Image recognition system for bonding position and bonding state

Abstract

The present application relates to a kind of image recognition systems of bonding position and bonding state, with the camera that can photograph the image of the bonding position on chip bonding before substrate, image after chip bonding to substrate, and the bonding mechanism that can be bonded to substrate with chip.The camera is movably connected on the camera track parallel with the walking direction of substrate;The bonding mechanism is movably connected on the bonding mechanism track parallel with the walking direction of substrate, and the bonding head can be on the bonding head track perpendicular to substrate;The extension line of the bonding head track is perpendicular to substrate.The camera of the present application can photograph almost every time one position and one bonded chip, reduces the number of times of camera shooting by about half, improves the identification efficiency by about one time, saves operation time by about half.

Description

Technical Field

[0001] This invention relates to an image recognition technology in the microelectronics industry. Background Technology

[0002] Before a wafer (or chip) is bonded to a substrate, its position on the substrate needs to be detected. The bonding head then places the wafer at its theoretical position on the substrate; this is one process of position detection. After the bonding head completes the bonding operation, the actual position of the wafer on the substrate needs to be detected again. Based on the actual position data, it is determined whether the bonding is qualified; this is another process of position detection.

[0003] Currently, the two testing processes on semiconductor chip bonding equipment are basically performed in the order described above.

[0004] The invention disclosed in application number 2024105211267 by this applicant is an image acquisition mechanism for improving alignment accuracy. From bottom to top, it comprises an IR camera, a transparent substrate, component B, solder or adhesive, component A, and a nozzle or bonding head. A controller is also included; the IR camera has a signal line connected to the controller; the controller controls the movement of the support platform via a control line. While this invention can acquire clear images of both components, the testing efficiency still needs improvement.

[0005] The invention with application number 2023112597169 provides a method, system, and wafer bonding inspection device for calibrating the position of multiple cameras. The method includes the following steps: acquiring multiple edge images of the same wafer using multiple cameras; determining multiple sets of edge information for the wafer based on each edge image, wherein the edge information includes the first coordinates of at least one edge point in each edge image; and determining the feature distance between the theoretical center of the wafer and each edge point based on the second coordinates of the theoretical center of the wafer and the first coordinates of each edge point. This invention, using multiple cameras, has high equipment costs and requires a large amount of image processing. Summary of the Invention

[0006] Purpose of the invention:

[0007] An image recognition system for bonding position and bonding state is proposed to improve equipment efficiency while maintaining accuracy.

[0008] Technical solution:

[0009] This system is based on detecting the chip state before and after bonding. It has a camera capable of capturing and identifying images of the chip's position on the substrate before bonding and the chip's position on the substrate after bonding, as well as a bonding mechanism (including a bonding head, such as a nozzle) capable of bonding the chip to the substrate. The camera is movably connected to a camera track (track ①) parallel to the substrate's travel direction; the bonding mechanism is movably connected to a bonding mechanism track (track ②) parallel to the substrate's travel direction, and the bonding head can move up and down on a bonding head track (track ③) perpendicular to the substrate; the camera track is above the substrate, above the lower end of the bonding track; the bonding head track is above the substrate, and its extension line is perpendicular to the substrate.

[0010] In this system, the chip bonding positions are arranged in ascending order: position A, position B, position C, position D, position E...; and the chip bonding process is arranged in ascending order: chip A, chip B, chip C, chip D, chip E...

[0011] In addition to photographing the first position and the first chip, or the last position and the last chip, the camera can photograph an adjacent position and a bonded chip at a time.

[0012] The system employs a recognition process involving the following sequence of images and bonding:

[0013] (1) The camera first takes a picture of position A (the first adjacent picture), and then the bonding mechanism bonds chip A at position A;

[0014] (2) At the moment the bonding mechanism is removed, the camera takes a picture of the bonded chip A and simultaneously takes a picture of position B (the second adjacent picture).

[0015] (3) The bonding mechanism bonds chip B at position B;

[0016] (4) At the moment the bonding mechanism is removed again, the camera takes a picture of the bonded chip B and simultaneously takes a picture of position C;

[0017] (5) Continue the bonding and shooting process according to the above rules until the last chip is photographed at the moment of bonding and removal at the last position.

