JP6769796B2 - Tilt inspection device for the hand part of the robot and its tilt inspection method - Google Patents

Description

The present invention relates to an inclination inspection device for a hand portion of a robot that holds a substrate and an inclination inspection method thereof.

For example, in the semiconductor manufacturing process, a desired manufacturing process is performed using a transfer device such as an OHT (Overhead Hoist Transfer) for a FOUP (Front-Opening Unified Pod) container containing a plurality of substrates. There is known a transport system configured to transport the substrate to the FOUP, take out the substrate from the transported FOUP using a transport robot, and supply the substrate into the manufacturing apparatus, or store the processed substrate in the FOUP again. The transfer robot used in such a transfer system is provided with a hand portion that holds the substrate at the tip of the arm, and the substrate is taken out and stored by moving the hand portion in the three-dimensional direction.

In such a transfer robot, if the hand portion is tilted, interference between the mounting table on which the substrate is placed in the container and the substrate held by the hand portion when the substrate is taken out or stored. May occur. In order to prevent this interference, it is necessary to inspect the inclination of the hand.

For example, in the tilt inspection device described in Patent Document 1, the tilt of the hand portion is indirectly detected by detecting the tilt of the substrate held by the hand portion by using an optical reflection type sensor. There is. Specifically, in this tilt inspection device, a plurality of optical reflection type sensors are arranged above the substrate, the distance between each optical reflection type sensor and the substrate is measured, and the obtained plurality of measurement results are obtained. By comparing, the inclination of the substrate is detected.

U.S. Pat. No. 6,300,464

However, in the above-mentioned tilt inspection device, it is necessary to secure an installation space for the optical reflection sensor above the substrate, which is one of the causes of increasing the size of the device above the substrate.

Further, in recent years, a robot has been developed in which a plurality of hand portions at the tip of an arm are mounted in a hierarchical manner at a desired interval in order to simultaneously transport a plurality of substrates stored in the FOUP. In the case of such a robot, it is necessary to detect the inclination of all the hand parts. However, in the case of the conventional tilt inspection device, in order to detect the tilt of the substrate held by the plurality of hand portions, an optical reflection sensor must be arranged between the hand portions. Therefore, it is necessary to widen the distance between the hand portions, but if the distance is widened, it becomes impossible to correspond to the distance between a plurality of substrates housed in the container, which is not realistic.

Therefore, an object of the present invention is to be able to detect the inclination of each hand portion without widening the interval between the plurality of hand portions.

The tilt inspection device for the hand portion of the robot according to one aspect of the present invention is a robot for detecting the tilt of the hand portion of the robot that holds and transfers a plurality of substrates by a plurality of hand portions arranged in a hierarchy. A housing for accommodating at least the same number of substrates as a plurality of hand parts in a layered manner, a multi-optical axis photoelectric sensor provided in the housing, and a multi-optical axis photoelectric sensor. A control unit that determines the inclination of the substrate based on the detection signal is provided, and the multi-optical axis photoelectric sensor is arranged on one side of a plurality of substrates inserted in the housing, and is arranged on the plurality of substrates. A light projecting unit that emits a light curtain consisting of lights of a plurality of parallel optical axes directed at it, and a light curtain that is arranged on the other side of a plurality of substrates inserted in a housing so that the light curtain is blocked by the plurality of substrates. The control unit includes a light receiving unit that outputs a detection signal based on the above to the control unit, and the control unit has a first inspection mode for acquiring detection signals for a plurality of boards arranged at reference positions in the housing, and a hand unit in the housing. After performing the second inspection mode to acquire the detection signals for the plurality of boards held in the first inspection mode, the plurality of sheets are based on the detection signal in the first inspection mode and the detection signal in the second inspection mode. By determining the inclination of the substrate, the inclination of the hand portion is inspected.

The above-mentioned multi-optical axis photoelectric sensor is provided in a state where a light projecting unit that projects light of the multi-optical axis as a light curtain and a light receiving unit that receives the light of the light curtain are separated from each other. When a plurality of substrates are arranged at intervals, light is blocked by each substrate, and the presence of the plurality of substrates can be detected at the same time by detecting the blocked portion. In such a configuration, when the substrate is tilted and arranged in the light curtain, the width of the light blocked by the substrate becomes large, and by detecting this width, the tilt of the plurality of substrates can be detected. As a result, the inclination of the hand portion holding the substrate can also be detected. Therefore, the inclination of each hand portion can be detected without increasing the distance between the plurality of hand portions.

Then, in the first inspection mode, the control unit acquires detection signals for a plurality of substrates arranged at reference positions in the housing. Further, the control unit acquires detection signals for a plurality of boards held by the hand unit in the housing in the second inspection mode. After that, the control unit determines the inclination of the plurality of substrates based on the detection signal in the first inspection mode and the detection signal in the second inspection mode. As a result, it is possible to compare the substrate installed at the reference position in the housing, that is, the substrate without inclination, with the substrate held by the hand portion, so that the accuracy of inclination detection can be improved.

Further, the traveling direction of the light when passing through the substrate may intersect with the insertion direction in which the hand portion is inserted into the housing.

