A pressure membrane that responds quickly and evenly to pressure changes

Abstract

The present invention discloses a pressure membrane capable of responding to pressure changes quickly and uniformly, wherein the pressure membrane is circular, and comprises a circular bottom, a vertical portion, an extension portion, and a sealing edge. The outer edge of the circular bottom is provided with a vertical portion circumferentially, and the inner side of the vertical portion and the inner side of the circular bottom form an air chamber cavity. The top of the vertical portion is provided with an extension portion circumferentially, and the extension portion is perpendicular to the vertical portion and parallel to the circular bottom. The extension portion is annularly covered on the top of the air chamber cavity, and the inner side of the extension portion is provided with a sealing edge perpendicular to the extension portion and parallel to the vertical portion. The upper surface of the circular bottom is provided with a convex point, and the lower surface of the circular bottom is a plane. The present invention adopts the above-mentioned pressure membrane capable of responding to pressure changes quickly and uniformly, and by changing its structure, the gas is effectively guided to cover various areas of the pressure membrane, so that the pressure membrane responds quickly and uniformly to changes in air pressure, reduces the impact of uneven pressure, ensures the consistency of the quality of the polished wafer, and further improves the business efficiency of the enterprise.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor chip processing, and in particular to a pressure membrane capable of quickly and evenly responding to pressure changes. Background Art

[0002] In the current semiconductor chip processing field, a grinding head is needed to polish the wafer. The pressure membrane is one of the many components of the grinding head. The pressure membrane is connected to the gas through the grinding head component to control the adsorption and unloading of the wafer by the pressure membrane, so that the wafer rubs on the grinding pad to achieve the purpose of polishing. The existing pressure membrane has too flat upper and lower surfaces, which makes the air pressure around its inner diameter insufficient, resulting in a delay in the local response when the pressure membrane adsorbs and unloads the wafer, and uneven force, resulting in uneven suction in different areas of the wafer, resulting in uneven polishing effects. Areas with excessive suction are over-polished, while areas with too little suction are under-polished, which seriously affects the quality and yield of the wafer.

[0003] In addition, this uneven pressure will also cause the pressure film to be easily damaged during operation, further increasing the instability of the grinding process and reducing production efficiency and product reliability. In order to solve these problems, it is necessary to improve and optimize the existing pressure film to improve its performance and stability and ensure the quality and consistency of wafer polishing. Summary of the invention

[0004] The purpose of the present invention is to provide a pressure membrane that can respond quickly and evenly to pressure changes. By changing its structure, the gas can be effectively guided to cover various areas of the pressure membrane, so that the pressure membrane can respond quickly and evenly to changes in air pressure, reduce the impact of uneven pressure, ensure the consistency of the quality of polished wafers, and further improve the company's operating efficiency.

[0005] To achieve the above-mentioned purpose, the present invention provides a pressure membrane that can respond quickly and evenly to pressure changes. The pressure membrane is circular, and includes a round bottom, a vertical portion, an extension portion, and a sealing edge. The outer edge of the round bottom is circumferentially provided with a vertical portion, and the vertical portion forms a circle along the circumference of the round bottom. The inner side of the vertical portion and the inner side of the round bottom form an air chamber cavity. An extension portion is circumferentially provided on the top of the vertical portion, and the extension portion is perpendicular to the vertical portion and parallel to the round bottom. The extension portion is annular and covers the top of the air chamber cavity. A sealing edge is circumferentially provided on the inner side of the extension portion, which is perpendicular to the extension portion and parallel to the vertical portion. The upper surface of the round bottom is provided with a convex point, and the lower surface of the round bottom is a plane.

[0006] Preferably, the connection between the vertical portion and the round bottom portion is formed in one piece, and the connection between the vertical portion and the extension portion is also formed in one piece, and the connection points between the vertical portion and the round bottom portion and the extension portion are both chamfered.

[0007] Preferably, the sealing edge and the extension portion are integrally formed.

[0008] Preferably, there are a plurality of convex points, and the plurality of convex points are evenly distributed on the upper surface of the circular bottom.

[0009] Preferably, the protrusions are evenly distributed in an annular array along the inner diameter of the upper surface of the circular bottom, the spacing between the protrusion annular arrays is the same as the diameter of the protrusions, and the outermost protrusion annular array of the circular bottom is set 1 mm away from the inner diameter edge of the circular bottom.

[0010] Preferably, the convex points are hemispherical, and the spacing between adjacent convex points in the annular array is the same as the diameter of the convex points.

