Mask inspection equipment

Abstract

To miniaturize a mask inspection device, and accurately inspect tension of a mask body.SOLUTION: A mask inspection device (1) includes: a workpiece receiving tool (10); a surface plate (20) arranged above the workpiece receiving tool (10); a pressing mechanism (30) for pressing a plate frame (502) of a mask printing plate (500) mounted on the workpiece receiving tool (10) against the lower surface of the surface plate (20); a measuring unit (80) arranged above the surface plate (20); a moving mechanism (40) for moving the measuring unit (80) at the upper position of the surface plate (20); and a control device (5) for controlling the operations of the pressing mechanism (30), the measuring unit (80), and the moving mechanism (40). The mask inspection device (1) measures a displacement amount of a mask body (504) when adding a predetermined load in the state where the plate frame (502) of the mask printing plate (500) is pushed against the lower surface of the surface plate (20).SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present disclosure relates to a mask inspection apparatus. [Background technology]

[0002] Mask printing plates are used in screen printing, a printing method. Mask printing plates are composed of a sheet-like mask body and a screen frame. A printing pattern is formed on the mask body. The printing pattern consists of holes that open in a specific shape. The mask body is supported under tension inside the screen frame. In screen printing, paste (ink) placed on the mask body is pressed and rubbed with a pressing member called a squeegee to imprint it into the holes of the printing pattern, and the paste that passes through the holes is printed (transferred) onto the workpiece.

[0003] In screen printing, when printing paste on a workpiece, a pressing member presses the mask body against the surface of the workpiece. Therefore, when the mask body separates from the surface of the workpiece following the movement of the pressing member, i.e., during plate separation, it is important to reliably separate the mask body from the surface of the workpiece without affecting the quality of the paste pattern printed on the workpiece. To improve plate separation of the mask body, it is necessary to manage the tension of the mask body. Therefore, the tension of the mask body is inspected.

[0004] A mask inspection device is used as a device for inspecting the tension of a mask body. An example of a mask inspection device is disclosed in Patent Document 1. The mask inspection device disclosed in Patent Document 1 is a metal mask tension measuring device. This tension measuring device measures the amount of displacement of the metal mask (mask body) when a certain load is applied to the metal mask. In this way, changes in the tension of the metal mask are inspected. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-062996 Summary of the Invention [Problem to be solved by the invention]

[0006] In the tension measuring device disclosed in Patent Document 1, a metal mask is placed on a metal mask table (surface plate), and a certain load is applied by placing a weight on the metal mask. If this tension measuring device is automated, a measuring unit including the weight and a movement mechanism for moving the measuring unit are installed on the metal mask table. Therefore, if the metal mask is large, the metal mask table must be enlarged to accommodate the size of the metal mask in order to avoid interference (clash) between the metal mask and the movement mechanism. This results in an increase in the size of the tension measuring device.

[0007] Furthermore, twisting and distortion can occur in the metal mask frame. In the tension measuring device disclosed in Patent Document 1, the metal mask is placed on a metal mask table, and then a template is placed on the metal mask. If twisting or distortion occurs in the frame, it is difficult to correct the twisting or distortion. When twisting or distortion occurs in the frame, it is difficult to accurately measure the displacement of the metal mask in response to the load applied by the weight. As a result, the tension of the metal mask cannot be inspected with high accuracy.

[0008] An object of the present disclosure is to make it possible to miniaturize a mask inspection apparatus and to inspect the tension of a mask body with high accuracy. [Means for solving the problem]

[0009] In order to achieve the above object, in the technique disclosed herein, the mask printing plate is set below the surface plate, and the frame of the mask printing plate is pressed against the surface plate to perform correction.

[0010] Specifically, a first aspect of the present disclosure is directed to a mask inspection device that inspects the tension of a mask printing plate, which is a sheet-shaped mask body having a printing pattern supported inside a plate frame under tension.

[0011] A first aspect of the mask inspection device comprises a work receiving device on which the mask printing plate is placed, a base plate arranged above the work receiving device, facing the frame of the mask printing plate placed on the work receiving device, and having an opening formed thereon corresponding to the mask body, a pressing mechanism that presses the frame of the mask printing plate placed on the work receiving device against the underside of the base plate by moving the work receiving device toward the base plate, a measurement unit arranged above the base plate that applies a downward load to the mask body through the opening and measures the amount of displacement of the mask body when the load is applied, a moving mechanism that moves the measurement unit at a position above the base plate, and a control device that controls the operation of the pressing mechanism, the measurement unit, and the moving mechanism to move the measurement unit between multiple measurement points set on the mask body and measure the amount of displacement of the mask body at each measurement point while the frame of the mask printing plate is pressed against the underside of the base plate.

[0012] In this first aspect, the mask printing plate is supported by a workpiece support below the surface plate. When the mask printing plate is placed under the surface plate, the measurement unit, the movement mechanism, and the mask printing plate are positioned on opposite sides of the surface plate, avoiding mutual interference. The measurement unit measures the displacement of the mask body of the mask printing plate when a load is applied through the opening in the surface plate. This configuration can accommodate even large mask printing plates, eliminating the need to enlarge the surface plate to accommodate the size of the mask printing plate. This allows for a more compact mask inspection device. Furthermore, the measurement of the displacement of the mask body when a load is applied by the measurement unit is performed with the mask printing plate's frame pressed against the underside of the surface plate. If the mask printing plate's frame is twisted or distorted, the twist or distortion can be corrected by pressing the frame against the underside of the surface plate. This allows the displacement of the mask body to be measured while correcting the twist or distortion of the frame. This allows the measurement unit to suitably measure the amount of displacement of the mask body relative to the applied load, and the tension of the mask body to be inspected with high precision.

[0013] A second aspect of the present disclosure is a mask inspection apparatus according to the first aspect, in which the mask printing plates to be inspected are a first mask printing plate and a second mask printing plate smaller than the first mask printing plate. The workpiece receiving device has a first mounting portion on which the frame of the first mask printing plate is mounted, a first positioning portion that positions the frame of the first mask printing plate on the first mounting portion, a second mounting portion on which the frame of the second mask printing plate is mounted, and a second positioning portion that positions the frame of the second mask printing plate on the second mounting portion. The first mounting portion and the second mounting portion are adjacent to each other via a step. A step wall surface forming the step between the first mounting portion and the second mounting portion functions as the first positioning portion or the second positioning portion.

