Wafer processing device, wafer thinning equipment and wafer processing method

Abstract

The invention belongs to the technical field of semiconductor processing, provides a wafer processing device, wafer thinning equipment and a wafer processing method, and aims to solve the technical problem that the processing cleanliness cannot meet the advanced packaging nanoscale requirement due to the fact that chippings are easy to overflow and pollute and impurities are generated by sliding friction between a stopper and a workbench in existing wafer ring-retaining thinning processing. The wafer processing device comprises a workbench, a main shaft, a first blocking piece and a second blocking piece, wherein the workbench is used for bearing a wafer, and the main shaft drives the grinding wheel with the diameter smaller than that of the wafer to thin the local surface of the wafer; the first blocking piece and the second blocking piece are arranged on the workbench and movably surround a main shaft operation area through air floatation, and at least one blocking piece can be opened in a pivoted mode and fixed through the supporting piece so that feeding and discharging of wafers can be achieved. Friction impurities are prevented from being generated through the air floating type blocking pieces, protection is formed through surrounding of the blocking pieces, chippings are prevented from overflowing, and the cleanliness of wafer thinning machining is improved.

Description

Technical Field

[0001] This application belongs to the field of semiconductor processing technology, and more specifically, relates to wafer processing apparatus, wafer thinning equipment and wafer processing method. Background Technology

[0002] Wafer ring thinning is a semiconductor wafer backside thinning process that retains a certain width of edge ring around the wafer without grinding, thinning only the central area, resulting in a wafer structure that is thinner in the middle and thicker at the edges. This not only meets the thickness requirements of chip manufacturing processes for ultra-thin wafers, but also significantly improves the mechanical strength of the wafer by relying on the edge support ring. It effectively reduces the risk of warping, chipping, and breakage of ultra-thin wafers in subsequent processes, making it a key thinning solution in ultra-thin wafers and advanced packaging.

[0003] For advanced packaging wafers, wafer bonding has extremely high cleanliness requirements. The corresponding ring thinning process needs to achieve nanometer-level cleanliness. However, the debris generated during the existing wafer thinning process can contaminate the wafer and nearby precision components, failing to meet the above cleanliness requirements. Summary of the Invention

[0004] In view of the above problems, this application provides a wafer processing apparatus, a wafer thinning device and a wafer processing method, thereby solving or at least alleviating one or more of the above-mentioned problems and other problems existing in the prior art.

[0005] A first aspect of this application provides a wafer processing apparatus, comprising: A worktable is used to hold wafers; The spindle is used to drive a grinding wheel with a diameter smaller than the wafer to perform ring-thinning on a local surface of the wafer, so that the horizontal projection of the grinding wheel during operation never exceeds the range of the horizontal projection of the wafer. The first baffle consists of a first float plate and a raised, semi-circular first annular baffle wall; The second baffle consists of a second float plate and a raised, semi-circular second annular baffle wall; The first stop and the second stop are disposed on the worktable and are movably enclosed in the working area of ​​the spindle by air flotation; At least one of the stops can be pivotally opened and fixed by a support to enable wafer transfer.

[0006] In one embodiment, the first float plate and the second float plate together form an annular air seal structure, which is used to introduce compressed air and spray it downward to form an annular wind wall located on the outer periphery of the wafer above the worktable. The annular wind wall is used to make the first float plate and the second float plate float above the worktable to avoid the formation of impurities due to friction. The annular wind wall is also used to block the overflow of debris generated by the wafer ring thinning process.

[0007] In one embodiment, the annular air seal structure includes an annular air seal channel disposed within the first float and the second float, and an air seal area communicating with the lower part of the annular air seal channel, wherein the air seal area is disposed downward through the bottom surface of the first float and the second float; The annular air-sealing channel is used to introduce compressed air, and the air-sealing zone is used to guide the compressed air downwards onto the worktable.

[0008] In one embodiment, the air seal area has a guide ramp that slopes downward toward the side of the main shaft, the guide ramp being used to guide compressed air toward the side of the main shaft to prevent debris from spilling out.

[0009] In one embodiment, the annular air-sealing channel and the air-sealing area are connected by a plurality of air holes, and the plurality of air holes are arranged at intervals along the extension direction of the annular air-sealing channel.

[0010] In one embodiment, the vent is circular with a diameter of 0.3mm-0.7mm, and the top width of the air-sealing area is equal to the diameter of the vent.

