JPH04167280A - Negative pressure composite levitation magnetic head and manufacture thereof - Google Patents

Abstract

PURPOSE:To shorten the time of forming a negative pressure generating surface and to enhance an accuracy by providing a recess for forming the negative pressure generating surface formed deeper than a step on a positive pressure generating surface, and a negative pressure generating surface forming member filled in the recess. CONSTITUTION:A recess 3 of a square groove shape having a predetermined depth from a flat surface 1b of a slider body 1 as a positive pressure generating surface 2 and opened at the flat surface 1b of the body 1 at the side of a medium and the end face 1c at the side of moving the medium is formed at the surface 1b of the body 1 at the side of the medium. A negative pressure generating surface forming member 4 is filled in the recess 3, its medium side part is removed to a predetermined step later, and a negative pressure generating surface 5 is formed in a step-down shape. Thus, the time of forming the negative pressure generating surface is shortened, and forming dimensional accuracy can be simply enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a negative pressure magnetic head used for recording and reproduction in a hard disk drive device connected to a computer, etc., and a method for manufacturing the same, and in particular to a negative pressure magnetic head used for recording and reproducing in a hard disk drive device connected to a computer, etc. The present invention relates to a negative pressure slider and a method for manufacturing the same, which can shorten surface forming time and improve precision.

"Prior Art" In recent years, as electronic devices have become more multifunctional and faster, there has been a strong demand for higher density recording and reproduction of data on hard disks, which serve as recording media used for data processing in electronic devices. As a means to meet such demands, attempts have been made to lower the flying height of a flying magnetic head used for recording and reproduction in a hard disk drive by keeping it below a certain level.

That is, for example, according to the slider 101 of the conventional twin-body floating magnetic head shown in FIG. 5, airflow generated by the rotation of the recording medium acts on a positive pressure generating surface that levitates the slider body from the recording medium. Since the flying blade is proportional to the speed of the recording medium, its flying height also increases in proportion to the speed, as shown by line a in Figure 7, and the difference in flying height between the inner and outer circumferences of the recording medium increases. This increases the recording and reproducing efficiency, which is disadvantageous in increasing the recording density particularly at the outer periphery of the recording medium where the flying height becomes large.

Therefore, as shown by the line b in FIG. 7, in order to make the rate of change in the flying height as small as possible within the range where the speed of the recording medium exceeds a predetermined speed, for example, as shown in FIG. A positive pressure generating surface 112 that lifts the slider body from the recording medium by receiving an air flow generated by the rotation of the recording medium, and a positive pressure generating surface 1
A so-called negative pressure slider has been proposed in which a negative pressure generating surface 113 is formed with a minute step difference of about 2 to 10 degrees with respect to 12. Publication No. 258329, Japanese Unexamined Patent Publication No. 62-2481
79, JP 61-160885, JP 62-9574, JP 63-113989, JP 62-246979, JP 62-1
0680, JP-A-63-76163, etc.).

In the negative pressure slider, negative pressure is generated by the expansion of the airflow generated by the rotation of the recording medium at the stepped portion between the positive pressure generating surface 112 and the negative pressure generating surface 113, and this negative pressure causes the slider body 111 to perform recording. It will be pressed against the medium. This negative pressure increases in proportion to the speed of the recording medium in a range where the speed of the recording medium exceeds a certain level, and therefore,
As shown by line b in FIG. 7, the rate of change in the flying height can be reduced within the range where the speed of the recording medium exceeds a predetermined speed.

Conventionally, this negative pressure generating surface 113 has been formed by etching the positive pressure generating surface 112 to a predetermined level difference by chemical etching or physical etching such as plasma etching (as disclosed in Japanese Patent Laid-Open No. 148685/1983, 1986-
258329, JP-A-61-160885, JP-A-62-10680, etc.), and is removed by mechanical processing such as grinding or polishing.

[Problems to be Solved by the Invention] However, since a large amount of time is required to etch the ceramic slider body 111 by chemical or physical etching, this is extremely disadvantageous in terms of increasing productivity. .

