Flatness measuring instrument for the upper surface of double-sided polishing equipment

Abstract

To provide an upper platen flatness measuring instrument for a double-sided polisher capable of easily measuring flatness of an upper platen of a double-sided polishing device without removing the upper platen from the double-sided polishing device.SOLUTION: In a state where one end of a dial gauge support device 46 is latched at an outer peripheral edge of an upper platen 16 via a first latch device 50 and the other end of the dial gauge support device 46 is latched at the outer peripheral edge of the upper platen 16 via a second latch device 56 and a third latch device 58, flatness of the upper platen 16 is measured using a first dial gauge 42 and a second dial gauge 44 fixed to the dial gauge support device 46. Since it is not necessary to press an upper plate flatness measuring instrument 40 from a lower side of the upper platen 16 to a bottom face of the upper platen 16, a worker does not go in under the upper platen 16 which is a heavy object, such that the work is made safe. Further, the flatness of the upper platen 16 can be easily measured without removing the upper platen 16 from a double-sided polishing device 12.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an upper plate span gauge for measuring the flatness of a lower platen of a double-side polishing machine used to mirror-polish both sides of a workpiece such as a semiconductor substrate. [Background technology]

[0002] When the workpiece is a semiconductor substrate such as a single crystal wafer of silicon, silicon carbide, gallium arsenide, InP (indium phosphide), etc., it is desirable to have both sides mirror-polished to a high degree of flatness.

[0003] For example, as described in Patent Document 1, a double-sided polishing machine includes a lower platen and an upper platen disposed opposite the lower platen at a predetermined distance. In order to polish a workpiece with high flatness, it is necessary to measure and manage the flatness of the lower platen, the upper platen, or the polishing pads attached to their polishing surfaces. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7218830 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, when measuring the flatness of the upper platen of a surface polishing apparatus such as that described in Patent Document 1 or the polishing pad attached to its polishing surface, the upper platen is lifted to a high position to greatly expand the space between the lower platen and the upper platen, thereby exposing the upper platen. In this case, a flatness measuring instrument is pressed against the lower surface of the upper platen from below, which requires the operator to enter under the heavy upper platen, resulting in a dangerous operation. Furthermore, when measuring the flatness from above a soft polishing pad attached to the upper platen, it is difficult to maintain a constant pushing force of the flatness measuring instrument, making it virtually impossible to measure. Therefore, the upper platen must be removed from the double-sided polishing apparatus and the flatness of the upper platen inverted outside the surface polishing apparatus must be measured, which poses a problem of laborious measurement of the flatness of the upper platen.

[0006] The present invention was made against the background of the above circumstances, and its purpose is to provide an upper platen flatness measuring device for a double-sided polishing machine that can easily measure the flatness of the upper platen of a double-sided polishing machine without removing the upper platen from the double-sided polishing machine. [Means for solving the problem]

[0007] The gist of the present invention is an upper surface plate flatness measuring device for a double-sided polishing machine having a lower surface plate and an upper surface plate disposed opposite the lower surface plate at a predetermined distance, the upper surface plate flatness measuring device measuring the flatness of the upper surface plate, the upper surface plate comprising: (b) a dial gauge support device that supports a plurality of first dial gauges at positions spaced apart by a predetermined distance along the diameter of the upper surface plate on one side of the center of rotation of the upper surface plate and a plurality of second dial gauges at positions spaced apart by a predetermined distance on the other side of the center of rotation of the upper surface plate; (c) a first hooking device that hooks one end of the dial gauge support device onto the outer periphery of the upper surface plate; and (d) a second hooking device that hooks one end of the dial gauge support device onto the outer periphery of the upper surface plate. Two locations spaced apart around the periphery of the upper surface plate and a second latching device and a third latching device that latch the portions to the outer periphery of the upper surface plate, respectively. [Effects of the Invention]

[0008] According to the flatness measuring device for the upper surface plate of the double-side polishing machine of the present invention, one end of the dial gauge support device is hooked to the outer periphery of the upper surface plate by the first hooking device, and the other end of the dial gauge support device is hooked to the outer periphery of the upper surface plate by the second hooking device and the third hooking device. Two locations spaced apart around the periphery of the upper surface plate The first and second dial gauges are each hooked to the outer periphery of the upper surface plate. In this manner, one end of the dial gauge support device is hooked to the outer periphery of the upper surface plate via the first hooking device, and the other end of the dial gauge support device is hooked to the outer periphery of the upper surface plate via the second hooking device and the third hooking device. With this, the flatness of the upper surface plate is measured using the first and second dial gauges fixed to the dial gauge support device. This eliminates the need to press the upper surface plate flatness measuring instrument upward toward the underside of the upper surface plate from below, thereby eliminating the need for a worker to enter under the heavy upper surface plate, resulting in safer work. Furthermore, the flatness of the upper surface plate can be easily measured without removing the upper surface plate from the double-sided polishing machine.

