Tiling device

Abstract

To provide a tiling device which can tile a module on a substrate with high accuracy.SOLUTION: A tiling device comprises: a stage 31 which supports a substrate 1; a head 32 which conveys a module 2 mounted with a plurality of elements to a position facing the substrate 1; an imaging unit 33 which faces the substrate 1 over a module 2 held by the head 32 and images an alignment mark M provided on the substrate 1 and an alignment mark m provided on the module 2 within the same visual field; and a focal distance adjustment unit 34 which is provided on the optical path connecting the alignment mark M and the imaging unit 33 and adjusts a focal distance to the alignment mark M of the imaging unit 33 such that the focus of the imaging unit 33 is simultaneously put into the alignment marks M, m. The head 32 tiles the module 2 on the substrate 1 on the basis of the image captured by the imaging unit 33.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a tiling device. [Background technology]

[0002] In recent years, development has been progressing on modules that incorporate multiple rows and columns of light-emitting diode (LED) elements on the order of tens to hundreds of micrometers. Arranging such modules in multiple rows and columns to manufacture display devices and lighting devices is being considered. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-9937 Summary of the Invention [Problem to be solved by the invention]

[0004] When arranging LED modules equipped with multiple LED elements in multiple rows and columns (hereinafter also referred to as tiling) as described above, for example, an alignment mark provided on the LED module and an alignment mark provided on the substrate are imaged, and the two are aligned based on the image.

[0005] In this type of alignment, the accuracy of position recognition during imaging is important. For example, the positional relationship between the camera capturing the LED module and the camera capturing the board can be a source of error. For example, thermal expansion and vibration can change the positional relationship between the cameras and the positional relationship in the captured images, making it difficult to align the LED module and board with high accuracy.

[0006] An object of the present invention is to provide a tiling device that can tile modules on a substrate with high precision. [Means for solving the problem]

[0007] The tiling device of the present invention comprises a stage for supporting a substrate, a head for transporting a module mounted with multiple elements to a position facing the substrate, an imaging unit that faces the substrate through the module held by the head and images a first alignment mark provided on the substrate and a second alignment mark provided on the module within the same field of view, and a focal length adjustment unit that is provided on an optical path connecting the first alignment mark and the imaging unit and adjusts the focal length of the imaging unit with respect to the first alignment mark so that the focus of the imaging unit is simultaneously on the first alignment mark and the second alignment mark, and the head tiled the module on the substrate based on the image captured by the imaging unit. [Effects of the Invention]

[0008] The tiling device of the present invention is capable of tiling modules on a substrate with high precision. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a plan view showing a substrate according to the embodiment. [Figure 2] 1A and 1B are a plan view and a side view showing a module according to an embodiment of the present invention; [Figure 3] FIG. 2 is a plan view showing a supply table and a tiling device according to the embodiment. [Figure 4] FIG. 1 is a side view showing a tiling device according to an embodiment. [Figure 4B] 1A and 1B are schematic diagrams illustrating a pickup state in an embodiment ((A) before alignment, (B) during pickup, and (C) after pickup). [Figure 5] FIG. 10 is a diagram illustrating a tiling procedure according to an embodiment. [Figure 6] FIG. 2 is a block diagram showing a control device according to the embodiment. [Figure 7] 10 is a flowchart illustrating a tiling procedure according to an embodiment. [Figure 8] 3A and 3B are diagrams illustrating an imaging field of view of an imaging unit according to an embodiment. [Figure 9] 10A and 10B are diagrams illustrating the direction in which modules should be tiled according to an embodiment. [Figure 10] 10A, 10B, and 10C are side views showing a focal length adjustment unit according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention (hereinafter referred to as the present embodiment) will be specifically described with reference to the drawings. First, the substrate and module will be described, and then the tiling device will be described. Note that each drawing is a schematic diagram of the present embodiment.

[0011] [substrate] As shown in FIG. 1, the substrate 1 of this embodiment is a substrate for a display device, and modules 2 (described later) are tiled on its surface. Alignment marks M are provided on the surface of the substrate 1 to align and tile the modules 2 at desired positions. The alignment marks M are provided at positions corresponding to the alignment marks m provided on the modules 2. That is, the alignment marks M and m are marks that serve as reference marks for tiling the modules 2 on the substrate 1. In this embodiment, four alignment marks M are provided for each module 2, corresponding to the alignment marks m provided at each of the four corners of the square module 2 (the module 2 is indicated by dotted lines in FIG. 1). That is, a set of four alignment marks M is provided so as to be located at the vertices of a square. These sets of four alignment marks M are provided in multiple rows and multiple columns on the surface of the substrate 1, thereby enabling tiling of the modules 2 on the substrate 1. FIG. 1 shows that the alignment marks M are provided so that four modules 2 can be tiled on the substrate 1. The surface of the substrate 1 is covered with a thin adhesive layer (not shown), and the substrate 1 and the module 2 are bonded via this adhesive layer. Note that the four corners and vertices include their vicinities.

[0012] [Module] 2(A) and 2(B), module 2, which is the target of tiling in this embodiment, includes a flexible substrate 21, alignment marks m provided on the surface of the flexible substrate 21, a plurality of light-emitting elements 22 mounted on the surface of the flexible substrate 21, and a sealing member 23 that seals the alignment marks m and the light-emitting elements 22. Module 2 is tiled on the surface of substrate 1 by a tiling device 3, which will be described later.

