Sucking disc of wafer thinning machine

Abstract

The utility model relates to a wafer thinning machine sucker comprising an adsorption disc body and a cleaning disc body which are fixedly connected, and a cavity is formed between the adsorption disc body and the cleaning disc body; a multi-through-hole area is arranged on the surface of the suction disc body, a connector communicated with a hose of a vacuum pump in the wafer thinning machine is arranged in the center of the cleaning disc body, the hole diameter of the connector is larger than that of each through hole in the multi-through-hole area, and a circulating medium flow channel is arranged in the cleaning disc body. A liquid inlet of the circulating medium flow channel is formed in the end face, away from the adsorption disc body, of the cleaning disc body, a plurality of medium jet orifices of the circulating medium flow channel are evenly formed around the outer periphery of the cleaning disc body, the axis directions of the medium jet orifices incline towards the adsorption disc body, and a connector penetrates through the cleaning disc body. The device can avoid cross contamination of the back surface of the wafer and the sucker, and meets the requirement of high cleanliness.

Description

Technical Field

[0001] This utility model belongs to the field of wafer thinning technology, specifically relating to a wafer thinning machine suction cup. Background Technology

[0002] Wafer thinning is a key process in semiconductor manufacturing, primarily used to reduce the thickness of wafers (usually silicon wafers) from hundreds of micrometers to tens or even a few micrometers. This process is particularly important in advanced packaging (such as 3D ICs and Chiplet), power devices, and MEMS (Micro-Electro-Mechanical Systems).

[0003] When using a wafer thinning machine to thin wafers, the wafer is first adsorbed onto the stage using a wafer thinning machine chuck to ensure that the wafer does not move or break during the thinning process. Then, the relative motion (rotational or linear motion) between the grinding wheel and the wafer completes the grinding process, resulting in the thinned wafer. Because the wafer thinning machine stage uses vacuum adsorption to fix the wafer, silicon powder and wastewater generated during the grinding process are easily sucked into the vacuum tubing of the stage and remain inside the system. When transferring the wafer, traditional single-tube chucks need to alternate between negative pressure adsorption and positive pressure release. This causes the silicon powder and wastewater accumulated inside the stage to seep back to the back of the wafer with the airflow during the stage unloading and blowing process. This not only causes back-side contamination of the wafer (such as residual particles and water stains) but also contaminates the adsorption surface of the chuck, forming a cross-contamination chain. This seriously affects the cleanliness of the process and the product yield, posing a significant challenge, especially for high-precision packaging or ultra-thin wafer manufacturing processes.

[0004] In short, the existing wafer thinning machine's suction cups are prone to adsorbing residual particles during operation, leading to cross-contamination between the back of the wafer and the suction cup, making it difficult to meet high cleanliness requirements. Utility Model Content

[0005] To address the aforementioned problems in the existing technology, this utility model provides a wafer thinning machine chuck. The technical problem to be solved by this utility model is achieved through the following technical solution:

[0006] This utility model provides a suction cup for a wafer thinning machine, comprising: an adsorption plate body and a cleaning plate body fixedly connected, and a cavity is formed between the adsorption plate body and the cleaning plate body;

[0007] The surface of the adsorption disk is provided with a multi-hole area. The center of the cleaning disk is provided with an interface that communicates with the hose of the vacuum pump inside the wafer thinning machine. The diameter of the interface is larger than the diameter of each hole in the multi-hole area. Furthermore, the cleaning disk is provided with a circulating medium channel. The liquid inlet of the circulating medium channel is located on the end face of the cleaning disk away from the adsorption disk. Multiple medium injection ports of the circulating medium channel are evenly arranged around the outer periphery of the cleaning disk, and the axial direction of the multiple medium injection ports is inclined towards the adsorption disk. The interface penetrates through the cleaning disk.

