Photoelectric sensor for wafer detection of robot end effector and robot

Abstract

The present invention provides a photoelectric sensor and a manipulator for wafer detection at the end effector of a manipulator, and relates to the field of semiconductor manufacturing technology. The photoelectric sensor includes a photosensitive element and a circuit control module. The circuit control module is electrically connected to the photosensitive element. The circuit control module is used to receive a sensing signal and compare the sensing signal with a threshold value to determine the state of the wafer; it is also used to adjust the brightness of the input light of the photosensitive element, and adjust the threshold value according to the specifications of the wafer sensed by the photosensitive element. The sensing signal is compared with the threshold value by the circuit control module, and the state of the wafer can be determined; by adjusting the brightness of the input light of the photosensitive element and adjusting the threshold value according to the specifications of the wafer sensed by the photosensitive element, the photosensitive element can detect the state of wafers of different specifications, ensuring that the photosensitive element has high accuracy for wafers of different specifications, and increasing the scope of use of the photosensitive element.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to a photoelectric sensor for wafer detection by a robot end effector and a robot. Background Art

[0002] Wafer transfer is scattered in almost every link of the wafer manufacturing process. The most commonly used equipment include wafer sorters and EFEMs. Among them, R-θ atmospheric vacuum robots have been widely used in FAB factories, such as Figure 1 As shown, the R-θ atmospheric vacuum manipulator, because it lacks the flexibility of the SCADA manipulator, is often designed as a dual-arm model to improve work efficiency. However, this dual-arm model places higher demands on the structural design of the manipulator's end effector. The end effector of a dual-arm manipulator is thinner, approximately 3 mm, and the distance between the two end effectors is generally around 10 mm, resulting in a compact structure.

[0003] Due to the variety of wafer specifications and different reflectivities, existing sensors will cause misjudgment when the wafer specifications change or when the material on the back of the upper arm end effector is reflective, seriously affecting the accuracy of sensor detection and limiting the scope of sensor use. Summary of the Invention

[0004] The present invention provides a photoelectric sensor for wafer detection at a robot end effector, which is used to solve the problems that the existing sensors at the end effector of the arm cannot match wafers of different specifications and have low detection accuracy.

[0005] The present invention provides a photoelectric sensor for wafer detection of a robot end effector, comprising:

[0006] Photosensitive element, used to sense the state of the wafer and output a sensing signal;

[0007] A circuit control module is electrically connected to the photosensitive element. The circuit control module is used to receive the sensing signal and compare the sensing signal with a threshold to determine the state of the wafer; it is also used to adjust the brightness of the input light of the photosensitive element and adjust the threshold according to the specifications of the wafer sensed by the photosensitive element.

[0008] According to an embodiment of the present invention, a photoelectric sensor for wafer detection of a robot end effector is provided, further comprising:

[0009] A signal amplification and output module is electrically connected to the circuit control module and the control terminal respectively. The signal amplification and output module is used to amplify the signal output by the circuit control module and output it to the control terminal; it is also used to electrically isolate the circuit control module from the control terminal.

[0010] According to an embodiment of the present invention, a photoelectric sensor for wafer detection of a robot end effector is provided, further comprising:

[0011] The communication module is electrically connected to the circuit control module and the interactive terminal respectively.

[0012] According to an embodiment of the present invention, a photoelectric sensor for wafer inspection of a robot end effector is provided. The circuit control module includes a controller, a signal conversion unit, a filtering unit, a comparator and a first resistor. The first connection end of the controller is connected to the first connection end of the signal conversion unit, the second connection end of the signal conversion unit and the first connection end of the comparator are commonly connected to the second connection end of the controller, the second connection end of the comparator, the first connection end of the filtering unit, the third connection end of the controller and the first connection end of the first resistor are commonly connected to the first connection end of the photosensitive element, the third connection end of the comparator, the second connection end of the filtering unit, the second connection end of the photosensitive element and the third connection end of the photosensitive element are commonly connected to a power supply unit, the fourth connection end of the photosensitive element is respectively connected to the fourth connection end and the fifth connection end of the controller, the second connection end of the first resistor, the fourth connection end of the comparator and the sixth connection end of the controller are all connected to the power supply unit, the fifth connection end of the comparator is connected to the signal amplification and output module, and the seventh connection end of the controller is connected to the communication module.

