Wafer-based polishing head and wafer polishing equipment

Abstract

The utility model discloses a wafer-based polishing head and wafer polishing equipment, and relates to the technical field of wafer polishing equipment, the wafer-based polishing head comprises a first assembling seat and a second assembling seat which are connected with each other, and the bottom surface of the second assembling seat is provided with an assembling groove; the pressurizing disc is connected with the second assembling seat in a sliding manner, and the pressurizing disc and the assembling groove form a first cavity; the elastic rubber film and the pressurizing disc form a second cavity; and the adsorption pad is arranged on the bottom surface of the elastic rubber film. And the first air pressure pipe is communicated with the first cavity and the second cavity. According to the polishing head based on the wafer and the wafer polishing equipment, the technical problem that the PV value of a product is affected due to the fact that the positive pressure borne by the edge of the wafer is smaller than the positive pressure borne by the center area of the wafer and the removal amount of the edge of the wafer is insufficient is solved, the pressurizing disc is additionally arranged in the cavity, the positive pressure borne by the edge of the wafer is larger than the positive pressure borne by the center area of the wafer, and the product yield is improved. Therefore, the removal amount of the edge of the wafer is improved, and the achievement of a PV value index is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of wafer polishing equipment, and particularly relates to a polishing head based on a wafer and a wafer polishing equipment. Background Art

[0002] The traditional polishing head solution for polishing is that there is a single cavity above the elastic rubber mold. The deformation of the elastic rubber mold is controlled by the cavity pressure, and the product is acted on to maintain the positive pressure during the handling and processing of the product.

[0003] However, due to the gap between the adsorption pad and the product and the pressure distribution problem of the elastic rubber mold, the positive pressure received by the edge of the wafer is less than that of the central region, resulting in the removal amount of the edge being lower than that of the central region. As the wafer size increases, the distribution difference of the forces received by the edge point and the center point on the wafer radius becomes larger, resulting in insufficient removal amount of the wafer edge, thus affecting the PV value of the product (the PV value is the difference between the highest point and the lowest point in the removal amount surface profile), especially being particularly obvious in the processing of 300mm diameter silicon wafers. Therefore, a polishing head based on a wafer and a wafer polishing equipment for solving the above problems are proposed. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a polishing head based on a wafer and a wafer polishing equipment, which solves the technical problem that the positive pressure received by the edge of the wafer is less than that of the central region, resulting in the removal amount of the wafer edge being lower than that of the central region, leading to insufficient removal amount of the wafer edge, thus affecting the PV value of the product.

[0005] To achieve the above purpose, the utility model provides a polishing head based on a wafer, including: a first mounting seat;

[0006] A second mounting seat, connecting the first mounting seat, and an assembly groove is provided on the bottom surface of the second mounting seat;

[0007] A pressure plate, arranged on the bottom surface of the second mounting seat, the pressure plate is slidably connected to the second mounting seat, and the pressure plate and the assembly groove form a first cavity;

[0008] An elastic rubber membrane, arranged below the pressure plate, the elastic rubber membrane and the pressure plate form a second cavity;

[0009] An adsorption pad, arranged on the bottom surface of the elastic rubber membrane, and the adsorption pad is used for adsorbing the wafer.

[0010] A first air pressure pipe, arranged on the first mounting seat, and the first air pressure pipe communicates the first cavity and the second cavity.

[0011] Preferably, a counterweight assembly is provided above the pressure plate. The counterweight assembly includes: a plurality of annular counterweight blocks arranged successively from top to bottom, and the plurality of annular counterweight blocks are fixed above the pressure plate by bolts.

[0012] Preferably, a plurality of stop pins are arranged in an array on the bottom surface of the second mounting seat, and a plurality of through holes are arranged in an array on the top surface of the pressure plate. Each through hole is slidably connected to one of the stop pins.

[0013] Preferably, a transmission plate is arranged between the first mounting seat and the second mounting seat, and the transmission plate is fixedly connected to the first mounting seat and the second mounting seat.

[0014] Preferably, a mounting seat is provided at the top of the first mounting seat, and the upper end of the mounting seat is connected to the output end of the driving device.

