Capsule film, polishing pressure head, equipment and method for polishing square substrate

Abstract

The invention discloses a capsule film, a polishing pressure head, equipment and a method for polishing a square substrate, the capsule film comprises at least two capsule film units which are arranged in a stacked mode, each capsule film unit comprises a bottom wall and a lateral extending wall surrounding the edge of the bottom wall, the bottom walls of the adjacent capsule film units are attached, and the lateral extending wall is arranged on the bottom wall of the corresponding capsule film unit. A pressurizing cavity is formed between the lateral extension walls of the adjacent capsule membrane units; at least one pressurizing cavity is used for transmitting pressure to the area, except the circle tangent to any opposite side, of the square base plate so as to independently adjust the pressure of the area where the four corners of the square base plate are located. According to the device, the pressure of the areas where the four corners of the square substrate are located is independently controlled, the material removal rate difference caused by the speed difference between the areas and the inner ring area can be compensated, and the technical effects that the material removal uniformity and the surface flatness of the square substrate are improved are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of polishing processing, and in particular, to a bladder film, a polishing head, a device and a method for polishing a square substrate. Background Art

[0002] As a chip advanced packaging technology, TGV (Through Glass Via) has been extensively researched and developed in various countries around the world. Its core material is a glass substrate, and the polishing of the glass substrate is involved in the production process. With the increasing size of the package, there are greater and thinner requirements for the size of the glass substrate.

[0003] However, the polishing of ultra-large and ultra-thin glass substrates (for example, glass substrates with a size specification of more than 500 mm in length, more than 500 mm in width, and a thickness between 0.5 mm and 1 mm) is only researched and developed in the laboratory. Due to the extremely large size, the polishing speed difference between the edge area and the central area of the glass substrate is extremely large. Due to the ultra-thin thickness, there are extremely high requirements for the surface flatness of the glass substrate, usually at the micron level.

[0004] In the prior art, the polishing accuracy of ultra-large and ultra-thin glass substrates cannot meet the requirements of mass production. Summary of the Invention

[0005] The main object of the present invention is to provide a bladder film for polishing a square substrate, so as to solve the problems in the related art that when polishing an ultra-large and ultra-thin square substrate, the material removal of the square substrate is uneven and the surface flatness is relatively low.

[0006] To achieve the above object, the present invention provides a bladder film for polishing a square substrate, including: At least two bladder film units stacked, each bladder film unit includes a bottom wall and a laterally extending wall surrounding the edge of the bottom wall, the bottom walls of adjacent bladder film units are attached, and there is a pressure chamber between the laterally extending walls of adjacent bladder film units; At least one of the pressure chambers is used to transmit pressure to the area outside the circle tangent to any pair of opposite sides of the square substrate, so as to separately adjust the pressure in the areas where the four corners of the square substrate are located.

[0007] Optionally, there is a pressure chamber within the laterally extending wall of the bladder film unit located at the uppermost layer, and the pressure chamber is used to separately adjust the pressure in the area within the circle tangent to any pair of opposite sides of the square substrate.

[0008] Optionally, the circle tangent to any pair of opposite sides of the square substrate is located between two adjacent pressure chambers.

[0009] Optionally, the circle tangent to any pair of opposite sides of the square substrate is located near the boundary between two adjacent pressure chambers.

[0010] Optionally, at least one inner boundary diameter of the pressurizing chamber is smaller than the diameter of the largest circumscribed circle of the square substrate, and the outer boundary diameter is larger than the diameter of the largest circumscribed circle of the square substrate.

[0011] Optionally, at least two of the pressurizing chambers are located within a circle tangent to any pair of opposite sides of the square substrate.

[0012] Optionally, at least two of the pressurizing chambers are used to transmit pressure to the area outside the circle tangent to any pair of opposite sides of the square substrate, so as to apply independent pressures to different areas of the four corners of the square substrate.

[0013] Optionally, at least one of the pressurizing chambers is used to transmit pressure to a spacer located outside the square substrate.

[0014] Optionally, the stiffness of the lateral extension wall located outside the pressurizing chamber is greater than the combined stiffness of the bottom wall located below the pressurizing chamber.

[0015] Optionally, the connection between the lower part of the lateral extension wall and the bottom wall is an acute angle.

[0016] Optionally, the capsule unit further includes a folding portion, and the folding portion is located at one end of the lateral extension wall away from the bottom wall.

[0017] According to another aspect of the present invention, there is provided a polishing head, including the above-mentioned capsule, and a first support member; The first support member is sleeved and fixed inside each of the capsule units, the diameter of the outer side surface of the first support member is larger than the inner diameter of the lateral extension wall, and the outer side surface of the first support member fits with the inner side surface of the lateral extension wall.

[0018] Optionally, it further includes a second support member, the second support member is sleeved and fixed outside each of the capsule units, the diameter of the inner side surface of the second support member is smaller than the outer diameter of the lateral extension wall after fitting with the first support member, and the lateral extension wall is clamped by the first support member and the second support member.

[0019] Optionally, the first support member and the second support member are arranged in a ring shape.

[0020] Optionally, when the connection between the lower part of the lateral extension wall and the bottom wall is an acute angle, the outer side surface of the first support member is an inclined surface, the maximum diameter and the minimum diameter of the inclined surface are respectively larger than the maximum inner diameter and the minimum inner diameter of the connection, and the inclined surface fits with the inner side surface of the connection.

[0021] Optionally, an arc chamfer is provided at one end of the first support member close to the bottom wall, and the arc chamfer fits with the inner side surface of the connection and the bottom wall.

[0022] Optionally, it further includes a housing, a retaining ring, a retaining ring fixing member and a sealing ring; The retaining ring is fixed to the lower end of the housing through the retaining ring fixing member; The capsule unit further includes a folding portion located at one end of the lateral extension wall away from the bottom wall. The folding portion of the outermost capsule unit among the plurality of capsule units is pressed and fixed between the retaining ring fixing member and the housing, and the folding portions of the remaining capsule units are pressed and fixed to the lower end surface of the housing through the sealing ring; A plurality of air channels are provided on the housing, and the air channels communicate with the corresponding pressurizing chambers.

