Wafer alignment bonding fine adjustment device and working method

Abstract

The invention relates to a wafer alignment bonding fine tuning device and a working method. The wafer alignment bonding fine tuning device comprises a mounting seat; the motion module is connected with a pressure sensing element used for detecting pressure transmitted in the motion process of the motion module; the connecting piece is connected with a contact piece attached to the pressure sensing element, and the connecting piece is configured to enable the displacement of the output end of the movement module to be transmitted to the suction cup through the pressure sensing element, the contact piece and the connecting piece; a strain gauge; and the displacement sensing element is arranged opposite to the strain gauge so as to be used for sensing the displacement of the strain gauge, and the displacement sensing element is configured to form a closed-loop feedback signal for the displacement of the motion module through the transmission of the displacement of the suction cup and the strain gauge. According to the wafer alignment bonding fine adjustment device, through cooperative arrangement of the motion module, the pressure sensing element, the connecting piece, the strain gauge and the displacement sensing element, displacement transmission, pressure detection and closed-loop feedback are achieved, and the wafer alignment bonding fine adjustment device has the advantages of achieving real-time displacement fine adjustment and pressure monitoring in the wafer bonding process.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a wafer alignment and bonding fine-tuning device and its working method. Background Technology

[0002] Wafer bonding technology is a key process in semiconductor manufacturing, achieving reliable connections between chips and substrates or packaging materials under high temperature and pressure environments. It is widely used in high-reliability fields such as automotive electronics, aerospace, and energy. High-precision bonding machines require precise position control systems to align and position chips and substrates at the micron level. Simultaneously, appropriate forces must be applied during the bonding process to form a stable connection.

[0003] However, traditional substrate bonding processes have significant drawbacks: In traditional substrate bonding processes, the alignment and bonding steps are performed by two different machines or at two independent stations, resulting in a fragmented process flow. The fine-tuning mechanism used in the alignment stage is only suitable for ambient temperature and pressure environments and cannot withstand the high-temperature vacuum conditions during the bonding process, and it lacks the ability to monitor the bonding status in real time.

[0004] For example, CN202110236019.6 states that the alignment and bonding equipment cannot provide a high-pressure environment, nor can it monitor the pressure during the bonding process.

[0005] For example, in CN202211529118.4, the alignment component and the bonding component are separated in the bonding system and bonding method, and there is a transmission process in between, which generates transmission error.

[0006] These issues make it difficult for existing technologies to meet the demands of high-precision bonding for real-time fine-tuning and process monitoring. Summary of the Invention

[0007] Therefore, the purpose of this invention is to provide a wafer alignment and bonding fine-tuning device and its working method, which has the advantages of realizing real-time displacement fine-tuning and pressure monitoring during the wafer bonding process, thereby improving alignment accuracy and bonding quality, avoiding position offset and pressure control inaccuracy problems in traditional processes, and improving bonding yield and reliability.

[0008] To address the aforementioned technical problems, this invention provides a wafer alignment and bonding fine-tuning device, comprising: a mounting base; a motion module fixedly mounted on the mounting base, wherein the output end of the motion module is connected to a pressure sensing element for detecting pressure transmitted during the motion of the motion module; a connector, one end of which is connected to a chuck for adsorbing the wafer, and the other end of which is fixedly connected to a contact element that conforms to the pressure sensing element, configured such that the displacement of the output end of the motion module is transmitted to the chuck through the pressure sensing element, the contact element, and the connector; a strain gauge, one end of which is fixedly mounted on the outer wall of the wafer bonding cavity, and the other end of which is fixedly connected to the contact element; and a displacement sensing element fixedly mounted on the mounting base, wherein the sensing head of the displacement sensing element is positioned opposite the strain gauge for sensing the displacement of the strain gauge, configured such that the displacement of the chuck is transmitted through the connector and the strain gauge to form a closed-loop feedback signal for the displacement of the motion module.

[0009] In one embodiment of the present invention, the fine-tuning device further includes an atmospheric offset module fixedly mounted on the mounting base, and a horizontal decoupling device is connected to the contact member, configured such that the thrust of the atmospheric offset module is provided to the connector through the horizontal decoupling device and the contact member to offset the vacuum atmospheric pressure generated when the wafer bonding cavity is evacuated.

[0010] In one embodiment of the present invention, the connector includes a rod connected to the suction cup, a bellows that can elastically extend and retract with the movement of the rod, and a connecting flange mounted on the outer wall of the wafer bonding cavity. The rod is configured such that one end connected to the suction cup is a fixed end, and the other end connected to the contact is a movable end. The movable end is provided with a mounting surface that is fixedly connected to the contact. The bellows is fitted over the outside of the rod, with one end connected to the mounting surface and the other end connected to the connecting flange.

[0011] In one embodiment of the present invention, the fixed end is provided with a flexible module, and the connector is connected to the suction cup through the flexible module. The flexible module is used to transmit the displacement of the motion module and to deform under overpressure to protect the motion module.

[0012] In one embodiment of the present invention, the output end of the motion module is connected to a mounting component that fits against the contact component, and the pressure sensing element is mounted on the end face of the mounting component that is opposite to the contact component.

[0013] In one embodiment of the present invention, a "π"-shaped mounting member two is connected to the contact member on the side away from the pressure sensing element. Both ends of the mounting member two are equipped with horizontal decoupling devices. The atmospheric cancellation module is configured as two symmetrically arranged modules, and is configured in a one-to-one correspondence with the horizontal decoupling device.

[0014] In one embodiment of the present invention, a gantry-shaped mounting component three is fixedly mounted on the mounting base, and the displacement sensing element is disposed on the mounting component three.

[0015] In one embodiment of the present invention, a mounting component four is installed on the outer wall of the wafer bonding cavity, and one end of the strain gauge is fixed to the mounting component four.

