A semiconductor wafer edge polishing device and its polishing method

Abstract

The present invention relates to the technical field of semiconductor wafer processing, and specifically to a semiconductor wafer edge polishing device and a polishing method thereof, including an operation platform, a polishing part, a positioning unit and a driving part. First, the present invention uses the reference surface of the reference plate as the placement reference during the placement process, ensuring the accuracy of the wafer position and guaranteeing the processing accuracy. Secondly, the auxiliary pressing part is used to balance the acting force generated by polishing at the processing position of the wafer, avoiding the problem of wafer damage caused by unbalanced force on the wafer. In addition, by controlling the distance of the lifting plate moving downward, the moving distance of the grinding disc approaching the wafer is strictly controlled, avoiding excessive stress applied by the grinding disc on the wafer during the process of moving and contacting the wafer, and at the same time avoiding excessive contact between the grinding disc and the wafer resulting in over-polishing of the wafer.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor wafer processing, and specifically to a semiconductor wafer edge polishing device and a polishing method thereof. Background Art

[0002] A semiconductor wafer is a basic material for manufacturing semiconductor devices, usually made of high-purity monocrystalline silicon. Since the edge region of the wafer is prone to become a stress concentration point, it may cause the generation or expansion of cracks in subsequent process steps. During wafer cutting and processing, some micro damages or defects may occur at the edge. Therefore, during the semiconductor wafer processing, it is necessary to grind and polish the edge of the wafer.

[0003] Currently, common edge polishing methods for wafers include mechanical polishing and chemical mechanical polishing. In the mechanical polishing operation process, mainly a grinding disc (abrasive) is used to grind and polish the edge of the wafer. In the current mechanical polishing operation process, first the wafer is fixed, and then the grinding disc is moved to grind the edge of the wafer, so that the required arc shape is formed at the edge of the wafer. Refer to Figure 9 .

[0004] The following problems exist in the above operation process: For the process of the wafer and the grinding disc approaching each other, the moving distance between the two is not strictly limited, so the grinding disc will generate a large mechanical stress on the wafer. At the same time, the stress generated by the grinding disc on the wafer cannot be balanced. Therefore, the wafer is unevenly stressed, so it is easy to cause damage to the wafer, affecting the reliability of the final product device. Secondly, it is easy to cause excessive polishing of the wafer, affecting the docking accuracy in the subsequent semiconductor wafer lithography process. Summary of the Invention

[0005] Based on this, it is necessary to provide a semiconductor wafer edge polishing device, aiming to solve the problems of the above-mentioned existing technologies.

[0006] The present application provides a semiconductor wafer edge polishing device, including: an operation platform, on which three platform plates are fixedly arranged. A polishing mechanism is arranged on the operation platform. The polishing mechanism includes a supporting plate corresponding to each platform plate. Three supporting plates are rotatably arranged on the operation platform, and a lower pressing plate for pressing the wafer on the supporting plate is arranged on the operation platform.

[0007] A polishing part for polishing the edge of the wafer is arranged on the platform plate. The polishing part includes a grinding disc for polishing the edge of the wafer. A positioning unit for supporting and positioning the wafer is arranged on the operation platform.

[0008] A driving part is arranged on the operation platform. The driving part drives the positioning unit to position and lock the wafer and drives the grinding disc to move a specified distance to perform edge polishing operation on the wafer.

[0009] The positioning unit includes a reference plate, and the reference plate that slides up and down is arranged on the working platform. The end faces of the reference plate facing the three platform plates are, from top to bottom, an arc-shaped avoidance surface and an arc-shaped reference surface in sequence. The axes of the avoidance surface and the reference surface are collinear with the axis of the supporting plate.

[0010] A secondary pressing part is arranged on the reference plate, and the force balance between the self-grinding disk and the reference plate on the wafer is maintained through the secondary pressing part.

[0011] According to a preferred embodiment, a frame-shaped rack that slides radially along the working platform is arranged on the platform plate. A grinding shaft with a vertical axis is rotatably arranged on the frame-shaped rack, and the grinding disk is fixedly sleeved on the grinding shaft. The driving part includes a self-rotating motor. An end face of the upper end of the working platform is fixedly provided with a self-rotating motor corresponding to each supporting plate and used for driving the supporting plate to rotate. A gear ring is rotatably arranged on the lower end face of the working platform. A transmission gear that meshes with the gear ring and corresponds to each grinding shaft is rotatably arranged on the lower end face of the working platform through a transmission shaft. The transmission shaft and the adjacent grinding shafts are connected and cooperated through a transmission belt. A driving gear that meshes with the gear ring is rotatably arranged on the lower side of the working platform through a driving shaft, and the driving shaft is connected to a driving motor installed on the working platform.

