JPH09219018A - Production of disk substrate for information memory - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a process for producing a disk substrate for information memory having high quality and high productivity by heating and pressurizing a glass blank within a molding flask and forming the glass blank while cutting the same to a prescribed shape. SOLUTION: The glass blank 21 is set between the upper plate 6 and middle plate 3 of the molding flask 1 consisting of the upper plate 6, the middle plate 3 and a support plate 4. A press mold 7 is pushed into the cavity 8 formed at the middle plate 3 from a guide hole 9 formed on the upper plate 6 and is pressurized by heating, by which the glass blank 21 is formed while the glass blank is cut to the prescribed shape. The formed glass blank is then polished to a prescribed thickness. The disk substrate for information memory obtd. in such a manner does not require chamfering of the end faces and, therefore, the productivity is improved. The occurrence of defective articles is lowered and the yield of products is improved. In addition, the distortion of the disk substrate by the residual stresses generated in the chamfering stage does not arise and the good quality is obtd. in smoothness as well.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a disk substrate for information storage, such as a hard disk (HD).

[0002]

2. Description of the Related Art Conventionally, when manufacturing a disk substrate for information storage including a hard disk (HD) or the like, various coatings have been applied to an aluminum plate to provide a substrate capable of storing information. However, a glass substrate has been used in place of the aluminum substrate in order to meet the demand for thinning of the HD because many steps are required for the production and the cost is high.

By the way, the glass substrate 41 is obtained by cutting a glass material plate 40 to a predetermined thickness, then grinding the outer and inner circumferences in a circular shape to form a donut shape, and chamfering each end surface 42 thereof. Had been obtained (see FIGS. 7 and 9).

[0004]

However, in the above-described conventional method for manufacturing a glass substrate, it takes a lot of time and labor to chamfer the end face 42 of the donut-shaped glass substrate 41, and the productivity is greatly reduced. There was a drawback that it also caused an increase in cost.

Further, there are drawbacks in that mist is generated at the time of mounting on a jig for chamfering or the like, which reduces the yield of products and adversely affects the working environment.

Further, the residual stress generated in the chamfering process distorts the glass substrate 41 for information storage to be obtained, and the smoothness thereof is impaired so that a desired quality cannot be obtained.

In the conventional manufacturing method, chipping or fine cracks are generated on the cut end face when the material plate 40 having a large size is cut into a required size as shown in FIG. 7, and such chipping or cracks occur. Far from being eliminated in the subsequent chamfering process, the glass substrate 41 is further increased.
Had the drawback that it would crack easily.

Further, the minute glass pieces caused by the chipping and cracks may adversely affect the incorporated information processing equipment.

The method of manufacturing a disk substrate for information storage of the present invention is intended to solve the above-mentioned drawbacks of the conventional example, and improves productivity by using a material other than an aluminum plate and adopting a completely different manufacturing method. In addition, the present invention provides a method for manufacturing an information storage disk substrate, which can improve the product yield and can supply an inexpensive and high quality information storage disk substrate.

[0010]

[Means for Solving the Problems] That is, a method for manufacturing a disk substrate for information storage according to the present invention comprises a step of setting a glass material in a mold, heating and pressurizing the material while cutting it into a predetermined shape, and the obtained material. And a step of polishing the plate to a predetermined thickness.

Further, the method of manufacturing the disk substrate for information storage of the present invention is characterized by including a step of heating and pressing the material plate obtained by molding so that the side surface thereof is formed into an arcuate convex surface. It is a thing.

Since the method of manufacturing the disk substrate for information storage of the present invention is configured as described above, the chamfering of the end face is not required, the productivity is dramatically improved, and a significant cost reduction can be achieved. .

Moreover, mist is not generated by chamfering processing, the number of defective products is reduced, the product yield is improved, and a good working environment can be maintained at all times.

