JP2007203403A - Workpiece holding frame member and workpiece holder using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent occurrence of deformation such as distortion and warping in a frame member when positioning and fixing the frame member for holding a workpiece on a surface plate. <P>SOLUTION: Even if a corner part of one optional square hole inner peripheral face among square hole inner peripheral faces of positioning holes 6a, 6b is formed in a distorted condition when forming a shape of the positioning holes 6a, 6b on a frame member side positioned by cylindrical positioning pins 7a, 7b on a surface plate side into a square shape and machining and forming the positioning holes 6a, 6b, the positioning holes 6a, 6b are precisely aligned with the positioning pins 7a, 7b in the other parts of the hole inner peripheral faces of the positioning holes 6a, 6b, and are easily fitted into the positioning pins 7a, 7b. When positioning and fixing the frame member, it is unnecessary to apply unreasonable force, compared with a conventional example of a positioning hole having a distorted elliptical shape, and occurrence of deformation such as distortion and warping is prevented in the frame member. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a workpiece holding frame material that holds a workpiece such as a glass substrate so as to surround the outer periphery thereof, and a workpiece holder using the workpiece holding frame, and more specifically, holds a workpiece to be polished. The present invention relates to a workpiece holding frame material suitable for the above and a workpiece holder using the same.

  Some processing apparatuses, for example, polishing apparatuses, polish a workpiece using a pair of surface plates that are opposed to each other so as to be relatively rotatable in the vertical direction (see, for example, Patent Document 1). In such a polishing apparatus, when a workpiece such as a large glass substrate exceeding 1 m is polished, the back surface of the workpiece is held by, for example, a lower surface plate by a holder. A polishing pad for polishing a surface to be processed (surface) of a workpiece is attached to an opposing upper surface plate. When polishing the surface of the workpiece, the surface of the workpiece is pressed against the polishing pad and the surface plates are rotated relative to each other while supplying the polishing liquid between the surface plates.

  In the above polishing apparatus, the holding tool is arranged on the lower surface plate and surrounds the outer periphery of the workpiece in addition to the backing material that is arranged on the lower surface plate and sucks and holds the back surface of the workpiece. A holding frame member is provided that holds the workpiece in such a manner that the workpiece is not displaced from the lower surface plate during polishing. The holding frame material is fixed to the lower surface plate with double-sided tape.

  Among the holding frame members, there is a divided type shown in FIG. 9, for example. The holding frame member shown in FIG. 9 is composed of a pair of first and second divided frame members 50a and 50b, and a holding recess for holding the outer periphery of the workpiece in a space surrounded by both divided frame members 50a and 50b. It is said.

  Both the first and second divided frame members 50a and 50b are configured in a “U” shape having a katakana name in plan view. The first divided frame member 50a has a “U” shape with a katakana name in plan view, and the second divided frame member 50b has a “U” character with a 180 ° opposite direction to the first divided frame member 50a. Each of the shapes is disposed so as to face each other, so that a holding recess for the workpiece is formed between the faces. The workpiece is fitted and held in a holding recess formed by the above-described facing of the two divided frame members 50a and 50b.

  A procedure for attaching such a holding frame member 50 to a predetermined position of the lower surface plate will be described.

  In the holding frame member 50, positioning holes 60a and 60b having a circular shape are formed at two locations on each of the first and second divided frame members 50a and 50b. A cylindrical positioning pin (not shown) is provided on the lower surface plate so as to be able to appear and retract at four positions corresponding to the positioning holes 60a and 60b.

And when fixing a holding frame material to a lower surface plate, a positioning pin protrudes in four places on a lower surface plate, for example, corresponds to two positioning holes 60a of the 1st division frame material 50a. Each positioning pin is fitted and aligned, and is attached to the lower surface plate with double-sided tape. Similarly, the second divided frame material 50b is aligned and attached to the lower surface plate, and then all The positioning pin is retracted into the lower surface plate.
Japanese Patent Laid-Open No. 9-57592

  In the holding frame member having the above-described configuration, the positioning holes 60a and 60b of the two divided frame members 50a and 50b are circularly moved by piercing the holding frame member 50 with a thin drill blade and moved once around the circumference. It is formed by punching.