[0012] According to a preferred embodiment, a fixed rod coaxial with the working platform is fixedly arranged on the working platform. The reference plate is sleeved on the fixed rod and slides up and down. A rotating plate sleeved on the fixed rod is rotatably arranged on the working platform. A scroll spring is jointly fixedly arranged between the rotating plate and the working platform. Three circumferentially distributed connecting plates are fixedly arranged on the rotating plate. A sliding block fixedly connected to the corresponding connecting plate is slidably arranged on the working platform. A spreading wheel for tightening the corresponding transmission belt is arranged on the sliding block. A locking part for locking the tightened state of the transmission belt is arranged on the working platform.

[0013] According to a preferred embodiment, the positioning unit further includes a lifting plate. A lifting plate that slides up and down is sleeved on the fixed rod. The lifting plate is located above the reference plate. Pressing columns that penetrate up and down are slidably arranged on the three branches of the lifting plate. A lower pressing plate is rotatably arranged on the lower end face of the pressing column. A pressing spring sleeved on the pressing column is jointly arranged between the lower pressing plate and the lifting plate.

[0014] According to a preferred embodiment, the locking part includes a locking groove. The locking groove is formed on the connecting plate. A locking column that cooperates with the locking groove is fixedly arranged on the lifting plate through a connecting frame. The locking column is inserted into the locking groove to lock the connecting plate and the sliding block, and maintain the tightened transmission state of the transmission belt.

[0015] According to a preferred embodiment, a pushing cylinder sleeved on the fixed rod and used for pushing the reference plate to move down is fixedly arranged on the lower end face of the lifting plate. An installation circular plate located below the reference plate is fixedly sleeved on the fixed rod. A supporting spring sleeved on the fixed rod is jointly fixedly arranged between the installation circular plate and the reference plate.

[0016] According to an advantageous embodiment, the auxiliary pressing part includes a lower pressing block, the lower pressing block is fixedly arranged on the avoidance surface, and a plurality of auxiliary pressing rollers are rotatably arranged on the lower end surface of the lower pressing block and are circumferentially distributed with respect to the axis of the arc surface of the avoidance surface.

[0017] According to an advantageous embodiment, a sliding frame is slidably arranged on the platform plate along the radial direction of the working platform. A return spring is fixedly arranged between the sliding frame and the platform plate. A moving block is slidably arranged in the sliding frame along its sliding direction. A frame-shaped frame is fixedly arranged on the moving block. A supplementary spring is fixedly arranged between the moving block and the sliding frame. The supplementary spring is used to adaptively compensate for the lost moving distance after the edge is worn. The driving part further includes a wedge block. The wedge block is fixedly arranged on the sliding frame. The inclined surface of the wedge block slopes upward from the platform plate to the working platform. Matching plates cooperating with the corresponding wedge blocks are fixedly arranged on the three branches of the lifting plate.

[0018] According to an advantageous embodiment, an adapting frame is slidably arranged on each of the three branches of the lifting plate along the corresponding length direction. A return spring is also fixedly arranged between the adapting frame and the lifting plate. An adapting block is slidably arranged in the adapting frame. A supplementary spring is also fixedly arranged between the adapting block and the adapting frame. The lower end surface of the adapting block is fixedly provided with two insertion rods located on both sides of the corresponding branch of the lifting plate and with vertical axes through a horizontal plate. Insertion slots corresponding to the insertion rods are formed in the horizontal section of the frame-shaped frame.

[0019] In summary, the present invention includes at least one of the following beneficial effects: First, the present invention first uses the reference surface of the reference plate as the placement reference during the placement process, ensuring the accuracy of the wafer position and guaranteeing the processing accuracy. Secondly, the auxiliary pressing part is used to balance the acting force generated by polishing the wafer at the processing location, avoiding damage to the wafer caused by unbalanced force, and by controlling the downward movement distance of the lifting plate, strictly controlling the movement distance of the grinding disc approaching the wafer, avoiding excessive stress applied by the grinding disc on the wafer during the process of moving and contacting the wafer, and at the same time avoiding excessive polishing of the wafer due to excessive contact between the grinding disc and the wafer.

[0020] Second, the reference surface on the reference plate in the present invention is used as the placement reference during the wafer placement process, improving the accuracy of the wafer placement position. At the same time, after it moves downward, the avoidance surface of the reference plate faces the wafer, avoiding the wafer from contacting the reference plate during the rotary polishing process and being interfered to affect the polishing, improving the stability of the wafer during the polishing process.

