JPH0658730B2 - Element for thin film magnetic head and method for manufacturing thin film magnetic head - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an element body for a thin film magnetic head and a method for manufacturing a thin film magnetic head, and more particularly to an element body for a thin film magnetic head capable of polishing a tip with a high life dimension accuracy. And a method of manufacturing a thin film magnetic head.

BACKGROUND ART There are various types of thin-film magnetic heads, one of which is one in which a groove is formed by machining on a part of a magnetic substrate, and the groove is filled with a non-magnetic insulator such as glass or ceramic. In the above, there is a thin film magnetic head formed by sequentially forming a film coil and a film core on the non-magnetic insulator.

In the thin film magnetic head having the above structure, a large number of magnetic head chips are formed at one time on one magnetic substrate in order to reduce the product cost. Therefore, a plurality of grooves filled with the non-magnetic insulator are collectively formed by machining. The magnetic substrate on which the plurality of grooves are formed is subjected to a nonmagnetic insulator filling step, a step of forming a coil and a film core in a film shape in a predetermined pattern shape, etc. Formed at the same time. The magnetic substrate on which a large number of magnetic head chips are formed is separated for each magnetic head chip, a protective substrate is adhered, and the tip end surface of the magnetic head is polished. At the time of this polishing process, it is necessary to accurately measure the life size (the distance between the edge of the groove in the direction of the magnetic head and the front face of the magnetic head), so a mark for measuring the life size near the front face of the magnetic head. Alternatively, the element is arranged and the magnetic head front end surface is polished while observing the element. The marks and elements for measuring the life size were formed by using photolithography when forming the film coil.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-described conventional thin film magnetic head element body and method of manufacturing a thin film magnetic head, the marks and elements for measuring the life size are extremely positioned at predetermined positions by using optical means such as photolithography. Can be formed accurately (with an error of about 1 μm or less), but the reference position of the life size is the side edge of the groove provided on the magnetic substrate in the direction of the tip of the magnetic head. Since it is processed, its accuracy is considerably inferior to that of pattern formation by optical means (about 5
Error of -10 μm). Therefore, even if the tip surface of the magnetic head is polished while observing the marks or elements accurately positioned by the optical means, a large error occurs in the position of the side edge portion of the groove portion which becomes the reference of the life size. Therefore, the accuracy of the life size follows the machining accuracy of the groove, which is low in precision due to machining, so the life size cannot be determined accurately, and therefore the life size of each magnetic head varies and the yield is good. However, there is a problem in that it cannot be manufactured.

Therefore, in the present invention, in the thin film magnetic head element body and the method for manufacturing the thin film magnetic head, the life size can be precisely processed to a predetermined value, and the manufacturing process can be simplified, thereby providing an accurate life size. Another object of the present invention is to provide an element body for a thin film magnetic head and a method for manufacturing the thin film magnetic head, which can obtain a thin film magnetic head having a good production yield and a low product cost.

Means for Solving the Problems In order to solve the above problems, in the present invention, a groove is formed in a part of a magnetic body, the groove is filled with a non-magnetic insulator, and the non-magnetic insulator is formed into a film shape. A thin-film magnetic head element formed by sequentially forming a coil and a film-shaped core and performing a polishing process to form a thin-film magnetic head, wherein the groove portion filled with the non-magnetic insulator and the magnetic head tip Is formed by an optical means such as photolithography over the non-magnetic insulator and the magnetic substance at the boundary portion with the magnetic substance in the direction where the medium facing surface is filled with the non-magnetic substance or the conductive material. An end portion defines a reference groove that defines a life size of zero, and a reference groove that is spaced apart from the reference groove by a predetermined distance and that is formed simultaneously with the formation of the reference groove by the optical means and that indicates a distance to the reference groove. It becomes.

In a method of manufacturing a thin film magnetic head, wherein a groove is formed in a part of a magnetic material, the groove is filled with a non-magnetic insulator, and a film coil and a film core are sequentially formed in the non-magnetic insulator. The nonmagnetic insulator is provided at the boundary between the groove filled with the nonmagnetic substance and the magnetic substance in the direction of the magnetic head tip, and the medium facing surface end portion has a life size of zero. And a step of forming a reference groove that defines a distance from the reference groove at a predetermined distance from the reference groove and forming an index indicating the distance to the reference groove at the same time by an optical means such as photolithography; The method comprises a step of charging a magnetic material or a conductive material, and a step of polishing the tip surface of the magnetic head while measuring the distance to the reference groove by the index.