  In this case, the positioning hole is formed in a perfect circle shape near the drilling start point along the circumference and near the drilling end point that returns to the drilling start point, and it is difficult to avoid the drill tip from shaking. I couldn't. Therefore, the positioning holes 60a and 60b are distorted in the vicinity of the punching process start point and the punching process end point, and the positioning holes 60a and 60b are finished in a distorted non-circular shape such as an ellipse instead of a perfect circle. It has been.

  When the positioning pins are advanced toward the positioning holes 60a and 60b having the non-circular shape as described above, the outer peripheral surface of the positioning pin is made to enter while strongly pressing against the inner peripheral surfaces of the positioning holes 60a and 60b. The holding frame member 50 is deformed such as being distorted or warped by a strong force applied from the positioning pins.

  As a result, it becomes difficult to hold the outer periphery of the holding frame material 50 without shifting the position of the work piece during the polishing process. In the worst case, the work piece is displaced during the polishing process. It jumps out of the holding recess of the material 50, or cracks or cracks occur.

  In this case, it is conceivable to form the positioning holes 60a and 60b by punching without using a drill. However, in the punching of the positioning holes 60a and 60b, burrs are formed on the peripheral portions of the positioning holes 60a and 60b by punching. There is a problem that the outer periphery of the workpiece cannot be held so that the outer periphery of the workpiece can be polished with high accuracy.

  Therefore, the problem to be solved by the present invention is to provide a holding frame material and a holder equipped with the holding frame material that enable a large rectangular flat plate-like workpiece to be positioned and held with high accuracy during processing. It is.

  (1) The workpiece holding frame material according to the present invention is a workpiece holding frame material that is fixed to a surface plate of a processing apparatus and holds the outer periphery of the workpiece. A plurality of positioning holes are provided for fitting to the plurality of positioning pins protruding from the board, and the shape of these positioning holes is formed in a polygonal shape.

  The workpiece holding frame material may be held over the entire outer periphery of the workpiece, or hold at least a part of the outer periphery, for example, 1/2 or 1/4. What is necessary is just to hold | maintain the outer periphery of a to-be-processed object combining several frame materials, when holding a part in this way.

  According to the present invention, since the positioning hole is polygonal, when forming this positioning hole, for example, a thin drill blade is pierced into the frame material and sequentially aligned with each side of the polygon to make one round relative When forming the workpiece so that it is cut out, it is difficult to avoid the drill tip blurring near the starting point of the processing and the end point returning to the starting point. Is used as the starting point and ending point of machining, even if the vicinity of the one corner is slightly distorted due to the deflection of the edge of the drill, the remaining portion, especially the The intermediate part of each side of the square can be processed with high accuracy.

  Therefore, when positioning by positioning a polygonal positioning hole on the positioning pin, even if the vicinity of the one corner is distorted, it is accurately aligned at the other side portions. Therefore, unlike the conventional example where the positioning hole is shaped like a distorted ellipse, there is no need to forcibly fit the positioning pin into the positioning hole, and the workpiece holding frame material is distorted or warped. Etc. can be effectively prevented.

  (2) In another embodiment of the workpiece holding frame material of the present invention, the positioning pin has a cylindrical shape, the positioning hole has a rectangular shape, and the processing device transfers the workpiece. It is to be polished.

  In the case of this embodiment, when positioning a rectangular positioning pin by fitting a rectangular positioning hole, it can be accurately aligned and fixed to the surface plate. It is possible to suppress the occurrence of distortion, warpage, etc., which can reduce the occurrence of the workpiece jumping out of the frame material during the polishing process, or the occurrence of cracks or cracks in the workpiece. .

  (3) In a preferred embodiment of the work piece holding frame material of the present invention, the work piece holding frame material is a combination of a pair of divided frame materials, and each of the divided frame materials is a vertical extending in the vertical direction. A frame portion, and a horizontal frame portion that bends and extends from the both ends of the vertical frame portion in the same horizontal direction at substantially right angles, and is combined in a state in which the end surfaces of the horizontal frame portions are butted together. A holding recess surrounding the workpiece is formed between each other, and the positioning hole is provided in the vicinity of a bent portion formed by the vertical frame portion and the horizontal frame portion.

  In the present specification, the meaning of “vertical” and “horizontal” is not limited to the vertical and horizontal meanings seen from the operator, and one direction and the other direction intersect at right angles in the vertical direction, One of the other means the horizontal direction.

  In the case of the said embodiment, it is preferable that the horizontal frame part of each division | segmentation frame material is mutually equal. In the case of such a divided frame material, the divided frame material has a “U” shape with a katakana name in plan view.