[0014] In this second aspect, the workpiece receiving device has a first placing portion and a second placing portion adjacent to each other with a step between them. The first mask printing plate placed on the first placing portion is positioned by the first positioning portion. The second mask printing plate placed on the second placing portion is positioned by the second positioning portion. The first positioning portion or the second positioning portion is configured as a step wall surface that forms a step between the first placing portion and the second placing portion. This makes it possible to realize a workpiece receiving device with a simple configuration that can position and place a first mask printing plate and a second mask printing plate of different sizes.

[0015] A third aspect of the present disclosure is the mask inspection apparatus of the first or second aspect, further comprising a camera unit disposed above the surface plate and configured to capture an image of the surface of the mask body of the mask printing plate through the opening, wherein the movement mechanism also functions as a mechanism for moving the camera unit.

[0016] In this third aspect, the mask inspection device includes a camera unit. The camera unit is moved by a moving mechanism and captures an image of the surface of the mask body through an opening in the surface plate. The control device can acquire the image captured by the camera unit and analyze the image by image processing or the like to inspect the surface condition of the mask body, such as whether any paste remains in the printed pattern on the mask body. The moving mechanism serves as both a mechanism for moving the measurement unit and the camera unit. This is advantageous for miniaturizing the mask inspection device.

[0017] A fourth aspect of the present disclosure is the mask inspection apparatus according to any one of the first to third aspects, wherein a metal mask is used as the mask printing plate to be inspected.

[0018] In this fourth aspect, a metal mask is the object of inspection. A metal mask is a type of mask printing plate, and is mainly used to print solder paste (cream solder) on a substrate as a workpiece. Even with a metal mask, good releasability from the substrate is crucial to improving the quality of the paste pattern. Therefore, the technology disclosed herein is also effective in a mask inspection device that inspects metal masks. [Effects of the Invention]

[0019] According to the technique of the present disclosure, the mask inspection device can be made smaller and the tension of the mask body can be inspected with high accuracy. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a mask inspection apparatus. [Figure 2] FIG. 2 is a plan view illustrating a schematic configuration of a mask printing plate to be inspected. [Figure 3] 3 is a plan view illustrating the schematic configuration of the inspection machine, in which the case where the first mask printing plate is set is illustrated by a two-dot chain line. [Figure 4] Figure 4 is a side view of the inspection machine as seen from arrow A in Figure 3. In Figure 4, the case where the first mask printing plate is set is illustrated by a solid line, and the case where the second mask printing plate and the third mask printing plate are set is illustrated by a two-dot chain line. For convenience, Figure 4 shows the first to third mask printing plates as cross sections. [Figure 5] Figure 5 is a side view of the inspection machine as seen from arrow B in Figure 3. In Figure 5, the case where the first mask printing plate is set is illustrated by a solid line, and the case where the second mask printing plate and the third mask printing plate are set is illustrated by a two-dot chain line. For convenience, Figure 5 shows the first to third mask printing plates as cross sections. [Figure 6A] FIG. 6A is a plan view illustrating the schematic configuration of the workpiece receiving tool together with the set state of the first mask printing plate and the surface plate (both indicated by two-dot chain lines). [Figure 6B]FIG. 6B is a plan view illustrating the schematic configuration of the workpiece receiving tool together with the second mask printing plate set and the surface plate (both indicated by two-dot chain lines). [Figure 6C] FIG. 6C is a plan view illustrating the schematic configuration of the workpiece receiving tool together with the set state of the third mask printing plate and the surface plate (both are indicated by two-dot chain lines). [Figure 7] FIG. 7 is a perspective view illustrating a schematic configuration of the measurement unit. [Figure 8] FIG. 8 is a cross-sectional view illustrating the configuration of the connecting mechanism of the measurement unit. [Figure 9] 9A to 9C are cross-sectional views illustrating the operation of the connecting mechanism of the measurement unit. [Figure 10] FIG. 10 is a block diagram illustrating the control device and main related devices. [Figure 11] Fig. 11 is a diagram equivalent to Fig. 5 illustrating the operation of the pressing mechanism during inspection in the mask inspection device. Fig. 11 illustrates the case where the first mask printing plate is set. For convenience, Fig. 11 shows the mask printing plate as a cross section. [Figure 12] 12 is a plan view illustrating an example of the operation of the mask inspection apparatus when inspecting the openings in the mask printing plate, in which the case where the first mask printing plate is set is illustrated by a two-dot chain line. [Figure 13] 13 is a plan view illustrating an example of a connecting operation between the measurement unit and the moving mechanism when inspecting the tension of a mask printing plate in a mask inspection device. In FIG. 13, the case where a first mask printing plate is set is illustrated by a two-dot chain line. [Figure 14] 14 is a plan view illustrating an example of the operation of the mask inspection device when inspecting the tension of the mask printing plate, in which the two-dot chain line illustrates the case where the first mask printing plate is set. [Figure 15] 15 is a cross-sectional view of a main part illustrating the operation of zero point adjustment during tension inspection of a mask printing plate in a mask inspection apparatus, in which a first mask printing plate is set. [Figure 16]16 is a cross-sectional view of a main part illustrating the operation of zero point adjustment during tension inspection of a mask printing plate in a mask inspection apparatus, in which a first mask printing plate is set. [Figure 17] 17 is a cross-sectional view of a main part illustrating an operation of measuring the displacement of the mask body during tension inspection of the mask printing plate in the mask inspection apparatus, in which the first mask printing plate is set. [Figure 18] 18 is a cross-sectional view of a main part illustrating an operation of measuring the displacement of the mask body during tension inspection of the mask printing plate in the mask inspection device, in which the first mask printing plate is set. DETAILED DESCRIPTION OF THE INVENTION

[0021] Exemplary embodiments will now be described in detail with reference to the accompanying drawings.