[0009] Preferably, a dial gauge support device is provided at one end thereof. No. 1 a dial gauge for adjusting a reference surface, and a pair of dial gauges provided at the other end of the dial gauge support device at positions spaced apart in the circumferential direction of the upper surface plate; Dial gauge for adjusting the second reference plane and dial gauge for adjusting the third reference plane and the first hooking device has a first adjusting screw for adjusting the gap between one end of the dial gauge support device and the upper surface plate, and the second hooking device and the third hooking device are configured to hook the pair of hooks at the other end of the dial gauge support device. Dial gauge for adjusting the second reference plane and dial gauge for adjusting the third reference plane The second and third adjustment screws are provided to adjust the distance between the upper surface plate and the portion where the upper surface plate is provided. No. 1 Dial gauge for adjusting the reference plane, pair Dial gauge for adjusting the second reference plane and dial gauge for adjusting the third reference plane However, by manipulating the dial gauge support device and the upper surface plate so that they are parallel to each other, the dial gauge support device suspended from the upper surface plate via the first hanging device, the second hanging device and the third hanging device can be set so that it is parallel to the upper surface plate, making it possible to easily measure the flatness of the upper surface plate. [Brief explanation of the drawings]

[0010] [Figure 1] 5 is a schematic diagram conceptually showing the basic configuration of a double-side polishing machine to which the upper surface plate flatness measuring device of FIG. 4 is applied. [Figure 2] 2 is a diagram showing a carrier provided in the double-side polishing apparatus of FIG. 1. FIG. [Figure 3] 2 is a view illustrating a state in which an upper surface plate of the double-side polishing apparatus of FIG. 1 is lifted up when measuring the flatness of the upper surface plate. FIG. [Figure 4] FIG. 1 is a front view illustrating an upper surface plate flatness measuring device according to an embodiment of the present invention. [Figure 5] 5 is a bottom view illustrating the upper surface plate flatness measuring device of FIG. 4. FIG. [Figure 6] 6 is a front view illustrating the configuration of the first, second, and third latching devices of FIG. 5. FIG. [Figure 7] 7 is a bottom view illustrating the configurations of the first, second, and third latching devices of FIG. 6. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] An application example of the present invention will be described in detail below with reference to the drawings. [Example]

[0012] FIG. 1 conceptually illustrates the main components of a double-sided polishing machine 12 to which an upper surface plate flatness measuring device 40, an example of the present invention, is applied. In FIG. 1, the double-sided polishing machine 12 includes a lower surface plate 14 and an upper surface plate 16, which are rotatably supported about a vertical rotation center line C1 and are arranged facing each other at a predetermined distance. A sheet-like polishing pad 14a is attached to the upper surface of the lower surface plate 14, and a sheet-like polishing pad 16a is attached to the lower surface of the upper surface plate 16. The polishing pad 14a attached to the upper surface of the lower surface plate 14 and the polishing pad 16a attached to the lower surface of the upper surface plate 16 function as planarized polishing surfaces for polishing both surfaces of a workpiece 28.

[0013] A surface plate driving device 18 is provided below the lower surface plate 14. The surface plate driving device 18 drives the lower surface plate 14 to rotate about the rotation center line C1, and also drives the upper surface plate 16 to rotate about the rotation center line C1 in the opposite direction to the lower surface plate 14 via an upper surface plate driving cylinder 20. The upper surface plate driving cylinder 20 protrudes from the lower surface plate 14 and is fitted into a central hole 16b of the upper surface plate 16 so as to be unable to rotate relative to it. A sun gear 24 that meshes with the outer peripheral teeth of the carrier 22 is formed on the upper surface plate driving cylinder 20.

[0014] A ring gear 26, which is an annular member having internal teeth 26a formed thereon, is fixed concentrically with the lower surface plate 14 on the outer periphery of the lower surface plate 14.