[0016] In one embodiment of the present invention, the pressure sensing element is a pressure sensor, the displacement sensing element is a displacement sensor, and the strain gauge is a spring.

[0017] The present invention also provides a method for operating a wafer alignment and bonding fine-tuning device, used to position the wafer and monitor pressure during the wafer bonding process, comprising the following steps: During the bonding process of upper and lower wafers or chips, the motion module generates a preset displacement, which is transmitted to the suction cup through the contact and connector. The pressure of the wafer or chip is detected by the pressure sensing element set between the output end of the motion module and the contact. The displacement of the suction cup is transmitted through the connector and strain gauge, and the displacement signal of the suction cup is obtained by the displacement sensing element. The displacement of the suction cup from the motion module is monitored by the displacement sensing element.

[0018] The wafer alignment and bonding fine-tuning device of the present invention, through the coordinated arrangement of motion module, pressure sensing element, connector, strain gauge and displacement sensing element, realizes displacement transmission, pressure detection and closed-loop feedback, and has the advantages of realizing real-time displacement fine-tuning and pressure monitoring in the wafer bonding process. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the wafer alignment and bonding fine-tuning device and bonding cavity of the present invention; Figure 2 This is an assembly diagram of the wafer alignment and bonding fine-tuning device of the present invention; Figure 3This is an exploded view of the wafer alignment and bonding fine-tuning device of the present invention; Figure 4 This is a schematic diagram of the wafer interconnect of the present invention; Figure 5 This is a structural diagram of a first embodiment of the wafer alignment and bonding fine-tuning device and bonding cavity of the present invention; Figure 6 This is an assembly diagram of a first embodiment of the wafer alignment and bonding fine-tuning device of the present invention; Figure 7 This is an exploded view of a first embodiment of the wafer alignment and bonding fine-tuning device of the present invention.

[0021] Explanation of reference numerals in the accompanying drawings: Atmospheric cancellation module 1, Connector 2, Horizontal decoupling device 3, Mounting component 2 31, Motion module 4, Mounting component 1 41, Pressure sensing element 5, Displacement sensing element 6, Mounting component 3 61, Flexible module 7, Mounting base 8, Strain gauge 9, Mounting component 4 91, Contact element 10, Rod 20, Moving end 21, Fixed end 22, Mounting surface 23, Connecting flange 24, Bellows 25. Detailed Implementation

[0022] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0023] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] It should be noted that the following description covers various aspects of embodiments within the scope of the appended claims. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0025] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0026] Additionally, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that practice can be carried out without these specific details.

[0027] In traditional wafer bonding processes, alignment and bonding steps are typically performed on different equipment or at independent stations, leading to transfer errors. Existing fine-tuning mechanisms cannot withstand the high-temperature vacuum environment of the bonding process during alignment and cannot monitor the bonding status and pressure in real time. For example, some equipment cannot provide a high-pressure environment or monitor bonding pressure, while others experience transfer errors due to the separation of alignment and bonding components. All of these limitations restrict bonding accuracy and reliability.

[0028] In response, this application proposes a wafer alignment and bonding fine-tuning device, referring to... Figure 1-3 As shown, it includes: a mounting base 8; a motion module 4, which is fixedly mounted on the mounting base 8, and the output end of the motion module 4 is connected to a pressure sensing element 5 for detecting the pressure transmitted during the motion of the motion module 4; a connector 2, one end of which is connected to a suction cup for adsorbing the wafer, and the other end of the connector 2 is fixedly connected to a contact element 10 that is in contact with the pressure sensing element 5, configured such that the displacement of the output end of the motion module 4 is transmitted to the suction cup through the pressure sensing element 5, the contact element 10 and the connector 2; a strain gauge 9, one end of which is fixedly mounted on the outer wall of the wafer bonding cavity, and the other end of the strain gauge 9 is fixedly connected to the contact element 10; and a displacement sensing element 6, which is fixedly mounted on the mounting base 8, and the sensing head of the displacement sensing element 6 is positioned opposite the strain gauge 9 to sense the displacement of the strain gauge 9, configured such that the displacement of the suction cup is transmitted through the connector 2 and the strain gauge 9 to form a closed-loop feedback signal for the displacement of the motion module 4. By integrating motion module 4, pressure sensing element 5, connector 2, strain gauge 9 and displacement sensing element 6, the precise transmission of displacement, real-time monitoring of bonding pressure and closed-loop feedback of chuck displacement are achieved, thereby effectively solving the transmission error caused by alignment and bonding separation in traditional technology, and overcoming the problem of not being able to monitor bonding pressure in real time and achieve closed-loop feedback.

[0029] The mounting base 8 serves as the fundamental support structure for the entire fine-tuning device, fixing and supporting other functional components to ensure the overall stability of the device and the relative positional accuracy of each component. The motion module 4 is an actuator capable of generating precise displacement output, such as a piezoelectric ceramic driver, voice coil motor, or stepper motor; its output is used to drive the subsequent displacement transmission chain. The pressure sensing element 5 is a sensor that converts applied pressure into an electrical signal, such as a piezoresistive sensor, capacitive sensor, or strain gauge sensor; it is used to monitor the pressure transmitted by the motion module 4 during its movement in real time. The connector 2 serves as a mechanical connection component, transmitting the displacement and force of the motion module 4 to the suction cup, and is also part of the suction cup displacement feedback path. The contact element 10 serves as the interface between the connector 2 and the pressure sensing element 5, ensuring that the output displacement and pressure of the motion module 4 can be effectively transmitted to the connector 2. The strain gauge 9 is a sensor capable of sensing minute deformations and converting them into electrical signals, such as a metal foil strain gauge or a semiconductor strain gauge; it is used here to sense the deformation caused by the displacement of the suction cup. The displacement sensing element 6 is a sensor capable of accurately measuring the displacement of an object. It can be an eddy current sensor, a capacitive sensor, or a laser displacement sensor. It senses the displacement of the strain gauge 9 to obtain the actual displacement information of the chuck. The chuck is a component used to adsorb and fix the wafer, typically achieving stable wafer gripping through vacuum adsorption. The wafer bonding cavity is a sealed space for wafer bonding operations, usually requiring the maintenance of a specific temperature, pressure, or vacuum environment.

