JPH0714137A - Method for working slider of thin-film magnetic head - Google Patents

Abstract

PURPOSE:To realize the method for working the sliders which are inexpensive and have excellent mass productivity by decreasing the than-hours for working of thin-film magnetic heads. CONSTITUTION:Many thin-film magnetic head elements which are arrayed in one row are formed as a slider substrate 3 and the plural slider substrates 3 are placed on a plate 4 to obtain a slider substrate block 5. A polyimide sheet 20 contg. an adhesive layer is then stuck onto this slider substrate block 5. Slider patterns are exposed by using a photoresist 21 of a positive type to form resist patterns 22. The slider substrate block 5 is immersed into an alkaline soln. and the unnecessary parts of the polyimide sheet 20 are remove. The slider substrate 3 of the parts where there are only the resist patterns 22 is etched. Slider grooves 24 are then formed without adversely affecting the thin- film magnetic head elements.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slider processing method used in manufacturing a thin film magnetic head.

[0002]

2. Description of the Related Art In recent years, magnetic recording / reproducing devices have been actively used for high-density recording and miniaturization. In such a magnetic recording / reproducing apparatus, a thin film magnetic head is used as the magnetic head. Further, stable electromagnetic conversion characteristics are required for small recording media. For this reason, it is necessary to keep the gap between the recording medium and the thin film magnetic head at a minute fixed interval.

In order to meet such requirements, the slider (floating surface or flying track) of a thin film magnetic head is changing from a simple shape in conventional machining to a complicated shape. A slider using a photolithography technique or an ion trimming technique is generally adopted.

FIG. 4 is an explanatory view showing a conventional slider manufacturing process using photolithography. As shown in FIG. 4A, a substrate made of ceramic or the like is processed into a flat plate shape, and the surface roughness of each surface of the substrate is finished to a predetermined accuracy. This substrate is used as a slider block 1, and a large number of thin film magnetic head elements 2 are formed in a matrix pattern on the upper surface thereof.

Next, as shown in FIG. 4B, the slider blocks 1 are cut and separated so that the thin film magnetic head elements 2 are arranged in a line along the XX direction. Then, one set of cut slider blocks is taken out and used as a slider substrate 3.

Next, as shown in FIG. 4 (c), a square plate or a disc-shaped plate 4 is prepared, and several slider substrates 3 are adhered side by side so that the medium facing surface 3a faces upward.
The workpiece formed in this manner is used as the slider substrate block 5
And The medium facing surfaces 3a of the plurality of slider substrates 3
Is a common surface formed by the slider forming surface 5a, and a slider groove is formed on this surface by processing using a photolithography method and an ion trimming method described later. Figure 4 (d)
Shows a state in which a plurality of floating rails 6 are formed on the slider substrate block 5 in accordance with the slider mask pattern.

Next, as shown in FIG. 4 (e), the slider substrate 3 on which the flying rail 6 is formed is removed from the plate 4. Then, the photoresist adhering to the slider substrate 3 is washed away, and the slider substrate 3 is cut into each slider unit as shown in FIG. In this way, a plurality of thin film magnetic heads 7 are manufactured at the same time, and the air bearing surfaces 8 are formed on both sides of the central slider groove.

A conventional slider forming process using the above-mentioned photolithography and ion trimming will be described in detail. FIG. 5 is an explanatory view showing a conventional slider forming process. As shown in FIG. 5A, a positive photoresist 9 is formed on the upper surface of the slider substrate block 5 including the substrate 3 and the plate 4. The film thickness of the photoresist 9 varies depending on the etching rates of the slider substrate block 5 and the photoresist 9 during ion etching, but here it is 30 to 60 μm.

Next, a photomask 10 having a pattern of the air bearing surface 8 is arranged on the photoresist 9 and exposed by an exposure device (not shown). As shown in FIG. 5B, when a positive photoresist 9 is used, a resist mask 11 is formed on a portion which becomes the air bearing surface 8 by melting the exposed portion.

Next, the slider substrate block 5 to which the resist mask 11 is attached is ion-etched by an ion trimming method. Thus, as shown in FIG. 5C, the resist mask 11 and the slider substrate 3 are both etched, and the slider groove 12 is formed. When a part of the resist mask 11 remains on the air bearing surface 8, the slider groove 12
Has a depth of 20 μm. Next, the resist mask 11 is removed by using a solvent to complete the slider 13 having the flying rails 8 as shown in FIG. 5D.