[0015] Preferably, a second air pressure pipe is provided on the second mounting seat. The second air pressure pipe is connected to the first air pressure pipe through a sealing joint, and the second air pressure pipe communicates the first cavity and the second cavity.

[0016] Preferably, the lower part of the pressure plate is concave, and the lower part of the pressure plate abuts against the edge position of the wafer.

[0017] Preferably, a retaining ring is provided on the bottom surface of the second mounting seat, and the inner side wall of the retaining ring is hermetically connected to the outer peripheral side surface of the elastic rubber membrane and the outer peripheral side surface of the adsorption pad respectively.

[0018] Preferably, the top surface of the adsorption pad fits the bottom surface of the elastic rubber membrane, and adsorption holes are provided on the bottom surface of the adsorption pad for adsorbing the wafer.

[0019] A wafer polishing device includes the polishing head based on a wafer as described in any one of the above.

[0020] Compared with the above background art, a polishing head based on a wafer provided by the present utility model has the following beneficial effects: By adding a pressure plate to the bottom surface of the second mounting seat, the positive pressure received by the edge of the wafer is the sum of the acting force generated by the deformation of the elastic rubber mold and the weight of the pressure plate, while the positive pressure received by the central area of the wafer is only the acting force generated by the deformation of the elastic rubber mold, so that the positive pressure received by the edge of the wafer is greater than the positive pressure received by the central area of the wafer, thereby increasing the removal amount of the edge of the wafer and effectively ensuring the achievement of the PV value index. Description of the Drawings

[0021] 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 be obtained according to the provided drawings.

[0022] Figure 1 The top view provided by the embodiment of the present invention;

[0023] Figure 2 is Figure 1 The schematic cross-sectional view at A-A in;

[0024] Figure 3 is Figure 2 The enlarged schematic view at B in.

[0025] Specifically, 1 - the first assembly seat; 2 - the second assembly seat; 3 - the pressure plate; 301 - the stepped groove; 4 - the first cavity; 5 - the elastic rubber membrane; 6 - the adsorption pad; 7 - the first air pressure tube; 8 - the weight assembly; 9 - the stop pin; 901 - the stopper; 10 - the transmission plate; 11 - the mounting seat; 12 - the second air pressure tube; 13 - the retaining ring; 14 - the second cavity. Specific embodiments

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0027] In order to enable those skilled in the art of this technology to better understand the solution of the present invention, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0028] As Figure 1 and Figure 2 shown, to achieve the above object, the present invention provides a polishing head based on a wafer, including: a first assembly seat 1 and a second assembly seat 2 connected to the first assembly seat 1. Among them, the bottom surface of the second assembly seat 2 is provided with an assembly groove, and the assembly groove is annular as a whole.

[0029] A pressure plate 3 is provided on the bottom surface of the second mounting base 2. The pressure plate 3 and the mounting groove form a first cavity 4, and the pressure plate 3 is slidably connected to the second mounting base 2, that is, the pressure plate 3 can move up and down relative to the second mounting base 2. In addition, the lower part of the pressure plate 3 is concave, and the lower part of the pressure plate 3 abuts against the edge position of the wafer. At this time, the gravity of the wafer is part of the positive pressure received by the edge of the wafer.

[0030] An elastic rubber membrane 5 is provided below the pressure plate 3. The elastic rubber membrane 5 and the pressure plate 3 form a second cavity 14. In the initial state, the elastic rubber membrane 5 is in a taut state, and the bottom surface of the elastic rubber membrane 5 is a plane. In addition, an adsorption pad 6 is adsorbed on the bottom surface of the elastic rubber membrane 5. The adsorption pad 6 is attached to the bottom surface of the elastic rubber membrane 5, and the adsorption pad 6 is used to adsorb the wafer.

