JPH08297810A - Substrate for magnetic head core and its production - Google Patents

Abstract

PURPOSE: To absorb the residual stresses caused by the warpage of the unit substrates occurring in magnetic films so as to obviate an unexpected accident and to obtain high reliability by interposing buffer substrates between the unit substrates of a substrate for magnetic head cores. CONSTITUTION: The substrate 1 for the magnetic head cores consists of the unit substrates 2... formed by laminating plural sheets (for example, 30 sheets) and the buffer substrates 3... interposed between the unit substrates 2 by each of the prescribed number of sheets (for example, 10 sheets). The unit substrates 2 are formed to a square shape of a thickness of 580μm and a length and breadth of 5mm. The unit substrates 2 consist of nonmagnetic substrates of, for example, a thickness of 560μm consisting of ceramics of an MnO-NiO system, magnetic films of, for example, a thickness of 20μm formed by sputtering on these substrates and glass films of, for example, a thickness of 0.5μm formed by glass film sputtering on these films. The magnetic films are formed by laminating five layers of 'SENDUST (R)' films of a thickness of 4μm formed by sputtering.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated type magnetic head core substrate used for manufacturing a magnetic head such as a VTR and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, development of magnetic heads having high saturation density and high magnetic permeability has been advanced in response to demands for higher density and wider band of magnetic recording such as VTR. As a magnetic head core substrate satisfying such requirements, an outline of a manufacturing process of a laminated type magnetic head core substrate using an alloy material such as Sendust or an amorphous alloy material is shown below.

That is, FIG. 18 shows a unit substrate A to be laminated. The unit substrate A is made of sendust or the like on a non-magnetic substrate B made of, for example, ceramics and having a thickness of about 1 mm. Thickness 10-20 μm
The metal magnetic film C is formed by sputtering or the like, and the bonding glass film D of 1 μm, for example, is formed on the magnetic film C by sputtering or the like. The unit board A produced in this way is shown in FIG.
As shown in FIG. 3, a predetermined number of layers are laminated, heated to melt the bonded glass film D, and further pressed from above to laminate and bond a plurality of unit substrates A, for example, 5 units, to prepare a magnetic head core substrate E. To be done.

However, after the unit substrates A are laminated and adhered to form the magnetic head core substrate E, the head cores F and F as shown in FIG. 20 are subjected to steps such as cutting, grooving, shaping and slicing. Is created, and this head core F, F
The magnetic head G is created by winding the wire.

The box-shaped stacking jig G shown in FIG.
A plurality of unit substrates A ... Are stored in a laminated state. The plurality of unit substrates A ... Are held by a pair of blocks H, H. Further, these unit substrates A ... Are pressed by the pressing mechanism J in the stacking direction with a pressing force f.

[0006]

However, the actual unit substrate A is warped due to the film stress of the magnetic film C as shown in FIG. Therefore, when a plurality of warped unit substrates A ... Are pressed by the pressing mechanism J in the stacking direction and the warps are forcibly corrected and bonded via the bonding glass film D, the unit substrates A ... If the residual stress stays in the magnetic head core substrate E in proportion to the number of stacked layers and the residual stress is larger than the adhesive strength of the bonding glass film D, the magnetic head core substrate E has a problem of peeling.

Further, it is difficult to uniformly form the magnetic film C on the actual unit substrate A, and the unit substrate A usually has a wedge shape as shown in FIG. If such wedge-shaped unit substrates A are stacked as they are, the stacking direction is deflected, as shown in FIG. 24, for example, and when pressing by the pressing mechanism J, the pressing becomes non-uniform. Adhesion strength of the magnetic head core substrate E becomes extremely weak in the end, because sufficient adhesion is not performed. This contributes to a decrease in the reliability of the magnetic head core substrate E.

The present invention has been made in view of the above circumstances, and a first object of the present invention is to provide a magnetic head core substrate that does not cause peeling and a method for manufacturing the same. A second object of the present invention is to provide a magnetic head core substrate and a method for manufacturing the same, which can uniformly apply pressure to the stacked head substrates when manufacturing the magnetic head core substrate by glass bonding. To provide.

[0009]

A magnetic head core substrate according to a first aspect of the present invention comprises a plurality of unit substrates and a buffer substrate interposed between the unit substrates, and the plurality of unit substrates are provided. Also, the buffer substrate is adhered in a laminated state, and the unit substrate is composed of a non-magnetic substrate and a magnetic film deposited on the non-magnetic substrate.

