Wafer thinning processing system and processing method

Abstract

The wafer thinning machining system comprises a main shaft, a machining platform, a base frame, electromagnetic force modules and a pressure adjusting unit, the machining platform is located below the main shaft, the main shaft is slidably connected to the base frame in the vertical direction, the two electromagnetic force modules are oppositely arranged in the vertical direction, one electromagnetic force module is connected to the main shaft, and the other electromagnetic force module is connected to the pressure adjusting unit. The pressure adjusting unit comprises a control module, a pressure detecting module and a power source, and the control module can change the power supply amount of the power source to the electromagnetic force modules according to the machining pressure so as to adjust the electromagnetic force between the two electromagnetic force modules. Therefore, the machining pressure between the machining head and the wafer is changed, the machining pressure between the machining head and the wafer is kept stable, the response speed is high, the adjusting precision is high, the thinning thickness of the wafer can be accurately controlled, and the machining efficiency of the wafer is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer processing, and in particular to a wafer thinning processing system and a processing method. Background Art

[0002] During chip processing, the wafers used to prepare chips need to undergo multiple mechanical, physical, chemical and thermal treatments, which will generate a lot of stress inside the wafer. In order to prevent the wafer from cracking and warping under stress, thereby affecting the flatness of the wafer, and to avoid wafer breakage, the wafer needs to be maintained at a certain thickness. Currently, the commonly used wafer thinning method is to first thin the wafer thickness by grinding, and then polish to remove the sub-surface damage layer and stress concentration layer of the wafer. During the grinding and polishing process, the spindle of the processing device applies pressure to the wafer through the processing head, but the processing surface of the wafer is not flat, resulting in unstable processing pressure applied to the wafer by the processing head. The current processing device can only adjust the processing pressure through the cylinder. The pressure adjustment accuracy of the cylinder is low, and the response speed is slow. It is difficult to control the thinning thickness of the wafer, which affects the processing efficiency of the wafer. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a wafer thinning processing system, which can adjust the processing pressure during the wafer thinning process, control the thinning thickness of the wafer, and improve the processing efficiency.

[0004] The present invention also provides a wafer thinning processing method performed by using the wafer thinning processing system.

[0005] A wafer thinning processing system according to a first aspect of the present invention includes:

[0006] The spindle, the lower end of which is used to mount the processing head;

[0007] A processing platform, located below the spindle and used to fix the wafer to be processed;

[0008] A base frame, the main shaft is vertically slidably connected to the base frame and can be lifted and lowered relative to the base frame;

[0009] Two electromagnetic force modules are arranged vertically opposite to each other, one of which is connected to the main shaft, and the other is connected to the base frame. When the two electromagnetic force modules are powered on, mutual electromagnetic force can be generated;

[0010] The pressure regulating unit includes a control module, a pressure detection module and a power supply. The power supply is electrically connected to the electromagnetic force module and supplies power to the electromagnetic force module. The pressure detection module is used to detect the processing pressure between the processing head and the wafer. The control module is used to change the power supply of the power supply to the electromagnetic force module according to the processing pressure to adjust the electromagnetic force between the two electromagnetic force modules.

[0011] The wafer thinning processing system according to the embodiment of the present invention has at least the following beneficial effects:

[0012] In the present invention, the control module can change the amount of power supplied to the electromagnetic force module by the power supply according to the processing pressure to adjust the electromagnetic force between the two electromagnetic force modules, thereby changing the processing pressure between the processing head and the wafer, thereby realizing real-time adjustment of the processing pressure according to the current processing conditions of the wafer, so that the processing pressure between the processing head and the wafer remains stable, and the adjustment of the electromagnetic force is achieved by changing the amount of power supplied to the electromagnetic force module by the power supply, with fast response speed and high adjustment accuracy, and can accurately control the thinning thickness of the wafer, thereby improving the processing efficiency of the wafer.

[0013] According to some embodiments of the present invention, the wafer thinning processing system also includes an elastic member capable of elastically stretching and contracting in the vertical direction, the elastic member is used to provide an upward elastic force to the main shaft, the elastic member is connected between the upper end of the main shaft and the upper end of the base frame, and / or the elastic member is connected between the lower end of the main shaft and the upper end of the base frame.

[0014] According to some embodiments of the present invention, the electromagnetic force module includes a coil and a magnet. The coil can generate a magnetic field when energized. The direction of the magnetic field acting on the coil by at least part of the magnet is the same as the direction of the magnetic field of the coil itself. The power supply is used to supply power to the coil.

[0015] According to some embodiments of the present invention, of the two electromagnetic force modules, the electromagnetic force module with a larger height is connected to the base frame, and the electromagnetic force module with a smaller height is connected to the main shaft, and there is an electromagnetic force of attraction between the two electromagnetic force modules;

[0016] Alternatively, of the two electromagnetic force modules, the electromagnetic force module with a smaller height is connected to the base frame, and the electromagnetic force module with a larger height is connected to the main shaft, and there is a repulsive electromagnetic force between the two electromagnetic force modules.

[0017] According to some embodiments of the present invention, the electromagnetic force module further includes an iron core, and the coil is sleeved on the outside of the iron core.

[0018] According to some embodiments of the present invention, the electromagnetic force module includes a coil and a plurality of magnets, wherein the plurality of magnets are arranged around the outer circumference of the coil, and each of the magnets has the same magnetic pole along the same vertical end.

[0019] According to some embodiments of the present invention, in the same electromagnetic force module, the coil located at the center of the electromagnetic force module is the first coil, and the other coils are the second coils, the second coil is arranged at least one circle around the circumference of the first coil, the magnet is arranged at least one circle around the circumference of the first coil, the coils and the magnets are arranged alternately along the radial direction of the first coil, the magnetic fields generated by all the coils have the same direction, and the magnetic poles of all the magnets at the same end along the vertical direction are the same;

[0020] Alternatively, the electromagnetic force module includes multiple magnetic units, which are arranged along the first direction and / or the second direction, and each of the magnetic units includes at least one magnet and a plurality of coils arranged around the magnet. In each of the magnetic units, the direction of the magnetic field applied by the magnet to the coil is the same as the direction of the magnetic field of the coil itself. The magnetic poles of the magnets in the magnetic units adjacent to each other along the first direction and / or the second direction at the same end along the first direction are opposite, and the first direction, the second direction, and the vertical direction are perpendicular to each other.

