JPS60151809A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To mass-produce magnetic heads where cores consisting of metallic magnetic materials are interposed between glasses, by cutting out many core chips from the third block as a base where the first block having metallic magnetic materials as the center material and the second block consisting of oxide magnetic materials are joined. CONSTITUTION:In this method, the third block B3 where the first block B1 having metallic magnetic materials as the center material and the second block B2 consisting of oxide magnetic materials are joined is used as the base and many core chips are cut out from this base. Consequently, productivity is improved considerably in comparison with a conventional example where center cores and auxiliary cores are assembled in core units. Since a glass 11 is packed in grooves 9a- prescribing a track width T of the first block B1 and part near front gaps of magnetic heads are backed with this glass, magnetic heads superior in mechanical strength are produced with a good yield.

Description

DETAILED DESCRIPTION OF THE INVENTION (() Field of Industrial Use) The present invention relates to a method of manufacturing a magnetic head that can be used in devices such as 8 mm video cameras.

(b) Prior Art In order to completely miniaturize the device, 8 mm video is designed to perform dense magnetic recording by combining a magnetic tape with high coercive force and a magnetic head with a core material exhibiting high saturation magnetic flux.

Sendust (Fθ-8i-
The thickness of Al (alloy) material is the same as the track width (for example, 20
μm), a pair of auxiliary cores are added on both sides of the center core, which has non-magnetic parts near the front gap of the center core, and the other parts are made of oxide magnetic material. Publicly known (for example, Japanese Patent Application Laid-Open No. 57-1580
However, this magnetic head is manufactured by processing and molding the center core and the auxiliary core at the core level, and is not suitable for mass production.

On the other hand, there is a method in which a block made of a metal magnetic material with a front gap is placed in the upper part, a block made of an oxide magnetic material is placed in the lower part, the two blocks are joined, and then the blocks are separated and molded into core chips. It is recognized that this method improves productivity compared to the above manufacturing method. However, this magnetic head has a configuration in which the core is narrowed down at the front gap in order to define the track width, so when this magnetic head is used, the area near the front gap receives a concentrated load and wears out, resulting in poor life characteristics. be.

(c) Purpose of the Invention The present invention has been developed in view of the above points, and is to manufacture a magnetic head suitable for mass production of a type of magnetic head in which a core made of a metal magnetic material is sandwiched between glass from both sides. It is intended to provide a method.

B)) Structure of the Invention The present invention is a method of manufacturing a magnetic head including the following steps [al to tg+].

(a) Two sheets of metal magnetic material (e.g. Fθ-AI!-8i
By combining different wafers with a film of non-magnetic material sandwiched between them, and welding a bonding material (for example, silver solder) to both wafers using grooves formed in at least one of the wafers. ('b) A plurality of grooves are formed from one surface of the first block in a direction intersecting the grooves, and a land portion having a width corresponding to the track width is formed between adjacent grooves. a step of filling the plurality of grooves with the glass having physical properties close to (or matching) the coefficient of thermal expansion of the magnetic material; (al made of an oxide magnetic material); a step of opening grooves to serve as coil windows on the plane of the second block; A step of placing both blocks so as to face each other and integrating them to form a sixth block; A step of machining to regulate the depth of the front gap; and a step of dividing the sixth block along the plurality of grooves so that the land portion remains at the center of the groove.

Kui 1 example FIGS. 1 to 3 illustrate the process tal.

Sendas? (Fθ-Al-8i alloy) wafer (
Prepare 11 and place an appropriate space (11L) on one side of it (11L).
2) Two parallel grooves 1a) ib) are opened using a Borazon island grain blade. Each groove 1a) (3'b
) has a V-shaped cross section, and the inner edge of one of the grooves (5a), that is, the ridgeline (4), is strictly defined. This is because the lower end of the front gap of the magnetic head is the so-called depth end. After creating each of the above-mentioned grooves, the - surface (1a) is polished to a mirror surface by lapping and polishing, and a non-magnetic material (for example 5102) is applied on the polished surface.
The thin film (5) is made to have a thickness corresponding to the gap length, for example, 0.
25 to 0.55 μm) by sputtering or vapor deposition. The wafer (1) processed in this way is placed on the mirror-polished '-surface (6a) of another Sendust wafer (6) so that the mirror surfaces face each other, and the grooves (3a) ( 51) Insert the silver solder wire (7) into the inside. Then, in a vacuum (or in a neutral atmospheric gas such as N2, Ar, etc.), pressurize and heat these two wires (11 (61) and weld them with the wire described above, forming the dotted line (X+) (N2).
Remove unnecessary portions (Nl) (N2) and create the first block (
B1) is obtained. In this example, the solidus temperature is approximately 680°C,
Using a silver brazing material of Ag-0u-Zn ternary alloy with a liquidus temperature of approximately 750°C, the maximum temperature was approximately 80°C in an N2 gas atmosphere.
Welding was carried out at 0°C. (8) is a bonding material (silver solder) layer. In addition to the above-mentioned welding method, the above-mentioned grooves 1a)('
5t)) may be filled with silver brazing material in advance, and the two wafers may be bonded using this silver brazing material.

FIGS. 4 and 5 are perspective views of the first block molded in steps (1) 1 and 101. From the first surface (Bll) of the first block (B1) to each groove 1a) (5
1) A plurality of grooves (No. 9) to (9θ) are formed in a direction intersecting (for example, perpendicular to ,
For example, grinding with Borazon organ stone (about 1000 to 2000) or polishing with a wire saw (Go 4000)
~6,000). In addition, this groove (9a
) to (9e), the gap depth of the magnetic head in the final finished product must be greater than (D) in FIG. This is to maintain the distance in the track constant until the depth end of the front gap fFl is reached.