[0015] The carrier 22 is interposed between the polishing pad 14a on the lower surface plate 14 and the polishing pad 16a on the upper surface plate 16. The carrier 22 is, for example, a circular plate as shown in FIG. 2 , and has a through hole 30 into which a workpiece 28 such as a semiconductor substrate is fitted, and outer teeth 22a. The outer teeth 22a of the carrier 22 are meshed with the inner teeth 26a of the sun gear 24 and the ring gear 26. As a result, both sides of the workpiece 28 fitted in the through hole 30 of the carrier 22 are polished while the carrier 22 revolves and rotates on the lower surface plate 14 in accordance with the rotation of the sun gear 24. The workpiece 28 has a thickness greater than that of the carrier 22.

[0016] 3 shows a state in which the upper surface plate 16 is lifted upward by a suspension device (not shown) when measuring the flatness of the lower surface of the upper surface plate 16. With the lower surface plate 14 and the upper surface plate 16 thus separated, an upper surface plate flatness measuring instrument 40 is used to measure the flatness of the lower surface of the upper surface plate 16.

[0017] Fig. 4 shows a front view of the upper surface plate flatness measuring instrument 40, and Fig. 5 shows a plan view of the upper surface plate flatness measuring instrument 40. The upper surface plate flatness measuring instrument 40 in Fig. 5 is shown with a plurality of first dial gauges 42, three in this embodiment, and a plurality of second dial gauges 44, three in this embodiment, removed.

[0018] The upper surface plate flatness measuring device 40 is attached to the lower surface of the upper surface plate 16 while the upper surface of the upper surface plate 16 is rotating. When the core wire C1 and the center of the upper surface plate flatness measuring device 40 or the dial gauge support device 46 are placed concentrically, three first dial gauges 42 are placed on one side of the rotation center line C1 in the radial direction of the upper surface plate 16, and three second dial gauges 44 are placed on the other side of the rotation center line C1. The contacts 42a of the first dial gauges 42 and the contacts 44a of the second dial gauges 44 are fixed in one direction, that is, in such a way that they are parallel to each other on the underside of the upper surface plate 16 when attached to the upper surface plate 16. The dial gauge support device 46 includes a first latching device 50 that latches a portion of one end of the dial gauge support device 46 where a first reference surface adjustment dial gauge 48 is provided onto the outer periphery of the upper surface plate 16, and a pair of second latching devices 56 and third latching devices 58 that latch two circumferentially separated portions of the other end of the dial gauge support device 46 where a pair of second reference surface adjustment dial gauges 52 and a pair of third reference surface adjustment dial gauges 54 are provided onto the outer periphery of the upper surface plate 16, respectively.

[0019] The dial gauge support device 46 comprises a first dial gauge fixing portion 60 on which three first dial gauges 42 are fixed at positions spaced at regular intervals along a first straight line L1 passing through the rotation center line C1 on the underside of the upper surface plate 16, a second dial gauge fixing portion 62 on which three second dial gauges 44 are fixed at positions spaced at regular intervals along a second straight line L2 linearly connected to the first straight line L1, and a pair of first dial gauge fixing portions 60 and 62 connected between the ends of the first dial gauge fixing portion 60 and the second dial gauge fixing portion 62 that are close to each other, and which fix the first dial gauges 44 at regular intervals along a second straight line L2 linearly connected to the first straight line L1. The upper surface plate 16 is provided with a longitudinal connecting portion 64 that integrally connects the dial gauge fixing portion 60 and the second dial gauge fixing portion 62 to each other, a first reference surface adjusting dial gauge 48 provided at one of both end portions of the first dial gauge fixing portion 60 that is farther from the second dial gauge fixing portion 62, and a pair of second reference surface adjusting dial gauges 52 and 54 provided at two locations spaced apart in the circumferential direction of the upper surface plate 16 at one of both end portions of the second dial gauge fixing portion 62 that is farther from the first dial gauge fixing portion 60.

[0020] The first line L1 and the second line L2 are located on a common diameter that passes through the rotation center line C1 of the upper surface of the lower surface plate 14. The first dial gauge fixing portion 60 has a first dial gauge fixing portion main body 66 whose width dimension gradually increases toward the rotation center line C1 of the upper surface plate 16. The first dial gauge fixing portion main body 66 is fastened to one end of a longitudinal connecting portion 64 with a first connecting screw 68, thereby integrally connecting the first dial gauge fixing portion main body 66 to the connecting portion 64. A first dial gauge fixing member 70, to which three first dial gauges 42 are fixed, is stacked and fixed to the first dial gauge fixing portion main body 66 with a first screw 72.

