Wafer bonding device

Abstract

A wafer bonding apparatus, the wafer bonding apparatus comprising: a first chuck having a first holding surface for contacting a first wafer; the second chuck is arranged opposite to the first chuck, and the second chuck is provided with a second holding surface used for being in contact with a second wafer; the driving rod can move in the direction perpendicular to the first holding face to drive the second chuck to be close to or / and far away from the first chuck, and the driving rod is flexibly connected to the center of the second chuck so that when the second chuck is close to the first chuck, the second holding face can be adjusted to be parallel to the first holding face, and then the first wafer and the second wafer can be jointed. The two chucks are ensured to be completely parallel, and the parallelism of the two chucks in the process of bonding the two wafers is improved, so that the stability in the wafer bonding process is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a wafer bonding device. Background Art

[0002] In the semiconductor manufacturing process, bonding or temporarily bonding two wafers is a common process. The equipment used to perform this process is a wafer bonding device. Existing wafer bonding devices include two chucks positioned opposite each other and spaced apart. A cylinder drives one chuck toward the other to bond the two wafers between the chucks. However, in existing wafer bonding devices, during the bonding process, the two chucks cannot be completely parallel to each other. In other words, the parallelism between the two chucks is poor, which affects the stability of the process. Summary of the invention

[0003] The Summary of the Invention introduces a series of simplified concepts that will be further described in the Detailed Description of the Invention. The Summary of the Invention is not intended to limit the key features and essential features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0004] In order to solve the existing problems, a first aspect of an embodiment of the present invention provides a wafer bonding device, which includes:

[0005] a first chuck having a first holding surface for contacting a first wafer;

[0006] a second chuck disposed opposite the first chuck, the second chuck having a second holding surface for contacting a second wafer; and

[0007] A drive rod can move in a direction perpendicular to the first holding surface to drive the second chuck to approach or / and move away from the first chuck. The drive rod is flexibly connected to the center of the second chuck to adjust the second holding surface to be parallel to the first holding surface when the second chuck approaches the first chuck, so that the first wafer and the second wafer can be joined.

[0008] In some embodiments of the present application, the drive rod includes a spherical convex surface abutting the center of the second chuck away from the second holding surface, and the second chuck can rotate around the spherical convex surface to adjust the second holding surface to be parallel to the first holding surface.

[0009] In some embodiments of the present application, the driving rod includes:

[0010] a rod extending in a direction perpendicular to the first holding surface and located at the center of the second chuck; and

[0011] A top head detachably connected to the rod body and located at the end facing the second chuck side, the top head having a spherical convex surface.

[0012] In some embodiments of the present application, a docking surface in contact with the spherical convex surface is provided on the side of the second chuck facing away from the second holding surface;

[0013] The docking surface is a plane parallel to the second holding surface, or the docking surface is a spherical concave surface that mates with the spherical convex surface.

[0014] In some embodiments of the present application, a gasket is detachably connected to the side of the second chuck facing away from the second holding surface, and a docking surface is provided on the side of the gasket facing away from the second holding surface.

[0015] In some embodiments of the present application, the wafer bonding device further includes:

[0016] A shrapnel structure connected to the drive rod, the shrapnel structure having a plurality of elastic arms arranged at intervals around the drive rod; and,

[0017] A plurality of connecting members, each connecting member corresponding to an elastic arm and connected between the corresponding elastic arm and the second chuck.

[0018] In some embodiments of the present application, mounting holes are provided through the elastic arms, and the connecting member includes:

[0019] A first screw that passes through the mounting hole in the corresponding elastic arm and is connected to the second chuck; and,

[0020] A first fastening nut connected to the first screw, the first fastening nut being located on the side of the elastic arm facing away from the second chuck to define the maximum distance between the elastic arm and the second chuck in the extending direction of the first screw.

[0021] In some embodiments of the present application, the wafer bonding device further includes:

[0022] A support portion at least partially located on the side of the first chuck facing away from the second chuck, the first chuck having a main body portion and an edge portion, the edge portion being fixed to the support portion through a support structure, and the main body portion being spaced apart from the support portion;

[0023] A second screw and a second fastening nut, the second screw being perpendicular to the first holding surface and passing through the support portion and then connected to the center of the main body portion, and the second fastening nut being connected to the second screw on the side of the support portion facing away from the main body portion to define the distance between the center of the main body portion and the support portion in the extending direction of the second screw;

[0024] A plurality of setscrews arranged around the second screw and spaced apart, the setscrews passing through the support portion and abutting against the surface of the main body portion facing away from the first holding surface to adjust the distance between the main body portion and the support portion at the position of the setscrews in the extending direction of the setscrews.

[0025] In some embodiments of the present application, the wafer bonding device further includes:

[0026] A first housing and a second housing that can be snapped together to form a sealed chamber or a phase-separated structure;

[0027] Wherein, the first chuck and the second chuck are located in the sealed chamber, and the part of the first housing on the side of the first chuck facing away from the second chuck constitutes a support portion; the driving rod passes through the second housing and is connected to the second chuck, and the driving rod can move relative to the second housing in a direction perpendicular to the first holding surface.

