Substrate transfer device

Abstract

The invention discloses a substrate conveying device which can prevent buckling of a substrate and can properly detect the thickness of the substrate. The substrate conveying device comprises a conveying path; the detection roller is arranged on the conveying path and provided with a first shaft which rotates along with the conveying of the substrate; a swinging arm which is parallel to the first shaft and swings around a second shaft along with the lifting of the detection roller; a rotation sensor that detects rotation of the swing arm about a second axis; and a controller configured to determine whether or not a transfer state of the substrate is good on the basis of a detection result of the rotation sensor, an arm axis connecting the first shaft and the second shaft being located between a horizontal reference line extending from the first shaft to an upstream side in the transfer direction and a vertical reference line extending from the first shaft to a vertically upward direction.

Description

Technical Field

[0001] The present specification relates to a substrate transport device that transports a substrate along a transport path. Background Art

[0002] Conventionally, there is known a substrate transport device that transports a substrate along a transport path, and the substrate transport device has a mechanism for detecting the thickness of the substrate in order to prevent two or more substrates from being transported in an overlapping state.

[0003] Here, the conventional substrate thickness detection mechanism comprises: an arm that can swing around an axis parallel to the conveying direction of the substrate; and a detection roller disposed at the front end of the arm. The appropriateness of the substrate thickness is determined based on the lifting amount of the detection roller when the substrate passes under the detection roller.

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] Patent Document 1: Japanese Patent Publication No. 48-64668 Summary of the invention

[0007] [Problems to be solved by the invention]

[0008] However, in the case of the conventional thickness detection mechanism, the detection roller cannot move in the conveying direction. Therefore, in the case of the conventional thickness detection mechanism, when the detection roller receives a force from the substrate in the downstream direction of the detection direction, the force cannot be dissipated, and sometimes a large reaction force acts on the substrate. In addition, the substrate may be buckled by the reaction force.

[0009] In addition, Patent Document 1 discloses a device for detecting double feeding of sheets. However, the technology of Patent Document 1 assumes the case of conveying sheets such as paper, and does not discuss the conveyance of substrates. Moreover, the technology of Patent Document 1 adjusts the size ratio of the two arms to improve the detection accuracy. As a result, in the case of the technology of Patent Document 1, the entire device is easily enlarged.

[0010] Therefore, this specification discloses a substrate transporting device that can prevent buckling of a substrate and appropriately detect the thickness of the substrate.

[0011] [Technical means to solve the problem]

[0012] The substrate conveying device disclosed in the present specification includes: a conveying path for conveying a substrate along a specified conveying direction; a detection roller, which is arranged on the conveying path and has a first axis that rotates along with the conveyance of the substrate; a swing arm, which rotates around a second axis and is connected to the detection roller and swings along with the lifting and lowering of the detection roller; a rotation sensor, which detects the rotation of the swing arm around the second axis; and a controller, which determines whether the conveying state of the substrate is good or not based on the detection result of the rotation sensor, wherein the arm axis connecting the first axis and the second axis is located between a horizontal reference line extending from the first axis toward the upstream side of the conveying direction and a vertical reference line extending from the first axis toward the vertical upper side.

[0013] At this time, the angle formed by the arm axis and the horizontal reference line may be greater than or equal to 45 degrees and less than 80 degrees.

[0014] Furthermore, the rotation sensor may be arranged outside the transport path in a horizontal direction.

[0015] Furthermore, the rotation sensor may include: a detection block arranged in a manner intersecting the second axis and rotating around the second axis as the swing arm swings; a detection hole penetrating the detection block in a direction orthogonal to the second axis; and a light-emitting element and a light-receiving element arranged facing each other with the detection hole sandwiched therebetween, wherein at least one of the light-emitting element and the light-receiving element is fixed relative to the transport path and changes its relative position relative to the detection hole as the detection block rotates.

[0016] [Effects of the Invention]

[0017] According to the substrate transport device disclosed in this specification, the thickness of the substrate can be appropriately detected and the buckling of the substrate can be effectively prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic plan view of a substrate transfer device.

[0019] Figure 2 It is a schematic front view of the substrate thickness detection mechanism.

[0020] Figure 3 This is a diagram showing the principle of detecting the thickness of a substrate by the substrate thickness detection mechanism.

