JP2013073636A - Glass substrate laminating holder, method for polishing end surface of glass substrate for magnetic recording medium using holder, and method for manufacturing glass substrate for magnetic recording medium using method for polishing end surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass substrate laminating holder which enhances machining accuracy and productivity in an end surface polishing process, is easily handled and can perform outer circumferential end surface polishing and inner circumferential end surface polishing without taking a glass substrate laminate apart.SOLUTION: The glass substrate laminating holder used for outer circumferential end surface polishing and/or inner circumferential end surface polishing of a glass substrate laminate with a disc-shaped glass substrate for a magnetic recording medium having a hole in the center laminated thereon has a shaft. The shaft is inserted into the hole of the glass substrate for a magnetic recording medium, supports an inner circumferential end surface of the glass substrate laminate, and adjusts the position of the glass substrate for a magnetic recording medium. The shaft includes a clamp bolt fitting part capable of fitting a clamp bolt with both ends of the shaft, and a shaft fixing part for supporting the glass substrate laminate around the shaft. A method for polishing an end surface of a glass substrate for a magnetic recording medium using the glass substrate laminating holder, and a method for manufacturing a glass substrate for a magnetic recording medium are provided.

Description

  The present invention relates to a glass substrate stacking jig, a method for polishing an end surface of a glass substrate for a magnetic recording medium using the jig, and a method for manufacturing a glass substrate for a magnetic recording medium using the end surface polishing method.

  Conventionally, an aluminum alloy substrate has been used for a disk-shaped magnetic disk used in a magnetic disk recording device or the like. However, in recent years, with the demand for high-density recording, glass substrates that are harder than aluminum alloy substrates and excellent in flatness and smoothness have become mainstream.

  In the manufacturing process of the glass substrate for magnetic recording media, there are processing steps in which processing such as grinding and polishing is performed on the flat surface and end surfaces (inner and outer peripheral surfaces) of the glass substrate. And as a method of improving the working efficiency when polishing the end face of the glass substrate, there is a method of forming a glass substrate laminate in which a plurality of glass substrates are laminated in the plane direction and simultaneously polishing the end faces of a large number of glass substrates. It is used.

  The end surface polishing of the glass substrate is performed on both the outer peripheral surface and the inner peripheral surface. Therefore, when polishing a glass substrate laminate as described above, conventionally, after laminating the glass substrate once on the outer peripheral end surface polishing jig and polishing the outer peripheral end surface, the glass substrate laminate is once disassembled. Then, after the glass substrate was again laminated on the inner peripheral end surface polishing jig, the inner peripheral end surface was polished.

  However, according to such a method, it is necessary to disassemble the glass laminate between the steps of the outer peripheral end face polishing and the inner peripheral end face polishing. In some cases, the glass substrate is scratched by foreign matter sandwiched between the glass substrates. In addition, since the number of processes increases, there is a problem in productivity.

  In order to solve such a problem, studies have been made on a jig that can continuously perform outer peripheral end face polishing and inner peripheral cross-section polishing without disassembling the glass substrate laminate (for example, Patent Document 1).

JP 2003-159539 A

  However, in patent document 1, since it has the structure which fixed the plate which installed the glass substrate up and down with the volt | bolt, and pinched | interposed the glass substrate, there was a problem that it took time and labor to assemble the apparatus and an assembly error was likely to occur. . Further, since there are many members, there is a problem in maintainability.

  Moreover, in patent document 1, when grind | polishing the outer end part of a glass substrate laminated body, the 1st plate was applied to the both ends of the glass substrate laminated body, and the 1st plate inserted by the inner hole of the glass substrate laminated body The first plate is fixed by the fastener to clamp the glass substrate. However, since the diameter of the first plate fastener is smaller than the diameter of the inner hole of the glass substrate laminate, the glass substrate may be displaced during the polishing process. In this case, the concentricity of the glass substrate to be obtained may be low, and the roundness (inner peripheral portion) or the outer peripheral portion of the glass substrate may have a low roundness.

  In view of the problems of the above-described conventional technology, the present invention improves processing accuracy and productivity in the end surface polishing step, is easy to handle, and further, without disassembling the glass substrate laminate, outer peripheral end surface polishing, inner peripheral end surface polishing. It aims at providing the glass substrate lamination jig | tool which can perform.

  In order to solve the above-mentioned problems, the present invention provides a glass substrate laminate treatment used for outer peripheral end face polishing and / or inner peripheral end face polishing of a glass substrate laminate in which a disk-shaped glass substrate for a magnetic recording medium having a circular hole in the center is laminated. A shaft that is inserted into a circular hole of the glass substrate for magnetic recording medium, supports an inner peripheral end surface of the glass substrate laminate, and aligns the glass substrate for magnetic recording medium. The shaft includes a clamp bolt fitting portion capable of fitting a clamp bolt to both ends of the shaft, and a shaft stop portion for supporting the glass substrate laminate around the shaft. Provide ingredients.