Further, there is no defect that cracks or strains are generated in the information storage disk substrate due to the residual stress generated in the chamfering process, and good quality can be obtained in smoothness.
It is possible to provide a disc substrate for information storage capable of achieving high density. Furthermore, it is possible to provide a disc substrate for information storage of high quality without the occurrence of chipping and cracks found in the conventional manufacturing method.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a method for manufacturing an information storage disk substrate of the present invention will be described in detail below with reference to the drawings.

1 to 4 show an example of a molding die used in the present invention, which is composed of a mold 1 and a pressing die 7. In the figure, reference numerals 2 and 3 denote a backing plate and an intermediate plate which form the mold 1, each of which is made of a carbon jig. Positioning posts 4 are erected at the four corners of the receiving plate 2 and are inserted into the positioning holes 5 provided at the four corners of the middle plate 3 for assembly. Reference numeral 6 denotes an upper plate set on the middle plate 3, and a glass block or a glass plate 21 is set between the upper plate 6 and the middle plate 3.

Reference numeral 22 denotes a core held in the center of the receiving plate 2 for forming the central opening of the disk substrate to be obtained. The core 22 is housed and positioned in a circular hole 23 formed in the lower portion of the receiving plate 2.

A pressing die 7 is made of a carbon jig, and is pushed into the cavity 8 formed in the middle plate 3 from the guide hole 9 formed in the upper plate 6 so that the glass block or the glass plate 21 is pressed. Can be reliably pressed and cut into a predetermined shape. 10 in the figure
Is a hole provided in the center of the die 7 for fitting into the core 22, and 11 is a positioning hole for fitting into the post 4.

2 and 3, the process of heat-molding the glass block or glass plate 21 using the mold 1 and the pressing mold 7 will be described.

First, as shown in FIG. 2, the post 4 is fitted into the positioning hole 5, the middle plate 3 is fixed on the receiving plate 2, and the glass block or the glass plate 21 is mounted on the middle plate 3.
Then, the upper plate 6 is mounted on the intermediate plate 3 while fitting the positioning holes 11 into the posts 4. Then, as shown in FIG. 3, the pressing die 7 is pressed in a state where the pressing die 7 is fitted in the guide hole 9 of the upper plate 6, and the pressing die 7 is heated for a predetermined time at a melting temperature equal to or higher than the softening temperature of the glass block or the glass plate 21. Is pressed into the cavity 8 to cut the glass block or glass plate 21 and form it into a predetermined donut shape.

The mold 1 and the pressing mold 7 set as described above are sent to a furnace having a slow heating slow cooling means by a transport means such as a conveyor. The above-mentioned furnace is formed to have a certain length in order to enhance mass productivity, and when the glass block or glass plate 21 carried into the furnace is delivered from the furnace end, it is said that it has already been molded and has been cooled and solidified. Has become. An electric heater is used as a heating source of this furnace, and is adjusted to have a temperature distribution convenient for melt-forming the glass block or the glass plate 21.

The glass block or glass plate 21 sent into the above furnace together with the mold 1 and the pressing die 7 is
It melts and softens as it moves in the furnace while being heated by an electric heater. In this case, heating is gradually performed, so that the glass block or glass plate 21 is pushed into the cavity 8 by the pressing die 7 and cut into a predetermined shape while leaving the outer edge. In the cavity 8, the material plate 12 is only softened while uniformly maintaining a predetermined shape as a whole, so that the obtained material plate 12 has a predetermined quality and naturally has a predetermined shape without causing internal distortion. In this heat molding step, the glass block or glass plate 21 is molded into a predetermined donut shape as shown in FIG. 3, and when slowly cooled and released from the furnace, it contracts and is released from the mold 1 and the pressing mold 7, The material plate 12 after being molded can be taken out.