According to a second aspect of the present invention, there is provided a magnetic head core substrate according to the first aspect, wherein the unit substrate and the buffer substrate are:
It is characterized by being bonded through a glass film. A magnetic head core substrate according to a third aspect of the present invention is the magnetic head core substrate according to the first aspect, wherein the number of the buffer substrates to be inserted between the unit substrates and the spacing are set according to the magnitude of the stress generated by the warp of the unit substrates. It is characterized by being.

A method of manufacturing a magnetic head core substrate according to a fourth aspect of the present invention comprises a plurality of unit substrates and a buffer substrate interposed between the unit substrates, wherein the plurality of unit substrates and the buffer are provided. The substrates are adhered in a laminated state, and the unit substrate comprises a non-magnetic substrate and a magnetic film deposited on the non-magnetic substrate. A glass film forming step of forming a glass film on the magnetic film and on at least one surface of the buffer substrate, a laminating step of laminating the buffer substrate and the unit substrate, and a laminating direction of the unit substrate in which the buffer substrate is interposed. And a bonding step of bonding the unit substrates pressed in the pressing step through the glass film.

A method of manufacturing a magnetic head core substrate according to a fifth aspect of the present invention comprises a plurality of unit substrates and a buffer substrate interposed between the unit substrates, wherein the plurality of unit substrates and the buffer are provided. The substrates are adhered in a laminated state, and the unit substrate is a method for manufacturing a magnetic head core substrate comprising a non-magnetic substrate and a magnetic film deposited on the non-magnetic substrate. A magnetic film measurement step of measuring the thickness of the magnetic film of the substrate, and based on the measurement results in this magnetic film measurement step, the unit substrate in which the cross sectional shape of the magnetic film is mountain-shaped is excluded and the cross sectional shape of the magnetic film is wedge-shaped. A unit substrate selecting step of selecting the unit substrate, a glass film forming step of forming a glass film on the magnetic film of the unit substrate selected in the unit substrate selecting step, and the unit substrate after the glass film forming step. A laminating step of layering, a pressurizing step of pressurizing the unit substrate in the stacking direction after the laminating step, and an adhering step of adhering the unit substrate pressed by the pressurizing step through the glass film. In the laminating step, the lamination direction of the unit substrate is pressed in the pressing step by utilizing the thick side end and the thin side end of the unit substrate having a wedge-shaped cross section of the magnetic film. It is characterized by matching the directions.

A method of manufacturing a magnetic head core substrate according to a sixth aspect of the present invention is the method of manufacturing a magnetic head core substrate according to the fifth aspect, wherein one end of the unit substrate having a wedge-shaped cross section of the laminated magnetic films has a thick side end and a thin side It is characterized in that four unit substrates, which are provided in the order of the side edge portion, the thin side edge portion, and the thick side edge portion, are repeatedly laminated as one cycle.

According to a seventh aspect of the present invention, there is provided a method of manufacturing a magnetic head core substrate according to the fifth aspect, wherein one end of the unit substrate having a wedge-shaped cross section of the laminated magnetic film has a thick side end and a thin side. Eight unit substrates each including a side end, a thin side end, a thick side end, a thin side end, a thick side end, a thick side end, and a thin side end It is characterized in that layers are repeatedly laminated as a cycle.

According to an eighth aspect of the present invention, there is provided a method of manufacturing a magnetic head core substrate, wherein a unit substrate is formed by laminating a plurality of non-magnetic substrates having a magnetic film formed thereon and adhering the non-magnetic substrates to each other. In a method of manufacturing a magnetic head core substrate comprising the buffer substrate that is inserted and adhered to absorb the stress generated by the warp of the unit substrate, a magnetic film measuring step of measuring the thickness of the magnetic films of the plurality of unit substrates. And a unit substrate selecting step of selecting a unit substrate having a cross-sectional shape of the magnetic film excluding a mountain shape and selecting a unit substrate having a wedge-shaped cross-sectional shape based on the measurement result in the magnetic film measuring step, and the unit substrate A glass film forming step of forming a glass film on the magnetic film of the unit substrate selected in the selecting step and on at least one surface of the buffer substrate, and the buffer substrate and the unit after the glass film forming step Laminating step of laminating the plates, pressurizing step of pressurizing the unit substrate in which the buffer substrate is interposed in the laminating direction, and adhering the unit substrate pressurized by the pressing step through the glass film. And a bonding step to
In the laminating step, by utilizing the thick side end and the thin side end of the unit substrate having a wedge-shaped cross section of the magnetic film, the laminating direction of the unit substrate matches the pressing direction in the pressing process. It is characterized by

According to a ninth aspect of the present invention, there is provided a method of manufacturing a magnetic head core substrate according to the eighth aspect, wherein one end of the unit substrate having a wedge-shaped cross section of the laminated magnetic films has a thick side end and a thin side end. It is characterized in that four unit substrates, which are provided in the order of the side edge portion, the thin side edge portion, and the thick side edge portion, are repeatedly laminated as one cycle.