[0013] The flexible substrate 21 is made of, for example, polyimide, and has a light-emitting element 22 mounted on its surface. As shown in FIG. 2(A), the flexible substrate 21 of this embodiment is square in plan view, and alignment marks m for aligning the module 2 to the substrate 1 are provided at the four corners of the flexible substrate 21, corresponding to the alignment marks M on the substrate 1. That is, the set of four alignment marks m is provided so as to be located at the vertices of the square. Note that, in this embodiment, four sets of alignment marks M, m are provided, but only two sets are actually used for alignment, as will be described later. Therefore, the number of sets of alignment marks M, m may be two. Note that the four corners and vertices include their vicinity.

[0014] The light emitting elements 22 are LED elements, and a plurality of them are mounted on the surface of the flexible substrate 21. The light emitting elements 22 of this embodiment are particularly LED elements on the order of micrometers, and their height is, for example, about 25 μm.

[0015] As shown in FIG. 2(B), the sealing member 23 is a transparent resin member that seals the alignment marks m and the light-emitting elements 22 provided on the surface of the flexible substrate 21. The sealing member 23 can be made of, for example, a thermosetting resin having a viscosity of about 4000 mPa·s before hardening. The sealing member 23 can be formed by hardening a hardening resin supplied to the surface of the module 2 on which the light-emitting elements 22 are mounted. The thickness of the sealing member 23 is, for example, 50 to 300 μm. Because the sealing member 23 is a transparent resin member as described above, the alignment marks m and the light-emitting elements 22 can be seen through the sealing member 23.

[0016] [Tiling device] [composition] As shown in FIGS. 3 and 4 , the tiling device 3 includes a housing C, a supply table S, a stage 31, a head 32, a moving mechanism 320, an imaging unit 33, a focal length adjustment unit 34, and a control device 8. The housing C houses the supply table S, the stage 31, the head 32, the moving mechanism 320, and the control device 8. The supply table S is movably mounted, supports the module 2, and supplies the module 2 to the tiling device 3. The stage 31 is movably mounted, and supports the substrate 1. The head 32 works in cooperation with the moving mechanism 320 to transfer the module 2 from the supply table S to the substrate 1. At this time, the imaging unit 33 captures images of the alignment mark M on the substrate 1 and the alignment mark m on the module 2 directly and / or via the focal length adjustment unit 34. Based on the image capture results, the moving mechanism 320 and the stage 31 align and place the module 2 at the placement position of the substrate 1, and tile the module 2. The control device 8 controls each component (see FIG. 6 ). In FIG. 3, the focal length adjustment unit 34 is omitted.

[0017] In FIG. 3, the direction in which the supply table S and the stage 31 are aligned is the X direction, the direction perpendicular to the X direction in a plane parallel to the surface of the stage 31 is the Y direction, and the direction perpendicular to the X and Y directions is the Z direction. The Z direction is the direction penetrating the paper in the figure. In this embodiment, the tiling device 3 is installed so that the Z direction is the vertical direction, and therefore the XY plane is a horizontal plane. In this case, the Z direction is the height direction, and the installation surface side is called the down side and the opposite side is called the up side. In other words, down is the direction of gravity. Furthermore, the rotation direction parallel to the XY plane is called the θ direction.

[0018] The supply table S has a flat surface and is a support table that supports one or more modules 2 on the surface. In this embodiment, as shown in FIG. 3, the supply table S supports four modules 2. The supply table S is movable in the Y direction by a linear motion mechanism (not shown) and moves back and forth between the inside and outside of the housing C. This allows the supply table S to carry the modules 2 to be tiled on the substrate 1 from the outside of the housing C to the inside of the housing C. As will be described later, the supply table S cooperates with the movement mechanism 320 to move the module 2 so that the module 2 to be picked up faces the head 32 so that the head 32 can pick up the module 2. The linear motion mechanism (not shown) is composed of, for example, a motor, a linear guide, and a ball screw, and the surface of the supply table S is supported by a slider of this linear guide. A separate loading device such as a robot may be provided to load the modules 2 onto the supply table S from outside the tiling device 3. At this time, the modules 2 may be loaded one by one, or multiple modules 2 may be loaded collectively using a tray.

[0019] The stage 31 has a flat surface and is a support platform that supports the substrate 1 on the surface. As shown in FIG. 3 , the stage 31 in this embodiment supports one substrate 1. The stage 31 is movable in the Y direction by a linear motion mechanism (not shown) and moves back and forth between the inside and outside of the housing C. This allows the stage 31 to transport the substrate 1 from the outside of the housing C to the inside of the housing C and to transport the substrate 1 on which the modules 2 are tiled from the inside of the housing C to the outside of the housing C. Furthermore, as will be described later, the movement mechanism 320 and the stage 31 work together to move the substrate 1 so that the head 32 faces the intended tiling position of the module 2 on the substrate 1 so that the head 32 can place the module 2 at a predetermined position on the substrate 1 and tile it. The linear motion mechanism (not shown) is composed of, for example, a motor, a linear guide, and a ball screw, and the surface of the stage 31 is supported by a slider of this linear guide. It is also possible to provide a separate unloading device such as a robot to unload the substrate 1 from the stage 31 to the outside of the tiling device 3.

[0020] In this embodiment, the alignment mark M on the surface of the substrate 1 placed on the stage 31 and the alignment mark m on the surface of the module 2 placed on the supply table S are set to be at the same height. This setting can be achieved by setting the height of the support surfaces of the supply table S and stage 31 using an adjustment mechanism (not shown), such as a fine adjustment mechanism using a push-pull screw, depending on the thickness of the flexible substrate 21 of the module 2 and the thickness of the substrate 1.