According to this configuration, the traveling direction of the light when passing through the substrate intersects the insertion direction in which the hand portion is inserted into the housing, so that the light projecting portion is located at a position that does not hinder the insertion of the hand portion. And the light receiving part can be arranged.

Further, a plurality of multi-optical axis photoelectric sensors may be arranged along the insertion direction.

According to this configuration, since a plurality of multi-optical axis photoelectric sensors are arranged along the insertion direction, it is possible to detect the inclination of the substrate with respect to the insertion direction by combining the detection results of the plurality of multi-optical axis photoelectric sensors. it can.

The method for inspecting the inclination of the hand portion of the robot according to another aspect of the present invention detects the inclination of the hand portion of the robot that holds and transfers a plurality of substrates by a plurality of hand portions arranged in a hierarchy. This is a method for inspecting the inclination of the hand part of a robot for this purpose. A light curtain is emitted from a light projecting part arranged on one side of a plurality of boards inserted in the housing toward the boards, and the light curtain is emitted into the housing. A light receiving unit that is arranged on the other side of the plurality of substrates and receives the light curtain that has passed through the plurality of substrates outputs a detection signal based on the light curtain being blocked by the plurality of substrates. When determining the inclination of a plurality of the boards based on the detection signals, the first inspection mode for acquiring the detection signals for the plurality of boards arranged at the reference positions in the housing and the hand portion in the housing After performing the second inspection mode to acquire the detection signals for the plurality of held boards, the plurality of boards are based on the detection signal in the first inspection mode and the detection signal in the second inspection mode. The inclination of the hand part is inspected by determining the inclination of.

According to this configuration, since the light emitting part is arranged on one side of the substrate and the light receiving part is arranged on the other side, the inclination of the substrate is detected without arranging the sensor above the substrate. be able to. Therefore, it is possible to detect the inclination of a plurality of substrates and the inclination of the hand portion holding the substrates without increasing the distance between the substrates. Then, in the first inspection mode, detection signals are acquired for a plurality of substrates arranged at reference positions in the housing. Further, in the second inspection mode, the detection signals for a plurality of substrates held in the hand portion in the housing are acquired. After that, the inclination of the plurality of substrates is determined based on the detection signal in the first inspection mode and the detection signal in the second inspection mode. As a result, it is possible to compare the substrate installed at the reference position in the housing, that is, the substrate without inclination, with the substrate held by the hand portion, so that the accuracy of inclination detection can be improved.

According to the present invention, it is possible to detect the inclination of each hand portion without widening the interval between the plurality of hand portions.

It is a perspective view which shows the robot, the inspection unit and the like which concerns on embodiment. It is a perspective view which shows the internal structure of the inspection unit which concerns on embodiment. It is a top view which shows the internal structure of the inspection unit which concerns on embodiment. It is explanatory drawing which shows the state of the light curtain of each of the 1st sensor and the 2nd sensor which concerns on embodiment. It is explanatory drawing which enlarges and shows the state of the light curtain of each of the 1st sensor and 2nd sensor shown in FIG. FIG. 5 is a side view of the substrate as viewed from the X-axis direction in order to show the presence or absence of inclination of the substrate in the holding state according to the embodiment. It is a block diagram which shows the main control composition of the inspection unit which concerns on embodiment. It is a flowchart which shows the inclination inspection method which the inspection unit which concerns on embodiment execute. FIG. 5 is a cross-sectional view of the substrate and the light curtain according to the embodiment as viewed from the Y-axis direction.

Hereinafter, the tilt inspection device according to the embodiment of the present invention will be described with reference to the drawings. It should be noted that all of the embodiments described below show a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement and connection forms of the components, steps and the order of steps shown in the following embodiments are examples, and are not intended to limit the present invention. Therefore, among the components in the following embodiments, the components not described in the independent claims indicating the highest level concept of the present invention will be described as arbitrary components.

Further, each figure is a schematic view and is not necessarily exactly illustrated. Further, in each figure, the same components are designated by the same reference numerals.

Hereinafter, embodiments will be described.

FIG. 1 is a perspective view showing a robot 20, an inspection unit 40, and the like according to the embodiment.

The robot 20 and the inspection unit 40 are, for example, a part of a transfer system installed in a factory. Although not shown, the transport system includes a containment unit, a transport unit, and a controller.

As shown in FIG. 1, the robot 20 includes a telescopic arm portion 21 that transfers a disc-shaped or polygonal substrate 70. A plurality of (preferably five, three in this embodiment) hand portions 23 are provided at the tip of the arm portion 21. The plurality of hand portions 23 are arranged in a layered manner at equal intervals in the vertical direction. The plurality of hand portions 23 hold the substrate 70 in a horizontal posture (a posture in which the main surface of the substrate 70 is horizontal) by supporting each of the plurality of substrates 70 from below. The hand portion 23 is formed in a Y shape in a plan view, and a suction portion 231 for sucking the substrate 70 is provided on the upper surface of the hand portion 23. The suction portion 231 keeps the substrate 70 in a horizontal posture on the hand portion 23. In the present embodiment, the suction type hand portion 23 that holds the substrate 70 by sucking it has been illustrated as an example, but it may be a clamp type hand portion that holds the substrate 70 by gripping it. ..

