection plate.

Next, the upper surface of the chip in FIG. 6 is used as a sliding surface for the magnetic recording medium and is polished by lapping or the like to the finishing line indicated by cylinder number x-x' in FIG. 5 to give it a predetermined shape such as a spherical shape.

That is, the sliding surface is polished until the depth of the magnetic gap, so-called gap depth, becomes a predetermined value. In this way, the thin film magnetic head is completed.

By the way, various characteristics such as recording and reproducing efficiency of a thin film magnetic head are greatly influenced by the gap depth. And since the gap depth of a thin film magnetic head is very small, on the order of several μm,
The amount of polishing of the sliding surface of the magnetic recording medium, which determines the gap depth of the thin-film magnetic head, must be controlled with extremely high precision.

Therefore, conventionally, in order to control the amount of polishing S, a layer with a predetermined pattern called a polishing mark is arranged in line with the pattern of the magnetic circuit of the head, and when the sliding surface of the magnetic recording medium is polished, the polished surface is visually observed using a microscope. A method is adopted in which the gap depth is indirectly determined by ΔIII based on the presence or absence and size of the polishing mark, and the amount of polishing is managed.

For example, the polishing mark is formed as an inverted triangular pattern of metal 1, as shown by reference numeral 7 in FIG. can be managed.

[Problems to be Solved by the Invention] In particular, in thin-film magnetic heads used in high-density floppy disk drives and still video devices, the area of the sliding surface of the magnetic recording medium is extremely small in order to improve head touch. Be taken. However, if an attempt is made to reduce the area of the sliding surface, there is a problem that there is no space for providing the above-mentioned polishing marks.

In the case of a thin film magnetic head for still video equipment, two channels with a track width of 60 μm are arranged side by side at an interval of 40 gm, and these two channels are
Since the media is accommodated within an extremely narrow 300 #Lm square sliding surface, the space in which polishing marks can be placed during the manufacturing process is extremely narrow, with a width of 40 to 14 OJLma degrees.

As described above, in the conventional method, when attempting to reduce the area of the sliding surface of the magnetic recording medium of a thin film magnetic head, there is no space for providing polishing marks, which makes it difficult to control the amount of polishing.

Means for Solving Problem E] In order to solve these problems, the method for manufacturing a thin film magnetic head according to the present invention includes a step of polishing and finishing the sliding surface of the magnetic recording medium of the thin 115I magnetic head. However, in this process, a configuration was adopted in which the amount of polishing was controlled using cutouts in a predetermined pattern formed in advance in the gap material layer constituting the magnetic gap of the head.

[Function] According to this method, a predetermined pattern for controlling the amount of polishing is formed in the gap material layer, so that the upper magnetic layer and the lower magnetic layer constituting the magnetic circuit, where conventional polishing marks were not formed, are formed in the gap material layer. The gap material layer can be formed using the entire area of the gap material layer including the area sandwiched between the layers. In other words, a sufficient space can be secured for forming the above-mentioned predetermined pattern, and if the gap material layer is provided with a notch, there is no need to form a gap material layer separately from the part that will become the magnetic gap. 'The space required for the NF rub mark is no longer needed.

[Embodiments] Details of embodiments of the present invention will be described below with reference to FIGS. 1 to 4.

1 Retired Emperor 11 FIG. 1 explains a method for manufacturing a thin film magnetic head according to a first embodiment of the present invention, and shows a partially transparent view of the thin film magnetic head before the sliding surface of a magnetic recording medium is polished. It is shown in In this figure, parts common to those in FIGS. 5 and 6 of the conventional example are given the same reference numerals. In the following explanation of the manufacturing method of this embodiment, parts common to the conventional method will be briefly mentioned, and different parts will be explained in detail (the same applies to the second embodiment).

In the manufacturing process of the thin film magnetic head according to this embodiment, the first
A lower magnetic layer 2 is formed on a substrate 1 shown in the figure in the same manner as in the prior art.

Next, a gap material layer 3 constituting a magnetic gap is formed on the lower magnetic layer 2. Here, in this embodiment, the gap material layer 3 is formed in a shape having a triangular notch 3a in a region sandwiched between the lower magnetic layer 2 and the upper magnetic layer 6, as a difference from the conventional one.

Next, an electrode coil 4 is formed in the same manner as in the conventional method, an insulating layer 5 is formed covering it, and an upper magnetic layer 6 is further formed thereon.

Next, a protective plate 9 is pasted onto these patterns using an insulating adhesive 8.

Next, as in the case of the conventional example, cutting is performed for each head l chip, and then the surface on the near side in the pjS1 diagram is used as the processed surface of the sliding surface of the magnetic recording medium to the finishing line indicated by the symbol x-x''. Polish and finish this.

Here, in this embodiment, the difference from the conventional method is that the amount of polishing of the sliding surface is controlled by using the νJ notch 3a of the gap material layer, that is, as the sliding surface is polished, as shown in FIG.
) The width W of the notch 3a appearing on the surface of the polishing piece becomes smaller. If the position of the triangular apex of the notch 3a is rubbed on the x-x' line of the finishing line of the sliding surface or slightly in front of it, the polished surface will reach the finishing line or just below it. Width W of notch 3a just before
becomes O, and as shown in FIG. 2(B), the notch 3a
disappears. By doing so, it becomes possible to manage the amount of polishing by visually observing the width W of the notch portion 3a using a microscope during polishing.

By polishing in this manner, the sliding surface is finished with a thin layer 11, and the magnetic head is completed.

