JPS59144019A - Magnetic head substrate - Google Patents

Abstract

PURPOSE:To reduce the wear of a tape and a head without using a protecting film nor lubricant on the surface of a magnetic tape by using a plate made of an aggregate of a glassy carbon material having density higher than a specific level with high smoothness to a substrate for a thin film magnetic head. CONSTITUTION:An aggregate is molded by compressing or extruding only a glassy carbon material having >=1.40g/cm<3> density obtained by converting the thermosetting resin, etc. into carbon or giving the vapor phase pyrolysis to CH4, etc. Such an aggregate or a molded aggregate of a mixture of the above-mentioned carbon material and the thermosetting resin is cut in a prescribed size to obtain a substrate for a thin film magnetic head. In such a way, no hole of >=0.5mu diameter exist on the surface of the substrate with extremely high smoothness secured to the substrate surface. In addition, the surface of the substrate is not damaged and the wear is reduced between a magnetic head and a magnetic recording medium without using any lubricant on the surface of the recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field to which the Invention Pertains] The present invention relates to a substrate that writes to and reads from a magnetic recording medium and is used in a magnetic head having a thin film. In particular, the present invention relates to a substrate used in a thin-film magnetic head suitable for performing high-density magnetic recording and a perpendicular magnetic recording type magnetic head.

[Description of prior art]

In recent years, as the amount of information has increased, there has been an increasing demand for higher recording densities in magnetic recording. In order to achieve this high recording density, research is being actively conducted to improve various parts related to magnetic recording, such as magnetic heads, and to develop new magnetic recording methods.

Regarding magnetic heads, general-purpose ring-type magnetic heads that use ferrite cores are thought to have limitations in high-density magnetic recording, and as an alternative magnetic head that enables high-density recording, JP-A-Sho 55-8401
A thin film magnetic head as disclosed in No. 8 has been developed.

The thin film magnetic head includes a non-magnetic substrate, a write or read transducer made of a plurality of thin film layers including a write or read transducing gap layer formed on one side of the non-magnetic substrate, and and a non-magnetic protective plate covering the thin film layer. These thin film layers are typically formed by sputtering or vapor deposition on non-magnetic substrates.

Furthermore, regarding magnetic recording methods, it has been shown that the conventional longitudinal magnetic recording method has a limit in increasing the recording density. A method has been proposed. When manufacturing magnetic heads used for perpendicular magnetic recording,
A soft magnetic thin film is formed on a nonmagnetic substrate by sputtering or vapor deposition.

The substrates used in these magnetic heads require sufficient surface smoothness because a thin film is formed thereon as described above, and the surfaces thereof are usually mirror-finished. If there are holes with a large diameter or a large number of holes in the substrate, even if mirror finishing is applied, the surface of the substrate will not have sufficient smoothness, and sputtering will occur on this surface. Alternatively, circular holes are present in the thin film formed by vapor deposition, and therefore, this thin film cannot have good magnetic properties. Furthermore, since it is difficult to remove gas from the pores, it is difficult to obtain the degree of vacuum required during sputtering or vapor deposition.

Currently, as substrates for these magnetic heads, aggregates of alumina-based ceramics that provide surface smoothness are generally used. However, this alumina-based ceramic material has high hardness and has the disadvantage that it easily scratches the surface of the recording medium when sliding with the magnetic recording medium.

To overcome this drawback, conventionally, a lubricant is applied to the surface of the non-magnetic substrate of a thin-film magnetic head on which the recording medium slides, or a protective film is coated on the surface of the magnetic recording medium. Even if a lubricant is applied, it is difficult to maintain the lubricating effect for a long time due to volatilization, etc., and the lubricant has to be reapplied periodically.Therefore, it is difficult to provide a protective film on the recording medium. This method has disadvantages in that the number of steps required to coat the protective film increases and the distance between the thin film magnetic head and the recording medium increases.