[0023] Optionally, a sealing ring is provided at one end of the folding portion away from the lateral extension wall. The sealing ring is used for pressing and fitting on the housing of the polishing head to seal the corresponding pressurizing chamber.

[0024] Optionally, a plurality of annular grooves distributed from the inside to the outside are provided on the lower end surface of the housing. The annular grooves respectively correspond to the joints between the folding portions of the capsule units and the lateral extension walls, and the annular grooves provide a movement space for the joints.

[0025] According to another aspect of the present invention, a polishing device is provided, including the above-mentioned capsule or the above-mentioned polishing head.

[0026] According to another aspect of the present invention, a method for polishing a square substrate is provided. Using the above-mentioned polishing head, the method includes the following steps: Arrange a dummy wafer on the polishing pad. The dummy wafer is circular and has a square hole provided thereon; Place the square substrate to be polished in the square hole, and make the lower surface of the square substrate contact the polishing pad. The movement of the square substrate in the horizontal direction is restricted by the square hole; Control the movement of the polishing head, adjust the position of the capsule, so that each of the pressurizing chambers on the capsule corresponds to the set areas on the square substrate and the dummy wafer; Make the lower surface of the capsule fit the upper surface of the square substrate; Control the pressure in each of the pressurizing chambers in the capsule to adjust the pressure transmitted to different areas on the square substrate and the dummy wafer to the set value; Control the rotation of the polishing head and the polishing pad to polish the square substrate.

[0027] In the embodiments of the present invention, at least two capsule units are arranged in a stacked manner. Each capsule unit includes a bottom wall and a laterally extending wall surrounding the edge of the bottom wall. The bottom walls of adjacent capsule units are attached, and there is a pressurizing cavity between the laterally extending walls of adjacent capsule units; at least one pressurizing cavity is used to transmit pressure to the area outside the circle tangent to any pair of opposite sides on the square substrate, so as to separately adjust the pressure in the areas where the four corners of the square substrate are located. On the one hand, at least the capsule units arranged in a stacked manner form at least a pressurizing cavity. Different pressurizing cavities transmit pressure to different areas of the square substrate. Among them, some pressurizing cavities can separately transmit pressure to the area outside the circle tangent to any pair of opposite sides on the square substrate (i.e., the corner area), so that the pressure borne by the corner area of the square substrate can be controlled separately. Some pressurizing cavities can transmit pressure to the area inside the circle tangent to any pair of opposite sides on the square substrate (i.e., the inner circle area), so that the pressure in this area of the square substrate can also be controlled separately. Thus, during the polishing process, separate pressure control of the corner area and the inner circle area of the square substrate is achieved, compensating for the difference in material removal rate caused by the speed difference between the corner area and other areas on the square substrate, and improving the technical effects of the material removal uniformity and surface flatness of the square substrate; Especially when polishing a large-size ultra-thin square substrate, by separately controlling the pressure in the pressurizing cavity corresponding to the corner area of the square substrate, the deformation caused by its own weight in the edge area of the large-size polishing head can be compensated, so as to adjust the pressure additionally applied to the corner area of the square substrate due to deformation in the edge area of the polishing head during the polishing process, and further improve the material removal uniformity and surface flatness of the square substrate; On the other hand, in the present invention, by stacking multiple capsule units, the corresponding multi-layer bottom walls of some pressurizing cavities are formed, thereby improving the stiffness of the bottom wall of the pressurizing cavity, making the pressure transmitted to the square substrate more uniform, and the manufacturing process of forming multiple pressurizing cavities by stacking multiple capsule units is simpler and the manufacturing cost is lower; On another aspect, after using multiple capsule units stacked, each capsule unit is independent, so that each pressurizing cavity is independent of each other, reducing the mutual influence between adjacent pressurizing cavities during the pressure change process, and further improving the pressure control effect and polishing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention, making other features, objects, and advantages of the present invention more obvious. The schematic embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 is a schematic cross-sectional structure diagram of a polishing head with a capsule according to an embodiment of the present invention; Figure 2 is a partial structure diagram of a capsule according to an embodiment of the present invention; Figure 3 is a schematic structural diagram of one of the capsule units in an embodiment of the present invention; Figure 4 is Figure 3 a partially enlarged structural diagram in Figure 5 is Figure 3 a structural diagram in which two support members are omitted; Figure 6 is a force diagram of the bottom wall of the capsule unit after installing the first support member in an embodiment of the present invention; Figure 7 is a force diagram of the laterally extending wall in an embodiment of the present invention; Figure 8 is a schematic diagram of a polishing indenter in an embodiment of the present invention; Figure 9 is a bottom view structural diagram of the polishing indenter in an embodiment of the present invention; Figure 10 is a schematic diagram of a pressurization chamber division in an embodiment of the present invention; Figure 11 is a schematic diagram of another pressurization chamber division in an embodiment of the present invention; Figure 12 is a partition diagram of a square substrate in an embodiment of the present invention; Wherein, 1, capsule; 10, capsule unit; 101, first capsule unit; 102, second capsule unit; 103, third capsule unit; 104, fourth capsule unit; 105, fifth capsule unit; 106, bottom wall; 107, laterally extending wall; 108, sealing ring; 109, folding portion; 110, joint; 2, housing; 3, retaining ring fixing member; 4, retaining ring; 5, spacer; 6, sealing ring; 7, square substrate; 70, inner ring region; 71, corner region; 8, first support member; 9, second support member; 11, annular gap; 12, pressure transmission interface; 13, pressurization chamber. Detailed implementation manners

[0029] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying 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 shall fall within the protection scope of the present invention.