[0021] The head 32 sucks and holds the module 2 supported on the supply table S and tiles it on the substrate 1 supported on the stage 31. As shown in FIG. 4 , the head 32 is supported by a linear motion mechanism 321 via an elevating mechanism 322 and is movable between the supply table S and the stage 31 so as to transfer the module 2 from the supply table S to the stage 31. The linear motion mechanism 321 is composed of, for example, a motor, a linear guide, and a ball screw, and is bridged above the supply table S and the stage 31, extending to face the surfaces of the supply table S and the stage 31. The linear guide is composed of a rail 321a, a guide 321b, a slider 321c, and a base 321d. The rail 321a is attached to the base 321d so as to be movable horizontally. A guide 321b is positioned so as to grip the rail 321a, and the guide 321b is attached to the slider 321c. The lifting mechanism 322 includes, for example, a motor, a linear guide, and a ball screw. The lifting mechanism 322 is supported by the slider of the linear motion mechanism 321 and extends in a direction toward and away from the supply table S and the stage 31. The linear guide has a slider 322c attached to the side of the head 32, and a guide 322b attached to the slider 322c. A rail 322a is attached to the slider 321c on the linear motion mechanism 321 side to enable vertical movement. The head 32 is supported by the slider of the lifting mechanism 322. The linear motion mechanism 321 and the lifting mechanism 322 form a movement mechanism 320. While FIG. 4 shows two rails 321a and two guides 321b, the number of rails 321a and guides 321b may be increased or decreased depending on the size of the base 321d and the slider 321c. The number of rails 321a and guides 322b may also be increased or decreased in the same manner.

[0022] A holding unit 32a is provided on the side of the head 32 facing the supply table S and the stage 31. The holding unit 32a has suction holes (not shown) on the surface facing the supply table S and the stage 31, and by generating negative pressure in these suction holes, it is possible to suction-hold and pick up the module 2 from the supply table S. The holding unit 32a can also release the module 2 and tile it on the substrate 1 by releasing the negative pressure generated in the suction holes. Furthermore, the holding unit 32a is rotatable in the θ direction relative to the head 32 by a θ-direction rotation mechanism (not shown), and can rotate the held module 2 in the θ direction. This allows the holding unit 32a to adjust the orientation of the module 2 when tiling it on the substrate 1. Note that this θ-direction rotation mechanism is also included in the movement mechanism 320.

[0023] The head 32 is provided with a contact sensor (not shown). This contact sensor detects when the holder 32a comes into contact with the module 2, or when the holder 32a comes into contact with the substrate 1 while holding the module 2. The contact sensor is, for example, a gap sensor such as an eddy current sensor. Based on the contact information detected by this contact sensor, the head 32 can suck and hold or release the module 2.

[0024] The holder 32a of this embodiment suction-holds the module 2 so that at least two of the alignment marks m provided at the four corners of the module 2 are visible from above. This is achieved by the holder 32a suction-holding a portion of the top surface of the module 2 that does not obstruct the alignment marks m from being viewed from above. Furthermore, in this embodiment, a transparent portion 32b made of a transparent material such as quartz glass is provided on the side of the holder 32a on the optical path connecting the alignment marks m of the module 2 suction-held by the holder 32a and the imaging unit 33. In other words, the imaging unit 33 captures an image of the alignment marks m through this transparent portion 32b. The lower surface of the transparent portion 32b is set to be at the same height as the lower surface of the holding portion 32a, so that the upper surface (sealing member 23 surface) of the module 2 is supported flatly and entirely by the holding portion 32a and the transparent portion 32b, and the head 32 can press the entire upper surface of the module 2 against the substrate 1 when tiling the module 2 on the substrate 1.

[0025] The imaging unit 33 is a camera having one optical system, such as a lens, and one imaging element that captures the alignment mark m of the module 2 and the alignment mark M of the substrate 1 in the same field of view. That is, the imaging unit 33 faces the substrate 1 through the module 2 held by the head 32, and is provided at a position where it can capture, in the same field of view, the alignment mark M provided on the substrate 1 and the alignment mark m provided on the module 2 positioned so as to face the current tiling location on the substrate 1. The focal length of the imaging unit 33 is set to a predetermined reference height position where the alignment mark m of the module 2 facing the substrate 1 is positioned.

[0026] The imaging units 33 in this embodiment are supported by the linear motion mechanism 321 above the head 32. More specifically, two imaging units 33 are provided, one at each end of a U-shaped frame 33a supported by the linear motion mechanism 321. One side of the frame 33a connecting the two parallel sides of the U-shape is supported by the linear motion mechanism 321, and the frame 33a is provided to be movable in the X direction in conjunction with the movement of the head 32 in the X direction. That is, the imaging units 33 are provided so as to be positioned above the alignment marks m and M when the holder 32a of the head 32 holds the module 2 and is transported to a position facing the substrate 1. As a result, as shown in FIG. 8 , each imaging unit 33 simultaneously captures images of the corresponding alignment marks m and M within the same field of view. "Capturing images within the same field of view" refers to capturing images of multiple objects simultaneously (collectively at once) within the imaging field of view. Each imaging unit 33 transmits an image of the alignment mark m and the alignment mark M to the control device 8, which will be described later. Each imaging unit 33 is installed at a height position where the focal length matches a predetermined reference height position where the alignment mark m of the module 2 facing the substrate 1 is positioned.