[Purpose of the invention]

The present invention makes it possible to form a thin film with excellent magnetic properties on a mirror-finished surface with extremely high surface smoothness, and without applying lubricant to the surface of the magnetic head. To provide a substrate for a magnetic head which does not permanently damage the surface of a magnetic recording medium without forming a protective film on the surface of the recording medium, and which causes less wear on the contact surface with the magnetic recording medium.

[Features of the invention]

The first invention is characterized in that it is a substrate for a magnetic head, which is composed of a glassy carbon material aggregate whose surface on which a thin film is formed has extremely high smoothness and whose density is 1.40 g/- or more. Also, the second invention is characterized in that the surface on which the thin film is formed has extremely high smoothness, and the density is 1.40 g/cI.
The present invention is a magnetic head substrate made of a composite material aggregate containing a glassy carbon material of grade A or higher and a thermosetting resin.

In this specification, "extremely high smoothness" means that no pores with a diameter of 0.5 μm or more are formed on the surface on which the thin film is formed.

Since the magnetic head substrate of the present invention does not have holes with a diameter of 0.5 μm or more on the surface on which the thin film is formed, a thin film with good magnetic properties can be formed on the substrate surface.

Although the density of the substrate is not directly related to the formation of a thin film with good magnetic properties, a substrate with a low density of 1.40 g/ad does not have a diameter of 0.5 μm or more on the surface on which the thin film is formed. Even if the substrate does not have pores, many pores are formed on the surface other than the surface on which the thin film is formed or inside the substrate, and when this substrate is used, it is difficult to obtain the degree of vacuum required for sputtering or vapor deposition. Otherwise, the abrasion loss during contact with the magnetic recording medium becomes large, and the object of the present invention cannot be achieved. Note that if the surface on which the thin film is formed does not have pores with a diameter of 0.1 μm or more, a thin film with better magnetic properties can be formed on the surface of the substrate.

To further explain the present invention, the carbon material according to the present invention includes a carbon material obtained by carbonizing a thermosetting resin, a carbon material obtained by carbonizing a thermosetting resin, and a carbon material obtained by carbonizing a thermosetting resin by copolymerization, cocondensation, etc. Carbon materials obtained by curing or by significantly inhibiting crystallization through chemical treatment during the hardening or carbonization process, and carbon materials obtained by thermal decomposition in the gas phase with low molecular weight hydrocarbons such as methane, ethylene, and benzene. Specific examples include polyacrylonitrile-based carbon materials, rayon-based carbon materials, pinch-based carbon materials, lignin-based carbon materials, phenolic-based carbon materials, furan-based carbon materials, alkyd resin-based carbon materials, and carbon materials. Examples include saturated polyester carbon materials, xylene resin carbon materials, and the like.

Further, examples of the thermosetting resin used in the present invention include phenol resin, epoxy resin, polyester resin, furan resin, Lily 7 resin, melamine resin, alkyd resin, xylene resin, and the like.

When these thermosetting resins are combined with the glassy carbon material, the thermosetting resin acts as a binder that binds the glassy carbon materials together, resulting in a durable non-woven material that is strong against mechanical damage such as collisions. A magnetic substrate can be obtained. However, if a large amount of thermosetting resin is composited with a glassy carbon material, a non-magnetic substrate will be formed which is subject to high wear. It is better to include more than

The magnetic head substrate of the present invention is composed of an aggregate of the above-mentioned carbon material or an aggregate of a composite of carbon material and thermosetting resin. Various widely known molding methods such as casting, compression, and extrusion are used to manufacture these aggregates, but the aggregates have no pores with a diameter of 0.5 μm or more and a density of 1.40 g/ In order to obtain an aggregate of cJ or more, when using the casting method, for example, at the stage of obtaining a carbon material precursor (thermosetting resin with a curing agent or a state in which it is cured by heat), the curing agent is uniformly applied. It can be obtained by dispersing the resin into a polyurethane resin or by heating it uniformly and adjusting the curing speed so that it does not become too fast. In the case of compression or extrusion molding, it can be obtained, for example, by wetting a carbon material with a thermosetting resin and molding it with as few voids as possible.