Furthermore, when grinding or polishing the slider body 111 by machining, it is difficult to ensure the necessary machining accuracy, and slight variations in machining accuracy may cause variations in the flying characteristics of the slider body 111 with respect to the speed of the medium. This greatly affects the recording and reproducing characteristics of the magnetic head, and is disadvantageous in ensuring reliability of product performance. In addition, in order to ensure the necessary machining accuracy, for example, high precision on the submicron order, it is necessary to significantly improve the control accuracy of machining equipment, which increases equipment costs and lengthens machining time, which increases productivity. A problem also arises above.

The present invention has been made in view of the above circumstances, and includes:
It is an object of the present invention to provide a negative pressure magnetic head having a negative pressure slider that can shorten the time for forming a negative pressure generating surface and improve accuracy, and a method for manufacturing the same.

Further, the second invention further aims to prevent the generation of cracks on the negative pressure generating surface.

``Means for Solving the Problems J'' A negative pressure magnetic head according to the present invention includes a slider body and a ferrite core, and the slider body receives an air flow generated by the rotation of the recording medium to remove the slider body from the recording medium. In order to achieve the above object, the negative pressure slider is formed with a positive pressure generating surface to be floated and a negative pressure generating surface having a minute step with respect to the positive pressure generating surface. The positive pressure generating surface is provided with a negative pressure generating surface forming recess formed deeper than the step, and a negative pressure generating surface forming member filled in this recess, and the negative pressure generating surface is configured to generate negative pressure. It is characterized in that it is formed by removing the surface forming member from the positive pressure generating surface to the depth of the step.

Further, in the negative pressure magnetic head of the present invention, in order to particularly achieve the purpose of preventing the occurrence of cracks in the negative pressure generating surface forming member, it is necessary that the negative pressure generating surface forming member has a coefficient of thermal expansion smaller than that of the slider body. Constructed of a material with a coefficient of thermal expansion.

Further, in the method of manufacturing a slider for a negative pressure magnetic head according to the present invention, a positive pressure generating surface is formed on the slider body, and a portion of the positive pressure generating surface is removed in a stepped manner to form a negative pressure generating surface. In order to achieve the above objective, assuming a method for manufacturing a negative pressure magnetic head in which a core is arranged on a negative pressure slider, a recess for forming a negative pressure generating surface is formed deeper than the step on the negative pressure generating surface, and this recess is formed on the negative pressure generating surface. A negative pressure generating surface is formed by filling the recess with a negative pressure generating surface forming member that is easier to process than the slider body, and then removing the negative pressure surface forming member from the positive pressure generating surface to the depth of the step. There is.

"Function" In general, it is the dimensional accuracy of the step between the positive pressure generating surface and the negative pressure generating surface that has a large influence on the flying characteristics of the negative pressure slider. The dimensional accuracy of the depth has almost no effect on the flying characteristics of the negative pressure slider.

Therefore, the recess can be formed, for example, by stamping the slider body material when filling it into a mold, or by performing machining at a relatively high processing rate after sintering.

In addition, in the present invention, methods for filling the recess with the negative pressure generating surface forming member include filling the recess with a liquid negative pressure generating surface forming member and curing it, or filling the recess with a solid negative pressure generating surface forming member. By melting or melting the forming member and then re-hardening it,
Possible methods include closely fitting a solid molded negative pressure generating surface forming member into the recess, or adhering a solid molded negative pressure generating surface forming member into the recess.

In addition, when the negative pressure generating surface forming member is heated and melted to fill the recess, it is recommended that the negative pressure generating surface forming member be formed of a material with a coefficient of thermal expansion smaller than that of the slider body. be done. This is because when the negative pressure generating surface forming member is cooled and solidified, compressive stress is applied to the negative pressure generating surface forming member and cracks are prevented from occurring in the negative pressure generating surface forming member.

Furthermore, in the present invention, the negative pressure generating surface is formed by removing the medium side portion of the negative pressure generating surface forming member filled in the recess of the positive pressure generating surface of the slider body; Since the forming member is easier to process than the slider body, negative pressure can be applied more easily and with higher accuracy in a shorter time than in the conventional method, which removes a slider member that is relatively difficult to process to a predetermined step depth. The generating surface forming member can be removed from the positive pressure generating surface to a depth of a predetermined step.

In the present invention, the method for removing the negative pressure generating surface forming member from the positive pressure generating surface to the depth of the step is not particularly limited. The surface forming member can be removed from the positive pressure generating surface to the depth of the step. Among these methods, the method of removing the negative pressure generating surface forming member from the positive pressure generating surface to the depth of the step by etching is advantageous because it takes a relatively short processing time and can obtain high processing dimensional accuracy. .

