An underbody cleaning device

Abstract

The application discloses a bottom surface cleaning device, which is installed on a base of a wafer thinning device, the wafer thinning device comprises a worktable and a grinding mechanical hand used in a wafer grinding process, and the bottom surface cleaning device is used for cleaning the bottom surface of the wafer after grinding and / or the bottom surface of the grinding mechanical hand, is located beside the worktable and is on a moving track of the grinding mechanical hand; the bottom surface cleaning device comprises a spraying piece for spraying liquid or gas upward, and is used for non-contact cleaning and / or drying the bottom surface of the wafer and / or the grinding mechanical hand.

Description

Technical Field

[0001] This invention relates to the field of semiconductor wafer processing technology, and in particular to a bottom surface cleaning device. Background Technology

[0002] Currently, the semiconductor industry manufactures semiconductor chips by forming electronic circuits such as ICs (Integrated Circuits) or LSIs (Large Scale Integrations) on the surface of semiconductor wafers. Before the wafer is diced into semiconductor chips, the back side of the wafer is ground using a grinding and thinning process. This back side refers to the side opposite to the device side where the electronic circuits are formed, also known as the substrate. Wafer back side thinning refers to the high-precision grinding of various materials such as silicon wafers or compound semiconductors before packaging, reducing their thickness to a suitable ultra-thin shape.

[0003] Grinding thins the wafer to a thickness of around 700 μm or even more. Due to this significant thickness removal, a large amount of large-sized contaminants, such as large particles, are generated during the grinding process. Furthermore, once the total wafer thickness is reduced to a certain level, such as below 7 μm, a small amount of chipping occurs at the wafer edges, resulting in debris. With long-term operation of the equipment, the large-sized contaminants carried on the bottom surface of the wafer after the grinding process accumulate on the surface of the transfer unit. Simultaneously, as the material loading point for the grinding process, these contaminants are transferred back to the grinding station, thus affecting the uniformity and consistency of the ground surface. Summary of the Invention

[0004] This invention provides a bottom cleaning device, which aims to at least solve one of the technical problems existing in the prior art.

[0005] This invention provides a bottom cleaning device, installed on the base of a wafer thinning equipment. The wafer thinning equipment includes a worktable and a grinding robot used in the wafer grinding process. The bottom cleaning device is used to clean the bottom surface of the wafer and / or the bottom surface of the grinding robot after grinding. It is located next to the worktable and on the moving trajectory of the grinding robot. The bottom cleaning device includes a spray element that sprays liquid or gas upwards for non-contact cleaning and / or drying of the bottom surface of the wafer and / or the grinding robot.

[0006] In one embodiment, the bottom cleaning device further includes a swing arm, a support, and a drive mechanism. The swing arm is located above the support, and a spray element is fixed to the free end of the swing arm. The positioning end of the swing arm is rotatably connected to the drive mechanism, thereby enabling the drive mechanism to control the swing arm to drive the spray element to swing horizontally.

[0007] In one embodiment, the bottom cleaning device further includes an outer cover with a top opening, within which the spray element moves.

[0008] In one embodiment, the bottom cleaning device further includes a photoelectric sensor for limiting the swing angle of the swing arm, the photoelectric sensor being installed at the top of the support near the positioning end of the swing arm.

[0009] In one embodiment, the bottom cleaning device further includes a brushing assembly for cleaning the bottom surface of the wafer and / or grinding robot.

[0010] In one embodiment, the scrubbing assembly includes a first scrubbing assembly, a second scrubbing assembly, and a polishing assembly.

[0011] In one embodiment, the first scrubbing assembly includes a first scrubbing member and a first support member.

[0012] In one embodiment, the second scrubbing assembly includes a second scrubbing element and a second driving element.

[0013] In one embodiment, the polishing assembly includes a polishing component and a third drive component.

[0014] In one embodiment, the grinding robot is a suction cup robot.

