Anti-suck vacuum chuck and vacuum chucking wafer clamp

Abstract

The application provides a vacuum chuck and a vacuum chuck wafer clamp, which can prevent back siphoning. The vacuum chuck comprises a vacuum chuck body, an axial air duct is arranged on the upper end of the vacuum chuck, one end of the air duct is connected with an external device, and the other end is communicated with a disc-shaped air duct arranged on the lower end of the vacuum chuck body; a back siphoning water air duct is further arranged on the vacuum chuck body, and the back siphoning water air duct is arranged on the outer side of the disc-shaped air duct arranged on the lower end of the vacuum chuck body; an air outlet is arranged on the back siphoning water air duct, and the air outlet is communicated with the air duct, so that the defect that electrolyte and polishing slurry back siphon into the device can be effectively solved.

Description

Technical Field

[0001] This invention belongs to the field of ultra-precision processing of semiconductor wafer substrates, and specifically relates to an anti-backflow vacuum chuck and a vacuum adsorption wafer clamp. Background Technology

[0002] As the substrate for semiconductor devices, the surface roughness of a wafer significantly impacts its inherent characteristics and the performance of devices fabricated from it. Therefore, to obtain a wafer surface with the desired roughness, ultra-precision machining, such as ultra-precision polishing and grinding, is required. Considering the thinness and fragility of wafers, using edge clamping or adhesive bonding during wafer fixation can lead to unstable wafer fixation, loosening, or even detachment. It can also generate uneven stress on the wafer surface, resulting in uneven material removal and minor damage to the polished surface. In severe cases, it can even cause the wafer to break. Compared to edge clamping and adhesive bonding, vacuum suction fixation is more ideal. To improve the efficiency of precision wafer machining, the wafer needs to rotate at high speed with the fixation device. If vacuum suction fixation is used, several external ventilation tubes need to be connected. During high-speed rotation, if the movement of the entire device is not differentiated between internal and external components, the external ventilation tubes may become entangled in the device, potentially causing the entire system to stop. It is also noted that even a slight deviation in the mounting angle (non-horizontal) during polishing can lead to a misalignment between the wafer's polished surface and the polishing pad, resulting in uneven material removal from the processed surface. This slight misalignment requires strict prevention in the field of ultra-precision machining. Furthermore, to obtain a wafer surface with the desired surface roughness, ultra-precision polishing is typically performed using chemical mechanical polishing (CMP) and electrochemical mechanical polishing (EMF). During processing, the wafer is immersed in an electrolyte or a polishing slurry containing abrasive particles. Therefore, it is necessary to prevent the electrolyte and polishing slurry from seeping back into the back of the wafer, causing oxidation and damage, as well as from seeping into the apparatus (vacuum channels). Summary of the Invention

[0003] The purpose of this invention is to provide an anti-backflow vacuum chuck and a vacuum adsorption wafer clamp, which solves the defects of existing vacuum chuck adsorption type wafer fixation where electrolyte and polishing slurry are drawn back into the device.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] The present invention provides a vacuum suction cup for preventing back suction, comprising a vacuum suction cup body, wherein an axially arranged air channel is provided at the upper end of the vacuum suction cup, one end of the air channel is connected to an external device, and the other end is connected to a disc-shaped air channel provided at the lower end of the vacuum suction cup body.

[0006] The vacuum suction cup body is also provided with an anti-backflow water air channel, which is located outside the disc-shaped air channel opened at the lower end of the vacuum suction cup body.

[0007] The anti-backflow water duct is provided with an air outlet, which is connected to the duct.

[0008] In this preferred embodiment, the anti-backflow water-air channel includes an axially arranged water-air channel on the upper end of the vacuum suction cup body, and an annular waterproof groove on the lower end of the vacuum suction cup body. The annular waterproof groove is located outside the disc-shaped air channel on the lower end of the vacuum suction cup body. One end of the water-air channel is connected to a water-storage ring for storing liquid, and the other end is connected to the annular waterproof groove. An air outlet is provided on the water-air channel, and the air outlet communicates with the air channel.

[0009] In this preferred embodiment, the anti-backflow water channel further includes a second sealing ring, which is installed at the lower end of the vacuum suction cup body and placed outside the annular waterproof groove.

[0010] In this preferred embodiment, the vacuum suction cup includes an upper vacuum suction cup and a lower vacuum suction cup, the upper vacuum suction cup is placed above the lower vacuum suction cup, wherein the upper end face of the upper vacuum suction cup is provided with an axially arranged third vertical air channel, one end of the third vertical air channel is connected to an external device, and the other end is connected to a disc-shaped air channel opened at the center of the lower end face of the lower vacuum suction cup.

