JPS63268110A - Manufacture of thin film magnetic head - Google Patents

Abstract

PURPOSE:To improve a recording and reproducing efficiency by executing the flattening cavity part processing of a prescribed thickness and flattening the level difference of the photoresist occurred at an insulating layer on a thin film coil. CONSTITUTION:On an Ni-Zn ferrite-made magnetic base 1, a first insulating layer 2 by an SiO2 thin film is formed, and on it, a thin film coil 3 is patterned to a prescribed shape with a chemical etching, etc. Next, a second insulating layer 4 of the SiO2 thin film is formed, further, a photoresist 5 is coated, a shape is flattened, the unnecessary part of first and second insulating layers 2 and 4 is ion-beam-etched, an intermediate insulating layer is inclination-processed to an optimum angle, next, a magnetic cavity part insulating layer 6 is formed with an SiO2 thin film and a magnetic core 7 is formed with a Sendust thin film. Thus, since the insulating layer 4 formed on the thin film coil 3 is flattened and the intermediate insulating layer is processed to an optimum inclination angle, the magnetic core 7 does not generate unevenness, and formed with an inclination at a part from a magnetic cavity part 8 to the upper part of the thin film coil 3, and therefore, a magnetic flux easily flows in the magnetic core 7 and the deterioration of a magnetic permeability can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a thin film magnetic head used in a magnetic recording/reproducing device.

2. Description of the Related Art In recent years, in the field of magnetic recording, thin film magnetic heads with narrow tracks and multi-tracks have become necessary as recording densities have increased.

The most important manufacturing process for this thin-film magnetic head is the formation of the magnetic core.In order to increase the magnetic efficiency of this magnetic core, it is not only necessary to simply increase the magnetic permeability, but also to process the magnetic core into a shape that facilitates the flow of magnetic flux. There is a need. To achieve this, two processes are required: (1) slanting the intermediate insulating layer from the magnetic gap to the insulating layer on the thin-film coil; and (2) flattening the unevenness formed on the thin-film coil. FIG. 4 is a plan view of a conventional thin film magnetic head, and FIG. 6 is a cross-sectional view taken along the line 4 of FIG. 4 to illustrate a method of manufacturing a conventional thin film magnetic head.

4 and 5, 1 is a magnetic substrate, 2 is a first insulating layer, 3 is a thin film coil, 4 is a second insulating layer, and 16 is a first insulating layer.
1e is a second photoresist, 6 is a magnetic gap insulating layer, 7 is a magnetic core, and 8 is a magnetic gap.

Next, the manufacturing process will be explained. FIG. 5a shows the process of forming the first insulating layer on the magnetic substrate 1. FIG. Next, as shown in FIG. 6, a thin film coil 3 is placed on the first insulating layer 2.
A fine pattern is formed using a chemical etching method or the like. Thereafter, the second insulating layer 4 is formed as shown in FIG. 6C. At this time, the second insulating layer 4 has a thin film coil 3
The unevenness is transferred as is. FIG. 6d shows a state in which the first photoresist 16 is flattened using a spin code in order to reduce (flatten) the unevenness of the second insulating layer 2. FIG. 6g shows the second insulating layer 4 and the first photoresist 16 etched at the same etching rate using an ion beam etching method or the like. FIG. 6f shows the magnetic gap 8, the substrate 1 and the magnetic core 7.
The second photoresist 16 is patterned to perform the etching necessary to remove the first insulating layer 2 and the second insulating layer 4 that are unnecessary for magnetically coupling the . As shown in FIG. 5g, the intermediate insulating layer from the magnetic gap 8 to the second insulating layer 4 on the thin film coil 3 is etched so as to be inclined, and then, after removing the second photoresist 16, As shown in the fourth diagram, a magnetic gap insulating layer 6 is formed, and a magnetic core 7 is formed.

Problems to be Solved by the Invention However, in the manufacturing process of the thin film magnetic head as described above, the first photoresist 15 applied to planarize the second insulating layer 4 eliminates the level difference caused by the thin film coil 3. It must be applied as shown. Coating such a first photoresist 16 is difficult. Therefore, the level difference after coating the first photoresist 16 is
As shown in FIG. The magnetic core 7 formed above also has an uneven shape with steps, leading to deterioration of magnetic permeability and deterioration of recording and reproducing efficiency.

In addition, since there is a planarization process and a process for tilting the intermediate insulating layer from the magnetic gap to the second insulating layer 4 on the thin-film coil 3, the manufacturing process becomes complicated and the manufacturing cost of the thin-film magnetic head is reduced. It was also a contributing factor to the increase.

