Wafer bonding device and method

Abstract

The present application relates to the field of wafer bonding technology, and discloses a wafer bonding device and method, wherein the wafer bonding device includes a bonding unit, the bonding unit includes a lower bond head and an upper bond head that are coaxially and relatively arranged, and at least one receiving platform provided between the lower bond head and the upper bond head. The wafer bonding device disclosed in the present application is provided with a receiving platform between the lower bond head and the upper bond head, so as to separate a plurality of accommodating spaces between the lower bond head and the upper bond head through the receiving platform. Since each accommodating space can accommodate a pair of wafers, and the receiving platform can follow the upper bond head and move synchronously toward the lower bond head under the action of the upper bond head, the wafer bonding device is satisfied with bonding multiple pairs of wafers at a time, and can effectively improve the bonding efficiency when facing a large number of wafers to be bonded.

Description

Technical Field

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

[0002] The contents of this section merely provide background information related to this application and may not constitute prior art.

[0003] Wafer bonding refers to the technology of tightly combining a pair of homogeneous or heterogeneous wafers through chemical and physical effects. During wafer bonding, the atoms on the bonding surface of the wafers react under the action of external forces and form covalent bonds to combine them into one, so that the bonding surfaces of the two wafers reach a specific bonding strength.

[0004] However, common wafer bonding devices can only bond one pair of wafers at a time. When faced with large quantities of wafers to be bonded, such devices have a significant problem of low bonding efficiency. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide a wafer bonding device capable of bonding multiple pairs of wafers simultaneously, in order to improve the bonding efficiency. At the same time, this application also provides a wafer bonding method.

[0006] The purpose of this application is achieved through the following technical solutions:

[0007] In one aspect, the present application discloses a wafer bonding apparatus, comprising a bonding unit, wherein the bonding unit comprises a lower bonding head and an upper bonding head disposed coaxially and oppositely, wherein the upper bonding head is configured to be capable of linear motion toward or away from the lower bonding head;

[0008] The bonding unit further includes:

[0009] At least one receiving platform is provided between the lower bond head and the upper bond head, the receiving platform, the lower bond head and the upper bond head having a common reference axis; at least one receiving platform separates a plurality of accommodating spaces arranged in sequence along the reference axis between the lower bond head and the upper bond head, each of the accommodating spaces being suitable for accommodating a pair of wafers;

[0010] In addition, the supporting platform located between the lower bond head and the upper bond head is also constructed as follows: when the upper bond head makes a linear motion close to the lower bond head, it can receive pressure from the upper bond head and move synchronously with the upper bond head from an initial position; when the upper bond head makes a linear motion away from the lower bond head, it can return to the initial position.

[0011] In some possible embodiments, the bonding unit further includes an elastic component corresponding to each of the receiving platforms, and the elastic component is configured to elastically maintain the corresponding receiving platform in the initial position.

[0012] In some possible embodiments, the elastic component includes a plurality of elastic members, and the plurality of elastic members are distributed on the same circumference with the reference axis as the center; one end of the elastic member is connected to the corresponding receiving platform, and the other end of the elastic member extends radially along the circumference in a direction away from the corresponding receiving platform and is then fixed.

[0013] In some possible embodiments, the bonding unit further includes a material receiving and arranging mechanism, and the material receiving and arranging mechanism includes a plurality of material receiving components and a plurality of movable arranging components;

[0014] The plurality of material receiving components and the plurality of movable aligning components are distributed on the same circumference with the reference axis as the center, and each of the material receiving components and each of the movable aligning components can make a linear motion along the radial direction of the circumference toward or away from the reference axis;

[0015] The receiving assembly includes receiving pieces corresponding to each of the accommodating spaces, and the receiving pieces are used to receive a pair of wafers in the corresponding accommodating spaces;

[0016] The movable alignment assembly includes alignment pieces corresponding to the respective accommodation spaces. The alignment pieces are configured to position the corresponding pair of wafers in the corresponding accommodation spaces from a circumferential direction of the pair of wafers.

[0017] In some possible embodiments, two wafers in a pair of wafers accommodated in each of the accommodation spaces are defined as a first wafer and a second wafer respectively;

[0018] The receiving member includes two receiving portions, which are sequentially arranged along a direction parallel to the reference axis so as to receive the first wafer and the second wafer respectively through the two receiving portions;

[0019] The surfaces of the two receiving portions for receiving the corresponding wafers are inclined surfaces, and the sides of the inclined surfaces close to the reference axis are lower.

[0020] In some possible embodiments, both the first wafer and the second wafer have straight edges;

[0021] The material receiving and aligning mechanism also includes at least one aligning column, one end of which is fixed and the other end of which extends in a direction parallel to the reference axis; the straight edges of the first wafer and the second wafer in each of the accommodating spaces are in contact with the circumferential outer wall of the aligning column.

