JPH07192214A - Magnetic head and its production - Google Patents

Abstract

PURPOSE:To form tracks with good accuracy of width when narrow width tracks are formed. CONSTITUTION:When two head cores 1, 2 having magnetic layers F1, F2 of different thickness, respectively, are joined to form a gap 3, the cores are joined in such a manner that the magnetic layer F1 having smaller thickness is butt- joined within the width of the magnetic layer F2 having larger thickness. Thereby, the track width is limited by the magnetic layer F1 of a smaller thickness, and the track width can be controlled with the accuracy of thickness of the magnetic layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head and a method of manufacturing the same, and more particularly to a laminated type magnetic head formed by sandwiching a magnetic layer between non-magnetic substrates and a method of manufacturing the same.

[0002]

2. Description of the Related Art In a magnetic recording / reproducing apparatus represented by a video tape recorder (VTR), a hard disk apparatus, etc., the track width of a magnetic head is becoming narrower as the recording density becomes higher. Among them, the laminated type magnetic head formed by sandwiching a magnetic layer between non-magnetic substrates is advantageous for narrowing the track because the track width is determined by the thickness of the magnetic layer.

FIG. 4 is a perspective view showing a core portion of a conventional laminated type magnetic head. The laminated type magnetic head includes a pair of head cores 1 and 2. Each of the head cores 1 and 2 has a structure in which the magnetic layer F is sandwiched between the non-magnetic substrates K from both sides.

On the other hand, the head core 2 is provided with a winding groove E1 and a glass material filling groove E2 used for joining. The head cores 1 and 2 are joined so that the magnetic layers F thereof face each other, and a gap 3 is formed between one magnetic layer F and the other magnetic layer F.

The magnetic layer F may be a single layer, or may have a structure in which magnetic layers and insulating layers are alternately laminated to suppress the generation of eddy currents.

5 (a) to 5 (e) show a method of manufacturing a core portion of a conventional laminated type magnetic head. As shown in FIG. 5 (a), a magnetic layer F is formed on a non-magnetic substrate K made of ceramic or the like by a method such as sputtering to prepare a large number of substrates A with magnetic layers. The thickness of the magnetic layer F finally becomes the track width of the magnetic head. This magnetic layer F is
It may be a single layer, or may have a structure in which magnetic layers and insulating layers are alternately laminated to suppress generation of eddy current.

FIG. 5B shows a block B in which a large number of these substrates A with magnetic layers are laminated. This block B is formed by sputtering glass on the magnetic layer F of the substrate A,
It can be made by heating under pressure and joining.

In FIG. 5 (c), the block B of FIG. 5 (b) is cut to be divided into two core blocks E and D, and one core block E having a mirror-finished divided surface is provided with a winding groove E1. , Where the glass material filling groove E2 is formed. After this,
A non-magnetic material such as SiO2 is formed on the mirror surface portion by sputtering, and this is used as a gap spacer, but abutted so that the magnetic layers F of the two core blocks E and D face each other.
After inserting a glass rod into the winding groove E1 and the glass material filling groove E2, pressure heating is performed to weld the two core blocks E and D together. This welded state is shown in FIG. 5 (d).

After that, the core block shown in FIG. 5 (d) is cut at the non-magnetic substrate K to obtain a magnetic head core as shown in FIG. This magnetic head core is further attached to a base plate, coil winding, and lapping of the tape running surface to complete a magnetic head.

By the way, FIG. 5 in the above manufacturing method
In the step (d), the two core blocks E and D may not be completely abutted with each other, and the magnetic layers F and F may be abutted with each other as shown in FIG. Track width is 10 μm
In the above, these deviations (hereinafter referred to as track deviations)
However, in recent years, high-density recording devices, especially hard disk devices, are required to have a track width of about 5 μm. The track deviation depends on the machine dimensional accuracy and the butt accuracy, but at present, about 1 μm is unavoidable. However, the deviation of 1 μm from the track width of 5 μm means that the track width is reduced by 20%, which is a non-negligible amount when the other track width variation factors are included.

[0011]

As described above, in a narrow track width in high density recording, especially at a track width of 10 μm or less, the accuracy of the track width is not negligible due to the deviation of the track width butting.

In view of the above problems, it is an object of the present invention to provide a magnetic head capable of forming a highly precise track width when forming a narrow track width, and a method of manufacturing the same. is there.

