Longitudinal frame part, mask holding device and mask holding method

Abstract

To provide a longitudinal frame part and a mask holding device which are excellent in attenuation characteristics of vibration.SOLUTION: There are provided a longitudinal part included in a mask holding part for holding a transparent mask having a substantially plate shape in a substantially vertical direction, or a mask holding device having the longitudinal part. The longitudinal part is formed by laminating a first layer made of a first material, a second layer made of a second material different from the first material, and an elastic layer arranged between the first layer and the second layer. The first material is any one of a metal material, ceramic, a metal matrix composite material and a fiber-reinforced resin, and the second material is any one of a metal material, ceramic, a metal matrix composite material, a fiber-reinforced resin and quartz glass.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vertical frame portion, a mask holding device, and a mask holding method. [Background technology]

[0002] Patent Document 1 discloses a mask holding device that includes a frame for holding a transparent, generally plate-shaped mask in a generally vertical direction, the frame having a generally rod-shaped lower frame portion extending generally horizontally and rod-shaped first and second vertical frame portions extending generally vertically so as to protrude upward from the lower frame portion, and a claw portion having a first claw portion provided on the first vertical frame portion and abutting against a first end surface of the mask, and a second claw portion provided on the second vertical frame portion and abutting against a second end surface of the mask. In this mask holding device, the frame holds the mask by the first claw portion abutting against the first end surface of the mask and the second claw portion abutting against the second end surface of the mask. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-040872 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, the vertical frame portion of a mask holding device such as the invention described in Patent Document 1 has generally been made of a metal matrix composite material. The vertical frame portion is made using elongated plate-shaped parts.

[0005] The mask, held vertically by a vertical frame, is inspected using a camera. However, the problem with long, thin plate-shaped components made of metal matrix composites is that vibrations do not dampen easily. If vibrations are not damped, the mask will vibrate in the thickness (depth) direction for a long time, which makes it difficult to focus the camera during inspection and capture clear images.

[0006] The present invention has been made in view of the above circumstances, and has as its object to provide a vertical frame portion and a mask holding device that have excellent vibration damping characteristics. [Means for solving the problem]

[0007] In order to solve the above problem, the vertical frame portion of the present invention is, for example, a vertical frame portion included in a mask holding portion that holds a transparent, approximately plate-shaped mask in an approximately vertical direction, and is characterized in that it is made up of a first layer made of a first material, a second layer made of a second material different from the first material, and an elastic layer arranged between the first layer and the second layer, wherein the first material is any one of a metal material, ceramics, metal matrix composite material, and fiber reinforced resin, and the second material is any one of a metal material, ceramics, metal matrix composite material, fiber reinforced resin, and quartz glass.

[0008] In addition, in order to solve the above-mentioned problems, the mask holding device of the present invention is, for example, a mask holding device having a frame-shaped frame, and first and second vertical frame portions which are rod-shaped and extend approximately vertically, and which are arranged on the frame so as to be movable in the left-right direction, and which is equipped with a mask holding portion that holds a transparent plate-shaped mask in an approximately vertical direction, wherein the first and second vertical frame portions are laminated with a first layer made of a first material, a second layer made of a second material different from the first material, and an elastic layer arranged between the first and second layers, and the first material is any of a metal material, ceramics, metal matrix composite material, and fiber reinforced resin, and the second material is any of a metal material, ceramics, metal matrix composite material, fiber reinforced resin, and quartz glass.

[0009] According to the vertical frame and mask holding device of the present invention, the vertical frame of the mask holding unit is laminated with a first layer made of a first material selected from a metal material, ceramics, metal matrix composite material, and fiber-reinforced resin; a second layer made of a second material different from the first material, selected from a metal material, ceramics, metal matrix composite material, fiber-reinforced resin, and quartz glass; and an elastic layer disposed between the first and second layers. This allows the vertical frame to have excellent vibration damping characteristics. This eliminates the need to move the camera's focal position to track vibrations in the thickness direction of the mask (camera focal direction) when inspecting a mask held by the vertical frame, allowing for clearer images to be captured and improving inspection performance.

[0010] The elastic layer may be a layer of hardened elastic adhesive and may have a thickness of approximately 0.1 mm or more and approximately 0.2 mm or less, thereby providing the elastic layer between the first and second layers while bonding the first and second layers together.

[0011] The first material may be aluminum, and the second material may be fine ceramics. This allows the first material to be a material with excellent workability, and the second material to be a material with high rigidity and low deformation. The first layer may also be formed with a recess in which a tab that abuts against the end surface of the mask is provided. This is possible by using a material with excellent workability for the first material.

[0012] The frame may have a horizontal frame portion that abuts against the rear surfaces of the first vertical frame portion and the second vertical frame portion and is provided so as to be movable up and down. This makes it possible to suppress vibration of the upper edge of the mask compared to a conventional configuration in which the upper edge is in an open state, thereby enabling more accurate inspection. Note that the horizontal frame portion preferably has the first layer, the elastic layer, and the second layer laminated in this order.