[0027] The focal length adjustment unit 34 is a transparent member made of quartz glass or the like that adjusts the focal length of the imaging unit 33 relative to the alignment mark M of the imaging unit 33 and focuses on the alignment mark M. That is, the focal length adjustment unit 34 is provided on the optical path connecting the alignment mark M of the substrate 1 and the imaging unit 33, and extends the focal length of the imaging unit 33 to the substrate 1. In this way, the focal length adjustment unit 34 moves the actual focal position away from the imaging unit 33, and is a member that adjusts the focus of the imaging unit 33 to also focus on the alignment mark M, based on the state in which the imaging unit 33 focuses on the alignment mark m of the module 2 that is close to the imaging unit 33. For example, the state in which the alignment mark m is located 1 mm above the top surface of the substrate 1 on which the alignment mark M is provided is set as the predetermined reference height position at which the alignment mark m is positioned. In this state, when capturing images of the alignment marks M and m within the same field of view, a focal length adjustment unit 34 having a thickness of approximately 0.3 mm is used on the optical path connecting the alignment mark M and the imaging unit 33. As shown in FIG. 8 , the focal length adjustment unit 34 is provided so as to cover half of the imaging field of view of the imaging unit 33 (the lower side in FIG. 8 ), thereby extending the focal length of the lower half of the imaging field of view of the imaging unit 33 compared to the focal length of the remaining half of the imaging field of view (the upper side in FIG. 8 ). In this embodiment, the module 2 held by the head 32 and the alignment mark m are projected in the upper half of the imaging field of view of the imaging unit 33, as will be described later. In this manner, the focal length adjustment unit 34 fixes and sets the focal length of the imaging unit 33 so that both predetermined alignment marks m and M are simultaneously in focus.

[0028] The focal length adjustment unit 34 is supported by the linear motion mechanism 321 via a support member (not shown) and is movable in the X direction in conjunction with the movement of the head 32 and the imaging unit 33 in the X direction. As a result, as indicated by the dashed arrow in FIG. 4 , the imaging unit 33 can focus on the alignment mark M while focusing on the alignment mark m of the module 2 held by the head 32 above the substrate 1. Therefore, the image captured by the imaging unit 33 is focused on both the alignment mark m and the alignment mark M, enabling highly accurate correction processing in the control device 8 (described later). In practice, not only the focal length adjustment unit 34 but also the transparent portion 32b extends the focal length of the imaging unit 33. Therefore, the focal length adjustment unit 34 is made of a transparent member that is thicker in the optical path direction connecting the substrate 1 and the imaging unit 33 than the transparent portion 32b.

[0029] The control device 8 is a device that controls the tiling device 3. The control device 8 is configured, for example, by a dedicated electronic circuit or a computer that operates on a predetermined program. That is, the control device 8 controls the operation of the tiling device 3 by controlling the operation of the supply table S, the stage 31, the head 32, the imaging unit 33, etc. As shown in FIG. 6 , the control device 8 includes a storage unit 81, an imaging control unit 82, a calculation unit 83, a movement control unit 84, a setting unit 85, and an input / output control unit 86.

[0030] The storage unit 81 is a storage medium such as an HDD or SSD. Data and programs necessary for system operation are stored in advance in the storage unit 81, and the storage unit 81 also stores data necessary for system operation. The imaging control unit 82 controls the operation of the imaging unit 33. That is, it controls imaging-related operations such as starting up the imaging unit 33, capturing images, stopping the imaging unit 33, transmitting images, and focusing. The calculation unit 83 calculates the amount of deviation of the alignment marks M and m based on the captured image received from the imaging unit 33, and transmits the calculated amount of deviation to the movement control unit 84.

[0031] The movement control unit 84 controls the movement of the supply table S, the stage 31, and the movement mechanism 320. This control is based on data and programs necessary for the operation of the system, which are pre-stored in the storage unit 81, images captured by the imaging unit 33, and calculation results by the calculation unit 83. In particular, the movement control unit 84 of this embodiment controls the alignment of the module 2 held by the head 32 with the substrate 1 supported by the stage 31, based on the amount of deviation of the alignment marks M and m calculated by the calculation unit 83. Note that the control by the movement control unit 84 may also be based on user commands input from an input device 91, which will be described later, for example.

[0032] The setting unit 85 is a processing unit that sets information in accordance with input in the storage unit 81. The input / output control unit 86 is an interface that controls signal conversion and input / output between each unit that is the subject of control.

[0033] An input device 91 and an output device 92 are connected to the control device 8. The input device 91 is input means such as a switch, touch panel, keyboard, or mouse that allows the operator to operate the tiling device 3 via the control device 8. The operator can use the input device 91 to input various pieces of information to be set in the memory unit 81. The output device 92 is output means such as a display, lamp, or meter that makes information for checking the status of the device visible to the operator. In addition, the output device 92 can display an input screen for information from the input device 91.

[0034] [Effect] Next, an example of the operation of this embodiment will be described with reference to FIGS. 4B, 5, and 7. FIG. 4B shows the state during pickup, and FIG. 5 shows the tiling procedure of this embodiment. FIG. 7 is a flowchart showing the tiling procedure of the tiling device 3. Although not shown, first, the module 2 is supported by the supply table S and carried into the housing C, and the substrate 1 is also supported by the stage 31 and carried into the housing C, and they wait so that the supply table S and the stage 31 are adjacent to each other (see FIG. 3). In addition, the head 32, the imaging unit 33, and the focal length adjustment unit 34 are supported by the linear motion mechanism 321 above the supply table S, and wait while facing the module 2 to be picked up this time that is supported by the supply table S.

