JP3145658B2 - Jig for magnetic head processing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jig used in a processing step and an assembling step of a magnetic head.

[0002]

2. Description of the Related Art As a magnetic head used in a magnetic recording apparatus, those equipped with a core slider consisting of titania-based ceramic, or a magnetic head in thin section on a substrate made of Al ₂ O ₃ -TiC based ceramic Thin film magnetic head, M which is a kind of this thin film magnetic head
There is an R head and the like.

Since this magnetic head has a minute and complicated shape, various jigs are used in a process of processing the above-mentioned ceramic material into a predetermined shape and assembling it as a magnetic head.

For example, a jig 10 shown in FIG. 1 is a so-called transfer tool, which is made of a plate having an irregularly shaped through-hole 11 and is used in a polishing process of an Al ₂ O ₃ —TiC ceramic substrate 1. I do. That is, in a state where the substrate 1 is stuck on the lower surface 13 of the jig 10, the upper surface 12 is held and pressed against a rotating polishing plate 14 as shown in FIG. 1 can be elastically pressed, and the thickness can be adjusted uniformly.

[0005] In addition, a jig for holding a ceramic material such as the substrate 1 when processing it by ion milling or the like, and a jig for holding a manufactured magnetic head when assembling it to an apparatus are also provided. is there.

[0006] These jigs for processing and assembling a magnetic head are conventionally formed of a metal such as stainless steel or a ceramic such as alumina.

[0007]

However, metal jigs used in processing and assembling processes of thin-film magnetic heads, especially MR heads, have too high a conductivity to cause handling accidents due to conduction short-circuits or metal strikes. There has been a problem that the yield is likely to decrease due to the accuracy deterioration due to the marks. In addition, the jig itself tends to be magnetized, which has a problem of adversely affecting components such as a thin-film magnetic head, particularly an MR head.

On the other hand, since a jig made of ceramics such as alumina is an insulating material, it is possible to solve the problems caused by short-circuit due to conduction and to reduce the yield reduction due to the deterioration of accuracy due to dents. There is a problem that the magnetic head is easily adversely affected because it is difficult to escape.

[0009]

Accordingly, the present invention provides a jig used in the processing step of a thin-film magnetic head, which is formed of a nonmagnetic ceramic having a volume resistivity of 10 ⁶ to 10 ⁹ Ω · cm. It is characterized by.

[0010] Here, the volume resistivity is set to 10 ⁶ to 10 ^9.
Ω · cm means that the volume resistivity is 10 ⁹ Ω · cm
If it is larger, the insulating property is so high that the effect of removing static electricity cannot be obtained. Conversely, the volume specific resistance value is 10 ⁶ Ω ·
When the diameter is smaller than cm, the charged static electricity escapes at a stretch, and the discharge action due to atmospheric friction cannot be prevented.

The non-magnetic ceramics are ceramics having a residual magnetic flux density of 14 Gauss or less.

[0012]

Embodiments of the present invention will be described below.

A jig 10 shown in FIG.
A plate-like body having, for use in the Al ₂ O ₃ -TiC based polishing steps 1 such as a substrate of ceramics. That is, jig 1
In a state where the substrate 1 is stuck to the lower surface 13 of the substrate 0, the upper surface 12 is held and pressed against a rotating polishing plate 14 as shown in FIG.
Can be elastically pressed, and the thickness can be adjusted uniformly.

The jig 10 is made of a non-magnetic ceramic having a volume resistivity of 10 ⁶ to 10 ⁹ Ω · cm.

[0015] Because of the proper volume specific resistance value, static electricity can be gradually released, so that static electricity is released at a stretch, thereby preventing discharge action due to atmospheric friction and preventing adverse effects on the magnetic head. it can.

What is important here is that if the volume resistivity of the jig 10 is too low, static electricity is released at once, causing a discharge action due to atmospheric friction, which adversely affects the magnetic head. Therefore, in the present invention, by controlling the volume resistivity to a moderately conductive range of 10 ⁶ to 10 ⁹ Ω · cm, static electricity is gradually released, and the jig 10 is less likely to adversely affect the magnetic head. I tried to get.

Further, as described above, the volume resistivity value is set to 1
Once you have a range of 0 ⁶ ~10 ⁹ Ω · cm, it is possible to prevent the handling accidents caused by conduction short circuit. In addition, the use of non-magnetic ceramics can prevent adverse effects on the magnetic head. Further, since the jig 10 is made of a ceramic having a high hardness, it is possible to prevent the accuracy from being deteriorated due to dents and wear.