[0021] According to a second aspect of the present invention, a wafer thinning method is performed by using the wafer thinning system in the first aspect of the present invention, and includes:

[0022] The wafer is placed on the top of the processing platform, and after the base frame carrying the spindle is controlled to descend to a preset height, the processing head starts to work and thins the wafer;

[0023] The pressure detection module detects the processing pressure between the processing head and the wafer, the control module sends a control instruction to the power supply according to the processing pressure, and the power supply changes the power supply to the electromagnetic force module according to the control instruction to adjust the electromagnetic force between the two electromagnetic force modules.

[0024] According to some embodiments of the present invention, the step of the power supply changing the power supply amount of the electromagnetic force module according to the control instruction includes:

[0025] Changing the current magnitude of the power supply passing through the electromagnetic force module;

[0026] And / or, the electromagnetic force module includes a coil and a magnet, the coil can generate a magnetic field when energized, the direction of the magnetic field acting on the coil by at least part of the magnet is the same as the direction of the magnetic field of the coil itself, and the power supply is used to supply power to the coil and restore or cut off the electrical connection between part of the coil and the power supply.

[0027] According to some embodiments of the present invention, the further comprising:

[0028] An elastic member is arranged between the main shaft and the base frame, and an upward elastic force is provided to the main shaft through the elastic member; after the base frame carrying the main shaft is controlled to descend to a preset height, the pressure between the processing head and the wafer is a first pressure F1, and the elastic member has a first compression amount L1; then, the base frame is controlled to retreat a preset distance, so that the pressure between the processing head and the wafer is a second pressure F2, and the elastic member has a second compression amount L2, L1>L2, F1>F2; then the processing head is controlled to start working with the second pressure F2.

[0029] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0031] Figure 1 A schematic diagram of an embodiment of a wafer thinning processing system of the present invention;

[0032] Figure 2 A control flow chart of an embodiment of a pressure regulating unit;

[0033] Figure 3 Schematic diagrams of some embodiments of electromagnetic force modules;

[0034] Figure 4 It is a three-dimensional diagram of some embodiments of the electromagnetic force module;

[0035] Figure 5 for Figure 4 A cross-sectional view of an embodiment of the electromagnetic force module;

[0036] Figure 6 is a schematic diagram of the arrangement of coils and magnets in some embodiments;

[0037] Figure 7 is a schematic diagram of the arrangement of coils and magnets in other embodiments;

[0038] Figure 8 is a schematic diagram of the arrangement of coils and magnets in other embodiments;

[0039] Fig. 9 for Figure 4 Schematic diagram of the electromagnetic force module with some of its structures hidden.

[0040] Reference numerals:

[0041] Spindle 100; first connecting part 110, second connecting part 120; processing platform 200; base frame 300; processing head 400; electromagnetic force module 500, coil 510, magnet 520, magnetic unit 530, shell 540, first mounting cavity 541, second mounting cavity 542, shell 543, mounting plate 544, iron core 550, bracket 560, cover plate 570, cooling plate 580, bottom plate 590; pressure regulating unit 600, control module 610, pressure detection module 620, power supply 630, operation module 640; elastic member 700. DETAILED DESCRIPTION

[0042] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0043] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0044] In the description of the present invention, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0045] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0046] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0047] Reference Figure 1 and Figure 2 The wafer thinning processing system includes a spindle 100, a processing platform 200 and a base frame 300. The lower end of the spindle 100 is used to install a processing head 400. The processing platform 200 is located below the spindle 100 and is used to fix the wafer to be processed so that the wafer maintains a stable position during the thinning process. The processing head 400 contacts the surface of the wafer during the processing and thins the wafer. The processing head 400 is not limited to a grinding wheel, a grinding head, etc. that can grind the wafer, or a polishing head that can polish the wafer. The spindle 100 is connected to the base frame 300 along the vertical sliding direction and can be raised and lowered relative to the base frame 300. The processing head 400 is fixedly installed at the lower end of the spindle 100 and can follow the spindle 100 to rise and fall, so as to approach or move away from the processing platform 200, adjust the relative position relationship between the processing head 400 and the wafer, and realize the feeding of the processing head 400.

[0048] Since the processing surface of the wafer is not flat during processing, the processing pressure between the wafer and the processing head 400 changes all the time and may be too large or too small. Therefore, it is necessary to apply additional force to the spindle 100 to maintain a stable processing pressure. The method of applying force to the spindle 100 using a cylinder is limited by the opening and closing frequency of the air valve and the processing accuracy. The corresponding speed is slow, the adjustment accuracy of the processing pressure is low, and it is difficult to control the thinning thickness of the wafer.

[0049] In the present invention, the wafer thinning processing system also includes an electromagnetic force module 500, two electromagnetic force modules 500 are arranged vertically opposite to each other, and after power is turned on, there is an electromagnetic force between the two electromagnetic force modules 500, and the electromagnetic force can be an electromagnetic attraction or repulsion. One electromagnetic force module 500 is connected to the spindle 100, and the other electromagnetic force module 500 is connected to the base frame 300, so that the spindle 100 is subjected to the electromagnetic force applied by the electromagnetic force module 500. It should be noted that during the wafer thinning process, the processing head 400 applies downward pressure to the wafer to keep the processing head 400 in contact with the wafer. This pressure is the processing pressure, and the processing pressure mainly comes from the combined force of the gravity of the spindle 100, the electromagnetic force provided by the electromagnetic force module 500, and other forces.

[0050] The wafer thinning processing system also includes a pressure regulating unit 600, which includes a control module 610, a pressure detection module 620 and a power supply 630. The pressure detection module 620 is not limited to being set as a piezoresistive pressure sensor, a strain gauge pressure sensor, etc. The power supply 630 is electrically connected to the electromagnetic force module 500 and supplies power to the electromagnetic force module 500 so that the electromagnetic force module 500 generates a magnetic field after being energized. The pressure detection module 620 is used to detect the processing pressure between the processing head 400 and the wafer. The control module 610 is not limited to being set as a PLC, ARM, PAC, industrial computer, etc. The control module 610 is used to change the amount of power supplied by the power supply 630 to the electromagnetic force module 500 according to the processing pressure, so as to adjust the electromagnetic force between the two electromagnetic force modules 500, and then change the processing pressure between the processing head 400 and the wafer, thereby realizing real-time adjustment of the processing pressure according to the current processing conditions of the wafer, so that the processing pressure between the processing head 400 and the wafer remains stable, and the adjustment of the electromagnetic force is achieved by changing the amount of power supplied by the power supply 630 to the electromagnetic force module 500, with fast response speed and high adjustment accuracy, and can accurately control the thinning thickness of the wafer, thereby improving the processing efficiency of the wafer.