[0011]

When argon ions are used as the ion trimming method, the processing rate of the slider material ceramic (altic) and the photoresist is generally about 1: 3. Therefore, the film thickness of the photoresist 9 needs to be about 60 μm in order to obtain the slider groove 12 of about 20 μm. Such a film thickness is not possible with a single application as long as a liquid photoresist is used. For this reason, several overcoatings are required, and the steps of resist coating and baking must be repeated. This method has a problem in that the photoresist film forming process becomes complicated. Also photoresist 9
As for the coating method, it is technically extremely difficult to make the film thickness uniform by the conventional spin coating method or roll coating method.

FIG. 6 is an explanatory view showing a problem that occurs when the photoresist 9 is applied to the slider substrate block 5. As shown in FIGS. 6A and 6B, the plate 4
Photoresist 9 is applied to each upper surface of the slider substrate 3 placed on the substrate and baked. At this time, the photoresist 9 permeates into the gap between the slider substrates 3 by the capillary phenomenon, and the film thickness of the photoresist 9 at that portion is reduced. The thin film magnetic head element 2 is several tens of μm from the end of the slider substrate 3.
Since it is formed in a place of about m, if such a decrease in the film thickness of the photoresist 9 (film slippage) occurs, the result of FIG.
As shown in (c), there is a problem that the thin film magnetic head element 2 is easily damaged during the ion trimming process.

If the film thickness of the photoresist 9 is further increased in order to prevent this, pattern formation becomes extremely difficult. Further, in the subsequent ion etching step, when the energy of the ion beam is increased in order to increase the processing rate, the surface temperature of the photoresist 9 irradiated with the ion beam rises, and pattern sagging and resist burning occur. Therefore, the slider substrate block 5
However, there was a defect that the processing accuracy of (1) deteriorated and the processed product became a defective product.

Recently, there is a mask using an organic resist material as disclosed in, for example, Japanese Patent Application Laid-Open No. 4-132011. Here, a method is used in which a hard-baked resist having a film thickness of about 50 μm is patterned by oxygen plasma etching, and then slider processing is performed by ion etching. However, this method has a drawback that it takes about 5 hours for the resist bake treatment and the oxygen plasma etching, and the number of steps increases. Further, the cost of the organic resist material is about 10 times as high as that of a normal resist, and there is a drawback that the processing cost becomes high.

A method of forming a pattern with a dry film resist has also been tried, but since its main component is an acrylic resin, it has poor corrosion resistance to ion etching and is not practical.

The present invention has been made in view of the above conventional problems, and by using a sheet having a corrosion resistance to dry etching, slider processing which does not cause resist film slip between slider substrates is performed. Realizing the method,
Another object of the present invention is to realize a thin film magnetic head which is excellent in productivity and product yield and can be produced at low cost.

[0017]

According to the invention of claim 1 of the present application, each thin film magnetic head element is arranged in a row in a flat slider block in which a plurality of thin film magnetic head elements are collectively formed on the upper surface. A slider processing method for a thin-film magnetic head in which a slider substrate is vertically cut as described above, and an air bearing surface based on a slider pattern is formed on the contact surface of the slider substrate that contacts the recording medium. On the plate so that they are aligned, a step of sticking a polyimide sheet having an adhesive layer applied and having corrosion resistance at the time of dry etching to the contact surface of the slider substrate, and coating a photoresist on the upper surface of the polyimide sheet. A step of exposing the slider pattern, a step of etching the photoresist film and leaving a portion where the slider pattern is formed, Of the portion of the substrate where the photoresist film is not present by dissolution, a step of forming a slider groove in the portion of the slider substrate where the polyimide sheet has been removed by ion etching, and a slider substrate having the slider groove formed. And a step of cutting into a predetermined magnetic head element unit, and forming a pair of air bearing surfaces on the slider substrate.

