Wafer bonding magnetic array alignment method

Abstract

The invention discloses a wafer bonding magnetic array alignment method, which is characterized in that a plurality of groups of magnetic array marks with geometrical shapes and symmetrical distribution characteristics are manufactured on a wafer in an MEMS (Micro Electro Mechanical System) mode, the plurality of groups of magnetic array marks are symmetrically distributed, a plurality of magnetic marks exist in each group of magnetic array, and the magnetic marks are distributed at equal intervals. A plurality of groups of magnetic sensing arrays with symmetrical distribution characteristics are pre-embedded in a clamping and bearing mechanism by adopting an MEMS (Micro Electro Mechanical System) mode, a plurality of magnetic sensors are arranged in each group of magnetic sensing arrays, and the magnetic sensors in each magnetic sensing array are distributed at equal intervals. And each magnetic sensor array collects magnetic field distribution information generated by the corresponding magnetic mark in real time, obtains spatial position information of each magnetic mark, and obtains spatial attitude information of the wafer through symmetrical distribution characteristics of the magnetic arrays and the magnetic sensor arrays. According to the invention, the information density of magnetic field distribution is improved, the processing capability of magnetic information is enhanced, and the efficiency and precision of wafer alignment and bonding are improved.

Description

Technical Field

[0001] The invention relates to the field of semiconductor packaging, and in particular to a wafer bonding alignment method, and in particular to a wafer bonding magnetic array alignment method. Background Art

[0002] Semiconductor devices are an important part of the modern electronics industry, and semiconductor packaging technology plays a very important role in the semiconductor industry with important features such as improving semiconductor device performance, increasing reliability, and providing device protection. With the emergence of new applications such as 5G and wearable devices and new demands such as miniaturization of electronic devices, semiconductor packaging technology is also growing rapidly and gradually maturing. Among them, wafer-level advanced packaging is a crucial research and application direction to achieve beyond Moore's Law. The wafer-level bonding equipment integrates a variety of functional units and realizes the complete process of wafer activation, cleaning, alignment, pre-bonding and verification inside the equipment. Due to its important strategic value, many well-known companies, universities and research institutes at home and abroad have conducted research on wafer-level packaging.

[0003] Wafer-level bonding refers to the high-precision alignment and bonding of two wafers, and the process of producing a certain interface bonding strength between the two wafers. The bonding process is generally: pre-processing, cleaning, visual alignment, and specific process methods of the wafer group to achieve the bonding of pairs of wafers. In this process, achieving wafer-level alignment accuracy is an extremely difficult challenge. The general wafer alignment system needs to identify and locate the image of the wafer, evaluate the alignment error through the positioning error between the optical marks preset on the wafer, and cooperate with the motion control system to eliminate the alignment error. It can be seen that the wafer alignment system is complex and sophisticated, and generally involves mechanical design, camera system, motion control, image algorithm and other fields. Among them, the cost of advanced image processing units and the difficulty of their integration in wafer bonding equipment are getting higher and higher, resulting in limited processing of optical images, thereby limiting the further improvement of wafer-level alignment accuracy.

[0004] Among the existing wafer alignment methods, Chinese patent CN201811103353.9 applied by Liu Yang of Wuhan Xinxin Integrated Circuit Manufacturing Co., Ltd. discloses a wafer key and method and device. A dual-chuck and dual-camera structure is adopted, and the wafer pair is placed on two chucks respectively. The opposing dual-camera system is used to respectively identify the marking pattern on the back of the chuck device carrying the wafer, and obtain the position error between the two chucks. By analyzing and recording the preset position of the wafer on the chuck, the wafer pair is indirectly aligned by aligning the two chucks. This method is an indirect alignment method, the accuracy is difficult to guarantee, and the structure is complex and difficult to implement. Chinese patent CN201410148217.7 applied by Chen Xing and others of Ruili Scientific Instruments (Shanghai) Co., Ltd. discloses a wafer alignment system and a wafer alignment method. The system requires at least four cameras to cover the image features of the two relative corners and the remaining edges of the wafer that define the positioning notch. A sufficiently large field of view is obtained by enough cameras to cover the transmission error of the wafer. This invention does not require alignment marks on the wafer, but requires a multi-channel image acquisition card to couple the images of multiple cameras. Its optical structure, image algorithm and mechanical structure are complex, and the difficult and cumbersome system will lead to reduced accuracy. Chinese patent CN202210174134.X applied for by Ye Lezhi and others from Beijing University of Technology discloses a wafer bonding alignment method and device. The device detects the spatial magnetic field distribution generated by the preset permanent magnetic poles on the wafer by inserting a magnetic sensor between two wafers, and finds the boundary or center of the magnetic pole, thereby realizing the detection of wafer position information. The device reduces the Z-direction travel of wafer bonding to a certain extent, but only detects the magnetic field generated by the isolated magnetic pole through a single magnetic sensor, and the accuracy is low. Summary of the invention

