Thickness measuring device

Abstract

The present invention provides a thickness measuring device that simplifies the adjustment of the mounting position and mounting angle of a distance meter. [Solution] The present invention is a thickness measuring device that measures the thickness of a measurement object based on the distances to the front and back of the measurement object measured by first and second non-contact distance meters DM1 and DM2. The first holding member 1 comprises a first outer cylinder 11, a first inner cylinder 12 that holds the first non-contact distance meter DM1 at its first tip and is fitted into the first outer cylinder 11, a first tilt adjustment part for adjusting the tilt of the first inner cylinder 12, and a first outer cylinder holding member for adjusting the position of the first outer cylinder 12. The diameter of the first inner and outer cylinders 11 and 12 decreases as the first tip portion approaches the first tip. The second holding member 2 comprises a second outer cylinder 21, a second inner cylinder 22 that holds the second non-contact distance meter DN2 at its second tip and is fitted into the second outer cylinder 21, and a first tilt adjustment part for adjusting the tilt of the second inner cylinder 22. 2 It is equipped with a tilt adjustment section, and the diameter of each of the second inner and outer cylinders 21 and 22 decreases as the second tip portion approaches the second tip.

Description

Technical Field

[0001] The present invention relates to a thickness measuring device for measuring the thickness of a measurement object.

Background Art

[0002] There are various known thickness measuring devices that measure the thickness of a measurement object by sandwiching the measurement object between a pair of first and second rangefinders facing each other and measuring the first distance from the first rangefinder to one side of the measurement object and the second distance from the second rangefinder to the other side of the measurement object, respectively (for example, Patent Document 1 and Patent Document 2, etc.).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the thickness measuring device having the above configuration, if the first measurement point by the first rangefinder and the second measurement point by the second rangefinder in the measurement object do not face each other on the one side and the other side, accurate measurement values cannot be obtained. For this reason, it is necessary to adjust the attachment positions and attachment angles of the first and second rangefinders so that the first line segment along the first measurement direction of the first rangefinder and the second line segment along the second measurement direction of the second rangefinder coincide. The adjustment takes a great deal of time and effort.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a thickness measuring device that can simplify the adjustment of the attachment positions and attachment angles of the first and second rangefinders. [Means for solving the problem]

[0006] As a result of various studies, the inventors have found that the above objective can be achieved by the present invention as described below. That is, a thickness measuring device according to one aspect of the present invention is a device for measuring the thickness of a plate-shaped object to be measured, comprising: a first non-contact distance meter for measuring a first distance from one side of the object to be measured without contact; a second non-contact distance meter disposed in front of the first non-contact distance meter with a predetermined space between them, for measuring a second distance from the other side of the object to be measured without contact; a thickness calculation unit for determining the thickness of the object to be measured based on the first and second distances measured by the first and second non-contact distance meter, respectively, and a third distance between the first and second non-contact distance meter; a first holding member for holding the first non-contact distance meter; and a second holding member for holding the second non-contact distance meter, wherein the first holding member comprises a first outer cylinder and a first tip facing the space for holding the first non-contact distance meter. The first outer cylinder is fitted inside the first inner cylinder, the first tilt adjustment part is for adjusting the tilt when fixing the first inner cylinder, and the first inner cylinder holding member is for adjusting the position of the first inner cylinder in a direction perpendicular to the central axis of the first inner cylinder while holding the first inner cylinder, and the first outer cylinder and the first inner cylinder each have a shape in which the diameter decreases as the first tip portion approaches the first tip, and the second holding member comprises a second outer cylinder, a second inner cylinder fitted inside the second outer cylinder and holding the second non-contact distance meter at the second tip facing the space, and a second tilt adjustment part is for adjusting the tilt when fixing the second inner cylinder, and the second outer cylinder and the second inner cylinder each have a shape in which the diameter decreases as the second tip portion approaches the second tip.

[0007] Such a thickness measuring device comprises a first outer cylinder, a first inner cylinder holding a first non-contact distance meter at its first tip, a first tilt adjustment unit for adjusting the tilt when fixing the first inner cylinder, and a first inner cylinder holding member for adjusting the position of the first inner cylinder in a direction perpendicular to the central axis of the first inner cylinder while holding the first inner cylinder, wherein the first outer cylinder and the first inner cylinder each have a shape in which the diameter decreases as the first tip portion approaches the first tip, and a second outer cylinder comprises a second inner cylinder holding a second non-contact distance meter at its second tip, and a second tilt adjustment unit for adjusting the tilt when fixing the second inner cylinder, wherein the second outer cylinder and the second inner cylinder each have a shape in which the diameter decreases as the second tip portion approaches the second tip. Therefore, in the above-mentioned thickness measuring device, by assembling the first and second inner cylinders with a predetermined assembly precision, adjusting the tilt of the central axis of the first inner cylinder using the first tilt adjustment unit, adjusting the tilt of the central axis of the second inner cylinder using the second tilt adjustment unit, and adjusting the position of the first inner cylinder using the first inner cylinder holding member so that the central axes of the first inner cylinder and the second inner cylinder coincide, the first non-contact distance meter is positioned to be narrowed, and the second non-contact distance meter is positioned to be narrowed, so that the first and second non-contact distance meter can be assembled to face each other with a positioning precision corresponding to the predetermined assembly precision. Accordingly, the above-mentioned thickness measuring device simplifies the adjustment of the mounting position and mounting angle of the first and second non-contact distance meter.

[0008] In another embodiment, the thickness measuring device described above further comprises a light irradiation unit that irradiates light onto at least one of the first measurement point of the first non-contact distance meter and the second measurement point of the second non-contact distance meter, each of which is a capacitive displacement sensor.

[0009] When the object to be measured is a silicon wafer in which oxygen donors have not been removed by heat treatment, and the first and second non-contact distance meters are both capacitive displacement sensors, measurement errors occur due to changes in electrical resistance caused by the oxygen donors, as disclosed in Patent Document 2. The above thickness measuring device is equipped with a light irradiation unit, which allows light to be irradiated onto the silicon wafer, thereby converting the valence electrons of the silicon wafer into conduction electrons, and thus eliminating the measurement errors. When the above thickness measuring device irradiates light onto the first measurement point, the first outer cylinder and the first inner cylinder each have a shape in which the diameter decreases as the first tip portion approaches the first tip, so that the first holding member does not obstruct the irradiation of light, and the irradiation of light is made easier. When the above thickness measuring device irradiates light onto the second measurement point, the second outer cylinder and the second inner cylinder each have a shape in which the diameter decreases as the second tip portion approaches the second tip, so that the second holding member does not obstruct the irradiation of light, and the irradiation of light is made easier.

[0010] In another embodiment, the thickness measuring device further includes a moving unit that moves the object to be measured and the first and second non-contact distance meters relative to each of the plurality of measurement points on the object to be measured, so that the first and second distances can be measured with the first and second non-contact distance meters, respectively, and the thickness calculation unit further determines the thickness distribution by determining the thickness of each of the plurality of measurement points.

[0011] Such a thickness measuring device can determine the thickness at each of multiple measurement points, thus enabling the measurement of the thickness distribution of the object being measured. [Effects of the Invention]

[0012] The thickness measuring device according to the present invention simplifies the adjustment of the mounting position and mounting angle of the first and second distance meters, respectively. [Brief explanation of the drawing]

[0013] [Figure 1] This is a side view showing the structural configuration of the thickness measuring device in the embodiment. [Figure 2] This is a top view showing the structural configuration of the thickness measuring device. [Figure 3] This is a rear view showing the structural configuration of the thickness measuring device with the main support member, upper mounting member, and lower mounting member removed. [Figure 4] This figure shows the structural configuration of the thickness measuring device as viewed from cross-section II shown in Figure 3. [Figure 5] This figure shows the structural configuration of the first holding member in the thickness measuring device. [Figure 6] This figure shows the structural configuration of the second holding member in the thickness measuring device. [Figure 7] This figure shows the structural configuration of the first and second outer cylinders in the first and second holding members of the thickness measuring device. [Figure 8] This is a block diagram showing the electrical configuration of the thickness measuring device. [Modes for carrying out the invention]

[0014] Hereinafter, one or more embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the disclosed embodiments. In each figure, components denoted by the same reference numerals are identified as identical components, and their descriptions are omitted where appropriate. In this specification, general reference numerals are used without subscripts, while individual components are indicated by subscripts.

