Automatic coupling method and device of photoelectric detector wafer

Abstract

The invention discloses an automatic coupling method and device for a photoelectric detector wafer, and the method comprises the steps: employing a visual recognition technology to achieve the coarse positioning of the coupling of a to-be-detected wafer chip, taking an optical power count value collected in real time as a search signal, carrying out the real-time analysis of the signal through combining with a breadth-first search algorithm, and carrying out the detection of the signal. Path planning is carried out on a three-dimensional space to determine a search path, precise control of a motion path is carried out on the three-axis precision platform through a software control system, finally, optical power value signals under each path position are traversed to find out a maximum value signal, the maximum value signal is moved to the position, and the maximum value signal is the optimal coupling position. Therefore, automatic coupling of wafers in a limited space is realized. The wafer coupling device has the beneficial effects that the automation degree of wafer coupling can be improved, the manual operation cost and the time cost are reduced, meanwhile, the precision and the stability of wafer coupling are improved, and adverse effects caused by manual operation errors are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of wafer coupling devices, and in particular relates to an automatic coupling method and a device for a photoelectric detector wafer. Background Art

[0002] Photodetector wafer is a special type of wafer, which is designed and manufactured for the manufacture of photodetectors. Photodetectors are semiconductor devices that can convert incident light signals into electrical signals. Photodetector wafers are usually made of high-quality silicon or other semiconductor materials that have good photoelectric conversion performance and stability.

[0003] The core function of a photodetector wafer is to convert optical signals into electrical signals. However, in practical applications, optical signals are often transmitted through optical fibers because optical fibers have the advantages of fast transmission speed, large bandwidth, and low loss. Therefore, in order to effectively convert the optical signals transmitted in the optical fiber into electrical signals, the photodetector wafer needs to be coupled with the optical fiber. Traditional photodetector wafer coupling methods usually require manual operation, and manual operation often requires the help of visual aids to find suitable coupling areas on the photodetector wafer. This method has low alignment accuracy and low production efficiency. It is also easy to cause wafer damage, affecting product quality and consistency. Summary of the invention

[0004] In order to solve the above problems, the present invention provides an automatic coupling method for a photodetector wafer, comprising the following steps: S1. Wafer fixing: placing the photodetector wafer on the surface of the carrier device and fixing the photodetector wafer; S2, chip positioning, using visual recognition technology to identify and locate the chip to be tested on the photodetector wafer, and move the identified and located chip to the position directly below the optical fiber coupling device to complete the initial positioning; S3, optical power data acquisition, obtaining the real-time optical power data value of the chip directly below through the optical power test device and optical fiber; S4, determining the coupling position, searching for the maximum optical power on the chip, and determining the area with the maximum optical power as the best alignment coupling area; S5. Complete the coupling, drive the optical fiber to move to the best alignment coupling area to complete the coupling.

[0005] Preferably, the method for searching the area of ​​maximum optical power on the chip in step S4 is to plan the path of maximum optical power for position points in a limited three-dimensional space according to the real-time optical power value data and the breadth-first search algorithm, drive the optical fiber to move along the planned path, and traverse the optical power values ​​at each path position to find the maximum optical power.

[0006] Preferably, when the optical fiber moves along the planned corresponding path in step S4, if the corresponding path is beyond the limited range, the maximum optical power value is determined as the maximum optical power value based on the maximum optical power value signal found under the traversed path; otherwise, step S3 is re-executed.

[0007] Preferably, after the photodetector wafer is fixed in step S1, the photodetector wafer needs to be leveled.

[0008] Preferably, in step S4, if it is detected that the optical power value fluctuates beyond a preset threshold value when the optical fiber moves along the planned path, the optical fiber position is automatically fine-tuned and step S3 is re-executed until the optical power value stabilizes.