According to a tenth aspect of the present invention, there is provided a method for manufacturing a magnetic head core substrate according to the eighth aspect, wherein one end of the unit substrate having a wedge-shaped cross section of the laminated magnetic film has a thick side end and a thin side. Eight unit substrates each including a side end, a thin side end, a thick side end, a thin side end, a thick side end, a thick side end, and a thin side end It is characterized in that layers are repeatedly laminated as a cycle.

A method of manufacturing a magnetic head core substrate according to an eleventh aspect of the present invention is the method of manufacturing the magnetic head core substrate according to the eighth aspect, wherein the buffer substrate is inserted between the unit substrates in units of four or eight unit substrates. It is characterized in that it is selectively performed according to the magnitude of the stress caused by the warp of the substrate.

[0019]

In the magnetic head core substrate according to any one of claims 1 to 3, since the buffer substrate is interposed between the unit substrates,
Since the buffer substrate absorbs the residual stress generated by the warp of the unit substrate due to the magnetic film, the unit substrate does not peel off during long-term use, which may cause an accident. High reliability can be obtained.

In the magnetic head core substrate manufacturing method according to the fourth aspect, since the buffer substrate is inserted between the unit substrates in the laminating step, even if the unit substrates warp in the pressing step, Most of the strain due to the warp is absorbed by the buffer substrate, and as a result, the residual stress of the entire magnetic head core substrate after the bonding step can be reduced. Therefore, the peeling of the unit substrate can be prevented, which can contribute to the improvement of reliability and yield. Not only that, since the residual stress is reduced, the number of laminated unit substrates can be increased more than ever, and the yield of magnetic head cores that can be taken out from this magnetic head core substrate can be increased. It can also contribute to cost reduction.

According to the fifth aspect of the present invention, there is provided a method of manufacturing a magnetic head core substrate, wherein in the laminating step, the thick-side end and the thin-side end of the wedge-shaped unit substrate are utilized to form the unit substrate in the laminating direction. Since the pressure is aligned with the pressure direction in the pressure step, the unit substrate can be pressed with a uniform pressure, and as a result, the adhesive strength of the unit substrate can be improved. It is possible to greatly contribute to the improvement of reliability by preventing various failures due to defects in advance.

According to the eighth aspect of the present invention, there is provided a method of manufacturing a magnetic head core substrate, wherein in the laminating step, the thick-side end and the thin-side end of the wedge-shaped unit substrate are utilized. Is adjusted to the pressing direction in the pressing step, and the buffer board is inserted between the unit boards at every cycle of four or eight unit boards. Therefore, even if the unit substrate is warped, it is possible to obtain a magnetic head core substrate with high adhesive strength, which can contribute to reliability and yield improvement. Since it is possible to increase the number of stacked unit substrates, it is possible to contribute to improvement of productivity and reduction of production cost.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a magnetic head core substrate 1 of a first embodiment. The magnetic head core substrate 1 is composed of a plurality of (for example, 30) unit substrates 2 ...
Buffer boards 3 are inserted for every predetermined number (for example, 10) of these unit boards 2. Then
The unit substrate 2 has a square shape with a thickness of, for example, 580 μm and a length and width of 5 mm. As shown in FIG. 2, the unit substrate 2 is made of MnO—NiO ceramics and has a thickness of, for example, 560 μm. The non-magnetic substrate 4 is formed on the non-magnetic substrate 4 by sputtering. Two
The magnetic film 5 has a thickness of 0 μm, and the glass film 6 having a thickness of, for example, 0.5 μm is formed on the magnetic film 5 by glass film sputtering. The magnetic film 5 is formed by stacking five sendust films having a thickness of 4 μm formed by sputtering. Further, as the material of the glass film 6, a low melting point bonding glass containing SiO ₂ , B ₂ O ₃ , Na ₂ O, K ₂ O or the like as a main component is preferable. Further, the thickness of the buffer substrate 3 is 900 μm, which is thicker than that of the unit substrates 2 ... The material of the buffer substrate 3 is the same as that of the non-magnetic substrate 4 such as alumina (Al ₂ O ₃ ) or ferrite that does not generate harmful gas at the temperature (for example, 650 ° C.) at the time of glass bonding. MnO-NiO
Ceramic-based materials are suitable. On at least one surface of the buffer substrate 3, a glass film 7 having a thickness of, for example, 0.5 μm for glass bonding to the unit substrate 2 is formed by sputtering. Since the magnetic film 5 is not formed on the buffer substrate 3, warpage does not occur.