[0011] The upper vacuum suction cup is also provided with an axially arranged first vertical water and air channel. One end of the first vertical water and air channel is connected to a water storage ring, and the other end is connected to an annular waterproof groove opened on the lower end of the lower vacuum suction cup. The annular waterproof groove is located outside the disc-shaped air channel opened at the lower end of the vacuum suction cup body.

[0012] A first sealing ring is installed on the lower end face of the upper vacuum suction cup, and the first sealing ring is located outside the annular waterproof groove;

[0013] A second sealing ring is installed on the lower end face of the lower vacuum suction cup, and the second sealing ring is placed outside the annular waterproof groove.

[0014] In this preferred embodiment, the lower end face of the upper vacuum suction cup is provided with interconnected annular groove air channels, and the third vertical air channel is connected to the disc-shaped air channel through the interconnected annular groove air channels.

[0015] This preferred embodiment provides a vacuum adsorption wafer fixture with anti-backflow capability, including the aforementioned vacuum chuck. The upper end of the vacuum chuck is connected to a driving assembly, and the lower end of the vacuum chuck is connected to a porous adsorption plate. The lower end of the porous adsorption plate is connected to the wafer to be processed.

[0016] In this preferred embodiment, the driving assembly includes a conical rotary stepped shaft and an air slip ring, wherein one end of the conical rotary stepped shaft is connected to an external drive, and the other end is fixedly connected to the upper end of a vacuum suction cup;

[0017] The air slip ring is fitted onto a conical rotating stepped shaft and is rotatably connected to the conical rotating stepped shaft;

[0018] The air slip ring has an outer air hole on its side wall. One end of the outer air hole is connected to an external device, and the other end of the outer air hole is connected to an air channel on the vacuum suction cup through the inner cavity of the air slip ring.

[0019] In this preferred embodiment, a conical recess is formed at the center of the upper end face of the vacuum suction cup, and the conical recess cooperates with the conical rotating shaft conical surface on the conical rotating stepped shaft;

[0020] The vacuum suction cup and the conical rotating stepped shaft are also connected by a connector, and there is a gap between the connector and the conical rotating stepped shaft.

[0021] In this preferred embodiment, the porous adsorption plate is uniformly and densely covered with a number of air holes.

[0022] In this preferred embodiment, the lower end face of the vacuum chuck is provided with an outer support flange that serves as a guide and support for the wafer to be processed during the installation process.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] This invention provides an anti-backflow vacuum suction cup, which sets up anti-backflow water and air channels within a specific location range of the vacuum suction cup body (i.e., the second protective measure is placed outside the disc-shaped air channel opened at the lower end of the vacuum suction cup body, and the first protective measure is placed outside the second protective measure), which can effectively prevent external liquids from being drawn back into the device (vacuum channels). Specifically:

[0025] The first and second sealing rings serve as the first line of defense to prevent the possible backflow of small amounts of liquid into the device's interior (vacuum passage).

[0026] The annular waterproof groove and the first vertical water-air channel are located inside the first layer of protection against liquid infiltration from the external environment and outside the outermost layer of the internal air channel. As a second layer of protection against liquid infiltration from the external environment, they can effectively prevent the occurrence of a small amount of liquid that may be sucked back into the device (vacuum channel).

[0027] The present invention provides a vacuum adsorption wafer clamp with anti-backflow function, which uses a vacuum chuck with anti-backflow function as a vacuum adsorption type clamp for the wafer to be processed, and can effectively solve the defects of existing vacuum chuck adsorption type clamps for wafers, which have the problem of electrolyte and polishing slurry backflow into the device.

[0028] Furthermore, an air slip ring is fitted onto the conical rotating stepped shaft, and an air hole is opened on the air slip ring. The air hole is used to connect the air channel on the vacuum chuck to the external air pump, so that the wafer to be processed is not entangled with the external pipe device during the processing.

[0029] Furthermore, the circular air channels and the numerous evenly distributed pores on the porous adsorption plate are interconnected, which can generate a stable and continuous vacuum suction on the lower surface of the porous adsorption plate, thereby achieving the purpose of vacuum adsorption and fixing the wafer to be processed.

[0030] Furthermore, the conical surface of the rotating shaft of the tapered cylindrical rotating stepped shaft is fitted to the conical recess surface of the upper vacuum suction cup, thereby realizing the transmission of load (force) between the tapered cylindrical rotating stepped shaft and the upper vacuum suction cup at the center position; at the same time, a small gap is provided between the connecting piece and the upper end face of the tapered cylindrical rotating stepped shaft, which ensures that a small displacement can occur between the tapered cylindrical rotating stepped shaft and the upper vacuum suction cup; combining the above two points can achieve the purpose of self-aligning horizontal calibration of the device. Attached Figure Description

[0031] Figure 1 This is a three-dimensional view of the device;

[0032] Figure 2 This is an overall cross-sectional view of the device and a schematic diagram of water and air flow;

[0033] Figure 3 The image shows the three-dimensional appearance (left), cross-sectional view (right), and gas flow diagram of the air slip ring.

