Vision alignment device for wafer bonding equipment

Abstract

The present invention relates to the technical field of wafer bonding, and particularly relates to a vision alignment device for a wafer bonding apparatus, mainly solving the technical problem of the relatively large volume of the existing vision alignment device. The vision alignment device for the wafer bonding apparatus includes a box body, which is docked with a manipulator through an operation window provided on the side wall of the box body. A gantry is provided inside the box body. By arranging an upper electrostatic chuck and an optical mechanism on the gantry, a lower electrostatic chuck is installed inside the gantry through a mounting frame and an alignment driving member, a thimble mechanism is installed on the mounting frame, and at the same time, a pre-bonding driving member is arranged through the middle parts of the alignment driving member and the lower electrostatic chuck, so that each part of the structure can act independently and without interference, and the structural compactness is relatively high, thereby making the volume of the device smaller, being applicable to scenarios with limited space, and at the same time being able to avoid an increase in the workload of vacuum pumping.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer bonding, and particularly to a vision alignment device for a wafer bonding apparatus. Background Art

[0002] Wafer bonding is a process of tightly bonding two polished homogeneous or heterogeneous wafers through chemical and physical actions to achieve vertical stacking and electrical interconnection in 3D integration and advanced packaging. Generally, a baking device, a vision alignment device, a bonding device, etc. are integrated in a wafer bonding apparatus. Among them, the main function of the vision alignment device is to calibrate the relative positions of the upper wafer and the lower wafer, and complete pre-bonding in the calibrated posture.

[0003] When in use, the vision alignment device is generally configured with a vacuum operation chamber, the vacuum operation chamber is connected to the alignment cavity through a gate valve, a manipulator is provided in the vacuum operation chamber. During operation, the alignment cavity is first evacuated, the manipulator picks up the upper wafer or the lower wafer and sends the upper wafer or the lower wafer into the alignment cavity through the gate valve, then the manipulator retracts, and finally the gate valve is closed for vision alignment and pre-bonding operations.

[0004] Since many structures such as optical components, alignment components, and pre-bonding components need to be provided in the vision alignment device, in order to ensure that the actions of each structure do not interfere with each other in the existing vision alignment device, a large space needs to be occupied, the overall volume of the device is relatively large, the application scenario is limited, and at the same time, the alignment cavity needs to maintain a vacuum environment during operation, and the relatively large volume also indirectly increases the workload of evacuation. Summary of the Invention

[0005] To overcome the technical defect of the relatively large volume existing in the existing vision alignment device, the present invention provides a vision alignment device for a wafer bonding apparatus.

[0006] The vision alignment device for a wafer bonding apparatus provided by the present invention includes:

[0007] A frame;

[0008] A box body, which is fixed on the frame and forms a sealed alignment cavity, an operation window is provided on the side wall of the box body, and an opening and closing valve is installed on the operation window;

[0009] A gantry, which is fixed in the alignment cavity;

[0010] An upper electrostatic chuck, which is fixed below the top beam of the gantry;

[0011] An alignment driving member, which is located in the gantry and installed on the bottom wall of the box body, and the output part of the alignment driving member is located at its top and is used to output six degrees of freedom of spatial movement;

[0012] A lower electrostatic chuck, which is indirectly fixed above the output part of the alignment driving part through a mounting bracket;

[0013] A thimble mechanism, which includes a lifting plate. The lifting plate is located below the lower electrostatic chuck. The lower electrostatic chuck is provided with at least three jacking holes distributed circumferentially. Needles corresponding to the jacking holes are provided on the lifting plate. The lifting plate is installed on the mounting bracket and can be driven to lift vertically so that the needles pass through the jacking holes to jack up the upper wafer or the lower wafer;

[0014] A pre-bonding driving part, whose housing is fixed on the machine frame and is located below the box body. The output shaft of the pre-bonding driving part penetrates through the bottom wall of the box body in a sealed manner. A vertically arranged first avoidance hole is provided in the middle of the alignment driving part. A vertically arranged second avoidance hole is provided in the middle of the lower electrostatic chuck. The output shaft of the pre-bonding driving part is used to jack up the lower wafer after sequentially passing through the first avoidance hole and the second avoidance hole;

[0015] An optical mechanism, which is installed on the gantry. Imaging windows are opened on the lower electrostatic chuck and / or the upper electrostatic chuck. The optical mechanism is used to obtain upper wafer images and lower wafer images through the imaging windows.