[0011] In one embodiment, the first float and / or the second float are provided with a pneumatic connector connected to a compressed air source. The pneumatic connector is connected to the annular air seal channel and is used to introduce compressed air into the annular air seal channel.

[0012] In one embodiment, the annular air seal channel is polygonal in shape.

[0013] In one embodiment, both the first float and the second float have beveled surfaces on their opposite sides. The annular air seal channel is rectangular, and the beveled surfaces are located at the corners of the annular air seal channel. Adjacent channels of the annular air seal channel pass through the same beveled surface. Both the first float and the second float are detachably provided with two sealing plugs for sealing the ports of adjacent channels of the annular air seal channel.

[0014] In one embodiment, a locking device is provided on the end face of the first float plate and the second float plate adjacent to each other, and a spring buckle is provided on the second float plate to engage with the locking device.

[0015] In one embodiment, the support member is provided in at least two parts, and each support member is provided with a support surface for abutting against the first float or the second float, the support surface being used to support the first float or the second float.

[0016] In one embodiment, the worktable is provided with a fixed shaft, and a bushing is provided on one side wall of the first or second float plate to engage with the fixed shaft. The bushing is configured to move axially along the fixed shaft and to rotate in conjunction with the fixed shaft.

[0017] A second aspect of this application provides a wafer processing apparatus, comprising: A worktable is used to hold wafers; The spindle is used to drive a grinding wheel with a diameter smaller than the wafer to thin a local surface of the wafer; A baffle assembly is disposed on the worktable. The baffle assembly has an annular air seal structure inside, which surrounds the outer periphery of the spindle. The annular air seal structure is used to introduce compressed air and spray it downward to form an annular air wall located on the outer periphery of the wafer above the worktable.

[0018] In one embodiment, the baffle assembly includes a first baffle and a second baffle. The first baffle consists of a first float and a raised semi-circular first annular baffle wall, and the second baffle consists of a second float and a raised semi-circular second annular baffle wall. The first baffle and the second baffle are disposed on the worktable and movably enclose the working area of ​​the spindle by air flotation.

[0019] A third aspect of this application provides a wafer thinning apparatus, including a wafer processing device.

[0020] A fourth aspect of this application provides a wafer processing method, including the following steps: Place the wafer on the worktable and close the first or second stop to enclose the spindle working area; Compressed air is introduced into the annular air-sealed channel, causing the first float plate and the second float plate to float on the worktable. The spindle is controlled to drive the grinding wheel to rotate and grind the wafer until grinding is completed. During this process, the first floating plate and the second floating plate form an annular air wall between themselves and the worktable to avoid the formation of impurities due to friction and to prevent the spillage of debris generated during wafer thinning. Stop supplying compressed air into the annular gas seal channel, open the first or second stop and support it on the support, then remove the wafer.

[0021] The beneficial effects of this application's embodiments are as follows: The wafer processing apparatus of this application, through the combination of a first and a second collapsible stopper, encloses the spindle's working area, forming a protective barrier that covers the working area. This effectively prevents silicon chips, polishing slurry, and other debris generated by the high-speed rotating grinding wheel during the wafer thinning process from splashing outwards, avoiding contamination of the wafer surface and surrounding precision parts, ensuring the cleanliness of the processing environment, and meeting the nanoscale cleanliness requirements of advanced packaging fields. Simultaneously, the first and second stoppers have annular sealing channels inside, forming an air-floating seal between the stopper's float plate and the worktable, keeping the float plate and worktable in a non-contact state, eliminating hard friction during sliding, preventing friction debris generation, and preventing wafer contamination. Furthermore, at least one stopper can pivotally open and be stably fixed by a support member, achieving flexible opening and closing of the stopper for easy wafer loading and unloading operations and daily equipment maintenance, while maintaining a stable posture when the stopper is open to prevent residual polishing slurry from dripping and causing secondary contamination; when the stopper is closed, it can quickly reset, forming a complete enclosed structure, ensuring the continuity of the processing flow. Meanwhile, the stop can move radially and axially in conjunction with the main shaft, always providing effective enclosure and protection for the work area. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the wafer edge support ring structure in one embodiment of this application; Figure 2 This is a schematic diagram of the structure of a wafer processing apparatus in one embodiment of this application; Figure 3 This is a schematic diagram of the structure of the stop and the internal annular air seal structure in one embodiment of this application; Figure 4 This is a schematic diagram showing the positional relationship between the annular air seal channel and the main shaft in one embodiment of this application; Figure 5 This is a schematic diagram of the structure of the stop and the spring clip in one embodiment of this application; Figure 6 As shown in one embodiment of this application Figure 5 A magnified view of a section at point A in the middle; Figure 7 This is a schematic diagram of the structure of the grinding wheel, wafer, mounting area, and annular gas seal channel in one embodiment of this application; Figure 8 This is a cross-sectional view of an annular air seal channel in one embodiment of this application; Figure 9 As shown in one embodiment of this application Figure 8 A magnified view of a section at point B in the middle; Figure 10 This is a schematic diagram of the structure of the spring clip and support member in one embodiment of this application; Figure 11 As shown in one embodiment of this application Figure 10 A magnified view of a section at point C.

