Wafer loading and unloading device, wafer polishing machine table

Abstract

The application discloses a wafer loading and unloading device and a wafer grinding machine table, and belongs to the technical field of wafer grinding machine tables.The wafer loading and unloading device comprises a support base, a base and a detection mechanism; the base is arranged on the support base, and the detection mechanism is arranged on the base; the detection mechanism comprises a support, a pressing rod and a sensor; the pressing rod is installed on the support, and the sensor is arranged on the pressing rod; the pressing rod comprises a front section and a tail section; the front section of the pressing rod is directed towards the center position of the base; the base is provided with an inductor corresponding to the sensor and a groove corresponding to the tail section of the pressing rod; after the base is placed with a wafer, the tail section of the pressing rod is embedded into the corresponding groove under the pressure of the wafer, and the bottom surface of the tail section of the pressing rod is in abutment with the inner surface of the bottom of the groove, and the sensor is in abutment with the inductor; after the wafer leaves the base, the front section of the pressing rod is naturally inclined forward to drive the tail section of the pressing rod to be raised, so that the sensor is disconnected from the inductor.The wafer loading and unloading device can improve the accuracy of wafer position detection during the loading and unloading process of wafer grinding processing, and can avoid false alarms to cause the wafer to be damaged during operation.

Description

Technical Field

[0001] This invention relates to the field of wafer processing technology, specifically to a wafer loading and unloading device and a wafer grinding machine. Background Technology

[0002] CMP (Chemical Mechanical Polishing) is an indispensable part of integrated circuit manufacturing. The CMP process combines surface chemical action and mechanical polishing technology to remove micron / nano-scale materials from the wafer surface, thereby achieving a highly flattened wafer surface with low surface roughness and low defects.

[0003] CMP implementation relies on large operating equipment, namely chemical mechanical polishing (CMP) machines, such as the LK machine from AMAT (Applied Materials Inc.). After entering the machine, the wafer is first attached to the polishing head, and then sequentially polished onto various polishing pads. The polishing head presses the wafer's surface to be polished against the rough polishing pads, achieving global planarization through the coupling of polishing fluid corrosion, particle friction, and polishing pad friction. Finally, the polished wafer is unloaded from the polishing head, cleaned, dried, and returned to the wafer carrier.

[0004] In some existing CMP (Chemical Mechanical Polishing) systems, the loading and unloading of wafers from the polishing head is handled by the HCLU (head clean load / unload unit). If the HCLU alarms or malfunctions, the wafers in operation will remain on the polishing head and cannot be directly ejected, easily leading to wafer damage and scrap. Furthermore, false alarms from the HCLU frequently occur in existing products, which not only wastes human resources but may also damage the wafers in operation. Summary of the Invention

[0005] This invention provides a wafer loading and unloading device and a wafer grinding machine to improve the accuracy of wafer position detection during wafer grinding and unloading, and to avoid false alarms that could damage the wafers during operation.

[0006] On one hand, embodiments of the present invention provide a wafer loading and unloading device, the device comprising: a support base, a base, and a detection mechanism; the base is disposed on the support base, and the detection mechanism is disposed on the base;

[0007] The detection mechanism includes: a bracket, a pressure rod, and a sensor; the pressure rod is mounted on the bracket, and the sensor is disposed on the pressure rod;

[0008] The pressure bar includes a front section and a tail section; the front section of the pressure bar faces the center of the base.

[0009] The base is provided with a sensor corresponding to the sensor and a groove corresponding to the tail section of the pressure rod;

[0010] After the wafer is placed on the base, the tail section of the pressure rod is embedded into the corresponding groove by the pressure of the wafer, and the bottom surface of the tail section of the pressure rod abuts against the bottom inner surface of the groove. The sensor is connected to the inductor. After the wafer leaves the base, the front section of the pressure rod naturally tilts forward, causing the tail section of the pressure rod to tilt up, thereby disconnecting the sensor from the inductor.

[0011] Optionally, the contact surface between the tail section of the pressure rod and the groove forms a vacuum-proof structure.

[0012] Optionally, the bottom surface and / or groove surface of the pressure rod tail section include a rough surface to form a pressure relief path, or the mutual contact area of ​​the pressure rod tail section and the groove is less than a first preset value.

