Wafer alignment device and method of alignment thereof, wafer bonding apparatus

Abstract

This invention discloses a wafer alignment device and method, and a wafer bonding apparatus, relating to the field of wafer bonding technology. The wafer alignment device includes a fixing module, a wafer transport module, a leveling module, a vision recognition module, an alignment module, and a lifting module. The fixing module is used to fix a fixture and drive the fixture to clamp and fix a first wafer and a second wafer. The wafer transport module is used to sequentially carry and transport the first wafer and the second wafer to the fixture. The wafer transport module includes a movable carrier base with a carrier tray for carrying the wafers. The leveling module is used to adjust the levelness of the second wafer relative to the first wafer. The vision recognition module is used to identify alignment marks on the first and second wafers. The alignment module is located below the carrier tray and is used to drive the carrier tray to move in a horizontal plane. The lifting module is configured to drive the leveling module, the alignment module, and the carrier tray to move up and down.

Description

Technical Field

[0001] This invention relates to the field of wafer bonding technology, and more particularly to a wafer alignment device and alignment method, and wafer bonding equipment. Background Technology

[0002] In semiconductor manufacturing processes, wafers must be precisely aligned before critical processes such as bonding or etching to ensure the yield and performance of the final device.

[0003] Existing alignment devices typically employ a two-stage process flow: "alignment first, clamping later." Specifically, wafer alignment is performed at a separate alignment station. The lower wafer is supported by a movable chuck or adsorption platform. A vision recognition module identifies alignment marks on the upper and lower wafers, and a multi-axis precision platform drives the lower wafer to move and rotate horizontally, achieving precise alignment with the upper wafer. After alignment, the aligned upper and lower wafers are transferred as a whole to a fixture, where they are clamped and fixed using grippers or clamping mechanisms to maintain their relative position before being transferred to subsequent process chambers. However, this "alignment first, clamping later" process flow has inherent drawbacks: after alignment, the aligned wafer pair must be removed from the original alignment station and undergo transfer and placement operations before finally being fixed in the fixture. During this transfer process, the aligned wafers are inevitably affected by factors such as robotic gripping, transport vibration, and placement impact, causing slight translational or rotational changes in their calibrated relative positions. Even with a high-precision transfer mechanism, its repeatability is difficult to match the motion accuracy of the alignment adjustment mechanism. As a result, the alignment accuracy in the final clamping state is often lower than the measurement accuracy when alignment is completed. Summary of the Invention

[0004] The purpose of this invention is to provide a wafer alignment device and method, and a wafer bonding equipment, so as to achieve synchronous clamping directly in the fixture during the wafer alignment process, thereby avoiding the decrease in accuracy caused by the transfer operation after alignment.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A wafer alignment apparatus, comprising:

[0007] A fixing module is used to fix the fixture and drive the fixture to clamp and fix the first wafer and the second wafer. Alignment marks are provided on both the first wafer and the second wafer.

[0008] A wafer transport module is located below the fixed module and is used to sequentially carry and transport the first wafer and the second wafer to the fixture; the wafer transport module includes a movable support base, and the support base is provided with a support tray for carrying the wafer;

[0009] A leveling module, located below the carrier disk, is used to adjust the levelness of the second wafer relative to the first wafer;

[0010] A visual recognition module is used to identify alignment marks on the first wafer and the second wafer;

[0011] An alignment module is located below the carrier disk and is used to drive the carrier disk to move in the horizontal plane so that the second wafer on the carrier disk and the first wafer on the fixture are aligned.

[0012] The lifting module is configured to drive the leveling module, the alignment module, and the support plate to lift.

[0013] As an optional embodiment of the wafer alignment device, the leveling module includes:

[0014] The leveling mechanism includes a first substrate, a second substrate, and leveling components evenly distributed between the first substrate and the second substrate; the first substrate can be connected to the carrier plate, and the leveling components are used to adjust the levelness of the carrier plate through the first substrate.

[0015] A leveling test piece is used to detect the levelness of the support plate.

[0016] As an optional embodiment of the wafer alignment device, the leveling detection element includes multiple pressure sensors, which are evenly distributed along the circumferential direction of the second substrate to detect the pressure at different positions of the leveling mechanism.

[0017] As an optional embodiment of the wafer alignment device, the leveling detection component includes multiple ball bearing assemblies, which are movable between the fixture and the carrier plate and are evenly distributed along the circumferential direction of the fixture.

[0018] As an optional embodiment of the wafer alignment device, the carrier is provided with a central hole, and a plurality of support portions extending from the inner wall of the central hole toward the center are arranged at intervals along the circumference of the central hole. The carrier plate is suspended on the plurality of support portions so that the leveling module, the alignment module and the lifting module can act on the carrier plate through the central hole.

[0019] As an optional embodiment of the wafer alignment device, the carrier disk includes a carrier surface and a plurality of elastic pin assemblies. A plurality of adsorption holes are spaced apart on the carrier surface, and the plurality of elastic pin assemblies are spaced apart circumferentially on the carrier surface. The plurality of elastic pin assemblies can be raised and lowered, selectively rising above the carrier surface or falling below the carrier surface.

[0020] As an optional embodiment of the wafer alignment device, the wafer transport module further includes a slide, which includes two opposing guide rails, and the two sides of the support are slidably connected to the two guide rails.

[0021] As an alternative to the wafer alignment apparatus, the vision recognition module includes an upper vision recognition unit and a lower vision recognition unit, and the vision recognition module is configured to selectively use the upper vision recognition unit or the lower vision recognition unit according to the light transmittance of the first wafer.

[0022] As an optional embodiment of the wafer alignment apparatus, the wafer alignment apparatus further includes:

[0023] The mounting bracket is located on one side of the fixed module;

[0024] A first driving unit is disposed on the mounting bracket. The first driving unit is connected to the upper vision recognition unit and is used to drive the upper vision recognition unit to switch between a working position facing the fixture and an idle position avoiding the fixture.

[0025] As an alternative to the wafer alignment device, the first driving unit includes:

[0026] The first drive module is mounted on the mounting bracket;

[0027] An adjusting arm is connected at one end to the first drive module and at the other end to the upper vision recognition unit; the first drive module drives the upper vision recognition unit to swing through the adjusting arm to switch between the working position and the idle position.

[0028] As an optional embodiment of the wafer alignment device, the first driving unit further includes a second driving module, which is connected between the adjusting arm and the upper vision recognition unit, and is used to drive the upper vision recognition unit to move along the X-axis, Y-axis and Z-axis directions.

[0029] As an optional embodiment of the wafer alignment device, a second driving unit is also included. The second driving unit is connected to the lower vision recognition unit and is used to drive the lower vision recognition unit to move in the X-axis, Y-axis and Z-axis directions.

[0030] A wafer alignment method, applied to a wafer alignment apparatus as described in any of the above embodiments, the wafer alignment method comprising:

[0031] The fixture is installed on the fixing module;

[0032] The first wafer is transported to the bottom of the fixture by the wafer transport module, and the lifting module rises and lifts the carrier plate so that the first wafer abuts against the fixture, and the fixture fixes the first wafer.

[0033] The second wafer is transported to the bottom of the fixture by the wafer transport module, and the lifting module lifts the second wafer to a preset position;

[0034] The leveling module is used to level the second wafer with the first wafer;

[0035] The visual recognition module identifies alignment marks on the first wafer and the second wafer, and using the alignment marks on the first wafer as a reference, the alignment module drives the carrier disk to move so as to align the alignment marks on the second wafer with the alignment marks on the first wafer.

[0036] The fixture fixes and levels the second wafer after alignment;

[0037] After the fixture secures the second wafer, it is removed along with the first and second wafers to proceed to the next process.

[0038] As an optional embodiment of the wafer alignment method, the leveling module includes multiple leveling components and multiple pressure sensors. The step of leveling the second wafer with the first wafer using the leveling module includes:

[0039] The multiple leveling components drive the carrier disk to move, causing the second wafer to fit against the first wafer;

[0040] Adjust each of the leveling components until the pressure values ​​detected by each of the pressure sensors are the same, and determine that the second wafer and the first wafer are leveled.

[0041] As an optional embodiment of the wafer alignment method, the leveling module includes multiple leveling components and multiple ball bearing components; the step of leveling the second wafer and the first wafer using the leveling module includes:

[0042] Control the movement of multiple ball bearing assemblies between the fixture and the carrier plate;

[0043] The multiple leveling components drive the carrier plate to move, so that each of the ball bearing components contacts the fixture and the carrier plate;

[0044] When all the ball bearing assemblies are in contact with the fixture and the carrier plate, it is determined that the second wafer is leveled with the first wafer.

[0045] As an optional embodiment of the wafer alignment method, the visual recognition module includes an upper visual recognition unit and a lower visual recognition unit;

[0046] The step of identifying alignment marks on the first wafer and the second wafer using the visual recognition module includes:

[0047] The upper visual recognition unit or the lower visual recognition unit is selected based on whether the first wafer is a transparent wafer.

[0048] When the first wafer is a transparent wafer, the upper visual recognition unit is moved above the fixed module to simultaneously identify the alignment marks of the first wafer and the second wafer through the first wafer;

[0049] When the first wafer is a non-transparent wafer, the lower vision recognition unit identifies the alignment marks of the first wafer and the second wafer in sequence.

[0050] A wafer bonding apparatus includes a wafer alignment device as described above for performing inter-wafer alignment prior to wafer bonding.