[0022] In some possible embodiments, the entire array member has an arc-shaped entire array surface.

[0023] In some possible embodiments, the wafer bonding apparatus further includes a cavity and a vacuum unit, wherein the cavity defines a bonding cavity, and the bonding unit is accommodated in the bonding cavity;

[0024] The vacuum unit is configured to vacuum the bonding chamber.

[0025] On the other hand, the present application discloses a wafer bonding method, using the wafer bonding device described above, the method comprising the following steps:

[0026] Step S1. Positioning multiple pairs of wafers to be bonded in the corresponding accommodation spaces;

[0027] Step S2. vacuuming the environment of the bonding unit and making the wafers in each of the accommodating spaces bonded together;

[0028] Step S3. Allow the upper bonding head to make a linear motion close to the lower bonding head. During this process, the upper bonding head can apply pressure to at least one of the receiving platforms to force the receiving platform to move synchronously with the upper bonding head from the initial position to complete the bonding of multiple pairs of wafers.

[0029] The technical solutions of the embodiments of the present application have at least the following advantages and beneficial effects:

[0030] The wafer bonding device disclosed in the present application is configured with a receiving platform between the lower bonding head and the upper bonding head to separate a plurality of accommodating spaces between the lower bonding head and the upper bonding head through the receiving platform. Each accommodating space can accommodate a pair of wafers, and the receiving platform can move synchronously toward the lower bonding head with the upper bonding head under the action of the upper bonding head. Therefore, the wafer bonding device is capable of bonding multiple pairs of wafers at a time, and can effectively improve the bonding efficiency when faced with a large number of wafers to be bonded. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic structural diagram of a wafer bonding device provided in an embodiment of the present application;

[0032] Figure 2 A schematic structural diagram of a bonding unit provided in an embodiment of the present application before use;

[0033] Figure 3 A schematic structural diagram of a bonding unit provided in an embodiment of the present application when aligning two pairs of wafers;

[0034] Figure 4 for Figure 3 A top view of the bonding unit is shown;

[0035] Figure 5 for Figure 4 Cross-sectional view along the AA axis;

[0036] Figure 6 A schematic structural diagram of a receiving platform and its corresponding elastic component provided in an embodiment of the present application;

[0037] Figure 7 A schematic diagram of the structure of the material splicing and aligning mechanism provided in an embodiment of the present application when aligning a pair of wafers;

[0038] Figure 8 A schematic structural diagram of a single material splicing assembly provided in an embodiment of the present application;

[0039] Figure 9 A schematic structural diagram of a single movable array assembly provided in an embodiment of the present application;

[0040] Figure 10 It is a structural diagram when two pairs of wafers are positioned in corresponding accommodation spaces.

[0041] Icon: 100-cavity, 101-bonding cavity, 200-bonding unit, 300-vacuum unit, 400-first wafer, 500-second wafer, 10-lower bonding head, 20-upper bonding head, 30-crimping shaft, 40-receiving platform, 50-assembly, 51-elastic part, 60-material receiving and arranging mechanism, 61-material receiving assembly, 611-material receiving part, 6111-receiving part, 62-movable arranging assembly, 621-arranging part, 6211-arranging surface, 63-arranging column, s-reference axis, k-accommodating space. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific implementation methods. The same figure marks in the accompanying drawings represent the same components. It should be noted that the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the described embodiments of this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0043] Compared to the embodiments shown in the drawings, feasible embodiments within the scope of protection of the present application may have fewer components, other components not shown in the drawings, different components, differently arranged components, or differently connected components, etc. In addition, two or more components in the drawings may be implemented in a single component, or a single component shown in the drawings may be implemented as multiple separate components.

[0044] Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meanings understood by persons of ordinary skill in the art to which this application belongs. The terms "first," "second," and similar terms used in this specification and claims do not denote any order, quantity, or importance, but are merely used to distinguish different components.

[0045] like Figure 1 , which shows the general structure of the wafer bonding apparatus disclosed in the embodiment of the present application. Specifically, the wafer bonding apparatus disclosed in the embodiment of the present application may include a chamber 100, a bonding unit 200 and a vacuum unit 300.

[0046] The cavity 100 defines a bonding cavity 101, and a bonding unit 200 for bonding wafers is accommodated in the bonding cavity 101. For example, the cavity 100 can be a member having a hollow interior and a door that can be opened or closed, wherein the hollow interior of the member can serve as the bonding cavity 101, and an openable and closable door (not shown in the figure) is provided to facilitate providing wafers to be bonded to the bonding unit 200 in the bonding cavity 101 or removing wafers bonded by the bonding unit 200.