[0021] The first dial gauge fixing member 70 is provided with a plurality of gauge fixing holes 74 along the first straight line L1, into which three first dial gauges 42 are inserted and fixed with set screws 74. The gauge fixing holes 74 are formed at equal intervals that are shorter than the spacing between the first dial gauges 42, and the number of the gauge fixing holes 74 is greater than the number of the first dial gauges 42.

[0022] The second dial gauge fixing portion 62 has a second dial gauge fixing portion main body 76 formed in a fan shape whose width increases the further away from the rotation center line C1 of the upper surface plate 16. The second dial gauge fixing portion main body 76 is integrally connected to the connecting portion 64 by fastening the end of the second dial gauge fixing portion main body 76 on the first dial gauge fixing portion 60 side to the other end of the connecting portion 64 with a second connecting screw 78. A second dial gauge fixing member 80, to which three second dial gauges 44 are fixed, is stacked and fixed to the second dial gauge fixing portion main body 76 with a second screw 82.

[0023] Similar to the first dial gauge fixing member 70, the second dial gauge fixing member 80 is provided with a plurality of gauge fixing holes 86 along the first straight line L1, into which three second dial gauges 44 are inserted and fixed with set screws 84. The gauge fixing holes 86 are formed at equal intervals that are shorter than the spacing between the second dial gauges 44, and the number of the gauge fixing holes 86 is greater than the number of the second dial gauges 44.

[0024] The connecting portion 64 comprises a linear connecting member 88 whose opposite ends are connected to the first dial gauge fixing portion main body 66 and the second dial gauge fixing portion main body 76 by a first connecting screw 68 and a second connecting screw 78, and a reinforcing plate 92 fixed to the side of the connecting member 88 by seven fastening screws 90. The reinforcing plate 92 is fixed to the connecting member 88 in a direction parallel to the rotation center line C1.

[0025] The first latching device 50, the second latching device 56, and the third latching device 58 are configured similarly, and therefore the first latching device 50 will be described as a representative. As shown in Fig. 6, the first latching device 50 includes a block-shaped upper arm 96 on which a micrometer 94 is erected and which is hooked onto the upper surface of the upper surface plate 16 via a contact (screw) 94a of the micrometer 94, a plate-shaped lower arm 98 which is hooked onto the lower surface of the first dial gauge fixing portion main body 66, and an arm connecting post 100 which connects one end of the upper arm 96 and one end of the lower arm 98, and is formed into a U-shape or hook-shape as a whole.

[0026] A U-shaped notch 102 is formed in the plate-like lower arm 98 at a position corresponding to the micrometer 94 provided on the upper arm 96. The U-shaped notch 102 is for fitting the first reference plane adjusting dial gauge 48 into when the dial gauge support device 46 is suspended from the upper surface plate 16, and positions the contact 48a of the first reference plane adjusting dial gauge 48 and the contact 94a of the micrometer 94 concentrically. In the second latching device 56, the contact 52a of the second reference plane adjusting dial gauge 52 and the contact 94a of the micrometer 94 are concentrically positioned, and in the third latching device 58, the contact 54a of the third reference plane adjusting dial gauge 54 and the contact 94a of the micrometer 94 are concentrically positioned.

[0027] The micrometer 94 of the first hanging device 50 functions as a first adjustment screw that adjusts the distance between one end of the dial gauge support device 46 and the upper surface plate 16, and the micrometer 94 of the second hanging device 56 and the micrometer 94 of the third hanging device 58 function as a second adjustment screw and a third adjustment screw that adjust the distance between the other end of the dial gauge support device 46 and the upper surface plate 16.

[0028] One reference surface creating support 110 is erected at the outer peripheral end of the first dial gauge fixing unit body 66, and two reference surface creating support 110 are erected at two circumferentially spaced locations on the outer peripheral end of the second dial gauge fixing unit body 76. Each of these reference surface creating support 110 has a diameter of, for example, about 5 mm and a tip with a radius of about 2.5 mm. The three reference surface creating support 110, each with such a shape, create a reference surface by contacting the granite surface plate. Furthermore, when the three reference surface creating support 110 come into contact with the polishing pad 14a on the surface of the upper surface plate 16, they can sink into the polishing pad 14a.

