Grinding head and grinding device

Abstract

Provided is a polishing head capable of preventing both side walls of an elastic film from contacting each other when a negative pressure is formed in a pressure chamber formed by the elastic film. The polishing head (7) includes: a first elastic film (41) for pressing a workpiece (W) against a polishing pad (2); a retaining ring (33) configured to surround the first elastic film (41); a second elastic film (50) for pressing the retaining ring (33) against the polishing pad (2); a carrier (35) on which the first elastic film (41) is fixed; and a mounting member (53) disposed in a pressure chamber (58) formed by the second elastic film (50) and configured to fix the second elastic film (50) to the carrier (35). The mounting member (53) has support portions (54A, 54B) that extend toward the retaining ring (33) along side walls (50A, 50B) of the second elastic film (50).

Description

TECHNICAL FIELD

[0001] The present application relates to a polishing head that presses a work such as a wafer, a substrate, a panel, or the like against a polishing pad to polish the work, and particularly relates to a pressing structure of a retaining ring that is arranged so as to surround the work. BACKGROUND

[0002] Chemical mechanical polishing (CMP) is a technique in which a work is brought into sliding contact with a polishing surface of a polishing pad while supplying a polishing liquid containing abrasive grains such as silicon dioxide (SiO2) to the polishing surface to polish the work. As shown in FIG. 1, a polishing apparatus for performing CMP is provided with a polishing table 501 that supports a polishing pad 500, a polishing head 505 that holds a work W, and a polishing liquid nozzle 508 that supplies a polishing liquid to the polishing pad 500. Figure 9

[0003] Polishing of the work W using such a polishing apparatus is performed as follows. The polishing table 501 is rotated together with the polishing pad 500, and a polishing liquid is supplied from the polishing liquid nozzle 508 to the polishing pad 500. The polishing head 505 presses the work W against the polishing pad 500 while rotating the work W. The work W is brought into sliding contact with the polishing pad 500 in the presence of the polishing liquid, and the surface of the work W is planarized by the combination of the chemical action of the polishing liquid and the mechanical action of the abrasive grains contained in the polishing liquid and the polishing pad 500.

[0004] In the polishing of the work W, the surface of the work W is brought into sliding contact with the rotating polishing pad 500, and thus a frictional force acts on the work W. Therefore, in the polishing of the work W, in order to prevent the work W from separating from the polishing head 505, the polishing head 505 is provided with a retaining ring 510. The retaining ring 510 is arranged so as to surround the work W, and in the polishing of the work W, the retaining ring 510 is rotated while pressing the polishing pad 500 on the outside of the work W.

[0005] Figure 10 is a cross-sectional view of a portion of the polishing head 505 shown in FIG. 1. As shown in FIG. 2, the polishing head 505 has a ring-shaped elastic membrane 512 for pressing the retaining ring 510 against the polishing pad 500. A pressure chamber 513 is formed on the inner side of the elastic membrane 512. When pressurized gas (for example, pressurized air) is supplied into the pressure chamber 513, the elastic membrane 512, which is subjected to the fluid pressure in the pressure chamber 513, presses the retaining ring 510 against the polishing pad 500. Therefore, in the polishing of the work W, the retaining ring 510 can prevent the work W from flying out of the polishing head 505. Figure 9 Figure 10

[0006] ​​​The grinding head 505 also has an elastic diaphragm 514 for pressing the workpiece W against the grinding pad 500. A pressure chamber 515 is formed inside the elastic diaphragm 514. When pressurized gas (e.g., pressurized air) is supplied into the pressure chamber 515, the elastic diaphragm 514, under the fluid pressure within the pressure chamber 515, presses the workpiece W against the grinding pad 500. Therefore, the workpiece W slides in contact with the grinding pad 500 while the grinding fluid is present on the grinding pad 500.

