JPH04147411A - Manufacturing method of thin film magnetic head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a thin film magnetic head used in magnetic disks, VTRs, etc.

[Conventional technology]

FIG. 1 is a sectional view of this type of thin film magnetic head. 1st
In the figure, 1 is a carrier formed of A ji T t C, etc., 2 is an electrical insulating film made of A#203 layer etc., which is provided on the carrier l and deposited by normal sputtering, and 3 is an electrical insulating film. 2 is a lower magnetic pole layer made of a soft magnetic film layer which is provided on the lower magnetic pole layer 3, 4 is a gap layer made of an A Il z 03 layer formed on the lower magnetic pole layer 3 and usually formed by sputtering, and 5 is a gap layer. 4 is used to write/read information, and is formed by commuting plating. 6 is a photoresist film or a 5f02 film formed by sputtering, and the coil part 5 is electrically connected to the coil part 5. An electrical insulating layer 7 is provided on the electrical insulating layer 6 and consists of a soft magnetic film layer that serves as a magnetic pole. 8 is an upper magnetic pole layer provided on the upper magnetic pole layer 7 for isolation from the outside air and protection against external forces. AA20 is usually made by sputtering.
It is a protective film consisting of three layers.

Next, a method of manufacturing a conventional thin film magnetic head will be explained. Since the AlTiC carrier 1 is electrically conductive as it is and it is impossible to directly form electrical circuit components thereon, an electrical insulating film 2 is once applied. As the electrical insulating film 2, Ajz0! is usually formed by sputtering. Use a membrane.

This Al1203 has moderate hardness and excellent electrical insulation, and is usually used as a layer of about 10 μm after forming a film of 15 μm or more and polishing the mirror surface. A lower magnetic pole layer 3, a gap layer 4, a coil portion 5, an electric insulating layer 6, and an upper magnetic pole layer 7 as a thin film magnetic head circuit are sequentially formed on the electrical insulating film 2 made of the A4203 layer. Finally, in order to protect this thin film magnetic head circuit, Al20. Preserve the membrane! i! ! membrane 8
It is usually applied on the magnetic pole layer 7 to a thickness of about 30 to 50 μm by sputtering. This protects the thin film magnetic head circuit from the atmosphere, prevents deterioration of the head circuit due to minute amounts of harmful gases and moisture in the atmosphere, and further prevents damage due to mechanical impact.

[Problem to be solved by the invention]

In magnetic storage devices that use thin-film magnetic heads manufactured using conventional manufacturing methods, the head output is minute, on the order of 0.1 mV, and is easily affected by noise, making noise reduction an important issue. . Since the main component of the noise of the thin film magnetic head itself is caused by thermal noise of the coil section 5, reducing the electrical resistance of the coil section 5 has become an important issue. Furthermore, since the electrical resistance increases in proportion to the temperature of the coil section 5 itself, it is necessary to suppress the temperature rise of the coil section 5 as much as possible during operations, mainly writing operations of the thin film magnetic head. In this case, since the electrical insulating film 2, the electrical insulating layer 6, and the protective film 8 are poor thermal conductors, there is a problem in that it is difficult to suppress the temperature rise of the coil portion 5.

By the way, in the conventional technique shown in JP-A No. 60-175206, an attempt is made to increase the heat sink effect by extending the thin layer that becomes the magnetic pole, but the magnetic pole layer usually has a thickness of 2 to 3 μm.
There is a problem in that it is thin and easily damaged by mechanical impact. There is also a method of inserting a metal layer between the magnetic pole and the protective film or substrate solely for the purpose of heat sinking, as in the prior art shown in Japanese Patent Application Laid-Open No. 64-4913.
This has the problem of complicating the manufacturing process.

This invention was made in order to solve the above-mentioned problems, and it is possible to efficiently suppress the temperature rise during use of the coil section, reduce thermal noise caused by the coil section, and reduce mechanical shock. An object of the present invention is to provide a method for manufacturing a thin-film magnetic head that is resistant to corrosion and can be manufactured through a simple manufacturing process.