[0029] The upper surface plate flatness measuring device 40 configured as described above is set upright on the first dial gauge fixing portion 60 and the second dial gauge fixing portion 62 on a highly flat reference surface plate made of granite, for example, and is supported by three reference surface creating supports 110 of the same height with rounded tips. With the first dial gauge fixing portion 60 and the second dial gauge fixing portion 62 of the dial gauge support device 46 parallel to the reference surface plate, the indications of the first dial gauges 42 and the second dial gauges 44 and the first reference surface adjusting dial gauge 48, the second reference surface adjusting dial gauge 52, and the third reference surface adjusting dial gauge 53 are aligned. The indications of the first dial gauge 48 for adjusting a reference plane, the second dial gauge 52 for adjusting a reference plane, and the third dial gauge 54 for adjusting a reference plane are set to zero in advance, for example. Next, the dial gauge support device 46 is suspended from the upper surface plate 16 by the first hooking device 50, the second hooking device 56, and the third hooking device 58 so that the rotation center line C1 of the underside of the upper surface plate 16 and the center of the dial gauge support device 46 are concentric. By operating the micrometer 94, the indications of the first dial gauge 48, the second dial gauge 52, and the third dial gauge 54 for adjusting a reference plane are set to zero, and the indications of the first dial gauge 42 and the second dial gauge 44 are read to measure the flatness of the upper surface plate 16. At this time, the three reference surface creating supports 110 with rounded tips do not dig into the hard granite surface plate but can dig into the soft polishing pad on the surface of the upper surface plate 16, making it easy to adjust the first dial gauge 48 for adjusting a reference plane to zero.

[0030] As described above, according to the upper surface plate flatness measuring device 40 of the double-side polishing apparatus 12 of this embodiment, one end of the dial gauge support device 46 is hooked to the outer periphery of the upper surface plate 16 by the first hooking device 50, and the portions of the other end of the dial gauge support device 46 where the pair of second reference surface adjustment dial gauges 52 and third reference surface adjustment dial gauges 54 are provided are respectively hooked to the outer periphery of the upper surface plate 16 by the second hooking device 56 and the third hooking device 58. In this manner, with one end of the dial gauge support device 46 hooked to the outer periphery of the upper surface plate 16 by the first hooking device 50 and the other end of the dial gauge support device 46 hooked to the outer periphery of the upper surface plate 16 by the second hooking device 56 and the third hooking device 58, the flatness of the upper surface plate 16 is measured using the multiple first dial gauges 42 and multiple second dial gauges 44 fixed to the dial gauge support device 46. This eliminates the need to press the upper surface plate flatness measuring device 40 upward from below the upper surface plate 16 toward the underside of the upper surface plate 16, making the work safer and eliminating the need for the worker to get under the heavy upper surface plate 16. In addition, it becomes possible to easily measure the flatness of the upper surface plate 16 without removing the upper surface plate 16 from the double-sided polishing apparatus 12.

[0031] The upper surface plate flatness measuring device 40 of the double-side polishing apparatus 12 of this embodiment is provided with a first reference surface adjusting dial gauge 48 provided at one end of the dial gauge support device 46, and a pair of second reference surface adjusting dial gauges 52 and third reference surface adjusting dial gauges 54 provided at the other end of the dial gauge support device 46 at positions spaced apart circumferentially of the upper surface plate 16, and the first hanging device 50 has a micrometer (first adjustment screw) 94 for adjusting the distance between one end of the dial gauge support device 46 and the upper surface plate 16, and the second hanging device 56 and the third hanging device 58 each have a micrometer (second adjustment screw and third adjustment screw) 94 for adjusting the distance between the portion at the other end of the dial gauge support device 46 where the pair of second reference surface adjusting dial gauges 52 and third reference surface adjusting dial gauges 54 are provided and the upper surface plate 16, respectively. As a result, when the dial gauge support device 46 is hung on the upper surface plate 16, the micrometers (first adjustment screw, second adjustment screw and third adjustment screw) 94 of the first hanging device 50, second hanging device 56 and third hanging device 58 are operated so that the first reference surface adjustment dial gauge 48, the pair of second reference surface adjustment dial gauges 52 and the third reference surface adjustment dial gauge 54 indicate that the dial gauge support device 46 and the upper surface plate 16 are parallel to each other.This makes it possible to set the dial gauge support device 46, which is suspended from the upper surface plate 16 via the first hanging device 50, second hanging device 56 and third hanging device 58, so that it is parallel to the upper surface plate 16, and makes it possible to easily measure the flatness of the upper surface plate 16.