[0007] like Figure 11 As shown in (a), when the grinding of workpiece W is completed, the grinding head 505 holding workpiece W leaves the grinding pad 500 and moves together with workpiece W to a predetermined release position. Furthermore, as... Figure 11 As shown in (b), a negative pressure is created in the pressure chamber 513, causing the retaining ring 510 to rise relative to the workpiece W. Then, as... Figure 11 As shown in (c), a jet of liquid (e.g., pure water) is sprayed from the release nozzle 519 toward the contact portion between the elastic membrane 514 and the workpiece W, thereby releasing the workpiece W from the elastic membrane 514.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2006-128582

[0011] Patent Document 2: Japanese Patent Application Publication No. 2009-131946

[0012] The technical problem that the invention aims to solve

[0013] However, as Figure 12 As shown, when a negative pressure is created in the pressure chamber 513, the two side walls of the elastic membrane 512 may be attracted by the vacuum and come into contact with each other. In this case, the retaining ring 510 cannot rise to the specified position, and the retaining ring 510 will obstruct the jet of liquid from the release nozzle 519. In addition, damage to the elastic membrane 512 is more likely to progress, thereby shortening the life of the elastic membrane 512. Summary of the Invention

[0014] Therefore, the present invention provides a grinding head that prevents the two side walls of the elastic membrane from contacting each other when a negative pressure is formed in the pressure chamber formed by the elastic membrane. Furthermore, the present invention provides a grinding apparatus equipped with such a grinding head.

[0015] Technical means for solving technical problems

[0016] In one embodiment, there is provided a polishing head for polishing a work by pressing the work against a polishing pad, comprising: a first elastic film for pressing the work against the polishing pad; a retaining ring configured to surround the first elastic film; a second elastic film for pressing the retaining ring against the polishing pad; a carrier to which the first elastic film is fixed; a mounting member configured in a pressure chamber formed by the second elastic film and fixing the second elastic film to the carrier; and a linking member linking the second elastic film to the retaining ring, the second elastic film having: a bottom wall connected to the linking member; and a side wall connected to the bottom wall, the mounting member having a support portion extending along the side wall toward the retaining ring.

[0017] In one embodiment, the side wall is a first side wall and a second side wall separated from each other, the support portion is two support portions extending along the first side wall and the second side wall, respectively, the mounting member has a recessed portion between the two support portions, and the linking member has a protruding portion that is housed in the recessed portion when the linking member moves toward the mounting member.

[0018] In one embodiment, the bottom wall has a curved cross-sectional shape toward the retaining ring, and at least a portion of the support portion is housed in the curved bottom wall when the linking member moves toward the mounting member.

[0019] In one embodiment, the mounting member has a groove extending along the support portion in a circumferential direction of the second elastic film.

[0020] In one embodiment, the mounting member has a plurality of through-holes penetrating the support portion, the plurality of through-holes being arranged in a circumferential direction of the second elastic film.

[0021] In one embodiment, a friction-reducing treatment is performed on a surface at least on an outer side of the support portion.

[0022] In one embodiment, there is provided a polishing device, comprising: a polishing table for supporting a polishing pad; and the above-described polishing head for polishing a work by pressing the work against the polishing pad.

[0023] Effects of the Invention

[0024] According to the present invention, the support portion supports an inner side of the side wall of the elastic film, and contact of the two side walls with each other can be prevented. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a schematic view showing one embodiment of a polishing device.

[0026] Figure 2 is a cross-sectional view of the polishing head.

[0027] Figure 3 is an enlarged cross-sectional view of the retaining ring and retaining ring pressing mechanism.

[0028] Figure 4 is an enlarged cross-sectional view of the retaining ring and retaining ring pressing mechanism when a negative pressure is formed in the second pressure chamber.

[0029] Figure 5 is an enlarged cross-sectional view of another embodiment of the mounting member.

[0030] Figure 6 is an enlarged cross-sectional view of another embodiment of the mounting member.

[0031] Figure 7 is an enlarged cross-sectional view of another embodiment of the mounting member.

[0032] Figure 8 is an enlarged cross-sectional view of another embodiment of the mounting member.

[0033] Figure 9 is a schematic view of a conventional polishing apparatus.

[0034] Figure 10 is a cross-sectional view of a part of the polishing head shown in Figure 9

[0035] Figure 11 Figure 11 Figure 11

[0036] Figure 12 is a view illustrating a problem point of the conventional polishing head.