[0051] The beneficial effects of this invention are:

[0052] The wafer alignment device and method provided by this invention fix a fixture to a fixing module. During the alignment process, the wafer transport module first transports a first wafer to the bottom of the fixture, and then lifts the carrier plate via a lifting module to fix the first wafer to the fixture. The wafer transport module then transports a second wafer to the bottom of the fixture. The lifting module drives a leveling module to rise and connect with the carrier plate, leveling the carrier plate so that the second wafer is parallel to the first wafer. A visual recognition module identifies the alignment marks of the first and second wafers. Based on the recognition result, an alignment module rises and drives the carrier plate to move horizontally, aligning the second wafer with the first wafer. Finally, the lifting module lifts the carrier plate to fix the second wafer to the fixture. This design, which completes alignment during clamping, avoids the step of transferring the aligned wafer from the alignment station to the clamping station, eliminating accuracy loss caused by transfer, placement, or accidental contact. Furthermore, when the lifting module drives the carrier plate to rise, bringing the second wafer closer to the first wafer, the leveling module can monitor the horizontal state of the carrier plate in real time and dynamically correct the horizontality of the second wafer while the alignment module performs alignment adjustments. This ensures that the second wafer and the first wafer remain parallel at final contact. The first wafer is directly fixed to the fixture, and the second wafer is aligned using the first wafer as a reference. After alignment, the second wafer is held by the same fixture. Throughout the process, the fixture serves as both the clamping mechanism and the carrier of the alignment reference, avoiding additional errors introduced by reference conversion and ensuring that the alignment accuracy in the final clamping state is highly consistent with the measurement accuracy after alignment.

[0053] The wafer bonding equipment provided by the present invention includes the wafer alignment device described above, which realizes the process capability of wafer alignment during clamping, avoids transfer accuracy loss, and improves the integration and process yield of the wafer bonding equipment. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the wafer alignment device provided in Embodiment 1 of the present invention;

[0055] Figure 2 This is a schematic diagram of the structure of the fixing module provided in Embodiment 1 of the present invention;

[0056] Figure 3 This is a schematic diagram of the fixture device provided in Embodiment 1 of the present invention not being pressed tightly onto the fixed module;

[0057] Figure 4 This is a schematic diagram of the structure of the drive gripper assembly on the fixing module provided in Embodiment 1 of the present invention;

[0058] Figure 5 This is a schematic diagram of the wafer transport module provided in Embodiment 1 of the present invention with the carrier fully withdrawn;

[0059] Figure 6 This is a cross-sectional view of the leveling module provided in Embodiment 1 of the present invention;

[0060] Figure 7 This is a cross-sectional view of the first leveling method of leveling the second wafer by cooperating with the leveling module, the carrier disk, and the fixture tooling provided in Embodiment 1 of the present invention;

[0061] Figure 8 This is a cross-sectional view of the second leveling method provided in Embodiment 1 of the present invention, in which the leveling module cooperates with the carrier disk and fixture to level the second wafer;

[0062] Figure 9 This is a schematic diagram of the installation structure of the upper visual recognition unit and the first driving unit provided in Embodiment 1 of the present invention;

[0063] Figure 10 This is a schematic diagram of the installation structure of the lower vision recognition unit and the second driving unit provided in Embodiment 1 of the present invention;

[0064] Figure 11 This is a flowchart of the wafer alignment method provided in Embodiment 2 of the present invention.

[0065] In the picture:

[0066] 100. Fixtures and tooling;

[0067] 201, First wafer; 202, Second wafer;

[0068] 1. Fixing module; 11. Hollow structure fixing plate; 111. Receiving groove; 12. Positioning assembly; 13. Clamping assembly; 14. Drive gripper assembly; 141. Lifting drive component; 142. First clamping component; 1421. First clamping drive component; 1422. First clamping part; 143. Second clamping component; 1431. Second clamping drive component; 1432. Second clamping part; 15. Ball assembly; 16. First drive component;

[0069] 2. Wafer transport module; 21. Slide; 22. Carrier base; 221. Handle; 222. Support; 23. Carrier plate; 231. Carrier surface; 2311. Adsorption hole; 232. Elastic pin assembly; 233. Center pin; 24. Locking assembly; 241. Second drive component; 242. Connector; 25. Photoelectric sensor;

[0070] 3. Leveling module; 31. Leveling mechanism; 311. Lifting cylinder; 312. Tension spring; 313. Limiting component; 3131. Needle roller guide post; 3132. Spherical bearing; 3133. Slider; 3134. Slide rail; 314. First base plate; 315. Second base plate; 32. Pressure sensor; 33. Vacuum chamber; 331. Vacuum adsorption port;

[0071] 41. Upper vision recognition unit; 42. Lower vision recognition unit; 43. First drive unit; 431. First drive module; 432. Adjusting arm; 433. Second drive module; 44. Limiting unit; 441. Limiting plate; 4411. Limiting groove; 4412. Working locking hole; 4413. Standby locking hole; 4414. Idle locking hole; 442. Limiting drive module; 45. Second drive unit; 451. Z-axis drive unit; 452. Y-axis drive unit; 453. X-axis drive unit; 454. Support frame;

[0072] 5. Alignment module;

[0073] 6. Lifting module; 61. Lifting platform; 62. Lifting drive module; 63. Guide assembly;

[0074] 7. Mounting bracket;

[0075] 8. Protective frame;

[0076] 9. Base. Detailed Implementation

[0077] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0078] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0079] Unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and connections within two components or interactions between two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0080] Unless otherwise expressly specified and limited, "above" or "below" a second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of a second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of a second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0081] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0082] Example 1:

[0083] like Figure 1 , Figure 5 and Figure 7 As shown, this embodiment provides a wafer alignment device, including a fixing module 1, a wafer transport module 2, a leveling module 3, a vision recognition module, an alignment module 5, and a lifting module 6. The fixing module 1 is used to fix the fixture 100 and drive the fixture 100 to clamp and fix a first wafer 201 and a second wafer 202. Both the first wafer 201 and the second wafer 202 are provided with alignment marks. The wafer transport module 2 is located below the fixing module 1 and is used to sequentially carry and transport the first wafer 201 and the second wafer 202 to the fixture 100. The wafer transport module 2 includes a movable support base 22, on which a support tray 23 for carrying the wafer is provided. The leveling module 3 is located below the support tray 23 and is used to adjust the levelness of the second wafer 202 relative to the first wafer 201. The vision recognition module is used to identify the alignment marks on the first wafer 201 and the second wafer 202. The alignment module 5 is located below the carrier plate 23 and is used to drive the carrier plate 23 to move in the horizontal plane so that the second wafer 202 on the carrier plate 23 and the first wafer 201 on the fixture 100 are aligned. The lifting module 6 is configured to drive the leveling module 3, the alignment module 5 and the carrier plate 23 to lift.

[0084] The wafer alignment device fixes the fixture 100 to the fixing module 1. During the alignment process, the wafer transport module 2 first transports the first wafer 201 to the bottom of the fixture 100, and the lifting module 6 lifts the carrier plate 23 to fix the first wafer 201 to the fixture 100. The wafer transport module 2 then transports the second wafer 202 to the bottom of the fixture 100. The lifting module 6 drives the leveling module 3 to rise and connect with the carrier plate 23 to level the carrier plate 23, making the second wafer 202 parallel to the first wafer 201. The visual recognition module identifies the alignment marks of the first wafer 201 and the second wafer 202. Based on the recognition result, the alignment module 5 rises and drives the carrier plate 23 to move in the horizontal plane, so that the second wafer 202 is aligned with the first wafer 201. Finally, the lifting module 6 lifts the carrier plate 23 to fix the second wafer 202 to the fixture 100. This design, which completes alignment during clamping, avoids the step of transferring the aligned wafer from the alignment station to the clamping station, eliminating the loss of precision caused by transfer, placement, accidental contact, and other operations.

[0085] In one embodiment, along the Z-axis, the leveling module 3 is located below the wafer transport module 2 and can be connected to the carrier plate 23; the alignment module 5 is located below the leveling module 3, and the lifting module 6 is located below the alignment module 5. The lifting module 6 drives the leveling module 3 to rise and fall through the alignment module 5, so that the leveling module 3 is connected to the carrier plate 23 to drive the carrier plate 23 to rise and fall, so as to transport the wafer to the fixture 100; at the same time, the leveling module 3 can abut against the carrier plate 23 to level the second wafer 202 on the carrier plate 23. After the visual recognition module recognizes the alignment marks on the first wafer 201 and the second wafer 202, according to the recognition result, the lifting module 6 drives the alignment module 5 to rise. After the leveling module 3 is connected to the carrier plate 23, the alignment module 5 drives the carrier plate 23 to move in the horizontal plane so that the second wafer 202 is aligned with the first wafer 201.

[0086] The leveling module 3 is positioned between the carrier plate 23 and the alignment module 5. When the lifting module 6 drives the carrier plate 23 to rise, bringing the second wafer 202 closer to the first wafer 201, the leveling module 3 can monitor the horizontal state of the carrier plate 23 in real time and dynamically correct the horizontality of the second wafer 202 while the alignment module 5 performs alignment adjustments. This ensures that the second wafer 202 and the first wafer 201 remain parallel when they finally come into contact. The first wafer 201 is directly fixed to the fixture 100. The second wafer 202 is aligned with the first wafer 201 as a reference. After alignment, the second wafer 202 is clamped by the same fixture 100. Throughout the process, the fixture 100 serves as both the clamping mechanism and the carrier of the alignment reference, avoiding additional errors introduced by reference conversion and ensuring that the alignment accuracy in the final clamping state is highly consistent with the measurement accuracy after alignment.

[0087] In other embodiments, the leveling module 3 can also be disposed between the alignment module 5 and the lifting module 6. When the alignment module 5 drives the carrier plate 23 to move in the horizontal plane, it only needs to drive the carrier plate 23 to move horizontally. The leveling module 3 is supported by the lifting module 6, which reduces the load on the alignment module 5 and improves the response speed and accuracy of the alignment adjustment.

[0088] like Figures 2-4 and Figure 7 As shown, the fixture 100 is designed according to existing technology, and its specific structure includes a support ring. The support ring is circumferentially spaced with multiple jaws and multiple pads, which are arranged in a one-to-one correspondence. When clamping and fixing the first wafer 201 and the second wafer 202, the pads are located between the first wafer 201 and the second wafer 202 to form and maintain the gap between them. The lower surface of the support ring is provided with an adsorption surface for adsorbing the first wafer 201. The jaws are used to clamp and fix the coaxially arranged first wafer 201 and second wafer 202 together on the support ring.