[0015] The beneficial effects of the embodiments of the present invention include: enabling the cleaning of the bottom surface of the wafer after grinding, and cleaning the bottom surface of the wafer when the grinding robot is not carrying the wafer, with good cleaning effect. Attached Figure Description

[0016] The advantages of the present invention will become clearer and easier to understand through the following detailed description in conjunction with the accompanying drawings, but these drawings are merely illustrative and do not limit the scope of protection of the present invention, wherein:

[0017] Figure 1 The wafer thinning apparatus provided in Embodiment 1 of the present invention is shown;

[0018] Figures 2 to 5 The bottom cleaning device provided in Embodiment 1 is shown;

[0019] Figure 6 The wafer thinning apparatus provided in Embodiment 2 of the present invention is shown;

[0020] Figures 7 to 10 The bottom cleaning device provided in Embodiment 2 is shown. Detailed Implementation

[0021] The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be construed as limiting the implementation methods and scope of protection of the present invention. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein. It should be understood that, unless specifically stated otherwise, for ease of understanding, the following description of specific embodiments of the present invention is based on the premise that the relevant equipment, devices, components, etc., are in their original static state and are not given external control signals or driving forces.

[0022] Furthermore, it should be noted that the terms used in this application to indicate orientation, such as front, back, up, down, left, right, top, bottom, front, back, horizontal, and vertical, are merely for ease of explanation and to aid in the understanding of relative position or direction, and are not intended to limit the orientation of any device or structure.

[0023] To illustrate the technical solution described in this invention, the following description will be provided with reference to the accompanying drawings and embodiments.

[0024] In this application, a wafer is also referred to as a wafer, silicon wafer, substrate, or substrate, etc., which have the same meaning and practical function.

[0025] The wafer thinning equipment provided in this embodiment is mainly used for back-side thinning of wafers. The back-side refers to the side of the wafer where no devices are laid, which is generally a substrate. The substrate material can be silicon, silicon oxide, silicon nitride, silicon carbide, sapphire, etc.

[0026] Figure 1 An embodiment of the present invention provides a wafer thinning apparatus, comprising:

[0027] Equipment front-end module 1 is used to realize the entry and exit of wafers. Equipment front-end module 1 is set at the front end of the wafer thinning equipment. Equipment front-end module 1 is a transition module that realizes the transfer of wafers from the outside to the inside of the equipment, so as to realize the "dry entry and dry exit" of wafers.

[0028] Grinding module 3 is used to grind the wafer, the grinding including rough grinding and fine grinding, and grinding module 3 is located at the end of the wafer thinning equipment;

[0029] The polishing module 2 is used to perform chemical mechanical polishing on the wafer after the grinding is completed. It also has the function of transferring the wafer between the three modules (equipment front-end module 1, grinding module 3 and polishing module 2). The polishing module 2 is located between the equipment front-end module 1 and the grinding module 3.

[0030] Understandable Figure 1 The wafer thinning device shown is only one example. In other implementations, the polishing module 2 can be omitted, leaving only the front-end module 1 and the grinding module 3. In addition, the grinding module 3 can also include multiple grinding passes, such as 3 passes, 4 passes, 5 passes, etc. Similar modified embodiments that can achieve the wafer grinding and thinning function should fall within the protection scope of this application.

[0031] Device front-end module 1:

[0032] The front-end module 1 of the equipment includes a wafer storage unit and a first transmission unit. The wafer storage unit is located on one side of the front end of the wafer thinning equipment, and the first transmission unit is located between the wafer storage unit and the polishing module 2 to realize the transmission of the wafer between the wafer storage unit and the polishing module 2.

[0033] A wafer storage unit consists of multiple front-opening unified pods (FOUPs), specifically two, three, or more.

[0034] The first transfer unit includes a wafer pick-and-place robot. The wafer pick-and-place robot can rotate, extend, or fold and retract, and can also move along a transfer track. The wafer pick-and-place robot can retrieve wafers to be processed from the wafer storage unit through the door structure of the wafer transfer box and send them to the polishing module 2, and can also receive processed wafers from the polishing module 2 and place them into the wafer transfer box.