[0037] Symbol Explanation

[0038] 1 Polishing Apparatus

[0039] 2 Polishing Pad

[0040] 2a Polishing Surface

[0041] 5 Polishing Table

[0042] 7 Polishing Head

[0043] 8 Polishing Liquid Supply Nozzle

[0044] 14 Support Shaft

[0045] 16 Polishing Head Swing Arm

[0046] 18 Polishing Head Shaft

[0047] ​​​​21 table-rotating motor

[0048] 30 head main body

[0049] 33 stopper ring

[0050] 35 carrier

[0051] 38 first elastic film

[0052] 38a pressing surface

[0053] 41 first pressure chamber

[0054] 45 stopper ring pressing mechanism

[0055] 47 connecting member

[0056] 47a protruding portion

[0057] 50 second elastic film

[0058] 50A, 50B side wall

[0059] 50C, 50D bottom wall

[0060] 53 mounting member

[0061] 54A, 54B support portion

[0062] 55 recessed portion

[0063] 58 second pressure chamber

[0064] 62A, 62B groove

[0065] 63A, 63B through-hole

[0066] F1, F2, F3 first fluid line

[0067] F4 second fluid line DETAILED DESCRIPTION

[0068] Hereinafter, an embodiment of the present application will be described with reference to the drawings. Figure 1 is a schematic view showing an embodiment of a polishing apparatus. The polishing apparatus 1 is an apparatus that polishes a workpiece W such as a wafer, a substrate, a panel, or the like, chemically and mechanically. As shown in Figure 1 the polishing apparatus 1 is provided with a polishing table 5 that supports a polishing pad 2 having a polishing surface 2a, a polishing head 7 that presses the workpiece W against the polishing surface 2a, and a polishing liquid supply nozzle 8 that supplies a polishing liquid (for example, a slurry containing abrasive grains) to the polishing surface 2a. The polishing head 7 is configured to be capable of holding the workpiece W on its lower surface.

[0069] The polishing apparatus 1 further has a support shaft 14, a polishing head swing arm 16 coupled to the upper end of the support shaft 14, and a polishing head shaft 18 rotatably supported to the free end of the polishing head swing arm 16. The polishing head 7 is fixed to the lower end of the polishing head shaft 18. A polishing head rotation mechanism (not shown) having a motor or the like is disposed in the polishing head swing arm 16. The polishing head rotation mechanism is coupled to the polishing head shaft 18 and configured to rotate the polishing head shaft 18 and the polishing head 7 in the direction indicated by the arrow.

[0070] The polishing head shaft 18 is coupled to a polishing head lifting mechanism (including a ball screw mechanism or the like) not shown. The polishing head lifting mechanism is configured to relatively move the polishing head shaft 18 up and down with respect to the polishing head swing arm 16. With the up and down movement of the polishing head shaft 18, the polishing head 7 is relatively moved up and down with respect to the polishing head swing arm 16 and the polishing table 5 as indicated by the arrow.

[0071] The polishing apparatus 1 further has a table rotation motor 21 that rotates the polishing pad 2 and the polishing table 5 with their shaft centers as centers. The table rotation motor 21 is disposed below the polishing table 5, and the polishing table 5 is coupled to the table rotation motor 21 via a table shaft 5a. The polishing table 5 and the polishing pad 2 are rotated by the table rotation motor 21 with the table shaft 5a as a center in the direction indicated by the arrow. The polishing pad 2 is attached to the upper surface of the polishing table 5. The exposed surface of the polishing pad 2 constitutes a polishing surface 2a that polishes a workpiece W such as a wafer.

[0072] The polishing of the workpiece W is performed as follows. The workpiece W is held in the polishing head 7 in a state where the polished surface faces downward. While the polishing head 7 and the polishing table 5 are rotated, respectively, a polishing liquid (for example, a slurry containing abrasive grains) is supplied from a polishing liquid supply nozzle 8 disposed above the polishing table 5 to the polishing surface 2a of the polishing pad 2. The polishing pad 2 is integrally rotated with the polishing table 5 with the center axis thereof as a center. The polishing head 7 is moved to a height defined by a polishing head lifting mechanism (not shown). Further, the polishing head 7 presses the workpiece W against the polishing surface 2a of the polishing pad 2 in a state of being maintained at the above defined height. The workpiece W is integrally rotated with the polishing head 7. In a state where the polishing liquid is present on the polishing surface 2a of the polishing pad 2, the workpiece W is in sliding contact with the polishing surface 2a. The surface of the workpiece W is polished by a combination of a chemical action of the polishing liquid and a mechanical action of the abrasive grains contained in the polishing liquid and the polishing pad 2.

[0073] Next, the polishing head 7 will be described in detail. Figure 2 is a cross-sectional view of the polishing head 7. The polishing head 7 has a head main body 30 and a retainer ring 33. The head main body 30 has a carrier 35 coupled to the polishing head shaft 18 and a first elastic film 38 mounted to the lower surface of the carrier 35.