[0031] A first air pressure tube 7 is provided on the first mounting base 1. The first air pressure tube 7 communicates with the first cavity 4, and the first cavity 4 communicates with the second cavity 14. The first air pressure tube 7 is connected to an external air source. Preferably, the external air source uses a double-pump vacuum machine, which has the function of providing positive pressure and negative pressure to the first air pressure tube 7 at the same time. Specifically, the external air source sucks the gas in the first cavity 4 and the second cavity 14 through the first air pressure tube 7. The inside of the first cavity 4 and the inside of the second cavity 14 are in a negative pressure state, causing the elastic rubber membrane 5 and the adsorption pad 6 to deform upward. After the elastic rubber membrane 5 and the adsorption pad 6 deform upward, they will generate a certain adsorption force on the wafer, so as to transport the wafer to a specified position.

[0032] In addition, after the elastic rubber membrane 5 and the adsorption pad 6 deform upward, they will be attached to the lower part of the pressure plate 3. Since the bottom surface shape of the pressure plate 3 is fixed, it is ensured that the second cavity 14 can apply a fixed vacuum adsorption force to the product, avoiding damage to the wafer due to excessive adsorption force. At the same time, it is also ensured that the vacuum adsorption force applied by the second cavity 14 to the product can stably grasp the wafer.

[0033] During use, the first cavity 4 and the second cavity 14 are inflated through the first air pressure tube 7. The inside of the first cavity 4 and the inside of the second cavity 14 are in a positive pressure state. The elastic rubber membrane 5 and the adsorption pad 6 deform downward. The pressure plate 3, the elastic rubber membrane 5 and the adsorption pad 6 act together on the upper surface of the wafer, and the wafer is polished by the polishing pad. Among them, the positive pressure received by the edge of the wafer is the sum of the force generated by the deformation of the elastic rubber mold and the weight of the pressure plate 3. The positive pressure received by the central area of the wafer is only the force generated by the deformation of the elastic rubber mold, so that the positive pressure received by the edge of the wafer is greater than the positive pressure received by the central area of the wafer, thereby increasing the removal amount of the edge of the wafer.

[0034] Above the pressure plate 3, a weight assembly 8 is provided to adjust the gravity of the pressure plate 3 according to different process requirements, and accurately control the edge removal amount of the wafer. Among them, the weight assembly 8 includes: a number of annular weight blocks arranged in sequence from top to bottom, and the number of annular weight blocks is fixed above the pressure plate 3 by bolts. Specifically, by controlling the number of annular weight blocks, the overall weight of the weight assembly 8 is increased or decreased, and the gravity applied by the pressure plate 3 on the wafer is accurately controlled, increasing the applicable range of the overall polishing head.

[0035] It should be noted that a number of stop pins 9 are arranged in an array on the bottom surface of the second mounting seat 2. The upper end of the stop pin 9 is threadedly connected to the second mounting seat 2 and locked on the bottom surface of the second mounting seat 2. A number of through holes are arranged in an array on the top surface of the pressure plate 3, and each through hole is slidably connected to a stop pin 9 respectively.

[0036] As Figure 3 shown, it should be noted that a stepped groove 301 is provided at the lower end of the through hole, and a stop head 901 is integrally provided at the bottom end of the stop pin 9. The outer diameter of the stop head 901 is larger than the inner diameter of the through hole to prevent the pressure plate 3 from detaching from the stop pin 9. The height of the stepped groove 301 is larger than the thickness of the stop head 901 to ensure that the pressure plate 3 can slide freely relative to the stop pin 9 within a certain height distance. When polishing the wafer, the top surface of the pressure plate 3 will not contact the second mounting seat 2 to ensure that the pressure plate 3 can stably provide its own weight and the weight of the mating component, and thus stably control the edge removal amount of the wafer.

[0037] A transmission plate 10 is arranged between the first mounting seat 1 and the second mounting seat 2. The transmission plate 10 is fixedly connected to the first mounting seat 1 and the second mounting seat 2. Specifically, the first mounting seat 1, the transmission plate 10 and the second mounting seat 2 are further fixedly connected together by a plurality of bolt rods to ensure that the second mounting seat 2 can rotate synchronously while the first mounting seat 1 rotates.

[0038] In addition, a mounting seat 11 is provided at the top of the first mounting seat 1. A number of positioning holes are arranged in an array on the surface of the mounting seat 11. Bolts pass through the positioning holes to connect the mounting seat 11 to the first mounting seat 1. The upper end of the mounting seat 11 is connected to the output end of the driving device, and the driving device drives the mounting seat 11 to rotate, thereby driving the first mounting seat 1 to rotate.