[0022] In the following description, the upper side of the mask inspection apparatus 1 in the vertical direction will be referred to as "upper" and the lower side as "lower," the side where the mask printing plate 500 is set on the workpiece receiving tool 10 will be referred to as "front," the back side as seen from the side where the mask printing plate 500 is set will be referred to as "rear," and the left side when seen from the front to the rear will be referred to as "left" and the right side will be referred to as "right." Note that the terms "first," "second," etc. described below are used to distinguish between terms to which these terms are attached, and do not limit the number or order of the terms.

[0023] The mask inspection apparatus 1 of this embodiment is used to inspect a mask printing plate 500 as an inspection object, and to perform an opening inspection to inspect the opening state of holes 501h in a printing pattern 501 of the mask printing plate 500, and a tension inspection to inspect the tension applied to a mask body 502. The mask inspection apparatus 1 shown in Fig. 1 is an apparatus that selectively performs an opening inspection and a tension inspection of the mask printing plate 500 in accordance with a user's operation. The mask inspection apparatus 1 may also be capable of continuously performing an opening inspection and a tension inspection of the mask printing plate 500.

[0024] As shown in FIG. 2, the mask printing plate 500 includes a printing frame 502 and a mask body 504. The printing frame 502 is, for example, a frame body formed in a rectangular shape in a plan view. The printing frame 502 is made of, for example, aluminum. The aluminum printing frame 502 is relatively lightweight and easy to handle, but may twist or warp, causing a loss of flatness. The mask body 504 is a sheet-like object and has a printing pattern 501. The printing pattern 501 is made of holes 501h that open in a predetermined shape.

[0025] The mask inspection device 1 inspects a metal mask as a mask printing plate 500. The mask body 504 of the metal mask is made of, for example, stainless steel. The mask body 504 is supported inside the frame 502 with the required tension applied. The metal mask is a so-called combination mask in which a mesh member (not shown) called gauze is attached to the frame 502, and the mask body 504 is fixed to the mesh member with an adhesive. The metal mask may also be a so-called direct-attached mask in which the mask body 504 is directly attached to the frame 502.

[0026] The mask inspection apparatus 1 is capable of handling mask printing plates 500 of a variety of sizes. The mask inspection apparatus 1 of this example inspects a first mask printing plate 500A, a second mask printing plate 500B, and a third mask printing plate 500C as the mask printing plates 500 (see FIGS. 6A to 6C). The first mask printing plate 500A, the second mask printing plate 500B, and the third mask printing plate 500C are designed to have different dimensions. The sizes of the first mask printing plate 500A, the second mask printing plate 500B, and the third mask printing plate 500C increase in size in that order.

[0027] The first mask printing plate 500A is a relatively large plate. The size of the first mask printing plate 500A is, for example, 736 mm x 736 mm. The second mask printing plate 500B is a plate smaller in size than the first mask printing plate 500A. The size of the second mask printing plate 500B is, for example, 550 mm x 650 mm. The third mask printing plate 500C is a plate smaller in size than the second mask printing plate 500B. The third mask printing plate 500C is, for example, 550 mm x 600 mm.

[0028] - Mask inspection system configuration - 1, the mask inspection apparatus 1 includes an inspection machine 3, a control device 5, and a storage device 7. As shown in FIGS. 3 to 5, the inspection machine 3 includes a workpiece receiving tool 10, a surface plate 20, a pressing mechanism 30, a moving mechanism 40, a camera unit 60, a guide mechanism 70, and a measurement unit 80.

[0029] <Work receiving tool> The work receiving tool 10 is a jig on which the mask printing plate 500 is placed. As shown in FIGS. 6A to 6C, the work receiving tool 10 receives the plate frame 502 of the mask printing plate 500. The work receiving tool 10 of this example is composed of a pair of receiving members 11. The pair of receiving members 11 are arranged at a distance from each other in the left-right direction. Each of the pair of receiving members 11 is formed in the shape of a strip extending in the front-rear direction. Each receiving member 11 is provided so that its length direction corresponds to the front-rear direction and its width direction corresponds to the left-right direction. Each receiving member 11 is composed of a horizontal plate portion 12 and a vertical wall portion 13.

[0030] The horizontal plate portion 12 of each receiving member 11 is provided with a first mounting portion 14 and a second mounting portion 15. The first mounting portion 14 is a portion on which the frame 502 of the first mask printing plate 500A is mounted (see FIG. 6A). The second mounting portion 15 is a portion on which the frame 502 of the second mask printing plate 500B and the frame 502 of the third mask printing plate 500C are mounted (see FIGS. 6B and 6C). The first mounting portion 14 and the second mounting portion 15 are adjacent to each other with a step interposed between them. The first mounting portion 14 is located on the closer sides of the pair of receiving members 11. The second mounting portion 15 is located on the farther sides of the pair of receiving members 11. The surface of the first mounting portion 14 that receives the frame 502 is formed at a higher position than the surface of the second mounting portion 15 that receives the frame 502.

[0031] The vertical wall portion 13 of each receiving member 11 is a wall portion that protrudes upward from the end of the horizontal plate portion 12. The vertical wall portion 13 is provided at the end of the first mounting portion 14 opposite the second mounting portion 15, i.e., at the end portions of the pair of receiving members 11 that are spaced apart from each other. The vertical wall portion 13 functions as a first positioning portion 16 that positions the frame 502 of the first mask printing plate 500A on the first mounting portion 14. In addition, a step wall surface 17 that forms a step between the first mounting portion 14 and the second mounting portion 15 functions as a second positioning portion 18 that positions the frame 502 of the second mask printing plate 500B and the frame 502 of the third mask printing plate 500C on the second mounting portion 15. Each receiving member 11 extends forward from the surface plate 20 in a plan view.

[0032] <Standard Plate> The surface plate 20 is a plate body that provides a reference plane (horizontal plane) for inspecting the mask printing plate 500. The surface plate 20 is, for example, a rectangular plate. The surface plate 20 is made of, for example, cast iron. The surface plate 20 is arranged above the workpiece receiving tool 10. The surface plate 20 is provided in a position facing the plate frame 502 of the mask printing plate 500 placed on the workpiece receiving tool 10. An inspection opening 22, a first confirmation window 24, and a second confirmation window 26 are formed in the surface plate 20.

