Wafer back contact type positioning and clamping fixing device and wafer bonding method

Abstract

The invention discloses a wafer back contact type positioning and clamping fixing device and a wafer bonding method.The wafer back contact type positioning and clamping fixing device comprises a bonding cavity, a lower suction cup, an upper pressing disc, a controller, a pressing driving mechanism, a positioning pressing rod, a clamping driving mechanism and a flexible clamping jaw, and the lower end of the positioning pressing rod can abut against the upper end wall of the lower suction cup; the clamping driving mechanisms are arranged on the two sides of the lower suction cup in an up-down sliding mode, the flexible clamping jaws are connected with the clamping driving mechanisms, the clamping driving mechanisms drive the flexible clamping jaws to slide in the radial direction of the lower suction cup, the flexible clamping jaws are used for clamping and fixing a wafer, and the inner circumferential wall of each flexible clamping jaw can abut against the outer circumferential wall of the wafer. The limiting block can abut against the lower end wall of the edge of the wafer, and the pressing driving mechanism and the clamping driving mechanism are electrically connected with the controller. According to the technical scheme, the wafer surface can be prevented from being polluted and damaged, the stability of the wafer bonding process can be effectively improved, the rejection rate is reduced, the cost is saved, and the high market application and popularization value is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of bonding equipment, and in particular to a wafer backside contact positioning and clamping device and a wafer bonding method. Background Art

[0002] In semiconductor manufacturing, bonding is a back-end packaging process. Wafer bonding is the process of tightly bonding two or more wafers together through physical or chemical methods. It is used for various purposes, such as connecting chips, reducing package size, improving wafer structural strength, and preventing wafer deformation during subsequent processing. It is categorized into wafer-to-wafer (W2W) and die-to-wafer (D2W). Bonding primarily involves directly bonding two clean, atomically flat semiconductor materials of the same or different materials under certain conditions after surface cleaning and activation. The two semiconductor materials are then integrated through van der Waals, molecular, and even atomic forces. W2W refers to a process that permanently bonds wafers together, or wafers to glass substrates or other wafers, through chemical or physical reactions. The bonding process involves the reaction of atoms at the interface of two wafers under the influence of external energy, forming covalent bonds, thereby bonding the wafers and achieving a certain interfacial bond strength. D2W refers to the process of attaching the chips cut from the wafers to the package substrate (lead frame or printed circuit board) after the dicing process. Chip bonding processes can be divided into traditional and advanced methods. Traditional methods utilize die bonding and wire bonding, while advanced methods employ technologies such as flip-chip bonding and hybrid bonding. Based on the bonding method, wafer bonding can be categorized as permanent bonding and temporary bonding. The difference is self-explanatory: permanent bonding does not require debonding, while temporary bonding requires debonding to reopen the joined wafers. In terms of interface materials, bonding can be categorized as adhesive bonding with an interlayer, eutectic bonding, metal thermal compression bonding, fusion bonding without an interlayer, and anodic bonding.

[0003] During the wafer-to-wafer bonding process, precise positioning and securing of the wafers are crucial to the wafer bonding process, directly impacting the quality of chip stacking packaging. Currently, traditional bonding equipment primarily uses electrostatic chucks (ESCs) to secure the wafers through an electrostatic field, achieving precise positioning and securing. However, ESCs are complex in structure and extremely expensive to manufacture, often costing over one million yuan, significantly increasing production costs for manufacturers.

[0004] While existing mechanical clamping solutions offer low cost, they can easily damage or contaminate the wafer edge. Their most significant drawback is the inability to precisely position the wafer and prevent it from shifting. Therefore, a low-cost, highly reliable wafer positioning and clamping device that can adapt to multi-physics coupling environments is urgently needed. Summary of the Invention

[0005] The main purpose of the present invention is to provide a wafer back side contact positioning and clamping device and a wafer bonding method, aiming to solve the problems mentioned in the background technology.

[0006] The control panel is located at the bottom of the equipment box, and the control panel is located at the bottom of the equipment box, and the control panel is located at the bottom of the equipment box. The camming mechanism is configured to move upwards and downwards, the camming mechanism being adapted to move the camming member toward the support frame, the support frame being adapted to move the camming member toward the support frame.