[0016] Optionally, the alignment driving part includes a six-axis platform and a piezoelectric platform. The bottom of the six-axis platform is fixed on the bottom wall of the box body. The piezoelectric platform is connected to the top of the six-axis platform. The mounting bracket is fixed on the top of the piezoelectric platform.

[0017] Optionally, a damping spring is provided between the mounting bracket and the top of the six-axis platform.

[0018] Optionally, the optical mechanism includes symmetrically distributed upper vision components and lower vision components. The upper vision components and the lower vision components are fixedly connected through a connecting frame. Imaging windows are opened on both the lower electrostatic chuck and the upper electrostatic chuck. The upper vision components are installed on the top beam of the gantry and are used to obtain upper wafer images through the imaging windows of the upper electrostatic chuck. The lower vision components are located below the lower electrostatic chuck and are used to obtain lower wafer images through the imaging windows of the lower electrostatic chuck.

[0019] Optionally, the upper vision components are slidably installed on the top beam of the gantry through a guide rail pair. The sliding direction of the upper vision components is perpendicular to the direction of the robot's entry and exit. And the upper vision components are connected with a driving part used to drive their sliding.

[0020] Optionally, the upper vision components are installed with the guide rail pair on one side in their sliding direction. The upper vision components are installed with a vacuum slide table on the other side in their sliding direction as the driving part.

[0021] Optionally, it further includes an ejection driving member. The housing of the ejection driving member is fixed above the top beam of the gantry. The upper electrostatic chuck is also provided with a through hole. The output shaft of the ejection driving member is arranged downward and is used to pass through the through hole to eject the pre-bonded wafer.

[0022] Optionally, a lighting glass is hermetically installed on the side wall of the box body.

[0023] Optionally, the opening and closing valve is a flap valve.

[0024] The technical solution provided by the present invention has the following advantages compared with the prior art:

[0025] The visual alignment device for wafer bonding equipment provided by the present invention is provided with a box body, and is docked with the manipulator through an operation window provided on the side wall of the box body. A gantry is arranged in the box body. By arranging the upper electrostatic chuck and the optical mechanism on the gantry, the lower electrostatic chuck is installed in the gantry through the mounting frame and the alignment driving member, the thimble mechanism is installed on the mounting frame, and at the same time, the pre-bonding driving member is arranged through the middle parts of the alignment driving member and the lower electrostatic chuck, so that each part of the structure can move independently and without interference, and the structural compactness is relatively high, so that the volume of the device is smaller, it can be applied to scenarios with limited space, and at the same time, it can also avoid the increase of the vacuum pumping workload. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present invention and used together with the specification to explain the principles of the present invention.

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings.

[0028] Figure 1 It shows a schematic structural diagram of the visual alignment device in the embodiment of the present invention;

[0029] Figure 2 It shows a schematic internal structure diagram of the visual alignment device in the embodiment of the present invention (removing the box body);

[0030] Figure 3 It shows a schematic assembly structural diagram of the lower electrostatic chuck, the thimble mechanism and the alignment driving member in the embodiment of the present invention;

[0031] Figure 4 It shows a schematic cooperation diagram of the lower electrostatic chuck and the thimble mechanism in the embodiment of the present invention;

[0032] Figure 5 Explosion diagram of the assembly structure of the gantry, lower electrostatic chuck and ejection driving member in the embodiment of the present invention;

[0033] Figure 6 Schematic diagram of the structure of the optical mechanism in the embodiment of the present invention.

