Vacuum table for warped panels

Abstract

A vacuum table includes: a vacuum plate having an opening on a top surface; a plurality of suction cups disposed on the top surface of the vacuum plate and having a bellows shape; and at least one vacuum source in fluid communication with the opening of the vacuum plate and the plurality of suction cups. The plurality of suction cups protrude from the top surface of the vacuum plate in an uncompressed state and are substantially coplanar with the top surface of the vacuum plate in a compressed state. The at least one vacuum source is 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 a method of flattening a substrate, and more particularly, to using a vacuum table to flatten a substrate. Background Art

[0002] The evolution of the semiconductor manufacturing industry has placed higher demands on yield management and more particularly, metrology and inspection systems. Critical dimensions are constantly shrinking, but the industry needs to shorten the time to achieve high-yield, high-value production. Minimizing the total time from detecting a yield issue to resolving the issue determines the return on investment for semiconductor manufacturers.

[0003] Manufacturing semiconductor devices such as logic and memory devices typically involves processing semiconductor wafers using a large number of manufacturing processes to form various features and multiple levels of the semiconductor device. For example, lithography is a semiconductor manufacturing process that involves transferring a pattern from a photomask to a photoresist disposed on a semiconductor wafer. Additional examples of semiconductor manufacturing processes include, but are not limited to, chemical mechanical polishing (CMP), etching, deposition, and ion implantation. The arrangement of multiple semiconductor devices fabricated on a single semiconductor wafer can be separated into individual semiconductor devices.

[0004] Prior to performing further processes on a glass panel or other substrate, flattening may be required during the glass panel or other substrate manufacturing process. For example, if the substrate is uneven, imaging it can be challenging. If the substrate is warped, then the focus will need to be continuously adjusted across a wide range of values, which can impede or even prevent effective inspection or metrology of the substrate. To flatten the substrate, a vacuum table can be used to apply a high vacuum flow to the substrate. However, existing vacuum tables are unable to adequately flatten the edges of warped panels. To address this issue, a clamping device can be used to push down the edges of the panel. However, due to the contact stress near the clamp, this poses a risk of damaging the active area of the panel. The clamp and other protrusions above the substrate also occupy valuable space that is limited by the position of the optical components. Each of these methods increases the complexity of the vacuum table and the maintenance requirements of the manufacturing process.

[0005] Accordingly, there is a need for a vacuum table that can flatten severely warped substrates and is easy to manufacture. Summary of the Invention

[0006] Embodiments of the present disclosure provide a vacuum table, which includes: a vacuum plate having an opening on a top surface; a plurality of suction cups disposed on the top surface of the vacuum plate and having a bellows shape; and at least one vacuum source fluidly connected to the opening of the vacuum plate and the plurality of suction cups. The opening may be defined between surface features on the top surface of the vacuum plate. The plurality of suction cups may protrude from the top surface of the vacuum plate in an uncompressed state and may be substantially coplanar with the top 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.

[0007] According to an embodiment of the present disclosure, the vacuum table may further include a gasket disposed on the top surface of the vacuum plate at the periphery of the vacuum plate. The gasket may be disposed in a sealing groove on the top surface of the vacuum plate and may protrude from the top surface of the vacuum plate. The gasket may protrude from the top surface of the vacuum plate by 200 to 500 micrometers.

[0008] According to an embodiment of the present disclosure, the plurality of suction cups protrude from the top surface of the vacuum plate by at least 6 mm in an uncompressed state.

[0009] According to an embodiment of the present disclosure, the plurality of suction cups may include: a first group of suction cups arranged close to the edge of the top surface of the vacuum plate; and a second group of suction cups arranged close to the corner of the top surface of the vacuum plate. The first group of suction cups may be arranged parallel to each edge of the top surface of the vacuum plate. The second group of suction cups may be arranged radially symmetrically in the corners of the top surface of the vacuum plate.

[0010] According to an embodiment of the present disclosure, the at least one vacuum source may include: a first vacuum source fluidly connected to the opening of the vacuum plate; and a second vacuum source fluidly connected to the plurality of suction cups. The second vacuum source may be configured to apply a negative pressure to compress the plurality of suction cups into the compressed state. The opening may be connected to a main distribution channel in the vacuum plate, and the first vacuum source may be fluidly connected to the opening via the main distribution channel. The plurality of suction cups may be connected to an auxiliary distribution channel in the vacuum plate, and the second vacuum source may be fluidly connected to the auxiliary distribution channel.