[0028] In some embodiments of the present application, the first holding surface of the first chuck is horizontally arranged, the second chuck is located above the first chuck, and the driving rod is located on the side of the second chuck facing away from the first chuck and can move in the vertical direction.

[0029] According to the wafer bonding device provided by the present invention, by setting the first chuck with a fixed position and making the driving rod flexibly connected to the center of the second chuck, when the second chuck approaches the first chuck, if the second chuck and the first chuck are not completely parallel, as the driving rod drives the second chuck to move towards the first chuck, the second chuck will perform a small-angle rotation to adjust the second holding surface to a state parallel to the first holding surface. Then, as the driving rod continues to move towards the first chuck, the bonding of the first wafer and the second wafer can be completed. This ensures that the two chucks are completely parallel, improves the parallelism of the two chucks during the wafer bonding process, and thus improves the stability of the wafer bonding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The following drawings of the present invention are used as part of the present invention to understand the present invention. The embodiments of the present invention shown in the drawings and their descriptions are used to explain the principles of the present invention.

[0031] In the drawings:

[0032] Figure 1 Shows a cross-sectional schematic view of a wafer bonding device according to a specific embodiment of the present invention;

[0033] Figure 2 Shows a cross-sectional schematic view of the second chuck and the driving rod according to a specific embodiment of the present invention;

[0034] Figure 3 Shows a schematic view of the state when the second chuck is inclined relative to the first chuck according to a specific embodiment of the present invention;

[0035] Figure 4 Shows a schematic view of the state when the second chuck is parallel and attached to the first chuck according to a specific embodiment of the present invention;

[0036] Figure 5Shows a schematic cross - sectional view of the set screw and the second screw under the second chuck in a specific embodiment of the present invention;

[0037] Figure 6 Shows a schematic top - view of the distribution of the set screw and the second screw in a specific embodiment of the present invention;

[0038] Figure 7 Shows a schematic cross - sectional view of a wafer bonding device in another specific embodiment of the present invention.

[0039] Reference numerals:

[0040] 10 - First chuck; 11 - First holding surface; 101 - Main body part; 102 - Edge part; 103 - Support structure;

[0041] 20 - Second chuck; 21 - Second holding surface; 22 - Docking surface; 23 - Gasket;

[0042] 30 - Driving rod; 31 - Rod body; 32 - Top head; 321 - Spherical convex surface;

[0043] 40 - Belleville spring structure; 41 - Elastic arm; 411 - Mounting hole;

[0044] 42 - First screw; 43 - First fastening nut;

[0045] 50 - First housing; 51 - Support part; 52 - Second screw; 53 - Second fastening nut; 54 - Set screw;

[0046] 60 - Second housing;

[0047] 71 - First wafer; 72 - Second wafer Specific embodiments

[0048] In the following description, numerous specific details are given to provide a more thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that the present invention may be practiced without one or more of these details. In other instances, well - known features of the art are not described to avoid obscuring the present invention.

[0049] It should be understood that the present invention can be implemented in different forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. In the drawings, the dimensions and relative dimensions of layers and regions may be exaggerated for clarity. Like reference numerals denote like elements throughout.

[0050] It should be understood that when an element or layer is referred to as being "on", "adjacent to", "connected to", or "coupled to" another element or layer, it can be directly on, adjacent to, connected or coupled to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on", "directly adjacent to", "directly connected to", or "directly coupled to" another element or layer, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or part from another element, component, region, layer, or part. Thus, without departing from the teachings of the present invention, the first element, component, region, layer, or part discussed below may be denoted as the second element, component, region, layer, or part.

[0051] Spatial relationship terms such as "under", "below", "lower", "beneath", "above", "upper", etc. are used herein for convenience in describing the relationship of one element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientation shown in the figures, the spatial relationship terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figures is flipped, then an element or feature described as "under" or "beneath" or "below" other elements or features will be oriented "above" the other elements or features. Thus, the exemplary terms "under" and "below" can include both an upper and a lower orientation. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are to be interpreted accordingly.

[0052] The purpose of the terms used herein is only to describe specific embodiments and is not a limitation of the present invention. As used herein, the singular forms "a", "an", and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. As used herein, the term "and / or" includes any and all combinations of the associated listed items.

[0053] Embodiment 1

[0054] Reference Figure 1 , an embodiment of the present invention provides a wafer bonding device, which mainly includes:

[0055] The first chuck 10, the first chuck 10 having a first holding surface 11 for contacting the first wafer 71;

[0056] A second chuck 20 disposed opposite to the first chuck 10, the second chuck 20 having a second holding surface 21 for contacting the second wafer 72; and,

[0057] A driving rod 30 movable in a direction perpendicular to the first holding surface 11 to drive the second chuck 20 to approach or / and move away from the first chuck 10, the driving rod 30 being flexibly connected to the center of the second chuck 20 so as to adjust the second holding surface 21 to be parallel to the first holding surface 11 when the second chuck 20 approaches the first chuck 10 and then bond the first wafer 71 and the second wafer 72.