  In the present invention, when the glass substrate laminate is formed, the inner peripheral end surface is supported by the shaft, so that a glass substrate for a magnetic recording medium (hereinafter also simply referred to as “glass substrate”) is accurately installed and fixed. It becomes possible. For this reason, a processing precision can be raised and the concentricity and roundness of the glass substrate obtained can be made high. Further, since the number of parts is small, an assembly error is unlikely to occur, and maintenance can be improved. Furthermore, even when the inner and outer peripheral end surfaces are polished, it is possible to continuously perform the glass substrate laminate without disassembling, so that the glass substrate is prevented from being scratched even when both end surfaces are polished. As a result, yield and productivity can be increased.

Explanatory drawing of the shaft which concerns on this invention Explanatory drawing of the structure at the time of outer periphery end surface grinding | polishing in 1st Embodiment which concerns on this invention Explanatory drawing of the clamp bolt in a 1st embodiment concerning the present invention Explanatory drawing about the inner peripheral end surface polishing jig in the first embodiment according to the present invention Explanatory drawing about the inner peripheral end surface polishing jig in the first embodiment according to the present invention Explanatory drawing about the glass substrate laminated body in 1st Embodiment which concerns on this invention

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments, and the following embodiments are not departed from the scope of the present invention. Various modifications and substitutions can be made.

[First Embodiment]
In the present embodiment, the glass substrate stacking jig of the present invention will be described.

  The glass substrate laminating jig of the present invention used for polishing the outer peripheral end surface and / or the inner peripheral end surface of a glass substrate laminate in which a disk-shaped glass substrate having a circular hole at the center part used for a magnetic recording medium is laminated is as follows. It has the composition of.

  First, a glass substrate lamination jig of the present invention is inserted into a circular hole of a glass substrate for magnetic recording medium, supports an inner peripheral end surface of the glass substrate laminate for magnetic recording medium, and positions of the glass substrate for magnetic recording medium Has a matching shaft. The shaft is formed with a clamp bolt fitting portion for fitting a clamp bolt at both ends of the shaft and a shaft stop portion for supporting the glass substrate laminate around the shaft.

  The said glass substrate lamination jig | tool is demonstrated below.

  FIG. 1 shows a shaft constituting the glass substrate laminating jig of the present invention. The shaft 10 includes an inner peripheral support portion (shaft portion) 11, a shaft stopper portion (glass substrate laminate holding portion) 12 provided on the shaft, and clamp bolt fitting portions 13 provided at both ends of the inner peripheral support portion. have.

  Here, the material of the shaft 10 is not particularly limited, but preferably has a certain degree of strength in order to hold the glass substrate laminate in the end surface polishing step. For example, various metals such as stainless steel, steel, and aluminum can be preferably used. However, it is preferable that the material is resistant to rust and has strength, and stainless steel is more preferable.

  Further, the shaft 10 may come into contact with the inner peripheral portion of the glass substrate when the glass substrate is taken in or out or the end face polishing process is performed, and the surface may be scratched or deformed. It will cause a drop. In order to avoid such a situation, it is preferable that at least a portion in contact with the glass substrate for a magnetic recording medium is coated with a protective film on the shaft and the shaft stopper. In particular, it is more preferable that the entire surface of the shaft 10 excluding the clamp bolt fitting portion 13 is coated with a protective film.

  As the protective film, a metal (plating) film such as hard chrome plating, a ceramic film such as chromium oxide, a diamond-like carbon film (hereinafter simply referred to as a DLC film), or the like can be used. It is particularly preferable to use a DLC film because of easy thickness control. The film thickness of the protective film is not particularly limited, and can be selected in consideration of the film strength, wear resistance, frequency of use of the member, cost, etc. For example, in the case of a DLC film, it is preferably 2 μm or more, and more preferably 4 μm or more.

  About the thickness of the inner peripheral support part 11 of a shaft, it is preferable that it is substantially the same as the internal diameter of a glass substrate laminated body. This is because the glass substrate laminate is laminated and supported on the inner peripheral support portion, so that the glass substrate can be reduced by reducing the distance between the inner peripheral support portion and the inner peripheral portion of the glass substrate laminate. This is because the positioning accuracy increases and the processing accuracy increases. However, if the distance between the inner peripheral part of the glass substrate and the inner peripheral support part is too small, there is a risk of damaging the glass substrate when attaching or detaching the glass substrate laminate. It is preferable to select the interval in consideration of the above. In addition, the diameter of the axial part of a shaft here includes the thickness of a protective film, when it has a protective film on the surface.