[0009] An automatic coupling device for a photoelectric detector wafer comprises a carrier platform, a three-axis precision translation stage, a fiber coupling device, a visual observation device and an optical power testing device, wherein the three-axis precision translation stage and the visual observation device are arranged on the upper side of the carrier platform, the three-axis precision translation stage is connected to the fiber coupling device and the fiber coupling device extends above the carrier platform, the end of the fiber coupling device clamps an optical fiber, and the optical fiber is connected to the optical power testing device.

[0010] Preferably, the support platform device includes a wafer support platform, a Z-axis lifting motion travel mechanism and a T-axis rotation motion travel mechanism, the Z-axis lifting motion travel mechanism drives the wafer support platform to lift and lower, and the T-axis rotation motion travel mechanism drives the wafer support platform to rotate.

[0011] Preferably, the three-axis precision translation stage includes a first X-axis motion adjustment stroke mechanism, a first Y-axis motion adjustment stroke mechanism and a first Z-axis motion adjustment stroke mechanism, the top of the first X-axis motion adjustment stroke mechanism is connected to the first Y-axis motion adjustment stroke mechanism and drives the first Y-axis motion adjustment stroke mechanism to move along the X-axis direction, the first Y-axis motion adjustment stroke mechanism is connected to the first Z-axis motion adjustment stroke mechanism and drives the first Z-axis motion adjustment stroke mechanism to move along the Y-axis direction, and the first Z-axis motion adjustment stroke mechanism is connected to the optical fiber coupling device and drives the optical fiber coupling device to move along the Z-axis direction.

[0012] Preferably, the visual observation device includes a second X-axis motion adjustment stroke mechanism, a second Z-axis motion adjustment stroke mechanism, a visual lens and a visual camera, the second X-axis motion adjustment stroke mechanism is connected to the second Z-axis motion adjustment stroke mechanism and drives the second Z-axis motion adjustment stroke mechanism to move along the X-axis direction, the second Z-axis motion adjustment stroke mechanism is connected to the visual lens and drives the visual lens to move along the Z-axis direction, and the visual lens is connected to the visual camera above.

[0013] Preferably, an adjustment arm is connected to a side of the optical fiber coupling device, a microscope is connected to the adjustment arm, and the microscope is aligned with the optical fiber.

[0014] The advantages of the present invention are: 1. The present invention significantly improves the efficiency and accuracy of coupling through an automated process, including visual recognition, real-time optical power monitoring and breadth-first search algorithm. Compared with traditional manual or semi-automatic methods, this method can find the optimal coupling position more quickly, reducing manual intervention and trial and error.

[0015] 2. The present invention can ensure high accuracy of the coupling process by using a high-precision three-axis programmable precision translation stage, combined with real-time optical power monitoring and accurate path planning. This helps to improve the performance of the photodetector and reduce performance loss caused by coupling errors.

[0016] 3. The present invention reduces the error caused by human factors through the automated process, so that each coupling operation can maintain a high degree of consistency and stability. This is crucial for mass production and quality control, and can significantly improve production efficiency.

[0017] The photoelectric detector wafer automatic coupling method and device of the present invention have significant advantages in improving coupling efficiency, accuracy, degree of automation and reducing production costs, and can realize the intelligent and efficient development of photoelectric detector manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the process of the present invention.

[0019] Figure 2 It is the overall structure diagram of the device of the present invention.

[0020] Figure 3 It is a structural diagram of the support platform device of the present invention.

[0021] Figure 4 This is a diagram of the three-axis precision translation stage and coupling device of the present invention.

[0022] Figure 5 It is a structural diagram of the visual observation device of the present invention.

[0023] In the figure: 1 wafer stage, 2 Z-axis lifting motion travel mechanism, 3 T-axis rotation motion travel mechanism, 4 first X-axis motion adjustment travel mechanism, 5 first Y-axis motion adjustment travel mechanism, 6 first Z-axis motion adjustment travel mechanism, 7 second X-axis motion adjustment travel mechanism, 8 second Z-axis motion adjustment travel mechanism, 9 visual lens, 10 visual camera, 11 adjustment arm, 12 microscope, 13 coupling seat, 14 workbench, 15 optical fiber. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Example 1

[0025] Combination Figure 1 , an automatic coupling method for a photodetector wafer, comprising the following steps: S1. Fix the wafer. Place the photodetector wafer on the surface of the carrier device. The carrier device consists of a wafer carrier 1, a Z-axis lifting motion travel mechanism 2 and a T-axis rotation motion travel mechanism 3. The photodetector wafer is placed on the wafer carrier 1. A number of negative pressure holes are provided on the wafer carrier to adsorb and fix the photodetector wafer.