Next, a method of manufacturing the magnetic head core substrate 1 having the above structure will be described. Plate 2 ... and buffer substrate 3 ...
A glass film forming step (FIG. 3, step SA1) of forming glass films 6 and 7 having a thickness of, for example, 0.5 μm on at least one surface of the substrate by sputtering, and a laminating jig 11 (see FIG. 4) after the glass film forming step. ) In which the buffer substrates 3 are inserted while the unit substrates 2 are laminated (FIG. 3, FIG.
Step SA2) and the buffer jig 3 by the laminating jig 11 ...
The pressurizing step (FIG. 3, step SA3) for pressing the unit substrates 2 ... In which the is inserted and the laminating jig 11 for pressing the unit substrates 2 ... The bonding step (FIG. 3, step SA4) of bonding the pressed unit substrates 2 by glass by melting and cooling and solidifying 6, 7 is performed. here,
The stacking jig 11 includes a box-shaped main body 12 and the main body 12
A pair of constriction blocks 14a, 14b arranged at both ends of the storage space 13 formed in the above, a contact plate 15 contacting one of the constriction blocks 14a, and a rear surface side of the contact plate 15. A leaf spring 16 provided, a pressure ball 17 that contacts the center of the leaf spring 16, a holding member 18 that rotatably holds the pressure ball 17, and a side plate 19 of the main body portion 12 are screwed. And a screw 20 for pressing the holding member 18 so that the holding member 18 can be contacted and separated. Then, in the lamination process, first,
By screwing the screw 20, the screw 20 is retracted in the direction of the arrow R1 to provide a sufficient space between the constriction blocks 14a and 14b. Next, after stacking 10 unit substrates 2 ..., The buffer substrate 3 is laminated. Further, ten unit boards 2 ... Are laminated after the buffer board 3, and then the buffer board 3 is again formed.
Are laminated. Finally, ten unit substrates 2 ... Are laminated.
Next, in the pressurizing step, by screwing the screw 20, the screw 20 is advanced in the direction of the arrow R2 to apply the pressing force.
8, the pressure ball 17, the plate spring 16 and the contact plate 15 are transmitted to the constriction block 14a. As a result, the constriction block 14a moves forward with respect to the other constriction block 14b,
The unit boards 2 with the buffer boards 3 interposed therebetween are firmly held by the pair of clamping blocks 14a and 14b. In addition, the bonding step is performed by the pair of pressing blocks 14
The laminating jig 11 that holds the unit substrates 2 by a, 14b firmly is placed in a glass bonding furnace (not shown) and heated at 650 ° C. for 1 hour to melt the glass films 6 and 7. . Then, when gradually cooled to room temperature, the unit substrates 2 with the buffer substrates 3 interposed therebetween are securely glass-bonded.

As described above, in the method of manufacturing the magnetic head core substrate 1 of this embodiment, the buffer substrate 3 is inserted between the unit substrates 2 in the laminating step, and therefore, as shown in FIG. Even if the unit substrates 2 are warped in the pressurizing step, most of the distortion caused by the warping is absorbed by the buffer substrate 3 having almost no warping because the magnetic film 5 is not formed. As a result, the residual stress of the entire magnetic head core substrate 1 after the bonding step can be reduced. Therefore, this residual stress does not become larger than the strength of the glass films 6 and 7, and the peeling of the unit substrates 2 can be prevented, which contributes to improvement in reliability and yield. it can. In addition, since the residual stress is reduced, the number of stacked unit substrates 2 can be increased more than in the conventional case, and thus the yield of magnetic head cores that can be taken out from the magnetic head core substrate 1 can be increased. It is also possible to contribute to improving the productivity and reducing the production cost.