[0008] Preferably, the cleaning disc body includes: a base disc and a cover plate coaxially assembled, wherein the cover plate is fixed to the mounting surface of the base disc facing the adsorption disc body to form a cavity for accommodating part of the circulating medium flow channel; the circulating medium flow channel is fixed to the inner surface and outer periphery of the base disc, and an axial boss is integrally formed in the central region of the end face of the base disc opposite to the mounting surface, the axial boss integrating the interface and the liquid inlet of the circulating medium flow channel, the liquid inlet penetrating the base disc.

[0009] Preferably, the circulating medium flow channel includes: a first radial flow channel, a second radial flow channel, a third radial flow channel, and an annular collection cavity; the first radial flow channel, the second radial flow channel, and the third radial flow channel are symmetrically distributed in an umbrella shape on the inner side of the annular collection cavity, one end of each radial flow channel is connected to the liquid inlet, and the other end is connected to an input port of the annular collection cavity, and the multiple output ends of the annular collection cavity serve as the multiple medium injection ports.

[0010] Preferably, the radius of the axial boss is smaller than the radius of the base disk.

[0011] Preferably, the radial extension of the base plate extends beyond the outer periphery of the cover plate.

[0012] Preferably, a sealing ring is also provided between the base plate and the cover plate.

[0013] Preferably, the adsorption disc body includes: a coaxially assembled annular retainer and an adsorption sheet, the surface of the adsorption sheet is provided with the multi-hole area, and the annular retainer is fixed to the top surface of the adsorption sheet facing away from the cleaning disc body by a pressing method, so as to fix the adsorption disc body and the cleaning disc body in a fixed connection.

[0014] Preferably, the fluid in the circulating medium channel is deionized water.

[0015] Preferably, the adsorption disc and the cleaning disc are fixedly connected by bolts.

[0016] Preferably, the angle between the axial direction of each medium injection nozzle and the adsorption disk body is in the range of 30° to 60°.

[0017] Compared with existing technologies, the beneficial effects of this invention are as follows: Addressing the problem that existing wafer thinning machine suction cups easily adsorb residual particles during operation, leading to cross-contamination between the wafer backside and the suction cup, and failing to meet high cleanliness requirements, this invention provides a wafer thinning machine suction cup. This suction cup achieves simultaneous optimization of wafer adsorption and cleaning functions through the integrated design of the adsorption plate and cleaning plate and their internal synergistic effect. The multi-hole area of ​​the adsorption plate, combined with the central interface of the cleaning plate, allows for the directional output of the cleaning medium from the outer inclined nozzle through a circulating medium channel while simultaneously adsorbing the wafer under negative pressure. This forms a fluid path that flushes outward from the wafer edge, effectively preventing the reverse penetration of grinding residues to the adsorption surface and the wafer backside. This structure separates the adsorption and cleaning areas through independent cavities and utilizes the differentiated aperture design of the interface and nozzle to ensure that the gas path and liquid path do not interfere with each other, significantly reducing the risk of cross-contamination and improving process cleanliness and equipment operational stability. Attached Figure Description

[0018] Figure 1 This is an exploded view of the structure of the wafer thinning machine chuck provided by this utility model;

[0019] Figure 2 This is an exploded view of the wafer thinning machine chuck provided by this utility model from another perspective;

[0020] Figure 3 This is a perspective view of the structure of the wafer thinning machine chuck provided by this utility model;

[0021] Figure 4 This is a structural diagram of the assembled wafer thinning machine chuck provided by this utility model;

[0022] Figure 5 This is a structural diagram of the assembled wafer thinning machine chuck provided by this utility model from another perspective.

[0023] Figure label:

[0024] 1-Adsorption disc body; 2-Cleaning disc body; 10A-Annular retainer; 10B-Adsorption sheet; 20A-Base disc; 20B-Cover plate; 21-Interface; 22-Circulating medium channel; 22A-First radial branch channel; 22B-Second radial branch channel; 22C-Third radial branch channel; 22D-Annular collecting cavity; 201-Axial boss; 221-Liquid inlet; 222-Medium injection port. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0026] Figure 1 This is an exploded view of the structure of the wafer thinning machine chuck provided by this utility model. Figure 2 This is an exploded view of the wafer thinning machine chuck provided by this utility model from another perspective. (See attached image.) Figure 1-2 As shown, the wafer thinning machine suction cup includes: an adsorption plate body 1 and a cleaning plate body 2 fixedly connected, and a cavity is formed between the adsorption plate body 1 and the cleaning plate body 2; the surface of the adsorption plate body 1 is provided with a multi-hole area 11, and the center of the cleaning plate body 2 is provided with an interface 21 that communicates with the hose (not shown in the figure) of the vacuum pump inside the wafer thinning machine. The aperture of the interface 21 is larger than the aperture of each through hole in the multi-hole area 11. Furthermore, the cleaning plate body 2 is provided with a circulating medium channel 22. The liquid inlet 221 of the circulating medium channel 22 is located on the end face of the cleaning plate body 2 away from the adsorption plate body 1. Multiple medium injection ports 222 of the circulating medium channel 22 are evenly arranged around the outer periphery of the cleaning plate body 2, and the axial direction of the multiple medium injection ports 222 is inclined towards the adsorption plate body 1. The interface 21 penetrates the cleaning plate body 2.

[0027] It should be noted that the adsorption disc 1 and the cleaning disc 2 are fixedly connected by bolts. Therefore, multiple bolt holes 3 are evenly distributed around the two discs. These bolt holes 3 penetrate the cleaning disc 2 and partially extend into the adsorption disc 1 to facilitate the fixing of the two by bolts (not shown in the figure). Each bolt hole is sealed with a sealing ring.

[0028] Please refer to Figure 1 and Figure 2 The adsorption disc 1 includes an integrally formed annular retainer 10A and an adsorption sheet 10B. The surface of the adsorption sheet 10B is provided with a multi-hole area 11. The annular retainer 10A surrounds the outer periphery of the adsorption sheet 10B to fix and connect the adsorption disc 1 and the cleaning disc 2. It should be understood that the annular retainer 10A is not ventilated.

[0029] Please refer to this section. Figure 1 and Figure 2 The cleaning disc 2 includes a base disc 20A and a cover plate 20B coaxially assembled, wherein the cover plate 20B is fixed to the mounting surface of the base disc 20A facing the adsorption disc 1 to form a cavity for accommodating a portion of the circulating medium channel 22; the circulating medium channel 22 is fixed to the inner surface and outer periphery of the base disc 20A, and an axial boss 201 is integrally formed in the central region of the end face of the base disc 20A facing away from the mounting surface. The axial boss 201 integrates an interface 21 and an inlet 221 of the circulating medium channel 22 inside, and the inlet 221 penetrates the base disc 20A.

[0030] Here, the radial extension of the base plate 20A extends beyond the outer periphery of the cover plate 20B, and a sealing ring 20C is provided between the base plate 20A and the cover plate 20B to fill the micro-uneven area between the base plate 20A and the cover plate 20B, evenly distribute the locking stress of the assembly surface, reduce the risk of local deformation, and during grinding or media spraying, the elastic material of the sealing ring 20C can absorb mechanical vibration, reduce noise and prevent the connector from loosening.

[0031] Please refer to Figure 2 The radius of the axial boss 201 is smaller than the radius of the base plate 20A. As an integrally formed part of the base plate 20A, the axial boss 201 effectively enhances the mechanical strength of the overall structure, resists vibration or pressure fluctuations during the adsorption / cleaning process, and prevents deformation leading to seal failure. Furthermore, by integrating the interface 21 (for connecting the vacuum pump) and the liquid inlet 221 (for receiving the cleaning medium) in the central area through the axial boss 201, physical isolation between the gas and liquid paths can be achieved, avoiding interference between the adsorption (negative pressure) and cleaning (medium jet) functions. On the other hand, it allows for a compact layout of the wafer thinning machine's suction cup, facilitating subsequent installation. In addition, by using the axial boss 201 to guide the cleaning medium from the liquid inlet 221 into the circulating medium channel 22, it ensures that the cleaning medium is evenly distributed to the outer peripheral spray nozzles, reducing turbulence and maintaining a stable flow rate, thereby improving cleaning efficiency.