[0013]

The invention according to claim 1 is
A magnetic head having a structure in which two head cores having a magnetic layer sandwiched from both sides by a non-magnetic substrate are abutted and fixed so that the magnetic layers face each other via a gap,
Each of the magnetic layers of the two head cores is characterized by having a thickness different from each other and having a structure in which a magnetic layer having a small thickness is abutted within the width of a magnetic layer having a large thickness.

According to a second aspect of the present invention, a non-magnetic layer and a magnetic layer are alternately laminated to form a laminated body, and the laminated body is divided to form a pair of core blocks. After grooving each core block and mirror-finishing the above-mentioned divided surfaces, after abutting so that the magnetic layers of the two core blocks face each other through a non-magnetic material corresponding to the gap length, adhesion is performed. Forming a core block, and cutting the core block with the non-magnetic layer to obtain a head core. When the two core blocks are abutted against each other, the corresponding magnetic layers before the two blocks are separated are shifted by one or an odd number of pitches and abutted against each other, and then bonded to form a core block. Than it is.

[0015]

In the above magnetic head, the two magnetic layers F1 and F2 having different thicknesses S and T are brought into contact with each other, and if the thickness of each layer is S <T, the layer thickness F1 is small.
Defines the true track width.

Therefore, in the method of manufacturing the magnetic head,
Forming a laminated body by changing the thickness of every other magnetic layer,
By dividing this into two core blocks, the corresponding magnetic layers before separating the two blocks are shifted by one or an odd number of pitches and abutted, so that Δ = T between the adjacent magnetic layers F1 and F2. Since the deviation of −S exists from the beginning, if the deviation at the time of butting is Δ or less, the track width is determined by F1 and the track width can be controlled by the thickness accuracy of the magnetic layer.

[0017]

EXAMPLES Examples will be described with reference to the drawings. FIG. 1 is a perspective view showing a core portion of a magnetic head according to an embodiment of the present invention.

In FIG. 1, the core of a laminated type magnetic head includes a pair of head cores 1 and 2. Each of the head cores 1 and 2 has a structure in which the magnetic layer F is sandwiched between the non-magnetic substrates K from both sides, but unlike the conventional case, the thickness of each magnetic layer is different. Here, the magnetic layers having different thicknesses in the head cores 1 and 2 are connected to F1 and F2, respectively.
And The head cores 1 and 2 have respective magnetic layers F1
, F2 are joined so as to abut each other through the gap 3. Assuming that the thicknesses of the magnetic layers F1 and F2 are S and T, and S <T, the magnetic layer F1 having a small thickness is abutted within the width of the magnetic layer F2 having a large thickness. Further, one head core 2 is provided with a winding groove E1 and a glass material filling groove E2 used for joining. The magnetic layers F1 and F2 may be a single layer, or may have a structure in which magnetic layers and insulating layers are alternately laminated to suppress the generation of eddy currents.

In the magnetic head using the core having the above structure,
The magnetic layer F1 having a small thickness defines the true track width.

FIG. 2 is a perspective view showing an embodiment of a method of manufacturing the core portion of the magnetic head.

As shown in FIG. 2A, the non-magnetic substrate K is
Substrate A1 with two magnetic layers F1 and F2 having different thicknesses
, A2 pairs are prepared.

The nonmagnetic substrates A1 and A2 are alternately stacked to form a block B as shown in FIG. 2 (b).

This block B is divided into two blocks as shown in FIG.
After dividing into two core blocks E and D, the divided surface is finished into a mirror surface, a winding groove E1 and a glass material filling groove E2 are formed, and then a gap film made of a non-magnetic material such as SiO2 is formed on the mirror surface portion. After the divided surfaces are abutted against each other and the glass rod is inserted into the winding groove E1 and the glass material filling groove E2, the core blocks E and D are welded by pressurizing and heating.

At this time, as shown in FIG. 2 (d), the magnetic layer is not abutted against the magnetic layer that was continuous when divided, but is abutted on the magnetic layer immediately adjacent to the magnetic layer by shifting one pitch. As a result, the magnetic layers F1 and F2 having different thicknesses abut against each other, and the thicknesses S and T of the magnetic layers F1 and F2 respectively.
If S <T, the track width is restricted by the magnetic layer F1 having a small thickness.

After that, the core block shown in FIG. 2D is cut and processed at the non-magnetic substrate K portion to obtain a magnetic head core as shown in FIG. This magnetic head core is further attached to a base plate, coil winding, and lapping of the tape running surface to complete a magnetic head.

Next, how the track shift at the left end of the core block of FIG. 2 (d) appears at the right end will be shown by a calculation formula. In the conventional system as shown in FIG. 5, when a butt displacement occurs as shown in FIG. 6, if the track displacement amount at the left end is Δμm, the right end has the same Δμ.
m, and the track width is reduced by Δμm in all tracks.