[0013] In order to solve the above problems, the mask holding device of the present invention is, for example, a mask holding device having a frame-shaped frame, and first and second vertical frame portions which are rod-shaped and extend approximately vertically, and which are arranged on the frame so as to be movable in the left-right direction, and which is equipped with a mask holding portion that holds a transparent plate-shaped mask in an approximately vertical direction, and is characterized in that a first ultrasonic sensor and a second ultrasonic sensor which measure distance using ultrasonic waves are arranged near the bottom end of the first vertical frame portion and the second vertical frame portion, respectively, and the first ultrasonic sensor transmits ultrasonic waves approximately horizontally toward the second vertical frame portion, and the second ultrasonic sensor transmits ultrasonic waves approximately horizontally toward the first vertical frame portion.

[0014] Furthermore, in order to solve the above-mentioned problems, the mask holding method according to the present invention is characterized by including, for example, the steps of holding a transparent plate-shaped mask in an approximately vertical direction, where the mask is held at the left-right center of the upper and lower end faces with an arm; bringing the mask held by the arm close to a mask holding unit having a substantially rod-shaped lower frame portion extending approximately horizontally and rod-shaped first and second vertical frame portions extending approximately vertically so as to protrude upward from the lower frame portion; and measuring the position of the mask relative to the mask holding unit by transmitting ultrasonic waves approximately horizontally from a first ultrasonic sensor provided on the first vertical frame portion and a second ultrasonic sensor provided on the second vertical frame portion to measure the distance.

[0015] Conventionally, the ultrasonic sensor for measuring the mask position was not installed in the mask holder but in a separate device, making it difficult to measure the mask position. Also, the mask had to be accurately loaded so that the mask position did not have to be measured.

[0016] According to the mask holding device and mask holding method of the present invention, the ultrasonic sensor is provided on the vertical frame, which allows for a simple configuration. For example, when a mask is to be loaded into the mask holding device using a device that cannot load the mask accurately, the mask can be loaded into the correct position by measuring the position of the mask just before gripping it.

[0017] The mask loading device may include a first claw provided on the first vertical frame and abutting against a first end surface of the mask, and a second claw provided on the second vertical frame and abutting against a second end surface of the mask, the first claw and the second claw being provided in a plurality of positions along the vertical direction, the first ultrasonic sensor being provided between a lower end of the first vertical frame and a third claw provided at the lowest of the plurality of first claws, and the second ultrasonic sensor being provided between a lower end of the second vertical frame and a fourth claw provided at the lowest of the plurality of second claws. In other words, the ultrasonic sensor may be provided near the lower end of the vertical frame. This reduces the influence of misalignment caused by swinging of the mask when it is loaded.

[0018] The mask may have a chamfered edge formed on the periphery, either flat or curved, and the first ultrasonic sensor and the second ultrasonic sensor may emit ultrasonic waves toward the end face of the mask where the chamfered edge is not formed. This is possible by providing ultrasonic sensors on the vertical frame portion. This allows accurate distance measurement. [Effects of the Invention]

[0019] According to the present invention, a frame having excellent vibration damping characteristics can be provided. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a perspective view showing an outline of a mask holding device 1. FIG. [Figure 2] 2 is a schematic view of the claw portion 14 when it is in the abutting position, and is a cross-sectional view taken along the line AA in FIG. 1. FIG. [Figure 3] 2 is a cross-sectional view showing an outline of a vertical frame portion 12. FIG. [Figure 4] Graph (A) shows the vibration characteristics of the vertical frame portion 12, and graph (B) shows the vibration characteristics of a conventional vertical frame portion made of a metal matrix composite material. [Figure 5] 2 is a block diagram showing the electrical configuration of the mask holding device 1. FIG. [Figure 6] 10 is a flowchart showing the flow of a process for holding the mask M in a substantially vertical direction. [Figure 7] 10 is a diagram showing a schematic view of a state in which the mask M is held in a substantially vertical direction. FIG. [Figure 8] FIG. 2 is a perspective view showing an outline of a mask holding device 2. [Figure 9] 2 is a cross-sectional view showing an outline of a horizontal frame portion 15. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The present invention relates to a mask holding device that holds a mask M in a substantially vertical direction and a vertical frame portion of the mask holding device, which is provided inside a mask inspection machine or the like that inspects the mask M.

[0022] The mask M is a transparent, approximately plate-shaped member made of quartz glass or the like, and is an exposure mask used to manufacture substrates for display devices such as organic electroluminescence (EL) and liquid crystal display devices. The mask M is a large, approximately rectangular substrate with sides of approximately 1 m, on which one or more transfer patterns for an image device are formed. The mask M also has a chamfered periphery to prevent chipping of the mask edge.