[0021] Figure 4 This is a schematic diagram showing the principle of rotation amount detection by a rotation sensor.

[0022] Figure 5 It is a schematic diagram showing the forces acting on the detection roller and the substrate.

[0023] Figure 6This is a schematic diagram showing the force that acts when the arm axis is located downstream in the conveyance direction from the center of the detection roller.

[0024] Figure 7 This is a schematic diagram of a conventional substrate thickness detection mechanism.

[0025] [Explanation of Symbols]

[0026] 10: Substrate transport device

[0027] 12: Transport path

[0028] 14, 14*: Substrate thickness detection mechanism

[0029] 16, 16*: Detection roller

[0030] 18, 18*: Connecting shaft

[0031] 20: Swing arm

[0032] 22: Rotation axis

[0033] 24: Bearings

[0034] 25: Rotation sensor

[0035] 26: Detection block

[0036] 28: Detection hole

[0037] 32: Light-emitting element

[0038] 34: Light receiving element

[0039] 40: Controller

[0040] 42: Processor

[0041] 44: Memory

[0042] 50: Distance sensor

[0043] 100: Substrate

[0044] Af: First axis

[0045] As: Second axis DETAILED DESCRIPTION

[0046] Hereinafter, the structure of the substrate transfer device 10 will be described with reference to the drawings. Figure 1 is a schematic plan view of the substrate transfer device 10. Figure 2 1 is a schematic front view of the substrate thickness detection mechanism 14. The substrate transport device 10 transports the substrate 100 along the transport path 12 from the upstream side in the transport direction to the downstream side in the transport direction. Figure 1 and Figure 2In the figure, the left side of the paper is the upstream side in the conveying direction, and the right side of the paper is the downstream side in the conveying direction. In addition, the substrate conveying device 10 heats the substrate 100 during the conveying process for the subsequent process, and a heater (not shown) for the heating is built into the conveying path 12. The substrate conveying device 10 can be used alone or incorporated into other devices (such as a bonding device for bonding a semiconductor element to the substrate 100).

[0047] The substrate transport device 10 further includes a substrate thickness detection mechanism 14 for detecting the thickness of the transported substrate 100. In order to detect the thickness of the substrate 100, the substrate thickness detection mechanism 14 includes a detection roller 16, a swing arm 20, and a rotation sensor 25.

[0048] The detection roller 16 is a roller that can rotate about the first axis Af as the center and can swing about the second axis As as the center. Figure 1 As shown, it is an axis that is substantially parallel to the surface of the conveying path 12 and substantially orthogonal to the conveying direction. The detection roller 16 is arranged on the passage of the substrate 100. In the absence of the substrate 100, the detection roller 16 contacts the surface of the conveying path 12 (i.e., the conveying surface). The substrate 100 in the conveying process passes under the detection roller 16 and is sent to the downstream side.

[0049] Moreover, the detection roller 16 can swing around the second axis As parallel to the first axis Af. The second axis As is located upstream of the first axis Af in the conveying direction and above the first axis Af. Therefore, when the line extending from the first axis Af toward the upstream of the conveying direction is set as the "horizontal reference line Lh", the line extending from the first axis Af toward the vertically upward is set as the "vertical reference line Lv", and the line connecting the first axis Af and the second axis As is set as the "arm axis La", the arm axis La is located between the horizontal reference line Lh and the vertical reference line Lv. The reason for setting the second axis As to this configuration will be described later. In any case, the detection roller 16 is raised and lowered by swinging (in other words, revolving) around the second axis As, and the substrate 100 is sent to the downstream side by rotating around the first axis Af.

[0050] The detection roller 16 is connected to the swing arm 20 via a connecting shaft 18. The connecting shaft 18 is a shaft member provided coaxially with the first axis Af. The center of the detection roller 16 is rotatably mounted on one end of the connecting shaft 18. Moreover, the other end of the connecting shaft 18 is fixed to the downstream end of the swing arm 20. Here, as described in Figure 1 As is clear from the above, the other end of the connecting shaft 18 is located outside the conveying path 12 in the horizontal direction. In addition, the swing arm 20 and the rotation sensor 25 are also located outside the conveying path 12 in the horizontal direction.