  When the workpiece is held by the holding recess formed by the workpiece holding frame material, a large workpiece can be held, and the vicinity of the bent portion, and thus the workpiece. It is possible to align with high accuracy in the vicinity of each corner of the rectangle.

 (4) In the embodiment of (3), the shape of the positioning hole may be a rectangle whose long side extends in the direction in which the vertical frame portion of the divided frame material extends.

  The vertical frame part is preferably longer than the horizontal frame part.

  In this embodiment, by making the positioning hole shape rectangular, for example, there are some errors in the positioning accuracy of the positioning hole in the longitudinal direction of the vertical frame portion and the positioning accuracy of the positioning pin in the longitudinal direction of the surface plate. Even when there is a positioning pin, when positioning by positioning a rectangular positioning hole on the positioning pin, the workpiece holding frame material is slid in the longitudinal direction and finely adjusted to fit the error. It can be easily positioned by absorbing.

  (5) In the embodiment of the above (3), both the divided frame members are constituted by a laminated plate obtained by laminating a fiber base material obtained by weaving warp yarns extending in the longitudinal direction and weft yarns extending in the lateral direction, and a resin, The positioning hole may have a rectangular shape, and each side forming the rectangle may be formed in a direction along the direction of the warp or the direction of the weft.

  In the case of this embodiment, the rectangular sides of the positioning hole are processed and formed so as to be along the vertical direction and the horizontal direction of the fiber base material in which warp and weft are knitted together. In comparison with the above, the fluffing of the fibers can be suppressed and processing can be performed with higher accuracy, and the fluffing of fibers from the inner surface of the positioning hole can also be suppressed.

(6) In another embodiment of the work piece holding frame material of the present invention, the positioning hole is a through hole, and the opening dimension on the surface plate side is larger than the opening dimension on the side opposite to the surface plate side. It is also bigger.
The positioning hole may be tapered so that the opening size decreases from the surface on the surface plate side to the surface on the opposite side.

  In this embodiment, when positioning the positioning hole of the work piece holding frame material with the positioning pin of the surface plate, the work piece holding frame material is smoothly guided by the positioning pin and the inner surface of the positioning hole. And can be easily positioned.

 (7) The workpiece holder of the present invention is fixed on the surface plate and holds the back surface of the workpiece by suction, and is fixed on the surface plate and holds the outer periphery of the workpiece. The workpiece holding frame material according to any one of (1) to (6) above is provided.

  According to the work piece holder of the present invention, the back surface of the work piece is sucked and held by the backing material, and the work piece holding frame material holds the outer periphery of the work piece to prevent displacement and the work piece. In addition, when fixing the workpiece holding frame material to the surface plate, it is possible to suppress the occurrence of distortion or warpage in the workpiece holding frame material. It is possible to reduce the occurrence of the work piece jumping out of the work piece holding frame material and the occurrence of cracks or cracks in the work piece.

  In the present invention, since the shape of the positioning hole of the workpiece holding frame material is a polygon, a problem that occurs during the formation of the positioning hole is stopped at one corner of the inner peripheral surface of the positioning hole. The workpiece holding frame material can be accurately positioned by the remaining portion.

  In the present invention, the workpiece holding frame material is distorted or deformed when positioning the workpiece holding frame material on the surface plate like the conventional positioning hole having a shape like a distorted ellipse. Therefore, it is possible to reduce the occurrence of the position shift during the processing and the occurrence of the occurrence of cracks and cracks.

  Hereinafter, a workpiece holding frame material according to an embodiment of the present invention and a workpiece holder provided with the workpiece holding frame material will be described with reference to the accompanying drawings.

(Embodiment 1)
Referring to FIG. 1, reference numeral 1 denotes a workpiece holder according to an embodiment. The workpiece holder 1 holds a glass substrate 2 as a workpiece to be polished on a lower surface plate 3 of a polishing apparatus as a processing apparatus.

  In addition to the backing material 4 that holds the back surface of the glass substrate 2 by suction, the workpiece holder 1 surrounds the outer periphery of the glass substrate 2 so as not to be displaced and holds the glass substrate 2. A material 5 is provided.

  The backing material 4 and the workpiece holding frame material 5 are both bonded and fixed to the lower surface plate 3 with a double-sided adhesive tape (not shown).