[0023] First Embodiment 1 is a perspective view showing an outline of a mask holding device 1 according to a first embodiment. In this specification, the direction substantially along the longitudinal direction of a frame 11 is defined as the x direction, the vertical direction is defined as the y direction, and the direction perpendicular to the x direction and y direction is defined as the z direction.

[0024] The mask holding device 1 is placed on a stage (not shown) and mainly includes a mask holding unit 10, a frame holding unit 20, and an ultrasonic sensor 30.

[0025] The mask holding portion 10 mainly includes a frame 11, vertical frame portions 12 and 13 provided on the frame 11, and claw portions 14 for gripping the mask M. The claw portions 14 are provided on the vertical frame portions 12 and 13, etc.

[0026] The frame 11 is formed in a substantially frame shape so as to surround the periphery of the vertically held mask M. The frame 11 holds the mask M so that the surface m1 of the mask M (the surface on which a pattern is formed) is parallel to the xy plane.

[0027] The frame 11 is mainly provided with vertical frame portions 12 and 13. The vertical frame portions 12 and 13 are rod-shaped members extending substantially vertically. To accommodate masks M of different sizes, the vertical frame portions 12 and 13 are movable in the horizontal direction (x direction). The vertical frame portions 12 and 13 will be described in detail later.

[0028] The claws 14 are provided on each of the vertical frame portions 12, 13 and the second block 21b (described in detail later). The claws 14 are movable between a contact position where they contact the mask M and a retracted position where they do not contact the mask M. The tips of the claws 14 provided on the vertical frame portions 12, 13 move in a substantially horizontal direction (x direction) between the contact position and the retracted position. The tips of the claws 14 provided on the second block 21b move in a substantially vertical direction (y direction) between the contact position and the retracted position.

[0029] Fig. 2 is a schematic diagram of the claw portion 14 in the abutment position, and is a cross-sectional view taken along line AA in Fig. 1. In Fig. 2, the dotted line indicates the state in which the claw portion 14 is in the retracted position, and the solid line indicates the state in which the claw portion 14 is in the abutment position.

[0030] The claw portion 14 mainly has a tip portion 141 and a linear guide 143. The tip portion 141 is a generally rectangular part that comes into contact with the mask M, and is made of a resin that has excellent heat resistance and mechanical strength, such as polyether ether ketone resin (PEEK). The tip of the tip portion 141 has a contact surface 142 that is cut obliquely when viewed from the y direction. The contact surface 142 comes into contact with a corner 11 between the chamfered portion c1 of the mask M and the left end face m3.

[0031] The linear motion guide 143 mainly includes a rail 143a and a drive portion 143b. The rail 143a is fixed to the vertical frame portion 13 (not shown in FIG. 2). The drive portion 143b is fixed to the rear side (the right side in FIG. 2) of the tip portion 141 and is movable along the rail 143a. In this way, the claw portion 14 (i.e., the tip portion 141) is movable between the retracted position and the abutting position as shown by the arrow in FIG. 2.

[0032] 2 (+x direction) to the mask M. As a result, the contact surface 142 presses the corner 11 from the diagonal front, and the back surface m2 of the mask M contacts the frame 11, thereby holding the mask M to the frame 11.

[0033] Returning to the explanation of FIG. 1, a frame holding unit 20 is provided below the mask holding unit 10. The frame holding unit 20 is placed on a stage (not shown) and has an adjustment mechanism 21 that changes the position of the lower edge of the mask M in the height direction (y direction). A plurality of adjustment mechanisms 21 are formed along the x direction. The adjustment mechanism 21 has a first block 21a whose upper surface is inclined with respect to the xz plane and a second block 21b whose lower surface is inclined with respect to the xz plane, and adjusts the height by changing the relative positional relationship between the first block 21a and the second block 21b. The adjustment mechanism 21 is already known, so a detailed description thereof will be omitted.

[0034] The ultrasonic sensor 30 is a sensor that measures distance using ultrasonic waves. The ultrasonic sensor 30 has an ultrasonic sensor 31 provided on the vertical frame portion 12 and an ultrasonic sensor 32 provided on the vertical frame portion 13. For example, the ultrasonic sensors 31 and 32 are small sensors with a diameter of about 10 mm, and can measure an object at a distance of about 40 mm with high accuracy.

[0035] The ultrasonic sensor 31 transmits ultrasonic waves substantially horizontally, i.e., in the -x direction, toward the vertical frame portion 13. The ultrasonic sensor 32 transmits ultrasonic waves substantially horizontally, i.e., in the +x direction, toward the vertical frame portion 12. The ultrasonic sensor 30 is already known, and therefore a detailed description thereof will be omitted.