[0007] Optionally, it also includes a linear module, a mounting plate and a flexible clamp fixing plate, the linear module is vertically arranged on both sides of the lower suction cup, the mounting plates are respectively fixedly connected to the sliders of the linear module, the clamping drive mechanism is arranged on the mounting plate, the clamping drive mechanism is a servo drive motor, the middle of the flexible clamp is fixedly connected to the output shaft of the servo drive motor, the linear module is electrically connected to the controller, the flexible clamp fixing plate is fixedly connected to the output shaft of the servo drive motor, and the flexible clamp is fixedly connected to the flexible clamp fixing plate.

[0008] Optionally, a clamping force detection sensor is also included, which is respectively arranged inside the servo drive motor, the clamping force detection sensor is connected to the push rod of the servo drive motor, the clamping force detection sensor is electrically connected to the controller, and the clamping force detection sensor is used to detect the clamping force of the flexible clamp.

[0009] Optionally, a laser displacement sensor is further included, which is arranged inside the servo drive motor, the laser displacement sensor is electrically connected to the controller, and the laser displacement sensor is used to detect the position of the flexible clamp.

[0010] Optionally, the pressing drive mechanism is a cylinder, and the cylinder rod of the cylinder is fixedly connected to the upper end of the positioning pressure rod.

[0011] Optionally, two side walls of the lower suction cup are provided with a plurality of avoidance grooves corresponding one to one with the limit blocks, and the limit blocks can be embedded in the avoidance grooves.

[0012] Optionally, the flexible clamping claw is formed of shape memory alloy.

[0013] Optionally, it also includes a pressure wheel arm, a pressure wheel and a push rod, the pressure wheel arm can be raised and lowered and arranged on the outside of the flexible clamp, the pressure wheel arm is rotatably connected to the flexible clamp fixing plate, the pressure wheel can be rotatably arranged at the lower end of the pressure wheel arm, the push rod can be slidably arranged on the mounting plate, the front end of the push rod abuts against the pressure wheel arm, and the pressure wheel can abut against the upper wafer.

[0014] Optionally, it also includes an L-shaped bracket, a lifting cylinder, a U-shaped connector and a pushing cylinder, the L-shaped bracket is arranged on the upper end wall of the flexible clamp fixing plate, the lifting cylinder is arranged at the upper end portion of the L-shaped bracket, the pushing cylinder is arranged on the mounting plate, the U-shaped connector is fixedly connected to the cylinder rod of the lifting cylinder, the upper end portion of the pressure wheel arm is rotatably connected to the U-shaped connector through a short shaft, and the cylinder rod of the pushing cylinder is fixedly connected to the push rod.

[0015] On the other hand, the present invention also provides a wafer bonding method using the above-mentioned wafer back side contact positioning and clamping device, comprising the following steps: The lower wafer to be bonded is placed into the bonding chamber with the front side facing upwards by the robot, and the flexible clamping claws are driven by the clamping drive mechanism to clamp the lower wafer on both sides. The clamping force detection sensor is used to make the clamping force of the flexible clamping claws on both sides consistent, so that it is aligned with the lower suction cup. Then, the linear module drives the flexible clamping claws to descend and place the lower wafer on the lower suction cup. Negative pressure is generated through the vacuum suction holes of the lower suction cup, thereby fixing the lower wafer on the lower suction cup. The upper wafer to be bonded is placed into the bonding chamber with its back side facing upwards by a robot arm, and the flexible clamping claws are driven by a clamping drive mechanism to clamp the upper wafer on both sides. The clamping force detection sensor is used to make the clamping force of the flexible clamping claws on both sides consistent, so that it is aligned with the lower wafer. The linear module then drives the flexible clamping claws down and suspends the upper wafer at a distance of 100um to 150um from the lower wafer. The positioning rod is pressed down by the pressing drive mechanism so that the positioning rod abuts against the center point of the upper wafer, thereby aligning the center point of the upper wafer with the center point of the lower wafer to ensure that the upper and lower wafers are not misaligned; The upper pressure plate is driven down to abut against the upper wafer, pressing the upper wafer against the lower wafer, thereby achieving bonding between the upper wafer and the lower wafer. The technical solution of the present invention has the following beneficial effects: in the technical solution of the present invention, the positioning pressure rod realizes lossless fixation and dynamic position compensation of the wafer through the coordinated action with the flexible clamping claw, effectively ensuring that the upper and lower wafers do not move after alignment, and ensuring that the air between the upper and lower wafers is discharged from the middle to the edge, which can reduce the air residue in the center during wafer bonding and effectively improve the quality of wafer bonding. When the flexible clamping claw clamps the wafer, the clamping force can be dynamically and accurately adjusted through the controller and the clamping force detection sensor, and the clamping force can be monitored in real time. While ensuring the precise centering of the wafer, the downward pressure of the positioning pressure rod is accurately controlled by the controller to avoid damaging the wafer. The flexible clamping claw of the present invention is non-frontal contact fixed, which avoids contamination and damage to the wafer surface. It is suitable for processes with high cleanliness requirements, can effectively improve the stability of the wafer bonding process, reduce the scrap rate, greatly save costs, and has high market application and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0017] Figure 1 This is a partial structural diagram of a wafer backside contact positioning and clamping device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a partially exploded structure of a wafer backside contact positioning and clamping device according to an embodiment of the present invention; Figure 3 This is a schematic diagram of another portion of the structure of a wafer backside contact positioning and clamping device according to an embodiment of the present invention; Figure 4 The present invention is a flowchart of the steps of a wafer bonding method using a wafer backside contact positioning and clamping device according to an embodiment of the present invention.