  And the shaft stop part 12 which comprises a shaft is a member which has the column shape fixed on the axis | shaft of a shaft, and has a function which supports the lower end part of the glass substrate laminated body inserted in the inner peripheral support part 11. . For this reason, it is preferable that the outer diameter of the shaft stopper 12 is configured to be larger than the inner diameter of the glass substrate constituting the glass substrate laminate and smaller than the outer diameter of the glass substrate. In addition, it is preferable that at least a part of the upper surface of the shaft stop portion 12, that is, the surface that supports the glass substrate laminate is perpendicular to the inner peripheral support portion 11. By having such a configuration, the glass substrate laminate can be firmly fixed, so that the glass substrate laminate can be prevented from being damaged during the movement or the polishing step, and the processing accuracy can be increased.

  Moreover, it is preferable that the axial stop part 12 is comprised so that the position can be adjusted on the axis | shaft of a shaft. This is because the change of the position of the shaft stopping portion can cope with the glass substrate laminate 25 having various thicknesses, and the versatility is enhanced.

  Clamp bolt fitting portions 13 are provided at both ends of the shaft 10. The clamp bolt fitting portion 13 is provided for fitting and attaching a clamp bolt used when polishing the outer periphery of the glass substrate laminate, and has a concave shape corresponding to the shape of the clamp bolt. ing.

  Using the glass substrate stacking jig having the shaft described above, the outer peripheral end face polishing and the inner peripheral end face polishing can be performed. First, the case of outer peripheral end face polishing will be described.

  When polishing the outer peripheral end surface of the glass substrate laminate, the outer peripheral end surface can be polished by attaching a clamp bolt to the clamp bolt fitting portion of the shaft. The specific configuration will be described with reference to FIG.

  In FIG. 2, the inner peripheral support portion 11 is inserted through a circular hole of the glass substrate laminate 25 in which the spacers 20 to 22 are arranged at both ends thereof, and supports the inner peripheral portion of the glass substrate laminate 25. Further, the glass substrate laminate 25 is supported at its lower end portion by a clamp bolt 12 via spacers 22 and spacers 23 and 24 via a spacer 22, and a clamp bolt 26 installed at the other upper end portion. It is fixed by tightening from above and below.

  For this reason, the position of the glass substrate laminate can be accurately held even during the outer peripheral end face polishing step, and the processing accuracy can be increased.

  Here, the clamp bolt 26 is not particularly limited as long as it is configured to be able to hold the glass substrate laminate 25 vertically from the vertical direction and to be installed on the outer peripheral end surface polishing jig. For example, the shape shown in FIGS. The configuration will be described with reference to FIG. 3 in which the clamp bolt portion is enlarged.

  The clamp bolt 26 used in the present invention preferably has a bolt part 31 and a washer part 32 that is not joined to the bolt part 31. The bolt part 31 is configured to pass through a hole provided in the center of the washer part 32 and has a substantially bar shape.

  The bolt part 31 has a function of installing the glass substrate laminate on the outer peripheral end surface polishing apparatus and a function of fastening and fixing the glass substrate laminate from the vertical direction.

  For this reason, the shape of the bolt portion 31 is configured such that one end portion can be connected to the outer peripheral end surface polishing apparatus, and the other end portion can be fixed to the shaft.

  Here, a shaft fitting portion is protruded (formed) at one end portion of the clamp bolt, that is, an end portion of the bolt portion 31 that is fixed to the shaft, and the shaft fitting portion is threaded in order from the tip portion. It is preferable to have a convex cylindrical portion 33 that does not have a thread and a threaded portion 34. In this case, the clamp bolt fitting portion of the shaft has a concave shape corresponding to the shape of the shaft fitting portion, that is, a concave cylindrical portion and a screw portion, and the convex cylindrical portion 33 and the concave shape are formed. It is comprised so that a cylindrical part may fit.

  Since the shaft fitting part of the clamp bolt and the clamp bolt fitting part of the shaft have such a configuration, the concave cylindrical part of the tip part of the clamp bolt and the corresponding concave part (concave cylindrical part) of the clamp bolt fitting part of the shaft Is a so-called stamping structure (cylindrical fitting). For this reason, when attaching the clamp bolt to the shaft, there is no eccentricity, it is possible to fix it at an accurate position and angle, and it is possible to improve the processing accuracy.

  Since the washer portion 32 is a member that is not joined to the bolt portion 31, the washer portion 32 has a function of preventing the rotation from propagating to the glass substrate laminate when the bolt portion 31 is fixed. Further, the washer portion 32 preferably has a shape in which the area of the surface 35 in contact with the glass substrate laminate is wider than the area of the surface 36 in contact with the bolt portion 31. By having such a shape, the pressure applied to the glass substrate laminate can be dispersed and the glass substrate laminate can be supported in a wide range.

  Moreover, about the glass substrate laminated body 25, what laminated | stacked only the glass substrate may be sufficient, but what laminated | stacked the glass substrate and the spacer alternately is preferable. By arranging the spacer between the glass substrates, it is possible to prevent the main plane of the glass substrate from being damaged. In addition, the shape of the spacer is not particularly limited, and may be any shape that does not interfere with the polishing. For example, the spacer may have the same disk shape as the glass substrate. Further, when the outer peripheral end face is polished, it is preferable that the outer diameter of the spacer is smaller than at least the outer diameter of the glass substrate.