[0005] The invention provides a wafer bonding magnetic array alignment method. The method uses a MEMS method to make several groups of magnetic array marks with geometric shapes and symmetrical distribution characteristics on a wafer, and the several groups of magnetic array marks are symmetrically distributed. There are several magnetic marks in each group of magnetic arrays, and each magnetic mark is equidistantly distributed. By using a MEMS method to pre-embed multiple groups of magnetic sensor arrays with symmetrical distribution characteristics in a clamping and carrying mechanism, there are several magnetic sensors in each group of magnetic sensor arrays, and the magnetic sensors in each magnetic sensor array are equidistantly distributed. The number of magnetic array marks is greater than or equal to the number of magnetic sensor arrays, the number of magnetic marks is less than or equal to the number of magnetic sensors, and each magnetic mark is covered under the corresponding magnetic sensor array. Each magnetic mark runs through the wafer or is made on one side of the wafer, and the exposed surface of the magnetic mark faces the clamping mechanism or the carrying mechanism. Each magnetic sensor is made on the surface of the clamping mechanism or the carrying mechanism, exposed on the mechanism surface and facing the wafer. Each magnetic sensor array collects the magnetic field distribution information generated by the corresponding magnetic mark in real time, obtains the spatial position information of each magnetic mark, and obtains the spatial posture information of the wafer through the symmetrical distribution characteristics of the magnetic array and the magnetic sensor array. When two or more wafers are stacked, a spatial vector error between the two or more wafers is obtained. This spatial error is eliminated through the motion system and alignment is completed. After alignment, the two wafers are bonded.

[0006] In order to achieve the above object, the wafer bonding magnetic array alignment method provided by the present invention comprises the following steps:

[0007] A) The carrying mechanism and the holding mechanism are brought close to each other in the vertical direction in an unloaded state, or the carrying mechanism and the clamping mechanism, or the carrying mechanism and the calibration sheet, or the holding mechanism and the calibration sheet, to perform self-calibration of the mechanism and draw the magnetic field environment.

[0008] B) Further, the carrying mechanism delivers the first wafer to the first preset position, and the carrying mechanism and the clamping mechanism are respectively placed on both sides of the first wafer. The plurality of magnetic sensor arrays at the first preset position correspond to the plurality of magnetic array marks of the first wafer, and any magnetic array mark cannot be completely placed outside the coverage range of the magnetic sensor array. Then the clamping mechanism holds the first wafer to the second preset position.

[0009] C) Further, the magnetic sensor array obtains the magnetic field distribution information generated by the first wafer magnetic array mark column at the second preset position, obtains the first wafer relative position information, and then obtains the first wafer absolute position information.

[0010] D) Further, the carrying mechanism delivers the second wafer to the first preset position, the carrying mechanism is placed under the second wafer, and the first wafer is held at the second preset position by the clamping mechanism and placed on the second wafer. A plurality of magnetic sensor arrays at the first preset position correspond to a plurality of magnetic array marks of the second wafer, and any magnetic array mark cannot be completely placed outside the coverage range of the magnetic sensor array.