[0013] Optionally, the bottom surface and / or groove surface of the tail section of the pressure rod are curved surfaces.

[0014] Optionally, the longitudinal section of the tail section of the pressure bar is circular or elliptical.

[0015] Optionally, from the top of the pressure rod to the direction of contact between the pressure rod and the groove, the transverse cross-section of the tail section of the pressure rod becomes smaller to reduce the contact area between the tail section of the pressure rod and the groove, and the contact surface between the tail section of the pressure rod and the groove is a plane and / or a curved surface.

[0016] Optionally, the surface of the tail section of the pressure bar may have the same or different shape as the bottom surface.

[0017] Optionally, a vacuum-proof structure is added between the pressure rod and the groove to prevent the pressure rod from forming a vacuum when it comes into contact with the groove.

[0018] Optionally, both the bracket and the pressure rod are provided with through holes. The pressure rod is fixed to the bracket by a screw passing through the through hole and can tilt forward or backward with the screw as the pivot.

[0019] Optionally, the bracket is fixedly mounted on the base.

[0020] Optionally, the bracket and the base are integrally formed.

[0021] Optionally, the front section of the pressure bar is provided with a counterweight so that the front section of the pressure bar can naturally tilt forward after the wafer leaves the base.

[0022] Optionally, the support base is also provided with a nozzle for spraying cleaning fluid onto the base.

[0023] Optionally, the support and the base are coaxial, with the base sleeved inside the support.

[0024] Optionally, there are multiple detection mechanisms, which are symmetrically distributed along the circumference of the base.

[0025] Optionally, the device further includes a drive mechanism for driving the base to move up and down axially.

[0026] On the other hand, embodiments of the present invention also provide a wafer polishing machine, including: a polishing assembly and the wafer loading and unloading device; the polishing assembly includes: a polishing head, a polishing disc, and a polishing pad; the polishing pad is fixed on the polishing disc;

[0027] The wafer loading and unloading device is used to place the wafer to be ground, load the wafer onto the grinding head for grinding and polishing, and place the wafer unloaded from the grinding head after grinding and polishing is completed.

[0028] Compared with the prior art, the technical solution of the embodiments of the present invention has the following beneficial effects:

[0029] The wafer loading and unloading device provided in this embodiment of the invention includes a support base, a base mounted on the support base, and a detection mechanism mounted on the base. The detection mechanism includes a bracket, a pressure rod, and a sensor mounted on the pressure rod. A sensor corresponding to the sensor and a groove corresponding to the tail section of the pressure rod are mounted on the base. After a wafer is placed on the base, the tail section of the pressure rod is embedded into the corresponding groove due to the pressure of the wafer, and the bottom surface of the tail section of the pressure rod partially abuts against the inner bottom surface of the groove, connecting the sensor and the sensor. Because the bottom surface of the tail section of the pressure rod only partially abuts against the inner bottom surface of the groove, the force exerted by the external air pressure on the bottom of the groove when the wafer leaves the base is very small. This ensures that when the front section of the pressure rod naturally tilts forward, it can cause the tail section of the pressure rod to tilt upwards, disconnecting the sensor from the sensor. This avoids detection errors caused by the tail section of the pressure rod failing to tilt due to external air pressure, effectively preventing false alarms and ensuring the safety of the wafer during operation.

[0030] Furthermore, considering that the wafer loading and unloading device also functions as a cleaning and polishing head, cleaning fluid will remain in the groove. In order to prevent the pressure rod tail section from squeezing out the cleaning fluid in the two contact surfaces and creating a vacuum, the contact surface between the pressure rod tail section and the groove is designed as a vacuum-proof structure, which effectively reduces the effect of external air pressure on the pressure rod tail section.

[0031] Furthermore, by designing various structures for the bottom surface and / or groove surface of the pressure bar tail section, products can be diversified, increasing market share and competitiveness.

[0032] The wafer grinding machine provided in this embodiment of the invention uses the above-mentioned wafer loading and unloading device to place the wafer to be ground and the wafer unloaded from the grinding head after grinding and polishing, so as to realize the detection of the wafer state, ensure the accuracy of the detection results, and thus ensure the safety of the wafer during operation. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of a wafer loading and unloading device provided in an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of a detection mechanism in one embodiment of the present invention;

[0036] Figure 3 This is another structural schematic diagram of the detection mechanism in an embodiment of the present invention;

[0037] Figure 4 These are the structures of several pressure bar tail sections in the embodiments of the present invention;

[0038] Figure 5 This is a schematic diagram of a wafer grinding machine provided in an embodiment of the present invention.