[0089] The fixing module 1 includes a hollow structure fixing plate 11 and multiple sets of clamping and fixing components. These components are spaced apart circumferentially along the hollow structure fixing plate 11. Each set includes a positioning component 12, a clamping component 13, and a driving gripper assembly 14. The fixture 100 is detachably mounted on the hollow structure fixing plate 11. The positioning component 12 is used for radial and / or circumferential positioning of the fixture 100. Specifically, the positioning component 12 includes a positioning block and a positioning pin that circumferentially abut against the fixture 100. The clamping component 13 is used to clamp and fix the bearing ring of the fixture 100 to the hollow structure fixing plate 11. Specifically, the clamping component 13 includes a rotary cylinder and a clamping column connected to the drive end of the rotary cylinder. The driving gripper assembly 14 is driven by the grippers of the fixture 100 and is used to drive the grippers to perform clamping or releasing wafer actions.

[0090] The specific structures of the positioning component 12 and the clamping component 13 can be designed with reference to the existing technology based on the structure of the fixture 100. This is not the focus of the improvement of the present invention, and will not be described in detail here.

[0091] like Figure 4As shown, the drive gripper assembly 14 includes a lifting drive 141, a first clamping component 142, and a second clamping component 143. The first clamping component 142 drives the grippers in the fixture 100 to clamp or release the wafer; the second clamping component 143 drives the shims in the fixture 100 to insert the shims between the wafers or remove them from below the adsorption surface. The lifting drive 141 is connected to the first clamping component 142 and the second clamping component 143 and drives the first clamping component 142 and the second clamping component 143 to move up and down. The lifting drive 141 uses a linear drive cylinder or motor in conjunction with a ball screw pair.

[0092] The first clamping component 142 and the second clamping component 143 are independently controlled and driven separately according to process requirements. The first clamping component 142 includes a first clamping drive 1421 and two first clamping parts 1422. The first clamping drive 1421 drives the two first clamping parts 1422 to rotate 90° in a direction closer to each other, so that the two first clamping parts 1422 change from a vertically separated state to a horizontal clamping state, clamping the jaw drive end in the fixture 100, thereby driving the jaw to open or close. The first clamping drive 1421 drives the two first clamping parts 1422 to rotate 90° in a direction further away from each other, so that the two first clamping parts 1422 return from the horizontal clamping state to the vertically separated state, releasing the jaw drive end in the fixture 100. The jaw drive end is provided with a first self-locking spring, which can keep the jaw drive end in its position.

[0093] The second clamping component 143 includes a second clamping drive 1431 and two second clamping portions 1432. The second clamping drive 1431 drives the two second clamping portions 1432 to rotate 90° in a direction closer to each other, so that the two second clamping portions 1432 change from a vertically separated state to a horizontal clamping state, clamping the pad driving end in the fixture 100, thereby removing or extending the pad. The second clamping drive 1431 drives the two second clamping portions 1432 to rotate 90° in a direction further away from each other, so that the two second clamping portions 1432 return from the horizontal clamping state to a vertically separated state, releasing the pad driving end in the fixture 100. The pad driving end is provided with a second self-locking spring, which can keep the pad driving end in its position.

[0094] Before placing the fixture 100, the two first clamping parts 1422 and the two second clamping parts 1432 are vertically separated. At this time, placing the fixture 100 on the fixing module 1 will not cause interference. After the fixture 100 is fixed on the fixing module 1, before wafer loading, the lifting drive 141 drives the first clamping part 142 and the second clamping part 143 to descend synchronously. The first clamping drive 1421 drives the two first clamping parts 1422 to switch to a horizontal clamping state to clamp the jaw drive end in the fixture 100. At the same time, the second clamping drive 1431 drives the two second clamping parts 1432 to switch to a horizontal clamping state to clamp the pad drive end in the fixture 100. At this time, the lifting drive 141 synchronously drives the first clamping part 142 and the second clamping part 143 to rise, driving the jaw drive end and the pad drive end to rise, thereby driving the jaw to open and the pad to be pulled out at the same time to prevent the wafer from being broken during loading. When the grippers open and the pads are removed, the first clamping drive 1421 drives the two first clamping parts 1422 to switch to a vertically separated state, and at the same time the second clamping drive 1431 drives the two second clamping parts 1432 to switch to a vertically separated state.

[0095] When the first wafer 201 is loaded and the spacer needs to be extended, both the first clamping component 142 and the second clamping component 143 are in the raised state. The second clamping drive component 1431 drives the two second clamping parts 1432 from the vertically separated state to the horizontal clamping state to clamp the spacer driving end. Then, the lifting drive component 141 drives the first clamping component 142 and the second clamping component 143 to descend synchronously. The second clamping drive component 1431 drives the spacer driving end to descend, thereby driving the spacer to extend. After the spacer is extended, the second clamping drive component 1431 drives the two second clamping parts 1432 to return to the vertically separated state.

[0096] When the second wafer 202 is loaded and the grippers need to be closed, the lifting drive 141 drives the first clamping component 142 and the second clamping component 143 to rise synchronously. The first clamping drive 1421 drives the two first clamping parts 1422 to switch to a horizontal clamping state to clamp the gripper drive end in the fixture 100. Then, the lifting drive 141 drives the first clamping component 142 and the second clamping component 143 to fall synchronously. The first clamping drive 1421 drives the gripper drive end to fall, thereby driving the grippers to close and clamp the second wafer 202 and the first wafer 201.

[0097] Both the first clamping drive 1421 and the second clamping drive 1431 adopt a rotary cylinder driven structure. Exemplarily, the first clamping drive 1421 includes a first rotary cylinder, the output shaft of which is connected to a first transmission gear. Two first clamping parts 1422 are respectively mounted on two first rotating shafts, each of which has a first driven gear meshing with the first transmission gear. The first rotary cylinder drives the first transmission gear to rotate, causing the two first rotating shafts to rotate synchronously in opposite directions, thus rotating the two first clamping parts 1422 90° each in a direction that brings them closer together or further apart. The second clamping drive 1431 includes a second rotary cylinder, the output shaft of which is connected to a second transmission gear. Two second clamping parts 1432 are respectively mounted on two second rotating shafts, each of which has a second driven gear meshing with the second transmission gear. The second rotary cylinder drives the second transmission gear to rotate, causing the two second rotating shafts to rotate synchronously in opposite directions, thus rotating the two second clamping parts 1432 90° each in a direction that brings them closer together or further apart.

[0098] like Figure 1 and Figure 5 As shown, the wafer transport module 2 also includes a slide 21, which includes two oppositely arranged guide rails. The guide rails are fixed to the bottom of the hollow structure fixing plate 11. The two sides of the support seat 22 are slidably connected to the two guide rails, so that the support seat 22 can slide out from the slide 21 to receive the wafer, and then slide into the slide 21 to transport the wafer to the bottom of the fixture 100.

[0099] In one embodiment, the wafer transport module 2 further includes a locking assembly 24, which includes a second drive member 241 and a connector 242. The second drive member 241 and the connector 242 are driven together. The carrier 22 is provided with a locking hole, and the second drive member 241 is used to drive the connector 242 to insert into or retract from the locking hole. The locking assembly 24 is located at the end of the guide rail. When the carrier 22 slides into the slide block 21 and moves to the end of the guide rail, it indicates that the carrier 22 has reached the locking position. At this time, the connector 242 corresponds to the locking hole, and the second drive member 241 drives the connector 242 to extend and insert into the locking hole, thereby locking the carrier 22. When the carrier 22 slides out, the second drive member 241 controls the connector 242 to retract, and the connector 242 disengages from the locking hole, allowing the carrier 22 to slide out from the slide block 21 to receive the wafer.

[0100] Furthermore, the wafer transport module 2 also includes a photoelectric sensor 25. A sensing element is provided on the carrier 22. The photoelectric sensor 25 cooperates with the sensing element to detect whether the carrier 22 has reached the locking position. The photoelectric sensor 25 is communicatively connected to the control unit. When the carrier 22 reaches the locking position, the photoelectric sensor 25 detects that the sensing element sends a signal to the control unit. The control unit then controls the second drive element 241 to drive the connector 242 to extend and engage with the locking hole for locking.

[0101] Specifically, the second driving component 241 is a linear driving component such as a cylinder, and the plug-in component 242 is a plug-in post adapted to the locking hole. The extension rod of the cylinder extends to drive the plug-in post to extend, and the retraction rod of the cylinder retracts to drive the plug-in post to retract. Two sets of locking components 24 and photoelectric sensors 25 are provided in a one-to-one correspondence, respectively located at the ends of the two guide rails; correspondingly, two locking holes and two sensing components are also provided.

[0102] The front side plate of the support seat 22 is provided with a handle 221, which can be used to pull the support seat 22 out of or into the slide seat 21.

[0103] In one embodiment, the support base 22 is provided with a central hole, and a plurality of support portions 222 extending from the inner wall of the central hole to the center are provided at intervals along the circumference of the central hole. The support plate 23 is suspended on the plurality of support portions 222 so that the leveling module 3, the alignment module 5 and the lifting module 6 can act on the support plate 23 through the central hole.

[0104] Specifically, the top of the support base 22 is provided with a central hole, and the support part 222 is a support plate. Three support plates are arranged along the circumference of the central hole. The upper surfaces of the three support plates are on the same horizontal plane, forming a support plane for the support plate 23, ensuring that the support plate 23 is placed stably.

[0105] Furthermore, multiple positioning plates are provided at intervals on the inner wall of the central hole. The positioning plates abut against the peripheral wall of the bearing plate 23 to radially position the bearing plate 23 and prevent it from shifting in the horizontal plane.

[0106] In one embodiment, the support plate 23 includes a support surface 231 and a plurality of elastic pin components 232. The support surface 231 is provided with a plurality of suction holes 2311 at intervals. The plurality of elastic pin components 232 are spaced apart in the circumferential direction of the support surface 231 and can be raised and lowered, selectively rising above the support surface 231 or falling below the support surface 231.