[0074] The lower surface of the first elastic film 38 constitutes a pressing surface 38a which is brought into contact with the upper surface of the workpiece W (the surface on the side opposite to the surface to be polished). A plurality of through-holes (not shown) are formed in the first elastic film 38. A plurality of first pressure chambers 41 are formed between the carrier 35 and the first elastic film 38. The central first pressure chambers 41 are circular, and the outer first pressure chambers 41 are annular. These first pressure chambers 41 are connected to a pressure adjusting device (not shown) through first fluid lines F1, F2, F3. When pressurized fluid (for example, pressurized air) is supplied to the first pressure chambers 41, the pressing surface 38a of the first elastic film 38 subjected to the fluid pressure in the first pressure chambers 41 presses the workpiece W against the polishing surface 2a of the polishing pad 2. When negative pressure is formed in the first pressure chambers 41, the workpiece W is held to the pressing surface 38a of the first elastic film 38 by vacuum suction. The number of the first pressure chambers 41 is not limited to Figure 2 In one embodiment, a separate first pressure chamber 41 can also be provided between the carrier 35 and the first elastic film 38.

[0075] The retaining ring 33 is arranged so as to surround the workpiece W and the first elastic film 38. More specifically, the retaining ring 33 is arranged so as to surround the outer periphery of the workpiece W and the pressing surface 38a of the first elastic film 38. The upper portion of the retaining ring 33 is connected to an annular retaining ring pressing mechanism 45. The retaining ring pressing mechanism 45 is configured to apply a uniform downward load to the entire upper surface of the retaining ring 33, thereby pressing the lower surface of the retaining ring 33 against the polishing surface 2a of the polishing pad 2.

[0076] The retaining ring pressing mechanism 45 includes a connecting member 47 fixed to the upper portion of the retaining ring 33, an annular second elastic film 50 connected to the connecting member 47, and a mounting member 53 mounting the second elastic film 50 to the carrier 35. The specific structure of the connecting member 47 is not particularly limited, and the connecting member 47 can be an upper retaining ring. A second pressure chamber 58 is formed in the interior of the second elastic film 50. The second pressure chamber 58 is connected to a pressure adjusting device (not shown) through a second fluid line F4. The mounting member 53 is arranged in the second pressure chamber 58. The second fluid line F4 extends through the mounting member 53 and communicates with the second pressure chamber 58. In the present embodiment, the mounting member 53 is annular and extends along the retaining ring 33.

[0077] When pressurized fluid (for example, pressurized air) is supplied to the second pressure chamber 58 through the second fluid line F4, the second elastic film 50 subjected to the fluid pressure in the second pressure chamber 58 pushes the connecting member 47 downward, and further, the connecting member 47 pushes the entire retaining ring 33 downward. In this way, the retaining ring pressing mechanism 45 presses the lower surface of the retaining ring 33 against the polishing surface 2a of the polishing pad 2.

[0078] Figure 3This is an enlarged sectional view of the retaining ring 33 and the retaining ring pressing mechanism 45. (See attached image.) Figure 3 As shown, the second elastic membrane 50 has: two sidewalls 50A and 50B, a bottom wall 50C connected to one sidewall 50A, and a bottom wall 50D connected to the other sidewall 50B. Sidewall 50A is located inside the other sidewall 50B, and bottom wall 50C is located inside the other bottom wall 50D. The upper end of the second elastic membrane 50, i.e., the upper ends of the two sidewalls 50A and 50B, is fixed to the carrier 35 by a mounting member 53. The mounting member 53 is fixed to the carrier 35 by screws (not shown). A connecting member 47 is connected to the two bottom walls 50C and 50D. The connecting member 47 is a movable member that moves up and down according to the pressure in the second pressure chamber 58. The connecting member 47 has a protrusion 47a that protrudes toward the mounting member 53 (i.e., upwards).

[0079] In this embodiment, the second elastic membrane 50 is a rolling diaphragm with two bottom walls 50C and 50D, which have a downwardly curved cross-section. This rolling diaphragm type of second elastic membrane 50 has the advantage that it does not rub against the inner surfaces of the connecting member 47 and the carrier 35 according to pressure changes within the second pressure chamber 58, thus allowing the second elastic membrane 50 to deform smoothly. However, the second elastic membrane 50 is not limited to the shape of this embodiment and can also be a non-rolling diaphragm type without downwardly curved bottom walls.