[0034] In the figure:

[0035] 1. Frame; 2. Box body; 21. Alignment cavity; 22. Operation window; 23. Lighting glass; 3. Gantry; 4. Upper electrostatic chuck; 41. Through hole; 5. Alignment driving member; 51. First avoidance hole; 52. Six-axis platform; 53. Piezoelectric platform; 54. Damping spring; 6. Lower electrostatic chuck; 61. Mounting frame; 62. Lifting hole; 63. Second avoidance hole; 7. Ejector pin mechanism; 71. Lifting plate; 72. Needle body; 8. Pre-bonding driving member; 9. Optical mechanism; 91. Imaging window; 92. Upper vision component; 93. Lower vision component; 94. Connecting frame; 95. Guide rail pair; 96. Vacuum slide; 10. Ejection driving member. Detailed implementation manners

[0036] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0037] In the description, it should be noted that the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. It should be noted that unless otherwise clearly defined and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific situations.

[0038] Many specific details are set forth in the following description in order to fully understand the present invention, but the present invention can also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only a part of the embodiments of the present invention, rather than all the embodiments.

[0039] The following combines Figures 1 to 6 to detail the specific embodiments of the present invention.

[0040] This embodiment provides a vision alignment device for a wafer bonding apparatus, which includes a frame 1, a box body 2, a gantry 3, an upper electrostatic chuck 4, an alignment driving member 5, a lower electrostatic chuck 6, a thimble mechanism 7, a pre-bonding driving member 8, and an optical mechanism 9.

[0041] Among them, the frame 1 is mainly used to provide hardware support for other components, and its specific structure is not limited.

[0042] Furthermore, in this embodiment, rollers are installed at the bottom of the frame 1 to facilitate the handling and movement of the entire device.

[0043] Among them, the box body 2 is fixed on the frame 1 and forms a sealed alignment cavity 21. An operation window 22 is provided on the side wall of the box body 2, and a switching valve is installed on the operation window 22.

[0044] It is easy to understand that since vision alignment needs to be carried out in a vacuum environment, the box body 2 should be actually designed with a vacuum pumping structure and a vacuum gauge tube for detecting the vacuum degree; at the same time, an adapter can be set according to needs to connect the detection mechanism, a hanging device can also be set to connect the lifting tool, and other structures can also be set to assist the operation.

[0045] Specifically, the switching valve in this embodiment is a gate valve.

[0046] Furthermore, in this embodiment, an illumination glass 23 is hermetically installed on the side wall of the box body 2. The illumination glass 23 can adjust the brightness inside the alignment cavity 21 to meet the brightness requirements for the operation of the optical mechanism 9.

[0047] Furthermore, in this embodiment, a silica gel plate is provided on the outer side wall of the box body 2. The silica gel plate has a certain flexibility and can reduce the shock caused by bumps to the internal structure of the device, thereby reducing the influence on the position accuracy of the internal structure of the device.

[0048] Among them, the gantry 3 is fixed inside the alignment cavity 21.

[0049] It is easy to understand that the gantry 3 is mainly used to install other components, and at the same time divides the alignment cavity 21 into multiple installation areas such as above the top beam of the gantry 3 and inside the gantry 3, making more full and effective use of the space inside the alignment cavity 21.

[0050] It is easy to understand that the gantry 3 is composed of a top beam and two columns. The structures of the top beam and the columns are not limited. For example, in this embodiment, both the top beam and the columns are set as H-shaped structures.

[0051] Among them, the upper electrostatic chuck 4 is fixed below the top beam of the gantry 3.

[0052] It is easy to understand that the electrostatic chuck is a mature structure in the art. Electrode holes for connecting electrodes are provided on its surface. During operation, a uniform electric field is provided for the entire disk surface through the electrodes, and charge polarization on the surface of the wafer is achieved based on Coulomb's law and Lorentz's law, thereby achieving the effect of wafer adsorption. The upper electrostatic chuck 4 and the lower electrostatic chuck 6 mentioned later are both made using this principle.