[0030] It should be noted that the terms "first", "second", etc. in the description, claims and the above-mentioned drawings of the present invention are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances for the embodiments of the present invention described herein.

[0031] In the present invention, the orientation or positional relationship indicated by the terms "upper", "lower", "inner", etc. is based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit that the indicated device, element or component must have a specific orientation, or be constructed and operated in a specific orientation.

[0032] Moreover, in addition to being used to represent an orientation or positional relationship, some of the above-mentioned terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0033] In addition, terms such as "arranged", "provided with", "connected", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or there is an internal connection between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above-mentioned terms in the present invention can be understood according to specific circumstances.

[0034] In addition, the meaning of the term "plurality" should be two or more.

[0035] It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with embodiments.

[0036] To solve related technical problems, as Figure 1 and Figure 2 shown, an embodiment of the present invention provides a capsule film for polishing a square substrate, including: At least two capsule film units 10 arranged in a stacked manner, each capsule film unit 10 includes a bottom wall 106 and a laterally extending wall 107 surrounding the edge of the bottom wall 106. The bottom walls 106 of adjacent capsule film units 10 are attached, and there is an annular gap 11 between the laterally extending walls 107 of adjacent capsule film units 10, so that there is a pressure chamber 13 between the laterally extending walls 107 of adjacent capsule film units 10. At least one pressure chamber 13 is used to transmit pressure to the area outside the circle tangent to any pair of opposite sides on the square substrate 7 to separately adjust the pressure in the areas where the four corners of the square substrate 7 are located.

[0037] In this embodiment, as Figure 2 shown, the capsule membrane 1 includes at least capsule units 10 arranged in layers. Each capsule unit 10 includes a bottom wall 106 and a lateral extension wall 107 surrounding the edge of the bottom wall 106. The bottom wall 106 and the lateral extension wall 107 enclose an inflatable chamber, and the upper end of the chamber is an opening. As Figure 1 shown, when the upper end of the capsule unit 10 is assembled with the housing 2 of the polishing indenter, the lower end face of the housing 2 or the upper pressing plate of the housing 2 that presses the upper end of the capsule unit 10 can close the upper opening of the chamber, so that by introducing a gaseous or liquid medium into the chamber, the pressure in the chamber can be changed, and further the expansion degree of the chamber and the pressure transmitted outward can be changed.

[0038] As Figure 2 shown, the diameters of the multiple capsule units 10 are different. The diameter referred to here includes the inner diameter and the outer diameter of the capsule unit 10. The multiple capsule units 10 are stacked in such a way that the larger diameter is on the outside and the smaller diameter is on the inside. The bottom walls 106 of adjacent capsule units 10 are in contact with each other, and there is an annular gap 11 between the lateral extension walls 107, so that a pressurizing chamber 13 is formed between the adjacent lateral extension walls 107. This independent chamber can be annular, and the pressurizing chamber 13 uses the outer ring part of the bottom wall 106 of the corresponding capsule unit 10 for pressure transmission. The outer ring part refers to the part of the bottom wall 106 of the capsule unit 10 that is not in contact with the bottom wall 106 of the upper-layer capsule unit 10.

[0039] As Figure 12 shown, in the polishing of the square substrate 7, it is particularly important to control the pressure at the four corners of the square substrate 7. Therefore, at least the areas where the four corners are located (corner areas 71) need to be controlled separately for pressure, and at least the areas on the square substrate 7 located inside the corners (inner ring area 70) need to be controlled separately for pressure. For this purpose, in this embodiment, there is at least one pressurizing chamber 13 for transmitting pressure to the area on the square substrate 7 outside the circle tangent to any pair of opposite sides (corner areas 71), so as to separately adjust the pressure in the areas where the four corners of the square substrate 7 are located.

[0040] It can be understood that on the square substrate 7, the area outside the circle tangent to any pair of opposite sides (corner areas 71) is the area where the four corners of the square substrate 7 are located. As Figure 12 , taking the square substrate 7 as a square as an example, the circle tangent to any pair of opposite sides of the square substrate 7 is the largest inscribed circle of the square substrate 7, and the area outside this circle (corner areas 71) is the four arcuate corners of the square substrate 7. Taking the square substrate 7 as a rectangle with unequal length and width as an example, as Figure 11, the circle can be a circle tangent to the short side of the square substrate 7, i.e., the largest inscribed circle of the square substrate 7, and the area outside the circle (the corner area 71) is two symmetric bow-shaped areas including the long sides of the square substrate 7. The circle can also be a circle tangent to the long side of the square substrate 7, and the area outside the circle is the four bow-shaped corners of the square substrate 7.

[0041] After such a setting, in this embodiment, pressure can be transmitted to the inner ring area 70 of the square substrate 7 through at least one pressurizing chamber 13 alone, and pressure can be transmitted to the corner area 71 of the square substrate 7 through at least one pressurizing chamber 13 alone, that is, pressure is transmitted to the areas where the four corners of the square substrate 7 are located. Thus, the pressure borne by the four corner areas 71 of the square substrate 7 can be controlled separately, and further, the material removal rate of the four corners can be controlled separately during the polishing process, compensating for the difference in material removal rate caused by the speed difference between the corner area 71 and other areas on the square substrate 7, and improving the material removal uniformity and surface flatness of the square substrate 7. Especially when polishing a large-size ultra-thin square substrate 7, by separately controlling the pressure in the pressurizing chamber 13 corresponding to the corner area 71 of the square substrate 7, the deformation caused by its own weight in the edge area of the large-size polishing head can be compensated, so as to adjust the additional pressure applied to the corner area 71 of the square substrate 7 due to the deformation in the edge area of the polishing head during the polishing process, and further improve the material removal uniformity and surface flatness of the square substrate 7.

