Leveling device and leveling method
By using leveling devices and methods, the problems of relative tilt and inconsistent reference planes before wafer bonding were solved, achieving high-precision alignment and bonding effects, and improving bonding yield and chip utilization.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 天津中科晶禾电子科技有限责任公司
- Filing Date
- 2026-05-09
- Publication Date
- 2026-06-05
AI Technical Summary
Before wafer bonding, the two wafers may be tilted or have inconsistent reference surfaces due to repeated loading of fixtures and chucks, which affects the alignment accuracy and bonding quality.
A leveling device is used, including a leveling mechanism and a pressure sensor. The leveling mechanism makes the second wafer fit with the first wafer, and the pressure sensor detects the pressure values at multiple contact points to determine whether leveling is required, ensuring that the two are parallel.
It improves alignment accuracy, bonding yield and chip area utilization, and avoids the risk of bonding failure.
Smart Images
Figure CN122161402A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor material bonding technology, and in particular to a leveling device and a leveling method. Background Technology
[0002] A wafer is the core substrate (also known as a substrate) for manufacturing semiconductor transistors or integrated circuits. It is called a wafer because it is made of crystalline materials and has a circular shape. As the fundamental carrier for semiconductor device manufacturing, the processing precision of the wafer directly determines the performance, reliability, and integration level of the semiconductor device. Wafer bonding or temporary bonding processes are key steps in semiconductor manufacturing to achieve three-dimensional integration and ultra-thin packaging of devices. They are widely used in MEMS, power devices, and advanced packaging, and are one of the core processes driving the semiconductor industry towards high integration and high performance.
[0003] Before bonding or temporary bonding of two wafers, wafer alignment is an indispensable pre-process. Alignment accuracy is a core performance parameter ensuring bonding quality, directly affecting chip area utilization, and is a crucial prerequisite for avoiding bonding failures and improving device yield. In actual production, the first and second wafers must first be mounted on a fixture before being transferred to the bonding chamber for bonding. The alignment process is completed during the wafer mounting process. Specifically, the fixture is mounted to a fixture adapter, the first wafer is fixed on the fixture, and then the second wafer is fixed on the chuck. Alignment is achieved by identifying the marks on the two wafers using an identification unit. However, because the fixture and chuck need to be installed and repeatedly loaded for each pair of wafers, factors such as repeated clamping, assembly gaps, and machining errors make it difficult to maintain ideal parallelism between the fixture and the chuck after each reloading. This leads to problems such as relative tilting and inconsistent reference surfaces between the two wafers before entering the alignment process, affecting alignment accuracy and bonding quality.
[0004] Therefore, there is an urgent need to provide a leveling device and a leveling method to solve the above-mentioned technical problems. Summary of the Invention
[0005] The purpose of this invention is to provide a leveling device and a leveling method, which aims to solve the problem in the prior art that two wafers to be bonded are relatively tilted or have inconsistent reference surfaces before entering the alignment process, which affects the alignment accuracy and bonding quality. The leveling device and leveling method can effectively improve the alignment accuracy, bonding yield, chip area utilization, and avoid the risk of bonding failure.
[0006] To achieve this objective, the present invention adopts the following technical solution:
[0007] The leveling device includes:
[0008] Base;
[0009] A support frame is mounted on the base, and a clamping fixture is provided on the support frame for fixing the first wafer;
[0010] A leveling mechanism is disposed on the base, with a chuck supported at its top. The chuck is positioned below the fixture and is used to fix the second wafer. The leveling mechanism is configured to allow the second wafer and the first wafer to fit together, so that the second wafer is parallel to the first wafer.
[0011] A pressure sensor is provided between the leveling mechanism and the base. The pressure sensor is used to detect the pressure values at multiple contact points between the leveling mechanism and the base to determine whether the second wafer and the first wafer are leveled.
[0012] In some possible implementations, the leveling mechanism includes:
[0013] A first substrate is disposed on the base;
[0014] The second substrate is disposed above the first substrate at a distance, and the second substrate is used to support the chuck;
[0015] Multiple driving components are provided, and the multiple driving components are evenly disposed between the first substrate and the second substrate. The driving components are used to drive the second substrate to move up and down in the vertical direction.
