CN115881600A - Paving device - Google Patents

Abstract

The invention aims to provide a pasting device which can paste a module on a substrate with high precision. The paving device comprises: a stage (31) for supporting the substrate (1); a head (32) that conveys a module (2) on which a plurality of elements are mounted to a position facing a substrate (1); an imaging unit (33) that faces the substrate (1) with the module (2) held by the head (32) therebetween, and that images, 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); and a focal length adjustment unit (34) that is provided on an optical path connecting the alignment mark (M) and the imaging unit (33), adjusts the focal length of the imaging unit (33) relative to the alignment mark (M) so that the focal point of the imaging unit (33) is simultaneously aligned with the alignment marks (M, M), and lays the module (2) on the substrate (1) by the head (32) based on the image captured by the imaging unit (33).

Description

Paving device

Technical Field

The invention relates to a paving device.

Background

In recent years, development of a module in which Light Emitting Diode (LED) elements of several tens to several hundreds of micrometers are mounted in a plurality of rows and columns has been advanced. And it is under study to arrange such modules further in a plurality of rows and columns to manufacture a display device or an illumination device.

[ Prior art documents ]

[ patent document ]

Patent document 1: japanese patent laid-open No. 2021-9937

Disclosure of Invention

[ problems to be solved by the invention ]

When the LED modules having the plurality of LED elements mounted thereon as described above are spread in a plurality of rows and columns (hereinafter also referred to as "tiling"), for example, alignment marks provided on the LED modules and alignment marks provided on the substrate are picked up, and the alignment of the two is performed based on the picked-up images.

In such positioning, the accuracy of recognizing the position at the time of imaging becomes important. For example, the positional relationship between a camera for photographing the LED module and a camera for photographing the substrate becomes a factor of error. For example, the positional relationship of the camera or the positional relationship in the captured image may change due to thermal expansion, vibration, or the like, and it may be difficult to accurately align the LED module and the substrate.

The invention aims to provide a pasting device which can paste a module on a substrate with high precision.

[ means for solving the problems ]

The paving device of the invention comprises: a stage supporting a substrate; a head that conveys a module on which a plurality of components are mounted to a position facing the substrate; an imaging unit that faces the substrate through the module held by the head, and that images a first alignment mark provided on the substrate and a second alignment mark provided on the module in the same field of view; and a focal length adjusting unit that is provided on an optical path connecting the first alignment mark and the image capturing unit, and adjusts a focal length of the image capturing unit with respect to the first alignment mark so that a focal point of the image capturing unit is simultaneously aligned with the first alignment mark and the second alignment mark, and the head lays the module on the substrate based on an image captured by the image capturing unit.

[ Effect of the invention ]

The pasting device of the invention can paste the module to the substrate with high precision.

Drawings

Fig. 1 is a plan view showing a substrate according to an embodiment.

Fig. 2 (a) is a plan view showing a module according to the embodiment, and fig. 2 (B) is a side view showing the module according to the embodiment.

Fig. 3 is a plan view showing the supply table and the placement device according to the embodiment.

Fig. 4A is a side view showing the placement device of the embodiment.

Fig. 4B (a) to 4B (C) are schematic diagrams showing a case of pickup in the embodiment (before alignment in fig. 4B (a), when pickup in fig. 4B (B), and after pickup in fig. 4B (C)).

Fig. 5 (a) to 5 (D) are diagrams illustrating a pasting flow according to the embodiment.

Fig. 6 is a block diagram showing a control device according to an embodiment.

Fig. 7 is a flowchart showing a posting flow of the embodiment.

Fig. 8 is a diagram showing an imaging field of view of the imaging unit according to the embodiment.

Fig. 9 (a) to 9 (C) are views for explaining the direction in which the module according to the embodiment is to be attached.

Fig. 10 (a), 10 (B), and 10 (C) are side views showing a focal length adjusting unit according to a modification.

[ description of symbols ]

1: substrate board

2: module

3: paving and sticking device

8: control device

21: flexible substrate

22: light emitting element

23: sealing member

31: carrying platform

32: head with a rotatable shaft

32a: holding part

32b: transparent part

33: image pickup unit

33a: frame structure

34: focal length adjusting part

81: storage unit

82: shooting control part

83: arithmetic unit

84: movement control unit

85: setting part

86: input/output control unit

91: input device

92: output device

320: moving mechanism

321: linear moving mechanism

321a, 322a: track

321b, 322b: guide piece

321c, 333c: sliding block

321d, 321: base seat

322: lifting mechanism

C: frame body

M, M: alignment mark

S: supply table

S01 to S08: step (ii) of

X, Y, Z, θ: direction of rotation

Detailed Description

Embodiments of the present invention (hereinafter, referred to as the present embodiments) will be specifically described with reference to the drawings. First, the substrate and the module will be described, and then, the placement device will be described. The drawings schematically show the present embodiment.

[ base plate ]

As shown in fig. 1, a substrate 1 of the present embodiment is a substrate of a display device, and a module 2 described later is placed on the surface thereof. An alignment mark M is provided on the surface of the substrate 1 to align and lay the module 2 at a desired position. The alignment mark M is provided at a position corresponding to the alignment mark M provided in the module 2. That is, the alignment marks M and M are marks serving as references for attaching the module 2 to the substrate 1. The alignment marks M in the present embodiment correspond to the alignment marks M provided at the four corners of the square module 2 one by one, and four alignment marks M are provided for one module 2 (the module 2 is indicated by a broken line in fig. 1). That is, the set of four alignment marks M is provided so as to be located at the vertices of a square. By providing these four sets of alignment marks M in a plurality of rows and columns on the surface of the substrate 1, the module 2 can be attached to the substrate 1. Fig. 1 shows a case where the alignment mark M is provided so that four modules 2 are laid 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 to each other through the adhesive layer. The four corners and the vertices include the vicinity thereof.