[0013] According to an embodiment of the present invention, a photoelectric sensor for wafer detection of a robot end effector is provided, wherein the circuit control module further comprises:

[0014] A second resistor, the fourth connection end of the photosensitive element is connected to the first end of the second resistor, and the second end of the second resistor is connected to the third connection end and the fourth connection end of the controller respectively.

[0015] According to an embodiment of the present invention, a photoelectric sensor for wafer detection of a robot end effector is provided, wherein the controller is an MCU controller.

[0016] According to an embodiment of the present invention, a photoelectric sensor for wafer detection of a robot end effector is provided, wherein the signal amplification output module includes an amplifier and a third resistor, the first connection end of the third resistor is connected to the fifth connection end of the comparator, the second connection end of the third resistor is connected to the first end of the amplifier, and the second end of the amplifier is connected to the control terminal.

[0017] According to an embodiment of the present invention, a photoelectric sensor for wafer detection of a robot end effector is provided, wherein the communication interface of the communication module is RS232 or RS485.

[0018] According to an embodiment of the present invention, a photoelectric sensor for wafer detection of a robot end effector is provided, wherein the interactive terminal is a PC, and the control terminal is a PLC control module.

[0019] The present invention also provides a robot, including a robot end effector, and also includes a photoelectric sensor for wafer detection of the robot end effector as described in any one of the above items, and the photosensitive element is embedded in the robot end effector.

[0020] The photoelectric sensor for wafer detection of the robot end effector provided in an embodiment of the present invention compares the sensing signal with the threshold through a circuit control module, and thus can determine the state of the wafer; by adjusting the brightness of the input light of the photosensitive element and adjusting the threshold according to the specifications of the wafer sensed by the photosensitive element, the photosensitive element can detect the state of wafers of different specifications, ensuring that the photosensitive element has high accuracy for wafers of different specifications, thereby increasing the scope of use of the photosensitive element. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 1 is a schematic diagram of the three-dimensional structure of the manipulator end effector provided by an embodiment of the present invention;

[0023] Figure 2 Schematic diagram of the structure of a photoelectric sensor for wafer detection at a manipulator end effector provided by an embodiment of the present invention;

[0024] Figure 3 This is a specific circuit diagram of a photoelectric sensor for wafer detection at the robot end effector provided by an embodiment of the present invention.

[0025] Reference numerals:

[0026] 100. Photosensitive element; 110. In-position sensor; 120. Offset sensor; 130. Upper arm; 140. Lower arm; 200. Circuit control module; 210. Controller; 220. Signal conversion unit; 230. Filter unit; 250. Comparator; 260. First resistor; 270. Second resistor; 300. Signal amplification and output module; 310. Amplifier; 320. Third resistor; 400. Communication module; 500. Power supply unit; 600. Control terminal; 700. Interactive terminal. DETAILED DESCRIPTION

[0027] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0028] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0029] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; and direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on the specific circumstances.

[0030] In the embodiments of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," or "above" a second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," or "below" a second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0031] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0032] The following combination Figure 1-Figure 3 The photoelectric sensor for wafer detection of a robot end effector according to an embodiment of the present invention is described.

[0033] Figure 1 The schematic diagram of the three-dimensional structure of the end effector of the manipulator provided by the embodiment of the present invention is illustrated as follows: Figure 1 As shown, the photoelectric sensor of the present invention is set on the end effector of the manipulator. Before introducing the photoelectric sensor, the end effector of the manipulator is introduced first. Since the end effector is used to transport wafers in a small and limited space, the size of the end effector is limited, especially the thickness. The R-θ atmospheric vacuum manipulator is designed as a double-arm mode, i.e., an upper arm 130 and a lower arm 140, and the distance between the two arms is fixed at 10mm±0.1. Figure 1 As shown, the photoelectric sensor can be either an in-position sensor 110 or an offset sensor 120, located on the end effector of the manipulator. The photoelectric sensor is embedded in a groove in the end effector, the depth of which is less than the thickness of the end effector (3 mm). When the photoelectric sensor of the present invention is located on the lower arm 140, it avoids interference from the upper arm 130, thereby improving detection accuracy.