[0016] Multiple limiting components are provided, and the multiple limiting components are evenly disposed between the first substrate and the second substrate. The limiting components can adaptively deflect according to the position of the second substrate.
[0017] Multiple tension springs are provided, and the multiple tension springs are evenly disposed between the first substrate and the second substrate.
[0018] In some possible implementations, the drive assembly includes a cylinder, the fixed end of which is connected to the first substrate, and the output end of which has a protruding structure that forms point contact with the second substrate.
[0019] In some possible implementations, a tension spring is provided on both sides of each cylinder, and the tension springs on both sides of the cylinder are symmetrically distributed.
[0020] In some possible implementations, the limiting assembly includes a needle roller guide post and a spherical bearing, wherein the fixed end of the needle roller guide post is fixedly connected to the first substrate, the inner ring of the spherical bearing is fixedly connected to the movable end of the needle roller guide post, and the outer ring of the spherical bearing is slidably connected to the second substrate.
[0021] In some possible implementations, the limiting component further includes a guide rail disposed at the bottom of the second substrate and a slider that slides with the guide rail, wherein the outer ring of the spherical bearing is fixedly connected to the slider.
[0022] In some possible implementations, three driving components are provided, and the three driving components are evenly distributed along the circumference of the first substrate; three limiting components are provided, and the three limiting components are evenly distributed along the circumference of the first substrate; and the three limiting components are disposed inside the three driving components.
[0023] In some possible implementations, the leveling device further includes an adsorption block disposed on the second substrate, the adsorption block having an adsorption air channel for adsorbing the chuck.
[0024] In some possible implementations, the leveling device further includes a lifting assembly and an alignment platform. The lifting assembly is mounted on the base, the alignment platform is disposed at the output end of the lifting assembly, and the leveling mechanism is disposed on the alignment platform. The lifting assembly is configured to drive the alignment platform and the leveling mechanism to rise and fall.
[0025] The leveling method, using a leveling device as described in any of the above schemes, includes the following steps:
[0026] The leveling mechanism is used to bring the second wafer and the first wafer into contact so that the second wafer is parallel to the first wafer.
[0027] When the pressure values at multiple contact points between the leveling mechanism and the base are the same, the second wafer and the first wafer are leveled.
[0028] The beneficial effects of this invention are:
[0029] The leveling device provided by the present invention, by setting up a leveling mechanism and a pressure sensor, the leveling mechanism is used to fit the second wafer and the first wafer together so that the second wafer is parallel to the first wafer. At the same time, the pressure sensor detects the pressure values at multiple contact points between the leveling mechanism and the base to determine whether the first wafer and the second wafer are leveled. This can effectively improve alignment accuracy, bonding yield, chip area utilization, and avoid the risk of bonding failure.
[0030] The leveling method provided by this invention is completed using the above-mentioned leveling device. During leveling, the second wafer and the first wafer are brought into contact and the second wafer is parallel to the first wafer through the leveling mechanism. When the pressure sensor detects that the pressure values at multiple contact points between the leveling mechanism and the base are the same, the first wafer and the second wafer are leveled. This method has high leveling accuracy and small leveling error, which can effectively improve alignment accuracy, bonding yield, chip area utilization, and avoid the risk of bonding failure. Attached Figure Description
[0031] Figure 1 This is a cross-sectional view of the leveling device provided in an embodiment of the present invention;
[0032] Figure 2 This is a three-dimensional view of the leveling mechanism provided in an embodiment of the present invention;
[0033] Figure 3 This is a partial cross-sectional view of the leveling mechanism provided in an embodiment of the present invention.
[0034] In the picture:
[0035] 10. First wafer; 20. Second wafer; 100. Fixture tooling; 200. Leveling mechanism; 110. First substrate; 120. Second substrate; 130. Drive assembly; 131. Cylinder; 132. Protrusion structure; 140. Limiting assembly; 141. Needle roller guide post; 142. Spherical bearing; 143. Guide rail; 144. Slider; 150. Tension spring; 300. Adsorption block; 400. Chuck; 500. Hook block. Detailed Implementation
[0036] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components 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.
