Fixing ring for grinding and polishing semiconductor wafer
By designing a fixed ring structure with meshing internal toothed ring, external toothed ring, and planetary ring, and grinding only the positioning ring in contact with the wafer, the problem of replacing the entire wafer after the fixed ring wears out is solved, thus extending the service life of the fixed ring and reducing replacement costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-06
- Publication Date
- 2026-03-31
AI Technical Summary
The existing retaining rings used for grinding and polishing semiconductor wafers need to be replaced as a whole after they wear out, resulting in resource waste and increased production costs.
Design a fixed ring structure including an internal toothed ring, an external toothed ring, a planetary ring, and a grinding positioning ring. The planetary ring meshes with the internal and external toothed rings. The grinding positioning ring is thicker than the planetary ring. Only the grinding positioning ring contacts the wafer for grinding. It can be replaced separately after wear.
It extends the service life of the retaining ring, reduces replacement costs, and improves production economy.
Smart Images
Figure CN224059535U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of wafer grinding and polishing technology, specifically to a fixing ring for semiconductor wafer grinding and polishing. Background Technology
[0002] In the semiconductor wafer manufacturing process, grinding and polishing is one of the key steps, aiming to obtain a high-precision, high-quality wafer surface. In this process, the retaining ring plays a crucial role, holding and securing the wafer to prevent displacement or over-grinding of the edges during grinding and polishing.
[0003] Currently, there are two main types of mounting rings on the market. Some mounting rings are mounted on the polishing head, directly contacting the wafer and moving with the polishing head for polishing; others are gear-shaped and positioned between two toothed rings, rotating through meshing with the toothed rings, simultaneously driving the wafer placed on them to be polished by polishing pads and polishing heads on the upper and lower sides. However, regardless of the type, the mounting ring needs to be polished along with the wafer during the polishing process, making it a wear-prone component. Especially some gear-shaped and large-area mounting rings with multiple holes for placing wafers, while capable of polishing multiple wafers at once, require replacement of the entire mounting ring once it wears out. This not only wastes resources but also significantly increases production costs. Therefore, developing a mounting ring for semiconductor wafer polishing that can reduce the wear area and allows for individual replacement of worn components is of significant practical importance. Utility Model Content
[0004] The present invention provides a fixing ring for grinding and polishing semiconductor wafers, which solves the problem that when a large fixing ring wears out, the entire fixing ring needs to be replaced, which not only wastes resources but also greatly increases production costs.
[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0006] A fixing ring for grinding and polishing semiconductor wafers includes an inner toothed ring, an outer toothed ring, a planetary ring, and a grinding positioning ring. The inner toothed ring has a first ring platform on its inner side, and the outer toothed ring has a second ring platform parallel to the first ring platform on its outer side. The planetary ring is located on the first and second ring platforms and meshes with the inner and outer toothed rings on its outer side. The planetary ring has multiple circumferentially oriented positioning holes, and the grinding positioning ring is located within these positioning holes. The grinding positioning ring also has placement holes for placing the wafer. The thickness of the grinding positioning ring is greater than the thickness of the planetary ring. Specifically, the height of the upper surface of the first and second ring platforms, i.e., the height of the surface used to place the planetary ring, is higher than the height of the surface that the annular polishing pad can rise to, thereby preventing the lower surface of the planetary ring from being polished by the annular polishing pad. In use, both the internal and external gear rings are installed on existing equipment equipped with annular polishing pads. The grinding and polishing equipment is started, and the internal and external gear rings begin to rotate synchronously under the drive of the equipment. Because the planetary ring meshes with the internal and external gear rings, the planetary ring revolves around the center of the internal and external gear rings, while also rotating on its own axis. During the rotation of the planetary rings, the grinding positioning ring located in its positioning hole also rotates along with them. At this time, the wafer placed in the grinding positioning ring's placement hole is ground and polished by the polishing heads and annular polishing pads located on the upper and lower sides. Due to the thickness of the grinding positioning ring... The thickness of the positioning ring is greater than that of the planetary ring, and the planetary ring is located on the first and second ring platforms. During the grinding and polishing process, only the grinding positioning ring and the wafer are ground together, while the planetary ring is basically not ground if the thickness of the grinding positioning ring is sufficient, thus reducing the area to be ground. After a period of use, if a certain grinding positioning ring reaches a certain wear level, making it unable to meet the precision requirements of grinding and polishing, simply remove the worn grinding positioning ring from the positioning hole of the planetary ring and replace it with a new grinding positioning ring to continue the wafer grinding and polishing work without replacing the entire positioning ring. With the structure of this application, since a grinding positioning ring is provided in the positioning hole between the planetary rings, and the thickness of the grinding positioning ring is greater than the thickness of the planetary ring, and the planetary ring is set on the first ring platform and the second ring platform, when the planetary ring is driven to rotate by the internal gear ring and the external gear ring, only the grinding positioning ring is polished by the polishing head and the annular polishing pad along with the wafer in its placement hole, which greatly reduces the polished area and extends the service life of the entire fixed ring; when any grinding positioning ring reaches a certain wear degree, only the grinding positioning ring needs to be replaced directly, without having to replace the entire fixed ring as in traditional fixed rings, which significantly reduces replacement costs and improves production economy.