〔Effect of the invention〕

As described above, the magnetic head substrate of the present invention has the surface smoothness required for forming a thin film on the substrate, and can obtain sufficient smoothness by mirror finishing. A thin film with good magnetic properties can be formed thereon by sputtering or vapor deposition. Moreover, the lubricity between the magnetic recording medium and the magnetic recording medium can be maintained for a long time without using a lubricant, the surface of the magnetic recording medium is not damaged, and the amount of loss due to abrasion is small. Furthermore, due to the conductivity of the carbon material, static electricity is not generated, and there is an effect that dust does not adhere to the substrate and the magnetic recording medium.

When the above-mentioned carbon material aggregate or composite material aggregate according to the present invention is used in a part other than a substrate that comes into contact with a magnetic recording medium, for example, a protective plate of a thin film magnetic head, a support of a soft magnetic thin film of a perpendicular magnetic recording head, etc. This can be said to be preferable because it provides sustainable lubricity between the magnetic recording media.

[Explanation based on examples]

In order to show specific embodiments of the magnetic head substrate of the present invention, the present invention will be explained in more detail with reference to examples. It is not limited.

(Example ■) Manufactured by cast molding, density 1.49 g/cd1 Shore hardness 112, thermal conductivity 3 kcal/m hr”
A furan-based glassy carbon material aggregate having the characteristics of C is cut into the shape and dimensions shown in the figure, and the sliding surface A with the recording medium and the surface B on which the thin film is formed are coarsely polished to 0 to gradually finely polished. and finally emery paper #
15,000 to produce a model substrate 1. When the mirror-finished surface B was observed with a scanning electron microscope, no pores with a diameter of 0.5 μm or more were observed on this surface, and only pores with a diameter of 0.01 μm or less were observed.

In order to evaluate the frictional properties between this model substrate 1 and the magnetic recording medium, the dynamic friction between the A side of the substrate 1 and the CO-adhered T-Fe203 coating film, the Ni-P plating thin film, and the Co-Cr spackle thin film The characteristics were measured using a friction tester, and the condition of the A side of the substrate 1 and the surface of the magnetic recording medium was observed with the naked eye. The results are shown in Table 1. The friction test device used in the measurements is a device that can measure dynamic friction characteristics under conditions close to actual usage conditions, as described in Japanese Patent Laid-Open No. 55-128142.

Next, this model substrate 1 was cut along line 1 C-C' in the figure, and Co-Zr with a thickness of 1 μl was placed on the B side of the cut piece.
A -Nb alloy thin film was formed by sputtering, and a Co--Zr--Nb alloy thin film having a thickness of 0.3 μm1 was formed on the B side of the other cut piece by sputtering. After these thin films were heat-treated in a rotating magnetic field, the coercive force Hc of each thin film was measured using a vibrating magnetic recording measuring device for soft magnetic thin films. The result is the second
Shown in the table.

(Example ■) Manufactured by cast molding, density 1.47 g/cd, Shore hardness IOO, thermal conductivity 7 kcal/m hr”
A model substrate 1 as shown in the figure was prepared by processing a furan-based glassy carbon material aggregate having characteristics of C in the same manner as in Example I, and when surface B was observed with a scanning electron microscope, this surface No pores with a diameter of 0.5 μm or more were observed, and only pores with a diameter of 0.05 μm or less were observed.

Thereafter, the friction between the model substrate 1 and the magnetic recording medium and the coercive force of the thin film were measured in the same manner as in Example (2).

Note that the thin film was made by the same method as in Example (2). These results are shown in Tables 1 and 2.