[ Module ]

As shown in fig. 2 (a) and 2 (B), the module 2 to be mounted according to the present embodiment includes a flexible substrate 21, an alignment mark m provided on a 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 for sealing the alignment mark m and the light emitting elements 22. The module 2 is mounted on the surface of the substrate 1 by a mounting device 3 described later.

The flexible substrate 21 includes, for example, polyimide, and the light-emitting element 22 is mounted on the surface thereof. As shown in fig. 2 (a), the flexible substrate 21 of the present embodiment is square in plan view, and alignment marks M for aligning the modules 2 to the substrate 1 are provided at four corners of the flexible substrate 21 so as to correspond to the alignment marks M of the substrate 1. That is, the set of four alignment marks m is provided so as to be positioned at the vertices of a square. In addition, the alignment marks M and the alignment marks M are provided in four sets in the present embodiment, but as described later, two sets are actually used for alignment. Thus, the alignment marks M and the alignment marks M may be two sets. The four corners and the vertices include the vicinity thereof.

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 element 22 of the present embodiment is, in particular, a micron-sized LED element, and has a height of, for example, about 25 μm.

As shown in fig. 2 (B), the sealing member 23 is a transparent resin member, and seals the alignment mark m and the light emitting element 22 provided on the surface of the flexible substrate 21. For the sealing member 23, for example, a thermosetting resin having a viscosity of about 4000mPa · s before curing can be used. The sealing member 23 can be formed by curing a curable resin supplied to the surface of the module 2 on which the light-emitting element 22 is mounted. The thickness of the sealing member 23 is, for example, 50 μm to 300 μm. As described above, since the sealing member 23 is a transparent resin member, the alignment mark m and the light emitting element 22 can be recognized through the sealing member 23.

[ paving device ]

[ Structure ]

As shown in fig. 3 and 4A, the placement 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 adjusting unit 34, and a control device 8. The housing C stores the supply stage S, the stage 31, the head 32, the movement mechanism 320, and the control device 8 therein. The supply table S is movably provided, supports the module 2, and supplies the module 2 to the placement device 3. The stage 31 is movably provided and supports the substrate 1. The head 32 moves the module 2 from the supply stage S to the substrate 1 in cooperation with the moving mechanism 320. At this time, the image pickup unit 33 directly and/or via the focal length adjustment unit 34 picks up the image of the alignment mark M of the substrate 1 and the alignment mark M of the module 2, and based on the result of the image pickup, the moving mechanism 320 and the stage 31 align, place, and lay the module 2 at the placement position of the substrate 1. The control device 8 controls each configuration (see fig. 6). In fig. 3, the focal length adjusting unit 34 is not shown.

In fig. 3, the direction in which the supply stage S and the stage 31 are arranged is defined as the X direction, and on a plane parallel to the top surface of the stage 31, the direction orthogonal to the X direction is defined as the Y direction, and the directions orthogonal to the X direction and the Y direction are defined as the Z direction. The Z direction is a direction penetrating the paper surface in the figure. In the present embodiment, the placement device 3 is provided so that the Z direction is vertical, and thus the XY plane becomes a horizontal plane. In this case, the Z direction is the height direction, the installation surface side is referred to as the lower side, and the opposite side is referred to as the upper side. That is, the lower direction means the direction of gravity. The rotation direction parallel to the XY plane is defined as the θ direction.

The supply station S is a support table having a flat table top on which one or more modules 2 are supported. In the present embodiment, as shown in fig. 3, the supply stage S supports four modules 2. The supply table S is provided movably in the Y direction by a linear movement mechanism not shown, and reciprocates inside and outside the housing C. Thus, the supply table S can carry the module 2 to be mounted on the substrate 1 from the outside of the housing C to the inside of the housing C. Further, as described later, the module 2 is moved in cooperation with the moving mechanism 320 so that the module 2 to be picked up faces the head 32, thereby enabling the head 32 to pick up the module 2. The linear movement mechanism, not shown, includes, for example, a motor, a linear guide, and a ball screw, and the table surface of the supply table S is supported by a slider of the linear guide. Further, a loading device including a robot or the like may be separately provided to load the module 2 from the outside of the placement device 3 to the supply stage S. In this case, the modules 2 may be carried in one by one, or a plurality of modules 2 may be carried in one by one using a tray.

The stage 31 is a support table having a flat table surface and supporting the substrate 1 on the table surface. As shown in fig. 3, the stage 31 of the present embodiment supports one substrate 1. The stage 31 is provided movably in the Y direction by a linear movement mechanism not shown, and reciprocates inside and outside the housing C. Thus, the stage 31 can carry the substrate 1 from the outside of the housing C into the housing C and carry the substrate 1 with the module 2 mounted thereon out of the housing C. Further, as will be described later, the moving mechanism 320 moves the substrate 1 in cooperation with the stage 31 so that the head 32 faces a predetermined position of the substrate 1 where the module 2 is to be mounted, and the module 2 can be mounted on the substrate 1 at the predetermined position and can be mounted by the head 32. The linear movement mechanism, not shown, includes, for example, a motor, a linear guide, and a ball screw, and the top surface of stage 31 is supported by a slider of the linear guide. Further, a carrying-out device including a robot or the like may be separately provided to carry out the substrate 1 from the stage 31 to the outside of the placement device 3.