[0015] FIG. 1 is a side view showing the structural configuration of the thickness measuring device in the embodiment. FIG. 2 is a top view showing the structural configuration of the thickness measuring device. FIG. 3 is a rear view showing the structural configuration of the thickness measuring device in a state where the main support member, the upper mounting member, and the lower mounting member are removed. FIG. 4 is a view showing the structural configuration of the thickness measuring device as seen from the I-I cross section shown in FIG. 3. FIG. 5 is a view showing the structural configuration of the first holding member in the thickness measuring device. FIG. 5A is a top view, FIG. 5B is a side view, and FIG. 5C is a cross-sectional view taken at the II-II cross section shown in FIG. 5B. FIG. 6 is a view showing the structural configuration of the second holding member in the thickness measuring device. FIG. 6A is a bottom view, FIG. 6B is a side view, and FIG. 6C is a cross-sectional view taken at the III-III cross section shown in FIG. 6B. FIG. 7 is a view showing the structural configuration of the first and second outer cylinders in the first and second holding members of the thickness measuring device. Since the first and second outer cylinders 11 and 21 are identical in shape and size to each other, only the first outer cylinder 11 is shown in FIG. 7. FIG. 7A is a top view, and FIG. 7B is a side view. FIG. 8 is a block diagram showing the electrical configuration of the thickness measuring device. In these FIGS. 1 to 7, for the purpose of showing the correspondence of each figure, for example, an xyz orthogonal coordinate system with the height direction (axial direction, thickness direction) as the z-axis is shown. In FIG. 1, the left-right direction of the paper surface is taken as the y-axis, and the front-back direction of the paper surface (depth direction of the paper surface) is taken as the x-axis. In the following description, this xyz orthogonal coordinate system is referred to as appropriate as necessary.

[0016] The thickness measuring device 1000 in the embodiment includes, for example, as shown in FIGS. 1 to 8, a first non-contact distance meter DM1, a second non-contact distance meter DM2, a first light irradiation unit LS1 (LS1-1, LS1-2), a second light irradiation unit LS2 (LS2-1, LS2-2), a first light intensity measurement unit LM1, a second light intensity measurement unit LM2, a control processing unit CL, a storage unit ME, a first holding member 1, and a second holding member 2. In this embodiment, further, an input unit IN, an output unit OU, and an interface unit (IF unit) IO are provided.

[0017] The first non-contact distance meter DM1 is electrically connected to the control processing unit CL and measures, in a non-contact manner, the first distance from one surface of the plate-like measurement object according to the control of the control processing unit CL. The first non-contact distance meter DM1 outputs the first distance of its measurement result to the control processing unit CL. The second non-contact distance meter DM2 is electrically connected to the control processing unit CL and measures, in a non-contact manner, the second distance from the other surface of the measurement object according to the control of the control processing unit CL. The second non-contact distance meter DM2 outputs the second distance of its measurement result to the control processing unit CL. Each of these first and second non-contact distance meters DM1 and DM2 is, for example, a capacitance displacement sensor, an eddy current displacement sensor, a laser displacement sensor, a confocal displacement sensor, or the like. In the present embodiment, a capacitance displacement sensor is used from the viewpoint of noise reduction. The first non-contact distance meter DM1 and the second non-contact distance meter DM2 are arranged so as to face each other with a space of a predetermined interval (first interval) so that the measurement object can be disposed between them.

[0018] The first light irradiation unit LS1 (LS1-1, LS1-1) is electrically connected to the control processing unit CL and is a device that irradiates light onto one surface of the measurement object according to the control of the control processing unit CL. As will be described later, the first light irradiation unit LS1 irradiates light from two symmetric points along the x-axis direction for one light irradiation location, and thus includes two first A and first B light irradiation units LS1-1 and LS1-2. The first A and first B light irradiation units LS1-1 and LS1-2 are configured to include, for example, white light emitting diodes or the like.

[0019] The first light intensity measurement unit LM1 is electrically connected to the control processing unit CL and measures, according to the control of the control processing unit CL, the intensity of the light (first light intensity) irradiated onto one surface of the measurement object by the first A and first B light irradiation units LS1-1 and LS1-2. The first light intensity measurement unit LM1 is configured to include, for example, a photodiode or the like. The first light intensity measurement unit LM1 outputs the first light intensity of its measurement result to the control processing unit CL.

[0020] The second light irradiation unit LS2 (LS2-1, LS2-1) is electrically connected to the control processing unit CL and is a device that irradiates light onto the other side of the object to be measured according to the control of the control processing unit CL. As will be described later, the second light irradiation unit LS1 irradiates light from two symmetrical points along the x-axis for a single light irradiation point, and therefore comprises two second A and second B light irradiation units LS2-1 and LS2-2. The second A and second B light irradiation units LS2-1 and LS2-2 are configured with, for example, white light-emitting diodes.

[0021] The second light intensity measuring unit LM2 is electrically connected to the control processing unit CL and, in accordance with the control of the control processing unit CL, measures the intensity of light (second light intensity) irradiated onto the other side of a plate-shaped object to be measured by the second A and second B light irradiation units LS2-1 and LS2-2. The second light intensity measuring unit LM2 is configured with, for example, a photodiode. The second light intensity measuring unit LM2 outputs the measured second light intensity to the control processing unit CL.

[0022] The first holding member 1 is a member for holding the first non-contact distance meter DM1, and in this embodiment, it comprises a first outer cylinder 11 and a first inner cylinder 12 that holds the first non-contact distance meter DM1 at a first tip facing the space and is fitted inside the first outer cylinder 11. The first outer cylinder 11 and the first inner cylinder 12 each have a shape in which the diameter decreases as the first tip portion approaches the first tip. The second holding member 2 is a member for holding the second non-contact distance meter DM2, and in this embodiment, it comprises a second outer cylinder 21 and a second inner cylinder 22 that holds the second non-contact distance meter DM2 at a second tip facing the space and is fitted inside the second outer cylinder 21. The second outer cylinder 21 and the first inner cylinder 22 each have a shape in which the diameter decreases as the second tip portion approaches the second tip.

[0023] Since the first outer cylinder 11 of the first retaining member 1 and the second outer cylinder 21 of the second retaining member 2 have the same structure, the following description will mainly focus on the first outer cylinder 11 of the first retaining member 1. The description of the second outer cylinder 21 of the second retaining member 2 will be omitted by listing the reference numerals for the configuration of the second outer cylinder 21 of the second retaining member 2 in parentheses after the reference numerals for the configuration of the first outer cylinder 11 of the first retaining member 1 that correspond to the configuration of the second outer cylinder 21 of the second retaining member 2.