As described above, according to this embodiment, in order to control the amount of polishing of the sliding surface, the conventional polishing mark is not provided, but instead, the notch 3a is provided in the gap material layer 3, and this is utilized. The amount of polishing is controlled. The cutout portion 3a is located between the upper magnetic layer 6 and the lower magnetic layer F, which are not provided with conventional polishing marks.
Since it is provided in the area sandwiched by 92, a sufficient space for providing it can be secured. The space required for conventional polishing marks is no longer required, and the surface area of the sliding surface of the magnetic recording medium can be made smaller. According to this embodiment, the #F wear amount on the sliding surface can be accurately controlled by using the notch 3a, and the gap depth can be determined with high precision, which improves various characteristics of the thin-film magnetic head. Uniformity can be achieved.

Further, in this embodiment, the thickness of the gap material layer 3 is, for example, lpm.
The following is an extremely quotient〈, since the end surface is not an inclined surface,
Observation of the width W of the notch 3a has little reading error;
It has the advantage of being accurate.

As a modified example, in addition to the notch 3a, another type of polishing mark, such as a comb tooth-shaped polishing mark for controlling the polishing amount in stages, is provided in the space where the conventional polishing mark is provided. If you manage the amount of polishing by using the polishing mark together with the notch 3a of the gap material layer 3, you can polish JI! Management can be performed more accurately.

11 Back 11 Next, FIG. 3 is a perspective view for explaining a method of manufacturing a thin film magnetic head according to a second embodiment of the present invention, showing a partially transparent structure of the thin film magnetic head before sliding surface polishing. It is.

As shown in the figure, in this embodiment, the shape of the notch 3a formed in the gap material layer 3 is different from that in the first embodiment, and the notch 3a is formed in a rectangular shape.
It is cut out to a position corresponding to the target gap depth d of the La air head.

In this embodiment, such a notch 3a is formed and the end point of the polishing is detected by observing the change in inductance of the thin film magnetic head depending on the amount of polishing during polishing of the sliding surface.

That is, in the head provided with the νJ notch 3a shown in FIG. 3, the inductance of the head changes as shown in FIG. i4 depending on the size of the gap depth corresponding to the amount of polishing. That is, while the region of the notch 3a is being polished, the contact area between the lower magnetic layer 2 and the upper magnetic layer 6 gradually decreases in accordance with the polishing, and the magnetic resistance of the magnetic circuit consisting of both magnetic layers 2.6 increases. The inductance L of the head gradually increases, and as shown in the region A in FIG. 4, the inductance L of the head gradually decreases at a constant slope.

However, as the polishing progressed further, the gap depth became d! When the contact area of the magnetic layer 2.6 on the gap material layer 3 side becomes 0, the magnetic resistance increases rapidly and the inductance L decreases rapidly as shown in FIG. After that, as the polishing progresses, the inductance L increases as shown in area B.
gradually decreases with a slightly gentler slope than in region A.

Therefore, by continuously observing the inductance L and detecting the point where the inductance L suddenly decreases, the point of the gap depth dl can be detected.

In this way, according to this embodiment, by utilizing the fact that the inductance L of the thin film magnetic head changes, the amount of polishing can be managed by electrical detection instead of J11 constant by visual observation using a microscope. can. The polishing process can also be automated by converting the change in inductance L into an electrical signal, extracting a detection signal of the gap depth d1, and using this detection signal as an off switch for the polishing machine.

It goes without saying that according to this embodiment, similar effects can be obtained for the same reasons as in the case of the first embodiment. 6 [Effects of the Invention] As is clear from the above description, the method for manufacturing a thin film magnetic head according to the present invention includes a step of polishing and finishing the magnetic recording medium sliding surface of the thin film magnetic head, and in this step, Since a configuration is adopted in which the amount of polishing is controlled using cutouts in a predetermined pattern formed in advance in the gap material layer constituting the magnetic gap of the head, a sufficient space can be secured for providing the predetermined pattern. , the area of the media sliding surface of the thin film magnetic head can be reduced, the amount of polishing can be accurately controlled, the gap depth can be determined with high accuracy, and the quality of the thin film magnetic head can be improved and uniformed. This excellent effect can be obtained.

[Brief explanation of drawings]

FIG. 1 is a partially transparent perspective view of the structure of a thin-film magnetic head before sliding surface polishing to explain the first embodiment of the present invention, and FIGS. 2(A) and 2(B) show the same embodiment An explanatory diagram of a method for controlling the amount of sliding surface polishing according to an example; FIG. 3 is a perspective view showing a partially transparent structure of a thin film magnetic head before sliding surface polishing, illustrating a second embodiment of the present invention; FIG. 4 is a diagram showing the relationship between the gap depth and the inductance of the head depending on the amount of polishing of the sliding surface in the head of FIG. 3, and FIG. 2 is a perspective view of a thin film magnetic head before a protective plate is bonded to explain the manufacturing method of the magnetic head, and FIG. 6 is a perspective view of the thin film magnetic head in a completed state. l...Substrate 2...Lower magnetic layer 3...
Gap material layer 3a... Notch portion 4... Electrode coil 5... Insulating layer 6... Upper magnetic layer 8
...Adhesive 9...Protection plate

Claims (1)

[Scope of Claims] 1) A step of polishing and finishing the sliding surface of the magnetic recording medium of the thin-film magnetic head, in which a predetermined pattern of cuts formed in advance in the gap material layer constituting the magnetic gap of the head is provided. A method for manufacturing a thin-film magnetic head, characterized in that the amount of polishing is controlled using a notch. 2) At least a part of the notch is formed in a region of the gap material layer sandwiched between an upper magnetic layer and a lower magnetic layer that constitute a magnetic circuit of a thin-film magnetic head. A method for manufacturing a thin-film magnetic head as described in 2.