Liquid-proof pressure head and single-side polishing machine

Abstract

The application provides a liquid inlet prevention pressure head and a single-side polishing machine, and relates to the technical field of wafer processing. The liquid inlet prevention pressure head comprises a base, a first gas guide channel arranged in the base, a pressure plate mechanism arranged below the base and capable of lifting and lowering, a bottom surface of the pressure plate mechanism having a pressing area, a liquid blocking cavity being arranged on the bottom surface of the pressure plate mechanism in the circumferential direction outside the pressing area, a second gas guide channel being arranged in the pressure plate mechanism and being in communication with the liquid blocking cavity, a pressure mechanism being arranged between the base and the pressure plate mechanism and being used for driving the pressure plate mechanism to lift and lower and adjusting the pressure applied to the wafer, and a connecting pipeline being arranged as a flexible pipe and having an extension and contraction allowance suitable for the displacement of the pressure plate mechanism, two ends of the connecting pipeline being in communication with the first gas guide channel and the second gas guide channel respectively. The liquid blocking cavity forms a protective gas film outside the wafer in the circumferential direction by filling the first gas guide channel with gas. The problem that the polishing liquid is easily sucked into the interior of the pressure head to cause abnormal wafer surface type in the related art is solved.

Description

Technical Field

[0001] This application relates to the technical field of wafer processing, and more specifically, to an anti-indentation hydraulic head and a single-sided polishing machine. Background Technology

[0002] Traditional vacuum adsorption pressure heads use vacuum negative pressure to adsorb wafer carriers onto a ceramic pressure head plate, and then press the wafers onto a polishing device for polishing.

[0003] However, when vacuum adsorbs wafer carriers, it often draws polishing slurry into the indenter. The liquid between the indenter and the wafer carrier can cause deformation of the wafer at this point. When testing the TTV value of the processed wafer, an abnormal concave TTV value will be observed at this point. (For example, the normal TTV value of a 6-inch wafer after polishing is 3μm, while the abnormal value with concavity can reach 10μm or even higher).

[0004] In addition, because the polishing slurry crystallizes quickly, it will clog the adsorption holes on the ceramic indenter plate after being drawn into the indenter. Over time, the adsorption force will decrease, which will also cause abnormal wafer surface shape. Utility Model Content

[0005] The purpose of this application is to provide a hydraulic head and a single-sided polishing machine that prevents the ingress of polishing fluid into the pressure head, thereby solving the problem in the related art where polishing fluid is easily sucked into the interior of the pressure head, causing abnormalities in the wafer surface.

[0006] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of this application.

[0007] According to a first aspect of this application, a pressure-resistant head is provided for pressing the wafer onto a polishing apparatus during wafer polishing, comprising:

[0008] The base has a first air guide channel inside;

[0009] The pressure plate mechanism is vertically and flexibly disposed below the base. The bottom surface of the pressure plate mechanism has a pressing area for pressing the wafer. The bottom surface of the pressure plate mechanism has an annular liquid-blocking cavity circumferentially opened on the pressing area. The pressure plate mechanism has a second gas guiding channel connected to the liquid-blocking cavity inside.

[0010] A pressurizing mechanism is disposed between the base and the pressure plate mechanism, and is used to drive the pressure plate mechanism to rise and fall and adjust the pressure applied to the wafer;

[0011] The connecting pipe is configured as a flexible pipe with a telescoping allowance to accommodate the displacement of the pressure plate mechanism. The two ends of the connecting pipe are respectively connected to the first air guide channel and the second air guide channel. By filling the first air guide channel with gas, the liquid blocking cavity can form a positive pressure protective gas film on the circumferential side of the wafer to prevent liquid from penetrating into the pressing area.

[0012] In an exemplary embodiment of this application, the pressure plate mechanism has an outer ring with an annular structure fixedly disposed around the liquid-blocking cavity. The bottom of the outer ring is provided with an exhaust hole for discharging excess gas in the liquid-blocking cavity. One end of the exhaust hole is connected to the liquid-blocking cavity, and the other end is connected to the external environment.

