JPH07148663A - Blasting machining method using electrocast mask - Google Patents

Abstract

PURPOSE:To enable machining with high outside dimensional accuracy by applying blasting machining to a workpiece using an electrocast mask as a mask, and machining the workpiece in the depth direction to machine the machined face of the workpiece into the specified shape. CONSTITUTION:An electrocast mask 13 is attached to the plate face of a workpiece 11 using an adhesive 14. The adhesive layer thickness of the adhesive 14 used in this case is as thin as several mum, and the bonding strength is powerful enough not to separate the electrocast mask 13 and a piezoelectric base 11 from each other even if blasting machining is applied to the cladding of the electrocast mask 13 with the workpiece 11. Blasting machining is then applied from the electrocast mask 13 side so as to machine the same shape as the shape of the electrocast mask 13 on the workpiece 11. At this time, the electrocast mask 13, masking material, is machined simultaneously. Upon the termination of blasting machining, the electrocast mask 13 and the adhesive layer of the adhesive 14 are removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine processing method for a piezoelectric vibrator and a fine processing method for a thin film head made of a non-magnetic material.

[0002]

2. Description of the Related Art Chemical etching and jet processing are used as a method for processing a piezoelectric vibrator. When the piezoelectric vibrator is externally processed by chemical etching, the shape of the processed cross section is not vertical because the etching rate varies depending on the crystal axis of the piezoelectric substrate.

On the other hand, when the outer shape of the piezoelectric vibrator is machined by using the jet machining, there is an advantage that the sectional shape becomes vertical.

In order to obtain a piezoelectric vibrator having a predetermined shape by using jet processing, it is necessary to install a masking material having a predetermined shape on the substrate. As the masking material, a photosensitive resin or a chemical etching mask made of a metal material by chemical etching is used.

Generally, a photosensitive resin is in the form of a film, and the thickness of the resin film is from several tens of μm to 100.
It is about μm. Then, a film of a photosensitive resin is attached on the piezoelectric substrate, and exposure and development processing is performed to form a masking material in a predetermined shape. However, if the thickness of the photosensitive resin film is large, the accuracy of the external dimensions of the masking material is deteriorated, and an error of about ± 10 μm occurs.

Therefore, when performing the jetting process, the accuracy of the external dimensions of the masking material also affects the accuracy of the external dimensions of the piezoelectric vibrator, and the accuracy of the external dimensions of the piezoelectric vibrator becomes plus or minus 10 μm or more. As a result, the basic characteristics of the piezoelectric vibrator are also adversely affected.

Further, since a photosensitive resin is used as a mask and a photolithography process is adopted, there is a problem that the manufacturing process becomes complicated.

On the other hand, the chemical etching mask made of a metal material has good workability because it is fixed on the piezoelectric substrate using an adhesive.

A method of manufacturing a chemical etching mask made of a metal material is such that a photosensitive resin is formed on both surfaces of a thin metal material, and the photosensitive resin is patterned, and the photosensitive resin is used as a mask to form an etching solution containing an acid. Is used to melt the metal to obtain a chemical etching mask having a predetermined shape.

FIG. 2 is a sectional view showing a chemical etching mask 21 made of a metal material. In the case of a chemical etching mask having a plate thickness of about t = 0.1 mm, the opening dimension d and the opening width w processing accuracy in the figure are plus or minus 20 μm.

As described above, since the chemical etching mask 21 has a poor external dimension accuracy of about ± 20 μm, the external accuracy of the workpiece that has been sprayed using the chemical etching mask is also poor.

Further, as shown in FIG. 2, since the cross-sectional shape of the chemical etching mask 21 is also not vertical, the abrasive grains are not vertically jetted onto the workpiece, and thus the abrasive grains are transferred to the workpiece in the shape of the mask. It is difficult to obtain a crystal piece having a desired external dimension accuracy.

Next, a conventional processing method for forming a groove on the air bearing surface of a thin film head and its problems will be described.