[0036] The ultrasonic sensors 31 and 32 are provided near the lower ends of the vertical frame portions 12 and 13, respectively. For example, the ultrasonic sensor 31 is provided between the lower end of the vertical frame portion 12 and the lowest claw portion 14 of the plurality of claw portions 14 provided along the vertical direction on the vertical frame portion 12. Also, for example, the ultrasonic sensor 31 is provided between the lower end of the vertical frame portion 13 and the lowest claw portion 14 of the plurality of claw portions 14 provided on the vertical frame portion 13.

[0037] The ultrasonic sensors 31 and 32 irradiate ultrasonic waves toward an end face (for example, the left end face m3) of the mask M where the chamfered portions c1 and c2 (see FIG. 2) are not formed. The ultrasonic sensors 31 and 32 each emit ultrasonic waves and receive the ultrasonic waves reflected back from the end face of the mask M, and measure the distance to the end face of the mask M by measuring the time from emission to reception. This is possible by providing the ultrasonic sensors 31 and 32 on the vertical frame portions 12 and 13.

[0038] Here, we will explain the structure of the vertical frame portions 12 and 13. Since the vertical frame portions 12 and 13 have the same configuration, we will explain using the vertical frame portion 12, and we will omit the explanation of the vertical frame portion 13.

[0039] 3 is a cross-sectional view showing an outline of the vertical frame portion 12. The vertical frame portion 12 has a first layer 121, a second layer 122, and an elastic layer 123 disposed between the first layer 121 and the second layer 122. The first layer 121, the second layer 122, and the elastic layer 123 are laminated together. The first layer 121 has a surface 121a facing the +z direction, and a recess 121b is formed in the surface 121a. A claw portion 14 is provided in the recess 121b.

[0040] The first layer 121 is made of a first material, and the second layer 122 is made of a second material. The first material is any one of a metal material, ceramics, metal matrix composite material, and fiber reinforced resin, and the second material is any one of a metal material, ceramics, metal matrix composite material, fiber reinforced resin, and quartz glass.

[0041] Metal materials include, for example, iron, iron alloys, aluminum, and non-ferrous alloys. Iron alloys include, for example, stainless steel, low-thermal expansion alloys (such as invar and super invar), and chromium-molybdenum steel. Non-ferrous alloys include, for example, copper alloys (beryllium copper), aluminum alloys (such as duralumin), magnesium alloys, and titanium alloys. Ceramics include, for example, fine ceramics (such as aluminum oxide (alumina), cordierite, silicon carbide, ferrite, and aluminum nitride) and zirconium dioxide (zirconia).

[0042] Metal matrix composites and fiber-reinforced resins are types of composite materials. Metal matrix composites are composite materials that use a metal as the base material (matrix). Examples of base metals include aluminum, silicon metal, copper, magnesium, and brass. In metal matrix composites, the reinforcing material combined with the matrix is, for example, fiber (carbon, etc.) or ceramics (silicon carbide, alumina, aluminum borate, aluminum nitride, etc.).

[0043] Fiber-reinforced resin is a composite material with a resin as the matrix and fibers as the reinforcing agent. The matrix resin can be, for example, a thermosetting resin such as an epoxy resin or an unsaturated polyester resin, or a thermoplastic resin such as methyl methacrylate. Examples of fiber-reinforced resin include carbon fiber-reinforced plastics, which use carbon fiber as the reinforcing agent, glass fiber-reinforced plastics, which use glass fiber as the reinforcing agent, and aramid fiber-reinforced plastics, which use aramid fiber as the reinforcing agent.

[0044] In this embodiment, the first layer 121 is made of aluminum, and the second layer 122 is made of fine ceramics (for example, alumina sintered body).

[0045] It is preferable that the first layer 121 be formed using a material that is easy to process. Therefore, the first layer 121 may be formed using any metal material, and is not limited to aluminum. However, it is preferable to use aluminum for the first layer 121 in order to reduce weight.

[0046] Since the second layer 122 has the purpose of reinforcing the first layer 121, it is desirable to use a material that is highly rigid and difficult to deform, that is, a material with a high modulus of longitudinal elasticity (Young's modulus). Therefore, in this embodiment, the second layer 122 is formed using fine ceramics.

[0047] In this embodiment, in order to ensure rigidity, the thickness t1 of the first layer 121 and the thickness t2 of the second layer 122 are each set to approximately 10 mm, although the thicknesses t1 and t2 are not limited to this.

[0048] The elastic layer 123 is formed of a flexible material that can be elastically deformed. In this embodiment, the elastic layer 123 is formed using an elastic adhesive, and the layer of the elastic adhesive that hardens becomes the elastic layer 123. The elastic adhesive is in a liquid or paste state with dynamic viscosity when applied, and becomes a rubber-like elastic body when hardened. For example, a fluorine-based, silicone-based (silicone resin, modified silicone resin, etc.), or urethane-based (urethane resin, silylated urethane resin, etc.) adhesive can be used as the elastic adhesive. In this embodiment, a silicone-based elastic adhesive is used. By using the elastic adhesive, the first layer 121 and the second layer 122 can be bonded together, and an elastic layer can be provided between the first layer 121 and the second layer 122.