[0039] Icon labels:

[0040] 11 Support base, 12 Base, 13 Testing mechanism;

[0041] 120 Shaft hole, 121 Groove, 123 Sensor;

[0042] 130 Screw, 131 Bracket, 132 Pressure Rod, 133 Sensor;

[0043] Longitudinal section of the tail section of the 100 compression bar;

[0044] 50 grinding components, 60 wafer loading and unloading devices;

[0045] 51 Grinding head, 52 Grinding disc, 53 Grinding pad, 54 Clamping ring, 55 Drive unit. Detailed Implementation

[0046] To make the above-mentioned objects, features, and beneficial effects of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0047] It should be noted that in the description of the embodiments of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not 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 the present invention.

[0048] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0049] It should also be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0050] A chemical mechanical polishing (CMP) machine typically includes a polishing head, a polishing disc, a polishing pad, and an HCLU (High-performance Cleaning Unit). The polishing pad is fixed on the polishing disc, and the wafer is fixed on the polishing head. During the polishing process, a certain pressure is applied to the polishing head, while the polishing slurry flows between the polishing pad and the wafer. The polishing slurry and the wafer surface rub against each other, thus achieving the polishing effect.

[0051] The HCLU (High-Capacity Container Regulator) handles the transfer between the wafer and the polishing head, and also provides deionized water for cleaning the polishing head. HCLUs typically have a detection mechanism to check if the wafer has left the HCLU. If the detection mechanism fails to detect the wafer while it is in the HCLU, or if it continues to detect the wafer after it has left the HCLU, a false alarm will be triggered. Statistical analysis of existing HCLU false alarms shows that almost all false alarms occur in the latter case. The reason is that after the wafer leaves the HCLU, due to external air pressure, the tail of the detection mechanism, which should have tilted upwards due to gravity, fails to do so, causing the mechanism to continuously trigger the corresponding detection signal and resulting in a false alarm. Although the probability of such a false alarm is inherently small, under the impact of high-volume production, even a low-probability event can eventually become inevitable.

[0052] Therefore, embodiments of the present invention provide a wafer loading and unloading device, which effectively avoids false alarms and ensures the safety of wafers during operation by improving the design of existing detection mechanisms.

[0053] like Figure 1 The diagram shown is a schematic representation of a wafer loading and unloading device provided in an embodiment of the present invention.

[0054] The wafer loading and unloading device includes a support base 11, a base 12, and a detection mechanism 13. The base 12 is mounted on the support base 11, and the detection mechanism 13 is mounted on the base 12.

[0055] In some embodiments, the support base 11 and the base 12 can be designed as a coaxial structure. For example, the support base 11 can be designed as a ring structure, and the base 12 can be designed as a disc structure, with the base 12 sleeved inside the support base 11. Additionally, for ease of installation and use, a shaft hole 120 can be provided at the center of the support base 11 and the base 12. The wafer loading and unloading device is fixed to the corresponding drive device through the shaft hole 120, and the wafer loading and unloading device is moved up and down by the drive device to adapt to the height of the grinding machine, facilitating the loading and unloading operation of the wafer to the grinding head.

[0056] It should be noted that the specific structure of the support 11 and the base 12 can be designed according to the actual application requirements, and the embodiments of the present invention do not limit it.

[0057] In some embodiments, the detection mechanism 13 may be provided with one or more, for example... Figure 1 In the embodiment shown, three detection mechanisms 13 are provided and are evenly distributed along the circumference of the base 12.

[0058] Simultaneously refer to Figure 2 , Figure 2 This is a schematic diagram of a detection mechanism in an embodiment of the present invention.

[0059] The testing mechanism 13 includes a bracket 131, a pressure rod 132, and a sensor 133. The pressure rod 132 is mounted on the bracket 131, and the sensor 133 is mounted on the pressure rod 132.

[0060] The pressure rod 132 includes a front section and a tail section; the front section of the pressure rod 132 faces the center of the base 12; the base 12 is provided with a sensor 123 corresponding to the sensor 133 and a groove 121 corresponding to the tail section of the pressure rod 132.