[0030] Specifically, the wafer alignment and bonding fine-tuning device provided in this embodiment includes a mounting base 8, which can be a robust metal base, such as made of stainless steel or aluminum alloy, to provide a stable support platform. The structure of the mounting base 8 can be designed as a flat plate, a box, or a frame to adapt to the installation requirements of different devices. The motion module 4 is fixedly mounted on the mounting base 8. The motion module 4 can adopt various driving methods, for example, it can be a linear slide driven by a lead screw and a stepper motor, or a piezoelectric actuator made of stacked piezoelectric ceramics. Its fixing method can be achieved by bolt connection, welding, or snap-fit ​​fixing to ensure the stability of the position of the motion module 4 during operation. A pressure sensing element 5 is connected to the output end of the motion module 4. The pressure sensing element 5 can be an independent pressure sensor, such as a thin-film pressure sensor or a piezoelectric sensor, which is mounted on the output shaft of the motion module 4 through an adapter element. One end of the connector 2 is connected to the chuck for adsorbing the wafer, and the other end is fixedly connected to the contact element 10. Connector 2 can be a solid or hollow rod, made of materials such as ceramic, metal, or composites, with sufficient rigidity to transmit displacement and force. The suction cup can fix the wafer using vacuum adsorption, and its connection to connector 2 can be achieved through flexible connection or mechanical snap-fit. Contact 10 can be a cylindrical or square sheet structure, fixed to the other end of connector 2 by bolts or adhesive. Contact 10 is in contact with pressure sensing element 5. This contact can be achieved through direct contact, for example, the end face of contact 10 directly contacting the sensing surface of pressure sensing element 5. Alternatively, it can be achieved by placing a thin elastic gasket between them to ensure good force transmission and sensing sensitivity. Thus, the displacement of the output end of motion module 4 can be transmitted to the suction cup through pressure sensing element 5, contact 10, and connector 2. One end of strain gauge 9 is fixedly mounted on the outer wall of the wafer bonding cavity, and the other end is fixedly connected to contact 10. The strain gauge 9 can be a flexible sheet, such as a reed, with one end fixed to a specific position on the outer wall of the cavity by adhesive or welding. A reed is a thin sheet structure with elastic deformation capability, usually made of metal or alloy. It undergoes reversible elastic deformation when subjected to external force and returns to its original shape after the force is removed. In displacement transmission and sensing, the reed can act as a flexible connector or elastic element, transmitting minute displacements to the sensor or indicating the stress condition through its own deformation. The other end of the strain gauge 9 is fixed to the contact element 10 in a similar manner, so that minute displacements of the contact element 10 can cause deformation of the strain gauge 9. The displacement sensing element 6 is fixedly mounted on the mounting base 8. The displacement sensing element 6 can be a non-contact sensor, such as a capacitive displacement sensor or a laser displacement sensor, fixed to the mounting base 8 by a bracket or clamp. The sensing head of the displacement sensing element 6 is positioned opposite the strain gauge 9, for example, maintaining a preset gap between the sensing head and the strain gauge 9.The displacement sensing element 6 is used to sense the displacement of the strain gauge 9, thereby indirectly obtaining the displacement information of the suction cup. Thus, the displacement of the suction cup is transmitted through the connector 2 and the strain gauge 9, and sensed by the displacement sensing element 6, forming a closed-loop feedback signal for the displacement of the motion module 4. This feedback signal can be received by the controller and used to adjust the output of the motion module 4 to achieve precise control of the suction cup displacement.

[0031] The wafer alignment and bonding fine-tuning device in this embodiment integrates displacement transmission, pressure monitoring, and displacement feedback functions, effectively solving the transmission error problem caused by alignment and bonding separation in traditional wafer bonding processes. This device can monitor the pressure during the bonding process in real time and provide a closed-loop feedback signal for the chuck displacement, thereby achieving precise control and status monitoring of the wafer bonding process. This significantly improves bonding accuracy and process reliability, and avoids bonding defects caused by uncontrolled pressure or displacement deviation.

[0032] In the embodiments described above in this application, a wafer alignment and bonding fine-tuning device is proposed to achieve wafer positioning and pressure monitoring. However, the vacuum atmospheric pressure generated when the wafer bonding cavity is evacuated may cause uneven stress on the device or structural damage, affecting bonding accuracy and stability. Therefore, the fine-tuning device also includes an atmospheric offset module 1 fixedly mounted on the mounting base 8. A horizontal decoupling device 3 is connected to the contact 10, configured such that the thrust of the atmospheric offset module 1 is provided to the connector 2 through the horizontal decoupling device 3 and the contact 10 to offset the vacuum atmospheric pressure generated when the wafer bonding cavity is evacuated. Specifically, the atmospheric offset module 1 is used to generate thrust to offset the external atmospheric pressure. The atmospheric offset module 1 can be implemented in various forms. For example, it can be a pneumatic actuator that generates the required thrust by precisely controlling the air pressure; or it can be an electromagnetic force generator that generates controllable electromagnetic thrust by adjusting the current; or it can be a pre-tensioned spring mechanism that provides constant or adjustable thrust through the elastic deformation of the spring. The atmospheric cancellation module 1 is fixedly mounted on the mounting base 8 to ensure the stability of its thrust output. The horizontal decoupling device 3 is a mechanical structure designed to allow the transmission of force or displacement in one direction (e.g., vertical). For example, the horizontal decoupling device 3 can employ a ball-head plunger to achieve vertical pressure transmission, while the rolling ball head at the end of the plunger enables non-vertical decoupling, eliminating the influence of cylinder motion errors on the mechanism's accuracy.

