A fully automatic wafer bonding machine based on magnetic alignment

Abstract

The present invention discloses a fully automatic wafer bonding machine based on magnetic alignment, which has a wafer loading module, a wafer buffer and pre-alignment module, and a wafer bonding module, and a dry manipulator for transmission is provided between each module. The upper and lower bonded wafers are transported by a dry manipulator, and the bonding is completed in each module through the processes of taking out, pre-alignment, bonding, buffering, and putting back, which is highly automated. The entire process is carried out in a closed outer cover to ensure a dust-free bonding environment and reduce the risk of wafer contamination. The present invention is provided with a magnetic sensor in the wafer bonding module, which can align the wafer at a distance of μm level and directly perform bonding accuracy detection after bonding. The Z-direction distance between the bonding module of the present invention and the wafer stage is 5 to 10 μm, which avoids the large stroke displacement of the bonding module and improves the accuracy and efficiency of wafer bonding.

Description

Technical Field

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

[0002] Integrated circuits are known as the cornerstone of the electronic information industry. At present, the integrated circuit industry is booming with the help of advanced packaging technology. Advanced packaging uses advanced semiconductor processes such as TSV and RDL, and bonding technologies such as C2W and W2W to perform 3D stacking of chips to improve the functional density of chips. Some well-known integrated circuit manufacturers are actively deploying 3D stacked chips and developing related technologies, such as TSMC's COWOS and Intel's EMIB. Wafer bonding can achieve high-density electrical interconnection between chips and is a key process in 3D packaging. High-precision and efficient wafer bonding can significantly improve the performance and reliability of semiconductor chips and meet the electronic information industry's demand for high-quality and large quantities of semiconductor chips.

[0003] Fully automatic wafer bonding based on magnetic alignment optimizes the wafer bonding process and integrates it into one device through design layout. From loading to unloading, alignment to bonding, and bonding to detection, all processes are coordinated by various mechanical structures and electrical devices without manual intervention. In traditional wafer bonding based on optical alignment, due to the position limitation of the CCD camera, the bonding stroke between the two wafers is large. The multiple large stroke displacements of the bonding device will cause inevitable errors between the position and alignment position of the wafer after bonding, which will have a great impact on the chip bonding accuracy. In addition, the wafer needs to be accurately detected by the detection device after bonding, which prolongs the wafer bonding process time and reduces efficiency. In wafer bonding based on magnetic alignment, the upper and lower wafers with chips are placed face to face and close to each other. Each wafer surface has symmetrically distributed magnetic columns. The two wafers are bonded by magnetic field recognition and alignment by magnetic sensors.

[0004] Patent CN112018002A applied by Tao Chao of Wuhan Xinxin Integrated Circuit Manufacturing Co., Ltd. discloses a wafer bonding device and a wafer bonding method. The device uses the light emitted by the mark reader to pass through the upper and lower layers of wafers, obtains the position of the metal mark on the wafer through the image sensor for alignment, and the bonding device with the wafer moves in the Z direction to complete the bonding. Affected by the focal length of the camera, there is a large distance between the two layers of wafers. The vibration caused by the large stroke displacement of the bonding device and the insufficient imaging accuracy caused by the limited penetration ability of the light source make it difficult to achieve high-precision bonding. Patent US10692747B2 applied by Thomas Wagenleitner et al. of EVGroup, Austria, proposes a wafer alignment device, which is provided with three optical detection units and two substrates to be bonded placed face to face. By repeatedly moving the substrates, the upper and lower optical detection units recognize the alignment marks of the two substrates and calculate the positions of the two substrates. The third detection unit performs detection to complete the alignment. The device uses two upper and lower optical detection units to achieve alignment. Compared with the single-lens alignment device, the volume is large. The repeated displacement of the substrate leads to a cumbersome alignment process, which is not conducive to achieving high-efficiency bonding. Summary of the invention