[0018] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0021] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0022] The present invention provides a wafer backside contact-type positioning and clamping device and a wafer bonding method.

[0023] like Figures 1 to 3As shown, in one embodiment of the present invention, the wafer back side contact positioning and clamping fixing device includes a bonding chamber (not shown), a lower suction cup 101, an upper pressure plate 102, a controller (not shown), a clamping drive mechanism (not shown), a positioning pressure rod 103, a clamping drive mechanism 104 and a flexible clamping claw 105. The lower suction cup 101 is arranged at the lower end of the bonding chamber, and the upper pressure plate 102 is arranged at the upper end of the bonding chamber so as to slide up and down, and the lower end wall of the upper pressure plate 102 can abut against the upper end wall of the lower suction cup 101. The outer periphery of the upper end surface of the lower suction cup 101 is provided with multiple A vacuum suction hole (not shown) is connected to the vacuum pump. The lower suction cup is used to fix the lower wafer. The lower suction cup 101 is used to align the upper and lower wafers when the bonding chamber has not yet been evacuated to a vacuum. When the upper and lower wafers are aligned, the vacuum of the lower suction cup 101 is turned off. The bonding chamber adopts a molecular pump vacuum generator to form a vacuum. The controller is set in the bonding process. The clamping drive mechanism is set at the upper end of the bonding chamber. The center point of the upper end of the upper pressure plate 102 is concave with a through hole (not shown). The positioning pressure rod 103 can be slid up and down through the through hole. The clamping drive mechanism The mechanism is fixedly connected to the upper end of the positioning pressure rod 103, and the positioning pressure rod 103 is driven to slide up and down by the clamping drive mechanism, and the lower end of the positioning pressure rod 103 can abut against the upper end wall of the lower suction cup 101. The clamping drive mechanism 104 is respectively arranged on both sides of the lower suction cup 101 for sliding up and down. The clamping drive mechanism 104 is arranged symmetrically on both sides. The outer contour of the flexible clamping claw 105 is arranged in an arc-shaped structure. The lower end of the inner circumferential wall at both ends of the flexible clamping claw 105 is convexly provided with a plurality of limit blocks 1051. The flexible clamping claw 105 is connected to the clamping drive mechanism 104, and the clamping drive mechanism 104 is connected to the clamping drive mechanism 104. The driving mechanism 104 drives the flexible clamping claws 105 to slide along the radial direction of the lower suction cup 101 respectively. The flexible clamping claws 105 are used to clamp and fix the wafer. The inner peripheral wall of the flexible clamping claws 105 can abut against the outer peripheral wall of the wafer, and the limit block 1051 can abut against the lower end wall of the edge of the wafer. The clamping driving mechanism and the clamping driving mechanism 104 are electrically connected to the controller respectively. The controller is equipped with a PID algorithm. The controller controls the actions of the clamping driving mechanism and the clamping driving mechanism 104, thereby controlling the downward pressure of the positioning pressure rod 103 and the clamping force of the flexible clamping claws 105.

[0024] Specifically, the lower suction cup 101 is used to align the upper and lower wafers when the bonding chamber has not yet been evacuated to a vacuum. After the alignment of the upper and lower wafers is completed, the vacuum of the lower suction cup 101 is turned off, and the bonding chamber uses a molecular pump vacuum generator to form a vacuum, thereby facilitating wafer bonding.