[0011] Another embodiment of the present disclosure provides a method for flattening a substrate. The method may include providing a vacuum table. The vacuum table may include: a vacuum plate having an opening on a top surface; a plurality of suction cups disposed on the top surface of the vacuum plate and having a bellows shape; and at least one vacuum source fluidly connected to the opening of the vacuum plate and the plurality of suction cups. The plurality of suction cups may protrude from the top surface of the vacuum plate in an uncompressed state and may be substantially coplanar with the top surface of the vacuum plate in a compressed state.

[0012] The method may further include placing the substrate on the top surface of the vacuum plate in contact with a plurality of suction cups and controlling at least one vacuum source to apply a negative pressure in the space between the substrate and the top surface of the vacuum plate and in the 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 top surface of the vacuum plate.

[0013] According to an embodiment of the present disclosure, the vacuum table may further include a gasket disposed on the top surface of the vacuum plate at the periphery of the vacuum plate, the gasket at least partially sealing the space between the substrate and the top surface of the vacuum plate.

[0014] According to an embodiment of the present disclosure, the substrate disposed on the top surface of the vacuum plate may be warped such that there is a deflection of up to 6 mm, and by flattening the substrate against at least a portion of the top surface of the top plate, the deflection may be reduced to substantially 0 mm.

[0015] Another embodiment of the present disclosure provides a vacuum table including: a vacuum plate having an opening in a top surface; a gasket disposed on the top surface of the vacuum plate at the periphery of the vacuum plate; and a vacuum source in fluid communication with the opening of the vacuum plate. The gasket may project from the top 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 a compressed state.

[0016] According to an embodiment of the present disclosure, in the uncompressed state, the gasket may project from the top surface of the vacuum plate by at least 6 mm.

[0017] According to an embodiment of the present disclosure, the gasket may project from the top surface of the vacuum plate at an angle. The angle may be 45 degrees.

[0018] According to an embodiment of the present disclosure, the gasket may have a bellows shape.

[0019] Another embodiment of the present disclosure provides a method of flattening a substrate. The method may include providing a vacuum table. The vacuum table may include: a vacuum plate having an opening in a top surface; a gasket disposed on the top surface of the vacuum plate at the periphery of the vacuum plate; and a vacuum source in fluid communication with the opening of the vacuum plate. The gasket may project from the top 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 a compressed state.

[0020] The method may further include placing the substrate on the top surface of the vacuum plate in contact with the gasket and controlling the vacuum source to apply a negative pressure in the space between the substrate and the top surface of the vacuum plate sealed by the gasket, thereby compressing the gasket into a compressed state and flattening the substrate against at least a portion of the top surface of the vacuum plate. Description of the Drawings

[0021] For a more complete understanding of the nature and objects of this disclosure, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which:

[0022] Figure 1 is a cross-sectional view of a vacuum table according to an embodiment of the present disclosure;

[0023] Figure 2 is Figure 1 another cross-sectional view of the vacuum table of

[0024] Figure 3 is Figure 1 a top view of the vacuum table of

[0025] Figure 4 is a flowchart of a method according to an embodiment of the present disclosure;

[0026] Figure 5 is a cross-sectional view of a vacuum table according to another embodiment of the present disclosure;

[0027] Figure 6 is Figure 5 another cross-sectional view of the vacuum table of

[0028] Figure 7 is Figure 5 a top view of the vacuum table of

[0029] Figure 8 is a cross-sectional view of a vacuum table according to another embodiment of the present disclosure;

[0030] Figure 9 is Figure 8 another cross-sectional view of the vacuum table of; and

[0031] Figure 10 is a flowchart of a method according to an embodiment of the present disclosure. Detailed Description

[0032] Although the claimed subject matter will be described in connection with certain embodiments, other embodiments (including those that do not provide all of the benefits and features set forth herein) are also within the scope of this disclosure. Various structural, logical, process, step, and electronic changes can be made without departing from the scope of this disclosure. Accordingly, the scope of this disclosure is defined only by reference to the appended claims.

[0033] As Figures 1 to 3As shown, embodiments of the present disclosure provide a vacuum table 100. The vacuum table 100 may include a vacuum plate 110. The vacuum plate 110 can be of various shapes. For example, the vacuum plate 110 can be circular, rectangular, or any other polygonal shape. The length and width of the vacuum plate 110 can vary depending on the size of the substrate to be planarized. For example, for a substrate of 510 mm × 515 mm, the vacuum plate 110 can be greater than or equal to 510 mm × 515 mm. To planarize a smaller substrate, a smaller vacuum plate 110 can be used.