[0005] The present invention provides a fully automatic wafer bonding machine based on magnetic alignment, which can be used for high-precision and high-efficiency wafer bonding processes. The present invention has a wafer loading module, a wafer buffer and pre-alignment module, and a wafer bonding module, and a dry manipulator for transmission is provided between each module. The upper and lower bonded wafers are transported by a dry manipulator, and the bonding is completed in each module through the processes of taking out, pre-alignment, bonding, buffering, and putting back, which is highly automated. The entire process is carried out in a closed outer cover, ensuring a dust-free bonding environment and reducing the risk of wafer contamination. The present invention is provided with a magnetic sensor in the wafer bonding module, which can align the wafer at a distance of μm level and directly perform bonding accuracy detection after bonding. The Z-direction distance between the bonding module of the present invention and the wafer stage is 5 to 10 μm, which avoids the large stroke displacement of the bonding module and improves the accuracy and efficiency of wafer bonding.

[0006] The present invention adopts the following technical solution:

[0007] A fully automatic wafer bonding machine based on magnetic alignment, comprising: a wafer loading module, a wafer buffer and pre-alignment module, and a wafer bonding module;

[0008] The wafer loading module consists of a first wafer box, a second wafer box, a third wafer box, a wafer loading table, and a first dry robot. The wafer loading module is installed at the front end to complete wafer loading; the wafer loading table is vertically installed on the bottom frame of the full-automatic wafer bonding machine, and one side of the wafer loading table is clamped and installed with the first wafer box, the second wafer box and the third wafer box arranged in parallel. The openings of the first wafer box, the second wafer box and the third wafer box are aligned with the windows of the wafer loading table, and the first dry robot is installed on the bonding machine platform on the other side of the wafer loading table through the robot base.

[0009] The wafer cache and pre-alignment module consists of a wafer storage platform, a wafer pre-alignment platform, a second dry robot and a third dry robot. The wafer cache and pre-alignment module has the functions of wafer positioning before bonding and wafer storage after bonding; the wafer pre-alignment platform and the wafer storage platform are installed on the bonding machine platform on the side of the first dry robot, and are arranged symmetrically up and down; the second and third dry robots are installed and fixed on the sides of the wafer pre-alignment platform and the wafer storage platform, and are arranged symmetrically up and down; the wafer is taken out from the first wafer box, the second wafer box and the third wafer box by the first dry robot, and then moved to the wafer storage platform or the wafer pre-alignment platform, and then moved to the wafer bonding module by the second dry robot and the third dry robot.

[0010] The wafer bonding module consists of an XY motion mechanism, a micro-nano adjustment platform, a wafer bonding stage, a bonding mechanism, and a bonding moving mechanism. The wafer bonding module is used to achieve rough and fine alignment of two wafers and high-precision bonding;

[0011] The XY motion mechanism includes a linear motor group, an air bearing and a mobile platform; the linear motor group is fixed on the marble platform of the bonding machine platform and is the power device for XY motion; the mobile platform is mounted on the linear motor; the air bearing is placed on the boss between the mobile platform and the marble platform to achieve X-axis positioning of the mobile platform; the micro-nano adjustment platform is connected to the mobile platform of the XY motion mechanism, and a wafer bonding platform is fixed on the micro-nano adjustment platform, which can adjust the position of the wafer bonding platform at the micron level; the bonding mobile mechanism is fixed on the top fixed frame of the marble platform frame,

[0012] The bonding moving mechanism includes a servo motor, a lead screw, a guide rail and a Z-direction moving platform. The upper part of the lead screw is connected to the servo motor, and the lower part of the lead screw passes through the Z-direction moving platform. The Z-direction moving platform is positioned by four guide rails.

[0013] The bonding mechanism includes a bonding head, an elastic connection block and a magnetic sensor. The bonding head is connected to the Z-direction moving platform through the elastic connection block, and the servo motor drives the lead screw and the bonding head to move along the Z direction. The upper surface of the bonding head has a magnetic sensor mounting hole, and the lower surface has a vacuum suction port. The bonding head equipped with a magnetic sensor can detect the spatial magnetic field of the wafer with a magnetic column, and complete the alignment and bonding of the wafer through real-time detection.