[0011] E) Furthermore, the magnetic sensor array simultaneously obtains the magnetic field distribution information generated by the first wafer magnetic array mark and the second wafer magnetic array mark, obtains the second wafer relative position information, and then obtains the second wafer absolute position information.

[0012] F) Further, according to the absolute position information of the first wafer and the second wafer, the spatial vector error information of the first wafer and the second wafer is obtained. The clamping mechanism drives the first wafer to perform fine adjustment and alignment.

[0013] G) Further, the position of the clamping mechanism after fine adjustment is set as a third preset position. The operation of step E is repeated until the space vector error between the first wafer and the second wafer is less than a preset tolerance limit.

[0014] H) Further, the first wafer is held by the clamping mechanism and is vertically moved close to the second wafer to complete the bonding process.

[0015] Preferably, when obtaining the absolute position information of the first wafer and the second wafer, the warping condition of the wafer is obtained to check whether it exceeds a preset tolerance limit.

[0016] Preferably, the first preset position and the second preset position can be corrected by a correction sheet.

[0017] Preferably, at the preset position, each magnetic mark in the magnetic array mark is under the coverage of the corresponding magnetic sensor array.

[0018] Preferably, in step F, the first wafer is parallel to the second wafer, and the distance between the first wafer and the second wafer is less than the thickness of one wafer.

[0019] Compared with the traditional optical alignment method, the Z-axis travel of the present invention is extremely micro, the system rigidity is large, and the system itself can always perform self-correction, eliminating the error caused by the system itself without external correction. Compared with the disclosed magnetic alignment method, the present invention uses magnetic array markers and magnetic sensor arrays, which greatly improves the information density of the magnetic field distribution and greatly enhances the processing ability of magnetic information. Improves the efficiency and accuracy of wafer alignment and bonding. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1It is a schematic diagram of a magnetic array mark made on a first wafer by MEMS and the distribution of the magnetic marks therein in an embodiment of the present invention.

[0021] Figure 2 It is a schematic diagram of the magnetic array marks and the distribution of the magnetic marks therein made on the second wafer by MEMS in an embodiment of the present invention.

[0022] Figure 3 It is a schematic diagram of a magnetic sensor array made by a holding mechanism of the present invention through MEMS and the distribution of magnetic sensors therein.

[0023] Figure 4 The present invention is a schematic diagram of a magnetic sensor array made by a carrier mechanism through MEMS and the distribution of magnetic sensors therein.

[0024] Figure 5 The present invention is a flowchart of a wafer bonding magnetic array alignment algorithm according to an embodiment of the present invention.

[0025] Figure 6 The present invention discloses a process for aligning a wafer bonding magnetic array according to an embodiment of the present invention.

[0026] Figure 7 The present invention is a schematic diagram of the implementation process of a wafer bonding magnetic array alignment method according to an embodiment of the present invention.

[0027] Figure 8 It is the spatial magnetic field distribution generated by some magnetic marks in a group of magnetic array marks detected by a group of magnetic sensor arrays according to an embodiment of the present invention.

[0028] In the figure: 10-first wafer; 101-first wafer magnetic array mark; 102-first wafer magnetic mark; 20-second wafer; -201-second wafer magnetic array mark; 202-second wafer magnetic mark; 30-holding mechanism; 301-holding mechanism vacuum suction hole; 302-holding mechanism magnetic sensor array; 303-holding mechanism magnetic sensor; 40-carrying mechanism; 401-carrying mechanism vacuum suction hole; 402-carrying mechanism magnetic sensor array; 403-carrying mechanism magnetic sensor; 50-planner. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings of the embodiments. The advantages and features of the present invention will become clearer according to the following description. It should be noted that the drawings are all in a very simplified form and use an inaccurate scale, which is only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0030] Figure 1It is a schematic diagram of the first wafer of the embodiment of the present invention and the magnetic array mark made by MEMS on the wafer and the distribution of the magnetic marks therein. For example, a plurality of magnetic array marks 101 are distributed on the first wafer 10, and the magnetic array mark 101 is composed of a plurality of magnetic marks 102 prepared by MEMS, each magnetic mark 102 is half buried in the surface of the wafer, the top of the magnetic mark 102 is level with the surface of the wafer, and the bottom is buried inside the wafer. The edge of each magnetic mark 102 at the edge position of each magnetic array mark 101 constitutes the edge of each magnetic array mark 101. Several of the magnetic array marks 101 are periodically distributed in a symmetrical or equidistant manner. Several of the magnetic marks 102 are periodically distributed in a symmetrical or equidistant manner. In this example, 16 of the magnetic array marks 101 form a magnetic array, the edge shape of the magnetic array is square, and the range covered by the magnetic array is smaller than the inscribed rectangle of the wafer.