[0051] It is understandable that the electromagnetic force module 500 should include a conductor. When the power supply 630 supplies power to the electromagnetic force module 500, the current passes through the conductor and generates a magnetic force, so that a mutual electromagnetic force is generated between the two electromagnetic force modules 500. In addition, by changing the magnitude of the current supplied by the power supply 630 to the electromagnetic force module 500, the magnitude of the electromagnetic force between the two electromagnetic force modules 500 can be changed. In addition, by setting the power supply 630 to supply current in the same direction to the two electromagnetic force modules 500, an electromagnetic force of attraction can be generated between the two electromagnetic force modules 500, and by setting the power supply 630 to supply current in the opposite direction to the two electromagnetic force modules 500, an electromagnetic force of repulsion can be generated between the two electromagnetic force modules 500.

[0052] In one embodiment, referring to Figure 3 and Figure 4The electromagnetic force module 500 includes a coil 510 and a magnet 520. The magnet 520 itself is magnetic and has two magnetic poles with opposite polarities, such as an N pole and an S pole. Based on the magnetic effect of the current, the coil 510 generates a magnetic field after being energized. In at least part of the electromagnetic force module 500, the coil 510 has the same magnetic pole as at least part of the magnet 520 at the same end in the vertical direction after being energized. The magnet 520 generates a magnetic field around it. The coil 510 located around the magnet 520 is within the range of the magnetic field generated by the magnet 520. The direction of the magnetic field generated by the magnet 520 acting on the coil 510 is the same as the magnetic field of the coil 510 itself. The magnetic fields generated are in the same direction, the magnetic field generated by the magnet 520 is superimposed on the magnetic field generated by the coil 510, and the superimposed magnetic field acts on another coil 510 in another electromagnetic force module 500, so that a mutual electromagnetic force is generated between the two electromagnetic force modules 500; in addition, the two magnets 520 facing each other in the two electromagnetic force modules 500 attract or repel each other, and there is a constant electromagnetic force between the two. In the same electromagnetic force module 500, the electromagnetic force exerted on the magnet 520 and the electromagnetic force exerted on the coil 510 are in the same direction and superimposed, which can increase the magnitude of the electromagnetic force between the two electromagnetic force modules 500.

[0053] It should be noted that after the coils 510 in the two electromagnetic force modules 500 are energized, the two facing coils 510 are located within the magnetic field range of each other and generate mutual electromagnetic force. Since the magnetic field generated by the magnet 520 is superimposed on the magnetic field generated by the adjacent coil 510, the electromagnetic force between the coils 510 is increased, and the electromagnetic force exerted on the magnet 520 is in the same direction as the electromagnetic force exerted on the coil 510 and can be superimposed, which increases the range of processing pressure that can be adjusted by the electromagnetic force regulating device, and can be suitable for use scenarios where the processing pressure is adjusted over a wide range.

[0054] It should be noted that the arrangement of the coils 510 and the magnets 520 in the two relatively arranged electromagnetic force modules 500 is the same, and a coil 510 in one electromagnetic force module 500 is always vertically opposite to a coil 510 in the other electromagnetic force module 500 and is located within the magnetic field range of the relative coil 510. Similarly, a magnet 520 in one electromagnetic force module 500 is always vertically opposite to a magnet 520 in the other electromagnetic force module 500 and is located within the magnetic field range of the relative magnet 520.

[0055] In one embodiment, two electromagnetic force modules 500 may be arranged symmetrically relative to the middle plane, and vertically perpendicular to the middle plane, so that the distance between the two coils 510 opposite to each other in the two electromagnetic force modules 500 and the distance between the two magnets 520 opposite to each other are as close as possible, and the two coils 510 opposite to each other in the two electromagnetic force modules 500 can be located in the strong magnetic field area of ​​each other to increase the electromagnetic force between the two electromagnetic components. "The two electromagnetic force modules 500 are arranged symmetrically relative to the middle plane" simply means that the structural arrangement of the electromagnetic force modules 500 is symmetrical to each other. On the premise that the magnetic field direction of the magnet 520 in the same electromagnetic force module 500 acting on the coil 510 is the same as the magnetic field direction of the coil 510 itself, the magnetic pole arrangement of the magnet 520 in different electromagnetic force modules 500 and the direction of the current passed into the coil 510 can be flexibly arranged according to actual conditions.

[0056] The power supply amount can be adjusted by changing the current passed into the coil 510, or by changing the number of coils 510 electrically connected to the power supply 630. That is, by reducing the current passed into the coil 510 by the power supply 630, the magnetic field generated by the coil 510 is reduced, and the electromagnetic force applied by the electromagnetic force module 500 to the spindle 100 is reduced; by increasing the current passed into the coil 510 by the power supply 630, the magnetic field generated by the coil 510 is increased, and the electromagnetic force applied by the electromagnetic force module 500 to the spindle 100 is increased; or, by cutting off the electrical conduction between the power supply 630 and part of the coils 510, the number of coils 510 that can generate a magnetic field is reduced, so that the electromagnetic force applied by the electromagnetic force module 500 to the spindle 100 is reduced, and after restoring the electrical conduction between the power supply 630 and the coil 510, the number of coils 510 that can generate a magnetic field is increased, so that the electromagnetic force applied by the electromagnetic force module 500 to the spindle 100 is increased.

[0057] Since the spindle 100 is heavy, the gravity of the spindle 100 is much greater than the processing pressure required by the wafer. The electromagnetic force module 500 applies an upward electromagnetic force to the spindle 100. In order to make the electromagnetic force adjustment range of the electromagnetic force module 500 meet the requirements of the wafer processing pressure, in one embodiment, refer to Figure 1 and Figure 2 The wafer thinning processing system also includes an elastic member 700 that can elastically expand and contract in the vertical direction. The elastic member 700 is used to provide an upward elastic force to the spindle 100. The elastic force applied by the elastic member 700 to the spindle 100 and the electromagnetic force applied by the electromagnetic force module 500 to the spindle 100 are in the same direction. The combined force of the elastic force, the electromagnetic force and the gravity of the spindle 100 is downward and forms a processing pressure on the wafer. The elastic force of the elastic member 700 can offset part of the gravity of the spindle 100, so that the adjustment range of the electromagnetic force can more easily meet the processing pressure requirements of the wafer.

[0058] Specifically, the elastic member 700 can be configured as an elastic element such as a spring or a spring sheet that can produce elastic deformation and automatically recover. Figure 1 The spindle 100 includes a first connecting portion 110 and a second connecting portion 120. The second connecting portion 120 is connected to the lower end of the first connecting portion 110. The cross-sectional area of ​​the first connecting portion 110 along the middle plane is larger than the cross-sectional area of ​​the second connecting portion 120 along the middle plane. The lower end of the second connecting portion 120 is provided for mounting the processing head 400. At least part of the first connecting portion 110 is located inside the base frame 300. One end of the elastic member 700 is connected to the surface of the bottom wall of the base frame 300, and the other end is connected to the lower end of the first connecting portion 110, providing an upward elastic force to the first connecting portion 110.