According to a third aspect of the present invention, a flat plate-like slider block having a plurality of thin film magnetic head elements formed on the upper surface thereof is vertically cut so that the thin film magnetic head elements are arranged in one row. A slider processing method for a thin-film magnetic head, wherein an air bearing surface is formed on a contact surface of a slider substrate that contacts a recording medium, the slider surface being formed on a plate so that the contact surfaces are aligned. A step of placing, a step of sticking a polyimide sheet having a corrosion resistance at the time of dry etching to which an adhesive layer is applied to the contact surface of the slider substrate, and irradiating the polyimide sheet with a laser beam through a mask of a slider pattern,
A step of forming a resist mask of a slider pattern by removing a laser beam irradiation portion, a step of forming a slider groove in a portion where the resist mask is removed by ion etching a slider substrate, and a slider groove are formed. And a step of cutting the slider substrate into predetermined magnetic head element units, and forming a pair of air bearing surfaces on the slider substrate.

[0019]

According to the first aspect of the invention having the above characteristics, the polyimide sheet coated with the adhesive layer is attached to the slider substrate. In this way, a desired thin film resist mask can be easily formed, and the film thickness can be made uniform over the entire surface of the slider substrate. Next, a photoresist is coated on the upper surface of the polyimide sheet and the slider pattern is exposed. Then, the photoresist film is left in a slant pattern by etching. Next, the part of the polyimide sheet without the photoresist film is dissolved, and the part where the polyimide sheet is removed is ion-etched,
A slider groove is formed. This can greatly reduce the number of steps required to form the air bearing surface.

According to the third aspect of the invention, the polyimide sheet coated with the adhesive layer is attached to the slider substrate. In this way, a desired thin film resist mask can be easily formed, and the film thickness can be made uniform over the entire surface of the slider substrate. Next, the polyimide sheet is irradiated with a laser beam through a mask to expose the slider pattern. Then, a resist mask is formed by removing the portion irradiated with the laser beam. Further, the slider substrate in the portion where the resist mask is not attached is ion-etched to form a slider groove. This makes it possible to use a polyimide sheet that does not require a heating step.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A slider processing method for a thin film magnetic head in a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is an explanatory diagram showing a slider forming process when a polyimide sheet as a resist mask and a thermoplastic polyimide resin for its adhesive layer are used. As shown in FIG. 1A, a plate 4 on which a plurality of slider substrates 3 are mounted is referred to as a slider substrate block 5. Next, FIG. 1 (b)
The polyimide sheet 20 is attached to the upper surface of the slider substrate block 5 as shown in FIG. The polyimide sheet 20 has a lower surface coated with a thermoplastic polyimide resin as an adhesive layer 20a, and is attached by a laminator used when attaching a dry film or a processing protective tape. Then, the slider substrate block 5 is heated to a temperature of 20.
At about 0 ° C., the adhesive layer 20 a melts and adheres to the slider substrate 3. When the slider substrate block 5 cannot be heated to this temperature, only the polyimide sheet 20 is heated and attached onto the slider substrate block 5.

Next, as shown in FIG. 1C, a normal liquid positive photoresist 2 is formed on the upper surface of the polyimide sheet 20.
Apply 1. Then, the photoresist 21 is baked to remove the solvent. Next, the slider pattern is formed on the photoresist 21 using an exposure device having an aligner, a stepper, or the like.
To expose. In this case, the thickness of the photoresist 21 is 1
A thickness of 0 μm is sufficient, and a highly accurate pattern can be easily obtained. Thus, as shown in FIG.
Photoresist mask 22 is formed at a position to be.

Next, the polyimide sheet 20 having the photoresist mask 22 formed thereon is etched. An alkaline solution is used for etching the polyimide sheet 20 used in this case. As this etching solution, 20 cc of pure water is mixed with 80 cc of ethyl alcohol. Next, 10 cc of potassium hydroxide was mixed, and finally hydrazine (H
₂ NNH ₂ ) is mixed with ₂ to 6 cc. Although the etching is performed by immersion, the etching rate can be increased by heating the etching solution depending on the pattern accuracy. For example, when the etching liquid is heated to 70 ° C. and used for the polyimide sheet 20 of 25 μm, the etching time is about 10 seconds.

