JP2010082700A - Apparatus for manufacturing glass substrate for information recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that a vacuum attracting force becomes unstable through deviation of an air passage for vacuum attraction at a rotary joint for connecting a movable part with a fixed part in a grinding device for vacuum attracting a disk-like glass on a rotary workpiece table in grinding the inner and outer circumferential surfaces of the disk-like glass having a through-hole at a center and also to solve a problem of friction heat being easily caused through increase of a contact area between the movable area and the fixed part due to complication of a device configuration since the air passage for vacuum attraction and a coolant supply path are extended in parallel inside the movable part for a long distance in the grinding device. <P>SOLUTION: Since a fluid suction pipe for vacuum attraction is arranged on the rotating axis of the rotary workpiece table for vacuum attracting the disk-like glass, the deviation of the path of the fluid suction pipe is not caused even when the rotary workpiece table is rotated, so that the reduction of the vacuum attracting force to the disk-like glass is prevented. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus for manufacturing a glass substrate for an information recording medium used in an information recording apparatus such as a hard disk.

  Conventionally, in the production of a glass substrate for information recording media, after cutting out a disk-shaped glass having a through hole in the center from a plate-shaped glass, the two main surfaces of the disk-shaped glass are coated with free abrasive grains and a polishing pad. The inner peripheral surface and the outer peripheral surface are ground to a predetermined thickness using a rotary grindstone or the like.

  In Patent Document 1, a disk-shaped glass having a through hole in the center is sucked under reduced pressure and fixed to the suction plate, and the suction plate is rotated while supplying coolant to the surface of the disk-shaped glass from the through hole. Describes a hard disk substrate grinding apparatus for grinding an inner peripheral surface and an outer peripheral surface of glass-like glass. Specifically, in FIGS. 1 and 6 of Patent Document 1, a coolant discharge port is provided at the center of the suction plate, and a suction hole for fixing the disk-shaped glass is provided outside the discharge port. Further, a coolant pipe is disposed immediately below the coolant discharge port, that is, on the rotation axis of the suction plate, and four air passages are disposed directly below the suction hole, that is, on the same circumference around the rotation axis of the suction plate. Further, in FIGS. 6 and 7 of Patent Document 1, a movable part that is directly below the suction plate and rotates the suction plate, and coolant and suction air are delivered in contact with the movable part. The structure of the rotary joint which consists of a fixing | fixed part is described.

JP 2000-107995 A

  However, in the technique described in Patent Document 1, since the air passage of the fixed portion and the air passage of the movable portion are displaced due to the rotation of the movable portion in the rotary joint, the suction force of the suction plate is increased during the rotation of the movable portion. There was a problem of strength. In addition, in order to compensate for the weakness of the suction force, a large number of suction holes must be formed in the suction plate, which causes a problem that the processing steps of the suction plate are complicated (FIGS. 2 and 4 of Patent Document 1). And see FIG. Furthermore, since the movable part is rotatably supported by being in contact with various peripheral members, there is a problem that the contact area with the peripheral members is large and heat generation due to friction is large. Therefore, the coolant must be used not only for grinding the disk-shaped glass but also for cooling the frictional heat between the movable part and its peripheral members, and there is a problem that the coolant supply path becomes complicated.

  The present invention has been made by paying attention to such problems of the prior art, and when grinding the inner peripheral surface and the outer peripheral surface of the disk-shaped glass, the main surface of the disk-shaped glass. It is an object of the present invention to provide an apparatus for manufacturing a glass substrate for an information recording medium, which can fix a disk-shaped glass to a work table with a necessary and sufficient strength by adsorbing only one of them under reduced pressure, and has a simple configuration.

  The first means for solving the above-mentioned problem has a coolant supply port in the center, has a fluid suction port outside the coolant supply port, is connected to the fluid suction port, and rotates. An apparatus for producing a glass substrate for an information recording medium, comprising: a rotating work table having a fluid suction pipe arranged on a shaft; and a fixed table that rotatably supports the rotating work table.

  The second means includes a gap connected between the coolant supply pipe embedded in the fixed base and the coolant supply port and functioning as the coolant supply pipe between the rotating work base and the fixed base. An apparatus for producing a glass substrate for an information recording medium according to the first means characterized by comprising:

  According to the present invention, by disposing a fluid suction pipe for vacuum suction on the rotating shaft of a rotary work table that vacuum-sucks disk-shaped glass, a deviation occurs on the path of the fluid suction pipe even if the rotary work table rotates. As a result, it is possible to prevent the reduced pressure adsorption force for the disk-shaped glass from being lowered. Also, with such a configuration, the number of fluid suction ports for vacuum-adsorbing the disk-shaped glass can be reduced, so that the configuration of the rotating work table is simplified and the rotating work table can be easily manufactured. Become.