[0080] The mounting member 53 has two support portions 54A and 54B protruding towards the retaining ring 33 along two side walls 50A and 50B. These support portions 54A and 54B extend downward and are located within the second pressure chamber 58. The support portions 54A and 54B are separated from each other, and a recess 55 is formed between the support portions 54A and 54B. In this embodiment, the recess 55 is annular. The recess 55 has a width greater than the width of the protrusion 47a of the connecting member 47. Examples of materials for the mounting member 53 include metals (e.g., stainless steel), hard resins, ceramics, etc.

[0081] Supports 54A and 54B extend along the inner surfaces of the two sidewalls 50A and 50B. When pressurized fluid (e.g., pressurized gas) is supplied into the second pressure chamber 58, the supports 54A and 54B can contact or separate from the inner surfaces of the two sidewalls 50A and 50B. When a negative pressure is formed in the second pressure chamber 58, the supports 54A and 54B can support these sidewalls 50A and 50B from the inside. That is, as... Figure 4As shown, when negative pressure is formed in the second pressure chamber 58, the side walls 50A, 50B are attracted toward each other by the negative pressure, but the movement of the side walls 50A, 50B to the inner side is restricted by the support portions 54A, 54B. As a structure, the support portions 54A, 54B can prevent the two side walls 50A, 50B from contacting each other.

[0082] Moreover, according to the present embodiment, as Figure 4 shown, when negative pressure is formed in the second pressure chamber 58, the link member 47 moves (i.e., rises) toward the mounting member 53, so that the protruding portion 47a of the link member 47 is housed in the recessed portion 55 of the mounting member 53. At the same time, the lower portions of the support portions 54A, 54B are housed in the bottom walls 50C, 50D that are curved downward. Thus, a large stroke (i.e., a long distance of movement) of the link member 47 and the retaining ring 33 is ensured. The retaining ring 33 can rise to a position higher than the contact portion of the first elastic film 38 with the workpiece W. Thus, the release nozzle 60 can eject a jet of liquid (e.g., pure water) toward the contact portion of the first elastic film 38 with the workpiece W, thereby releasing the workpiece W from the first elastic film 38. Moreover, since the support portions 54A, 54B can prevent the side walls 50A, 50B of the second elastic film 50 from being greatly deformed, the life of the second elastic film 50 can be extended.

[0083] Figure 5 is an enlarged sectional view that shows another embodiment of the mounting member 53. The structures of the present embodiment that are not specifically described are the same as those of the embodiment described with reference to Figures 1-4 FIG. 2, and thus repeated descriptions are omitted. As shown in Figure 5 the mounting member 53 has grooves 62A, 62B that extend along the support portions 54A, 54B in the circumferential direction of the second elastic film 50. In the present embodiment, two annular grooves 62A, 62B extend along the inner sides of the two support portions 54A, 54B. These grooves 62A, 62B can quickly form negative pressure in the entire annular second pressure chamber 58 when gas in the second pressure chamber 58 is exhausted through the second fluid line F4. Thus, the entire retaining ring 33 can smoothly and quickly rise.

[0084] In the embodiment shown in Figure 5 FIG. 2, the grooves 62A, 62B are formed along the upper ends of the support portions 54A, 54B. However, the positions of the grooves 62A, 62B are not limited to the embodiment shown in Figure 5 FIG. 2. For example, as shown in Figure 6 FIG. 3, the grooves 62A, 62B can be located between the upper ends and the lower ends of the support portions 54A, 54B.

[0085] As shown in Figure 7As shown, in one embodiment, grooves 62A and 62B may also be formed on the outer side (outer surface) of the support portions 54A and 54B. Figure 7 In the illustrated embodiment, two annular grooves 62A and 62B extend along the outer sides of the two supports 54A and 54B. When pressurized fluid (e.g., pressurized air) is supplied into the second pressure chamber 58, the pressurized fluid flows into the grooves 62A and 62B and acts on the sidewalls 50A and 50B, causing the sidewalls 50A and 50B of the second elastic membrane 50 to separate from the supports 54A and 54B. As a result, the second elastic membrane 50 can smoothly deform according to the pressure in the second pressure chamber 58, thereby enabling the retaining ring 33 to move smoothly. In one embodiment, the mounting member 53 may also include... Figure 5 or Figure 6 The slots (first slot) 62A, 62B and shown Figure 7 The two slots shown are 62A and 62B (second slot).