[0107] Specifically, the elastic pin assembly 232 includes a fixed seat, a movable seat, and a support pin. The movable seat is elastically connected to the fixed seat and forms a sealed cavity with the fixed seat. The support pin is located on the top of the movable seat. The adsorption hole 2311 and the sealed cavity are both connected to the vacuum system. The vacuum system evacuates the vacuum and drives the movable seat to move downward, so that the support surface formed by the multiple support pins is lower than the bearing surface 231, and at the same time, the adsorption hole 2311 generates an adsorption force.

[0108] When the carrier disk 23 carries the first wafer 201, the bonding surface of the first wafer 201 faces downwards. To reduce contact with the bonding surface and avoid scratches or contamination, the carrier disk 23 uses a point contact method with support pins to carry the first wafer 201. The vacuum system is not working, the adsorption holes 2311 have no adsorption force, and there is no negative pressure in the sealed cavity. The moving seat is kept in an upward extended state under the elastic force of the spring, and the tops of multiple support pins together form a support surface, which is higher than the carrier surface 231. The first wafer 201 is placed on the support surface and supported only by multiple point contact support pins. The bonding surface and the carrier surface 231 remain suspended, achieving contactless support of the bonding surface of the first wafer 201 and avoiding scratches or particle contamination of the bonding surface by the carrier surface 231.

[0109] When the carrier disk 23 carries the second wafer 202, the bonding surface of the second wafer 202 faces upward, and the back surface (non-bonding surface) of the second wafer 202 faces downward and contacts the carrier disk 23. At this time, the second wafer 202 needs to be firmly adsorbed onto the carrier disk 23 for subsequent alignment and lifting operations. The vacuum system operates, and the adsorption hole 2311 and the sealing cavity simultaneously generate negative pressure. The negative pressure in the sealing cavity drives the moving seat to move downward against the spring force, causing the support pin to descend, so that the top of the support pin is lower than the carrier surface 231; simultaneously, the adsorption hole 2311 generates adsorption force, adsorbing and fixing the back surface of the second wafer 202 onto the carrier surface 231. This achieves automatic avoidance of the support pin and reliable adsorption and fixation of the wafer, ensuring the stability of the second wafer 202's position during subsequent alignment and lifting operations.

[0110] A center pin 233 is provided at the center of the bearing surface 231. When bearing a large wafer, the center of the wafer may collapse due to gravity. The center pin 233 is used to support the center of the wafer, prevent the wafer from deforming, and ensure that the entire wafer remains flat.

[0111] like Figure 6 As shown, the leveling module 3 includes a leveling mechanism 31 and a leveling detection component. The leveling mechanism 31 includes a first substrate 314, a second substrate 315, and leveling components evenly distributed between the first substrate 314 and the second substrate 315. The first substrate 314 can be connected to the carrier plate 23, and the leveling components are used to adjust the levelness of the carrier plate 23 through the first substrate 314. The leveling detection component is used to detect the levelness of the carrier plate 23. The leveling detection component is communicatively connected to the control unit and is used to send a detection signal characterizing the levelness of the carrier plate 23 to the control unit. Based on the received signal, the control unit sends a control command to the leveling component to drive the leveling mechanism 31 to operate until the carrier plate 23 reaches a preset levelness.

[0112] Specifically, the first substrate 314 is located at the top of the leveling mechanism 31 and can be connected to the carrier plate 23. Two vacuum chambers 33 are spaced apart at the top of the first substrate 314. The top surface of each vacuum chamber 33 has a vacuum adsorption port 331 communicating with its inner cavity. The inner cavity of each vacuum chamber 33 is connected to a vacuum system. The second substrate 315 is located at the bottom of the leveling mechanism 31 and is connected to the alignment module 5. The leveling assembly is used to adjust the level of the carrier plate 23 connected to the first substrate 314 by driving the first substrate 314 to produce a slight displacement relative to the second substrate 315.

[0113] When the lifting module 6 drives the leveling module 3 to rise through the alignment module 5, and the first base plate 314 of the leveling module 3 comes into contact with the carrier plate 23, the vacuum system works, causing the vacuum adsorption port 331 of the vacuum chamber 33 to generate an adsorption force, adsorbing and fixing the carrier plate 23 to the top surface of the vacuum chamber 33.

[0114] Furthermore, the vacuum adsorption port 331 can be connected to both the inlet of the adsorption hole 2311 on the carrier disk 23 and the inlet of the sealing cavity, so that when leveling the second wafer 202 on the carrier disk 23, a vacuum is simultaneously provided to the vacuum adsorption port 331, the adsorption hole 2311 and the sealing cavity of the elastic pin assembly 232 through the same vacuum system: a vacuum is provided to the vacuum adsorption port 331 to adsorb and fix the leveling module 3 to the carrier disk 23; a vacuum is provided to the adsorption hole 2311 of the carrier disk 23 to adsorb and fix the second wafer 202; and a vacuum is provided to the sealing cavity of the elastic pin assembly 232 to drive the support pin to descend.

[0115] In one embodiment, the leveling assembly includes lifting cylinders 311. During the leveling process, multiple lifting cylinders 311 work together to tilt the first base plate 314 to adjust its levelness. The lifting cylinders 311 have built-in locking mechanisms that mechanically lock the drive rods of the lifting cylinders 311 after leveling is completed. This overcomes minor displacement of the drive rods caused by gas compression and slow leakage caused by wear of the seals after long-term use, ensuring the stability of the leveling position.

[0116] Furthermore, the leveling assembly also includes two tension springs 312, which are respectively disposed on both sides of the lifting cylinder 311. The two ends of the tension springs 312 are respectively connected to the first substrate 314 and the second substrate 315. The two tension springs 312 are symmetrically arranged on both sides of the lifting cylinder 311, and continuously apply tension, so that the first substrate 314 always tends to move closer to the second substrate 315. This preload forces the spherical protrusion to maintain close contact with the first substrate 314, while avoiding the first substrate 314 from tilting or shifting to one side due to uneven tension on one side.

[0117] In one embodiment, the leveling mechanism 31 further includes multiple limiting components 313, which are evenly distributed inside the multiple leveling components. Each limiting component 313 includes a needle roller guide post 3131 and a spherical bearing 3132. The fixed end of the needle roller guide post 3131 is located on the second substrate 315. The inner ring of the spherical bearing 3132 is connected to the movable end of the needle roller guide post 3131, and the outer ring of the spherical bearing 3132 is slidably connected to the first substrate 314. The needle roller guide post 3131 has a precise vertical guiding function and can limit horizontal offset and torsion. The needle roller guide post 3131 ensures that the first substrate 314 does not wobble or misalign during lifting and lowering, providing a stable vertical support reference for the spherical bearing 3132. In conjunction with the lifting cylinder 311, it achieves the vertical upward positioning of the first substrate 314. Meanwhile, the spherical bearing 3132 has an angle adaptive capability, enabling it to deflect at a small angle in any direction. When the drive strokes of multiple lifting cylinders 311 are inconsistent, the first base plate 314 will tilt. The spherical bearing 3132 can automatically make a small-angle adaptive deflection in real time according to the tilt angle of the first base plate 314, avoiding stiffness, jamming, stress concentration, and motion blockage caused by rigid connection. In addition, by setting the outer ring of the spherical bearing 3132 to slide with the first base plate 314, when the first base plate 314 tilts, the connection point between the first base plate 314 and the limiting component 313 will generate a small horizontal displacement. The sliding connection can absorb this micro-displacement, retain unidirectional sliding, and ensure smooth and non-interfering movement. In this embodiment, the needle roller guide post 3131 and the spherical bearing 3132 are standard parts, and the specific structure of the needle roller guide post 3131 and the spherical bearing 3132 will not be described in detail.

[0118] Specifically, the limiting component 313 also includes a slide rail 3134 disposed at the bottom of the first substrate 314 and a slider 3133 that slides in cooperation with the slide rail 3134. The outer ring of the spherical bearing 3132 is fixedly connected to the slider 3133. The sliding cooperation between the slider 3133 and the slide rail 3134, as well as the angular adaptive capability of the spherical bearing 3132, can achieve dual adaptation of angle and micro-displacement, ensuring smooth and interference-free movement of the first substrate 314.

[0119] In this embodiment, three lifting cylinders 311 are provided, and the three lifting cylinders 311 are evenly distributed along the outer edge of the second substrate 315; three limiting components 313 are provided, and the three limiting components 313 are evenly distributed circumferentially on the inner side of the lifting cylinders 311. The three lifting cylinders 311 evenly distributed on the outer edge constitute a stable three-point support system, which can uniquely and accurately determine the posture of the first substrate 314, providing a deterministic adjustment benchmark for leveling; at the same time, the three limiting components 313 evenly distributed on the inner side form an auxiliary constraint near the center of the first substrate 314, effectively resisting the lateral force and torsional torque generated by the bearing plate 23 during alignment and lifting, preventing the first substrate 314 from horizontal movement or rotation, thereby protecting the outer lifting cylinders 311 from lateral loads and avoiding bending of the drive rod of the lifting cylinders 311 or uneven wear of the seals; this ensures both the flexibility of the leveling action of the lifting cylinders 311 and the overall rigidity of the system after leveling.

[0120] The leveling detection component is used to detect the levelness of the bearing plate 23 and sends the detection signal to the control unit. The control unit controls the leveling component to operate based on the received signal.

[0121] In one embodiment, combined with Figure 7 and Figure 10 As shown, the leveling detection component includes multiple pressure sensors 32, which are evenly distributed along the circumferential direction of the second substrate 315 to detect the pressure at different positions of the leveling mechanism 31.

[0122] Specifically, three pressure sensors 32 are provided, which are evenly distributed between the second substrate 315 and the alignment module 5. All three pressure sensors 32 are communicatively connected to the control unit and can send the detected pressure value to the control unit.

[0123] The leveling method of the leveling module 3 of the pressure sensor 32 described above is suitable for application scenarios in the bonding process between the first wafer 201 and the second wafer 202 where there is no requirement for whether the bonding surfaces of the first wafer 201 and the second wafer 202 are in contact before bonding.