[0061] In some embodiments, the bracket 131 can be fixedly mounted on the base 12. In specific implementations, the bracket 131 and the base 12 can be separate structures or integrally formed structures.

[0062] A through hole is provided at the junction of the front and rear sections of the pressure rod 132. A through hole is also provided on the bracket 131. The pressure rod 132 is fixed to the bracket 131 by a screw 130 passing through the through hole. The pressure rod 132 can tilt forward or backward at a certain angle around the screw as a pivot, so that the sensor 133 can detect whether the wafer is placed on the base 12 and ensure the accuracy of the detection. Specifically, after the wafer is placed on the base 12, the rear section of the pressure rod 132 is embedded into the corresponding groove 121 by the pressure of the wafer, and the bottom surface of the rear section of the pressure rod 132 abuts against the bottom inner surface of the groove 121. The sensor 133 is connected to the sensor 123. The corresponding detection unit or device can determine that the wafer is currently located on the base 12 based on the output signal of the sensor 133. After the wafer leaves the base 12, for example, after the wafer is transferred to the grinding head by the drive mechanism, due to its own gravity, the front section of the pressure rod 132 naturally tilts forward, causing the tail section of the pressure rod 132 to tilt up, so that the sensor 133 is disconnected from the sensor 123; the corresponding detection unit or device can determine that the wafer is not on the base 12 based on the output signal of the sensor 133.

[0063] In some embodiments, the driving mechanism may also be part of the wafer loading and unloading device of the present invention, and the embodiments of the present invention do not limit this.

[0064] It should be noted that, in specific implementation, in order to enable the front section of the pressure bar 132 to naturally tilt forward under its own weight when it is not under wafer pressure, a specific shape structure or counterweight design can be used to make the weight of the front section of the pressure bar 132 greater than the weight of the tail section of the pressure bar 132.

[0065] In the wafer loading and unloading device provided in this embodiment of the invention, when the tail section of the pressure rod 132 in the detection mechanism 13 is embedded into the corresponding groove 121 under the pressure of the wafer, the bottom surface of the tail section of the pressure rod 132 abuts against the bottom inner surface of the groove 121. Compared with the prior art, this reduces the contact area between the two, thereby reducing the effect of external air pressure. Therefore, when the wafer leaves the base, it can effectively ensure that when the front section of the pressure rod 132 tilts forward naturally, it can drive the tail section of the pressure rod 132 to tilt up, thereby disconnecting the sensor from the detector and avoiding detection errors caused by the tail section of the pressure rod 132 failing to tilt up due to the influence of external air pressure.

[0066] In some embodiments, the wafer loading and unloading device can also function as a cleaning tool for the polishing head. For example, cleaning fluid (such as deionized water) can be sprayed onto the base 12 through nozzles (not shown) on the support 11 to clean the polishing head. In this case, cleaning fluid will remain in the groove 121. To prevent the contact between the tail section of the pressure rod 132 and the groove 121 from squeezing out the cleaning fluid and creating a vacuum, in some embodiments, the contact surface between the tail section of the pressure rod 132 and the groove 121 can be designed as a vacuum-proof structure to effectively reduce the effect of external air pressure on the tail section of the pressure rod 132.

[0067] For example, the bottom surface of the tail section of the pressure rod 132 and / or the surface of the groove 121 may include a rough surface (such as a curved surface or a raised structure) to form a pressure relief path, or the mutual contact area between the tail section of the pressure rod 132 and the groove 121 may be less than a first preset value, which may be determined experimentally based on the structure of the tail section of the pressure rod 132 and the groove 121.

[0068] The tail section and the front section of the pressure bar 132 may have the same or different shapes. The weight of the front section of the pressure bar 132 (if there is additional counterweight, it refers to the weight after adding the counterweight) must be greater than the weight of the tail section of the pressure bar 132.

[0069] In some embodiments, the longitudinal cross-section of the tail section of the pressure bar 132 may be, but is not limited to, circular, elliptical, or other shapes.