[0026] Afterwards, visual recognition technology is used to make visual recognition templates for all chips on the photodetector wafer. Making visual recognition templates refers to using a visual camera 10 or other types of image sensors to take high-definition photos of the wafer, obtain chip images on the wafer, select a clear, complete, and representative chip image as the initial template, optimize and segment it through image processing technology, remove invalid background and noise, and obtain the final recognition template. Afterwards, the wafer is subjected to sweeping processing. Sweeping processing refers to using visual recognition technology such as a charge coupled device sensor, a visual camera 10, etc. to capture the alignment marks on the surface of the wafer. There are appropriate alignment marks such as crosshairs, notches, etc. on the edge or surface of the wafer. These marks will serve as reference points for alignment, and the position and posture of the wafer are detected in real time, and the information is transmitted to the control system. According to the information provided by the visual recognition system, the control system will calculate the deviation between the current position of the wafer and the target position, i.e., the horizontal line. Then, the control system will issue an instruction to change the position of the wafer by rotating the angle of the wafer stage 1 to eliminate this deviation, so as to ensure that the accuracy and stability of the wafer meet the requirements of the subsequent coupling process. The control system in this embodiment includes an industrial control computer and a motion control card to accurately control the movement of the corresponding equipment.

[0027] S2, chip positioning, using visual recognition technology to identify and locate the chip to be tested on the photodetector wafer, and then using visual cameras 10 and other devices to collect images of the wafer, obtain high-quality images, extract the characteristic information of the chip in the image, such as shape, size, edge, etc., compare the extracted characteristic information with the data in the database, identify the chip to be tested on the wafer, and calculate the precise coordinates of the chip on the wafer. The chip after identification and positioning is moved to the position directly below the fiber coupling device. The chip after identification and positioning can be moved to the position directly below the fiber coupling device by moving the wafer stage 1 or directly moving the fiber coupling device. The control system uses the chip coordinates to plan the path and control the wafer stage 1 or the fiber coupling device to move accurately. During the displacement movement, the position change of the chip or the fiber coupling device is monitored in real time by the visual camera 10, and the real-time data is fed back to the control system. The control system adjusts and optimizes according to the feedback information to ensure that the chip can be accurately moved to the position directly below the fiber coupling. When the chip is moved to the position directly below the fiber coupling, the initial position alignment is completed.

[0028] S3, optical power data acquisition, through the optical power test device and optical fiber to obtain the real-time optical power data value of the chip directly below; the optical power test device is an optical power meter, which is connected to the optical fiber through the optical fiber interface to collect the optical power data transmitted in the optical fiber in real time. When the chip emits an optical signal and transmits it to the optical fiber interface of the optical power meter through the optical fiber, the photodetector inside the optical power meter will capture the optical signal and convert it into an electrical signal. Subsequently, the electrical signal is amplified, filtered, and converted into a digital signal by the analog-to-digital converter for analysis and processing by the control system.

[0029] S4. Determine the coupling position, search for the maximum optical power on the chip, and determine the area with the maximum optical power as the best alignment coupling area. The coupling area refers to the area where the optical signal between the optical fiber and the chip can be efficiently transmitted, and the best alignment coupling area refers to the area in which the relative position between the optical fiber and the chip is optimal, so that the optical power reaches the maximum. By moving the optical fiber at different positions to measure the optical power emitted by the chip, it is determined which position receives the maximum optical power.