[0011] Preferably, the sealing edge is annular and coaxially arranged in the air chamber cavity.

[0012] The advantages and positive effects of the pressure membrane capable of quickly and uniformly responding to pressure changes described in the present invention are:

[0013] 1. The present invention arranges convex points on the plane of the pressure membrane and utilizes the principle of gas acceleration. By adding obstacles to the direction of gas movement, the gas will be accelerated exponentially. Because the flow area becomes smaller, the gas needs to pass at a faster speed to ensure the same flow capacity as the upstream. The gas and air pressure around each convex point are interrelated and interact with each other, and the forces are equal. The bottom surface flow rate is faster, and the structure of the convex point is more conducive to separation from other components of the grinding head than the original plane structure, thereby achieving the purpose of rapid response.

[0014] 2. The present invention adopts a chamfered corner setting at the connection between the vertical part, the round bottom and the extension part. Compared with the chamfered right angle setting, the force-bearing surface of the rounded corner is smoother than the chamfered right angle, which is more conducive to the circulation of gas.

[0015] 3. In order to increase the overall air tightness of the pressure membrane, the present invention adds a sealing edge to the original straight opening, and assembles it more closely with other components of the grinding head into a closed structure to further prevent gas loss.

[0016] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the existing pressure membrane structure;

[0018] Figure 2 It is a schematic diagram of the pressure membrane structure of the present invention;

[0019] Figure 3 It is a schematic cross-sectional view of the pressure membrane of the present invention;

[0020] Figure 4is a schematic cross-sectional view of a sealing edge in a pressure membrane of the present invention;

[0021] Figure 5 This is a schematic diagram of the pressure membrane of the present invention bearing air pressure.

[0022] Reference numerals

[0023] 1. Extension part; 2. Round bottom; 3. Bump; 4. Vertical part; 5. Sealing edge; 6. Chamfered corner; 7. Air chamber cavity. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0025] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0026] Example

[0027] A pressure membrane capable of rapidly and uniformly responding to pressure changes, the pressure membrane is circular and comprises a circular bottom portion 2, a vertical portion 4, an extension portion 1, and a sealing edge 5.

[0028] A vertical portion 4 is circumferentially provided on the outer edge of the circular bottom portion 2, and the vertical portion 4 forms a circle along the circumference of the circular bottom portion 2. The inner side of the vertical portion 4 and the inner side of the circular bottom portion 2 form an air chamber cavity 7. An extension portion 1 is circumferentially provided on the top of the vertical portion 4, and the extension portion 1 is perpendicular to the vertical portion 4 and parallel to the circular bottom portion 2. The connection between the vertical portion 4 and the circular bottom portion 2 is integrally formed, and the connection between the vertical portion 4 and the extension portion 1 is also integrally formed. The connection between the vertical portion 4 and the circular bottom portion 2 and the extension portion 1 is respectively provided with a chamfer 6.

[0029] The extension part 1 is annularly covered on the top of the air chamber cavity 7, and a sealing edge 5 is provided on the inner circumference of the extension part 1, which is perpendicular to the extension part 1 and parallel to the vertical part 4, and the sealing edge 5 is integrally formed with the extension part 1. The sealing edge 5 is annularly coaxially arranged in the air chamber cavity 7.

[0030] like Figure 2-3As shown, the upper surface of the circular bottom 2 is provided with a convex point 3, and the lower surface of the circular bottom 2 is a plane. There are multiple convex points 3, and the multiple convex points 3 are evenly distributed on the upper surface of the circular bottom 2. The convex points 3 are evenly distributed along the inner diameter of the upper surface of the circular bottom 2 in a circular array, and the spacing between the convex point 3 circular arrays is the same as the diameter of the convex point 3. The outermost convex point 3 circular array of the circular bottom 2 is set 1mm away from the inner diameter edge of the circular bottom 2. The convex point 3 is hemispherical, and the spacing between adjacent convex points 3 in the circular array is the same as the diameter of the convex point 3.

[0031] like Figure 1 As shown, the existing structure of the pressure membrane has a flat inner diameter, which bears uneven gas pressure. The present invention utilizes the gas acceleration principle: the flow continuity theorem. By adding obstacles to the direction of gas movement, the gas will be accelerated exponentially. Because the flow area becomes smaller, the gas needs to pass at a faster speed to ensure the same flow capacity as the upstream. Figure 5 As shown, using this principle, the structure of the pressure membrane is optimized, and the entire plane is covered with hemispherical obstacles, which can also be called bumps 3. The gas and air pressure around each bump 3 are interrelated and interact with each other, and the forces are equal. The flow rate on the bottom surface is faster, and the structure of the bump 3 is more conducive to separation from other components of the grinding head than the original plane structure, so as to achieve the purpose of rapid response. The size and spacing of each bump 3 are controlled by the mold, and the bump 3 is evenly distributed. The surface roughness and the flatness of the bottom are determined according to the overall size ratio of the pressure membrane. The size of the bump 3 corresponds to the size of the wafer. For example, a 6-inch wafer corresponds to a bump 3. Spacing 1mm, height 0.5mm.