Further, the magnetic head core substrate 1 of the embodiment
, Since the buffer substrates 3 are interposed between the unit substrates 2, the buffer substrate 3 absorbs the residual stress generated by the warp of the unit substrates 2 due to the magnetic film 5, so that The unit substrates 2 ... Are not peeled off during use for a period of time and an accident does not occur accidentally, and high reliability can be obtained.

In the above embodiment, the buffer substrate 3
Although the number of inserted sheets of ... Is two, it is necessary to appropriately adjust the number of sheets according to the magnitude of the stress due to the warp of the unit substrates 2. Further, the interposing interval of the buffer boards 3 ... Does not necessarily have to be constant.

Next, a method of manufacturing the magnetic head core substrate 31 of the second embodiment of the present invention will be described. FIG.
The structure of the magnetic head core substrate 31 of this embodiment is shown. That is, the magnetic head core substrate 31 is a unit substrate 32 including a plurality of (for example, 30) laminated layers.
It consists of Thus, the unit substrate 32 has a square shape with a thickness of, for example, 580 μm and a length and width of 5 mm. The unit substrate 32 is made of MnO—NiO ceramics and has a thickness of, for example, 560 μm.
A magnetic film 35 having a thickness of, for example, 20 μm formed on the non-magnetic substrate 34 by sputtering, and a glass film 36 having a thickness of, for example, 0.5 μm formed on the magnetic film 35 by glass film sputtering. It consists of The magnetic film 35 is formed by stacking five layers of sendust films having a thickness of 4 μm formed by sputtering. The material of the glass film 36 is SiO ₂ , B.
Adhesive glass having a low melting point and containing ₂ O ₃ , Na ₂ O, K ₂ O or the like as a main component is suitable.

Therefore, the method of manufacturing the magnetic head core substrate 31 of this embodiment includes a magnetic film measuring step (FIG. 7, step SB1) for measuring the thickness of the magnetic films 35 of the plurality of unit substrates 32. A unit substrate selection step (FIG. 7, step SB2) for excluding the wedge-shaped (see FIG. 8) cross-sectional shape of the magnetic film 35 based on the measurement result in the magnetic film measurement step (see FIG. 9); A glass film forming step (FIG. 7, step SB3) of forming a glass film 36 on the magnetic film 35 of the unit substrates 32 ... Selected by the unit substrate selecting step by sputtering, and a unit after the glass film forming step. Laminating step (step SB4 in FIG. 7) for accommodating the substrates 32 in the accommodating space 13 of the laminating jig 11, and a pressing process for pressing the unit substrates 32 ... in the laminating direction by the laminating jig 11 after the laminating step. (Figure 7, step SB5) and, for example, 650 stacking jig 11 which presses the unit substrates 32 ...
This is composed of a bonding step (step SB6 in FIG. 7) for bonding the pressed unit substrates 32 by glass by heating at ° C for 1 hour to melt and then cooling and solidifying the glass film 36. By the way, FIG. 10 shows the unit substrates 32a, 32b, 32c, 32 in the sputter table 38.
The positions of d, 32e, and 32f are shown. On the other hand, FIG.
Are unit boards 32a, 32b, 32c, 32d,
The relationship between the positions of 32e and 32f and the cross-sectional shape of the magnetic film 35 and the maximum / minimum film thickness difference are shown. These indicate that there is almost no difference in the film thickness of the magnetic film in the circumferential direction of the sputter table 38. Also, spatter table 3
The cross-sectional shape of the magnetic film 35 on the inner side in the diametrical direction of 8 is a wedge shape, whereas the cross-sectional shape of the magnetic film 35 on the outer side in the diametrical direction is a mountain shape. Therefore, a region of the sputtering table 38 having a wedge-shaped cross section is previously determined experimentally. By doing so, the sorting operation in the unit substrate sorting step can be efficiently performed. That is, the unit substrate selection step includes a wedge-shaped substrate sampling step (FIG. 12, step SC1) of excluding the mountain-shaped magnetic film 35 from the wedge-shaped cross-sectional shape based on the measurement result in the magnetic film measurement step, and the wedge-shaped substrate. Of the wedge-shaped cross-sections sampled in the sampling step, the orientation is controlled to the unit substrate 32R ... (See FIG. 13) that is thick on the right side and thin on the left side and the unit substrate 32L ... (See FIG. 13) that is thin on the right side and thick on the left side. The alignment step (FIG. 12, step SC2) is performed.