In the present 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 stage S are set to the same height. In this setting, the height of the support surface of the supply table S and the stage 31 can be set by an adjustment mechanism, not shown, such as a fine adjustment mechanism including a push-pull screw, in accordance with the thickness of the flexible substrate 21 of the module 2, the thickness of the substrate 1, and the like.

The head 32 is a head that holds the module 2 supported by the supply stage S by suction and attaches it to the substrate 1 supported by the stage 31. As shown in fig. 4A, the head 32 is supported by the linear movement mechanism 321 via the lifting mechanism 322, and is movably provided between the supply stage S and the stage 31 so as to be able to transfer the module 2 from the supply stage S to the stage 31. The linear movement mechanism 321 includes, for example, a motor, a linear guide, and a ball screw, is arranged above the supply stage S and the stage 31, and extends so as to face the top surfaces of the supply stage S and the stage 31. The linear guide includes a rail 321a, a guide 321b, a slider 321c, and a base 321d. The rail 321a is mounted on the base 321d so as to be movable in the horizontal direction. A guide 321b is provided to grip the rail 321a, and the guide 321b is attached to the slider 321c. The elevating mechanism 322 includes, for example, a motor, a linear guide, and a ball screw, is supported by the slider of the linear movement mechanism 321, and extends in a direction approaching and separating from the supply stage S and the stage 31. A slider 322c of the linear guide is attached to the side surface of the head 32, and a guide 322b is attached to the slider 322c. The rail 322a is vertically movably attached to a slider 321c on the linear movement mechanism 321 side. The head 32 is supported by a slider of the lift mechanism 322. The linear movement mechanism 321 and the lifting mechanism 322 constitute a movement mechanism 320. In fig. 4A, two rails 321a and two guides 321b are shown, but the number may be increased or decreased depending on the size of the base 321d or the slider 321c. The number of the rails 322a and the guides 322b may be increased or decreased in the same manner.

A holding portion 32a is provided on the side of the head 32 facing the supply stage S and the stage 31. The holding portion 32a is provided with suction holes, not shown, on a surface facing the supply stage S and the stage 31, and the suction holes generate a negative pressure to suck and hold the module 2, thereby enabling the module 2 to be picked up from the supply stage S. The holding portion 32a releases the negative pressure generated in the suction hole, and thereby releases the module 2 and can be attached to the substrate 1. Further, the holding portion 32a is provided rotatably in the θ direction with respect to the head 32 by a θ direction rotation mechanism, not shown, and can rotate the held module 2 in the θ direction. Thus, the holding portion 32a can adjust its direction when the module 2 is mounted on the substrate 1. The rotation mechanism in the θ direction is also included in the movement mechanism 320.

The head 32 is provided with a contact sensor, not shown. The contact sensor detects that the holding portion 32a has contacted the module 2 or has contacted 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 the contact sensor, the head 32 can perform suction holding or releasing of the module 2.

The holding portion 32a of the present embodiment holds the module 2 by suction so that at least two of the alignment marks m provided at the four corners of the module 2 can be recognized from above. This is achieved by the holding portion 32a sucking a portion of the upper surface of the holding module 2 that does not hinder the reading of the alignment mark m from above. Further, in the present embodiment, a transparent portion 32b including a transparent member such as quartz glass is provided on a side surface of the holding portion 32a on an optical path connecting the alignment mark m of the module 2 sucked and held by the holding portion 32a and the imaging portion 33. That is, the imaging unit 33 images the alignment mark m through the transparent part 32b. The lower surface of the transparent portion 32b is set to the same height as the lower surface of the holding portion 32a, so that the upper surface (the surface of the sealing member 23) of the module 2 is flatly supported by the holding portion 32a and the transparent portion 32b over the entire surface, and the head 32 can press the entire upper surface of the module 2 against the substrate 1 when the module 2 is mounted on the substrate 1.

The imaging unit 33 is a camera having one optical system such as a lens for imaging the alignment mark M of the module 2 and the alignment mark M of the substrate 1 in the same field of view and one imaging element. That is, the imaging unit 33 is provided at a position facing the substrate 1 via the module 2 held by the head 32, and is capable of imaging, 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 portion of the substrate 1 to be pasted this time. The focal length of the imaging unit 33 is set to a predetermined reference height position at which the alignment mark m of the module 2 facing the substrate 1 is positioned.

The imaging unit 33 of the present embodiment is supported above the head 32 by the linear movement mechanism 321. More specifically, the imaging unit 33 is provided at each of both ends of a U-shaped frame 33a supported by the linear movement mechanism 321, and two imaging units are provided in total. 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 by supporting one of the two parallel sides of the U-shape to be connected to the linear movement mechanism 321. That is, the imaging unit 33 is provided so as to be positioned above the alignment mark M and the alignment mark M in a state where the holding unit 32a of the head 32 holds the module 2 and conveys the module to a position facing the substrate 1. As a result, as shown in fig. 8, the imaging units 33 simultaneously image the alignment mark M and the alignment mark M corresponding to each other in the same field of view. The term "photographing in the same field of view" means that a plurality of subjects are photographed simultaneously (collectively at once) in the field of view. Each imaging unit 33 transmits an image obtained by imaging the alignment mark M and the alignment mark M to the control device 8 described later. Each imaging unit 33 is provided at a height position where the focal length coincides with a predetermined reference height position at which the alignment mark m of the module 2 facing the substrate 1 is positioned.