[0053] It should be noted that, to cooperate with the work of other components, the upper electrostatic chuck 4 is also provided with an imaging window 91 and a through hole 41. For better understanding, the specific functions of the imaging window 91 and the through hole 41 will be described in combination with the corresponding components later.

[0054] Among them, the alignment driving member 5 is located inside the gantry 3 and is installed on the bottom wall of the box body 2. The output part of the alignment driving member 5 is located at its top and is used to output six degrees of freedom of spatial movement.

[0055] Specifically, the alignment driving member 5 in this embodiment includes a six-axis platform 52 and a piezoelectric platform 53. The bottom of the six-axis platform 52 is fixed on the bottom wall of the box body 2, the piezoelectric platform 53 is connected to the top of the six-axis platform 52, and the mounting frame 61 is fixed on the top of the piezoelectric platform 53. During operation, the six-axis platform 52 drives the piezoelectric platform 53, the mounting frame 61, and the lower electrostatic chuck 6 to move integrally in six degrees of freedom in space, thereby realizing arbitrary adjustment of the position of the lower wafer in space, and further realizing rough alignment of the lower wafer and the upper wafer; the piezoelectric platform 53 utilizes its own high-precision characteristics to further adjust the position of the lower wafer after rough alignment of the lower wafer and the upper wafer, thereby realizing fine alignment of the lower wafer and the upper wafer. Coarse alignment is achieved through the six-axis platform 52, and then fine alignment is achieved through the piezoelectric platform 53. In this way, the alignment accuracy can be effectively improved on the premise of ensuring the alignment efficiency. More specifically, the six-axis platform 52 includes an annular plate at the top and a fixing plate at the bottom. The annular plate is connected to the piezoelectric platform 53, the fixing plate is connected to the bottom of the box body 2, and the annular plate and the fixing plate are movably connected by six telescopic driving pairs. The six degrees of freedom of spatial movement of the annular plate are realized through the cooperation of the six telescopic driving pairs; the piezoelectric platform 53 is of a square annular structure. The piezoelectric platform 53 includes a base and an output part. The output part is installed on the top of the base through a piezoelectric driving structure and is connected to the mounting frame 61. The piezoelectric driving structure utilizes the inverse piezoelectric effect of piezoelectric ceramic materials to generate spatial movement by controlling the mechanical deformation of the piezoelectric ceramic materials, thereby realizing the spatial movement of the output part.

[0056] It should be noted that the operation of traditional motors will emit tiny particles and molecular precipitates, which are likely to contaminate the vacuum environment of the alignment cavity 21. The alignment driving member 5 in this embodiment adopts a combined structure of a six-axis platform 52 and a piezoelectric platform 53, which can avoid tiny particles and molecular precipitates, and thus can avoid the contamination of the vacuum environment.

[0057] Furthermore, in this embodiment, a damping spring 54 is provided between the mounting bracket 61 and the top of the six-axis platform 52. The damping spring 54 can share part of the weight of the mounting bracket 61 and its attached structures, thereby reducing the load borne by the piezoelectric platform 53, and further preventing the piezoelectric platform 53 from being crushed. Specifically, the damping spring 54 includes a pin shaft and a spring body. The lower end of the pin shaft is fixed to the top of the six-axis platform 52, the upper end of the pin shaft passes through the bottom of the mounting bracket 61 with a clearance, and the spring body is sleeved on the pin shaft and is in a compressed state. The two ends of the spring body are respectively abutted against the six-axis platform 52 and the mounting bracket 61, so as to utilize the elastic force generated by the compression of the spring body to share part of the weight of the mounting bracket 61 and its attached structures.

[0058] It should be noted that, for cooperating with other components to work, the alignment driving member 5 is also provided with a first avoidance hole 51. For better understanding, the specific functions of the first avoidance hole 51 will be described in conjunction with the corresponding components later.

