Vacuum table for warped panels

Abstract

The vacuum table includes a vacuum plate having an opening on an upper surface thereof, a plurality of suction cups having a bellows shape disposed on the upper surface of the vacuum plate, and at least one vacuum source in fluid communication with the opening in the vacuum plate and the plurality of suction cups, the plurality of suction cups protruding from the upper surface of the vacuum plate in an uncompressed state and being substantially coplanar with the upper surface of the vacuum plate in a compressed state, the at least one vacuum source configured to apply a negative pressure to compress the plurality of suction cups into the compressed state.

Description

[Technical Field]

[0001] The present disclosure relates to methods for planarizing a substrate, and more particularly to planarizing a substrate using a vacuum table. [Background technology]

[0002] As the semiconductor manufacturing industry evolves, the demands on yield management, particularly for metrology and inspection systems, are intensifying. As critical dimensions continue to shrink, the industry is still under pressure to reduce the time to achieve high yields and high-value production. Reducing the total time from detecting a yield problem to correcting it determines the return on investment for semiconductor manufacturers.

[0003] In the fabrication of semiconductor devices, such as logic and memory devices, semiconductor wafers are typically processed using a number of manufacturing processes to form the various features and levels of the semiconductor devices. For example, in a semiconductor manufacturing process known as lithography, a pattern is transferred from a reticle onto a photoresist array on the semiconductor wafer. Additional examples of semiconductor manufacturing processes include, but are not limited to, chemical mechanical polishing (CMP), etching, deposition, and ion implantation. An array of semiconductor devices may be fabricated on a single semiconductor wafer and then separated into individual semiconductor devices.

[0004] Flattening is sometimes required during the manufacturing process of glass panels or other substrates so that further processing can be performed on the glass panel or other substrate. For example, imaging a substrate that is not flat can be a challenge. A warped substrate requires constant focus adjustment over a wide range, which can hinder or even prevent effective inspection or metrology of the substrate. To flatten a substrate, a high vacuum flow can be applied to the substrate using a vacuum table. However, existing vacuum tables fail to properly flatten the edges of warped panels. To address this issue, clamping devices can be used to press down on the edges of the panel. However, this carries the risk of damaging the active area of ​​the panel due to contact stress near the clamps. Clamps and other protrusions above the substrate can also take up valuable space limited by the location of optical components. Either of these methods increases the complexity of the vacuum table and the maintenance requirements of the manufacturing process. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent Application Publication No. 2018 / 166314 Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, there is a need for a vacuum table that is capable of flattening severely warped substrates and is easy to manufacture. [Means for solving the problem]

[0007] In one embodiment of the present disclosure, a vacuum table is provided that includes a vacuum plate having an opening on an upper surface thereof, a plurality of suction cups disposed on the upper surface of the vacuum plate and having a bellows-like shape, and at least one vacuum source in fluid communication with the opening in the vacuum plate and the plurality of suction cups. The opening may be defined between surface features on the upper surface of the vacuum plate. The plurality of suction cups may protrude from the upper surface of the vacuum plate in an uncompressed state and be substantially coplanar with the upper surface of the vacuum plate in a compressed state. The at least one vacuum source may be configured to apply a negative pressure to compress the plurality of suction cups into the compressed state.

[0008] According to certain embodiments of the present disclosure, the vacuum table may further include a gasket disposed on the upper surface of the vacuum plate around the periphery of the vacuum plate. The gasket may be disposed in a sealing groove on the upper surface of the vacuum plate and protrude from the upper surface of the vacuum plate. The gasket may protrude from the upper surface of the vacuum plate by 200 to 500 microns (1 micron = 1 μm).

[0009] In one embodiment of the present disclosure, the plurality of suction cups protrude at least 6 mm from the top surface of the vacuum plate in an uncompressed state.

[0010] According to certain embodiments of the present disclosure, the plurality of suction cups can include a first set of suction cups arranged near the edges of the upper surface of the vacuum plate and a second set of suction cups arranged near the corners of the upper surface of the vacuum plate. The first set of suction cups can be arranged parallel to each edge of the upper surface of the vacuum plate. The second set of suction cups can be arranged radially symmetrically about the corners of the upper surface of the vacuum plate.