Embodiment A negative pressure slider and a method for manufacturing the same according to an embodiment of the negative pressure magnetic head of the present invention will be described below with reference to FIG.

FIG. 1(C) is a perspective view of a negative pressure slider according to an embodiment used in the negative pressure magnetic head of the present invention. 1. The negative pressure magnetic head of the present invention is composed of a negative pressure slider body 1 and a ferrite core 6 disposed in the slider body 1.

This negative pressure slider has a positive pressure generating surface 2 that receives an air flow generated by the rotation of the binding medium and levitates the slider body l from the recording medium, and a negative pressure generating surface 2 that has a minute step with respect to the positive pressure generating surface 2. It has a surface 5. The positive pressure generating surface 2 is provided with a recess 3 for forming a negative pressure generating surface formed deeper than the step, and a glass 4 serving as a negative pressure generating surface forming member filled in the recess 3. . And for example 4
The negative pressure generating surface 5 is formed by etching the medium side portion of the lead-based low melting point glass 4 which softens at 50 to 460 DEG C. from the positive pressure generating surface 2 to the depth of the step.

Next, a method for manufacturing a negative pressure slider according to an embodiment of the method of the present invention will be described. Note that since the ferrite core 6 is disposed after the slider 1 is completed, other explanations will be omitted.

The slider body 1 is made by a conventional method in that it is made by filling a mold with powder of ceramic such as calcium titanate (or Mn-Zn ferrite, etc.), molding it, and then sintering it.

As shown in FIG. 1(a), the slider body 1 is formed into a rectangular parallelepiped, and extends from an end surface 1a on the medium transfer source side (diagonally upper left side in the figure) to the medium side (upper left side in the figure). plane 1b
A positive pressure generating surface 2 is formed over the entire area.

Further, the medium side flat surface 1b of the slider body 1 has a predetermined depth from the flat surface 1b as the positive pressure generating surface 2, and the medium side flat surface 1b of the slider body 1 and the medium transfer destination side (in the figure , diagonally lower right side) square groove-shaped recess 3 opened in the end face IC
is formed.

This recess 3 can also be formed by machining such as grinding or polishing after sintering, but here, the number of manufacturing steps can be reduced and the recess 3 can be formed more efficiently than by machining. Therefore, a convex portion corresponding to the concave portion 3 is provided in the mold for the slider body 1, and the slider body 1 is
It is formed by embossing during molding.

This recess 3 is filled with a negative pressure generating surface forming member 4 that is easier to process than the slider body 1. The material of the negative pressure generating surface forming member 4 is not particularly limited, and may be selected in consideration of the processing method used in the step of later removing the medium side portion to a predetermined level difference.

In this embodiment, the negative pressure generating surface 5 is etched by etching which can remove the negative pressure generating surface forming member 4 in a short time and with high precision.
In consideration of the step-like formation, glass 4 is filled as the negative pressure generating surface forming member 4.

There are no particular restrictions on the specific method for filling the recess with the glass 4. For example, as shown in FIG.
Simply place it on a plate and heat it to dissolve it.

The type of glass 4 is selected by comprehensively considering etching rate, coefficient of thermal expansion, reactivity with slider body 1, etc. However, in order to prevent cracks from occurring in the glass 4 when the glass 4 melted in the recess 3 is cooled and solidified, the coefficient of thermal expansion of the glass 4 is smaller than that of the slider body 1. and glass 4
The type of glass 4 is determined so that compressive stress acts on the glass 4 during cooling and solidification.

Thereafter, by polishing the slider body 1 and the glass 4, the slider is accurately finished to have predetermined external dimensions, as shown in FIG. 1(b). At this stage, the positive pressure generating surface 2 is finally finished, and the surfaces 4b and 4C of the glass 4 are polished to be almost flush with the flat surface 1b on the medium side of the slider body 1 and the end surface 1C on the medium transfer destination side, respectively. Ru.

Thereafter, the medium-side portion of the glass 4 is removed until a predetermined step is formed with respect to the medium-side plane 1b of the slider body 1, that is, the positive pressure generating surface 2, and the negative pressure generating surface 5 is formed. .