[0030] The specific method is to plan the maximum optical power path for the limited three-dimensional space position points according to the breadth-first search algorithm based on the real-time optical power value data, and use the breadth-first search algorithm to plan multiple paths so as to systematically traverse each position point in the limited three-dimensional space above the chip. The breadth-first search is a graph traversal algorithm. It starts from the starting point, first visits the neighboring points around the starting point, and then expands outward layer by layer until the target point is found or all reachable points are traversed. The ultimate goal of the algorithm is to measure the maximum optical power value. The real-time optical power value data is used as the input of the algorithm to guide the search process. The optical fiber is driven to move along the planned path and traverse each path. After completing the search of a path, it is determined whether all paths have been traversed. If so, the optical fiber is driven to move to the maximum optical power area. If not, the optical fiber is driven along the initial point of the next path to prepare for continued search. When preparing to search, it is necessary to determine whether the next path exceeds the set range. If not, step S3 is re-executed and the search is re-performed until all path searches are completed and the maximum optical power area is determined. If the next path exceeds the set range, the maximum optical power area is directly determined based on the path that has been traversed. This is because once the path exceeds the set range, it indicates that the chip to be tested may be damaged, and the chip needs to be checked as soon as possible after the search is completed. After determining the best coupling area based on the maximum optical power, continue to search for the best coupling area for the next chip until the search for the best coupling area of ​​all chips is completed. Finally, step S5 is completed, the coupling is completed, and the optical fiber is driven to move to the best alignment coupling area to complete the coupling.

[0031] The entire coupling process is highly automated, from wafer fixation, positioning, optical power data collection to determination of coupling position, all of which are achieved through control systems and visual recognition technology, reducing manual intervention and improving the accuracy and stability of wafer coupling. The breadth-first search algorithm is used to plan the maximum optical power path, systematically traverse the limited three-dimensional space, and find the optimal coupling area. This intelligent search algorithm can quickly and accurately determine the optimal coupling position, improve the efficiency and accuracy of coupling, and significantly improve the production efficiency and product quality of photodetectors. Example 2

[0032] Combination Figure 2-5The present embodiment discloses an automatic coupling device for a photodetector wafer, which is used to implement the above-mentioned coupling method, including a carrier device, a three-axis precision translation stage, a fiber coupling device, a visual observation device and an optical power testing device. The carrier device is installed on the inner middle side of the corresponding work frame 14, and an opening structure is provided above the corresponding work frame 14. The three-axis precision translation stage and the visual observation device are arranged on the upper surface of the work frame 14 and are located on the upper side of the carrier device. The three-axis precision translation stage is connected to the fiber coupling device and the fiber coupling device extends to the top of the carrier device. The end of the fiber coupling device clamps the optical fiber 15, and the optical fiber 15 is connected to the optical power testing device.

[0033] The carrier device includes a wafer table 1, a Z-axis lifting motion stroke mechanism 2 and a T-axis rotation motion stroke mechanism 3. The Z-axis lifting motion stroke mechanism 2 drives the wafer table 1 to lift and lower, and the T-axis rotation motion stroke mechanism 3 drives the wafer table 1 to rotate. The specific structure of the carrier device is a well-known technology in the art, as described in the specification of patent number 2020220400826, and this embodiment will not be repeated. The wafer table 1 is used to place and fix the wafer. The surface of the wafer table 1 is provided with a negative pressure hole, which can adsorb the wafer. The bottom of the carrier device is provided with an X-axis motion adjustment stroke mechanism and a Y-axis motion adjustment stroke mechanism to drive the wafer to move. It is used to move the chip after identification and positioning to the position directly below the optical fiber coupling device. The T-axis rotation motion stroke mechanism 3 drives the wafer table 1 to rotate to achieve the wafer leveling operation.