[0014] The bonding method of the equipment is as follows: the transport mechanism (not shown in the figure) places the first wafer box containing upper and lower wafers, the second wafer box and the third wafer box without wafers at the designated position of the wafer loading platform. The first dry manipulator takes out the upper wafer from the first wafer box and puts it into the wafer pre-alignment platform. The wafer pre-alignment platform absorbs the wafer and drives the wafer to rotate, and the wafer mark reader on the platform positions the wafer. The second dry manipulator takes out the upper wafer from the wafer pre-alignment platform and puts it into the wafer holding table. The air flotation is turned on, and the XY motion mechanism transports the wafer bonding table with the wafer to the bottom of the wafer bonding module, and the wafer is sucked up by the wafer bonding mechanism. When the upper wafer is taken out from the wafer pre-alignment platform, the first dry manipulator takes out the lower wafer from the second wafer box, and after pre-alignment, the second dry manipulator puts it into the wafer bonding table. The XY moving mechanism is used for coarse alignment. The magnetic sensor in the bonding mechanism can detect the change of the spatial magnetic field in real time and obtain the position of the wafer magnetic column. The XY moving mechanism transports the wafer to a position close to the bonding position, and then uses the micro-nano adjustment platform to fine-tune the fine alignment. The bonding between the two wafers is completed through the bonding module to obtain a bonded wafer. After the bonding is completed, the bonding accuracy of the wafer is detected by the magnetic sensor and the position offset is fed back to the next bonding. The third dry robot takes out the bonded wafer from the wafer bonding table and puts it into the wafer storage table. After the first dry robot completes the transfer action of the second upper wafer, the first dry robot takes it out from the wafer storage platform and puts it into the third wafer box. When the third wafer box is full of bonded wafers, the transportation mechanism takes away all wafer boxes and places new wafer boxes.

[0015] The upper and lower surfaces of the wafer are processed into cylindrical grooves by semiconductor technology, and magnetic materials are deposited in the grooves to form symmetrically distributed magnetic columns, which have permanent magnetic properties after magnetization.

[0016] The upper and lower edges of the wafer are provided with notches for identifying the wafer rotation angle and positioning the wafer.

[0017] The first robot, the second robot and the third robot are three-degree-of-freedom robots. The execution domain of the three-degree-of-freedom robot includes each wafer box and a wafer table, and the robot base is equipped with a lifting module.

[0018] The wafer pre-alignment platform consists of a rotating table and a wafer mark reader. The rotating table is evenly distributed with vacuum holes, which can adsorb the wafer and drive it to rotate. The notches on the wafer can be identified by the wafer mark reader during rotation. The wafer mark reader calculates the rotation angle of the wafer and feeds it back to the rotating table to stop the wafer at a predetermined position.

[0019] The XY moving mechanism is located on the marble platform, and drives the wafer bonding platform to move along the X direction and the Y direction to perform rough alignment of wafer bonding.

[0020] Further, the XY moving mechanism comprises:

[0021] The X-axis moving mechanism is composed of an X-axis linear motor, an air bearing, a moving platform, and a slider, and can perform μm-level displacement in the X-axis.

[0022] The Y-axis moving mechanism is composed of a Y-axis linear motor, an air-floating platform, a Y-axis guide rail, and a slider, and can perform μm-level displacement in the Y-axis.

[0023] Furthermore, the bonding mechanism comprises:

[0024] The bonding head with evenly distributed air holes can pick up the upper and lower wafers on the wafer bonding table through vacuum extraction. The back of the bonding head is provided with a magnetic sensor mounting hole.

[0025] The elastic connecting block plays the role of elastic damping when the bonding head applies bonding force, achieving soft landing of the wafer.