[0035] First, as shown in FIG. 4B(A), the movement control unit 84 controls the movement of the supply table S and the movement mechanism 320 so that the imaging unit 33 and the module 2 have a predetermined positional relationship. Here, the predetermined positional relationship is a positional relationship in which the imaging unit 33 can image the alignment mark m of the module 2 on the supply table S via the focal length adjustment unit 34. Next, the imaging control unit 82 causes the imaging unit 33 to image the alignment mark m of the module 2 to be picked up this time, which is supported on the supply table S, and transmits this imaged image to the movement control unit 84. Because the alignment mark m of the module 2 placed on the supply table S is at the same height as the alignment mark M of the substrate 1 placed on the stage 31, when the imaging unit 33 images the alignment mark m of the module 2 on the supply table S, a clear, in-focus image can be obtained via the focal length adjustment unit 34. Based on this captured image, the movement control unit 84 calculates the position of the alignment mark m relative to the imaging unit 33 by known image processing, and controls the movement of the supply table S and the movement mechanism 320 so as to achieve a predetermined positional relationship. That is, the supply table S is moved in the Y direction and the head 32 is moved in the X direction, and the head 32 is positioned at a predetermined position relative to the module 2, i.e., the pickup position, as shown in FIG. 5(A) (step S01).

[0036] Next, as shown in FIG. 4B(B), the head 32 is moved in the Z direction toward the module 2, and the holding portion 32a of the head 32 is brought into contact with the upper surface of the module 2. Furthermore, a negative pressure is generated in the holding portion 32a of the head 32, and the module 2 is held by suction. As shown in FIG. 4B(C), the head 32 is moved to a height where it can move above the substrate 1 while holding the module 2 by suction, thereby picking up the module 2 from the supply table S (step S02). Note that when the module 2 is picked up, the alignment mark m of the module 2 is held at a height where it can be imaged in focus by the imaging unit 33 without using the focal length adjustment unit 34.

[0037] Next, as shown in FIG. 5(B), head 32 suction-holding module 2 is moved in the X direction toward the position on substrate 1 where module 2 will be tiled this time, which is stored in memory unit 81, and stage 31 supporting substrate 1 is moved in the Y direction. As a result, module 2 is transported above substrate 1 supported by stage 31 (step S03). Here, in the example of FIG. 5, the position on substrate 1 where module 2 will be tiled this time is the upper right position of substrate 1, then the upper left position of substrate 1, and then the lower left position. During this movement, movement control unit 84 calculates the position of alignment mark m on module 2 that is shifted by a predetermined amount in the XY plane with respect to alignment mark M on substrate 1 where module 2 will be tiled, in order to image alignment mark M on substrate 1 where module 2 will be tiled and alignment mark m on module 2 within the same field of view, and then moves module 2 and substrate 1 relatively so that alignment mark m is positioned at that position. In this case, the predetermined amount of the position that is shifted by a predetermined amount is an amount based on the field of view range such that the alignment mark M of the substrate 1 can be imaged by the imaging unit 33 without going through the focal length adjustment unit 34, and the alignment mark m of the module 2 can be imaged by the imaging unit 33 via the focal length adjustment unit 34, within the same field of view of the imaging unit 33.

[0038] Next, the movement control unit 84 moves the head 32 to a height where the alignment marks M and m are imaged within the same field of view. This height is a height where the focus of the imaging unit is aligned with the alignment mark m and also aligned with the alignment mark M via the focal length adjustment unit 34. This height is based on a pre-stored design value of the focal length. Then, under the control of the imaging control unit 82, the imaging unit 33 captures an image in which the alignment mark m provided on the module 2 and the alignment mark M provided on the substrate 1 are captured within the same field of view, and transmits the image to the calculation unit 83 and the movement control unit 84 (step S04). The imaging field of view of the imaging unit 33 at this time will be described with reference to FIG. 8.

[0039] FIG. 8 shows the imaging unit 33 capturing an image of the alignment mark m of the module 2 and the alignment mark M of the substrate 1. The imaging unit 33 is positioned so that both alignment marks m and M are captured in the same field of view. In the figure, the module 2 is hatched. The area indicated by a circle in FIG. 8 is the field of view. Alignment marks M and m are shown within the circle, i.e., within the same field of view. In this case, the outline of the module 2 and alignment mark m are captured in the upper part of the figure, and the imaging unit 33 captures the alignment mark m in the upper area of ​​the figure. At the same time, the alignment mark M is captured in the lower part of the figure, and the imaging unit 33 captures the alignment mark M in the lower area of ​​the figure.

[0040] Here, a focal length adjustment unit 34 made of a transparent member is present on the optical path from the imaging unit 33 to the alignment mark M. In other words, the focal length adjustment unit 34 is present in the lower region of FIG. 8. This focal length adjustment unit 34 causes the imaging unit 33 to focus on the alignment mark M. That is, the imaging control unit 82 adjusts the focus of the imaging unit 33 to the alignment mark m of the module 2, and the focal length adjustment unit 34 also adjusts the focus to the alignment mark M of the substrate 1. This allows the imaging unit 33 to focus on and capture images of both alignment marks M and m, which are located at different distances.