[0124] The specific working steps are as follows: The lifting module 6 drives the leveling module 3 to lift the support plate 23 through the alignment module 5, lifting the second wafer 202 to a preset position. At this time, there is a preset gap between the second wafer 202 and the first wafer 201. The control unit controls the drive rods of the three lifting cylinders 311 to extend synchronously, driving the first substrate 314 to rise, and causing the second wafer 202 in the support plate 23 to move upward until it contacts and adheres to the first wafer 201. After the second wafer 202 contacts the first wafer 201, the three pressure sensors 32 detect the pressure value at their respective positions in real time and send the detected pressure value to the control unit. The control unit continuously compares the pressure values ​​of the three pressure sensors 32 and controls the corresponding lifting cylinders 311 to move. When the pressure values ​​detected by the three pressure sensors 32 are equal, it indicates that the second wafer 202 and the first wafer 201 have been evenly adhered and reached a horizontal state. The control unit determines that the leveling is complete and controls the lifting cylinders 311 to stop moving.

[0125] In one embodiment, combined with Figure 2 and Figure 8 As shown, the leveling detection component includes multiple ball bearing assemblies 15 and a first driving member 16 for moving the ball bearing assemblies 15. The multiple ball bearing assemblies 15 are movable between the fixture 100 and the carrier plate 23 and are evenly distributed along the circumferential direction of the fixture 100. Each ball bearing assembly 15 includes a ball and a connecting member. The ball contacts one of the fixture 100 and the carrier plate 23. The leveling mechanism 31 adjusts the levelness of the carrier plate 23 so that the ball contacts the other of the fixture 100 and the carrier plate 23. The output end of the first driving member 16 is connected to one end of the connecting member, and the ball is movably disposed at the other end of the connecting member. The upper and lower sides of the ball protrude from the upper and lower end surfaces of the connecting member, respectively. The first driving member 16 is preferably a translation cylinder, and the translation rod of the translation cylinder is connected to one end of the connecting member for driving the connecting member to move horizontally.

[0126] Optionally, multiple ball bearing assemblies 15 and a first driving member 16 for moving the ball bearing assemblies 15 are disposed on the fixed module 1. The multiple ball bearing assemblies 15 are distributed circumferentially along the hollow structure fixed plate 11, and multiple first driving members 16 are provided corresponding to each ball bearing assembly 15. The hollow structure fixed plate 11 has a receiving groove 111 in its circumferential direction. The ball bearing assemblies 15 are received in the receiving groove 111. During leveling, the first driving member 16 drives the ball bearing assemblies 15 to extend out of the receiving groove 111 and move between the fixture 100 and the carrier plate 23. After leveling, the first driving member 16 drives the ball bearing assemblies 15 to retract into the receiving groove 111 to avoid interference with other components. By providing the receiving groove 111, the ball bearing assemblies 15 are received in the receiving groove 111, avoiding interference with other components, preventing collisions, jamming, or foreign objects from entering during movement, and improving operational stability and service life.

[0127] Of course, in other embodiments, the ball assembly 15 and the first drive member 16 may also be disposed in the circumferential direction of the carrier disk 23.

[0128] The leveling method of the leveling module 3 of the ball bearing assembly 15 described above is suitable for situations where the bonding surfaces of the first wafer 201 and the second wafer 202 must not be in contact before bonding. The specific working steps are as follows: The control unit controls the first driving component 16 to move, causing the ball bearing assembly 15 to extend from the receiving groove 111 and move between the fixture 100 and the carrier plate 23. At this time, the upper side of the ball bearing abuts against the bottom surface of the fixture 100. There is a preset gap between the second wafer 202 and the first wafer 201, and a small gap between the top surface of the carrier plate 23 and the lower side of the ball bearing. The control unit controls the extension and retraction of the drive rods of the three lifting cylinders 311, adjusting the level of the carrier plate 23 via the first substrate 314, causing the carrier plate 23 to slowly rise or adjust its posture. A contact sensor is provided on the lower side of the ball bearing to detect whether the ball bearing is in contact with the top surface of the carrier plate 23. When the carrier plate 23 is leveled to a certain position, the lower side of the balls contacts the top surface of the carrier plate 23, and the contact sensor emits a contact signal. The control unit receives the contact sensor signals from each ball assembly 15. When the contact sensors of all ball assemblies 15 emit contact signals, it indicates that the carrier plate 23 and the fixture 100 are completely parallel, that is, the second wafer 202 and the first wafer 201 are in a horizontal state. The control unit determines that the leveling is complete and controls the lifting cylinder 311 to stop operating.

[0129] The leveling module 3 provided in this embodiment can be configured with different leveling detection components to be applicable to wafer leveling application scenarios with different process requirements, thereby improving the versatility of the equipment.

[0130] The alignment module 5 adopts the UVW platform. The working principle of the UVW platform is to achieve precise multi-degree-of-freedom adjustment of the wafer supported on it by controlling the translation of the platform in the X and Y axes and the rotation around the Z axis.

[0131] In one embodiment, such as Figure 1 and Figure 9As shown, the visual recognition module includes an upper visual recognition unit 41 and a lower visual recognition unit 42. The visual recognition module is configured to selectively use either the upper visual recognition unit 41 or the lower visual recognition unit 42 based on the light transmittance of the first wafer 201. When the first wafer 201 is a transparent wafer, the upper visual recognition unit 41 moves above the fixed module 1 and simultaneously recognizes the alignment marks on the first wafer 201 and the second wafer 202 through the first wafer 201. When the first wafer 201 is a non-transparent wafer, the lower visual recognition unit 42 sequentially recognizes the alignment marks on the first wafer 201 and the second wafer 202. By configuring the upper visual recognition unit 41 and the lower visual recognition unit 42, it can be compatible with both transparent and non-transparent wafers. In production, wafers of different materials can be processed without changing equipment, greatly improving the versatility of the equipment.

[0132] Specifically, both the upper visual recognition unit 41 and the lower visual recognition unit 42 include a CCD camera and a microscope. The microscope is used to magnify the image of the alignment mark captured by the CCD camera. The arrangement, specific connection structure, and working principle of the CCD camera and microscope are existing technologies and will not be described in detail here.

[0133] In one embodiment, the wafer alignment apparatus further includes a mounting bracket 7 and a first driving unit 43. The mounting bracket 7 is disposed on one side of the fixing module 1; the first driving unit 43 is disposed on the mounting bracket 7 and is connected to the upper vision recognition unit 41, used to drive the upper vision recognition unit 41 to switch between a working position facing the fixture 100 and an idle position avoiding the fixture 100. During alignment, the space above the fixing module 1 involves the operation of picking up and placing the fixture 100. By driving the upper vision recognition unit 41 to switch between the working position and the idle position through the first driving unit 43, mechanical interference is avoided.

[0134] Specifically, the mounting bracket 7 includes a support base and two support legs located below the support base. The first drive unit 43 and the upper vision recognition unit 41 are both located on the support base. The support legs raise the height of the support base so that the upper vision recognition unit 41 can face the wafer on the fixture 100 when it is in the working position.

[0135] In some embodiments, the first drive unit 43 includes a first drive module 431 and an adjusting arm 432. The first drive module 431 is mounted on the mounting bracket 7. One end of the adjusting arm 432 is connected to the first drive module 431, and the other end is connected to the upper vision recognition unit 41. The first drive module 431 drives the upper vision recognition unit 41 to swing through the adjusting arm 432, so as to switch between the working position and the idle position. By adopting the swinging motion of the adjusting arm 432, the upper vision recognition unit 41 moves into or out of the fixture 100 along an arc trajectory. Compared with linear translation, the swinging motion can achieve a more compact layout in a space without affecting the layout of other components. Moreover, the swinging motion enables the upper vision recognition unit 41 to achieve rapid position switching, which helps to shorten the working cycle of the alignment operation.

[0136] When the adjustment arm 432 swings, the rod of the first cylinder extends, which can drive the adjustment arm 432 to swing away from the fixed module 1; when the rod of the first cylinder retracts, it can drive the adjustment arm 432 to swing closer to the fixed module 1, thereby realizing the switching of the upper vision recognition unit 41 between the idle position and the working position.

[0137] In one embodiment, the wafer alignment device further includes a limiting unit 44, which includes two limiting plates 441 disposed opposite to each other, each limiting plate 441 having a limiting groove 4411. A limiting member is provided on each of the opposite sides of the adjusting arm 432, and the limiting member slides in cooperation with the corresponding limiting groove 4411. The limiting groove 4411 extends along the length direction of the limiting plate 441, and the extension direction of the limiting groove 4411 defines the movement path of the limiting member, thereby constraining the movement trajectory of the adjusting arm 432 in the swing plane, ensuring that it moves strictly according to a preset arc, and avoiding trajectory deviations caused by deformation of the adjusting arm 432.

[0138] Specifically, two limiting plates 441 are respectively located on the outside of the two adjusting plates, and the lower ends of the two limiting plates 441 are respectively hinged to the inner sides of the two support blocks. The upper ends of the two limiting plates 441 extend upward at an angle and are connected through a limiting rod. The limiting rod is used to limit the extreme position of the upward swing of the adjusting arm 432.

[0139] Two limiting components are respectively located on the outside of the two adjusting plates, and the limiting components are set as limiting posts that are adapted to the limiting groove 4411.

[0140] In one embodiment, the limiting plate 441 is further provided with at least one locking hole communicating with the limiting groove 4411; the limiting unit 44 also includes a limiting drive module 442, which is connected to the limiting plate 441 and is used to drive the limiting plate 441 to rotate, so that the limiting member switches between the limiting groove 4411 and the locking hole to lock or unlock the position of the adjusting arm 432. By providing a locking hole on the limiting plate 441, the limiting post can be locked with the corresponding locking hole in both the working position and the idle position to ensure the stability of the upper visual recognition unit 41. The sliding engagement of the limiting member in the limiting groove 4411 ensures that when locking is required, the limiting member can be accurately aligned with the locking hole on the side wall of the limiting groove 4411.