The accommodating unit is a hoop (FOUP: Front Opening Unified Pod) accommodating 25 semiconductor wafers (board 70) in a layered manner. Specifically, the accommodating unit has a housing for accommodating a plurality of substrates 70, and a flange portion attached to the upper surface of the housing. A lid is provided on the housing, and the lid is closed when the housing unit is transported, and the lid is opened when the substrate 70 is housed in the housing or taken out of the housing. The housing unit is conveyed with the flange portion held by the conveying portion.

The inspection unit 40 is an inclination inspection device for detecting the inclination of the hand portion 23 provided at the tip of the arm portion 21 of the robot 20.

The inspection unit 40 has almost the same appearance shape as the accommodation unit, and has a structure that can be mounted on a mounting table 53 (EFEM (Equipment Front End Module)) on which the transported accommodation unit is mounted in the semiconductor manufacturing process. Is. The inspection unit 40 has a housing 41 and a flange portion (not shown) attached to the upper surface of the housing 41. The housing 41 is provided with a lid (not shown), the lid is closed when the inspection unit 40 is transported, and the lid is opened when the arm portion 21 is inspected. In the inspection unit 40, the flange portion 42 is held by the transport portion 50 and transported.

The controller comprehensively controls the robot 20, the transport unit, and the inspection unit 40. Specifically, the controller is electrically connected to the robot 20 and the transport unit. The controller is also electrically connected to the inspection unit 40 mounted on the mounting table 53. As a result, the controller can send and receive various control signals to the robot 20, the transport unit, and the inspection unit 40.

The controller includes, for example, a CPU, a RAM, a ROM, and the like, and the CPU centrally controls the robot 20, the transport unit, and the inspection unit 40 by expanding the program stored in the ROM into the RAM and executing the program. Further, the controller is provided with a display unit (not shown) for displaying various information.

Next, the inspection unit 40 will be described in detail.

FIG. 2 is a perspective view showing the internal configuration of the inspection unit 40 according to the embodiment. FIG. 3 is a top view showing the internal configuration of the inspection unit 40 according to the embodiment. The direction in which the arm portion 21 of the robot 20 inserts the substrate 70 into the inspection unit 40 is referred to as an “insertion direction”. In the present embodiment, the insertion direction is parallel to the Y-axis direction. The direction in which the arm portion 21 takes out the substrate 70 from the inspection unit 40 is opposite to the insertion direction.

As shown in FIGS. 2 and 3, the bottom of the housing 41 of the inspection unit 40 is provided with a support portion 43 for supporting the substrate 70 and an inspection portion 80 for inspecting the arm portion of the robot 20. There is.

The support portion 43 supports the outer peripheral edge of the disk-shaped substrate 70 at three places, and keeps the substrate 70 in a horizontal posture. In the present embodiment, the case where the support portion 43 supports the three substrates 70 in a layered manner at equal intervals in the Z-axis direction (vertical direction) will be described as an example, but the substrate that the support portion 43 can support will be described. The number of 70 sheets may be 4 or more. The support portion 43 may accommodate at least the same number of substrates 70 as the plurality of hand portions 23 in a layered manner at equal intervals.

The support portion 43 includes three supports 431, 432, and 433, which are arranged at desired intervals in the circumferential direction of the substrate 70. The support 431 is arranged at the back inside the inspection unit 40. The supports 432 and 433 are arranged on the front side in the insertion direction from the center of the substrate 70, and are arranged so as to face each other in the direction orthogonal to the insertion direction (X-axis direction). A plurality of horizontal slits 434 are formed side by side in the vertical direction on each of the supports 431, 432, and 433. The substrate 70 is inserted into the slit 434 and placed on the bottom surface of the slit 434 to support the substrate 70 in a horizontal posture. The position of the substrate 70 placed on the bottom surface of the slit 434 is used as a reference position.

The inspection unit 80 indirectly inspects the inclination of the hand unit 23 of the arm unit 21 by targeting the substrate 70 for inspection. The inspection unit 80 includes a first detection unit 81 for detecting a position on the back side of the substrate 70 in the insertion direction, and a second detection unit 82 for detecting a position on the substrate 70 in front of the insertion direction.

The first detection unit 81 includes a first sensor 811 and a pair of first reflection units 812.

The first sensor 811 is a transmissive photoelectric sensor, specifically, a multi-optical axis photoelectric sensor. Specifically, the first sensor 811 includes a first light emitting unit 813 and a first light receiving unit 814. The first light projecting unit 813 has a large number of light projecting elements arranged in a row at equal intervals along the Z-axis direction. Since a light beam having parallel optical axes is emitted from a large number of light projecting elements of the first light projecting unit 813, a band-shaped light curtain 450 is formed as a whole.

