JPH06195622A - Production of magnetic head - Google Patents

Abstract

PURPOSE:To provide the process for production of the small-sized magnetic head having excellent strength of gap butt welding and accuracy by a method of butt joining a pair of magnetic core half bodies consisting of magnetic alloy films with nonmagnetic reinforcing materials via nonmagnetic gap spacers. CONSTITUTION:A laminated substrate block is formed of plural sheets of the nonmagnetic substrates stuck and formed with the magnetic alloy films 1. This block is cut to form plural sheets of wafers of magnetic core half body members having two surfaces parallel with each other. Winding grooves 6 are dug and formed on the surfaces of the wafers. Magnetic head chips are formed by polishing the surfaces of the wafers 2 to mirror finished surfaces, forming gap spacer films 3 on at last one surface of the wafers, laminating and joining the wafers to form a magnetic core block, cutting this block to half the thickness of the wafers to form magnetic core bars and cutting these magnetic core bars at the bisecting plane of the substrates.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a magnetic head used in a magnetic recording / reproducing apparatus such as a VTR or HDD.

[0002]

2. Description of the Related Art In a magnetic recording / reproducing system such as a VTR or HDD, it is desired to improve temporal recording density (higher frequency band) and spatial recording density (narrower track, shorter wavelength). To achieve this, a magnetic head with a narrow gap and a narrow track width can be placed close to a high coercive force medium capable of short-wavelength recording, and electromagnetic signals can be input and output while both are traveling relatively at high speed. It is a prerequisite.

As a magnetic head for such high density recording, a magnetic alloy film laminated core type magnetic head as shown in FIG. 2 shown in Japanese Patent Laid-Open No. 2-168406 is effective.

The magnetic path of the magnetic head shown in FIG. 2 is composed of a magnetic alloy film 1 having a high saturation magnetic flux density so as to correspond to a medium having a high coercive force. The magnetic alloy film is preferably formed by laminating a relatively thin magnetic alloy film via an electrically insulating film in order to prevent the magnetic characteristics of the thick magnetic alloy film from deteriorating under the influence of eddy currents at high frequencies. In the description, the magnetic alloy film is referred to as a magnetic alloy film regardless of whether it is a single-layer film or a laminated film.

The magnetic alloy film 1 is a non-magnetic reinforcing substrate 2
They are sandwiched by 0s and are abutted and joined to each other via a non-magnetic gap spacer 3. Reference numeral 4 is a glass for reinforcing the gap butt joint.

The magnetic head shown in FIG. 2 has a known ferrite head and M even with respect to the problem of high speed sliding on the recording medium.
Compared with an IG (metal-in-gap) head, it is advantageous in that it has a magnetic core structure that does not include a ferrite material that easily causes sliding noise.

The magnetic head shown in FIG. 2 is manufactured through the steps shown in FIGS. That is, as shown in FIG. 3, first, a glass layer 5 is adhered and formed on one surface of a substrate 20 made of crystallized glass, non-magnetic ceramic or the like by a coating firing method, a sputtering method or the like, and a magnetic layer is formed on the other surface. The alloy film 1 is deposited by a thickness corresponding to the track width by a sputtering method or the like.

Next, as shown in FIG. 4, a plurality of the substrates are stacked and heated in a vacuum or in an inert gas atmosphere while being pressurized in the direction of arrow P in the figure to heat the glass layer 5. The substrates are laminated and joined by melting to obtain a laminated substrate block 91 as shown in FIG. Here, the bonding glass layer 5 is interposed between the substrate 2 and the magnetic alloy film 1, but the bonding glass layer is not shown in the following figures for simplification.

Next, the laminated substrate block 91 is cut along the broken line D--E in FIG. 5 to obtain wafers 92a, 92b to be magnetic core half members as shown in FIG.

Next, as shown in FIG.
A pair of sheets 92a and 92b is used as a pair, and a glass groove is excavated on the surface of one of the wafers to be the gap abutting surface to fill the glass 40. In addition, the winding groove 6 is excavated on the surface of the other wafer which is to be the gap abutting surface. After that, the gap abutting surfaces of the pair of wafers are mirror-polished,
A gap spacer film (not shown) is deposited.

Next, as shown in FIG. 8, the pair of wafers are butted and heated in a vacuum or in an inert gas atmosphere while being pressurized in the direction of arrow Q in the figure to heat the glass groove. The glass 40 in the inside is melted and flowed, and the glass is poured to the tip of the winding groove 6 and gap-butted and joined to obtain a magnetic core bar 94. Hereinafter, this step is abbreviated as a gap welding step.

Finally, after the surface of the magnetic core bar 94 facing the recording medium is curved along the alternate long and short dash line F in FIG. 9, the magnetic core bar is sliced along the alternate long and short dash line G in FIG. A magnetic head chip 95 such as

[0013]

As a magnetic head for high-density magnetic recording, the lateral widths Wa and Wb of the magnetic core halves shown in FIG. 1, that is, the manufacturing steps are reversed from the viewpoint of miniaturization. For example, the wafer 92a. The thicknesses Ta and Tb of 92b are limited, and in order to cope with the shortening of the wavelength of the recording signal, it is required to narrow the gap length and improve the accuracy.