[0034] The three-axis precision translation stage includes a first X-axis motion adjustment travel mechanism 4, a first Y-axis motion adjustment travel mechanism 5 and a first Z-axis motion adjustment travel mechanism 6. The top of the first X-axis motion adjustment travel mechanism 4 is connected to the first Y-axis motion adjustment travel mechanism 5 and drives the first Y-axis motion adjustment travel mechanism 5 to move along the X-axis direction. The first Y-axis motion adjustment travel mechanism 5 is connected to the first Z-axis motion adjustment travel mechanism 6 and drives the first Z-axis motion adjustment travel mechanism 6 to move along the Y-axis direction. The first Z-axis motion adjustment travel mechanism 6 is connected to the optical fiber coupling device and drives the optical fiber coupling device to move along the Z-axis direction. The three-axis precision translation stage is used to adjust the position of the optical fiber and drive the optical fiber to move along the path of the planned number.

[0035] The visual observation device includes a second X-axis motion adjustment stroke mechanism 7, a second Z-axis motion adjustment stroke mechanism 8, a visual lens 9 and a visual camera 10. The second X-axis motion adjustment stroke mechanism 7 is connected to the second Z-axis motion adjustment stroke mechanism 8 and drives the second Z-axis motion adjustment stroke mechanism 8 to move along the X-axis direction. The second Z-axis motion adjustment stroke mechanism 8 is connected to the visual lens 9 and drives the visual lens 9 to move along the Z-axis direction. The top of the visual lens 9 is connected to the visual camera 10. The visual observation device is used to identify and locate the chip and perform auxiliary work.

[0036] The X-axis motion adjustment stroke mechanism, the Y-axis motion adjustment stroke mechanism and the Z-axis motion adjustment stroke mechanism in the present embodiment are all well-known technologies in the art. Each motion adjustment stroke mechanism is composed of a motor, a lead screw, a guide rail and a slide, or can also be directly composed of a motor, a guide rail and a slide. When the control system receives a motion command, it will control the motor on the corresponding stroke mechanism to start and rotate. The rotational motion of the motor is decelerated and transmitted to the lead screw, and the rotational motion of the lead screw is converted into the linear motion of the slide, thereby realizing the displacement in the X-axis, Y-axis and Z-axis directions. At the same time, the sensor detects the actual position of the movement in real time and feeds back the position information to the controller. The controller adjusts the movement of the motor in real time according to the feedback information and the instruction requirements to ensure the accuracy and stability of the movement.

[0037] The optical fiber coupling device includes a coupling seat 13, one end of which is connected to the first Z-axis motion adjustment stroke mechanism 6, and the other end is provided with a clamping device and clamps the optical fiber. One end of the optical fiber is connected to an optical power test device, that is, an optical power meter. The side of the optical fiber coupling device is connected to an adjustment arm 11, and a microscope 12 is connected to the adjustment arm 11. The microscope 12 is aligned with the optical fiber and is used to observe the distance between the optical fiber and the wafer. The real-time observation function of the microscope 12 enables the operator to grasp the relative position between the optical fiber and the wafer at any time, so as to facilitate timely discovery and correction of any deviations. The adjustment arm 11 can rotate to adjust the position of the fiberscope for convenient observation.

[0038] The entire device of this embodiment is highly automated. Through the control system and visual recognition technology, it can automatically complete the wafer fixation, positioning, optical power data collection and coupling position determination. The intelligent search algorithm is used to plan the optical power maximum value path, making the coupling process more intelligent and efficient. The highly automated coupling process significantly shortens the coupling time and improves production efficiency. At the same time, it reduces manual intervention, reduces the possibility of human error, and further improves the product yield and performance.

[0039] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for automatic coupling of a photodetector wafer, characterized in that: The steps include: S1. Wafer fixing: placing the photodetector wafer on the surface of the carrier device and fixing the photodetector wafer; S2, chip positioning, using visual recognition technology to identify and locate the chip to be tested on the photodetector wafer, and move the identified and located chip to the position directly below the optical fiber coupling device to complete the initial positioning; S3, optical power data acquisition, obtaining the real-time optical power data value of the chip directly below through the optical power test device and optical fiber; S4, determining the coupling position, searching for the maximum optical power area on the chip, and determining that the maximum optical power area is the best alignment coupling area; S5. Complete the coupling, drive the optical fiber to move to the best alignment coupling area to complete the coupling.