[0034] Figure 4 This is a top view of the upper vacuum suction cup and a schematic diagram of gas flow in the interconnected annular groove air channels;

[0035] Figure 5 The image shows the three-dimensional appearance of the upper vacuum suction cup (left) and its top view (right);

[0036] Figure 6A three-dimensional view (right) and a magnified view (left) of the self-aligning horizontal calibration assembly;

[0037] Figure 7 This is a cross-sectional view of the liquid storage component;

[0038] Figure 8 A three-dimensional view of the liquid storage component;

[0039] Figure 9 Here is a 3D view of the lower vacuum suction cup;

[0040] Figure 10 This is the front view of the lower vacuum suction cup;

[0041] Figure 11 Here is another 3D view of the lower vacuum suction cup;

[0042] Wherein: 1-conical cylindrical rotating stepped shaft, 11-first vertical air passage, 12-horizontal air passage, 131-connector, 13-first connecting hole, 14-conical surface of rotating shaft, 15-second connecting hole; 2-air slip ring, 21-outer layer of air slip ring, 211-external fixing hole, 212-outer layer air hole, 22-inner layer of air slip ring, 221-second vertical air passage, 222-inner layer air hole, 23-middle layer of air slip ring; 3-water storage ring, 31-third connecting hole, 32-inner water and air hole, 33-upper air hole, 34-air hole plug; 4-upper vacuum suction cup, 41-conical concave surface, 42-third vertical air passage, 4 3-First vertical water-air channel; 44-First sealing ring; 45-Interconnected annular groove air channel; 46-Fourth connecting hole; 5-Lower vacuum suction cup; 51-Fourth vertical air channel; 52-Annular waterproof groove; 53-Second vertical water-air channel; 54-Disc-shaped air channel; 55-First annular surface; 561-Second annular surface; 562-Third annular surface; 563-Fourth annular surface; 57-Second sealing ring; 58-Outer supporting flange; 6-Porous adsorption plate; 7-Wafer to be processed; 8-L-shaped water-air pipe; 91-Horizontal air pipe; 92-L-shaped air pipe; 93-U-shaped air pipe; 94-Outlet pipe; 95-T-shaped connecting pipe. Detailed Implementation

[0043] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0044] This invention is mainly used in ultra-precision wafer processing, such as ultra-precision polishing and grinding, to provide continuous and stable vacuum suction during the process, so as to achieve the purpose of vacuum adsorption and fixation of the wafer, and to realize self-aligning horizontal calibration of the wafer position, while avoiding liquid backflow into the back of the wafer and the inside of the device (vacuum channel).

[0045] Example 1

[0046] A vacuum suction cup with anti-backflow function, characterized in that it includes a vacuum suction cup body, wherein an axially arranged air passage is provided at the upper end of the vacuum suction cup, one end of the air passage is connected to an external device, and the other end is connected to a disc-shaped air passage 54 provided at the lower end of the vacuum suction cup body.

[0047] The vacuum suction cup body is also provided with an anti-backflow water air channel. The anti-backflow water air channel includes a first protective measure and a second protective measure. The second protective measure is located outside the disc-shaped air channel 54 opened at the lower end of the vacuum suction cup body, and the first protective measure is located outside the second protective measure.

[0048] The second protective measure is equipped with an air outlet, which is connected to the air duct.

[0049] Example 2

[0050] Compared with Embodiment 1, the second protective measure in this embodiment includes an axially arranged water-air channel on the upper end of the vacuum suction cup body and an annular waterproof groove 52 on the lower end of the vacuum suction cup body. The annular waterproof groove 52 is placed between the disc-shaped air channel 54 and the second protective measure. One end of the water-air channel is connected to a water-storage ring 3 for storing liquid, and the other end is connected to the annular waterproof groove 52. An air outlet is provided on the water-air channel, and the air outlet communicates with the air channel.

[0051] Example 3

[0052] This embodiment is superior to Embodiment 1 in that the first protective measure includes a second sealing ring 57, which is installed at the lower end of the vacuum suction cup body and is located outside the second protective measure.

[0053] The first and second sealing rings serve as the first line of defense to prevent the possible backflow of small amounts of liquid into the device's interior (vacuum passage).

[0054] The annular waterproof groove and the first vertical water-air channel are located inside the first layer of protection against liquid infiltration from the external environment and outside the outermost layer of the internal air channel. As a second layer of protection against liquid infiltration from the external environment, they can effectively prevent the occurrence of a small amount of liquid that may be sucked back into the device (vacuum channel).