  The backing material 4 is composed of, for example, a polyurethane resin foam sheet. The backing material 4 is bonded to the lower surface plate 3 exposed in the holding recess surrounded by the workpiece holding frame material 5 fixed to the lower surface plate 3 by the double-sided adhesive tape described above.

  The glass substrate 2 is held on the lower surface plate 3 in a state where the back surface is held by the backing material 4 and the outer periphery thereof is held by the workpiece holding frame material 5.

  The polishing pad 10 is affixed and held on the lower surface of the upper surface plate 11 that is disposed facing the upper surface of the lower surface plate 3.

  In the processing apparatus having the above-described configuration, the glass substrate is supplied by supplying the polishing liquid containing the abrasive grains between the lower surface plate 3 and the upper surface plate 11 and relatively rotating both surface plates 3 and 11. 2 (surface to be processed) can be polished by the polishing pad 10.

  FIG. 2 shows a plane of the workpiece holding frame material 5 holding the glass substrate 2. The workpiece holding frame member 5 is configured by combining two first and second divided frame members 51 and 52.

  The first divided frame member 51 has a vertical frame portion 51a extending in the vertical direction in FIG. 2 and the same right-and-left from both ends of the vertical frame portion 51a so that the shape in plan view becomes a “U” shape in Katakana. And two horizontal frame portions 51b that are bent at a right angle in the direction and extend to the same length.

  The second divided frame member 52 has a vertical frame portion that is the same length as the vertical frame portion 51a and extends in the vertical direction so that the shape in plan view is a shape that is 180 degrees opposite to the “U” shape of Katakana. 52a and two horizontal frame portions 52b that are bent at the same right-left direction from both ends of the vertical frame portion 52a and extend to the same length as the horizontal frame portion 51b.

  The first and second divided frame members 51 and 52 are arranged such that the end surfaces of the horizontal frame portions 51b and 52b are abutted with each other. With this arrangement, a rectangular holding recess 12 is formed between the first and second divided frame members 51 and 52 facing each other. For example, the holding recess 12 has such a size that a large rectangular glass substrate 2 having a vertical and horizontal dimension of 1 m × 1 m or more can be fitted and held.

  The first divided frame member 51 includes positioning holes 6a in the vicinity of two bent portions where the two horizontal frame portions 51b are bent at right angles to the vertical frame portion 51a.

  The second divided frame member 52 also includes positioning holes 6b in the vicinity of two bent portions where the two horizontal frame portions 52b are bent at right angles to the vertical frame portion 52a.

  On the other hand, in the lower surface plate 3, a total of four positioning pins (not shown in FIG. 2) are arranged in a projecting manner corresponding to each of the total of the four positioning holes 6a and 6b. These four positioning pins are configured to be able to protrude and retract from the lower surface plate 3.

  From the above, the four positioning holes 6a and 6b and the four positioning pins are formed in the vicinity of the corners of the glass substrate 2 held in the holding recess 12 formed by the workpiece holding frame material 5. Will be.

  The first and second divided frame members 51 and 52 may be made of a single layer polymer material made of polycarbonate, unilate, polyetherketone resin, crystallized polyester (with glass fiber) unilate, high molecular weight polyethylene or the like. Or, a laminate in which several layers of a fiber base material made of cloth, paper, aramid fiber, glass, tetron epoxy, carbon fiber, etc. and a resin such as epoxy resin, phenol resin, silicon resin, etc., are press-molded. You may comprise with a board.

  The thickness of the 1st, 2nd division | segmentation frame materials 51 and 52 is about several mm, for example.

  3 (a), 3 (b), and 3 (c) show the first divided frame member 51 in order to explain the attachment procedure to the lower surface plate 3 of the first and second divided frame members 51 and 52. 2 is a side view seen from the direction of arrow A in FIG. 2, and the second divided frame member 52 is a side view seen from the direction of arrow B in FIG.

  3A, 3B, and 3C show cylindrical positioning pins 7a and 7b that can be moved in and out of the lower surface plate 3. FIG. A description of the protruding and retracting mechanism of the positioning pins 7a and 7b with respect to the lower surface plate 3 is omitted. These positioning pins 7a and 7b correspond to the positioning holes 6a and 6b of the first and second divided frame members 51 and 52, respectively.

  First, as shown in FIG. 3A, the positioning pins 7 a and 7 b are projected from the lower surface plate 3.

