Pre-bonding mechanism of visual alignment device in wafer bonding equipment

Abstract

The invention relates to the technical field of wafer bonding, in particular to a pre-bonding mechanism of a visual alignment device in wafer bonding equipment, and mainly solves the technical problem that the overall size of the device is large due to the fact that the pre-bonding mechanism of the visual alignment device in the existing wafer bonding equipment is complex in structure. The pre-bonding mechanism of the visual alignment device in the wafer bonding equipment comprises a box body, butt joint with a mechanical arm is achieved through an operation window arranged on the side wall of the box body, a portal frame is arranged in the box body, an upper electrostatic chuck is arranged on the portal frame, a lower electrostatic chuck is installed in the portal frame through an installation frame and an alignment driving piece, and the mechanical arm is arranged in the box body. The ejector pin mechanism is mounted on the mounting frame, and the pre-bonding driving part penetrates through the middle parts of the alignment driving part and the lower electrostatic chuck, so that the structures of all parts can act independently and do not interfere with one another, the structure compactness is high, and the device is smaller in size and can be suitable for being used in a space-limited scene; and meanwhile, the increase of the vacuumizing workload can be avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer bonding, and in particular to a pre-bonding mechanism of a visual alignment device in wafer bonding equipment. Background Art

[0002] Wafer bonding is the process of tightly combining two mirror-polished homogeneous or heterogeneous wafers through chemical and physical effects to achieve vertical stacking and electrical interconnection in 3D integration and advanced packaging. Wafer bonding equipment generally integrates baking devices, visual alignment devices, bonding devices, etc. Among them, the main function of the visual 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] The visual alignment device is generally equipped with a vacuum operating chamber when in use. The vacuum operating chamber is connected to the alignment chamber through a plug valve. A robot is installed in the vacuum operating chamber. During operation, the alignment chamber is first evacuated, the robot picks up the upper wafer or the lower wafer and sends the upper wafer or the lower wafer to the alignment chamber through the plug valve. The robot is then retracted, and finally the plug valve is closed to perform visual alignment and pre-bonding operations.

[0004] Since the pre-bonding operation involves many actions such as lifting and ejection of the upper and lower wafers, the pre-bonding mechanism of the visual alignment device in the existing wafer bonding equipment is generally more complex in structure design, resulting in a larger overall size of the device and limited application scenarios. Summary of the invention

[0005] In order to overcome the technical defect that the pre-bonding mechanism of the visual alignment device in the existing wafer bonding equipment has a complex structure and leads to a large overall volume of the device, the present invention provides a pre-bonding mechanism of the visual alignment device in the wafer bonding equipment.

[0006] The pre-bonding mechanism of the visual alignment device in the wafer bonding equipment provided by the present invention comprises: frame; A box body, which is fixed on the frame and forms a closed counter cavity, and a side wall of the box body is provided with an operation window, and an opening and closing valve is installed in the operation window; A gantry frame, which is fixed in the alignment cavity; An upper electrostatic chuck, which is fixed below the top beam of the gantry; An alignment driving member, which is located in the gantry and mounted on the bottom wall of the box, wherein the output portion of the alignment driving member is located at the top thereof and is used to output six-degree-of-freedom motion in space; A lower electrostatic chuck, which is indirectly fixed above the output portion of the alignment drive member through a mounting frame; A pin mechanism, comprising a lifting plate, the lifting plate being located below the lower electrostatic chuck, the lower electrostatic chuck being provided with at least three lifting holes distributed in the circumferential direction, the lifting plate being provided with pin bodies corresponding to the lifting holes, the lifting plate being mounted on the mounting frame and being driven to lift vertically so that the pin bodies pass through the lifting holes to lift the upper wafer or the lower wafer; A pre-bonding drive member, whose shell is fixed on the frame and located below the box body, the output shaft seal of the pre-bonding drive member passes through the bottom wall of the box body, a first avoidance hole arranged vertically is provided in the middle of the alignment drive member, and a second avoidance hole arranged vertically is provided in the middle of the lower electrostatic suction cup, and the output shaft of the pre-bonding drive member is used to lift the lower wafer after passing through the first avoidance hole and the second avoidance hole in sequence.