[0055] Example 4

[0056] The present invention also provides a vacuum adsorption wafer fixture with anti-backflow, including the aforementioned vacuum chuck, the upper end of which is connected to a driving component, the lower end of which is connected to a porous adsorption plate 6, and the lower end of which is connected to the wafer to be processed. This effectively solves the defect of existing vacuum chuck adsorption type wafer fixation where electrolyte and polishing slurry are backflowed into the device.

[0057] Example 5

[0058] To achieve the self-aligning horizontal calibration, the conical rotating stepped shaft and the upper vacuum chuck satisfy the following: a conical recess 41 is formed at the center of the upper end face of the vacuum chuck, and the conical recess 41 cooperates with the rotating shaft conical surface 14 on the conical rotating stepped shaft 1.

[0059] The vacuum suction cup and the conical rotating stepped shaft 1 are also connected by a connector 131, and there is a gap between the connector 131 and the conical rotating stepped shaft 1.

[0060] Example 6

[0061] To achieve the purpose of the aforementioned device for preventing external pipe entanglement, an air slip ring 2 is included, wherein the air slip ring 2 is fitted on a conical rotating stepped shaft 1 and is rotatably connected to the conical rotating stepped shaft 1;

[0062] The air slip ring 2 has an outer air hole 212 on its side wall. One end of the outer air hole 212 is connected to an external device, and the other end of the outer air hole 212 is connected to an air channel on the vacuum suction cup through the inner cavity of the air slip ring 2.

[0063] Example 7

[0064] Specifically, refer to Figures 1 to 11 This invention provides a vacuum adsorption wafer clamp with anti-backflow mechanism, comprising the following parts: a conical rotating stepped shaft 1, an air slip ring 2, a water storage ring 3, an upper vacuum suction cup 4, a lower vacuum suction cup 5, a porous adsorption plate 6, a wafer to be processed 7, an L-shaped water-air pipe 8, and an external connecting air pipe. The air slip ring 2 is fitted onto the upper end of the conical rotating stepped shaft 1 and is rotatably connected to it. The water storage ring 3 is fitted and fixed to the lower end of the conical rotating stepped shaft 1. The upper vacuum suction cup 4 is positioned below the water storage ring 3 and connected to the lower end of the conical rotating stepped shaft 1. The lower vacuum suction cup 5 is connected to the lower end of the upper vacuum suction cup 4. The porous adsorption plate 6 is installed at the lower end of the lower vacuum suction cup 5, and the wafer to be processed 7 is installed at the lower end of the porous adsorption plate 6.

[0065] The conical cylindrical rotating stepped shaft 1 includes a four-step shaft body, which consists of a first step shaft, a second step shaft, a third step shaft, and a fourth step shaft, with the shaft diameters of the first step shaft, the second step shaft, the third step shaft, and the fourth step shaft increasing sequentially. The free end face of the fourth step shaft is provided with a conical body.

[0066] The third step shaft has an axially arranged first vertical air passage 11 and a radially arranged horizontal air passage 12 on one side. One end of the first vertical air passage 11 is connected to the air slip ring 2; the other end of the first vertical air passage 11 is connected to the horizontal air passage 12, and the free end of the horizontal air passage 12 is connected to a horizontal air pipe 91.

[0067] The free end of the horizontal air pipe 91 is connected to a T-shaped connecting pipe 95. The two connecting ports of the T-shaped connecting pipe 95 are respectively connected to a U-shaped air pipe 93 and an L-shaped air pipe 92. The free end of the L-shaped air pipe 92 is connected to the upper vacuum suction cup 4. The free end of the U-shaped air pipe 93 is connected to the water storage ring 3.

[0068] The first step shaft of the tapered cylindrical rotating stepped shaft 1 is connected to an external drive to drive the fixture to rotate at high speed relative to the external environment. At the same time, the tapered cylindrical rotating stepped shaft 1 can also transmit the load (force) applied to it from the outside.

[0069] An air slip ring 2 is fitted at the first step shaft.

[0070] The air slip ring 2 includes an outer air slip ring layer 21, an inner air slip ring layer 22, and an intermediate air slip ring layer 23. The outer air slip ring layer 21 is fitted onto a conical selection step shaft 1, and the inner air slip ring layer 22 is fitted onto the conical selection step shaft 1 and placed inside the cavity of the outer air slip ring layer 21.

[0071] Two intermediate layers 23 of the air slip ring are provided, which are respectively fitted onto the two ends of the inner layer 22 of the air slip ring.

[0072] The outer layer 21 of the air slip ring has an outer layer air hole 212 on its side wall, and the outer layer air hole 212 is connected to the inner cavity of the outer layer 21 of the air slip ring.

[0073] The outer pore 212 is connected to an external vacuum pump through an outlet pipe 94.