2 (Example ■) Density 1, 45 g/cd manufactured by cast molding
t, Shore hardness 78, thermal conductivity 15 kcal/m
A model substrate 1 as shown in the figure was prepared by processing a phenolic glassy carbon material aggregate having the characteristics of hr'c in the same manner as in Example I, and when surface B was observed with a scanning electron microscope, No pores with a diameter of 0.5 μm or more were observed on this surface, and only pores with a diameter of about 0.2 μl were observed.

Thereafter, the friction between the model substrate 1 and the magnetic recording medium and the coercive force of the thin film were measured in the same manner as in Example (2).

Note that the thin film was made by the same method as in Example I. These results are shown in Tables 1 and 2.

(Example ■) Phenolic glassy carbon fiber (manufactured by Nippon Kynor■,
A composite vitreous carbon material aggregate having a density of 1.46 g/cJ, which was formed by compression molding and was composed of 70% by volume (registered trademark Kynol) and 30% by volume of a general-purpose resol resin for lamination, was prepared in the same manner as in Example I. A model substrate 1 as shown in the figure is prepared by processing method 3, and surface B is
When observed under a scanning electron microscope, no pores with a diameter of 0.5 μm or more were observed on the surface, and only pores with a diameter of 0.4 μm or less were observed.

Thereafter, the friction between the model substrate 1 and the magnetic recording medium and the coercive force of the thin film were measured in the same manner as in Example (2).

Note that the thin film was made by the same method as in Example (2). These results are shown in Tables 1 and 2.

(Comparative Example I) Density 1.37 g/a (Shore hardness 80, thermal conductivity 10 kcal/m hr"C) manufactured by cast molding
A model substrate l as shown in the figure was prepared by processing a furan-based glassy carbon material aggregate having the characteristics in the same manner as in Example I, and when surface B was observed with a metallurgical microscope,
Although pores with a diameter of less than 0.5 μm were also observed on this surface,
In addition, pores with a diameter of 0.6 to 0.7 μm were also observed.

The coercive forces of the model substrate 1 and the thin film of the magnetic recording medium were then measured in the same manner as in Example I. The thin film was made in the same manner as in Example 4 (Example 2). The results are shown in Table 2.

(Comparative example ■) Density 1.35 g/cra manufactured by cast molding
, Shore hardness 70, thermal conductivity 13 kcal/m h
A model substrate l as shown in the figure was prepared by treating a phenolic glassy carbon material aggregate having the characteristics of r'c in the same manner as in example Although some pores with a diameter of less than 0.5 μm were observed, other pores with a diameter of 0.9 to 1.1 μm were also observed.

The coercive forces of the model substrate 1 and the thin film of the magnetic recording medium were then measured in the same manner as in Example I. Note that the thin film was made by the same method as in Example I. The results are shown in Table 2.

(Comparative Example ■) A model substrate 1 as shown in the figure was prepared by treating alumina ceramics (manufactured by Nippon Electric Glass ■, trade name: Neoceram) in the same manner as in Example I, and surface B was examined using a scanning electron microscope. Upon observation, no pores with a diameter of 0.5 μm or more were found on this Table 5 surface.
Only pores of 0.01 μm or less were observed.

Thereafter, the friction between the model substrate 1 and the magnetic recording medium was measured in the same manner as in Example 1. The results are shown in Table 1.

(Test Results) As is clear from Tables 1 and 2, the magnetic head substrate of the present invention has excellent lubricity with the magnetic recording medium, does not damage the head sliding surface and the recording medium, and It can be seen that the coercive force is small and the magnetic properties are excellent.
(Hereinafter referred to as the margin of this page) 6 Table 1 7 Table 2

[Brief explanation of the drawing]