[0058] The specific technical effects and principles are as follows: In the prior art, the driving shaft of the driving cylinder moves along its extending direction, thereby driving one of the chucks to approach or move away from the other chuck. The driving shaft is rigidly connected to the chuck, and the perpendicularity between the driving shaft and the chuck is mainly adjusted by the set screws provided on the wafer bonding device to achieve the adjustment of the parallelism (also called relative levelness) between the two chucks. After the adjustment is completed, the relative position between the two chucks is fixed, and during the bonding process, the relative levelness between them cannot be adjusted. However, this adjustment method has relatively high requirements for the self-precision of the chuck and the driving shaft (requiring both chucks to be perpendicular to the driving shaft). If the self-precision requirements are relatively low (as long as the perpendicularity between one of the chucks and the driving shaft is poor), the parallelism between the two chucks will be poor, thus affecting the stability during the process. In addition, in the prior art, since the relative levelness between the two chucks remains unchanged during the bonding process, when encountering wafers of different batches (with different thickness uniformities), it is necessary to readjust the relative levelness between the two chucks, resulting in low adjustment efficiency.

[0059] In the above embodiments of the present application, referring to Figure 3 and Figure 4 , by providing the first chuck 10 with a fixed position and flexibly connecting the driving rod 30 to the center of the second chuck 20, when the second chuck 20 approaches the first chuck 10, if the second chuck 20 and the first chuck 10 are not completely parallel, as the driving rod 30 drives the second chuck 20 to move towards the first chuck 10, the second chuck 20 will rotate by a small angle to adjust the second holding surface 21 to a state parallel to the first holding surface 11. Then, as the driving rod 30 continues to move towards the first chuck 10, the bonding of the first wafer 71 and the second wafer 72 can be completed. Ensure that the two chucks are completely parallel, improve the parallelism between the two chucks during the bonding of the two wafers, and thus improve the stability during the wafer bonding process.

[0060] Exemplarily, the first chuck 10 in the present application can be arranged in ways such as but not limited to being fixedly arranged or movably arranged. In a preferred embodiment, the first chuck 10 can be fixedly arranged. Once the arrangement of the first chuck 10 is completed, the setting angle of the first holding surface 11 of the first chuck 10 is determined. The second chuck 20 is flexibly connected to the driving rod 30, and the driving direction of the driving rod 30 is perpendicular to the first holding surface 11. Therefore, during assembly, it is only necessary to ensure the perpendicularity between the driving direction of the driving rod 30 and the first holding surface 11, without the need to ensure the perpendicularity between the driving rod 30 and the second holding surface 21 of the second chuck 20, thereby simplifying the assembly and manufacturing precision requirements of the second chuck 20.

[0061] During the bonding process such as but not limited to bonding and adhesion using the wafer bonding device shown in the embodiments of the present application, the driving rod 30 drives the second chuck 20 to approach the first chuck 10. Refer to Figure 3 and Figure 4 , if the second chuck 20 and the first chuck 10 are not completely parallel, partial areas of the second holding surface 21 will come into contact with the first holding surface 11 or the wafer on the first holding surface 11 first (for example, Figure 3 the right side part of the second holding surface 21 in comes into contact with the first holding surface 11 first), while other partial areas on the second holding surface 21 do not come into contact with the first holding surface 11 or the wafer on the first holding surface 11 (for example, Figure 3 the left side part of the second holding surface 21 in does not come into contact with the first holding surface 11).

[0062] After that, as the driving rod 30 drives the second chuck 20 to continue moving towards the first chuck 10, the second chuck 20 will use the partial area on the second holding surface 21 that first comes into contact with the first holding surface 11 or the wafer on the first holding surface 11 as the rotation force application point (for example, Figure 3 the right side part of the second holding surface 21 in is the rotation force application point for driving the second chuck 20 to rotate), use the part where the second chuck 20 contacts the driving rod 30 as the fulcrum, and rotate around the driving rod 30 by a small angle to adjust the second holding surface 21 to a state parallel to the first holding surface 11, which is beneficial for the second chuck 20 to apply force evenly to different positions of the wafer and ensure the uniformity of the driving contact force applied to different radius areas of the wafer. Then, as the driving rod 30 continues to move towards the first chuck 10, the bonding of the first wafer 71 and the second wafer 72 can be completed in ways such as but not limited to bonding and adhesion.

[0063] The above method does not require adjustment of the verticality between the second chuck 20 and the drive rod 30, thereby improving work efficiency. It also ensures that the two chucks are completely parallel, improves the parallelism of the two chucks in the process of bonding the two wafers, and ensures the uniformity of the driving bonding force applied to different radius areas on the inverted wafer, thereby improving the stability of the wafer bonding process and reducing the defective rate of the product. Through the above improvement method, the wafer bonding device provided by this application will not change the process characteristics due to slight changes in the machine hardware, and the accuracy requirements for the chuck can be reduced by one level, effectively improving the stability of the process.

[0064] Below, reference Figures 1 to 7 The wafer bonding apparatus according to the embodiment of the present invention is described in detail.