[0024] The first outer cylinder 11(21) is, mainly as shown in FIG. 7, a hollow frustum-shaped (tapered) member having a predetermined height (length) DC11(DC21) along the z-axis direction. The first outer cylinder 11(21) includes one end 111(211) with a relatively small outer diameter DM11(DM21) and the other end 112(212) that faces the one end 111(211) in the z-axis direction and has a relatively large outer diameter DM12(DM22) (DM11(DM21) < DM12(DM22)). In the portion of this other end 112(212), the outer diameter is constant at DM12(DM22) for a predetermined height (length) DC13(DC23) along the z-axis direction. That is, in this portion, it has a hollow cylindrical shape (i.e., a cylindrical shape) (DC11(DC21) > DC13(DC23)). In this other end 112(212) portion, in this embodiment, a pair of first and second flat surfaces 114a(214a), 114b(214b) are formed so as to face each other along the x-axis direction in order to make it easier to grip the first outer cylinder 11(21) with a tool (not shown, clamping tool) for gripping the first outer cylinder 11(21). Therefore, in this example, at the other end 112(212), the first outer cylinder 11(21) is not circular. The first outer cylinder 11(21) has a first A taper portion 113 (second A taper portion 213) whose outer diameter gradually decreases as it approaches the one end 111(211) along the z-axis direction from the end of the cylindrical shape with a constant diameter at the outer diameter DM12(DM22). Therefore, the outer surface of the first A taper portion 113 (second A taper portion 213) is an inclined surface (taper surface). Inside the first outer cylinder 11(21), a substantially cylindrical cavity 115(215) that is in communication and forms a through-opening along the z-axis direction is formed.The cavity 115 (215) is formed from the other end 112 (212) for a predetermined height (length) DC14 (DC24) along the z-axis, in a cylindrical shape with an inner diameter DM15 (DM25) (DM15 (DM25)<DM12(DM22)、DC14(DC24)> DC13 (DC23), in this example, the inner diameter DM15 (DM25) is the same diameter as the outer diameter DM11 (DM21). From one end 111 (211) to a predetermined height (length) DC12 (DC22) along the z-axis, the inner diameter is formed to be slightly smaller than the aforementioned inner diameter which is the same diameter as the outer diameter DM11 (DM21), and gradually decreases along the z-axis toward one end 111 (211) until it becomes the inner diameter DM13 (DM11 (DM21) > DM14 (DM24), DM14 > DM13). For this reason, from one end 111 (211) to a predetermined height (length) DC12 (DC22) along the z-axis, the inner surface 116 (216) of the cavity 115 (15) is an inclined surface (tapered surface). At the other end 112(212), the cavity 115(215) opens with an inner diameter DM15(DM25). At the other end 111(211), the cavity 115(215) opens with an inner diameter DM13(DM23). The first outer cylinder 11(21) has a screw groove 1131(2131) formed on its inner surface from the other end 112(212) to a predetermined height (length) DC15(DC25) along the z-axis.

[0025] The first inner cylinder 12, as mainly shown in Figure 5, has a generally cylindrical shape and consists of a first flange portion 121, a first inner cylinder body portion 122, and a first tip portion 123. The first flange portion 121 is connected to the first base end side of the first inner cylinder body portion 122, and the first tip portion 123 is connected to the first tip side of the first inner cylinder body portion 122. More specifically, the first flange portion 121 has a generally annular plate shape with an outer diameter DN11 that is larger than the outer diameter DN12 of the first cylindrical body portion 122, and has four screw holes 1211a to 1211d for attaching the first inner cylinder 12 to the y-axis adjustment plate member 34 described later by screw fastening. These four screw holes 1211a to 1211d are formed at equal intervals along the circumferential direction and are through openings that extend along the z-axis direction. The first flange portion 121 has four set screw holes 1213a to 1213d for fine-tuning the inclination of the first inner cylinder 12 with respect to the y-axis adjustment plate member 34. These four set screw holes 1213a to 1213d are formed at equal intervals along the circumferential direction and each is a through opening extending along the z-axis direction. The first flange portion 121 has four notches 1212a to 1212d formed at equal intervals along the circumferential direction to avoid the two x-axis adjustment screws in the x-axis adjustment plate member 33 and the two y-axis adjustment screws in the y-axis adjustment plate member 34, which will be described later. The first inner cylinder body portion 122 has a cylindrical shape extending along the z-axis direction. The first tip portion 123 is shorter than the first inner cylinder body portion 122 and has a substantially cylindrical shape extending along the z-axis direction, and is connected to the first inner cylinder body portion 122 via a constricted portion 1234. The first tip portion 123 has a first B tapered portion 1232 whose outer diameter gradually decreases as it approaches the first tip 1231 along the z-axis. The first B inclination angle of the outer circumferential surface of this first B tapered portion 1232 with respect to the z-axis is the same as the first A inclination angle of the inner circumferential surface of the first A tapered portion 113 of the first outer cylinder 11 with respect to the z-axis. A cylindrical cavity 124 is formed inside the first flange portion 121, the first inner cylinder body portion 122, and the first tip portion 123, communicating along the z-axis and forming a through opening.In the cavity 124 in the 1B taper portion 1232, a portion with an inner diameter DN14 slightly smaller than the inner diameter DN13 of the cavity 124 in the first flange portion 121 and the first inner cylinder body portion 122 is formed. The cavity 124 opens at the first tip 1231 with an inner diameter DN14 (DN14 < DN13). This inner diameter DN14 is substantially the same as the outer diameter of the first non-contact distance meter DM1. The first tip 1231 has an outer diameter DN15 (DN14 < DN15). The outer diameter DN15 of the first inner cylinder 12 is smaller than the inner diameter DM13 of the first outer cylinder 11 (DN15 < DM13). Four slit-shaped slit grooves (cuts) 1233a to 1233d are formed in the first tip portion 123. Each of these four slit grooves 1233a to 1233d extends along the z-axis direction and is formed by being cut along the radial direction. The four slit grooves 1233a to 1233d are formed at equal intervals along the circumferential direction. Each of the four slit grooves 1233a to 1233d extends slightly along the z-axis direction up to the first inner cylinder body portion 122. Threads 1221 are formed on the outer peripheral surface of the region of the first inner cylinder body portion 122 close to the first tip portion 123.

[0026] As mainly shown in FIG. 6, the second inner cylinder 22 generally has a cylindrical shape and consists of a second flange portion 221, a second inner cylinder body portion 222, and a second tip portion 223. A second flange portion 211 is connected and formed on the second base end side of the second inner cylinder body portion 222, and a second tip portion 223 is connected and formed on the second tip side of the second inner cylinder body portion 222. More specifically, the second flange portion 221 has an annular plate shape with an outer diameter DN21 larger than the outer diameter DN22 of the second cylindrical body portion 222, and four screw holes 2211a to 2211d are formed for screwing and attaching the second inner cylinder 22 to the bottom plate member 41. These four screw holes 2211a to 2211d are formed at equal intervals along the circumferential direction and are through openings extending along the z-axis direction respectively. Four set screw holes 2213a to 2213d are formed in the second flange portion 221 for finely adjusting the inclination of the second inner cylinder 22 with respect to the bottom plate member 41. These four set screw holes 2213a to 2213d are formed at equal intervals along the circumferential direction and are through openings extending along the z-axis direction respectively. The second inner cylinder body portion 222 has a cylindrical shape extending along the z-axis direction. The second tip portion 223 has a substantially cylindrical shape shorter than the second inner cylinder body portion 222 and extending along the z-axis direction, and is connected to the second inner cylinder body portion 222 via a constricted portion 2234. The second tip portion 223 has a second B taper portion 2232 with a shape in which the outer diameter gradually decreases as it approaches the second tip 2231 along the z-axis direction. The second B inclination angle of the outer peripheral surface of the second B taper portion 2232 with respect to the z-axis is the same as the second A inclination angle of the inner peripheral surface of the second A taper portion 213 of the second outer cylinder 21 with respect to the z-axis. Inside the second flange portion 221, the second inner cylinder body portion 222, and the second tip portion 223, a cylindrical cavity 224 is formed which is axially communicating and is a through opening. In the cavity 224 of the second B taper portion 2232, a portion with an inner diameter DN24 slightly smaller than the inner diameter DN23 of the cavity 224 in the second flange portion 221 and the second inner cylinder body portion 222 is formed (DN24 < DN23). This inner diameter DN24 is substantially the same as the outer diameter of the second non-contact distance meter DM2.The cavity 224 opens at the second tip 2231 with an inner diameter DN24. The second tip 2231 has an outer diameter DN25 (DN24 < DN25). The outer diameter DN25 of the second inner cylinder 22 is smaller than the inner diameter DM23 of the second outer cylinder 21 (DN25 < DM23). Four slit-shaped slit grooves (cuts) 2233a to 2233d are formed in the second tip portion 223. Each of these four slit grooves 2233a to 2233d extends along the z-axis direction and is formed by being cut along the radial direction, and the four slit grooves 2233a to 2233d are formed at equal intervals along the circumferential direction. Each of the four slit grooves 2233a to 2233d extends slightly along the z-axis direction up to the second inner cylinder main body portion 222. Threads 2221 are formed on the outer peripheral surface of the region of the second inner cylinder main body portion 222 close to the second tip portion 223.