[0011] According to certain embodiments of the present disclosure, the at least one vacuum source can include a first vacuum source in communication with an opening in the vacuum plate and a second vacuum source in communication with the plurality of suction cups. The second vacuum source can be configured to apply a negative pressure to compress the plurality of suction cups into a compressed state. The opening can be coupled to a primary distribution channel in the vacuum plate, with the first vacuum source in communication with the opening via the primary distribution channel. The plurality of suction cups can be coupled to a secondary distribution channel in the vacuum plate, with the second vacuum source in communication with the secondary distribution channel.

[0012] Another embodiment of the present disclosure provides a method for planarizing a substrate. The method can include providing a vacuum table. The vacuum table can include a vacuum plate having an opening on an upper surface thereof, a plurality of suction cups having a bellows shape disposed on the upper surface of the vacuum plate, and at least one vacuum source in communication with the openings in the vacuum plate and the plurality of suction cups. The plurality of suction cups can protrude from the upper surface of the vacuum plate in an uncompressed state and be substantially coplanar with the upper surface of the vacuum plate in a compressed state.

[0013] The method may further include placing the substrate on the upper surface of the vacuum plate in contact with the plurality of suction cups, and controlling at least one vacuum source to apply a negative pressure in a space between the substrate and the upper surface of the vacuum plate, and in a space between the substrate and the plurality of suction cups, thereby compressing the plurality of suction cups into a compressed state and flattening the substrate against at least a portion of the upper surface of the vacuum plate.

[0014] According to one embodiment of the present disclosure, the vacuum table further comprises a gasket disposed on the upper surface of the vacuum plate around the periphery of the vacuum plate, the gasket being capable of at least partially sealing a space between the substrate and the upper surface of the vacuum plate.

[0015] According to one embodiment of the present disclosure, when a substrate placed on the upper surface of a vacuum plate is warped and has a deflection of up to 6 mm, the deflection can be reduced to essentially 0 mm by flattening the substrate against at least a portion of the upper surface of the upper plate.

[0016] In another embodiment of the present disclosure, a vacuum table is provided that includes a vacuum plate having an opening on an upper surface thereof, a gasket disposed on the upper surface of the vacuum plate around a periphery of the vacuum plate, the gasket may protrude from the upper surface of the vacuum plate in an uncompressed state, and the vacuum source may be configured to apply a negative pressure to compress the gasket into the compressed state.

[0017] According to certain embodiments of the present disclosure, in an uncompressed state, the gasket can protrude at least 6 mm from the top surface of the vacuum plate.

[0018] According to certain embodiments of the present disclosure, the gasket may protrude away from the upper surface of the vacuum plate at an angle, which may be 45 degrees.

[0019] According to certain embodiments of the present disclosure, the gasket may have a bellows shape.

[0020] Another embodiment of the present disclosure provides a method for planarizing a substrate. The method can include providing a vacuum table. The vacuum table can include a vacuum plate having an opening on an upper surface thereof, a gasket disposed on the upper surface of the vacuum plate around a periphery of the vacuum plate, and a vacuum source in communication with the opening in the vacuum plate. The gasket can protrude from the upper surface of the vacuum plate in an uncompressed state, and the vacuum source can be configured to apply a negative pressure to compress the gasket into a compressed state.

[0021] The method may further include placing a substrate on the upper surface of the vacuum plate in contact with the gasket, and controlling the vacuum source to apply a negative pressure in a space between the substrate and the upper surface of the vacuum plate and sealed by the gasket, thereby compressing the gasket into a compressed state and flattening the substrate against at least a portion of the upper surface of the vacuum plate.