[0051] The swing arm 20 is an arm member that swings around the second axis As. In the illustrated example, the second axis As is located at the downstream end of the swing arm 20 in the conveying direction. Furthermore, a rotating shaft 22 is fixed to the swing arm 20. The rotating shaft 22 is an axial member that is coaxially arranged with the second axis As and extends in a direction away from the conveying path 12. The rotating shaft 22 is rotatably held by a plurality of bearings 24. The rotating shaft 22 rotates along with the swing of the swing arm 20 and the detection roller 16.

[0052] A rotation sensor 25 is installed at the middle part of the rotating shaft 22 to detect the rotation amount of the rotating shaft 22 and the lifting amount of the detection roller 16. The rotation sensor 25 includes a detection block 26, a light emitting element 32 and a light receiving element 34. A detection hole 28 is formed in the detection block 26 and passes through in a direction parallel to the conveying direction. The light emitting element 32 and the light receiving element 34 are arranged on both sides of the detection hole 28. The principle of detecting the rotation amount by such a rotation sensor 25 will be described later. In addition, there is no limitation on the arrangement positions of the light emitting element 32 and the light receiving element 34. For example, the two may be fixed to the conveying path 12. Moreover, for the detection block 26, a component having a hole opened in a tubular member may be used for easy processing.

[0053] The controller 40 determines the thickness of the substrate 100 based on the detection value output from the rotation sensor 25, and determines the quality of the conveying state based on the thickness, that is, whether the substrate 100 is conveyed in a state where multiple sheets are overlapped. For example, when the thickness of the substrate 100 is greater than a predetermined reference value, the controller 40 determines that the substrate 100 is conveyed in a state where two sheets are overlapped, and stops conveying the substrate 100 or notifies a user of a warning. This controller 40 is a computer that physically includes a processor 42, a memory 44, and the like.

[0054] Next, refer to Figure 3 The detection principle of the thickness of the substrate 100 by the substrate thickness detection mechanism 14 is described below. Figure 3 As shown in the upper half of FIG. 1 , the detection roller 16 is usually in contact with the conveying surface. When the substrate 100 is conveyed from the upstream side to the downstream side, the front end of the substrate 100 abuts against the peripheral surface of the detection roller 16. With the abutment, the detection roller 16 is pressed toward the downstream side in the conveying direction. In order to disperse the pressing force, the detection roller 16 rotates around the first axis Af as the center and swings around the second axis As as the center, floating from the surface of the conveying path 12.

[0055] And, by detecting the roller 16 floating, as Figure 3As shown in the lower half of the figure, the substrate 100 can pass through the lower side of the detection roller 16. Moreover, the friction force between the substrate 100 and the detection roller 16 is converted into a force that causes the detection roller 16 to rotate. Through the rotation, the substrate 100 is sent to the downstream side of the conveying direction. Hereinafter, the rotation direction of the detection roller 16 for sending the substrate 100 toward the downstream of the conveying direction is referred to as the "forward rotation direction Rn", and the rotation direction toward the opposite side is referred to as the "reverse direction Rr".

[0056] Here, the greater the thickness of the substrate 100 passing under the detection roller 16, the greater the swing amount of the detection roller 16 and the rotation amount of the rotation shaft 22. Therefore, by detecting the rotation amount of the rotation shaft 22, the thickness of the substrate 100 can be acquired.

[0057] In this example, a rotation sensor 25 is provided to detect the rotation amount of the rotating shaft 22. The principle of the rotation amount detection performed by the rotation sensor 25 is described. As described above, the rotation sensor 25 includes: a detection block 26 fixed to the rotating shaft 22, a light emitting element 32, and a light receiving element 34. The detection block 26 tilts with the rotation of the rotating shaft 22. In addition, a detection hole 28 is formed in the detection block 26, which passes through in a direction orthogonal to the second axis As. The light emitting element 32 and the light receiving element 34 are arranged on both sides of the detection hole 28. In addition, the light emitting element 32 is fixed to the detection block 26 and tilts together with the detection block 26. The light receiving element 34 is fixed relative to the conveying path 12, and the relative positional relationship with the detection block 26 changes with the rotation of the rotating shaft 22.