Next, another embodiment of the present invention will be described.

The jig 20 shown in FIG. 2 is a plate-shaped body made of non-magnetic ceramics having a volume resistivity of 10 ⁶ to 10 ⁹ Ω · cm and having a groove 21. Then, the substrate 1 of the Al ₂ O ₃ —TiC-based sintered body is placed in the groove 21,
Processing can be performed by the ion milling device 22 from the upper surface.

The jig 30 shown in FIG. 3 is made of a non-magnetic ceramic having a volume resistivity of 10 ⁶ to 10 ⁹ Ω · cm, and has two slits 31. Then, when assembling the manufactured magnetic head into a magnetic recording device, a part of the gimbal holding the magnetic head can be held in the slits 31.

As described above, the jig for processing and assembling a magnetic head according to the present invention is a method for grinding a ceramic material forming a magnetic head.
Jigs for holding workpieces in processing steps such as polishing and ion milling, and holding heads etc. in the assembly process such as when assembling as a magnetic head or assembling the obtained magnetic head to a magnetic recording device Means a jig or the like for performing

The jig for processing and assembling a magnetic head according to the present invention can be used for processing and assembling various magnetic heads, but is particularly preferably used for processing and assembling a thin film magnetic head, especially an MR head.

In the above embodiment, an example is shown in which the entire jig is formed of nonmagnetic ceramics having a volume resistivity of 10 ⁶ to 10 ⁹ Ω · cm.
It is sufficient that a portion, such as the above, which comes into contact with the workpiece is formed of the above-mentioned ceramics, and a jig can be formed in combination with another material.

In the jig for processing and assembling a magnetic head according to the present invention, the volume resistivity value is 10 ⁶ to 10 ⁹ Ω · c.
As the non-magnetic ceramic having m, for example, conductive zirconia ceramics, conductive alumina ceramics, silicon carbide ceramics, titania-based ceramics, and conductive forsterite-based ceramics are used.

As the conductive zirconia ceramics,
Fe ₂ O ₃ , NiO, Co
10% to 35% by weight of at least one of ₃ O ₄ and Cr ₂ O ₃
Or contained in a range of, or TiC, WC, contains in the range of 10 to 25 wt% of one or more kinds of carbides such as TaC, balance _{Y 2 O 3, CaO, MgO} , stabilizers such as CeO ₂ The zirconia which is partially stabilized by the method described above, has a zirconia content other than monoclinic crystal of 90% or more, preferably 95% or more, based on the total zirconia content in the sintered body.

That is, the crystalline state of zirconia has three states of cubic, tetragonal, and monoclinic. In particular, tetragonal zirconia undergoes stress-induced transformation to external stress to form monoclinic zirconia. Phase transformation and volume expansion that occurs at this time form micro-cracks around monoclinic zirconia and can prevent the progress of external stress, thereby increasing the strength of zirconia ceramics. If the amount of other zirconia is less than 90%, the strength is deteriorated due to the inclusion of the conductivity-imparting agent.

The zirconia has an average crystal grain size of 0.1.
If it is larger than 5 μm, mechanical properties such as bending strength and hardness are greatly reduced, and if it is less than 0.2 μm, it is difficult to manufacture. Therefore, the average crystal grain size of zirconia is preferably 0.2 to 0.5 μm.

Further, Fe ₂ O ₃ ,
When one or more of NiO, Co ₃ O ₄ and Cr ₂ O ₃ are used, the content of these conductivity-imparting agents is 10 to
The reason for setting the content to 35% by weight is that if the content is 10% by weight, the effect of lowering the resistance value is small and the resistance cannot be reduced to 10 ⁹ Ω · cm or less. At the same time, the resistance value becomes less than 10 ⁶ Ω · cm, and there is a possibility that magnetism may be generated.

Further, TiC, W
Even when one or more carbides such as C and TaC are used, if the content of the conductivity-imparting agent is less than 10% by weight, the resistance cannot be reduced to 10 ⁹ Ω · cm or less. If it exceeds 25% by weight, the resistance value becomes 10 ⁶
This is because it is less than Ω · cm, and there is a possibility that magnetism may occur.

If the average crystal particle diameter of these conductivity-imparting agents is too large, the mechanical properties such as the bending strength and hardness of the zirconia ceramics are reduced, so that the thickness is preferably 5 μm or less, preferably 3 μm or less.