[0026] The positive effects of the present invention are as follows:

[0027] The fully automatic bonding equipment based on magnetic alignment disclosed in the present invention has the characteristics of full automation and high integration. The equipment includes a wafer loading module, a wafer pre-alignment cache module and a wafer bonding module. The modules are closely connected and compact in structure, providing technical guarantee for an efficient and clean wafer bonding process. The present invention introduces a wafer bonding technology based on magnetic alignment, which uses a magnetic sensor to monitor the changes in the spatial magnetic field intensity of the two wafers during the alignment process in real time and detect the position offset after bonding, thereby improving the wafer alignment and bonding accuracy. At the same time, the wafer bonding stroke using magnetic alignment bonding is only 5 to 10 μm, which reduces the position error caused by large stroke displacement and achieves high-quality wafer bonding. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A top view of a fully automatic wafer bonding device based on magnetic alignment according to the present invention is shown.

[0029] Figure 2 A three-dimensional diagram of a fully automatic wafer bonding device based on magnetic alignment according to the present invention is shown.

[0030] Figure 3 Shows Figure 1 and Figure 2 The operation flow of the fully automatic wafer bonding equipment based on magnetic alignment is shown.

[0031] Figure 4 It is a structural stereogram of a bonding module of a fully automatic wafer bonding device based on magnetic alignment according to the present invention.

[0032] Figure 5 It is a structural front view of a bonding module of a fully automatic wafer bonding device based on magnetic alignment according to the present invention.

[0033] Figure 6 It is a schematic diagram of the dry robot and wafer structure of the present invention.

[0034] 1. Wafer loading module; 2. Wafer buffer and pre-alignment module; 3. Wafer bonding module; 4. First wafer box; 5. Second wafer box; 6. Third wafer box; 7. Wafer loading platform; 8. First dry manipulator; 9. Wafer storage platform; 10. Third dry manipulator; 11. XY motion mechanism; 12. Bonding movement mechanism; 13. Bonding mechanism; 14. Frame; 15. Second dry manipulator; 16. Wafer pre-alignment platform; 17. Wafer bonding platform; 18. Micro-nano adjustment platform;

[0035] 1110 air floating platform, 1120 X-axis linear motor, 1130 Y-axis guide rail, 1140 Y-axis linear motor, 1150 moving platform, 1160 air bearing, 1210 bearing guide rail, 1220 ball screw, 1230 servo motor, 1240 motor fixing bracket, 1310 Z-axis platform connecting block, 1320 elastic connecting block, 1330 magnetic sensor, 1340 bonding suction head DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described in conjunction with the accompanying drawings of the embodiment of the present invention. The examples cited are only used to explain the present invention and are not used to limit the scope of the present invention. The following is a detailed description of the fully automatic wafer bonding equipment based on magnetic alignment according to the embodiment of the present invention in conjunction with the accompanying drawings.

[0037] Figure 1 and Figure 2 The schematic top view and the stereoscopic view respectively show a wafer bonding device of an embodiment of the present disclosure. The wafer bonding device comprises a wafer loading module 1 for placing a wafer box, a wafer pre-alignment platform 16 for circumferentially positioning the upper and lower wafers, and a wafer storage platform 9 for placing the bonded wafers after the bonding module completes the wafer bonding.

[0038] Figure 3Arrows are used to illustrate the bonding process of the wafer bonding equipment, including:

[0039] 1) The transport unit (not shown in the figure) places the first wafer box 4 , the second wafer box 5 and the third empty wafer box 6 containing the upper and lower wafers on the corresponding positions of the wafer loading platform 7 .

[0040] 2) The dry robot 8 in the wafer loading module adjusts its height through the bottom lifting mechanism to absorb and take out the upper wafer in the first wafer box 4.

[0041] 3) The dry robot 8 transports the upper wafer to the wafer pre-alignment platform 16 .