[0033] Through the above technical solution, when the wafer bonding cavity is evacuated, due to the pressure difference between the inside and outside of the cavity, the chuck and the wafer it holds are subjected to an upward vacuum atmospheric pressure. At this time, the atmospheric cancellation module 1 generates a thrust in the opposite direction to this vacuum atmospheric pressure. This thrust first acts on the horizontal decoupling device 3, which, while transmitting the vertical thrust, effectively isolates any potential lateral forces or constraints in the horizontal direction, ensuring the purity of the thrust transmission. Subsequently, this thrust is transmitted to the connector 2 through the contact member 10, and finally acts on the chuck. In this way, the thrust generated by the atmospheric cancellation module 1 can accurately cancel the effect of the vacuum atmospheric pressure on the chuck, thereby maintaining the force balance of the chuck and the wafer it holds. This effectively avoids chuck displacement, structural deformation, or damage caused by vacuum atmospheric pressure, significantly improving the stability and accuracy of the wafer bonding process, and ensuring the reliable operation of the fine-tuning device in a vacuum environment.

[0034] In the above-described solution of this application, a connector 2 is proposed to transfer the displacement of the motion module 4 to the chuck. However, during its implementation, since the wafer bonding cavity is in a vacuum environment, the connector 2 needs to ensure sealing to prevent vacuum leakage, while allowing the rod to maintain flexibility and stability during movement; otherwise, vacuum failure, motion obstruction, or decreased accuracy may occur. Therefore, this application further proposes a specific structural design for the connector 2, referring to... Figure 4As shown, the connector 2 includes a rod 20 connected to the suction cup, a bellows 25 that can elastically expand and contract with the movement of the rod 20, and a connecting flange 24 mounted on the outer wall of the wafer bonding cavity. The rod 20 is configured such that one end connected to the suction cup is a fixed end 22, and the other end connected to the contact member 10 is a movable end 21. The movable end 21 has a mounting surface 23 that is fixedly connected to the contact member 10. The bellows 25 is fitted onto the outside of the rod 20, with one end connected to the mounting surface 23 and the other end connected to the connecting flange 24. Specifically, the rod 20, as a key component connecting the suction cup and the contact member 10, is mainly responsible for accurately transmitting the displacement of the motion module 4. The end of the rod 20 connected to the suction cup is configured as the fixed end 22, which is the key part for achieving mechanical connection between the rod 20 and the suction cup, ensuring that the displacement of the motion module 4 can be accurately transmitted to the suction cup. The other end of the rod 20, which connects to the contact 10, is configured as a movable end 21. The movable end 21 serves as the interface between the rod 20 and the contact 10, responsible for transmitting the displacement of the rod 20 to the contact 10. The design of the movable end 21 should ensure a precise fit with the contact 10 to reduce gaps and errors during displacement transmission. The movable end 21 has a mounting surface 23 for fixed connection with the contact 10. This mounting surface 23 is a surface on the movable end 21 specifically designed for mechanical connection with the contact 10. The mounting surface 23 is typically precision-machined to ensure its flatness and perpendicularity, thereby ensuring stable and precise installation of the contact 10. The mounting surface 23 may have threaded holes, locating pin holes, or keyways to securely fix the contact 10 to it using bolts, pins, or other fasteners, ensuring reliable displacement transmission. A bellows 22 is fitted over the rod 20, its core function being to provide a dynamic seal while allowing axial movement of the rod 20. The bellows 22 can be made of metal, such as stainless steel or nickel alloy, through welding or hydroforming processes. These bellows offer excellent pressure resistance, temperature resistance, and corrosion resistance, and have a long elastic life, capable of withstanding multiple expansion and contraction cycles without failure. Alternatively, bellows made of polymer materials, such as polytetrafluoroethylene (PTFE) or fluororubber, can be used. These materials exhibit good chemical inertness and flexibility in specific applications. The corrugated shape and wall thickness of the bellows 22 can be optimized according to the required stroke, stiffness, and pressure rating to ensure sufficient elastic expansion and contraction capacity while maintaining the vacuum seal integrity of the wafer bonding cavity during the movement of the rod 20. The connecting flange 24 is mounted on the outer wall of the wafer bonding cavity, providing a stable mounting base and sealing interface for the bellows 22. The connecting flange 24 is typically made of a metal material matching the outer wall of the cavity, such as stainless steel, and is securely fixed to the outer wall of the cavity by bolting or welding. Its design should include a structure for sealing the connection to the other end of the bellows 22, such as a flat flange with an O-ring groove or a welded interface, to ensure the reliability and sealing of the connection in a vacuum environment.

[0035] Through the above technical solution, this application effectively resolves the contradiction between the sealing performance and movement flexibility of the connector in a vacuum environment. The design of the rod 20 allows the displacement of the motion module 4 to be directly and stably transmitted to the chuck, avoiding displacement loss or jamming caused by improper connection. The bellows 22 is fitted onto the outside of the rod 20. Its elastic expansion and contraction characteristics not only allow the rod 20 to move freely, but more importantly, it forms a dynamic vacuum seal during the movement of the rod 20, effectively preventing external atmosphere from entering the wafer bonding cavity, thereby maintaining the vacuum environment inside the cavity. The connecting flange 24 provides a robust mounting base for the bellows 22, ensuring the stability and reliability of the entire sealing structure. The firm connection between the fixed end 22 of the rod 20 and the chuck, and the precise fixation between the mounting surface 23 on the movable end 21 and the contact element 10, together ensure the accuracy and stability of displacement transmission. Overall, this connector structure effectively solves the sealing problem in a vacuum environment while ensuring high-precision displacement transmission, significantly improving the working reliability and bonding accuracy of the wafer alignment and bonding fine-tuning device under complex working conditions.