  Next, as shown in FIG. 3B, the positioning holes 6a and 6b of the first and second divided frame members 51 and 52 are fitted to the positioning pins 7a and 7b, respectively, so that the first and second divided frame members are fitted. 51 and 52 are positioned. After this positioning, the lower surfaces of the first and second divided frame members 51 and 52 are bonded and fixed to the lower surface plate 3 with a double-sided adhesive tape (not shown). Thus, the first and second divided frame members 51 and 52 are positioned and fixed to the lower surface plate 3.

  After the positioning and fixing, as shown in FIG. 3C, the positioning pins 7a and 7b are retracted from the corresponding positioning holes 6a and 6b, respectively, and retracted into the lower surface plate 3.

  FIG. 4 shows an enlarged view of the positioning holes 6a and 6b of the first and second divided frame members 51 and 52. FIG. These positioning holes 6a and 6b are square in shape and penetrate the first and second divided frame members 51 and 52, respectively.

  Thus, as will be described later, when the positioning holes 6a and 6b of the respective divided frame members 51 and 52 are fitted to the positioning pins 7a and 7b, the divided frame members 51 are forcibly fitted and positioned. , 52 can be prevented from being distorted or warped.

  In this embodiment, as an example, the length of each side on the inner peripheral surface of the positioning holes 6a and 6b is set to 16.0 to 16.6 mm with respect to the outer diameter of 15.0 mm of the positioning pins 7a and 7b. The length of each side of 6a and 6b is made larger by about 1.0 to 1.6 mm than the outer diameter of the positioning pin 7. In addition, each side in the inner peripheral surface of the positioning holes 6a and 6b is a side view of the positioning holes 6a and 6b and each side constituting the square.

  The positioning holes 6a and 6b are cut out in the same manner as in the prior art, for example, by inserting the cutting edge of a thin drill into each of the divided frame members 51 and 52 so as to sequentially move along the square sides of the positioning holes 6a and 6b. By processing, positioning holes 6a and 6b are formed in the divided frame members 51 and 52, respectively. In this processing, as described above, it is difficult to avoid the fluctuation of the drill tip near the punching start point and the punching end point.

  Therefore, any one of the four corners on the inner peripheral surfaces of the positioning holes 6a and 6b shown in FIG. 4 is set as a hollowing start point, and the inner corner 6A is set as a hollowing end point. If the positioning holes 6a and 6b are cut into a square shape with the cutting edge, there is a very high possibility that the corner 6A will have a distorted shape due to the fluctuation of the cutting edge of the drill.

  However, in the embodiment, when positioning the cylindrical outer peripheral surface of the positioning pin 7 with the square inner peripheral surfaces of the positioning holes 6a and 6b, the outer periphery of the positioning pins 7a and 7b is positioned. The holes 6a and 6b are positioned by coming into contact with the inner peripheral surface excluding any corners 6A. As a result, since the corner 6A hardly contributes to the positioning, even if the corner 6A has a distorted shape, the positioning accuracy is not affected.

  Since the square inner peripheral surfaces of the positioning holes 6a and 6b are processed with high accuracy except for the arbitrary one corner 6A, when the positioning pins 7a and 7b are fitted into the positioning holes 6a and 6b, respectively. In addition, there is no need to forcefully fit a conventional distorted positioning hole into a positioning pin. As a result, it is possible to eliminate the occurrence of distortion or warpage due to an excessive force applied to the divided frame members 51 and 52.

  In particular, when the divided frame members 51 and 52 are formed of a laminated plate obtained by laminating and pressing a fiber base material in which the warp yarn 13 and the weft yarn 14 are knitted and a resin, as shown in FIG. Each side of the inner peripheral surfaces of the holes 6a and 6b can be processed and formed along the direction of the warp yarn 13 (vertical direction in the drawing) or the direction of the weft yarn 14 (transverse direction in the drawing).

  As a result, the fluffing of the fibers on the inner peripheral surface of the positioning hole 6 is suppressed as compared with the conventional circular positioning holes and can be processed with higher accuracy, and the fibers fluffed from the inner peripheral surface of the positioning holes 6a and 6b Dropping off is also suppressed.