[0070] like Figure 3 As shown, in some embodiments, the direction from the top of the pressure rod 132 to the contact between the pressure rod 132 and the groove (i.e., Figure 3 In the Z direction (indicated by the arrow in the diagram), the transverse cross section of the tail section of the pressure rod 132 becomes smaller to reduce the contact area between the tail section of the pressure rod 132 and the groove, and the contact surface between the tail section of the pressure rod 132 and the groove is a plane and / or a curved surface.

[0071] like Figure 4 As shown, several structures of the tail section of the pressure bar 132 are illustrated. The transverse cross section decreases from top to bottom, and the longitudinal cross section 100 can be any shape, whether regular or irregular. This embodiment of the invention does not limit the shape of the longitudinal cross section 100.

[0072] In some embodiments, the surface and bottom surface of the tail section of the pressure rod 132 may have the same or different shapes. For example, the surface of the tail section of the pressure rod 132 may be a plane and the bottom surface may be a curved surface.

[0073] In some embodiments, a vacuum-proof structure may be added between the pressure rod 132 and the groove 121 to prevent the pressure rod 132 from forming a vacuum adsorption when it comes into contact with the groove 121. The vacuum-proof structure may be a protrusion and / or a pit provided on the bottom surface of the groove 121. The shape of the protrusion and pit may be circular or strip-shaped, and there may be one or more of them. This embodiment of the invention does not limit the specificity of the structure.

[0074] Accordingly, this embodiment of the invention also provides a wafer grinding machine, which uses the above-mentioned wafer loading and unloading device to place the wafer to be ground and the wafer unloaded from the grinding head after grinding and polishing, so as to realize the detection of the wafer state, ensure the accuracy of the detection results, and thus ensure the safety of the wafer during operation.

[0075] like Figure 5 The diagram shown is a structural schematic of a wafer grinding machine provided in an embodiment of the present invention.

[0076] The wafer polishing machine includes a polishing assembly 50 and the aforementioned wafer loading and unloading device 60. The polishing assembly 50 includes a polishing head 51, a polishing disc 52, and a polishing pad 53; the polishing pad 53 is fixed on the polishing disc 52.

[0077] The wafer loading and unloading device 50 is used to place the wafer to be ground and load the wafer onto the grinding head 51. For example, the grinding head 51 is provided with a clamping ring 54, which clamps the wafer.

[0078] The embodiments of the present invention do not limit the positional relationship and driving method of the grinding assembly 50 and the wafer loading and unloading device 60, nor the wafer disassembly and installation method, and can be designed according to specific application needs. In addition, in practical applications, the wafer loading and unloading devices used to place the wafer to be ground and the ground wafer can be different wafer loading and unloading devices, and the required number of wafer loading and unloading devices can be one or more.

[0079] For example, in a non-limiting embodiment, the axis of the grinding assembly 50 can be aligned with the axis of the wafer loading and unloading device 60, so that when the wafer loading and unloading device 60 rotates around the axis, the grinding head 51 can be aligned with the wafer loading and unloading device 60 during its movement relative to the wafer loading and unloading device 60, thereby realizing the disassembly and installation of the wafer; the axis of the grinding head 51 can be aligned with the center of the grinding disk 52, so that the grinding head 51 can be aligned with the grinding disk 52 during its movement relative to the grinding disk 52, so as to grind and polish the wafer.

[0080] In the actual grinding process, when the wafer loading and unloading device 60 is driven to rotate a certain position and direction away from the grinding assembly 50, the grinding head 51 can move to directly above the wafer loading and unloading device 60 under the driving action to achieve position alignment with the wafer loading and unloading device 60. The wafer can be transferred from the wafer loading and unloading device 60 to the grinding head 51 or removed from the grinding head 51 through the wafer loading and unloading device 60.

[0081] Driven by the drive device 55, the grinding head 51 can cause the wafer to contact the grinding pad 53 and move relative to the grinding disk 52 to grind and polish the wafer. After grinding and polishing is completed, the wafer loading and unloading device 50 places the wafer unloaded from the grinding head.

[0082] By using the wafer loading and unloading device 60, the accuracy of wafer position detection can be ensured, and false alarms can be prevented, thereby better ensuring the safety of wafers during the operation of the wafer grinding machine.

[0083] It should be noted that the terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion.

[0084] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article indicates that the preceding and following related objects have an "or" relationship.