[0049] The elastic adhesive used for the elastic layer 123 preferably has a Shore A hardness after hardening of not less than 30 and not more than 60. The Shore A hardness is measured in accordance with ISO 7619-1:2010.

[0050] By disposing elastic layer 123 between first layer 121 and second layer 122, even if a force in the thickness direction is locally applied to vertical frame portion 12, the vibration can be alleviated by the elastic adhesive. Furthermore, even if the dimensional changes due to temperature or the like differ between first layer 121 and second layer 122, the difference can be absorbed by elastic layer 123 where the difference has occurred, and the adhesive state between first layer 121 and second layer 122 can be stably maintained.

[0051] To reduce vibrations, it is preferable that the thickness of the elastic layer 123 is thick, but a thick elastic layer 123 reduces the rigidity of the vertical frame portion 12. Therefore, in order to strike a balance between these factors, it is preferable that the thickness t3 of the elastic layer 123 be approximately 0.1 mm or more and approximately 0.2 mm or less.

[0052] The vibration characteristics of the vertical frame portions 12 and 13 will be explained using Figure 4. Figure 4(A) is a graph showing the vibration characteristics of the vertical frame portion 12, and Figure 4(B) is a graph showing the vibration characteristics of a conventional vertical frame portion made of metal matrix composite material (metal matrix ceramics, MMC). The vertical frame portion 12 and the conventional vertical frame portion have approximately the same dimensions: length approximately 1400 mm, width approximately 200 mm, and thickness approximately 20 mm. The graph in Figure 4 shows the measurement results obtained by the acceleration sensor when the vertical frame portion 12 and the conventional vertical frame portion were fixed at both ends, an acceleration sensor was attached to the center, and a hammer was applied from the opposite side. The vertical axis of Figure 4 represents the vibration amplitude of the vertical frame portion, i.e., the mask M held by it, in the thickness direction (z direction).

[0053] The horizontal axis in Figure 4 represents time, with 1 square representing 0.1 seconds in Figure 4(A) and 0.5 seconds in Figure 4(B). The vibration of the vertical frame section 12 decays to approximately zero in approximately 0.5 seconds, whereas the vibration of the conventional vertical frame section continues for approximately 3 to 4 seconds before it decays to approximately zero. In this way, the vibration of the vertical frame section 12, which has the elastic layer 123 disposed between the first layer 121 and the second layer 122, decays quickly. The resonance frequency of the vertical frame section 12 is 26 Hz, while the resonance frequency of the conventional vertical frame section is 36 Hz, confirming that both have high rigidity.

[0054] 5 is a block diagram showing the electrical configuration of the mask holding device 1. The mask holding device 1 mainly includes a control unit 51, a storage unit 52, an input unit 53, and an output unit .

[0055] The control unit 51 is a program-controlled device such as a CPU (Central Processing Unit) that is a computing device, and operates according to a program stored in the storage unit 52. The detailed operation of the control unit 51 will be described later.

[0056] The storage unit 52 is a non-volatile memory, a volatile memory, or the like, and stores programs and the like executed by the control unit 51, and operates as a work memory for the control unit 51. The input unit 53 includes input devices such as a keyboard and a mouse. The output unit 54 is a display, or the like.

[0057] Next, the flow of processing performed by the control unit 51 will be described. Fig. 6 is a flowchart showing the flow of processing for holding the mask M in a substantially vertical direction. Fig. 7 is a diagram schematically showing the state in which the mask M is held in a substantially vertical direction. Before processing begins, the vertical frame units 12, 13 are at their farthest positions, the second block 21b of the adjustment mechanism 22 is at the bottom end, and the claw unit 14 is in the standby position.

[0058] (Step S1) First, a device (for example, a transport device) different from the mask holding device 1 holds the mask M in a substantially vertical direction with an arm 101 of the transport device. At this time, the arm 101 holds the center of the upper and lower end faces (end faces on the ±y side) of the mask M in the left-right direction (x direction).

[0059] (Step S2) Next, the transport device moves the arm 101 in the -z direction to insert the mask M into the mask holding device 1 and bring the mask M closer to the mask holding part 10. As a result, the mask M is placed on the front side (+z side) of the frame 11 (not shown in FIG. 7).

[0060] (Step S3) Next, the control unit 51 measures the distance by transmitting ultrasonic waves from the ultrasonic sensors 31 and 32 in a substantially horizontal direction, and measures the position of the mask M relative to the mask holding unit 10. In this way, the position of the mask M is measured immediately before the mask M is gripped by the claws 14.