Further, in the above manufacturing method, in the step of forming the reference groove and the index, a coil groove in which the film coil is formed by being filled with a conductive material is simultaneously formed by the optical means.

EXAMPLE FIG. 1 shows an example of an element body for a thin film magnetic head according to the present invention. The thin-film magnetic head body 1 shown in the figure is generally composed of a film-shaped core 3 and a film-shaped coil 4 (shown by satin in the figure) formed on a substrate 2 by a thin-film method. The substrate 2 is made of a soft magnetic material such as Sendust (registered trademark) or ferrite and forms one core of the thin film magnetic head 1. A groove 5 is machined at a predetermined position of the substrate 2, and the groove 5 is melt-filled with a non-magnetic insulator 6 (shown by diagonal lines in the figure) such as glass or ceramic. On the upper surface of the non-magnetic insulator 6, a lower coil 4b of the film coil 4 to be described later, which is disposed on the lower surface of the film core 3, is formed. The lower coil 4b is formed by filling the coil groove 7 patterned by optical means (such as photolithography) with a conductive material such as Al or Cu. The coil groove 7 is a non-magnetic insulator 6
A plurality of coils are formed on the upper surface in correspondence with a predetermined number of turns. Among them, the coil groove closest to the magnetic head tip surface 8 (the surface in sliding contact with the recording medium) extends over the non-magnetic insulator 6 and the substrate 2. The reference groove 9 serves as a reference for the formed life dimension. Similar to the coil groove 7, the reference groove 9 is filled with a conductive material and is formed so as to straddle the non-magnetic insulator 6 of the reference groove 9 and the substrate 2. The medium facing surface end of the reference groove 9 defines a life size of zero. To do. The reference position for the life size is the side edge indicated by arrow B in the figure. The life size (the life size of the thin-film magnetic head 1 is indicated by an arrow H in the figure) has a great influence on the strength, durability and magnetic recording / reproducing characteristics of the magnetic head, and therefore must be determined with high accuracy. Especially in the thin-film magnetic head 1, since the above-mentioned influence is great, it is necessary to determine the life size within an error range of about 1 μm. As will be described later in detail, when polishing the magnetic head front end surface 8 in order to determine the life size, in general, a mark as shown in FIG.
The element is provided by using a photolithography technique or the like, and the polishing process is performed while observing the element. Reference groove 9 as described above
Since both the mark and the element are provided at the same time by the optical means, they are positioned with extremely high accuracy, and the polishing accuracy of the magnetic head tip surface 8 is also extremely high, so that the life size is determined with high accuracy.

The film core 3 is formed on the substrate 2 in which the lower coil 4b and the reference groove 9 are formed, with the insulating layer 10 made of, for example, SiO ₂ interposed therebetween. Membrane core 3 is sendust,
A gap 11 is formed via a magnetic substrate 2 made of a hard magnetic material having a high saturation magnetic flux density such as Malloy or Co-Zr type amorphous, and an insulating layer 10 serving as a gap material. The film core 3 is formed on the lower coil 4b formed on the substrate 2 and extends over a predetermined length. Also the membranous core 3
Has a relatively large thickness (about 5
μm).

An upper coil 4a is patterned on the upper surface of the film core 3 with an insulating layer (not shown) interposed therebetween, and a lower coil 4b is formed.
At the same time, the film coil 4 is formed to excite the film core 3. A protective substrate (not shown in FIG. 1) made of ceramic or the like is attached on the substrate 2 on which the film core 3 and the film coil 4 are formed. The strength is getting stronger.

An embodiment of a method of manufacturing a thin film magnetic head according to the present invention will be described below with reference to FIGS. 3 to 10 according to a manufacturing procedure. The same components as those of the thin film magnetic head element body 1 shown in FIG. 1 are designated by the same reference numerals. Further, in the manufacturing process described below, each step before the cutting step of the magnetic head chip is collectively carried out at a large number of places on one magnetic substrate to form a large number of magnetic head chips at the same time. One of the magnetic head chips is shown in an enlarged manner and will be described.