[0042] 4) The wafer pre-alignment platform 16 searches for the wafer notch to achieve initial positioning. The wafer pre-alignment platform has two parts: a rotating platform and a wafer mark reader. The wafer mark reader can use infrared rays to identify the notch of the rotating wafer. The rotating platform absorbs the wafer and rotates. When the wafer mark reader identifies the notch, the rotating platform stops rotating and positioning is completed.

[0043] 5) The dry robot 15 picks up the upper wafer from the wafer alignment platform 16 and transports it to the wafer bonding platform 17. The air floating platform 1110 is connected to the air bearing 1160, and the XY moving mechanism transports the wafer bonding platform 17 to the bottom of the bonding mechanism 13. The magnetic sensor 1330 on the back of the bonding head 1340 detects the spatial magnetic field distribution of the upper wafer alignment magnetic column, obtains and records the position of the upper wafer, and the bonding head 1340 sucks up the upper wafer.

[0044] In this embodiment, the height of the wafer alignment platform is consistent with that of the wafer bonding platform, and the dry robot 15 does not need to adjust the height between the two platforms, thereby achieving efficient wafer handling.

[0045] 6) The dry robot 8 takes the lower wafer out of the wafer box 5 .

[0046] In this embodiment, considering the movement time and processing efficiency comprehensively, the most efficient technical route is to simultaneously perform the upper wafer taking-out action 4) of the dry robot 15 and the lower wafer taking-out action 6) of the dry robot 8 .

[0047] 7) The robot arm 8 transports the lower wafer to the wafer pre-alignment platform 16 .

[0048] 8) The wafer pre-alignment platform 16 completes the initial positioning of the lower wafer.

[0049] 9) The dry robot 15 takes out the lower wafer from the wafer pre-alignment platform 16 and transports it to the wafer bonding platform 17. The XY moving mechanism moves the wafer bonding platform with the lower wafer to the bottom of the bonding head for rough alignment. The magnetic sensor 1330 on the back of the bonding head detects the spatial superposition magnetic field of the upper and lower magnetic columns to obtain the alignment position of the two wafers, and then uses the micro-nano adjustment platform 18 to achieve fine alignment. The bonding head moves in the Z direction to complete the bonding.

[0050] In this embodiment, the magnetic sensor performs bonding accuracy detection after bonding is completed, and feeds back the detected position error to the next bonding to improve the bonding accuracy.

[0051] 10) The dry robot arm 10 takes out the bonded wafer from the wafer bonding stage 17 .

[0052] 11) The dry robot 10 transports the bonded wafer to the wafer storage platform 9.

[0053] 12) The dry robot arm 8 takes out the bonded wafer from the wafer storage table 17 .

[0054] 13) The dry robot 8 places the bonded wafer into the wafer box 6.

[0055] See also Figure 4 and Figure 5 , which is a schematic diagram of the alignment and bonding of the wafer bonding module of the present invention. The XY moving mechanism 11 is arranged on a marble base, and is mainly composed of a high-precision linear motor, an air bearing and a guide rail. The XY superposition method is used to realize the movement of the wafer bonding platform in the XY coordinate system to perform rough alignment of the wafer bonding. The mobile platform along the Y direction is sleeved with an air floating platform 1110, and air bearings 1160 are installed on both sides of the mobile platform. When the air source is connected, low-damping movement in the X and Y directions can be realized to suppress displacement vibration. The micro-nano adjustment platform 18 is fixed on the air floating platform 1110, on which the wafer bonding platform 17 is carried. The micro-nano regulator 18 can be used to perform nanometer-level position adjustment on the wafer bonding platform.