[0007] Optionally, the alignment drive component 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, the piezoelectric platform is connected to the top of the six-axis platform, and the mounting frame is fixed on the top of the piezoelectric platform.

[0008] Optionally, a damping spring is provided between the mounting frame and the top of the six-axis platform.

[0009] Optionally, it also includes an ejection drive component, the shell of which is fixed above the top beam of the gantry, the upper electrostatic suction cup is also provided with a through hole, and the output shaft of the ejection drive component is arranged downward and is used to eject the pre-bonded wafer after passing through the through hole.

[0010] Optionally, a lighting glass is sealed and mounted on the side wall of the box.

[0011] Optionally, the opening and closing valve is a gate valve.

[0012] The technical solution provided by the present invention has the following advantages compared with the prior art: The pre-bonding mechanism of the visual alignment device in the wafer bonding equipment provided by the present invention is provided with a box body, and docking with a robot is achieved through an operation window arranged on the side wall of the box body. A gantry is arranged in the box body, and an upper electrostatic suction cup is arranged on the gantry, and a lower electrostatic suction cup is installed in the gantry through a mounting frame and an alignment drive component, and a ejector mechanism is installed on the mounting frame. At the same time, the pre-bonding drive component is arranged through the middle of the alignment drive component and the lower electrostatic suction cup, so that each part of the structure can move independently and do not interfere with each other, and the structure is highly compact, so that the device is smaller in size and can be suitable for use in scenes with limited space, and the increase in the vacuuming workload can also be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 A schematic diagram showing the structure of a visual alignment device in an embodiment of the present invention; Figure 2 A schematic diagram showing the internal structure of the visual alignment device in an embodiment of the present invention (excluding the box); Figure 3 A schematic diagram showing the assembly structure of the lower electrostatic chuck, the ejector mechanism and the alignment driving member in an embodiment of the present invention; Figure 4 A schematic diagram showing the cooperation between the lower electrostatic chuck and the ejector mechanism in an embodiment of the present invention; Figure 5 An exploded view showing the assembly structure of the gantry, the lower electrostatic chuck and the ejection drive member in an embodiment of the present invention; Figure 6 A schematic diagram showing the structure of an optical mechanism in an embodiment of the present invention.

[0016] In the figure: 1. Frame; 2. Box; 21. Alignment cavity; 22. Operation window; 23. Illumination glass; 3. Gantry; 4. Upper electrostatic suction cup; 41. Through hole; 5. Alignment drive; 51. First avoidance hole; 52. Six-axis platform; 53. Piezoelectric platform; 54. Damping spring; 6. Lower electrostatic suction cup; 61. Mounting frame; 62. Lifting hole; 63. Second avoidance hole; 7. Ejector mechanism; 71. Lifting plate; 72. Needle body; 8. Pre-bonded drive; 9. Optical mechanism; 91. Imaging window; 92. Upper visual component; 93. Lower visual component; 94. Connecting frame; 95. Guide pair; 96. Vacuum slide; 10. Ejector drive. DETAILED DESCRIPTION

[0017] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0018] In the description, it should be noted that the terms "first" and "second" are only used for descriptive purposes and should not be understood as indicating or implying relative importance. It should be noted that, unless otherwise clearly specified 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 a direct connection, or it can be an indirect connection through an intermediate medium, or it can be internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0019] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0020] Combine the following Figures 1 to 6 The specific embodiments of the present invention are described in detail.

[0021] The present embodiment provides a pre-bonding mechanism of a visual alignment device in a wafer bonding device, comprising a frame 1, a box 2, a gantry 3, an upper electrostatic suction cup 4, an alignment drive 5, a lower electrostatic suction cup 6, a pin mechanism 7, and a pre-bonding drive 8.

[0022] The rack 1 is mainly used to provide hardware support for other components, and the specific structure is not limited.

[0023] Furthermore, in this embodiment, rollers are installed at the bottom of the frame 1 to facilitate the transportation and movement of the entire device.