[0007] Furthermore, a wear-resistant annular coating is provided on the lower surface of the planetary ring, and the radial width of the wear-resistant annular coating is consistent with the width of the first and second ring platforms. With this structure, when the wear-resistant annular coating on the lower surface of the planetary ring is in operation, because its radial width is consistent with the width of the first and second ring platforms, the area in contact with the first and second ring platforms during planetary ring rotation can uniformly distribute friction, effectively buffering wear between the planetary ring and the first and second ring platforms.
[0008] Furthermore, a first limiting stage is provided on the positioning hole, and a second limiting stage is provided on the grinding positioning ring to cooperate with the first limiting stage; a fourth limiting stage is provided on the placement hole to cooperate with a third limiting stage on the wafer. This structure effectively ensures that the grinding positioning ring and the wafer can rotate together with the planetary ring, guaranteeing the grinding and polishing effect.
[0009] Furthermore, the inner diameter of the first ring stage is larger than the outer diameter of the annular polishing pad, while the outer diameter of the second ring stage is smaller than the inner diameter of the annular polishing pad. This structure ensures that the annular polishing pad does not come into contact with the first or second ring stages during operation, preventing it from being polished by the annular polishing pad and avoiding interference with the annular polishing pad's upward movement.
[0010] Furthermore, the grinding positioning ring has multiple circumferentially oriented liquid guide grooves. This structure guides the grinding fluid to flow obliquely, ensuring that the grinding fluid is evenly distributed in the contact area of the wafer annular polishing pad, thus guaranteeing the smooth progress of the grinding and polishing process.
[0011] Beneficial effects: With the structure of this application, since a grinding positioning ring is provided in the positioning hole between the planetary rings, and the thickness of the grinding positioning ring is greater than the thickness of the planetary ring, and the planetary ring is set on the first ring platform and the second ring platform, when the planetary ring is driven to rotate by the internal gear ring and the external gear ring, only the grinding positioning ring is polished by the polishing head and the annular polishing pad along with the wafer in its placement hole, which greatly reduces the polished area and extends the overall service life of the fixed ring; when any grinding positioning ring reaches a certain wear degree, only the grinding positioning ring needs to be replaced directly, without the need to replace the entire fixed ring as in traditional fixed rings, which significantly reduces replacement costs and improves production economy. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the planetary rings from an oblique perspective in this embodiment;
[0013] Figure 2 This is a bottom-view schematic diagram of the planetary rings in this embodiment;
[0014] Figure 3 This is an example. Figure 2Schematic diagram of the AA section;
[0015] Reference numerals: 1. Internal gear ring; 2. External gear ring; 3. Planetary ring; 4. Grinding positioning ring; 5. First ring platform; 6. Second ring platform; 7. Placement hole; 8. Wear-resistant annular coating; 9. Inclined liquid guide groove. Detailed Implementation
[0016] The following will provide a more detailed description of the technical solution of a fixing ring for grinding and polishing semiconductor wafers according to the present invention, with reference to the embodiments.
[0017] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0018] like Figure 1 , Figure 2 , Figure 3 As shown, a fixing ring for semiconductor wafer grinding and polishing in this embodiment includes an inner toothed ring 1, an outer toothed ring 2, a planetary ring 3, and a grinding positioning ring 4. A first ring platform 5 is provided on the inner side of the inner toothed ring 1, and a second ring platform 6 parallel to the first ring platform 5 is provided on the outer side of the outer toothed ring 2. The planetary ring 3 is located on the first ring platform 5 and the second ring platform 6, and its outer side meshes with the inner toothed ring 1 and the outer toothed ring 2. Multiple positioning holes are circumferentially formed on the planetary ring 3, and the grinding positioning ring 4 is located within these positioning holes. The grinding positioning ring 4 has placement holes 7 for placing wafers. The thickness of the grinding positioning ring 4 is greater than the thickness of the planetary ring 3. Specifically, the height of the upper surface of the first ring platform 5 and the second ring platform 6, i.e., the height of the surface used to place the planetary ring 3, is higher than the height of the surface that the annular polishing pad can rise to, thereby preventing the lower surface of the planetary ring 3 from being polished by the annular polishing pad. The lower surface of the planetary ring 3 is provided with a wear-resistant annular coating 8, the radial width of which is consistent with the width of the first ring platform 5 and the second ring platform 6. A first limiting stage is provided on the positioning hole, and a second limiting stage is provided on the grinding positioning ring 4 to cooperate with the first limiting stage; a fourth limiting stage is provided on the placement hole 7 to cooperate with the third limiting stage on the wafer. The inner diameter of the first ring platform 5 is larger than the outer diameter of the annular polishing pad, and the outer diameter of the second ring platform 6 is smaller than the inner diameter of the annular polishing pad. Multiple oblique liquid guide grooves 9 are circumferentially formed on the grinding positioning ring 4. Figure 1 , 2Figures 1 and 3 are for illustrative purposes only, showing the teeth of the internal toothed ring 1 and the external toothed ring 2, but the planetary ring 3 meshes with the internal toothed ring 1 and the external toothed ring 2.