[0056] The wafer bonding module includes a bonding moving mechanism 12 and a bonding mechanism 13. The motor and the lead screw are fixed on the motor fixing frame 1240 at the top of the marble frame. The lead screw 1220 is connected to the coupling and the servo motor above, and a Z-direction moving platform is installed below. The Z-direction moving platform is equipped with a bearing guide rail 1210; the bonding mechanism is composed of a bonding head 1340 and an elastic connecting block 1320. The bonding head is fixed to the Z-direction moving platform through an elastic connecting block. The elastic connecting block 1320 can apply a flexible bonding force to prevent the wafer from being crushed. The bonding head has an air path structure inside, and a 3x3 rectangular array magnetic sensor is installed on the back. Compared with traditional optical cameras, magnetic sensors are small in size and can effectively detect spatial magnetic field changes within 10μm. Based on the characteristics of magnetic sensors, the Z-direction distance between the wafer bonding stage and the bonding head in this embodiment is 5 to 10μm, shortening the bonding stroke.

[0057] Figure 6 The figure shows a dry robot arm with an upper (lower) wafer 19 adsorbed thereon. The surface of the wafer is processed into grooves and notches through semiconductor technology. Magnetic material is deposited in the grooves to form magnetic columns 1910. The number of magnetic columns 1910 can be multiple and symmetrically distributed. In this embodiment, two symmetrical magnetic columns are used to achieve alignment. The magnetic columns have permanent magnetic properties after being charged with magnetic tape. The notches 1920 on the edge of the wafer are used to position the wafer.

[0058] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A fully automatic wafer bonding machine based on magnetic alignment, Features: It includes wafer loading module, wafer buffer and pre-alignment module, and wafer bonding module; The wafer loading module is composed of a first wafer box, a second wafer box, a third wafer box, a wafer loading platform, and a first dry robot. The wafer loading module is installed at the front end to complete wafer loading; The wafer loading platform is vertically mounted on the bottom frame of the fully automatic wafer bonding machine, and the first wafer box, the second wafer box and the third wafer box arranged in parallel are clamped and mounted on one side of the wafer loading platform, and the openings of the first wafer box, the second wafer box and the third wafer box are aligned with the window of the wafer loading platform, and the first dry robot is mounted on the bonding machine platform on the other side of the wafer loading platform through the robot base; The wafer cache and pre-alignment module consists of a wafer storage platform, a wafer pre-alignment platform, a second dry robot, and a third dry robot. The wafer cache and pre-alignment module has the functions of wafer positioning before bonding and wafer storage after bonding; the wafer pre-alignment platform and the wafer storage platform are installed on the bonding machine platform on the side of the first dry robot, and are arranged symmetrically up and down; The second and third dry manipulators are installed and fixed on the sides of the wafer pre-alignment platform and the wafer storage platform, and are arranged symmetrically up and down; the wafer is taken out from the first wafer box, the second wafer box, and the third wafer box by the first dry manipulator, and then moved to the wafer storage platform or the wafer pre-alignment platform, and then moved to the wafer bonding module by the second dry manipulator and the third dry manipulator; The wafer bonding module consists of an XY motion mechanism, a micro-nano adjustment platform, a wafer bonding stage, a bonding mechanism, and a bonding moving mechanism. The wafer bonding module is used to achieve rough and fine alignment of two wafers and high-precision bonding; The XY motion mechanism includes a linear motor group, an air bearing and a mobile platform; the linear motor group is fixed on the marble platform of the bonding machine platform and is the power device for XY motion; the mobile platform is mounted on the linear motor; the air bearing is placed on the boss between the mobile platform and the marble platform to achieve X-axis positioning of the mobile platform; the micro-nano adjustment platform is connected to the mobile platform of the XY motion mechanism, and a wafer bonding platform is fixed on the micro-nano adjustment platform, which can adjust the position of the wafer bonding platform at the micron level; the bonding mobile mechanism is fixed on the top fixed frame of the marble platform frame, The bonding moving mechanism includes a servo motor, a lead screw, a guide rail and a Z-direction moving platform. The upper part of the lead screw is connected to the servo motor, and the lower part of the lead screw passes through the Z-direction moving platform. The Z-direction moving platform is positioned by four guide rails. The bonding mechanism includes a bonding head, an elastic connection block and a magnetic sensor. The bonding head is connected to the Z-direction moving platform through the elastic connection block, and the lead screw and the bonding head are driven by a servo motor to move along the Z direction. The upper surface of the bonding head has a magnetic sensor mounting hole, and the lower surface has a vacuum suction port. The bonding head equipped with a magnetic sensor can detect the spatial magnetic field of the wafer with a magnetic column, and complete the alignment and bonding of the wafer through real-time detection. The first wafer box containing upper and lower wafers, the second wafer box and the third wafer box without wafers are placed at the designated positions on the wafer loading platform; the first dry robot takes out the upper wafer from the first wafer box and puts it into the wafer pre-alignment platform; the wafer pre-alignment platform absorbs the wafer and drives the wafer to rotate, and the wafer mark reader on the platform positions the wafer; the second dry robot takes out the upper wafer from the wafer pre-alignment platform and puts it into the wafer holding table; the air flotation is turned on, and the XY motion mechanism transports the wafer bonding table with the wafer to the bottom of the wafer bonding module, and the wafer is sucked up by the wafer bonding mechanism; when the upper wafer is taken out from the wafer pre-alignment platform, the first dry robot takes out the lower wafer from the second wafer box, and after pre-alignment The second dry robot puts the wafer into the wafer bonding table; the XY moving mechanism is used for coarse alignment, and the magnetic sensor in the bonding mechanism detects the spatial magnetic field changes in real time to obtain the position of the wafer magnetic column. The XY moving mechanism transports the wafer to a position close to the bonding position, and then uses the micro-nano adjustment platform to fine-tune and complete the fine alignment. The bonding between the two wafers is completed through the bonding module to obtain a bonded wafer; after the bonding is completed, the magnetic sensor is used to detect the bonding accuracy of the wafer and the position offset is fed back to the next bonding; the third dry robot takes out the bonded wafer from the wafer bonding table and puts it into the wafer storage table. After the first dry robot completes the transmission action of the second upper wafer, the first dry robot takes it out from the wafer storage platform and puts it into the third wafer box; When the third wafer box is full of bonded wafers, the transport mechanism takes away all the wafer boxes and places new wafer boxes.