[0035] Polishing Module 2:

[0036] The polishing module 2 includes a second transmission unit 21, a third transmission unit 22, a chemical mechanical polishing unit 23, and a post-processing unit 24. The second transmission unit 21, the chemical mechanical polishing unit 23, and the post-processing unit 24 occupy the edges of the polishing module 2, respectively, while the third transmission unit 22 is located in the center.

[0037] Specifically, the second transfer unit 21 is located on one edge of the polishing module 2 and distributed along the length of the device, connecting the front-end module 1 and the grinding module 3. The chemical mechanical polishing unit 23 is located on the other edge of the polishing module 2 and is adjacent to the grinding module 3 and the second transfer unit 21, respectively. The post-processing unit 24 is located on another edge of the polishing module 2 and is adjacent to the front-end module 1, the second transfer unit 21, and the chemical mechanical polishing unit 23, respectively. The third transfer unit 22 is located near the center of the polishing module 2 and is surrounded by the second transfer unit 21, the chemical mechanical polishing unit 23, and the post-processing unit 24, used to realize the mutual transfer of wafers between the second transfer unit 21, the chemical mechanical polishing unit 23, and the post-processing unit 24.

[0038] In one embodiment, the second transmission unit 21 includes a temporary storage section and a moving buffer section for temporarily storing and transporting wafers. The temporary storage section is located near the front-end module 1 of the device and is used for temporarily storing or transferring wafers. The moving buffer section is arranged along the direction from the front-end module 1 of the device to the grinding module 3 and is bidirectionally movable.

[0039] In one embodiment, the third transfer unit 22 includes a central robot arm for transferring the ground wafer from the moving buffer section to the chemical mechanical polishing unit 23, transferring the polished wafer from the chemical mechanical polishing unit 23 to the post-processing unit 24, and transferring the cleaned wafer from the post-processing unit 24 to the temporary storage section.

[0040] After the wafer is taken out from the front-end module 1 of the equipment, it is transported to the grinding module 3 via the second transmission unit 21 for grinding. After the wafer is ground in the grinding module 3, it is transported to the chemical mechanical polishing unit 23 via the second transmission unit 21 and the third transmission unit 22 for polishing. After polishing and cleaning, the wafer is then transferred back to the front-end module 1 of the equipment via the third transmission unit 22 and the second transmission unit 21.

[0041] The post-processing unit 24 is used to clean and dry the polished wafer, and may include a horizontal brushing device and a single-chamber cleaning device.

[0042] Grinding Module 3:

[0043] The grinding module 3 includes a grinding unit 31, a cleaning unit 32, and a fourth transmission unit 33.

[0044] The grinding unit 31 is used to perform wafer grinding and thickness measurement. For example... Figure 1 As shown, the grinding unit 31 includes a base 311, a worktable 312 mounted on the base, a chuck 313 disposed on the worktable, and a grinding wheel corresponding to the position of the chuck. The worktable is used to support the wafer and can rotate about its vertical central axis. Figure 1As shown, in one embodiment, three suction cups are provided, which can rotate between the rough grinding station, the fine grinding station, and the loading / unloading station 314. Two grinding wheels perform rough grinding and fine grinding respectively. It is understood that... Figure 1 This is just one example; the number of suction cups and grinding wheels can also be other values, such as 1, 2, 4, 5, 6, etc. for the number of suction cups, and 1, 3, 4, etc. for the number of grinding wheels.

[0045] The cleaning unit 32 is used to perform suction cup cleaning, polishing and wafer cleaning.

[0046] The fourth transfer unit 33 includes a grinding robot 331 for transferring wafers. The grinding robot 331 refers to the robot used in the grinding module 3, used to transfer wafers between the grinding unit 31 and the second transfer unit 21. Specifically, it is used to transfer wafers between the suction cup and the moving buffer unit corresponding to the loading / unloading station. The grinding robot 331 picks up the wafer from the moving buffer unit of the second transfer unit 21 and feeds it into the grinding unit 31 for grinding. After grinding and cleaning, the grinding robot 331 picks up the wafer from the grinding unit 31 and places it in the moving buffer unit for subsequent wafer transfer. The grinding robot 331 has a vacuum-drawing pipeline inside to achieve vacuum adsorption of the wafer. Alternatively, the grinding robot 331 can also be implemented by a mechanism with grippers. In this embodiment, the grinding robot 331 can also rotate the wafer.