[0033] The inspection opening 22 is formed in a portion of the surface plate 20 corresponding to the mask body 504 of the mask printing plate 500 placed on the workpiece receiving tool 10. The inspection opening 22 is opened in an area required for measuring the displacement of the mask body 504 common to the multiple mask printing plates 500 to be inspected (in this example, the first to third mask printing plates 500A, 500B, and 500C). The inspection opening 22 is formed, for example, in a shape such that a long hole extending outward is added to one side of a rectangular opening (the left side in the example shown in FIG. 2 ). The inspection opening 22 is located between the pair of receiving members 11 in a plan view and is provided so as to overlap the edge portions of the horizontal plate portions 12 of each receiving member 11. The long hole portion 22a of the inspection opening 22 extends so as to overlap the first mounting portion 14 and the second mounting portion 15 of one receiving member 11.

[0034] The first confirmation window 24 and the second confirmation window 26 are each openings for confirming the placement state of the mask printing plate 500 on the workpiece receiving tool 10. Both the first confirmation window 24 and the second confirmation window 26 are formed on the front side of the surface plate 20. The first confirmation window 24 and the second confirmation window 26 are formed separately on both sides in the left-right direction. The first confirmation window 24 is located on the left front side of the inspection opening 22, and allows an upward view of the first placement portion 14 and the second placement portion 15 of the left receiving member 11. The second confirmation window 26 is located on the right front side of the inspection opening 22, and allows an upward view of the first placement portion 14 and the second placement portion 15 of the right receiving member 11.

[0035] The first confirmation window 24 is formed, for example, by a rectangular opening. The second confirmation window 26 is formed, for example, by a rectangular notch that is open to the front side. The second confirmation window 26 exposes the mask printing plate 500 (at least the corners of the plate frame 502) above the surface plate 20 over a wider area than the first confirmation window 24. This makes the second confirmation window 26 usable as a working area when adjusting the placement position of the mask printing plate 500 relative to the workpiece receiving tool 10.

[0036] <Press mechanism> The pressing mechanism 30 is a mechanism that presses the plate frame of the mask printing plate placed on the work receiving tool 10 against the underside of the surface plate. The pressing mechanism 30 includes a support stay 32 and an actuator 34. The support stay 32 and the actuator 34 are provided for each receiving member 11. One end of the support stay 32 is fixed to the vertical wall portion 13 of the receiving member 11. The other end of the support stay 32 is attached to the actuator 34. The actuator 34 is disposed below the surface plate 20. The actuator 34 is attached to the underside of the surface plate 20.

[0037] The pressing mechanism 30 supports the work receiving tool 10 in a suspended state. The actuator 34 is a mechanical component that moves the work receiving tool 10 up and down via the support stay 32. The actuator 34 is configured, for example, by an air cylinder. The pressing mechanism 30 moves the work receiving tool 10 upward by operation of the actuator 34. As a result, the plate frame 502 of the mask printing plate 500 is placed against the underside of the surface plate 20 and pressed with a predetermined pressure. The pressing mechanism 30 also moves the work receiving tool 10 downward by operation of the actuator 34. As a result, the plate frame 502 of the mask printing plate 500 is separated from the underside of the surface plate 20.

[0038] <Movement mechanism> The moving mechanism 40 is a mechanism that moves the measuring unit 80 above the surface plate 20. The moving mechanism 40 also functions as a mechanism that moves the camera unit 60. The moving mechanism 40 supports the camera unit 60 so that it can move in the front-to-back and left-to-right directions. The moving mechanism 40 is configured to include a first linear motion mechanism 41 and a second linear motion mechanism 45. The first linear motion mechanism 41 is a mechanism that moves the camera unit 60 and the measuring unit 80 in the left-to-right direction. The second linear motion mechanism 45 is a mechanism that moves the camera unit 60 and the measuring unit 80 in the front-to-back direction.

[0039] The first linear motion mechanism 41 has a first feed screw mechanism 42 and a first drive motor 44. The first feed screw mechanism 42 is installed on the surface plate 20 behind the inspection opening 22. The first feed screw mechanism 42 includes a carriage 43, a linear guide, and a ball screw (neither of which are shown). The first drive motor 44 operates the first feed screw mechanism 42. The first drive motor 44 is configured to be able to switch its rotation direction. The first drive motor 44 is, for example, a servo motor. The first linear motion mechanism 41 moves the carriage 43 in the left-right direction by driving the first drive motor 44.

[0040] The second linear motion mechanism 45 is installed on the carriage 43 of the first feed screw mechanism 42. The second linear motion mechanism 45 is disposed in an orientation perpendicular to the first linear motion mechanism 41 so as to span the entire length of the inspection opening 22 in the front-to-rear direction. The second linear motion mechanism 45 has a second feed screw mechanism 46 and a second drive motor 48. The second feed screw mechanism 46 is configured to include a carriage 47, a linear guide, and a ball screw (neither of which are shown). The second drive motor 48 operates the second feed screw mechanism 42. The second drive motor 48 is configured to be able to switch its rotation direction. The second drive motor 48 is, for example, a servo motor. The second linear motion mechanism 45 moves the carriage 47 in the front-to-rear direction by driving the second drive motor 48.

[0041] The movement mechanism 40 moves the carriage 47 together with the second linear motion mechanism 45 in the left-right direction by operating the first drive motor 44. The movement mechanism 40 moves the carriage 47 of the second linear motion mechanism 45 in the front-rear direction by operating the second drive motor 48. The carriage 47 of the second linear motion mechanism 45 is installed with its main surface facing left. A bracket 49 is attached to the main surface of the carriage 47. The bracket 49 extends from the carriage 47 to the left. A connecting stay 50 is fixed to the bracket 49 so as to extend from the bracket 49. An insertion hole 52 is formed at the tip of the connecting stay 50.

[0042] <Camera unit> The camera unit 60 is a device that photographs the surface of the mask body 504 of the mask printing plate 500 through the inspection opening 22 of the surface plate 20. The camera unit 60 has a photographing device and an illumination device, not shown. The photographing device is composed of a known photographing device such as a CCD (Charge Coupled Device) camera or a CMOS (Complementary Metal Oxide Semiconductor) camera. The illumination device is a device that irradiates light toward the subject to be photographed. The illumination device is composed of, for example, an LED (Light Emitting Diode).