The first light receiving unit 814 receives the light curtain 450 emitted from the first light projecting unit 813. Specifically, the first light receiving unit 814 has a large number of light receiving elements arranged in a row at equal intervals along the Z-axis direction. The light receiving element of the first light receiving unit 814 may be able to detect the presence or absence of each light beam of the light emitting element of the first light emitting unit 813. Then, when the light curtain 450 is partially shielded, the light receiving element corresponding to the shielded portion does not receive light. The first light receiving unit 814 creates a detection signal for detecting the amount and position of blocked light by integrating the detection results from the light receiving elements that are not receiving light among a large number of light receiving elements. It is also possible to create a detection signal by integrating the detection results from the light receiving element among a large number of light receiving elements. In this way, the detection signal becomes a different signal based on the light curtain 450 being blocked. Specifically, the detection signal is a different signal depending on the position where the light curtain 450 is blocked and the area.

Examples of the multi-optical axis photoelectric sensor include IG-026 manufactured by KEYENCE CORPORATION and ZX-GT28 manufactured by OMRON Corporation.

As shown in FIG. 3, the first light emitting unit 813 and the first light receiving unit 814 are arranged at positions facing each other across the substrate 70 on the back side of the inspection unit 40, and are fixed on the bottom of the housing 41. ing. The first light projecting unit 813 is arranged so that the light emitting surface 813a facing the back side is parallel to the X-axis direction. The first light receiving unit 814 is arranged so that the light receiving surface 814a facing the back side is parallel to the X-axis direction.

Of the pair of first reflection units 812, one first reflection unit 812 is arranged behind the first projection unit 813 so as to face the first projection unit 813, and the other first reflection unit 813. The unit 812 is arranged on the back side of the first light receiving unit 814 so as to face the first light receiving unit 814.

One first reflection unit 812 reflects the light curtain 450 emitted by the first light projection unit 813 at a right angle and directs it toward the other first reflection unit 812. Also in the other first reflecting unit 812, the light curtain 450 reflected by one first reflecting unit 812 is reflected at a right angle and directed toward the first light receiving unit 814 (see FIG. 3). As a result, the light curtain 450 emitted by the first light projecting unit 813 is reflected by one first reflecting unit 812 to be parallel to the X-axis direction, and then reflected by the other first reflecting unit 812. As a result, the light is received by the first light receiving unit 814. The position of the back portion on the substrate 70 is detected at a portion parallel to the X-axis direction in the light curtain 450. That is, the traveling direction of the portion of the light curtain 450 parallel to the X-axis direction is a direction orthogonal to the insertion direction.

The second detection unit 82 includes a second sensor 821 and a pair of second reflection units 822.

The second sensor 821 includes a second light emitting unit 823 and a second light receiving unit 824. Since the second sensor 821 is the same sensor as the first sensor 811, the details thereof will be omitted, and the locations where the second light emitting unit 823 and the second light receiving unit 824 are arranged will be described below.

As shown in FIG. 3, the second light emitting unit 823 and the second light receiving unit 824 are arranged at positions facing each other across the substrate 70 on the front side of the inspection unit 40, and are fixed on the bottom of the housing 41. ing. The lateral arrangement of the second light emitting unit 823 and the second light receiving unit 824 is reversed from the positional relationship of the first light emitting unit 813 and the first light receiving unit 814. The second light emitting unit 823 is arranged so that the light emitting surface 823a facing the front is parallel to the direction orthogonal to the insertion direction. The second light receiving portion 824 is arranged so that the light receiving surface 824a facing the front side is parallel to the direction orthogonal to the insertion direction.

Of the pair of second reflecting units 822, one second reflecting unit 822 is arranged in front of the second light emitting unit 823 so as to face the second light projecting unit 823, and the other second reflecting unit 823. The 822 is arranged in front of the second light receiving unit 824 so as to face the second light receiving unit 824.

Then, one second reflecting unit 822 reflects the light curtain 460 emitted by the first light emitting unit 813 at a right angle and directs it toward the other second reflecting unit 822. The other second reflecting unit 822 also reflects the light curtain 460 reflected by the other second reflecting unit 822 at a right angle and directs it toward the second light receiving unit 824. As a result, the light curtain 460 emitted by the second light projecting unit 823 is reflected by one second reflecting unit 822 to be parallel to the X-axis direction, and then reflected by the other second reflecting unit 822. As a result, the light is received by the second light receiving unit 824. The position of the front side portion on the substrate 70 is detected at the portion parallel to the X-axis direction in the light curtain 460.

Here, the position of the substrate 70 is detected in a state in which the substrate 70 is supported by the support portion 43 of the inspection unit 40 and is in the reference position (reference state), and the substrate 70 is lifted from the support portion 43 by the arm portion 21 of the robot 20. It is performed in the held state (holding state).

FIG. 4 is an explanatory diagram showing the states of the light curtains 450 and 460 of the first sensor 811 and the second sensor 821 according to the embodiment. Note that FIG. 4 illustrates a case where three substrates 70 are arranged in the light curtains 450 and 460.

FIG. 4A shows a case where the substrate 70 in the reference state is irradiated with the light curtain 450 of the first sensor 811. As shown in FIG. 4A, the light curtain 450 is partially blocked by each of the three substrates 70 in the reference state and is incident on the first light receiving portion 814 of the first sensor 811. Each of the shielded portions 450a, 450b, and 450c of the light curtain 450 corresponds to one substrate 70. As a result, the first light receiving unit 814 creates and outputs a detection signal of each substrate 70 in the reference state based on the portions 450a, 450b, and 450c.