[0027] As can be seen from the above, the first inner cylinder 12 and the second inner cylinder 22 are of the same size and the same shape (DN11 = DN21, DN12 = DN22, DN13 = DN23, DN14 = DN24, DN15 = DN25), except that notch portions 1212a to 1212d are formed in the first flange portion 121 while such notch portions are not formed in the second flange portion 221.

[0028] These first and second holding members 1 and 2 are supported by the main support member 3. As mainly shown in FIGS. 1 to 4, this main support member 3 includes a support main body member 31, a top plate member 32, an x-axis direction adjustment plate member 33, a y-axis direction adjustment plate member 34, a pair of first and second upper side wall members 35a and 35b, a pair of first and second upper light irradiation part support members 36a and 36b, an upper light intensity measurement part support member 37, an upper attachment member 38, a bottom plate member 41, a pair of first and second lower side wall members 42a and 42b, a pair of first and second lower light irradiation part support members 43a and 43b, a lower light intensity measurement part support member 44, a lower attachment member 45, and a standing member 46.

[0029] The upper mounting member 38 is a rectangular plate-like member, and its length along the x-axis is longer than the outer diameter DN11 of the first flange portion 121 in the first inner cylinder 12. In other words, the upper mounting member 38 has a predetermined size that is wider than the outer diameter DN11 of the first flange portion 121.

[0030] The first and second upper side wall members 35a and 35b are each trapezoidal plate-shaped members. The first and second upper side wall members 35a and 35b are attached to the upper mounting member 38 with their long sides facing upward and their short sides facing downward, extending along the y-axis. More specifically, the first upper side wall member 35a is fixed to the upper mounting member 38 by screwing it to one of a pair of first and second sides of the upper mounting member 38 that face each other in the x-axis direction, with two firsta and seconda screws SC1a and SC2a spaced apart along the z-axis at a predetermined interval (first interval). The second upper side wall member 35b is fixed to the upper mounting member 38 by screwing it to the other side of the first and second sides of the upper mounting member 38 with two firstb and secondb screws SC1b and SC2b spaced apart along the z-axis at the first interval, so as to face the first upper side wall member 35a in the x-axis direction.

[0031] The top plate member 32 is a rectangular plate-like member that holds the first inner cylinder 12 via an x-axis adjustment plate member 33 and a y-axis adjustment plate member 34. The length of the top plate member 32 along the y-axis is longer than the length of each long side of the first and second upper side wall members 35a and 35b. The top plate member 32 is positioned inside each portion of each long side (each long side portion) of the first and second upper side wall members 35a and 35b, and is screwed to the long side portion of the first upper side wall member 35a with two thirda and fourtha screws SC3a and SC4a at a predetermined interval (second interval) along the y-axis, and to the long side portion of the second upper side wall member 35b with two thirdb and fourthb screws SC3b and SC4b at a second interval along the y-axis, thereby fixing it to the first and second upper side wall members 35a and 35b. In the front portion of the top plate portion 32 in the y-axis direction, a circular through-opening (first through-opening) is formed, with a center point (first center point) located at the center position in the x-axis direction and on a center line extending along the y-axis direction, and an inner diameter that is larger than the outer diameter DN12 of the first inner cylinder body portion 122 of the first inner cylinder 12 and smaller than the outer diameter DN11 of the first flange portion 121. The inner diameter of this first through-opening is not approximately the same as the outer diameter DN12 of the first inner cylinder body portion 122, but is larger than the outer diameter DN12 of the first inner cylinder body portion 122 so that the first inner cylinder 12 can move along the x-axis direction by the x-axis direction adjustment plate member 32 and the first inner cylinder 12 can move along the y-axis direction by the y-axis direction adjustment plate member 32.

[0032] The x-axis direction adjustment plate member 33 is a rectangular plate-like member for adjusting the position in the x-axis direction of the first inner cylinder 12, and its length along the y-axis direction is shorter than the length of the top plate member 32, for example, half the length of the top plate member 32. The x-axis direction adjustment plate member 33 has a circular through-opening (second through-opening) formed therein, with its approximate center position (the intersection of two diagonals) as the center point (second center point), and having approximately the same diameter as the outer diameter DN12 of the first inner cylinder body portion 122 of the first inner cylinder 12. The x-axis direction adjustment plate member 33 has oval screw holes (x-position adjustment screw holes) AP1a and AP1b extending in the x-axis direction formed in the first and second corner portions, which are two diagonal portions of the four corner portions of the x-axis direction adjustment plate member 33. The widths in the y-axis direction of each of these x-position adjustment screw holes AP1a and AP1b are longer than the diameters of the threaded portions of the 5a and 5b screws SC5a and SC5b, respectively, and shorter than the diameters of the heads of these screws. Therefore, the x-axis direction adjustment plate member 33 is screwed and fixed to the top plate member 32 by the 5a and 5b screws SC5a and SC5b, but by loosening the 5a and 5b screws SC5a and SC5b, it is movable in the x-axis direction relative to the top plate member 32, and its position in the x-axis direction can be adjusted.

[0033] The y-axis direction adjustment plate member 34 is a roughly rectangular plate-shaped member for adjusting the y-axis position of the first inner cylinder 12, and its length along the y-axis direction is slightly shorter than the length of the x-axis direction adjustment plate member 33. The y-axis direction adjustment plate member 33 has a circular through-opening (third through-opening) formed therein, with its approximate center position (the intersection of two diagonals) as the center point (third center point), and having a diameter approximately the same as the outer diameter DN12 of the first inner cylinder body portion 122 of the first inner cylinder 12. Of the four corner portions (corner portions) of the y-axis direction adjustment plate member 33, notches are formed in each portion corresponding to the first and second corner portions of the x-axis direction adjustment plate member 33 so as to allow operation of the 5a and 5b screws SC5a and SC5b, and the remaining two third and fourth corner portions have oval screw holes (y-position adjustment screw holes) AP2a and AP2b extending in the y-axis direction. The widths in the x-axis direction of each of these y-position adjustment screw holes AP2a and AP2b are longer than the diameters of the threaded portions of the 6a and 6b screws SC6a and SC6b, respectively, and shorter than the diameters of the heads of these screws. Therefore, the y-axis direction adjustment plate member 33 is screwed and fixed to the x-axis direction adjustment plate member 33 by the 6a and 6b screws SC6a and SC6b, but by loosening the 6a and 6b screws SC6a and SC6b, it is possible to move it in the y-axis direction relative to the top plate member 32 (x-axis direction adjustment plate member 33), and adjust its position in the y-axis direction.