The focal length adjusting unit 34 is a transparent member such as quartz glass that adjusts the focal length of the imaging unit 33 with respect to the alignment mark M so as to focus on the alignment mark M. That is, the focal length adjusting 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 is a member that, since the actual focal position is separated from the imaging unit 33, the focal point of the imaging unit 33 is also aligned with the alignment mark M with respect to the state in which the imaging unit 33 is in focus with the alignment mark M of the module 2 at a short distance from the imaging unit 33. For example, a state in which the alignment mark M is located 1mm above the upper surface of the substrate 1 on which the alignment mark M is provided is a predetermined reference height position at which the alignment mark M is positioned. In this state, when the alignment mark M and the alignment mark M are imaged in the same field of view, a focal length adjusting unit 34 having a thickness of about 0.3mm is used on an optical path connecting the alignment mark M and the imaging unit 33. As shown in fig. 8, the focal length adjusting unit 34 is provided so as to cover a half (lower side in fig. 8) of the imaging field of view of the imaging unit 33, and thereby extends the focal length of the lower half of the imaging field of view of the imaging unit 33 as compared with the focal length of the remaining half (upper side in fig. 8) of the imaging field of view. As described later, the module 2 and the alignment mark m held by the head 32 are projected on the upper half of the imaging field of view of the imaging unit 33 in the present embodiment. In this way, the focal length of the imaging unit 33 is fixedly set by the focal length adjusting unit 34 so that the predetermined alignment mark M and the predetermined alignment mark M are both focused at the same time.

The focal length adjusting unit 34 is supported by the linear movement mechanism 321 via a support member, not shown, and is provided movably 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 broken line arrow in fig. 4A, the imaging unit 33 can focus the alignment mark M of the module 2 held by the head 32 above the substrate 1, and also can focus the alignment mark M. Therefore, the captured image of the imaging unit 33 becomes a captured image of both the in-focus alignment mark M and the alignment mark M, and therefore, the correction processing in the control device 8 to be described later can be realized with high accuracy. In practice, not only the focal length adjustment unit 34 but also the transparent unit 32b extends the focal length of the imaging unit 33. Therefore, the focal length adjustment unit 34 includes a transparent member thicker than the transparent portion 32b in the optical path direction connecting the substrate 1 and the imaging unit 33.

The control device 8 is a device that controls the placement device 3. The control device 8 includes, for example, a dedicated electronic circuit or a computer or the like that operates with a predetermined program. That is, the control device 8 controls the operation of the placement device 3 by controlling the operations of the supply stage S, the stage 31, the head 32, the imaging unit 33, and the like. 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.

The storage unit 81 is a storage medium such as a Hard Disk Drive (HDD) or a Solid State Drive (SSD). The storage unit 81 stores data and programs necessary for the operation of the system, and also stores data necessary for the operation of the system. The imaging control unit 82 controls the operation of the imaging unit 33. That is, the image pickup unit 33 performs control related to image pickup, such as start, image pickup, stop, image transmission, and focus. The calculation unit 83 calculates the alignment mark M and the amount of deviation of the alignment mark 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.

The movement control unit 84 controls the movement of the supply stage S, the stage 31, and the movement mechanism 320. The control is based on data and programs necessary for the operation of the system, which are stored in advance in the storage unit 81, the captured image captured by the imaging unit 33, the calculation result of the calculation unit 83, and the like. In particular, the movement controller 84 according to the present embodiment performs control of positioning the module 2 held by the head 32 to the substrate 1 supported by the stage 31, based on the misalignment amounts of the alignment mark M and the alignment mark M calculated by the calculator 83. The control by the movement control unit 84 may be based on a user command input from an input device 91 described later, for example.

The setting unit 85 is a processing unit that sets information in the storage unit 81 in response to an input. The input/output control unit 86 is an interface for controlling signal exchange or input/output with each unit to be controlled.

The input device 91 and the output device 92 are connected to the control device 8. The input device 91 is an input means for an operator to operate a switch, a touch panel, a keyboard, a mouse, and the like of the placement device 3 via the control device 8. The operator can input various kinds of information set in the storage unit 81 through the input device 91. The output device 92 is an output means such as a display, a lamp, and a meter, which displays information for confirming the state of the device in a state recognizable by the operator. Further, the output device 92 can display an input screen of information from the input device 91.

[ Effect ]

Next, an operation example of the present embodiment will be described with reference to fig. 4B (a) to 4B (C), fig. 5 (a) to 5 (D), and fig. 7. Fig. 4B (a) to 4B (C) show the case at the time of pickup, and fig. 5 (a) to 5 (D) show the placement flow of the embodiment. Fig. 7 is a flowchart showing a pasting flow of the pasting device 3. Although not shown, first, the module 2 is supported by the supply stage S and carried into the housing C, the substrate 1 is also supported by the stage 31 and carried into the housing C, and the supply stage S and the stage 31 stand by adjacent to each other (see fig. 3). The head 32, the imaging unit 33, and the focus adjustment unit 34 are supported by the linear movement mechanism 321 above the supply stage S, and stand by with respect to the module 2 to be picked up this time supported by the supply stage S.