[0024] Figure label: 100. Wafer; 200. Edge support ring; 300. Grinding wheel; 1. Worktable; 101. Mounting area; 2. Spindle; 3. First stop; 31. First float; 32. First annular baffle; 4. Second stop; 41. Second float; 42. Second annular baffle; 5. Support; 6. Annular gas seal structure; 61. Annular gas seal channel; 62. Gas seal area; 63. Guide slope; 64. Air hole; 7. Pneumatic connector; 8. Beveled surface; 9. Sealing plug; 10. Clamp; 11. Spring clip; 12. Fixed shaft; 13. Bushing. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in the specific implementation of this application should fall within the protection scope of the embodiments of this application.

[0026] To keep the drawings concise, each drawing only schematically shows the parts relevant to the disclosure; these do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one," and "several" includes "two" and "more than two."

[0027] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0028] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0029] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of description and simplification of operation, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0030] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0031] It should be understood that, unless the context clearly states otherwise, the terms "comprising," "including," or "having" as used herein refer to the presence of an element, but do not exclude the presence or addition of one or more other elements. Furthermore, "comprising" and / or "including" as used herein specify the presence of shapes, numbers, steps, operations, members, elements, and / or combinations thereof, and do not exclude the presence or addition of one or more other shapes, numbers, operations, elements, and / or combinations thereof. Some embodiments of this application are described in detail below with reference to the accompanying drawings. Where there is no conflict between the embodiments, the following embodiments and features can be combined with each other. The steps in the following method embodiments are for illustrative purposes only and are not intended to limit this application.

[0032] Embodiments of this application provide a wafer processing apparatus for performing ring-based thinning on a wafer 100. Ring-based thinning (also known as Taiko thinning) is a selective back-side thinning process for wafer 100 used in semiconductor manufacturing. It involves precisely thinning only the effective device area at the center of the wafer 100 using specialized grinding equipment or etching processes to achieve the required ultra-thin thickness, while retaining a ring-shaped area of ​​a certain width around the wafer 100 that is not thinned, maintaining a thickness close to the original wafer 100. This results in a stepped structure with a thinner central area and a thicker edge area. The annular retention area is the edge support ring 200, which can provide sufficient mechanical rigidity and support for the overall structure. It effectively solves the problems of easy warping, brittleness, and difficulty in handling and subsequent processing of wafer 100 after traditional full-wafer thinning. It significantly improves the stability and yield of ultra-thin wafer 100 in subsequent processes such as back metal deposition, wafer 100 bonding, ion implantation, and dicing. It is particularly suitable for the manufacturing of semiconductor products with stringent requirements for wafer 100 thickness, mechanical strength, and warpage control, such as power devices, MEMS chips, and advanced packaging.

[0033] like Figure 1 As shown, during the ring-based thinning process of wafer 100, the central region on the back of wafer 100 is ground to an ultra-thin thickness (e.g., 50-100 μm). During the ring-based thinning process, wafer 100 will gradually become thinner in the central region, forming a stepped structure at the position of the central region and the edge support ring 200. At this time, some of the debris from wafer 100 during the thinning process will be thrown to the corner of the stepped structure by the grinding fluid under the high-speed rotation of the grinding wheel 300, while another part will be thrown out of the grinding area, polluting the surrounding environment and causing damage to nearby precision parts.

[0034] like Figure 2 As shown in the embodiment of this application, a wafer processing apparatus suitable for the 100mm ring-stayed thinning process of ultra-thin wafers is provided. It solves the problems of easy overflow and contamination of debris in the ring-stayed thinning process, metal impurities generated by sliding friction between the stop and the worktable 1, and difficulty in meeting the processing cleanliness requirements of advanced packaging. The following is a complete description in conjunction with the structure and working process.