[0042] In the present invention, as Figure 2 shown, since multiple capsule units 10 are stacked, the thickness of the bottom walls 106 of the multiple formed pressurizing chambers 13 shows a decreasing trend from the inside to the outside. The thickness of the bottom wall 106 corresponding to the pressurizing chamber 13 at the center is the sum of the thicknesses of the bottom walls 106 of all the capsule units 10, and the thickness of the bottom wall 106 corresponding to the outermost pressurizing chamber 13 is equal to the thickness of the bottom wall 106 of the capsule unit 10.

[0043] According to Preston's equation ( is the material removal rate, is Preston's constant, is the polishing pressure, is the instantaneous relative velocity of any point on the surface of the square substrate 7 with respect to the polishing pad). Under the condition of the same polishing pressure, the material removal rate in the central region is less than that in the edge region. Therefore, to keep the material removal rate consistent, it is necessary to increase the pressure in the central region of the square substrate 7, or decrease the pressure in the edge region of the square substrate 7, or do both simultaneously. Generally speaking, the bladder 1 needs to generate a greater pressure in the central region. In the present invention, by stacking multiple bladder units 10, the bottom wall 106 of the pressure chamber 13 near the middle is thicker, so as to maintain sufficient stiffness and avoid excessive deformation of the bottom wall 106 under a large pressure, and then better transfer the pressure to the region near the middle of the square substrate 7. And stacking multiple bladder units 10 to form multiple pressure chambers 13 is simpler in the manufacturing process and lower in manufacturing cost. On the other hand, after stacking multiple bladder units 10, each bladder unit 10 is independent, making each pressure chamber 13 independent of each other, reducing the mutual influence between adjacent pressure chambers 13 during the pressure change process, and further improving the pressure control effect and polishing effect.

[0044] For the topmost bladder unit 10, there is a pressure chamber 13 within the lateral extension wall 107 of the topmost bladder unit 10. The pressure chamber 13 is used to independently adjust the pressure in the region of the square substrate 7 within the circle tangent to any pair of opposite sides. Specifically, the chamber of the topmost bladder unit 10 itself serves as a pressure chamber 13. This pressure chamber 13 is circular, and this pressure chamber 13 uses the bottom wall 106 of the bladder unit 10 to transfer pressure, so as to independently adjust the pressure in the region of the square substrate 7 within the circle tangent to any pair of opposite sides (inner circle region 70).

[0045] In a specific embodiment, the inner circle region of the square substrate can be completely covered by one pressure chamber 13. At this time, this pressure chamber 13 is located in the middle of the whole bladder and is circular as a whole. The diameter of the pressure chamber 13 is equal to the diameter of the inner circle region of the square substrate 7. Of course, the maximum inscribed circle coverage range of the square substrate 7 can also be covered by multiple pressure chambers 13. At this time, the multiple pressure chambers 13 at least include a circular pressure chamber 13 and an annular pressure chamber 13, which need to be formed by stacking two bladder units 10, as Figure 10 shown in the regions 4 and 5 respectively represent a pressure chamber 13. The circular pressure chamber 13 (i.e., region 5) is located in the middle of the whole bladder, and its diameter is smaller than the diameter of the maximum inscribed circle of the square substrate 7. The outer diameter of the annular pressure chamber 13 (i.e., region 4) located on the outside is equal to the diameter of the maximum inscribed circle of the square substrate 7.

[0046] Since there is a laterally extending wall 107 between adjacent pressure chambers 13 and the laterally extending wall 107 has a certain wall thickness, there is a gap between adjacent pressure chambers 13, and the width of this gap is approximately equal to or equal to the wall thickness at the lower end of the laterally extending wall 107.

[0047] In one embodiment, a circle tangent to any pair of opposite sides on the square substrate 7 is located between two adjacent pressure chambers 13, that is, corresponding to the lower end of the laterally extending wall 107 between two adjacent pressure chambers 13, and this circle can be located at any position at the lower end of the laterally extending wall 107. Taking the square substrate 7 as a square as an example, the diameter of the outer boundary of a pressure chamber 13 in the capsule 1 is smaller than the length of the square substrate 7, and this pressure chamber 13 is used to transmit pressure to the inner circle area 70 on the square substrate 7. The diameter of the inner boundary of a pressure chamber 13 is larger than the length of the square substrate 7, and this pressure chamber 13 is used to transmit pressure to the corner area 71 on the square substrate 7. The same applies to the square substrate 7 with unequal length and width, which will not be elaborated here.

[0048] In another embodiment, a circle tangent to any pair of opposite sides on the square substrate 7 is located near the boundary between two adjacent pressure chambers 13. Specifically, the circle tangent to any pair of opposite sides on the square substrate 7 can be located near the outer boundary of a pressure chamber 13, or the circle tangent to any pair of opposite sides on the square substrate 7 can be located near the inner boundary of a pressure chamber 13. When it is located near the outer boundary of a pressure chamber 13, the outer boundary diameter of this pressure chamber 13 can be equal to the maximum inscribed circle diameter of the square substrate 7, or equal to the maximum tangent circle diameter tangent to the long side of the square substrate 7, or any value between the maximum inscribed circle diameter and the maximum tangent circle diameter, or slightly smaller than the maximum inscribed circle diameter of the square substrate, or slightly larger than the maximum tangent circle diameter.

[0049] Similarly, when it is located near the inner boundary of a pressure chamber 13, the inner boundary of this pressure chamber 13 can be equal to the maximum inscribed circle diameter of the square substrate 7, or equal to the maximum tangent circle diameter tangent to the long side of the square substrate 7, or any value between the maximum inscribed circle diameter and the maximum tangent circle diameter, or slightly smaller than the maximum inscribed circle diameter of the square substrate, or slightly larger than the maximum tangent circle diameter.

[0050] However, in any case, there is at least one pressure chamber 13 that can transmit pressure to the area outside the circle tangent to any pair of opposite sides on the square substrate 7 to separately adjust the pressure in the areas where the four corners of the square substrate 7 are located.

