JPH04157607A - Thin-film magnetic head - Google Patents

Abstract

PURPOSE:To obtain the title head having as high a recording capacity as Sendust poles while having as high a mass-production property as permalloy poles, by a method wherein magnetic gap parts of upper and lower poles are constituted of a magnetic material of high saturation flux density and the other parts thereof of a magnetic material of ordinary flux saturation density. CONSTITUTION:One of magnetic gap parts 5 and 7 of upper and lower poles 3 and 2 is constituted of Sendust or a magnetic material similar thereto, and the other parts of the upper and lower poles 3 and 2 of permalloy or a magnetic material similar thereto. When the parts 7 and 5 of the upper and lower poles 3 and 2 are formed of the Sendust as stated above, the parts 7 and 5 of the Sendust are not saturated even when the parts 8 and 4 of the permalloy are saturated magnetically, since Bs of the Sendust is so large as 11000 gausses, and therefore a head thus constituted can generate a stronger recording magnetic field than the one of which the upper and lower poles 3 and 2 are all constituted of the permalloy. While having as high a recording capacity as the one of which the whole of the upper and lower poles is constituted of the Sendust or the magnetic material similar thereto, the head according to this constitution is much easier to manufacture than it and excellent in a mass- production property.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a thin film magnetic head used for magnetic recording and reproduction.

In the past, in this type of thin-film magnetic head, the upper and lower poles 27 and 22 were usually made of permalloy or a magnetic material similar to permalloy, as shown in FIG. "Latest Magnetic Recording Technology and Equipment" Sogo Gijutsu Publishing 19
84 Chapter 1 Section 4).

FIG. 5 is a schematic diagram of a conventional thin film magnetic head separated into layers. In FIG. 5, 21 is a substrate, 22 is a lower pole (permalloy), 23 is a magnetic gap spacer (A7203), 24. 2 E3 C insulating layer (photoresist), 25 a thin film fill (Cu), 27 an upper pole (permalloy), and 28 a terminal (Cu).

a. The reason why conventional thin-film magnetic heads have upper and lower poles made of permalloy or permalloy-like materials is that permalloy has high magnetic permeability and excellent properties as a magnetic herad pole, and that permalloy has excellent properties as a magnetic pole. This is because thick poles (several μm thick) with good shape accuracy can be easily manufactured in a short time.

Here, to give a concrete numerical example, the shape accuracy (in the vertical and horizontal directions) defines the track width, and the most advanced one is 10 ± 0.5 μm, and the thickness is related to the efficiency of the magnetic head. is approximately 3±0.2 μm. This value can be easily obtained using conventional techniques by combining photolithography and plating.

The problem with permalloy is that the saturation magnetic flux density Bs is low at about 8000 Gauss, so the coercive force Hc of the recording medium is 1300 Gauss.
0 e is the upper limit. For this reason, high Hc (coercive force) and recording media (Hc = about 15000 e) used to shorten the recording wavelength and increase linear recording density,
Recording is not possible due to insufficient strength of the magnetic field generated by the magnetic head.

In response to the insufficient recording magnetic field of permalloy poles, attempts have been made to change the pole material number to a material having a higher saturation magnetic flux density Bs, for example, sendust.

However, unlike permalloy, sendust cannot be plated, so in order to form the poles, in the previous numerical example, sputtering was performed to a thickness of 3 μm, followed by sputtering to a thickness of 3 μm.
Ion milling is required to remove sendust of m.
Both are permalloy.

Compared to conventional metallurgy, it is technically more difficult and time-consuming, requires expensive equipment, and is not suitable for mass production.

Therefore, the problem faced by the present invention is to realize a thin film magnetic head that has mass productivity comparable to that of Permalloy Pole and has high recording ability comparable to that of Sendust Pole.

As a means for solving the above problems, the thin film magnetic head of the present invention is provided such that at least one of the magnetic gap portions of the upper and lower poles is made of sendust or a magnetic material with a high saturation magnetic flux density equivalent to it, and・The rest of the lower pole is made of permalloy or a magnetic material with an equivalent saturation magnetic flux density.

