Base plate conveying device

Abstract

To disclose a base plate conveying device that can appropriately detect the thickness of base plates while preventing base plates from buckling.SOLUTION: A base plate conveying device 10 includes a conveyance path 12, a detection roller 16 that is provided on the conveyance path 12 and has a first shaft Af that rotates as base plates 100 is conveyed, a swing arm 20 that is parallel to the first shaft Af and swings around a second shaft As while the detection roller 16 rises and falls, a rotation sensor 25 that detects the rotation of the swing arm 20 around the second shaft As, and a controller 40 that determines whether the conveying state of substrates 100 is good or bad based on the detection result of the rotation sensor 25; an arm shaft line La connecting the first shaft Af and the second shaft As is located between a horizontal reference line Lh extending from the first shaft Af upstream in the conveyance direction and a vertical reference line Lv extending vertically upward from the first shaft Af.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present specification discloses a substrate transport apparatus for transporting a substrate along a transport path. [Background technology]

[0002] Conventionally, a substrate transport device that transports a substrate along a transport path has been known. Such a substrate transport device has a mechanism for detecting the thickness of the substrate to prevent two or more substrates from being transported while overlapping each other.

[0003] Conventional substrate thickness detection mechanisms include an arm that can swing around an axis parallel to the substrate transport direction, and a detection roller attached to the tip of the arm, and determine whether the substrate thickness is appropriate based on the amount of elevation of the detection roller when the substrate passes under the detection roller. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 48-64668 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the case of a conventional thickness detection mechanism, the detection roller cannot move in the transport direction. Therefore, in the case of a conventional thickness detection mechanism, when the detection roller receives a force from the substrate in the downstream direction in the detection direction, the force cannot be released, and a large reaction force acts on the substrate. This reaction force can cause the substrate to buckle.

[0006] Patent Document 1 discloses a device for detecting double-feeding of sheets. However, the technology of Patent Document 1 is intended for the transport of sheets such as paper, and does not consider the transport of substrates. In addition, the technology of Patent Document 1 improves detection accuracy by adjusting the dimensional ratio of the two arms. As a result, the technology of Patent Document 1 tends to make the entire device larger.

[0007] Therefore, this specification discloses a substrate transport device that can appropriately detect the thickness of a substrate while preventing buckling of the substrate. [Means for solving the problem]

[0008] The substrate transport device disclosed in this specification comprises a transport path for transporting a substrate in a predetermined transport direction, a detection roller provided on the transport path and having a first axis which rotates as the substrate is transported, a swing arm which rotates around a second axis, the swing arm being connected to the detection roller and swinging as the detection roller rises and falls, a rotation sensor which detects the rotation of the swing arm around the second axis, and a controller which determines whether the transport condition of the substrate is good or bad based on the detection result of the rotation sensor, and is characterized in that the arm axis line connecting the first axis and the second axis is located between a horizontal reference line extending from the first axis upstream in the transport direction and a vertical reference line extending vertically upward from the first axis.

[0009] In this case, the angle between the arm axis and the horizontal reference line may be equal to or greater than 45 degrees and less than 80 degrees.

[0010] The rotation sensor may be disposed horizontally outside the transport path.

[0011] In addition, the rotational sensor comprises a detection block that is arranged to intersect with the second axis and rotates around the second axis as the oscillating arm oscillates, a detection hole that penetrates the detection block in a direction perpendicular to the second axis, and a light-emitting element and a light-receiving element that are arranged opposite each other across the detection hole, and at least one of the light-emitting element and the light-receiving element is fixed with respect to the conveying path, and a relative position with respect to the detection hole may change as the detection block rotates. Effect of the Invention

[0012] According to the substrate transport device disclosed in this specification, it is possible to effectively prevent buckling of the substrate while appropriately detecting the thickness of the substrate. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a schematic plan view of a substrate transport device. [Diagram 2] FIG. 4 is a schematic front view of a substrate thickness detection mechanism. [Diagram 3] 5A to 5C are diagrams illustrating the principle of detection of the thickness of a substrate by a substrate thickness detection mechanism. [Figure 4] 3A and 3B are schematic diagrams illustrating the principle of rotation amount detection by a rotation sensor. [Diagram 5] 5A and 5B are schematic diagrams showing forces acting on a detection roller and a substrate. [Figure 6] 13 is a schematic diagram showing a force acting when the arm axis is positioned downstream in the conveying direction from the center of the detection roller; FIG. [Figure 7] FIG. 1 is a schematic diagram of a conventional substrate thickness detection mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The configuration of the substrate transport device 10 will be described below with reference to the drawings. FIG. 1 is a schematic plan view of the substrate transport device 10. FIG. 2 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. In FIGS. 1 and 2, the left side of the paper is the upstream side in the transport direction, and the right side of the paper is the downstream side in the transport direction. The substrate transport device 10 heats the substrate 100 during the transport process for a post-process, and a heater (not shown) for the heating is built into the transport path 12. The substrate transport device 10 may be used alone or may be incorporated into other devices (for example, a bonding device that bonds a semiconductor element to the substrate 100).