[0021] Third, in the present invention, the docking inside the upper side direction of the frame-shaped frame is completed by inserting the insertion rods into the corresponding insertion slots, improving the stability of the frame-shaped frame during the movement process. Finally, the branches of the lifting plate and the platform plate form a stability maintenance framework on the upper and lower sides, so indirectly improving the stability during the grinding of the grinding disc. Description of the Drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0023] Figure 1 The three-dimensional structural schematic diagram of a semiconductor wafer edge polishing device provided according to an embodiment of the present invention is shown.

[0024] Figure 2 The three-dimensional structural schematic diagram among the operation platform, the lifting plate and the auxiliary pressing part provided according to an embodiment of the present invention is shown.

[0025] Figure 3 The partial sectional three-dimensional structural schematic diagram among the lower pressing plate, the lifting plate and the fitting plate provided according to an embodiment of the present invention is shown.

[0026] Figure 4 The one provided according to an embodiment of the present invention is shown Figure 3 The enlarged view at A in

[0027] Figure 5 The right view among the wedge block, the pushing cylinder and the lifting plate provided according to an embodiment of the present invention is shown.

[0028] Figure 6 The partial sectional three-dimensional schematic diagram among the scroll spring, the lifting plate and the connecting plate provided according to an embodiment of the present invention is shown.

[0029] Figure 7 The one provided according to an embodiment of the present invention is shown Figure 6 The enlarged view at B in

[0030] Figure 8 The partial sectional three-dimensional schematic diagram among the reference plate, the lifting plate and the compensating spring provided according to an embodiment of the present invention is shown.

[0031] Figure 9 The schematic diagram of the contact process between the wafer and the grinding disc provided according to an embodiment of the present invention is shown.

[0032] Among them, the above-mentioned attached drawings include the following reference numerals: 1, working platform; 10, platform plate; 2, polishing mechanism; 20, supporting plate; 21, lower pressing plate; 3, polishing part; 30, grinding disc; 31, frame-shaped frame; 32, grinding shaft; 4, positioning unit; 40, reference plate; 41, avoiding surface; 42, reference surface; 43, lifting plate; 44, lower pressing column; 440, pressing spring; 45, pushing cylinder; 450, mounting circular plate; 451, supporting spring; 46, sliding frame; 460, reset spring; 461, moving block; 462, compensating spring; 47, adapting frame; 470, adapting block; 471, inserting rod; 5, driving part; 51, gear ring; 52, transmission gear; 53, transmission belt; 54, driving gear; 55, scroll spring; 550, connecting plate; 551, sliding block; 552, spreading wheel; 56, locking part; 560, locking groove; 561, locking column; 57, wedge block; 570, cooperating plate; 6, auxiliary pressing part; 60, lower pressing block; 61, auxiliary pressing roller. Detailed implementation manners

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific implementation manners of the present invention will be given with reference to the attached drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0034] As Figure 1 , Figure 2 and Figure 3 shown, a semiconductor wafer edge polishing device includes: a working platform 1, on which three circumferentially distributed platform plates 10 are fixedly arranged. A polishing mechanism 2 is arranged on the working platform 1. The polishing mechanism 2 includes supporting plates 20 corresponding to the platform plates 10 one by one. Three circumferentially distributed supporting plates 20 for supporting and placing wafers are rotatably arranged on the working platform 1 through an L-shaped frame. A lower pressing plate 21 for pressing the wafer onto the supporting plate 20 is arranged on the working platform 1.

[0035] As Figure 1 , Figure 2 and Figure 3 shown, a polishing part 3 for polishing the edge of the wafer is arranged on the platform plate 10. The polishing part 3 includes a grinding disc 30. A positioning unit 4 for supporting and positioning the wafer is arranged on the working platform 1.

[0036] As Figure 2 and Figure 3As shown, a driving part 5 is arranged on the working platform 1. The driving part 5 drives the positioning unit 4 to position and lock the wafer and drives the grinding disc 30 to perform edge polishing on the wafer.

