Image recognition system for bonding position and bonding state

Abstract

The invention relates to an image recognition system for a bonding position and a bonding state. The image recognition system is provided with a camera and a bonding mechanism, wherein the camera can shoot an image of a position to be bonded on a substrate before a chip is bonded and an image after the chip is bonded on the substrate, and the bonding mechanism can bond the chip on the substrate. The camera is movably connected to a camera track parallel to the walking direction of the base plate; the bonding mechanism is movably connected to a bonding mechanism track parallel to the walking direction of the substrate, and the bonding head can be arranged on a bonding head track perpendicular to the substrate; the extension line of the bonding head track is perpendicular to the substrate. According to the invention, the camera can shoot one adjacent position and one bonded chip almost every time, so that the shooting frequency of the camera is reduced by about half, the identification efficiency is improved by about one time, and the operation time is saved by about half.

Description

Technical Field

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

[0002] Before the wafer (or chip) on the wafer is mounted (bonded) on the substrate, the position of the wafer on the substrate needs to be detected, and then the bonding head will mount the wafer at the theoretical position on the substrate. This is a process of position detection. After the bonding head completes the bonding work, it is necessary to detect the actual position of the wafer on the substrate again, and judge whether the mounting is qualified based on the actual position data. This is another process of position detection.

[0003] At present, the two detection processes on semiconductor chip bonding equipment are basically carried out in the above-mentioned order.

[0004] The invention with application number 2024105211267 filed by the applicant discloses an image acquisition mechanism for improving the centering accuracy, which comprises, from bottom to top, an IR camera, a transparent substrate, a component B, solder or adhesive, a component A, a nozzle or a bonding head. There is also a controller, and the IR camera has a signal line connected to the controller; the controller controls the movement of the carrying platform through the control line connection. Although the invention can obtain clear images of the two components, the test efficiency needs to be improved.

[0005] The invention with application number 2023112597169 provides a multi-camera position calibration method, system and wafer bonding detection equipment. The multi-camera position calibration method includes the following steps: using multiple cameras to collect multiple edge images of the same wafer; according to each edge image, respectively determine multiple sets of edge information of the wafer, wherein the edge information includes the first coordinate of at least one edge point in each edge image; according to the second coordinate of the center of the theoretical circle of the wafer, and the first coordinate of each edge point, respectively determine the characteristic distance between the center of the theoretical circle and each edge point. The invention uses multiple cameras, which has a high equipment cost and a large amount of image processing. Summary of the invention

[0006] Purpose of the invention: An image recognition system for bonding positions and bonding states is provided that can improve equipment operating efficiency while maintaining accuracy.

[0007] Technical solution: This system is based on the premise of detecting the chip status before and after bonding. It has a camera that can capture and identify the image of the position to be bonded on the substrate before chip bonding, the image of the chip after bonding to the position on the substrate, and a bonding mechanism (including a bonding head, such as a nozzle) that can bond the chip to the substrate. The camera is movably connected to a camera track (track ①) parallel to the direction of movement of the substrate; the bonding mechanism is movably connected to a bonding mechanism track (track ②) parallel to the direction of movement of the substrate, 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, higher than the lower end of the bonding track; the bonding head track is above the substrate, and its extension line is perpendicular to the substrate.

[0008] In this system, according to the sequence of chip bonding positions, there are positions A, position B, position C, position D, position E... with increasing sequence numbers; according to the sequence of the chip bonding process, there are chips A, chip B, chip C, chip D, chip E... with increasing sequence numbers.

[0009] In addition to photographing the first position and the first chip, or the last position and the last chip, the camera can photograph one adjacent position and one bonded chip at a time.

[0010] The system uses the following sequence of photographing and bonding recognition processes: (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; (2) When 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). (3) The bonding mechanism bonds chip B at position B; (4) When the bonding mechanism is moved away again, the camera takes a picture of the bonded chip B and position C at the same time; (5) Continue the bonding and photographing process according to the above rules until the last chip is photographed at the moment of bonding and removal at the last position.

[0011] The bonding mechanism can move left and right on the bonding mechanism track, 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 to release the carried chip and bond it to various bonding positions on the substrate.

[0012] The camera shooting position in the present invention is taken when the bonding mechanism leaves the position; the camera shoots the bonded chip at the moment when the bonding mechanism leaves the chip (such as an interval of 0.5-0.01 seconds).

[0013] 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 substrate image seen by the camera is an image seen from the top of the substrate looking down. One function of the camera is to identify the position to be bonded before the bonding head bonds the wafer (or chip) on the substrate. Another function of the camera is to detect and confirm the bonding status of the wafer (or chip) after bonding the wafer (or chip).

[0014] Preferably, at the moment when the bonding mechanism moves away (such as rightward movement), 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), and then the bonding mechanism moves back to the next station on track ② (such as picking up the chip). At the moment when the bonding mechanism moves away, the camera simultaneously shoots adjacent chips and positions from above to avoid the blocking of light by the bonding mechanism, and obtain higher quality photos and more comprehensive information.