[0015] The substrate transport device 10 further includes a substrate thickness detection mechanism 14 that detects the thickness of the substrate 100 being transported. 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.

[0016] The detection roller 16 is a roller that can rotate about a first axis Af and can swing about a second axis As. The first axis Af is an axis that is substantially parallel to the surface of the transport path 12 and substantially perpendicular to the transport direction, as shown in FIG. The detection roller 16 is disposed on the path through which the substrate 100 passes. When the substrate 100 is not present, the detection roller 16 is in contact with the surface (i.e., the transport surface) of the transport path 12. During the transport process, the substrate 100 passes under the detection roller 16 and is sent downstream.

[0017] The detection roller 16 can also swing about a second axis As parallel to the first axis Af. The second axis As is located upstream of the first axis Af in the transport direction and above the first axis Af. Therefore, if a line extending from the first axis Af toward the upstream of the transport direction is defined as a "horizontal reference line Lh", a line extending vertically upward from the first axis Af is defined as a "vertical reference line Lv", and a line connecting the first axis Af and the second axis As is defined as an "arm axis La", the arm axis La is located between the horizontal reference line Lh and the vertical reference line Lv. The reason for such an arrangement of the second axis As will be described later. In any case, the detection roller 16 moves up and down by swinging (in other words, revolving) about the second axis As, and sends the substrate 100 downstream by rotating about the first axis Af.

[0018] The detection roller 16 is connected to the swing arm 20 via a connecting shaft 18. The connecting shaft 18 is a shaft member arranged coaxially with the first axis Af. The center of the detection roller 16 is rotatably attached to one end of the connecting shaft 18. The other end of the connecting shaft 18 is fixed to the downstream end of the swing arm 20. As is clear from FIG. 1, the other end of the connecting shaft 18 is located outside the horizontal direction of the conveying path 12. As a result, the swing arm 20 and the rotation sensor 25 are also located outside the horizontal direction of the conveying path 12.

[0019] The swing arm 20 is an arm member that swings about a 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 a shaft member that is arranged coaxially with the second axis As and extends in a direction away from the conveying path 12. This rotating shaft 22 is rotatably held by a plurality of bearings 24. The rotating shaft 22 rotates as the swing arm 20 and the detection roller 16 swing.

[0020] A rotation sensor 25 is attached to the middle of the rotating shaft 22 to detect the amount of rotation of the rotating shaft 22 and thus the amount of elevation of the detection roller 16. The rotation sensor 25 has a detection block 26, a light-emitting element 32, and a light-receiving element 34. The detection block 26 is formed with a detection hole 28 penetrating 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 amount of rotation by the rotation sensor 25 will be described later. The positions of the light-emitting element 32 and the light-receiving element 34 are not limited, and both may be fixed to the conveying path 12, for example. The detection block 26 may be a pipe-shaped member with a hole drilled therein to facilitate processing.

[0021] The controller 40 judges the thickness of the substrate 100 based on the detection value output from the rotation sensor 25, and judges whether the transport state is good or bad, i.e., whether multiple substrates 100 are being transported while overlapping, based on the thickness. For example, when the thickness of the substrate 100 is equal to or greater than a specified reference value, the controller 40 judges that two substrates 100 are being transported while overlapping, and stops transporting the substrate 100 or issues a warning to the user. Such a controller 40 is physically a computer including a processor 42, a memory 44, etc.

[0022] Next, the principle of detection of the thickness of the substrate 100 by the above-mentioned substrate thickness detection mechanism 14 will be described with reference to FIG. 3. As shown in the upper part of FIG. 3, the detection roller 16 is usually in contact with the transport surface. When the substrate 100 is transported from the upstream side to the downstream side, the leading edge of the substrate 100 comes into contact with the circumferential surface of the detection roller 16. With this contact, the detection roller 16 is pressed toward the downstream side in the transport direction. To release this pressing force, the detection roller 16 rotates about the first axis Af while oscillating about the second axis As, and rises above the surface of the transport path 12.