[0059] In addition, the repulsive force or attractive force generated between the electromagnetic force modules 500 can be selected according to the position where the electromagnetic force module 500 is connected to the spindle 100 and the specific processing pressure requirements. For example, the two electromagnetic force modules 500 are both located above the spindle 100, and the electromagnetic force modules 500 can generate an attractive electromagnetic force, so that the spindle 100 is subjected to the upward force of the electromagnetic force module 500, or the two electromagnetic force modules 500 are both located below the spindle 100, and the electromagnetic force modules 500 can generate a repulsive electromagnetic force, so that the spindle 100 is subjected to the upward force of the electromagnetic force module 500.

[0060] In one embodiment, in two electromagnetic force modules 500, the magnetic poles of the two magnets 520 facing each other at one end are the same, and a repulsive electromagnetic force is generated between the two magnets 520. Since the direction of the magnetic field generated after the coil 510 is energized is the same as the direction of the magnetic field of the magnetic pole acting on the coil 510, a repulsive electromagnetic force is also generated between the two coils 510 disposed oppositely in the vertical direction. In this case, the two electromagnetic force modules 500 have a repulsive electromagnetic force. Alternatively, in another embodiment, in two electromagnetic force modules 500, the magnetic poles of the two magnets 520 facing each other at one end are opposite, and an attractive electromagnetic force is generated between the two magnets 520. Since the direction of the magnetic field generated after the coil 510 is energized is the same as the direction of the magnetic field of the magnetic pole acting on the coil 510, an attractive electromagnetic force is also generated between the two coils 510 disposed oppositely in the vertical direction. In this case, the two electromagnetic force modules 500 have an attractive electromagnetic force.

[0061] For example, in Figure 3 In the embodiment shown, electromagnetic force module A and electromagnetic force module B are distributed vertically and symmetrically relative to the middle plane. Electromagnetic force module A is located above electromagnetic force module B, and electromagnetic force module B is located below electromagnetic force module A. Electromagnetic force module A includes magnet A and coil A, and electromagnetic force module B includes magnet B and coil B. Figure 3As shown in Figure (a), in electromagnetic force module A, the vertical component of the magnetic field inside magnet A is upward, the vertical component of the magnetic field outside magnet A and acting on coil A is downward, and the vertical component of the magnetic field inside coil A generated after energization is downward. Then the magnetic field generated after energization of coil A is in the same direction as the magnetic field outside magnet A and can be superimposed. Coil B is located within the range of the superimposed magnetic field and is subjected to the electromagnetic force exerted by the superimposed magnetic field. In electromagnetic force module B, the vertical component of the magnetic field inside magnet B is downward, the vertical component of the magnetic field outside magnet B and acting on coil B is upward, and the vertical component of the magnetic field inside coil B generated after energization is upward. Then the magnetic field generated after energization of coil B is in the same direction as the magnetic field outside magnet B and can be superimposed. Coil A is located within the range of the superimposed magnetic field and is subjected to the electromagnetic force exerted by the superimposed magnetic field. In this case, the magnetic poles of the facing ends of magnet A and magnet B are the same, and they repel each other. The magnetic poles of the facing ends of coil A and coil B are the same, and they repel each other, so a repulsive electromagnetic force is generated between the electromagnetic force module A and the electromagnetic force module B.

[0062] like Figure 3 As shown in Figure (b), in electromagnetic force module A, the vertical component of the magnetic field inside magnet A is upward, the vertical component of the magnetic field outside magnet A and acting on coil A is downward, and the vertical component of the magnetic field inside coil A generated after energizing is downward. Then, the magnetic field generated after energizing is in the same direction as the magnetic field outside magnet A and can be superimposed. Coil B is located within the range of the superimposed magnetic field and is subjected to the electromagnetic force exerted by the superimposed magnetic field. In electromagnetic force module B, the vertical component of the magnetic field inside magnet B is upward, the vertical component of the magnetic field outside magnet B and acting on coil B is downward, and the vertical component of the magnetic field inside coil B generated after energizing is downward. Then, the magnetic field generated after energizing is in the same direction as the magnetic field outside magnet B and can be superimposed. Coil A is located within the range of the superimposed magnetic field and is subjected to the electromagnetic force exerted by the superimposed magnetic field. In this case, the magnetic poles of the facing ends of magnets A and magnet B are opposite, and the two attract each other. The magnetic poles of the facing ends of coils A and coil B are opposite, and the two attract each other, then an attractive electromagnetic force is generated between the electromagnetic force modules A and the electromagnetic force modules A.

[0063] In addition, two electromagnetic force modules 500 may be provided, wherein the electromagnetic force module 500 with a larger height is connected to the frame, and the electromagnetic force module 500 with a smaller height is connected to the spindle 100, and there is an electromagnetic force of attraction between the two electromagnetic force modules 500, and the electromagnetic force module 500 applies an upward force to the spindle 100. Alternatively, two electromagnetic force modules 500 may be provided, wherein the electromagnetic force module 500 with a smaller height is connected to the base frame 300, and the electromagnetic force module 500 with a larger height is connected to the spindle 100, and there is an electromagnetic force of repulsion between the two electromagnetic force modules 500, and the electromagnetic force module 500 applies an upward force to the spindle 100.

[0064] In one embodiment, the wafer thinning processing system also includes a driving mechanism, which is used to drive the spindle 100 to rise and fall. When the spindle 100 feeds downward, the processing head 400 moves to a preset height to thin the wafer to a preset thickness. When the thickness of a certain layer of the wafer is thinned, the driving mechanism can continue to control the base frame 300 to descend, so that the spindle 100 drives the processing head 400 to continue to feed downward. In addition, the driving mechanism of the base frame 300 can also realize the change of elastic force; for example, when the driving mechanism drives the main shaft 100 to descend to a certain height, the elastic member 700 has a corresponding compression amount, and when the driving mechanism continues to drive the main shaft 100 to descend, the elastic member 700 continues to be compressed, and the compression amount and elastic force of the elastic member 700 increase; when the driving mechanism drives the base frame 300 to rise, the elastic member 700 rebounds, and the compression amount and elastic force of the elastic member 700 decrease; therefore, according to the required processing pressure of the wafer, the driving mechanism can also drive the base frame 300 to rise and fall, change the compression amount of the elastic member 700, and then adjust the current processing pressure between the processing head 400 and the wafer.