[0032] To clearly see the structural composition of the circulating medium channel 22. Figure 3 This is a perspective view of the structure of the chuck for the wafer thinning machine provided by this utility model. Figure 3 As shown, the circulating medium flow channel 22 includes: a first radial flow channel 22A, a second radial flow channel 22B, a third radial flow channel 22C, and an annular collection cavity 22D; the first radial flow channel 22A, the second radial flow channel 22B, and the third radial flow channel 22C are symmetrically distributed in an umbrella shape on the inner side of the annular collection cavity 22D. One end of each radial flow channel is connected to the liquid inlet 221, and the other end is connected to an inlet of the annular collection cavity 22D. The multiple output ends of the annular collection cavity 22D serve as multiple medium injection ports 222.

[0033] Here, the angle between the axis of each medium injection port 222 and the adsorption disk 1 is in the range of 30° to 60°, preferably 45°.

[0034] Here, the fluid in the circulating medium channel 22 is deionized water. It should be understood that this invention does not limit the type of fluid introduced into the circulating medium channel 22. The fluid can also be a cleaning solution that does not chemically react with the wafer, such as ultrapure water, nonionic surfactant solution, and ultrapure water with added surfactant, etc.

[0035] Figure 4This is a structural diagram of the assembled wafer thinning machine chuck provided by this utility model. Figure 5 This is another structural view of the assembled wafer thinning machine chuck provided by this utility model. Now, in conjunction with... Figure 4 and Figure 5 Provide an example description. It should be understood that, for clarity, Figure 4 The direction of water discharge is indicated by a medium injection port 222, and its tilt angle is denoted as θ.

[0036] In actual operation, the vacuum pump hose is connected to the interface 21 at the cleaning disc 2, and the water pipe is connected to the inlet 221 of the circulating medium channel 22. Then, the vacuum pump is turned on to introduce negative pressure into the cavity between the adsorption disc 1 and the cleaning disc 2. Negative pressure is generated on the surface of the adsorption disc 1 to adsorb and fix the wafer. The wafer thinner uses a grinding wheel to grind the wafer. After grinding is completed, the suction cup of the wafer thinner begins to move and prepare to adsorb the wafer. When the suction cup contacts the wafer, negative pressure is introduced and the solenoid valve is opened simultaneously to introduce deionized water. Multiple medium spray nozzles 222 spray water from the edge of the suction cup outward, and the water droplet is located on the inner edge of the wafer. Then, the wafer stage of the thinner starts back-blowing. Since the water is rinsed from the inner edge of the wafer to the outer edge, the silicon powder water blown out by the stage will be immediately flushed to the outer edge of the wafer and discharged to prevent it from overflowing onto the wafer. When the suction cup adsorbs the wafer and moves away from the stage, the wafer is no longer at risk of contamination. The water rinsing stops, and the subsequent transfer continues.

[0037] To address the problem that existing wafer thinning machine suction cups easily attract residual particles during operation, leading to cross-contamination between the wafer backside and the suction cup, and failing to meet high cleanliness requirements, this invention provides a wafer thinning machine suction cup. This suction cup utilizes a separate structure for the adsorption and cleaning discs, along with an internal cavity design, to achieve physical isolation between the adsorption negative pressure area and the cleaning medium flow channel. Combined with the centralized integration of the gas-liquid interface via axial bosses, it avoids the inherent defect of silicon powder wastewater backflow during wafer adsorption, common in traditional single-tube suction cups. The circulating medium flow channel, through the synergistic action of umbrella-shaped radial distribution channels and annular collection chambers, evenly distributes the cleaning medium to the inclined spray nozzles surrounding the outer periphery of the discs, forming a directional rinsing flow field from the wafer edge outwards. This effectively flushes away residual grinding particles and blocks their path back to the adsorption surface. Simultaneously, the sealing ring between the base disc and the cover plate, along with the compact assembly design, ensures high sealing performance of the gas-liquid pipeline, preventing external contaminants from intruding or internal media leakage, further improving the reliability of the system operation. This adsorption tray not only significantly reduces the risk of contamination on the back of the wafer and the suction cup itself, but also optimizes equipment maintenance efficiency through its modular structure. It is particularly well-suited to the stringent process requirements of advanced packaging technology for high cleanliness and low damage to ultra-thin wafers, providing key technical support for improving the yield and controlling the cost of semiconductor manufacturing processes.