[0031] Figure 2 FIG. 1 is a schematic diagram of a second wafer and a magnetic array mark made on the wafer by MEMS and the distribution of the magnetic marks therein according to an embodiment of the present invention. Figure 1 and Figure 2 As shown, the second wafer 20 has a structure similar to that of the first wafer 10. The magnetic array mark 201 of the second wafer 20 is set correspondingly to the magnetic array mark 101 of the first wafer 10. The magnetic mark 202 in the magnetic array mark 201 of the second wafer 20 is set correspondingly to the magnetic mark 102 in the magnetic array mark 101 of the first wafer 10. Correspondingly, the magnetic arrays of the second wafer 20 and the first wafer 10 have the same coverage.

[0032] Figure 3The present invention is a schematic diagram of the clamping mechanism and the magnetic sensor array made by MEMS on the clamping mechanism and the distribution of magnetic sensors therein. Exemplarily, the clamping mechanism 30 can move in the Z direction, and the vacuum suction holes 301 are evenly distributed on the clamping mechanism 30. A plurality of magnetic sensor arrays 302 are distributed on the clamping mechanism, and the magnetic sensor array 302 is composed of a plurality of magnetic markers 303 prepared by MEMS. Each magnetic sensor 303 is half buried on the surface of the clamping mechanism 30, and the top of the magnetic sensor 303 is level with the surface of the clamping mechanism 30, and the bottom is buried inside the clamping mechanism. Each magnetic sensor array 302 of the clamping mechanism 30 is arranged corresponding to each magnetic array mark 101 on the first wafer 10 and each magnetic array mark 201 on the second wafer 20. The edge of each magnetic sensor 303 at the edge position of each magnetic sensor array 302 constitutes the edge of each magnetic sensor array 302. The edge coverage of each magnetic sensor array 302 is greater than the edge coverage of each corresponding magnetic array mark 101 or magnetic array mark 201 , and the number of magnetic sensors 303 in each magnetic sensor array 302 is greater than the number of magnetic marks 102 or magnetic marks 202 in each corresponding magnetic array mark 101 or magnetic array mark 201 .

[0033] Figure 4 The carrier mechanism of the embodiment of the present invention is shown in FIG. 40. For example, the carrier mechanism 40 can perform XY-rotational motion, and a plurality of vacuum suction holes 401 are evenly distributed on the carrier mechanism 40. In some examples, there are magnetic array marks 402 and magnetic marks 403 on the carrier mechanism 40 corresponding to those on the clamping mechanism 30.

[0034] The alignment method should provide a carrying mechanism, a holding device, a first wafer, a second wafer and a planner.

[0035] Figure 5 and Figure 6 It is disclosed that the alignment method comprises the following steps:

[0036] A) The carrying mechanism and the holding mechanism are brought close to each other in the vertical direction in an unloaded state, or the carrying mechanism and the clamping mechanism, or the carrying mechanism and the calibration sheet, or the holding mechanism and the calibration sheet, to perform self-calibration of the mechanism and draw the magnetic field environment.

[0037] Specifically, the calibration plate can be replaced by either the first wafer or the second wafer, or a product with a similar structure to the first wafer or the second wafer can be prepared. If there is no first wafer or second wafer, and no calibration plate, a magnetic sensor array needs to be placed in the supporting mechanism. The magnetic sensor arrays in the supporting mechanism and the supporting mechanism sense and verify each other, measure the deviation between the distribution position and the manufacturing position of the magnetic sensors in each other's magnetic sensor arrays in the mechanism, and measure the relative spatial positions of each other, and compensate and correct them in the planning. The compensation and correction data include the impact of the environment. This step is necessary when there are environmental changes, especially changes in the electromagnetic environment.

