Non-contact wafer detection device

Abstract

The utility model discloses a non-contact wafer detection device, which comprises a working table, and a mechanical arm, a wafer bin group, a turnover device and an image acquisition device which are arranged on the working table, the movable end of the mechanical arm is connected with the suction cup, the wafer bin set and the turnover device are located on the operation path of the mechanical arm, the wafer bin set is used for storing wafers, and the mechanical arm, the turnover device and the image collecting device are connected with the controller. The image acquisition device comprises a first image acquisition device and a second image acquisition device; the first image acquisition device is used for acquiring an image of the wafer on the turnover device, and the second image acquisition device is connected with the mechanical arm and is used for acquiring an image of the wafer bin. According to the device, full-automatic detection of the wafer in a non-contact state is realized, a non-contact mode is adopted for detection, contact between a worker and the wafer is avoided, damage to the wafer in the operation process is avoided, and meanwhile, the detection efficiency can be improved and the manufacturing cost of the wafer can be reduced through automatic detection.

Description

Technical Field

[0001] The utility model relates to the technical field of wafer detection, in particular to a non-contact wafer detection device. Background Art

[0002] The importance of wafer inspection and classification in semiconductor manufacturing is self-evident. It is not only related to the performance and reliability of the chip, but also directly affects the efficiency and cost of the entire production process. Therefore, wafer inspection is the first step to ensure the quality of semiconductor products. Through inspection, defects on the wafer, such as particle contamination, cracks, uneven film thickness, etc., can be discovered in time. If these defects are not identified and handled in time, they will lead to chip performance degradation or complete failure.

[0003] Existing inspection methods include manual inspection and semi-automatic inspection. During manual inspection, the inspector holds a vacuum pen to pick up the wafer, then visually inspects the wafer, and then classifies the inspected wafers according to the inspection results and stores them in the corresponding wafer bin. During the inspection process, the vacuum pen is unevenly stressed, which causes local stress on the wafer, resulting in damage to the wafer, and the inspection efficiency is low, and the wafer is also damaged. Semi-automatic inspection is to pick up the wafer through a picking mechanism, and move the wafer to the inspection position for visual inspection by the inspector. This device improves the inspection efficiency of the wafer to a certain extent. However, since wafer inspection not only requires detection of the state but also identification of the model, the existing visual target recognition method can effectively identify the damage and model of the wafer. Therefore, how to apply the visual target recognition technology to the wafer inspection technology to achieve efficient and accurate detection of wafers, so as to reduce the inspection cost in the wafer production process. Utility Model Content

[0004] In view of the problems existing in the prior art, the utility model provides a non-contact wafer detection device to achieve efficient and accurate detection of wafers and reduce the detection cost in the production process of wafers.

[0005] The utility model is realized by the following technical solutions:

[0006] A non-contact wafer detection device comprises a workbench, and a mechanical arm, a wafer bin group, a turning device and an image acquisition device arranged on the workbench;

[0007] The movable end of the robotic arm is connected to a suction cup, a wafer bin group and a flipping device are located on the operating path of the robotic arm, the wafer bin group is used to store wafers, and the robotic arm, the flipping device and the image acquisition device are respectively connected to a controller.

[0008] The image acquisition device comprises a first image acquisition device and a second image acquisition device;

[0009] The first image acquisition device is used to acquire images of the wafer on the flipping device, and the second image acquisition device is connected to the robotic arm and is used to acquire images of the wafer bin.

[0010] Preferably, the first image acquisition device 2 comprises a support frame, a fixing rod, a horizontal rod and a camera;

[0011] The lower end of the support frame is connected to the workbench, the fixed rod is vertically arranged on the top of the support frame and can adjust the height, the horizontal rod is connected to the fixed rod through a cross bar, the camera is arranged at the end of the horizontal rod, and the horizontal rod can move relative to the cross bar.

[0012] Preferably, the camera is arranged on the top of the flipping device, and a light source is arranged between the camera and the flipping device.

[0013] Preferably, the light source includes a lamp stand, to which a U-shaped lamp is connected, and the U-shaped lamp is located above the wafer.

[0014] Preferably, the mechanical arm is connected to the suction cup via a cantilever, and the second image acquisition device is arranged on the cantilever.