[Means to solve the problem]

In the method for manufacturing a thin film magnetic head according to the present invention, either or both of the electrical insulating film 2 and the protective film 8 on the carrier 1 have a thermal conductivity of at least a predetermined value (0.2caρ/cm-3·°C). A#N, Bed as a good thermal conductive material.

Using diamonds etc., the above AI! , N, Bed, diamond, etc. are formed by a dry process.

[Effect]

Either or both of the electrical insulating film 2 and the protective film 8 on the carrier l has a thermal conductivity of a predetermined value (0.2c a 17cm・S・℃
) or more as a good thermal conductive material.

It is formed by depositing a film of Bed, diamond, etc. in a dry process. Therefore, either or both of the electrical insulating film 2 and the protective film 8 act as a good heat sink.

〔Example〕

The structure of the thin film magnetic head according to the embodiment of the present invention is the same as the structure shown in FIG. 1 described above. A method of manufacturing the thin film magnetic head of this embodiment will be explained below.

First, as a first example, an electrical insulating film 2 and a protective film 8 will be described.
The case where AβN is used will be described. /IN of electrical insulating film 2
The film is formed by a dry process such as sputtering using a sintered AffiN material as a target. In order to reduce the internal stress of the film and obtain uniform film quality, a conventional RF method will be adopted. The thicker the film is, the more desirable it is, and in practice it is set to about 30 μm, for example. Thereafter, each layer is formed in the same manner as in the conventional method, and finally, the protective film 8 is formed in the same manner as described above.

The film thickness is, for example, 30 to 50 μm.

Next, as a second embodiment, an electrical insulating film 2. B to protective film 8
A case using eO will be described. The BeO film of the electrical insulating film 2 is formed by sputtering using a sintered BeO material as a target. In order to reduce the internal stress of the film and obtain uniform film quality, a conventional RF method will be adopted. The film thickness is approximately 30 μm as in the first embodiment. Thereafter, each layer is formed in the same manner as in the conventional method, and finally, a protective film 8 is applied to a thickness of 30 to 50 μm in the same manner as described above.

Further, as a third embodiment, a case where diamond is used for the electrical insulating film 2 will be described. The diamond film of the electrical insulating film 2 is formed by, for example, a dry process such as a CVD method under conditions that provide high thermal conductivity and high crystallinity. of course,
The conditions must also reduce the internal stress of the membrane. The film thickness is set as thick as possible while satisfying the above conditions. After that, the first. Each layer is formed in the same manner as in the second embodiment, and finally the protective film 8 is applied. To form a diamond film using the conventional CVD method, it is necessary to heat the base to about 450° C. or higher. At this high temperature, the properties of the magnetic pole layer 3.7 and the glabellar electric insulating layer 6 made of organic materials often deteriorate, so a diamond film cannot be used unless careful consideration is given. Therefore, here, the first. In the case of the second embodiment, the electrical insulating layer 6 etc. is made of AlN or B.
It is better to use eO.

Incidentally, heat generation in the thin film magnetic head occurs during information writing to the opposing recording medium. Usually, the coil resistance is about 30Ω and the write current is about 50mA.
Power consumption is large at approximately 75 mW.

The thin-film magnetic head considered here performs both a write operation and a read operation independently, and noise during a read operation immediately after a long-time write operation, which is the worst temperature condition, poses a problem. Regarding the temperature of the coil section 5 immediately after the long-time write operation, the conventional example, the first example, the second example, and the third example
A comparison of the cases of the embodiments shown in FIG. 2 is obtained. These examples have a difference of 20 to 20% from the ambient temperature compared to the conventional example.
It can be seen that the temperature has dropped by 50°C.