  In addition, the present invention provides rotation between a rotating work table and a fixed table by providing a gap that is connected to a coolant supply pipe and a coolant supply port embedded in the fixed table and functions as a coolant supply pipe. The contact area between the work table and the fixed table can be reduced, and the generation of frictional heat due to the rotation of the rotating work table can be suppressed. Further, the presence of the coolant in the gap can reduce the friction between the rotating work table and the fixed table by using the coolant as a lubricant, and can efficiently remove the generated frictional heat.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIG. 1 as appropriate.

  FIG. 1 is a schematic diagram showing the structure of an apparatus 100 for manufacturing a glass substrate for information recording medium according to the present invention. FIG. 1A is a plan view of a glass substrate for information recording medium 100 as viewed from above. FIG.1 (b) is sectional drawing along the AA line of Fig.1 (a). In addition, the dotted line in Fig.1 (a) shows the internal structure which does not appear in an external appearance.

  An apparatus 100 for manufacturing a glass substrate for an information recording medium includes a fixed base 110, a rotating work base 120, a coolant supply port 130, three fluid suction ports 140-1 to 140-3, a coolant supply pipe 150, a gap 160, and six coolants. A path 170-1 to 170-6 and a fluid suction pipe 180 are provided.

  The fixing table 110 is fixed to the base of the information recording medium glass substrate manufacturing apparatus 100 (not shown) so as not to rotate, and includes a coolant supply pipe 150. In addition, the fixing base 110 has a groove (ie, an outer portion) of a groove or gap 160 connected to the coolant supply pipe 150. The coolant supply pipe 150 is connected to a coolant supply pump (not shown).

  The rotary work table 120 is connected to a rotary drive device (not shown) and has a groove that constitutes a part (inner part) of the gap 160. Accordingly, the gap 160 is formed by the rotary work table 120 being rotatably fitted to the fixed table 110. Further, the rotary work table 120 is connected to the coolant supply port 130 having a depth from the center of the upper surface to substantially the same position as the coolant supply pipe 150, and the coolant supply port 130 and the gap 160. There are six coolant paths 170-1 to 170-6 for supplying water.

The coolant path 170 is arranged radially from the rotation axis on a plane perpendicular to the rotation axis of the rotary work table 120. Further, since the coolant path 170 is arranged symmetrically with the AA line as the boundary line, the weight balance of the rotating work table 120 is not impaired, and unnecessary vibration occurs even when the rotating work table 120 rotates. I will not let you.

  When grinding the inner peripheral surface of the disk-shaped glass fixed to the upper surface of the rotating work table 120, a grinding wheel for the inner peripheral surface is inserted into the coolant supply port 130 from the upper surface side of the rotating work table 120.

  Further, the rotary work table 120 has three fluid suction ports 140-1 to 140-3 installed outside the coolant supply port 130 on the upper surface thereof. Each of the fluid suction ports 140 is connected to the fluid suction pipe 180 so as not to cross the coolant supply port 130 and the coolant path 170 through the inside of the rotary work table 120.

  Here, the fluid used for the vacuum adsorption of the disk-shaped glass may be either gas or liquid, but the coolant supplied from the coolant supply port 130 can be used, and free air used when grinding the disk-shaped glass. It is preferable to use a liquid that is less likely to cause clogging of the fluid suction port 140 even when abrasive grains or polishing scraps flow in and that does not require a drain removal mechanism in the fluid suction pipe 180.

  The fluid suction pipe 180 is connected to a decompression pump (not shown), and when the disc-shaped glass is adsorbed on the upper surface of the rotating work table 120, the decompression suction force by the decompression pump is applied to the disc-shaped glass via the fluid suction port 140. introduce. The fluid suction pipe 180 is arranged so that the center line thereof coincides with the rotation axis of the rotary work table 120. By arranging the fluid suction pipe 180 on the rotation axis of the rotary work table 120 in this way, even when a rotary joint is installed in the middle of the fluid suction pipe 180, the vacuum suction pipe 180 is used for decompression adsorption. The fluid path is no longer displaced, and the vacuum suction force for the disk-shaped glass is stabilized.