[0043] The camera unit 60 is disposed above the base 20. The camera unit 60 is attached to the bracket 49 and is positioned to the side (for example, in front) of the bracket 49. The camera unit 60 is installed with the photographing lens facing downward. The camera unit 60 moves in the horizontal direction (front-back and left-right) by being driven by the movement mechanism 40. The camera unit 60 photographs the subject with the photographing device while illuminating the subject with light from the lighting device. The photographing results of the camera unit 60 are output to the control device 5.

[0044] Guide mechanism The guide mechanism 70 is a mechanism that supports the measurement unit 80 and guides the movement of the measurement unit 80. The guide mechanism 70 is installed on the surface plate 20. The guide mechanism 70 has a pair of first linear guides 71 and a second linear guide 75.

[0045] A pair of first linear guides 71 are installed separately on the rear and front sides of the inspection opening 22. The front first linear guide 71 is installed in front of the first confirmation window 24 so as not to overlap the second confirmation window 26. Each first linear guide 71 includes a first rail 72 and a first slider 73. The first rail 72 is a guide that guides the sliding of the first slider 73. The first rail 72 extends linearly in the left-right direction. The first slider 73 is attached to the first rail 72 so as to be slidable in the longitudinal direction.

[0046] The second linear guide 75 is provided perpendicular to the first rail 72 so as to span the entire length of the inspection opening 22 in the front-to-rear direction. The second linear guide 75 has a second rail 76 and a second slider 77. The second rail 76 is a guide that guides the sliding of the second slider 77. The second rail 76 extends linearly in the front-to-rear direction. Both end portions of the second rail 76 are fixed to different first sliders 73. The second slider 77 is attached to the second rail 76 so as to be slidable in the longitudinal direction.

[0047] <Measurement unit> The measurement unit 80 is a device that applies a downward load to the mask body 504 of the mask printing plate 500 through the inspection opening 22 and measures the amount of displacement of the mask body 504 when the load is applied. The measurement unit 80 is disposed above the surface plate 20. The measurement unit 80 is supported by the second slider 77 via a bracket 81. The bracket 81 is attached to the second slider 77.

[0048] The bracket 81 is an L-shaped metal fitting in a side view, and has a support plate portion 82. The support plate portion 82 is provided with its main surface facing right. The measurement unit 80 is attached to the support plate portion 82. When the tension test of the mask printing plate 500 is not being performed, the measurement unit 80 is retracted to a position near one end in the left-right direction of the surface plate 20 (a position near the left end in this example) (see FIGS. 3 and 5). As shown in FIG. 7, the measurement unit 80 has a weight 83, a displacement meter 84, an actuator 87, and a connecting mechanism 92.

[0049] The weight 83 is a cylindrical metal block. The displacement meter 84 is a sensor that measures the amount of deflection (amount of movement) when the mask body 504 of the mask printing plate 500 deflects downward under the load of the weight 83. The displacement meter 84 is configured, for example, by a contact-type linear displacement sensor. The actuator 87 is a mechanical component that moves the weight 83 and the displacement meter 84 in the vertical direction. The actuator 87 is fixed to the support plate portion 82 of the bracket 81. It is configured, for example, by an electric slider. The actuator 87 has a movable plate 88 that moves in the vertical direction.

[0050] The displacement meter 84 is fixed to a movable plate 88 of an actuator 87. The displacement meter 84 has a rectangular parallelepiped main body 85 and a rod-shaped contactor 86. The contactor 86 is constantly biased toward the protruding side from the main body 85. The displacement meter 84 is disposed in a position in which the contactor 86 extends downward from the main body 85. A plate-shaped support piece 89 is provided on the movable plate 88 below the displacement meter 84. An insertion hole (not shown) is formed in the support piece 89. A bolt 91 attached to the top of the weight 83 is inserted into this insertion hole. The weight 83 is suspended from the support piece 89 via the bolt 91.

[0051] The length of the bolt 91 that protrudes upward from the insertion hole of the support piece 89 changes depending on the downward movement of the movable plate 88 after the weight 83 is placed on the mask printing plate 500. In the measurement unit 80, when the movable plate 88 descends, it is placed on the surface of the mask printing plate 500 (on the plate frame 502 during zero-point adjustment, and on the mask body 504 during displacement measurement) (see FIGS. 15 and 17). This applies a predetermined load to the mask printing plate 500. When the movable plate 88 further descends, the upper part of the bolt 91 approaches the contact 86 of the displacement meter 84 and abuts against the tip of the contact 86 (see FIGS. 16 and 18). When upward pressure against the biasing force is applied from the bolt 91, the contact 86 is displaced toward the main body 85. The displacement meter 84 is configured to be able to measure the displacement of the contact 86.

[0052] The connecting mechanism 92 is a mechanism that connects the measurement unit 80 to the moving mechanism 40. The connecting mechanism 92 has a pair of guide plates 93, a connecting rod 96, and an actuator 98. As shown in FIG. 8 , the pair of guide plates 93 are L-shaped metal fittings. Each guide plate 93 is fixed to the support plate portion 82 of the bracket 81. The pair of guide plates 93 are arranged to face each other in the vertical direction. The pair of guide plates 93 are arranged with a gap between them. An insertion space 94 is provided between the pair of guide plates 93. The insertion space 94 is a space into which the connecting stay 50 of the moving mechanism 40 is inserted.

[0053] An insertion hole 95 is formed in each guide plate 93. The insertion holes 95 of a pair of guide plates 93 correspond to each other in the vertical direction. The connecting rod 96 and actuator 98 are disposed below the lower guide plate 93. The connecting rod 96 is attached to a piston rod 99 of the actuator 98 in an orientation extending in the vertical direction. The actuator 98 is fixed to the support plate portion 82 of the bracket 81. The actuator 98 is a mechanical component that moves the connecting rod 96 in the vertical direction. The actuator 98 is configured by, for example, an air cylinder.