The method for removing the medium-side portion of the glass 4 is not particularly limited, and for example, it is also possible to remove the medium-side portion of the glass 4 by mechanical processing with a relatively high processing rate, such as grinding or polishing. Here, in order to further save processing effort and time and to obtain high processing accuracy, a method was adopted in which the medium side portion of the glass 4 was removed by etching.

That is, an etching resist is applied to the end surface 4C of the glass 4 on the medium transfer destination side, and an etching agent such as hydrogen fluoride is brought into contact with the slider to etch only the surface 4b of the glass 4 on the medium side.

Here, the etching rate of the glass 4 with respect to hydrogen fluoride is the etching rate of calcium titanate with respect to hydrogen fluoride, that is,
Since the etching rate is sufficiently larger than the etching rate of the slider body l, the amount of etching of the glass 4 can be controlled with extremely high precision simply by controlling the etching time by considering the etching rate of the glass 4 with respect to hydrogen fluoride. Therefore, simply by strictly managing the time of the etching process, the flat surface 1b of the slider body 1 on the medium side can be formed with extremely high precision.
A predetermined step can be formed between the surface 4b of the glass 4 on the medium side and the surface 4b of the glass 4 on the medium side.

Thus, as shown in FIG. 1(C), a negative pressure slider according to an embodiment of the present invention is obtained.

According to this negative pressure slider and its manufacturing method, the dimensional accuracy of the recess 3 can be made relatively rough, so the recess 3 can be formed at the same time as the slider body is molded, or the machining rate is high after the slider body is sintered. It can be formed by machining.

In addition, by strictly controlling the etching time of the glass 4 filled in the recess 3, the negative pressure generating surface 5 can be formed by removing only the required level difference from the positive pressure generating surface 2 with high precision.
It is possible to improve the dimensional accuracy of minute steps to reduce variations in the flying characteristics of the slider body 1 with respect to the speed of the medium, and to reduce the variations in the recording and reproducing characteristics of the magnetic head to increase confidence in the performance of the product. I can do it.

Moreover, the recess 3 can be formed in a short time by embossing or machining, and since the etching rate of the glass 4 is much larger than that of the slider body 1, the positive pressure generating surface 2 can be formed by etching the slider body 1. Compared to the conventional example in which a step is formed between the positive pressure generating surface 2 and the negative pressure generating surface 5, the step can be formed between the positive pressure generating surface 2 and the negative pressure generating surface 5 in a much shorter time.

In the above embodiment, one rectangular negative pressure generating surface 5 is formed, but for example, as shown in FIG.
Two parallel recesses 13 are formed in the slider body 11 to form the positive pressure □ generating surface 12 in an E-shape, and a predetermined amount of the medium side portion of the negative pressure generating surface forming member 14 filled in each recess 13 is removed. It is configured so that two negative pressure generating surfaces 15 are formed,
As shown in FIG. 3, a double-barreled positive pressure generating surface 22 is formed on the slider body 21, a rectangular recess 23 is formed in each rail portion, and a negative pressure generating surface forming member 2 is filled in the recess.
It is also possible to form the negative pressure generating surface 25 by removing a predetermined amount of the medium side portion of 4.

Further, in the above embodiment, the description of the magnetic head is omitted because it is not directly related to the present invention, but for example, as in the composite head shown in FIG. The present invention can also be applied to the case where they are joined by 37. In this case, before forming the negative pressure generating surface 35 by etching the glass 34 which is filled in the recess 33 of the positive pressure generating surface 32 and forming the negative pressure generating surface 35, an etching resist is applied to the low melting point glass 37. Low melting point glass 37 during coating and etching
What is necessary is to prevent the etching. Note that this etching resist is removed after etching is completed.