[0032] Although one embodiment of the present invention has been described above, the present invention can also be applied in other aspects.

[0033] For example, the upper surface plate flatness measuring device 40 in the above-mentioned embodiment was equipped with three first dial gauges 42 and three second dial gauges 44, but it may also be equipped with four or more first dial gauges 42 and four or more second dial gauges 44.

[0034] Furthermore, the first dial gauge 42 and each second dial gauge 44 provided on the upper surface plate flatness measuring device 40 may be of a mechanical type or an electronic type.

[0035] Furthermore, although the first dial gauge fixing portion 60 of the upper surface plate flatness measuring instrument 40 in the above-described embodiment was composed of the first dial gauge fixing portion main body 66 and the first dial gauge fixing member 70 fixed thereto, the first dial gauge fixing portion main body 66 and the first dial gauge fixing member 70 may be composed of an integral member. Similarly, the second dial gauge fixing portion 62 was composed of the second dial gauge fixing portion main body 76 and the second dial gauge fixing member 80 fixed thereto, but the second dial gauge fixing portion main body 76 and the second dial gauge fixing member 80 may be composed of an integral member.

[0036] Although not specifically exemplified, the present invention can be used with various modifications within the scope of the invention. [Explanation of symbols]

[0037] 12: Double-sided polishing machine 14: Lower surface plate 14a: Polishing pad 16: Upper surface plate 16a: Polishing pad 18: Surface plate driving device 20: Upper surface plate driving cylinder 22: Carrier 22a: Peripheral teeth 24: Sun gear 26: Ring gear 26a: Inner teeth 28: Part to be polished 30:Through hole 40: Upper surface plate flatness measuring instrument 42: First dial gauge 42a: Contact 44: Second dial gauge 44a: Contactor 46: Dial gauge support device 48: Dial gauge for first reference adjustment 50: 1st latching device 52: Dial gauge for second reference adjustment 54: Third reference adjustment dial gauge 56:Second latching device 58: Third latching device 60: First dial gauge fixing part 62: Second dial gauge fixing part 64:Connection part 66: First dial gauge fixing part body 68: First connecting screw 70: First dial gauge fixing member 72: First screw 73: Push screw 74: Gauge fixing hole 76: Second dial gauge fixing part body 78: Second connecting screw 80: Second dial gauge fixing member 82: Second screw 84: Push screw 86: Gauge fixing hole 88: Longitudinal connecting member 90: Fastening screw 92: Reinforcement plate 94: Micrometer (adjustment screw) 94a: Contactor 96: Upper arm 98: Lower arm 100: Arm connecting column 102: U-shaped notch 110: Reference plane creation support C1: Center line of rotation

Claims

1. A double-sided polishing machine includes a lower polishing plate and an upper polishing plate disposed opposite the lower polishing plate at a predetermined distance, and the upper polishing plate flatness measuring device measures the flatness of the upper polishing plate, a dial gauge support device that supports a plurality of first dial gauges at positions spaced apart by a predetermined distance on one side of the rotation center of the upper surface plate along the diameter of the upper surface plate, and supports a plurality of second dial gauges at positions spaced apart by a predetermined distance on the other side of the rotation center of the upper surface plate; a first hooking device that hooks one end of the dial gauge support device onto the outer periphery of the upper surface plate; a second latching device and a third latching device that latch two portions of the other end of the dial gauge support device, which are spaced apart in the circumferential direction of the upper surface plate, onto the outer circumferential edge of the upper surface plate, respectively.

1. A flatness measuring device for an upper surface plate of a double-side polishing machine.

2. a first reference surface adjusting dial gauge provided at one end of the dial gauge support device; a pair of second and third reference surface adjustment dial gauges provided at the other end of the dial gauge support device at positions spaced apart in the circumferential direction of the upper surface plate, the first hooking device has a first adjustment screw for adjusting the gap between one end of the dial gauge support device and the upper surface plate, The second and third hooking devices have second and third adjustment screws, respectively, for adjusting the distance between the upper surface plate and a portion of the other end of the dial gauge support device where the pair of second and third reference surface adjusting dial gauges are provided.

2. The flatness measuring device for an upper surface plate of a double-side polishing machine according to claim 1.

Images