2. A fully automatic wafer bonding machine based on magnetic alignment according to claim 1, Features: Grooves are machined on the upper and lower surfaces of the wafer by semiconductor technology, and magnetic materials are deposited in the grooves to form symmetrically distributed magnetic columns, which have permanent magnetic properties after magnetization.

3. The fully automatic wafer bonding machine based on magnetic alignment according to claim 1, Features: The upper and lower edges of the wafer are provided with notches for identifying the wafer rotation angle and positioning the wafer.

4. The fully automatic wafer bonding machine based on magnetic alignment according to claim 1, Features: The first robot, the second robot and the third robot are three-degree-of-freedom robots. The execution domain of the three-degree-of-freedom robot includes each wafer box and a wafer table, and the robot base is equipped with a lifting module.

5. The fully automatic wafer bonding machine based on magnetic alignment according to claim 1, Features: The wafer pre-alignment platform consists of a rotating table and a wafer mark reader. The rotating table is evenly distributed with vacuum holes, which adsorb the wafer and drive it to rotate. The notches on the wafer can be identified by the wafer mark reader during rotation. The wafer mark reader calculates the rotation angle of the wafer and feeds it back to the rotating table to stop the wafer at a predetermined position.

6. The fully automatic wafer bonding machine based on magnetic alignment according to claim 1, Features: The XY moving mechanism is located on the marble platform, and drives the wafer bonding platform to move along the X direction and the Y direction to perform rough alignment of wafer bonding.

7. The fully automatic wafer bonding machine based on magnetic alignment according to claim 1, Features: The bonding mechanism comprises: The bonding head with evenly distributed air holes picks up the upper and lower wafers on the wafer bonding table through vacuum extraction, and the back of the bonding head is provided with a magnetic sensor mounting hole; The elastic connecting block plays the role of elastic damping when the bonding head applies bonding force, achieving soft landing of the wafer.

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