[0038] B) Further, the carrying mechanism delivers the first wafer to the first preset position, and the carrying mechanism and the clamping mechanism are respectively placed on both sides of the first wafer. The plurality of magnetic sensor arrays at the first preset position correspond to the plurality of magnetic array marks of the first wafer, and any magnetic array mark cannot be completely placed outside the coverage range of the magnetic sensor array. Then the clamping mechanism holds the first wafer to the second preset position.

[0039] Specifically, the first wafer is parallel to the carrying mechanism. The first preset position is located at the position of the carrying mechanism after the carrying mechanism and the holding mechanism are close to each other in the vertical direction and the deviation is corrected in step A. The vacuum suction holes evenly distributed on the surface of the carrying mechanism ensure that the relative position between the two does not change when the carrying mechanism carries the first wafer. After the carrying mechanism carries the first wafer to the first preset position, the holding mechanism moves along the Z axis to the position of the first wafer. After contact, it is determined based on the contact pressure that the vacuum suction holes of the carrying mechanism are closed, and the vacuum suction holes of the holding mechanism are opened, and the holding mechanism holds the first wafer to the second preset position. The second preset position is located at the position of the holding mechanism after the carrying mechanism and the holding mechanism are close to each other in the vertical direction and the deviation is corrected in step A.

[0040] C) Further, the magnetic sensor array obtains the magnetic field distribution information generated by the first wafer magnetic array mark column at the second preset position, obtains the first wafer relative position information, and then obtains the first wafer absolute position information. The magnetic field distribution information and the relative position information of the first wafer obtained at this time will be stored in the planner.

[0041] D) Further, the carrying mechanism delivers the second wafer to the first preset position, the carrying mechanism is placed under the second wafer, and the first wafer is held at the second preset position by the clamping mechanism and placed on the second wafer. A plurality of magnetic sensor arrays at the first preset position correspond to a plurality of magnetic array marks of the second wafer, and any magnetic array mark cannot be completely placed outside the coverage range of the magnetic sensor array. If any magnetic array mark is completely placed outside the coverage range of the magnetic sensor array, the carrying mechanism should be rotated to place each magnetic array mark partially outside the coverage range of the corresponding magnetic sensor array. If the rotation still cannot achieve this effect, step A should be re-executed.

[0042] E) Furthermore, the magnetic sensor array simultaneously obtains the magnetic field distribution information generated by the first wafer magnetic array mark and the second wafer magnetic array mark, obtains the second wafer relative position information, and then obtains the second wafer absolute position information.

[0043] Specifically, according to the information of the first preset position and the second preset position, the first wafer and the second wafer are positioned between the carrying mechanism and the holding mechanism. The position of each magnetic mark on the first wafer and the second wafer can be determined. And this information can be processed more accurately in the planner.

[0044] F) Further, according to the absolute position information of the first wafer and the second wafer, the spatial vector error information of the first wafer and the second wafer is obtained. The clamping mechanism drives the first wafer to perform fine adjustment and alignment.

[0045] Specifically, after obtaining the spatial vector error information between the first wafer and the second wafer, the carrier mechanism can be adjusted in the XY-rotation direction so that the magnetic mark on the first wafer is aligned with the magnetic mark on the second wafer. During the fine-tuning process, the vacuum nozzle of the carrier mechanism ensures that the relative position between the carrier mechanism and the second wafer does not shift.

[0046] G) Further, the position of the clamping mechanism after fine adjustment is set as a third preset position. Repeat the operation of step E until the space vector error between the first wafer and the second wafer is less than a preset tolerance limit. The determination of the third preset position requires multiple rapid fine adjustments.

[0047] H) Further, the first wafer is held by the clamping mechanism and is vertically moved close to the second wafer to complete the bonding process.