[0041] Furthermore, in step S04, the elevation mechanism 322 may move the head 32 in a direction (Z direction) toward or away from the imaging unit 33 to adjust the height position of the alignment mark m of the module 2 so that it is in focus with the imaging unit 33. The upper surface of the module 2 is held by the holder 32a. That is, the alignment mark m of the module 2 and the holder 32a are held via the sealing member 23. Therefore, if there is variation in the thickness of the module 2 (as described above, the thickness of the sealing member 23 of the module 2 varies because it is formed by spreading a curable resin), there is a risk that the module 2 will not be in focus. In this case, by raising or lowering the height position of the head 32, the distance from the imaging unit 33 to the alignment mark m can be adjusted to accommodate the variation in the thickness of the sealing member 23. Such focusing can be performed by the imaging unit 33 using a known method.

[0042] As described above, the height of the head 32 is determined based on the design value of the focal length at which the imaging unit 33 focuses on the alignment mark m of the module 2. In other words, when imaging the alignment marks M and m, the alignment mark m of the module 2 is positioned at a predetermined distance (height) above the substrate 1. This distance allows movement when aligning the module 2 with the tiling position of the substrate 1. This distance is the height (distance) of the module 2 from the substrate 1 and corresponds to the distance adjusted by the focal length adjustment unit 34. Therefore, when imaging the alignment marks M and m, this distance is the initial value, which is the position in the Z direction (the distance between the module 2 and the substrate 1) and is constant. Therefore, the thickness of the focal length adjustment unit 34 is determined by this distance. In other words, the thickness of the focal length adjustment unit 34 is fixed. However, unlike the sealing member 23 of the module 2, the thickness of the substrate 1 hardly varies and hardly deviates from the design value. Therefore, the focus of the imaging unit 33 on the alignment mark M on the substrate 1 via the focal length adjustment unit 34 does not deviate significantly even if it is set based on the focal length with respect to the alignment mark m of the module 2. Therefore, even if there is variation in the thickness of the module 2 and the module 2 cannot be focused at the design value, the alignment mark M on the substrate 1 is in focus, so the head 32 may control the module 2 to move up and down based on the thickness of the module 2 so that the focus is on the alignment mark m of the module 2. This makes it possible to respond to fluctuations in the position of the alignment mark m due to variations in the thickness of the individual modules 2, and to more precisely focus on the alignment mark m.

[0043] After step S04, the calculation unit 83 detects the respective positions of the alignment marks M and m based on the captured image as shown in FIG. 8 and calculates the positional relationship between the alignment marks M and m (step S05). That is, the calculation unit 83 calculates the direction and amount of misalignment between the alignment marks M and m. In this embodiment, two imaging units 33 are provided. These two imaging units 33 can capture two captured images as shown in FIG. 8. The direction and amount of misalignment between the substrate 1 and the module 2 are calculated based on the captured images from two locations. The example shown in FIG. 9(A) illustrates a case where the orientation and position of the substrate 1 (the orientation in which the module 2 should be tiled) and the module 2 held by the head 32 do not match. The dotted circle indicates the imaging field of view. There are two imaging units 33, and each shows its field of view. The two imaging units 33 then capture images of the alignment marks M and m in their respective field of view ranges on the left and right. From the captured images of the left and right alignment marks M and m, the positional relationship (direction and amount of misalignment) between the left and right alignment marks M and m is calculated. In addition, the positional relationship (direction and amount of misalignment) between the left and right alignment marks M and between the left and right alignment marks m is calculated, and from the results, the angle between the line connecting the two alignment marks M and the line connecting the two alignment marks m is calculated. This angle is the angle between the substrate 1 and the module 2. From the results of these calculations, the positional relationship (direction and amount of misalignment) between the substrate 1 and the module 2 is determined. In other words, by calculating the direction and amount of misalignment in the alignment marks M and m based on the images captured by the two imaging units 33, misalignment in the XY and θ directions is corrected, enabling accurate tiling as shown in FIG. 9(C).

[0044] Note that the example in FIG. 9(A) shows an extreme directional deviation for ease of understanding. However, because module 2 is aligned with head 32 when picked up, it is unlikely that a directional deviation will occur that would result in the positional relationship between alignment mark M and alignment mark m being reversed, as shown in FIG. 9(B). If module 2 were to shift during head 32 movement and the positional relationship between alignment mark M and alignment mark m were to be reversed, one of the two alignment marks M would be hidden by module 2, making it impossible to capture the mark. In such a case, an error is generated and processing is halted. Also, as explained in step 03, in order to capture alignment mark M and alignment mark m within the same field of view, module 2 is positioned such that alignment mark m is shifted a predetermined amount in the XY plane relative to alignment mark M. Therefore, reversing the positional relationship between alignment mark M and alignment mark m is avoided. However, there is a possibility that module 2 may fall outside the field of view. In this case, one of the alignment marks will not be captured, and processing is also halted as an error. Therefore, the misalignment between the substrate 1 and the module 2 may be calculated from the difference in the amount of misalignment between the left and right alignment marks M and m (direction and amount of misalignment) rather than calculating the angle formed by the line connecting the two alignment marks M and m described above. In other words, the direction of misalignment (angle) may be calculated from the distance between the left and right alignment marks M and m. In this case, the calculation process can be simplified.