[0065] First, it should be noted that the flexible connection between the drive rod 30 and the second chuck 20 means that the second chuck 20 can rotate around the drive rod 30 within a small angle range (e.g., 1°-10°, where the rotation angle refers to the second chuck 20 rotating in any direction perpendicular to the drive rod 30). The rotation can be damped or non-damped. This allows the second chuck 20 to rotate around the drive rod 30 using the portion of the area in contact with the first chuck 10 or the wafer as the rotation force point and the portion in contact with the drive rod 30 as the fulcrum, thereby adjusting the second holding surface 21 to a state parallel to the first holding surface 11.

[0066] When realizing the flexible connection between the driving rod 30 and the second chuck 20, various methods can be used, for example, elastic structures such as but not limited to high temperature resistant rubber, springs, etc. Some methods are exemplified below.

[0067] Exemplary, reference Figure 2 The drive rod 30 may include a spherical convex surface 321 that abuts the center of the second chuck 20 on the side facing away from the second holding surface 21. The second chuck 20 can rotate around the spherical convex surface 321 to adjust the second holding surface 21 to be parallel to the first holding surface 11. By making the surface of the drive rod 30 that contacts the second chuck 20 a spherical convex surface 321, the force position between the spherical convex surface 321 on the drive rod 30 and the second chuck 20 can be changed in real time according to the force applied to the second chuck 20, thereby indirectly adjusting the uniformity of the driving engagement force applied by the drive rod 30 to different positions of the wafer. During the process of the second chuck 20 rotating around the drive rod 30, the second chuck 20 rotates around the spherical convex surface 321, thereby enabling the second chuck 20 to rotate smoothly around the drive rod 30, without a sudden change in the force transmitted between the drive rod 30 and the wafer, which is conducive to the drive rod 30 stably applying the driving engagement force to the wafer.

[0068] Exemplary, reference Figure 2The central axis of the spherical convex surface 321 can be arranged parallel to the driving direction of the drive rod 30, thereby facilitating the perpendicularity between the second chuck 20 and the drive rod 30. Of course, in other embodiments, the central axis of the spherical convex surface 321 is not limited to being arranged parallel to the drive rod 30; it can have any inclination angle, as long as its area is large enough to ensure that the second chuck 20 remains in contact with the spherical convex surface 321 during its rotation around the spherical convex surface 321. The diameter of the spherical convex surface 321 can be appropriately determined based on factors such as the size and material of the chuck.

[0069] In some embodiments, reference Figure 2 The driving rod 30 may include: a rod body 31 extending in a direction perpendicular to the first retaining surface 11 and located at the center of the second chuck 20; and a plug 32 detachably connected to the rod body 31 at the end facing the second chuck 20. The plug 32 has a spherical convex surface 321. By adopting a detachable connection between the rod body 31 and the plug 32, the spherical convex surface 321 is provided on the side of the plug 32 facing the second chuck 20. Therefore, if the spherical convex surface 321 is severely worn after repeated use, the plug 32 can be replaced to replace the spherical convex surface 321, thereby ensuring that the spherical convex surface 321 with better morphological quality is always used during the bonding process.

[0070] There are many ways to detachably connect the plug 32 and the rod body 31. For example, they can be connected by thread, by clamping, or by bonding.

[0071] Of course, in other embodiments, the rod body 31 can also be used as the driving rod 30, and the spherical convex surface 321 can be directly set at the end of the rod body 31 facing the second chuck 20, so that the spherical convex surface 321 and the driving rod 30 are an integrated structure.

[0072] Exemplary, reference Figure 2A docking surface 22 that contacts the spherical convex surface 321 may be provided on the side of the second chuck 20 facing away from the second retaining surface 21. The docking surface 22 is a plane parallel to the second retaining surface 21. Specifically, during the rotation of the second chuck 20 around the spherical convex surface 321, the docking surface 22 on the second chuck 20 is always in contact with the spherical convex surface 321. The docking surface 22 is configured as a plane parallel to the second retaining surface 21, thereby achieving a point-to-plane contact between the second chuck 20 and the drive rod 30. This allows the second chuck 20 to rotate within a small angle range in any direction perpendicular to the drive rod 30. Since the docking surface 22 only contacts a point area of the spherical convex surface 321, its contact area is small, which can improve the sensitivity of the second chuck 20 to rotate around the driving rod 30. As long as there is an arbitrarily small inclination angle between the second retaining surface 21 and the first retaining surface 11, as the driving rod 30 continues to move toward the first chuck 10, the second retaining surface 21 can be adjusted to a state parallel to the first retaining surface 11, thereby improving the sensitivity and accuracy of the adjustment.

[0073] Specifically, refer to Figure 3 When the right side of the second holding surface 21 contacts the first holding surface 11 first, one of the spherical force points on the spherical convex surface 321 contacts and transmits force to the docking surface 22. Figure 3 On the basis of the above, as the driving rod 30 continues to drive the second chuck 20 closer to the first chuck 10, the spherical force point on the spherical convex surface 321 that contacts the docking surface 22 changes, thereby automatically adjusting the angle of the second chuck 20 to move to Figure 4 The second holding surface 21 is adjusted to be parallel to the first holding surface 11, so that the driving bonding force of the same outer diameter area on the wafer is finally the same, ensuring the uniformity of the driving bonding force applied to different radius areas on the wafer.