[0034] The first inner cylinder 12 is inserted through the third through-opening of the y-axis direction adjustment plate member 34, with its first tip portion 123 and first inner cylinder body portion 122 being aligned with the respective notches 1212a and 1212c formed in the first flange portion 121, and is fixed to the y-axis direction adjustment plate member 34 by screwing it with four 7a to 7d screws SC7a to SC7d. The first tip portion 123 and first inner cylinder body portion 122 of the first inner cylinder 12 are inserted through the second through-opening of the x-axis direction adjustment plate member 33, with the respective notches formed in the y-axis direction adjustment plate member 34 being aligned with the respective first and second corner portions of the x-axis direction adjustment plate member 33, and are temporarily fixed to the x-axis direction adjustment plate member 33 by screw 6a and 6b screws SC6a and SC6b. The first tip portion 123 and the first inner cylinder body portion 122 of the first inner cylinder 12 are inserted through the first through-opening of the top plate member 32 and temporarily fastened to the top plate member 32 with screws SC5a and SC5b, respectively. The adjustment of the x-position in the x-axis direction and the y-position in the y-axis direction will be described later.

[0035] The first and second upper light irradiation support members 36a and 36b are members for supporting the first light irradiation units LS1-1 and LS1-2. More specifically, the first and second upper light irradiation support members 36a and 36b are L-shaped plate members, each having, in a side view (viewed from the x-axis direction), a mounting portion (first mounting portion) extending in the x-axis direction and a support portion (first support portion) connected to the first mounting portion and extending in the y-axis direction. In a rear view (viewed from the y-axis direction), the first support portion is bent diagonally inward (inward of the pair of first and second upper side wall members 35a and 35b) at approximately its center in the y-axis direction. The first upper light irradiation support member 36a is fixed to the first upper side wall member 35a by screwing it to its first mounting portion, and the first light irradiation unit LS1-1 is fixed to the diagonally bent portion (bent portion) of the first support portion by screwing it to it. The bending angle of this bent portion is adjusted so that the first light irradiation unit LS1-1 can irradiate the light irradiation point on one side of the plate-shaped object being measured. Similarly, the second upper light irradiation support member 36b is fixed to the second upper side wall member 35b by screws at its first mounting portion, and the first light irradiation unit LS1-2 is fixed to the bent portion of the first support portion by screws. The bending angle of this bent portion is adjusted so that the first light irradiation unit LS1-2 can irradiate the light irradiation point on one side of the plate-shaped object being measured. Note that the first light irradiation units LS1-1 and LS1-2 are not shown in Figure 2.

[0036] The upper light intensity measuring unit support member 37 is a member for supporting the first light intensity measuring unit LM1. More specifically, the upper light intensity measuring unit support member 37 is an L-shaped plate-like member that, when viewed from the side (viewed from the x-axis direction), has a mounting portion (second mounting portion) extending in the x-axis direction and a support portion (second support portion) connected to the second mounting portion and extending in the y-axis direction. The upper light intensity measuring unit support member 37 is fixed to the upper mounting member 38 by screws at the second mounting portion, and the first light intensity measuring unit LM1 is fixed to the second support portion by screws so that it is sandwiched between the upper light intensity measuring unit support member 37 and the upper light intensity measuring unit holding member 39, so that the intensity of light (first light intensity) irradiated onto one side of a plate-shaped object to be measured can be measured. Note that the first light intensity measuring unit LM1 is not shown in Figures 1 to 4.

[0037] The upper mounting member 38, which assembles the pair of first and second upper side wall members 35a, 35b, the top plate member 32, the x-axis adjustment plate member 33, the y-axis adjustment plate member 34, the pair of first and second upper light irradiation support members 36a, 36b, and the upper light intensity measuring support member 37, is attached and fixed to the support body member 31 by four first to fourth bolts BT11, BT12, BT21, and BT22.

[0038] The lower mounting member 45 is a rectangular plate-like member, and its length along the x-axis is longer than the outer diameter DN21 of the second flange portion 221 in the second inner cylinder 22. In other words, the lower mounting member 45 has a predetermined size that is wider than the outer diameter DN21 of the second flange portion 221.

[0039] The first and second lower side wall members 42a and 42b are each rectangular plate-shaped members. The first and second lower side wall members 42a and 42b are each attached to the lower mounting member 45 so as to extend along the y-axis. More specifically, the first lower side wall member 42a is fixed to the lower mounting member 45 by screwing it to one of a pair of third and fourth sides of the lower mounting member 45 that face each other in the x-axis direction with two 11a and 12a screws SC11a and SC12a spaced apart along the z-axis direction (third spacing). The second lower side wall member 42b is fixed to the lower mounting member 45 by screwing it to the other side of the third and fourth sides of the lower mounting member 45 so as to face the first lower side wall member 42a in the x-axis direction with two 11b and 12b screws SC11b and SC12b spaced apart along the z-axis direction (third spacing).

[0040] The bottom plate member 41 is a rectangular plate-like member that holds the second inner cylinder 22. The bottom plate member 41 is positioned inside the first and second lower side wall members 42a and 42b, and is screwed to the first lower side wall member 42a with two 13a and 14a screws SC13a and SC14a at a predetermined interval (fourth interval) along the y-axis, and screwed to the second lower side wall member 42b with two 13b and 14b screws SC13b and SC14b at a fourth interval along the y-axis, thereby fixing it to the first and second lower side wall members 42a and 42b. When the second inner cylinder 22 is attached to the support body member 31 by the bottom plate member 41 and the lower mounting member 45, it is fixed in place by screwing it with four 15a to 15d screws SC15a to SC15d while finely adjusting the inclination of the second inner cylinder 22 so that its central axis is perpendicular to the bottom plate member 41, so that it is approximately facing the first inner cylinder 12. To finely adjust the inclination of the second inner cylinder 22 so that it is exactly vertical, an external sensor such as a spirit level is used, and the 15d set screws SB15a to SB15d are manually operated while referring to the measured value.

[0041] The first and second lower light irradiation support members 43a and 43b are members for supporting the second light irradiation units LS2-1 and LS2-2. More specifically, the first and second lower light irradiation support members 43a and 43b are L-shaped plate members, respectively, when viewed from the side (viewed from the x-axis direction), having a mounting portion (third mounting portion) that extends in the x-axis direction and a support portion (third support portion) connected to the third mounting portion and extending in the y-axis direction. When viewed from the rear (viewed from the y-axis direction), the third support portion is bent diagonally inward (inward of the pair of first and second lower side wall members 42a and 42b) at approximately its center in the y-axis direction. The first lower light irradiation support member 43a is fixed to the first lower side wall member 42a by screwing it to its third mounting portion, and the second light irradiation unit LS2-1 is fixed to the diagonally bent portion (bent portion) of the third support portion by screwing it to it. The bending angle of this bent portion is adjusted so that the second light irradiation unit LS2-1 can irradiate the light irradiation point on the other side of the plate-shaped object being measured. Similarly, the second lower light irradiation support member 42b is fixed to the second lower side wall member 42b by screws at its third mounting portion, and the second light irradiation unit LS2-2 is fixed to the bent portion of the third support portion by screws. The bending angle of this bent portion is adjusted so that the second light irradiation unit LS2-2 can irradiate the light irradiation point on the other side of the plate-shaped object being measured.

[0042] The lower light intensity measuring unit support member 44 is a member for supporting the second light intensity measuring unit LM2. More specifically, the lower light intensity measuring unit support member 44 is an L-shaped plate-like member that, when viewed from the side (viewed from the x-axis direction), has a mounting portion (fourth mounting portion) extending in the x-axis direction and a support portion (fourth support portion) connected to the fourth mounting portion and extending in the y-axis direction. The lower light intensity measuring unit support member 44 is fixed to the lower mounting member 45 by screws at the fourth mounting portion, and the second light intensity measuring unit LM2 is fixed to the fourth support portion by screws via a spacer 47 for adjusting the height so that the second light intensity measuring unit LM2 is sandwiched between the lower light intensity measuring unit support member 44 and the lower light intensity measuring unit holding member 47, so that the intensity of light (second light intensity) irradiated on the other side of a plate-shaped object to be measured can be measured. Note that the second light intensity measuring unit LM2 is not shown in Figures 1 to 4.