In the laminating process, as shown in FIG. 14, for example, 20 sheets such as 32R, 32L, 32L, and 32R are laminated in one cycle. By doing so, the unit substrates 32 ... Can be stacked in the pressing direction in the pressing process. Here, as shown in FIG.
32R, 32L, 32R, 32L, 32R, 32L, ...
As such, in the stacking that simply cancels the wedge shape, the stacking direction is the pressing direction (FIG. 15, arrow R3 direction).
It is not preferable because it is biased against. Therefore, in the pressurizing step of four sheets laminated in one cycle such as 32R, 32L, 32L, 32R, the wedge shape of the unit substrates 32 ... (In the direction of the arrow R3), the pair of compression blocks 14a and 14b can be aligned.
As a result, the unit substrates 32R ..., 32L ... can be pressed with a uniform pressing force. Therefore, the unit substrates 32 are firmly adhered to each other via the glass film 36.

As described above, in the method of manufacturing the magnetic head core substrate according to the second embodiment, the thick side end and the thin side end of the wedge-shaped unit substrates 32R ... Since the stacking direction of the unit substrates 32R ..., 32L ... is made to coincide with the pressurizing direction in the pressurizing step, the unit substrates 32R ..., 32L ... can be pressed with a uniform pressing force. As a result, , Unit board 32R ...
Since the adhesive strength of 32L ... can be improved, various failures due to defective adhesion can be prevented, which can greatly contribute to the improvement of reliability.

In the laminating process of the above embodiment,
For example, as shown in FIG. 16, 32R, 32L, 32L, and 32R, for example, 20 sheets are stacked in one cycle, but as shown in FIG. 16, 32R, 32L, 32L, 32R, 32L, 32
R, 32R, 32L, for example, 8 sheets in one cycle, for example, 2
Similar effects can be obtained by stacking four sheets.

Further, as shown in FIG. 17, 52R, 5
2L, 52L, 52R (or 52R, 52L, 52
L, 52R, 52L, 52R, 52R, 52L), the buffer substrates 53 shown in the first embodiment may be inserted every four cycles (or eight cycles). By doing so, not only is the wedge shape of the unit substrates 52 cancelled, but the stacking direction can be made to coincide with the pressing direction, so that the unit substrates 52 can be pressed with a uniform pressing force, and the unit substrates 52. Even if the warp occurs, the buffer substrate 53 ...
Can be absorbed. Therefore, due to the synergistic effect of these two, a glass film (not shown) on the magnetic film 55.
The unit substrate 52 can be firmly adhered by the glass film (not shown) on the buffer substrate 53, and the occurrence of an accident such as peeling of the unit substrate 52 can be completely prevented. . As a result, not only the reliability and the yield can be improved, but also the number of stacked unit substrates 52 can be increased, which can contribute to the productivity improvement and the production cost reduction.

In this case, the buffer substrates 53 are not necessarily inserted every four cycles (or every eight cycles), but may be inserted every two cycles or more depending on the magnitude of the residual stress. You may

[0035]

In the magnetic head core substrate according to the first to third aspects of the present invention, since the buffer substrate is interposed between the unit substrates, it is caused by the warp of the unit substrate due to the magnetic film. Since the residual stress is absorbed by the buffer substrate, the unit substrate is prevented from peeling off during long-term use, which may result in an unexpected accident, and high reliability can be obtained.

In the method of manufacturing the magnetic head core substrate according to the fourth aspect of the present invention, since the buffer substrate is interposed between the unit substrates in the laminating process, the unit substrates warp in the pressing process. However, as a result of the distortion caused by the warp being mostly absorbed by the buffer substrate, the residual stress of the entire magnetic head core substrate after the bonding step can be reduced. Therefore, the peeling of the unit substrate can be prevented, which can contribute to the improvement of reliability and yield. Not only that, since the residual stress is reduced, the number of laminated unit substrates can be increased more than ever, and the yield of magnetic head cores that can be taken out from this magnetic head core substrate can be increased. It can also contribute to cost reduction.

In the method of manufacturing a magnetic head core substrate according to any one of claims 5 to 7 of the present invention, the thick side end and the thin side end of the wedge-shaped unit substrate are utilized in the laminating step.
Since the stacking direction of the unit substrates is made to coincide with the pressing direction in the pressing process, the unit substrates can be pressed with a uniform pressing force, and as a result, the adhesive strength of the unit substrates can be improved. As a result, various failures due to defective adhesion can be prevented in advance, which can greatly contribute to the improvement of reliability.