[0047] In addition, in this invention, the grinding module 3 also includes a bottom surface cleaning device, which can be implemented in various ways, as detailed below:

[0048] Example 1

[0049] Figures 1 to 5 A bottom cleaning device 50 provided in Embodiment 1 is shown.

[0050] like Figure 1 As shown, the bottom cleaning device 50 is installed on the base 311 of the grinding module 3, next to the worktable 312, and on the movement trajectory of the grinding robot 331. The bottom cleaning device 50 can be used to clean the bottom surface of the wafer after grinding during the transfer of the wafer by the grinding robot 331, and the bottom cleaning device 50 can also be used to clean the bottom surface of the grinding robot 331.

[0051] like Figures 3 to 5 As shown, in Embodiment 1, the bottom cleaning device 50 includes a spray element 51 that sprays liquid or gas upwards for non-contact cleaning and / or drying of the bottom surface of the wafer and / or grinding robot 331. Figure 3 and Figure 4As shown, in one embodiment, the bottom cleaning device 50 further includes a swing arm 52, a support 53 and a drive mechanism 54. The swing arm 52 is located above the support 53. The free end of the swing arm 52 is fixed with a spray element 51. The positioning end of the swing arm 52 is rotatably connected to the drive mechanism 54, thereby enabling the drive mechanism 54 to control the swing arm 52 to drive the spray element 51 to swing horizontally.

[0052] The support 53 is mounted on the base 311 of the grinding module 3 at its bottom end, and a swing arm 52 is provided at the top end of the support 53. The support 53 has a hollow structure, and a drive mechanism 54 is installed inside the support 53. The drive mechanism 54 controls the swing arm 52's swing start / stop, amplitude, speed, angle, and other movement modes. The drive mechanism 54 may include a reducer and a servo motor, with the servo motor connected to the swing arm 52 through the reducer. A spray element 51 is fixed to the free end of the swing arm 52. The spray element 51 can swing back and forth with the swing arm 52. During the reciprocating movement, the spray element 51 sprays fluid upwards. At the same time, the grinding robot 331 rotates with the wafer or rotates independently. With the swing and rotation movements combined, the cleaning range of the spray element 51 can cover the entire bottom surface of the wafer or the grinding robot 331.

[0053] In one embodiment, the spray element 51 is hinged to the swing arm 52, and the spray angle of the spray element 51 is adjustable. Furthermore, the spray element 51 has an ultrasonic vibration section capable of spraying fluid with ultrasonic or megaphonic properties to improve rinsing force and cleaning effect; the spray element 51 can be an ultrasonic spray element or a megaphonic spray element. The spray element 51 can be one or more nozzles or spray bars.

[0054] The spray nozzle 51 can swing along with the swing arm 52 while spraying fluid upwards onto the bottom surface of the wafer or the bottom surface of the grinding robot 331. The swing trajectory of the spray nozzle 51 should at least cover the radius area of ​​the wafer, and may also cover the diameter area. The swing trajectory of the spray nozzle 51 can move between the edge of the wafer and the center of the wafer, or it can pass through the center of the wafer while moving from one edge of the wafer to another. The grinding robot 331 moves with the wafer above the spray nozzle 51 for cleaning, and the spray nozzle 51 can rinse and dry the bottom surface of the wafer. In addition, when the grinding robot 331 is not carrying a wafer, the grinding robot 331 can move alone above the spray nozzle 51 for cleaning, in which case the spray nozzle 51 can rinse and dry the bottom surface of the grinding robot 331.

[0055] like Figures 2 to 4 As shown, in one embodiment, the bottom cleaning device 50 further includes an outer cover 55 with a top opening, within which the spray element 51 moves. The outer cover 55 is used to prevent liquid from splashing outwards during the cleaning process and contaminating other devices, and to reduce liquid splashing.

