JPH0337811A - Thin film magnetic head and its manufacture - Google Patents

Abstract

PURPOSE:To prevent the crack and chip of a substrate and a film occurring by reducing working stress when mechanical working is applied by forming the film thickness of a coil insulating layer in an area outside a narrow track working position less than a distance between upper and lower magnetic cores. CONSTITUTION:The film thickness of the coil insulating layer 5 consisting of an inorganic material other than a part between the lower magnetic core 2 and the upper magnetic core 8 formed on a nonmagnetic substrate 1 and the part of a signal coil 6 is formed thinly. Or, the insulating layer 5 is formed at only the part between the upper and lower magnetic cores and the part of the signal coil 6 i.e. a side inner than the narrow track working position. Thereby, the film thickness of the insulating layer 5 can be formed thinly, and also, an area with thick film thickness can be reduced, therefore, the internal stress of the film can be reduced, and a defect such as the crack and the chip of the substrate due to the working stress, etc., can be prevented occurring, which enables a thin film head with high reliability to be formed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a thin film magnetic head used in a magnetic recording/reproducing device such as a VTR, and relates to a head structure for eliminating defects such as cracks and chips caused by film stress. and its manufacturing method.

[Conventional technology]

Conventionally, as described in Japanese Patent Application Laid-Open No. 63-304413.

In a thin film magnetic head, the total film thickness of the signal coil and insulation layer formed between the upper and lower magnetic cores needs to be thick in order to reduce leakage magnetic flux loss flowing between the upper and lower magnetic cores. Further, the tape reservoir is machined into a narrow track in order to obtain good tape contact.

This conventional technique will be explained using drawings.

Figures 8(a) and (b) are a head plan view showing the narrow track processing position, a side view as seen from the tape sliding surface side, and Figure 9 is the xx' dividing line in Figure 8(a). FIG.

1 is a non-magnetic substrate, 2 is a lower magnetic core, 3 is a lower magnetic core embedding material, 4 is a map material for gap depth detection, 8 is an upper magnetic core, 9 is a protective film, B-B'c-c' is a narrow This is the track processing position. In this way, during narrow track processing, the top of the nonmagnetic substrate, the protective film 9, the embedding material 3, and the coil insulating layer 5 are cut.

Furthermore, in a system in which a recording medium and a magnetic head come into contact with each other and slide, the head must be made of a material with good wear resistance. For example, core materials include Fe-AQ-8i and Co-
Nb-Zr-based magnetic thin films are used, and these core materials require heat treatment at 400°C or higher to obtain the desired magnetic properties, so the embedded material 3 and coil if! l Edge material 5
Inorganic materials such as SiO2 are used.

[Problem to be solved by the invention]

However, in the above-mentioned conventional technology, the thickness of the coil insulation layer between the upper and lower magnetic cores and outside the signal coil region is thick. In addition, the embedding material and coil insulating layer as mentioned above,
In general, it has a large film stress on the order of lo'dyn/aJ because it is formed by a sputtering method and because the thermal expansion coefficient of the magnetic film is close to that of the substrate and there is a considerable mismatch with that. Therefore, there is a problem in that excessive stress is generated in the film or the substrate, and the substrate or film is cracked or chipped due to external cutting stress during narrow track processing.

The present invention aims to improve the yield of head formation by reducing the stress in the insulating layer without sacrificing head performance and eliminating defects such as cracks and chips.

[Means to solve the problem]

In order to achieve the above objective, the thickness of the insulating layer between the upper and lower magnetic cores and in areas other than the signal coil portion is reduced, or
The insulating layer is formed only between the upper and lower magnetic cores and the signal coil portion, that is, only inside the narrow track processing position, or the above two methods are performed simultaneously.

[Effect]

By reducing the thickness of the insulating layer or by reducing the area where the film is thick, defects in internal response of the film are eliminated.

〔Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1(a) is a plan view showing a first embodiment of the thin film magnetic head according to the present invention, FIG. 1(b) is a front view as seen from the tape sliding surface, and FIG. 2 is the same as that shown in FIG. Manufacture of the thin film magnetic head of the first embodiment, as shown by a cross-sectional view taken along parting line A-A', FIG. 3 is a cross-sectional view of the tape sliding surface, and a cross-sectional view taken along parting line A-A' in FIG. It's a method.