[0047] In addition, the bonding chamber 101 can be a relatively closed chamber when bonding wafers, and the vacuum unit 300 is used to vacuum the closed bonding chamber 101. The vacuum unit 300 may include a component capable of vacuuming the bonding chamber 101, such as a vacuum pump. It is understandable that by arranging a vacuum unit 300 capable of vacuuming the bonding chamber 101, the bonding chamber 101 can be vacuumed before the bonding unit 200 bonds the wafer, until the vacuum degree in the bonding chamber 101 reaches a predetermined vacuum degree, so that the bonding unit 200 can complete the bonding of the wafer in a vacuum environment with a predetermined vacuum degree, thereby helping to improve the bonding quality of the wafer. The vacuum degree when vacuuming the bonding chamber 101 can be determined according to the type of wafer and the actual working conditions, and is not limited here.

[0048] like Figure 2 As shown, a bonding unit 200 for bonding wafers may include a lower bond head 10 and an upper bond head 20 that are coaxially and oppositely disposed, and the upper bond head 20 is configured to be capable of linear motion toward or away from the lower bond head 10. For example, the upper bond head 20 may be driven by a crimping shaft 30 capable of reciprocating linear motion to be linearly moved toward or away from the lower bond head 10.

[0049] It is known that the common wafer bonding device in the prior art usually only includes the two components, namely the lower bond head 10 and the upper bond head 20 mentioned above. When bonding a pair of wafers, the pair of wafers are placed and positioned on the lower bond head 10, and then the upper bond head 20 is made to move linearly close to the lower bond head 10 until the upper bond head 20 contacts the upper wafer of the pair of wafers positioned on the lower bond head 10, so as to continuously apply a certain pressure to the pair of wafers through the upper bond head 20, thereby completing the bonding of the pair of wafers.

[0050] This type of wafer bonding device can only bond one pair of wafers at a time, resulting in low bonding efficiency when faced with a large number of wafers to be bonded.

[0051] To this end, the present application further improves the structure of the bonding unit 200 so that the bonding unit 200 can bond multiple pairs of wafers at a time to improve the bonding efficiency.

[0052] Specifically, the bonding unit 200 further includes at least one receiving platform 40 disposed between the lower bond head 10 and the upper bond head 20. The receiving platform 40, the lower bond head 10, and the upper bond head 20 share a common reference axis s. In other words, the receiving platform 40, the lower bond head 10, and the upper bond head 20 are coaxially arranged. In the embodiment of the present application, the receiving platform 40 can have a shape substantially identical to that of the wafer to be bonded.

[0053] Combine Figure 2 、 Figure 3 and Figure 5 As shown, at least one receiving platform 40 separates a plurality of accommodating spaces k arranged in sequence along the reference axis s between the lower bond head 10 and the upper bond head 20, and each accommodating space k is suitable for accommodating a pair of wafers. For example, the drawings of the present application show a situation in which a receiving platform 40 is provided between the lower bond head 10 and the upper bond head 20, so that two accommodating spaces k arranged in sequence along the reference axis s are separated between the lower bond head 10 and the upper bond head 20 by one receiving platform 40, thereby achieving the ability to bond two pairs of wafers at a time. Of course, in other embodiments of the present application, the number of receiving platforms 40 can also be multiple. In this case, more accommodating spaces k can be formed between the lower bond head 10 and the upper bond head 20 by simply arranging the plurality of receiving platforms 40 in sequence along the reference axis s.

[0054] In addition, the receiving platform 40 located between the lower bond head 10 and the upper bond head 20 is also constructed as follows: when the upper bond head 20 makes a linear motion close to the lower bond head 10, it can receive pressure from the upper bond head 20 and move synchronously with the upper bond head 20 from the initial position; when the upper bond head 20 makes a linear motion away from the lower bond head 10, it can return to the initial position.

[0055] In other words, before the upper bond head 20 makes a linear motion toward the lower bond head 10, the receiving platform 40 located between the lower bond head 10 and the upper bond head 20 is in the initial position. On this basis, when the upper bond head 20 makes a linear motion toward the lower bond head 10, the upper bond head 20 can apply a pressure toward the lower bond head 10 to the receiving platform 40, so that the receiving platform 40 can move synchronously with the upper bond head 20 from the initial position toward the lower bond head 10 under the action of the pressure; conversely, when the upper bond head 20 makes a linear motion away from the lower bond head 10, the receiving platform 40 can automatically retract to the initial position.

[0056] In this way, when multiple pairs of wafers need to be bonded, the multiple pairs of wafers to be bonded are first positioned in the corresponding receiving spaces k. For example, when there are multiple receiving platforms 40, for the receiving space k formed between the lower bond head 10 and the receiving platform 40 located at the bottom, a pair of wafers can be positioned on the lower bond head 10; for the receiving space k formed between the upper bond head 20 and the receiving platform 40 located at the top, a pair of wafers can be positioned on the receiving platform 40 located at the top; and for the receiving space k formed between two adjacent receiving platforms 40, a pair of wafers can be positioned on the receiving platform 40 located at the bottom of the two adjacent receiving platforms 40.