[0036] In the above-described scheme of this application, the connector 2 is directly connected to the suction cup to transmit the displacement of the motion module 4. However, in its implementation, the motion module may be damaged due to the lack of a protection mechanism when overpressure occurs. To address this, this application further proposes that a flexible module 7 be provided at the fixed end 22. The connector 2 is connected to the suction cup through the flexible module 7. The flexible module 7 is used to transmit the displacement of the motion module 4 and to deform under overpressure to protect the motion module 4. Specifically, the flexible module 7 refers to a mechanical structure or material component with elastic deformation capability, designed to undergo reversible deformation under load, thereby achieving buffering, shock absorption, or force transmission functions. Specifically, the flexible module 7 can be implemented in various forms. For example, it can be a spring structure, such as a helical spring, disc spring, or wave spring, providing the required flexibility through its own compression or tension. Alternatively, the flexible module 7 can also be an elastomer, such as a gasket or bushing made of rubber, silicone, or other polymeric elastic materials, absorbing and releasing energy through the elastic deformation of the material itself. Furthermore, the flexible module 7 can also be a flexible hinge, achieving flexibility through a thin-walled structure design with a specific geometry, utilizing the local elastic bending of the material. These implementations ensure that the flexible module 7 effectively transmits displacement under normal operating conditions and provides protection during overload. The fixed end 22 refers to the end of the connecting member 20 that connects to the suction cup; here, the flexible module 7 achieves an elastic connection with the suction cup. The connecting member 2 is connected to the suction cup via the flexible module 7, describing the position and function of the flexible module 7 in the entire force transmission path, i.e., as a buffer between the connecting member 2 and the suction cup. The flexible module 7 is used to transmit the displacement of the motion module 4, meaning that under normal operating conditions, the flexible module 7 should have sufficient stiffness to accurately transmit the displacement generated by the motion module 4, ensuring the precise movement of the suction cup. Simultaneously, the flexible module 7 is used to deform under overpressure conditions to protect the motion module 4; that is, when subjected to pressure exceeding a preset range, the flexible module 7 absorbs impact energy through its own elastic or plastic deformation, thereby preventing excessive force from directly acting on the motion module 4 and preventing damage.

[0037] Through the above technical solution, the introduction of the flexible module 7 in the wafer alignment and bonding fine-tuning device provides elastic buffering capability to the connection between the connector 2 and the chuck. Under normal operating conditions, the flexible module 7 can accurately and efficiently transmit the displacement generated by the motion module 4 to the chuck, ensuring the micron-level precision requirements of the wafer alignment and bonding process. More importantly, when unexpected overpressure occurs during the bonding process, such as excessive contact force between the wafer and the substrate or impact, the flexible module 7 will preferentially undergo elastic deformation to absorb and disperse excess impact force or pressure, thereby effectively preventing excessive load from being directly transmitted to the motion module 4. This deformation mechanism acts like a mechanical fuse, significantly reducing the risk of damage to the motion module 4 due to overload, greatly improving the reliability and service life of the entire device. Therefore, this solution not only ensures the accuracy of displacement transmission but also provides effective overpressure protection for the critical motion module 4, enabling the wafer alignment and bonding fine-tuning device to operate stably and safely in complex and variable bonding environments.

[0038] In the above-described scheme of this application, a pressure sensing element 5 is proposed to detect the pressure transmitted during the movement of the motion module. However, in its implementation, the direct connection between the output end of the motion module 4 and the contact 10 may lack a stable mounting structure, leading to unstable pressure transmission, affecting detection accuracy, and thus reducing the monitoring reliability of the bonding process. Therefore, the output end of the motion module 4 is connected to a mounting component 41 that fits against the contact 10, and the pressure sensing element 5 is mounted on the end face of the mounting component 41 opposite to the contact 10. Thus, the pressure sensing element 5 forms a "sandwich" structure between the mounting component 41 and the contact 10. Specifically, the mounting component 41 is a structural component used to connect and fix other parts. Its main function is to provide a stable physical interface between the output end of the motion module 4 and the contact 10 to ensure accurate transmission of pressure and displacement. The mounting component 41 can be a block or disc structure made of high-strength metal (such as stainless steel or aluminum alloy), with its surface precision ground to ensure good fit with the contact 10, and firmly connected to the output end of the motion module 4 by bolts or welding. The connection between the output end of motion module 4 and mounting component 41 is designed to provide a rigid or semi-rigid connection, ensuring that the displacement and force generated by motion module 4 can be effectively transmitted to mounting component 41. The fit between mounting component 41 and contact component 10 refers to tight contact between the two to ensure continuous transmission of pressure signals and avoid signal attenuation or distortion due to gaps or looseness. Pressure sensing element 5 is a device that converts the applied pressure into a measurable electrical signal for real-time monitoring of pressure changes during wafer bonding. Mounting pressure sensing element 5 on the opposite end face of mounting component 41 and contact component 10 means that the element is directly placed in the path through which motion module 4 transmits pressure to contact component 10. For example, a groove can be machined into the end face of mounting component 41, and pressure sensing element 5 can be embedded therein, so that its sensing surface directly contacts the corresponding end face of contact component 10, thereby achieving direct, real-time monitoring of the transmitted pressure. Alternatively, a mounting base can be provided on the end face of the contact 10, and the pressure sensing element 5 can be fixed on the mounting base so that its sensing surface is in close contact with the end face of the mounting 41, ensuring that the pressure signal can be transmitted to the sensing element without loss.