[0034] Figure 2 The schematic diagram of the structure of the photoelectric sensor for wafer detection of the robot end effector provided by the embodiment of the present invention is illustrated as follows: Figure 2As shown, the photoelectric sensor for wafer detection at the robot end effector includes a photosensitive element 100 and a circuit control module 200. The photosensitive element 100 is used to sense the state of the wafer and output a sensing signal. The circuit control module 200 is electrically connected to the photosensitive element 100 and is used to receive the sensing signal and compare the sensing signal with a threshold value to determine the state of the wafer. The circuit control module 200 is also used to adjust the brightness of the input light of the photosensitive element 100 and adjust the threshold value according to the specifications of the wafer sensed by the photosensitive element 100. Since the reflectivity of wafers of different specifications is also different, the reflectivity of the wafer will also change when different wafers are replaced. Therefore, it is necessary to adjust the brightness and threshold value of the input light of the photosensitive element 100 so that the photoelectric sensor can accurately identify the status of wafers of different specifications. By adjusting the threshold value, the influence of the reflection of the material on the back of the upper arm end effector can be eliminated.

[0035] The photoelectric sensor for wafer detection of the robot end effector provided in an embodiment of the present invention compares the sensing signal with the threshold value through the circuit control module 200, and thus can determine the state of the wafer; by adjusting the brightness of the input light of the photosensitive element 100 and adjusting the threshold value according to the specifications of the wafer sensed by the photosensitive element 100, the photosensitive element 100 can detect the states of wafers of different specifications, ensuring that the photosensitive element 100 has high accuracy for wafers of different specifications, thereby increasing the scope of use of the photosensitive element 100.

[0036] In an embodiment of the present invention, the photoelectric sensor for wafer inspection on the robot end effector further includes a signal amplification and output module 300, which is electrically connected to the circuit control module 200 and the control terminal 600. The signal amplification and output module 300 functions as both an output circuit for the circuit control module 200 and an input circuit for the control terminal 600. The signal amplification and output module 300 is configured to amplify the signal output by the circuit control module 200 and output it to the control terminal 600. This amplification ensures that the signal output by the circuit control module 200 meets the interface requirements of the input module of the control terminal 600. The control terminal 600 is a PLC control module, but the type of control terminal 600 is not limited to this and may also be another type of controller 210. Furthermore, the signal amplification and output module 300 is configured to provide electrical isolation between the circuit control module 200 and the control terminal 600.

[0037] In an embodiment of the present invention, the photoelectric sensor for wafer inspection on the robot end effector further includes a communication module 400, which is electrically connected to the circuit control module 200 and the interactive terminal 700. The communication module 400 is used to implement communication between the circuit control module 200 and the interactive terminal 700, and the communication interface of the communication module 400 is RS232 or RS485. The interactive terminal 700 is a PC, and the communication module 400 is directly connected to the PC via the communication interface. The PC is equipped with a display and a human-computer interface, which can monitor the current light sensitivity and threshold value. The operator can directly adjust them through the human-computer interface.

[0038] In an embodiment of the present invention, Figure 3 The specific circuit diagram of the photoelectric sensor for wafer detection of the robot end effector provided by the embodiment of the present invention is illustrated as follows: Figure 3 As shown, the circuit control module 200 includes a controller 210, a signal conversion unit 220, a filtering unit 230, a comparator 250 and a first resistor 260. The first connection end of the controller 210 is connected to the first connection end of the signal conversion unit 220, the second connection end of the signal conversion unit 220 and the first connection end of the comparator 250 are connected to the second connection end of the controller 210, the second connection end of the comparator 250, the first connection end of the filtering unit 230, the third connection end of the controller 210 and the first connection end of the first resistor 260 are connected to the first connection end of the photosensitive element 100, and the comparator 210 is connected to the first connection end of the photosensitive element 100. The third connection terminal of the comparator 250, the second connection terminal of the filter unit 230, the second connection terminal of the photosensitive element 100 and the third connection terminal of the photosensitive element 100 are connected to the power supply unit 500. The fourth connection terminal of the photosensitive element 100 is connected to the fourth connection terminal and the fifth connection terminal of the controller 210 respectively. The second connection terminal of the first resistor 260, the fourth connection terminal of the comparator 250 and the sixth connection terminal of the controller 210 are all connected to the power supply unit 500. The fifth connection terminal of the comparator 250 is connected to the signal amplification output module 300. The seventh connection terminal of the controller 210 is connected to the communication interface.

[0039] In an embodiment of the present invention, Figure 3 As shown, the circuit control module 200 further includes a second resistor 270 , the fourth connection end of the photosensitive element 100 is connected to the first end of the second resistor 270 , and the second end of the second resistor 270 is connected to the third connection end and the fourth connection end of the controller 210 respectively.