  In this way, in the information recording medium glass substrate manufacturing apparatus 100, the coolant is supplied from the fixed base 110 to the rotary work base 120 in the vicinity of the coolant supply port 130, thereby simplifying the configuration of the rotary work base 120. Can do. As a result, it is possible to reduce the weight of the rotating work table 120 or to reduce the rotation drive device connected to the rotating work table 120 so that the entire apparatus can be made compact.

  Next, the operation of the information recording medium glass substrate manufacturing apparatus 100 when grinding the inner and outer peripheral surfaces of the disk-shaped glass will be described.

  First, before the disk-shaped glass is placed on the upper surface of the rotating work table 120, the coolant supply pipe 150, the gap 160, the coolant path 170, and the coolant supply port 130 are filled with the accumulated coolant, and the fluid suction port. 140 and fluid suction tube 180 are also filled with the same solution as the coolant. Furthermore, the upper surface of the rotating work table 120 is in a state where water droplets of coolant are scattered.

  On the upper surface of the rotating work table 120 in this state, a single disk-shaped glass having a through-hole in the center is centered on the upper surface of the rotating work table 120 so that the rotation axis of the rotating work table 120 and the center of the disk-shaped glass overlap. To do. At this time, a thin film of a solution containing a coolant is formed between the upper surface of the rotating work table 120 and the disk-shaped glass without a gap.

  Next, a decompression pump (not shown) connected to the fluid suction pipe 180 is operated. The decompression force of the decompression pump is transmitted to the disk-shaped glass through the fluid suction pipe 180 and the fluid suction port 140, and the disk-shaped glass is adsorbed on the upper surface of the rotating work table 120.

Next, a coolant supply pump (not shown) connected to the coolant supply pipe 150 is operated, and the coolant is supplied from the central through hole of the disk-shaped glass through the coolant supply pipe 150, the gap 160, the coolant path 170 and the coolant supply port 130. Overflow. The coolant overflowing from the through hole flows on the upper surface of the disk-shaped glass and drops on the fixed base 110.

  Next, two rotating grindstones (not shown) are operated to grind the inner and outer peripheral surfaces of the disk-shaped glass. At this time, the rotating grindstone for the inner peripheral surface is inserted into the coolant supply port 130. During this grinding, the coolant functions as a grinding fluid.

  Next, when the disk-shaped glass is ground to a predetermined inner diameter and outer diameter, the operations of the two rotating grindstones are stopped, and then the rotation of the rotating work table 120 is also stopped. On the other hand, the coolant supply pump continues to overflow the coolant from the through hole of the disk-shaped glass without stopping for a certain period thereafter. By carrying out like this, the grinding | polishing waste which has accumulated in the coolant supply port 130 produced at the time of grinding of the internal peripheral surface of disk shaped glass can be removed from the coolant supply port 130 and the upper surface of disk shaped glass.

  Next, after the coolant supply pump is stopped, the decompression pump is reversely operated to cause the liquid to flow backward from the fluid suction port 140. By doing so, the disk-shaped glass is lifted from the upper surface of the rotating work table 120 and is easily removed from the rotating work table 120.

  Next, the glass unloading device (not shown) picks up the ground disk-shaped glass from the upper surface of the rotating work table 120, whereby the grinding process of the inner and outer peripheral surfaces of the disk-shaped glass is completed.

  In the above-described embodiment of the present invention, the coolant may be a grinding fluid containing colloidal silica or cerium oxide fine particles.

(A) It is a top view which shows the structure of the manufacturing apparatus of the glass substrate for information recording media which shows embodiment of this invention. (B) It is sectional drawing along the AA line of (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Glass substrate manufacturing apparatus for information recording media 110 Fixed base 120 Rotating work base 130 Coolant supply port 140 Fluid suction port 150 Coolant supply pipe 160 Gap 170 Coolant path 180 Fluid suction pipe

Claims (2)

A rotary work base having a coolant supply port in the center, a fluid suction port outside the coolant supply port, and a fluid suction pipe connected to the fluid suction port and disposed on the rotation shaft When,
A fixed base that rotatably supports the rotary work table;
An apparatus for manufacturing a glass substrate for an information recording medium, comprising:   Between the rotating work table and the fixed table, there is a gap that is connected to a coolant supply pipe embedded in the fixed table and the coolant supply port, and functions as the coolant supply pipe. The apparatus for manufacturing a glass substrate for an information recording medium according to claim 1.

Images