In this embodiment, as shown in FIG. 2 (d), the set of the non-magnetic substrate K and the magnetic layer F1 and the set of the non-magnetic substrate K and the magnetic layer F2 in the core block E or D are 1 to 1 in total. 2n
(N is a positive integer) for each group, non-magnetic substrate,
The thicknesses of the magnetic layers are (L1, S1), (L2, T2),
(L3, S3), ..., (L2n-1, S2n-1),
(L2n, T2n), the position where one track is displaced from the left end of the core block E is the origin, the distance to the 2nth track is K2n, and the left end of the core block D is the origin.
If the distance to the 2n-1st track is L2n, then 2
The n-th track deviation Δ2n is K2n = T2 + (L3 + S3) + ... + (L2n + T2n) L2n = S1 + (L2 + T2) + ... + (L2n−1 + S2n-1) Δ2n = K2n−L2n L2n + T2n)-(L2 + S1) = (L2n-L2) + (T2n-S1).

In order for the track width to be regulated by the thickness of the magnetic layer F1, that is, S, Δ2n = K2n-L2n> 0, and at this time, T2n-S1> L2-L2n. That is,
The difference between the thicknesses of the magnetic layers F2 and F1 is determined by the thickness L of the non-magnetic substrate K.
It is necessary to keep it larger than the variation of. Actually, it is sufficient to allow a further margin in consideration of the accuracy of the butting. However, if the difference between the magnetic layers F1 and F2 is set to 2 μm, it is sufficiently possible to regulate the track width by the smaller magnetic layer, and Since the magnetic layer thickness can be controlled within ± 5%, it is possible to supply a more accurate track width.

FIG. 3 shows a modification of the method of manufacturing the magnetic head of the present invention. 3 (a) and 3 (b) are the steps (a) and (b) of FIG.
The magnetic layers F1 and F2 having different thicknesses on both surfaces of the non-magnetic substrate K (where S and T are the thicknesses of the layers, S <
T) is formed on the magnetic layer F for the non-magnetic substrate K.
The block B may be formed by stacking a large number of 1 and F2 in a state where the left and right positions are alternately reversed. The subsequent steps are the same as those in (c) to (d) of FIG.

[0030]

As described above, according to the present invention, by abutting two head cores having magnetic layers having different thicknesses, it is possible to prevent a decrease in track width due to a track shift at the time of abutting, A highly accurate track width can be formed.

[Brief description of drawings]

FIG. 1 is a perspective view showing a core portion of a magnetic head according to an embodiment of the invention.

FIG. 2 is a perspective view showing an embodiment of a method of manufacturing the core portion of the magnetic head of FIG.

FIG. 3 is a perspective view showing a modified example of the present invention.

FIG. 4 is a perspective view showing a core portion of a conventional magnetic head.

5 is a perspective view showing a method of manufacturing the core portion of the magnetic head of FIG.

FIG. 6 is a perspective view showing a defect of the conventional manufacturing method.

[Explanation of symbols]

 1, 2 ... Head core 3 ... Gap K ... Non-magnetic substrate F1, F2 ... Magnetic layer A1, A2 ... Substrate with magnetic layer E, D ... Core block E1 ... Winding groove E2 ... Glass material filling groove

Claims (2)

[Claims] 1. A magnetic layer sandwiched by nonmagnetic substrates from both sides.
In a magnetic head having a structure in which two head cores are abutted and fixed to each other via gaps so that the magnetic layers face each other, the magnetic layers of the two head cores are formed to have different thicknesses and have a large magnetic thickness. A magnetic head having a structure in which a magnetic layer having a small thickness is abutted within the width of the layer. 2. A non-magnetic layer and a magnetic layer are alternately laminated to form a laminated body, the laminated body is divided to form a pair of core blocks, and a groove is formed in each of the core blocks on one side or both sides. After processing and mirror-finishing the divided surfaces, the magnetic layers of the two core blocks are butted so as to face each other through a non-magnetic material corresponding to the gap length, and then bonded to form a core block. In the method of manufacturing a magnetic head, wherein the core block is cut and processed by the non-magnetic layer to obtain a head core, the magnetic layers are made different in thickness every other layer, and two core blocks after division are butted. At this time, a method of manufacturing a magnetic head, characterized in that the corresponding magnetic layer, which was before separating the two blocks, is shifted by 1 or an odd number of pitches and abutted, and then bonded to form a core block.