A groove of a predetermined shape is provided on the air bearing surface of the thin film head. This is a groove for stabilizing the relative position between the thin film head and the disk by allowing air to flow into the groove on the air bearing surface of the thin film head.

Since the groove of the thin film head is designed on the basis of fluid engineering, the external dimension accuracy is plus or minus 5 μm.
Such severe accuracy is required. At present, there are a wire saw and a jet processing method as a method for processing the groove on the air bearing surface of the thin film head.

With a wire saw, only straight groove machining is possible, but when using the jet machining method, curved groove machining is possible. Therefore, in terms of fluid mechanics, the thin film head produced by jet machining is more fluid dynamics. Stable.

The manufacturing process of the thin film head by jet processing will be described below. Alumina titanium carbide (Al ₂ O ₃ —TiC), which is the material for the thin film head, is laminated with a film of a photosensitive resin with a thickness of several tens of μm, exposed and developed to form the photosensitive resin into a predetermined shape. Then, it is used as a masking material.

After that, injection machining is performed to obtain a groove having a predetermined shape. However, the external dimension accuracy of the masking material is about plus or minus 10 μm, which is bad as in the case of processing the piezoelectric vibrator by the jet processing.

Therefore, the outer dimension accuracy of the groove on the air bearing surface of the thin film head is about ± 10 μm, which is less than the dimension accuracy required for the outer dimension accuracy of the groove on the air bearing surface of the thin film head. Therefore, the relative position between the thin film head and the disk also becomes unstable.

[0020]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to provide an injection machining method which enables machining with high accuracy in external dimensions.

[0021]

In order to achieve the above object, the manufacturing method of the present invention employs the manufacturing method described below.

According to the manufacturing method of the present invention, an electroformed mask is set on the processed surface of the work piece, and the electroformed mask is used as a mask to perform the jetting process on the work piece to perform the processing in the depth direction. The machined surface of the workpiece is machined into a predetermined shape.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view showing, in the order of steps, a jet processing method using an electroformed mask according to the present invention.

First, as shown in FIG. 1A, the material of the piezoelectric substrate 11, which is the workpiece, is a quartz AT plate having a thickness of about 100 μm.

As shown in FIG. 4, a plurality of alumina-titanium carbides, which are the material of the magnetic head which is the object to be processed, are laminated to form a single substrate 12.

Next, as shown in FIG. 1B, the material of the electroformed mask 13 is nickel-phosphorus. The electroformed mask 13 has a thickness of about 50 μm and a Vickers hardness of about 100.
0 is very hard. The external dimension accuracy of the electroformed mask 13 is about ± 2 μm, which is extremely high.

Here, the manufacturing process of the electroformed mask 13 shown in FIG. 1B will be briefly described, and the sectional shape of the electroformed mask 13 will be described. FIG. 3 is a cross-sectional view showing the manufacturing process of the electroformed mask.

First, as shown in FIG. 3A, a thick film resist 32 is formed on a flat metal substrate 31. in this case,
Copper or the like is used for the metal substrate 31. The patterning accuracy of the thick film resist 32 is about ± 2 μm.

Next, as shown in FIG. 3B, an electroformed mask 33 is formed on the metal substrate 31 by electrolytic plating. At this time, since the cross section of the thick film resist 32 is vertical, the electroformed mask 3
The cross section of 3 is also vertical. The electroformed mask 3 at this time
Nickel-phosphorus or the like is used for the three materials.

Then, as shown in FIG. 3C, the thick film resist 32 is peeled off, and an electroformed mask 33 is formed on the metal substrate 31.

Finally, as shown in FIG. 3D, the electroformed mask 33 is obtained by using an etching solution that does not dissolve the electroformed mask 33 but does dissolve the metal substrate 31.

In this way, it is possible to obtain an electroformed mask 33 having a vertical sectional shape and high precision.

Next, as shown in FIG.
The electroformed mask 13 shown in FIG.
It is attached to the plate surface of the piezoelectric substrate 1 shown in FIG. The thickness of the adhesive layer of the adhesive 14 used here is as thin as several μm,
The adhesive strength is so strong that the electroformed mask 13 and the piezoelectric substrate 11 are not separated even when the electroforming mask 13 and the piezoelectric substrate 11 are bonded together by jetting.