[0034] The vacuum plate 110 can have a top surface 111 on which a substrate 101 to be planarized can be placed. The substrate 101 can be an organic substrate panel, a glass carrier panel, a glass core panel, or other workpiece to be planarized. The substrate 101 can have a thickness of 0.2 mm to 4 mm. The substrate 101 can be warped into a convex shape, a concave shape, or other complex shapes, such as a saddle shape or a potato chip shape, an example of which is shown in Figure 1 FIGURES. The warp of the substrate 101 can be defined by the maximum distance from the substrate 101 to a horizontal plane. The warp of the substrate 101 can be up to 6 mm, but other values are also possible.

[0035] The top surface 111 of the vacuum plate 110 can have openings 112. The openings can be distributed throughout the top surface 111 of the vacuum plate 110 and can be connected by a main distribution channel 114 inside the vacuum plate 110. The top surface 111 of the vacuum plate 110 can further include surface features 113. The surface features 113 can be depressions or protrusions in the top surface 111 of the vacuum plate. For example, the surface features 113 can be a network of grooves, a porous structure, or a pin structure defined in the top surface 111 of the vacuum plate 110. In the embodiment shown in Figures 1 to 3 FIGURES, the surface features 113 are defined as a plurality of rectangular protrusions on the top surface 111 of the vacuum plate. For example, the rectangular protrusions can be 10 mm × 10 mm blocks or 5 mm × 5 mm blocks arranged in an array. The openings 112 can be defined in the spaces between the rectangular protrusions. With the surface features 113, the openings 112 can communicate with a larger area of the substrate 101 because air can travel between the surface features 113.

[0036] The vacuum table 100 can further include a plurality of suction cups 120. The plurality of suction cups 120 can be arranged on the top surface 111 of the vacuum plate 110. For example, the plurality of suction cups 120 can be arranged at the periphery of the top surface of the vacuum plate 111, radially outward from the openings 112 and the surface features 113. Each of the plurality of suction cups 120 can be arranged in a corresponding groove 115 in the top surface 111 of the vacuum plate 110 and can be connected by an auxiliary distribution channel 116 inside the vacuum plate 110. By being placed at the periphery of the vacuum plate 110, the plurality of suction cups 120 can engage the edge of the substrate 101 for local planarization.

[0037] The plurality of suction cups 120 may have a bellows shape. In other words, the plurality of suction cups 120 may be compressed between an uncompressed state and a compressed state. In the uncompressed state ( Figure 1 as shown), the plurality of suction cups 120 may protrude from the top surface 111 of the vacuum plate 110. For example, in the uncompressed state, the plurality of suction cups 120 may protrude from the top surface 111 of the vacuum plate 110 by at least 6 mm. Thus, even in the case where the maximum warpage is 6 mm, the plurality of suction cups 120 can still contact the surface of the substrate 101. It should be understood that the plurality of suction cups 120 may protrude more or less from the top surface 111 of the vacuum plate 110 in order to flatten a substrate 101 having more or less warpage. In the compressed state ( Figure 2 as shown), the plurality of suction cups 120 may be substantially coplanar with the top surface 111 of the vacuum plate 110. Thus, when the plurality of suction cups 120 are in the compressed state, the substrate 101 can be flattened against the top surface 111 of the vacuum plate 110.

[0038] In some embodiments, the plurality of suction cups 120 may have a rectangular shape. For example, the rectangular shape may be a rounded rectangular shape. Other circular or polygonal shapes are possible.

[0039] The plurality of suction cups 120 may include a first set of suction cups 121 and a second set of suction cups 122 ( Figure 3 as shown). The first set of suction cups 121 may be arranged near the edge of the top 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 top surface 111 of the vacuum plate 110. Thus, the first set of suction cups 121 may be configured for local flattening of the edge of the substrate 101. The second set of suction cups 122 may be arranged near the corners of the top surface 111 of the vacuum plate 110. For example, the second set of suction cups 122 may be radially symmetrically arranged in the corners of the top surface 111 of the vacuum plate 110. Thus, the second set of suction cups 122 may be configured for local flattening of the corners of the substrate 101. With the first set of suction cups 121 and the second set of suction cups 122, the plurality of suction cups 120 are arranged to handle portions of a substrate that may be more difficult to flatten.