[0015] Further preferably, after the bonding head picks up the chip, the bonding mechanism returns on track ② (such as moving to the left) while the bonding head makes a basically synchronous downward movement on track ③. The time period for the bonding mechanism to move to the left on track ② is slightly shorter than the time period for the bonding head to move downward, that is, after the bonding mechanism moves into place, the bonding head descends to the lowest position to bond the chip, so that the bonding mechanism remains in a stable position when bonding the chip.

[0016] Beneficial effects: The present application simultaneously performs the two processes of detecting the theoretical position on the substrate that needs to be bonded and detecting the actual position of the wafer after bonding. Moreover, when the bonding head is performing the bonding operation, the camera moves to the next position, thereby improving the efficiency of the bonding work.

[0017] This application can take clear photos of the chip position and the chip. The obtained picture information can be collected and compared with the standard picture to determine whether the position is correct and whether the chip bonding has defects.

[0018] This application can simultaneously capture adjacent positions and chips, reducing the number of camera shots by about half, increasing recognition efficiency by about double, and saving about half of the operation time.

[0019] The second shot is taken at the moment when the bonding mechanism moves away, which ensures that the shooting can capture two adjacent positions and does not take up too much extra time interval. At the same time, the time segment of the up and down movement of the bonding head of the present invention is within the time segment of the left and right movement of the bonding mechanism. The two movements are performed synchronously, which can save waiting time and further improve bonding efficiency (it can save more than half of the operation time). BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural and flow diagram of a traditional recognition system; Figure 2 It is a structural and flow diagram of the identification system of this application; Figure 3 It is a partial structural diagram of the identification system of this application.

[0021] In the figure, 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 DESCRIPTION

[0022] Embodiment 1: like Figure 1 A structural and flow chart of a traditional recognition system is shown.

[0023] Figure 1 Before bonding at position A [9], camera 1 takes a picture first; Next, chip 6 is bonded at position A [9]. In order to confirm the state after bonding, camera 1 must wait above the bonding point (chip A [6]) and wait for the bonding mechanism to move away.

[0024] After confirming the bonding status of point A [9], camera 1 moves to the next bonding point (position B

[10] ); when arriving at bonding position B

[10] , in order to ensure bonding accuracy, before performing substrate position recognition, it is necessary to wait for the vibration of camera 1 to disappear before performing substrate recognition. For this reason, in terms of equipment efficiency, the movement of camera 1 between bonding points (position A [9] to position B

[10] ) and the vibration reduction time before substrate recognition will generate unnecessary extra time.

[0025] Then, chip 7 is bonded at position B

[10] . In order to confirm the state after bonding, camera 1 must wait above the bonding point (chip B [7]) again, waiting for the bonding mechanism to move away.

[0026] Embodiment 2: like Figure 2 A schematic diagram of the structure and flow of the identification system of the present application is shown.

[0027] After the camera 1 takes a picture and identifies the substrate position at the bonding point position A [9], the chip 6 is bonded at point A [9].

[0028] The bonding mechanism retreats from point A [9], almost without stopping, and immediately moves to the next bonding point (position B

[10] ).

[0029] While the bonding mechanism moves rightward on track ②【3】, the bonding head 【5】 moves upward on track ③【4】.

[0030] When the substrate at position B

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

[10] .

[0031] Then, chip B [7] is bonded at position B

[10] . After the bonding mechanism is moved away, camera 1 takes pictures from above position B

[10] and position C

[11] , and simultaneously takes pictures of chip B [7] and position C

[11] .

[0032] By analogy, the camera 1 takes pictures synchronously between the front chip 6, 7 or 8 and the adjacent subsequent bonding position, and the recognition time is about half of the traditional time; the vibration reduction time before movement and recognition can also be reduced; furthermore, the movement of track ② [3] and track ③ [4] can basically be 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. A bonding position and bonding state image recognition system, comprising a camera (1) capable of capturing an image of a chip (6, 7 or 8) before bonding and an image of the chip (6, 7 or 8) after bonding to a substrate, and a bonding mechanism capable of bonding the chip (6, 7 or 8) to the substrate; 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 a bonding head (5) is capable of moving up and down on a bonding head track perpendicular to the substrate; the system is characterized in that: In addition to photographing the first position and the first chip, or the last position and the last chip, the camera (1) can also photograph an adjacent position and a bonded chip each time.

2. The image recognition system for bonding position and bonding state according to claim 1, characterized in that: The camera (1) is capable of synchronously capturing an image of a chip after bonding and a position image of a subsequent adjacent chip to be bonded.

3. The image recognition system for bonding position and bonding state according to claim 1 or 2, characterized in that: The camera (1) takes pictures at the position where the bonding mechanism leaves the position; the camera (1) takes pictures of the bonded chip at the moment when the bonding mechanism leaves the chip.

4. The image recognition system for bonding position and bonding state according to claim 3, characterized in that: At the moment when the bonding mechanism moves away, the bonding head (5) performs a substantially synchronous upward movement on the bonding head track; moreover, the time when the bonding head (5) rises is slightly earlier than the time when the bonding mechanism moves away.

5. The image recognition system for bonding position and bonding state according to claim 3 or 4, characterized in that: After the bonding head (5) picks up the chip, the bonding mechanism returns on the bonding track while the bonding head (5) performs a substantially synchronous downward movement on the bonding head track; moreover, the time period for the bonding mechanism to return is slightly shorter than the time period for the bonding head (5) to descend.

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