  The glass substrate laminating jig having the above configuration is installed and fixed on the outer peripheral end surface polishing apparatus, and a polishing liquid containing abrasive grains is supplied by applying a polishing brush or a polishing pad to the outer peripheral portion of the glass substrate laminate 25. While polishing the outer peripheral end face.

  Next, the case of inner peripheral end surface polishing will be described.

  As a glass substrate laminating jig used when polishing the inner peripheral end face, in addition to the shaft, it is possible to fix the glass substrate laminated body when polishing the inner peripheral end face of the glass substrate laminated body. It further has an inner peripheral end surface polishing jig having a structure. The inner peripheral end surface polishing jig is capable of fixing the glass substrate laminate inside, and after fixing the glass substrate laminate inside the inner peripheral end surface polishing jig, a jig capable of extracting the shaft. If it is, the shape and structure can be used without limitation.

  For example, as an inner peripheral end surface polishing jig, a shaft on which a glass substrate laminate is laminated and fixed, an opening that can be inserted without disassembling the glass substrate laminate, a fixing member that fixes the glass substrate laminate, and a shaft And a jig having a shaft outlet that can be taken out.

  Here, the opening preferably has an opening diameter substantially the same as the outer diameter of the glass substrate constituting the glass substrate laminate. If the outer diameter of the glass substrate and the opening are the same, the glass substrate laminate may be damaged when the glass substrate laminate is inserted. It is preferable to provide a clearance (clearance) that does not cause damage when inserted into the tool.

  Examples of the fixing member include a member that is fixed by tightening from the upper and lower surfaces of the glass substrate laminate. For example, it is a method of pressing the glass substrate laminate from above and below with fixing plates provided on the upper and lower surfaces of the glass substrate laminate.

  However, in order to polish the inner peripheral end face, it is preferable that the portion corresponding to the circular hole portion of the glass substrate laminate of the fixing plate has an opening. Such an opening can also serve as a shaft outlet. Moreover, when tightening, it is preferable to disperse the pressure by pressing substantially the entire surface of the glass substrate on the upper and lower surfaces of the glass substrate laminate to prevent damage to the glass substrate.

  It is preferable that the shaft outlet has an opening diameter that is substantially the same as the outer diameter of the shaft stopper, which is the largest outer diameter portion of the shaft. By having such a configuration, the shaft and the glass substrate laminate can be accurately fixed to the inner peripheral end surface polishing jig, and then the shaft can be taken out.

  A specific configuration example of the inner peripheral end surface polishing jig will be described with reference to FIGS. 4 and 5, but is not limited to such a configuration. Here, FIG. 4 is a perspective view of the inner peripheral end surface polishing jig, and FIG. 5 is a cross-sectional view when the shaft holding and fixing the glass substrate laminate is installed inside.

  As shown in FIG. 4, the inner peripheral end surface polishing jig 40 preferably includes a holder main body 41 having an opening on the upper surface, an upper holding portion 42 and a positioning portion 43 thereof.

  The holder main body 41 includes a lower frame portion 44, a side frame portion 45, and an upper frame portion 46.

  The lower frame portion 44 can vertically support the glass substrate laminate, and is configured so that the shaft can be extracted from the bottom surface. For example, as shown in FIG. 5, a through-hole that can fix and remove the shaft stopper 12 of the shaft 10 is provided. In addition, a glass substrate laminate made of a buffer member or the like fixed to the lower frame portion is provided with a spacer in FIG. 5 for the portion that contacts and supports the lower end portion of the glass substrate laminate on the upper surface of the lower frame portion. A body lower end support portion can also be provided. And about a lower frame part, the mechanism and member for fixing with a grinding | polishing apparatus at the time of grinding | polishing can be provided. For example, a bolt hole for installing a base plate for connection with the polishing apparatus, a fitting portion, or the like can be provided.

  Here, the through hole provided in the lower frame portion for fixing the shaft stopper 12 of the shaft 10 and the shaft stopper 12 of the shaft 10 are fitted (clearance (gap between the shaft stopper 12 and the through hole)). ) Is small), that is, it is preferable that the through hole and the shaft stopper 12 form a stamping structure. By having such a configuration, the shaft can be fixed vertically to the inner peripheral end surface polishing jig 40 without any eccentricity, and the processing accuracy can be improved.

  The side frame portion 45 has a cylindrical shape so as to connect the lower frame portion 44 and the upper frame portion 46 and cover the outermost peripheral surface of the glass substrate laminate. And it has the storage chamber which accommodates a glass substrate laminated body in an inside. Moreover, it is preferable to provide the opening part 47 so that the side frame part can visually observe the glass substrate laminated body accommodated in the storage chamber from the outside. The opening 47 functions as a discharge hole for discharging the polishing liquid used in the polishing process, and contributes to weight reduction of the apparatus.