"Effects of the Invention" As described above, in the present invention, a negative pressure generating part equivalent to that of the conventional one can be formed extremely easily, resulting in an inexpensive slider, resulting in a negative pressure magnetic head that is low in cost as a whole and has stable flying characteristics. . In addition, in the manufacturing method of the present invention, recesses are efficiently formed in the slider body, which has low workability such as etching rate, by embossing during molding or machining after sintering, and negative pressure generating surfaces are formed in the recesses. After filling the member, a positive pressure generating surface is formed by processing such as polishing, and then the medium side portion of the negative pressure generating surface forming member is removed to form the negative pressure generating surface. The dimensional accuracy of the step between the negative pressure generating surface and the negative pressure generating surface depends on the machining accuracy of the process for removing the medium side portion of the negative pressure generating surface. Therefore, the dimensional accuracy of the recess can be made relatively rough, and it is sufficient to mold the recess at the same time as the slider body, so the number of man-hours does not increase substantially.As a result, the conventional negative Compared to the manufacturing process of the pressure slider, the filling process for the negative pressure generating surface forming member and the process for removing the medium side portion thereof are increased, but the workability of the negative pressure generating surface forming member is higher than that of the slider body. , the processing time of this removal step is shortened, and the total process time is shorter in the present invention.

In particular, in the present invention, when the negative pressure generating surface forming member is made of glass, which has a sufficiently higher etching rate than the slider body, and the medium side portion of the negative pressure generating surface forming member is removed by etching, the negative pressure generating surface forming member is The process time for removing the media side portion of the pressure generating surface forming member is significantly shortened compared to the conventional method in which the slider body is removed by etching, and the machining dimensional accuracy can be managed simply by controlling the etching time, making machining easy. Dimensional accuracy can be improved.

In particular, in the present invention, when the negative pressure generating surface forming member is heated and melted and filled in the recess, and is made of a material having a coefficient of thermal expansion smaller than that of the slider body, When the melted negative pressure generating surface forming member is cooled and solidified, it is subjected to compressive stress, thereby preventing the negative pressure generating surface forming member from cracking.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the method of the present invention and a negative pressure slider according to an embodiment of the present invention manufactured by the method, and FIG. A perspective view of the negative pressure generating surface forming member, FIG. 1(b) is a perspective view of the negative pressure slider after finishing the positive pressure generating surface of the negative pressure slider, and FIG. 1(C) is a perspective view of the completed negative pressure magnetic head. 2, 3, or 4 are perspective views of negative pressure sliders according to different embodiments of the present invention, FIG. 5 is a perspective view of a conventional twin-barrel type levitated magnetic Herad slider, and FIG. 7 is a perspective view of a conventional negative pressure slider, and FIG. 7 is a levitation characteristic diagram showing a comparison of the levitation characteristics of a conventional twin-body type levitation magnetic RAD slider and a negative pressure slider. 1...Slider body 2...Positive pressure generating surface 3...Concave portion 4...Negative pressure generating surface forming member (glass) 5...Negative pressure generating surface 11...Slider body 12...・Positive pressure generating surface 13...Concave portion 14...Negative pressure generating surface forming member 15...Negative pressure generating surface 21...Slider body 22...Positive pressure generating surface 23...Concave portion 24 ...Negative pressure generating surface forming member 25...Negative pressure generating surface 31...Slider body 32...Positive pressure generating surface 33...Concave portion 34...Negative pressure generating surface forming member (glass) 35... Negative pressure generating surface Applicant Kyocera Co., Ltd. Agent Yoshiteru Takagi Figure 3 Figure 4

Claims (3)

[Claims] (1) A negative pressure generating surface that has a positive pressure generating surface that levitates the slider body from the recording medium in response to an air flow generated by the rotation of the recording medium, and a negative pressure generating surface that has a minute difference in level with respect to the positive pressure generating surface. In a negative pressure composite flying magnetic head in which a core is disposed on a pressure slider, a negative pressure generating surface is provided with a negative pressure generating recess formed deeper than the step in the step. A negative pressure composite floating magnetic head characterized by being provided with a forming member. (2) The negative pressure generating surface forming member is made of a material which is heated and melted and filled into the recess, and which has a coefficient of thermal expansion smaller than that of the slider body. Negative pressure composite floating magnetic head. (3) Negative pressure composite floating type in which a core made of ferrite is arranged in a negative pressure slider with a positive pressure generating surface formed on the slider body and a negative pressure generating surface recessed in a minute step with respect to the positive pressure generating surface. In a method for manufacturing a magnetic head, a recess is formed in a negative pressure generating surface, a negative pressure generating surface forming member that is easier to process than the slider body is filled in the recess, and then the negative pressure generating surface forming member is replaced with a positive pressure generating surface. 1. A method for manufacturing a negative pressure composite floating magnetic head, characterized in that a negative pressure generating surface is formed by removing the surface to the depth of the step.