[0013] In one exemplary embodiment of this application, the connecting pipe is disposed outside the pressure plate mechanism and the pressurizing mechanism.

[0014] In one exemplary embodiment of this application, the pressurization mechanism is configured as an airbag.

[0015] In one exemplary embodiment of this application, a torque transmission and stroke limiting mechanism is further included, which is connected between the base and the pressure plate mechanism, for torque transmission between the base and the pressure plate mechanism and for limiting the maximum downward stroke of the pressure plate mechanism relative to the base.

[0016] In an exemplary embodiment of this application, the torque transmission and stroke limiting mechanism includes a connector and a connecting hole. The connector is fixed vertically to one of the base and the pressure plate mechanism, and the connecting hole is opened vertically in the other of the base and the pressure plate mechanism. The end of the connector is inserted into the connecting hole and a limiting member is fixedly provided thereon. The radial dimension of the limiting member is larger than the port dimension of the connecting hole. The connector and the limiting member can slide axially within the connecting hole.

[0017] In one exemplary embodiment of this application, the base is provided with a first negative pressure airflow channel; the pressure plate mechanism is provided with a second negative pressure airflow channel inside, and an adsorption cavity is opened at the bottom in the pressing area; the first negative pressure airflow channel is connected to the second negative pressure airflow channel, the second negative pressure airflow channel is connected to the adsorption cavity, and a carrier for pressing the wafer is provided below the pressing area. By evacuating the first negative pressure airflow channel, the carrier is made to adhere to the pressing area of ​​the pressure plate mechanism, so that a negative pressure state is formed in the adsorption cavity.

[0018] In one exemplary embodiment of this application, a sealing pin is embedded between the first negative pressure airflow channel and the second negative pressure airflow channel, and the sealing pin is provided with an air guide channel along the axial direction for connecting the first negative pressure airflow channel and the second negative pressure airflow channel;

[0019] The sealing pin is fixed to the base, and the pressure plate mechanism can be slidably connected to the sealing pin along the vertical direction; or...

[0020] The sealing nail is fixed to the pressure plate mechanism, and the base can be slidably connected to the sealing nail in the vertical direction.

[0021] In one exemplary embodiment of this application, multiple adsorption cavities are provided, and the multiple adsorption cavities are distributed in concentric circles on the lower surface of the pressure plate mechanism.

[0022] According to a second aspect of this application, a single-sided polishing machine is provided, characterized in that it includes any of the above-mentioned anti-ingress hydraulic head and polishing device, wherein the anti-ingress hydraulic head is disposed above the polishing device.

[0023] The exemplary embodiments of this application may have some or all of the following beneficial effects:

[0024] The anti-ingress hydraulic head provided in the example embodiment of this application uses a pressure plate mechanism to press a wafer onto a polishing device for polishing. At this time, the wafer is directly below the pressing area. The pressure applied to the wafer by the pressure plate mechanism can be adjusted by a pressurizing mechanism to meet the processing requirements of the wafer under different working conditions. During wafer polishing, gas is introduced from the top port of the first gas guide channel, then enters the connecting pipe through the first gas guide channel, and then enters the second gas guide channel through the connecting pipe. The gas then flows into the liquid-blocking chamber from the second gas guide channel, thereby forming a protective gas film. This protective gas film effectively blocks the polishing liquid from entering the inside of the pressing area, preventing the polishing liquid from easily seeping into the pressure head, thus improving the wafer polishing yield and reducing the likelihood of abnormal wafer surface shapes.