[0074] Of course, it should be noted that the docking surface 22 is not limited to the above-mentioned plane method, and other methods can also be used.

[0075] For example, in other embodiments, the mating surface 22 may be a spherical concave surface (not shown) that mates with the spherical convex surface 321. Specifically, the spherical convex surface 321 and the spherical concave surface have equal or similar diameters, allowing the spherical convex surface 321 to be accommodated within the spherical concave surface and enabling the second chuck 20 to rotate within a small angle range in any direction perpendicular to the drive rod 30. Of course, in this embodiment, the higher the machining precision of the spherical convex surface 321 and the spherical concave surface, the greater the adjustment sensitivity.

[0076] In some embodiments, reference Figure 2, a gasket 23 is detachably connected to the side of the second chuck 20 away from the second holding surface 21, and a docking surface 22 is provided on the side of the gasket 23 away from the second holding surface 21. That is, by detachably arranging the gasket 23 on the second chuck 20 and arranging the docking surface 22 on the gasket 23, after the docking surface 22 has been used for too long and its surface has suffered relatively serious wear, the docking surface 22 can be replaced by replacing the gasket 23, which is beneficial to keeping the docking surface 22 in a good state during the wafer bonding process to improve process stability.

[0077] Regarding the shape of the gasket 23, it can be of any shape. In some embodiments, the top view shape of the gasket 23 can be circular, square, etc., as long as it can provide a large enough area for setting the docking surface 22 so that the docking surface 22 and the spherical convex surface 321 do not separate during the rotation process.

[0078] There are various ways to detachably connect the gasket 23 and the second chuck 20. In some embodiments, the gasket 23 can be detachably arranged on the second chuck 20 by means such as but not limited to bonding, clamping, screw connection, etc.

[0079] Exemplarily, referring to Figure 2 , Figure 3 and Figure 4 , the wafer bonding device may further include: a shrapnel structure 40 connected to the driving rod 30 and a plurality of connecting pieces. The shrapnel structure 40 has a plurality of elastic arms 41 arranged at intervals around the driving rod 30. Each connecting piece corresponds to an elastic arm 41 and is connected between the corresponding elastic arm 41 and the second chuck 20. By setting the shrapnel structure 40, a flexible connection between the driving rod 30 and the second chuck 20 is realized, which is beneficial for the second chuck 20 to rotate at a small angle around the driving rod 30. At the same time, it is also beneficial for the driving rod 30 to conduct the driving force generated by it to the second chuck 20 through the shrapnel structure 40 and the connecting pieces, which is beneficial to improving the uniformity of the driving joint force at different positions on the wafer. And when the shrapnel structure 40 is paired with the spherical convex surface 321, by setting elastic arms 41 of equal size, it is beneficial to ensure the perpendicularity between the second chuck 20 and the driving rod 30 to improve the parallelism between the second holding surface 21 and the first holding surface 11.

[0080] It should be noted that the connector can be connected to the elastic arm 41 and the second chuck 20 in a variety of ways. For example, the connector and the second chuck 20 can be fixedly connected, and the connector and the elastic arm 41 can also be fixedly connected. Of course, in other embodiments, since the drive rod 30 and the second chuck 20 are also in contact via the spherical convex surface 321 and the docking surface 22, one end of the connector can be fixedly connected to the second chuck 20, and the other end of the connector can be connected to the elastic arm 41 in a one-way limited manner. As long as the spacing between the elastic arm 41 and the second chuck 20 is not too large, the second chuck 20 and the drive rod 30 can be flexibly connected. The maximum angle of rotation of the second chuck 20 relative to the drive rod 30 can be adjusted by adjusting the maximum spacing between the elastic arm 41 and the second chuck 20.

[0081] For example, the number of elastic arms 41 can be any number, such as 3, 4, 5, 6, or 8. The multiple elastic arms 41 can be evenly spaced around the circumference of the drive rod 30. The number of corresponding connecting members is equal to the number of elastic arms 41, and the connecting members can be connected between the corresponding elastic arms 41 and the area on the second chuck 20 opposite the elastic arms 41.

[0082] There are many ways to configure the connectors, some of which are exemplified below.

[0083] In some embodiments of the present application, reference is made to Figure 2 The elastic arm 41 is provided with a mounting hole 411. The connector includes a first screw 42 that passes through the mounting hole 411 on the corresponding elastic arm 41 and is connected to the second chuck 20, and a first fastening nut 43 connected to the first screw 42. The first fastening nut 43 is located on the side of the elastic arm 41 facing away from the second chuck 20 to limit the maximum distance between the elastic arm 41 and the second chuck 20 in the direction in which the first screw 42 extends.