2. The automatic coupling method of a photodetector wafer according to claim 1, characterized in that: The method for searching the maximum optical power area on the chip in step S4 is to plan the optical power maximum path for the limited three-dimensional space position points according to the real-time optical power value data according to the breadth-first search algorithm, drive the optical fiber to move along the planned path, and traverse the optical power values ​​at each path position to find the maximum optical power.

3. The automatic coupling method of a photodetector wafer according to claim 2, characterized in that: In step S4, when the optical fiber moves along the planned corresponding path, if the corresponding path is beyond the limited range, the maximum optical power value signal found under the traversed path is determined as the maximum optical power value; otherwise, step S3 is re-executed.

4. The automatic coupling method of a photodetector wafer according to claim 3, characterized in that: After the photoelectric detector wafer is fixed in step S1, the photoelectric detector wafer needs to be leveled.

5. The automatic coupling method of a photodetector wafer according to claim 4, characterized in that: In step S4, if the optical power value fluctuation is detected to exceed a preset threshold value when the optical fiber moves along the planned path, the optical fiber position is automatically fine-tuned and step S3 is re-executed until the optical power value stabilizes.

6. An automatic coupling device for a photodetector wafer, characterized in that: The invention comprises a carrier platform device, a three-axis precision translation platform, an optical fiber coupling device, a visual observation device and an optical power test device, wherein the three-axis precision translation platform and the visual observation device are arranged on the upper side of the carrier platform device, the three-axis precision translation platform is connected to the optical fiber coupling device and the optical fiber coupling device extends above the carrier platform device, the end of the optical fiber coupling device clamps an optical fiber (15), and the optical fiber (15) is connected to the optical power test device.

7. The automatic coupling device for photodetector wafer according to claim 6, characterized in that: The carrier platform device comprises a wafer carrier (1), a Z-axis lifting motion travel mechanism (2) and a T-axis rotation motion travel mechanism (3); the Z-axis lifting motion travel mechanism (2) drives the wafer carrier (1) to lift and lower, and the T-axis rotation motion travel mechanism (3) drives the wafer carrier (1) to rotate.

8. The automatic coupling device for photodetector wafer according to claim 7, characterized in that: The three-axis precision translation stage comprises a first X-axis motion adjustment stroke mechanism (4), a first Y-axis motion adjustment stroke mechanism (5) and a first Z-axis motion adjustment stroke mechanism (6); the upper portion of the first X-axis motion adjustment stroke mechanism (4) is connected to the first Y-axis motion adjustment stroke mechanism (5) and drives the first Y-axis motion adjustment stroke mechanism (5) to move along the X-axis direction; the first Y-axis motion adjustment stroke mechanism (5) is connected to the first Z-axis motion adjustment stroke mechanism (6) and drives the first Z-axis motion adjustment stroke mechanism (6) to move along the Y-axis direction; and the first Z-axis motion adjustment stroke mechanism (6) is connected to the optical fiber coupling device and drives the optical fiber coupling device to move along the Z-axis direction.

9. The automatic coupling device for photodetector wafer according to claim 8, characterized in that: The visual observation device comprises a second X-axis motion adjustment stroke mechanism (7), a second Z-axis motion adjustment stroke mechanism (8), a visual lens (9) and a visual camera (10); the second X-axis motion adjustment stroke mechanism (7) is connected to the second Z-axis motion adjustment stroke mechanism (8) and drives the second Z-axis motion adjustment stroke mechanism (8) to move along the X-axis direction; the second Z-axis motion adjustment stroke mechanism (8) is connected to the visual lens (9) and drives the visual lens (9) to move along the Z-axis direction; and the visual lens (9) is connected to the visual camera (10) above.

10. The automatic coupling device for photodetector wafer according to claim 9, characterized in that: An adjustment arm (11) is connected to the side of the optical fiber coupling device, a microscope (12) is connected to the adjustment arm (11), and the microscope (12) is aligned with the optical fiber.

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