Next, as shown in FIG.
The electroforming mask 13 and the piezoelectric substrate 11 shown in (c) are bonded to each other, and spraying is performed from the electroforming mask 13 side. The spray nozzle 15 is located several cm away from the electroforming mask 13, and sprays abrasive grains 16 having a particle size of several μm to several tens μm from the spray nozzle 15 at a pressure of several Kgf / cm ² . The material of the abrasive grains 16 is silicon carbide, alumina, or the like.

Then, a shape similar to that of the electroformed mask 13 can be processed on the piezoelectric substrate 11. At this time, the electroforming mask 13 which is a masking material is processed at the same time.
Since the processing speed of the piezoelectric substrate 11 is several times the processing speed of the electroformed mask 13, the electroformed mask 13 withstands until the piezoelectric substrate 11 is processed into a predetermined shape.

Next, as shown in FIG. 1 (e), when the spraying process is completed, the adhesive layer of the electroforming mask 13 and the adhesive 14 is removed. The processing time required for the jet processing is about several tens of minutes, and the processing depth of the piezoelectric substrate 11 is several tens of μm.

Since the external dimension accuracy of the electroformed mask 13 is as good as about ± 2 μm, the piezoelectric substrate 1 after processing is good.
The external dimension accuracy of the shape 1 is about ± 2 μm, which is very good.

Since the cross section of the electroformed mask 13 is vertical, the abrasive grains 16 ejected from the ejection nozzle 15 hit the piezoelectric substrate 11 perpendicularly, so that the electroformed mask 13 can be machined with high precision according to its shape.

Further, as shown in FIG. 1 (f), by setting the processing time as long as about 1 hour, the cross-sectional shape of the piezoelectric substrate 11 becomes substantially vertical.

The same processing steps as those described above are applied to a processed product, as shown in FIG. 4, which is made by laminating a plurality of substrates 12 of alumina titanium carbide, which is a material for a thin film head, into a single substrate. By doing so, the outer shape of the groove on the air bearing surface of the thin film head can be processed with an accuracy of about ± 2 μm.

Further, the workpiece is not limited to the piezoelectric substrate and the alumina titanium carbide, but a predetermined shape can be obtained by subjecting the substrate such as ceramics, glass or metal to the jetting process using the electroforming mask. It can be processed with high accuracy of plus or minus 2 μm.

[0042]

As described above, according to the manufacturing method of the present invention, a piezoelectric substrate or an alumina titanium carbide substrate is provided by installing a high-precision electroformed mask as a mask for jet processing on a workpiece. Therefore, it is possible to perform the outer shape processing of the vibrator and the outer shape processing of the groove on the air bearing surface of the thin film head with high accuracy of plus or minus 2 μm.

Furthermore, in the manufacturing method of the present invention, since the masking material can be formed without using the photolithography process, the process can be simplified and the number of processes can be reduced. Occurs.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing, in the order of steps, an injection processing method using an electroformed mask according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an etching mask made of metal.

FIG. 3 is a cross-sectional view showing the process of manufacturing an electroformed mask in the order of processes.

FIG. 4 is a cross-sectional view showing an injection processing method using an electroformed mask in an example of the present invention.

[Explanation of symbols]

 11 Piezoelectric Substrate 13 Electroforming Mask 14 Adhesive 15 Injection Nozzle 16 Abrasive Grains 31 Metal Substrate 33 Electroforming Mask

Claims (2)

[Claims] 1. An electrocast mask is set on a processed surface of a workpiece, and the electrocast mask is used as a mask to perform jet processing on the workpiece to machine the workpiece in a depth direction. An injection machining method using an electroformed mask, characterized in that the machined surface of a workpiece is machined into a predetermined shape. 2. A jet processing method using an electroforming mask, wherein the work piece is a piezoelectric vibrator or a magnetic head.