[0048] Below, combined with the attached Figure 1 , 2, 3, 4, and 7 describe specific examples of the present invention. In the first step, the first wafer 10 is placed on the carrier mechanism 40, and the vacuum suction hole 401 is opened. The holding mechanism 30 moves downward along the Z axis and stops before contacting the first wafer 10. The first wafer 10 is regarded as a calibration plate, and the alignment system is self-calibrated. In the second step, the current position of the carrier mechanism 401 is regarded as the first preset position, and the current position of the holding mechanism 30 is regarded as the second preset position. At this time, each magnetic array mark 101 of the first wafer 10 is placed under the corresponding magnetic sensor array 402 of the carrier mechanism 40. The holding mechanism 30 continues to move downward along the Z axis until it contacts the first wafer 10, the vacuum suction hole 401 is closed, the vacuum pore 301 is opened, the first wafer 10 is sucked up, and returned to the second preset position. At this time, each magnetic array mark 101 of the first wafer 10 is placed under the corresponding magnetic sensor array 302 of the holding mechanism 30. The magnetic sensor array 302 collects the magnetic information of the magnetic marker 102 collected by each magnetic sensor 303 and sends it to the planner 50. The magnetic sensor array 402 collects the magnetic information of the magnetic marker 102 collected by each magnetic sensor 403 and sends it to the planner 50. The planner 50 solves and saves the first wafer position information, saves the first preset position and the second preset position information, and saves the current magnetic field information. In the third step, the carrier mechanism 40 withdraws from the first preset position, places the second wafer 20 on the carrier mechanism 40, and opens the vacuum suction hole 401. The carrier mechanism 40 carries the second wafer 20 to the first preset position. At this time, each magnetic array mark 201 of the second wafer 20 is placed under the corresponding magnetic sensor array 402 of the carrier mechanism 40. The carrier mechanism 40 and the holding mechanism 20 sandwich the first wafer 10 and the second wafer 20. At this time, the top of each magnetic marker 102 in the first wafer 10 faces the top of each magnetic marker 202 in the second wafer 20. The magnetic sensor array 302 collects the magnetic information of the magnetic marker 202 collected by each magnetic sensor 303 and sends it to the planner 50. The magnetic sensor array 402 collects the magnetic information of the magnetic marker 202 collected by each magnetic sensor 403 and sends it to the planner 50. Step 3: The planner 50 solves the position information of the second wafer 20 based on the stored information, calculates the spatial vector error between the first wafer 10 and the second wafer 20, and the carrier mechanism 40 makes fine adjustments in the XY-rotation direction based on the error, and then judges in the planner whether the error between each magnetic marker 102 in the first wafer 10 and the second wafer 20 and the corresponding magnetic marker 202 is less than the tolerance limit. Step 4: If the alignment accuracy requirement is met, subsequent operations such as bonding are performed. If the alignment accuracy requirement is not met, the fine-tuning and judgment operations of the third step are repeated until the alignment accuracy requirement is met.

[0049] The present invention proposes a wafer bonding magnetic array alignment method, which uses MEMS technology to prepare magnetic array marks and magnetic marks on the surface of the wafer, and uses MEMS technology to prepare magnetic sensor arrays and sensors in the detection mechanism to achieve detection of wafer position information and alignment between wafers. Compared with the traditional optical alignment method, the present invention has an extremely micro-distance Z-axis stroke, high system rigidity, and the system itself can perform self-correction at all times, eliminating the errors caused by the system itself without external correction. Compared with the disclosed magnetic alignment method, the present invention uses magnetic array marks and magnetic sensor arrays, which greatly improves the information density of the magnetic field distribution and greatly enhances the processing ability of magnetic information. The efficiency and accuracy of wafer alignment and bonding are improved.