[0039] Through the above technical solution, mounting component 41 serves as a stable interface between the output end of motion module 4 and contact component 10, effectively avoiding loosening or deviation that may occur with direct connection, enhancing the rigidity of the overall structure, and thus ensuring the stability of pressure transmission. The tight fit between mounting component 41 and contact component 10 eliminates gaps, ensuring the continuity and directness of pressure transmission and reducing signal loss. Simultaneously, mounting the pressure sensing element 5 on the opposite end face of mounting component 41 and contact component 10, placing it directly at a critical point in the pressure transmission path, enables real-time and accurate capture of pressure changes applied by motion module 4, significantly improving the accuracy of pressure detection. Overall, the introduction of mounting component 41 not only strengthens connection stability but also, through its specific mounting position, allows the pressure sensing element 5 to more effectively perform its detection function, thereby achieving more reliable closed-loop feedback during wafer bonding, effectively solving the problems of unstable pressure transmission and affected detection accuracy, and improving the monitoring reliability of the bonding process.

[0040] In the above-mentioned scheme of this application, a horizontal decoupling device 3 is proposed to transmit the thrust of the atmospheric cancellation module 1 to cancel the vacuum atmospheric pressure generated when the wafer bonding cavity is evacuated. However, in its implementation, the thrust transmission may be uneven or unstable due to asymmetrical or unbalanced device arrangement, affecting the cancellation effect and even causing device vibration or positioning error. In this regard, this application further proposes that a "π"-shaped mounting part 31 is connected to the side of the contact member 10 away from the pressure sensing element 5. Horizontal decoupling devices 3 are installed at both ends of the mounting part 31. The atmospheric cancellation module 1 is set as two symmetrically arranged, and is arranged one-to-one with the horizontal decoupling device 3. Specifically, a "π"-shaped mounting part 31 is connected to the side of the contact member 10 away from the pressure sensing element 5. This mounting part 31 is a structural component, and its "π"-shaped design is intended to provide a symmetrical and stable connection platform for installing other components, while ensuring its own structural rigidity and avoiding unnecessary deformation under stress. Mounting component 2 31 can be integrally molded or assembled from multiple parts, such as a central connecting plate and two lateral extension arms. Precision machining and assembly ensure its "π"-shaped structure and overall rigidity. Horizontal decoupling devices 3 are installed at both ends of mounting component 2 31. The function of the horizontal decoupling devices 3 is to transmit the thrust of the atmospheric cancellation module 1 while isolating or reducing the coupling force in the horizontal direction, ensuring that the thrust mainly acts in the vertical direction and allowing a certain degree of small horizontal displacement to avoid stress concentration or impact on positioning accuracy. Installing them at both ends of mounting component 2 31 is to achieve uniform distribution and balanced transmission of the thrust. Two atmospheric cancellation modules 1 are symmetrically arranged, corresponding one-to-one with the horizontal decoupling devices 3. The atmospheric cancellation modules 1 generate thrust to counteract the vacuum atmospheric pressure generated during the evacuation of the wafer bonding cavity, thereby maintaining the stable force state of the connector 2 and the chuck. Setting them as two symmetrical modules, corresponding one-to-one with the two horizontal decoupling devices 3, ensures that the canceling thrust acts uniformly and balancedly on the connector 2, avoiding tilting, vibration, or positioning errors caused by uneven force.

[0041] Through the above technical solution, a "π"-shaped mounting bracket 31 is connected to the contact 10, providing a wide and rigid mounting base for the horizontal decoupling device 3. Two horizontal decoupling devices 3 are symmetrically mounted at both ends of the mounting bracket 31, with two atmospheric cancellation modules 1 corresponding to them one-to-one, forming a symmetrical and balanced force transmission path. When the atmospheric cancellation module 1 generates thrust, these two thrusts act evenly on the mounting bracket 31 through their respective horizontal decoupling devices 3, and are then transmitted to the contact 10 and the connector 2. This symmetrical arrangement ensures a uniform spatial distribution of thrust, effectively avoiding single-point or eccentric force, thereby significantly improving the uniformity and stability of atmospheric cancellation thrust transmission and effectively counteracting vacuum atmospheric pressure. This solution effectively avoids tilting, vibration, or chuck positioning errors in the connector 2 caused by thrust imbalance, thus ensuring high-precision alignment and stable pressure control of the wafer during the bonding process. In addition, the arrangement of the "π"-shaped mounting part 31 away from the pressure sensing element 5 also avoids the interference of the thrust on the measurement accuracy of the pressure sensing element 5, further ensuring the performance of the entire device.

[0042] In the aforementioned scheme of this application, a displacement sensing element 6 is fixedly mounted on a mounting base 8 to sense the displacement of the strain gauge and form a closed-loop feedback signal. However, in this process, direct fixing may lead to unstable position of the displacement sensing element or susceptibility to vibration interference, affecting the accuracy of displacement monitoring and the reliability of closed-loop feedback. To address this, this application further proposes that a gantry-shaped mounting component 3 61 is fixedly mounted on the mounting base 8, and the displacement sensing element 6 is mounted on the mounting component 3 61. Specifically, the gantry-shaped mounting component 3 61 is a support structure with high rigidity and high stability, its shape resembling a "gantry," typically consisting of two vertical support arms and a horizontal beam connecting its top. Its main function is to provide a robust mounting base for the displacement sensing element 6 that is not easily affected by external vibration or deformation. The displacement sensing element 6 is mounted on the horizontal beam, thereby ensuring the positional accuracy and stability of the displacement sensing element 6 during operation. By fixing a gantry-type mounting bracket 361 to the mounting base 8 and placing the displacement sensing element 6 on the mounting bracket 361, the gantry structure, with its inherent high rigidity and stability, can effectively resist the influence of external vibration and deformation. This ensures that the displacement sensing element 6 maintains a precise mounting position and a stable relative relationship with the strain gauge 9 throughout the wafer bonding fine-tuning process. Therefore, the displacement sensing element 6 can more accurately sense the minute displacement of the strain gauge 9, thereby providing a high-precision chuck displacement signal. This high-precision displacement feedback signal significantly improves the reliability and accuracy of the displacement closed-loop control of the motion module 4, enabling the wafer alignment and bonding fine-tuning device to achieve more stable and precise displacement transmission and control, effectively avoiding monitoring errors caused by unstable installation of the displacement sensing element, and thus improving the alignment accuracy and bonding quality of the wafer bonding.