[0084] Specifically, refer to Figure 2 , Figure 3 and Figure 4 One end of the first screw rod 42 can be threadedly connected to the second chuck 20, thereby achieving a fixed connection between the first screw rod 42 and the second chuck 20. The other end of the first screw rod 42 passes through the mounting hole 411 on the corresponding elastic arm 41 and is then threadedly connected to the first fastening nut 43. The first fastening nut 43 defines the maximum distance between the elastic arm 41 and the second chuck 20 in the extension direction of the first screw rod 42. This maximum distance can be adjusted to a preset distance, so that when the second chuck 20 is in a natural non-interference state, the second retaining surface 21 and the driving rod 30 are arranged perpendicularly, which is conducive to improving the parallelism between the second retaining surface 21 and the first retaining surface 11.

[0085] And since the first fastening nut 43 only limits the maximum distance between the elastic arm 41 and the second chuck 20 in the extension direction of the first screw 42, and does not limit the minimum distance between the elastic arm 41 and the second chuck 20 in the extension direction of the first screw 42, the resistance of the elastic arm 41 to rotation interference can be reduced during the rotation of the second chuck 20 around the spherical convex surface 321, thereby improving the sensitivity of the parallelism adjustment of the two chucks.

[0086] Exemplarily, the spring structure 40 may include an annular body and a plurality of elastic arms 41 extending from the annular body. The annular body is inserted into the drive rod 30 to achieve assembly and fixation of the spring structure 40. Exemplarily, the annular body may be disposed between the plug 32 and the rod body 31. In this case, the plug 32 also has the function of fastening the annular body to the rod body 31, thereby simplifying the assembly of the spring structure 40 and the plug 32.

[0087] Exemplary, reference Figure 2 The second chuck 20 may be provided with a reinforcement protrusion on the side away from the second holding surface 21 , and one end of the first screw 42 is passed through the reinforcement protrusion, thereby improving the reliability of the connection between the first screw 42 and the second chuck 20 .

[0088] Exemplary, reference Figure 2 The first screw 42 may have a nut, and a countersunk groove may be provided on the second holding surface 21. The nut of the first screw 42 may be accommodated in the countersunk groove and its surface may be flush with the second holding surface 21, thereby not affecting the uniform application of driving engagement force to the wafer.

[0089] In some embodiments, reference Figure 4 and Figure 5 , the wafer bonding apparatus may further include:

[0090] A support portion 51 is at least partially located on a side of the first chuck 10 facing away from the second chuck 20 . The first chuck 10 includes a main portion 101 and an edge portion 102 . The edge portion 102 is fixed to the support portion 51 via a support structure 103 . The main portion 101 is spaced apart from the support portion 51 .

[0091] A second screw rod 52 and a second fastening nut 53, wherein the second screw rod 52 is arranged perpendicular to the first retaining surface 11 and passes through the support portion 51 and is connected to the center of the main portion 101. The second fastening nut 53 is connected to the second screw rod 52 on the side of the support portion 51 facing away from the main portion 101 to define the distance between the center of the main portion 101 and the support portion 51 in the extending direction of the second screw rod 52; and

[0092] A plurality of set screws 54 are arranged around the second screw 52 at intervals. The set screws 54 pass through the support portion 51 and abut against the surface of the main body portion 101 facing away from the first holding surface 11, so as to adjust the distance between the main body portion 101 and the support portion 51 at the position of the set screws 54 in the extending direction of the set screws 54.

[0093] Specifically, referring to Figure 4 , Figure 5 and Figure 6 , a support portion 51 is provided on the side of the first chuck 10 away from the second chuck 20. While the edge portion 102 of the first chuck 10 is extended and connected to the support portion 51 through the support structure 103, a space is provided between the main body portion 101 of the first chuck 10 and the support portion 51, that is, the main body portion 101 of the first chuck 10 is "suspended". A second screw 52 and a plurality of set screws 54 are provided between the main body portion 101 of the first chuck 10 and the support portion 51.

[0094] Among them, referring to Figure 4 , Figure 5 and Figure 6 , one end of the second screw 52 is connected to the center of the main body portion 101, and the other end of the second screw 52 passes through the support portion 51 and is connected with a second fastening nut 53. Thus, by tightening or loosening the second fastening nut 53, the distance between the center of the main body portion 101 and the support portion 51 in the direction of the second screw 52 can be adjusted. The stiffness of the support portion 51 is usually greater than that of the main body portion 101 of the first chuck 10. Thus, with the tightening or loosening of the second fastening nut 53, the morphology of the center of the main body portion 101 can be changed, so that a small deformation occurs near the center of the main body portion 101, and thus the driving engagement force at the centers of the two wafers can be changed.

[0095] For example, referring to Figure 4 and Figure 5 , when increasing the distance between the center of the main body portion 101 and the support portion 51 in the direction of the second screw 52, the upward deformation at the center of the main body portion 101 can be increased, so as to increase the driving engagement force at the centers of the two wafers. When decreasing the distance between the center of the main body portion 101 and the support portion 51 in the direction of the second screw 52, the upward deformation at the center of the main body portion 101 can be decreased, so as to decrease the driving engagement force at the centers of the two wafers.