A polyimide sheet 20 as shown in FIG. 1 (e)
Of the photoresist mask 22 is completed.
To remove. Next, the surface of the slider substrate 3 is etched using ion etching to form the slider groove 23. The ion etching rate of the polyimide sheet 20 is about the same as that of the conventional positive photoresist. Therefore, when AlTiC is used as the slider substrate 3,
In order to form the slider groove 23 of μm, the film thickness of the polyimide sheet 20 may be set to 75 μm. The polyimide sheet 20 having such a film thickness is generally commercially available as a standard product.

Finally, when the polyimide sheet 20 remaining on the surface is removed with a solution as shown in FIG. 1 (f), FIG.
The slider 24 as shown in FIG. This slider 2
4 is cut to complete a thin film magnetic head 7 having two air bearing surfaces 8 as shown in FIG.

Next, a slider processing method for a thin film magnetic head according to the second embodiment of the present invention will be described. FIG. 2 is an explanatory diagram of a slider forming process when a polyimide sheet having an acrylic and silicon adhesive layer is used as a resist mask of the slider. Similar to the first embodiment
As shown in FIG. 2A, a plurality of slider substrates 3 placed on the upper surface of the plate 4 is referred to as a slider substrate block 5.

Next, as shown in FIG. 2B, a polyimide sheet 30 having an acrylic or silicon adhesive layer 30a is attached to the upper surface of the slider substrate block 5.
The polyimide sheet 30 is attached in the same manner as in the first embodiment, but heating of the slider substrate block 5 or the polyimide sheet 30 is not required at this time, and it may be attached at room temperature. Next, when patterning the polyimide sheet 30, the adhesive layer 3 is formed by etching the polyimide sheet 30 with the alkaline solution used in the first embodiment.
0a remains without being etched. Therefore, it is necessary to perform patterning by another method.

FIG. 2C is a diagram showing a step of patterning the polyimide sheet 30 using the excimer laser processing, and details thereof are shown in FIG. FIG. 3 is an explanatory diagram of a mask image method using an excimer laser.

Polyimide sheet 3 by excimer laser
The processing of 0 is performed with high accuracy in a short time. Such laser processing is widely used not only for manufacturing slider patterns, but also for processing flexible printed boards and TAB tapes. There are roughly two types of processing methods, a direct mask method and a mask image method. Here, the mask image method is often used from the viewpoint of high precision fine processing.

In the excimer laser processing device 31, a gas such as ArF, KrF or XeF is used as a laser light source. The laser beam 32 emitted from this light source is incident on the lens 34 through the metal mask 33. Since the mask image method is a mask reduction type processing method, the pattern of the metal mask 33 does not need to be highly accurate. In FIG. 3, when the distance from the metal mask 33 to the lens 34 is a, the distance from the lens 34 to the workpiece 35 is b, and the focal length of the lens 34 is f, the following equation is established. 1 / a + 1 / b = 1 / f When the magnification is M, M = a / b, and the value of M is 2 to 5
To a degree.

The XY stage 36 is for placing the workpiece 35 and feeding it in a fine motion. Here, the slider substrate block 5 coated with the polyimide sheet 30 is placed. Then, the image processing device 37 takes in the mask alignment data, and based on this, the XY stage 36 can be positioned with high accuracy using a feedback loop.

As an excimer beam processing condition, an energy density of the laser beam is about 1 J / cm ² , and a good processed surface shape can be obtained. Incidentally, there is a phenomenon that the processing by the excimer laser has a threshold value of energy density depending on the material of the work piece, and the work piece is not processed by the laser beam having an intensity less than a certain value. Here, the threshold value of the energy density for processing the polyimide sheet 30 is sufficiently smaller than that of the slider substrate 3 made of ceramic or the like. Therefore, when the excimer laser processing is performed, only the polyimide sheet 30 is processed as shown in FIG.
Is not processed.

The slider substrate block 5 on which the slider pattern is formed as described above is subjected to an ion etching process. When the slider substrate block 5 in the state shown in FIG. 2D is ion-etched, slider grooves 38 are formed as shown in FIG. 2E. By dipping this substrate in a solvent such as acetone, the remaining adhesive layer 30a is removed. Then, the slider 39 as shown in FIG. 2 (f) is obtained.

Thereafter, the slider 39 is cut into a single slider as shown in FIG. 4 (f) to complete a thin film magnetic head. As described above, since the pattern processing by the excimer laser does not require the photolithography process, the man-hours are greatly reduced and the processing capacity is significantly improved as compared with the conventional processing method.