[0037] As Figure 3 shown, the positioning unit 4 includes a reference plate 40. A fixed rod coaxial with the working platform 1 is fixedly arranged on the working platform 1. The reference plate 40 is sleeved on the fixed rod and can slide up and down. Refer to Figure 3 and Figure 8 . The end faces of the reference plate 40 facing the three platform plates 10 are, from top to bottom, an arc-shaped avoidance surface 41 and an arc-shaped reference surface 42 in sequence. The axes of the avoidance surface 41 and the reference surface 42 are collinear with the axis of the supporting plate 20. When the reference surface 42 faces the wafer, the wafer being attached to the reference surface 42 is used as the placement reference. When the avoidance surface 41 faces the wafer, edge polishing is performed on the wafer. In order to reduce the friction generated between the reference plate 40 and the wafer during the downward movement of the reference plate 40, the reference surface 42 is made of materials with low friction coefficient, high purity and good wear resistance, such as ceramics, Teflon, silicon carbide, silicon and other materials.

[0038] As Figure 2 and Figure 3 shown, an auxiliary pressing part 6 is arranged on the reference plate 40 to maintain the force balance on the wafer from the contact point between the grinding disc 30 and the wafer to the reference plate 40 through the auxiliary pressing part 6.

[0039] It should be noted that since semiconductor wafers are very fragile and vulnerable to particles, chemicals and static electricity, the operation is performed by a manipulator (which belongs to the prior art) during the process of picking and placing semiconductor wafers. Before the edge polishing operation, the manipulator grabs the wafer and places it on the supporting plate 20, and then positioning and edge polishing are carried out. In order to protect the pollution-free nature of the wafer processing environment, a protective cover capable of sliding up and down is arranged on the upper end face of the working platform 1. During the process of placing and taking out the wafer, the protective cover moves up for avoidance. After the protective cover moves down, the processing environment is protected by the protective cover during wafer processing. Refer to Figure 1 .

[0040] During operation, three wafers are placed on the support plate 20, and the position of the wafers is controlled by the robot so that the edge of the wafer is close to the reference surface 42 of the reference plate 40. At this time, the axis of the grinding disc 30 coincides with the axis of the corresponding support plate 20, and the positioning operation of the support plate 20 is completed. Then the driving unit 5 works, firstly moving the lower pressure plate 21 downward to press the wafer to complete the positioning of the wafer. The driving unit 5 makes the grinding discs 30 in the three polishing parts 3 close to the corresponding wafers, and finally the grinding discs 30 move to contact with the wafers, and then the driving unit 5 makes the grinding discs 30 The grinding wheel 30 rotates synchronously with the wafer, and the two rotate in opposite directions. The grinding wheel 30 polishes the circumferential edge of the wafer. Secondly, while the lower pressure plate 21 presses the wafer, the reference plate 40 moves downward, and the reference surface 42 of the reference plate 40 moves to the bottom of the wafer as the reference plate 40 moves downward. Finally, the avoidance surface 41 of the reference plate 40 is opposite to the wafer, and the reference surface 42 of the reference plate 40 is staggered with the wafer, so as to avoid the friction of the reference plate 40 on the rotation polishing process of the wafer. Secondly, the auxiliary pressure part 6 presses the wafer to maintain the stability during the polishing process.

[0041] like Figure 2 , Figure 3 , Figure 5 , Figure 6 and Figure 7 As shown, a frame 31 is provided on the platform plate 10 for radial sliding along the working platform 1, a grinding shaft 32 with a vertical axis is rotatably provided on the frame 31, the grinding disc 30 is fixedly sleeved on the grinding shaft 32, the driving part 5 includes a self-rotating motor, a self-rotating motor corresponding to the supporting plate 20 and used to drive the corresponding supporting plate 20 to rotate is fixedly provided on the upper end surface of the working platform 1, a gear ring 51 is rotatably provided on the lower end surface of the working platform 1, a transmission gear 52 meshing with the gear ring 51 and corresponding to the grinding shaft 32 is rotatably provided on the lower end surface of the working platform 1 through a transmission shaft, the transmission shaft and the adjacent grinding shaft 32 are connected and cooperated by a transmission belt 53, a driving gear 54 meshing with the gear ring 51 is rotatably provided on the lower side of the working platform 1 through a driving shaft, and the driving shaft is connected to a driving motor installed on the working platform 1.

[0042] like Figure 2 , Figure 6 and Figure 7 As shown, the working platform 1 is rotatably provided with a rotating plate sleeved on a fixed rod, a spiral spring 55 is fixedly provided between the rotating plate and the working platform 1, three circumferentially distributed connecting plates 550 are fixedly provided on the rotating plate, a sliding block 551 fixedly connected to the corresponding connecting plate 550 is slidably provided on the working platform 1, a stretching wheel 552 for tightening the corresponding transmission belt 53 is provided on the sliding block 551, and a locking portion 56 for locking the transmission belt 53 in a taut state is provided on the working platform 1.