[0059] Among them, the lower electrostatic chuck 6 is indirectly fixed above the output part of the alignment driving member 5 through the mounting bracket 61.

[0060] It should be noted that, for cooperating with other components to work, the lower electrostatic chuck 6 is also provided with an imaging window 91, a jacking hole 62 and a second avoidance hole 63. For better understanding, the specific functions of the imaging window 91, the jacking hole 62 and the second avoidance hole 63 will be described in conjunction with the corresponding components later.

[0061] Among them, the ejector pin mechanism 7 includes a lifting plate 71. The lifting plate 71 is located below the lower electrostatic chuck 6. The lower electrostatic chuck 6 is provided with at least three circumferentially distributed jacking holes 62. The lifting plate 71 is provided with pin bodies 72 corresponding to the jacking holes 62. The lifting plate 71 is installed on the mounting bracket 61 and is driven to vertically lift and lower so that the pin bodies 72 can pass through the jacking holes 62 to jack up the upper wafer or the lower wafer. During operation, the manipulator first sends the upper wafer into the alignment cavity 21. The pin bodies 72 rise to jack up the upper wafer until it contacts the lower surface of the upper electrostatic chuck 4. At the same time, the upper electrostatic chuck 4 adsorbs the upper wafer by static electricity. Then the pin bodies 72 fall back to their original positions. The manipulator then sends the lower wafer into the alignment cavity 21. The pin bodies 72 rise to jack up the lower wafer. After the manipulator exits the alignment cavity 21, the pin bodies 72 fall back to their original positions, so that the lower wafer is adsorbed on the upper surface of the lower electrostatic chuck 6.

[0062] It is easy to understand that the jacking holes 62 are provided as at least three. The main purpose is to ensure the stability of the pin bodies 72 jacking up the wafer. The main purpose of the jacking holes 62 is to avoid the movement of the pin bodies 72, so that the pin bodies 72 can penetrate through the lower electrostatic chuck 6 to contact the wafer.

[0063] Among them, the housing of the pre-bonding driver 8 is fixed on the frame 1 and is located below the box body 2. The output shaft of the pre-bonding driver 8 penetrates through the bottom wall of the box body 2 in a sealed manner. A first avoidance hole 51 arranged vertically is provided in the middle of the alignment driver 5, and a second avoidance hole 63 arranged vertically is provided in the middle of the lower electrostatic chuck 6. The output shaft of the pre-bonding driver 8 is used to lift the lower wafer after sequentially passing through the first avoidance hole 51 and the second avoidance hole 63. After the lower wafer completes visual alignment with the upper wafer, the pre-bonding driver 8 operates to raise its output shaft and sequentially pass through the first avoidance hole 51 and the second avoidance hole 63 to lift the lower wafer until it contacts the upper wafer, so as to complete the pre-bonding of the upper wafer and the lower wafer.

[0064] It should be noted that during rough alignment, the six-axis platform 52 has adjusted the gap between the upper wafer and the lower wafer to be relatively small. Therefore, when the pre-bonding driver 8 lifts the lower wafer, the influence on the position accuracy of the lower wafer is relatively small, which can meet the process requirements.

[0065] It is easy to understand that the inner hole of the ring plate of the six-axis platform 52 and the inner hole of the square ring structure of the piezoelectric platform 53 together form the first avoidance hole 51. The first avoidance hole 51 and the second avoidance hole 63 are mainly used to avoid the movement of the output shaft of the pre-bonding driver 8, so that the output shaft of the pre-bonding driver 8 can sequentially pass through the alignment driver 5 and the lower electrostatic chuck 6 to contact the lower wafer.

[0066] Specifically, the pre-bonding driver 8 in this embodiment is an electric cylinder with relatively high precision.

[0067] Among them, the optical mechanism 9 is installed on the gantry 3. Imaging windows 91 are provided on the lower electrostatic chuck 6 and / or the upper electrostatic chuck 4. The optical mechanism 9 is used to obtain the upper wafer image and the lower wafer image through the imaging window 91. During operation, the optical mechanism 9 obtains the upper wafer image and the lower wafer image, and determines the direction and magnitude of the compensation displacement of the lower wafer based on the position difference between the upper wafer mark and the lower wafer mark.