[0058] Figure 4 2 is a schematic diagram showing the principle of the rotation amount detection performed by the rotation sensor 25. Figure 4 The light receiving element 34 shown in the example is a split type light receiving element whose light receiving portion is split into a first light receiving plate 34a and a second light receiving plate 34b. At this time, the first light receiving plate 34a and the second light receiving plate 34b output electrical signals according to the amount of received light independently of each other.

[0059] When the detection roller 16 contacts the conveying surface, the detection hole 28 Figure 4 As shown in the upper half of the figure, the light emitting element 32 and the light receiving element 34 are facing each other. At this time, the light beam output from the light emitting element 32 is irradiated to the center of the light receiving element 34. Therefore, the light amounts detected by the first light receiving sheet 34a and the second light receiving sheet 34b are equal to each other.

[0060] On the other hand, when the detection roller 16 floats from the contact surface and the rotation shaft 22 rotates, as shown in FIG. Figure 4As shown in the lower half of the figure, the detection block 26 is tilted. At this time, the relative positional relationship between the light receiving element 34 and the detection hole 28 changes. And, as a result, the light beam output from the light emitting element 32 will be irradiated to a position deviated from the center of the light receiving element 34. Figure 4 In the example of the lower half of , the light beam is irradiated to a position deviated from the first light receiving sheet 34a. At this time, a deviation occurs between the amount of light detected by the first light receiving sheet 34a and the amount of light detected by the second light receiving sheet 34b. This deviation in the amount of light detected depends on the amount of rotation of the rotating shaft 22, and further, depends on the thickness of the substrate 100. Therefore, the controller 40 determines the thickness of the substrate 100 based on the deviation in the amount of light detected, and determines whether the conveying state of the substrate 100 is good or not based on the thickness.

[0061] As is clear from the above description, in this example, the detection roller 16 that rotates about the first axis Af and swings about the second axis As is used to detect the thickness of the substrate 100. The reason for adopting this configuration will be described while comparing with the conventional technology. Figure 7 1 is a schematic diagram showing a conventional substrate thickness detection mechanism 14*.

[0062] like Figure 7 As shown, the conventional substrate thickness detection mechanism 14* also has a detection roller 16* that can rotate and swing. However, the center axis of the swing of the detection roller 16* (hereinafter referred to as the "fourth axis Aq") is parallel to the conveying direction. Moreover, the center axis of the rotation of the detection roller 16* (hereinafter referred to as the "third axis At") is orthogonal to the fourth axis Aq, and is tilted as the detection roller 16 swings. In addition, a connecting shaft 18* is connected to the detection roller 16*. The connecting shaft 18* is coaxially arranged with the third axis At so as to be able to swing around the fourth axis Aq. In the substrate thickness detection mechanism 14*, as the substrate 100 abuts against the detection roller 16*, the detection roller 16* floats and the connecting shaft 18* tilts. In addition, the controller 40 determines the thickness of the substrate 100 based on the tilt of the connecting shaft 18*. The tilt of the connecting shaft 18* is detected by a distance sensor 50 arranged directly above the connecting shaft 18*.

[0063] This kind of conventional substrate thickness detection mechanism 14* can also roughly detect the thickness of the substrate 100. However, in the case of the substrate thickness detection mechanism 14*, the substrate 100 is sometimes unable to pass through the detection roller 16*, so that the substrate 100 is subjected to the reaction force from the detection roller 16* and is bent. This is because, although the detection roller 16* can move in the up and down directions, it cannot move in the conveying direction. At this time, even if the detection roller 16* receives a force from the substrate 100 in the downstream direction of the conveying direction, it cannot dissipate the force. Moreover, the static friction force at the contact point Pb between the lower end of the detection roller 16* and the surface of the conveying path 12 tends to become high, so it is difficult for the detection roller 16* to rotate in the forward direction Rn. As a result, sometimes a large reaction force acts on the substrate 100 from the detection roller 16*, causing the substrate 100 to bend.

[0064] Therefore, in this example, as described above, the rotation axis (first axis Af) and the swing axis (second axis As) are set to be parallel to each other. Figure 5 The force acting on the detection roller 16 and the substrate 100 at this time is explained. Figure 5 As shown in FIG. 1 , consider a case where the front end of the substrate 100 contacts the peripheral surface of the detection roller 16. At this time, the contact point between the substrate 100 and the detection roller 16 is called the "first contact point Pa", and the contact point between the detection roller 16 and the conveying surface is called the "second contact point Pb". In addition, the force acting on the detection roller 16 in the downstream direction of the conveying direction is called the "force toward the downstream Fd", and the force acting on the detection roller 16 in the upstream direction of the conveying direction is called the "force toward the upstream Fu".