[0096] Referring to Figure 4 , Figure 5 and Figure 6, and multiple top screws 54 are arranged at circumferential intervals around the second screw 52, one end of the top screw 54 presses on the surface of the main part 101 away from the second chuck 20, and the other end of the top screw 54 is threadedly connected to the support part 51, so that as the top screw 54 rotates forward or reverse, the distance between the main part 101 and the support part 51 at the top screw 54 can be changed, so as to change the morphology of the main part 101 at the top screw 54, causing it to undergo slight deformation in some areas, thereby adjusting the driving engagement force at the position on the wafer opposite to the top screw 54.

[0097] For example, reference Figure 4 and Figure 5 When the push screw 54 is rotated to move it upward, the distance between the main portion 101 of the push screw 54 and the support portion 51 can be increased, thereby increasing the upward deformation of the main portion 101 of the push screw 54, thereby increasing the driving engagement force between the two wafers at the push screw 54. When the push screw 54 is rotated to move it downward, the distance between the main portion 101 of the push screw 54 and the support portion 51 can be reduced, thereby reducing the upward deformation of the main portion 101 of the push screw 54, thereby reducing the driving engagement force between the two wafers at the push screw 54.

[0098] There are many ways to arrange the plurality of top screws 54 in a circumferentially spaced manner around the second screw rod 52, and some of the ways are shown as follows. Figure 6 The plurality of top screws 54 are arranged in an array around the circumference of the second screw 52 with the second screw 52 as the center. In other embodiments, the plurality of top screws 54 can be arranged in a point-radiated manner around the circumference of the second screw 52 with the second screw 52 as the center.

[0099] Through the above method, the deformation at the center of the main part 101 is adjusted by the second screw 52 + second fastening nut 53, and the deformation of other areas of the main part 101 is adjusted by the top screw 54, so that the size of the driving bonding force applied to part of the wafer can be adjusted, which is conducive to more uniform driving bonding force at different positions of the wafer.

[0100] For example, before performing the wafer bonding process, the parallelism and the driving engagement force distribution between the two holding surfaces can be tested using a pressure-sensitive test paper to identify areas with abnormal driving engagement force distribution. The areas with abnormal driving engagement force distribution refer to those where the driving engagement force deviates from the average value of the driving engagement forces in all areas of the entire holding surface and is greater than or less than a certain set threshold. Subsequently, the setscrew 54 closest to the area with abnormal driving engagement force distribution is located, and the adjustment method (clockwise rotation or counterclockwise rotation, and the amount of rotation) of the located setscrew 54 is calculated. Then, the corresponding setscrew 54 is adjusted in the determined manner to adjust the parallelism and the driving engagement force distribution between the two holding surfaces to a state with good parallelism and uniform driving engagement force distribution.

[0101] Exemplarily, referring to Figure 7 , the wafer bonding device may further include: a first housing 50 and a second housing 60 that can be snapped together to form a sealed chamber or be separated; wherein, the first chuck 10 and the second chuck 20 are located in the sealed chamber, and a portion of the first housing 50 on the side of the first chuck 10 facing away from the second chuck 20 constitutes a support portion 51; the driving rod 30 passes through the second housing 60 and is connected to the second chuck 20, and the driving rod 30 can move relative to the second housing 60 in a direction perpendicular to the first holding surface 11.

[0102] By providing the first housing 50 and the second housing 60, it is convenient to enclose the space where the first chuck 10 and the second chuck 20 are located to form a sealed chamber, so as to provide a sealed process environment with high pressure and high temperature, which is beneficial to improving the uniformity of wafer bonding. Moreover, using a portion of the structure of the first housing 50 as the support portion 51 for arranging the second screw 52 and the setscrew 54 is beneficial to simplifying the structure. The driving rod 30 and the second chuck 20 can move in a direction perpendicular to the first holding surface 11. Thus, the first housing 50 and the second housing 60 can be snapped together first, and then the driving rod 30 moves to drive the second chuck 20 closer to the first chuck 10, decoupling the movements of the two, so as to improve the accuracy and controllability of their respective movements.

[0103] Exemplarily, referring to Figures 1 to 7 , the first holding surface 11 of the first chuck 10 is horizontally arranged, the second chuck 20 is located above the first chuck 10, and the driving rod 30 is located on the side of the second chuck 20 facing away from the first chuck 10 and can move in the vertical direction. By horizontally arranging the first chuck 10, vertically arranging the driving rod 30, and flexibly connecting the driving rod 30 to the center of the second chuck 20, it is possible to utilize the gravity of the second chuck 20 to achieve an effect similar to that of a tumbler, adjusting the second chuck 20 to a state parallel to the first chuck 10, thereby simplifying the adjustment difficulty and also being beneficial to adjusting the parallelism of the first bonding surface and the second bonding surface.

[0104] Of course, in some other embodiments, the first chuck 10 is not limited to the horizontally arranged manner. In addition, other manners can be adopted. For example, in some embodiments, the first chuck 10 is vertically arranged while the driving shaft is horizontally arranged.