Further, in addition to the zirconia and the conductivity-imparting agent, a firing temperature inhibitor may be contained in a range of 3% by weight or less. In the case where Fe ₂ O ₃ , NiO, Co ₃ O ₄ , or Cr ₂ O ₃ is used as a conductivity-imparting agent as a firing temperature inhibitor, an oxide such as Ca, K, Na, Mg, Zn, or Sc is contained. And Ti as a conductivity-imparting agent.
When using a carbide such as C, WC, TaC, etc., Al ₂
O ₃ and TiO ₂ may be contained.

If these sintering temperature inhibitors are contained in a range of 3% by weight or less, the sintering temperature can be lowered to suppress the grain growth of zirconia and the conductivity-imparting agent. Characteristic can be enhanced.

Such a conductive zirconia ceramic has a Vickers hardness of 10 to 13 GPa, a three-point bending strength of 6
It can be 50 to 1400 MPa.

As the conductive alumina ceramic, 65 to 85% by weight of Al ₂ O ₃ is used as a main component, and Fe ₂ O ₃ , NiO, Co ₃ O ₄ , Cr
One or more of ₂ O ₃ are contained in a range of 15 to 35% by weight, and the remainder is used as a sintering aid such as MgO, CaO, SiO _{2 and the} like, and fired in an air atmosphere.

This conductive alumina ceramic has a Vickers hardness of 10.5 to 18 GPa and a three-point bending strength of 200.
To 450 MPa.

Further, as the silicon carbide ceramics, 90 to 98% by weight of SiC is a main component, and 1 to 7% by weight of Al ₂ O ₃ is used as a sintering aid, and Y ₂ O ₃ and CeO _{2 are used.}
May be added in the range of 1 to 5% by weight in total, and fired in a vacuum or in an inert gas atmosphere. Thus, sinterability can be enhanced and toughness can be improved by adding a sintering aid within the above range.

This silicon carbide ceramic has a Vickers hardness of 22 to 24.5 GPa and a three-point bending strength of 450 to 6
00 MPa.

Further, titania-based ceramics include:
In TiO ₂ 50 to 99 wt%, the balance BaO, CaO,
A titania-based ceramic made of one or more of SrO, Al ₂ O ₃ , ZrO ₂ , SiO ₂ , and MgO is formed into a predetermined shape, fired, and then non-oxidized in a reducing atmosphere, an inert atmosphere, or in a vacuum. 900-1 in the atmosphere
What has been heat-treated at 200 ° C. may be used.

This titania ceramic has a Vickers hardness of 6.5 to 9 GPa and a three-point bending strength of 170 to 300.
MPa.

Further, the conductive forsterite ceramic is made of a composite oxide of MgO and SiO ₂ of 40 to 80%.
%, And a sintered body containing iron oxide in the range of 60 to 20% by weight, respectively. This conductive forsterite-based ceramic can be obtained by molding a raw material powder having the above composition into a predetermined shape, and then firing it at 1200 to 1300 ° C. When the sintered body is measured by X-ray diffraction, 2MgO · It has crystals of SiO ₂ and MgOSiO ₃ and at least one crystal of MgFe ₂ O ₃ and Fe ₃ O ₄ .

The conductive forsterite ceramics described above can have a Vickers hardness of 5.4 to 8.3 GPa and a three-point bending strength of 125 to 225 MPa. Since the conductive forsterite ceramic has a low Vickers hardness as described above, for example, the jig 2 shown in FIG.
When the diamond tool is used as 0 and the substrate 1 is cut with a diamond tool or the like, the diamond tool can be hardly damaged even when the substrate 1 is cut into the jig 20 at the same time.

Further, the above ceramics are made non-magnetic so as not to adversely affect the magnetic head.
Here, "non-magnetic" means that the residual magnetic flux density is 14 gauss or less, and the content may be adjusted to be within this range by adjusting the content of the above-described conductivity imparting agent and the like.

In the above ceramics, it is preferable that the Vickers hardness is 8.5 GPa or more, especially 10.5 GPa or more, in order to prevent the accuracy from being deteriorated due to dents and wear. Further, in order to prevent breakage or the like during use, a bending strength of 200 MPa or more, particularly 700 MPa
It is preferable that it is above. From the viewpoint of such mechanical properties, the above-described conductive zirconia ceramics is optimal.

When manufacturing the jig for processing and assembling a magnetic head according to the present invention, each of the above-mentioned ceramic raw materials is prepared, mixed with a predetermined binder component, and then subjected to press molding.
It can be obtained by molding into a predetermined shape by a method such as extrusion molding, injection molding, cast molding or the like, and then firing it under the conditions corresponding to each raw material.