[0022] For a more complete understanding of the nature and scope of the present disclosure, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which: [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a cross-sectional view of a vacuum table according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is another cross-sectional view of the vacuum table of FIG. 1. [Figure 3] FIG. 2 is a top view of the vacuum table of FIG. 1. [Figure 4] 1 is a flowchart of a method according to an embodiment of the present disclosure. [Figure 5] FIG. 10 is a cross-sectional view of a vacuum table according to another embodiment of the present disclosure. [Figure 6] FIG. 6 is another cross-sectional view of the vacuum table of FIG. 5. [Figure 7] FIG. 6 is a top view of the vacuum table of FIG. 5. [Figure 8] FIG. 10 is a cross-sectional view of a vacuum table according to another embodiment of the present disclosure. [Figure 9] FIG. 9 is another cross-sectional view of the vacuum table of FIG. 8. [Figure 10] 1 is a flowchart of a method according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0024] Although the claimed subject matter is described in terms of certain embodiments, other embodiments are within the scope of this disclosure, including embodiments that do not provide all of the benefits and features described herein. Various structural, logical, process, step, and electronic changes may be made without departing from the scope of this disclosure. Thus, the scope of this disclosure is defined solely by reference to the appended claims.

[0025] As shown in FIGS. 1-3 , one embodiment of the present disclosure provides a vacuum table 100. The vacuum table 100 may include a vacuum plate 110. The vacuum plate 110 may have a variety of shapes. For example, the vacuum plate 110 may be circular, rectangular, or any other polygonal shape. The length and width of the vacuum plate 110 may vary depending on the size of the substrate to be planarized. For example, for a 510 mm x 515 mm substrate, the vacuum plate 110 may be 510 mm x 515 mm or larger. To planarize a smaller substrate, a smaller vacuum plate 110 may be used.

[0026] The vacuum plate 110 may have a substrate 101 on its upper surface 111 that requires planarization. The substrate 101 may be an organic substrate panel, a glass carrier panel, a glass core panel, or other workpiece that requires planarization. The substrate 101 may have a thickness of 0.2 mm to 4 mm. The substrate 101 may be warped in a convex, concave, or other complex shape, such as a saddle or potato chip shape, an example of which is shown in FIG. 1. The warp of the substrate 101 may be defined by the maximum distance from the substrate 101 to a horizontal surface. The warp of the substrate 101 may be as large as 6 mm, but may also be other values.

[0027] The upper surface 111 of the vacuum plate 110 may have openings 112. The openings may be distributed across the upper surface 111 of the vacuum plate 110 and connected by primary distribution channels 114 within the vacuum plate 110. The upper surface 111 of the vacuum plate 110 may further include surface features 113. The surface features 113 may be depressions or protrusions in the upper surface 111 of the vacuum plate 110. For example, the surface features 113 may be defined in the upper surface 111 of the vacuum plate 110 as a network of grooves, a porous structure, or a pin structure. In the embodiment shown in FIGS. 1-3, the surface features 113 are defined as a plurality of rectangular protrusions on the upper surface 111 of the vacuum plate. For example, the rectangular protrusions may be an array of 10 mm by 10 mm blocks or 5 mm by 5 mm blocks. The openings 112 may be defined in the spaces between the rectangular protrusions. The surface features 113 allow air to pass between the surface features 113, thereby allowing the opening 112 to communicate with a larger area of ​​the substrate 101.

[0028] The vacuum table 100 may further include a plurality of suction cups 120. The plurality of suction cups 120 may be disposed on the upper surface 111 of the vacuum plate 110. For example, the plurality of suction cups 120 may be arranged around the periphery of the upper surface 111 of the vacuum plate, radially outward from the openings 112 and the surface features 113. Each of the plurality of suction cups 120 may be disposed within an individual recess 115 in the upper surface 111 of the vacuum plate and connected by a secondary distribution channel 116 within the vacuum plate 110. By being located around the periphery of the vacuum plate 110, the plurality of suction cups 120 may contact the edge of the substrate 101 to provide localized planarization.