[0050] 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 wafer bonding magnetic array alignment method, characterized in that: The method manufactures several groups of magnetic array marks with geometric shapes and symmetrical distribution characteristics on a wafer by MEMS, wherein the several groups of magnetic array marks are symmetrically distributed, and there are several magnetic marks in each group of magnetic arrays, and the magnetic marks are equidistantly distributed; a plurality of groups of magnetic sensor arrays with symmetrical distribution characteristics are pre-embedded by MEMS in a clamping and carrying mechanism, wherein there are several magnetic sensors in each group of magnetic sensor arrays, and the magnetic sensors in each magnetic sensor array are equidistantly distributed; the number of magnetic array marks is greater than or equal to the number of magnetic sensor arrays, the number of magnetic marks is less than or equal to the number of magnetic sensors, and each magnetic mark covers the corresponding magnetic sensor array. Under the above, each magnetic marker passes through the wafer or is made on one side of the wafer, and the exposed surface of the magnetic marker faces the clamping mechanism or the supporting mechanism; each magnetic sensor is made on the surface of the clamping mechanism or the supporting mechanism, exposed on the surface of the mechanism and facing the wafer; each magnetic sensor array collects the magnetic field distribution information generated by the corresponding magnetic marker in real time, obtains the spatial position information of each magnetic marker, and obtains the spatial posture information of the wafer through the symmetrical distribution characteristics of the magnetic array and the magnetic sensor array; when two or more wafers are superimposed, the spatial vector error of the two or more wafers is obtained; the motion system is used to eliminate this spatial error and complete the alignment, and the two wafers are bonded after the alignment.

2. A wafer bonding magnetic array alignment method according to claim 1, characterized in that: The method comprises the following steps: A) The carrying mechanism and the holding mechanism are brought close to each other in the vertical direction in an unloaded state, or the carrying mechanism and the clamping mechanism, or the carrying mechanism and the calibration sheet, or the holding mechanism and the calibration sheet, to perform self-calibration of the mechanism and draw the magnetic field environment; B) the carrying mechanism delivers the first wafer to a first preset position, the carrying mechanism and the clamping mechanism are respectively placed on both sides of the first wafer; a plurality of magnetic sensor arrays at the first preset position correspond to a plurality of magnetic array marks of the first wafer, and any magnetic array mark is not completely placed outside the coverage range of the magnetic sensor array; the clamping mechanism holds the first wafer to a second preset position; C) the magnetic sensor array acquires the magnetic field distribution information generated by the first wafer magnetic array mark column at the second preset position, obtains the first wafer relative position information, and obtains the first wafer absolute position information; D) the carrying mechanism delivers the second wafer to the first preset position, the carrying mechanism is placed under the second wafer, and the first wafer is held at the second preset position by the clamping mechanism and placed on the second wafer; a plurality of magnetic sensor arrays at the first preset position correspond to a plurality of magnetic array marks of the second wafer, and any magnetic array mark is not completely placed outside the coverage range of the magnetic sensor array; E) the magnetic sensor array simultaneously acquires the magnetic field distribution information generated by the first wafer magnetic array mark and the second wafer magnetic array mark, obtains the second wafer relative position information, and then obtains the second wafer absolute position information; F) acquiring spatial vector error information of the first wafer and the second wafer according to the absolute position information of the first wafer and the second wafer; the clamping mechanism drives the first wafer to perform fine adjustment and alignment; G) setting the position of the clamping mechanism after fine adjustment to a third preset position; repeating the step E until the space vector error between the first wafer and the second wafer is less than a preset tolerance limit; H) The first wafer is held by the clamping mechanism and vertically approaches the second wafer to complete the bonding process.

3. A wafer bonding magnetic array alignment method according to claim 1, characterized in that: When the absolute position information of the first wafer and the second wafer is obtained, the warpage of the wafer is obtained to check whether it exceeds a preset tolerance limit.

4. A wafer bonding magnetic array alignment method according to claim 1, characterized in that: The first preset position and the second preset position are corrected by a correction sheet.

5. The wafer bonding magnetic array alignment method according to claim 1, characterized in that: At the preset position, each magnetic marker in the magnetic array marker is under the coverage of the corresponding magnetic sensor array.

6. A wafer bonding magnetic array alignment method according to claim 1, characterized in that: In the step F, the first wafer is parallel to the second wafer, and the distance between the first wafer and the second wafer is less than one wafer thickness.

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