[0043] The lower mounting member 45, which assembles the pair of first and second lower side wall members 42a, 42b, the bottom plate member 41, the pair of first and second lower light irradiation support members 43a, 43b, and the lower light intensity measuring support member 44, is attached and fixed to the support body member 31 by four fifth to eighth bolts BT31, BT32, BT41, and BT42.

[0044] The upper mounting member 38 is attached to the support body member 31 at a predetermined upper height position, and the lower mounting member 45 is attached to the support body member 31 at a predetermined lower height position, so that a space is formed between the first non-contact distance meter DM1 held by the first inner cylinder 12 and the second non-contact distance meter DM2 held by the second inner cylinder 22, allowing a plate-shaped object to be measured to be sandwiched between them without contact.

[0045] Thus, to ensure that the support body member 31, to which the upper mounting member 38, to which the first and second upper side wall members 35a, 35b, top plate member 32, x-axis adjustment plate member 33, y-axis adjustment plate member 34, first and second upper light irradiation support members 36a, 36b, and upper light intensity measuring support member 37 are attached, is equipped with a support body member 31 to which the lower mounting member 45, to which the first and second lower side wall members 42a, 42b, bottom plate member 41, first and second lower light irradiation support members 43a, 43b, and lower light intensity measuring support member 44 are attached, is equipped with an upright member 46, which is a long, narrow rectangular plate-shaped member, is attached to the lower end of the support body member 31.

[0046] In the first and second holding members 1 and 2, which are supported by the main support member 3, the x position is adjusted, the y position is adjusted, and the first and second non-contact distance meters DM1 and DM2 are held, as follows.

[0047] First, a jig (position adjustment jig) is prepared, which is a cylindrical member having an outer diameter approximately the same as the inner diameter DN14 of the cavity 124 of the first inner cylinder 12 and the inner diameter DN24 of the cavity 224 of the second inner cylinder 22.

[0048] Next, the first outer cylinder 11 is attached to the first inner cylinder 12, and the second outer cylinder 21 is attached to the second inner cylinder 22. If attachment is difficult, at least one of the upper mounting member 38 and the lower mounting member 45 may be temporarily removed from the support body member 31, and then reattached to the support body member 31 after the above attachment.

[0049] Next, the temporarily fastened screws SC5a and SC5b, which were previously fastened, are loosened so that the x-axis adjustment plate member 33 can move in the x-axis direction, and the temporarily fastened screws SC6a and SC6b, which were previously fastened, are loosened so that the y-axis adjustment plate member 34 can move in the y-axis direction.

[0050] Next, in this state, the position adjustment jig is inserted into the cavity 124 of the first inner cylinder 12, and further inserted into the cavity 224 of the second inner cylinder 22. The inclination of the first inner cylinder 12 with respect to the y-axis adjustment plate member 34 is finely adjusted by using four set screws SB7a to SB7d so that the position adjustment jig aligns with the z-axis direction, while the x-axis adjustment plate member 33 is moved in the x-axis direction and the y-axis adjustment plate member 34 is moved in the y-axis direction. Whether or not the position adjustment jig aligns with the z-axis direction can be determined, for example, by whether or not the position adjustment jig can move smoothly up and down (can move along the z-axis direction). If the position adjustment jig can move smoothly up and down, it can be determined that the position adjustment jig aligns with the z-axis direction.

[0051] Next, when the position adjustment jig is aligned in the z-axis direction, the 6a and 6b screws SC6a and SC6b are tightened to fix the y-axis direction adjustment plate member 34 to the x-axis direction adjustment plate member 33, and the 5a and 5b screws SC5a and SC5b are tightened to fix the x-axis direction adjustment plate member 33 to the top plate member 32.

[0052] This adjusts the x-position and the y-position.

[0053] Next, the second non-contact distance meter DM2 is positioned at the second tip of the cavity 224 in the second inner cylinder 22 and held by a holding tool (e.g., pliers) not shown in the figure. After attaching the ring-shaped second nut 26 to the second inner cylinder 22, the second outer cylinder 21 is moved downward along the z-axis direction with the holding tool. This narrows the width (spacing, circumferential length) of the slit shapes in the slit grooves 2233a to 2233d, tightening the second non-contact distance meter DM2 to the second inner cylinder 22 and fixing the second non-contact distance meter DM2 to the second tip of the second inner cylinder 22. The second outer cylinder 21 and the second inner cylinder 22 are provided with screw grooves 2131 and screw threads 2221, respectively, and function as a nut that tightens the second tip of the second inner cylinder 22 while fixing the second outer cylinder 21 to the second inner cylinder 22. Furthermore, a second nut 26 is tightened to ensure that the second outer cylinder 21 is fixed to the second inner cylinder 22. Similarly, the first non-contact distance meter DM1 is positioned at the first tip of the cavity 124 in the first inner cylinder 12 and held by a holding tool (e.g., pliers) not shown, and after attaching the ring-shaped first nut 16 to the first inner cylinder 12, the first outer cylinder 11 is moved upward along the z-axis direction with the holding tool. This narrows the width (spacing, circumferential length) of the slit shape in the slit grooves 1233a to 1233d, tightening the first non-contact distance meter DM1 to the first inner cylinder 12 and fixing the first non-contact distance meter DM1 to the first tip of the first inner cylinder 12. The first outer cylinder 11 functions as a nut that secures the first outer cylinder 11 to the first inner cylinder 12 while tightening the first tip portion of the first inner cylinder 12, as the first outer cylinder 11 and the first inner cylinder 12 are provided with screw grooves 1131 and screw threads 1221, respectively. Furthermore, the first nut 16 is tightened to ensure that the first outer cylinder 11 is secured to the second inner cylinder 12.

[0054] This ensures that the first and second non-contact distance meters DM1 and DM2 are held in the first and second inner cylinders 12 and 22, respectively.

[0055] According to this, by simply adjusting the first inner cylinder 12 with the position adjustment jig so that it faces the second inner cylinder 22, the first and second non-contact distance meters DM1 and DM2 can be held in the first and second inner cylinders 12 and 22, respectively, by the first and second outer cylinders 11 and 21, respectively, so that they face each other directly. This simplifies the adjustment of the mounting position and mounting angle of the first and second non-contact distance meters DM1 and DM2.

[0056] The four set screw holes 1213a to 1213d and the four set screws SB7a to SB7d correspond to an example of a first tilt adjustment section for adjusting the tilt when fixing the first inner cylinder. The x-axis adjustment plate member 33, the 5a screw SC5a and the 5b screw SC5b, and the y-axis adjustment plate member 34, the 6a screw SC6a and the 6b screw SC6b correspond to an example of a first inner cylinder holding member for adjusting the position of the first inner cylinder in a direction perpendicular to the central axis of the first inner cylinder while holding the first inner cylinder. The four set screw holes 2213a to 2213d and the four 15a to 15d set screws SB15a to SB15d correspond to an example of a second tilt adjustment section for adjusting the tilt when fixing the second inner cylinder.

[0057] In Figure 8, the input unit IN is electrically connected to the control processing unit CL and is a device that inputs various commands, such as a command to instruct the start of measurement, and various data necessary for operating the thickness measuring device 1000, such as the name of the object to be measured. Examples include multiple input switches assigned to predetermined functions, a keyboard, a mouse, etc. The output unit OU is electrically connected to the control processing unit CL and is a device that outputs commands, data, and calculation results input from the input unit IN according to the control of the control processing unit CL. Examples include display devices such as CRT displays, LCDs (liquid crystal displays), and organic EL displays, and printing devices such as printers.