[0024] The box body 2 is fixed on the frame 1 and forms a closed alignment cavity 21 . The side wall of the box body 2 is provided with an operation window 22 , and the operation window 22 is installed with an opening and closing valve.

[0025] It is easy to understand that since the visual alignment needs to be carried out in a vacuum environment, the box 2 should be installed with a vacuum pumping structure and a vacuum gauge for detecting the vacuum degree during the actual design; at the same time, an adapter can be provided as needed to connect the detection mechanism, a hanger can be provided to connect the sling, and other structures can be provided to assist the operation.

[0026] Specifically, the on-off valve of this embodiment is a gate valve.

[0027] Furthermore, in this embodiment, a lighting glass 23 is sealed and installed on the side wall of the box body 2. The lighting glass 23 can adjust the brightness in the alignment cavity 21 to meet the brightness requirements of the optical mechanism 9 during operation.

[0028] Furthermore, in this embodiment, a silicone plate is provided on the outer wall of the box body 2. The silicone plate has a certain flexibility and can reduce the shock caused by collision to the internal structure of the device, thereby reducing the impact on the position accuracy of the internal structure of the device.

[0029] The gantry 3 is fixed in the alignment cavity 21 .

[0030] It is easy to understand that the gantry 3 is mainly used to install other components. At the same time, the alignment cavity 21 is divided into multiple installation areas such as above the top beam of the gantry 3 and inside the gantry 3, so as to more fully and effectively utilize the space in the alignment cavity 21.

[0031] It is easy to understand that the gantry 3 is composed of a top beam and two columns. The structure of the top beam and the columns is not limited. For example, in this embodiment, the top beam and the columns are both configured as H-shaped structures.

[0032] The upper electrostatic suction cup 4 is fixed below the top beam of the gantry 3 .

[0033] It is easy to understand that the electrostatic chuck is a mature structure in the art, and its surface is provided with electrode holes for connecting electrodes. When working, the electrodes provide a uniform electric field for the entire disk surface, and the charge polarization on the wafer surface is realized according to 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.

[0034] It should be noted that, in order to cooperate with 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 are explained in conjunction with the corresponding components in the following text.

[0035] The alignment driving member 5 is located in the gantry 3 and is installed on the bottom wall of the box body 2. The output portion of the alignment driving member 5 is located at the top thereof and is used to output six-degree-of-freedom motion in space.

[0036] Specifically, the alignment drive member 5 of 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 2, the piezoelectric platform 53 is connected to the top of the six-axis platform 52, and the mounting frame 61 is fixed to the top of the piezoelectric platform 53. When working, the six-axis platform 52 drives the piezoelectric platform 53, the mounting frame 61 and the lower electrostatic suction cup 6 to move along the six degrees of freedom in space, so as to achieve arbitrary adjustment of the position of the lower wafer in space, and then achieve rough alignment of the lower wafer and the upper wafer; the piezoelectric platform 53 uses its own high-precision characteristics to further adjust the position of the lower wafer after the rough alignment of the lower wafer and the upper wafer, so as to achieve fine alignment of the lower wafer and the upper wafer. The rough alignment is achieved through the six-axis platform 52, and the fine alignment is achieved through the piezoelectric platform 53, so that the alignment accuracy can be effectively improved under the premise of ensuring the alignment efficiency. More specifically, the six-axis platform 52 includes a ring plate located at the top and a fixed plate located at the bottom, the ring plate is connected to the piezoelectric platform 53, the fixed plate is connected to the bottom of the box 2, the ring plate and the fixed plate are movably connected through six telescopic drive pairs, and the six-degree-of-freedom spatial movement of the ring plate is realized through the cooperation of the six telescopic drive pairs; the piezoelectric platform 53 is a square ring 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 drive structure and is connected to the mounting frame 61, the piezoelectric drive structure utilizes the inverse piezoelectric effect of the piezoelectric ceramic material, and generates spatial movement by controlling the mechanical deformation of the piezoelectric ceramic material, thereby realizing the spatial movement of the output part.