[0043] like Figure 1 , Figure 2and Figure 6 As shown, the positioning unit 4 further includes a lifting plate 43. A lifting plate 43 that slides up and down and is in a trident shape is sleeved on the fixed rod. The lifting plate 43 is driven by an external electric guide rod (not shown in the figure) to move up and down. The locking portion 56 includes a locking groove 560. The locking groove 560 is formed on the connecting plate 550. A locking column 561 that cooperates with the locking groove 560 is fixedly provided on the lifting plate 43 through a connecting frame. The locking column 561 is inserted into the locking groove 560 to lock the connecting plate 550 and the sliding block 551, maintaining the tensioned transmission state of the transmission belt 53. In order to cooperate with the subsequent adaptive movement process of the grinding disc 30 during the polishing process, the aperture of the locking groove 560 is larger than the diameter of the locking column 561.

[0044] After the wafer is placed on the supporting plate 20, the external electric guide rod works, causing the lifting plate 43 to move downward. The lifting plate 43 moves downward, causing the three grinding discs 30 to approach the wafer. The scroll spring 55 is in a deformed state initially. During the process of the grinding disc 30 approaching the wafer, the grinding shaft 32 approaches the wafer synchronously. The elastic force generated by the deformation of the scroll spring 55 causes the rotating plate to drive the sliding block 551 and the spreading wheel 552 to rotate adaptively through the connecting plate 550, and the transmission belt 53 is initially maintained in a tensioned state during this process. Secondly, as the lifting plate 43 continues to move downward, the grinding disc 30 contacts the wafer and cooperates with the corresponding reference surface 42 to position the reference. At the same time, the lower pressing plate 21 presses the wafer. Then, the connecting plate 550 gradually rotates to directly below the corresponding locking column 561. The lifting plate 43 drives the locking column 561 thereon to be inserted into the corresponding locking groove 560, finally locking the spreading wheel 552 and maintaining the tensioned transmission state of the transmission belt 53.

[0045] When polishing operations need to be performed, the driving motor and the self-rotating motor operate synchronously. The self-rotating motor drives the supporting plate 20, the wafer, and the lower pressing plate 21 to rotate synchronously. The driving motor drives the driving gear 54 to rotate synchronously and drives the ring gear 51 to rotate synchronously through the cooperation between the driving gear 54 and the ring gear 51. Through the meshing between the ring gear 51 and the transmission gear 52, the three transmission gears 52 drive the transmission shaft to rotate synchronously. Finally, through the transmission of the transmission belt 53, the three grinding shafts 32 drive the grinding discs 30 to rotate synchronously, and the grinding discs 30 rotate in the opposite direction to the wafer. The grinding discs 30 polish the edge of the wafer.

[0046] As Figure 3As shown, all three branches of the lifting plate 43 are located directly above the corresponding supporting plates 20. The lifting plate 43 is located above the reference plate 40. Pressing columns 44 are slidably penetrated through the three branches of the lifting plate 43 in the up and down direction. The lower pressing plate 21 is rotatably arranged on the lower end surface of the pressing column 44. In order to avoid contaminating or damaging the wafer, the end surfaces of the lower pressing plate 21 and the supporting plate 20 that contact the wafer are made of materials with high purity and low pollution risk. A pressing spring 440 sleeved on the pressing column 44 is commonly arranged between the lower pressing plate 21 and the lifting plate 43. Among them, the pressing spring 440 can be rotatably connected to the lower pressing plate 21 or abuts against the lower pressing plate 21, so as not to affect the rotation process of the lower pressing plate 21 with the wafer during the polishing process.

[0047] As Figure 5 shown, a pushing cylinder 45 sleeved on the fixed rod and used to push the reference plate 40 downward is fixedly arranged on the lower end surface of the lifting plate 43. An installation circular plate 450 is fixedly sleeved on the fixed rod and located below the reference plate 40. A supporting spring 451 sleeved on the fixed rod is commonly fixedly arranged between the installation circular plate 450 and the reference plate 40.

[0048] As Figure 2 、 Figure 3 and Figure 4 shown, the auxiliary pressing part 6 includes a pressing block 60. The pressing block 60 is fixedly arranged on the avoiding surface 41. A plurality of auxiliary pressing rollers 61 distributed circumferentially with the axis of the arc surface of the avoiding surface 41 as the center are rotatably arranged on the lower end surface of the pressing block 60. The material of the auxiliary pressing rollers 61 is the same as that of the lower pressing plate 21 and the supporting plate 20.