In view of the above-mentioned problems, the present invention eliminates the unevenness of the magnetic core 7, that is, performs a flattening process to eliminate the unevenness of the second insulating layer 4. The present invention provides a method for manufacturing a thin film magnetic head that improves the characteristics of the magnetic core and reduces manufacturing costs by performing slope processing on the intermediate insulating layer leading to the second insulating layer. Means for Achieving In order to achieve the above object, the method for manufacturing a thin film magnetic head of the present invention simultaneously performs planarization processing and slope processing of the intermediate insulating layer from the magnetic gap to the insulating layer on the thin film coil.

Function: With this manufacturing method, the insulating layer formed on the thin film coil after etching is flattened, and the intermediate insulating layer is processed at an optimal angle of inclination, so the magnetic core has no unevenness and is free from the magnetic gap. The portion leading to the top of the thin film coil is also formed with an inclination, so there is no step. Therefore, magnetic flux can easily flow through the magnetic core, preventing deterioration of magnetic permeability and improving recording and reproducing characteristics. Since the flattening process and the tilting process are performed simultaneously, the manufacturing process can be simplified and manufacturing costs can be reduced.

EXAMPLE An example of the present invention will be described below. Figure 1 shows the manufacturing process of a thin film magnetic heald according to the present invention. Components similar to those in Figure 4 are given the same numbers. , the explanation is omitted. 6 is a photoresist.

Next, the manufacturing process will be explained. FIG. 1a shows a first insulating layer 2 on a magnetic substrate 1 (Ni-Zn ferrite).
(5i02 thin film) is formed, and then the thin film coil 3 is patterned into a predetermined shape by chemical etching or the like. FIG. 1 shows a state in which a second insulating layer 4 (5iOz thin film) is formed on the thin film coil 3. At this time, the unevenness of the thin film coil 3 is directly transferred to the second insulating layer 4. In FIG. 1C, a photoresist 5 is applied to planarize the second insulating layer 4, and then an unnecessary first layer is applied to magnetically couple the magnetic gap 8, the substrate 1, and the magnetic core 7. A pattern for performing etching necessary to remove the insulating layer 2 and the second insulating layer 4 is formed on the photoresist 5. This photoresist 6 will be described in detail later, but has a predetermined thickness and a step difference.

Next, as shown in FIG. 1d, an ion beam etching method using an ion beam is used to tilt the intermediate insulating layer from the magnetic gap 8 to the second insulating layer 4 on the thin film coil 3 at an optimal angle. used. This method performs etching by colliding accelerated murine ions with the sample to be etched, and by controlling the ion incidence angle with respect to the sample, the etching cross-sectional shape (tilt angle) can be freely controlled. It has the characteristics of being able to After that, as shown in FIG. 1e, the magnetic gap insulating layer 6 is
02 thin film, and the magnetic core 7 is formed of Sendust thin film.

As described above, the photoresist 5 has a predetermined step and thickness. The reason for this will be explained below using FIG. 2. FIG. 2 shows in detail the processes from C to d in FIG. 1, that is, the planarization process and the slope process of the intermediate insulating layer.

(Hereinafter, the process shown in FIG. 2 will be referred to as flattening gap tilt machining.) In FIG. 2, the same parts as in FIG.

Further, the step of the photoresist 6 is Rc, the thickness is H1, the step of the second insulating layer 4 is S, and the difference between the first insulating layer 2 and the second insulating layer 4 is
Let L be the sum of the thicknesses of The bottom of the recess of the insulating layer 4 of No. 2 is shown.

The ion beam etching conditions during this processing are such that the first insulating layer 2 and the second insulating layer 4 are etched to optimize the inclination angle of the intermediate insulating layer. At this time, the first
The etching rate of the isolated layer 2 and the second insulating layer 4 is ra, and the etching rate of the photoresist 5 is rO. In FIG. 2a, etching is started at the etching rate. In Figure 2, the etched side is a Mu person.
It shows the situation when moving from the line to the line BB'. At this time, the photoresist 6 on the thin film coil 3 is (H+R, -
8) is etched, and the time required for this is t.
l, then rot, = H+ Rc −S ---(1
), tl becomes t+=(H+Rc S)/ro --(2). Further etching progresses until the etched surface becomes C-a.
When the t-line is reached, the etching is finished. The time from FIG. 2 to FIG. 2 C is defined as t2. At this time, the second insulating layer 4 on the thin film coil 3 is etched by S, and the photoresist 6 left between the thin film coils 3 is etched by (S).
-Ra) is etched. Therefore r5 t2= 8 ・・・・・・・・・・・・
・・(3)rQ t2=S −R(+ ・・
・・・・・・・・・・・・(4) Equation (3), (4
) ceremony! 1lt2 and solving for R(+), we get: Therefore, if the step RC of the photoresist 5 before planarization shown in FIG. 2a is set to a value that satisfies equation (5), then The second insulating layer 4 can be completely planarized.