[0018] The bonding mechanism can move left and right on the bonding mechanism track, moving from above position A to above the position of the last chip. The bonding head can move up and down on the bonding head track, releasing the carried chip and bonding it to the various bonding positions on the substrate.

[0019] In this invention, the camera takes pictures when the bonding mechanism leaves its position above the bonding mechanism; the camera takes pictures of the bonded chip at the instant the bonding mechanism leaves the chip (e.g., an interval of 0.5-0.01 seconds).

[0020] That is, the camera moves along track ①. The bonding mechanism moves along track ②. The bonding head moves up and down along track ③ in the Z direction. The camera's imaging range ensures that it can illuminate two adjacent areas of the substrate (A and B in Figure 1). The image of the substrate seen by the camera is an image seen from above the substrate. One function of the camera is to identify the bonding position before the bonding head bonds the wafer (or chip) onto the substrate. Another function of the camera is to detect and confirm the bonding status of the wafer (or chip) after bonding.

[0021] Preferably, at the instant the bonding mechanism moves away (e.g., to the right), the bonding head moves upward on track ③ in a basically synchronous manner (the bonding head rises slightly earlier than the bonding mechanism moves away to avoid affecting the bonded chip). Then, the bonding mechanism moves backward on track ② to the next station (e.g., to pick up a chip). Immediately after the bonding mechanism moves away, the camera simultaneously captures images of adjacent chips and their positions from above, avoiding light obstruction by the bonding mechanism and obtaining higher quality photos and more comprehensive information.

[0022] Further optimization involves the bonding head picking up the chip, and while the bonding mechanism returns (e.g., moves left) on track ②, the bonding head performs a basically synchronous downward movement on track ③. The time period for the bonding mechanism to move left on track ② is slightly shorter than the time period for the bonding head to move downward. That is, after the bonding mechanism has moved into place, the bonding head moves down to the lowest position to bond the chip, thus keeping the position of the bonding mechanism stable when bonding the chip.

[0023] Beneficial effects:

[0024] This application simultaneously detects the theoretical positions on the substrate to be bonded and the actual positions of the bonded wafers. Furthermore, while the bonding head is performing the bonding operation, the camera moves to the next position, thereby improving the bonding efficiency.

[0025] This application can clearly capture images of the chip location and the chip itself. The acquired image information can be compared with standard images to determine whether the location is correct and whether the chip bonding has defects.

[0026] This application can simultaneously capture images of adjacent locations and chips, reducing the number of camera shots by about half, improving recognition efficiency by about 100%, and saving about half of the operation time.

[0027] The second shot is taken at the instant the bonding mechanism moves away, ensuring that both adjacent positions are captured without taking up too much extra time. Simultaneously, the up-and-down movement of the bonding head coincides with the left-and-right movement of the bonding mechanism, allowing the two movements to occur synchronously, saving waiting time and further improving bonding efficiency (saving more than half of the operation time). Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure and process of a traditional identification system;

[0029] Figure 2 This is a schematic diagram of the structure and process of the identification system of this application;

[0030] Figure 3 This is a partial structural diagram of the identification system of this application.

[0031] In the diagram, 1-camera; 2-track ①; 3-track ②; bonding mechanism (4-track ③; 5-bonding head); 6-chip A; 7-chip B; 8-chip C; 9-position A; 10-position B; 11-position C; 12-position D. Detailed Implementation

[0032] Example 1:

[0033] like Figure 1 The diagram shows a structure and process of a traditional identification system.

[0034] Figure 1 Before bonding at position A[9], camera 1 takes a picture first;

[0035] Next, chip 6 is bonded at position A [9]. In order to confirm the bonded state, camera 1 must stand by above the bonding point (chip A [6]) and wait for the bonding mechanism to move away.

[0036] After confirming the bonding status at point A [9], camera 1 moves to the next bonding point (position B

[10] ). Upon reaching bonding position B

[10] , to ensure bonding accuracy, the substrate identification is performed only after the vibration of camera 1 has subsided. For this reason, in terms of equipment efficiency, the movement of camera 1 between bonding points (from position A [9] to position B

[10] ) and the vibration reduction time before substrate identification will generate unnecessary additional time.