[0037] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0038] In the description of this invention, unless otherwise expressly specified and limited, "above" or "below" the 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 the second feature includes the first feature being 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" the second feature includes the first feature being 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.
[0039] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0040] This embodiment provides a leveling device and leveling method, which is suitable for situations where there is no requirement for whether the bonding surfaces of the two wafers are in contact before bonding, but is generally not suitable for situations where there are special requirements for the cleanliness of the bonding surfaces.
[0041] like Figures 1 to 3 As shown, the leveling device includes a base, a support frame, and a leveling mechanism 200. Both the support frame and the leveling mechanism 200 are mounted on the base. A fixture 100 is mounted on the support frame to fix a first wafer 10. A chuck 400 is mounted on the top of the leveling mechanism 200 and is positioned below the fixture 100. The chuck 400 is used to fix a second wafer 20. The leveling mechanism 200 is configured to bring the second wafer 20 into contact with the first wafer 10, making the second wafer 20 parallel to the first wafer 10. A pressure sensor is installed between the leveling mechanism 200 and the base. The pressure sensor detects the pressure values at multiple contact points between the leveling mechanism 200 and the base to determine whether the second wafer 20 and the first wafer 10 are leveled.
[0042] The leveling device provided in this embodiment, by setting up a leveling mechanism 200 and a pressure sensor, uses the leveling mechanism 200 to make the second wafer 20 and the first wafer 10 fit together so that the second wafer 20 is parallel to the first wafer 10. At the same time, the pressure sensor detects the pressure values at multiple contact points between the leveling mechanism 200 and the base to determine whether the first wafer 10 and the second wafer 20 are leveled. This can effectively improve alignment accuracy, bonding yield, chip area utilization, and avoid the risk of bonding failure.
[0043] In some embodiments, the leveling mechanism 200 includes a first substrate 110, a second substrate 120, a driving component 130, a limiting component 140, and tension springs 150. The first substrate 110 is disposed on a base; the second substrate 120 is disposed at intervals above the first substrate 110 and is used to support the chuck 400; multiple driving components 130 are provided, and the multiple driving components 130 are evenly disposed between the first substrate 110 and the second substrate 120, and the driving components 130 are used to drive the second substrate 120 to move up and down in the vertical direction; multiple limiting components 140 are provided, and the multiple limiting components 140 are evenly disposed between the first substrate 110 and the second substrate 120, and the limiting components 140 can adaptively deflect according to the position of the second substrate 120; multiple tension springs 150 are provided, and the multiple tension springs 150 are evenly disposed between the first substrate 110 and the second substrate 120. By setting multiple limiting components 140 and multiple driving components 130, each of the multiple driving components 130 can independently drive the second substrate 120 to rise and fall in the vertical direction, adjust the tilt posture of the second substrate 120, and thereby adjust the parallelism of the chuck 400 set on the second substrate 120 and the second wafer 20 on the chuck 400. At the same time, the multiple limiting components 140 can adaptively deflect according to the position of the second substrate 120, adapt to the change of the tilt angle of the second substrate 120, eliminate rigid interference during the leveling process, avoid jamming, and make the second wafer 20 and the first wafer 10 fit together, and the second wafer 20 is parallel to the first wafer 10. One end of the tension spring 150 is connected to the first substrate 110 and the other end is connected to the second substrate 120. The tension spring 150 can always apply a downward reverse preload to the second substrate 120, which works in coordination with the upward driving force of the driving component 130 to prevent the second substrate 120 from becoming loose, suspended or displaced during the driving process of the driving component 130, and improve the reliability of the leveling process.