[0051] For example, when the length and width of the square substrate are 500 mm, the diameter of the outer boundary of a pressure chamber or the inner boundary of a pressure chamber fluctuates within ±10% of 500 mm. When the length and width are 1000 mm, the diameter of the outer boundary of a pressure chamber or the inner boundary of a pressure chamber fluctuates within ±5% of 1000 mm. That is, the larger the size of the square substrate, the smaller the percentage difference between the diameter of the boundary of the corresponding pressure chamber and the diameter of the largest inscribed circle of the square substrate, so that the boundary of the pressure chamber is as close as possible to the edge of the square substrate.

[0052] As a preferred embodiment, the diameter of the outer boundary of a pressure chamber 13 is equal to the diameter of the largest inscribed circle of the square substrate 7, so that the pressure chamber 13 can transmit pressure to the central region of the edge of the square substrate 7, improving the polishing effect of this region.

[0053] In some embodiments, more pressure chambers 13 can also jointly cover the inner ring region 70 of the square substrate 7 (that is, the region within the circle tangent to any pair of opposite sides on the square substrate). Obviously, the more the number of pressure chambers 13, the more refined the partition pressure control can be performed on the inner ring region 70 of the square substrate 7, and the polishing effect can be improved. However, the corresponding production cost and manufacturing requirements become higher, and the pressure control difficulty also increases. Therefore, the corresponding structural form can be selected according to actual needs, and this embodiment is not limited herein.

[0054] In addition, for the pressure chamber that transmits pressure to the corner region 71 of the square substrate 7 (the region outside the circle tangent to any pair of opposite sides on the square substrate), the diameter of its outer boundary can be equal to the diameter of the largest circumscribed circle of the square substrate 7, and of course, it can also be greater than the diameter of the largest circumscribed circle of the square substrate 7.

[0055] When they are equal, the edge of the bottom wall 106 of the pressure chamber 13 just presses on the vertex angle of the square substrate 7 (such as Figure 10 the region 2 shown), and the pressure control difficulty of the vertex angle increases. For this reason, in this embodiment, the diameter of the inner boundary of at least one pressure chamber 13 is smaller than the diameter of the largest circumscribed circle of the square substrate 7, and the diameter of the outer boundary is greater than the diameter of the largest circumscribed circle of the square substrate 7.

[0056] Specifically, in this embodiment, the region covered by the pressure chamber 13 when transmitting pressure can slightly exceed the vertex angle when including the vertex angle of the square substrate 7 (such as Figure 11 the region 2 shown), so that the bottom wall 106 of the pressure chamber 13 corresponding to the region 2 can better transmit the pressure to the vertex angle of the square substrate.

[0057] In one embodiment, at least two of the pressure chambers 13 are located within a circle tangent to any pair of opposite sides on the square substrate 7. That is, at least two adjacent pressure chambers 13 among the plurality of pressure chambers 13 are respectively used to transmit pressure to the inner and outer layers of the inner ring region 70, that is, the inner ring region 70 is further divided into two inner and outer distributed regions, and the corresponding regions are individually pressure-controlled by two pressure chambers 13, so as to achieve more refined pressure control in the inner ring region 70 and improve the polishing effect of the inner ring region 70 on the square substrate 7.

[0058] Similarly, in one embodiment, at least two of the pressure chambers 13 are used to transmit pressure to the region outside the circle tangent to any pair of opposite sides on the square substrate 7, so as to individually apply pressure to different regions of the corner region 71 of the square substrate 7. That is, at least two adjacent pressure chambers 13 among the plurality of pressure chambers 13 are respectively used to transmit pressure to the inner and outer layers of the corner region 71, that is, the corner region 71 is further divided into two inner and outer distributed regions, and the corresponding regions are individually pressure-controlled by two pressure chambers 13, so as to achieve more refined pressure control in the corner region 71 and improve the polishing effect of the corner region 71 on the square substrate 7.

[0059] When polishing the square substrate 7 with a circular polishing head, a spacer 5 needs to be arranged outside the square substrate 7 to limit the horizontal position of the square substrate 7 on the polishing pad. At the same time, pressure also needs to be applied to the spacer 5 to press it tightly on the polishing pad. For this reason, in this embodiment, at least one of the pressure chambers 13 (such as Figure 10 the area 1 shown) transmits pressure to the square substrate spacer 5.

[0060] Specifically, as Figure 9 shown, the spacer 5 is a circular sheet with a square hole in the middle, and the square hole is used to accommodate the square substrate 7. Among the plurality of pressure chambers 13, the pressure chamber 13 (such as Figure 10 the area 2 shown) corresponding to the corner region of the square substrate 7 also corresponds to a part of the spacer 5 at the same time. When this pressure chamber 13 transmits pressure to the corner region of the square substrate 7, it also transmits pressure to the spacer 5. However, the diameter of this pressure chamber 13 should not be too large beyond the square substrate 7. This pressure chamber 13 can only correspond to the inner ring region of the spacer 5, and additional pressure chambers 13 are required for the edge region.

[0061] In one embodiment, as Figure 2 、 Figure 10 and Figure 11As shown, the capsule membrane 1 includes five capsule membrane units 10, namely, a first capsule membrane unit 101, a second capsule membrane unit 102, a third capsule membrane unit 103, a fourth capsule membrane unit 104, and a fifth capsule membrane unit 105, which are distributed from the outside to the inside in sequence. Among them, a pressure chamber 13 (area 1) formed between the first capsule membrane unit 101 and the second capsule membrane unit 102 is used to transmit pressure to the edge area of the companion piece 5. Two pressure chambers 13 (area 2 and area 3) formed between the second capsule membrane unit 102 and the third capsule membrane unit 103, and between the third capsule membrane unit 103 and the fourth capsule membrane unit 104 jointly transmit pressure to the corner area of the square substrate 7. A pressure chamber 13 (area 4) formed between the fourth capsule membrane unit 104 and the fifth capsule membrane unit 105, and a pressure chamber 13 (area 5) of the fifth capsule membrane unit 105 itself jointly transmit pressure to the coverage range of the largest inscribed circle of the square substrate 7. Of course, the above description is not restrictive and can be adjusted according to actual needs.