[0061] (Step S4) Next, based on the measurement results of the ultrasonic sensors 31 and 32 in step S3, the control unit 51 uses a drive unit (not shown) to move the vertical frame units 12 and 13 to a position where the mask M can be gripped by the claw units 14. The control unit 51 also controls the adjustment mechanism 22 (not shown in FIG. 7) and the drive unit (not shown) to move the second block 21b (not shown in FIG. 7) upward (in the +y direction) so that the second block 21b and the lower end surface of the mask M come into contact with each other.

[0062] (Step S5) Next, the control unit 51 moves the claw portions 14 from the standby position to the abutting position. At this time, all of the claw portions 14 are moved simultaneously. As a result, the mask holding unit 10 holds the mask M.

[0063] According to this embodiment, vertical frame portions 12, 13 can be made to have excellent vibration damping characteristics by disposing elastic layer 123 between first layer 121 and second layer 122. Because vertical frame portions 12, 13 instantly damp vibrations caused by external forces, there is no need to move the focal position of the camera to track vibrations of mask M in the z direction when performing an inspection, etc., and clear images can be captured, improving inspection performance.

[0064] Furthermore, in this embodiment, a simple configuration can be achieved by providing ultrasonic sensors 31, 32 on the vertical frame portions 12, 13. When the mask M is loaded using a transport device or the like in which the arm 101 holds the center portions of the upper and lower end faces of the mask M in the left-right direction, the position of the mask M often deviates from the correct loading position of the mask M due to, for example, the tilt of the mask M. In such cases, by adding a step of measuring the position of the mask M with the ultrasonic sensors 31, 32, the position of the loaded mask M can be corrected, and the mask holding portion 10 can hold the mask M correctly.

[0065] In addition, in this embodiment, the ultrasonic sensors 31, 32 are provided near the lower ends of the vertical frame portions 12, 13, for example, between the lower ends of the vertical frame portions 12, 13 and the lowest of the claw portions 14 provided on the vertical frame portions 12, 13, thereby making the ultrasonic sensors 31, 32 less susceptible to the influence of tilting the mask M.

[0066] As shown in Figure 7, arm 101 is held at its lower end, and is shaped so that the mask M it holds can easily swing around the lower end (see the dotted arrow in Figure 7). When mask M swings, the positional deviation near the upper end of mask M increases. For this reason, ultrasonic sensors 31 and 32 are provided near the lower ends of vertical frame portions 12 and 13 to reduce the change in distance during distance measurement and improve measurement accuracy.

[0067] In this embodiment, the first layer 121 is formed using a metal material (the first material is a metal material), and the second layer 122 is formed using a fine ceramic (the second material is a fine ceramic), but the first and second materials are not limited to this. The first material may be any of a metal material, ceramics, a metal matrix composite material, and a fiber reinforced resin, and the second material may be any of a metal material, ceramics, a metal matrix composite material, a fiber reinforced resin, and quartz glass.

[0068] However, in order to make the first material a material with excellent workability and the second material a material with high rigidity and resistance to deformation, it is desirable to combine the first and second materials as follows: For example, the first material may be a metal (aluminum, iron, etc.) and the second material may be quartz glass or fiber-reinforced resin, the first material may be a fiber-reinforced resin (e.g., carbon fiber-reinforced plastic) and the second material may be fine ceramics, the first material may be a metal matrix composite material and the second material may be a metal (aluminum, iron, etc.), or the first material and the second material may be a metal matrix composite material.

[0069] In the present embodiment, elastic layer 123 is formed using an elastic adhesive, but the form of elastic layer 123 is not limited to this. For example, the elastic layer may include an elastic body such as rubber and adhesive portions provided on both sides of the elastic body. In this case, the adhesive portions may or may not be elastic adhesive. In addition, it is preferable that the elastic body has a Shore A hardness of 30 or more and 60 or less as measured in accordance with ISO 7619-1:2010.

[0070] In addition, in this embodiment, the ultrasonic sensors 31, 32 are provided on the vertical frame portions 12, 13, but the ultrasonic sensors 31, 32 are not essential. Furthermore, it is not essential that the ultrasonic sensors 31, 32 are provided on the vertical frame portions 12, 13, which have a layered structure, and they may be provided on vertical frame portions with a conventional structure.

[0071] <Second embodiment> In the first embodiment of the present invention, the mask M is held using the claws 14 provided on the vertical frame portions 12, 13 and the second block 21b, but the positions at which the claws 14 are provided are not limited to this.

[0072] In the second embodiment of the present invention, the mask holding part has a horizontal frame part, and the horizontal frame part is also provided with a claw part. The mask holding device 2 according to the second embodiment will be described below. The same parts as those in the first embodiment are given the same reference numerals, and the description will be omitted.

[0073] 8 is a perspective view showing an outline of the mask holding device 2. The mask holding device 2 mainly includes a mask holding part 10A, a frame holding part 20 (not shown in FIG. 9), and an ultrasonic sensor 30.