[0025] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0026] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0027] Figure 1A front sectional view of an anti-ingress hydraulic head according to an embodiment of this application is shown;

[0028] Figure 2 A bottom schematic diagram of an anti-ingress hydraulic head according to an embodiment of this application is shown.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Base; 11. First air guide channel; 12. First negative pressure airflow channel; 2. Pressure plate mechanism; 21. Connecting plate; 211. Second air guide channel; 212. Second negative pressure airflow channel; 22. Pressure plate; 221. Liquid blocking chamber; 222. Inflation hole; 223. Adsorption chamber; 3. Airbag; 4. Connecting pipe; 5. Outer ring; 51. Exhaust hole; 6. First limiting screw; 61. First limiting hole; 7. Second limiting screw; 71. Second limiting hole; 8. Sealing nail; 9. Carrier plate. Detailed Implementation

[0031] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed descriptions will be omitted. Furthermore, the drawings are merely illustrative of this application and are not necessarily drawn to scale.

[0032] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples in the accompanying drawings. It is understood that if the device of the icon is flipped so that it is upside down, the component described as "upper" will become the component described as "lower." When a structure is "upper" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.

[0033] The terms “a,” “one,” “the,” and “at least one” are used to indicate the existence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first” and “second” are used only as markers and are not a limitation on the number of objects.

[0034] Example 1

[0035] Reference Figure 1 and Figure 2As shown in the embodiments of this application, an anti-ingress hydraulic head is used to press the wafer onto the polishing device during the wafer polishing process, comprising:

[0036] The base 1 has a first air guide channel 11 inside;

[0037] The pressing mechanism 2 is vertically and flexibly disposed below the base 1. The bottom surface of the pressing mechanism 2 has a pressing area for pressing the wafer. The bottom surface of the pressing mechanism 2 has an annular liquid-blocking cavity 221 with a ring structure opened outward from the pressing area. The pressing mechanism 2 has a second air guiding channel 211 connected to the liquid-blocking cavity 221 inside.

[0038] A pressurizing mechanism is disposed between the base 1 and the pressure plate mechanism 2, and is used to drive the pressure plate mechanism 2 to rise and fall and to adjust the pressure applied by the pressure plate mechanism 2 to the wafer;

[0039] The connecting pipe 4 is configured as a flexible pipe and has a telescoping allowance to accommodate the displacement of the pressure plate mechanism 2. The two ends of the connecting pipe 4 are respectively connected to the first air guide channel 11 and the second air guide channel 211. By filling the first air guide channel 11 with gas, the liquid blocking cavity 221 can form a positive pressure protective gas film on the circumferential side of the wafer to prevent liquid from seeping into the pressing area.

[0040] In this embodiment, the pressure plate mechanism 2 includes a connecting plate 21 and a pressure plate 22. The connecting plate 21 is disposed between the base 1 and the pressure plate 22, and the pressure plate 22 is fixedly connected to the lower part of the connecting plate 21 by screws. A pressure mechanism is connected between the bottom of the base 1 and the upper surface of the connecting plate 21. The pressure plate 22 is made of ceramic plate. The pressing area for pressing the wafer is disposed on the lower surface of the pressure plate 22, and the center of the pressing area and the center of the pressure plate 22 are located on the same axis. When polishing the wafer surface, the pressure head presses the wafer onto the polishing device, so that the wafer is located in the pressing area. The polishing device can be a polishing cloth, but this is not a limitation. According to the wafer processing requirements, the pressure applied by the pressure plate mechanism 2 can be adjusted by the pressure mechanism to improve the polishing quality and polishing efficiency of the wafer.

[0041] In this embodiment, the second air channel 211 has a plurality of air holes 222, which are evenly spaced along the circumference of the liquid blocking cavity 221, and each air hole 222 is connected to the interior of the liquid blocking cavity 221.

[0042] During wafer polishing, gas can be introduced into the first gas channel 11 using a gas filling device. This device can be a blower, air pump, or similar equipment; there are no restrictions on its use. After gas is introduced into the first gas channel 11, it enters the second gas channel 211 through the connecting pipe 4. The gas in the second gas channel 211 then flows into the liquid-blocking cavity 221 through the gas filling hole 222, forming a protective gas film. Simultaneously introducing gas into the liquid-blocking cavity 221 through several gas filling holes 222 improves the stability of the protective gas film, thereby enhancing the barrier effect against the polishing slurry. The protective gas film effectively blocks the polishing slurry outside the pressing area, preventing it from easily penetrating the pressure head, thus improving the wafer polishing yield and reducing the likelihood of wafer surface abnormalities.