[0015] Preferably, the flipping device comprises a fixing seat, a servo motor, a wafer clamp and a position detection device;

[0016] The lower end of the fixing seat is fixed on the workbench, the servo motor is installed on the upper end of the fixing seat, the wafer clamp is connected to the output shaft of the servo motor through the adapter, and the wafer clamp is close to one side of the mechanical arm.

[0017] Preferably, the position detection device is a photoelectric switch.

[0018] Preferably, the wafer clamp is a U-shaped structure, and its inner wall is provided with a clamping groove for clamping the wafer.

[0019] Preferably, the suction cup comprises a base plate, an air cavity and a positioning angle;

[0020] A plurality of air cavities are distributed on the base plate, and the positioning angle circles are respectively at the edges of the base plate. An air channel is arranged in the base plate, and the air channel is connected with each air cavity, and the air outlet of the air channel is located at the edge of the base plate.

[0021] Preferably, an air outlet is provided in the air cavity, and the airflow generated by the air outlet flows along the tangential direction of the air cavity.

[0022] Compared with the prior art, the utility model has the following beneficial technical effects:

[0023] Compared with the prior art, the utility model has the following beneficial technical effects:

[0024] The utility model provides a non-contact wafer detection device, which arranges a wafer bin, an image acquisition device, a flipping device, a mechanical arm and a suction cup connected to the mechanical arm on a workbench, a controller connects the flipping device and the signal end of the mechanical arm, and respectively recognizes the image of the wafer bin and the image of the wafer to be tested through two image acquisition devices, and accurately recognizes the defects and models of the wafers in combination with a visual recognition program, and then uses the mechanical arm and the suction cup to classify and store the wafers. The device realizes fully automatic detection of wafers in a non-contact state, adopts a non-contact detection method, avoids contact between staff and wafers, and solves the damage to wafers during the operation process. At the same time, automated detection can improve detection efficiency and reduce the manufacturing cost of wafers. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is an appearance diagram of the non-contact wafer detection device of the utility model;

[0026] Figure 2 This is a plan layout diagram of the non-contact wafer detection device of the utility model;

[0027] Figure 3 It is a structural schematic diagram of the non-contact wafer detection device of the utility model;

[0028] Figure 4 This is a schematic diagram of the connection between the manipulator and the suction cup of the utility model;

[0029] Figure 5 This is a schematic diagram of the structure of the suction cup of the utility model;

[0030] Figure 6 It is a structural schematic diagram of the suction cup airway of the utility model;

[0031] Figure 7 This is a schematic diagram of the structure of the wafer bin group of the utility model;

[0032] Figure 8 This is a schematic diagram of the structure of the turning device of the utility model;

[0033] Fig. 9 This is a schematic diagram of the structure of the wafer clamp of the utility model;

[0034] Fig.10 It is a structural schematic diagram of the position detection device of the utility model;

[0035] Fig.11 This is a schematic diagram of the structure of the image acquisition device of the utility model;

[0036] Fig.12 It is a structural schematic diagram of the light source of the utility model.

[0037] In the figure: 1. workbench; 2. first image acquisition device; 3. wafer bin group; 4. robot arm; 5. flip device; 6. suction cup; 7. second image acquisition device; 8. cantilever; 9. wafer; 21. lamp holder; 22. lighting lamp; 23. camera; 24. fixing rod; 25. horizontal rod; 31. wafer slot; 32. wafer bin; 33. fixing frame; 51. fixing seat; 52. servo motor; 53. wafer clamp; 54. clamping groove; 55. clamping plate; 56. angle detection device; 57. adapter; 61. base plate; 62. air cavity; 63. positioning angle; 64. airway; 65. air inlet. DETAILED DESCRIPTION

[0038] The present invention will be further described in detail below in conjunction with the accompanying drawings, which are intended to explain the present invention rather than to limit it.

[0039] See also Figure 1-12 A non-contact wafer detection device includes a workbench 1, and a mechanical arm 4, a wafer bin group 3, a flip device 5, an image acquisition device and a light source arranged on the workbench, the movable end of the mechanical arm is connected to a suction cup 6, the image acquisition device is located on the upper part of the flip device 5, the wafer bin group 3 and the flip device 5 are located on the operation path of the mechanical arm, the wafer bin group 3 is used to store wafers 9, the mechanical arm 4, the flip device 5 and the image acquisition device are respectively connected to a controller, the controller is used to control the operation path of the mechanical arm 4 and the flip angle of the flip device 5 to the wafer, and at the same time analyze the collected wafer image to identify the model and status of the wafer.