[0057] After completing the positioning of multiple pairs of wafers to be bonded, the upper bond head 20 is allowed to make a linear motion close to the lower bond head 10. During this process, the upper bond head 20 will first contact a pair of wafers positioned on the uppermost receiving platform 40, and apply pressure to the receiving platform 40 through the pair of wafers to force the receiving platform 40 to move synchronously with the upper bond head 20. By analogy, as the upper bond head 20 continues to approach the lower bond head 10, the receiving platforms 40 located between the upper bond head 20 and the lower bond head 10 will successively follow the upper bond head 20 to move synchronously until the receiving platform 40 located at the bottom is pressed onto a pair of wafers positioned on the lower bond head 10. Thereafter, the upper bond head 20 can continue to apply pressure toward the lower bond head 10 to achieve bonding of multiple pairs of wafers at the same time. After the bonding of multiple pairs of wafers is completed, the upper bonding head 20 only needs to be moved away from the lower bonding head 10 so that each receiving platform 40 returns to its initial position, and the bonded multiple pairs of wafers can be removed.

[0058] Among them, the following method can be used to enable each receiving platform 40 to move synchronously with the upper bond head 20 from the initial position after receiving pressure from the upper bond head 20, and to automatically return to the initial position when the upper bond head 20 makes a linear motion away from the lower bond head 10.

[0059] Specifically, the bonding unit 200 may further include an elastic component 50 corresponding to each receiving platform 40 , and the elastic component 50 is used to elastically maintain the corresponding receiving platform 40 in an initial position.

[0060] For example, Figure 4 and Figure 6 As shown, each elastic component 50 may further include a plurality of elastic members 51. The plurality of elastic members 51 are distributed on the same circumference (ie, Figure 4 The circle shown by the dotted line in the middle), and one end of each elastic member 51 is connected to the corresponding receiving platform 40, and the other end of each elastic member 51 is extended along the radial direction of the circumference in the direction away from the corresponding receiving platform 40 and then fixed.

[0061] In this way, for a single receiving platform 40, when the receiving platform 40 does not receive pressure from the upper bonding head 20, the receiving platform 40 can be elastically maintained in the initial position under the joint action of multiple elastic members 51. On this basis, combined with the above, when the upper bonding head 20 makes a linear motion close to the lower bonding head 10, the receiving platform 40 will receive pressure from the upper bonding head 20 and move synchronously with the upper bonding head 20. During this process, the elastic member 51 corresponding to the receiving platform 40 will undergo elastic deformation and pre-store an elastic force. Accordingly, when the bonding of multiple pairs of wafers is completed and the upper bonding head 20 makes a linear motion away from the lower bonding head 10, the receiving platform 40 can be returned to the initial position under the action of the elastic force released by the corresponding elastic member 51.

[0062] The elastic member 51 used to elastically maintain the receiving platform 40 in its initial position can be a spring. Furthermore, for multiple elastic members 51 corresponding to a single receiving platform 40, the multiple elastic members 51 can be distributed in an annular array on the same circumference, so that the force exerted on the receiving platform 40 by each elastic member 51 is more uniform. For example, the drawings of this application illustrate a single receiving platform 40 with three elastic members 51 distributed in an annular array arranged circumferentially.

[0063] On this basis, in order to reliably position the multiple wafers to be bonded in the corresponding accommodation space k, as shown in FIG. Figure 2 and Figure 3 As shown, the bonding unit 200 in the embodiment of the present application may further include a material receiving and aligning mechanism 60. The material receiving and aligning mechanism 60 is used to receive multiple pairs of wafers to be bonded in the corresponding accommodation space k and to align each pair of wafers. "Aligning" each pair of wafers refers to positioning the two wafers in each pair of wafers so that the axes of the two wafers in each pair of wafers coincide. In the embodiment of the present application, it can also be understood as making the axes of the two wafers in each pair of wafers coincide with the reference axis s mentioned above.

[0064] Specifically, the material receiving and arranging mechanism 60 may include a plurality of material receiving components 61 and a plurality of movable arranging components 62. The plurality of material receiving components 61 are distributed on the same circumference (i.e. Figure 4 The material receiving components 61 are arranged on a circle (shown by the dashed line in the middle), and each receiving component 61 is capable of linear motion in the radial direction of the circle toward or away from the reference axis s. For example, each receiving component 61 can be driven by an independent linear actuator (not shown) to perform reciprocating linear motion in the radial direction of the circle. The linear actuator can be a conventional linear drive device such as a cylinder or an electric push rod.

[0065] For example, the drawings of the present application show a situation where three material receiving components 61 are provided. Of course, the number of material receiving components 61 is not limited to this and is not limited here.