[0049] As Figure 3 and Figure 8 shown, a sliding frame 46 is slidably arranged along the radial direction of the working platform 1 on the platform plate 10. A reset spring 460 is commonly fixedly arranged between the sliding frame 46 and the platform plate 10. A moving block 461 is slidably arranged in the sliding frame 46 along its sliding direction. A frame-shaped frame 31 is fixedly arranged on the moving block 461. A supplementary spring 462 is commonly fixedly arranged between the moving block 461 and the sliding frame 46. The moving distance lost due to edge wear is adaptively compensated by the supplementary spring 462. The driving part 5 further includes a wedge block 57. The wedge block 57 is fixedly arranged on the sliding frame 46. The inclined surface of the wedge block 57 slopes upward from the platform plate 10 to the working platform 1 direction. Three branches of the lifting plate 43 are all fixedly provided with matching plates 570 for cooperating with the corresponding wedge blocks 57.

[0050] During the downward movement of the lifting plate 43, the lifting plate 43 drives the matching plate 570 and the lower pressure plate 21 to move downward synchronously. The lower pressure plate 21 contacts the wafer before the matching plate 570 contacts the wedge block 57. As the lifting plate 43 continues to move downward, the pressure spring 440 is compressed. The elastic force generated by the deformation of the pressure spring 440 causes the lower pressure plate 21 to press tightly against the wafer, thereby avoiding the problem of position deviation during the subsequent downward movement of the reference plate 40.

[0051] As the lifting plate 43 continues to move downward, the lifting plate 43 drives the matching plate 570 to move downward and contact the wedge block 57. By applying pressure to the inclined surface of the wedge block 57, the wedge block 57 pushes the sliding frame 46 to move, and the sliding block 551 drives the moving block 461, the frame 31 and the grinding wheel 30 to synchronously approach the reference plate 40. It should be noted that the downward movement distance of the lifting plate 43 is a set value, that is, when the lifting plate 43 moves to the lowermost position, the grinding wheel 30 is in close contact with the wafer, and the compensation spring 462 set at this time is in a compressed state, that is, the grinding wheel 30 maintains a state of having a slight clamping force on the wafer (the value of the clamping force is controlled by controlling the downward movement distance of the lifting plate 43 to avoid excessive force on the wafer causing damage), thereby completing the preparation work before wafer polishing.

[0052] The lower pressure block 60 then drives the auxiliary pressure roller 61 thereon to press the upper end surface of the wafer. Therefore, at this time, only the grinding wheel 30 is in contact with the circumferential surface of the wafer, and the auxiliary pressure roller 61, the lower pressure plate 21 and the supporting plate 20 are in contact with the upper and lower surfaces of the wafer, so as to prevent the wafer from being disturbed by the outside during the rotational polishing process. Through the downward pressing action of the auxiliary pressure roller 61, two relative action areas are formed with the grinding position of the grinding wheel 30, so as to maintain the radial force balance of the wafer, and improve the stability of the wafer during the polishing process.

[0053] like Figure 8 As shown, an adapter frame 47 is slidably provided on the three branches of the lifting plate 43 along the corresponding length direction, and a reset spring 460 is also fixed between the adapter frame 47 and the lifting plate 43. An adapter block 470 is slidably provided in the adapter frame 47, and a compensation spring 462 is also fixedly provided between the adapter block 470 and the adapter frame 47. The lower end surface of the adapter block 470 is fixedly provided with two plug-in rods 471 located on both sides of the corresponding branches of the lifting plate 43 and with vertical axes through a horizontal plate, and a plug-in groove corresponding to the plug-in rod 471 is opened in the horizontal section of the frame 31.

[0054] When the lifting plate 43 moves downward and the mating plate 570 has not yet contacted the corresponding wedge block 57, the lifting plate 43 drives the insertion rod 471 thereon to insert into the corresponding insertion slot, completing the docking in the upper side direction of the frame 31, improving the stability of the frame 31 during movement, and ultimately enabling the branches of the lifting plate 43 and the platform plate 10 to form a stability framework on the upper and lower sides, indirectly improving the stability during the grinding of the grinding disc 30.

[0055] After the mating plate 570 cooperates with the wedge block 57, the upper compensation spring 462 and the lower compensation spring 462 are also compressed by a set degree. Therefore, when the grinding disc 30 continuously performs edge polishing on the wafer subsequently, the elastic force generated by the deformation of the two corresponding upper and lower compensation springs 462 causes the adapter block 470 and the moving block 461 to drive the frame 31 and the grinding disc 30 to approach the wafer, ensuring that the edge of the wafer can be polished and ground into the required arc shape. Refer to Figure 9 .