FIG. 4B shows a case where the substrate 70 in the holding state is irradiated with the light curtain 450 of the first sensor 811. As shown in FIG. 4B, the light curtain 450 is partially blocked by each of the three substrates 70 in the holding state, and is incident on the first light receiving portion 814 of the first sensor 811. Each of the shielded portions 450d, 450e, and 450f of the light curtain 450 corresponds to one substrate 70. As a result, the first light receiving unit 814 creates and outputs a detection signal of each substrate 70 in the holding state based on the portions 450d, 450e, and 450f.

FIG. 4C shows a case where the substrate 70 in the reference state is irradiated with the light curtain 460 of the second sensor 821. As shown in FIG. 4C, the light curtain 460 is partially blocked by each of the three substrates 70 in the reference state, and is incident on the second light receiving unit 824 of the second sensor 821. Each of the shielded portions 460a, 460b, and 460c of the light curtain 460 corresponds to one substrate 70. As a result, the second light receiving unit 824 creates and outputs a detection signal of each substrate 70 in the reference state based on the portions 460a, 460b, and 460c.

FIG. 4D shows a case where the substrate 70 in the holding state is irradiated with the light curtain 460 of the second sensor 821. As shown in FIG. 4D, the light curtain 460 is partially blocked by each of the three substrates 70 in the holding state, and is incident on the second light receiving portion 824 of the second sensor 821. Each of the shielded portions 460d, 460e, and 460f of the light curtain 460 corresponds to one substrate 70. As a result, the second light receiving unit 824 creates and outputs the detection signal of each substrate 70 in the holding state based on the portions 460d, 460e, and 460f.

The light curtain 460 of the second sensor 821 has a portion 460g, 460h, 460i blocked by the hand portion 23. The substrate 70 and the hand are placed where the light curtain 460 is irradiated so that the portions 460g, 460h, 460i blocked by the hand portion 23 and the portions 460d, 460e, 460f blocked by the substrate 70 can be distinguished. It is necessary to form a gap between the portion 23 and the portion 23. Then, the second light receiving unit 824 also creates and outputs a detection signal for the portion 460g, 460h, 460i. As will be described later, the detection signals for the portions 460g, 460h, and 460i are not used for position detection of the substrate 70.

FIG. 5 is an enlarged explanatory view showing the states of the light curtains 450 and 460 of the first sensor 811 and the second sensor 821 shown in FIG. 4, respectively. In FIG. 5, the portion corresponding to one substrate 70 is enlarged and shown.

By using the detection signal of the first light receiving unit 814 of the first sensor 811, the shielded portion 450a of the light curtain 450 shown in FIG. 5 (a) and the shield of the light curtain 450 shown in FIG. 5 (b). The difference ΔL1 from the obtained portion 450d can be obtained. Further, by using the detection signal of the second light receiving unit 824 of the second sensor 821, the blocked portion 460a of the light curtain 460 shown in FIG. 5 (c) and the light curtain 460 shown in FIG. 5 (d) are used. The difference ΔL2 from the blocked portion 460d can be obtained.

FIG. 6 is a side view of the substrate 70 as viewed from the X-axis direction in order to show the presence or absence of inclination of the substrate 70 in the holding state according to the embodiment. In FIG. 6, the substrate 70 in the reference state is shown by a broken line. Further, FIG. 6A shows a non-tilted substrate 70, and FIG. 6B shows a tilted substrate 70. In the present embodiment, the inclination of the substrate 70 is emphasized, but the actual inclination of the substrate 70 is slight.

As shown in FIG. 6A, when the substrate 70 in the holding state is not tilted, the difference ΔL1 on the first sensor 811 side is maintained in order to maintain parallelism with the substrate 70 in the reference state. , The difference ΔL2 on the second sensor 821 side is the same value. On the other hand, as shown in FIG. 6B, when the substrate 70 in the holding state is tilted, the difference ΔL1 on the first sensor 811 side and the difference ΔL2 on the second sensor 821 side are different. That is, by acquiring and comparing the difference ΔL1 and the difference ΔL2, it is possible to determine whether or not the substrate 70 in the holding state has an inclination. Further, by using the difference between the difference ΔL1 and the difference ΔL2 and the distance L3 between the light curtains 450 and 460, the inclination of the substrate 70 in the holding state (specifically, the inclination in the rotation direction about the X axis: Hereinafter, it may be referred to as the first inclination.).

FIG. 7 is a block diagram showing a main control configuration of the inspection unit 40 according to the embodiment. As shown in FIG. 7, the inspection unit 40 includes the first light emitting unit 813 and the first light receiving unit 814 of the first sensor 811 and the second light emitting unit 823 and the second light receiving unit 824 of the second sensor 821. A storage unit 48 and a control unit 49 electrically connected to the storage unit 48 are provided. The control unit 49 is, for example, a microcomputer provided with a CPU, RAM, ROM, etc., and the CPU detects the inclination of the hand unit 23 of the robot 20 by expanding the program stored in the ROM into the RAM and executing the program. Further, the control unit 49 stores the detected inclination of the hand unit 23 in the storage unit 48.