[0066] And, as Figure 8 As shown, each receiving assembly 61 further includes a receiving piece 611 corresponding to each receiving space k, and the receiving piece 611 is used to receive a pair of wafers in the corresponding receiving space k. In other words, both wafers in a pair of wafers in a single receiving space k can be received on the receiving piece 611 at the same time.

[0067] For ease of description, the embodiment of the present application defines the two wafers in a pair of wafers accommodated in each accommodation space k as a first wafer 400 and a second wafer 500. Figure 8 As shown, the material receiving member 611 may include two receiving portions 6111, and the two receiving portions 6111 are sequentially arranged along a direction parallel to the reference axis s, so that the two receiving portions 6111 can be arranged in a Figure 7 The manner shown is to receive the first wafer 400 and the second wafer 500 respectively. Furthermore, the surfaces of the two receiving portions 6111 for receiving the corresponding wafers can be set as inclined surfaces, and the side of the inclined surface close to the reference axis s is lower, so as to better fit with the edge of the wafer, thereby reliably receiving the wafer.

[0068] Furthermore, each receiving assembly 61 can be configured to be capable of reciprocating linear motion in a direction parallel to the reference axis s. For example, each receiving assembly 61 can be further configured with a linear actuator capable of driving each receiving assembly 61 to reciprocate linear motion in a direction parallel to the reference axis s, wherein the linear actuator can be a conventional linear drive device such as a cylinder or an electric push rod. Moreover, the output end of the linear actuator for driving the receiving assembly 61 to reciprocate linear motion in a direction parallel to the reference axis s can be connected to the aforementioned linear actuator for driving the receiving assembly 61 to reciprocate linear motion in the radial direction of the circumference, so that each receiving assembly 61 can independently perform reciprocating linear motion in the radial direction of the circumference and can also independently perform reciprocating linear motion in a direction parallel to the reference axis s.

[0069] It is worth noting that by adopting a receiving piece 611 with two receiving parts 6111 to respectively receive the first wafer 400 and the second wafer 500 of a pair of wafers, and allowing each receiving component 61 to perform reciprocating linear motion in a direction parallel to the reference axis s, it is beneficial to adjust the position of the receiving piece 611 on the receiving component 61 in the corresponding accommodation space k according to the placement requirements of the wafers, thereby helping to provide sufficient activity space for components such as robotic arms that place wafers, so that the wafers to be bonded can be automatically placed in the corresponding accommodation space k and received on the corresponding receiving part 6111 with the help of the robotic arm. For example, after each receiving component 61 moves radially along the circumference toward the reference axis s so that the receiving piece 611 enters the corresponding accommodating space k, each receiving component 61 can be moved upward in a direction parallel to the reference axis s, so that the receiving piece 611 extending into each accommodating space k is located in an upper position in the corresponding accommodating space k, so that the robotic arm can smoothly place the two wafers to be bonded on the two receiving parts 6111 of the receiving piece 611 in the corresponding accommodating space k. After the placement of the wafers in each storage space k is completed, each material receiving component 61 can simultaneously move downward in a direction parallel to the reference axis s, so that the material receiving component 611 in each storage space k can drive the corresponding wafer to move to a position lower in the corresponding storage space k, thereby facilitating the subsequent reliable positioning of the wafer to be bonded at the target position in the storage space k. For example, for the storage space k formed between the lower bonding head 10 and the receiving platform 40 located at the bottom, it is beneficial for the first wafer 400 and the second wafer 500 in the storage space k to be reliably positioned on the lower bonding head 10.

[0070] In the embodiment of the present application, the plurality of movable array components 62 are also distributed on the same circumference (ie, Figure 4The movable array components 62 are arranged on a circle (shown by the dashed line in the middle), and each movable array component 62 is capable of linear motion in the radial direction of the circle toward or away from the reference axis s. For example, each movable array component 62 can be driven by an independent linear actuator (not shown) to perform reciprocating linear motion in the radial direction of the circle. The linear actuator can be a conventional linear drive device such as a pneumatic cylinder or an electric push rod.

[0071] For example, the drawings of the present application show a situation where two movable array components 62 are provided. Of course, the number of movable array components 62 is not limited to this and is not limited here.

[0072] And, as Figure 9 As shown, each movable arranging assembly 62 further includes an arranging piece 621 corresponding to each accommodation space k. Figure 7 The illustrated method positions the corresponding pair of wafers in the corresponding accommodation space k from the circumferential direction of the pair of wafers.

[0073] Specifically, when a plurality of wafers to be bonded need to be positioned in the corresponding accommodation space k, the process can be roughly divided into a material receiving stage and an alignment stage.