[0025] Specifically, it also includes a linear module (not shown), a mounting plate 106 and a flexible jaw fixing plate 107, the linear module is vertically arranged on both sides of the lower suction cup 101, the mounting plate 106 is fixedly connected with the slider of the linear module, the clamping driving mechanism 104 is arranged on the mounting plate 106, the clamping driving mechanism 104 is a servo driving motor, the middle of the flexible jaw 105 is fixedly connected with the output shaft of the servo driving motor, the linear module is electrically connected with the controller, the flexible jaw fixing plate 107 is fixedly connected with the output shaft of the servo driving motor, the flexible jaw 105 is fixedly connected with the flexible jaw fixing plate 107, the flexible jaw is driven to rise and fall by the linear module, and wafer bonding is realized.

[0026] Specifically, it also includes a clamping force detection sensor (not shown), which is arranged in the servo driving motor, the push rod of the servo driving motor is connected with the clamping force detection sensor, the clamping force detection sensor is electrically connected with the controller, the clamping force detection sensor is used for detecting the clamping force of the flexible jaw, and the clamping force is monitored in real time, so that the wafer is prevented from being damaged due to excessive clamping force while ensuring accurate centering.

[0027] Specifically, it also includes a laser displacement sensor (not shown), which is arranged in the servo driving motor, the laser displacement sensor is electrically connected with the controller, and the laser displacement sensor is used for detecting the position of the flexible jaw, so as to facilitate accurate centering of the wafer.

[0028] Specifically, the pressing driving mechanism is a gas cylinder, the cylinder rod of the gas cylinder is fixedly connected with the upper end of the positioning pressing rod 103, and the pressing force of the gas cylinder is accurately controlled to prevent the wafer from being damaged.

[0029] Specifically, the two side walls of the lower suction cup 101 are concavely provided with a plurality of avoidance grooves 1011 corresponding to the limiting blocks 1051, and the limiting blocks 1051 can be embedded in the avoidance grooves 1011.

[0030] Specifically, the flexible jaw 105 is formed of shape memory alloy, which is a material composed of two or more metal elements having shape memory effect through thermal elasticity and martensite phase transformation and its reverse transformation. The shape memory alloy can change shape flexibly, so as to flexibly adapt to the clamping and fixing of wafers of various sizes and models, so that the adaptability of the flexible jaw is wider, and the wafer is well protected, and the wafer can be effectively prevented from being damaged.

[0031] Specifically, as shown in FIG. 6, the flexible jaw 105 is formed of shape memory alloy, which is a material composed of two or more metal elements having shape memory effect through thermal elasticity and martensite phase transformation and its reverse transformation. Figure 3As shown, it also includes a pressure wheel arm 108, a pressure wheel 109 and a push rod 110. The pressure wheel arm 108 can be raised and lowered and is arranged on the outside of the flexible clamp 105. The pressure wheel arm 108 is rotatably connected to the flexible clamp fixing plate 107. The pressure wheel 109 is rotatably arranged at the lower end of the pressure wheel arm 108. The push rod 110 can be slidably arranged on the mounting plate 106 back and forth. The front end of the push rod 110 abuts against the pressure wheel arm 108, and the pressure wheel 109 abuts against the upper wafer 300. When the wafer is aligned, the pressure wheel can be pushed to the upper end of the wafer and the wafer is pressed under the action of the gravity of the pressure wheel, which can effectively prevent the wafer from loosening and affecting the bonding alignment accuracy.

[0032] Specifically, if Figure 3 As shown, it also includes an L-shaped bracket 111, a lifting cylinder 112, a U-shaped connecting head 113 and a pushing cylinder 114. The L-shaped bracket 111 is arranged on the upper end wall of the flexible clamp fixing plate 107, the lifting cylinder 112 is arranged at the upper end of the L-shaped bracket 111, and the pushing cylinder 114 is arranged on the mounting plate 106. The U-shaped connecting head 113 is fixedly connected to the cylinder rod of the lifting cylinder 112, and the upper end of the pressure wheel arm 108 is rotatably connected to the U-shaped connecting head 113 through a short axis. The cylinder rod of the pushing cylinder 114 is fixedly connected to the push rod 110. When the wafer is aligned, the pressure wheel is lifted by the lifting cylinder, and then the push rod is driven to move forward under the action of the push rod cylinder, and the roller is pushed to the upper end of the wafer by the push rod, and then the wafer is pressed under the gravity of the pressure wheel, which can effectively prevent the wafer from loosening.