- Sendust or a material with magnetic properties equivalent to Sendust, which forms the magnetic gap part of the upper and lower poles, has a higher saturation magnetic flux density Bs than a material with magnetic properties equivalent to Permalloy (Sendus): 11000 Gauss, Permalloy: 8000 Gauss) O Therefore, a pole with a material such as sendust in the magnetic gap can generate a stronger recording magnetic field than a pole made only of permalloy, and as a result, it is possible to record on a recording medium with a higher Hc. becomes () (-coercive force for Malloy only) 1 c
= 130008 is the upper limit, if Sendust is added, Hc
= 15000 e possible). This is an essential condition for increasing the linear recording density.

On the other hand, materials such as permalloy or permalloy, which make up most of the pole, can be manufactured by plating, so it is much easier to achieve shape accuracy and thickness than with materials such as sendust or sendust, which must be made by sputtering or ion milling. It is highly mass-producible.

disaster prevention Hereinafter, the present invention will be explained with reference to the drawings.

FIG. 1 is a perspective view of an embodiment of the thin film magnetic head of the present invention. 2 is a front view of the embodiment shown in FIG. 1, viewed from the direction of arrow A.

In each figure, straight lines and parts unrelated to the claims (protective film, insulating film, electrodes, etc.) are omitted for ease of explanation.

In Figures 1 and 2, 1 is the substrate, 2 is the lower pole, and 3
is the upper pole, 4 is the permalloy part that is the remainder of the lower pole, 5 is the sendust part that is the magnetic gap part of the lower pole, 6 is the magnetic gap spacer, 7 is the sendust part that is the magnetic gap part of the upper pole, 8 is the upper pole The remaining part of the pole is a permalloy part, 9 is a thin film coil, and 10 is an upper/lower pole connection part.

Next, an outline of the manufacturing process of this embodiment will be explained.

Substrate 1 (material: A4TiC) whose surface has been thoroughly cleaned and dried
) on top of the lower pole plating base (Ti) in a thin layer (0.2μm).
) to sputter.

2) Form a negative pattern of the lower pole 2 on the plating base using photoresist.

3) Form the permalloy portion 4 of the lower pole 2 by electroplating (thickness: 2 μm).

4) Remove photoresist.

5) Sputter a thin sendust film over the entire surface (thickness 0.
5 μm).

6) Remove the Ti base of the photoresist plating on the positive pattern of the lower pole 2.

8) Gap spacer (Aj203) 0.4μ throughout
Sputter m.

9) Coil plating base Ti is thinly applied to the entire surface (0.2μ
m) Sputter.

10) Form a negative pattern of the coil using photoresist.

11) Plate the coil with Cu (thickness: 4 μm).

12) Remove photoresist.

13) Remove the coil plating base Ti film by ion milling.

14) Sputter an insulating film (Al5O12, 3 μm) over the entire surface.

15) In order to make a hole 10 for connecting the upper and lower poles in the center of the coil, a negative pattern is formed using photoresist.

1B) Upper and lower pole connection parts 10 are made by ion milling.
Remove the insulating film and gap spacer.

17) Sputter the upper Poulsen dust portion 7 (0.5 μm thick).

18) Form a negative pattern for the upper pole using photoresist.

19) Electroplating the permalloy part 8 (thickness 2 μm) of the upper pole (using the sendust part 7 of the upper pole as the plating base).

20) Remove photoresist.

21) The part of the sendust part 7 of the upper pole used as the plating base (the part protruding from the permalloy part 8 of the upper pole) is removed by ion milling.

22) Sputter a protective film Uj20a (thickness: 30 μm) over the entire surface (not shown).

The above is the manufacturing process of the main element of the thin film magnetic head of the present invention.

Next, the operation of the thin film magnetic head of the present invention will be explained.

Coil 9 for magnetic recording on a recording medium (not shown)
When a recording current is applied to the upper pole 3 and the lower pole 2, a magnetic flux flows back through the upper and lower pole connecting portions 10, and the magnetic flux leaks into the air at the magnetic gap spacer portion 6, increasing the medium recording magnetic field. becomes.

In order to record on a recording medium with a high Hc (15000e), a strong recording magnetic field is required, so a strong recording current must be passed. If the upper and lower poles 3.2 are made of permalloy only as in the past, the permalloy B
Since s is as small as 8000 Gauss, no matter how strong the recording current is passed through the coil 9, the upper and lower poles 3 and 2 become magnetically saturated and a strong recording magnetic field cannot be generated.