[0074] The inner layer 22 of the air slip ring has a second vertical air passage 221 arranged axially on its side wall, and the second vertical air passage 221 is connected to the first vertical air passage 11.

[0075] One end of the second vertical airway 221 is an open end and the other end is a closed end, with its open end connected to the first vertical airway 11.

[0076] The second vertical air passage 221 has an inner air hole 222 on its side wall, and the second vertical air passage 221 is connected to the inner cavity of the outer layer 21 of the air slip ring through the inner air hole 222.

[0077] The top of the outer layer 21 of the air slip ring has a plurality of external fixing holes 211 arranged along its circumference, and is fixedly connected to external devices through the external fixing holes 211.

[0078] The water storage ring 3 has a circular structure and is mounted on the top of the upper vacuum suction cup 4.

[0079] Multiple third connection holes 31 are evenly distributed along the circumference of the outer side wall of the water storage ring 3. The third connection holes 31 are used to connect with the upper vacuum suction cup 4 to form an integral structure.

[0080] An inner water vapor hole 32 is provided on the inner wall of the water storage ring 3. The inner water vapor hole 32 is connected to the first vertical water vapor channel 43 opened on the upper vacuum suction cup 4 through the L-shaped water vapor pipe 8.

[0081] The top of the water storage ring 3 is provided with an upper air hole 33, which is connected to the free end of the U-shaped air pipe 93.

[0082] A conical recess 41 is provided at the center of the upper end face of the upper vacuum suction cup 4, and the conical recess 41 cooperates with the conical surface 14 of the rotating axis of the cone.

[0083] The upper vacuum suction cup 4 has a plurality of first connecting holes 13 evenly distributed along its circumference on its upper end surface. The first connecting holes 13 are connected with the connector 131 to the fourth step shaft end face of the conical rotating stepped shaft 1 to form an integral structure.

[0084] A third vertical air passage 42 is provided on one side of the upper vacuum suction cup 4, and the third vertical air passage 42 is connected to the free end of the L-shaped air pipe 92.

[0085] The lower end face of the upper vacuum suction cup 4 is provided with an interconnected annular groove air passage 45, which is connected to the free end of the third vertical air passage 42.

[0086] The lower end face of the upper vacuum suction cup 4 is also provided with a sealing groove, and a first sealing ring 44 is assembled in the sealing groove.

[0087] The lower end face of the upper vacuum suction cup 4 has a plurality of fourth connecting holes 46 evenly distributed along its circumference. The fourth connecting holes 46 are connected with the connector to realize the connection between the upper vacuum suction cup 4 and the lower vacuum suction cup 5.

[0088] The lower vacuum suction cup 5 is a frustum structure with a T-shaped cross-section. A disc-shaped air channel 54 is provided at the center of the small end face of the lower vacuum suction cup 5. From the disc-shaped air channel 54 to the side wall of the small end face of the lower vacuum suction cup 5, a first annular surface 55, a second annular surface 561, a third annular surface 562, a fourth annular surface 563 and an outer supporting flange 58 are arranged in sequence.

[0089] A second sealing ring 57 is provided between the fourth annular surface 563 and the third annular surface 562, and an annular waterproof groove 52 is provided between the third annular surface 562 and the second annular surface 561.

[0090] A fourth vertical airway 51 is provided at the center of the disc-shaped airway 54. One end of the fourth vertical airway 51 is connected to the annular groove airway 45, and the other end is connected to the disc-shaped airway 54.

[0091] The annular waterproof groove 52 is also provided with a second vertical water vapor channel 53. One end of the second vertical water vapor channel 53 is an open end and the other end is a closed end. The open end of the second vertical water vapor channel 53 is connected to the first vertical water vapor channel 43.

[0092] The stepped groove structure at the small end of the lower vacuum chuck is used to install the porous adsorption plate and the wafer to be processed. At the same time, the flange structure formed by the stepped groove plays a certain guiding and supporting role in the installation process of the porous adsorption plate and the wafer to be processed. The lower part of the vertical air channel at the center of the lower vacuum chuck is connected to the disc-shaped air channel formed by the stepped groove structure between the lower vacuum chuck and the porous adsorption plate, as well as the several uniformly distributed micro-nano-scale pores of the porous adsorption plate.

[0093] The wafer to be processed is attached to the porous adsorption plate along the inner side of the outer support flange of the lower vacuum chuck. The outer support flange structure of the lower vacuum chuck plays a certain guiding and supporting role during wafer mounting. The lower surface of the porous adsorption plate is attached to the upper surface of the wafer to be processed, so as to achieve the purpose of adsorbing the wafer to be processed. The wafer to be processed only contacts the annular support flange and part of the annular surface of the lower vacuum chuck, and the contact area with the lower vacuum chuck is small. It mainly contacts the lower surface of the porous adsorption plate. The porous adsorption plate is made of porous ceramic or porous metal material. The lower surface of the adsorption plate is uniformly and densely covered with a number of micro-nano-scale pores, which can avoid the wafer to be processed being subjected to uneven stress.