[0054] 9, the connecting mechanism 92 moves the connecting rod 96 upward by operation of the actuator 98. At this time, when the connecting stay 50 of the moving mechanism 40 is inserted into the insertion space 94 and the through-hole 52 of the connecting stay 50 and the through-hole 52 of each guide plate 93 correspond to each other in the vertical direction, the connecting rod 96 is inserted in a skewer-like manner through the through-hole 52 of the connecting stay 50 and the through-hole 95 of each guide plate 93. As a result, the measurement unit 80 is connected to the moving mechanism 40 (the carriage 47 of the second linear motion mechanism 45) via the connecting stay 50.

[0055] When the measuring unit 80 is connected to the moving mechanism 40, it can be moved in horizontal directions (front-back and left-right directions) by driving the moving mechanism 40. The measuring unit 80 is pulled by driving the first linear motion mechanism 41. As a result, the measuring unit 80 moves left-right while being guided by the first linear guide 71. The measuring unit 80 is pulled by driving the second linear motion mechanism 45. As a result, the measuring unit 80 moves front-back while being guided by the second linear guide 75.

[0056] Control Device The control device 5 comprehensively controls the operation of the inspection machine 3. As shown in Fig. 10, the control device 5 is electrically connected to the actuator 34 of the pressing mechanism 30, the drive motors 44 and 48 of the moving mechanism 40, the camera unit 60, and the displacement meter 84, actuator 87, and linking mechanism 92 (actuator 98) of the measuring unit 80. The control device 5 is a controller based on a well-known microcomputer.

[0057] The control device 5 has a CPU (Central Processing Unit) 5a and a memory 5b. The memory 5b stores various programs and data. The CPU 5a executes the programs read from the memory 5b. By executing the programs, the control device 5 controls the inspection machine 3 (pressing mechanism 30, moving mechanism 40, camera unit 60, and measurement unit 80) according to the automatic mode sequence. The control device 5 causes the inspection machine 3 to inspect the openings in the mask printing plate 500 and inspect the tension of the mask printing plate 500.

[0058] The control device 5 sets a plurality of measurement points P1 to P5 on the portion of the mask body 504 of the mask printing plate 500 placed on the workpiece receiving tool 10 that is exposed through the inspection opening 22 of the surface plate 20 (see FIGS. 6A to 6C). The measurement points P1 to P5 are points at which the amount of displacement of the mask body 504 is measured when a predetermined load is applied by the measurement unit 80 during a tension test of the mask printing plate 500. In this example, the plurality of measurement points P1 to P5 are set at five points: a central position P1 of the inspection opening 22 and positions P2 to P4 near the four corners of the inspection opening 22.

[0059] The control device 5 sets a reset point P0 according to the size of the mask printing plate 500. The reset point P0 is a point where the measurement value of the displacement meter 84 is reset to zero (see FIGS. 6A to 6C). In a tension test of the mask printing plate 500, the reset point P0 is set at the position of the frame 502 of the mask printing plate 500 placed on the workpiece receiving tool 10 in the elongated hole portion 22a of the inspection opening 22. The position of the frame 502 of the mask printing plate 500 varies depending on whether the mask printing plate 500 to be tested is the first mask printing plate 500A, the second mask printing plate 500B, or the third mask printing plate 500C.

[0060] In the tension test of the mask printing plate 500, the control device 5 moves the measurement unit 80 between a plurality of measurement points P1 to P5 set on the mask body 504. The control device 5 controls the operations of the pressing mechanism 30, the measurement unit 80, and the movement mechanism 40 so as to measure the amount of displacement of the mask body 504 at each of the measurement points P1 to P5 while pressing the plate frame 502 of the mask printing plate 500 against the lower surface of the surface plate 20. The control device 5 stores the measurement results (the amount of displacement of the mask body 504) in the tension test of the mask printing plate 500 in the storage device 7, individually managing them by serial number or the like for each mask printing plate 500.

[0061] In tension testing of the mask printing plate 500, the control device 5 controls the operations of the pressing mechanism 30, the measuring unit 80, and the moving mechanism 40 to move the measuring unit 80 to the reset point P0, and, with the plate frame 502 of the mask printing plate 500 pressed against the underside of the surface plate 20 at the reset point P0, measure the amount of displacement of the plate frame 502, thereby resetting the measurement value to zero. Before measuring the amount of displacement of the mask body 504 at the measurement points P1 to P5, the control device 5 causes the measuring unit 80 to perform zero-point adjustment, which resets the measurement value to zero.

[0062] <Storage device> The storage device 7 stores various types of information. The storage device 7 is configured with a known storage device such as an HDD (Hard Disk Drive) or SSD (Solid State Drive). The storage device 7 is either built into the inspection machine 3 or configured integrally with the control device 5. The storage device 7 may be configured with an external storage device provided outside the inspection machine 3. The storage device 7 stores photographed images acquired during the opening inspection of the mask printing plate 500 and information on defective areas detected by analyzing the photographed images. The storage device 7 also stores measured values ​​of the amount of displacement of the mask body 504 when a predetermined load is applied, which are acquired during the tension inspection of the mask printing plate 500.

[0063] -Operation of mask inspection equipment- To inspect the openings in the mask printing plate 500 using the mask inspection device 1, the user first slides the mask printing plate 500 under the surface plate 20 and sets it on the workpiece receiving tool 10 as shown in FIGS. 6A to 6C.

[0064] When the mask printing plate 500 to be inspected is the first mask printing plate 500A, the mask printing plate 500 is positioned by placing the plate frame 502 on the first mounting section 14 along the vertical wall sections 13 (first positioning sections 16) of both receiving members 11 (see FIG. 6A). When the mask printing plate 500 to be inspected is the second mask printing plate 500B, the mask printing plate 500 is positioned by placing the plate frame 502 on the second mounting section 15 along the stepped wall surfaces 17 (second positioning sections 18) of both receiving members 11 (see FIG. 6B). If the mask printing plate 500 to be inspected is the third mask printing plate 500C, the mask printing plate 500 is positioned by placing the plate frame 502 on the second mounting portion 15 along the stepped wall surface 17 (second positioning portion 18) of one of the receiving members 11 (in this example, the right-side receiving member 11) (see Figure 6C).