[0045] Furthermore, the calculation unit 83 transmits the calculation result to the movement control unit 84, and the movement control unit 84 moves the stage 31 in the Y direction, the head 32 in the X direction, and the holder 32a in the θ direction based on the calculation result, as shown in FIG. 5(C), to align the module 2 on the substrate 1 so that the alignment marks M and m overlap in a plan view (step S06). Finally, the movement control unit 84 moves (lowers) the head 32 toward the substrate 1, thereby tiling the module 2 on the substrate 1 (step S07). Thereafter, the head 32 releases the suction hold of the module 2, moves (raises) in a direction away from the substrate 1, and then moves again in the X direction to move above the supply table S, specifically above the module 2 to be suction-held next, as shown in FIG. 5(D) (step S08). By repeating the above steps S01 to S08, the modules 2 are tiled on the substrate 1. When the supply table S becomes empty or when modules 2 are tiled over the entire surface of the substrate 1, the movement control unit 84 moves the supply table S or the stage 31 to the outside of the housing C, and then returns to the inside of the housing C supporting new modules 2 or substrates 1. In this way, tiling is performed continuously.

[0046] [effect] (1) The tiling device 3 of this embodiment comprises a stage 31 that supports the substrate 1, a head 32 that transports a module 2 mounted with multiple elements to a position facing the substrate 1, an imaging unit 33 that faces the substrate 1 through the module 2 held by the head 32 and captures images of an alignment mark M provided on the substrate 1 and an alignment mark m provided on the module 2 within the same field of view, and a focal length adjustment unit 34 that is provided on the optical path connecting the alignment mark M and the imaging unit 33 and adjusts the focal length of the imaging unit 33 with respect to the alignment mark M so that the focus of the imaging unit 33 is simultaneously on the alignment marks M and m, and the head 32 tiled the module 2 on the substrate 1 based on the image captured by the imaging unit 33.

[0047] This allows the module 2 to be tiled on the substrate 1 based on captured images simultaneously focused on both alignment marks M and m, which are at different distances from the imaging unit, thereby enabling tiling with higher accuracy than conventional techniques. In order to tile the module 2 on the substrate 1, the module 2 needs to move over the substrate 1. Therefore, when the module 2 is positioned so as to face the location on the substrate 1 where the module 2 is to be tiled, a gap exists between the substrate 1 and the module 2. Therefore, the distance from the imaging unit 33, which captures images of the alignment marks on the substrate 1 and the module 2, to the module 2 is shorter than the distance to the substrate 1. In other words, when the imaging unit 33 is focused on the module 2, the substrate 1 is not in focus. Similarly, when the imaging unit 33 is focused on the substrate 1, the module 2 is not in focus. Therefore, in the past, the alignment mark M on the substrate 1 and the alignment mark m on the module 2 were separately imaged using cameras (corresponding to the imaging unit 33 in this embodiment) focused on each of them, and the positional relationship between the substrate 1 and the module 2 was indirectly calculated from the positions of the alignment marks recognized from each image and the positional relationship between the two cameras. However, in this case, the camera position changes due to thermal expansion, vibrations occurring during imaging, and other factors, making it difficult to perform high-precision alignment. Furthermore, when two additional cameras (imaging units 33) are used to recognize the positions of the alignment marks on the substrate 1 and the module 2 at two locations to align the orientations and positions of the substrate 1 and the module 2, and two separate images of the alignment marks on the substrate 1 and the module 2 are taken, it is difficult to perform high-precision alignment due to errors in the positional relationship between the two additional cameras caused by thermal expansion or vibrations occurring during imaging. Furthermore, using four cameras in this way inevitably makes the device configuration complex. On the other hand, the imaging unit 33 of this embodiment images the alignment mark M on the substrate 1 and the alignment mark m on the module 2 in the same field of view, so the relative positional relationship between the alignment marks M and m does not change even if vibrations or the like occur during imaging. Also, instead of using four cameras as described above, only two imaging units 33 are required.This reduces the error between cameras by half, enabling highly accurate alignment and simplifying the device configuration.

[0048] (2) With the imaging unit 33 focused on the alignment mark M, the head 32 moves the module 2 in a direction toward or away from the imaging unit 33 depending on the thickness of the module 2 held by the head 32, and focuses the imaging unit 33 on the alignment mark m. This makes it possible to more precisely focus on the alignment mark m of the module 2. Furthermore, even if there is variation in the thickness of the substrate 1 or module 2, since it is easy to focus, the module 2 can be tiled on the substrate 1 with high precision.

[0049] [Variations] (1) In the above embodiment, the focal length adjustment unit 34 is supported by the linear motion mechanism 321 and is configured to move in the X direction in conjunction with the head 32 and the imaging unit 33. However, this is not limited to this. For example, as shown in FIG. 10(A), the focal length adjustment unit 34 may be provided integrally with the transparent portion 32b on the side surface of the holding portion 32a of the head 32. This simplifies the alignment of the focal length adjustment unit 34 with respect to the imaging unit 33. In particular, it is possible to easily adjust the position within the field of view so that, for example, half of the field of view is covered by the focal length adjustment unit 34.

[0050] (2) Furthermore, as shown in Fig. 10(B), the focal length adjustment unit 34 may be provided in the imaging unit 33. In this way, similar to the above-described modified example, it is possible to easily align the focal length adjustment unit 34 with the imaging unit 33.