According to the eighth aspect of the present invention, there is provided a method for manufacturing a magnetic head core substrate, comprising:
By utilizing the thick side end and the thin side end of the wedge-shaped unit substrate, the stacking direction of the unit substrates is made to coincide with the pressing direction in the pressing step, and the buffer substrate is interposed between the unit substrates. Since the insertion is selectively performed according to the magnitude of the stress caused by the warp of the unit substrates for each cycle of four or eight unit substrates, even if the unit substrates are warped,
A magnetic head core substrate having high adhesive strength can be obtained, which contributes to improvement of reliability and yield, and moreover, since the number of laminated unit substrates can be increased, productivity is improved and production cost is also reduced. Can contribute.

[Brief description of drawings]

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

FIG. 2 is an enlarged cross-sectional view of a main part of a magnetic head core substrate according to an embodiment of the present invention.

FIG. 3 is a flowchart showing a method of manufacturing a magnetic head core substrate according to an embodiment of the present invention.

FIG. 4 is a diagram showing a laminating jig used in a method for manufacturing a magnetic head core substrate according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of a method of manufacturing a magnetic head core substrate according to an embodiment of the present invention.

FIG. 6 is a configuration diagram of a magnetic head core substrate according to another embodiment of the present invention.

FIG. 7 is a flowchart showing a method of manufacturing a magnetic head core substrate according to another embodiment of the present invention.

FIG. 8 is a cross-sectional view of a unit substrate used in a method of manufacturing a magnetic head core substrate according to another embodiment of the present invention.

FIG. 9 is a cross-sectional view of a unit substrate removed in a method of manufacturing a magnetic head core substrate according to another embodiment of the present invention.

FIG. 10 is a plan view of a sputtering table for forming a magnetic film on a unit substrate in a method of manufacturing a magnetic head core substrate according to another embodiment of the present invention.

11 is a diagram showing the relationship between the position on the sputtering table shown in FIG. 10 and the magnetic film.

FIG. 12 is a flow chart showing a unit substrate selection step in a method of manufacturing a magnetic head core substrate according to another embodiment of the present invention.

FIG. 13 is a cross-sectional view showing two types of unit substrates oriented in a method of manufacturing a magnetic head core substrate according to another embodiment of the present invention.

FIG. 14 is a diagram showing a laminating step in a method of manufacturing a magnetic head core substrate according to another embodiment of the present invention.

15 is a diagram showing a comparative example with respect to the stacking process shown in FIG.

FIG. 16 is a diagram showing a modified example of the method of manufacturing the magnetic head core substrate according to another embodiment of the present invention.

FIG. 17 is a diagram showing a modified example of the method of manufacturing the magnetic head core substrate of another embodiment of the present invention.

FIG. 18 is a cross-sectional view of a unit substrate according to a conventional technique.

FIG. 19 is a cross-sectional view of a conventional magnetic head core substrate.

FIG. 20 is a perspective view showing a magnetic head using a conventional magnetic head core substrate.

FIG. 21 is a diagram showing a stacking jig used for manufacturing a magnetic head core substrate according to a conventional technique.

FIG. 22 is a cross-sectional view showing a warp of a unit substrate in the related art.

FIG. 23 is a cross-sectional view showing a wedge shape of a unit substrate according to a conventional technique.

24 is a diagram showing a laminating process using the unit substrate shown in FIG. 23.

[Explanation of symbols]

1, 31: magnetic head core substrate, 2, 32, 52: unit substrate, 3, 53: buffer substrate, 4, 34: non-magnetic substrate,
5, 35: magnetic film, 6, 36: glass film, 14a, 14
b: A pressure block.

Claims (11)