1 is a non-magnetic substrate, 2 is a lower magnetic core, 3 is a lower magnetic core embedding material made of a non-magnetic insulating material, 4 is a marker for gap depth detection, 5 is a coil insulating layer made of an inorganic material such as SiO, 6 is a signal coil, 7 is a gap, 8 is an upper magnetic core, and 9 is a protective film.

FIG. 3 shows a side view of the manufacturing method of the thin film magnetic head of the first embodiment as seen from the moving surface of the tape m, and a royal diagram A-A'.
This will be explained using a cross-sectional view.

(B) Form a groove for inserting the lower magnet in the non-magnetic substrate 1' by dicing, sawing, ion milling or the like.

(c), (d) A lower magnetic film 2 is formed in the groove by sputtering or the like, and a lower magnetic core is formed by ion milling or the like.

(e), (f) A lower magnetic core embedding material 3 is formed by sputtering or the like, and is planarized and polished.

(g), (h) A gap depth detection marker 4 is formed into a film by sputtering or the like, and patterning is performed by ion milling.

The insulating layer 5 is formed by sputtering, etc., and the signal coil 6 is formed by vapor deposition, etc., and then patterned by ion etching, etc. After forming the insulating layer on the upper layer of the signal coil, the gap forming part and the upper and lower magnetic core connections are formed. A groove is formed by ion etching or the like.

(i), (j) After forming the gap material 7 in the gap forming part by sputtering or the like, and forming an upper magnetic film on this layer by sputtering or the like, ions (k) and (Q) are formed around the upper magnetic core 8. The insulating layer 5 is removed by ion etching or the like to an extent that the gap depth marker 4 in the lower layer does not disappear, and the protective film 9 is formed by sputtering or the like.

Further, the wafer is cut into strips using a dicing saw or the like, and the tape contacting surface is rounded, and then narrow track processing is performed using a dicing saw or the like to form chips.

FIG. 4 is a diagram of a sliding surface of a thin film magnetic tape according to a second embodiment of the present invention, and FIG. 5 shows a manufacturing method, and the same parts as in FIG. 3 are designated by the same numbers. In this embodiment, the thickness of the coil insulating layer at the portion in contact with the upper core can also be made thinner. In Fig. 5, steps (a) to (f) are shown in Fig. 3 (a).
) to (f), so they will be omitted and only the subsequent steps will be explained.

(g), (h) Gap depth detection marker 4 is formed into a film by sputtering, etc., and patterned by ion milling, etc., and the coils (i) and (j) of the first layer ↓
After forming the signal coil 6 of the first layer by vapor deposition or the like, patterning is performed by ion etching or the like to form a second coil insulating layer. At this time, the coiled layer 5 is formed only in the signal coil region, and is not formed on the depth marker 4 or the upper part of the core.

(k), CQ) After forming the second layer signal coil 6, the third N
A second coil insulating layer is formed in the same region as the second coil insulating layer, and a gap forming portion and a groove for connecting the upper and lower magnetic cores are formed by ion etching or the like.

Here, steps 1, (i) to (Q) are replaced with a method in which all the coil insulating layers are formed in the same manner as the first Nth coil insulating layer, and then the depth marker 4 and the upper part of the core are removed by ion etching etc. 6 (m), (n,) A gap material 7 is formed in the gap forming portion by sputtering or the like, and an upper magnetic film is formed on this upper layer by sputtering or the like, and then an upper magnetic core 8 is formed by ion etching or the like. Form.

(o), (p) A protective film 9 is formed by sputtering or the like.

Further, the wafer is cut into strips using a dicing saw or the like, and the tape contacting surface is rounded, and then narrow track processing is performed using a dicing saw or the like to form chips.

In the second embodiment, the shape is such that the thickness of the insulating layer does not increase during the patterning process of the insulating layer on the signal coil, so after forming the upper core as in the first embodiment, There is no need to remove the insulating layer, which shortens the process.

1st. According to the second embodiment, since the thickness of the insulating layer is reduced, stress can be reduced.

FIG. 6(a) is a plan view of a thin film magnetic head showing a third embodiment of the present invention, and FIG. 6(b) is a front view seen from the tape sliding surface side after narrow track processing. It is. In FIG. 7, the coil insulating layer forming area of FIG. 6(a) is further narrowed.