[0039] It should be noted that a second air pressure pipe 12 is provided on the second mounting seat 2. The second air pressure pipe 12 is connected to the first air pressure pipe 7 through a sealing joint. Specifically, the second air pressure pipe 12 is coaxially arranged with the second mounting seat 2. The second air pressure pipe 12 communicates with the first cavity 4 and the second cavity 14, and the air pressure inside the first cavity 4 and the second cavity 14 always remains the same. The external air source controls the air pressure inside the first cavity 4 and the second cavity 14 through the first air pressure pipe 7 and the second air pressure pipe 12.

[0040] Among them, a plurality of first air exchange holes and a plurality of first air exchange holes (not shown in the figure) are arranged in an array on the outer side wall of the second air pressure tube 12. The first cavity 4 is communicated through the first air exchange holes, and the second air pressure tube 12 sequentially penetrates through a plurality of counterweight blocks and the pressure plate 3, and is communicated with the second cavity 14 through the second air exchange holes.

[0041] In one embodiment of the present invention, a retaining ring 13 is provided on the bottom surface of the second mounting seat 2. The retaining ring 13 is connected to the bottom surface of the second mounting seat 2 through a bolt rod. The inner side wall of the retaining ring 13 is hermetically connected to the outer peripheral side surface of the elastic rubber membrane 5 and the outer peripheral side surface of the adsorption pad 6 respectively. That is, the pressure plate 3 is hermetically arranged inside the elastic rubber membrane 5, thereby forming a stable sealing effect on the first cavity 4 and the second cavity 14.

[0042] In addition, the setting of the retaining ring 13 can limit the radial position of the wafer. When the wafer is driven by the first mounting seat 1 to rotate at a high speed, when the wafer moves such as shifting, the retaining ring 13 can have a certain holding and limiting effect on the wafer in the mirror image direction, so as to ensure that the wafer is accurately polished.

[0043] In one embodiment of the present invention, the top surface of the adsorption pad 6 fits the bottom surface of the elastic rubber membrane 5. The bottom surface of the adsorption pad 6 is provided with adsorption holes for adsorbing the wafer. When the first cavity 4 and the second cavity 14 are in a positive pressure state, the adsorption pad 6 as a whole no longer generates an adsorption effect on the pressure plate 3. The setting of the adsorption holes can provide a small adsorption force for the adsorption pad 6, thereby increasing the friction force between the pressure plate 3 and the adsorption pad 6, so that the friction force between the pressure plate 3 and the adsorption pad 6 is greater than the friction force between the wafer and the polishing sheet, ensuring that the adsorption pad 6 can drive the wafer to rotate synchronously under the holding action of the gravity of the pressure plate 3 and the acting force generated by the deformation of the elastic rubber mold.

[0044] When the present invention is in use, an external air source sucks the gas in the first cavity 4 and the second cavity 14 through the first air pressure tube 7 and the second air pressure tube 12. The inside of the first cavity 4 and the inside of the second cavity 14 are in a negative pressure state, and the elastic rubber membrane 5 and the adsorption pad 6 generate upward deformation. After the elastic rubber membrane 5 and the adsorption pad 6 are deformed upward, a certain adsorption force is generated on the wafer. Move the overall polishing head to move the wafer to a designated position. The external air source inflates the first cavity 4 and the second cavity 14 through the first air pressure tube 7 and the second air pressure tube 12. The inside of the first cavity 4 and the inside of the second cavity 14 are in a positive pressure state, and the elastic rubber membrane 5 and the adsorption pad 6 generate downward deformation. The pressure plate 3, the elastic rubber membrane 5 and the adsorption pad 6 act together on the upper surface of the wafer. Among them, the positive pressure received by the edge of the wafer is the sum of the acting force generated by the deformation of the elastic rubber mold and the weight of the pressure plate 3, and the positive pressure received by the central area of the wafer is only the acting force generated by the deformation of the elastic rubber mold. The wafer is polished by the relative high-speed rotation of the polishing sheet with respect to the wafer.