[0062] During the pressure transmission process, the pressure in the pressure chamber 13 is transmitted to the square substrate 7 through the corresponding bottom wall 106. To ensure a better pressure transmission effect, it is expected that the bottom wall 106 of the pressure chamber 13 is more likely to produce a stiffness change compared to the lateral extension wall 107. Therefore, in this embodiment, the stiffness of the lateral extension wall located outside the pressure chamber is greater than the composite stiffness of the bottom wall located below the pressure chamber.

[0063] Specifically, since the thickness of the bottom wall 106 corresponding to the pressure chamber 13 at different positions is different, the bottom wall 106 of the central pressure chamber 13 is thicker as a whole, which is equal to the sum of the thicknesses of the bottom walls 106 of multiple capsule membrane units 10, and the bottom wall 106 of the outermost pressure chamber 13 is the thinnest, equal to the thickness of the bottom wall 106 of a single capsule membrane unit 10. Therefore, the stiffness of the bottom walls 106 of different pressure chambers 13 is different. When designing, it is necessary to make the stiffness of the lateral extension wall 107 greater than the stiffness of the single-layer bottom wall 106 of each pressure chamber 13 and the composite stiffness of the multi-layer bottom walls 106. In practical applications, the lateral extension walls 107 of the capsule membrane units 10 at different positions can have different stiffnesses. The stiffness of the lateral extension wall 107 of the capsule membrane unit 10 located in the center is the largest, and the stiffness of the lateral extension wall 107 of the capsule membrane unit 10 located on the outside is the smallest.

[0064] When polishing a large-sized square substrate 7, the overall size of the capsule membrane 1 is also larger. Therefore, the diameter of the bottom wall 106 of each capsule membrane unit 10 is relatively larger, which easily causes the bottom wall 106 of the capsule membrane unit 10 to bend, wrinkle, etc., resulting in poor pressure transmission effect. Therefore, as Figures 3 to 5As shown, in this embodiment, a polishing head is provided, which includes the above-mentioned capsule membrane and a first support member. The first support member 8 is sleeved and fixed inside each capsule unit 10. The diameter of the outer side surface of the first support member 8 is greater than the inner diameter of the lateral extension wall 107 of the corresponding capsule unit 10, and the outer side surface of the first support member 8 is in contact with the inner side surface of the lateral extension wall 107.

[0065] Specifically, in this embodiment, the first support member 8 is of a rigid structure. Each capsule unit 10 is provided with a first support member 8. The diameter of the outer side surface of the first support member 8 is greater than the inner diameter of the lateral extension wall 107 of the corresponding capsule unit 10. After the first support member 8 is sleeved inside the capsule unit 10, the outer side surface of the first support member 8 is in contact with the inner side surface of the lateral extension wall 107 and applies an outward expansion force to the bottom wall 106 of the capsule unit 10 (as Figure 6 shown), so that the bottom wall 106 is tightened to ensure the flatness of the bottom wall 106. After multiple capsule units 10 are stacked, the tightened bottom wall 106 can also improve the fitting degree of the bottom walls 106 of adjacent capsule units 10, and can prevent gas from entering the fitting surface of adjacent bottom walls 106 when pressurizing the pressure chamber 13, resulting in local bulging.

[0066] At the same time, after the first support member 8 applies an outward expansion force to the bottom wall 106 of the capsule unit 10, the stiffness of the bottom wall 106 can be increased, so that the pressure transmission can be better carried out.

[0067] On the basis of the above embodiment, the capsule membrane 1 further includes a second support member 9. The second support member 9 is sleeved and fixed outside each capsule unit 10. The diameter of the inner side surface of the second support member 9 is smaller than the outer diameter of the lateral extension wall 107 after being in contact with the first support member 8, and the lateral extension wall 107 is clamped by the first support member 8 and the second support member 9.

[0068] Specifically, in this embodiment, the second support member 9 is of a rigid structure. Each capsule unit 10 is provided with a second support member 9. The lateral extension wall 107 of the capsule unit 10 is clamped by the first support member 8 and the second support member 9, so as to further improve the stiffness of the lateral extension wall 107. In one embodiment, the first support member 8 and the second support member 9 are arranged in a ring shape.

[0069] The first support member 8 and the second support member 9 clamp the lower part of the lateral extension wall 107. The composite stiffness of the first support member 8, the lower part of the lateral extension wall 107, and the second support member 9 is greater than the composite stiffness of the bottom walls 106 of each pressure chamber 13.

[0070] Specifically, in this embodiment, the heights of the first support member 8 and the second support member 9 are both smaller than the height of the lateral extension wall 107, and the first support member 8 and the second support member 9 are clamped at the lower part of the lateral extension wall 107, so that the bottom wall 106 of the capsule unit 10 can be better tightened, and the stiffness of the part of the lateral extension wall 107 close to the bottom wall 106 can be improved.

[0071] On the basis of the above embodiment, the stiffness of the part of the lateral extension wall 107 above the first support member 8 and the second support member 9 can also be set to be greater than the composite stiffness of the bottom wall 106 of each pressurizing chamber 13.

[0072] To better tighten the bottom wall 106 of the capsule unit 10, as Figure 4 shown, in this embodiment, the connection part 1050 between the lower part of the lateral extension wall 107 and the bottom wall 106 of the capsule unit 10 is an acute angle. Specifically, in this embodiment, the connection part 1050 is a part of the lower part of the lateral extension wall 107, the connection part 1050 and the bottom wall 106 form an acute angle, the outer side surface of the first support member 8 is an inclined surface 80, and the inclined surface 80 fits with the inner side surface of the connection part 1050.