However, when the thicknesses Ta and Tb of the wafer are reduced, the wafer is likely to warp in the step of polishing the gap abutting surface of FIG. 7, the flatness of the gap abutting surface is lowered, and the gap welding step of FIG. 8 is performed. The joint strength of the gap abutting and the dimensional accuracy of the gap length are reduced.

On the other hand, it is conceivable to polish the gap abutting surface in the state of a thick wafer, and after welding, scrape the side surface of the welding block to control the lateral width, but the number of steps is increased and the loss of material is increased. Also increases.

In consideration of the above-mentioned problems of the prior art, the present invention manufactures a small magnetic head having excellent strength and accuracy of gap butt welding while suppressing material loss and increase in man-hours as much as possible. It is intended to clarify the way to do it.

[0017]

According to the method of manufacturing a magnetic head of the present invention, a pair of magnetic core halves made of a magnetic alloy film sandwiched by a nonmagnetic reinforcing substrate are butted against each other via a nonmagnetic gap spacer. In the method of manufacturing a magnetic head formed by joining, (1) a step of stacking and joining a plurality of non-magnetic substrates on which a magnetic alloy film is formed to form a laminated substrate block, and (2) forming the laminated substrate block. Cutting and forming a plurality of wafers of a magnetic core half member having two surfaces parallel to each other, and (3) excavating a winding groove on at least one of the two surfaces parallel to each other of the wafer. Forming, and (4) mirror polishing two parallel surfaces of the wafer,
(5) a step of forming a gap spacer film on at least one of the two surfaces of the wafer which are parallel to each other, and (6) stacking and joining a plurality of the wafers (that is, the term used in the conventional manufacturing method is used). For example, a step of collectively gap welding) to form a laminated magnetic core block, and (7) cutting the laminated magnetic core block along a plane that divides the thickness of the wafer into two to form a magnetic core bar. And (8) cutting the magnetic core bar along a plane that divides the thickness of the substrate into two to form a magnetic head chip.

[0018]

According to the above manufacturing method of the present invention,
The laminated magnetic core block formed by collectively welding a plurality of wafers in the step (6) is cut along the plane dividing the thickness of each wafer into two to form a magnetic core bar in the step (7). Since it will go through the process of doing, (2) ~
Even if the thickness of the wafer related to the step (6) is made thicker than in the case of the conventional manufacturing method, no material loss is caused, and if such a thick wafer is used, the gap of (4) The wafer is less likely to warp in the surface polishing process, and (6)
The joint strength of the gap butting and the dimensional accuracy of the gap length in the collective welding step of are improved.

[0019]

Embodiments of the method of manufacturing a magnetic head according to the present invention will be described below.

In the method of manufacturing a magnetic head according to the present invention, a pair of magnetic core halves made of a magnetic alloy film 1 held by a non-magnetic reinforcing substrate 20 are butted and joined together via a non-magnetic gap spacer 3. In the method of manufacturing a magnetic head as shown in FIG. 2, first, as shown in FIG. 3, a glass layer 5 is applied to one surface of a substrate 20 made of crystallized glass, non-magnetic ceramic or the like by a firing method, a sputtering method, or the like. Is adhered and formed by the magnetic alloy film 1 on the other surface.
Is deposited by a sputtering method or the like by a thickness corresponding to the track width.

Next, as shown in FIG. 4, a plurality of the substrates are stacked and heated in a vacuum or in an inert gas atmosphere while being pressurized in the direction of arrow P in the figure, and the glass layer 5 is heated. The substrates are laminated and joined by melting to obtain a laminated substrate block 91 as shown in FIG. The steps up to this point are the same as those in the conventional manufacturing method.

Next, the laminated substrate block 91 is cut along a broken line D-E in FIG. 5 to obtain a wafer 92 of a magnetic core half member as shown in FIG. 10 having two surfaces parallel to each other. At this time, the thickness T of the wafer 92 is a thickness obtained by adding the width [Wa + Wb] of the magnetic head core in FIG. 2 to the shaving margin in the subsequent polishing step and the shaving margin in the cutting step.

Next, as shown in FIG.
The glass groove is excavated on one surface of No. 2 to fill the glass 40, and the winding groove 6 is excavated on the other surface. Thereafter, both the one surface and the other surface of the wafer 92 are mirror-polished,
A gap spacer film (not shown) is deposited on at least one surface.

Next, as shown in FIG. 12, a plurality of the above-mentioned wafers are stacked and heated in a vacuum or in an inert gas atmosphere while being pressurized in the stacking direction to remove the glass in the glass grooves. The laminated magnetic core block 93 is obtained by melting and flowing the glass to the tip of the winding groove.