[0023] Then, as the detection roller 16 is lifted up, the substrate 100 can pass under the detection roller 16, as shown in the lower part of Fig. 3. Also, the frictional force between the substrate 100 and the detection roller 16 is converted into a force that rotates the detection roller 16. This rotation sends the substrate 100 downstream in the transport direction. Hereinafter, the rotation direction of the detection roller 16 for sending the substrate 100 downstream in the transport direction is referred to as the "forward rotation direction Rn", and the rotation direction in the opposite direction is referred to as the "reverse rotation direction Rr".

[0024] Here, the greater the thickness of the substrate 100 passing under the detection roller 16, the greater the amount of oscillation of the detection roller 16 and therefore the amount of rotation of the rotating shaft 22. Therefore, by detecting the amount of rotation of the rotating shaft 22, the thickness of the substrate 100 can be obtained.

[0025] In this example, a rotation sensor 25 is provided to detect the amount of rotation of the rotating shaft 22. The principle of rotation amount detection by the rotation sensor 25 will be described. As described above, the rotation sensor 25 has 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. The detection block 26 is formed with a detection hole 28 penetrating in a direction perpendicular to the second axis As. The light emitting element 32 and the light receiving element 34 are disposed on both sides of the detection hole 28. 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 to the transport path 12, and the relative positional relationship with the detection block 26 changes with the rotation of the rotating shaft 22.

[0026] Fig. 4 is a schematic diagram showing the principle of rotation amount detection by the rotation sensor 25. The light receiving element 34 shown in Fig. 4 is a split type light receiving element in which the light receiving portion is split into a first light receiving piece 34a and a second light receiving piece 34b. In this case, the first light receiving piece 34a and the second light receiving piece 34b output electrical signals according to the amount of received light independently of each other.

[0027] When the detection roller 16 is in contact with the conveying surface, the detection hole 28 is kept horizontal as shown in the upper part of Fig. 4, and the light emitting element 32 and the light receiving element 34 face each other. In this case, the light beam output from the light emitting element 32 hits the center of the light receiving element 34. Therefore, the amounts of light detected by the first light receiving piece 34a and the second light receiving piece 34b are equal to each other.

[0028] On the other hand, when the detection roller 16 floats off the ground surface and the rotating shaft 22 rotates, the detection block 26 tilts as shown in the lower part of FIG. 4. In this case, the relative positional relationship between the light receiving element 34 and the detection hole 28 changes. As a result, the light beam output from the light emitting element 32 hits a position shifted from the center of the light receiving element 34. In the example in the lower part of FIG. 4, the light beam hits the first light receiving piece 34a at a biased position. In this case, a deviation occurs between the amount of light detected by the first light receiving piece 34a and the amount of light detected by the second light receiving piece 34b. This deviation in the amount of detected light depends on the amount of rotation of the rotating shaft 22, and further on the thickness of the substrate 100. Therefore, the controller 40 judges the thickness of the substrate 100 based on this deviation in the amount of detected light, and judges whether the substrate 100 is in a good or bad transport state based on the thickness.

[0029] As is clear from the above description, in this example, the thickness of the substrate 100 is detected using the detection roller 16 that rotates about the first axis Af and oscillates about the second axis As. The reason for adopting such a configuration will be explained in comparison with the conventional technology. Figure 7 is a schematic diagram showing a conventional substrate thickness detection mechanism 14*.

[0030] As shown in FIG. 7, the conventional substrate thickness detection mechanism 14* also has a detection roller 16* that can rotate and swing. However, the central axis of the swing of this detection roller 16* (hereinafter referred to as the "fourth axis Aq") is parallel to the conveying direction. The central axis of the rotation of the detection roller 16* (hereinafter referred to as the "third axis At") is perpendicular to the fourth axis Aq and tilts with the swing of the detection roller 16. A connecting shaft 18* is connected to the detection roller 16*. The connecting shaft 18* can swing around the fourth axis Aq and is arranged coaxially with the third axis At. In this substrate thickness detection mechanism 14*, when the substrate 100 comes into contact with the detection roller 16*, the detection roller 16* floats and the connecting shaft 18* tilts. The controller 40 determines the thickness of the substrate 100 based on the amount of tilt of this connecting shaft 18*. The amount of tilt of the connecting shaft 18* is detected by a distance sensor 50 arranged directly above the connecting shaft 18*.