[0065] In the mask inspection device 1, when a user instructs to inspect the opening of the mask printing plate 500, the actuator 34 of the pressing mechanism 30 is actuated to move the workpiece receiver 10 upward, and the plate frame 502 of the mask printing plate 500 is pressed against the lower surface of the surface plate 20, as shown in Fig. 11 . Then, as shown in Fig. 12 , the drive motors 44, 48 of the movement mechanism 40 are actuated to move the camera unit 60 so as to scan the entire area of ​​the mask body 504 exposed from the inspection opening 22. At this time, the camera unit 60 illuminates and photographs the surface of the mask body 504. The photographed image taken by the camera unit 60 is input to the control device 5.

[0066] The captured image input to the control device 5 is subjected to image analysis by the control device 5. This allows inspection of defects in the opening state of the printed pattern 501, such as ink residue adhering to the holes 501h of the printed pattern 501. The results of the opening inspection of the mask printing plate 500 (whether it is normal or defective, and if it is defective, the position information of the defective part) are stored in the storage device 7. The inspection results stored in the storage device 7 are displayed on a display (not shown). The user can check the inspection results and their history on the display.

[0067] In the mask inspection device 1, when the opening inspection of the mask printing plate 500 is completed, the actuator 34 of the pressing mechanism 30 is actuated to move the work receiving tool 10 downward, and the plate frame 502 of the mask printing plate 500 is separated from the lower surface of the surface plate 20. As a result, the mask printing plate 500 placed on the work receiving tool 10 can be pulled out toward the front, and the inspected mask printing plate 500 can be taken out from the inspection machine 3.

[0068] To perform a tension inspection of the mask printing plate 500 using the mask inspection device 1, first, the user slides the mask printing plate 500 under the surface plate 20 and sets it on the workpiece receiving tool 10 as shown in Figures 6A to 6C. The method for positioning the mask printing plate 500 with respect to the workpiece receiving tool 10 at this time is as described above.

[0069] In the mask inspection apparatus 1, when a user scans to instruct the execution of a tension inspection of the mask printing plate 500, the actuator 34 of the pressing mechanism 30 is actuated to move the workpiece receiver 10 upward, and the plate frame 502 of the mask printing plate 500 is pressed against the lower surface of the surface plate 20, as shown in FIG. 11 . Next, as shown in FIG. 13 , the drive motors 44, 48 of the moving mechanism 40 are actuated to move the carriage 47 of the second linear motion mechanism 45 toward the measuring unit 80. At this time, as shown in FIG. 8 , the connecting stay 50 is inserted into the insertion space 94 of the measuring unit 80 at a position where the insertion hole 52 corresponds to the insertion hole 95 of each guide plate 93. Furthermore, as shown in FIG. 9 , the actuator 98 of the connecting mechanism 92 is actuated to connect the measuring unit 80 to the moving mechanism 40.

[0070] Next, the drive motors 44 and 48 of the movement mechanism 40 are actuated to pull the measurement unit 80 by the connecting stay 50 and move it to the reset point P0. Then, as shown in FIGS. 15 and 16 , at the reset point P0, the actuator 87 of the measurement unit 80 is actuated to perform zero-point adjustment, and the measurement value of the displacement meter 84 is reset to zero. Thereafter, as shown in FIG. 14 , the drive motors 44 and 48 of the movement mechanism 40 are actuated to pull the measurement unit 80 by the connecting stay 50 and move it sequentially to the plurality of measurement points P1 to P5. Then, as shown in FIGS. 17 and 18 , at each of the measurement points P1 to P5, the actuator 87 of the measurement unit 80 is actuated to place a weight 83 on the surface of the mask body 504, and a predetermined load is applied to the mask body 504. Furthermore, at each of the measurement points P1 to P5, the displacement meter 84 measures the displacement of the mask body 504 relative to the predetermined load.

[0071] The measurement results (measured values ​​of the displacement of the mask body 504) measured at each of the measurement points P1 to P5 by the measurement unit 80 are input to the control device 5. The measurement results input to the control device 5 can be used to calculate the tension of the mask body 504 in the mask printing plate 500. The user may determine whether the tension of the mask body 504 is normal or defective based on the measurement results input to the control device 5, or the control device 5 may make the determination using a threshold value. The measurement results from the tension inspection of the mask printing plate 500 are stored in the storage device 7. The measurement results stored in the storage device 7 are displayed on a display (not shown). The user can check the measurement results and their history (i.e., the changes in the tension of the mask body 504) on the display.

[0072] In the mask inspection device 1, when the tension inspection of the mask printing plate 500 is completed, the actuator 34 of the pressing mechanism 30 is actuated to move the work receiving tool 10 downward, and the plate frame 502 of the mask printing plate 500 is separated from the lower surface of the surface plate 20. As a result, the mask printing plate 500 placed on the work receiving tool 10 can be pulled out toward the front, and the inspected mask printing plate 500 can be removed from the inspection machine 3.

[0073] -Features of the embodiment- In the mask inspection apparatus 1 of this embodiment, the mask printing plate 500 is supported by the workpiece receiving device 10 below the surface plate 20. When the mask printing plate 500 is placed under the surface plate 20, the measurement unit 80 and the moving mechanism 40 are positioned on opposite sides of the surface plate 20, avoiding mutual interference. The measurement unit 80 then measures the displacement of the mask body 504 of the mask printing plate 500 when a load is applied through the inspection opening 22 in the surface plate 20. This configuration allows for the use of even large mask printing plates 500, eliminating the need to enlarge the surface plate 20 to accommodate the size of the mask printing plate 500. This allows for the miniaturization of the mask inspection apparatus 1. Furthermore, the measurement of the displacement of the mask body 504 when a load is applied by the measurement unit 80 is performed with the frame 502 of the mask printing plate 500 pressed against the underside of the surface plate 20. If twist or distortion occurs in the frame 502 of the mask printing plate 500, the frame 502 can be pressed against the lower surface of the surface plate 20 to correct the twist or distortion that has occurred in the frame 502. This makes it possible to measure the amount of displacement of the mask body 504 while correcting the twist or distortion of the frame 502. This makes it possible to suitably measure the amount of displacement of the mask body 504 in response to the load applied by the measurement unit 80, and to accurately inspect the tension of the mask body 504.