[0019] In use, the inner gear ring 1 and the outer gear ring 2 are installed on the existing equipment equipped with an annular polishing pad. The grinding and polishing equipment is started, and the inner gear ring 1 and the outer gear ring 2 begin to rotate synchronously under the drive of the equipment. Since the planetary ring 3 meshes with the inner gear ring 1 and the outer gear ring 2, the planetary ring 3 revolves around the center of the inner gear ring 1 and the outer gear ring 2, and simultaneously rotates on its own axis. During the rotation of the planetary ring 3, the grinding positioning ring 4 located in its positioning hole also rotates along with it. At this time, the wafer placed in the placement hole 7 of the grinding positioning ring 4 is ground and polished under the action of the polishing heads and annular polishing pads located on the upper and lower sides. The thickness of ring 4 is greater than that of planetary ring 3, and planetary ring 3 is located on the first ring platform 5 and the second ring platform 6. During the grinding and polishing process, only the grinding positioning ring 4 is ground together with the wafer, while planetary ring 3 is basically not ground if the thickness of the grinding positioning ring 4 is sufficient, thereby reducing the area to be ground. After a period of use, if a certain grinding positioning ring 4 reaches a certain degree of wear, making it impossible to meet the precision requirements of grinding and polishing, simply remove the worn grinding positioning ring 4 from the positioning hole of planetary ring 3 and replace it with a new grinding positioning ring 4 to continue the wafer grinding and polishing work without replacing the entire fixed ring. With the structure of this application, since a grinding positioning ring 4 is provided in the positioning hole between the planetary rings 3, and the thickness of the grinding positioning ring 4 is greater than the thickness of the planetary ring 3, and the planetary ring 3 is set on the first ring platform 5 and the second ring platform 6, when the planetary ring 3 is driven to rotate by the internal toothed ring 1 and the external toothed ring 2, only the grinding positioning ring 4 is polished by the polishing head and the annular polishing pad along with the wafer in its placement hole 7, which greatly reduces the polished area and extends the service life of the entire fixed ring; when any grinding positioning ring 4 reaches a certain wear degree, it is only necessary to directly replace the grinding positioning ring 4, without having to replace the entire fixed ring as in the traditional fixed ring, which significantly reduces replacement costs and improves production economy.
[0020] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A retaining ring for polishing semiconductor wafers, characterized by: The application relates to a wafer polishing device, which comprises an inner tooth ring, an outer tooth ring, a planet ring and a grinding positioning ring; the inner side of the inner tooth ring is provided with a first ring table, the outer side of the outer tooth ring is provided with a second ring table parallel to the first ring table, the planet ring is located on the first ring table and the second ring table and is engaged with the inner tooth ring and the outer tooth ring on the outer side; a plurality of positioning holes are circumferentially arranged on the planet ring, the grinding positioning ring is located in the positioning hole, and a placing hole for placing a wafer is arranged on the grinding positioning ring; the thickness of the grinding positioning ring is greater than the thickness of the planet ring.
2. The retaining ring for polishing semiconductor wafers according to claim 1, wherein: The lower side of the planet ring is provided with a wear-resistant annular coating, and the radial ring width length of the wear-resistant annular coating is consistent with the ring width length of the first ring table and the second ring table.
3. The retaining ring for polishing semiconductor wafers according to claim 1, wherein: The positioning hole is provided with a first limiting table, and the grinding positioning ring is provided with a second limiting table matched with the first limiting table; the placing hole is provided with a fourth limiting table matched with a third limiting table on the wafer.
4. The retaining ring for polishing semiconductor wafers according to claim 1, wherein: The inner diameter of the first ring table is greater than the outer diameter of the annular polishing pad, and the outer diameter of the second ring table is smaller than the inner diameter of the annular polishing pad.
5. The retaining ring for polishing semiconductor wafers according to claim 1, wherein: A plurality of inclined liquid guide grooves are circumferentially arranged on the grinding positioning ring.