[0033] On the other hand, Figure 4 As shown, the present invention also proposes a wafer bonding method using the above-mentioned wafer back side contact positioning and clamping device, comprising the following steps: S100: The lower wafer to be bonded is placed into the bonding chamber with the front side facing upward by the robot arm, and the flexible clamping claws are driven by the clamping drive mechanism to clamp the lower wafer on both sides. The clamping force detection sensor is used to make the clamping force of the flexible clamping claws on both sides consistent, so that they are aligned with the lower suction cup. The flexible clamping claws are then driven down by the linear module to place the lower wafer on the lower suction cup. Negative pressure is generated through the vacuum suction holes of the lower suction cup, thereby fixing the lower wafer on the lower suction cup. S200: The upper wafer to be bonded is placed into the bonding chamber with its back side facing upwards by a robot arm, and the clamping drive mechanism drives the flexible clamps to clamp the upper wafer on both sides. The clamping force detection sensor ensures that the clamping force of the flexible clamps on both sides is consistent, so that the flexible clamps are aligned with the lower wafer. The linear module then drives the flexible clamps to descend and suspend the upper wafer at a distance of 100um to 150um from the lower wafer. S300: The positioning pressure rod is driven downward by the pressing drive mechanism so that the positioning pressure rod abuts against the center point of the upper wafer, thereby aligning the center point of the upper wafer with the center point of the lower wafer to ensure that the upper and lower wafers are not misaligned; S400: driving the upper pressure plate to descend so as to abut against the upper wafer, pressing the upper wafer tightly against the lower wafer, thereby achieving bonding between the upper wafer and the lower wafer.

[0034] Specifically, the technical solution of the present invention realizes lossless fixation and dynamic position compensation of the wafer through the coordinated action of the positioning pressure rod and the flexible clamping claw, effectively ensuring that the upper and lower wafers do not move after alignment, and ensuring that the air between the upper and lower wafers is discharged from the middle to the edge during the bonding process, which can reduce the air residue in the center during wafer bonding and effectively improve the quality of wafer bonding. When clamping the wafer, the flexible clamping claw can dynamically and accurately adjust the clamping force through the controller and the clamping force detection sensor, monitor the clamping force in real time, and avoid damage to the wafer due to excessive clamping force while ensuring precise alignment. The downward pressure of the positioning pressure rod is accurately controlled by the controller to avoid damaging the wafer. The flexible clamping claw of the present invention is non-frontal contact fixation, which avoids contamination and damage to the wafer surface. It is suitable for processes with high cleanliness requirements, can effectively improve the stability of the wafer bonding process, reduce the scrap rate, greatly save costs, and has high market application and promotion value.

[0035] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A wafer backside contact positioning and clamping device, characterized in that: The control panel is located at the bottom of the control panel, and the control panel is located at the bottom of the control panel, and the control panel is connected with the control panel to form a control panel, wherein the control panel is connected with the control panel to form a control panel. The upper end wall of the suction cup abuts, and the clamping drive mechanism is respectively arranged on both sides of the lower suction cup for sliding up and down, and the clamping drive mechanism is arranged symmetrically on the left and right, and the outer contour of the flexible clamp is arranged in an arc-shaped structure, and the lower end parts of the inner circumferential wall at both ends of the flexible clamp are convexly provided with a plurality of limit blocks, and the flexible clamp is connected to the clamping drive mechanism, and the flexible clamp is driven by the clamping drive mechanism to slide along the radial direction of the lower suction cup, and the flexible clamp is used to clamp and fix the wafer, and the inner circumferential wall of the flexible clamp can abut against the outer circumferential wall of the wafer, and the limit block can abut against the lower end wall of the edge of the wafer, and the clamping drive mechanism and the clamping drive mechanism are respectively electrically connected to the controller, and a PID algorithm is provided in the controller, and the actions of the clamping drive mechanism and the clamping drive mechanism are controlled by the controller, thereby controlling the downward pressure of the positioning pressure rod and the clamping force of the flexible clamp.