[0141] For example, a locking hole is provided at each end of the limiting groove 4411. The locking hole at the end closer to the support block is the working locking hole 4412 when the upper visual recognition unit 41 is in the working position, and the locking hole at the end farther from the support block is the idle locking hole 4414 when the upper visual recognition unit 41 is in the idle position. Further, a standby locking hole 4413 is provided between the working locking hole 4412 and the idle locking hole 4414. In actual operation, when the first cylinder drives the adjusting arm 432 to move the upper visual recognition unit 41 to the working position, the upper visual recognition unit 41 simultaneously recognizes the alignment marks on the first wafer 201 and the second wafer 202. After recognition, the first cylinder drives the adjusting arm 432 to move the visual recognition unit to the standby position. At this time, the limiting post engages with the standby locking hole 4413 and locks, awaiting the next recognition. When the vision recognition module uses the lower vision recognition unit 42, the first cylinder drives the adjusting arm 432 to move the upper vision recognition unit 41 to the idle position. At this time, the limit post and the idle locking hole 4414 cooperate to lock.

[0142] The limit drive module 442 is a second cylinder. Two second cylinders are respectively installed on the upper end face of two support blocks. The cylinder rod is connected to the outside of the limit plate 441. The working locking hole 4412, the standby locking hole 4413, and the idle locking hole 4414 are all located on the side of the limit groove 4411 away from the fixed end of the second cylinder. When the cylinder rod extends, the limit plate 441 rotates to the side away from the fixed end of the second cylinder, and the limit post moves from the locking hole to the limit groove 4411. When the cylinder rod retracts, the limit plate 441 rotates to the side closer to the fixed end of the second cylinder, and the limit post moves from the limit groove 4411 to the locking hole.

[0143] In one embodiment, the first driving unit 43 further includes a second driving module 433, which is connected between the adjusting arm 432 and the upper visual recognition unit 41, and is used to drive the upper visual recognition unit 41 to move along the X-axis, Y-axis and Z-axis directions. When the adjusting arm 432 swings and moves the upper visual recognition unit 41 to the working position, the second driving module 433 drives the upper visual recognition unit 41 to adjust its position in three-dimensional space, so that the upper visual recognition unit 41 is precisely adjusted to match the position of the alignment mark, ensuring that the alignment mark is located in the center of the field of view and the image is clear.

[0144] Specifically, the second drive module 433 includes an X-axis drive module, a Y-axis drive module, and a Z-axis drive module. The X-axis drive module is mounted on the adjusting arm 432 and is connected to the Y-axis drive module to drive the Y-axis drive module to move along the X-axis direction. The Y-axis drive module is connected to the Z-axis drive module to drive the Z-axis drive module to move along the Y-axis direction, thereby achieving the search and positioning of the alignment mark. The Z-axis drive module is connected to the upper vision recognition unit 41 and is used to drive the upper vision recognition unit 41 to move along the Z-axis direction to adjust the visual focal plane height and ensure clear imaging. The specific structures of the X-axis drive module, Y-axis drive module, and Z-axis drive module can be referred to existing technology designs and will not be elaborated here.

[0145] For example, two alignment marks are provided on the wafer, and correspondingly, two upper vision recognition units 41 are provided. Two X-axis drive modules, two Y-axis drive modules, and two Z-axis drive modules are provided. The two Y-axis drive modules are slidably mounted on the two X-axis drive modules to drive the two Z-axis drive modules in a one-to-one correspondence. The two Z-axis drive modules drive the two upper vision recognition units 41 in a one-to-one correspondence. Each upper vision recognition unit 41 recognizes one alignment mark.

[0146] In one embodiment, such as Figure 10 As shown, the wafer alignment apparatus also includes a second driving unit 45, which is connected to the lower vision recognition unit 42 and is used to drive the lower vision recognition unit 42 to move along the X-axis, Y-axis, and Z-axis directions. The position and focal plane of the lower vision recognition unit 42 are adjusted so that the optical axis of the lower vision recognition unit 42 can recognize the center position of the alignment mark.

[0147] Specifically, the second drive unit 45 includes a Z-axis drive unit 451, a Y-axis drive unit 452, and an X-axis drive unit 453. The X-axis drive unit 453 is connected to the Y-axis drive unit 452 and is used to drive the Y-axis drive unit 452 to move along the X-axis. The Y-axis drive unit 452 is connected to the Z-axis drive unit 451 and is used to drive the Z-axis drive unit 451 to move along the Y-axis. The Z-axis drive unit 451 is connected to the lower vision recognition unit 42 through a support frame 454 and is used to drive the lower vision recognition unit 42 to move along the Z-axis. The support frame 454 is provided so that the height of the lower vision recognition unit 42 matches the height of the recognition space.

[0148] The Z-axis drive unit 451 adopts a horizontal Z-axis. The drive motor of the Z-axis drive unit 451 is connected to the wedge block, pushing it in a predetermined direction on the horizontal guide rail. The moving block is in contact with the inclined surface of the wedge block. When the wedge block moves horizontally, its inclined surface generates a vertical component force, forcing the moving block to rise or fall along the vertical guide rail. The support frame 454 is fixedly connected to the moving block and moves with the moving block, thereby driving the lower vision recognition unit 42 to achieve lifting and lowering in the Z-axis direction. The Y-axis drive unit 452 and the X-axis drive unit 453 can be designed with reference to existing technology.

[0149] The second driving unit 45 and the lower vision recognition unit 42 are provided in two corresponding positions, respectively located on both sides along the X-axis, to recognize the two alignment marks on the wafer respectively.

[0150] In one embodiment, the lifting module 6 includes a lifting platform 61 and a lifting drive module 62 driven by the lifting platform 61. The lifting drive module 62 drives the lifting platform 61 to rise or fall. The lifting drive module 62 includes a lifting motor, a pulley assembly, and a lifting screw. The lifting motor is located outside the lifting platform 61. The pulley assembly includes a drive wheel, a conveyor belt, and a driven wheel. The lifting motor is connected to the drive wheel, and the driven wheel is located below the lifting platform 61. The drive wheel and the driven wheel are connected by the conveyor belt. The driven wheel is fixedly connected to the nut seat of the lifting screw by screws, and one end of the lifting screw is connected to the lifting platform 61. The lifting motor drives the drive wheel to rotate, and the drive wheel drives the driven wheel to rotate through the conveyor belt. The driven wheel drives the nut seat of the lifting screw to rotate, thereby driving the lifting screw to rise or fall, and thus driving the lifting platform 61 to rise or fall.

[0151] The lifting module 6 places the lifting motor on its side, avoiding the stacking of drive units directly below the lifting platform 61. This provides ample installation space for components such as the alignment module 5 and leveling module 3, allowing for the integration of more modules in the vertical direction of the alignment device. Simultaneously, it effectively lowers the overall center of gravity, improving the stability of the alignment device. Furthermore, the external placement of the lifting motor facilitates heat dissipation during operation, and allows operators easy access for maintenance or replacement without disassembling the lifting platform 61.

[0152] Of course, in other embodiments, the lifting module 6 can also be replaced by a linear drive component such as a linear drive cylinder.

[0153] In one embodiment, the lifting module 6 further includes a plurality of guide components 63 disposed below the lifting platform 61 for guiding the lifting of the lifting platform 61. Specifically, four guide components 63 are provided, evenly distributed around the circumference of the lifting screw. Each guide component 63 includes a fixedly disposed guide cylinder and a guide post movably disposed within the guide cylinder. The guide post is connected to the lifting platform 61 and is used to provide guidance when the lifting drive module 62 drives the lifting platform 61 to lift.

[0154] Combination Figure 1 As shown, the wafer alignment device also includes a protective frame 8 and a base 9. The protective frame 8 is used to protect the leveling module 3, alignment module 5, and lifting module 6 located below the wafer transport module 2. There are two protective frames 8, which are respectively located below the two guide rails of the slide block 21 and are fixedly connected to the corresponding guide rails. The base 9 is located below the two protective frames 8, and the lifting drive module 62, guide cylinder, and mounting bracket 7 are all fixed on the base 9.

[0155] The protective frame 8 has a hollow structure, forming an internal space to accommodate at least a portion of the leveling module 3, alignment module 5, and lifting module 6. An opening is provided on the side of the protective frame 8, and a second drive unit 45 is fixed to the protective frame 8 and extends into the interior through the opening, connecting to the lower vision recognition unit 42. The protective frame 8 effectively isolates the leveling module 3, alignment module 5, and lifting module 6 from the influence of the external environment.

[0156] Example 2:

[0157] like Figure 11 As shown, this embodiment provides a wafer alignment method applied to the wafer alignment apparatus provided in Embodiment 1. The wafer alignment method includes:

[0158] S10. Install the fixture 100 onto the fixed module 1.

[0159] Before installing the fixture 100, the first clamping component 142 and the second clamping component 143 of the circumferential drive gripper assembly 14 of the hollow structure fixing plate 11 are first switched to the installation avoidance state, that is, the two first clamping parts 1422 of the first clamping component 142 are vertically separated, and the two second clamping parts 1432 of the second clamping component 143 are also vertically separated.

[0160] Next, the fixture 100 is placed on the hollow structure fixing plate 11. At this time, the positioning component 12 positions the fixture 100 radially and circumferentially to ensure its accurate installation position. After positioning is completed, the clamping component 13 is activated to clamp and fix the bearing ring of the fixture 100 to the hollow structure fixing plate 11.

[0161] After the fixture 100 is fixed, the lifting drive 141 drives the first clamping component 142 and the second clamping component 143 to descend synchronously, so that they respectively mate with the driving ends of the jaws and the driving ends of the pads in the fixture 100. The first clamping drive 1421 drives the two first clamping parts 1422 to rotate 90° in a direction that brings them closer to each other, so that the two first clamping parts 1422 change from a vertically separated state to a horizontal clamping state, clamping the driving ends of the jaws in the fixture 100. The second clamping drive 1431 drives the two second clamping parts 1432 to rotate 90° in a direction that brings them closer to each other, so that the two second clamping parts 1432 change from a vertically separated state to a horizontal clamping state, clamping the pad driving end in the fixture 100. Then, the lifting drive 141 simultaneously drives the first clamping component 142 and the second clamping component 143 to rise, driving the jaw driving end and the pad driving end to rise. The first clamping drive 1421 drives the two first clamping parts 1422 to switch to a vertically separated state, and at the same time, the second clamping drive 1431 drives the two second clamping parts 1432 to switch to a vertically separated state, thereby driving the jaw to open and the pad to be removed at the same time, so as to avoid interference with the adsorption surface of the fixture 100 and ensure that the subsequent adsorption surface can be tightly attached and fixed to the first wafer 201.