[0056] The outer cover 55 is a cylindrical shape with an open top. The upper part of the outer cover 55 has a notch on the side near the swing arm 52. The notch provides the swing space for the swing arm 52. The swing arm 52 extends into the outer cover 55 through the notch, and the swing arm 52 will not interfere with the end face of the notch during the swing process. That is, the swing arm 52 will not collide with the outer cover 55 during the movement.

[0057] like Figure 2 As shown, the outer cover 55 completely covers the bottom surface of the wafer and the grinding robot 331. The top of the outer cover 55 is arc-shaped, and the radius of the arc matches the radius of the bottom surface of the grinding robot 331. Specifically, the radius of the arc is equal to or slightly larger than the radius of the bottom surface of the grinding robot 331, and the radius of the arc can be 1 to 1.2 times the radius of the bottom surface of the grinding robot 331. The height of the top of the outer cover 55 is lower than the height of the bottom surface of the grinding robot 331, specifically 1 to 5 mm lower. The grinding robot 331 stops when it moves directly above the outer cover 55, at which point the cleaning process is performed. The spray component 51 oscillates inside the outer cover 55 to clean or dry the bottom surface of the wafer or the grinding robot 331. The outer cover 55 can collect the liquid that splashes during the cleaning process, preventing the liquid from spreading and contaminating other devices. After cleaning is completed, the grinding robot 331 is removed. The grinding robot 331 does not need to move up and down when cleaning or passing through the outer cover 55, which simplifies the operation steps and the mechanical structure.

[0058] In addition, the bottom of the outer cover 55 is provided with a drain outlet, which is connected to a drainage device to collect and remove pollutants such as gas, liquid and fixed particles collected by the outer cover 55.

[0059] like Figure 5 As shown, in one embodiment, the bottom cleaning device 50 further includes a photoelectric sensor 56 for limiting the swing angle of the swing arm 52. The photoelectric sensor 56 is mounted on the top of the support 53 near the positioning end of the swing arm 52. Further, the photoelectric sensor 56 can be as follows: Figure 5 Two sensors are provided, respectively located on both sides of the positioning end of the swing arm 52. When the swing arm 52 swings to one side and triggers the photoelectric sensor 56 on one side, it reverses or stops. When the swing arm 52 swings to the other side and triggers the photoelectric sensor 56 on the other side, it reverses or stops. This enables the swing arm 52 to swing back and forth within the range defined by the two photoelectric sensors 56, thereby enabling the spray component 51 to only rinse the bottom surface of the wafer or the bottom surface of the grinding robot 331, without exceeding the preset range and causing an accident.

[0060] The working process of Example 1 includes:

[0061] Wafer bottom cleaning process: The grinding robot 331 moves the wafer to the top of the outer cover 55. The grinding robot 331 drives the wafer to rotate, and at the same time the sprayer 51 starts to spray liquid. The swing arm 52 drives the sprayer 51 to swing, together completing the cleaning of the entire wafer bottom surface.

[0062] The grinding robot cleaning process: After the grinding robot 331 places the wafer in the moving buffer section of the second transmission unit 21, it can perform bottom cleaning when returning without load. The cleaning method of the bottom surface of the grinding robot 331 is completely the same as that of the wafer. The bottom surface of the grinding robot 331 rotates while the spray component 51 swings to clean.

[0063] During the two cleaning processes described above, the grinding robot 331 stops swinging and receives spraying above the outer cover 55.

[0064] Example 1 utilizes the spray component 51 to achieve non-contact cleaning of the bottom surface of the wafer and / or the bottom surface of the grinding robot 331 during the movement process. This avoids damage to the wafer and prevents secondary contamination of the wafer or grinding robot 331 by contaminants generated by contact cleaning. In addition, this example does not use consumables and does not require replacement of consumables, which can significantly reduce cleaning costs.

[0065] Example 2

[0066] Figures 6 to 10 Another bottom cleaning device 60 provided in Embodiment 2 is shown.