First, as shown in fig. 4B (a), the movement of the supply stage S and the movement mechanism 320 is controlled by the movement control unit 84 so that the imaging unit 33 and the module 2 are in a predetermined positional relationship. The predetermined positional relationship here is a positional relationship in which the imaging unit 33 can image the alignment mark m of the module 2 on the supply stage S via the focal length adjustment unit 34. Next, the imaging section 33 images the alignment mark m of the module 2 to be picked up this time supported by the supply stage S by the imaging control section 82, and sends the imaged image thereof to the movement control section 84. Since the alignment marks M of the module 2 placed on the supply stage S are set to the same height as the alignment marks M of the substrate 1 placed on the stage 31, when the image pickup unit 33 picks up the alignment marks M of the module 2 on the supply stage S, a sharp focused image can be obtained through the focus adjustment unit 34. The movement control unit 84 calculates the position of the alignment mark m with respect to the imaging unit 33 by known image processing based on the captured image, and controls the movement of the supply stage S and the movement mechanism 320 so as to have 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, so that the head 32 is aligned to a predetermined position, that is, a position where picking is performed, with respect to the module 2 as shown in fig. 5 a (step S01).

Then, 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. Further, the holding portion 32a of the head 32 is caused to generate a negative pressure to suction and hold the module 2. As shown in fig. 4B (C), the head 32 is moved to a height that is clear of the substrate 1 in a state where the module 2 is held by suction, and the module 2 is picked up from the supply stage S (step S02). In addition, at the time of picking up, the module is held at a position at a height at which the imaging unit 33 can take an image of focusing the alignment mark m of the module 2 without passing through the focal length adjustment unit 34.

Next, as shown in fig. 5 (B), the head 32 that has sucked and held the module 2 is moved in the X direction and the stage 31 that has supported the substrate 1 is moved in the Y direction toward the position on the substrate 1 where the module 2 is to be applied this time, which is stored in the storage section 81. Thereby, the module 2 is transported to above the substrate 1 supported by the stage 31 (step S03). Here, the position on the substrate 1 of the secondary placement module 2 is, for example, the upper right position of the substrate 1, and then the upper left position of the substrate 1, and then the position is moved to the lower left position in fig. 5 (a) to 5 (D). In this movement, the movement control unit 84 images the alignment mark M provided at the position on the substrate 1 to which the module 2 is to be applied and the alignment mark M provided in the module 2 in the same field of view, calculates a position on the XY plane where the alignment mark M provided in the module 2 is displaced by a predetermined amount from the alignment mark M provided at the position on the substrate 1 to which the module 2 is to be applied, and moves the module 2 and the substrate 1 relative to each other to position the alignment mark M at this position. The predetermined amount of the position deviated by the predetermined amount at this time is based on the field of view range within the same field of view of the imaging unit 33, as described below, in which the imaging unit 33 can image the alignment mark M of the substrate 1 without the focus adjustment unit 34, and the imaging unit 33 can image the alignment mark M of the module 2 via the focus adjustment unit 34.

Then, the head 32 is moved to a height at which the alignment mark M and the alignment mark M are imaged in the same field of view by the movement control unit 84. The height is an in-focus alignment mark M of the photographing section, and is also aligned with the height of the alignment mark M via the focus adjustment section 34. The height is a height based on a design value of a focal length stored in advance. Then, the imaging control unit 82 causes the imaging unit 33 to capture an image in which the alignment mark M provided on the module 2 and the alignment mark M provided on the substrate 1 are positioned within the same field of view, and transmit the captured 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.

Fig. 8 shows a case where the imaging unit 33 is imaging the alignment mark M of the module 2 and the alignment mark M of the substrate 1. The imaging unit 33 performs positioning to image the alignment mark M and the alignment mark M in the same field of view, and simultaneously maps the two alignment marks. In the figure, the module 2 is partially hatched. The area shown by the circle in fig. 8 is the shooting field of view. An alignment mark M and an alignment mark M are displayed in the circle, that is, in the same photographing field of view. At this time, the outer shape of the module 2 and the alignment mark m are shown on the upper side in the drawing, and the imaging unit 33 images the alignment mark m in the upper side region in the drawing. At the same time, the alignment mark M is projected on the lower side in the figure, and the imaging unit 33 images the alignment mark M in the lower area in the figure.

Here, the focal length adjustment unit 34 including a transparent member is positioned on the optical path up to the alignment mark M of the imaging unit 33. That is, the focus adjustment section 34 is located in the lower region in fig. 8. The focus adjustment unit 34 adjusts the focus of the image pickup unit 33 to the alignment mark M. That is, the imaging control unit 82 focuses the imaging unit 33 on the alignment mark M of the module 2, and the focus adjustment unit 34 also focuses the alignment mark M of the substrate 1. Thus, the imaging unit 33 can perform imaging by focusing on both the alignment mark M and the alignment mark M at different distances.