However, as in the present invention, the part 7 of the lower upper pole 3, 2,
If 5 is made of Sendust, Sendust's Bs
Since it is as thick as 11,000 Gauss, the permalloy part 8,
Even if 4 is magnetically saturated, the sendust parts 7 and 5 are not saturated,
It is possible to generate a stronger recording magnetic field than when the upper and lower poles 3 and 2 are all made of permalloy.

For this reason, the thin film magnetic head with the structure of the present invention can record on high Bs media (Bs=150008), which was previously impossible to record on.
can be recorded. As is well known, the high Bs medium is
Since it is possible to increase the recording density (linear density) compared to media, the use of the thin film magnetic head of the present invention allows for miniaturization of magnetic recording devices.

Large capacity becomes possible.

Next, another embodiment of the present invention will be described with reference to FIGS. 3 and 4.

FIG. 3 is a perspective view of another embodiment of the thin film magnetic head of the present invention.

FIG. 4 is a front view of the embodiment shown in FIG. 3, viewed from the direction of arrow A.

The numbers for explanation are the same for those corresponding to the first embodiment, FIG. 1, and FIG. 2.

The features of the second embodiment will be described below in comparison with the first embodiment.

In the first embodiment, both the upper and lower poles 7.5 on the magnetic gear e side were made of sendust film, but the second
In the embodiment, only a portion 7 of the upper pole 3 on the side of the magnetic gear θ is made of sendust film, and the entire lower pole 2 is made of permalloy.

With this configuration, the manufacturing process of the second embodiment is clearly simpler than that of the first embodiment, and mass productivity is further improved.

On the other hand, the recording ability of the magnetic head of the second embodiment is almost the same as that of the first embodiment. The reason for this is that the magnetic field required during recording is generated from the trailing edge and edge, and the contribution of the leading edge and edge is small. In the second embodiment, the trailing edge is the sendust portion 7 of the upper pole, and since this is made of sendust, a strong magnetic field necessary for recording can be generated from the trailing edge. Therefore, the recording capability of the second embodiment is not much different from that of the first embodiment.

Therefore, the second embodiment has almost the same high performance as the first embodiment in terms of recording ability, and is also much more suitable for mass production than the first embodiment.

As explained above, the thin film magnetic head of the present invention has the following characteristics:
At least one of the magnetic gap parts of the lower pole is made of Sendust or a similar magnetic material, and the rest of the upper Φ lower pole is made of Permalloy or a similar magnetic material, so that all of the upper and lower poles are made of Sendust or a magnetic material similar to it. Although it has the same high recording ability as those made of similar magnetic materials, it is much easier to manufacture and has the advantage of being mass-producible.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention, FIG. 2 is a front view from the direction of arrow A in FIG. 1, FIG. 3 is a perspective view of a second embodiment of the present invention, and FIG. FIG. 3 is a front view taken from the direction of arrow A, and FIG. 5 is a schematic diagram of a conventional thin film head of this type, and each layer is drawn separately to make the structure easier to understand. , 1, 21... Board, 2.22... Lower pole, 3.27... Upper pole, 4... Bottom of lower pole (permalloy part), 5
...Magnetic gap part of lower pole (sendust part), 6.23...Magnetic gap spacer, 7...
...Magnetic gap part of the upper pole (sendust part), 8...Remaining part of the upper pole (permalloy part))9
．． 25... Thin film coil, 10... Upper/lower pole connection part, 24.28...
...Insulating layer, 28...Terminal. Patent applicant: Kansai NEC Co., Ltd.
(, hf-) Figure 3 Figure 14 [Figure I5

Claims (2)

[Claims] (1) In a thin film magnetic head in which a lower pole, a thin film coil, an upper pole, and a protective film are sequentially laminated on a substrate, the magnetic gap portions of the upper and lower poles are made of a magnetic material with high saturation magnetic flux density, and the upper and lower poles are made of a magnetic material with high saturation magnetic flux density. A thin film magnetic head characterized in that the remainder of the lower pole is made of a magnetic material with a normal saturation magnetic flux density. (2) A thin film magnetic head according to claim 1, characterized in that the magnetic material with a high saturation magnetic flux density is Sendust, and the magnetic material with a normal saturation magnetic flux density is Permalloy.