[0065] The pressure regulating unit 600 also includes an operation module 640, which can be integrated into a PC. The operation module 640 is communicatively connected to the control module 610. The communication connection is not limited to Bluetooth, wifi, infrared, wire connection and other connection methods. The PC provides a human-computer interaction interface to display the current processing status of the wafer thinning processing system and for the operator to adjust various processing parameters.

[0066] In addition, refer to Figure 5 The electromagnetic force module 500 also includes an iron core 550, and the coil 510 is sleeved on the outside of the iron core 550. After the coil 510 is energized, the iron core 550 is magnetized in the magnetic field generated by the coil 510, which can enhance the magnetic induction intensity of the magnetic field generated by the coil 510, thereby enhancing the electromagnetic force between the electromagnetic force modules 500.

[0067] It can be understood that each electromagnetic force module 500 may include multiple coils 510 and / or multiple magnets 520, and the multiple magnets 520 in different electromagnetic force modules 500 interact with each other, so that the electromagnetic force between the magnets 520 in different electromagnetic force modules 500 increases, and the magnetic field generated by the multiple magnets 520 can act on the same coil 510, so that the electromagnetic force between the coils 510 in different electromagnetic force modules 500 increases, thereby increasing the electromagnetic force between the electromagnetic force modules 500; or, the magnetic field generated by the magnet 520 can act on different coils 510, so that the multiple coils 510 in different electromagnetic force modules 500 synchronously generate electromagnetic force, so that the electromagnetic force between the coils 510 in different electromagnetic force modules 500 increases.

[0068] In addition, the arrangement direction of the coil 510 and the magnet 520 is parallel to the middle plane, so that the vertical component of the magnetic field generated by the magnet 520 can be superimposed on the vertical component of the magnetic field generated by the coil 510 itself. Since the two electromagnetic force modules 500 are distributed vertically, the magnetic fields generated by the two electromagnetic force modules 500 can enable the two electromagnetic force modules 500 to generate electromagnetic forces that interact with each other vertically, so that the electromagnetic force adjustment device can provide and adjust the vertical electromagnetic force. Since the direction of the electromagnetic force is stable, it is beneficial to keep the spindle 100 balanced and stable during the wafer thinning process.

[0069] It should be noted that the above-mentioned “arrangement direction of the coil 510 and the magnet 520” includes the arrangement direction of multiple coils 510, the arrangement direction between multiple magnets 520, and the arrangement direction of mixed coils 510 and magnets 520. In addition, the closer the area is to the magnet 520, the denser the magnetic flux lines are, and the farther the area is from the magnet 520, the sparser the magnetic flux lines are. Therefore, the coil 510 is greatly affected by the magnetic field generated by the nearest magnet 520. The direction of the magnetic field generated by the coil 510 after being energized is the same as the direction of the magnetic field generated by the magnet 520 closest to it, so that as many magnetic flux lines as possible are in the area where the coil 510 is located, increasing the magnetic field strength after the superposition of the two magnetic fields, and increasing the distance between the coil 510 and other magnets 520 with different magnetic properties, reducing the influence of other magnets 520 on the coil 510. In addition, in the two electromagnetic force modules 500, the distances between the facing coils 510 and the facing magnets 520 are the shortest, and there are mutual electromagnetic forces between the facing coils 510 and the facing magnets 520 and 520 in the two electromagnetic force modules 500, and they are less affected by other coils 510 and magnets 520.

[0070] In addition, the cross-sections of the coil 510 and the magnet 520 parallel to the middle plane are not limited to being set to circular, polygonal, etc. In order to facilitate the arrangement of the coil 510 and the magnet 520 along the middle plane and effectively utilize the space of the electromagnetic force module 500 on the middle plane, the cross-sectional diameters of the coil 510 and the magnet 520 can be set to be approximately equal.

[0071] For example, Figure 6 As shown in Figure (c), the electromagnetic force module 500 includes a coil 510 and a plurality of magnets 520. The plurality of magnets 520 are arranged around the outer circumference of the coil 510. The magnetic poles of each magnet 520 at the same end in the vertical direction are the same. The coil 510 is located in the intersection area of ​​the magnetic fields generated by the plurality of magnets 520, that is, the coil 510 is located within the range of the magnetic field generated by each magnet 520. The magnetic field of the coil 510 itself can be superimposed on the magnetic fields generated by the plurality of magnets 520, which can effectively increase the adjustment range of the electromagnetic force adjustment device for the processing pressure.

[0072] like Figure 6 In Figure (d), the electromagnetic force module 500 includes a magnet 520 and a plurality of coils 510, and the plurality of coils 510 are arranged around the periphery of the magnet 520. After each coil 510 is energized, the magnetic poles at the same end in the vertical direction are the same, that is, the direction of the magnetic field generated by each coil 510 is the same, and each coil 510 is within the magnetic field range generated by the magnet 520. The magnetic field generated by the magnet 520 can be superimposed with the magnetic field generated by each coil 510, which can effectively increase the adjustment range of the electromagnetic force adjustment device for the processing pressure. It should be noted that in this embodiment, there is a preset spacing between adjacent coils 510 to avoid the coils 510 being too close to each other and weakening the magnetic field.

[0073] In addition, for Figure 7 In the situations shown in Figures (c) and (d), the coil 510 or the magnet 520 may be wound with multiple turns to increase the number of coils 510, or the coil 510 may be placed within the magnetic field range generated by more magnets 520, thereby increasing the magnetic field strength after the magnetic field generated by the coil 510 and the magnetic field generated by the magnet 520 are superimposed.

[0074] Exemplarily, as shown in Figure (e) of Figure 7, in the same electromagnetic force module 500, the coil 510 located at the center of the electromagnetic force module 500 is the first coil 510a, and the other coils 510 are the second coils 510b. The second coil 510b is arranged circumferentially around the first coil 510a with at least one circle, and the magnet 520 is arranged circumferentially around the first coil 510a with at least one circle. The second coil 510b and the magnet 520 are alternately arranged radially along the first coil 510a, and after all the coils 510 are energized, the magnetic poles at the same end in the vertical direction are the same, that is, the magnetic field directions generated by all the coils 510 are the same, and the magnetic poles at the same end in the vertical direction of all the magnets 520 are the same.