[0040] In an embodiment of the present invention, controller 210 is an MCU controller 210. Controller 210 is used to adjust the brightness of the light input to photosensitive element 100 and the threshold of comparator 250. This allows for variations in the amount of light reflected by photosensitive element 100 due to varying wafer specifications, thereby adapting to the needs of diverse environments and enabling reliable detection. Furthermore, controller 210 can detect the light-sensing state and threshold, and make adjustments based on the detected values.

[0041] In an embodiment of the present invention, Figure 3 As shown, the signal amplification and output module 300 includes an amplifier 310 and a third resistor 320. The first connection end of the third resistor 320 is connected to the fifth connection end of the comparator 250, the second connection end of the third resistor 320 is connected to the first end of the amplifier 310, and the second end of the amplifier 310 is connected to the control terminal 600. In practical applications, the signal from the photosensitive element 100 must be fed back to the device's control system. This invention primarily connects the signal to a commonly used PLC control module. Therefore, an amplifier 310 is connected after the comparator 25 signal. First, the circuit design is suitable for the PLC access module. Second, the amplifier 310 electrically isolates the control circuit from the PLC control module to prevent mutual interference between the two modules.

[0042] The present invention also provides a robot, including a robot end effector, and also includes the photoelectric sensor for wafer detection of the robot end effector as described in any one of the above embodiments, and the photosensitive element 100 is embedded in the robot end effector.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A photoelectric sensor for wafer detection of a robot end effector, characterized in that: include: Photosensitive element, used to sense the amount of light reflected from the wafer and output a sensing signal; a circuit control module electrically connected to the photosensitive element, the circuit control module being configured to receive the sensing signal and compare the sensing signal with a threshold value to determine the specifications of the wafer; and further configured to adjust the brightness of the input light of the photosensitive element and adjust the threshold value according to the specifications of the wafer to eliminate the influence of reflections from the material on the back of the upper arm end effector; a signal amplification and output module, electrically connected to the circuit control module and the control terminal, respectively, for amplifying the signal output by the circuit control module and outputting it to the control terminal; and for electrically isolating the circuit control module from the control terminal; The circuit control module includes a controller, a signal conversion unit, a filtering unit, a comparator and a first resistor, the first connection end of the controller is connected to the first connection end of the signal conversion unit, the second connection end of the signal conversion unit and the first connection end of the comparator are commonly connected to the second connection end of the controller, the second connection end of the comparator, the first connection end of the filtering unit, the third connection end of the controller and the first connection end of the first resistor are commonly connected to the first connection end of the photosensitive element, the third connection end of the comparator, the second connection end of the filtering unit, the second connection end of the photosensitive element and the third connection end of the photosensitive element are commonly connected to a power supply unit, the fourth connection end of the photosensitive element is respectively connected to the fourth connection end and the fifth connection end of the controller, the second connection end of the first resistor, the fourth connection end of the comparator and the sixth connection end of the controller are all connected to the power supply unit, the fifth connection end of the comparator is connected to the signal amplification and output module, and the seventh connection end of the controller is connected to the communication module; The signal amplification output module includes an amplifier and a third resistor, the first connection end of the third resistor is connected to the fifth connection end of the comparator, the second connection end of the third resistor is connected to the first end of the amplifier, and the second end of the amplifier is connected to the control terminal.

2. The photoelectric sensor for wafer detection of the robot end effector according to claim 1, characterized in that: Also includes: The communication module is electrically connected to the circuit control module and the interactive terminal respectively.

3. The photoelectric sensor for wafer detection of the robot end effector according to claim 1, characterized in that: The circuit control module further includes: A second resistor, the fourth connection end of the photosensitive element is connected to the first end of the second resistor, and the second end of the second resistor is connected to the third connection end and the fourth connection end of the controller respectively.

4. The photoelectric sensor for wafer detection of the robot end effector according to claim 3, characterized in that: The controller is an MCU controller.

5. The photoelectric sensor for wafer detection of the robot end effector according to claim 3, characterized in that: The communication interface of the communication module is RS232 or RS485.

6. The photoelectric sensor for wafer detection of the robot end effector according to claim 2, characterized in that: The interactive terminal is a PC, and the control terminal is a PLC control module.

7. A manipulator, comprising a manipulator end effector, characterized in that: It also includes the photoelectric sensor for wafer detection of the robot end effector according to any one of claims 1 to 6, and the photosensitive element is embedded in the robot end effector.

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