In step S04, the head 32 may be further moved in a direction (Z direction) toward and away from the imaging unit 33 by the elevating mechanism 322 to adjust the height position of the alignment mark m of the module 2 so as to focus the imaging unit 33. The upper surface of the module 2 is held by the holding portion 32a. That is, the alignment mark m and the holding portion 32a of the module 2 are held via the sealing member 23. Therefore, when there is variation in the thickness of the module 2 (as described above, the thickness of the sealing member 23 of the module 2 is formed by stretching the curable resin, and therefore there is variation), there is a possibility that the focusing on the module 2 cannot be performed. At this time, the height position of the head 32 is moved up and down, so that the distance from the imaging unit 33 to the alignment mark m can be adjusted to absorb the thickness variation of the sealing member 23. Such focusing can be performed by the photographing section 33 by a known method.

As described above, the height of the head 32 is positioned based on the design value of the focal length of the imaging unit 33 with respect to the alignment mark m of the module 2. That is, when the alignment marks M and M are imaged, the alignment marks M of the module 2 are positioned above the substrate 1 at a predetermined interval (height). The interval is an interval that is movable when aligning the module 2 to the placement position of the substrate 1. The distance is the height (distance) of the module 2 from the substrate 1, and corresponds to the distance adjusted by the focal length adjusting unit 34. Therefore, the distance is a position in the Z direction (the distance between the module 2 and the substrate 1) and is fixed as an initial value when the alignment mark M and the alignment mark M are captured. Therefore, the thickness of the focal length adjusting section 34 is determined by the interval. That is, the thickness of the focal length adjusting section 34 is fixed. At this time, unlike the sealing member 23 of the module 2, the thickness of the substrate 1 is hardly varied and also hardly deviates from the design value. Therefore, the focus of the imaging unit 33 with respect to the alignment mark M of the substrate 1 via the focus adjustment unit 34 is not greatly deviated even when the focus is set with respect to the focus of the alignment mark M of the module 2. Therefore, even when there is variation in the thickness of the module 2 and the focusing of the module 2 cannot be performed depending on the design value, the head 32 can be controlled based on the thickness of the module 2 so as to move the module 2 up and down and align the alignment mark M of the module 2, because the alignment mark M of the substrate 1 is focused. This makes it possible to cope with the positional variation of the alignment mark m due to the thickness variation of each module 2, and to more strictly focus the alignment mark m.

After step S04, based on the captured image shown in fig. 8, the calculation unit 83 detects the positions of the alignment marks M and M, and calculates the positional relationship between the alignment marks M and M (step S05). That is, the direction and amount of misalignment between the alignment mark M and the alignment mark M are calculated. In the present embodiment, two imaging units 33 are provided. The two imaging units 33 can acquire two captured images shown in fig. 8. The direction and amount of deviation between the substrate 1 and the module 2 are calculated based on the two captured images. The example shown in fig. 9 (a) shows a case where the substrate 1 (the direction in which the module 2 is to be mounted) and the module 2 held by the head 32 are misaligned in the direction and position. The circle shown by the dotted line indicates the shooting field of view. There are two imaging units 33, each of which indicates a field of view. Then, the two imaging units 33 image the alignment mark M and the alignment mark M in the right and left viewing ranges. The positional relationship (the direction and amount of deviation) between the alignment marks M and the left and right alignment marks M is calculated from the captured images of the alignment marks M and the left and right alignment marks M. Then, the positional relationship (the shift direction and the shift amount) between the left and right alignment marks M and the positional relationship (the shift direction and the shift amount) between the left and right alignment marks M are calculated, and the angle formed by the line connecting the two alignment marks M and the line connecting the two alignment marks M is calculated based on the results. The angle is the angle of the substrate 1 and the module 2. The positional relationship (the direction and amount of displacement) between the substrate 1 and the module 2 is determined from the results of these calculations. That is, the misalignment direction and the misalignment amount of the alignment mark M and the alignment mark M are calculated based on the captured images of the two imaging units 33, and the misalignment in the XY direction and the θ direction is corrected, so that accurate placement can be achieved as shown in fig. 9 (C).

In addition, although the example of fig. 9 (a) shows an extreme direction deviation for easy understanding, since the alignment is performed with respect to the head 32 at the time of picking up the module 2, the direction deviation is hardly generated to such an extent that the positional relationship between the alignment mark M and the alignment mark M is reversed, as shown in fig. 9 (B), for example. If the module 2 is displaced during the movement of the head 32 and the positional relationship between the alignment mark M and the alignment mark M is reversed, the alignment mark M at either of the two positions is hidden by the module 2 and the image cannot be captured at all. In this case, the process is stopped as an error. Then, as described in step 03, in order to image the alignment mark M and the alignment mark M in the same field of view, the module 2 is positioned at a position where the alignment mark M is displaced by a predetermined amount from the alignment mark M on the XY plane. Therefore, the positional relationship between the alignment mark M and the alignment mark M is prevented from becoming reversed. However, there is a possibility that the alignment mark may be out of the visual field range, and at this time, the process may be stopped as an error because any alignment mark cannot be captured. Therefore, the deviation in the direction between the substrate 1 and the module 2 may be calculated based on the difference in the positional relationship between the alignment marks M on the left and right sides (the deviation direction and the deviation amount) without calculating the angle formed by the line connecting the two alignment marks M and the line connecting the two alignment marks M. That is, the direction (angle) of the deviation may be calculated based on the intervals between the left and right alignment marks M and the alignment mark M. In this case, the arithmetic processing can be simplified.