The figure is an external perspective view of a model board made of a material used in a magnetic head according to an embodiment of the present invention. 1...Model board. 8 Procedure? tlr iE book March 4, 1980 1, Display of the case 1988 Patent Application No. 019293 2, Name of the invention Magnetic head substrate 3, Person making the amendment Relationship to the case Patent applicant address Chuo, Tokyo Ward Nihonbashi Kayabacho-chome 14-10
Name (091) Kao Soap Co., Ltd. Representative: Yoshibe Maruta 4, Agent Address: 26-26 Kita-2-chome, Sekimachi, Nerima-ku, Tokyo! 8(i
I? =-1゜Name Patent attorney (7823) Naoie Ide゛Stomach 5
, Date of amendment order (voluntary amendment) 6. Number of inventions increased by amendment None 7. Column 8 of "Detailed description of the invention" of the specification subject to amendment, Contents of amendment ill Page 4, line 19 of the specification 20th line of the same page [
- Conventionally, on the surface of a non-magnetic substrate of a thin-film magnetic head on which a recording medium slides," is corrected to "-Conventionally, on the surface of a magnetic recording medium on which a thin-film magnetic head slides." (2) On page 5, line 12 of the specification, "-1 and on the surface of the magnetic head" is corrected to "-1 and on the surface of the magnetic recording medium." (3) Specification page 12, line 2 to page 4, line [-
After heat-treating these thin films, use a vibrating magnetic recording and measuring device for soft magnetic thin films. Correct it with “Use-”. Procedural amendment March 15, 1980 Director of the Patent Office Kazuo Wakasugi 1. Indication of the case 1988 Patent Application No. 019293 2. Name of the invention Substrate for magnetic head 3. Person making the amendment Relationship to the case Patent applicant address: 14-10, Kayabacho-chome, Nihonbashi, Chuo-ku, Tokyo
Name Title (091) Kao Soap Co., Ltd. Representative Yoshibe Maruta 4, Agent Address 26-18 Kita-2-chome, Sekimachi, Nerima-ku, Tokyo Name Patent Attorney (7823) Naotaka Ide) 5 Date of Amendment Order (Spontaneous) (Amendment) 6. Number of inventions increased by the amendment None 7. Subject of amendment 8. Contents of amendment (1) The name of the invention in the specification is amended to 1Ti11 Substrate for air and throat. (2) Amend the claims of the specification as shown in Attachment 1. (3) Correct the information from the 4th line on page 2 of the Memorandum to the 14th line on page 10 as shown in Attachment 2. [Attachment l] 2. Claims (11) In the basics for a magnetic head in which a thin film constituting a write/read converter for writing to or reading from a magnetic recording medium is formed on one surface, Basics for a magnetic head characterized by having extremely high smoothness on the surface and being composed of a glassy carbon material aggregate with a density of 1.40 g/cJ or more. (2) For magnetic recording media In a magnetic head base in which a thin film constituting a write/read converter for writing or reading data is formed on one surface, the surface on which the thin film is formed has extremely high smoothness and has a density of 1. .40 g/cd or more of a composite material assembly containing a glassy carbon material and a thermosetting resin. [Attachment 2] 3. Detailed description of the invention [Invention TECHNICAL FIELD The present invention relates to a substrate for writing to and reading from a magnetic recording medium and used in a magnetic head having a thin film.In particular, the present invention relates to a thin film magnetic head suitable for high-density magnetic recording and a perpendicular magnetic recording system. The present invention relates to a substrate used in a magnetic head. [Description of Prior Art] In recent years, with the increase in the amount of information, there has been an increasing demand for higher recording densities in magnetic recording. In order to achieve this higher recording density, In recent years, research has become active in improving various parts related to magnetic recording, such as magnetic heads, and developing new magnetic recording methods. Looking at magnetic heads, general-purpose ring-shaped magnetic heads using ferrite cores are It is believed that there is a limit to density magnetic recording, and instead of this, JP-A-55-8401 was developed as a magnetic head that enables higher recording density.
A thin film magnetic head as disclosed in No. 8 has been developed. The thin film magnetic head includes a non-magnetic substrate, a write or read transducer made of a plurality of thin film layers including a write or read transducing gap layer formed on one side of the non-magnetic substrate, and and a non-magnetic protective plate covering the thin film layer. These thin film layers are typically formed by sputtering or vapor deposition on non-magnetic substrates. Furthermore, regarding magnetic recording methods, it has been shown that the conventional longitudinal magnetic recording method has a limit in increasing the recording density. A method has been proposed. When manufacturing magnetic heads used for perpendicular magnetic recording,