[0058] The input unit IN and output unit OU may be configured as touch panels. In this configuration, the input unit IN is a position input device that detects and inputs the operating position, such as a resistive or capacitive touchscreen, and the output unit OU is a display device. In this touch panel, a position input device is provided on the display surface of the display device, and one or more candidate input contents that can be input to the display device are displayed. When the user touches the display position that displays the input content they want to input, the position input device detects that position, and the display content displayed at the detected position is input to the thickness measuring device 1000 as the user's operation input. With such a touch panel, the user can easily understand the input operation intuitively, thus providing a user-friendly thickness measuring device 1000.

[0059] The IF section IO is electrically connected to the control processing unit CL and, in accordance with the control of the control processing unit CL, is a circuit that inputs and outputs data to and from external devices, for example. Examples include an RS-232C serial communication interface circuit, an interface circuit using the Bluetooth® standard, and an interface circuit using the USB standard. Alternatively, the IF section IO may also be a communication interface circuit that sends and receives communication signals to and from external devices, such as a data communication card or a communication interface circuit conforming to the IEEE 802.11 standard.

[0060] The memory unit ME is electrically connected to the control processing unit CL and is a circuit that stores various predetermined programs and various predetermined data in accordance with the control of the control processing unit CL.

[0061] The various predetermined programs mentioned above include, for example, a control processing program, which includes, for example, a control program and a thickness calculation program. The control program controls each part DM1, DM2, LS1, LS2, LM1, LM2, IN, OU, IO, ME of the thickness measuring device 1000 according to the function of each part. The thickness calculation program is a program that determines the thickness of the object to be measured based on the first and second distances measured by the first and second non-contact distance meters DM1 and DM2, respectively, and the third distance between the first and second non-contact distance meters DM1 and DM2.

[0062] The aforementioned various predetermined data include, for example, the name of the object to be measured, the third distance, and the measurement results, which are data necessary for executing each of these programs.

[0063] Such a memory unit ME may include, for example, a non-volatile memory element such as ROM (Read Only Memory) or a rewritable non-volatile memory element such as EEPROM (Electrically Erasable Programmable Read Only Memory). The memory unit ME also includes RAM (Random Access Memory) which serves as the working memory of the control processing unit CL, which stores data generated during the execution of the predetermined program. Furthermore, the memory unit ME may be configured to include a hard disk drive or solid-state drive (SSD) with a relatively large storage capacity.

[0064] The control processing unit CL is a circuit for measuring the thickness of a target object by controlling each part DM1, DM2, LS1, LS2, LM1, LM2, IN, OU, IO, and ME of the thickness measuring device 1000 according to the function of each part. The control processing unit CL is configured, for example, with a CPU (Central Processing Unit) and its peripheral circuits. When the control processing program is executed, the control unit CL1 and the thickness calculation unit CL2 are functionally configured in the control processing unit CL.

[0065] The control unit CL1 controls each part M1, DM2, LS1, LS2, LM1, LM2, IN, OU, IO, and ME of the thickness measuring device 1000 according to the function of each part, and is in charge of the overall control of the thickness measuring device 1000. During measurement, the control unit CL1 causes the first and second non-contact distance meters DM1 and DM2 to measure the first and second distances, respectively, and receives the measurement results of the first and second distances, respectively, from the first and second non-contact distance meters DM1 and DM2. During the measurement by the first and second non-contact distance meters DM1 and DM2, the control unit CL1 causes the first and second light irradiation units LS1 and LS2, respectively, to irradiate light during the measurement. The control unit CL1 causes the first light intensity measuring unit LM1 to measure the light intensity irradiated by the first light irradiation unit LS1, receives the measurement result from the first light intensity measuring unit LM1, and if there is a difference between the measurement result and a predetermined target light intensity, controls the first light irradiation unit LS1 to achieve the target light intensity. The control unit CL1 causes the second light intensity measuring unit LM2 to measure the light intensity irradiated by the second light irradiation unit LS2, receives the measurement result from the second light intensity measuring unit LM2, and if there is a difference between the measurement result and the target light intensity, controls the second light irradiation unit LS2 to achieve the target light intensity.

[0066] The thickness calculation unit CL2 determines the thickness of the object to be measured based on the first and second distances measured by the first and second non-contact distance meters DM1 and DM2, respectively, and the third distance between the first and second non-contact distance meters DM1 and DM2. More specifically, the thickness calculation unit CL2 determines the thickness of the object to be measured by subtracting the first and second distances, respectively, from the third distance ((thickness of the object to be measured) = (third distance) - (first distance) - (second distance)).

[0067] The control unit CL1 then outputs the thickness of the object to be measured, calculated by the thickness calculation unit CL2, to the output unit OU, which then outputs the thickness of the object to be measured in a way that is recognizable to the user (operator). The control unit CL1 may also output the thickness of the object to be measured to an external device via the IF unit IO.

[0068] In such a thickness measuring device 1000, the control processing unit CL, input unit IN, output unit OU, IO unit 7, and storage unit ME can be configured by a computer such as a desktop or notebook computer.

[0069] When the thickness measuring device 1000 with this configuration is powered on, it performs the necessary initialization of each part and starts operating. The control processing unit CL is functionally configured with a control unit CL1 and a thickness calculation unit CL2 through the execution of its control processing program.

[0070] The user (operator) supports the plate-shaped object to be measured with an object support member (not shown in the figure), places the object to be measured between the first and second non-contact distance meters DM1 and DM2, and instructs the thickness measuring device 1000 to start the measurement.

[0071] The thickness measuring device 1000 is controlled by the control unit CL1 of the control processing unit CL to irradiate the first and second light irradiation units LS1 (LS1-1, LS1-2) and LS2 (LS2-1, LS2-2) with light, and to measure the light intensity of the light irradiated by the first and second light irradiation units LM1 and LM2, respectively, and to receive the respective measurement results. If there is a difference between the measurement result of the first light intensity measurement unit LM1 and the target light intensity, the control unit CL1 controls the first light irradiation unit LS1 to achieve the target light intensity. If there is a difference between the measurement result of the second light intensity measurement unit LM2 and the target light intensity, the control unit CL1 controls the second light irradiation unit LS2 to achieve the target light intensity.

[0072] The thickness measuring device 1000, via the control unit CL1 of the control processing unit CL, causes the first and second non-contact distance meters DM1 and DM2, respectively, to measure the first and second distances, respectively, and receives the measurement results of the first and second distances, respectively, from the first and second non-contact distance meters DM1 and DM2, respectively.

[0073] The thickness measuring device 1000 then uses the thickness calculation unit CL2 of the control processing unit CL to determine the thickness of the object to be measured based on the first and second distances measured by the first and second non-contact distance meters DM1 and DM2, respectively, and the third distance between the first and second non-contact distance meters DM1 and DM2, and outputs the determined thickness of the object to the output unit OU.

[0074] As described above, the thickness measuring device 1000 in the embodiment comprises a first outer cylinder 11, a first inner cylinder 12 that holds the first non-contact distance meter DM1 at its first tip, and the first tilt adjustment section (as an example thereof, set screw holes 1213a to 1213d and set screws SB7a to SB7d The first outer cylinder 11 and the first inner cylinder 12 each have a shape in which the diameter decreases as the first tip portion approaches the first tip, and the second outer cylinder 21 and the second inner cylinder 22 each have a shape in which the diameter decreases as the second tip portion approaches the second tip. Therefore, the thickness measuring device 1000 can be assembled by assembling the first and second inner cylinders 12 and 22 respectively with a predetermined assembly accuracy, adjusting the tilt of the central axis of the first inner cylinder 12 using the first tilt adjustment unit, adjusting the tilt of the central axis of the second inner cylinder 22 using the second tilt adjustment unit, and adjusting the position of the first inner cylinder 12 using the first inner cylinder holding member so that the central axis of the first inner cylinder 12 and the central axis of the second inner cylinder 22 coincide. After that, by simply fitting the first inner cylinder 12 inside the first outer cylinder 11 and fitting the second inner cylinder 22 inside the second outer cylinder 21, the first non-contact distance meter DM1 is positioned so as to be narrowed, and the second non-contact distance meter DM2 is positioned so as to be narrowed, so that the first and second non-contact distance meter DM1 and DM2 are facing each other with a positioning accuracy corresponding to the predetermined assembly accuracy. Therefore, the thickness measuring device 1000 described above makes it easy to adjust the mounting position and mounting angle of the first and second non-contact distance meters DM1 and DM2, respectively.