[0094] The porous adsorption plate 6 is installed at the small end of the lower vacuum suction cup 5, and the upper surface of the porous adsorption plate 6 is in contact with the first annular surface 55.

[0095] The upper surface of the wafer 7 to be processed is attached to the lower surface of the porous adsorption plate 6, and is attached to the second annular surface 561, the third annular surface 562 and the fourth annular surface 563 of the lower vacuum chuck 5.

[0096] The outer support flange 58 of the lower vacuum chuck 5 plays a certain guiding and supporting role during the installation of the wafer 7 to be processed; in order to meet the processing conditions, the inner height of the outer support flange 58 of the lower vacuum chuck 5 should be lower than the thickness of the wafer 7 to be processed.

[0097] The lower surface of the porous adsorption plate 6 is uniformly covered with several micro-nano-scale pores, which can ensure stable vacuum adsorption of the wafer while avoiding uneven force on the wafer 7 to be processed.

[0098] The working principle of vacuum adsorption fixation of the wafer to be processed in this invention is as follows:

[0099] An external vacuum pump is connected to the outer air vent 212 of the outer layer 22 of the air slip ring via an outlet pipe 94; the outer air vent 212 of the outer layer 22 of the air slip ring is connected to the inner air vent 222 of the middle layer 23 and the inner layer 22 of the air slip ring; the inner air vent 222 of the inner layer 22 of the air slip ring is connected to the second vertical air passage 221 of the inner layer 22 of the air slip ring; the second vertical air passage 221 of the inner layer 22 of the air slip ring is connected to the first vertical air passage 11 of the conical rotating stepped shaft 1; the first vertical air passage 11 of the conical rotating stepped shaft 1 is connected to the horizontal air passage 12 of the conical rotating stepped shaft 1; the horizontal air passage 12 of the conical rotating stepped shaft 1 is connected to the T-shaped connecting pipe 95 via a horizontal air pipe 91; the T-shaped connecting pipe 95 is connected to the U-shaped air pipe. Channel 93 is connected to the upper air hole 33 of the water storage ring 3; T-shaped connecting pipe 95 is connected to the third vertical air channel 42 of the upper vacuum chuck 4 through L-shaped air channel 92; the third vertical air channel 42 of the upper vacuum chuck 4 is connected to the interconnected annular groove air channel 45 of the upper vacuum chuck 4; the interconnected annular groove air channel 45 of the upper vacuum chuck 4 is connected to the fourth vertical air channel 51 of the lower vacuum chuck 5; the fourth vertical air channel 51 of the lower vacuum chuck 5 is connected to the disc-shaped air channel 54 of the lower vacuum chuck 5; the disc-shaped air channel 54 of the lower vacuum chuck 5 is connected to a number of micro-nano-scale air holes evenly distributed on the porous adsorption plate 6; this air channel connection relationship can generate a stable and continuous vacuum suction force on the lower surface of the porous adsorption plate 6, so as to achieve the purpose of vacuum adsorption and fixing the wafer 7 to be processed.

[0100] This invention addresses the working principle of self-aligning horizontal calibration:

[0101] A conical recess 41 is formed at the center of the upper surface of the upper vacuum suction cup 4. The bottom of the conical cylindrical rotating stepped shaft 1 is a rotating shaft cone 14 with the same taper as the conical recess 41. The rotating shaft cone 14 of the conical cylindrical rotating stepped shaft 1 is fitted and installed in close contact with the conical recess 41 of the upper vacuum suction cup 4, thereby realizing the transmission of load (force) between the conical cylindrical rotating stepped shaft 1 and the upper vacuum suction cup 4 at the center position.

[0102] The conical rotary stepped shaft 1 and the upper vacuum suction cup 4 are connected as a whole at the first connecting hole 13 by a connector 131. A small gap is provided between the connector 131 and the upper end face of the fourth step of the conical rotary stepped shaft 1. Figure 6 As shown in the enlarged view, the tiny gap ensures that a small displacement can occur between the conical rotating stepped shaft 1 and the upper vacuum chuck 4; combining the above two points can achieve the purpose of self-aligning horizontal calibration of the device.