  Furthermore, in the square positioning holes 6a and 6b, as shown in FIG. 5, for example, the inner peripheral surfaces thereof can be positioned by abutting at two points on the cylindrical positioning pins 7a and 7b. . Thereby, for example, one of the two positioning holes 6a in the longitudinal direction (vertical direction in the drawing) of the first divided frame member 51 shown in FIG. By bringing the pin 7a into contact with the outer peripheral surface at two points, the inner peripheral surface of the other positioning hole 6a is placed in the other positioning hole 6a with the provisional (provisional) positioning between the longitudinal direction and the direction orthogonal thereto. Positioning can be easily performed by contacting the outer peripheral surface of the positioning pin 7a at one point.

  6 is a side view of the first divided frame member 51 as viewed from the direction of arrow A in FIG. 2 in the workpiece holding frame member 5 according to another embodiment of the present invention, and the second divided frame member 52. Is shown as a side view seen from the direction of arrow B in FIG.

  In the embodiment shown in FIG. 6, the positioning holes 6 a 1 and 6 b 1 of the first and second divided frame members 51 and 52 are formed as through holes so that the hole opening dimension increases toward the lower surface plate 3. The opening size on the lower surface plate 3 side is larger than the opening size on the side opposite to the lower surface plate 3 side.

  When positioning the inner peripheral surfaces of the positioning holes 6a1 and 6b1 of the first and second divided frame members 51 and 52 on the outer peripheral surfaces of the positioning pins 7a and 7b of the lower surface plate 3, respectively. Can be positioned smoothly using the tapered shape.

  Further, the backing material 4 may be wider than the workpiece holding frame material 5. In this case, an insertion hole through which the positioning pin is inserted is formed in the backing material 4 to hold the workpiece. What is necessary is just to fix to the lower surface plate 3 ahead of the frame material 5.

  Further, in order to eliminate the fluff of fibers on the inner peripheral surface of the positioning hole, the inner peripheral surface may be processed, for example, heat treatment, resin coating, or sandpaper polishing.

  FIG. 7 is a plan view of a workpiece holding frame member according to still another embodiment of the present invention, and FIG. 8 is a partially enlarged view of FIG. However, FIG. 8 shows both the positioning holes 6a2 and 6b2 of the first and second divided frame members 51 and 52 of FIG. Referring to these drawings, positioning holes 6a2 and 6b2 are formed in the first and second divided frame members 51 and 52, respectively. The positioning holes 6a2 and 6b2 have a rectangular shape.

  Each divided frame member 51, 52 has vertical frame portions 51a, 52a and horizontal frame portions 51b, 52b extending from both ends of the vertical frame portions 51a, 52a in the same manner as in the above-described embodiment. Although each of the positioning holes 6a2 and 6b2 is formed into a rectangular shape that is long in the longitudinal direction of the vertical frame portions 51a and 52a (vertical direction in FIGS. 7 and 8), for example, The long side is 17.6 mm and the short side is 16 mm. The length of the long side is preferably within 1.1 times the length of the short side.

  Thus, by making the shape of the positioning holes 6a2 and 6b2 rectangular, for example, the processing accuracy in the longitudinal direction of the positioning holes 6a2 and 6b2 of the divided frame members 51 and 52 and the positioning pins 7a and 7b of the lower surface plate 3 are used. Even when there is a slight error in the positional accuracy in the longitudinal direction, the first and the second when the rectangular positioning holes 6a2 and 6b2 are fitted to the positioning pins 7a and 7b of the lower surface plate 3 for positioning. By sliding the two-divided frame members 51 and 52 while making fine adjustments by sliding them in the longitudinal direction, the error can be easily absorbed and positioned.

  Other configurations are the same as those in the first embodiment.

  Hereinafter, the present invention will be described in more detail based on examples.

  The divided frame materials corresponding to the above-described Embodiments 1 and 2 are Examples 1 and 2, and the conventional divided frame material is a comparative example, and a glass substrate is held by a workpiece holder using the divided frame material. Polishing was performed to evaluate the occurrence frequency of cracks in the glass substrate.

  The divided frame material of Example 1 formed square positioning holes with a side of 16 mm, and the divided frame material of Example 2 formed rectangular positioning holes with a long side of 17.6 mm and a short side of 16 mm. Moreover, the comparative example which is a prior art example formed the circular positioning hole whose internal diameter is 16 mm.