[0068] It should be understood that the imaging window 91 can be provided only on the lower electrostatic chuck 6. At this time, the optical mechanism 9 needs to be arranged below the lower electrostatic chuck 6, and an infrared optical element with penetration ability needs to be used to be able to obtain the upper wafer image and the lower wafer image at the same time; the imaging window 91 can also be provided only on the upper electrostatic chuck 4. At this time, the optical mechanism 9 needs to be arranged above the upper electrostatic chuck 4, and an infrared optical element with penetration ability needs to be used to be able to obtain the upper wafer image and the lower wafer image at the same time; the imaging window 91 can also be provided on both the upper electrostatic chuck 4 and the lower electrostatic chuck 6. The optical mechanism 9 needs to be provided with two sets of vision components and be located below the lower electrostatic chuck 6 and above the upper electrostatic chuck 4 respectively to obtain the upper wafer image and the lower wafer image respectively. This embodiment adopts this solution.

[0069] Specifically, the optical mechanism 9 of this embodiment includes an upper vision component 92 and a lower vision component 93 that are symmetrically distributed. The upper vision component 92 and the lower vision component 93 are fixedly connected by a connecting frame 94. Both the lower electrostatic chuck 6 and the upper electrostatic chuck 4 are provided with imaging windows 91. The upper vision component 92 is installed on the top beam of the gantry 3 and is used to obtain an upper wafer image through the imaging window 91 of the upper electrostatic chuck 4. The lower vision component 93 is located below the lower electrostatic chuck 6 and is used to obtain a lower wafer image through the imaging window 91 of the lower electrostatic chuck 6. It is easy to understand that since the upper vision component 92 and the lower vision component 93 are fixedly connected by the connecting frame 94 and are symmetrically distributed, the relative positions of the upper vision component 92 and the lower vision component 93 are determined, and the relative positions of the obtained upper wafer image and lower wafer image are also determined. During operation, the upper vision component 92 and the lower vision component 93 are respectively used to obtain the upper wafer image and the lower wafer image, which can achieve the purpose of high definition and low distortion, thus being more conducive to ensuring the pre-bonding accuracy.

[0070] Furthermore, the upper vision component 92 of this embodiment is slidably installed on the top beam of the gantry 3 through a guide pair 95. The sliding direction of the upper vision component 92 is perpendicular to the direction of the robot's entry and exit, and the upper vision component 92 is connected to a driving member for driving its sliding. Through the guide pair 95, the upper vision component 92 and the lower vision component 93 can move relative to both sides of the direction of the robot's entry and exit, so as to be applicable to the visual alignment of wafers of different specifications or different markings.

[0071] Even further, the upper vision component 92 of this embodiment is installed with a guide pair 95 on one side in its sliding direction, and a vacuum slide table 96 is installed on the other side in its sliding direction as the driving member. The vacuum slide table 96 not only serves as a power element but also has a supporting and guiding function, which can further save the occupied space and is more conducive to reducing the overall volume of the device.

[0072] It should be noted that in this embodiment, both the upper electrostatic chuck 4 and the lower electrostatic chuck 6 are provided with two imaging windows 91. There are two markings on both the upper wafer and the lower wafer. The optical mechanism 9 is provided with two sets that are symmetrically distributed left and right. The two sets of optical mechanisms 9 respectively capture the two markings on the upper wafer or the lower wafer through the two imaging windows 91 to more accurately determine the position of the upper wafer or the lower wafer.