[0162] Through the above steps, the installation of the fixture 100 and the initial state setting of the grippers and gaskets are completed, preparing for the subsequent adsorption and fixation of the first wafer 201.

[0163] S20. The first wafer 201 is transported to the bottom of the fixture 100 by the wafer transport module 2. The lifting module 6 raises the support plate 23 so that the first wafer 201 abuts against the fixture 100 and the fixture 100 fixes the first wafer 201.

[0164] Using the handle 221 on the carrier 22, the carrier 22 is pulled out from the slide 21. The robotic arm places the first wafer 201 onto the carrier tray 23, with the bonding surface facing down, on the support surface formed by the four support pins, forming point contact support. Then, the carrier 22 is pushed back into the slide 21. When the carrier 22 reaches the locking position, the photoelectric sensor 25 detects the signal sent by the sensing element to the control unit. The control unit controls the second drive element 241 to drive the connector 242 to extend and engage with the locking hole for locking.

[0165] Then the control unit controls the lifting motor of the lifting module 6 to rotate forward, and then drives the lifting screw through the pulley assembly to lift the lifting platform 61. The lifting platform 61 drives the carrier plate 23 to rise through the alignment module 5 and the leveling module 3, so that the first wafer 201 on the carrier plate 23 abuts against the adsorption surface of the fixture 100, and controls the adsorption surface of the fixture 100 to generate adsorption force to adsorb and fix the first wafer 201.

[0166] After the fixture 100 fixes the first wafer 201, the lifting motor reverses, thereby driving the lifting screw through the pulley assembly to lower the lifting platform 61, which in turn lowers the alignment module 5, the leveling module 3, and the carrier plate 23. The carrier plate 23 descends onto the carrier seat 22, and the alignment module 5 and the leveling module 3 descend to their initial positions. At the same time, the second clamping drive 1431 drives the two second clamping parts 1432 to rotate 90° in a direction away from each other, so that the two second clamping parts 1432 return from a horizontal clamping state to a vertically separated state, releasing the shim drive end in the fixture 100. At this time, the shim resets under its own elastic force and is located below the first wafer 201.

[0167] S30. The second wafer 202 is transported to the bottom of the fixture 100 by the wafer transport module 2, and the lifting module 6 lifts the second wafer 202 to the preset position.

[0168] Continuing with step S20, the second wafer 202 is transported. The back of the second wafer 202 is first placed on the support surface formed by four support pins. After the carrier 22 is pushed back into the slide 21 and locked, the control unit controls the lifting motor of the lifting module 6 to rotate forward, thereby causing the lifting platform 61 to drive the alignment module 5 and the leveling module 3 to rise. The top surface of the vacuum chamber 33 of the leveling module 3 contacts the carrier plate 23, the vacuum system is turned on, and the vacuum adsorption port 331 of the vacuum chamber 33 generates an adsorption force to adsorb and fix the carrier plate 23. At the same time, a vacuum is provided for the sealing cavity of the elastic pin assembly 232, driving the support pin to descend, so that the second wafer 202 falls onto the carrier surface 231. The adsorption hole 2311 on the carrier surface 231 generates an adsorption force to adsorb and fix the second wafer 202. Then, the carrier plate 23 is driven to rise, so that the second wafer 202 rises to a preset position. At this time, there is a preset gap between the second wafer 202 and the first wafer 201.

[0169] S40. The second wafer 202 and the first wafer 201 are leveled by the leveling module 3.

[0170] The leveling method is selected based on the bonding process requirements of the first wafer 201 and the second wafer 202. If the application scenario does not require whether the bonding surfaces of the first wafer 201 and the second wafer 202 are in contact before bonding, the first leveling method is selected. The specific leveling steps of the first leveling method include:

[0171] S41, the leveling mechanism 31 drives the carrier disk 23 to move, so that the second wafer 202 is attached to the first wafer 201.

[0172] The control unit controls the drive rods of the three lifting cylinders 311 to extend synchronously, driving the first substrate 314 to rise, which in turn moves the second wafer 202 in the carrier plate 23 upward until it contacts and adheres to the first wafer 201.

[0173] S42. Adjust each leveling component until the pressure values ​​detected by each pressure sensor 32 are the same, and determine that the second wafer 202 and the first wafer 201 are leveled.

[0174] After the second wafer 202 comes into contact with the first wafer 201, the three pressure sensors 32 detect the pressure value at their respective positions in real time and send the detected pressure value to the control unit. The control unit continuously compares the pressure values ​​of the three pressure sensors 32 and fine-tunes each leveling component according to the difference in pressure values. When the pressure values ​​detected by the three pressure sensors 32 are equal, it indicates that the second wafer 202 and the first wafer 201 have been evenly attached and have reached a horizontal state. The control unit determines that the leveling is complete and controls the lifting cylinder 311 to stop operating.

[0175] If it is required that the bonding surfaces of the first wafer 201 and the second wafer 202 must not be in contact before bonding, a second leveling method is adopted. The specific steps of the second leveling method include:

[0176] S41': Control multiple ball bearing assemblies 15 to move between the fixture 100 and the carrier plate 23.

[0177] The control unit controls the first drive member 16 to move, which drives the ball assembly 15 to extend from the receiving groove 111 and move between the fixture 100 and the carrier plate 23. At this time, the upper side of the ball abuts against the bottom surface of the fixture 100. There is a preset gap between the second wafer 202 and the first wafer 201, and there is a small gap between the top surface of the carrier plate 23 and the lower side of the ball.

[0178] S42´, the leveling mechanism 31 drives the carrier plate 23 to move, so that each ball assembly 15 is in contact with the fixture 100 and the carrier plate 23.

[0179] The control unit controls the extension and retraction of the drive rods of the three lifting cylinders 311, and adjusts the level of the support plate 23 through the first base plate 314, so that the support plate 23 slowly rises or adjusts its posture.

[0180] A contact sensor is provided on the underside of the ball bearing to detect whether the ball bearing is in contact with the top surface of the support plate 23. When the support plate 23 is leveled to a certain position, the underside of the ball bearing contacts the top surface of the support plate 23, and the contact sensor sends a contact signal.

[0181] S43' When all ball bearing assemblies 15 are in contact with the fixture 100 and the carrier plate 23, it is determined that the second wafer 202 is leveled with the first wafer 201.

[0182] The control unit receives contact sensor signals from each ball assembly 15. When all contact sensors of the ball assemblies 15 emit contact signals, it indicates that the carrier plate 23 and the fixture 100 are completely parallel, that is, the second wafer 202 and the first wafer 201 are in a horizontal state. The control unit determines that the leveling is complete and controls the lifting cylinder 311 to stop operating.

[0183] S50. The alignment marks on the first wafer 201 and the second wafer 202 are identified by the visual recognition module. Using the alignment mark on the first wafer 201 as a reference, the alignment module 5 drives the carrier disk 23 to move so as to align the alignment mark on the second wafer 202 with the alignment mark on the first wafer 201.

[0184] In one embodiment, the upper visual recognition unit 41 or the lower visual recognition unit 42 is selected based on whether the first wafer 201 is a transparent wafer. When the first wafer 201 is a transparent wafer, the upper visual recognition unit 41 is moved above the fixed module 1 to simultaneously recognize the alignment marks of the first wafer 201 and the second wafer 202 through the first wafer 201. When the first wafer 201 is a non-transparent wafer, the lower visual recognition unit 42 recognizes the alignment marks of the first wafer 201 and the second wafer 202 in sequence.

[0185] The alignment marks of the first wafer 201 and the second wafer 202 are both set on the bonding surface by the recognition pattern identified by the upper vision recognition unit 41.

[0186] The first driving unit 43 drives the upper vision recognition unit 41 to move to the working position, so that the upper vision recognition unit 41 is located above the fixture 100. Through the transparent first wafer 201, it simultaneously recognizes the alignment marks on the first wafer 201 and the second wafer 202, and sends the position coordinates of the two alignment marks to the control unit. The control unit calculates the recognition result based on the position coordinates of the two alignment marks. If the two alignment marks are not aligned, the lifting driving module 62 drives the alignment module 5 to rise and abut against the second wafer 202. The alignment module 5 drives the second wafer 202 to rotate according to the recognition result until the alignment marks on the first wafer 201 and the second wafer 202 are aligned with each other, and the alignment is completed.

[0187] According to the recognition pattern identified by the lower vision recognition unit 42, the alignment mark of the first wafer 201 is located on the bonding surface, and the alignment mark of the second wafer 202 is located on the back side (non-bonding surface). At this time, the upper vision recognition unit 41 is in an idle position.

[0188] After the wafer transport module 2 transports the first wafer 201 to the fixture 100 for adsorption and fixation, the second drive unit 45 drives the lower vision recognition unit 42 to move and align to find the alignment mark of the first wafer 201, and takes a picture of the alignment mark of the first wafer 201. After recognition, the lifting module 6 drives the alignment module 5 and the leveling module 3 to descend; the carrier 22 slides out from the slide 21 to receive the second wafer 202. At the same time, the second clamping drive 1431 drives the two second clamping parts 1432 to change from a vertically separated state to a horizontal clamping state to clamp the pad driving end. Then, the lifting drive 141 drives the first clamping component 142 and the second clamping component 143 to descend synchronously. The second clamping component 143 drives the pad driving end to descend, thereby driving the pad to extend. After the pad extends, the second clamping drive 1431 drives the two second clamping parts 1432 to change back to a vertically separated state.