All of the divided frame materials were made of glass fiber reinforced epoxy resin plates, and R601 manufactured by Nitta Haas was used as the backing material. The outer diameter of the positioning pin of the surface plate of the polishing apparatus is 15 mm, and the polishing pad is Suba640D52 manufactured by Nitta Haas, and lime glass is used for 5 minutes and 30 seconds (with water only for 15 seconds) under a polishing pressure of 300 gf / cm ^2. Polishing (thickness 0.7 mm) was performed.

  As a result, the occurrence frequency of cracks with respect to the total number of polished sheets of 7000 was 1.2% in Example 1, 0.8% in Example 2, and 2.3% in the comparative example, which is a conventional example. It was.

  In the comparative example, the frequency of occurrence of cracks is 2.3%, whereas in Example 1 having a square positioning hole, the frequency of occurrence of cracks is 1.2%, which is approximately half that of the comparative example. Furthermore, in Example 2 having a rectangular positioning hole, the occurrence frequency of cracks is 0.8%, which is reduced to about 1/3 of the comparative example.

  Thus, it can be seen that in the divided frames of Examples 1 and 2, the defect rate of the glass substrate is remarkably improved as compared with the divided frame of the conventional example.

  It is useful for improving productivity by reducing the occurrence of defects such as cracks and cracks in polishing glass substrates for liquid crystal displays.

FIG. 1 is a cross-sectional view of a state in which a workpiece is held on a lower surface plate by a workpiece holder according to an embodiment of the present invention. FIG. 2 is a plan view of the workpiece holding frame member in a state where the glass substrate is held. FIG. 3A is a side view showing a state immediately before the division frame member is attached to the lower surface plate, and FIG. 3B is a side view showing a state where the positioning pins are fitted in the positioning holes in the attached state. FIG. 3C is a side view showing a state in which the positioning pin is retracted out of the positioning hole in the same attachment state. FIG. 4 is a partially enlarged view near the positioning hole. FIG. 5 is a diagram showing a contact state between the positioning hole and the positioning pin. FIG. 6 is a side view corresponding to FIG. 3 of another embodiment of the present invention. FIG. 7 is a plan view corresponding to FIG. 2 of still another embodiment of the present invention. FIG. 8 is a partially enlarged view of the vicinity of the positioning hole in FIG. FIG. 9 is a plan view of a conventional workpiece holding frame member.

Explanation of symbols

1 Workpiece Holder 2 Glass Substrate (Workpiece)
3 Lower surface plate 4 Backing material 5 Workpiece holding frame material 51 First divided frame material 52 Second divided frame material 6a, 6b Positioning hole
7a, 7b Positioning pin

Claims (7)

In the workpiece holding frame that is fixed to the surface plate of the processing device and holds the outer periphery of the workpiece,
The workpiece holding frame member includes a plurality of positioning holes that fit into the plurality of positioning pins protruding from the surface plate, and the shape of the positioning holes is formed in a polygon. Workpiece holding frame material. The positioning pin has a cylindrical shape,
The positioning hole has a rectangular shape,
The processing device is for polishing the workpiece.
The workpiece holding frame material according to claim 1. The workpiece holding frame material is a combination of a pair of divided frame materials,
Each of the divided frame members includes a vertical frame portion extending in the vertical direction, and a horizontal frame portion extending by bending at substantially the same horizontal direction from both ends of the vertical frame portion. The positioning hole is formed in the vicinity of the bent portion formed by the vertical frame portion and the horizontal frame portion, which is combined with the end surfaces of the frame portions being butted together to form a holding recess surrounding the workpiece. The workpiece holding frame material according to claim 1, wherein:   The workpiece holding frame material according to claim 3, wherein a shape of the positioning hole is a rectangle whose long side extends in a direction in which the vertical frame portion of the divided frame material extends.   Both divided frame members are composed of a laminated board in which a fiber base material and a resin in which warp yarns extending in the longitudinal direction and weft yarns extending in the lateral direction are knitted together, and the shape of the positioning hole is a rectangular shape. The workpiece holding frame material according to claim 3 or 4, wherein each side formed is formed in a direction along the direction of the warp or the direction of the weft.   6. The positioning hole according to claim 1, wherein the positioning hole is a through hole, and an opening dimension on the surface plate side is larger than an opening dimension on the side opposite to the surface plate side. Workpiece holding frame material described in 1.   The backing material which is fixed on the surface plate and holds the back surface of the work piece by suction, and the outer periphery of the work piece which is fixed on the surface plate and holds the work piece. A workpiece holding tool comprising: a workpiece holding frame material.

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