[0038] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0039] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the present invention's conception through the foregoing teachings or related technical or knowledge. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A chuck for a wafer thinning machine, characterized by, include: An adsorption disc (1) and a cleaning disc (2) are fixedly connected, and a cavity is formed between the adsorption disc (1) and the cleaning disc (2); The surface of the adsorption disk (1) is provided with a multi-hole area (11). The center of the cleaning disk (2) is provided with an interface (21) that communicates with the hose of the vacuum pump inside the wafer thinning machine. The aperture of the interface (21) is larger than the aperture of each through hole in the multi-hole area (11). The cleaning disk (2) is provided with a circulating medium channel (22). The liquid inlet (221) of the circulating medium channel (22) is located on the end face of the cleaning disk (2) away from the adsorption disk (1). Multiple medium injection ports (222) of the circulating medium channel (22) are evenly arranged around the outer periphery of the cleaning disk (2). The axial direction of the multiple medium injection ports (222) is inclined toward the adsorption disk (1). The interface (21) penetrates the cleaning disk (2).

2. The wafer thinning machine chuck of claim 1, wherein, The cleaning disc (2) includes a base disc (20A) and a cover plate (20B) coaxially assembled, wherein the cover plate (20B) is fixed to the mounting surface of the base disc (20A) facing the adsorption disc (1) to form a cavity that accommodates part of the circulating medium channel (22). The circulating medium channel (22) is fixed to the inner surface and outer periphery of the base plate (20A). Furthermore, an axial boss (201) is integrally formed in the central area of ​​the end face of the base plate (20A) facing away from the mounting surface. The axial boss (201) integrates the interface (21) and the liquid inlet (221) of the circulating medium channel (22). The liquid inlet (221) penetrates the base plate (20A).

3. The wafer thinning machine chuck of claim 2, wherein, The circulating medium channel (22) includes: a first radial branch channel (22A), a second radial branch channel (22B), a third radial branch channel (22C), and an annular collection cavity (22D); The first radial diversion channel (22A), the second radial diversion channel (22B), and the third radial diversion channel (22C) are symmetrically distributed in an umbrella shape on the inner side of the annular collection cavity (22D). One end of each radial diversion channel is connected to the liquid inlet (221), and the other end is connected to an input port of the annular collection cavity (22D). The multiple output ends of the annular collection cavity (22D) serve as the multiple medium injection ports (222).

4. The wafer thinning machine chuck of claim 2, wherein, The radius of the axial boss (201) is smaller than the radius of the base plate (20A).

5. The wafer thinning machine chuck of claim 2, wherein, The radial extension of the base plate (20A) extends beyond the outer periphery of the cover plate (20B).

6. The wafer thinning machine chuck of claim 2, wherein, A sealing ring (20C) is also provided between the base plate (20A) and the cover plate (20B).

7. The wafer thinning machine chuck of claim 1, wherein The adsorption disc body (1) includes: an integrally formed annular retainer (10A) and an adsorption sheet (10B). The surface of the adsorption sheet (10B) is provided with the multi-hole area (11). The annular retainer (10A) surrounds the outer periphery of the adsorption sheet (10B) to fix the adsorption disc body (1) and the cleaning disc body (2).

8. The wafer thinning machine chuck of claim 1, wherein, The fluid in the circulating medium channel (22) is deionized water.

9. The wafer thinning machine chuck of claim 1, wherein, The adsorption disc (1) and the cleaning disc (2) are fixedly connected by bolts.

10. The wafer thinning machine chuck of claim 1, wherein, The angle between the axial direction of each medium injection port (222) and the adsorption disk (1) ranges from 30° to 60°.

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