[0044] Optionally, the drive assembly 130 includes a cylinder 131. The fixed end of the cylinder 131 is connected to the first substrate 110, and the output end of the cylinder 131 has a protruding structure 132. The protruding structure 132 forms point contact with the second substrate 120. Point contact transmits driving force through a small contact area, which can avoid large-area contact between the cylinder 131 and the second substrate 120, reduce friction or compression of the second substrate 120 by the cylinder 131, and prevent the second substrate 120 from warping or deforming due to uneven contact force. At the same time, point contact concentrates the driving force of the cylinder 131 on the contact point, reducing the lifting lag and offset problems caused by dispersed force, facilitating precise control of the lifting height and lifting speed of the second substrate 120, and ensuring smooth lifting process of the second substrate 120.
[0045] In some embodiments, a tension spring 150 is provided on both sides of each cylinder 131, and the tension springs 150 on both sides of the cylinder 131 are symmetrically distributed. The symmetrical arrangement of tension springs 150 on both sides of each cylinder 131 enables the tension of the tension springs 150 to be symmetrically distributed on both sides of the cylinder 131, ensuring that the contact point between the second substrate 120 and the protrusion is uniformly stressed, and at the same time, it is balanced with the upward driving force of the output end of the cylinder 131, avoiding the second substrate 120 from tilting or shifting to one side due to uneven tension on one side.
[0046] Optionally, both the first substrate 110 and the second substrate 120 are provided with hook blocks 500. The hook blocks 500 are provided with mounting holes for hooking the tension spring 150. The two ends of the tension spring 150 are respectively connected to the first substrate 110 and the second substrate 120 through the hook blocks 500. The hook blocks 500 can serve as the connection reference for the tension spring 150, and are fixed at preset positions on the first substrate 110 and the second substrate 120 respectively, accurately defining the connection points at both ends of the tension spring 150, and preventing the tension spring 150 from shifting, falling off, or tangling during stretching and contraction. The hooking cooperation between the tension spring 150 and the hook blocks 500 can quickly realize the installation and disassembly of the tension spring 150, reducing maintenance costs. The hook blocks 500 can prevent the tension of the tension spring 150 from directly acting on the first substrate 110 and the second substrate 120, preventing damage or deformation of the first substrate 110 and the second substrate 120 due to localized stress concentration.
[0047] Optionally, the limiting component 140 includes a needle roller guide post 141 and a spherical bearing 142. The fixed end of the needle roller guide post 141 is fixedly connected to the first substrate 110, the inner ring of the spherical bearing 142 is fixedly connected to the movable end of the needle roller guide post 141, and the outer ring of the spherical bearing 142 is slidably connected to the second substrate 120. The needle roller guide post 141 has a precise vertical guiding function and can limit horizontal offset and torsion. The needle roller guide post 141 can ensure that the second base plate 120 does not wobble or misalign during the lifting process, and provides a stable vertical support reference for the spherical bearing 142. Together with the drive component 130, it realizes the vertical positioning of the second base plate 120. The spherical bearing 142 has an angle adaptive capability and can generate a small angle deflection in any direction. When the drive strokes of multiple drive components 130 are inconsistent, the second base plate 120 will tilt. The spherical bearing 142 can follow the tilt angle of the second base plate 120 in real time and automatically make a small angle adaptive deflection to avoid the stiffness, jamming, stress concentration and movement jamming caused by rigid connection. In addition, by setting the outer ring of the spherical bearing 142 to slide and connect with the second base plate 120, when the second base plate 120 tilts, the connection point between the second base plate 120 and the limiting component 140 generates a small horizontal displacement. The sliding connection can absorb the micro displacement, retain unidirectional sliding, and ensure smooth and non-interfering movement. In this embodiment, both the needle roller guide post 141 and the spherical bearing 142 are standard parts, and the specific structures of the needle roller guide post 141 and the spherical bearing 142 will not be described in detail.
[0048] In some embodiments, the limiting component 140 further includes a guide rail 143 disposed at the bottom of the second substrate 120 and a slider 144 slidably engaged with the guide rail 143, with the outer ring of the spherical bearing 142 fixedly connected to the slider 144. The sliding engagement between the slider 144 and the guide rail 143, along with the angular adaptive capability of the spherical bearing 142, enables dual adaptation of angle and micro-displacement, ensuring smooth and interference-free movement of the second substrate 120.