  The upper frame part 46 consists of a ring-shaped member, and is comprised so that the cyclic | annular upper end part of a side frame part can be fixed to a lower surface. In addition, a circular opening having a diameter larger than the outer diameter of the glass substrate is formed on the inner periphery, and the glass substrate laminate can be inserted or removed.

  The lower frame portion 44, the side frame portion 45, and the upper frame portion 46 are fixed and assembled to the holder main body 41. The fixing means for these members is not limited and can be fixed by screws or the like, but is preferably fixed by welding in order to prevent a reduction in processing accuracy due to loosening of the screws.

  The upper holding part 42 is attached to the upper surface part of the holder main body 41, and is fixed and held by sandwiching the glass substrate laminate disposed therein with the lower frame part 44. The upper holding portion 42 has a central hole 48 passing through in the center thereof in the axial direction, and is configured such that the upper holding portion can be installed in a state where the shaft is installed in the inner peripheral end surface polishing jig. The material of the upper holding portion 42 is not particularly limited as in the case of the holder main body, and can be formed of a metal such as stainless steel, for example. The upper holding portion 42 is fixed by sandwiching the glass substrate laminate between the lower frame portion of the holder main body, and the glass substrate laminate 25 and the glass substrate laminate 25 so that the glass substrate is not damaged when being fixed. It is preferable to provide various buffer members between them.

  The means for fixing the upper holding portion 42 to the holder body 41 is not particularly limited, and any method can be adopted as long as it can be accurately fixed to an appropriate position. For example, as shown in FIG. 4, a plurality of bolt holes 49 may be provided in the upper holding portion 42 and fixed to the holder main body from the upper surface side with the bolts 50. It is also possible to fix by screwing the upper holding portion and the holder main body at corresponding locations and screwing the upper holding portion into the holder main body.

  Furthermore, it is preferable to use a positioning member 43 in order to accurately define the position of the shaft. The positioning member 43 includes, for example, a cylindrical bearing portion 52 having a shaft hole 51 inserted through the upper end of the shaft, a pair of arm portions 53 protruding in the radial direction from the bearing portion 52, and a positioning pin penetrating each arm portion. 54. Then, by inserting the shaft 10 into the shaft hole 51 of the positioning member and inserting the positioning pin 54 into the pin insertion holes 55 and 56 provided in the upper holding portion and the holder body, the position of the shaft can be accurately defined. It becomes possible. By using such a member, when the shaft is fixed to the inner peripheral end surface polishing jig, the positioning can be performed accurately, and the processing accuracy can be improved.

  Here, it is preferable to form a so-called stamping structure (cylindrical fitting) so that the shaft hole 51 of the positioning member 43 and the shaft 10 are fitted (so that the gap is reduced when both are fitted). . By having such a configuration, the shaft 10 can be fixed to the inner peripheral end surface polishing jig 40 vertically without any eccentricity, and the processing accuracy can be improved.

  Further, it is preferable that the positioning pin 54 and the pin insertion hole 56 also form a stamping structure. By having such a configuration, there is no eccentricity when the positioning member 43 is attached to the inner peripheral end surface polishing jig 40, and it is possible to fix the positioning member 43 at an accurate position and angle, thereby improving processing accuracy.

  In addition, the glass substrate laminate 25 has also been described with respect to the outer peripheral end surface polishing. However, the glass substrate laminate 25 may be formed by laminating only the glass substrate, but the glass substrate for magnetic recording medium and the spacer are alternately laminated. Is preferred. Similarly, the shape of the spacer is not particularly limited, and may be any shape as long as it does not interfere with polishing. For example, the spacer may have the same disk shape as the glass substrate. Further, when the inner peripheral end face is polished, it is preferable that the inner diameter of the spacer is larger than at least the inner diameter of the glass substrate.

  The glass substrate laminate 25 laminated on the inner peripheral support portion 11 of the shaft is installed on the inner end surface polishing jig 40 having the above-described configuration, and the glass substrate laminate is used as the inner peripheral end surface polishing jig. Secure inside. Thereafter, the shaft 10 can be extracted and used for an inner peripheral end surface polishing step.

As a specific procedure for fixing the glass substrate laminate to the internal end surface polishing jig and polishing the inner peripheral end surface, for example, a method having the following steps can be used.
(A) The shaft 10 on which the glass substrate laminate 25 is laminated and fixed is inserted into the holder main body 41 of the work holder through the circular opening of the upper frame portion. At this time, the shaft locking portion 12 of the shaft is fixed (axially stopped) by a through hole provided in the lower frame portion 44 of the holder main body 41.