[0073] Specifically, after being set like this, the first support member 8 applies an inclined upward force to the connection part 1050 (as Figure 7 shown), and the direction of this force forms an obtuse angle with the bottom wall 106, so that the bottom wall 106 can be better stretched to be flat. To improve the fitting degree between the inclined surface 80 and the connection part 1050, the maximum diameter and the minimum diameter of the inclined surface 80 are respectively larger than the maximum inner diameter and the minimum inner diameter of the connection part 1050.

[0074] To avoid damage to the capsule by the first support member 8, in this embodiment, an arc chamfer is provided at one end of the first support member 8 close to the bottom wall 106, and the arc chamfer fits with the inner side surface of the connection part 1050 and the bottom wall 106.

[0075] The capsule needs to be installed on the housing 2 of the polishing chuck, and each pressurizing chamber 13 needs to be closed after installation. To facilitate the installation of the capsule unit 10, Figures 2 to 5 shown, in this embodiment, the capsule unit 10 further includes a folding part 109, and the folding part 109 is located at one end of the lateral extension wall 107 away from the bottom wall 106. Specifically, the folding part 109 can be turned inwards or outwards, and the upper surface of the folding part 109 can fit with the end face of the housing 2 of the polishing chuck to form a sealing surface, so as to seal each pressurizing chamber 13 and ensure sufficient sealing performance. Moreover, after the folding part 109 is provided, there is an included angle between the folding part 109 and the lateral extension wall 107, and this included angle gradually becomes larger during the downward movement of the bottom wall 106 of the capsule unit 10, so as to provide an additional displacement amount and avoid the generation of tensile elastic force on the lateral extension wall 107.

[0076] To further facilitate sealing, in this embodiment, a sealing ring 108 is provided at one end of the folding portion 109 away from the lateral extension wall 107. The sealing ring 108 is used to press-fit on the housing 2 of the polishing head to seal the corresponding pressurizing chamber 13.

[0077] Optionally, the polishing head further includes a housing 2, a retaining ring 4, a retaining ring fixing member 3, and a sealing ring 6; The retaining ring 4 is fixed to the lower end of the housing 2 through the retaining ring fixing member 3; The capsule unit 10 further includes a folding portion 109. The folding portion 109 is located at one end of the lateral extension wall 107 away from the bottom wall 106. The folding portion 109 of the outermost capsule unit 10 among the plurality of capsule units 10 is tightly fixed between the retaining ring fixing member 3 and the housing 2, and the folding portions 109 of the remaining capsule units 10 are tightly fixed to the lower end surface of the housing 2 through the sealing ring 6; A plurality of air channels are provided on the housing 2, and the air channels communicate with the corresponding pressurizing chambers 13.

[0078] In this embodiment, the upper end of the housing 2 is used to connect with the machine tool equipment. The retaining ring fixing member 3 is fixed to the lower end of the housing 2 and can be fixed to the housing 2 by screws. The retaining ring 4 is fixed to the lower end of the retaining ring fixing member 3 and can be fixed by bonding. The retaining ring 4 can be a circular ring, and the capsule film 1 is installed in the retaining ring 4 and fixedly connected to the lower end surface of the housing 2. During polishing, the accompanying sheet 5 is also installed in the retaining ring 4 to limit the square substrate 7. Among the plurality of capsule units 10, the folding portion 109 at the upper end of each capsule unit 10 needs to be fixed to the housing 2 to seal the corresponding pressurizing chamber 13. To save components, in this embodiment, for the folding portion 109 of the outermost capsule unit 10, it can be pressed against the housing 2 through the retaining ring fixing member 3, and the folding portions 109 of the remaining capsule units 10 can be tightly fixed to the housing 2 through the corresponding sealing rings 6. When including five capsule units 10, three sealing rings 6 are required.

[0079] In one implementation, a plurality of annular grooves 20 distributed from the inside to the outside are provided on the lower end surface of the housing 2. The annular grooves 20 respectively correspond to the joints 110 between the folding portion 109 of the capsule unit 10 and the lateral extension wall 107, and the annular grooves 20 provide a movement space for the joints 110.

[0080] Specifically, since there is an angle between the folding portion 109 and the lateral extension wall 107, the joint 110 where the angle is located will generate a certain movement during the movement of the bottom wall 106. The provision of the annular groove can provide a movement space for the joint 110, and the width of the annular groove can be designed according to requirements.

[0081] According to another aspect of the present invention, a polishing device is provided, including the above-mentioned capsule film 1 or the above-mentioned polishing head.

[0082] According to another aspect of the present invention, there is provided a method for polishing a square substrate, which uses the above-mentioned bladder 1, or the above-mentioned polishing head, or the above-mentioned polishing equipment. The method includes: A spacer 5 is arranged on the polishing pad. The spacer 5 is circular, and a square hole is provided on the spacer 5. The length and width of the square hole match the length and width of the square substrate 7 to be polished. The thickness of the spacer 5 is slightly less than the thickness of the square substrate 7, and the diameter of the spacer 5 matches the inner diameter of the retaining ring 4 on the polishing head; The square substrate 7 to be polished is placed in the square hole, and the lower surface of the square substrate 7 is brought into contact with the polishing pad. The movement of the square substrate 7 in the horizontal direction is restricted by the square hole. Specifically, the square substrate 7 can be adsorbed by a robotic arm and transferred into the square hole. During the polishing process, the spacer 5 is constrained within the retaining ring 4, and the square substrate 7 is constrained within the spacer 5, thereby restricting the horizontal position of the square substrate 7; Control the movement of the polishing head to adjust the position of the bladder 1 so that each of the pressure chambers 13 on the bladder 1 corresponds to a set area on the square substrate 7 and the spacer 5. That is, some of the pressure chambers 13 on the bladder 1 correspond to the inner ring area divided on the square substrate 7, and some of the pressure chambers 13 correspond to the divided corner areas; Make the lower surface of the bladder 1 fit with the upper surface of the square substrate 7; Control the pressure in each of the pressure chambers 13 in the bladder 1 to adjust the pressure transmitted to different areas on the square substrate 7 and the spacer 5 to a set value. The specific pressure value can be determined according to parameters such as the size and rotation speed of the square substrate 7, and this embodiment does not limit it here; Control the rotation of the polishing head and the polishing pad to polish the square substrate 7.