Next, as shown in FIG. 1, the laminated magnetic core block 93 is cut along a plane AB that divides the thickness of the wafer 92 into two to form a magnetic core bar 94.

The subsequent steps are the same as those in the manufacturing method of the conventional example, but after the surface of the magnetic core bar 94 facing the recording medium is curved along the alternate long and short dash line F in FIG. The magnetic head chip 95 as shown in FIG. 2 is obtained by cutting along the alternate long and short dash line G, that is, the surface dividing the thickness of the substrate 20 into two.

According to the above manufacturing method of the present invention, the laminated magnetic core block 93 formed by collectively welding a plurality of wafers in the step of FIG. Since the process of cutting along the plane that divides the thickness into two and forming the magnetic core bar 94 is performed, the thickness T of the wafer 92 related to the process of FIGS. Even if the thickness is made thicker than that in the case, the material is not lost, and if such a thick wafer is used, the wafer is less likely to warp in the gap surface polishing step of FIG. 10, and the gap butting bonding in the collective welding step of FIG. 11 is performed. Dimensional accuracy of strength and gap length is improved.

Further, according to the manufacturing method of the present invention, as shown in FIG.
Since a plurality of wafers 92 are collectively welded in the step 2 to form the laminated magnetic core block 93, the number of steps can be reduced as compared with the case where two wafers are welded as one pair many times, and Compared to the case where a large number of wafers are set as one pair and a large number of wafers are set in a large welding furnace for welding, the size of the welding furnace can be reduced, and the uneven temperature distribution in the large welding furnace causes Good or bad, that is, the flow condition of glass, the bonding strength depending on it, the residual stress, the recording / reproducing output depending on it, and the like do not vary.

In the collective welding step of FIG. 12, in order to obtain a magnetic head of plus azimuth and minus azimuth from one laminated magnetic core block when manufacturing a magnetic head with a so-called azimuth angle, the winding It is also effective to stack the wafers by changing the direction of the tip of each groove for each layer of the wafer.

[0030]

According to the present invention, a magnetic head manufactured by butt-joining a pair of magnetic core halves made of a magnetic alloy film held by a non-magnetic reinforcing substrate via a non-magnetic gap spacer. In this method, it is possible to manufacture a small-sized magnetic head with excellent strength and precision of gap butt welding, with little variation in recording / reproducing characteristics, while suppressing loss of material and increase in man-hours compared to conventional manufacturing methods. Become.

[Brief description of drawings]

FIG. 1 is an external perspective view of a laminated magnetic core block for explaining an embodiment of the present invention.

FIG. 2 is an external perspective view of a magnetic head obtained by a manufacturing method of an example of the present invention and a manufacturing method of a conventional example.

FIG. 3 is a perspective view of a substrate for explaining an example of the present invention and a conventional example.

FIG. 4 is a perspective view showing a state in which substrates are stacked to explain an example of the present invention and a conventional example.

FIG. 5 is a perspective view of a laminated substrate block for explaining an example of the present invention and a conventional example.

FIG. 6 is a perspective view of a wafer for explaining a conventional example.

FIG. 7 is a perspective view of a wafer for explaining a conventional example.

FIG. 8 is a perspective view showing a state in which wafers are butted, for explaining a conventional example.

FIG. 9 is a perspective view of a magnetic core bar for explaining an example of the present invention and a conventional example.

FIG. 10 is a perspective view of a wafer for explaining an embodiment of the present invention.

FIG. 11 is a perspective view of a wafer for explaining an embodiment of the present invention.

FIG. 12 is an external perspective view of a laminated magnetic core block for explaining an embodiment of the present invention.

[Explanation of symbols]

 1 Magnetic Alloy Film 20 Non-Magnetic Substrate 3 Gap Spacer 4 Glass 40 Glass 6 Winding Groove 91 Laminated Substrate Block 92 Wafer 93 Laminated Magnetic Core Block 94 Magnetic Core Bar 95 Magnetic Head Chip

Claims (1)

[Claims] 1. A method of manufacturing a magnetic head, comprising a pair of magnetic core halves made of a magnetic alloy film sandwiched by a non-magnetic reinforcing substrate, butted and joined to each other through a non-magnetic gap spacer. Forming a laminated substrate block by stacking and joining a plurality of non-magnetic substrates on which are adhered, and cutting the laminated substrate block to form a plurality of magnetic core half member wafers having two surfaces parallel to each other. A step of excavating a winding groove on at least one of the two surfaces of the wafer which are parallel to each other, a step of mirror-polishing the two surfaces of the wafer which are parallel to each other, and a step of paralleling the wafer to each other. Forming a gap spacer film on at least one of the two surfaces, and stacking and bonding a plurality of the wafers to form a laminated magnetic core block. Forming, a step of cutting the laminated magnetic core block along a surface dividing the thickness of the wafer into two parts to form a magnetic core bar, and a surface dividing the magnetic core bar into two parts of the thickness of the substrate. And a step of forming a magnetic head chip by cutting along the line.