[0074] Among them, in the material receiving stage, such as Figure 5 As shown, first, multiple material receiving components 61 are simultaneously made to perform linear motion close to the reference axis s along the radial direction of the circumference, so that the material receiving parts 611 on each material receiving component 61 are synchronously extended into the corresponding accommodation space k. Among them, the material receiving parts 611 extended into each accommodation space k are all located at the upper position in the corresponding accommodation space k. Thereafter, for a pair of wafers that need to be positioned in a single accommodation space k, the first wafer 400 and the second wafer 500 of the pair of wafers can be placed on the two receiving parts 6111 of each material receiving part 611 in the accommodation space k respectively with the help of a robot arm, so that the first wafer 400 and the second wafer 500 can be simultaneously received by the material receiving parts 611 corresponding to the accommodation space k on each material receiving component 61, so that the first wafer 400 and the second wafer 500 are accommodated in the corresponding accommodation space k. Similarly, after each storage space k contains a pair of wafers, each receiving component 61 moves downward simultaneously in a direction parallel to the reference axis s, so that the receiving component 611 in each storage space k can drive the corresponding wafer to move to the lower position in the corresponding storage space k, and then enter the alignment stage.

[0075] During the alignment phase, the plurality of movable alignment components 62 simultaneously make linear motions along the radial direction of the circumference close to the reference axis s until the alignment pieces 621 on each movable alignment component 62 are aligned with the reference axis s. Figure 7The method shown is used to offset the circumferential outer walls of the first wafer 400 and the second wafer 500 in the corresponding accommodating space k, so as to achieve accurate positioning of the wafers in each accommodating space k at the same time, and ensure that the first wafer 400 and the second wafer 500 in each accommodating space k are aligned with each other as much as possible.

[0076] After the first wafer 400 and the second wafer 500 in each receiving space k are aligned with each other, the wafer bonding stage can be entered. In the wafer bonding stage, the plurality of receiving components 61 can be synchronously moved along the radial direction of the circumference away from the reference axis s, so that the receiving parts 611 on each receiving component 61 are simultaneously withdrawn from the corresponding receiving space k, thereby allowing the first wafer 400 and the second wafer 500 in each receiving space k to fall freely and fit together and be positioned in the corresponding receiving space k, with reference to FIG. Figure 10 For example, when there are multiple receiving platforms 40, for the accommodation space k formed between the lower bond head 10 and the receiving platform 40 located at the bottom, the first wafer 400 and the second wafer 500 in the accommodation space k will fall on the lower bond head 10, and the two will fit together; for the accommodation space k formed between the upper bond head 20 and the receiving platform 40 located at the top, the first wafer 400 and the second wafer 500 in the accommodation space k will fall on the receiving platform 40 located at the top, and the two will fit together; for the accommodation space k formed between two adjacent receiving platforms 40, the first wafer 400 and the second wafer 500 in the accommodation space k will fall on the receiving platform 40 located at the bottom of the two adjacent receiving platforms 40, and the two will fit together. It can be understood that since the first wafer 400 and the second wafer 500 in a single accommodating space k are falling, the alignment parts 621 on each movable alignment component 62 are always in contact with the circumferential outer walls of the corresponding first wafer 400 and the second wafer 500. Therefore, the positions of the first wafer 400 and the second wafer 500 after falling will not be offset, but will remain in a state of accurate alignment.

[0077] Finally, after multiple pairs of wafers are accurately positioned in the corresponding accommodating spaces k, multiple movable alignment components 62 can be synchronously allowed to perform linear motion along the radial direction of the circumference away from the reference axis s until the alignment parts 621 on each movable alignment component 62 are out of contact with the circumferential outer wall of the corresponding wafer. Then, the upper bonding head 20 can perform linear motion close to the lower bonding head 10 to complete the bonding of multiple pairs of wafers.

[0078] Further, continue to refer to Figure 9The aligning members 621 on each movable aligning assembly 62 may further include an arcuate aligning surface 6211. Thus, in combination with the above, when the multiple movable aligning assemblies 62 simultaneously perform linear motion along the radial direction of the circumference close to the reference axis s, the arcuate aligning surfaces 6211 of the aligning members 621 can abut against the circumferential outer walls of the corresponding wafers, thereby increasing the contact area between the aligning members 621 on each movable aligning assembly 62 and the circumferential outer walls of the corresponding wafers and improving the aligning effect.

[0079] Secondly, refer to Figure 7 As shown, considering that the wafers to be bonded may generally have straight edges, in order to further accurately position the first wafer 400 and the second wafer 500 in each accommodating space k, the material receiving and aligning mechanism 60 may also include at least one aligning column 63.