In FIG. 3, reference numeral 2 denotes a substrate made of a ferromagnetic material such as sendust or ferrite, and an inverted trapezoidal groove 5 is formed on the substrate 2. The groove 5 can be processed by diamond cutting by mechanical processing, chemical etching by chemical processing or sputter etching by physical processing (generally mechanical processing). A non-magnetic and inorganic non-magnetic insulator 6 (indicated by satin in the figure) in the groove portion 5,
For example, in the case of lead glass, this is also melt-filled so as to be slightly higher than the surface of the substrate 2. In addition, the non-magnetic insulator 6
May be formed by vapor deposition of Al ₂ O ₃ or SiO ₂ . After filling the non-magnetic insulator 6, the surface is polished and the fourth
As shown in the figure, the surfaces of the substrate 2 and the lead glass are flush with each other. The boundary between the non-magnetic insulator 6 and the substrate 2 on the same surface serves as the groove end 16.

A photoresist is evenly applied to the upper portion of the substrate 2 thus polished, covered with a photomask, and subjected to steps such as light irradiation and development, and then the non-magnetic insulator 6 is used as a surface for the pattern for the lower coil 4b and the reference groove 9. A pattern for mark and a pattern for mark 12 are drawn, and the coil groove 7, the reference groove 9 and the mark groove 12a are formed by etching or the like (shown in FIG. 5). At this time, as shown in FIG. 5, the position of the reference groove 9 is
It is arranged so that the groove end 16 is included in the reference groove 9.

As described above, both the reference groove 9 and the mark groove 12a are formed at the same time by the optical means, so that they are positioned with high precision. Therefore, the separation distance between the reference groove 9 and the mark groove 12a is also determined to a predetermined dimension with high accuracy (error of 1 μm or less). As will be described later, the polishing process of the magnetic head tip surface 8 for determining the life size is performed while observing the mark 12, but the reference groove 9 that serves as a reference for the life size and the groove for the mark 12 that serves as a guide for the polishing process. Since both 12a are formed at the same time by optical means, the life size can be determined with high accuracy. Further, among the mark grooves 12a, the edge of the smallest mark groove 12a _{-1 in} the direction of the magnetic head tip surface 8 (indicated by arrow C in the figure) and the side edge of the reference groove 9 in the direction of the magnetic head tip surface 8 (see the figure) The separation distance (indicated by the middle arrow B) is selected to be equal to the predetermined life size. Still other mark groove 1
2a _-2 and 12a _-3 are formed with predetermined dimensions.

The reference groove 9 is formed at the boundary between the groove portion 5 filled with the non-magnetic insulator 6 and the magnetic substrate 2 in the direction of the magnetic head tip surface 8 as shown in FIG. Board 2
Is formed so as to extend over the Therefore, the etching of the reference groove 9 needs to simultaneously etch the non-magnetic insulator 6 and the magnetic substrate 2 which are different materials,
Only the reference groove 9 may be processed by reactive ion etching. 6 is a sectional view taken along the line AA of FIG. 5, and the depth of the coil groove 7 is d. The coil groove 7 is provided in the longitudinal direction with respect to the groove portion 5, and the number of each of the coil grooves 7 determines the number of turns of the film coil 4 of the thin film magnetic head 1.

After processing the coil groove 7, the reference groove 9 and the groove for providing the mark 12, a non-magnetic conductive metal such as A1 or Cu is deposited on the substrate 2 by sputtering or vapor deposition. After its thickness is deposited larger than the depth d of the coil groove 7,
Coil groove 7 by polishing the surface to give a mirror finish
To a depth d'which is slightly smaller than the initial depth d.
The upper surface is made flat, and the lower coil 4b as shown in FIG.
To form. At this time, 12a _-1 , 12a for the mark 12
_-2 and 12a _-3 are also filled with non-magnetic conductive metal and mark 1
2 is formed (the mark shown in FIG. 2 (A) is formed in the figure).