[0035] In the thinning process of wafer 100 with ring retention, the edge support ring 200 of the outer periphery of wafer 100 is usually retained, and only the central area is ground and thinned. Therefore, the spindle 2 not only needs to drive the grinding wheel 300 to rotate at high speed, but also needs to complete the vertical feed motion and the horizontal linkage movement to achieve full coverage processing of the central area of ​​wafer 100. In addition, it should be noted that the side of the edge support ring 200 of wafer 100 facing the central area of ​​wafer 100 in this application is a stepped slope. This allows the processing debris to be cleaned away along the slope as much as possible during thinning and cleaning.

[0036] Specifically, this device includes a worktable 1, which is used to horizontally place and fix the wafer 100 to be processed. In the center of the worktable 1 is a circular mounting area 101 for placing the wafer 100, the diameter of which is larger than the diameter of the wafer 100. A spindle 2 is positioned above the mounting area 101 on the worktable 1, the diameter of which is smaller than the diameter of the mounting area 101. The spindle drives a grinding wheel with a diameter smaller than the wafer to perform ring thinning on a localized surface of the wafer, ensuring that the horizontal projection of the grinding wheel 300 during operation never exceeds the horizontal projection range of the wafer 100. It should be noted that the edge size of the ring is generally 3mm, and the grinding wheel 300 used for a 12-inch 300mm wafer 100 has a size of 270-290mm, with a diameter smaller than the wafer 100 diameter by 10-30mm. When performing ring-thinning processing on wafer 100 under the drive mechanism, the spindle 2 drives the grinding wheel 300 to reciprocate along the radial direction (X direction) of wafer 100, and its movement range does not exceed the mounting area 101; at the same time, during the thinning process, the spindle 2 drives the grinding wheel 300 to move in the Z direction to meet the multi-dimensional movement requirements of ring-thinning.

[0037] like Figure 3 and Figure 4 Because the spindle 2 continuously moves horizontally and vertically during machining, traditional fixed sealing structures cannot follow the movement of the spindle 2, making it difficult to provide continuous closed protection for the machining area. Impurities such as silicon chips and grinding fluid generated during grinding are splashed outwards by the centrifugal force and airflow of the grinding wheel 300, not only contaminating the surface of the wafer 100 but also adhering to precision parts such as the spindle 2 and guide rails, affecting the equipment's accuracy and lifespan. To solve this problem, this device features a first stop 3 and a second stop 4 above the worktable 1 and around the working area of ​​the spindle 2, forming a closed protective area that can move with the spindle 2. The first stop 3 is composed of a first float plate 31 and an upwardly protruding first annular baffle 32, and the second stop 4 is composed of a second float plate 41 and an upwardly protruding second annular baffle 42. Both the first annular baffle 32 and the second annular baffle 42 are semi-circular structures. When the first stop 3 and the second stop 4 are closed and assembled, they can form a complete ring, tightly surrounding the outer periphery of the spindle 2, completely enclosing the grinding area and preventing the debris from spreading outward.

[0038] like Figure 4As shown, further considering the actual needs of wafer 100 loading, unloading, and equipment maintenance, the first stop 3 and the second stop 4 are pivotally connected to the worktable 1 to have an openable / closeable function. If the stop is not reliably supported after opening, it will not only easily shake, but also cause residual polishing slurry on the surface to drip everywhere, contaminating the worktable 1 and the processing environment. To this end, the device is equipped with a support 5 at the corresponding position on the worktable 1. The top of the support 5 is provided with an inclined support surface adapted to the stop. The first stop 3 or the second stop 4 can pivot open around the set position and stably overlap on the support 5, maintaining an inclined posture, which not only facilitates the smooth flow of polishing slurry along the inclined surface, but also allows for quick reset and closure before processing.

[0039] like Figure 5 and Figure 6 As shown, to ensure smoother opening, closing, and following motion of the stop, a fixed shaft 12 is installed on the top surface of the worktable 1. A bushing 13 is installed on the side wall corresponding to the stop. The bushing 13 is movably fitted onto the outside of the fixed shaft 12. When the main shaft 2 moves, the bushing 13 can move slightly along the axial direction of the fixed shaft 12, following the stop. Importantly, the inner diameter of the bushing 13 is larger than the diameter of the fixed shaft 12, with a gap between them. This gap serves to meet the lifting and lowering requirements of the stop during air buoyancy and to enable pivoting. The flipping principle of the bushing 13 and the fixed shaft 12 is similar to a hinge, preventing jamming or sticking during the stop's movement and ensuring stability when moving in conjunction with the main shaft 2.