A soft magnetic thin film is formed on a nonmagnetic substrate by sputtering or vapor deposition. The substrate used in these magnetic heads requires sufficient surface smoothness because a thin film is formed thereon as described above, and the surface is usually mirror-finished. If there are pores with a large diameter or a large number of pores in the above-mentioned substrate, even if mirror finishing is applied, the surface of the substrate will not have sufficient smoothness, and sputtering will occur on this surface. Alternatively, circular holes are present in the thin film formed by vapor deposition, and therefore, this thin film cannot have good magnetic properties. Furthermore, since it is difficult to remove gas from the pores, it is difficult to obtain the degree of vacuum required during sputtering or vapor deposition. Currently, aggregates of alumina-based ceramics that provide surface smoothness are generally used as substrates for these magnetic heads. However, this alumina-based ceramic material has high hardness and has the disadvantage that it easily scratches the surface of the recording medium when sliding with the magnetic recording medium. In order to eliminate this drawback, conventionally, lubricant is applied to the surface of the magnetic recording medium on which the thin-film magnetic head slides.
Alternatively, the surface of the magnetic recording medium is coated with a protective film, but even if lubricant is applied, it is difficult to maintain the lubricating effect for a long time due to volatilization, etc., so it is necessary to reapply the lubricant periodically. However, providing a protective film on the recording medium increases the number of steps required to cover the protective film, and increases the distance between the thin film magnetic head and the recording medium. (Objective of the Invention) The present invention has extremely high surface smoothness, makes it possible to form a thin film with good magnetic properties on a mirror-finished surface, and applies a lubricant to the surface of a magnetic recording medium. To provide a base for a magnetic head that does not permanently damage the surface of a magnetic recording medium without damaging the surface of the magnetic recording medium, without forming a protective film on the surface of the magnetic recording medium, and with less wear on the contact surface with the magnetic recording medium. [Features of the Invention] The first feature of the invention is that the surface on which the thin film is formed has extremely high smoothness and is composed of a glassy carbon material aggregate having a density of 1.40 g/c+& or more. The second invention is characterized in that the surface on which the thin film is formed has extremely high smoothness and has a density of 1.40 g/cJ.
The present invention is a magnetic head base made of a composite material aggregate containing the above-mentioned glassy carbon material and thermosetting resin. In this specification, "extremely high smoothness" means that no pores with a diameter of 0.5P or more are formed on the surface on which the thin film is formed. Since the substrate for a magnetic head of the present invention does not have holes with a diameter of 0.5 μm or more formed on the surface on which the thin film is formed, a thin film with good magnetic properties can be formed on the surface of the substrate. Although the density of the substrate is not directly related to the formation of a thin film with good magnetic properties, a substrate with a low density of less than 1.40 g/c+I1 has a diameter of 0.5 mm on the surface on which the thin film is formed.
Even if there are no pores larger than μm, many pores are formed on the surface other than the thin film forming surface or inside the substrate, and when this substrate is used, the degree of vacuum required for sputtering or vapor deposition may be reduced. Otherwise, the object of the present invention cannot be achieved because it becomes difficult to obtain or the wear loss becomes large upon contact with a magnetic recording medium. Note that the surface on which the thin film is formed has a diameter of 0. If the substrate does not have pores larger than IP, a thin film with better magnetic properties can be formed on the surface of the substrate. To further explain the present invention, the carbon material according to the present invention includes a carbon material obtained by carbonizing a thermosetting resin, a carbon material obtained by carbonizing a thermosetting