Further, the calculation unit 83 transmits the calculation result to the movement control unit 84, and as shown in fig. 5C, the movement control unit 84 moves the stage 31 in the Y direction, the head 32 in the X direction, and the holding unit 32a in the θ direction based on the calculation result to align the module 2 to the substrate 1 so that the alignment mark M and the alignment mark M overlap in a plan view (step S06). Finally, the movement controller 84 moves (lowers) the head 32 toward the substrate 1, thereby bonding the module 2 to the substrate 1 (step S07). Subsequently, the head 32 releases the suction holding of the module 2, moves (ascends) in the direction away from the substrate 1, and then moves again in the X direction, and moves to above the supply table S, specifically, above the module 2 to be suction-held next, as shown in fig. 5D (step S08). By repeating the above steps S01 to S08, the module 2 is mounted on the substrate 1. When the supply stage S is empty or when the module 2 has been already placed on the entire surface of the substrate 1, the movement controller 84 moves the supply stage S or the stage 31 to the outside of the housing C, supports a new module 2 or substrate 1, and returns the module or substrate to the inside of the housing C. This allows continuous placement.

[ Effect ]

(1) The placement device 3 of the present embodiment includes: a stage 31 for supporting the substrate 1; a head 32 that conveys the module 2 on which the plurality of elements are mounted to a position facing the substrate 1; an imaging unit 33 that faces the substrate 1 via the module 2 held by the head 32, and that images the alignment mark M provided on the substrate 1 and the alignment mark M provided on the module 2 in the same field of view; and a focal length adjusting unit 34 provided on an optical path connecting the alignment mark M and the imaging unit 33, for adjusting a focal length of the imaging unit 33 with respect to the alignment mark M so that a focal point of the imaging unit 33 is simultaneously aligned with the alignment mark M and the alignment mark M, and the head 32 attaches the module 2 to the substrate 1 based on an image captured by the imaging unit 33.

Accordingly, since the module 2 can be applied to the substrate 1 based on the captured images of the alignment mark M and the alignment mark M having different distances from the imaging unit with the focus simultaneously, the module can be applied with higher precision than in the conventional art. In order to apply the module 2 to the substrate 1, the module 2 has to be moved over the substrate 1. Therefore, when the module 2 is positioned to face a portion of the substrate 1 where the module 2 is to be laid, a gap exists between the substrate 1 and the module 2. Therefore, the distance from the imaging unit 33 to the module 2 of the imaging unit 33 that images the alignment mark of the substrate 1 or the module 2 is shorter than the distance from the imaging unit 33 to the substrate 1. That is, the substrate 1 cannot be brought into focus in the state where the module 2 is brought into focus. Similarly, the in-focus module 2 cannot be brought into focus with the substrate 1 in focus. Therefore, conventionally, images are taken by cameras (corresponding to the image pickup unit 33 of the present embodiment) that focus on the alignment marks M of the substrate 1 and the alignment marks M of the module 2, respectively, and the positional relationship between the substrate 1 and the module 2 is indirectly calculated from the positional relationship between the positions of the alignment marks recognized from the respective images and the two cameras. However, in this case, the position of the camera changes due to thermal expansion, vibration generated during imaging, or the like, and it is difficult to perform highly accurate positioning. Further, in order to align the directions of the substrate 1 and the module 2, two cameras (imaging units 33) are additionally used to independently image the alignment marks of the substrate 1 and the module 2 at two locations, respectively, so that the position of the alignment marks of the substrate 1 and the module 2 can be recognized at two locations, and when performing the alignment for placement, it is difficult to perform the alignment with high accuracy due to an error caused by thermal expansion, vibration generated during imaging, or the like in the positional relationship between the two cameras additionally used. Further, since four cameras are used in this manner, the apparatus configuration also has to be complicated. On the other hand, since the imaging unit 33 of the present embodiment images the alignment mark M of the substrate 1 and the alignment mark M of the module 2 in the same field of view, the relative positional relationship between the alignment mark M and the alignment mark M does not change even if vibration or the like occurs during imaging. As described above, two image pickup units 33 may be used instead of four cameras. Therefore, the error between the cameras is also halved, and the alignment with high accuracy can be performed, and the apparatus configuration can be simplified.

(2) In a state where the alignment mark M of the image pickup unit 33 is brought into focus, the head 32 moves the module 2 in a direction of approaching/separating from the image pickup unit 33 in accordance with the thickness of the module 2 held by the head 32, thereby bringing the alignment mark M of the image pickup unit 33 into focus. This makes it possible to more strictly align the alignment mark m of the in-focus module 2. Further, even if there is variation in the thickness of the substrate 1 or the module 2, the module 2 can be applied to the substrate 1 with high accuracy because the module 2 can be easily brought into focus.

[ modified examples ]

(1) In the above embodiment, the focal length adjustment unit 34 is supported by the linear movement mechanism 321, and is provided to move in the X direction in conjunction with the head 32 and the imaging unit 33, but the present invention is not limited thereto. For example, as shown in fig. 10 (a), the transparent portion 32b may be provided integrally with the side surface of the holding portion 32a of the head 32. This can simplify the positioning of the focus adjustment unit 34 with respect to the imaging unit 33. In particular, it is possible to easily realize the position adjustment in which half of the range is set to the field of view via the focal length adjustment unit 34, for example, in the field of view.

(2) As shown in fig. 10 (B), the focus adjustment unit 34 may be provided in the imaging unit 33. With this, as in the modification, the focus adjustment unit 34 can be easily positioned with respect to the imaging unit 33.