[0074] The mask holding part 10A mainly has a frame 11 (not shown in FIG. 9), vertical frame parts 12 and 13, a claw part 14, and a horizontal frame part 15. The horizontal frame part 15 is provided on the frame 11 and can be moved up and down by a drive part (not shown).

[0075] Furthermore, the horizontal frame portion 15 can abut against the rear surfaces (-z side surfaces) of the vertical frame portions 12, 13. A magnet is provided on one side of the front surface (+z side surface) of the horizontal frame portion 15 and the rear surfaces of the vertical frame portions 12, 13, and a magnetic material is provided on the other side. The horizontal frame portion 15 is moved up and down away from the vertical frame portions 12, 13, and when the horizontal frame portion 15 is positioned in the desired position, the horizontal frame portion 15 is brought closer to the vertical frame portions 12, 13, whereby the horizontal frame portion 15 abuts against the rear surfaces of the vertical frame portions 12, 13.

[0076] The horizontal frame portion 15 is provided with claw portions 14. After the horizontal frame portion 15 is brought into contact with the rear surfaces of the vertical frame portions 12 and 13, the mask M is held in place using the claw portions 14 provided on the vertical frame portions 12 and 13, the horizontal frame portion 15, and the second block 21b.

[0077] 9 is a cross-sectional view showing an outline of horizontal frame portion 15. Similar to vertical frame portion 12, horizontal frame portion 15 has a first layer 151 formed of a first material, a second layer 152 formed of a second material, and an elastic layer 153 disposed between first layer 151 and second layer 152. First layer 151, second layer 152, and elastic layer 153 are laminated. Note that first layer 151 may have recesses or the like formed therein for providing claw portions 14.

[0078] In this embodiment, for example, first layer 151 is formed using aluminum, second layer 152 is formed using fine ceramics, and elastic layer 153 is formed using an elastic adhesive. Furthermore, for example, first layer 151 and second layer 152 each have a thickness of approximately 10 mm, and elastic layer 153 has a thickness of approximately 0.1 mm or more and approximately 0.2 mm or less. By disposing elastic layer 153 between first layer 151 and second layer 152 in this way, even if a force is locally applied to horizontal frame portion 15 in the plate thickness direction, the vibration is alleviated and the vibration quickly decelerates.

[0079] According to this embodiment, by providing the horizontal frame portion 15, the mask M can be held more firmly and vibration of the mask M in the z direction can be further reduced. For example, if the horizontal frame portion 15 is not provided, the upper edge of the mask M is in an open state and vibration occurs, but by providing the horizontal frame portion 15, vibration of the upper edge can be suppressed. Therefore, highly accurate inspection can be performed based on a clear image of the mask M.

[0080] According to this embodiment, horizontal frame portion 15 has excellent vibration damping characteristics, as it is configured such that elastic layer 153 is disposed between first layer 151 and second layer 152. Therefore, clearer images can be captured than when horizontal frame portions are formed using a conventional configuration (for example, formed from a metal matrix composite material), improving inspection performance.

[0081] In this embodiment, a layered horizontal frame portion 15 is used in which an elastic layer 153 is disposed between a first layer 151 and a second layer 152, but the configuration of the horizontal frame portion is not limited to this. For example, the horizontal frame portion may be a plate-like member formed of a metal matrix composite material or the like, similar to a vertical frame portion of a conventional configuration.

[0082] The above describes an embodiment of the present invention in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present invention.

[0083] In the embodiment of the present invention, a transparent, substantially plate-shaped mask M having a flat chamfered portion (so-called C-surface) formed on the periphery has been described, but the shape of the mask M is not limited to this. For example, a mask having a curved chamfered portion (so-called R-surface) formed on the periphery may also be used. Also, for example, a mask having a chamfered periphery with different sizes on the front and back sides may also be used.

[0084] In the present invention, the term "approximately" is a concept that includes not only cases where something is strictly identical, but also errors or deformations that do not cause loss of identity. For example, an "approximately cubic shape" is not limited to a strict cubic shape. Furthermore, for example, when expressing something as simply vertical, coincident, etc., it includes not only cases where something is strictly vertical, coincident, etc., but also cases where something is approximately vertical, approximately coincident, etc. Furthermore, in the present invention, the term "nearby" is a concept that indicates, for example, when referring to the vicinity of A, that something is close to A and may or may not include A. [Explanation of symbols]

[0085] 1, 2: Mask holding device 10, 10A: Mask holding part 11: Frame 11a: Lower frame part 11e: Convex part 12, 13: Vertical frame section 13: Vertical frame section 14: Claw part 15:Horizontal frame part 20: Frame holding part 21:Adjustment mechanism 21a: Block 1 21b: Second Block 22:Adjustment mechanism 30, 31, 32: Ultrasonic sensors 51: Control unit 52: Storage section 53: Input section 54: Output section 101: Arm 121, 151: 1st layer 121a: surface 121b: recess 122, 152: 2nd layer 123, 153: Elastic layer 141:Tip 142: Contact surface 143: Linear guide 143a: Rail 143b: Drive unit