[0040] It should be noted that the first floating plate 31 and the second floating plate 41 are made of the same material, which can be either a metal plate or a frosted glass plate. The overall weight of the two combined is relatively large. Taking the metal plate as an example, in actual processing, the first floating plate 31 and the second floating plate 41 need to move horizontally synchronously with the spindle 2. If the bottom surface of the floating plate is in direct contact with the surface of the worktable 1, metal debris will be generated due to friction during the sliding process. These micron-sized impurities may fall into the edge support ring 200 and the central thinning area of ​​the wafer 100 when the floating plate moves. During the processing, under the combined influence of the centrifugal force of the high-speed rotation of the wafer 100, the rotation of the grinding wheel 300, and the flow of the grinding fluid, the debris generated by the thinning of the wafer 100 and the debris generated by the friction of the floating plate will accumulate at the corner of the edge support ring 200 and the central thinning area. Because the debris is extremely small, it cannot be completely removed even with subsequent cleaning. For advanced packaging processes that require nanoscale cleanliness, these metal debris (which are conductive) will cause subsequent wafer 100 bonding failure, significantly reducing product yield. At the same time, the tiny gap between the float plate and the worktable 1 cannot be sealed, and the grinding debris will still overflow from the gap. Traditional sealing structures cannot solve the two major problems of frictional impurities and debris overflow at the same time.

[0041] like Figure 5As shown, to address the aforementioned problems, this embodiment incorporates an annular air seal structure 6 within the first float plate 31 and the second float plate 41. This structure utilizes compressed air to simultaneously achieve air buoyancy support and annular air wall sealing, resolving friction and leakage issues. The annular air seal structure 6 is ring-shaped and primarily comprises an annular air seal channel 61 and an air seal area 62. The annular air seal channel 61 is embedded within the first float plate 31 and the second float plate 41, extending in a polygonal ring shape and surrounding the outer perimeter of the main shaft 2. It is connected to a compressed air source (either for storage or generation) via a flexible hose, ensuring uniform distribution and stable pressure of the compressed air within the channel. The air seal area 62 is located directly below the annular air seal channel 61, vertically penetrating the bottom surfaces of the first float plate 31 and the second float plate 41, allowing the airflow to directly spray downwards and act on the surface of the worktable 1. Due to the significant weight of the float plates, the vertical rise of the float plates during air sealing is extremely small, approximately 1 mm. This tiny gap not only keeps the float plates in a suspended state but also prevents debris from flying out through the gap between the float plates and the worktable 1.

[0042] like Figure 7 , Figure 8 and Figure 9 As shown, furthermore, to ensure more uniform airflow output and avoid excessively high or low local pressure affecting air flotation and sealing performance, multiple air holes 64 are provided between the annular air-sealing channel 61 and the air-sealing zone 62. The air holes 64 are evenly spaced along the extension direction of the annular air-sealing channel 61. The air holes 64 are cylindrical through holes with a diameter controlled between 0.3 mm and 0.7 mm. The top width of the air-sealing zone 62 is consistent with the diameter of the air holes 64 to avoid turbulence caused by abrupt changes in cross-section of the airflow and reduce pressure loss.

[0043] It should be noted that after the wafer 100 is placed in the middle of the worktable 1, a gap remains between the outer periphery of the wafer 100 and the inner edge of the worktable 1 placement area. This gap allows debris generated during the ring thinning process to be discharged from the gap and fall to the bottom inner side of the worktable 1, facilitating subsequent cleaning and reducing debris contamination of the wafer 100. Furthermore, to further enhance the sealing effect and prevent airflow from diffusing outwards and causing protection failure, a guide slope 63 is provided inside the air seal area 62. The guide slope 63 slopes downwards towards the spindle 2, spraying compressed air downwards and guiding the airflow to the gap in the processing area. This creates a continuous, sealed annular airflow wall around the wafer 100, completely confining debris within the processing area. It is understandable that the guide slope 63 guides the gas to flow into the gap of the machining area, which enables the air seal area 62 surrounding the spindle 2 to form a relatively closed space. If there is no guide slope 63, or if the guide slope 63 faces the outside of the spindle 2, most of the airflow will flow to the outside of the spindle 2. At this time, the debris entering the air seal area 62 will be carried out of the machining area by the airflow, contaminating the precision parts around the worktable 1, causing the air seal area 62 to lose its sealing function.