[0040] See also Figure 7 The wafer bin group 3 includes a fixing frame 33 and a plurality of wafer bins 32 arranged thereon. The plurality of wafer bins are stacked up and down and face the robot arm 2. The upper and lower wafer bins are detachably connected, and the lower wafer bin is detachably connected to the fixing frame to facilitate the rapid disassembly and assembly of the wafer bins. In this embodiment, two wafer bins are placed at a time, and two layers of four wafer bins are set. Figure 7 The wafer bin on the upper right side of the middle is the wafer bin for inspection, which places the wafers to be inspected. The wafer bin on the lower right side is the abnormal wafer bin, which places defective wafers, which can be understood as wafers that are judged to be abnormal after inspection, and the wafers have stains, scratches, defects, etc. The two wafer bins on the left are used for wafers that are judged to be normal after inspection, and wafers of the same model are placed in the same wafer bin.

[0041] Installing the wafer bin in an up-and-down stacking manner can effectively utilize the height space of the workbench, reduce the volume of the entire workbench, and thus reduce the cost of the workbench. It can also be installed in a sequential arrangement manner.

[0042] The first image acquisition device 2 and the flipping device 6 are arranged on the workbench and located on one side of the wafer chamber group 3. The first image acquisition device 2 is used to acquire the image of the wafer on the flipping device.

[0043] See also Fig.11 and 12 The first image acquisition device 2 includes a support frame, a fixed rod 24, a horizontal rod 25 and a camera 23. The lower end of the support frame is connected to the workbench. The fixed rod 24 is vertically arranged on the top of the support frame and can adjust the height. The horizontal rod 25 is connected to the fixed rod through a cross bar. The camera 23 is arranged at the end of the horizontal rod. The horizontal rod can be moved relative to the cross bar to adjust the position of the camera so that it is located directly above the wafer. The image of the wafer is collected by the camera. The camera is an industrial camera, such as a CCD camera. The camera is connected to a controller to transmit the collected image to the controller in real time. A program for wafer defect and model recognition method is preset in the controller, for example, a program for wafer defect detection method, and another example is a visual recognition algorithm based on target detection. The program is used to accurately identify wafer defects and models, and the wafers are classified and stored according to the recognition results of the wafers.

[0044] The wafer defect detection method first performs noise reduction filtering on the image to solve the problem of noise introduced during image acquisition and uneven image grayscale affecting defect recognition, thereby improving detection accuracy. Secondly, the Soble operator is combined with a double threshold segmentation method to segment the defects in the wafer image, and then morphological processing is used to eliminate non-defects in the defects, and then the features of the defects are extracted. Finally, the damage feature parameters are identified using a machine learning method, and at the same time, the information of the wafer is obtained based on the coded image, which greatly improves the detection accuracy and efficiency of the wafer and reduces the detection cost of the wafer.

[0045] The support frame is provided with a lamp frame 21, to which a U-shaped lamp is connected and is located above the wafer. The U-shaped lamp increases the illumination of the wafer area to improve the imaging quality and provide good lighting conditions for wafer detection. An adjustable lighting lamp 22 is also provided on the workbench, and the lamp head is connected to the adjustment frame, and the adjustment frame is fixed on the workbench. For example, the adjustment frame is a bamboo tube, and the position of the lamp head can be adjusted by bending the bamboo tube to increase the brightness of the wafer. When the inspection table is maintained, the maintenance area is illuminated by the position of the lamp head.

[0046] See also Figure 8 , 9 and 10, the flipping device 5 includes a fixing base 51, a servo motor 52, a wafer clamp 53 and a position detection device.

[0047] The lower end of the fixing seat is fixed on the table top of the workbench and is located on one side of the wafer chamber group. The servo motor 52 is installed on the upper end of the fixing seat 51. The wafer clamp 53 is connected to the output shaft of the servo motor through the adapter 57. The wafer clamp 53 is close to one side of the robotic arm, and the suction cup is driven to flip by the servo motor.

[0048] The closed end of the wafer clamp 53 is connected to one end of the adapter, and the other end of the adapter is connected to the servo motor. The open end of the wafer clamp 53 is located on the side close to the robotic arm, and the wafer clamp 53 is located directly below the U-shaped lamp. The camera is suspended above the wafer clamp 53 through a support frame.