[0031] Even with such a conventional substrate thickness detection mechanism 14*, the thickness of the substrate 100 can be detected. However, in the case of this substrate thickness detection mechanism 14*, the substrate 100 cannot pass through the detection roller 16*, and the substrate 100 may buckle due to the reaction force from the detection roller 16*. This is because the detection roller 16* can move in the vertical direction but cannot move in the transport direction. In this case, even if the detection roller 16* receives a force from the substrate 100 in the downstream direction in the transport direction, the detection roller 16* cannot release the force. In addition, the static friction force at the contact point Pb between the lower end of the detection roller 16* and the surface of the transport path 12 tends to be high, so the detection roller 16* is unlikely to rotate in the forward rotation direction Rn. As a result, a large reaction force acts on the substrate 100 from the detection roller 16*, and the substrate 100 may buckle.

[0032] Therefore, in this example, as described above, the rotation axis (first axis Af) and the oscillation axis (second axis As) are parallel to each other. In this case, the forces acting on the detection roller 16 and the substrate 100 will be described with reference to FIG. 5. Consider the case where the leading end of the substrate 100 abuts against the circumferential surface of the detection roller 16 as shown in FIG. 5. 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 "downstream force Fd," and the force acting on the detection roller 16 in the upstream direction of the conveying direction is called the "upstream force Fu."

[0033] Consider the balance of forces when the leading edge of substrate 100 contacts detection roller 16. In order for detection roller 16 to oscillate in oscillation direction S or rotate in the forward rotation direction Rn, it is necessary that downstream force Fd is greater than upstream force Fu, that is, Fd>Fu. Here, the downstream force Fd and the upstream force Fu can be expressed by the following formulas 1 and 2, respectively. Fd=Fav×sinθ+Fah×cosθ Equation 1 Fu = Fbh + T × cosφ =K(WT×sinφ)+T×cosφ Equation 2

[0034] Here, Fav is the force with which the substrate 100 presses the detection roller 16 at the first contact point Pa, Fah is the frictional force at the first contact point Pa, Fbh is the static frictional force at the second contact point Pb, T is the force that the detection roller 16 receives 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. Also, θ is the angle that the straight line connecting the center point of the detection roller 16 and the first contact point Pa makes with the vertical reference line Lv. Also, φ is the angle that the arm axis La makes with the horizontal reference line Lh.

[0035] If the upstream force Fu is excessively large, an excessively large reaction force acts on the substrate 100 before Fd>Fu is satisfied, causing the substrate 100 to buckle. Therefore, it is necessary to reduce the upstream force Fu in order to reduce the buckling of the substrate 100. As is clear from Equation 2, when the tilt angle φ of the swing arm 20 is 90 degrees, the upstream force Fu is T×cosφ=0, and T×sinθ is maximized, so that the upstream force Fu is minimized.

[0036] Therefore, if the only purpose is to prevent the buckling of the substrate 100, it is best to set φ=90°. However, if φ=90°, the detection roller 16 will oscillate in both the upstream and downstream directions, making the mechanism unstable. Therefore, in order to stabilize the mechanism, the inclination angle φ needs to be less than 90°, and may be, for example, 85° or less, 80° or less, or 70° or less. Also, if the inclination angle φ is close to 0°, the detection roller 16 will not easily oscillate in the oscillation direction S even if it receives a downstream force Fd. Therefore, in order to easily oscillate the detection roller 16, the inclination angle φ may be set to a certain large value, for example, 30° or more, 40° or more, or 45° or more.

[0037] As shown in FIG. 6, the arm axis La may be positioned downstream of the center of the detection roller 16 in the transport direction. However, in this case, the swing direction S when the detection roller 16 receives a downstream force from the substrate 100 is diagonally downward as shown in FIG. 6. In this case, the more the pressing force applied from the substrate 100 to the detection roller 16 increases, the closer the detection roller 16 is to the transport surface. In other words, in this case, the detection roller 16 is less likely to float up. Also, the closer the detection roller 16 is to the transport surface, the greater the reaction force the detection roller 16 receives from the transport surface, and the greater the frictional force generated between the two, and therefore the upstream force Fu. As a result, the upstream reaction force acting on the substrate 100 also increases, making the substrate 100 more likely to buckle.

[0038] As is clear from the above description, in this example, the arm axis La is positioned between the horizontal reference line Lh and the vertical reference line Lv. This makes it possible to reduce the reaction force acting on the substrate 100 in the upstream transport direction, thereby effectively preventing the substrate 100 from buckling.

[0039] 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 that are disposed opposite each other across the detection hole 28. With this configuration, the thickness detection accuracy can be improved compared to the conventional technology.