On the other hand, the first. The second insulating layers 2, 4 are formed at the time (t1+t2) during which the process progresses from a to c in FIG.
Since it is necessary to etch the insulating layer by L during the etching process, ra(t++tz)=L -''- (6).

According to equations (2), (4), and (6), if t + j t2 is eliminated, rB・-=L ・・・・・・・・・・・・ (
'7)O That is, if the thickness H of the photoresist 5 is made to satisfy the formula (8), the magnetic gap 8 is formed at the same time as the planarization process is performed.

In this embodiment, since the inclination angle of the intermediate insulating layer is 46 degrees, the etching rate ratio ro/rs is 0.78 from FIG. 3 when the ion beam incident angle is 46 degrees. Since the step S of the second insulating layer 40 is set to 2 μm, and the sum of the thicknesses of the first insulating layer 2 and the second insulating layer 4 is set to 3 μm, equations (8) and (6) show that the photoresist 6 The thickness H is 2
．． 3 μm, and the step R must be 0.33 pm. The photoresist 6 was coated as described above by controlling the spin cord rotation speed and the viscosity of the photoresist 5 during coating of the photoresist 6. In this example, a rubber cyclized photoresist was used as the photoresist 6, and a predetermined film thickness and level difference were obtained by setting the spin cord rotation speed to 300 Orpm and the viscosity to 12009.

By using the method described above, the inclination angle of the intermediate insulating layer is set to 45°.
, the level difference of the second insulating layer 4 after planarization was set to 0.1 μm or less.

In this embodiment, the magnetic gap insulating layer 6 was formed after the flattening gap inclination processing, but during the planarization gap inclination processing, the first and second insulating layers of the portion that will become the magnetic gap 8 are formed. It is also possible to set the thickness H of the photoresist 6 so that a portion of the layer 2.4 is left unetched, and the thickness of the etched residue becomes the same thickness g as the magnetic gap insulating layer 6. In this case, the thickness H of the photoresist 6 is determined by the following formula % formula % (9) instead of formula (8). Effects of the Invention As described above, according to the method for manufacturing a thin film magnetic head of the present invention, for example, the insulation on the thin film coil Insulation under conditions where the photoresist layer is etched to a predetermined thickness H and the step R3, that is, 1 (=-L 1I rB; the intermediate insulating layer from the magnetic gap to the insulating layer on the thin film coil is etched at an optimal angle. Layer etching rate ro; Etching rate S of the photoresist under the above etching conditions; Step L of the insulating layer formed on the thin film coil; Coating to the thickness of the insulating layer to be etched in the magnetic gap, and flattening the gap. As a result, there are no steps or the like in the shape of the magnetic core formed after this process, making it easier for magnetic flux to flow and significantly improving recording and reproducing efficiency.Furthermore, the flattening and magnetic gap are formed at the same time. Since the manufacturing process can be greatly simplified and the manufacturing cost can be reduced, it is possible to provide a thin film magnetic head with excellent magnetic recording and reproducing efficiency at low cost.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a method for manufacturing a thin film magnetic head in an embodiment of the present invention, FIG. 2 is a schematic diagram of flattening gap processing in an embodiment of the present invention, and FIG. 3 is an ion beam etching method. FIG. 4 is a plan view of a conventional thin film magnetic head, and FIG. 5 is a schematic diagram showing a method of manufacturing a conventional thin film magnetic head. DESCRIPTION OF SYMBOLS 1... Magnetic substrate, 2... First insulating layer, 3... Thin film coil, 4... Second insulating layer, 6... ... Photoresist, 6 ... Magnetic gap insulating layer, 7 ... Magnetic core, 8 ...
...Magnetic gap. Name of agent: Patent attorney Toshio Nakao and 1 other person/-
Figure 2 Figure 3 A On-Roam incident power θ

Claims (2)

[Claims] (1) When sequentially forming a first insulating layer, a thin film coil, a second insulating layer, and a thin film magnetic core on a magnetic substrate, flatten the unevenness of the second insulating layer to which the unevenness of the thin film coil has been transferred. A method for manufacturing a thin-film magnetic head, characterized in that processing for forming a sloped portion of an intermediate insulating layer from a magnetic gap portion to the second insulating layer on the thin-film coil are simultaneously performed. (2) The etching rate of the insulating layer when processing the slope of the intermediate insulating layer at the optimum angle, r_s, the etching rate of the photoresist at this time, r_o, the step of the insulating layer formed on the thin film coil, S, the magnetic gap. When the thickness of the insulating layer etched in is L, the step R_c and thickness H after photoresist application are R_c=S*[1-(r_o/r_s)], H=(r_
2. The method of manufacturing a thin film magnetic head according to claim 1, wherein etching is performed under photoresist coating conditions such that o/r_s)L.