When the inspection unit 40 is mounted on the mounting table 53 (see FIG. 1), the control unit 49 can be electrically connected to the controller of the transport system and communicate with the controller. When the inspection start instruction signal is input from the controller, the control unit 49 controls each unit to detect the inclination of the substrate 70. By detecting the inclination of the substrate 70, the inclination of the hand portion 23 of the robot 20 is indirectly detected.

Hereinafter, a detection method for detecting the inclination of the hand unit 23 will be described.

FIG. 8 is a flowchart showing a tilt inspection method executed by the inspection unit 40 according to the embodiment.

As shown in FIG. 8, when the control unit 49 of the inspection unit 40 receives the inspection start instruction signal from the controller, the first light projecting unit 813 and the second light projecting unit 823 are made to emit light to light the light curtains 450 and 460. Form (step S1).

At this time, the controller controls the robot 20 to hold the plurality of boards 70 by the hand portion 23 of the arm portion 21, and then installs the plurality of boards 70 at reference positions in the housing 41. After that, the arm portion 21 is retracted from the inspection unit 40. As a result, light is emitted from the first light projecting unit 813 and the second light projecting unit 823 arranged on one side of the substrate 70 toward the substrate 70. After the arm unit 21 is retracted, the controller outputs the installation completion signal of the board 70 to the control unit 49.

When the control unit 49 receives the installation completion signal, it receives the detection signals from the first light receiving unit 814 and the second light receiving unit 824 in the reference state (step S2: first inspection mode). Specifically, the plurality of substrates 70 in the reference state are the reference targets, and since these substrates 70 partially block the light curtains 450 and 460, the first light receiving unit 814 and the second light receiving unit 814 and the second light receiving unit From 824, detection signals for each of a plurality of reference objects are output. When the control unit 49 receives the detection signal, the control unit 49 outputs a reception completion signal to the controller. Upon receiving the reception completion signal, the controller controls the robot 20 to hold the plurality of boards 70 by the hand portion 23 of the arm portion 21, and then puts the robot into the holding state. In the holding state, the controller outputs a holding completion signal of the board 70 to the control unit 49.

When the control unit 49 receives the holding completion signal, it receives the detection signals from the first light receiving unit 814 and the second light receiving unit 824 in the holding state (step S3: second inspection mode). Specifically, the plurality of substrates 70 in the holding state are to be inspected, and since these substrates 70 partially block the light curtains 450 and 460, the first light receiving unit 814 and the second light receiving unit 814 are partially blocked. From 824, detection signals for each of a plurality of inspection targets are output. At this time, the detection signal corresponding to the hand unit 23 is also output from the second light receiving unit 824, but since the thickness of the hand unit 23 and the thickness of the substrate 70 are significantly different, the detection signal is based on the substrate 70. It is possible to distinguish between the thing and the thing based on the hand part 23. Specifically, a predetermined threshold value may be set in advance, and a detection signal in which the blocked region is larger than the threshold value may be determined to be due to the hand unit 23 and ignored.

Next, the control unit 49 detects the inclination of each substrate 70 by comparing the detection signal in the first inspection mode with the detection signal in the second inspection mode (step S4). At this time, the control unit 49 stores the inclination of the substrate 70 and the detection time thereof in the storage unit 48 in association with each other.

Next, the control unit 49 determines whether or not the inclination of the substrate 70 is within the permissible range (step S5), and if it is within the permissible range, proceeds to step S6 and exceeds the permissible range. If so, the process proceeds to step S8.

In step S6, the control unit 49 allows the inclination of each hand unit 23 from the past inclination of the substrate 70 and its detection time stored in the storage unit 48 and the current inclination of the substrate 70 and its detection time. Indirectly predict the time when the range is exceeded (prediction time). Specifically, the inclination of each hand portion 23 is allowed by plotting the inclination of the substrate 70 in the past and its detection time and the inclination of the current substrate 70 and its detection time on a graph and creating an approximate curve. Indirectly predict when the range will be exceeded.

Next, the control unit 49 outputs the predicted time to the controller (step S7). As a result, the controller can display on the display unit the predicted time when the inclination of each hand unit 23 exceeds the allowable range. If the predicted time is near the present, the controller may display a warning on the display. If the data is not accumulated as much as predictable, steps S6 and S7 may be omitted.

In step S8, the control unit 49 outputs an error signal indicating that the inclination of the substrate 70 has already exceeded the allowable range to the controller. As a result, the controller can display on the display unit that an error has occurred in the hand unit 23.

[Effects, etc.]
As described above, according to the present embodiment, the light receiving units 814 and 824 of the multi-optical axis photoelectric sensor are inside the light curtain 450 and 460 composed of the light of a plurality of parallel optical axes emitted by the light projecting units 813 and 823. When a plurality of substrates 70 at least spaced apart from each other are arranged, signals blocked by the respective substrates 70 can be detected. As a result, the positions of the plurality of substrates 70 can be detected at the same time, and the inclination of the substrates 70 can be detected by the width of the blocked light curtains 450 and 460. If the inclinations of the plurality of substrates 70 can be detected in this way, the inclinations of the plurality of hand portions 23 can also be indirectly detected. Therefore, the inclination of each hand unit 23 can be detected without increasing the distance between the plurality of hand units 23.