Claims

1. A vertical frame portion included in a mask holding portion that holds a transparent, substantially plate-shaped mask in a substantially vertical direction, a first layer made of a first material, a second layer made of a second material different from the first material, and an elastic layer disposed between the first layer and the second layer; the first material is any one of a metal material, a ceramic, a metal matrix composite material, and a fiber reinforced resin; The second material is any one of a metal material, a ceramic, a metal matrix composite material, a fiber reinforced resin, and a quartz glass. A vertical frame portion characterized by:

2. The elastic layer is a layer of hardened elastic adhesive, and has a thickness of approximately 0.1 mm or more and approximately 0.2 mm or less. The vertical frame portion according to claim 1 .

3. The first material is aluminum, and the second material is fine ceramics.

3. The vertical frame portion according to claim 1 or 2.

4. A mask holding device having a frame-shaped frame, and first and second vertical bar-shaped frame portions extending substantially vertically, the first and second vertical frame portions being provided on the frame so as to be movable in the left-right direction, and having a mask holding portion that holds a transparent plate-shaped mask in a substantially vertical direction, The first vertical frame portion and the second vertical frame portion are laminated with a first layer made of a first material, a second layer made of a second material different from the first material, and an elastic layer disposed between the first layer and the second layer, the first material is any one of a metal material, a ceramic, a metal matrix composite material, and a fiber reinforced resin; The second material is any one of a metal material, a ceramic, a metal matrix composite material, a fiber reinforced resin, and a quartz glass. A mask holding device characterized by:

5. The frame has a horizontal frame portion that abuts against the rear surfaces of the first vertical frame portion and the second vertical frame portion and is provided so as to be movable up and down.

5. The mask holding device according to claim 4.

6. The horizontal frame portion is formed by laminating the first layer, the elastic layer, and the second layer in this order.

6. The mask holding device according to claim 5.

7. The elastic layer is a layer of hardened elastic adhesive, and has a thickness of approximately 0.1 mm or more and approximately 0.2 mm or less.

7. A mask holding device according to claim 4, wherein the mask holding device is a mask holding device.

8. a recess in which a tab that abuts against an end surface of the mask is provided is formed in the first layer; The first material is aluminum, and the second material is fine ceramics.

7. A mask holding device according to claim 4 or 6.

9. A mask holding device having a frame-shaped frame, and first and second vertical bar-shaped frame portions extending substantially vertically, the first and second vertical frame portions being provided on the frame so as to be movable in the left-right direction, and having a mask holding portion that holds a transparent plate-shaped mask in a substantially vertical direction, a first ultrasonic sensor and a second ultrasonic sensor that measure distances using ultrasonic waves are provided near the bottom ends of the first vertical frame portion and the second vertical frame portion, respectively; the first ultrasonic sensor transmits ultrasonic waves substantially horizontally toward the second vertical frame portion, The second ultrasonic sensor transmits ultrasonic waves substantially horizontally toward the first vertical frame portion. A mask holding device characterized by:

10. a claw portion including a first claw portion provided on the first vertical frame portion and abutting against a first end surface portion of the mask, and a second claw portion provided on the second vertical frame portion and abutting against a second end surface portion of the mask; The first claw portion and the second claw portion are provided in plural along the vertical direction, the first ultrasonic sensor is provided between a lower end of the first vertical frame portion and a third claw portion provided at the lowermost side of the plurality of first claw portions, The second ultrasonic sensor is provided between a lower end of the second vertical frame portion and a fourth claw portion provided at the lowermost side of the plurality of second claw portions.

10. The mask holding device according to claim 9.

11. a chamfered portion having a flat or curved surface is formed on the periphery of the mask; The first ultrasonic sensor and the second ultrasonic sensor irradiate ultrasonic waves toward an end surface of the mask where the chamfered portion is not formed.

11. The mask holding device according to claim 9 or 10.

12. a step of holding a transparent plate-shaped mask in a substantially vertical direction by holding the central portions of the upper and lower end surfaces in the left-right direction with arms; bringing the mask held by the arms close to a mask holding section having a substantially rod-shaped lower frame section extending substantially horizontally, and rod-shaped first and second vertical frame sections extending substantially vertically so as to protrude upward from the lower frame section; a step of measuring the position of the mask relative to the mask holding part by transmitting ultrasonic waves substantially horizontally from a first ultrasonic sensor provided on the first vertical frame part and a second ultrasonic sensor provided on the second vertical frame part and measuring the distance; A mask holding method comprising:

Images