[0056] As Figures 1 - 9 shown, in addition, a semiconductor wafer edge polishing method is also included, which includes the following steps: S1. Placing the wafer: The wafer is grasped by a manipulator and placed on the corresponding supporting plate 20, and the circumferential surface of the wafer is closely attached to the corresponding reference surface 42 on the reference plate 40, completing the positioning and placing process of the wafer.

[0057] S2. Locking the wafer: After the wafer is placed on the supporting plate 20, the external electric guide rod works to make the lifting plate 43 move downward. The lifting plate 43 drives the lower pressing plate 21 to move downward synchronously, and when the lower pressing plate 21 contacts the wafer, the pressing spring 440 deforms, and the elastic force generated by the deformation makes the lower pressing plate 21 press the corresponding wafer.

[0058] S3. Disengaging and avoiding: When the lower pressing plate 21 presses the wafer, the lifting plate 43 pushes the reference plate 40 downward through the push cylinder 45, causing the reference surface 42 to disengage from the state of contacting the circumferential surface of the wafer, avoiding the polishing process of the wafer. Secondly, the driving part 5 makes the grinding disc 30 approach the wafer, and finally the grinding disc 30 moves to the specified position and contacts the wafer.

[0059] S4. Edge polishing: The driving part 5 works to make the grinding disc 30 and the wafer rotate synchronously, and the rotation directions of the two are opposite, and the grinding disc 30 polishes and grinds the circumferential edge of the wafer.

[0060] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, back, top, bottom, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom", etc. is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description. Without contrary instructions, these orientation words do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the present invention; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0061] In addition, the terms "first", "second", "No. 1", "No. 2" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", "No. 1", "No. 2" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0062] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "arranged", "connected", "installed", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0063] The embodiments of this specific implementation manner are all preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A semiconductor wafer edge polishing device, characterized in that, Including: An operation platform, on which three platform plates are fixedly arranged. A polishing mechanism is arranged on the operation platform. The polishing mechanism includes a supporting plate. Three supporting plates for supporting and placing wafers are rotatably arranged on the operation platform. A lower pressing plate for pressing the wafer onto the supporting plate is arranged on the operation platform. A polishing part for polishing the edge of the wafer is arranged on the platform plate. The polishing part includes a grinding disc for polishing the edge of the wafer. A positioning unit for supporting and positioning the wafer is arranged on the operation platform. A driving part is arranged on the operation platform. The driving part drives the positioning unit to position and lock the wafer and drives the grinding disc to move a specified distance to polish the edge of the wafer. The positioning unit includes a reference plate. A reference plate that slides up and down is arranged on the operation platform. The end face of the reference plate facing the three platform plates is sequentially an avoidance face and a reference face from top to bottom. The axes of the avoidance face and the reference face are collinear with the axis of the supporting plate. When the reference face faces the wafer, the wafer fitting the reference face is used as the placement reference. When the avoidance face faces the wafer, the edge of the wafer is polished. An auxiliary pressing part is arranged on the reference plate to maintain the force balance between the contact point of the grinding disc and the wafer and the reference plate on the wafer.

2. The semiconductor wafer edge polishing device according to claim 1, wherein: A frame-shaped frame is slidably arranged along the radial direction of the operation platform on the platform plate. A grinding shaft with a vertical axis is rotatably arranged on the frame-shaped frame. The grinding disc is fixedly sleeved on the grinding shaft. The driving part includes a self-rotating motor. Self-rotating motors corresponding to the supporting plates one by one and used for driving the supporting plates to rotate are fixedly arranged on the upper end face of the operation platform. A gear ring is rotatably arranged on the lower end face of the operation platform. Transmission gears corresponding to the grinding shafts one by one and meshing with the gear ring are rotatably arranged on the lower end face of the operation platform through transmission shafts. The transmission shafts are connected and cooperated with adjacent grinding shafts through transmission belts. A driving gear meshing with the gear ring is rotatably arranged on the lower side of the operation platform through a driving shaft. The driving shaft is connected with a driving motor installed on the operation platform.