Further, since the traveling direction of the light when passing through the substrate 70 is orthogonal to the insertion direction in which the hand portion 23 is inserted into the housing 41, the light projecting unit is located at a position that does not hinder the insertion of the hand portion 23. 813, 823 and light receiving units 814, 824 can be arranged. Further, since the traveling direction of the light passing through the substrate 70 is orthogonal to the insertion direction, it is possible to easily detect the inclination of the substrate 70 with respect to the insertion direction.

In the above embodiment, the case where the traveling direction of the light passing through the substrate 70 is orthogonal to the insertion direction has been described as an example, but the traveling direction of the light intersects the insertion direction. You just have to do it.

Further, since a plurality of transmissive photoelectric sensors are arranged along the insertion direction, the inclination of the substrate 70 with respect to the insertion direction can be detected by combining the detection results of the plurality of transmissive photoelectric sensors.

Further, by inspecting the substrate 70 held by the hand portion 23, the inclination of the hand portion 23 can be indirectly detected without directly inspecting the hand portion 23. Specifically, in the first inspection mode, detection signals are acquired for a plurality of substrates 70 arranged at reference positions in the housing 41. Further, in the second inspection mode, the detection signals for the plurality of substrates 70 held by the hand unit 23 in the housing 41 are acquired. After that, the inclination of the plurality of substrates 70 is determined based on the detection signal in the first inspection mode and the detection signal in the second inspection mode. As a result, the substrate 70 installed at the reference position in the housing 41, that is, the substrate 70 having no inclination can be compared with the substrate 70 held by the hand portion 23, so that the accuracy of the inclination detection can be improved. Can be done.

[Other embodiments]
The tilt inspection device according to the present invention has been described above based on the above-described embodiment, but the present invention is not limited to the above-described embodiment.

For example, in the above embodiment, the case where the first inclination of the substrate 70 is detected based on the detection signals of the first sensor 811 and the second sensor 821 has been described. However, based on the detection signals of the first sensor 811 and the second sensor 821, the inclination of the substrate 70 in the rotation direction about the Y axis (hereinafter, may be referred to as the second inclination) is detected. Is also possible. Specifically, as shown in FIG. 3, two intersections P11 and P12 formed by the outer circumferences of the light curtain 450 and the substrate 70 of the first sensor 811 and the outer circumferences of the light curtain 460 and the substrate 70 of the second sensor 821 form. The two intersections P21 and P22 are connected to form a pair of virtual straight lines V1 and V2 that intersect each other. The angle θ formed by the pair of virtual straight lines V1 and V2 (specifically, the angle formed by the intersection P11, the center O of the substrate 70, and the intersection P22) may be 90 degrees or more and 120 degrees or less. By doing so, it is possible to secure a region necessary for detecting the second inclination of the substrate 70.

FIG. 9 is a cross-sectional view of the substrate 70 and the light curtain 450 according to the embodiment as viewed from the Y-axis direction.

FIG. 9A shows a case where the substrate 70 in the reference state is irradiated with the light curtain 450 of the first sensor 811. As shown in FIG. 9A, the light curtain 450 is partially blocked by the substrate 70 in the reference state and is incident on the first light receiving portion 814 of the first sensor 811. The shielded portion 450j of the light curtain 450 corresponds to the substrate 70. As a result, the first light receiving unit 814 creates and outputs a detection signal of the substrate 70 in the reference state based on the portion 450j. By using this detection signal, the thickness t1 of the blocked portion 450j of the light curtain 450 shown in FIG. 9A can be obtained. Since the substrate 70 is not tilted in the reference state, the thickness t1 corresponds to the thickness of the substrate 70.

FIG. 9B shows a case where the substrate 70 in the holding state is irradiated with the light curtain 450 of the first sensor 811. As shown in FIG. 9B, the light curtain 450 is partially blocked by the substrate 70 in the reference state and is incident on the first light receiving portion 814 of the first sensor 811. The shielded portion 450k of the light curtain 450 corresponds to the substrate 70. As a result, the first light receiving unit 814 creates and outputs a detection signal of the substrate 70 in the holding state based on the portion 450k. By using this detection signal, the thickness t2 of the blocked portion 450k of the light curtain 450 shown in FIG. 9B can be obtained. When the substrate 70 is not tilted in the holding state, the thickness t2 becomes the thickness t1. On the other hand, when the substrate 70 is tilted in the holding state, the thickness t2 becomes larger than the thickness t1. That is, by comparing the thickness t1 and the thickness t2, it is possible to determine whether or not the substrate 70 is tilted. Further, when the length L of the substrate 70 in the light curtain 450 is known, it is possible to obtain the second inclination from the difference between the thickness t2 and the thickness t1 and the length L4.

Here, the case where the first sensor 811 is used to detect the second inclination of the substrate 70 has been described as an example, but when the second sensor 821 is also used, the second inclination is determined by the same procedure. Can be detected. It is also possible to detect a more detailed posture of the substrate 70 by obtaining the second inclination of the substrate 70 from each of the first sensor 811 and the second sensor 821.