[0032] like Figure 4 As shown, the connection between the vertical portion 4 and the round bottom portion 2 and the extension portion 1 is set as a chamfered corner 6. Compared with the chamfered right angle setting, the force-bearing surface of the rounded corner is smoother than the chamfered right angle, which is more conducive to the flow of gas. The specific size of the chamfered corner 6 is determined according to the overall size ratio of the pressure membrane, and there should be no burrs.

[0033] In order to increase the air tightness of the pressure membrane as a whole, a sealing edge 5 is added to the original straight opening to form a closed structure with other components of the grinding head to further prevent the loss of gas. The specific size of the sealing edge 5 is suitable to match the size of the grinding head assembly.

[0034] When loading wafers, the air pump is connected to the grinding head, and gas is extracted from the grinding head gas path, and the pressure membrane is in a negative pressure state, and then the wafer is adsorbed, and the loading is completed; when unloading wafers, the grinding head is connected to the air pump, and gas enters the pressure membrane from the grinding head gas path. The pressure membrane is filled with gas and becomes a positive pressure state, and then it is separated from the wafer, and the wafer is unloaded. In the process of loading and unloading wafers, the two pressure membranes with different structures show great differences, and the results are as follows:

[0035] ① The pressure film with bumps of the present invention: when loading and unloading wafers, each area responds in unison, and there is no delay in loading and unloading actions, and the time is fixed at 1.5 seconds;

[0036] ② The pressure membrane without protrusions (the pressure membrane has the same structure as the present invention except that it has no protrusions), the responses of each zone are inconsistent, and there is a delay in loading and unloading actions, and it takes 3-4.5 seconds to complete loading and unloading.

[0037] Therefore, the present invention adopts the above-mentioned pressure membrane that can quickly and evenly respond to pressure changes, and changes its structure to effectively guide the gas to cover various areas of the pressure membrane, so that the pressure membrane can quickly and evenly respond to changes in air pressure, thereby reducing the time and material costs caused by repeated grinding or excessive grinding due to uneven pressure, and extending the service life of the pressure membrane. At the same time, it ensures the consistency of the quality of the ground wafers, further improving the operating efficiency of the enterprise.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A pressure membrane capable of responding quickly and evenly to pressure changes, characterized in that: The pressure membrane is circular, and includes a circular bottom, a vertical portion, an extension portion, and a sealing edge. A vertical portion is circumferentially arranged on the outer edge of the circular bottom, and the vertical portion forms a circle along the circumference of the circular bottom. The inner side of the vertical portion and the inner side of the circular bottom form an air chamber cavity. An extension portion is circumferentially arranged on the top of the vertical portion, and the extension portion is perpendicular to the vertical portion and parallel to the circular bottom. The extension portion is annularly covered on the top of the air chamber cavity. A sealing edge perpendicular to the extension portion and parallel to the vertical portion is circumferentially arranged on the inner side of the extension portion. A convex point is arranged on the upper surface of the circular bottom, and the lower surface of the circular bottom is a plane. The connection between the vertical portion and the round bottom portion is formed in one piece, and the connection between the vertical portion and the extension portion is also formed in one piece, and the connection between the vertical portion and the round bottom portion and the extension portion is rounded; There are multiple convex points, which are evenly distributed on the upper surface of the circular bottom; the convex points are evenly distributed along the inner diameter of the upper surface of the circular bottom in an annular array, the spacing between the convex point annular arrays is the same as the diameter of the convex points, and the outermost convex point annular array of the circular bottom is set 1mm away from the inner diameter edge of the circular bottom; the convex points are hemispherical, and the spacing between adjacent convex points in the annular array is the same as the diameter of the convex points.

2. A pressure membrane capable of rapidly and uniformly responding to pressure changes according to claim 1, characterized in that: The connection between the sealing edge and the extension portion is integrally formed.

3. A pressure membrane capable of rapidly and uniformly responding to pressure changes according to claim 1, characterized in that: The sealing edge is annular and coaxially arranged in the air chamber cavity.

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