[0086] Figure 8 This is an enlarged cross-sectional view showing another embodiment of the mounting component 53. The structure and references of this embodiment are not specifically described. Figures 1-4 The implementation methods described are the same, therefore repeated descriptions are omitted. For example... Figure 8 As shown, the mounting component 53 has multiple through holes 63A and 63B penetrating the support portions 54A and 54B. Figure 8 In the diagram, only one through hole 63A formed in the support portion 54A and one through hole 63B formed in the support portion 54B are shown, but multiple through holes 63A and 63B are arranged along the circumference of the second elastic membrane 50. Each through hole 63A and 63B penetrates the support portion 54A and 54B in the radial direction of the second elastic membrane 50.

[0087] With reference Figure 7 The described implementation is the same. When pressurized fluid (e.g., pressurized air) is supplied into the second pressure chamber 58, the pressurized fluid flows into the plurality of through holes 63A, 63B and acts on the side walls 50A, 50B, causing the side walls 50A, 50B of the second elastic membrane 50 to separate from the supports 54A, 54B. As a result, the second elastic membrane 50 can smoothly deform according to the pressure in the second pressure chamber 58, thereby enabling the retaining ring 33 to move smoothly. In one embodiment, the mounting member 53 may also include... Figure 5 or Figure 6 The slots 62A, 62B and shown Figure 8 The multiple through holes 63A and 63B shown are two examples.

[0088] exist Figures 2-8In each of the illustrated embodiments, friction reduction processing can also be performed on at least the outer side surfaces of the support portions 54A, 54B. The friction reduction processing is processing that can reduce the friction between the support portions 54A, 54B and the second elastic film 50. As examples of the friction reduction processing, covering the support portions 54A, 54B with a fluororesin (e.g., polytetrafluoroethylene), rough surface processing (e.g., sandblasting processing, embossing processing) of the surfaces of the support portions 54A, 54B can be listed.

[0089] The support portions 54A, 54B on which the friction reduction processing is performed can allow the second elastic film 50 to smoothly deform in accordance with the pressure in the second pressure chamber 58. As a result, the flapper ring 33 can be allowed to smoothly move.

[0090] The above-described embodiments are described with the aim of allowing those skilled in the art to implement the present application. Various changes in form and details can be made to the above-described embodiments without departing from the spirit and scope of the present application. Therefore, the technical scope of the present application is not limited to the embodiments described above, but encompasses various modifications within the technical scope of the present application. Accordingly, the technical scope of the present application is not limited to the embodiments described above, but encompasses various modifications within the technical scope of the present application. Therefore, the technical scope of the present application is not limited to the embodiments described above, but encompasses various modifications within the technical scope of the present application.

Claims

1. A grinding head for pressing a workpiece against a grinding pad to grind the workpiece, characterized in that, have: A first elastic membrane is used to press the workpiece onto the abrasive pad; A retaining ring configured to surround the first elastic membrane; A second elastic membrane is formed to press the retaining ring against the abrasive pad; The carrier, wherein the first elastic membrane is fixed to the carrier; The mounting component is disposed in the pressure chamber and fixes the second elastic membrane to the carrier; as well as A connecting component that connects the second elastic membrane to the retaining ring. The second elastic membrane has: The bottom wall is connected to the connecting component; as well as A first sidewall and a second sidewall, which are connected to the bottom wall. The mounting component has a first support portion and a second support portion, which extend along the first sidewall and the second sidewall toward the retaining ring, respectively, and the first support portion and the second support portion are disposed in the pressure chamber.

2. The grinding head according to claim 1, characterized in that, The mounting component has a recess located between the first support portion and the second support portion. The connecting member has a protrusion that is received within the recess when the connecting member moves toward the mounting member.

3. The grinding head according to claim 1 or 2, characterized in that, The bottom wall has a cross-sectional shape that bends toward the retaining ring. As the connecting component moves toward the mounting component, at least a portion of the first support and the second support are received within the curved bottom wall.

4. The grinding head according to claim 1 or 2, characterized in that, The mounting component has a groove that extends circumferentially along the first support and the second support of the second elastic membrane.

5. The grinding head according to claim 1 or 2, characterized in that, The mounting component has a plurality of through holes penetrating the first support portion and the second support portion, the plurality of through holes being arranged circumferentially on the second elastic membrane.

6. The grinding head according to claim 1 or 2, characterized in that, Friction reduction treatment is applied to at least the outer surfaces of the first support portion and the second support portion.

7. A grinding apparatus, characterized in that, have: A grinding table for supporting the grinding pad; and A grinding head as described in any one of claims 1 to 6, used to press a workpiece against the grinding pad to grind the workpiece.

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