Further, in the above embodiment, the case where three substrates 70 are arranged in the light curtain 450 and 460 and the inclination of the three substrates 70 is detected at once has been described as an example, but one sensor. By increasing the height of the light curtains 450 and 460 of (first sensor 811 and second sensor 821), it is possible to collectively detect the inclination of four or more substrates 70. Further, if a plurality of multi-optical axis photoelectric sensors are arranged in the Z-axis direction, it is possible to collectively detect more tilts of the substrate 70.

Further, in the above-described embodiment, the case where the inclination of the hand portion 23 is indirectly detected by targeting the substrate 70 held by the hand portion 23 as an example has been described. However, by targeting the hand unit 23 for inspection, it is possible to directly detect the inclination of the hand unit 23. In this case, the hand portion 23 that does not hold the substrate 70 is arranged in the housing 41 of the inspection unit 40. After that, light is projected onto the hand unit 23 from the first light projecting unit 813 of the first sensor 811 and the second light projecting unit 823 of the second sensor 821, whereby the hand unit 23 emits light to the light curtain 450. It will block 460. Further, since the first light receiving unit 814 and the second light receiving unit 824 output a detection signal based on the light curtain 450 and 460 being blocked by the hand unit 23 to the control unit 49, the control unit 49 is based on the detection signal. The inclination of the hand unit 23 can be detected.

In addition, it is realized by arbitrarily combining the components and functions in the embodiment and the modified example within the range obtained by applying various modifications to the embodiment and the gist of the present invention. The form to be used is also included in the present invention.

20 Robot 21 Hand arm 23 Hand part 41 Housing 42 Flange part 40 Inspection unit (Inclination inspection device for the hand part of the robot)
43 Support unit 48 Storage unit 49 Control unit 53 Mounting stand 70 Board (inspection target)
80 Inspection unit 81 First detection unit 82 Second detection unit 231 Suction unit 431, 432, 433 Support 434 Slit 450, 460 Light curtain 450a, 450b, 450c, 450d, 450e, 450f, 450g, 450h, 450i, 450j, 450k, 460a, 460b, 460c, 460d, 460e, 460f, 460g, 460h, 460i Shielded part 811 First sensor (transmission type photoelectric sensor, multi-optical axis photoelectric sensor)
812 First reflection unit 813 First light projection unit 813a Light emitting surface 814 First light receiving unit 814a Light receiving surface 821 Second sensor (multi-optical axis photoelectric sensor)
822 Second reflecting unit 823 Second light emitting unit 823a Light emitting surface 824 Second light receiving unit 824a Light receiving surface

Claims (4)

An inclination inspection device for the hand portion of a robot for detecting the inclination of the hand portion of the robot that holds and transfers a plurality of boards by a plurality of hand portions arranged in a layered manner.
A housing that accommodates at least the same number of the substrates as the plurality of hand portions in a layered manner.
The multi-optical axis photoelectric sensor provided in the housing and
A control unit for determining the inclination of the substrate based on the detection signal of the multi-optical axis photoelectric sensor is provided.
The multi-optical axis photoelectric sensor is
A light projecting unit that is arranged on one side of a plurality of the substrates inserted in the housing and emits a light curtain composed of light of a plurality of parallel optical axes directed toward the plurality of substrates.
A light receiving unit that is arranged on the other side of the plurality of substrates inserted in the housing and outputs the detection signal based on the light curtain being blocked by the plurality of substrates is provided. ,
The control unit has a first inspection mode for acquiring the detection signals for a plurality of the boards arranged at reference positions in the housing, and the control unit for the plurality of boards held by the hand unit in the housing. After performing the second inspection mode for acquiring the detection signal, the inclination of the plurality of substrates is based on the detection signal in the first inspection mode and the detection signal in the second inspection mode. An inclination inspection device for the hand portion of a robot that inspects the inclination of the hand portion by determining. The inclination inspection device for a robot hand portion according to claim 1, wherein the traveling direction of the light when passing through the substrate intersects the insertion direction in which the hand portion is inserted into the housing. The tilt inspection device for a hand portion of a robot according to claim 2, wherein a plurality of the multi-optical axis photoelectric sensors are arranged along the insertion direction. This is a method for inspecting the inclination of the hand portion of a robot for detecting the inclination of the hand portion of the robot that holds and transfers a plurality of substrates by a plurality of hand portions arranged in a layered manner.
A light curtain is emitted from a plurality of light projecting units arranged on one side of the plurality of substrates inserted in the housing toward the substrate.
A light receiving portion that is arranged on the other side of the plurality of substrates inserted in the housing and receives the light curtain that has passed through the plurality of substrates is shielded by the plurality of substrates. When outputting a detection signal based on the fact that the substrate is generated and determining the inclination of a plurality of the substrates based on the detection signal,
The first inspection mode for acquiring the detection signals for a plurality of the boards arranged at reference positions in the housing and the detection signals for the plurality of boards held in the hand portion in the housing are acquired. After performing the second inspection mode, the inclination of the plurality of substrates is determined based on the detection signal in the first inspection mode and the detection signal in the second inspection mode. , A method for inspecting the inclination of the hand portion of a robot for inspecting the inclination of the hand portion.

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