[0073] In addition, the vision alignment device of this embodiment further includes an ejecting driving member 10. The housing of the ejecting driving member 10 is fixed above the top beam of the gantry 3. The upper electrostatic chuck 4 is also provided with a through hole 41. The output shaft of the ejecting driving member 10 is arranged downward and is used to pass through the through hole 41 to eject the pre-bonded wafer. During operation, after the lower wafer and the upper wafer are pre-bonded, even if the upper electrostatic chuck 4 is powered off, there may still be residual static electricity between the upper wafer and the upper electrostatic chuck 4, resulting in the wafer not falling off. Therefore, this embodiment adds an ejecting driving member 10 to eject the wafer after pre-bonding, so that the wafer is separated from the upper electrostatic chuck 4 and falls on the manipulator to ensure the smooth progress of subsequent processes.

[0074] It is easy to understand that the through hole 41 is mainly used to avoid the movement of the output shaft of the ejecting driving member 10, so that the output shaft of the ejecting driving member 10 can pass through the upper electrostatic chuck 4 to contact the upper wafer.

[0075] Specifically, the ejecting driving member 10 of this embodiment is an electric push rod.

[0076] The working process of the vision alignment device for the wafer bonding equipment in this embodiment is as follows:

[0077] S1. Evacuate the alignment cavity 21 surrounded by the box body 2 to make the vacuum degree of the alignment cavity 21 meet the process requirements;

[0078] S2. The manipulator holds the upper wafer and sends the upper wafer into the alignment cavity 21 through the operation window 22. The ejector pin rises to lift the upper wafer until it contacts the lower surface of the upper electrostatic chuck 4. The upper electrostatic chuck 4 is powered on and adsorbs the upper wafer by static electricity. The manipulator exits the alignment cavity 21;

[0079] S3. The manipulator holds the lower wafer and sends the lower wafer into the alignment cavity 21 through the operation window 22. The ejector pin rises to lift the lower wafer until it separates from the manipulator. The manipulator exits the alignment cavity 21. The ejector pin falls to make the lower wafer land on the upper surface of the lower electrostatic chuck 6. The lower electrostatic chuck 6 is powered on and adsorbs the lower wafer by static electricity;

[0080] S4. The upper vision component 92 obtains the upper wafer image through the imaging window 91 of the upper electrostatic chuck 4. The lower vision component 93 obtains the lower wafer image through the imaging window 91 of the lower electrostatic chuck 6. The direction and magnitude of the compensation displacement of the lower wafer are determined by the position difference between the marks on the upper wafer image and the marks on the lower wafer image;

[0081] S5. Coarse alignment of the lower wafer is performed through the six-axis platform 52, and fine alignment of the lower wafer is performed through the piezoelectric platform 53. Finally, the marks on the lower wafer image and the marks on the upper wafer image overlap, and the alignment is completed;

[0082] S6. Actuate the pre - bonding driver 8 to lift the lower wafer until it contacts the upper wafer. The lower wafer and the upper wafer are electrostatically adsorbed to complete the pre - bonding.

[0083] S7. The manipulator enters the alignment cavity 21 through the operation window 22. Actuate the ejection driver 10 to eject the pre - bonded wafer until it detaches from the upper electrostatic chuck 4 and lands on the manipulator. The manipulator carries the pre - treated wafer and exits the alignment cavity 21.

[0084] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Although the foregoing embodiments have been described in detail, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and they should all be covered by the protection scope of the claims.