2. The wafer backside contact positioning and clamping device according to claim 1, characterized in that: It also includes a linear module, a mounting plate and a flexible clamp fixing plate. The linear module is vertically arranged on both sides of the lower suction cup. The mounting plates are respectively fixedly connected to the sliders of the linear module. The clamping drive mechanism is arranged on the mounting plate. The clamping drive mechanism is a servo drive motor. The middle of the flexible clamp is fixedly connected to the output shaft of the servo drive motor. The linear module is electrically connected to the controller. The flexible clamp fixing plate is fixedly connected to the output shaft of the servo drive motor. The flexible clamp is fixedly connected to the flexible clamp fixing plate.

3. The wafer backside contact positioning and clamping device according to claim 2, characterized in that: It also includes a clamping force detection sensor, which is respectively arranged inside the servo drive motor, the clamping force detection sensor is connected to the push rod of the servo drive motor, the clamping force detection sensor is electrically connected to the controller, and the clamping force detection sensor is used to detect the clamping force of the flexible clamp.

4. The wafer backside contact positioning and clamping device according to claim 2, characterized in that: It also includes a laser displacement sensor, which is arranged inside the servo drive motor and is electrically connected to the controller. The laser displacement sensor is used to detect the position of the flexible clamping claw.

5. The wafer backside contact positioning and clamping device according to claim 1, characterized in that: The pressing drive mechanism is a cylinder, and the cylinder rod of the cylinder is fixedly connected to the upper end of the positioning pressure rod.

6. The wafer backside contact positioning and clamping device according to claim 1, characterized in that: The two side walls of the lower suction cup are concavely provided with a plurality of avoidance grooves corresponding to the limit blocks one by one, and the limit blocks can be embedded in the avoidance grooves.

7. The wafer backside contact positioning and clamping device according to claim 1, characterized in that: The flexible clamping claw is formed of shape memory alloy.

8. The wafer backside contact positioning and clamping device according to claim 2, characterized in that: It also includes a pressure wheel arm, a pressure wheel and a push rod. The pressure wheel arm can be raised and lowered and is arranged on the outside of the flexible clamp. The pressure wheel arm is rotatably connected to the flexible clamp fixing plate. The pressure wheel can be rotatably arranged at the lower end of the pressure wheel arm. The push rod can be slidably arranged on the mounting plate back and forth. The front end of the push rod abuts against the pressure wheel arm, and the pressure wheel can abut against the upper wafer.

9. The wafer backside contact positioning and clamping device according to claim 8, characterized in that: It also includes an L-shaped bracket, a lifting cylinder, a U-shaped connecting head and a pushing cylinder. The L-shaped bracket is arranged on the upper end wall of the flexible clamp fixing plate, the lifting cylinder is arranged on the upper end portion of the L-shaped bracket, and the pushing cylinder is arranged on the mounting plate. The U-shaped connecting head is fixedly connected to the cylinder rod of the lifting cylinder, the upper end portion of the pressure wheel arm is rotatably connected to the U-shaped connecting head through a short shaft, and the cylinder rod of the pushing cylinder is fixedly connected to the push rod.

10. A wafer bonding method according to any one of claims 1 to 9, wherein: The wafer bonding method comprises the following steps: The lower wafer to be bonded is placed into the bonding chamber with the front side facing upwards by the robot, and the flexible clamping claws are driven by the clamping drive mechanism to clamp the lower wafer on both sides. The clamping force detection sensor is used to make the clamping force of the flexible clamping claws on both sides consistent, so that it is aligned with the lower suction cup. Then, the linear module drives the flexible clamping claws to descend and place the lower wafer on the lower suction cup. Negative pressure is generated through the vacuum suction holes of the lower suction cup, thereby fixing the lower wafer on the lower suction cup. The upper wafer to be bonded is placed into the bonding chamber with its back side facing upwards by a robot arm, and the flexible clamping claws are driven by a clamping drive mechanism to clamp the upper wafer on both sides. The clamping force detection sensor is used to make the clamping force of the flexible clamping claws on both sides consistent, so that it is aligned with the lower wafer. The linear module then drives the flexible clamping claws down and suspends the upper wafer at a distance of 100um to 150um from the lower wafer. The positioning rod is pressed down by the pressing drive mechanism so that the positioning rod abuts against the center point of the upper wafer, thereby aligning the center point of the upper wafer with the center point of the lower wafer to ensure that the upper and lower wafers are not misaligned; The upper pressure plate is driven down to abut against the upper wafer, pressing the upper wafer against the lower wafer, thereby achieving bonding between the upper wafer and the lower wafer.

Images