[0067] like Figure 6 As shown, the bottom cleaning device 60 is also installed on the base 311 of the grinding module 3, next to the worktable 312 and on the movement trajectory of the grinding robot 331. It can be used to clean the bottom surface of the wafer after grinding during the process of the grinding robot 331 carrying the wafer for transfer, and can also be used to clean the bottom surface of the grinding robot 331.

[0068] like Figure 7 As shown in Embodiment 2, the bottom cleaning device 60 includes a spray element 61 and a brushing assembly 62. The spray element 61 sprays fluid upwards, and the brushing assembly 62 uses brushing force, friction, or polishing force to clean the bottom surface of the wafer and / or the grinding robot 331. The spray element 61 and the brushing assembly 62 can operate independently to cooperate in cleaning the bottom surface of the wafer or the bottom surface of the grinding robot 331. The spray element 61 can be a fan-shaped nozzle to achieve large-area spraying. The height of the spray element 61 is lower than that of the brushing assembly 62. The spray element 61 is used for non-contact cleaning and auxiliary cleaning, while the brushing assembly 62 adopts a contact treatment method. The spray element 61 can be one or more nozzles or spray bars.

[0069] The brushing assembly 62 includes a first brushing assembly 63, a second brushing assembly 64, and a polishing assembly 65. The different assemblies can be raised and lowered independently to clean the wafer or grinding robot 331 separately.

[0070] The first brushing assembly 63 includes a first brushing element 631 and a first support element 632. The first brushing element 631 can be made of elastic materials such as sponge or PVC and is used to clean the bottom surface of the wafer. The bottom of the first brushing element 631 is connected to a liquid supply assembly for supplying liquid to it to keep it moist. The first support element 632 is connected below the first brushing element 631 to support the first brushing element 631 in contact with the wafer for brushing. Further, as an optional embodiment, the first support element 632 can drive the first brushing element 631 to move up and down. The first brushing element 631 can rise to contact the wafer and perform brushing, and then fall down to end the brushing process.

[0071] The second brushing assembly 64 includes a second brushing component 641 and a second driving component 642. The second brushing component 641 can be a brush structure with protrusions on its surface, such as a bristle brush or a roller brush, used to clean the bottom surface of the grinding robot 331. The second driving component 642 is connected below the second brushing component 641 to drive the second brushing component 641 to move up and down. After the second brushing component 641 is raised, it can contact the bottom surface of the grinding robot 331 to perform brushing, and the brushing ends when it is lowered.

[0072] The polishing assembly 65 includes a polishing component 651 and a third drive component 652. The polishing component 651 can be made of hard materials such as an oilstone and is used to polish the bottom surface of the grinding robot 331. The third drive component 652 is connected below the polishing component 651 to drive the polishing component 651 to move up and down. After the polishing component 651 is raised, it can contact the bottom surface of the grinding robot 331 to perform polishing, and after it is lowered, the polishing ends.

[0073] Figures 8 to 10 The operation of the bottom cleaning device 60 in Embodiment 2 is shown, including:

[0074] Wafer bottom cleaning: See Figure 8 When the grinding robot 331 moves the wafer to the bottom cleaning device 60, the first brush 631 comes into contact with the wafer. After the first brush 631 is filled with water, it can clean the bottom surface of the wafer. At the same time, the grinding robot 331 rotates with the wafer, and the spraying device 61 can spray liquid onto the bottom surface of the wafer at the same time. The combined action completes the cleaning of the bottom surface of the wafer.

[0075] Wafer bottom surface drying: After cleaning, the grinding robot 331 continues to rotate with the wafer, while the spray unit 61 sprays air onto the bottom surface of the wafer for drying.