[Claims] 1. A plurality of unit boards, and a buffer board interposed between these unit boards, wherein the plurality of unit boards and the buffer board are bonded in a laminated state, and
The magnetic head core substrate, wherein the unit substrate comprises a non-magnetic substrate and a magnetic film deposited on the non-magnetic substrate. 2. The magnetic head core substrate according to claim 1, wherein the unit substrate and the buffer substrate are bonded to each other through a glass film. 3. The magnetic field according to claim 1, wherein the number of the buffer boards to be inserted between the unit boards and the interval of the buffer boards are set according to the magnitude of the stress generated by the warp of the unit boards. Substrate for head core. 4. A plurality of unit substrates and a buffer substrate interposed between the unit substrates, wherein the plurality of unit substrates and the buffer substrate are bonded in a laminated state, and
The unit substrate is a non-magnetic substrate and a method for manufacturing a magnetic head core substrate comprising a magnetic film deposited on the non-magnetic substrate, wherein a glass is formed on the magnetic film of the unit substrate and on at least one surface of the buffer substrate. A glass film forming step of forming a film; a laminating step of laminating the buffer substrate and the unit substrate; a pressurizing step of pressurizing a unit substrate in which the buffer substrate is interposed in a stacking direction; And a step of adhering the unit substrate, which has been pressed by the method, through the glass film, to the magnetic head core substrate. 5. A plurality of unit boards and a buffer board interposed between the unit boards, wherein the plurality of unit boards and the buffer board are bonded in a laminated state, and
In the method for manufacturing a magnetic head core substrate, wherein the unit substrate is a non-magnetic substrate and a magnetic film deposited on the non-magnetic substrate, a magnetic film for measuring the thickness of the magnetic films of the plurality of unit substrates. Based on the measurement step and the measurement result in the magnetic film measurement step, the unit substrate selection step of excluding the unit substrate having a mountain-shaped cross section of the magnetic film and selecting the unit substrate having a wedge-shaped cross section of the magnetic film, A glass film forming step of forming a glass film on the magnetic film of the unit substrate selected in the unit substrate selecting step, a laminating step of laminating the unit substrate after the glass film forming step, and a laminating step after the laminating step. The step of pressing the unit substrates in the laminating direction and the step of adhering the unit substrates pressed by the pressing step through the glass film include the magnetic film in the laminating step. A magnetic head core substrate, characterized in that the stacking direction of the unit substrates is matched with the pressing direction in the pressing step by utilizing the thick side end and the thin side end of the unit substrate having a wedge-shaped cross section. Manufacturing method. 6. A laminated magnetic film has a wedge-shaped cross-sectional shape, and one end of a unit substrate is provided in order of a thick side end, a thin side end, a thin side end, and a thick side end. 6. The method for manufacturing a magnetic head core substrate according to claim 5, wherein the four unit substrates are repeatedly laminated in one cycle. 7. A unit substrate having a wedge-shaped cross section of laminated magnetic films has a thick side end, a thin side end, a thin side end, a thick side end, a thin side end, 6. The magnetic head core substrate according to claim 5, wherein eight unit substrates each having a thick-side end portion, a thick-side end portion, and a thin-side end portion provided in this order are repeatedly stacked for one cycle. Production method. 8. A unit substrate formed by laminating and adhering a plurality of non-magnetic substrates having a magnetic film formed thereon, and inserting and adhering between the unit substrates to absorb stress generated by the warp of the unit substrate. In the method of manufacturing a magnetic head core substrate including the buffer substrate, the magnetic film measuring step of measuring the thickness of the magnetic film of the plurality of unit substrates, and the magnetic film measurement step based on the measurement result in the magnetic film measuring step. A unit substrate selection step of excluding a unit substrate having a mountain-shaped cross section and selecting a unit substrate having a wedge-shaped cross section of the magnetic film, and a magnetic film of the unit substrate selected in the unit substrate selection step and the above A glass film forming step of forming a glass film on at least one surface of the buffer substrate, a laminating step of laminating the buffer substrate and the unit substrate after the glass film forming step, and a single step in which the buffer substrate is interposed. The method comprises a pressing step of pressing the substrates in the stacking direction, and an adhesion step of bonding the unit substrates pressed by the pressing step through the glass film. A magnetic head core substrate, characterized in that the stacking direction of the unit substrates is matched with the pressing direction in the pressing step by utilizing the thick side end and the thin side end of the unit substrate having a wedge-shaped cross section. Manufacturing method. 9. One end of a unit substrate having a wedge-shaped cross section of laminated magnetic films is provided in the order of a thick side end, a thin side end, a thin side end, and a thick side end. 9. The method for manufacturing a magnetic head core substrate according to claim 8, wherein the four unit substrates are repeatedly laminated in one cycle. 10. A laminated magnetic film having a wedge-shaped cross-sectional shape, wherein one end of a unit substrate has a thick side end, a thin side end, a thin side end, a thick side end, a thin side end, 9. The magnetic head core substrate according to claim 8, wherein eight unit substrates each having a thick-side end portion, a thick-side end portion, and a thin-side end portion are provided in this order in a cycle. Production method. 11. A buffer substrate is selectively inserted between unit substrates in accordance with the magnitude of stress generated by the warp of the unit substrates for each cycle of four or eight unit substrates. The method for manufacturing a magnetic head core substrate according to claim 8.