[0043] In this embodiment, to maintain the pressure balance within the liquid-blocking cavity 221, an outer ring 5 is provided circumferentially outside the liquid-blocking cavity 221. The outer ring 5 is fixedly connected to the lower surface of the pressure plate 22. Multiple vent holes 51 are provided at the bottom of the outer ring 5, evenly spaced along the circumference of the outer ring 5, and staggered with multiple inflation holes 222. One end of each vent hole 51 communicates with the liquid-blocking cavity 221, and the other end communicates with the external environment. This staggered distribution of the vent holes 51 and inflation holes 222 effectively prevents gas from being directly discharged from the vent holes 51 after being filled into the liquid-blocking cavity 221 by the inflation holes 222. When the liquid-blocking cavity 221 reaches gas saturation, excess gas is discharged through the vent holes 51, thereby maintaining the pressure balance within the liquid-blocking cavity 221.

[0044] In this embodiment, the connecting pipe 4 is made of a flexible material, such as a rubber tube or a corrugated pipe, to accommodate the lifting and lowering movement of the pressure plate mechanism 2. Specifically, the connecting pipe 4 is located outside the pressure plate mechanism 2 and the base 1. The end of the first air guide channel 11 extends to one side of the base 1, and the beginning of the second air guide channel 211 extends to one side of the pressure plate mechanism 2. The top of the connecting pipe 4 is fixedly connected to the end of the first air guide channel 11, and the bottom of the connecting pipe 4 is fixedly connected to the beginning of the second air guide channel 211. The flexibility of the connecting pipe 4 allows its length to be dynamically adjusted with the displacement of the pressure plate mechanism 2, thereby avoiding interference.

[0045] Furthermore, the first gas guide channel 11, the connecting pipe 4, and the second gas guide channel 211 together constitute a gas path system for supplying gas to the liquid-blocking chamber 221. This gas path system not only achieves stable gas transmission but also effectively avoids the space limitations of the pressurization mechanism through the layout of the external connecting pipe 4.

[0046] In one specific embodiment of this application, the pressurizing mechanism is configured as an airbag 3. By changing the air pressure inside the airbag 3, the position of the pressure plate mechanism 2 can be adjusted, and the pressure applied to the wafer can be changed. It should be noted that the airbag 3 described above is merely illustrative and is not intended to limit this application. In other feasible embodiments, the pressurizing mechanism can also be configured as a hydraulic system, a magnetic adjustment system, etc.

[0047] In this embodiment, a torque transmission and stroke limiting mechanism is further provided between the base 1 and the pressure plate mechanism 2 to realize torque transmission between the two and limit the maximum downward stroke of the pressure plate mechanism 2 relative to the base 1. Specifically, the torque transmission and stroke limiting mechanism includes:

[0048] A connector is fixed vertically to one of the base 1 and the connecting plate 21;

[0049] A connecting hole is formed vertically in one of the base 1 and the connecting plate 21, for the end of the connector to be inserted, and has space for the connector to slide axially.

[0050] A limiting member is fixed to the end of the connector that is inserted into the connecting hole, and the radial dimension of the limiting member is larger than the port dimension of the connecting hole.

[0051] When the pressure plate mechanism 2 performs vertical lifting and lowering motion, the connecting member drives the limiting member to slide axially along the connecting hole. Since the radial dimension of the limiting member is larger than the size of the connecting hole port, a limiting mechanism is formed, thereby limiting the downward travel range of the pressure plate mechanism 2. This ensures that the pressure plate mechanism 2 will not detach from the base 1.

[0052] When the base 1 rotates, the connector and limiting member are inserted into the connecting hole to form a horizontal restriction. Therefore, when the base 1 rotates, it will drive the pressure plate mechanism 2 to rotate together, ensuring the synchronization of their movements.