[0076] Bottom surface treatment of grinding robot 331: After placing the wafer in the moving buffer section of the second transfer unit 21, the grinding robot 331 can perform bottom surface treatment when it returns to the bottom surface cleaning device 60 without load. See [link to relevant documentation]. Figure 9 The grinding and polishing part 651 rises to grind the bottom surface of the grinding robot 331. See [link / reference]. Figure 10 The second brushing component 641 rises to clean the bottom surface of the grinding robot 331. The polishing component 651 and the second brushing component 641 rise in sequence, cooperating with the rotation of the bottom surface of the grinding robot 331 to complete the grinding and cleaning of the bottom surface of the grinding robot 331 in sequence. The spraying component 61 can also spray liquid at the same time.

[0077] In summary, the embodiments of the present invention achieve cleaning of the bottom surface of the wafer after grinding, and cleaning of the bottom surface of the grinding robot 331 when it is not carrying a wafer, with good cleaning effect.

[0078] The accompanying drawings in this specification are schematic diagrams used to illustrate the concept of the invention and to schematically show the shapes of the various parts and their interrelationships. It should be understood that, in order to clearly show the structure of the various components of the embodiments of the invention, the drawings are not drawn to the same scale, and the same reference numerals are used to indicate the same parts in the drawings.

[0079] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0080] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A bottom surface cleaning device, characterized in that, Mounted on a base of a wafer thinning equipment, the wafer thinning equipment includes a worktable and a grinding robot used in the wafer grinding process. A bottom cleaning device, located next to the worktable and along the movement trajectory of the grinding robot, is used to clean the bottom surface of the wafer and / or the bottom surface of the grinding robot after grinding. The bottom cleaning device includes a spray element that sprays liquid or gas upwards for non-contact cleaning and / or drying of the bottom surface of the wafer and / or the grinding robot. It also includes a swing arm, a support, and a drive mechanism. The swing arm is located above the support, with the spray element fixed to its free end. The positioning end of the swing arm is rotatably connected to the drive mechanism, allowing the drive mechanism to control the swing arm to drive the spray element to swing horizontally. The swing trajectory of the spray element at least covers the wafer radius area, and the swing trajectory extends from the wafer edge to the wafer center. The device also includes a top-opening outer cover, within which the spray nozzle moves. The outer cover is cylindrical with a top opening and a notch on the upper part near the swing arm, providing space for the swing arm to swing. The top of the outer cover is arc-shaped, with a radius 1 to 1.2 times the radius of the bottom surface of the grinding robot. The top of the outer cover is 1 to 5 mm lower than the bottom surface of the grinding robot, so that the grinding robot does not need to move up and down when cleaning or passing through the outer cover. It also includes photoelectric sensors for limiting the swing angle of the swing arm. Two photoelectric sensors are provided, respectively located on both sides of the positioning end of the swing arm. When the swing arm swings to one side and triggers the photoelectric sensor on one side, it reverses or stops; when it swings to the other side and triggers the photoelectric sensor on the other side, it reverses or stops, thus enabling the swing arm to swing back and forth within the range defined by the two photoelectric sensors.

2. The bottom surface cleaning device as described in claim 1, characterized in that, The spray element is hinged to the swing arm, and the spray angle of the spray element is adjustable.

3. The bottom surface cleaning device as described in claim 1, characterized in that, The spray element has an ultrasonic vibration component, which is capable of spraying fluid with ultrasonic waves.

4. The bottom surface cleaning device as described in claim 1, characterized in that, The support is a hollow structure, and the drive mechanism is installed inside the support. The drive mechanism includes a reducer and a servo motor.

5. The bottom surface cleaning device as described in claim 1, characterized in that, The bottom of the outer cover is provided with a drain outlet, which is connected to a drainage device.

6. The bottom surface cleaning device as described in claim 1, characterized in that, The grinding robot is a suction cup type robot.

7. A wafer thinning apparatus, characterized in that, include: The worktable is used to hold the wafers for grinding; the grinding robot is used to transfer the wafers. And the bottom cleaning device as described in claim 1, wherein the bottom cleaning device is installed on the movement trajectory of the grinding robot; when the grinding robot moves with the ground wafer directly above the outer cover, the spray component cleans the bottom surface of the wafer; when the grinding robot returns unloaded, the spray component cleans the bottom surface of the grinding robot.

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