[0037] Then, chip 7 is bonded at position B

[10] . In order to confirm the bonded state, camera 1 must stand by above the bonding point (chip B [7]) and wait for the bonding mechanism to move away.

[0038] Example 2:

[0039] like Figure 2 The diagram shown illustrates the structure and process of the identification system of this application.

[0040] After the camera 1 takes a picture and identifies the substrate at the bonding point A [9], the chip 6 is then bonded at point A [9].

[0041] The bonding mechanism retreats from point A[9] without stopping and immediately moves to the next bonding point (position B

[10] ).

[0042] As the bonding mechanism moves to the right on track ② [3], the bonding head [5] moves upward on track ③ [4].

[0043] When the substrate at position B

[10] can be identified, within the field of view of the same camera 1, the camera 1 can simultaneously identify and confirm the respective states of the bonded chip A[6] and position B

[10] .

[0044] Then, chip B7 is bonded at position B

[10] ; after the bonding mechanism is removed, the field of view of camera 1 is above position B

[10] and position C

[11] , and chip B[7] and position C

[11] are photographed simultaneously.

[0045] Similarly, camera 1 takes pictures simultaneously between the preceding chip 6, 7 or 8 and the adjacent subsequent bonding positions, and the recognition time is about half that of the traditional method; the vibration reduction time before movement and recognition can also be reduced; furthermore, the movement of track ② [3] and track ③ [4] can be basically within the same time period, which can reduce more unnecessary waiting and delay time, thereby increasing the bonding production efficiency by more than double.

Claims

1. An image recognition system for bonding position and bonding state, comprising a camera (1) capable of capturing images of the chip position before bonding and images of the chip after bonding to a substrate, and a bonding mechanism capable of bonding the chip to the substrate, the bonding mechanism comprising a bonding head; the camera (1) is movably connected to a camera track parallel to the substrate travel direction, the bonding mechanism is movably connected to a bonding mechanism track parallel to the substrate travel direction, and the bonding head (5) is capable of moving up and down on a bonding head track perpendicular to the substrate; Its features are: In addition to capturing images of the first chip and the first position, or the last chip and the last position, the camera (1) can simultaneously capture an image of a chip that has been bonded first and an image of the position of the next adjacent chip to be bonded. The camera (1) takes the image of the bonded chip immediately after the bonding mechanism leaves the chip; the camera (1) takes the position image 0.5-0.01 seconds after the bonding mechanism leaves the position. At the instant the bonding mechanism leaves the top of the chip, the bonding head (5) moves upward in a basically synchronous manner on the bonding head track; however, the time point when the bonding head (5) rises is slightly earlier than the time point when the bonding mechanism moves away. After the bonding head (5) picks up the chip, the bonding mechanism returns on the bonding track while the bonding head (5) performs a basically synchronous downward movement on the bonding head track; however, the time period for the bonding mechanism to return is slightly shorter than the time period for the bonding head (5) to descend. After the bonding mechanism moves into place, the bonding head descends to the lowest position to bond the chip.

2. A process for identifying and bonding chips, comprising, according to the order of chip bonding positions, positions A, B, C, and the last position arranged in ascending order of their serial numbers; and chips A, B, C, and the last chip arranged in ascending order of their serial numbers, according to the order of the chip bonding process; characterized in that: The image recognition system for bonding position and bonding state as described in claim 1 has the following sequential process of image capture and bonding recognition: (1) The camera first takes a picture of position A, and then the bonding mechanism bonds chip A at position A; (2) At the moment the bonding mechanism is removed, the camera takes a picture of the bonded chip A and simultaneously takes a picture of position B; (3) The bonding mechanism bonds chip B at position B; (4) At the moment the bonding mechanism is removed again, the camera takes a picture of the bonded chip B and simultaneously takes a picture of position C; (5) Continue the bonding and shooting process according to the above rules until the last chip is photographed at the moment of bonding and removal at the last position.

Images