[0103] The working principle of the liquid ingress prevention device of this invention:

[0104] To prevent small amounts of cleaning water, electrolyte, polishing slurry, or other liquids from being drawn back into the back of the wafer or the interior of the device (vacuum channel), an annular waterproof groove 52 is provided between the second annular surface 561 and the third annular surface 562 of the lower vacuum chuck 5. The annular waterproof groove 52 of the lower vacuum chuck 5 is connected to the second vertical water-air channel 53 of the lower vacuum chuck 5. The second vertical water-air channel 53 of the lower vacuum chuck 5 is connected to the first vertical water-air channel 43 of the upper vacuum chuck 4. The first vertical water-air channel 43 of the upper vacuum chuck 4 is connected to the inner water-air hole 32 of the water storage ring 3 through the L-shaped water-air pipe 8. Any liquids that may be drawn back into the water storage ring 3 are retained in the water storage ring 3 after passing through the annular water storage ring 3, while the air is connected to the T-shaped connecting pipe 95 through the upper air hole 33 of the water storage ring 3 and the U-shaped air pipe 93.

[0105] To facilitate the drainage of residual liquid, a small hole is made on the upper side of the water storage ring 3 and sealed with an air vent plug 34. After the device has been used for a period of time, the air vent plug 34 is pulled out, and the residual liquid in the water storage ring is drained using a syringe or other means.

[0106] The annular waterproof groove 52 and the second vertical water-air channel 53 of the lower vacuum suction cup 5 are located outside the porous adsorption plate 6 and the second annular surface 561 of the lower vacuum suction cup 5, and inside the second sealing ring 57 of the lower vacuum suction cup 5; the first vertical air channel 43 of the upper vacuum suction cup 4 is located outside the interconnected annular groove air channel 45 of the upper vacuum suction cup 4, and inside the first sealing ring 44 of the upper vacuum suction cup 4; that is, the locations of the annular waterproof groove 52, the second vertical water-air channel 53, and the first vertical water-air channel 43. Located inside the first layer of protection against liquid infiltration from the external environment (the first sealing ring 44 of the upper vacuum chuck 4 and the second sealing ring 57 of the lower vacuum chuck 5) and outside the outermost layer of the internal air passage (the interconnected annular groove air passage 45 of the porous adsorption plate 6, the second annular surface 561 of the lower vacuum chuck 5, and the upper vacuum chuck 4), it serves as a second layer of protection against liquid infiltration from the external environment. It effectively prevents the possible backflow of small amounts of liquid into the back of the wafer or the interior of the device (vacuum passage).

[0107] The wafer vacuum adsorption fixation and self-aligning horizontal calibration device of the present invention has at least the following advantages:

[0108] 1. The porous adsorption plate 6 has a number of uniformly distributed micro-nano-scale pores, which can provide a continuous and stable vacuum suction force to the wafer 7 to be processed without generating uneven stress on the wafer 7 to be processed. The wafer 7 to be processed is installed along the inner side of the outer support flange 58 of the lower vacuum chuck 5, which can play a certain guiding role and a certain supporting role during the installation process, and can prevent the wafer to be processed from sliding laterally to a certain extent.

[0109] 2. The air slip ring 2 allows the movement of the internal part of the device that rotates at high speed relative to the external environment and the external part that is stationary relative to the external environment to be distinguished, which can avoid the situation where the external air pipe gets tangled in the device during the high-speed rotation of the whole device.

[0110] 3. The conical cylindrical rotating stepped shaft 1 and the upper vacuum chuck 4 constitute a self-aligning horizontal calibration assembly, and the connecting piece 131 is in Figure 6 The small gap maintained between position 13 and the conical rotating stepped shaft 1; combined with the fitting installation of the rotating shaft cone surface 14 at the bottom of the conical rotating stepped shaft 1 with the same taper and the conical recess surface 41 at the center of the upper vacuum chuck 4, the component can maintain a certain amount of movement (adjustment) margin while ensuring the transmission of load (force), thereby achieving the purpose of self-aligning horizontal calibration, which can effectively avoid the situation where the lower half of the device or the wafer is not horizontal or not fitted during installation and processing.

[0111] 4. The lower vacuum suction cup 5 and the upper vacuum suction cup 4 are provided with annular waterproof groove 52 and second vertical water-air channel 53 and first vertical water-air channel 43 within a specific position range, which become a second protective measure to prevent external liquids from being sucked back into the back of the wafer or the inside of the device (vacuum channel); the water-air channel is connected to the air channel, and while the external vacuum pump provides a stable and continuous vacuum suction, the first protective measure formed by the first sealing ring 44 of the upper vacuum suction cup 4 and the second sealing ring 57 of the lower vacuum suction cup 5, and the second protective measure formed by the annular waterproof groove 52 and the second vertical water-air channel 53 and the first vertical water-air channel 43 can effectively prevent external liquids from seeping into the back of the wafer or the inside of the device (vacuum channel); at the same time, the water storage ring 3 can collect a small amount of liquid that may seep in, and the water storage ring 3 is provided with a drain hole and a corresponding air plug 34, so that the residual liquid in the water storage ring can be discharged by a syringe or other means after the device has been used for a period of time.