[0037] It should be noted that the operation of traditional motors will emit tiny particles and molecular precipitation, which can easily pollute the vacuum environment of the alignment cavity 21. The alignment drive 5 of this embodiment adopts a combined structure of a six-axis platform 52 and a piezoelectric platform 53, which can avoid the precipitation of tiny particles and molecules, thereby avoiding the pollution of the vacuum environment.

[0038] Furthermore, in this embodiment, a damping spring 54 is provided between the mounting frame 61 and the top of the six-axis platform 52. The damping spring 54 can share part of the weight of the mounting frame 61 and the accessory structure, thereby reducing the load-bearing capacity of 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 has a gap that passes through the bottom of the mounting frame 61, the spring body is sleeved on the pin shaft and is in a compressed posture, and the two ends of the spring body are respectively abutted against the six-axis platform 52 and the mounting frame 61, so that the elastic force generated by the compression of the spring body is used to share part of the weight of the mounting frame 61 and the accessory structure.

[0039] It should be noted that, in order to cooperate with other components, the alignment driving member 5 is also provided with a first avoidance hole 51. For better understanding, the specific function of the first avoidance hole 51 will be explained in conjunction with the corresponding components in the following text.

[0040] The lower electrostatic suction cup 6 is indirectly fixed above the output portion of the alignment driving member 5 through a mounting frame 61 .

[0041] It should be noted that, in order to cooperate with other components, the lower electrostatic suction cup 6 is also provided with an imaging window 91, a lifting hole 62 and a second avoidance hole 63. For better understanding, the specific functions of the imaging window 91, the lifting hole 62 and the second avoidance hole 63 are explained in conjunction with the corresponding components in the following text.

[0042] Among them, the ejector mechanism 7 includes a lifting plate 71, which is located below the lower electrostatic suction cup 6. The lower electrostatic suction cup 6 is provided with at least three lifting holes 62 distributed along the circumferential direction. The lifting plate 71 is provided with a needle body 72 corresponding to the lifting holes 62. The lifting plate 71 is installed on the mounting frame 61 and is driven to be vertically lifted so that the needle body 72 passes through the lifting hole 62 to lift the upper wafer or the lower wafer. When working, the robot first sends the upper wafer to the alignment cavity 21, and the needle body 72 rises to lift the upper wafer to the lower surface of the upper electrostatic suction cup 4, and the upper electrostatic suction cup 4 adsorbs the upper wafer by static electricity; then the needle body 72 falls back to its original position, and the robot sends the lower wafer to the alignment cavity 21 again, and the needle body 72 rises to lift the lower wafer. After the robot exits the alignment cavity 21, the needle body 72 falls back to its original position, so that the lower wafer is adsorbed on the upper surface of the lower electrostatic suction cup 6.

[0043] It is easy to understand that there are at least three lifting holes 62, the main purpose of which is to ensure the stability of the needle body 72 in lifting the wafer; the main purpose of the lifting hole 62 is to avoid the movement of the needle body 72 so that the needle body 72 can penetrate the lower electrostatic suction cup 6 to contact the wafer.

[0044] Among them, the shell of the pre-bonding drive member 8 is fixed on the frame 1 and is 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. The middle part of the alignment drive member 5 is provided with a vertically arranged first avoidance hole 51, and the middle part of the lower electrostatic suction cup 6 is provided with a vertically arranged second avoidance hole 63. 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. After the lower wafer completes the visual alignment with the upper wafer, the pre-bonding drive member 8 moves to make its output shaft rise and sequentially pass through the first avoidance hole 51 and the second avoidance hole 63, and then lift the lower wafer to contact the upper wafer to complete the pre-bonding of the upper wafer and the lower wafer.

[0045] 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 a smaller one, so the pre-bonding drive 8 has little effect on the position accuracy of the lower wafer when lifting the lower wafer, which can meet the process requirements.

[0046] 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 drive 8, so that the output shaft of the pre-bonding drive 8 can pass through the alignment drive 5 and the lower electrostatic suction cup 6 in sequence to contact the lower wafer.