[0053] In one specific embodiment of the torque transmission and stroke limiting mechanism in this application, the connecting member includes a first limiting screw 6 and a second limiting screw 7, and the connecting hole includes a first limiting hole 61 and a second limiting hole 71. The bottom of the first limiting screw 6 is fixed to the upper surface of the connecting plate 21, the first limiting hole 61 is opened on the lower surface of the base 1, and the top of the first limiting screw 6 is inserted into the first limiting hole 61. The second limiting screw 7 is inverted and mounted on the lower surface of the base 1, the second limiting hole 71 is opened on the upper surface of the connecting plate 21, and the bottom of the second limiting hole 71 is inserted into the second limiting hole 71. The heads of the first limiting screw 6 and the second limiting screw 7 serve as limiting members.

[0054] In this embodiment, the base 1 is provided with a first negative pressure airflow channel 12; the pressure plate mechanism 2 is provided with a second negative pressure airflow channel 212, and an adsorption cavity 223 is opened at the bottom within the pressing area; wherein, the first negative pressure airflow channel 12 and the second negative pressure airflow channel 212 form a through airflow path, and the end of the second negative pressure airflow channel 212 is directly connected to the adsorption cavity 223. A carrier 9 for pressing the wafer is provided below the pressing area. When the first negative pressure airflow channel 12 is evacuated, the gas in the adsorption cavity 223 is extracted, causing the carrier 9 to adhere tightly to the lower surface of the pressure plate 22 under negative pressure, while a stable negative pressure state is formed in the adsorption cavity 223, thereby achieving the adsorption and fixation of the carrier 9.

[0055] Furthermore, a sealing nail 8 is embedded between the first negative pressure airflow channel 12 and the second negative pressure airflow channel 212. The interior of the sealing nail 8 is through-holes along its own axial direction. In this embodiment, the sealing nail 8 is fixed to the base 1, and the pressure plate mechanism 2 can be slidably connected to the sealing nail 8 in the vertical direction. In other embodiments, the sealing nail 8 can also be fixed to the pressure plate mechanism 2, and the sealing nail 8 can be slidably connected to the base 1 in the vertical direction. The interior of the sealing nail 8 is provided with an air guide channel through-holes along its own axial direction for connecting the first negative pressure airflow channel 12 and the second negative pressure airflow channel 212. Through the sealing nail 8, the first negative pressure airflow channel 12 and the second negative pressure airflow channel 212 are kept in a connected state at all times, and will not be interrupted due to the raising and lowering of the pressure plate mechanism 2, thereby ensuring the stability of the connection between the first negative pressure airflow channel 12 and the second negative pressure airflow channel 212.

[0056] In this embodiment, multiple adsorption cavities 223 are provided on the lower surface of the pressure plate mechanism 2 (i.e., the lower surface of the pressure plate 22), and the multiple adsorption cavities 223 are distributed in a concentric circle. The multi-ring distribution of adsorption cavities 223 enables uniform and stable adsorption force to be obtained in all areas of the surface of the carrier 9, thereby improving the stability and reliability of the adsorption of the carrier 9 by the pressure plate mechanism 2. Specifically, the concentrically arranged adsorption cavities 223 ensure that a balanced negative pressure is obtained from the edge to the center of the carrier 9, effectively reducing the occurrence of carrier 9 shifting or loosening due to uneven local adsorption force.

[0057] Example 2

[0058] In this application embodiment, a single-sided polishing machine is disclosed, including any of the anti-ingress hydraulic head in Embodiment 1 and a polishing device, wherein the anti-ingress hydraulic head is disposed above the polishing device.

[0059] Other embodiments of this application will readily conceive of by those skilled in the art upon consideration of the specification and practice of the embodiments thereof. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not claimed in this application. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this application are indicated by the appended claims.