Then, a non-magnetic insulating layer (not shown) having a predetermined thickness is formed from the upper portion of the magnetic head by sputtering, vapor deposition, or the like, and sendust or a magnetic layer for the magnetic core is formed on the lower coil 4b. A ferromagnetic material such as ferrite is patterned by a known method to form the film core 3 (see Part 8). The width L ₁ of the film core 3 is set smaller than the length L ₂ of the lower coil 4b. Then, an insulating material (not shown) is arranged on the surface of the film core 3, and the upper coil 4a is further arranged by a known method. The upper coil 4a is arranged so as to wind the film core 3 together with the lower coil 4b, and the upper coil 4a is spirally connected to the lower coil 4b to form the film coil 4. The above steps are collectively performed on one magnetic substrate. Therefore, a large number of magnetic head chips each having the film core 3 and the film coil 4 are formed on the magnetic substrate. The large number of magnetic head chips are separated by using a dicing saw or the like to obtain individual magnetic head chips 13 shown in FIG.

On the magnetic head chip 13, a protective substrate 14 (shown by a chain line in FIG. 9) made of ceramic or the like is pressure-bonded. The protective substrate 14 is provided to protect the film core 3 and the film coil 4 which are weak in strength and to enhance the strength of the thin film magnetic head 1.

Subsequently, the magnetic head chip 13 to which the protective substrate 14 is adhered
The magnetic head tip surface 8 is subjected to polishing to be polished into a predetermined shape and a predetermined life size is determined.
In the step of separating the single magnetic substrate to obtain the individual magnetic head chips 13, the cutting is performed by using a mechanical cutting means. Therefore, the cutting positioning accuracy is poor, and the side edges of the reference groove 9 (indicated by the arrow B in FIG. 9; this position serves as a reference for the life size as described above) and the tip of the magnetic head due to the separated individual magnetic head chips 13. There is also variation in the distance from the surface 8 (this distance becomes the life size). Polishing is performed in order to eliminate this variation and to determine a predetermined life size, and to make the magnetic head tip surface 8 contact the magnetic tape well. This polishing process is performed while observing the marks 12 simultaneously formed in the process of forming the lower coil 4b. After the mark 12 is formed, the film-shaped core 3, the upper coil 4a, the protective substrate 14, etc. are formed on the mark 12, so that the polishing process cannot be performed while observing the mark 12 from above the magnetic head chip 13. . Therefore, according to the polishing process, the polishing process is performed while observing the mark 12 appearing on the front surface 8 of the magnetic head. The procedure will be described with reference to FIG.
The drawings shown in FIG. 10 are views of the magnetic head tip surface 8 of the magnetic head chip 13. Further, reference numeral 15 indicated by a satin in each figure is an adhesive layer for adhering the protective substrate 14. For example, it is assumed that when a magnetic head chip 13 is obtained by cutting off one magnetic substrate, one mark 12 _-3 appears on the magnetic head tip surface 8 as shown in FIG. 10 (A). As described above, since the life size is positioned at the smallest mark 12 _-1 of the _three marks 12, it is necessary to grind the life size to a considerable extent. Understood by. Therefore, it is possible to carry out rough cutting to some extent, and the polishing time can be shortened. As the polishing process is performed, a second mark 12 _-2 appears on the magnetic head front end surface 8 (shown in FIG. 10B). By looking at this mark 12 _-2 , it is understood that a slight amount of polishing may be performed until the life size. Therefore, the polishing rate is reduced to perform fine polishing, and when the third mark 12 _-1 appears as shown in FIG. 10C, the polishing process is terminated and the thin film magnetic head 1 shown in FIG. 1 is obtained.

As described above, the reference groove 9 as a reference mark grooves 12a and life dimensions of the marks 12 are both positioned with high accuracy at the same time by optical means, therefore the side edge of the reference groove 9 which is a life size B and the mark grooves 12a _{- Since the} distance between the edges C of ₁ is also determined to a predetermined size with high accuracy, the life size can be determined with high accuracy in the above polishing step, and the life size variation is eliminated, so that the thin film magnetic head element body is manufactured. The yield of the magnetic head formed of 1 can also be improved. Further, the manufacturing process can be simplified by forming the reference groove 9 simultaneously with the forming process of the lower coil 4b.