resin, and a carbon material obtained by carbonizing a thermosetting resin by copolymerization, cocondensation, etc. Carbon materials obtained by curing or by significantly inhibiting crystallization through chemical treatment during the hardening or carbonization process, and carbon materials obtained by thermally decomposing low molecular weight hydrocarbons such as methane, ethylene, and benzene in the gas phase. Specific examples include polyacrylonitrile-based carbon materials, rayon-based carbon materials, pinch-based carbon materials, lignin-based carbon materials, phenolic-based carbon materials, furan-based carbon materials, alkyd resin-based carbon materials, and non-carbon materials. Examples include saturated polyester carbon materials, xylene resin carbon materials, and the like. Further, examples of the thermosetting resin used in the present invention include phenol resin, epoxy resin, polyester resin, furan resin, urea resin, melamine resin, alkyl resin, xylene resin, and the like. When these thermosetting resins are combined with the glassy carbon material, the thermosetting resin acts as a binder that binds the glassy carbon materials together, resulting in a durable non-woven material that is strong against mechanical damage such as collisions. A magnetic substrate can be obtained. However, if a large amount of thermosetting resin is composited with a glassy carbon material, it becomes a non-magnetic substrate that is subject to high wear. It is recommended to include the following. The magnetic head substrate of the present invention is composed of an aggregate of the above-mentioned carbon material or an aggregate of a composite of carbon material and thermosetting resin. Various well-known molding methods such as casting, compression, and extrusion are used to manufacture these aggregates, but the aggregates have no pores with a diameter of 0.5μi11 or more and a density of 1.40 g/ - In order to obtain the above aggregate, when using the casting method, for example, a precursor of a carbon material (a thermosetting resin cured with a curing agent or heat) is used.
In the step of obtaining the curing agent, the curing agent is uniformly dispersed or heated uniformly, and the curing speed is adjusted so as not to become too fast. In the case of compression or extrusion molding, it can be obtained, for example, by wetting a carbon material with a thermosetting resin and molding it with as few voids as possible. [Effects of the Invention] As described above, the magnetic head substrate of the present invention has the surface smoothness required for forming a thin film on the substrate, and sufficient smoothness can be obtained by mirror finishing. Furthermore, a thin film with good magnetic properties can be formed on the substrate by sputtering or vapor deposition. Moreover, the lubricity between the magnetic recording medium and the magnetic recording medium can be maintained for a long time without using a lubricant, the surface of the magnetic recording medium is not damaged, and the amount of loss due to abrasion is small. Furthermore, due to the conductivity of the carbon material, static electricity is not generated, and there is an effect that dust does not adhere to the substrate and the magnetic recording medium. When the above-mentioned carbon material aggregate or composite material aggregate according to the present invention is used in a part other than the base that comes into contact with a magnetic recording medium, for example, a protective plate of a thin film magnetic head, a support of a soft magnetic thin film of a perpendicular magnetic recording head, etc. This can be said to be preferable because it provides sustainable lubricity between the magnetic recording media. [Explanation based on Examples] Hereinafter, the present invention will be explained in more detail using Examples in order to show specific embodiments of the magnetic head substrate of the present invention. It does not limit the technical scope of the invention.

Claims (1)

[Claims] (11) In a magnetic head substrate in which a thin film constituting a write/read converter for writing to or reading from a magnetic recording medium is formed on one surface, the surface on which the thin film is formed is A substrate for a magnetic head characterized by being composed of a glassy carbon material aggregate having extremely high smoothness and a density of 1.40 g/era or more. (2) Writing or reading on a magnetic recording medium. In a magnetic head substrate on which a thin film constituting a write/read converter is formed on one surface, the surface on which the thin film is formed has extremely high smoothness and a density of 1.40 g/cJ or more. A magnetic head substrate comprising a composite material aggregate containing a glassy carbon material and a thermosetting resin.