[0075] It is defined that each circle of components arranged around the first coil 510a constitutes an electromagnetic body. Along the radial direction of the first coil 510a and gradually away from the first coil 510a, the electromagnetic bodies of each circle are named as the first circle electromagnetic body, the second circle electromagnetic body, the third circle electromagnetic body...; through the above configuration, the first circle electromagnetic body only includes a plurality of magnets 520, and the first coil 510a is surrounded by the magnets 520. The first coil 510a is located within the magnetic field generated by the magnets 520 of each first circle electromagnetic body and can be superimposed with the magnetic field generated by the magnets 520 in the first circle electromagnetic body. The second circle electromagnetic body only includes a plurality of The second coil 510b and the third circle electromagnetic body only include a plurality of magnets 520. The second coil 510b in the second circle electromagnetic body is radially adjacent to the two circles of magnets 520 respectively and is located within the magnetic field generated by the two circles of magnets 520. That is, both the first coil 510a and the second coil 510b can be located within the magnetic field generated by the magnets 520 in the first circle electromagnetic body, and the magnetic field generated by the second coil 510b can be superimposed with the magnetic field generated by the magnets 520 in the two adjacent circles, thereby greatly increasing the electromagnetic force between the two electromagnetic force modules 500 and expanding the adjustment range of the electromagnetic force adjustment device for the processing pressure.

[0076] In addition, the first coil 510a is set at the center of the electromagnetic force module 500, and the first circle electromagnetic body only includes the magnet 520. On the one hand, the position closer to the first coil 510a is arranged more closely along the circumference of the first coil 510a, and the magnet 520 of the first circle is closer to the first coil 510a. On the one hand, it is ensured that the first circle has a large number of magnets 520 to surround the first coil 510a. The first coil 510a is located within the magnetic field generated by multiple magnets 520, and the distance between the first coil 510a and the magnet 520 can be reduced, so that the first coil 510a is in the area with higher magnetic field strength of the magnet 520, thereby increasing the electromagnetic force between the electromagnetic force modules 500. On the other hand, compared with the method of setting the magnet 520 at the center of the electromagnetic force module 500 and arranging the coil 510 around the magnet 520, it can avoid the coils 510 from being too close to affect each other and weaken the magnetic field.

[0077] Furthermore, adjacent circles of magnets 520 and second coils 510b are staggered along the circumferential direction of the first coil 510a. On the one hand, the distance between adjacent second coils 510b in the same circle is increased to avoid the second coils 510b from influencing each other and weakening the magnetic field. On the other hand, the second coil 510b is located between adjacent circles of magnets 520 in the circumferential direction. The second coil 510b can be within the magnetic field generated by multiple magnets 520, thereby increasing the magnetic field strength after the magnetic field generated by the second coil 510b and the magnetic field generated by the magnet 520 are superimposed.

[0078] Alternatively, the second coil 510b and the magnet 520 may also be alternately arranged in at least one circle along the circumference of the first coil 510a, that is, the electromagnetic body includes both the coil 510 and the magnet 520. Figure 7 In Figure (f), the first circle electromagnetic body only includes multiple magnets 520a, and the multiple magnets 520a are arranged around the outer circumference of the first coil 510a, and the second circle electromagnetic body includes multiple magnets 520b and multiple second coils 510b, and the multiple magnets 520b and the multiple second coils 510b are alternately arranged around the circumference of the first coil 510a. The second coil 510b in the first circle electromagnetic body and the magnet 520b in the second circle electromagnetic body are staggered along the circumference of the first coil 510a, so that the magnets 520a in the first circle electromagnetic body and the magnets 520b in the second circle electromagnetic body can jointly surround the second coil 510b in the second circle electromagnetic body, and the magnetic field generated by a large number of magnets 520 can act on the second coil 510b and superimpose with the magnetic field generated by the second coil 510b, thereby increasing the electromagnetic force between the electromagnetic force module 500; and the first coil 510a and the second coil 510b are spaced far apart, which can avoid the coils 510 from affecting each other and weakening the magnetic field.

[0079] It should be noted that for Figure 6 Figure (c) in Figure 6 Figure (d) in Figure 7 Figure (e) and Figure 7 In the embodiment shown in Figure (f), each circle of electromagnetic bodies is not limited to a circular arrangement, a polygonal arrangement, etc., for example, one circle of electromagnetic bodies is a circular arrangement, one circle of electromagnetic bodies is a hexagonal arrangement, one circle of electromagnetic bodies is a pentagonal arrangement, etc.

[0080] In one embodiment, if Figure 8 The electromagnetic force module 500 includes a plurality of magnetic units 530, and the magnetic units 530 are arranged along a first direction and / or a second direction, and the first direction and the second direction are both parallel to the middle plane. Each magnetic unit 530 includes at least one magnet 520 and a plurality of coils 510 arranged around the outer periphery of the magnet 520. In each magnetic unit 530, after being energized, the coil 510 has the same magnetic pole as the magnet 520 at the same end in the vertical direction. The direction of the magnetic field applied by the magnet 520 on the coil 510 is the same as the direction of the magnetic field of the coil 510 itself. The magnetic poles of the magnets 520 at the same end in the vertical direction in the magnetic units 530 adjacent to each other along the first direction are opposite. Similarly, the magnetic poles of the magnets 520 at the same end in the vertical direction in the magnetic units 530 adjacent to each other along the second direction are opposite.

[0081] On the one hand, the coil 510 is surrounded by multiple magnets 520, and the magnetic field generated by the coil 510 in each magnetic unit 530 can be superimposed on the magnetic field of the multiple magnets 520 acting on the coil 510, and the multiple magnetic units 530 provide magnetic fields at the same time, which can increase the electromagnetic force between the two electromagnetic force modules 500; on the other hand, the distance between the coils 510 with the same magnetic field direction is increased to avoid the coils 510 from affecting each other and weakening the magnetic field, and the magnets 520 are surrounded by the outer circumference of the coil 510, and the coils 510 in adjacent magnetic units 530 are separated by magnets 520, and the adjacent magnets 520 in adjacent magnetic units 530 have opposite vertical magnetic poles, and the magnetic field direction of one magnet 520 acting on another magnet 520 is the same as the magnetic field direction of the other magnet 520 itself, so that the magnetic fields generated by the adjacent magnets 520 can be superimposed, which can further increase the electromagnetic force between the electromagnetic force modules 500.

[0082] It should be noted that the vertical magnetic pole of each coil 510 is opposite to the vertical magnetic pole of the closest coil 510 or magnet 520, and the vertical magnetic pole of each magnet 520 is opposite to the vertical magnetic pole of the closest coil 510 or magnet 520, so that the magnetic field generated by the coil 510 can be superimposed with the magnetic fields generated by multiple magnets 520 to maximize the enhancement of the electromagnetic force between the electromagnetic force modules 500.

[0083] In addition, the number of magnets 520 in each magnetic unit 530 is not limited. Figure 8 In FIG. (g), each magnetic unit 530 includes four magnets 520, such as Figure 8 In FIG. 5( h ) , each magnetic unit 530 includes five magnets 520 .