[0044] like Figure 5 As shown, to ensure a stable air supply to the annular air seal structure 6, pneumatic connectors 7 are installed on both the first float 31 and the second float 41, with at least one pneumatic connector 7 provided. However, to ensure the uniformity of air output in the air seal zone 62, multiple pneumatic connectors 7 can be provided at intervals, as long as it does not affect the opening of the baffle. The pneumatic connector 7 is connected to a compressed air source. The airflow smoothly enters the annular air seal channel 61 through the pneumatic connector 7, then enters the air seal zone 62 through evenly distributed air holes 64, and finally is directionally ejected along the guide slope 63, forming an annular closed air seal zone 62 between the first float 31 and the second float 41.

[0045] like Figure 5 and 6 As shown, considering the machining difficulty of polygonal annular channels, rectangular processing channels can be selected. This is because rectangular processing channels only require starting from the side wall of the float plate, horizontally penetrating the side wall, and aligning the intersection points of adjacent channels. Thus, when four channels are machined, a connected annular channel can be formed. Furthermore, a beveled surface 8 is provided at the corner of the first float plate 31 and the second float plate 41 on opposite sides. Adjacent segments of the annular air-sealing channel 61 intersect and penetrate this beveled surface 8, reducing the machining difficulty at the channel intersection and facilitating forming. To prevent air leakage and pressure loss at the channel ports, sealing plugs 9 can be detachably installed at each port to tightly seal the channel ports, ensuring reliable sealing and no leakage throughout the annular air-sealing channel 61. It should be noted that the usage and function of the sealing plugs 9 are existing technologies and will not be elaborated upon here.

[0046] like Figure 10 and Figure 11 As shown, to ensure a tight fit between the first float plate 31 and the second float plate 41 and to prevent gaps at the joint that could lead to wind wall breakage and debris leakage, clips 10 and spring clips 11 are respectively installed on their adjacent end faces. Clips 10 and spring clips 11 can be aligned and engaged for quick positioning and locking, ensuring that the two stops form a complete and continuous annular air seal structure 6 and protective structure after assembly, preventing misalignment or gaps due to the movement of the main shaft 2. Furthermore, magnetic snaps or arc-shaped protrusions with matching grooves are provided at the joint surfaces of the first float plate 31 and the second float plate 41 to improve the sealing performance after assembly, ensuring no misalignment occurs during air flotation, uniform air seal strength at all positions of the float plates, and without affecting the pivoting and opening of individual stops.

[0047] Another embodiment of this application discloses a wafer processing apparatus, which includes a worktable 1 for carrying wafers, a spindle 2 for driving a grinding wheel with a diameter smaller than the wafer to thin a local surface of the wafer, and a baffle assembly. The baffle assembly is disposed on the worktable 1 and sleeved around the outer periphery of the spindle 2 to cover the processing area of ​​the worktable. An annular air seal structure 6 is provided within the baffle assembly, surrounding the working area of ​​the spindle 2. The baffle assembly includes a first stop 3 and a second stop 4, which together form a closed protective area that can move with the spindle 2. The first stop 3 consists of a first floating plate 31 and an upwardly protruding first annular baffle wall 32, and the second stop 4 consists of a second floating plate 41 and an upwardly protruding second annular baffle wall 42. Both the first annular baffle wall 32 and the second annular baffle wall 42 are semi-circular structures. The baffle assembly completely encloses the grinding area, preventing debris from spreading outwards.

[0048] The annular gas seal structure 6 is annular and includes an annular gas seal channel 61 and a gas seal area 62. The annular gas seal channel 61 is embedded inside the first floating plate 31 and the second floating plate 41, extending in a polygonal annular shape and surrounding the outer periphery of the main shaft 2. It can form an annular air wall between the baffle assembly and the worktable, and make the baffle assembly float above the worktable. The remaining structure of the wafer processing apparatus in this embodiment is the same as that in the above embodiment, and will not be described in detail here.