[0083] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A bladder film for polishing a square substrate, characterized in that, Comprising: At least two capsule units arranged in a stack, each of the capsule units including a bottom wall and a laterally extending wall surrounding the edge of the bottom wall, the bottom walls of adjacent capsule units being in contact, and there being a pressurizing chamber between the laterally extending walls of adjacent capsule units; At least one of the pressurizing chambers is used to transfer pressure to an area outside the circle tangent to any pair of opposite sides on the square substrate, so as to individually adjust the pressure in the areas where the four corners of the square substrate are located.

2. The capsule according to claim 1, wherein There is a pressurizing chamber inside the laterally extending wall of the capsule unit located at the uppermost layer, and the pressurizing chamber is used to individually adjust the pressure in the area inside the circle tangent to any pair of opposite sides on the square substrate.

3. The capsule according to claim 1, wherein, The circle tangent to any pair of opposite sides on the square substrate is located between two adjacent pressurizing chambers.

4. The capsule according to claim 1, characterized in that, The circle tangent to any pair of opposite sides on the square substrate is located near the boundary between two adjacent pressurizing chambers.

5. The bladder film for polishing a square substrate according to claim 1, wherein The inner boundary diameter of at least one of the pressurizing chambers is smaller than the diameter of the largest circumscribed circle of the square substrate, and the outer boundary diameter is larger than the diameter of the largest circumscribed circle of the square substrate.

6. The bladder film for polishing a square substrate according to claim 1, wherein, At least two of the pressurizing chambers are located inside the circle tangent to any pair of opposite sides on the square substrate.

7. The bladder film for polishing a square substrate according to claim 1, characterized in that, At least two of the pressurizing chambers are used to transfer pressure to an area outside the circle tangent to any pair of opposite sides on the square substrate, so as to apply independent pressures to different areas of the four corners of the square substrate.

8. The bladder film for polishing a square substrate according to claim 1, characterized in that, At least one of the pressurizing chambers is used to transfer pressure to a spacer located outside the square substrate.

9. The bladder film for polishing a square substrate according to claim 1, wherein, The stiffness of the laterally extending wall outside the pressurizing chamber is greater than the combined stiffness of the bottom wall below the pressurizing chamber.

10. The bladder film for polishing a square substrate according to claim 1, characterized in that, The connection between the lower part of the laterally extending wall and the bottom wall forms an acute angle.

11. The bladder film for polishing a square substrate according to claim 1, characterized in that, The capsule unit further includes a folding portion, and the folding portion is located at one end of the laterally extending wall away from the bottom wall.

12. A polishing head, characterized in that, Comprising the capsule as described in any one of claims 1 to 11, and a first support member; The first support member is sleeved and fixed inside each of the capsule units, the diameter of the outer side surface of the first support member is larger than the inner diameter of the laterally extending wall, and the outer side surface of the first support member is in contact with the inner side surface of the laterally extending wall.

13. The polishing head according to claim 12, characterized in that, Further comprising a second support member, the second support member is sleeved and fixed outside each of the capsule units, the diameter of the inner side surface of the second support member is smaller than the outer diameter of the laterally extending wall after being in contact with the first support member, and the laterally extending wall is clamped by the first support member and the second support member.

14. The polishing head according to claim 13, wherein The first support member and the second support member are arranged in a ring shape.

15. The polishing head according to claim 13, characterized in that, When the connection between the lower part of the laterally extending wall and the bottom wall forms an acute angle, the outer side surface of the first support member is an inclined surface, and the inclined surface is in contact with the inner side surface of the connection.

16. The polishing head according to claim 15, characterized in that, An arc chamfer is provided at one end of the first support member close to the bottom wall, and the arc chamfer is in contact with the inner side surface of the connection and the bottom wall.

17. The polishing head according to claim 12, wherein Further comprising a housing, a retaining ring, a retaining ring fixing member and a sealing ring; The retaining ring is fixed to the lower end of the housing by the retaining ring fixing member; The capsule unit further includes a folding part, which is located at one end of the lateral extension wall away from the bottom wall. The folding part of the lowermost capsule unit among the plurality of capsule units is tightly fixed between the retaining ring fixing member and the housing, and the folding parts of the remaining capsule units are tightly fixed on the lower end surface of the housing through the sealing ring; A plurality of air channels are provided on the housing, and the air channels communicate with the corresponding pressurizing chambers.

18. The polishing head according to claim 17, wherein The lower end surface of the housing is provided with a plurality of annular grooves distributed from the inside to the outside, and the annular grooves respectively correspond to the joints between the folding parts of the capsule units and the lateral extension walls, and the annular grooves provide a movement space for the joints.

19. A polishing device, characterized in that, Including the capsule according to any one of claims 1 to 11, or the polishing pressing head according to any one of claims 12 to 18.

20. A method for polishing a square substrate, characterized in that, Using the capsule according to any one of claims 1 to 11, or the polishing pressing head according to any one of claims 12 to 18, the method includes the following steps: Arrange a spacer on the polishing pad. The spacer is circular and is provided with a square hole; Place the square substrate to be polished in the square hole, and make the lower surface of the square substrate contact the polishing pad, and limit the movement of the square substrate in the horizontal direction through the square hole; Control the movement of the polishing pressing head, adjust the position of the capsule, so that each of the pressurizing chambers on the capsule corresponds to the set areas on the square substrate and the spacer; Make the lower surface of the capsule fit with the upper surface of the square substrate; Control the pressure in each of the pressurizing chambers in the capsule to adjust the pressure transmitted to different areas on the square substrate and the spacer to the set value; Control the rotation of the polishing pressing head and the polishing pad to polish the square substrate.

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