[0080] Among them, reference Figure 5 As shown, one end of the alignment column 63 can be fixed to the lower bonding head 10, and the other end of the alignment column 63 extends in a direction parallel to the reference axis s. The straight edges of the first wafer 400 and the second wafer 500 in each accommodation space k can contact the circumferential outer wall of the alignment column 63, so that the straight edges of each wafer are limited by the alignment column 63. For example, the drawings of this application show a situation where two alignment columns 63 are provided, and the two alignment columns 63 can be arranged relative to each other to limit the straight edges of each wafer at two different positions.

[0081] It is understandable that the arrangement of the alignment column 63 can assist in locating the position of each wafer before the multiple movable alignment components 62 perform alignment and positioning on the wafers, thereby preventing the wafers from shifting to a large extent. Secondly, in order to prevent the upper bond head 20 from interfering with the alignment column 63 when it makes a linear motion close to the lower bond head 10, the end of the alignment column 63 away from the lower bond head 10 can be passed through the upper bond head 20, and the alignment column 63 can be slidably engaged with the upper bond head 20. In addition, by allowing the alignment column 63 to slide with the upper bond head 20, the alignment column 63 can also play a role in limiting and guiding the upper bond head 20, thereby preventing the upper bond head 20 from shifting when it moves toward the lower bond head 10.

[0082] On the other hand, embodiments of the present application further disclose a wafer bonding method, which utilizes the wafer bonding apparatus described above. For ease of description, embodiments of the present application will be described using a wafer bonding apparatus having a receiving platform 40 disposed between a lower bond head 10 and an upper bond head 20 as an example.

[0083] Specifically, the method may include the following steps:

[0084] Step S1: Position two pairs of wafers to be bonded in corresponding accommodation spaces k respectively.

[0085] Specifically, the multiple receiving assemblies 61 of the receiving and arranging mechanism 60 are first synchronously moved along the radial direction of the circumference and close to the reference axis s until the receiving member 611 of each receiving assembly 61 extends into the corresponding receiving space k. The receiving member 611 extending into each receiving space k is located at an upper position within the corresponding receiving space k.

[0086] Secondly, two pairs of wafers are placed on the receiving pieces 611 in the two receiving spaces k respectively by using a robot arm. Among them, for a pair of wafers placed in a single receiving space k, the straight edges of the first wafer 400 and the second wafer 500 of the pair of wafers are in contact with the circumferential outer wall of the entire column 63, and the first wafer 400 and the second wafer 500 are respectively supported on the inclined surfaces of the two receiving parts 6111 of the receiving piece 611. Subsequently, each receiving assembly 61 simultaneously moves downward in a direction parallel to the reference axis s, so that the receiving piece 611 in each receiving space k can drive the corresponding wafer to move to a lower position in the corresponding receiving space k, with reference to Figure 5 shown.

[0087] Secondly, the multiple movable aligning components 62 of the material receiving and aligning mechanism 60 synchronously make linear motions close to the reference axis s along the radial direction of the circle until the aligning surface 6211 of the aligning part 621 on each movable aligning component 62 abuts against the circumferential outer wall of the first wafer 400 and the second wafer 500 in the corresponding accommodating space k, thereby completing the preliminary positioning of the first wafer 400 and the second wafer 500 in each accommodating space k.

[0088] Step S2: evacuate the environment of the bonding unit 200 and bond the wafers in the respective accommodating spaces k together. Specifically, the bonding chamber 101 is evacuated by the vacuum unit 300 until the vacuum level in the bonding chamber 101 reaches a predetermined level.

[0089] After the vacuum degree of the bonding chamber 101 reaches the predetermined vacuum degree, the multiple receiving components 61 synchronously make linear motions away from the reference axis s along the radial direction of the circumference, so that the first wafer 400 and the second wafer 500 in each accommodation space k fall freely and fit together in the corresponding accommodation space k under the vacuum environment. For example, for the accommodation space k formed between the lower bonding head 10 and the receiving platform 40, the first wafer 400 and the second wafer 500 in the accommodation space k will fall on the lower bonding head 10, and the two will fit together; for the accommodation space k formed between the upper bonding head 20 and the receiving platform 40, the first wafer 400 and the second wafer 500 in the accommodation space k will fall on the receiving platform 40, and the two will fit together, refer to Figure 10 shown.

[0090] Step S3. Let the upper bonding head 20 make a linear motion close to the lower bonding head 10. During this process, the upper bonding head 20 can apply pressure to the receiving platform 40 to force the receiving platform 40 to move synchronously with the upper bonding head 20 from the initial position to complete the bonding of the two pairs of wafers.