The wafer (1
It has a coefficient of thermal expansion that is equal to or close to the coefficient of thermal expansion of 1+6+ (usually about 130 to 150 x 107 Zo), and the working temperature is about 100℃ or more lower than the solidus temperature of the silver wax ladle for welding, but it is possible to melt the lath 0υ with light. Tensuru. The glass used in this example has a composition of t%, Pb05Q, 5i023
Q, in 2015, made of Na2O5, the coefficient of thermal expansion is about 1
35×10-7/, C1 softening temperature about 450°C, and working temperature about 550°C.

This glass material was heat-treated at a maximum temperature of 650° C. and was melted and flashed in an N2 gas atmosphere. Incidentally, in the first block (B1), excess protruding glass was removed, and the upper surface (B11) was polished to a good degree of flatness.

FIG. 6 is a perspective view of the second block obtained in step 11. This second block (B2) is made of an oxide magnetic material (for example, magnetic ferrite),
B21) There are grooves (12
+ has been established by processing Diamond Kamaishi with IQ11 processing. Furthermore, this plane (B21) is finished with good flatness by polishing.

FIG. 7 is a perspective view of the third block for explaining the steps (el, ifl, and fgl. Second block (B2)
The upper surface (B
+1) are placed facing each other so that the grooves (9a) to (9θ) are perpendicular to each other, and both blocks (B1) (B2) are pressurized in a nitrogen or N2 atmosphere. Heat treatment is performed, and both blocks (Bl) (B2) are welded with glass OD to obtain a third block (B3). The maximum welding temperature during this welding is 50℃ from the softening temperature of glass ttU.
A moderately high temperature is desirable. This is because if the fluidity becomes too large, glass will flow into the grooves (13).

When integrating both blocks (Bj) (B2), a film made of a glass material having the same or lower softening point than the above-mentioned glass was attached on the plane (B21) of the second block fBl separately from this embodiment. , this glass film may be used.

Regarding the 6th block (B5), the dashed line (N3) in the figure
As shown in , the groove bottoms of the plurality of grooves (9a) to (9θ) are removed, and the upper portions (N3) are removed. 1 more
Desired gap depth + DI as shown by dotted chain line (N4)
While ensuring this, the surface that will be in contact with the tape is rounded in post-processing. Next, as shown by the dashed line (N5), the land portions (10R,) to (1
0i) using a wire saw or the like. By setting the direction of this squishing at a predetermined angle C] from the normal direction of the front gap, it is possible to create a so-called azimuth angle.

FIG. 8 shows a perspective view of a core chip that has been cut out and subjected to thickness processing, etc. This core tip is composed of a front core 031 made of Sendust core CJI having a front gap iFl'c with glass circles arranged on both sides, and a rear core 031 made of ferrite. This core chip is attached to a head base, a coil is attached thereto, it is further attached to a rotating body, and the tape contacting surface is rounded to form a finished magnetic head.

FIG. 9 is a perspective view of the first block of another embodiment. This means that instead of welding the two wafers together using silver metal, each wafer e'11011 is individually attached to the groove t321.
C33) is provided, and the lath 0 into this groove C32θ3)
At the same time as filling a, the glass may be infiltrated between the abutting surfaces. Note that the groove c351 is a guide groove for the penetration glass.

(f) Effects of the Invention The present invention provides a third block formed by combining a first block having a metal magnetic material as a core material and a second block made of an oxide magnetic material.
Since this is a method of cutting out a large number of core chips based on a block, productivity can be significantly improved compared to the conventional method in which the center core and auxiliary cores are assembled core by core. Further, since the groove defining the track width of the first block is filled with glass and the glass backs the front gap of the magnetic head, a magnetic head with excellent mechanical strength can be manufactured with high yield. I can do it.

[Brief explanation of the drawing]

Figures 1, 2, and 3 show the process 1a of obtaining a $1 block.
The explanatory diagram of l, Figures 4 and 5 are the process! A perspective view of the first block molded by b1+01, FIG.
FIG. 7 is a perspective view of the second block obtained by the process (
A perspective view of the third block to explain ellflgl, FIG. 8 is a perspective view of one core chip, and FIG. 9 is a $1
FIG. 6 is a perspective view of another embodiment of the block. Explanation of main codes (B1), fi1 block, (9a) to (9e)...
・Multiple grooves, (tOa) to (10(L)...Land part, optional...Glass, (B2)...Second block, [
W+...Coil window, (Bg)...Third block. Applicant Sanyo Electric Co., Ltd. Agent Patent Attorney Masao Sano Japanese Patent Application Sho GO-151809 (5)

Claims (1)

[Claims] 1. Two wafers made of metallic magnetic material are brought together with a film of non-magnetic material sandwiched between them, and both wafers are integrated by welding a bonding material using grooves formed in at least one of the wafers. forming a first block;
a step of opening a plurality of grooves from one surface of the first block in the direction of the toilet lid to the groove, leaving a land portion of a width corresponding to the track width between adjacent grooves; A step of filling with glass having physical properties close to (or matching) the coefficient of thermal expansion of the metal magnetic material, a step of opening grooves to serve as coil windows in the plane of the second block made of the oxide magnetic material, and a step of mounting the first block on the plane of the second block so that the plurality of grooves face the grooves of the second block, and integrating the image blocks to form a sixth block; removing the upper part of the third block including the groove bottoms of the plurality of grooves and further rounding the removed surface to regulate the depth of the front gap; A method of manufacturing a magnetic head comprising the step of dividing the land portion into the groove so that the land portion remains in the center portion of the groove.