[0189] After the carrier 22 receives the second wafer 202 and pushes it back into the slide 21, the lifting module 6 drives the alignment module 5 and the leveling module 3 to rise and level the second wafer 202. Then, the lifting module 6 controls the alignment module 5 and the leveling module 3 to return to their initial positions, and the lower vision recognition unit 42 takes a picture of the alignment marks on the back of the second wafer 202. The control unit receives the two picture records and calculates the position coordinates of the two alignment marks to obtain the recognition result. If the two alignment marks are not aligned, the lifting drive module 62 drives the alignment module 5 to rise and contact the second wafer 202. The alignment module 5 drives the second wafer 202 to rotate according to the recognition result until the alignment marks on the first wafer 201 and the second wafer 202 are aligned, completing the alignment.

[0190] S60, the second wafer 202 after fixing, leveling and aligning is completed using fixture 100.

[0191] After the second wafer 202 is aligned, the lifting drive 141 drives the first clamping component 142 and the second clamping component 143 to rise synchronously. The first clamping drive 1421 drives the two first clamping parts 1422 to switch to a horizontal clamping state to clamp the jaw drive end in the fixture 100. Then, the lifting drive 141 drives the first clamping component 142 and the second clamping component 143 to fall synchronously. The first clamping component 142 drives the jaw drive end to fall, thereby driving the jaw to close. The jaw fixes the second wafer 202 and the first wafer 201 together in the fixture 100.

[0192] S70. After the fixture 100 fixes the second wafer 202, the fixture 100, together with the first wafer 201 and the second wafer 202, is removed and the process proceeds to the next step.

[0193] The robotic arm transports the fixture 100, along with the first wafer 201 and the second wafer 202, to the next process.

[0194] Example 3:

[0195] This embodiment provides a wafer bonding equipment, including the wafer alignment device provided in Embodiment 1, which realizes the process capability of wafer alignment during clamping, avoids transfer accuracy loss, and improves the integration and process yield of the wafer bonding equipment.

[0196] After the first wafer 201 and the second wafer 202 are aligned by the wafer alignment device, they are loaded by the fixture 100 and transferred to the bonding chamber. During the bonding process, the gap between the wafers is eliminated by vacuuming, so that the wafers are changed from the initial suspended state to the tightly attached state, thus realizing bonding.

[0197] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A wafer alignment apparatus, characterized in that, include: A fixing module (1) is used to fix a fixture (100) and drive the fixture (100) to clamp and fix a first wafer (201) and a second wafer (202). Alignment marks are provided on both the first wafer (201) and the second wafer (202). A wafer transport module (2) is located below the fixed module (1) and is used to sequentially carry and transport the first wafer (201) and the second wafer (202) to the fixture (100); the wafer transport module (2) includes a movable support base (22) and a support plate (23) for carrying the wafer is provided on the support base (22); A leveling module (3) is located below the carrier disk (23) and is used to adjust the level of the second wafer (202) relative to the first wafer (201). A visual recognition module is used to identify alignment marks on the first wafer (201) and the second wafer (202); Alignment module (5) is located below the carrier disk (23) and is used to drive the carrier disk (23) to move in the horizontal plane so that the second wafer (202) on the carrier disk (23) and the first wafer (201) on the fixture (100) are aligned. The lifting module (6) is configured to drive the leveling module (3), the alignment module (5) and the support plate (23) to lift.

2. The wafer alignment apparatus according to claim 1, characterized in that, The leveling module (3) includes: The leveling mechanism (31) includes a first substrate (314), a second substrate (315), and leveling components evenly distributed between the first substrate (314) and the second substrate (315); the first substrate (314) can be connected to the carrier plate (23), and the leveling components are used to adjust the level of the carrier plate (23) through the first substrate (314). A leveling test piece is used to test the levelness of the bearing plate (23).

3. The wafer alignment apparatus according to claim 2, characterized in that, The leveling detection component includes multiple pressure sensors (32), which are evenly distributed along the circumferential direction of the second substrate (315) to detect the pressure at different positions of the leveling mechanism (31).

4. The wafer alignment apparatus according to claim 2 or 3, characterized in that, The leveling test component includes multiple ball bearing assemblies (15), which are movable between the fixture (100) and the carrier plate (23) and are evenly distributed along the circumferential direction of the fixture (100).

5. The wafer alignment apparatus according to claim 1, characterized in that, The support base (22) is provided with a central hole, and a plurality of support parts (222) extending from the inner wall of the central hole to the center are arranged at intervals along the circumference of the central hole. The support plate (23) is suspended on the plurality of support parts (222) so that the leveling module (3), the alignment module (5) and the lifting module (6) can act on the support plate (23) through the central hole.

6. The wafer alignment apparatus according to claim 1, characterized in that, The support plate (23) includes a support surface (231) and a plurality of elastic pin components (232). The support surface (231) is provided with a plurality of suction holes (2311) at intervals. The plurality of elastic pin components (232) are spaced apart in the circumferential direction of the support surface (231), and the plurality of elastic pin components (232) can be raised and lowered, and can selectively rise above the support surface (231) or fall below the support surface (231).

7. The wafer alignment apparatus according to claim 1, characterized in that, The wafer transport module (2) further includes a slide (21), which includes two guide rails arranged opposite to each other, and the two sides of the support base (22) are slidably connected to the two guide rails.

8. The wafer alignment apparatus according to claim 1, characterized in that, The visual recognition module includes an upper visual recognition unit (41) and a lower visual recognition unit (42), and the visual recognition module is configured to selectively use the upper visual recognition unit (41) or the lower visual recognition unit (42) according to the light transmittance of the first wafer (201).

9. The wafer alignment apparatus according to claim 8, characterized in that, The wafer alignment device further includes: The mounting bracket (7) is located on one side of the fixing module (1); A first drive unit (43) is provided on the mounting bracket (7). The first drive unit (43) is connected to the upper vision recognition unit (41) and is used to drive the upper vision recognition unit (41) to switch between a working position facing the fixture (100) and an idle position avoiding the fixture (100).

10. The wafer alignment apparatus according to claim 9, characterized in that, The first driving unit (43) includes: The first drive module (431) is mounted on the mounting bracket (7); An adjusting arm (432) is connected at one end to the first driving module (431) and at the other end to the upper visual recognition unit (41); the first driving module (431) drives the upper visual recognition unit (41) to swing through the adjusting arm (432) to switch between the working position and the idle position.

11. The wafer alignment apparatus according to claim 10, characterized in that, The first driving unit (43) further includes a second driving module (433), which is connected between the adjusting arm (432) and the upper visual recognition unit (41) and is used to drive the upper visual recognition unit (41) to move along the X-axis, Y-axis and Z-axis directions.

12. The wafer alignment apparatus according to claim 8, characterized in that, It also includes a second driving unit (45), which is connected to the lower vision recognition unit (42) and is used to drive the lower vision recognition unit (42) to move in the X-axis, Y-axis and Z-axis directions.

13. A wafer alignment method, characterized in that, The wafer alignment method, applied to the wafer alignment apparatus as described in any one of claims 1-12, comprises: The fixture (100) is installed on the fixing module (1); The first wafer (201) is transported to the lower part of the fixture (100) by the wafer transport module (2), and the lifting module (6) rises and lifts the carrier plate (23) so that the first wafer (201) abuts against the fixture (100) and the fixture (100) fixes the first wafer (201). The second wafer (202) is transported to the lower part of the fixture (100) by the wafer transport module (2), and the lifting module (6) lifts the second wafer (202) to a preset position; The second wafer (202) and the first wafer (201) are leveled by the leveling module (3); The visual recognition module identifies the alignment marks on the first wafer (201) and the second wafer (202), and using the alignment mark on the first wafer (201) as a reference, the alignment module (5) drives the carrier disk (23) to move so as to align the alignment mark on the second wafer (202) with the alignment mark on the first wafer (201). The fixture (100) fixes the second wafer (202) after leveling and alignment. After the fixture (100) fixes the second wafer (202), the fixture (100) together with the first wafer (201) and the second wafer (202) are removed and proceeded to the next process.

14. The wafer alignment method according to claim 13, characterized in that, The leveling module (3) includes multiple leveling components and multiple pressure sensors (32). The step of leveling the second wafer (202) and the first wafer (201) through the leveling module (3) includes: The multiple leveling components drive the carrier disk (23) to move, so that the second wafer (202) is in contact with the first wafer (201); Adjust each of the leveling components until the pressure values ​​detected by each of the pressure sensors (32) are the same, and determine that the second wafer (202) and the first wafer (201) are leveled.

15. The wafer alignment method according to claim 13, characterized in that, The leveling module (3) includes multiple leveling components and multiple ball bearing components (15). The step of leveling the second wafer (202) and the first wafer (201) through the leveling module (3) includes: Control the movement of multiple ball bearing assemblies (15) between the fixture (100) and the carrier plate (23); The multiple leveling components drive the carrier plate (23) to move, so that each of the ball components (15) contacts the fixture (100) and the carrier plate (23); When all the ball bearing assemblies (15) are in contact with the fixture (100) and the carrier plate (23), it is determined that the second wafer (202) is leveled with the first wafer (201).

16. The wafer alignment method according to claim 13, characterized in that, The visual recognition module includes an upper visual recognition unit (41) and a lower visual recognition unit (42); The step of identifying alignment marks on the first wafer (201) and the second wafer (202) using the visual recognition module includes: Depending on whether the first wafer (201) is a transparent wafer, the upper visual recognition unit (41) or the lower visual recognition unit (42) is selected; When the first wafer (201) is a transparent wafer, the upper visual recognition unit (41) is moved above the fixed module (1) to simultaneously recognize the alignment marks of the first wafer (201) and the second wafer (202) through the first wafer (201); When the first wafer (201) is a non-transparent wafer, the lower vision recognition unit (42) identifies the alignment marks of the first wafer (201) and the second wafer (202) in turn.

17. A wafer bonding apparatus, characterized in that, Includes the wafer alignment apparatus as described in any one of claims 1-12, for performing inter-wafer alignment before wafer bonding.

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