[0043] In the above-mentioned scheme of this application, a strain gauge 9 is proposed to transmit the displacement signal of the chuck to form a closed-loop feedback. However, in its implementation, one end of the strain gauge 9 needs to be firmly fixed to the outer wall of the wafer bonding cavity to ensure stable transmission of the displacement signal and avoid measurement errors caused by unstable installation or environmental vibration, which would affect the accuracy of the closed-loop control. To address this, this application further proposes that a mounting component 4 91 is installed on the outer wall of the wafer bonding cavity, and one end of the strain gauge 9 is fixed to the mounting component 4 91. Specifically, the mounting component 4 91 is a structural component specifically designed to fix the strain gauge 9. Its function is to provide a stable and reliable mounting base for the strain gauge 9, ensuring that the strain gauge 9 can accurately sense displacement. The mounting component 4 91 can be a boss structure on the outer wall of the wafer bonding cavity, and its surface is finely processed to ensure the installation accuracy of the strain gauge 9. The fact that one end of the strain gauge 9 is fixed to the mounting component 4 91 means that a firm, displacement-free connection is established between the strain gauge 9 and the mounting component 4 91. This fixing method is designed to ensure that the strain gauge 9 can accurately transmit the displacement of the suction cup to the displacement sensing element 6, without being affected by loose installation or external interference.

[0044] Through the above technical solution, mounting component 4 91 is fixed to the outer wall of the wafer bonding cavity, providing a rigid and stable mounting base for strain gauge 9. One end of strain gauge 9 is firmly fixed to mounting component 4 91, thereby ensuring that strain gauge 9 maintains its stable mounting position during the wafer bonding process, even in complex environments such as high temperature, vacuum, or mechanical vibration, avoiding measurement errors caused by loosening or displacement. This stable fixing method allows the displacement of the chuck to be accurately and stably transmitted through connector 2 and strain gauge 9, and accurately captured by displacement sensing element 6, thus forming a precise closed-loop feedback signal for the displacement of motion module 4. This significantly improves the control accuracy and reliability of the entire wafer alignment and bonding fine-tuning device, which is crucial for achieving micron-level precise alignment and bonding, and effectively solves the problem of inaccurate displacement signal transmission caused by unstable fixing of strain gauge 9.

[0045] Based on the above structure, this invention proposes a method for operating a wafer alignment and bonding fine-tuning device, used to position the wafer and monitor pressure during the wafer bonding process, comprising the following steps: During the bonding process of upper and lower wafers or chips, the motion module 4 generates a preset displacement, which is transmitted to the suction cup through the contact element 10 and the connector 2. The pressure of the wafer or chip is detected by the pressure sensing element 5 set between the output end of the motion module 4 and the contact element 10. The displacement of the suction cup is transmitted through the connector 2 and the strain gauge 9, and the displacement signal of the suction cup is obtained by the displacement sensing element 6. The displacement of the suction cup from the motion module 4 is monitored by the displacement sensing element 6.

[0046] The motion module 4 is an actuator that provides precise displacement output. Its function is to generate a precise displacement according to preset parameters during wafer or chip bonding to drive the chuck for positioning and bonding. The contact 10 and connector 2 together form the displacement transmission path, ensuring that the preset displacement generated by the motion module 4 is accurately transmitted to the chuck holding the wafer. The pressure sensing element 5 is a sensor used to measure the pressure exerted on the wafer or chip during bonding in real time. It is located between the output end of the motion module 4 and the contact 10, and can directly sense the force applied to the wafer by the motion module 4. The displacement of the chuck is transmitted through the connector 2 and strain gauge 9. The connector 2, as a mechanical connection, transmits the motion of the chuck to the strain gauge 9. The strain gauge 9, specifically referring to a spring in this application, is a flexible element with a specific elastic modulus and geometry, with one end fixed and the other end deforming with the displacement of the connector 2. This deformation directly reflects the displacement of the chuck, providing a measurable physical quantity for subsequent displacement detection. The reed's design ensures linearity and repeatability of displacement transmission, while its deformation is easily and accurately captured by the displacement sensing element 6. The displacement sensing element 6 is a sensor used to accurately measure the chuck displacement. It is positioned opposite the strain gauge 9, sensing the deformation or positional change of the strain gauge 9 through non-contact or contact methods to obtain the chuck displacement signal. By monitoring the displacement of the chuck from the motion module 4, the displacement sensing element 6 aims to achieve closed-loop feedback control of the chuck's actual displacement. The displacement sensing element 6 continuously monitors the chuck displacement signal and compares it with the preset displacement of the motion module 4. This monitoring allows real-time monitoring of whether the chuck accurately executes the commands of the motion module 4 and whether any deviations exist. This enables the system to adjust based on the actual displacement feedback signal, thereby ensuring positioning accuracy and stability during the wafer bonding process.

[0047] Through the above technical solution, this application achieves precise control of wafer positioning and pressure monitoring during wafer bonding. Specifically, when the upper and lower wafers or chips are bonded, the motion module 4 generates a preset displacement, which is efficiently and accurately transmitted to the chuck through the contact element 10 and the connector 2, ensuring the initial positioning accuracy of the wafer. Simultaneously, the pressure sensing element 5, located between the output end of the motion module 4 and the contact element 10, can detect the pressure borne by the wafer or chip during bonding in real time, effectively avoiding wafer damage due to excessive pressure or weak bonding due to insufficient pressure, significantly improving bonding reliability. Furthermore, the actual displacement of the chuck is transmitted through the connector 2 and strain gauge 9, and the displacement signal of the chuck is accurately acquired by the displacement sensing element 6, forming a real-time displacement feedback loop. This feedback mechanism enables the system to continuously monitor the displacement of the chuck from the motion module 4 and promptly detect and correct any displacement deviations, thereby ensuring high-precision positioning and dynamic adjustment capabilities during the bonding process. In view of this, this application effectively solves the problems of inaccurate control, transmission error and unstable bonding quality caused by the inability to monitor pressure and displacement feedback in real time in traditional methods, and significantly improves the accuracy, stability and yield of wafer bonding.