[0065] Consider the balance of forces when the front end of the substrate 100 contacts the detection roller 16. In order to make the detection roller 16 swing in the swing direction S or rotate in the normal rotation direction Rn, the force Fd toward the downstream must be greater than the force Fu toward the upstream, that is, Fd>Fu. Here, the force Fd toward the downstream and the force Fu toward the upstream can be expressed by the following equations 1 and 2, respectively.

[0066] Fd=Fav×sinθ+Fah×cosθ Formula 1

[0067] Fu=Fbh+T×cosφ

[0068] =K(WT×sinφ)+T×cosφEquation 2

[0069] In addition, Fav is the force with which the substrate 100 presses the detection roller 16 at the first contact point Pa, Fah is the friction force at the first contact point Pa, Fbh is the static friction force at the second contact point Pb, T is the force received by the detection roller 16 from the swing arm 20, W is the mass of the detection roller 16, and K is the friction coefficient between the conveying surface and the detection roller 16. Moreover, θ is the angle formed by the straight line connecting the center point of the detection roller 16 and the first contact point Pa and the vertical reference line Lv. Moreover, φ is the angle formed by the arm axis La and the horizontal reference line Lh.

[0070] If the force Fu toward the upstream is too large, an excessive reaction force will act on the substrate 100 before Fd>Fu is satisfied, causing the substrate 100 to buckle. Therefore, in order to reduce the buckling of the substrate 100, it is required to reduce the force Fu toward the upstream. As is clear from Formula 2, regarding the force Fu toward the upstream, when the inclination angle φ of the swing arm 20 is 90 degrees, T×cosφ=0, and T×sinθ reaches the maximum, so the force Fu toward the upstream becomes the minimum.

[0071] Therefore, if the purpose is only to prevent the substrate 100 from being buckled, it is best to set φ=90°. However, when φ=90° is set, the detection roller 16 will swing to either the upstream side or the downstream side, and thus becomes unstable in terms of structure. Therefore, in order to make it stable in terms of structure, the inclination angle φ must be set to less than 90°. For example, the inclination angle φ may also be less than 85°, less than 80°, or less than 70°. Moreover, when the inclination angle φ is close to 0°, it is difficult for the detection roller 16 to swing in the swinging direction S even if it is subjected to the force Fd toward the downstream. Therefore, in order to make the detection roller 16 easy to swing, the inclination angle φ may also be set to a certain large value, for example, to be greater than 30°, greater than 40°, or greater than 45°.

[0072] In addition, if Figure 6 As shown in FIG. 1 , it is also considered that the arm axis La is located on the downstream side of the conveying direction from the center of the detection roller 16. However, in this case, the swing direction S of the detection roller 16 when receiving the force toward the downstream from the substrate 100 is as follows: Figure 6 The figure shows the oblique downward direction. At this time, the more the pressing force applied to the detection roller 16 from the substrate 100 increases, the closer the detection roller 16 is to the conveying surface. In other words, at this time, it is difficult for the detection roller 16 to float. Moreover, the closer the detection roller 16 is to the conveying surface, the greater the reaction force received by the detection roller 16 from the conveying surface, the greater the friction force generated between the two, and further, the force Fu toward the upstream. As a result, the reaction force acting on the substrate 100 toward the upstream also increases, so the substrate 100 is easily buckled.

[0073] As is clear from the above description, in this example, the arm axis La is located between the horizontal reference line Lh and the vertical reference line Lv. This can suppress the reaction force acting on the substrate 100 upstream in the conveying direction, thereby effectively preventing the substrate 100 from buckling.

[0074] As described above, in this example, the thickness of the substrate 100 is detected using the light emitting element 32 and the light receiving element 34 disposed opposite to each other with the detection hole 28 interposed therebetween. With this configuration, the thickness detection accuracy can be improved compared to the conventional technology.