[0112] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. An anti-suckback vacuum chuck, characterized by, Includes a vacuum suction cup body, the upper end of which has an axially arranged air passage, one end of which is connected to an external device, and the other end is connected to a disc-shaped air passage (54) at the lower end of the vacuum suction cup body. The vacuum suction cup body is also provided with an anti-backflow water air channel. The anti-backflow water air channel includes a first protection measure and a second protection measure. The second protection measure is placed outside the disc-shaped air channel (54) opened at the lower end of the vacuum suction cup body, and the first protection measure is placed outside the second protection measure. The second protective measure is provided with an air outlet, which is connected to the air passage; the second protective measure includes an axially arranged water-air passage opened at the upper end of the vacuum suction cup body, and an annular waterproof groove (52) opened at the lower end of the vacuum suction cup body, the annular waterproof groove (52) being placed between the disc-shaped air passage (54) and the second protective measure; one end of the water-air passage is connected to a water storage ring (3) for storing liquid, and the other end is connected to the annular waterproof groove (52); an air outlet is provided on the water-air passage, which is connected to the air passage; the first protective measure includes a second sealing ring (57), the second sealing ring (57) being installed at the lower end of the vacuum suction cup body and placed outside the second protective measure.

2. The anti-backflow vacuum suction cup according to claim 1, characterized in that, The vacuum suction cup includes an upper vacuum suction cup (4) and a lower vacuum suction cup (5). The upper vacuum suction cup (4) is positioned above the lower vacuum suction cup (5). The upper end face of the upper vacuum suction cup (4) is provided with an axially arranged third vertical air passage (42). One end of the third vertical air passage (42) is connected to an external device, and the other end is connected to a disc-shaped air passage (54) opened at the center of the lower end face of the lower vacuum suction cup (5). The upper vacuum suction cup (4) is also provided with an axially arranged first vertical water and air channel (43). One end of the first vertical water and air channel (43) is connected to a water storage ring (3), and the other end is connected to an annular waterproof groove (52) opened on the lower end of the lower vacuum suction cup (5). The annular waterproof groove (52) is located outside the disc-shaped air channel (54) opened at the lower end of the vacuum suction cup body. The lower end face of the upper vacuum suction cup (4) is equipped with a first sealing ring (44), which is located outside the annular waterproof groove (52). The lower vacuum suction cup (5) is equipped with a second sealing ring (57) on its lower end face, and the second sealing ring (57) is placed on the outside of the annular waterproof groove (52).

3. The anti-backflow vacuum suction cup according to claim 2, characterized in that, The lower end face of the upper vacuum suction cup (4) is provided with an interconnected annular groove air passage (45), and the third vertical air passage (42) is connected to the disc-shaped air passage (54) through the interconnected annular groove air passage (45).

4. A vacuum adsorption wafer clamp with anti-backflow feature, characterized in that, The vacuum chuck includes any one of claims 1-3, wherein the upper end of the vacuum chuck is connected to the driving assembly, the lower end of the vacuum chuck is connected to the porous adsorption plate (6), and the lower end of the porous adsorption plate (6) is connected to the wafer to be processed.

5. The anti-backflow vacuum adsorption wafer jig according to claim 4, characterized in that, The drive assembly includes a conical rotating stepped shaft (1) and an air slip ring (2), wherein one end of the conical rotating stepped shaft (1) is connected to an external drive, and the other end is fixedly connected to the upper end of a vacuum suction cup; The air slip ring (2) is fitted on the conical rotating stepped shaft (1) and is rotatably connected to the conical rotating stepped shaft (1); The air slip ring (2) has an outer air hole (212) on its side wall. One end of the outer air hole (212) is connected to an external device, and the other end of the outer air hole (212) is connected to the air channel opened on the vacuum suction cup through the inner cavity of the air slip ring (2).

6. The anti-backflow vacuum adsorption wafer jig according to claim 4, characterized in that, A conical recess (41) is provided at the center of the upper end face of the vacuum suction cup, and the conical recess (41) cooperates with the rotating shaft conical surface (14) on the conical cylindrical rotating stepped shaft (1); The vacuum suction cup and the conical rotating stepped shaft (1) are also connected by a connector (131), and there is a gap between the connector (131) and the conical rotating stepped shaft (1).

7. The anti-backflow vacuum adsorption wafer jig according to claim 4, characterized in that, The porous adsorption plate (6) has a number of pores evenly distributed on it.

8. A vacuum adsorption wafer clamp for preventing backflow according to claim 4, characterized in that, The lower end face of the vacuum chuck is provided with an outer support flange (58) for guiding and supporting the wafer to be processed during the installation process.

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