Currently, a Cu thin film is used for the coil material, but the resistivity of the Cu material is 1.7X1 at 20°C, as stated in the Rikagaku Handbook.
It can be seen that the influence of temperature is extremely large, as it is 0'-6Ω・cm at 100°C and 2.3×106Ω・cm. If this change in resistivity between 20°C and 100°C is considered linear, it is 0.075X10-6Ω・am/10
℃, that is, a rise in specific resistance of 0.075×10−′Ω·cin occurs for every 10℃. Based on the relationship between the temperature immediately after the operation of the thin film magnetic head shown in FIG. 2 and the temperature change in this resistivity, the Cu resistivity in each case is as shown in FIG. 3. In the case of diamond/B e O, which has the greatest effect of lowering the temperature, the average value is 2.12XIO-6Ω・cm,
From 2.49 xlo-6Ω・crn in the conventional case,
It can be seen that the specific resistance can be reduced by 15%.

The thermal noise of a thin film magnetic head is approximately proportional to the coil resistance, and the present invention can reduce the noise by a maximum of about 15%. If this is expressed as an S/N ratio, an improvement of 20Ilog110.85=1.4 dB is obtained by definition. In other words, in an example where the operating ambient temperature is 40°C, the thin film magnetic head can be lowered by up to 50°C, and as a result, the specific resistance of the coil is reduced by about 15%, and the S/N ratio is reduced to 1.4 d.
B: It can be improved.

As explained above, in the past, the electrical insulation y2. Of the electrical insulating layer 6 and the protective film 8, in the embodiment, the electrical insulating film 2 and the protective film 8 are changed to good thermal conductors.

Conventional AI! The thermal conductivity of ZOA membrane is 0.07 ca
β/Cm-8・℃, whereas the AlN film of the example
The thermal conductivity of each BeO film and diamond film is 0.2C.
aj2/cIn-8・℃ or higher, 0.6 c a l/c
m・s・”c or more, 2 Cal/cm-8・℃ or more, which is high.

Therefore, these films act as a good heat sink and effectively suppress the rise in temperature of the coil portion 5. The electrical insulating film 2 is as thick as about 10 μm, and the protective film 8 is as thick as 30 to 50 μm, and furthermore, since they are close to the heat generating part (coil part 5), the rise in temperature of the coil part 5 is suppressed. In addition, compared to the prior art disclosed in the publication, in which a metal layer for the sole purpose of a heat sink is inserted between the magnetic pole and the protective film or the substrate, this embodiment has a simpler manufacturing process and a thin film magnetic layer. Easy to create heads. Moreover, since it is hard, it is resistant to mechanical shock.

Here, we aimed to improve the thermal conductivity of the thin film that constitutes the multilayer film together with the coil portion that is the heating element, but it can also be applied to the carrier of the multilayer film. Currently, in thin film magnetic heads, AJT,
C is used, but instead of this, AAN, BeO
It is highly conceivable that the heat sink performance can be further improved by using a sintered body or diamond crystal.

〔Effect of the invention〕

As described above, according to the present invention, either or both of the electrical insulating film and the protective film on the carrier are coated with Al1N and Bed.

Since the film is formed using a dry process using a good heat conductive material such as diamond, the temperature rise during use of the coil part is effectively suppressed, thermal noise caused by the coil part is reduced, and mechanical shock is avoided. The advantage is that a thin-film magnetic head can be produced with a simple manufacturing process.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a thin film magnetic head according to an embodiment of the present invention and a conventional example, FIG. 2 is a diagram for explaining the difference in ambient temperature of the coil section between the embodiment and the conventional example, and FIG. It is a figure which shows the temperature and specific resistance of the Cu coil in an example and a conventional example. DESCRIPTION OF SYMBOLS 1... Carrier, 2... Electrical insulating film, 3... Lower magnetic pole layer, 4... Gap layer, 5... Coil part, 6...
Electrical insulating layer, 7... Upper magnetic pole layer, 8... Protective film. Agent Patent Attorney Jun Miyazono

Claims (1)

[Claims] In a thin-film magnetic head in which an electrical insulating film is provided on a carrier, and a lower magnetic pole layer, a gap layer, a coil portion, an electrical insulating layer, an upper magnetic pole layer, and a protective film are sequentially laminated on the electrical insulating film, the above-mentioned A method for manufacturing a thin-film magnetic head, characterized in that a film of a good heat conductive material such as AlN, BeO, or diamond is formed on either or both of an electrical insulating film and a protective film on a carrier using a dry process. .