[0029] The suction cups 120 may have a bellows shape. In other words, the suction cups 120 may be compressible between an uncompressed state and a compressed state. In the uncompressed state (see FIG. 1 ), the suction cups 120 may protrude from the upper surface 111 of the vacuum plate 110. For example, the suction cups 120 may protrude at least 6 mm from the upper surface 111 of the vacuum plate 110 in the uncompressed state. This allows the suction cups 120 to contact the surface of the substrate 101 even in the case of a maximum bow of 6 mm. It should be understood that the suction cups 120 may protrude more or less from the upper surface 111 of the vacuum plate 110 to flatten a substrate 101 with more or less bow. In the compressed state (see FIG. 2 ), the suction cups 120 may be substantially coplanar with the upper surface 111 of the vacuum plate 110. Thus, when the plurality of suction cups 120 are in a compressed state, the substrate 101 can be flattened against the upper surface 111 of the vacuum plate 110 .

[0030] In certain embodiments, the plurality of suction cups 120 may have a rectangular shape. For example, the rectangular shape may be a rounded rectangular shape, or may have other rounded or polygonal shapes.

[0031] The plurality of suction cups 120 may include a first set of suction cups 121 and a second set of suction cups 122 (see FIG. 3 ). The first set of suction cups 121 may be arranged near the edge of the upper surface 111 of the vacuum plate 110. For example, the first set of suction cups 121 may be arranged parallel to the edge of the upper surface 111 of the vacuum plate 110. In this manner, the first set of suction cups 121 may be configured for localized planarization of the edge of the substrate 101. The second set of suction cups 122 may be arranged near the corners of the upper surface 111 of the vacuum plate 110. For example, the second set of suction cups 122 may be arranged radially symmetrically at the corners of the upper surface 111 of the vacuum plate 110. In this manner, the second set of suction cups 122 may be configured for localized planarization of the corners of the substrate 101. With a first set of suction cups 121 and a second set of suction cups 122, the plurality of suction cups 120 can be arranged to accommodate portions of the substrate that may be more difficult to planarize.

[0032] In certain embodiments, the first set of suction cups 121 and the second set of suction cups 122 can be the same shape, or alternatively, the first set of suction cups 121 and the second set of suction cups 122 can be different shapes and selected for localized planarization of the edges and corners of the substrate, respectively.

[0033] The vacuum table 100 may further include at least one vacuum source 130. The at least one vacuum source 130 may be a vacuum pump having a power of 2-40 kPa. The at least one vacuum source 130 may be in communication with the primary distribution channel 114 and the secondary distribution channel 116. The at least one vacuum source 130 may be configured to apply a negative pressure through the openings 112 and the plurality of suction cups 120. When the substrate 101 is placed on the upper surface 111 of the vacuum plate 110 and a negative pressure is applied by the at least one vacuum source 130, the plurality of suction cups 120 may be compressed into a compressed state, thereby flattening the substrate 101 against the upper surface 111 of the vacuum plate 110.

[0034] In certain embodiments, the at least one vacuum source 130 can include a first vacuum source 131 and a second vacuum source 132. The first vacuum source 131 can be in communication with the opening 112 via the primary distribution channel 114. The second vacuum source 132 can be in communication with the plurality of suction cups 120 via the secondary distribution channel 116. In this manner, the second vacuum source 132 can be configured to apply a negative pressure to compress the plurality of suction cups 120 into a compressed state, thereby flattening the substrate 101 against the upper surface 111 of the vacuum plate 110. The first vacuum source 131 and the second vacuum source 132 can be operated simultaneously to apply a negative pressure through the opening 112 and the plurality of suction cups 120. In certain embodiments, the first vacuum source 131 can be operated before the second vacuum source 132. The first vacuum source 131 can be a vacuum pump having a power of 2 to 25 kPa, and the second vacuum source 132 can be a vacuum pump having a power of 18 to 40 kPa. The second vacuum source 132 does not need to have much power to flatten the substrate 101 because the plurality of suction cups 120 are sealed with the substrate 101 to create a static vacuum, allowing the plurality of suction cups 120 to collapse and apply a downward force to the substrate 101.