[0105] There are various ways to implement the movement of the driving rod 30 in a direction perpendicular to the first holding surface 11. In some embodiments, the driving rod 30 can be a telescopic rod in a driving cylinder or a hydraulic cylinder. In some other embodiments, the movement of the driving rod 30 in a direction perpendicular to the first holding surface 11 can also be achieved through structures such as a linear motor, a gear rack, etc. The driving engagement force between the two wafers can be amplified proportionally by controlling the driving force of the driving rod 30.

[0106] It should be noted that the first holding surface 11 and the second holding surface 21 can be planes for contacting the wafer. A clamping ring structure can be provided at the edges of the first holding surface 11 and the second holding surface 21 to confine the wafer within the corresponding holding surface range.

[0107] Exemplarily, structures such as but not limited to adsorption holes can also be provided on the first holding surface 11 and the second holding surface 21 for adsorbing and holding the wafer.

[0108] So far, the main structure of the wafer bonding device according to an embodiment of the present invention has been completed. It can be understood that the wafer bonding device of this embodiment not only includes the above structures, but in addition, it can also include other required structures, all of which are included within the scope of the wafer bonding device of this embodiment.

[0109] The present invention has been described through the above embodiments. However, it should be understood that the above embodiments are only for the purpose of exemplification and illustration, and are not intended to limit the present invention within the scope of the described embodiments. In addition, those skilled in the art can understand that the present invention is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of protection required by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalent scope.

Claims

1. A wafer bonding device, characterized in that, include: a first chuck having a first holding surface for contacting a first wafer; a second chuck disposed opposite the first chuck, the second chuck having a second holding surface for contacting a second wafer; and A drive rod can move in a direction perpendicular to the first holding surface to drive the second chuck closer to or / and away from the first chuck, and the drive rod is flexibly connected to the center of the second chuck to adjust the second holding surface to be parallel to the first holding surface when the second chuck approaches the first chuck, so that the first wafer and the second wafer can be joined.

2. The wafer bonding device according to claim 1, wherein The driving rod includes a spherical convex surface abutting against the center of the second chuck away from the second holding surface. The second chuck can rotate around the spherical convex surface to adjust the second holding surface to be parallel to the first holding surface.

3. The wafer bonding apparatus according to claim 2, wherein The driving rod comprises: a rod extending in a direction perpendicular to the first holding surface and located at the center of the second chuck; and A plug is detachably connected to the rod body and is located at an end portion facing the second chuck, wherein the plug has the spherical convex surface.

4. The wafer bonding apparatus according to claim 2, wherein A docking surface in contact with the spherical convex surface is provided on the second chuck at a side facing away from the second holding surface; The docking surface is a plane parallel to the second retaining surface, or the docking surface is a spherical concave surface matched with the spherical convex surface.

5. The wafer bonding device according to claim 4, characterized in that, A gasket is detachably connected to the second chuck at a side facing away from the second holding surface, and the gasket is provided with the docking surface at a side facing away from the second holding surface.

6. The wafer bonding apparatus according to any one of claims 2 to 5, characterized in that, Also includes: a spring structure connected to the driving rod, the spring structure having a plurality of elastic arms spaced around the driving rod; as well as, A plurality of connecting members, each of which corresponds to one of the elastic arms and is connected between the corresponding elastic arm and the second chuck.

7. The wafer bonding device according to claim 6, wherein, The elastic arm is provided with a mounting hole, and the connecting member includes: A first screw rod passing through the corresponding mounting hole on the elastic arm and connected to the second chuck; and A first fastening nut connected to the first screw rod is located on a side of the elastic arm away from the second chuck to limit a maximum distance between the elastic arm and the second chuck in an extending direction of the first screw rod.

8. The wafer bonding apparatus according to claim 1, wherein Also includes: a support portion at least partially located on a side of the first chuck facing away from the second chuck, the first chuck having a main portion and an edge portion, the edge portion being fixed to the support portion via a support structure, and the main portion being spaced apart from the support portion; a second screw and a second fastening nut, wherein the second screw is arranged perpendicular to the first retaining surface and passes through the support portion and is connected to the center of the main portion; the second fastening nut is connected to the second screw on the side of the support portion facing away from the main portion to define the distance between the center of the main portion and the support portion in the extension direction of the second screw; A plurality of jackscrews are arranged at intervals around the second screw, and the jackscrews penetrate the support portion and press against the surface of the main body portion facing away from the first retaining surface to adjust the distance between the main body portion and the support portion at the jackscrew in the extension direction of the jackscrews.

9. The wafer bonding device according to claim 8, wherein, Also includes: A first shell and a second shell that can be snapped together to form a sealed chamber or separated; In which, the first chuck and the second chuck are located in the sealed chamber, and the part of the first shell located on the side of the first chuck away from the second chuck constitutes the supporting part; the driving rod passes through the second shell and is connected to the second chuck, and the driving rod can move relative to the second shell in a direction perpendicular to the first retaining surface.

10. The wafer bonding apparatus according to claim 1, wherein, The first holding surface of the first chuck is arranged horizontally, the second chuck is located above the first chuck, and the driving rod is located on the side of the second chuck away from the first chuck and can move in a vertical direction.

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