EFFECTS OF THE INVENTION As described above, in the thin film magnetic head element of the present invention according to the first aspect of the invention, the medium facing surface end of the reference groove defines a life dimension of zero, and the reference groove is separated from the reference groove by a predetermined distance. It is possible to precisely process the service life dimension to a specified value by providing an index indicating the distance to the reference groove, which has an accurate service life dimension, good manufacturing yield, and product cost. It has special features such as being able to provide an inexpensive thin film magnetic head.

Further, the method of manufacturing a thin film magnetic head according to the second aspect of the present invention comprises the step of polishing the magnetic head tip surface while measuring the distance to the reference groove by the index. The life dimension can be precisely machined to a predetermined value, whereby a thin film magnetic head having an accurate life dimension, a good manufacturing yield, and a low product cost can be provided.

Further, in the method of manufacturing the thin film magnetic head according to the third aspect of the present invention, the manufacturing process is performed by simultaneously forming the coil for forming the film coil together with the reference groove in the step of forming the reference groove. So that it can be simplified,
As a result, it is possible to provide a thin film magnetic head having a good manufacturing yield and a low product cost.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of an element body for a thin film magnetic head according to the present invention, and FIG.
FIGS. 3 to 9 are views showing various marks as a guide for processing, and FIG. 3 to FIG. 9 are perspective views and sectional views for explaining an embodiment of a method of manufacturing a thin film magnetic head according to the present invention in accordance with the manufacturing procedure. FIG. 10 is a side view for explaining the procedure for polishing the front end surface of the magnetic head. 1 ... Element for thin film magnetic head, 2 ... Substrate, 3 ... Membrane core, 4 ... Membrane coil, 4b ... Lower coil, 5 ...
Groove part, 6 ... Non-magnetic insulator, 7 ... Coil groove, 8 ... Magnetic head tip surface, 9 ... Reference groove, 12, 12 _-1 , 1,
2 _-2 , 12 _-3 ... mark, 12a, 12a _-1 , 12
a _-2 , 12a _-3 ... mark groove, 13 ... magnetic head chip, 16 ... groove end.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-58-108017 (JP, A) JP-A-57-113411 (JP, A) JP-A-52-28307 (JP, A) JP-A-56- 29832 (JP, A) JP-A-58-128014 (JP, A)

Claims (3)

[Claims] 1. A groove is formed in a part of a magnetic body, the groove is filled with a non-magnetic insulator, and a film coil and a film core are sequentially formed in the non-magnetic insulator, which is polished. In a thin-film magnetic head element body that is formed into a thin-film magnetic head, the non-magnetic insulating material is formed at a boundary portion between the groove portion filled with the non-magnetic insulating material and the magnetic material in a direction toward the tip of the magnetic head. A reference groove formed over the body and the magnetic body by optical means such as photolithography, filled with a non-magnetic body or a conductive material, and the medium facing surface end portion of which defines a life dimension of zero; An element body for a thin-film magnetic head, comprising: an index which is formed at a predetermined distance from the groove and is formed simultaneously with the formation of the reference groove by the optical means, and which indicates a distance to the reference groove. 2. A thin film magnetic head having a groove formed in a part of a magnetic material, the groove being filled with a non-magnetic insulator, and a film coil and a film core being sequentially formed in the non-magnetic insulator. In the manufacturing method, the medium facing surface end portion is provided across the non-magnetic insulator and the magnetic body at a boundary portion between the groove filled with the non-magnetic body and the magnetic body in the magnetic head tip direction. And a step of forming a reference groove that defines a life size of zero and a position that is provided at a predetermined distance from the reference groove, and an index that indicates the distance to the reference groove by an optical means such as photolithography at the same time, A thin film magnetic device comprising: a step of filling the reference groove with a non-magnetic material or a conductive material; and a step of polishing the tip end surface of the magnetic head while measuring the distance to the reference groove by the index. Head Production method. 3. A coil groove in which the film coil is formed by filling a conductive material in the step of forming the reference groove and the index is simultaneously formed by the optical means. A method of manufacturing a thin-film magnetic head according to claim (2).