[0035] The vacuum table 100 may further include a gasket 140. The gasket 140 may be made of a flexible material, such as soft silicone foam. The gasket 140 may be disposed within a sealing groove 117 on the upper surface 111 of the vacuum plate 110. The sealing groove 117 may be disposed around the periphery of the upper surface 111 of the vacuum plate 110, radially outward from the plurality of suction cups 120. The gasket 140 may be configured to seal the space between the substrate 101 and the upper surface 111 of the vacuum plate 110. In this manner, the gasket 140 may reduce leakage and more efficiently planarize the substrate 101 when a negative pressure is applied by the at least one vacuum source 130. The gasket 140 may protrude from the upper surface 111 of the vacuum plate 110. For example, the gasket 140 may protrude 200-500 microns from the upper surface 111 of the vacuum plate 110 and may be non-coplanar. By protruding from the upper surface 111, the gasket 140 can contact the substrate 101 after the plurality of suction cups 120 collapse into a compressed state, thereby sealing the space between the substrate 101 and the upper surface 111 of the vacuum plate 110. It should be understood that the gasket 140 can be deformed to be coplanar with the upper surface 111 of the vacuum plate 110, thereby completely flattening the substrate 101 against the upper surface 111 of the vacuum plate 110.

[0036] The vacuum table 100 of the present disclosure allows for the flattening of a severely warped substrate 101 by applying negative pressure in the space between the substrate 101 and the upper surface 111 of the vacuum plate 110, as well as in the space between the substrate 101 and a plurality of suction cups 120. The plurality of suction cups 120 can protrude to contact even the most warped portion of the substrate 101 and compress to completely flatten the substrate 101 against the upper surface 111 of the vacuum table 110, and the arrangement of the suction cups 120 can be configured for localized flattening in areas of the substrate 101 that may be difficult to flatten.

[0037] In one embodiment of the present disclosure, there is provided a substrate planarization method 200. As shown in Figure 4, the method 200 may include the following steps.

[0038] In step 210, a vacuum table is prepared. The vacuum table may be equivalent to vacuum table 100 described herein, and details thereof will not be repeated here.

[0039] In step 220, a substrate is placed on top of the vacuum plate and contacts the plurality of suction cups. The substrate can be an organic substrate panel, a glass carrier panel, a glass core panel, or any other workpiece requiring planarization. The substrate can be 0.2 mm to 4 mm thick. The substrate can be warped in a convex, concave, or other complex shape, such as a saddle or potato chip shape, an example of which is shown in FIG. 1. The warp of a substrate can be defined by the maximum distance from the substrate to a horizontal surface. In certain embodiments, the substrate warp can be as much as 6 mm.

[0040] When a substrate is placed on the upper surface of the vacuum plate, the substrate can be brought into contact with the plurality of suction cups and at least partially compressed, thereby sealing the plurality of suction cups with the substrate.

[0041] In certain embodiments, the vacuum table further comprises a gasket disposed on the upper surface of the vacuum plate around a periphery of the vacuum plate such that, when the substrate is disposed on the upper surface of the vacuum plate, the gasket at least partially seals a space between the substrate and the upper surface of the vacuum plate.

[0042] In step 230, at least one vacuum source is controlled to apply a negative pressure in the space between the substrate and the upper surface of the vacuum plate and in the space between the substrate and the plurality of suction cups. When the substrate is placed on the upper surface of the vacuum plate and negative pressure is applied by the at least one vacuum source, the plurality of suction cups can be compressed into a compressed state, thereby flattening the substrate against the upper surface of the vacuum plate. By flattening the substrate against at least a portion of the upper surface of the upper plate, the warp of the substrate can be reduced to substantially 0 mm.

[0043] The disclosed method 200 allows for the flattening of severely warped substrates by applying negative pressure in the space between the substrate and the top surface of the vacuum plate, as well as between the substrate and a plurality of suction cups. The suction cups can be protruding to contact even the most warped portions of the substrate and compress to completely flatten the substrate against the top surface of the vacuum table, and the suction cup array can be configured for localized flattening in areas of the substrate that may be difficult to flatten.

[0044] As shown in FIGS. 5-9, another embodiment of the present disclosure provides another vacuum table 300. The vacuum table 300 may include a vacuum plate 310. The vacuum plate 310 may have a variety of shapes. For example, the vacuum plate 310 may be circular, rectangular, or any other polygonal shape. The length and width of the vacuum plate 310 may vary depending on the size of the substrate to be planarized. For example, for a 510 mm x 515 mm substrate, the vacuum plate 310 may be 510 mm x 515 mm or larger. To planarize a smaller substrate, a smaller vacuum plate 310 may be used.