[0075] That is, in Figure 7 In the case of the conventional substrate thickness detection mechanism 14* shown in FIG. 1 , the thickness of the substrate 100 is detected based on the change in the distance between the connecting shaft 18* and the distance sensor 50. However, in this case, in order to improve the detection sensitivity, the connecting shaft 18* must be extended. However, if the connecting shaft 18* is extended, another problem will be caused by the overall enlargement of the device. As a result, it is difficult to improve the thickness detection sensitivity in the conventional technology.

[0076] On the other hand, in this example, as repeatedly described, the thickness of the substrate 100 is detected by the light emitting element 32 and the light receiving element 34 disposed on both sides of the detection hole 28. At this time, the detection sensitivity can be improved by reducing the spot diameter of the light from the light emitting element 32 toward the light receiving element 34. In addition, the spot diameter can be easily reduced by, for example, reducing the diameter of the detection hole 28 or providing an aperture, a lens, or both in the middle of the optical path of the detection light. In other words, according to this example, it is possible to prevent the device from being enlarged and to easily improve the detection sensitivity.

[0077] At this time, according to Figure 1 As clearly stated, in this example, the rotation sensor 25 is arranged outside the conveying path 12 in the horizontal direction. This is to avoid the influence of heat generated from the conveying path 12. That is, sometimes the substrate 100 is heated by a heater embedded in the conveying path 12 in consideration of post-processing. At this time, the space above the conveying path 12 will naturally become high temperature. If the rotation sensor 25 is arranged in the high temperature space, detection errors caused by temperature changes are likely to occur. Therefore, in this example, Figure 1 As shown in FIG. 1 , the rotation sensor 25 is offset outward in the horizontal direction of the conveying path 12. Thus, the thickness of the substrate 100 can be detected more accurately.

[0078] In addition, the structures described so far are all examples, and other structures may be changed as long as they include the structure described in claim 1. For example, in the above description, a light receiving element 34 divided into two light receiving sheets 34a and 34b is used, but the structure of the light receiving element 34 may be appropriately changed. For example, the light receiving element 34 may be divided into three or more light receiving sheets. Moreover, the light receiving element 34 may be a non-divided light receiving element. For example, the light receiving element 34 may be a structure having only the second light receiving sheet 34b but not the first light receiving sheet 34a. At this time, the amount of light received detected by the second light receiving sheet 34b changes with the swing of the detection roller 16 and the rotation of the detection block 26. The controller 40 may also judge the thickness of the substrate 100 based on the change in the amount of light received. Moreover, as long as the amount of light received in the light receiving element 34 changes with the rotation of the detection block 26, the mounting form of the light emitting element 32 and the light receiving element 34 may be appropriately changed. For example, the light emitting element 32 may be fixed to the detection block 26, and the light receiving element 34 may be fixed to the conveyance path 12. Furthermore, other types of sensors may be used as long as the floating amount of the detection roller 16 can be detected with high accuracy.

Claims

1. A substrate transport device, characterized in that: include: A transport path for transporting the substrate along a specified transport direction; A detection roller, provided on the conveying path, having a first shaft that rotates along with the conveyance of the substrate; A swing arm rotates around the second axis and is connected to the detection roller, and swings along with the lifting and lowering of the detection roller; a rotation sensor for detecting the rotation of the swing arm around the second axis; as well as The controller determines whether the conveying state of the substrate is good or not based on the detection result of the rotation sensor. The arm axis connecting the first shaft and the second shaft is located between a horizontal reference line extending from the first shaft toward the upstream side in the conveying direction and a vertical reference line extending from the first shaft toward the vertically upward direction.

2. The substrate transport device according to claim 1, wherein: The angle formed by the arm axis and the horizontal reference line is greater than 45 degrees and less than 80 degrees.

3. The substrate transport device according to claim 1, wherein: The rotation sensor is arranged outside the transport path in the horizontal direction.

4. The substrate transport device according to any one of claims 1 to 3, characterized in that: The rotation sensor comprises: a detection block arranged to intersect the second axis and to rotate about the second axis as the swing arm swings; a detection hole, penetrating the detection block in a direction orthogonal to the second axis; and The light emitting element and the light receiving element are arranged facing each other with the detection hole sandwiched therebetween. Here, at least one of the light emitting element and the light receiving element is fixed relative to the transport path, and its relative position relative to the detection hole changes with the rotation of the detection block.

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