3. The semiconductor wafer edge polishing device according to claim 2, wherein: A fixed rod coaxial with the operation platform is fixedly arranged on the operation platform. The reference plate is sleeved on the fixed rod and slides up and down. A rotating plate sleeved on the fixed rod is rotatably arranged on the operation platform. A scroll spring is jointly fixedly arranged between the rotating plate and the operation platform. Three circumferentially distributed connecting plates are fixedly arranged on the rotating plate. Sliding blocks fixedly connected with the corresponding connecting plates are slidably arranged on the operation platform. A spreading wheel for tightening the corresponding transmission belt is arranged on the sliding block. A locking part for locking the tightened state of the transmission belt is arranged on the operation platform.

4. A semiconductor wafer edge polishing device according to claim 3, characterized in that: The positioning unit further includes a lifting plate. A lifting plate that slides up and down is sleeved on the fixed rod. The lifting plate is located above the reference plate. Pressing columns that penetrate up and down are slidably arranged on the three branches of the lifting plate. The lower pressing plate is rotatably arranged on the lower end faces of the pressing columns. A pressing spring sleeved on the pressing columns is jointly arranged between the lower pressing plate and the lifting plate.

5. A semiconductor wafer edge polishing device according to claim 4, characterized in that: The locking part includes a locking groove. The locking groove is opened on the connecting plate. A locking column matched with the locking groove is fixedly arranged on the lifting plate through a connecting frame. The locking column is inserted into the locking groove to lock the connecting plate and the sliding block and maintain the tightened transmission state of the transmission belt.

6. The semiconductor wafer edge polishing device according to claim 4, characterized in that: A pushing cylinder sleeved on the fixed rod and used to push the reference plate downward is fixedly arranged on the lower end surface of the lifting plate. An installation circular plate located below the reference plate is fixedly sleeved on the fixed rod. A supporting spring sleeved on the fixed rod is fixedly arranged between the installation circular plate and the reference plate.

7. A semiconductor wafer edge polishing device according to claim 1, wherein: The auxiliary pressing part includes a pressing block. The pressing block is fixedly arranged on the avoiding surface. A plurality of auxiliary pressing rollers circumferentially distributed with the axis of the arc surface of the avoiding surface as the center are rotatably arranged on the lower end surface of the pressing block.

8. A semiconductor wafer edge polishing device according to claim 2, characterized in that: A sliding frame is slidably arranged on the platform plate along the radial direction of the working platform. A reset spring is fixedly arranged between the sliding frame and the platform plate. A moving block is slidably arranged in the sliding frame along its sliding direction. A frame-shaped rack is fixedly arranged on the moving block. A supplementary spring is fixedly arranged between the moving block and the sliding frame. The moving distance lost after the edge wears is adaptively compensated by the supplementary spring. The driving part further includes a wedge block. The wedge block is fixedly arranged on the sliding frame. The inclined surface of the wedge block slopes upward from the platform plate to the working platform direction. Matching plates cooperating with the corresponding wedge blocks are fixedly arranged on the three branches of the lifting plate.

9. A semiconductor wafer edge polishing device according to claim 4, characterized in that: On each of the three branches of the lifting plate, an adapting frame is slidably arranged along the corresponding length direction. A reset spring is also fixedly arranged between the adapting frame and the lifting plate. An adapting block is slidably arranged in the adapting frame. A supplementary spring is also fixedly arranged between the adapting block and the adapting frame. Two vertically axis plugging rods located on both sides of the corresponding branch of the lifting plate are fixedly arranged on the lower end surface of the adapting block through a horizontal plate. Plugging grooves corresponding to the plugging rods are formed in the horizontal section of the frame-shaped rack.

10. A semiconductor wafer edge polishing method, which is completed in cooperation with a semiconductor wafer edge polishing device according to any one of claims 1 to 9, characterized in that, It includes the following steps: S1. Place the wafer: The wafer is grabbed by a manipulator and placed on the corresponding supporting plate, and the circumferential surface of the wafer is closely attached to the corresponding reference surface on the reference plate, completing the positioning and placing process of the wafer. S2. Lock the wafer: After the wafer is placed on the supporting plate, the positioning unit drives the lower pressing plate to move downward synchronously and presses the corresponding wafer. S3. Disengage and avoid: When the lower pressing plate presses the wafer, the reference plate is pushed downward, so that the reference surface is disengaged from the state of contacting the circumferential surface of the wafer, avoiding the polishing process of the wafer. Secondly, the driving part makes the grinding disks all approach the wafer. Finally, the grinding disks move to the specified positions and contact the wafer. S4. Edge polishing: The driving part works to make the grinding disks and the wafer rotate synchronously, and their rotation directions are opposite. The grinding disks polish and grind the circumferential edge of the wafer.

Images