[0045] The vacuum plate 310 can be configured to accommodate a substrate 301 to be planarized on its upper surface 311. The substrate 301 can be an organic substrate panel, a glass carrier panel, a glass core panel, or other workpiece to be planarized. The substrate 301 can have a thickness of 0.2 mm to 4 mm. The substrate 301 can be warped in a convex, concave, or other complex shape, such as a saddle or potato chip shape, an example of which is shown in FIG. 5. The warp of the substrate 301 can be defined by the maximum distance from the substrate 301 to a horizontal surface. The warp of the substrate 301 can be as large as 6 mm, but can also be other values.

[0046] The upper surface 311 of the vacuum plate 310 may have openings 312. The openings may be distributed across the upper surface 311 of the vacuum plate 310 and connected by primary distribution channels 314 within the vacuum plate 310. The upper surface 311 of the vacuum plate 310 may further include surface features 313. The surface features 313 may be depressions or protrusions in the upper surface 311 of the vacuum plate. For example, the surface features 313 may be defined in the upper surface 311 of the vacuum plate 310 as a network of grooves, a porous structure, or a pin structure. In the embodiment shown in FIGS. 4 and 5, the surface features 313 are defined as a plurality of rectangular protrusions on the upper surface 311 of the vacuum plate. For example, the rectangular protrusions may be an array of 10 mm by 10 mm blocks or 5 mm by 5 mm blocks. The openings 312 may be defined in the spaces between the rectangular protrusions. The surface features 313 allow air to pass between them, allowing the opening 312 to communicate with a larger area of ​​the substrate 301 .

[0047] 5-7, the vacuum table 300 may further include a gasket 320. The gasket 320 may be disposed on a sealing surface 317 on the side of the vacuum plate 310. The sealing surface 317 may be disposed around the periphery of the top surface 311 of the vacuum plate, outward from the openings 312 and surface features 313. By being located on the periphery of the vacuum plate 310, the gasket 320 may abut against the edge of the substrate 301 to provide localized flattening. The gasket 320 may also include notches and / or slits (see FIG. 7) in the corners 321 to allow it to more easily conform to the substrate 301.

[0048] The gasket 320 can be made of a flexible material. For example, the gasket 320 can be made of soft silicone foam. In other words, the gasket 320 can be compressible between an uncompressed state and a compressed state. In the uncompressed state, the gasket 320 can protrude from the upper surface 311 of the vacuum plate 310. For example, the gasket 320 can protrude at least 6 mm from the upper surface 311 of the vacuum plate 310 in the uncompressed state (see FIG. 5). This allows the gasket 320 to contact the surface of the substrate 301 even in the case of a maximum bow of 6 mm. It should be understood that the gasket 320 can protrude more or less from the upper surface 311 of the vacuum plate 310 to flatten a substrate 301 with more or less bow. In the compressed state (see FIG. 6), the gasket 320 can be substantially coplanar with the upper surface 311 of the vacuum plate 310. Because it has been compressed from an uncompressed state to a compressed state, gasket 320 can remain in contact with substrate 301. Thus, when gasket 320 is in a compressed state, substrate 301 can be flattened against top surface 311 of vacuum plate 310. It should be understood that gasket 320 can be deformed to become coplanar with top surface 311 of vacuum plate 310, thereby completely flattening substrate 301 against top surface 311 of vacuum plate 310.

[0049] In certain embodiments, the gasket 320 may protrude from the top surface 311 of the vacuum plate 310 at an angle θ. For example, the angle θ may be 45 degrees. This allows the substrate 301 to contact the angled surface of the gasket 320, thereby allowing the gasket 320 to accommodate a wider range of substrates 301.

[0050] In certain embodiments, gasket 320 may be a concertina gasket 320a, as shown in Figures 8 and 9. Concertina gasket 320a may be disposed within sealing groove 317a on upper surface 311 of vacuum plate 310. Concertina gasket 320a is shown in an uncompressed state in Figure 8 and may be compressed downward to a compressed state (see Figure 9) to flatten substrate 301 against upper surface 311 of vacuum plate 310.