Claims

1. A hydraulic head for pressing a wafer onto a polishing apparatus during wafer polishing, characterized in that, include: The base has a first air guide channel inside; The pressure plate mechanism is vertically and flexibly disposed below the base. The bottom surface of the pressure plate mechanism has a pressing area for pressing the wafer. The bottom surface of the pressure plate mechanism has an annular liquid-blocking cavity circumferentially opened on the pressing area. The pressure plate mechanism has a second gas guiding channel connected to the liquid-blocking cavity inside. A pressurizing mechanism is disposed between the base and the pressure plate mechanism, and is used to drive the pressure plate mechanism to rise and fall and to adjust the pressure applied to the wafer by the pressure plate mechanism; The connecting pipe is configured as a flexible pipe with a telescoping allowance to accommodate the displacement of the pressure plate mechanism. The two ends of the connecting pipe are respectively connected to the first air guide channel and the second air guide channel. By filling the first air guide channel with gas, the liquid blocking cavity can form a positive pressure protective gas film on the circumferential side of the wafer to prevent liquid from penetrating into the pressing area.

2. The anti-ingress hydraulic head according to claim 1, characterized in that, The pressure plate mechanism has an outer ring with an annular structure fixedly arranged around the liquid-blocking cavity. The bottom of the outer ring is provided with an exhaust hole for discharging excess gas in the liquid-blocking cavity. One end of the exhaust hole is connected to the liquid-blocking cavity, and the other end is connected to the external environment.

3. The anti-ingress hydraulic head according to claim 1, characterized in that, The connecting pipe is located outside the pressure plate mechanism and the pressurizing mechanism.

4. The anti-ingress hydraulic head according to claim 1, characterized in that, The pressurization mechanism is configured as an airbag.

5. The anti-ingress hydraulic head according to claim 1, characterized in that, It also includes a torque transmission and stroke limiting mechanism connected between the base and the pressure plate mechanism, for torque transmission between the base and the pressure plate mechanism and for limiting the maximum downward stroke of the pressure plate mechanism relative to the base.

6. The anti-ingress hydraulic head according to claim 5, characterized in that, The torque transmission and stroke limiting mechanism includes a connector and a connecting hole. The connector is fixed vertically to one of the base and the pressure plate mechanism. The connecting hole is opened vertically in the other of the base and the pressure plate mechanism. The end of the connector is inserted into the connecting hole and a limiting member is fixed thereon. The radial dimension of the limiting member is larger than the port dimension of the connecting hole. The connector and the limiting member can slide axially within the connecting hole.

7. The anti-ingress hydraulic head according to any one of claims 1-6, characterized in that, The base is provided with a first negative pressure airflow channel; the pressure plate mechanism is provided with a second negative pressure airflow channel, and an adsorption cavity is opened at the bottom in the pressing area; the first negative pressure airflow channel is connected to the second negative pressure airflow channel, and the second negative pressure airflow channel is connected to the adsorption cavity. A carrier for pressing the wafer is provided below the pressing area. By evacuating the first negative pressure airflow channel, the carrier is made to adhere to the pressing area of ​​the pressure plate mechanism, so that a negative pressure state is formed in the adsorption cavity.

8. The anti-ingress hydraulic head according to claim 7, characterized in that, A sealing pin is embedded between the first negative pressure airflow channel and the second negative pressure airflow channel, and the sealing pin has an axially formed air guide channel for connecting the first negative pressure airflow channel and the second negative pressure airflow channel; The sealing pin is fixed to the base, and the pressure plate mechanism can be slidably connected to the sealing pin along the vertical direction; or... The sealing nail is fixed to the pressure plate mechanism, and the base can be slidably connected to the sealing nail in the vertical direction.

9. The anti-ingress hydraulic head according to claim 7, characterized in that, The adsorption chamber is provided in multiple ways, and the multiple adsorption chambers are distributed in concentric circles on the lower surface of the pressure plate mechanism.

10. A single-sided polishing machine, characterized in that: The invention includes any one of the anti-ingress hydraulic head and polishing device according to claims 1-9, wherein the anti-ingress hydraulic head is disposed above the polishing device.

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