[0047] Specifically, the pre-bonding driving member 8 of this embodiment is an electric cylinder with high precision.

[0048] In addition, the visual alignment device of this embodiment also includes an ejector drive 10, the shell of the ejector drive 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 ejector drive 10 is arranged downward and is used to eject the pre-bonded wafer after passing through the through hole 41. During operation, after the lower wafer and the upper wafer are pre-bonded, even if the upper electrostatic suction cup 4 is powered off, there may still be residual static electricity between the upper wafer and the upper electrostatic suction cup 4, causing the wafer not to fall off, so this embodiment adds an ejector drive 10 to eject the wafer after pre-bonding, so that the wafer is separated from the upper electrostatic suction cup 4 and falls on the robot arm to ensure the smooth progress of subsequent processes.

[0049] It is easy to understand that the through hole 41 is mainly used to prevent the output shaft of the ejection driving member 10 from moving, so that the output shaft of the ejection driving member 10 can pass through the upper electrostatic chuck 4 to contact the upper wafer.

[0050] Specifically, the ejection driving member 10 of this embodiment is an electric push rod.

[0051] In addition, in order to facilitate the understanding of the overall working process of the device, the optical mechanism 9 of the other components of the device is now introduced.

[0052] The optical mechanism 9 is mounted on the gantry 3, and 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 the upper wafer image and the lower wafer image through the imaging window 91. When working, the optical mechanism 9 obtains the upper wafer image and the lower wafer image, and determines the direction and magnitude of the lower wafer compensation displacement by the position difference between the upper wafer mark and the lower wafer mark.

[0053] It should be understood that the imaging window 91 can be opened only on the lower electrostatic chuck 6. In this case, the optical mechanism 9 needs to be arranged below the lower electrostatic chuck 6, and a penetrating infrared optical element needs to be used to simultaneously acquire the upper wafer image and the lower wafer image; the imaging window 91 can also be opened only on the upper electrostatic chuck 4. In this case, the optical mechanism 9 needs to be arranged above the upper electrostatic chuck 4, and a penetrating infrared optical element needs to be used to simultaneously acquire the upper wafer image and the lower wafer image; the imaging window 91 can also be set on both the upper electrostatic chuck 4 and the lower electrostatic chuck 6. The optical mechanism 9 needs to have two sets of visual components and be respectively located below the lower electrostatic chuck 6 and above the upper electrostatic chuck 4 to respectively acquire the upper wafer image and the lower wafer image. This embodiment adopts this solution.

[0054] Specifically, the optical mechanism 9 of this embodiment includes an upper visual component 92 and a lower visual component 93 that are symmetrically distributed. The upper visual component 92 and the lower visual component 93 are fixedly connected by a connecting frame 94. The lower electrostatic chuck 6 and the upper electrostatic chuck 4 are both provided with an imaging window 91. The upper visual component 92 is mounted on the top beam of the gantry 3 and is used to obtain the upper wafer image 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 the lower wafer image through the imaging window 91 of the lower electrostatic chuck 6. It is easy to understand that since the upper visual component 92 and the lower visual component 93 are fixedly connected and symmetrically distributed by the connecting frame 94, the relative position of the upper visual component 92 and the lower visual component 93 is determined, and the relative position of the acquired upper wafer image and the lower wafer image is also determined. When working, the upper wafer image and the lower wafer image are respectively obtained by the upper visual component 92 and the lower visual component 93, which can achieve the purpose of high clarity and low distortion, thereby being more conducive to ensuring the pre-bonding accuracy.

[0055] Furthermore, the upper visual component 92 of this embodiment is slidably mounted on the top beam of the gantry 3 through a guide rail pair 95, the sliding direction of the upper visual component 92 is perpendicular to the direction of entry and exit of the robot, and the upper visual component 92 is connected to a driving member for driving its sliding. The guide rail pair 95 can make the upper visual component 92 and the lower visual component 93 move on both sides relative to the direction of entry and exit of the robot, so that it can be suitable for visual alignment of wafers of different specifications or different marks.