(3) Further, as shown in fig. 10 (C), the focal length adjusting unit 34 may be provided directly to the head 32. At this time, the focus adjustment unit 34 moves up and down with the up and down movement of the head 32, but the focus of the imaging unit 33 is aligned with the alignment mark M as long as the imaging unit 33 is positioned on the optical path of the imaging alignment mark M, and thus, the alignment can be performed. The arrangement and shape of the focal length adjusting unit 34 must be such that the focal length adjusting unit 34 does not appear on the optical path of the imaging alignment mark m. For example, the focal length adjustment unit 34 shown in fig. 10C has a hole (shown by a broken line) on the optical path of the imaging alignment mark m, and the imaging unit 33 can image the alignment mark m through the hole. Therefore, during imaging of the alignment mark m, imaging can be performed in a focused state without passing through the focus adjustment unit 34.

(4) In the above embodiment, the imaging unit 33 is supported by the linear movement mechanism 321, but the present invention is not limited thereto. For example, the substrate 1 may be fixed to the frame C above the substrate. This can avoid the influence of vibration caused by the movement of the imaging unit 33, vibration caused in the placement device 3, and the like, and can reduce the error in positioning. In this case, the stage 31 is configured to be movable not only in the Y direction but also in the X direction, and thereby the alignment mark M of the substrate 1 can be moved to a position directly below the imaging unit 33 provided in the housing C.

(5) In the above embodiment, two imaging units 33 are provided to perform imaging simultaneously, but if the relative angular deviation between the module 2 picked up and held and the substrate 1 supported by the stage 31 is within a tolerable range, the θ alignment (directional alignment) of the module 2 with respect to the substrate 1 is not necessary, and in this case, one imaging unit 33 may be provided. Since the device configuration can be simplified and the image processing and calculation for registration can be simplified, the tact time for placement can be shortened, and productivity can be improved. Further, an optical system including a mirror or a prism and allowing a plurality of portions to be viewed may be applied to the optical system of the imaging unit 33 or an optical system outside the imaging unit 33 to image two sets of alignment marks M, M at a time. In this case, one imaging unit 33 may be provided. Further, one imaging unit 33 may be moved to image two sets of alignment marks M, M. At this time, information on the relative direction of the substrate 1 and the module 2 can also be obtained. In either case, the apparatus structure can be simplified, and the number of used members can be reduced, whereby the apparatus cost can be reduced, and the occurrence of failure can be suppressed. Further, the calibration operation between the two imaging units 33 is not required, and the manufacturing and maintenance of the apparatus can be facilitated.

(6) In the above embodiment, the alignment mark M placed on the surface of the substrate 1 of the stage 31 and the alignment mark M placed on the surface of the module 2 of the supply stage S are set to the same height, and when the alignment mark M placed on the surface of the module 2 of the supply stage S is imaged by the imaging unit 33, the alignment mark is imaged via the focal length adjusting unit 34. However, even when the height of the alignment mark M of the module 2 placed on the supply stage S is set to a height at which the module 2 is held by the head 32 and the alignment mark M are imaged, the pickup position can be recognized. At this time, when the image is captured by the imaging unit 33, the alignment mark m is directly imaged in the field of view without passing through the focus adjustment unit 34.

[ other embodiments ]

The present invention is not limited to the above-described embodiments, and constituent elements may be modified and embodied in the implementation stage without departing from the spirit and scope thereof. Further, various inventions can be formed by appropriate combinations of a plurality of constituent elements disclosed in the embodiments. For example, several constituent elements may be deleted from all the constituent elements shown in the embodiments. Further, the constituent elements of the different embodiments may be appropriately combined.

Claims (7)

1. A placement device comprising:

a stage supporting a substrate;

a head that conveys a module on which a plurality of components are mounted to a position facing the substrate;

an imaging unit that faces the substrate through the module held by the head, and that images a first alignment mark provided on the substrate and a second alignment mark provided on the module in the same field of view; and

a focus adjustment unit which is provided on an optical path connecting the first alignment mark and the image pickup unit, and adjusts a focus of the image pickup unit with respect to the first alignment mark so that a focus of the image pickup unit is simultaneously aligned with the first alignment mark and the second alignment mark,

the head attaches the module to the substrate based on the image captured by the imaging section.

2. The applicator of claim 1, wherein

In a state where the focus of the photographing section is brought into focus with the first alignment mark via the focus adjustment section,

the head moves the module toward/away from the image pickup section according to a thickness of the module held by the head, thereby bringing a focus of the image pickup section into alignment with the second alignment mark.

3. The applicator of claim 1, wherein

The focal length adjusting part is supported by a linear moving mechanism,

and the focal length adjusting part is provided in a manner of moving in the X direction in linkage with the head and the shooting part.

4. The applicator of claim 1, wherein

The focal length adjusting section is provided to the head.

5. The applicator of claim 1, wherein

The focal length adjustment unit is provided in the head holding unit.

6. The paving device of claim 1 wherein

The focal length adjustment unit is provided in the imaging unit.

7. Paving device according to any one of claims 1 to 6, wherein

The number of the shooting parts is two,

two sets of the first alignment marks and the second alignment marks are provided,

the respective imaging units simultaneously image the respective sets of the first alignment marks and the second alignment marks in the same field of view.

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