[0091] Specifically, the plurality of movable alignment assemblies 62 are first synchronously moved radially along the circumference away from the reference axis s, so that the alignment members 621 of each movable alignment assembly 62 are disengaged from the corresponding wafers. The upper bond head 20 is then driven by the crimping shaft 30 to move linearly toward the lower bond head 10. During this process, the upper bond head 20 first contacts a pair of wafers positioned on the receiving platform 40 and applies pressure to the receiving platform 40 through the pair of wafers, forcing the receiving platform 40 to move synchronously with the upper bond head 20 from its initial position toward the lower bond head 10 until the receiving platform 40 follows the upper bond head 20 and contacts the pair of wafers positioned on the lower bond head 10. During this process, the plurality of elastic members 51 of the elastic assembly 50 corresponding to the receiving platform 40 undergo elastic deformation to pre-store elastic force. Thereafter, the upper bond head 20 can continue to apply pressure toward the lower bond head 10 to achieve simultaneous bonding of two pairs of wafers.

[0092] After the bonding of the two pairs of wafers is completed, the crimping shaft 30 drives the upper bonding head 20 to move linearly away from the lower bonding head 10, and the receiving platform 40 can return to its initial position under the action of the elastic force released by multiple elastic members 51. After that, the two pairs of bonded wafers can be removed manually or by a robotic arm.

[0093] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A wafer bonding device comprising a bonding unit, wherein the bonding unit comprises a lower bonding head and an upper bonding head disposed coaxially and oppositely, wherein the upper bonding head is configured to move linearly toward or away from the lower bonding head; The bonding unit further includes: At least one receiving platform is provided between the lower bond head and the upper bond head, the receiving platform, the lower bond head and the upper bond head having a common reference axis; at least one receiving platform separates a plurality of accommodating spaces arranged in sequence along the reference axis between the lower bond head and the upper bond head, each of the accommodating spaces being suitable for accommodating a pair of wafers; Furthermore, the receiving platform located between the lower bond head and the upper bond head is further configured such that: when the upper bond head makes a linear motion approaching the lower bond head, it can receive pressure from the upper bond head and move synchronously with the upper bond head from an initial position; and when the upper bond head makes a linear motion away from the lower bond head, it can return to the initial position. The bonding unit further includes an elastic component corresponding to each of the receiving platforms, the elastic component being configured to elastically maintain the corresponding receiving platform in the initial position; the elastic component includes a plurality of elastic members, the plurality of elastic members being distributed on the same circumference with the reference axis as the center; one end of the elastic member is connected to the corresponding receiving platform, and the other end of the elastic member is extended along the radial direction of the circumference in a direction away from the corresponding receiving platform and then fixed; The bonding unit further comprises a material receiving and arranging mechanism, which comprises a plurality of material receiving components and a plurality of movable arranging components; The plurality of material receiving components and the plurality of movable aligning components are distributed on the same circumference with the reference axis as the center, and each of the material receiving components and each of the movable aligning components can make a linear motion along the radial direction of the circumference toward or away from the reference axis; The receiving assembly includes receiving pieces corresponding to each of the accommodating spaces, and the receiving pieces are used to receive a pair of wafers in the corresponding accommodating spaces; The movable alignment assembly includes an alignment member corresponding to each of the accommodation spaces, and the alignment member is configured to position the corresponding pair of wafers in the corresponding accommodation space from the circumference of the pair of wafers; The two wafers in a pair of wafers accommodated in each of the accommodation spaces are defined as a first wafer and a second wafer; the first wafer and the second wafer both have straight edges; The material receiving and aligning mechanism also includes at least one aligning column, one end of which is fixed, and the other end of which extends in a direction parallel to the reference axis, passes through the upper bonding head, and slides with the upper bonding head; the straight edges of the first wafer and the second wafer in each of the accommodating spaces are in contact with the circumferential outer wall of the aligning column.

2. The wafer bonding device according to claim 1, wherein: The receiving member includes two receiving portions, which are sequentially arranged along a direction parallel to the reference axis so as to receive the first wafer and the second wafer respectively through the two receiving portions; The surfaces of the two receiving portions for receiving the corresponding wafers are inclined surfaces, and the sides of the inclined surfaces close to the reference axis are lower.

3. The wafer bonding device according to claim 1, wherein: The aligning piece has an arc-shaped aligning surface.

4. The wafer bonding device according to claim 1, wherein: It also includes a cavity and a vacuum unit, wherein the cavity defines a bonding cavity, and the bonding unit is accommodated in the bonding cavity; The vacuum unit is configured to vacuum the bonding chamber.

5. A wafer bonding method, characterized in that: Using the wafer bonding apparatus according to any one of claims 1 to 4, the method comprises the following steps: Step S1. Positioning multiple pairs of wafers to be bonded in the corresponding accommodation spaces; Step S2. vacuuming the environment of the bonding unit and making the wafers in each of the accommodating spaces bonded together; Step S3. Allow the upper bonding head to make a linear motion close to the lower bonding head. During this process, the upper bonding head can apply pressure to at least one of the receiving platforms to force the receiving platform to move synchronously with the upper bonding head from the initial position to complete the bonding of multiple pairs of wafers.

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