Claims

1. A visual alignment device for wafer bonding equipment, characterized in that: include: Rack(1); A box body (2) is fixed on the frame (1) and forms a closed alignment cavity (21); a side wall of the box body (2) is provided with an operating window (22), and an opening and closing valve is installed in the operating window (22); A gantry (3) fixed in the alignment cavity (21); An upper electrostatic suction cup (4) fixed below the top beam of the gantry (3); An alignment driving member (5) is located in the gantry (3), the alignment driving member (5) comprising a six-axis platform (52) and a piezoelectric platform (53), the bottom of the six-axis platform (52) being fixed to the bottom wall of the box (2), the piezoelectric platform (53) comprising a base and an output portion, the base of the piezoelectric platform (53) being connected to the top of the six-axis platform (52), the output portion of the piezoelectric platform (53) being mounted on the base of the piezoelectric platform (53) via a piezoelectric driving structure, the output portion of the piezoelectric platform (53) serving as the output portion of the alignment driving member (5) and being used to output spatial six-degree-of-freedom motion; A lower electrostatic suction cup (6) which is indirectly fixed above the output portion of the alignment driving member (5) via a mounting frame (61); A pin ejector mechanism (7), comprising a lifting plate (71), the lifting plate (71) being located below the lower electrostatic chuck (6), the lower electrostatic chuck (6) being provided with at least three lifting holes (62) distributed along the circumferential direction, a pin body (72) being provided on the lifting plate (71) corresponding to the lifting holes (62), the lifting plate (71) being mounted on the mounting frame (61) and being driven to be vertically lifted so that the pin body (72) passes through the lifting holes (62) to lift the upper wafer or the lower wafer; A pre-bonding drive member (8), the shell of which is fixed on the frame (1) and located below the box body (2); the output shaft of the pre-bonding drive member (8) is sealed and passes through the bottom wall of the box body (2); a first avoidance hole (51) arranged vertically is provided in the middle of the alignment drive member (5); a second avoidance hole (63) arranged vertically is provided in the middle of the lower electrostatic suction cup (6); the output shaft of the pre-bonding drive member (8) is used to sequentially pass through the first avoidance hole (51) and the second avoidance hole (63) and then lift the lower wafer; An optical mechanism (9) is mounted on the gantry (3); the lower electrostatic chuck (6) and / or the upper electrostatic chuck (4) are provided with an imaging window (91); and the optical mechanism (9) is used to obtain an upper wafer image and a lower wafer image through the imaging window (91).

2. The visual alignment device for wafer bonding equipment according to claim 1, characterized in that: A damping spring (54) is provided between the mounting frame (61) and the top of the six-axis platform (52).

3. The visual alignment device for wafer bonding equipment according to claim 1, characterized in that: The optical mechanism (9) comprises an upper visual component (92) and a lower visual component (93) which are symmetrically distributed. The upper visual component (92) is fixedly connected to the lower visual component (93) via a connecting frame (94). Both the lower electrostatic chuck (6) and the upper electrostatic chuck (4) are provided with imaging windows (91). The upper visual component (92) is mounted on the top beam of the gantry (3) and is used to obtain an image of the upper wafer through the imaging window (91) of the upper electrostatic chuck (4). The lower visual component (93) is located below the lower electrostatic chuck (6) and is used to obtain an image of the lower wafer through the imaging window (91) of the lower electrostatic chuck (6).

4. The visual alignment device for wafer bonding equipment according to claim 3, characterized in that: The upper visual component (92) is slidably mounted on the top beam of the gantry (3) via a guide rail pair (95); the sliding direction of the upper visual component (92) is perpendicular to the entry and exit direction of the robot, and the upper visual component (92) is connected to a driving member for driving the upper visual component (92) to slide.

5. The visual alignment device for wafer bonding equipment according to claim 4, characterized in that: The guide rail pair (95) is installed on one side of the upper visual component (92) in the sliding direction thereof, and a vacuum slide table (96) is installed on the other side of the upper visual component (92) in the sliding direction thereof to serve as the driving member.

6. The visual alignment device for wafer bonding equipment according to claim 1, characterized in that: It also includes an ejection drive member (10), the shell of the ejection drive member (10) is fixed above the top beam of the gantry (3), the upper electrostatic suction cup (4) is also provided with a through hole (41), and the output shaft of the ejection drive member (10) is arranged downward and is used to pass through the through hole (41) to eject the pre-bonded wafer.

7. The visual alignment device for wafer bonding equipment according to any one of claims 1 to 6, characterized in that: A lighting glass (23) is sealed and mounted on the side wall of the box body (2).

8. The visual alignment device for wafer bonding equipment according to any one of claims 1 to 6, characterized in that: The on-off valve is a gate valve.

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