[0084] It should be noted that Figure 6-Figure 8 The "S" and "N" are only used to indicate whether the magnetic poles at the same end of the coil 510, the coil 510 and the magnet 520, or the magnet 520 and the magnet 520 are consistent along the vertical direction. The magnetic poles of the coil 510 and the magnet 520 can be reasonably adjusted according to the actual processing conditions.

[0085] Reference Figure 5 and Fig. 9 The electromagnetic force module 500 also includes a shell 540, which is provided with a first mounting cavity 541 and a second mounting cavity 542. The magnet 520 is fixed in the first mounting cavity 541, and the coil 510 is fixed in the second mounting cavity 542. The magnet 520 and the coil 510 are assembled in the shell 540, so that the electromagnetic force module 500 is an integral structure and is applied to the wafer thinning equipment, which is more convenient to use.

[0086] like Figure 5As shown, the shell 540 includes an outer shell 543 and a mounting plate 544. The outer shell 543 is snapped onto one side of the mounting plate 544 along the vertical direction. The inner cavity of the shell 540 is defined between the outer shell 543 and the mounting plate 544. The mounting plate 544 is embedded in the inner part of the outer shell 543. The threaded fasteners are inserted into the outer shell 543 and the mounting plate 544 along the circumferential side of the outer shell 543, and the outer shell 543 and the mounting plate 544 are locked.

[0087] The electromagnetic force module 500 further includes a bracket 560, which is mounted on the side of the mounting plate 544 facing the housing 543. The interior of the bracket 560 defines a first mounting cavity 541 and a second mounting cavity 542, which penetrate vertically. The threaded fastener is inserted into the mounting plate 544 on the side of the mounting plate 544 facing away from the housing 543, and the iron core 550 is fixed to the mounting plate 544. The coil 510 is sleeved on the outer periphery of the iron core 550. The electromagnetic force module 500 further includes a plurality of cover plates 570, at least part of which is located in the first mounting cavity 541. The cover plates 570 are located on the side of the magnet 520 facing away from the mounting plate 544. The periphery of the magnet 520 is limited by the cavity wall of the first mounting cavity 541. The two ends of the magnet 520 are respectively limited by the mounting plate 544 and the cover plates 570, and are firmly fixed in the first mounting cavity 541.

[0088] The installation method of the cover plate 570 to the first installation cavity 541 is not limited to snap-in, plug-in, etc.; illustratively, the inner wall of the first installation cavity 541 and the cover plate 570 are provided with mutually cooperating snaps, and the cover plate 570 is snap-fitted to the inside of the first installation cavity 541 to limit the magnet 520.

[0089] In addition, the electromagnetic force module 500 also includes a cooling plate 580, which is attached to at least one vertical surface of the shell 540. The cooling plate 580 is not limited to being set as a liquid cooling plate, a refrigeration plate, etc., and can provide cooling. The coil 510 generates heat during operation, and the heat is easily accumulated inside the shell 540, causing the electromagnetic force module 500 to be high temperature, affecting the working efficiency of the electromagnetic force regulating device. The cooling plate 580 is used to cool the shell 540 to keep the electromagnetic force module 500 within a suitable temperature range.

[0090] The electromagnetic force module 500 also includes a base plate 590. The mounting plate 544, the cooling plate 580 and the base plate 590 can be locked and fixed by threaded fasteners. The cooling plate 580 is located between the base plate 590 and the mounting plate 544, which can reduce the impact of the external environment on the cooling plate 580 and enhance the overall structural strength of the electromagnetic force module 500.

[0091] In one embodiment, the cooling plate 580 is located between the bottom plate 590 and the mounting plate 544, and the bottom plates 590 of the two electromagnetic force modules 500 are disposed back to back so that the two electromagnetic force modules 500 are closer to each other, thereby enhancing the electromagnetic force between the electromagnetic force regulating devices.

[0092] The present invention also provides a wafer thinning processing method, which is performed by the above-mentioned wafer thinning processing system. The wafer thinning processing method comprises the following steps:

[0093] The wafer is placed on the top of the processing platform 200 and fixed, and the base frame 300 is controlled to carry the rotating shaft down to a preset height. At this time, the processing head 400 contacts the surface of the wafer, and the processing head 400 is controlled to work and thin the wafer. During the wafer thinning process, the pressure detection module 620 detects the processing pressure between the processing head 400 and the wafer, and the control module 610 sends a control instruction to the power supply 630 according to the processing pressure. The power supply 630 changes the power supply to the electromagnetic force module 500 according to the control instruction to adjust the electromagnetic force between the two electromagnetic force modules 500. The adjustment of the electromagnetic force is achieved by changing the power supply of the power supply 630 to the electromagnetic force module 500, with fast response speed and high adjustment accuracy, and can accurately control the thinning thickness of the wafer and improve the processing efficiency of the wafer.

[0094] The way to change the amount of power supplied by the power supply 630 to the electromagnetic force module 500 may be to change the magnitude of the current supplied by the power supply 630 to the electromagnetic force module 500, that is, to reduce the current supplied by the power supply 630 to the coil 510 to reduce the electromagnetic force applied by the electromagnetic force module 500 to the spindle 100, and to increase the current supplied by the power supply 630 to the coil 510 to increase the electromagnetic force applied by the electromagnetic force module 500 to the spindle 100. Alternatively, the way to change the amount of power supplied by the power supply 630 to the electromagnetic force module 500 may be to cut off the electrical conduction between the power supply 630 and part of the coil 510, reduce the number of coils 510 capable of generating a magnetic field, reduce the electromagnetic force applied by the electromagnetic force module 500 to the spindle 100, and after restoring the electrical conduction between the power supply 630 and the coil 510, increase the number of coils 510 capable of generating a magnetic field, and increase the electromagnetic force applied by the electromagnetic force module 500 to the spindle 100.

[0095] In addition, in the case where an elastic member 700 is provided between the spindle 100 and the base frame 300, the elastic member 700 can provide an upward elastic force to the spindle 100. After the base frame 300 is controlled to carry the spindle 100 down to a preset height, the pressure between the processing head 400 and the wafer is a first pressure F1, and the elastic member 700 has a first compression amount L1; then, the base frame 300 is controlled to carry the spindle 100 back a preset distance upward, and the pressure between the processing head 400 and the wafer is a second pressure F2, and the elastic member 700 has a second compression amount L2, and F1>F2, L1<L2; then, the processing head 400 is controlled to work at the second pressure F2.