[0051] Gasket 320 can be configured to seal the space between substrate 301 and upper surface 311 of vacuum plate 310, thereby reducing leakage and allowing for more efficient planarization of substrate 301 when a negative pressure is applied by vacuum source 330.

[0052] The vacuum table 300 may further include a vacuum source 330. The vacuum source 330 may be a vacuum pump having a power of 0.3 to 9.0 kPa. The vacuum source 330 may be in fluid communication with the primary distribution channel 314. In this manner, the vacuum source 330 may be configured to apply a negative pressure through the opening 312. When the substrate 301 is placed on the upper surface 311 of the vacuum plate 310 and a negative pressure is applied by the vacuum source 330, the gasket 320 may be compressed into a compressed state, thereby flattening the substrate 301 against the upper surface 311 of the vacuum plate 310.

[0053] The vacuum table 300 of the present disclosure allows for the flattening of a severely warped substrate 301 by applying negative pressure within the space between the substrate 301 and the upper surface 311 of the vacuum plate 310, which is sealed by a gasket 320. The gasket 320 can be configured to protrude to abut even the most warped portion of the substrate 301 and compress to completely flatten the substrate 301 against the upper surface 311 of the vacuum table 310, and by sealing the edges of the substrate 301, the gasket 320 can reduce leakage in areas of the substrate 301 that may be difficult to flatten.

[0054] Another embodiment of the present disclosure provides a substrate planarization method 400. As shown in Figure 10, the method 400 may include the following steps.

[0055] In step 410, a vacuum table is prepared. The vacuum table may be equivalent to vacuum table 300 described herein, and details thereof will not be repeated here.

[0056] In step 420, a substrate is placed on top of the vacuum plate and contacted with the gasket. The substrate can be an organic substrate panel, a glass carrier panel, a glass core panel, or any other workpiece requiring planarization. The substrate can be 0.2 mm to 4 mm thick. The substrate can be warped in a convex, concave, or other complex shape, such as a saddle or potato chip shape, an example of which is shown in FIG. 5. The warp of a substrate can be defined by the maximum distance from the substrate to a horizontal surface. In certain embodiments, the substrate warp can be as much as 6 mm.

[0057] When a substrate is placed on the upper surface of the vacuum plate, the substrate can contact and at least partially compress the gasket, which in turn can at least partially seal the space between the substrate and the upper surface of the vacuum plate.

[0058] In step 430, the vacuum source is controlled to apply a negative pressure to a space between the substrate and the upper surface of the substrate and sealed by the gasket. When the substrate is placed on the upper surface of the vacuum plate and negative pressure is applied by the vacuum source, the gasket is compressed and the substrate can be flattened against the upper surface of the vacuum plate. By flattening the substrate against at least a portion of the upper surface of the upper plate, the warp of the substrate can be reduced to substantially 0 mm.

[0059] The disclosed method 400 allows for the flattening of severely warped substrates by applying negative pressure within the space between the substrate and the top surface of the vacuum plate, which is sealed by a gasket. The gasket can be configured to protrude to abut even the most warped portions of the substrate, compress to completely flatten the substrate against the top surface of the vacuum table, and seal around the edges of the substrate, reducing leakage in areas of the substrate that may be difficult to flatten.

[0060] Although the present disclosure has been described in connection with one or more specific embodiments, other embodiments of the present disclosure may be made without departing from the scope of the present disclosure, which is limited only by the appended claims and their reasonable interpretation.

Claims

1. a vacuum table, a vacuum plate having an opening on its top surface; a plurality of bellows-shaped suction cups disposed on the upper surface of the vacuum plate, the plurality of suction cups projecting from the upper surface of the vacuum plate in an uncompressed state and being substantially coplanar with the upper surface of the vacuum plate in a compressed state; at least one vacuum source in communication with the openings in the vacuum plate and the plurality of suction cups; wherein the at least one vacuum source is configured to apply a negative pressure to compress the plurality of suction cups into the compressed state.