[0045]

The present invention will be specifically described below.

As an embodiment of the present invention, a jig 10 shown in FIG.
Were made of conductive zirconia ceramics, conductive alumina ceramics, silicon carbide ceramics, titania-based ceramics, and conductive forsterite-based ceramics.

For the conductive zirconia ceramics, conductive alumina ceramics, and conductive forsterite ceramics, the volume resistivity and the residual magnetic flux density were changed by changing the content of the conductivity-imparting agent. Silicon carbide ceramics change the volume resistivity and residual magnetic flux density by changing the ratio of SiC and sintering aid, and titania ceramics change the heat treatment conditions after firing to change the volume resistivity. , And the residual magnetic flux density was changed.

Using these, the degree of static electricity removal and whether or not it was non-magnetic were measured.

Regarding the degree of static electricity removal, the jig 10
A voltage of 1000 V is applied to the lower surface 13 of the jig 10, the voltage and the descent time are measured on the upper surface 12 of the jig 10, and the descent time until the voltage value on the upper surface 12 becomes 100 V is 0.1 to
Those within 20 seconds were evaluated as ○, and others were evaluated as ×. In addition, regarding the volume specific resistance value, JIS-
It was measured by a super insulation resistance meter specified in C2141.

Further, whether or not it was non-magnetic was measured by measuring the residual magnetic flux density with a vibrating sample magnetometer, and those having a magnetic flux density of 14 Gauss or less were evaluated as non-magnetic.

The composition of the conductive zirconia ceramics constituting the jig 10 is as shown in Table 1, and its characteristics and results are as shown in Table 2. Each of the above zirconia ceramics was partially stabilized by adding ₃ mol% of Y ₂ O ₃ to ZrO ₂ , and the conductivity-imparting agent was Fe.
₂ O ₃ , NiO, Co ₃ O ₄ , Cr ₂ O ₃ , TiC, W
C and TaC were used.

Table 3 shows the composition of the conductive alumina ceramics, and Table 4 shows its properties and results. Table 5 shows the composition of the silicon carbide ceramics, and Table 6 shows its properties and results. Table 7 shows the composition of the titania-based ceramics and heat treatment conditions, and Table 8 shows the properties and results. Table 9 shows the composition of the conductive forsterite ceramics, and Table 10 shows the properties and results.

[0053]

[Table 1]

[0054]

[Table 2]

[0055]

[Table 3]

[0056]

[Table 4]

[0057]

[Table 5]

[0058]

[Table 6]

[0059]

[Table 7]

[0060]

[Table 8]

[0061]

[Table 9]

[0062]

[Table 10]

As a result, regarding the conductive zirconia ceramics, first, the sample no. Samples Nos. 1 to 7 contain Fe ₂ O ₃ as a conductivity-imparting agent.
o. No. 1 has a volume specific resistance value of more than 10 ⁹ Ω · cm because the content of Fe ₂ O ₃ is less than 10% by weight. As a result, it takes time until the voltage reaches a predetermined value, and the static electricity removing effect is obtained. I couldn't.

The sample No. Nos. 6 and 7 have a Fe ₂ O ₃ content of more than 35% by weight and a volume resistivity of 10 ⁶ Ω.
・ Because it was smaller than cm, it was found that the voltage dropped to a predetermined value in a short time and static electricity escaped at once. Moreover, Fe
Due to the large content of ₂ O ₃ , it had magnetism.

On the other hand, the sample No. 2 to 5 are Fe ₂ O
_Since the content of ₃ was in the range of 10 to 35% by weight, non-magnetic, and the volume resistivity was in the range of 10 ⁶ to 10 ⁹ Ω · cm, it was found that static electricity could be removed at an appropriate speed.

The sample No. Nos. 8 to 13 each use NiO, Co ₃ O ₄ , and Cr ₂ O ₃ as the conductivity-imparting agent, all of which have a content in the range of 10 to 35% by weight and a volume specific resistance value of 10 ⁶ to 10 ⁹ Ω · cm
Was in the range. Therefore, static electricity could be removed at an appropriate speed.

On the other hand, the sample No. Samples Nos. 14 to 17 each contained TiC as a conductivity-imparting agent. Sample No. 14 had a volume specific resistance of more than 10 ⁹ Ω · cm because the content of TiC was less than 10% by weight, and a sufficient static electricity removing effect was not obtained. Sample N
o. No. 17 has a volume specific resistance of less than 10 ⁶ Ω · cm because the content of TiC is more than 25% by weight, and it was found that static electricity escapes at a stretch. In addition, since the content of TiC was large, it had magnetism. On the other hand, the sample No.
In Nos. 15 and 16, the TiC content was in the range of 10 to 25% by weight, and the volume resistivity was in the range of 10 ⁶ to 10 ⁹ Ω · cm. Therefore, it turned out that static electricity can be removed at an appropriate speed.