[0056] Furthermore, the upper visual component 92 of this embodiment is provided with a guide rail pair 95 on one side of its sliding direction, and the upper visual component 92 is provided with a vacuum slide 96 as a driving member on the other side of its sliding direction. The vacuum slide 96 not only serves as a power element but also has a supporting and guiding function, which can further save space and is more conducive to reducing the overall volume of the device.

[0057] It should be noted that, in the present embodiment, both the upper electrostatic chuck 4 and the lower electrostatic chuck 6 are provided with two imaging windows 91, two marks are provided on the upper wafer and the lower wafer, and the optical mechanism 9 is provided with two sets symmetrically distributed on the left and right. The two sets of optical mechanisms 9 respectively capture the two marks 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.

[0058] The working process of the pre-bonding mechanism of the visual alignment device in the wafer bonding equipment of this embodiment is as follows: S1. The chamber 21 surrounded by the box 2 is evacuated so that the vacuum degree of the chamber 21 meets the process requirements; S2. The robot carries the upper wafer and delivers the upper wafer into the alignment chamber 21 through the operation window 22. The ejector pin rises and lifts the upper wafer to contact the lower surface of the upper electrostatic chuck 4. The upper electrostatic chuck 4 is energized and absorbs the upper wafer by static electricity. The robot withdraws from the alignment chamber 21. S3. The robot carries the lower wafer and delivers the lower wafer into the alignment chamber 21 through the operation window 22. The ejector pin rises and lifts the lower wafer to detach from the robot. The robot exits the alignment chamber 21. The ejector pin falls back so that the lower wafer falls on the upper surface of the lower electrostatic chuck 6. The lower electrostatic chuck 6 is powered on and absorbs the lower wafer by electrostatic force. S4. The upper visual component 92 acquires the upper wafer image through the imaging window 91 of the upper electrostatic chuck 4, and the lower visual component 93 acquires the lower wafer image through the imaging window 91 of the lower electrostatic chuck 6, and determines the direction and magnitude of the compensation displacement of the lower wafer by the position difference between the mark of the upper wafer image and the mark of the lower wafer image; S5. The lower wafer is roughly aligned by the six-axis platform 52, and the lower wafer is finely aligned by the piezoelectric platform 53, so that the mark of the lower wafer image and the mark of the upper wafer image overlap, and the alignment is completed; S6. The pre-bonding drive 8 moves to lift the lower wafer to contact the upper wafer, and the lower wafer and the upper wafer are adsorbed by electrostatic attraction to complete pre-bonding; S7. The robot enters the alignment chamber 21 through the operation window 22, and the ejection drive 10 is actuated to eject the pre-bonded wafer to detach it from the upper electrostatic chuck 4 and drop it onto the robot. The robot carries the pre-treated wafer out of the alignment chamber 21.

[0059] The above is only a specific implementation of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions are given with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions 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 pre-bonding mechanism of a visual alignment device in a wafer bonding device, 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) and is mounted on the bottom wall of the box (2); an output portion of the alignment driving member (5) is located at the top thereof and is used to output six-degree-of-freedom spatial 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) has a shell fixed on the frame (1) and located below the box body (2); an output shaft seal of the pre-bonding drive member (8) 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); and the output shaft of the pre-bonding drive member (8) is used to lift the lower wafer after passing through the first avoidance hole (51) and the second avoidance hole (63) in sequence.

2. The pre-bonding mechanism of the visual alignment device in the wafer bonding equipment according to claim 1, characterized in that: The alignment driving component (5) comprises 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 (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).

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

4. The pre-bonding mechanism of the visual alignment device in the 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.

5. The pre-bonding mechanism of the visual alignment device in the wafer bonding equipment according to any one of claims 1 to 4, characterized in that: A lighting glass (23) is sealed and mounted on the side wall of the box body (2).

6. The pre-bonding mechanism of the visual alignment device in the wafer bonding equipment according to any one of claims 1 to 4, characterized in that: The on-off valve is a gate valve.

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