[0035]

As described in detail above, according to the present invention, by applying the technique of processing a polyimide sheet to the processing of a slider of a thin film magnetic head, a very simplified process can be realized. Therefore, the unevenness of the resist film between the slider substrates that occurs when the conventional resist mask is used is eliminated, and the slider processing method excellent in mass productivity can be realized at a low price.

[Brief description of drawings]

FIG. 1 is a process drawing showing a slider processing method for a thin film magnetic head in a first embodiment of the invention.

FIG. 2 is a process drawing showing a slider processing method for a thin film magnetic head in a second embodiment of the invention.

FIG. 3 is a diagram showing a configuration of an excimer laser processing apparatus used for forming a slider pattern in a slider processing method according to a second embodiment.

FIG. 4 is a process drawing showing the method of manufacturing the thin film magnetic head.

FIG. 5 is an explanatory diagram showing a photolithography process used in a conventional slider processing method in a thin film magnetic head.

FIG. 6 is an explanatory diagram showing a state of a resist film produced in a conventional photolithography process.

[Explanation of symbols]

 1 Slider Block 2 Thin Film Magnetic Head Element 3, 24, 39 Slider Substrate 4 Plate 5 Slider Substrate Block 6 Flying Rail 7 Thin Film Magnetic Head 8 Airborne Surface 20, 30 Polyimide Sheet 20a, 30a Adhesive Layer 21 Photoresist 22 Photoresist Mask 23, 38 Slider groove 24, 39 Slider 31 Excimer laser processing device 32 Laser beam 33 Metal mask 34 Lens 35 Workpiece 36 XY stage 37 Image processing device

Claims (4)

[Claims] 1. A flat plate-shaped slider block having a plurality of thin film magnetic head elements collectively formed on an upper surface thereof is vertically cut into a slider substrate so that the thin film magnetic head elements are arranged in one row, and is brought into contact with a recording medium. A slider processing method for a thin-film magnetic head, wherein an air bearing surface is formed on a contact surface of the slider substrate based on a slider pattern, the method comprising placing a plurality of slider substrates on a plate so that the contact surfaces are aligned. A step of applying a polyimide sheet having a corrosion resistance during dry etching to which an adhesive layer is applied to the contact surface of the slider substrate, and a step of coating a photoresist on the upper surface of the polyimide sheet and exposing a slider pattern, Etching the photoresist film, leaving a portion where the slider pattern is formed; A step of removing a portion not having a photoresist film by melting; a step of forming a slider groove in a portion of the slider substrate where the polyimide sheet has been removed by ion etching; and a slider substrate having the slider groove formed therein. And a step of cutting into a predetermined magnetic head element unit, and forming a pair of air bearing surfaces on the slider substrate. 2. The slider processing of a thin film magnetic head according to claim 1, wherein the adhesive layer of the polyimide sheet is a thermoplastic polyimide, and the polyimide sheet is dissolved by using an alkaline solution when the slider pattern is formed. Method. 3. A flat plate-shaped slider block having a plurality of thin film magnetic head elements collectively formed on its upper surface is cut longitudinally so that each thin film magnetic head element is arranged in a row to form a slider substrate, which is brought into contact with a recording medium. A slider processing method for a thin-film magnetic head, wherein an air bearing surface is formed on a contact surface of the slider substrate based on a slider pattern, the method comprising placing a plurality of slider substrates on a plate so that the contact surfaces are aligned. A step of sticking a polyimide sheet coated with an adhesive layer and having corrosion resistance during dry etching to the contact surface of the slider substrate, irradiating the polyimide sheet with a laser beam through a mask of a slider pattern, and irradiating the laser beam Forming a resist mask having a slider pattern by removing a portion of the resist pattern; Forming a slider groove in the portion where the resist mask is removed by etching, and cutting the slider substrate in which the slider groove is formed into predetermined magnetic head element units. A method for processing a slider of a thin film magnetic head, which comprises forming a pair of air bearing surfaces. 4. The method for processing a slider of a thin film magnetic head according to claim 3, wherein the adhesive layer of the polyimide sheet is an acrylic resin or a silicon resin.