At this time, R is formed on the end surface of the lower surface, but a portion where R is not formed tends to remain on the upper surface. The material plate 12 having no R formed on its end face is set again between the form frame 1 and the die 7 as shown in FIG. 4, and heated to a predetermined temperature. Due to the surface tension of the melt-softened material plate 12, an arcuate convex surface 13 is reliably formed on the side surface. The pressurizing / heating step may be performed in the same furnace as described above, or the pressurizing / heating step may be separately performed in a batch system.

FIGS. 5 and 6 show an information storage disk substrate 31 obtained by heating and melting, and the outer side surface and the inner side surface thereof form arcuate convex surfaces 13. In order to obtain the information storage disk substrate 31 whose side surface is the arcuate convex surface 13 by heating and melting, the melting temperature and the degree of pressurization of the die 7 are adjusted, and the side surface is changed by the surface tension of the glass in the molten state. It is necessary to adjust so that the convex surface has an arc shape.

The surface of the information storage disk substrate 31 thus obtained is polished to a predetermined thickness.
Even if this polishing is performed, the obtained information storage disk substrate 31 has not yet formed an acute angle between the front and back surfaces and the side surfaces, and has a smooth surface without residual stress due to chamfering. , Ready to ship.

In the above, the mold 1 and the pressing mold 7 are used.
The disk substrate for storing information having an appropriate shape can be easily manufactured by forming the disk substrate into an arbitrary shape such as an elliptical shape or a polygonal shape as well as a circular shape. This has a remarkable effect in other aspects such as the degree of freedom of shape, ease of processing, etc., as compared with the conventional provision of a material plate by cutting.

Further, in the above-mentioned embodiment, the heating and melting step is carried out in two steps, but the heating and melting step may be carried out only once or in three or more steps.

[0028]

Since the method of manufacturing the disk substrate for information storage according to the present invention is constructed as described above, the chamfering of the end face is not required, the productivity is dramatically improved, and a significant cost reduction is achieved. You can

Moreover, mist is not generated by chamfering, the number of defective products is reduced, the product yield is improved, and a good working environment can be maintained at all times.

Further, there is no defect that the information storage disk substrate is distorted by the residual stress generated in the chamfering process, good quality is obtained in smoothness, and the information storage disk substrate capable of high density is provided. It is possible to provide a high-quality disk substrate for information storage without the occurrence of chipping and cracks found in conventional manufacturing methods.

[Brief description of drawings]

FIG. 1 is a perspective view of a mold and a pressing mold used in a method for manufacturing an information storage disk substrate of the present invention.

FIG. 2 is an enlarged cross-sectional view of a glass block or a glass plate when pressure is applied.

FIG. 3 is an enlarged cross-sectional view of the glass block or glass plate when heated and pressed and cut.

FIG. 4 is an enlarged cross-sectional view at the time of reheating a glass block or a glass plate.

FIG. 5 is a perspective view showing an information storage disk substrate obtained by heating and melting.

FIG. 6 is a cross-sectional view of an information storage disk substrate.

FIG. 7 is a perspective view showing a method of manufacturing a conventional information storage disk substrate.

FIG. 8 is a perspective view of a conventional information storage disk substrate.

FIG. 9 is an enlarged cross-sectional view of a conventional information storage disk substrate.

[Explanation of symbols]

 1 Formwork 2 Support Plate 3 Middle Plate 4 Positioning Post 5 Positioning Hole 6 Upper Plate 7 Stamping 8 Cavity 9 Guide Hole 10 Hole 11 Positioning Hole 12 Material Plate 13 Arc Convex Surface 21 Glass Block or Glass Plate 22 Medium Child 23 Circular hole 31 Information storage disk substrate

Claims (2)

[Claims] 1. A method comprising the steps of setting a glass material in a mold, heating and pressurizing the material while cutting it into a predetermined shape, and polishing the obtained material plate to a predetermined thickness. Manufacturing method of information storage disk substrate. 2. The method for manufacturing an information storage disk substrate according to claim 1, further comprising the step of heating and pressing the material plate obtained by molding so that the side surface thereof is formed into an arcuate convex surface.