[0075] When the object to be measured is a silicon wafer in which oxygen donors have not been removed by heat treatment, and the first and second non-contact distance meters DM1 and DM2 are capacitive displacement sensors, measurement errors occur due to changes in electrical resistance caused by the oxygen donors, as disclosed in Patent Document 2. The thickness measuring device 1000 is equipped with first and second light irradiation units LS1 (LS1-1, LS1-2) and LS2 (LS2-1, LS2-2), which allow light to be irradiated onto the silicon wafer, thereby converting the valence electrons of the silicon wafer into conduction electrons, and thus eliminating the measurement errors. When light is irradiated onto the first measurement point, the thickness measuring device 1000 has a shape in which the diameter of the first outer cylinder 11 and the first inner cylinder 12 decreases as the first tip portion approaches the first tip, so that the first holding member 1 does not obstruct the irradiation of light, and the irradiation of light is made easier. In the above-described thickness measuring device 1000, when light is irradiated onto the second measurement point, the second outer cylinder 21 and the second inner cylinder 22 each have a shape in which the diameter decreases as the second tip portion approaches the second tip. Therefore, the obstruction caused by the second holding member 2 during light irradiation can be reduced, and the irradiation of light can be made easier.

[0076] The thickness measuring device 1000 described above may also determine the thickness distribution of the object to be measured. In this case, as shown by the dashed lines in Figure 8, the thickness measuring device 1000 further includes a moving unit MV that moves the object to be measured and the first and second non-contact distance meters DM1 and DM2 relative to each of the multiple measurement points on the object to be measured, so that the first and second distances can be measured at each of the multiple measurement points with the first and second non-contact distance meters DM1 and DM2, respectively. The thickness calculation unit CL2 further determines the thickness distribution by determining the thickness at each of the multiple measurement points. For example, the moving unit MV includes a frame member, three first to third support pins, a drive unit, and a lifting and rotating unit. The frame member comprises a first extension member, which is a prism shape positioned on the outside of the first lower side wall member 42a in the x-axis direction and extending along the y-axis direction; a second extension member, which is a prism shape positioned on the outside of the second lower side wall member 42b in the x-axis direction and extending along the y-axis direction; and a connecting member, which is a prism shape connected to one end of each of the first and second extension members and extending along the x-axis direction, and is a member that exhibits a substantially U-shape when viewed from above (viewed from the z-axis direction). The first to third support pins are each column-shaped members. The first and second support pins are erected on the first extension member and the third support pin is erected on the second extension member, so that each of the first to third support pins is located at the vertices of a triangle. Alternatively, the first support pin may be erected on the first extension member and the second and third support pins may be erected on the second extension member, so that each of the first to third support pins is located at the vertices of a triangle. The first to third support pins are each formed with a cone-shaped tip to support the object to be measured from below with point contact. The first to third support pins are each formed to a length (height) such that the object to be measured is positioned between the first and second non-contact distance meters DM1 and DM2 when the object to be measured is placed on them and supported. The drive unit is electrically connected to the control unit CL and is a device that moves the frame member in both directions along the y-axis according to the control of the control unit CL.The lifting and rotating unit is electrically connected to the control processing unit CL and is a device that lifts and lowers the object to be measured and rotates the object to be measured according to the control of the control processing unit CL. The lifting and rotating unit is positioned at a predetermined distance from the second inner cylinder 22 along the y-axis direction.

[0077] In such a moving unit MV, first, the object to be measured is placed on the first to third support pins and supported by the first to third support pins. Next, the drive unit moves the frame member along the y-axis toward the first and second non-contact distance meters DM1 and DM2, and the first and second distances are measured at each of the multiple measurement points on the object to be measured using the first and second non-contact distance meters DM1 and DM2, respectively. Subsequently, when the measurement is completed, the drive unit moves the frame member along the y-axis toward the first and second non-contact distance meters DM1 and DM2, and the movement stops when the object to be measured is positioned so that it can be raised and lowered and rotated by the lifting and rotating unit. Next, the lifting and rotating unit raises the object to be measured, releasing it from the support of the first to third support pins, rotates the object to be measured by a predetermined angle, and lowers the object to be measured so that it is supported again by the first to third support pins. Then, as described above, measurement is performed, and the lifting and rotating are performed. This process of measurement, lifting, and rotation is repeated, and measurements are taken across the entire object being measured. By determining the thickness of each measurement point, the overall thickness distribution of the object can be determined.

[0078] Since such a thickness measuring device 1000 can determine the thickness of each of the multiple measurement points, it can measure the thickness distribution of the object being measured.

[0079] To illustrate the present invention, the embodiments have been adequately and fully described above with reference to the drawings. However, those skilled in the art should recognize that it is easy to modify and / or improve upon the embodiments described above. Therefore, unless such modifications or improvements implemented by those skilled in the art fall outside the scope of the claims, such modifications or improvements shall be considered to be included within the scope of the claims. [Explanation of Symbols]

[0080] 1000 Thickness measuring device DM1 1st non-contact distance meter DM2 2nd non-contact distance meter LS1 (LS1-1, LS1-2) 1st light irradiation section LS2 (LS2-1, LS2-2) 1st light irradiation section CL2 Thickness Calculation Unit MD moving part 1. First retaining member 2. Second retaining member 11. First Inner Cylinder 12. First outer cylinder 21. Second inner cylinder 22. Second outer cylinder

Claims

1. A thickness measuring device for measuring the thickness of a plate-shaped object, A first non-contact distance meter that measures a first distance from one side of the object to be measured in a non-contact manner, A second non-contact distance meter is positioned to face the first non-contact distance meter with a predetermined space between them, and measures the second distance from the other side of the object to be measured in a non-contact manner. A thickness calculation unit that determines the thickness of the object to be measured based on the first and second distances measured by the first and second non-contact distance meters, respectively, and the third distance between the first and second non-contact distance meters, A first holding member for holding the first non-contact distance meter, The system comprises a second holding member for holding the second non-contact distance meter, The first holding member comprises a first outer cylinder, a first inner cylinder that holds the first non-contact distance meter at a first tip facing the space and is fitted inside the first outer cylinder, a first tilt adjustment part for adjusting the tilt when fixing the first inner cylinder, and a first inner cylinder holding member for adjusting the position of the first inner cylinder in a direction perpendicular to the central axis of the first inner cylinder while holding the first inner cylinder. The first outer cylinder and the first inner cylinder each have a shape in which the diameter of the first tip portion decreases as it approaches the first tip. The second holding member comprises a second outer cylinder, a second inner cylinder that holds the second non-contact distance meter at a second tip facing the space and is fitted inside the second outer cylinder, and a second tilt adjustment part for adjusting the tilt when fixing the second inner cylinder. The second outer cylinder and the second inner cylinder each have a shape in which the diameter of the second tip portion decreases as it approaches the second tip. Thickness measuring device.

2. Each of the first and second non-contact distance meters is a capacitive displacement sensor, The device further includes a light irradiation unit that irradiates light onto at least one of the first measurement point of the first non-contact distance meter and the second measurement point of the second non-contact distance meter. The thickness measuring device according to claim 1.

3. The system further includes a moving unit that moves the measurement target and the first and second non-contact distance meters relative to each of the multiple measurement points on the measurement target, so that the first and second distances can be measured with the first and second non-contact distance meters, respectively. The thickness calculation unit further determines the thickness distribution by determining the thickness of each of the plurality of measurement locations. The thickness measuring device according to claim 1.

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