[0085] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. Furthermore, the system embodiments described above are merely illustrative. The modules and units described as separate components may or may not be physically separate; that is, they may be located on a single network unit or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0086] While this application discloses the above information, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of this application; therefore, the scope of protection of this application shall be determined by the scope defined in the claims.

Claims

1. A wafer loading and unloading device, characterized in that, The device includes: a support base, a base, and a detection mechanism; the base is disposed on the support base, and the detection mechanism is disposed on the base; The detection mechanism includes: a bracket, a pressure rod, and a sensor; the pressure rod is mounted on the bracket, and the sensor is disposed on the pressure rod; The pressure bar includes a front section and a tail section; the front section of the pressure bar faces the center of the base. The base is provided with a sensor corresponding to the sensor and a groove corresponding to the tail section of the pressure rod; After the wafer is placed on the base, the tail section of the pressure rod is embedded into the corresponding groove by the pressure of the wafer, and the bottom surface of the tail section of the pressure rod abuts against the bottom inner surface of the groove. The sensor is connected to the inductor. After the wafer leaves the base, the front section of the pressure rod naturally tilts forward, causing the tail section of the pressure rod to tilt up, thereby disconnecting the sensor from the inductor.

2. The wafer loading and unloading device according to claim 1, characterized in that, The contact surface between the tail section of the pressure rod and the groove forms a vacuum-proof structure.

3. The wafer loading and unloading device according to claim 2, characterized in that, The bottom surface and / or groove surface of the tail section of the pressure rod include a rough surface to form a pressure relief path, or the mutual contact area of ​​the tail section of the pressure rod and the groove is less than a first preset value.

4. The wafer loading and unloading device according to claim 3, characterized in that, The bottom surface and / or groove surface of the tail section of the pressure rod are curved surfaces.

5. The wafer loading and unloading device according to claim 4, characterized in that, The longitudinal cross-section of the tail section of the pressure bar is circular or elliptical.

6. The wafer loading and unloading device according to claim 3, characterized in that, From the top of the pressure rod to the direction of contact between the pressure rod and the groove, the transverse cross-section of the tail section of the pressure rod decreases to reduce the contact area between the tail section of the pressure rod and the groove, and the contact surface between the tail section of the pressure rod and the groove is a plane and / or a curved surface.

7. The wafer loading and unloading device according to claim 1, characterized in that, The surface of the tail section of the pressure bar may have the same or different shape as the bottom surface.

8. The wafer loading and unloading device according to claim 1, characterized in that, A vacuum-proof structure is added between the pressure rod and the groove to prevent the pressure rod from forming a vacuum when it comes into contact with the groove.

9. The wafer loading and unloading device according to claim 1, characterized in that, Both the bracket and the pressure rod are provided with through holes. The pressure rod is fixed to the bracket by a screw passing through the through hole and can tilt forward or backward with the screw as the pivot.

10. The wafer loading and unloading device according to claim 1, characterized in that, The bracket is fixedly installed on the base.

11. The wafer loading and unloading device according to claim 1, characterized in that, The bracket and the base are integrally formed.

12. The wafer loading and unloading device according to claim 1, characterized in that, The front section of the pressure bar is equipped with a counterweight so that the front section of the pressure bar can naturally tilt forward after the wafer leaves the base.

13. The wafer loading and unloading device according to claim 1, characterized in that, The support base is also equipped with a nozzle for spraying cleaning fluid onto the base.

14. The wafer loading and unloading apparatus according to any one of claims 1 to 13, characterized in that, The support and the base are coaxial, and the base is sleeved inside the support.

15. The wafer loading and unloading apparatus according to claim 14, characterized in that, There are multiple detection mechanisms, which are symmetrically distributed along the circumference of the base.

16. The wafer loading and unloading apparatus according to claim 14, characterized in that, The device further includes: A drive mechanism is used to drive the base to move up and down axially.

17. A wafer grinding machine, characterized in that, include: Grinding assembly, and wafer loading and unloading apparatus as described in any one of claims 1 to 16; The grinding assembly includes: a grinding head, a grinding disc, and a grinding pad; the grinding pad is fixed on the grinding disc. The wafer loading and unloading device is used to place the wafer to be ground, load the wafer onto the grinding head for grinding and polishing, and place the wafer unloaded from the grinding head after grinding and polishing is completed.

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