[0049] Optionally, three driving components 130 are provided, and the three driving components 130 are evenly distributed along the circumference of the first substrate 110; three limiting components 140 are provided, and the three limiting components 140 are evenly distributed along the circumference of the first substrate 110; and the three limiting components 140 are disposed inside the three driving components 130. When the three cylinders 131 independently adjust their extension to tilt the second substrate 120 to adjust the wafer parallelism, the needle roller guide post 141 extends and retracts vertically with the height of the second substrate 120 to ensure vertical positioning accuracy and rigidity. The spherical bearing 142 deflects at any small angle with the tilt of the second substrate 120 to adapt to angle changes and eliminate rigid interference. The slider 144 slides slightly in the horizontal direction to compensate for the horizontal displacement of the connection point caused by the tilt. The three work together to ensure that the limiting component 140 provides vertical support and guidance without restricting the posture adjustment of the second substrate 120, so that the second substrate 120 can be smoothly, without jamming, and with high precision angle and parallelism adjustment under the drive of the multi-cylinder 131.
[0050] In some embodiments, the leveling device further includes an adsorption block 300 disposed on the second substrate 120. The adsorption block 300 has an adsorption air channel for adsorbing the chuck 400. By adsorbing the chuck 400 with the adsorption block 300, surface contact or multi-point precise adsorption can be achieved, reducing assembly gaps and cumulative errors, and improving the relative positional accuracy between the chuck 400 and the second substrate 120.
[0051] Optionally, the leveling device further includes a lifting assembly and an alignment platform. The lifting assembly is mounted on the base, the alignment platform is located at the output end of the lifting assembly, and the leveling mechanism 200 is located on the alignment platform. The lifting assembly is configured to drive the alignment platform to rise and fall. By setting up the lifting assembly, the lifting assembly can drive the alignment platform to rise and fall, thereby adjusting the height of the leveling mechanism 200, the chuck 400 located on the leveling mechanism 200, and the second wafer 20 on the chuck 400 through the rise and fall of the alignment platform, thus facilitating the adjustment of the position of the second wafer 20.
[0052] This embodiment also provides a leveling method, which uses the above-described leveling device and includes the following steps:
[0053] S1. The leveling mechanism 200 is used to bring the second wafer 20 and the first wafer 10 into place so that the second wafer 20 is parallel to the first wafer 10.
[0054] S2. When the pressure values at multiple contact points between the leveling mechanism 200 and the base are the same, the second wafer 20 and the first wafer 10 are leveled.
[0055] The leveling method provided in this embodiment is completed using the above-mentioned leveling device. During leveling, the leveling mechanism 200 makes the second wafer 20 and the first wafer 10 fit together and the second wafer 20 is parallel to the first wafer 10. When the pressure sensor detects that the pressure values at multiple contact points between the leveling mechanism 200 and the base are the same, the first wafer 10 and the second wafer 20 are leveled. This method has high leveling accuracy and small leveling error, which can effectively improve alignment accuracy, bonding yield, chip area utilization, and avoid the risk of bonding failure.
[0056] In some embodiments, before the second wafer 20 and the first wafer 10 are bonded, the step further includes:
[0057] S01, Fixture 100 adsorbs and fixes the first wafer 10;
[0058] S02, chuck 400 adsorbs and fixes the second wafer 20;
[0059] S03. The alignment platform and leveling mechanism 200 are driven to rise by the lifting component, so that the second wafer 20 fixed to the chuck 400 is moved to a preset position, and there is a gap between the second wafer 20 and the first wafer 10.
[0060] The alignment platform is raised and lowered by a lifting assembly, which in turn adjusts the leveling mechanism 200 and the adsorption block 300, as well as the height of the chuck 400 on the adsorption block 300 and the second wafer 20 on the chuck 400, facilitating the adjustment of the position of the second wafer 20. For example, in the initial position, the chuck 400 and the fixture 100 are at a certain distance to facilitate the fixing of the first wafer 10 and the second wafer 20. After the first wafer 10 and the second wafer 20 are fixed, the positions of the alignment platform, leveling mechanism 200, adsorption block 300, and chuck 400 are adjusted by the lifting assembly to avoid interference or collision between the components and improve the reliability of use.