In this case, as described above, when the shaft locking portion 12 of the shaft is inserted into the through hole provided in the lower frame portion 44 of the holder main body 41, the shape of the through hole and the shaft locking portion 12 is formed so as to form a stamping structure. The size is preferably defined. With the above configuration, the shaft locking portion can be fixed to the lower frame portion of the holder main body with no eccentricity, and the verticality can be fixed high, and the processing accuracy can be improved.
(B) The spacer 21, the upper holding part 42, and the positioning member 43 are attached to the upper end of the holder body, and the glass substrate laminate is fixed in the holder.

  As for the positioning pin 54 and the pin insertion hole 56, it is preferable that the positioning pin 54 and the pin insertion hole 56 have a corresponding shape and size so as to have a stamping structure (cylindrical fitting) as described above. By having such a configuration, when the shaft 10 is fixed to the holder main body 41, the perpendicularity can be increased, so that the processing accuracy at the time of polishing can be increased.

  As for the shaft hole 51 and the shaft 10 of the positioning member, it is preferable that the shaft hole 51 and the shaft 10 of the positioning member have a corresponding shape and size so as to have an imprint structure (cylindrical fitting) as described above. . By having such a configuration, the positioning accuracy of the shaft 10 is increased and the verticality of the shaft can be increased, so that the processing accuracy during polishing can be increased.

In addition, as described above, it is preferable that the shaft locking portion 12 and the through hole of the holder main body 41, the positioning pin 54 and the pin insertion hole 56, and the positioning member shaft hole 51 and the shaft 10 have a so-called stamping structure. However, it is preferable that these three parts have a stamping structure when particularly high machining accuracy is required. This has a higher positioning accuracy and perpendicularity of the shaft by having such a configuration, so the positioning accuracy when the glass substrate laminate is fixed and held on the inner peripheral end surface polishing jig is increased, This is because the processing accuracy can be increased.
(C) The shaft is extracted downward from the through hole provided in the lower frame portion 44 of the holder main body, and when the positioning member 43 is used in the step (B), the positioning member is also removed.
(D) Inserting a polishing brush into the center hole of the glass substrate laminate from above, and supplying the polishing liquid from above, reciprocating in the axial direction while rotating the table and polishing brush to which the holder body is fixed. The inner peripheral end face of the body 25 is polished.

  The inner peripheral end face can be polished by the steps as described above. After polishing, it is possible to insert the shaft 10 through a through hole provided in the lower frame portion and take out the glass substrate laminate, or disassemble the glass substrate laminate and take out the glass substrates individually. It is also possible.

  As described above, the outer peripheral end surface polishing method and the inner peripheral end surface polishing method using the glass substrate laminating jig of the present invention have been described. However, either the outer peripheral end surface polishing or the inner peripheral end surface polishing can be performed. And both polishing processes can also be performed continuously.

  When performing continuously, it is sufficient to use the glass substrate laminate after finishing either the outer peripheral end face polishing step or the inner peripheral end face polishing step for the other polishing step while being fixed to the shaft.

  In addition, also when performing grinding | polishing continuously, although the glass substrate laminated body 25 can also be taken as what laminated | stacked only the glass substrate, using what laminated | stacked the glass substrate and the spacer alternately may be used. preferable.

  The shape of the spacer is not particularly limited, and may be any shape that does not interfere with polishing. For example, the same disk shape as that of the glass substrate is preferable.

  Here, the glass substrate laminate will be described with reference to FIG. FIG. 6A schematically shows a cross-sectional view of the glass substrate laminate taken along the line AA ′ of FIG. 6B, and FIG. 6B shows the glass of FIG. The figure seen from the bottom face side of a substrate layered product is shown. A dotted line in FIG. 6A indicates a circular hole portion at the center of the glass substrate.

  As the spacer, for example, as shown in FIG. 6B, the outer diameter is smaller than the outer diameter of the magnetic recording medium glass substrate, and the inner diameter is larger than the circular hole diameter of the magnetic recording medium glass substrate. It is preferable to use a spacer. Such a shape can be particularly preferably used in the process when the outer peripheral end face polishing process and the inner peripheral end face polishing process are continuously performed, but can also be used when only one of the end faces is polished. it can. The spacer is shaped and sized as described above when the outer peripheral end surface and the inner peripheral end surface of the glass substrate are polished by polishing so that the spacer does not come into contact with a polishing brush, a polishing pad, or the like. This is because it is preferable. For this reason, for example, as shown in FIG. 6B, the gap a between the outer glass substrate and the spacer and the gap b between the inner glass substrate and the spacer are at least larger than the width (removal allowance) for end face polishing. A large size is particularly preferred.

  As described above, in the present invention, even when either outer peripheral end face polishing or inner peripheral end face polishing is performed, since the number of parts is small, polishing can be easily performed and productivity can be improved. . In addition, the maintainability of the apparatus can be improved as compared with the prior art.