[0049] Another embodiment of this application discloses a wafer thinning device, including two of the above-mentioned wafer processing devices, corresponding to a rough grinding worktable and a fine grinding worktable respectively; the device also includes a wafer box to be processed (for placing the wafer 100 to be thinned by ring retention processing), a robot, a vision positioning stage, a robotic arm, a measuring unit, a cleaning stage, a cleaning and drying stage, and a finished wafer box (for placing the processed wafer 100). During the ring-thinning process, a robot first removes a wafer 100 from the wafer cassette to be thinned and places it on a vision positioning stage for centering. Then, a robotic arm transfers the positioned wafer 100 to the rough grinding stage of the wafer 100 processing unit for rough grinding. The measurement unit monitors the rough grinding thickness of the wafer 100 in real time. After the fine grinding is completed, the robotic arm transfers the wafer 100 to the fine grinding stage again. After the fine grinding is completed, the robotic arm transfers the wafer 100 to the cleaning stage for cleaning, and then to the cleaning and drying stage for drying. Finally, the robot places the processed wafer 100 into the wafer cassette.

[0050] It should be noted that the aforementioned stops are provided on both the rough grinding worktable 1 and the fine grinding worktable 1.

[0051] Another embodiment of this application discloses a wafer processing method. During processing, one of the stops is first opened, and the wafer 100 is placed in the processing area of ​​the worktable 1. Then, the stop is closed. Compressed air at a constant pressure is first introduced into the annular air-sealing channel 61 through the pneumatic connector 7. The airflow enters the air-sealing area 62 through the evenly distributed air holes 64 and is sprayed downward along the guide slope 63 to make the float plate float. Then, the spindle 2 and the grinding wheel 300 are started, and the spindle 2 is controlled to move along a preset path to drive the grinding wheel 300 to perform thinning processing on the wafer 100.

[0052] In the above scheme, on the one hand, the ejected airflow forms a stable air film between the first float plate 31, the second float plate 41, and the worktable 1, smoothly lifting the two float plates and keeping them in a non-contact state with the worktable 1. This completely eliminates hard friction during relative sliding, preventing the generation of metal friction impurities from the source and ensuring the surface cleanliness of the wafer 100. On the other hand, the tilted airflow forms an annular wind wall around the processing area. This wind wall surrounds the working area of ​​the wafer 100 and the spindle 2, forming a flexible, sealed barrier that completely confines contaminants such as silicon chips and polishing fluid generated during ring thinning within the processing area, preventing them from splashing outwards and contaminating surrounding precision components. During the spindle 2's linkage processing, the float plates can move freely and smoothly with the spindle 2 under the support of the air film. The annular baffle always remains in an enclosed state, and the annular wind wall continuously provides stability, achieving frictionless, leak-free, and high-cleanliness processing throughout the entire process.

[0053] After processing is completed, the spindle 2 and grinding wheel 300 stop rotating, and the compressed air supply is stopped. The air film and annular wind wall then disappear. The first stop 3 or the second stop 4 is pivoted around the fixed shaft 12 and opened, and is stably supported by the support 5. The processed wafer 100 can then be safely removed, and the wafer 100 to be processed can be loaded. After the wafer 100 is placed in place, the opened stop is reset and closed, and the clamp 10 is engaged with the spring clip 11 for positioning. The first annular baffle 32 and the second annular baffle 42 re-enclose to form a complete annular protective structure, and the next processing cycle can be started. The overall operation is convenient, the processing continuity is strong, and it can fully adapt to the large-scale production needs of ultra-thin wafer 100 with ring thinning.

[0054] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A wafer processing apparatus, characterized in that, include: A worktable is used to hold wafers; The spindle is used to drive a grinding wheel with a diameter smaller than the wafer to perform ring-thinning on a local surface of the wafer, so that the horizontal projection of the grinding wheel during operation never exceeds the range of the horizontal projection of the wafer. The first baffle consists of a first float plate and a raised, semi-circular first annular baffle wall; The second baffle consists of a second float plate and a raised, semi-circular second annular baffle wall; The first stop and the second stop are disposed on the worktable and are movably enclosed in the working area of ​​the spindle by air flotation; At least one of the stops can be pivotally opened and fixed by a support to enable wafer transfer.