[0061] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.
Claims
1. A leveling device, characterized in that, include: Base; A support frame is mounted on the base, and a fixture (100) is provided on the support frame. The fixture (100) is used to fix the first wafer (10). A leveling mechanism (200) is disposed on the base. The top of the leveling mechanism (200) carries a chuck (400), which is located below the fixture (100). The chuck (400) is used to fix the second wafer (20). The leveling mechanism (200) is configured to allow the second wafer (20) and the first wafer (10) to fit together, so that the second wafer (20) is parallel to the first wafer (10). A pressure sensor is provided between the leveling mechanism (200) and the base. The pressure sensor is used to detect the pressure value at multiple contact points between the leveling mechanism (200) and the base to determine whether the second wafer (20) and the first wafer (10) are leveled.
2. The leveling device according to claim 1, characterized in that, The leveling mechanism (200) includes: A first substrate (110) is disposed on the base; A second substrate (120) is disposed above the first substrate (110) at a distance, and the second substrate (120) is used to support the chuck (400); Multiple driving components (130) are provided, and the multiple driving components (130) are evenly disposed between the first substrate (110) and the second substrate (120). The driving components (130) are used to drive the second substrate (120) to move up and down in the vertical direction. Multiple limiting components (140) are provided, and the multiple limiting components (140) are evenly disposed between the first substrate (110) and the second substrate (120). The limiting components (140) can adaptively deflect according to the position of the second substrate (120). Multiple tension springs (150) are provided, and the multiple tension springs (150) are evenly disposed between the first substrate (110) and the second substrate (120).
3. The leveling device according to claim 2, characterized in that, The drive assembly (130) includes a cylinder (131), the fixed end of which is connected to the first substrate (110), and the output end of the cylinder (131) has a protrusion structure (132), which forms a point contact with the second substrate (120).
4. The leveling device according to claim 3, characterized in that, Each cylinder (131) is provided with a tension spring (150) on both sides, and the tension springs (150) on both sides of the cylinder (131) are symmetrically distributed.
5. The leveling device according to claim 2, characterized in that, The limiting component (140) includes a needle roller guide post (141) and a spherical bearing (142). The fixed end of the needle roller guide post (141) is fixedly connected to the first substrate (110), the inner ring of the spherical bearing (142) is fixedly connected to the movable end of the needle roller guide post (141), and the outer ring of the spherical bearing (142) is slidably connected to the second substrate (120).
6. The leveling device according to claim 5, characterized in that, The limiting component (140) further includes a guide rail (143) disposed at the bottom of the second substrate (120) and a slider (144) that slides with the guide rail (143), wherein the outer ring of the spherical bearing (142) is fixedly connected to the slider (144).
7. The leveling device according to claim 2, characterized in that, Three driving components (130) are provided, and the three driving components (130) are evenly distributed along the circumference of the first substrate (110); three limiting components (140) are provided, and the three limiting components (140) are evenly distributed along the circumference of the first substrate (110); and the three limiting components (140) are located inside the three driving components (130).
8. The leveling device according to claim 2, characterized in that, The leveling device further includes an adsorption block (300), which is disposed on the second substrate (120). The adsorption block (300) has an adsorption air channel for adsorbing the chuck (400).
9. The leveling device according to claim 1, characterized in that, The leveling device further includes a lifting component and a positioning platform. The lifting component is installed on the base, the positioning platform is located at the output end of the lifting component, and the leveling mechanism (200) is located on the positioning platform. The lifting component is configured to drive the positioning platform and the leveling mechanism (200) to rise and fall.
10. A leveling method, characterized in that, Using the leveling device as described in any one of claims 1-9, the leveling method includes the steps of: The leveling mechanism (200) is used to bring the second wafer (20) and the first wafer (10) together so that the second wafer (20) is parallel to the first wafer (10); When the pressure values at multiple contact points between the leveling mechanism (200) and the base are the same, the second wafer (20) and the first wafer (10) are leveled.