In particular, when the outer peripheral end surface polishing and the inner peripheral end surface polishing are performed continuously, it becomes possible to carry out without disassembling the glass substrate laminate, thereby improving the concentricity of the glass substrate, Generation | occurrence | production of the damage | wound to a glass substrate can be prevented and reduced. Further, since the operation becomes easier than the conventional jig, it becomes easy to improve the productivity.
[Second Embodiment]
In this embodiment, a method for polishing an end face of a glass substrate for a magnetic recording medium using the glass substrate stacking jig described in the first embodiment will be described.

  Specifically, it is a polishing method for the outer peripheral end face and the inner peripheral end face of the glass substrate for magnetic recording medium using the glass substrate laminating jig described in the first embodiment.

  A clamp bolt is attached to the clamp bolt fitting part of the shaft holding the glass substrate laminate, and the outer peripheral end surface of the glass substrate laminate is polished.

  The shaft holding the glass substrate laminate is fixed to the inner peripheral end surface polishing jig, and after fixing the glass substrate laminate to the inner peripheral end surface polishing jig, the shaft is pulled out and the inner peripheral end surface of the glass substrate laminate is removed. Is a method for polishing an end face of a glass substrate for a magnetic recording medium, wherein the inner peripheral end face is polished.

  Here, as described in the first embodiment, the method of polishing the end surface of the glass substrate for a magnetic recording medium is not particularly limited as to which of the outer peripheral end surface and the inner peripheral end surface is polished first. After the outer peripheral end face is polished, the inner peripheral end face is preferably polished.

  This is because when the outer peripheral end surface is polished, the shaft is inserted into the circular hole provided in the central portion of the glass substrate laminate, and the glass substrate laminate is fixed. This is because it may occur. For this reason, by performing the inner peripheral end face polishing step after the outer peripheral end face polishing step, it is preferable to perform the polishing in the above order because it can be removed even if the inner peripheral end face is damaged when performing the outer peripheral end face polishing step.

  Also in this case, as the glass substrate laminate, it is preferable to use a laminate in which glass substrates for magnetic recording media and spacers are alternately laminated as described in the first embodiment. As for the spacer, as described in the first embodiment, as shown in FIG. 6B, the outer diameter is smaller than the outer diameter of the magnetic recording medium glass substrate, and the inner diameter is a glass substrate circle for the magnetic recording medium. It is preferable to use a disk-shaped spacer larger than the hole diameter.

According to such an end surface polishing method, it becomes possible to continuously polish the outer peripheral end surface and the inner peripheral end surface of the glass substrate without disassembling the glass substrate laminate, thereby improving the concentricity of the glass substrate, Generation | occurrence | production of the damage | wound to the glass substrate during operation can be prevented and reduced. Further, since the operation becomes easy, it becomes easy to improve productivity.
[Third Embodiment]
In this embodiment, a method for manufacturing a glass substrate for a magnetic recording medium will be described.

  Specifically, an end surface polishing step for polishing an inner peripheral end surface and an outer peripheral end surface of a disk-shaped glass substrate for a magnetic recording medium, a main plane polishing step for polishing a main plane of the glass substrate for a magnetic recording medium, and the magnetic And a step of cleaning the glass substrate for recording medium. In the end surface polishing step, the end surface polishing method described in the second embodiment is performed.

  In addition, the process (shape provision process) which processes a glass base substrate in a disk shape can also be provided before an end surface grinding | polishing process. It does not specifically limit about the glass base substrate used in this case, Various glass substrates can be used, For example, amorphous glass and crystallized glass may be sufficient, and the tempered glass which has a tempered layer in the surface layer of a glass substrate ( For example, chemically strengthened glass) may be used. Further, the molding method is not limited, and those molded by a float method, a fusion method, a press molding method, or a redraw method can be used.

  For the outer peripheral end face polishing step and the inner peripheral end face polishing step, a method similar to the method described in the second embodiment can be employed.

  The main plane polishing step is a step of polishing the upper and lower main planes of the glass substrate for magnetic recording media, and is performed using a polishing pad and a polishing liquid containing abrasive grains as a polishing tool by, for example, a double-side polishing apparatus. Can do. The main surface polishing step may be only primary polishing, primary polishing and secondary polishing may be performed, or tertiary polishing may be performed after secondary polishing.

  The cleaning step is a step of precisely cleaning and drying the magnetic recording medium glass substrate.

  The glass substrate for magnetic recording media is manufactured through these steps. Then, a thin film such as a magnetic layer is formed on the magnetic recording medium glass substrate to manufacture a magnetic disk.

  In the manufacturing process of the glass substrate for magnetic recording medium and the magnetic disk, glass substrate cleaning (inter-process cleaning) and glass substrate surface etching (inter-process etching) may be performed between the processes.

  Moreover, you may implement the main surface grinding process which grinds both the upper and lower main surfaces of a glass substrate, and adjusts the flatness and plate | board thickness of a glass substrate. Grinding is performed by loose abrasive grinding using a loose abrasive, or by fixed abrasive grinding using a fixed abrasive tool. The main surface grinding step may be performed before the main surface polishing step, and is performed either before or after the shape imparting step, before or after the outer peripheral end surface polishing step, before or after the inner peripheral end surface polishing step. May be.