[0045] In summary, through the additional pressure plate 3, the positive pressure received by the edge of the wafer is the sum of the acting force generated by the deformation of the elastic rubber mold and the weight of the pressure plate 3, while the positive pressure received by the central area of the wafer is only the acting force generated by the deformation of the elastic rubber mold. The positive pressure received by the edge of the wafer is greater than that received by the central area of the wafer, thereby increasing the removal amount of the edge of the wafer and ensuring the achievement of the PV value index.

[0046] In addition to the above wafer-based polishing head, the present utility model also provides a wafer polishing device including the wafer-based polishing head disclosed in the above embodiments. For the structures of other parts of the wafer polishing device, reference may be made to the prior art and will not be elaborated herein.

[0047] It should be noted that in this specification, relational terms such as first and second are only used to distinguish one entity from several other entities, and do not necessarily require or imply any actual relationship or order between these entities.

[0048] In this article, specific examples are used to elaborate on the principle and implementation mode of the present utility model. The description of the above embodiments is only used to help understand the method and its core idea of the present utility model. It should be pointed out that for those of ordinary skill in the art in this technical field, without departing from the principle of the present utility model, several improvements and modifications can be made to the present utility model, and these improvements and modifications also fall within the protection scope of the present utility model.

Claims

1. A wafer-based polishing head, characterized in that, Comprising: A first mounting seat; A second mounting seat, connected to the first mounting seat, and an assembly groove is provided on the bottom surface of the second mounting seat; A pressure plate, arranged on the bottom surface of the second mounting seat, the pressure plate is slidably connected to the second mounting seat, and the pressure plate and the assembly groove form a first cavity; An elastic rubber membrane, arranged below the pressure plate, and the elastic rubber membrane and the pressure plate form a second cavity; An adsorption pad, arranged on the bottom surface of the elastic rubber membrane, and the adsorption pad is used for adsorbing a wafer; A first air pressure tube, arranged on the first mounting seat, and the first air pressure tube communicates the first cavity and the second cavity; 2. The polishing head based on a wafer according to claim 1, characterized in that, A counterweight assembly, arranged above the pressure plate, and the counterweight assembly includes: a plurality of annular counterweight blocks arranged in sequence from top to bottom, and the plurality of annular counterweight blocks are fixed above the pressure plate by bolts; 3. A wafer-based polishing head according to claim 2, characterized in that, A plurality of stop pins are arranged in an array on the bottom surface of the second mounting seat, and a plurality of through holes are arranged in an array on the top surface of the pressure plate, and each through hole is slidably connected to one of the stop pins; 4. A wafer-based polishing head according to claim 1, wherein, A transmission plate is arranged between the first mounting seat and the second mounting seat, and the transmission plate is fixedly connected to the first mounting seat and the second mounting seat; 5. A wafer-based polishing head according to claim 4, characterized in that, A mounting seat is provided at the top of the first mounting seat, and the upper end of the mounting seat is connected to the output end of the driving device; 6. A wafer-based polishing head according to any one of claims 1-5, characterized in that, A second air pressure tube is provided on the second mounting seat, the second air pressure tube is connected to the first air pressure tube through a sealing joint, and the second air pressure tube communicates the first cavity and the second cavity; 7. A wafer-based polishing head according to any one of claims 1-5, characterized in that, The lower part of the pressure plate is concave, and the lower part of the pressure plate abuts against the edge position of the wafer; 8. A wafer-based polishing head according to claim 7, characterized in that, A retaining ring is provided on the bottom surface of the second mounting seat, and the inner side wall of the retaining ring is hermetically connected to the outer peripheral side surface of the elastic rubber membrane and the outer peripheral side surface of the adsorption pad respectively; 9. The polishing head based on a wafer according to claim 8, wherein, The top surface of the adsorption pad fits against the bottom surface of the elastic rubber membrane, and adsorption holes are provided on the bottom surface of the adsorption pad, and the adsorption holes are used for adsorbing the wafer; 10. A wafer polishing device, characterized in that, Comprising the wafer-based polishing head according to any one of the above claims 1-9.

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