[0049] The wafer clamp comprises an upper clamp body and a lower clamp body of a U-shaped structure, the upper clamp body and the lower clamp body have the same structure, a clamping plate 55 extending toward the axial center of the U-shape is formed on two parallel inner walls of the U-shaped clamp body, and the clamping plate is located in the middle of the thickness of the clamp body, the upper clamp body and the lower clamp body are stacked and fixed up and down, and a clamping groove 54 is formed between the clamping plates of the upper clamp body and the lower clamp body, and part of the edge of the wafer is overlapped in the card slot so that the wafer is suspended in the wafer clamp, the servo motor drives the wafer clamp to rotate, the camera obtains images of both sides of the wafer, the controller identifies the model and defects of the wafer, and then classifies and stores them through the robotic arm.

[0050] Two position detection devices are arranged on the fixed seat and located at the upper and lower parts of the adapter seat, and are used to detect whether the flip angle of the wafer is in a horizontal state. The position detection device includes a slot-type photoelectric switch 56 and a detection plate 57. The photoelectric switch is fixed at the front end of the fixed seat and located below the adapter seat. One end of the detection plate is connected to the adapter seat, and the adapter seat drives the detection plate to rotate synchronously. When the detection plate is located in the groove of the photoelectric switch, the servo motor stops rotating. The servo motor detects once every 180° rotation to realize positioning detection on both sides of the wafer.

[0051] See also Figure 4 , 5 and 6, the fixed end of the robotic arm is connected to the workbench, the moving end of the robotic arm is connected to the suction cup, the suction cup is located below the moving end of the robotic arm, and the robotic arm drives the suction cup to move horizontally and up and down.

[0052] The mobile end of the mechanical arm 4 is provided with a cantilever 8, the upper end of the cantilever is connected to the mechanical arm, and the lower end of the cantilever is connected to the suction cup 6. The second image acquisition device 7 is arranged on the cantilever. In the process of the suction cup taking and placing the wafer, the second image acquisition device is facing the wafer bin to collect the real-time image of the current wafer bin. The second image acquisition device is an industrial camera, and its signal end is connected to the controller. The controller determines the number and position of the wafers in the wafer bin according to the collected photos and in combination with the image recognition method. The program of the visual recognition algorithm is preset in the controller. The visual recognition algorithm is based on the edge information detection method. Method, using contour matching algorithm to identify and locate objects in the image, this method searches for edge contours of objects, and matches these contours with known templates to determine the number of wafers. Since the number of wafers is taken and placed in a certain order, once the number of wafers is determined, the position of the space and the position of the wafer can be determined; or image detection method, in this embodiment, a computer vision image analysis method is adopted, the camera captures the real-time picture of the wafer bin, and then analyzes the wafer through computer vision to calculate its position and deviation, and the controller adjusts the corresponding posture of the robotic arm to perform the wafer picking operation.

[0053] The suction cup includes a base 61, an air cavity 62 and a positioning angle 63; the base is a planar structure, and a plurality of air cavities are evenly spaced on the base. The circumferences of the positioning angles are respectively at the edges of the base. The diameter of the circle formed by the positioning angles is the same as the diameter of the wafer. The wafer is located between the plurality of positioning angles to position the wafer during transportation. An air channel 64 is provided in the base, and the air channel is connected to each air cavity 62. The air outlet of the air channel is located at the edge of the base and close to the lower part of the cantilever. In this embodiment, four suction cups are circumferentially distributed on the top surface of the suction cup base and form a convex The ring structure has an air outlet in the air cavity, the inner wall of the air cavity is a conical surface, and the airflow from the air outlet flows tangentially along the inner wall of the air cavity and forms a swirling vortex in the air cavity. The airflow rotates upward along the conical side wall of the air cavity and forms an air film between the base and the top surface of the conical ring. The wafer is suspended on the top of the base through the air film. At the same time, the vortex forms a negative pressure area in the center of the air cavity, which forms an adsorption effect on the wafer, so that the wafer is adsorbed on the top of the suction cup base and forms an air film between the suction cup base, thereby realizing non-contact transfer of the wafer.

[0054] The detection process of the above-mentioned non-contact wafer detection device is described in detail below.