In FIGS. 6(a), (b), and 7, the same parts as in FIG. 3 are indicated by the same numbers.

In this example, the insulating layer 5 is formed only on the signal coil 6, the gap forming part 7, and the gap depth marker 4, and the forming range of the thick part of the insulating layer is narrowed inward from the narrow track processing position. .

This makes it possible to reduce stress in the M edge layer and furthermore,
N is not directly affected by the stress caused by narrow track machining.

Furthermore, by performing the second step or the second embodiment and the third embodiment in the same manner, the internal stress of the insulating layer can be further reduced, and the influence of the applied stress can be eliminated.

In the first, second, and third embodiments, the gap depth marker 4 was formed by shaping the lower magnetic core embedding material 3 and forming a flat 5 shield, and an insulating layer was formed on the upper layer. A layer with good selective etching properties is formed on the marker 4. Alternatively, by embedding the gap depth marker 4 in the lower magnetic core embedding material 3, the coil insulating layer around the front can disappear, so that the influence of stress due to the insulating layer is eliminated.

Alternatively, by creating a pattern that does not cut the insulating layer, stress during machining can be reduced.
A highly reliable thin-film magnetic head with no cracks or chips in the substrate or film can be manufactured at a high yield.

[Brief explanation of drawings]

1 to 3 are explanatory diagrams of a first embodiment of the present invention, FIG. 1(a) is a plan view of the thin film magnetic head of the present invention, and FIG. 1(b) is a tape sliding surface. Figure, Figure 2 is Figure 1 A-A
FIG. 3 is a process diagram showing a method of manufacturing the thin film magnetic head of the first embodiment. 4 and 5 are explanatory diagrams of a thin film magnetic head according to a second embodiment of the present invention, and FIG. 4 is a diagram of a tape sliding surface;
FIG. 5 is a manufacturing method, FIGS. 6 and 7 are explanatory diagrams of a third embodiment of the present invention, and FIGS. 6(a) and 7 are plan views of a thin film magnetic head of the present invention. FIG. 6(b) is a side view seen from the tape sliding surface side, FIGS. 8 and 9 are explanatory diagrams of conventional embodiments, and FIG. 8(a) is a plan view of the thin film magnetic head. 8(b) is a side view seen from the tape sliding surface side, and FIG. 9 is a sectional view taken along line xx' in FIG. 7(a). 1... Non-magnetic substrate, 2... Lower magnetic core, 3...
Lower magnetic core embedding material, 4... gap depth marker 5... insulating layer. 1st glimpse (0-) plot 2 嬬悶 2nd Hanakuni

Claims (1)

[Scope of Claims] 1. A non-magnetic substrate, a lower magnetic core, a coil, and an insulating layer formed around them are in contact with the lower magnetic core at a rear core connection part to form a magnetic circuit via a gap material. In a thin-film magnetic head formed by laminating upper magnetic cores, the thickness of the coil insulating layer in the area other than the front of the upper magnetic core is such that, at least in the area outside the narrow track processing position, the thickness of the coil insulating layer is equal to that between the upper and lower magnetic cores. A thin film magnetic head characterized by being smaller than the distance. 2. A nonmagnetic substrate, a lower magnetic core, a coil, and an insulating layer formed around them, and an upper magnetic core that contacts the lower magnetic core at the rear core connection part and forms a magnetic circuit via a gap material. A thin film magnetic head comprising: a thin film magnetic head comprising: a pattern width of a coil insulating layer around the front portions of the upper and lower magnetic cores is narrower than a narrow track processing position; 3. The thin film magnetic head according to claim 2, wherein the thickness of the coil insulating layer around the front portions of the upper and lower magnetic cores is smaller than the distance between the upper and lower magnetic cores. 4. Layer the lower magnetic core, coil insulating layer, and coil conductor on a non-magnetic substrate, perform patterning, and form a film of magnetic material to form a magnetic circuit through the gap material to form the upper magnetic core. , a thin film magnetic head characterized in that the coil insulating layer other than a certain area in contact with the front part of the coil and the upper and lower magnetic cores is made thinner than the distance between the upper and lower magnetic cores, a protective film is formed on the upper layer, and a chip is processed. manufacturing method.