[0040] That is, in the case of the conventional substrate thickness detection mechanism 14* shown in Fig. 7, 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. In this case, however, in order to increase the detection sensitivity, the connecting shaft 18* needs to be lengthened. However, lengthening the connecting shaft 18 causes another problem in that the entire device becomes larger accordingly. As a result, it has been difficult to increase the thickness detection sensitivity with the conventional technology.

[0041] Meanwhile, in this example, as described repeatedly, the thickness of the substrate 100 is detected by the light emitting element 32 and the light receiving element 34 arranged on both sides of the detection hole 28. In this case, the detection sensitivity can be improved by narrowing the spot diameter of the light directed from the light emitting element 32 to the light receiving element 34. The spot diameter can be easily narrowed, for example, by reducing the diameter of the detection hole 28 or by providing an aperture or a lens, or both, in the optical path of the detection light. In other words, according to this example, the detection sensitivity can be easily improved while preventing the device from becoming large.

[0042] As is clear from FIG. 1, in this example, the rotation sensor 25 is disposed horizontally outside the transport path 12. This is to avoid the influence of heat generated from the transport path 12. That is, in consideration of post-processing, the substrate 100 may be heated by a heater embedded in the transport path 12. In this case, the space above the transport path 12 will naturally become hot. If the rotation sensor 25 is disposed in such a high-temperature space, detection errors due to temperature changes are likely to occur. Therefore, in this example, as shown in FIG. 1, the rotation sensor 25 is offset horizontally outside the transport path 12. This allows the thickness of the substrate 100 to be detected more accurately.

[0043] The configurations described above are all examples, and other configurations may be changed as long as the configuration described in claim 1 is included. For example, in the above description, the light receiving element 34 divided into two light receiving pieces 34a and 34b is used, but the configuration of the light receiving element 34 may be changed as appropriate. For example, the light receiving element 34 may be divided into three or more light receiving pieces. In addition, the light receiving element 34 may be a non-split type light receiving element. For example, the light receiving element 34 may have only the second light receiving piece 34b and not the first light receiving piece 34a. In this case, the amount of light received by the second light receiving piece 34b changes with the oscillation of the detection roller 16 and the rotation of the detection block 26. The controller 40 may determine the thickness of the substrate 100 based on this change in the amount of light received. In addition, if the amount of light received by 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 changed as appropriate. 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 transport path 12. Also, other types of sensors may be used as long as they can detect the amount of lift of the detection roller 16 with high accuracy. [Explanation of symbols]

[0044] 10 substrate transport device, 12 transport path, 14, 14* substrate thickness detection mechanism, 16, 16* detection roller, 18, 18* connecting shaft, 20 swing arm, 22 rotating shaft, 24 bearing, 25 rotation sensor, 26 detection block, 28 detection hole, 32 light emitting element, 34 light receiving element, 40 controller, 42 processor, 44 memory, 50 distance sensor, 100 substrate, Af first axis, As second axis.

Claims

1. a transport path for transporting the substrate in a predetermined transport direction; a detection roller provided on the transport path and having a first shaft that rotates in association with the transport of the substrate; a swing arm that rotates around a second shaft, the swing arm being connected to the detection roller and swinging in accordance with the elevation and lowering of the detection roller; a rotation sensor that detects rotation of the swing arm around the second axis; a controller that determines whether the substrate is in a good or bad state based on a detection result of the rotation sensor; Equipped with an arm axis line connecting the first axis and the second axis is located between a horizontal reference line extending from the first axis to the upstream side in the conveying direction and a vertical reference line extending vertically upward from the first axis; A substrate transport device comprising:

2. 2. The substrate transport apparatus according to claim 1, A substrate transport device, wherein an angle between the arm axis and the horizontal reference line is greater than or equal to 45 degrees and less than 80 degrees.

3. 2. The substrate transport apparatus according to claim 1, The substrate transport device, wherein the rotation sensor is disposed horizontally outside the transport path.

4. The substrate transport device according to any one of claims 1 to 3, The rotation sensor includes: a detection block that is disposed so as to intersect with the second axis and that rotates about the second axis in response to the swing of the swing arm; a detection hole penetrating the detection block in a direction perpendicular to the second axis; a light emitting element and a light receiving element disposed opposite each other with the detection hole therebetween; At least one of the light emitting element and the light receiving element is fixed to the transport path, and a relative position of the light emitting element and the light receiving element to the detection hole changes with rotation of the detection block. A substrate transport device comprising:

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