[0074] In the mask inspection apparatus 1 of this embodiment, the workpiece receiving tool 10 has a first receiving section 14 and a second receiving section 15 that are adjacent to each other with a step between them. The first mask printing plate 500A placed on the first receiving section 14 is positioned by a first positioning section 16. The second mask printing plate 500B and the third mask printing plate 500C placed on the second receiving section 15 are positioned by a second positioning section 18. The second positioning section 18 is composed of a step wall surface 17 that forms a step between the first receiving section 14 and the second receiving section 15. This makes it possible to realize a workpiece receiving tool 10 with a simple configuration that can position and receive the first mask printing plate 500A, the second mask printing plate 500B, and the third mask printing plate 500C of different sizes.

[0075] The mask inspection apparatus 1 of this embodiment includes a camera unit 60. The camera unit 60 is moved by the moving mechanism 40 and captures an image of the surface of the mask body 504 through the inspection opening 22 in the surface plate 20. The control device 5 can acquire the image captured by the camera unit 60 and analyze the image by image processing or the like to inspect the surface condition of the mask body 504, such as whether any paste remains in the print pattern 501 of the mask body 504. The moving mechanism 40 also serves as a mechanism for moving the measurement unit 80 and the camera unit 60. This is advantageous for miniaturizing the mask inspection apparatus 1.

[0076] In this embodiment, the mask inspection apparatus 1 inspects a metal mask. A metal mask is a type of mask printing plate 500 and is primarily used to print solder paste (cream solder) on a substrate as a workpiece. Even with a metal mask, good release of the plate from the substrate is crucial to improving the quality of the paste pattern. Therefore, the technology disclosed herein is also effective in a mask inspection apparatus 1 that inspects a metal mask.

[0077] As described above, preferred embodiments have been described as examples of the technology of the present disclosure. However, the technology of the present disclosure is not limited to these, and can be applied to embodiments in which appropriate modifications, substitutions, additions, omissions, etc. are made. It will be understood by those skilled in the art that various modifications are possible to the above-described embodiments without departing from the spirit of the technology of the present disclosure, and that such modifications also fall within the scope of the technology of the present disclosure.

[0078] For example, in the above embodiment, the measurement unit 80 is configured to apply a predetermined load to the mask body 504 of the mask printing plate 500 by placing the weight 83 on the mask body 504, but this is not limited to this. The measurement unit 80 can have any configuration, such as a configuration in which a cylindrical pressing body is pressed against the mask body 504 of the mask printing plate 500 by driving an electric slider, thereby applying a predetermined load to the mask body 504.

[0079] In the above embodiment, a contact-type linear displacement sensor is used as the displacement meter 84 included in the measurement unit 80, but this is not limiting. The displacement meter 84 may be configured by a displacement sensor of another type, such as a laser type.

[0080] Furthermore, in the above embodiment, a metal mask has been given as an example of an object to be inspected by the mask inspection apparatus 1, but this is not limiting. A metal mask is merely one example of the mask printing plate 500, and the object to be inspected by the mask inspection apparatus 1 may also be a screen mask having a mask body 504 in which a mask film made of a resin composition is formed on a mesh member woven with wires, as long as it is a mask printing plate 500 in which a sheet-like mask body 504 having a printing pattern 501 is supported inside a plate frame 502 in a tensioned state. [Industrial Applicability]

[0081] As described above, the technique of the present disclosure is useful for a mask inspection apparatus that inspects the tension applied to the mask body of a mask printing plate. [Explanation of symbols]

[0082] P1~P5 measurement points 1 Mask inspection equipment 5. Control device 10 Workpiece holder 14 First placement section 15 Second loading section 16 First positioning part 18 Second positioning part 17 Step wall 20 Surface Plate 22 Inspection opening (opening) 30 Pressing mechanism 40 Moving mechanism 60 Camera Unit 80 measurement units 500 mask printing plates 500A 1st mask printing plate 500B 2nd mask printing plate 501 Printing Pattern 502 printing frame 504 Masked Body

Claims

1. A mask inspection device inspects a mask printing plate, which is an inspection object and is formed by supporting a sheet-like mask having a printing pattern inside a printing frame in a tensioned state, and inspects the tension of the mask, a workpiece receiving tool on which the mask printing plate is placed; a surface plate disposed above the work receiving device, facing the plate frame of the mask printing plate placed on the work receiving device, and having an opening formed thereon corresponding to the mask body; a pressing mechanism that presses the plate frame of the mask printing plate placed on the work receiving device against the lower surface of the surface plate by moving the work receiving device toward the surface plate; a measurement unit disposed above the surface plate, applying a downward load to the mask body through the opening and measuring a displacement of the mask body when the load is applied; a moving mechanism that moves the measurement unit above the surface plate; a control device that controls the operations of the pressing mechanism, the measuring unit, and the moving mechanism so as to move the measuring unit among a plurality of measurement points set on the mask body and measure the displacement amount of the mask body at each of the measurement points while pressing the plate frame of the mask printing plate against the lower surface of the surface plate. A mask inspection apparatus characterized by:

2. 2. The mask inspection apparatus according to claim 1, As the mask printing plates, a first mask printing plate and a second mask printing plate having a size smaller than the first mask printing plate are to be inspected, the work receiving device has a first mounting portion on which the frame of the first mask printing plate is mounted, a first positioning portion that positions the frame of the first mask printing plate on the first mounting portion, a second mounting portion on which the frame of the second mask printing plate is mounted, and a second positioning portion that positions the frame of the second mask printing plate on the second mounting portion, the first placement portion and the second placement portion are adjacent to each other via a step, A step wall surface forming the step between the first placement portion and the second placement portion functions as the first positioning portion or the second positioning portion. A mask inspection apparatus characterized by:

3. 3. The mask inspection apparatus according to claim 1, a camera unit disposed above the surface plate for capturing an image of the surface of the mask body of the mask printing plate through the opening; The movement mechanism also functions as a mechanism for moving the camera unit. A mask inspection apparatus characterized by:

4. 4. The mask inspection apparatus according to claim 1, The metal mask is used as the mask printing plate to be inspected. A mask inspection apparatus characterized by:

Images