2. 10. The vacuum table of claim 1 further comprising: A vacuum table including a gasket disposed on the top surface of the vacuum plate and around the periphery of the vacuum plate.

3. 3. The vacuum table of claim 2, wherein the gasket is disposed in a sealing groove on the upper surface of the vacuum plate and protrudes beyond the upper surface of the vacuum plate.

4. 4. The vacuum table of claim 3, wherein the gasket protrudes from the top surface of the vacuum plate by 200 to 500 microns.

5. 2. The vacuum table of claim 1, wherein the plurality of suction cups protrude at least 6 mm from the top surface of the vacuum plate in the uncompressed state.

6. 2. The vacuum table of claim 1, wherein the plurality of suction cups comprises: a first set of suction cups arranged near the edge of the top surface of the vacuum plate; a second set of suction cups arranged near the corners of the top surface of the vacuum plate; A vacuum table containing

7. 7. The vacuum table of claim 6, wherein the first set of suction cups are aligned parallel to each edge of the top surface of the vacuum plate.

8. 7. The vacuum table of claim 6, wherein the second set of suction cups are arranged radially symmetrically at the corners of the top surface of the vacuum plate.

9. 2. The vacuum table of claim 1, wherein the at least one vacuum source: a first vacuum source in communication with the opening in the vacuum plate; a second vacuum source in fluid communication with the plurality of suction cups; wherein the second vacuum source is configured to apply a negative pressure to compress the plurality of suction cups into the compressed state.

10. 10. The vacuum table of claim 9, wherein the opening is connected to a primary distribution channel in the vacuum plate, and the first vacuum source communicates with the opening through the primary distribution channel.

11. 10. The vacuum table of claim 9, wherein the plurality of suction cups are connected to a secondary distribution channel in the vacuum plate, the second vacuum source being in communication with the secondary distribution channel.

12. 2. The vacuum table of claim 1, wherein the openings are defined between surface features on the top surface of a vacuum plate.

13. 1. A method of planarizing a substrate, comprising: a vacuum table, a vacuum plate having an opening on its top surface; a plurality of bellows-shaped suction cups disposed on the upper surface of the vacuum plate, the plurality of suction cups projecting from the upper surface of the vacuum plate in an uncompressed state and being substantially coplanar with the upper surface of the vacuum plate in a compressed state; at least one vacuum source in communication with the openings in the vacuum plate and the plurality of suction cups; providing a vacuum table comprising: placing the substrate on the upper surface of the vacuum plate in contact with the plurality of suction cups; and controlling the at least one vacuum source to apply a negative pressure in a space between the substrate and the upper surface of the vacuum plate and in a space between the substrate and the plurality of suction cups, thereby compressing the plurality of suction cups into the compressed state and flattening the substrate against at least a portion of the upper surface of the vacuum plate; method.

14. 14. The method of claim 13, wherein the vacuum table further comprises a gasket disposed on the upper surface of the vacuum plate around a periphery of the vacuum plate, the gasket at least partially sealing the space between the substrate and the upper surface of the vacuum plate.

15. 14. The method of claim 13, wherein the substrate placed on the upper surface of the vacuum plate is warped and has a bow of up to 6 mm, and the bow is reduced to substantially 0 mm by flattening the substrate against at least a portion of the upper surface of the upper plate.

16. a vacuum table, a vacuum plate having an opening on its top surface; a gasket disposed on the upper surface of the vacuum plate and around the periphery of the vacuum plate; a vacuum source in communication with the opening in the vacuum plate; wherein the gasket protrudes from the top surface of the vacuum plate in an uncompressed state, and the vacuum source is configured to apply a negative pressure to compress the gasket into a compressed state.

17. 17. A vacuum table according to claim 16, wherein in the uncompressed state, the gasket protrudes from the top surface of the vacuum plate by at least 6 mm.

18. 17. The vacuum table of claim 16, wherein the gasket projects at an angle away from the top surface of the vacuum plate.

19. 19. The vacuum table of claim 18, wherein the angle is 45 degrees.

20. 17. The vacuum table of claim 16, wherein the gasket has a bellows shape.

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