  Furthermore, when high mechanical strength is required for the glass substrate for magnetic recording media, a strengthening step (for example, a chemical strengthening step) for forming a reinforcing layer on the surface layer of the glass substrate is performed before the polishing step, after the polishing step, or the polishing step You may carry out between.

  According to the method for manufacturing a glass substrate for a magnetic recording medium described above, in the end surface polishing step, it becomes possible to carry out without disassembling the glass substrate laminate, thereby improving the concentricity of the glass substrate and operating the glass substrate laminate. Generation | occurrence | production of the damage | wound to a glass substrate inside can be prevented and reduced. Further, since the operation becomes easy, it becomes easy to improve productivity.

DESCRIPTION OF SYMBOLS 10 Shaft 12 Shaft stop part 13 Clamp bolt fitting part 25 Glass substrate laminated body 26 Clamp bolt 60 Glass substrate 61 Spacer

Claims (10)

A glass substrate stacking jig used for outer peripheral end surface polishing and / or inner peripheral end surface polishing of a glass substrate laminate in which a disk-shaped glass substrate for a magnetic recording medium having a circular hole in the center is laminated,
Inserted into a circular hole of the glass substrate for magnetic recording medium, supporting an inner peripheral end surface of the glass substrate laminate, and having a shaft for aligning the glass substrate for magnetic recording medium;
The shaft has a clamp bolt fitting portion capable of fitting a clamp bolt to both ends of the shaft, and a shaft stopping portion that supports the glass substrate laminate around the shaft.
A glass substrate laminating jig comprising: When the glass substrate lamination jig performs the outer peripheral end surface polishing of the glass substrate laminate,
The glass substrate laminating jig according to claim 1, wherein the clamp bolt fitting portion has a clamp bolt. When the glass substrate stacking jig performs inner peripheral end face polishing of the glass substrate stack,
An inner peripheral end surface polishing jig that is a structure capable of fixing the glass substrate laminate inside;
The glass substrate lamination jig according to claim 1 or 2, wherein the inner peripheral end surface polishing jig is capable of extracting the shaft after fixing the glass substrate laminate in the inner peripheral end surface polishing jig. Ingredients. The clamp bolt has a shaft fitting portion protruding at one end,
The shaft fitting portion has a convex cylindrical portion not having a screw thread in order from the tip portion, and a screw portion,
The clamp bolt fitting portion has a concave cylindrical portion corresponding to the shape of the shaft fitting portion, and a screw portion,
The glass substrate lamination jig | tool as described in any one of Claims 1 thru | or 3 comprised so that the said convex cylindrical part and the said concave cylindrical part may fit.   5. The glass substrate stacking jig according to claim 1, wherein at least a portion of the shaft that contacts the glass substrate for a magnetic recording medium is coated with a protective film made of diamond-like carbon. A method for polishing an end surface of a glass substrate for a magnetic recording medium using the glass substrate laminating jig according to claim 1,
A clamp bolt is attached to the clamp bolt fitting portion of the shaft holding the glass substrate laminate, and the outer peripheral end surface of the glass substrate laminate is polished on the outer peripheral end surface.
The shaft holding the glass substrate laminate is fixed to an inner peripheral end surface polishing jig, the glass substrate laminate is fixed to the inner peripheral end surface polishing jig, and then the shaft is pulled out, A method for polishing an end face of a glass substrate for a magnetic recording medium, comprising polishing a peripheral end face to an inner peripheral end face.   The method for polishing an end face of a glass substrate for a magnetic recording medium according to claim 6, wherein the glass substrate laminate is formed by alternately laminating glass substrates for a magnetic recording medium and spacers.   The end face of the glass substrate for a magnetic recording medium according to claim 7, wherein the spacer has a disk shape whose outer diameter is smaller than the outer diameter of the glass substrate for magnetic recording medium and whose inner diameter is larger than the diameter of the glass substrate circular hole for the magnetic recording medium. Polishing method.   The method for polishing an end surface of a glass substrate for a magnetic recording medium according to any one of claims 6 to 8, wherein the inner peripheral end surface is polished after the outer peripheral end surface is polished. An end surface polishing step of polishing the inner peripheral end surface and the outer peripheral end surface of the glass substrate for magnetic recording medium;
A main surface polishing step of polishing the main surface of the glass substrate for magnetic recording medium;
Cleaning step of glass substrate for magnetic recording medium;
In a method for producing a glass substrate for a magnetic recording medium having
The method for producing a glass substrate for a magnetic recording medium, wherein the end surface polishing step comprises polishing the end surface of the glass substrate for a magnetic recording medium using the method for polishing an end surface of the glass substrate for a magnetic recording medium according to any one of claims 6 to 9. .

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