[0055] The controller outputs a detection instruction, and the robotic arm moves to the wafer bin to be inspected. At this time, the cantilever is in a vertical state. The second image acquisition device collects the image currently facing the wafer bin. The controller executes the visual recognition algorithm program to confirm the position and posture of the wafer in the wafer bin, and then adjusts the position of the suction cup to suck the wafer from below.

[0056] The suction cup moves the wafer to the flipping device, inserts the wafer into the clamping groove of the wafer clamp, and the first image acquisition device acquires the image of the first side of the wafer, and then the flipping device drives the wafer to flip 180°, and the first image acquisition device acquires the image of the second side of the wafer. One side of the wafer is provided with the signal information of the wafer, such as digital code, bar code, QR code, etc., and the other side is the working surface of the wafer, and the defects of the working surface are detected. The controller identifies the wafer model and defects according to the preset detection program. According to the recognition result, the robot arm inserts the wafer into the corresponding wafer bin through the suction cup. During the detection, the device realizes the non-contact transfer of the wafer through the suction cup, and the flipping device flips the wafer at the same time, and combines the target visual algorithm to realize the automatic identification and detection of the wafer. Through the above process, the automatic transportation of the wafer during the detection process is realized, avoiding the contact between the staff and the wafer, solving the damage to the wafer during the operation process, and improving the inspection efficiency.

[0057] The above content is only for explaining the technical idea of ​​the utility model and cannot be used to limit the protection scope of the utility model. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the utility model shall fall within the protection scope of the claims of the utility model.

Claims

1. A non-contact wafer detection device, characterized in that: It includes a workbench, and a mechanical arm, a wafer bin group, a turning device and an image acquisition device arranged on the workbench; The movable end of the mechanical arm is connected to the suction cup, the wafer bin group and the turning device are located on the operation path of the mechanical arm, the wafer bin group is used to store wafers, and the mechanical arm, the turning device and the image acquisition device are respectively connected to the controller; The image acquisition device comprises a first image acquisition device and a second image acquisition device; The first image acquisition device is used to acquire images of the wafer on the flipping device, and the second image acquisition device is connected to the robotic arm and is used to acquire images of the wafer bin.

2. A non-contact wafer detection device according to claim 1, characterized in that: The first image acquisition device includes a support frame, a fixing rod, a horizontal rod and a camera; The lower end of the support frame is connected to the workbench, the fixed rod is vertically arranged on the top of the support frame and can adjust the height, the horizontal rod is connected to the fixed rod through a cross bar, the camera is arranged at the end of the horizontal rod, and the horizontal rod can move relative to the cross bar.

3. A non-contact wafer detection device according to claim 2, characterized in that: The camera is arranged on the top of the flipping device, and a light source is arranged between the camera and the flipping device.

4. The non-contact wafer detection device according to claim 3, characterized in that: The light source comprises a lamp frame, a U-shaped lamp is connected to the lamp frame, and the U-shaped lamp is located above the wafer.

5. The non-contact wafer detection device according to claim 1, characterized in that: The mechanical arm is connected to the suction cup through a cantilever, and the second image acquisition device is arranged on the cantilever.

6. The non-contact wafer detection device according to claim 1, characterized in that: The flipping device includes a fixing seat, a servo motor, a wafer clamp and a position detection device; The lower end of the fixing seat is fixed on the workbench, the servo motor is installed on the upper end of the fixing seat, the wafer clamp is connected to the output shaft of the servo motor through the adapter, and the wafer clamp is close to one side of the mechanical arm.

7. The non-contact wafer detection device according to claim 6, characterized in that: The position detection device is a photoelectric switch.

8. The non-contact wafer detection device according to claim 6, characterized in that: The wafer clamp is a U-shaped structure, and its inner wall is provided with a clamping groove for clamping the wafer.

9. The non-contact wafer detection device according to claim 1, characterized in that: The suction cup comprises a base plate, an air cavity and a positioning angle; A plurality of air cavities are distributed on the base plate, and the positioning angle circles are respectively at the edges of the base plate. An air channel is arranged in the base plate, and the air channel is connected with each air cavity, and the air outlet of the air channel is located at the edge of the base plate.

10. The non-contact wafer detection device according to claim 9, characterized in that: An air outlet is provided in the air cavity, and the airflow generated by the air outlet flows along the tangential direction of the air cavity.

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