2. The wafer processing apparatus according to claim 1, characterized in that, The first floating plate and the second floating plate together form an annular air seal structure. The annular air seal structure is used to introduce compressed air and spray it downward to form an annular wind wall located on the outer periphery of the wafer above the worktable. The annular wind wall is used to make the first floating plate and the second floating plate float above the worktable to avoid the formation of impurities due to friction. The annular wind wall is also used to block the overflow of debris generated by the wafer ring thinning process.

3. The wafer processing apparatus according to claim 2, characterized in that, The annular air seal structure includes an annular air seal channel disposed within the first float and the second float, and an air seal area communicating with the lower part of the annular air seal channel. The air seal area is disposed downward through the bottom surface of the first float and the second float. The annular air-sealing channel is used to introduce compressed air, and the air-sealing zone is used to guide the compressed air downwards onto the worktable.

4. The wafer processing apparatus according to claim 3, characterized in that, The air seal area has a guide slope that slopes downward toward the side closer to the main shaft. The guide slope is used to guide compressed air toward the side of the main shaft to prevent debris from overflowing.

5. The wafer processing apparatus according to claim 3, characterized in that, The annular air-sealing channel and the air-sealing area are connected by a number of air holes, which are arranged at intervals along the extension direction of the annular air-sealing channel.

6. The wafer processing apparatus according to claim 5, characterized in that, The vent is circular with a diameter of 0.3mm-0.7mm, and the top width of the air-sealing area is equal to the diameter of the vent.

7. The wafer processing apparatus according to claim 3, characterized in that, The first float and / or the second float are provided with a pneumatic connector connected to a compressed air source. The pneumatic connector is connected to the annular air seal channel and is used to introduce compressed air into the annular air seal channel.

8. The wafer processing apparatus according to claim 3, characterized in that, The annular air seal channel is polygonal in shape.

9. The wafer processing apparatus according to claim 3, characterized in that, Both the first float and the second float have beveled surfaces on their opposite sides. The annular air seal channel is rectangular, and the beveled surfaces are located at the corners of the annular air seal channel. Adjacent channels of the annular air seal channel pass through the same beveled surface. Both the first float and the second float are detachably provided with two sealing plugs for sealing the ports of adjacent channels of the annular air seal channel.

10. The wafer processing apparatus according to claim 9, characterized in that, The first float and the second float are provided with a locking device on their adjacent end faces, and the second float is provided with a spring buckle that engages with the locking device.

11. The wafer processing apparatus according to claim 1, characterized in that, The support member is provided in at least two parts, and each support member is provided with a support surface for abutting against the first float or the second float, the support surface being used to support the first float or the second float.

12. The wafer processing apparatus according to claim 1, characterized in that, The workbench is provided with a fixed shaft, and a bushing is provided on one side wall of the first or second float plate to engage with the fixed shaft. The bushing is configured to move axially along the fixed shaft and rotate with the fixed shaft.

13. A wafer processing apparatus, characterized in that, include: A worktable is used to hold wafers; The spindle is used to drive a grinding wheel with a diameter smaller than the wafer to thin a local surface of the wafer; A baffle assembly is disposed on the worktable. The baffle assembly has an annular air seal structure inside, which surrounds the outer periphery of the spindle. The annular air seal structure is used to introduce compressed air and spray it downward to form an annular air wall located on the outer periphery of the wafer above the worktable.

14. The wafer processing apparatus according to claim 13, characterized in that, The baffle assembly includes a first baffle and a second baffle. The first baffle consists of a first float plate and a raised semi-circular first annular baffle wall. The second baffle consists of a second float plate and a raised semi-circular second annular baffle wall. The first baffle and the second baffle are disposed on the worktable and movably enclose the working area of ​​the spindle by air flotation.

15. A wafer thinning equipment, characterized in that, Includes the wafer processing apparatus according to any one of claims 1-12 and 13-14.

16. A wafer processing method, comprising processing a wafer using the wafer thinning equipment of claim 15, characterized in that, Includes the following steps: Place the wafer on the worktable and close the first or second stop to enclose the spindle working area; Compressed air is introduced into the annular air-sealed channel, causing the first float plate and the second float plate to float on the worktable. The spindle is controlled to drive the grinding wheel to rotate and grind the wafer until grinding is completed. During this process, the first floating plate and the second floating plate form an annular air wall between themselves and the worktable to avoid the formation of impurities due to friction and to prevent the spillage of debris generated during wafer thinning. Stop supplying compressed air into the annular gas seal channel, open the first or second stop and support it on the support, then remove the wafer.

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