Further, the sample No. Nos. 18 to 21 use WC and TaC as the conductivity-imparting agents, respectively, and their contents are in the range of 10 to 25% by weight, and the volume resistivity is 10 ⁶ to 10 ⁹ Ω · cm. Range. Therefore, the static electricity could be removed at an appropriate speed.

In the case of conductive alumina ceramics, silicon carbide ceramics, titania-based ceramics, and conductive forsterite-based ceramics, sample No. 23, 24, 26, 27, 29, 30, 31, 3,
2, 35 to 37 and 42 to 46 have a volume resistivity value of 10
The range was ⁶ to 10 ⁹ Ω · cm. Therefore, the static electricity could be removed at an appropriate speed.

As a result, in the case of conductive zirconia ceramics, Fe ₂ O ₃ , Ni
When O, Co ₃ O ₄ , or Cr ₂ O ₃ is used, its content is 10 to 35% by weight, and TiC,
When WC and TaC were used, it was found that the content should be 10 to 25% by weight. Further, in the case of conductive alumina ceramics, Fe ₂
When using O ₃ , NiO, Co ₃ O ₄ , and Cr ₂ O ₃ ,
The content may be 15 to 35% by weight, and in the case of silicon carbide ceramics, 90 to 98% by weight of SiC
On the other hand, 1 to 7% by weight of Al ₂ O ₃ as a sintering aid and Y
It was found that the total content of ₂ O ₃ and CeO ₂ should be 1 to 5% by weight.

Further, in the case of titania-based ceramics, 50 to 99% by weight of TiO ₂ and the balance BaO, Ca
O, SrO, Al ₂ O ₃ , ZrO ₂ , SiO ₂ , MgO
It has been found that heat treatment may be performed at 900 to 1200 ° C. in a non-oxidizing atmosphere such as a reducing atmosphere, an inert atmosphere, or a vacuum after firing. In addition, it has been found that the conductive forsterite ceramics may contain the composite oxide of MgO and SiO ₂ in the range of 40 to 80% by weight and the iron oxide in the range of 60 to 20% by weight.

In this way, the volume resistivity value 10 ⁶
It can be seen that a ceramic having a resistivity of 910 ⁹ Ω · cm can be obtained, and a jig for processing and assembling a magnetic head capable of removing static electricity at an appropriate speed can be provided.

[0073]

As described above in detail, according to the present invention, a jig used in a processing step or an assembling step of a magnetic head is formed of a ceramic having a volume resistivity of 10 ⁶ to 10 ⁹ Ω · cm. As a result, static electricity can be gradually released, so that static electricity can be released without causing a handling failure due to conduction short-circuit, and the use of non-magnetic ceramics can prevent the magnetic head from being adversely affected. . In addition, a conductive short circuit accident can be prevented, and the use of ceramics having high hardness enables the device to be used satisfactorily for a long period of time.

Therefore, the jig of the present invention can be favorably used in the working process and the assembling process in the manufacturing process of the thin film magnetic head, especially the MR head among the magnetic heads.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a jig for processing and assembling a magnetic head according to the present invention.

FIG. 2 is a perspective view showing a use state of the jig for processing and assembling a magnetic head shown in FIG. 1;

FIG. 3 is a perspective view showing another embodiment of a jig for processing and assembling a magnetic head according to the present invention.

FIG. 4 is a perspective view showing another embodiment of the jig for processing and assembling a magnetic head according to the present invention.

[Explanation of symbols]

 10: jig 11: through hole 12: upper surface 13: lower surface 20: jig 21: groove 30: jig 31: slit

Claims (2)

(57) [Claims] 1. A method for polishing a ceramic material forming a thin film magnetic head.
A jig used to hold a workpiece or the like in a processing step such as shaving, polishing, or ion milling. The jig has a volume resistivity of 10 ⁶ to 10 ⁹ Ω · cm and is formed of nonmagnetic ceramics. A magnetic head processing jig characterized by the following. 2. The magnetic material according to claim 1, wherein said ceramic is made of any one of conductive zirconia ceramics, conductive alumina ceramics, silicon carbide ceramics, titania ceramics, and conductive forsterite ceramics. Jig for head processing.