[0096] In this process, the spindle 100 is first lowered to a preset height by the base 300, at which time there is an initial pressure F1 between the processing head 400 and the wafer, and the elastic member 700 has an initial compression amount L1, which is greater than the processing pressure required by the wafer. Then the base 300 is controlled to retract, and the compression amount of the elastic member 700 increases. At this time, the pressure between the processing head 400 and the wafer is reduced to F2, which matches the processing pressure required by the wafer, and the processing head 400 can continue to be controlled to work at the second pressure F2. That is, the lifting and lowering of the base can change the compression amount of the elastic member 700, so as to change the elastic force applied by the elastic member 700 to the spindle 100, so that the pressure applied by the processing head 400 to the wafer is within the range that can be adjusted by the electromagnetic force module 500.

[0097] Further, the electromagnetic force range applied by the electromagnetic force module 500 to the spindle 100 is defined as 0-F. Before the processing head 400 processes the wafer, such as when the processing pressure is adjusted to F2, the electromagnetic force applied by the electromagnetic force module 500 to the spindle 100 is set to F / 2, so that during the thinning process of the wafer by the processing head 400, by changing the electromagnetic force applied by the electromagnetic force module 500 to the spindle 100, the actual processing pressure can be less than F2 or greater than F2, so as to adapt to the situation where the processing pressure of the wafer is too large or too small during the processing. That is, when the electromagnetic force is adjusted between 0-F / 2, the actual processing pressure is less than F2, and when the electromagnetic force is adjusted between F / 2-F, the actual processing pressure is greater than F2.

[0098] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A wafer thinning processing system, characterized in that: include: The spindle, the lower end of which is used to mount the processing head; A processing platform, located below the spindle and used to fix the wafer to be processed; A base frame, the main shaft is vertically slidably connected to the base frame and can be lifted and lowered relative to the base frame; Two electromagnetic force modules are arranged vertically opposite to each other, one of which is connected to the main shaft, and the other is connected to the base frame. When the two electromagnetic force modules are powered on, mutual electromagnetic force can be generated; The pressure regulating unit includes a control module, a pressure detection module and a power supply. The power supply is electrically connected to the electromagnetic force module and supplies power to the electromagnetic force module. The pressure detection module is used to detect the processing pressure between the processing head and the wafer. The control module is used to change the power supply of the power supply to the electromagnetic force module according to the processing pressure to adjust the electromagnetic force between the two electromagnetic force modules.

2. The wafer thinning processing system according to claim 1, characterized in that: The wafer thinning processing system also includes an elastic member capable of elastically expanding and contracting in the vertical direction, wherein the elastic member is used to provide an upward elastic force to the main shaft, and the elastic member is connected between the upper end of the main shaft and the upper end of the base frame, and / or the elastic member is connected between the lower end of the main shaft and the upper end of the base frame.

3. The wafer thinning processing system according to claim 1, characterized in that: The electromagnetic force module includes a coil and a magnet. The coil can generate a magnetic field when energized. The direction of the magnetic field of at least part of the magnet acting on the coil is the same as the direction of the magnetic field of the coil itself. The power supply is used to supply power to the coil.

4. The wafer thinning processing system according to claim 3, characterized in that: Of the two electromagnetic force modules, the electromagnetic force module with a larger height is connected to the base frame, and the electromagnetic force module with a smaller height is connected to the main shaft, and there is an electromagnetic force of attraction between the two electromagnetic force modules; Alternatively, of the two electromagnetic force modules, the electromagnetic force module with a smaller height is connected to the base frame, and the electromagnetic force module with a larger height is connected to the main shaft, and there is a repulsive electromagnetic force between the two electromagnetic force modules.

5. The wafer thinning processing system according to claim 3, characterized in that: The electromagnetic force module also includes an iron core, and the coil is sleeved on the outside of the iron core.

6. The wafer thinning processing system according to claim 3, characterized in that: The electromagnetic force module includes a coil and a plurality of magnets. The plurality of magnets are arranged around the outer circumference of the coil, and the magnetic poles of each magnet along the same vertical end are the same.

7. The wafer thinning processing system according to claim 3, characterized in that: In the same electromagnetic force module, the coil located at the center of the electromagnetic force module is the first coil, and the other coils are the second coils, the second coil is arranged at least one circle around the circumference of the first coil, the magnet is arranged at least one circle around the circumference of the first coil, the coils and the magnets are arranged alternately along the radial direction of the first coil, the magnetic fields generated by all the coils are in the same direction, and the magnetic poles of all the magnets at the same end along the vertical direction are the same; Alternatively, the electromagnetic force module includes multiple magnetic units, which are arranged along the first direction and / or the second direction, and each of the magnetic units includes at least one magnet and a plurality of coils arranged around the magnet. In each of the magnetic units, the direction of the magnetic field applied by the magnet to the coil is the same as the direction of the magnetic field of the coil itself. The magnetic poles of the magnets in the magnetic units adjacent to each other along the first direction and / or the second direction at the same end along the first direction are opposite, and the first direction, the second direction, and the vertical direction are perpendicular to each other.

8. A wafer thinning method, characterized in that: The method is performed by using a wafer thinning processing system according to any one of claims 1 to 7, comprising: The wafer is placed on the top of the processing platform, and after the base frame carrying the spindle is controlled to descend to a preset height, the processing head starts to work and thins the wafer; The pressure detection module detects the processing pressure between the processing head and the wafer, the control module sends a control instruction to the power supply according to the processing pressure, and the power supply changes the power supply to the electromagnetic force module according to the control instruction to adjust the electromagnetic force between the two electromagnetic force modules.

9. The wafer thinning method according to claim 8, characterized in that: The step of the power supply changing the power supply amount of the electromagnetic force module according to the control instruction comprises: Changing the current magnitude of the power supply passing through the electromagnetic force module; And / or, the electromagnetic force module includes a coil and a magnet, the coil can generate a magnetic field when energized, the direction of the magnetic field acting on the coil by at least part of the magnet is the same as the direction of the magnetic field of the coil itself, and the power supply is used to supply power to the coil and restore or cut off the electrical connection between part of the coil and the power supply.

10. The wafer thinning method according to claim 8, characterized in that: Also includes: An elastic member is provided between the main shaft and the base frame, and an upward elastic force is provided to the main shaft through the elastic member; After controlling the base frame carrying the spindle to descend to a preset height, the pressure between the processing head and the wafer is a first pressure F1, and the elastic member has a first compression amount L1; then, controlling the base frame to retreat a preset distance, so that the pressure between the processing head and the wafer is a second pressure F2, and the elastic member has a second compression amount L2, L1>L2, F1>F2; then controlling the processing head to start working at the second pressure F2.

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