[0051] (3) Furthermore, as shown in FIG. 10(C), the focal length adjustment unit 34 may be provided directly on the head 32. In this case, the focal length adjustment unit 34 moves up and down as the head 32 moves up and down. However, if the imaging unit 33 is located on the optical path for imaging the alignment mark M, the focal point of the imaging unit 33 will be aligned with the alignment mark M, allowing for alignment. The location and shape of the focal length adjustment unit 34 must be considered so that the focal length adjustment unit 34 does not intersect with the optical path for imaging the alignment mark m. For example, the focal length adjustment unit 34 shown in FIG. 10(C) has a hole (shown by a dotted line in the figure) on the optical path for imaging the alignment mark m, through which the imaging unit 33 can image the alignment mark m. Therefore, when imaging the alignment mark m, the image can be captured in focus without going through the focal length adjustment unit 34.

[0052] (4) In the above embodiment, the imaging unit 33 is supported by the linear motion mechanism 321, but this is not limiting. For example, the imaging unit 33 may be fixed to the housing C above the substrate 1. This can avoid the effects of vibrations caused by the movement of the imaging unit 33 and vibrations generated in the tiling device 3, thereby reducing alignment errors. In this case, by configuring the stage 31 to be movable not only in the Y direction but also in the X direction, the alignment mark M on the substrate 1 can be moved to directly below the imaging unit 33 provided in the housing C.

[0053] (5) In the above embodiment, two imaging units 33 are provided to simultaneously capture images. However, if the relative angular misalignment between the picked-up and held module 2 and the substrate 1 supported by the stage 31 is within an allowable range, θ alignment (orientation alignment) of the module 2 relative to the substrate 1 is not necessary. In such a case, only one imaging unit 33 may be used. This simplifies the device configuration and simplifies image processing and calculations for alignment, thereby shortening the tiling takt time and improving productivity. Furthermore, an optical system capable of observing multiple locations using mirrors or prisms can be applied to the optical system of the imaging unit 33 or an optical system external to the imaging unit 33 to simultaneously capture images of two sets of alignment marks M and m. Even in this case, only one imaging unit 33 can be used. Furthermore, one imaging unit 33 may be moved to capture images of two sets of alignment marks M and m. Information on the relative orientation of the substrate 1 and the module 2 can be obtained. In either case, the device configuration can be simplified, and fewer components are used, thereby reducing device costs and preventing malfunctions. Furthermore, calibration work between the two imaging units 33 is no longer necessary, which makes it easier to manufacture and maintain the device.

[0054] (6) In the above embodiment, the alignment mark M on the surface of the substrate 1 placed on the stage 31 and the alignment mark m on the surface of the module 2 placed on the supply table S are set to the same height, and when the imaging unit 33 images the alignment mark m on the surface of the module 2 placed on the supply table S, the alignment mark is imaged via the focal length adjustment unit 34. However, the pickup position can also be recognized when the height of the alignment mark m of the module 2 placed on the supply table S is set to the height when the module 2 is held by the head 32 and the alignment mark m and the alignment mark M are imaged simultaneously. In this case, when imaging is performed by the imaging unit 33, the alignment mark m is imaged directly in the field of view without using the focal length adjustment unit 34.

[0055] [Other embodiments] The present invention is not limited to the above-described embodiments, and the components can be modified and embodied in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining multiple components disclosed in the above-described embodiments. For example, some components may be omitted from all the components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined. [Explanation of symbols]

[0056] 1 board 2 Modules 21 Flexible PCB 22 Light-emitting element 23 Sealing member 3 Tiling device 31 Stages 32 heads 32a Holding part 32b Transparent part 320 Moving mechanism 321 Linear motion mechanism 322 Lifting mechanism 33 Imaging unit 34 Focal length adjustment section 8 Control Device 81 Storage section 82 Imaging control unit 83 Arithmetic section 84 Movement control unit 85 Setting section 86 Input / Output Control Unit 91 Input Device 92 Output Devices C chassis M, m alignment marks S supply stand

Claims

1. a stage for supporting the substrate; a head for transporting a module on which a plurality of elements are mounted to a position facing the substrate; an imaging unit that faces the substrate through the module held by the head and images a first alignment mark provided on the substrate and a second alignment mark provided on the module within the same field of view; a focal length adjustment unit that is provided on an optical path connecting the first alignment mark and the imaging unit, and that adjusts the focal length of the imaging unit with respect to the first alignment mark so that the imaging unit is focused on the first alignment mark and the second alignment mark simultaneously; Equipped with the head tiling the modules on the substrate based on the image captured by the imaging unit; Tiling device.

2. In a state where the imaging unit is focused on the first alignment mark via the focal length adjustment unit, the head moves the module in a direction approaching or moving away from the imaging unit in accordance with a thickness of the module held by the head, and focuses the imaging unit on the second alignment mark; The tiling device according to claim 1 .

3. the focal length adjustment unit is supported by a linear motion mechanism, The head and the imaging unit are provided to move in the X direction in conjunction with each other. The tiling device according to claim 1.

4. The focal length adjustment unit is provided on the head. The tiling device according to claim 1.

5. The focal length adjustment unit is provided on a holder of the head. The tiling device according to claim 1.

6. The focal length adjustment unit is provided in the imaging unit. The tiling device according to claim 1.

7. Two imaging units are provided, two sets of the first alignment mark and the second alignment mark are provided; each of the imaging units simultaneously captures an image of each pair of the first alignment mark and the second alignment mark within the same field of view; 7. A tiling device according to claim 1.

Images