[0048] One specific embodiment of the wafer alignment and bonding fine-tuning device of this application is as follows, referring to... Figure 5-7 As shown: Motion module 4 uses a linear motion module, which features high precision and controllable position. It can be replaced by other mechanisms capable of linear motion, including various linear motors, lead screw motors, and slider motors.

[0049] Atmospheric pressure cancellation module 1 uses a cylinder, which can be replaced by a structure that can provide support force using a spring.

[0050] The horizontal decoupling device 3 uses a ball-head plunger, which can realize vertical pressure transmission. At the same time, the rolling ball head at the end of the ball-head plunger can realize non-vertical decoupling, eliminating the influence of cylinder motion error on the accuracy of the mechanism.

[0051] Strain gauge 9 uses a spring.

[0052] The flexible module 7 includes flexible hinges and mounting components. The flexible hinges and springs can be made of materials with a high ratio of ultimate tensile strength to elastic modulus, such as spring steel or titanium alloy. The flexible hinges can accurately transmit the displacement of the motion module, while protecting the motion module through slight deformation under overpressure.

[0053] The displacement sensing element 6 adopts a contact displacement sensor to monitor the displacement of the bellows. Alternatively, displacement sensors such as grating rulers can be used through reasonable layout.

[0054] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A wafer alignment and bonding fine tuning apparatus, characterized by, include: Mounting base; A motion module is fixedly mounted on the mounting base, and the output end of the motion module is connected to a pressure sensing element for detecting the pressure transmitted during the motion of the motion module. A connector, one end of which is connected to a suction cup for adsorbing the wafer, and the other end of which is fixedly connected to a contact element that is in contact with the pressure sensing element, is configured such that the displacement of the output end of the motion module is transmitted to the suction cup through the pressure sensing element, the contact element and the connector. A strain gauge, one end of which is fixedly mounted on the outer wall of the wafer bonding cavity, and the other end of which is fixedly connected to a contact element; A displacement sensing element is fixedly mounted on the mounting base, and the sensing head of the displacement sensing element is positioned opposite the strain gauge to sense the displacement of the strain gauge. It is configured such that the displacement of the suction cup is transmitted through the connector and the strain gauge to form a closed-loop feedback signal for the displacement of the motion module.

2. The wafer alignment and bonding fine tuning apparatus of claim 1, wherein: The fine-tuning device also includes an atmospheric offset module fixedly mounted on the mounting base. A horizontal decoupling device is connected to the contact element, configured such that the thrust of the atmospheric offset module is provided to the connector through the horizontal decoupling device and the contact element to offset the vacuum atmospheric pressure generated when the wafer bonding cavity is evacuated.

3. The wafer alignment and bonding fine tuning apparatus of claim 1, wherein: The connector includes a rod connected to the suction cup, a bellows that can elastically extend and retract with the movement of the rod, and a connecting flange mounted on the outer wall of the wafer bonding cavity. The rod is configured such that one end connected to the suction cup is a fixed end, and the other end connected to the contact is a movable end. The movable end has a mounting surface that is fixedly connected to the contact. The bellows is fitted onto the outside of the rod, with one end connected to the mounting surface and the other end connected to the connecting flange.

4. The wafer alignment and bonding fine-tuning device according to claim 3, characterized in that: The fixed end is provided with a flexible module, and the connector is connected to the suction cup through the flexible module. The flexible module is used to transmit the displacement of the motion module and to deform under overpressure to protect the motion module.

5. The wafer alignment and bonding fine-tuning device according to any one of claims 1-4, characterized in that: The output end of the motion module is connected to a mounting component that fits against the contact component, and the pressure sensing element is mounted on the end face of the mounting component that is opposite to the contact component.

6. The wafer alignment and bonding fine-tuning device according to claim 2, characterized in that: The contact element is connected to a "π"-shaped mounting component two on the side away from the pressure sensing element. Both ends of the mounting component two are equipped with horizontal decoupling devices. The atmospheric cancellation module is set as two symmetrically arranged modules, and is set one-to-one with the horizontal decoupling device.

7. The wafer alignment and bonding fine-tuning device according to any one of claims 1-4, characterized in that: A gantry-shaped mounting component three is fixedly mounted on the mounting base, and the displacement sensing element is disposed on the mounting component three.

8. The wafer alignment and bonding fine-tuning device according to claim 7, characterized in that: Mounting component four is installed on the outer wall of the wafer bonding cavity, and one end of the strain gauge is fixed to mounting component four.

9. The wafer alignment and bonding fine-tuning device according to any one of claims 1-4, characterized in that: The pressure sensing element is a pressure sensor, the displacement sensing element is a displacement sensor, and the strain gauge is a spring.

10. A method for operating a wafer alignment and bonding fine-tuning device, used for positioning and pressure monitoring of the wafer during wafer bonding, characterized in that: Includes the following steps: During the bonding process of upper and lower wafers or chips, the motion module generates a preset displacement, which is transmitted to the suction cup through the contact and connector. The pressure of the wafer or chip is detected by the pressure sensing element set between the output end of the motion module and the contact. The displacement of the suction cup is transmitted through the connector and strain gauge, and the displacement signal of the suction cup is obtained by the displacement sensing element. The displacement of the suction cup from the motion module is monitored by the displacement sensing element.

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