[0040] In some embodiments, the first set of suction cups 121 and the second set of suction cups 122 may have the same shape. Alternatively, the first set of suction cups 121 and the second set of suction cups 122 may be different shapes and may be selected respectively for local flattening of the edge and corners of the substrate.

[0041] 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 to 40 KPa. The at least one vacuum source 130 may be in fluid communication with the main distribution channel 114 and the auxiliary distribution channel 116. Accordingly, the at least one vacuum source 130 may be configured to apply a negative pressure through the opening 112 and the plurality of suction cups 120. When the substrate 101 is placed on the top surface 111 of the vacuum plate 110 and the at least one vacuum source 130 applies a negative pressure, the plurality of suction cups 120 may be compressed into a compressed state, thereby flattening the substrate 101 against the top surface 111 of the vacuum plate 110.

[0042] In some embodiments, the at least one vacuum source 130 may include a first vacuum source 131 and a second vacuum source 132. The first vacuum source 131 may be in fluid communication with the opening 112 via the main distribution channel 114. The second vacuum source 132 may be in fluid communication with the plurality of suction cups 120 via the auxiliary distribution channel 116. Accordingly, the second vacuum source 132 may 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 top surface 111 of the vacuum plate 110. The first vacuum source 131 and the second vacuum source 132 may be operated simultaneously to apply a negative pressure through the opening 112 and the plurality of suction cups 120. In some embodiments, the first vacuum source 131 may be operated before the second vacuum source 132. The first vacuum source 131 may be a vacuum pump having a power of 2 to 25 KPa, and the second vacuum source 132 may be a vacuum pump having a power of 18 to 40 KPa. The second vacuum source 132 may require less power to flatten the substrate 101 because the plurality of suction cups 120 form a seal with the substrate 101 and create a static vacuum, which allows the plurality of suction cups 120 to collapse and apply a downward force to the substrate 101.

[0043] The vacuum table 100 may further include a gasket 140. The gasket 140 may include a flexible material, such as soft silicone foam. The gasket 140 may be disposed in a sealing groove 117 on the top surface 111 of the vacuum plate 110. The sealing groove 117 may be disposed at the periphery of the top 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 top surface 111 of the vacuum plate 110. Thus, when a negative pressure is applied by at least one vacuum source 130, the gasket 140 may reduce leakage and flatten the substrate 101 more efficiently. The gasket 140 may protrude from the top surface 111 of the vacuum plate 110. For example, the gasket 140 may protrude 200 to 500 microns, but may not be coplanar with the top surface 111 of the vacuum plate 110. By protruding from the top surface 111, the gasket 140 may contact the substrate 101 to seal the space between the substrate 101 and the top surface 111 of the vacuum plate 110 after the plurality of suction cups 120 collapse into a compressed state. It should be understood that the gasket 140 may be deformed to be coplanar with the top surface 111 of the vacuum plate 110 to completely flatten the substrate 101 against the top surface 111 of the vacuum plate 110.

[0044] With the vacuum table 100 of the present disclosure, a severely warped substrate 101 can be flattened by applying a negative pressure in the space between the substrate 101 and the top surface 111 of the vacuum plate 110 and in the space between the substrate 101 and the plurality of suction cups 120. The plurality of suction cups 120 may protrude to engage even the most warped portions of the substrate 101 and compress to completely flatten the substrate 101 against the top surface 111 of the vacuum table 110, and the arrangement of the suction cups 120 may be configured for local flattening in areas of the substrate 101 that may be difficult to flatten.

[0045] Embodiments of the present disclosure provide a method 200 for flattening a substrate. As shown in Figure 4 the method 200 may include the following steps.

[0046] In step 210, a vacuum table is provided. The vacuum table may correspond to the vacuum table 100 described herein, and its details will not be repeated herein.

[0047] In step 220, the substrate is placed on the top surface of the vacuum plate in contact with the plurality of suction cups. The substrate may be an organic substrate panel, a glass carrier panel, a glass core panel, or other workpiece to be flattened. The substrate may have a thickness of 0.2 mm to 4 mm. The substrate may be warped into a convex shape, a concave shape, or other complex shapes, such as a saddle shape or a potato chip shape, an example of which is shown in Figure 1 The warping of the substrate may be defined by the maximum distance from the substrate to a horizontal plane. In some embodiments, the warping of the substrate may be up to 6 mm.

[0048] When the substrate is placed on the top surface of the vacuum plate, the substrate can contact and at least partially compress a plurality of suction cups. Accordingly, the plurality of suction cups can form a seal with the substrate.

[0049] In some embodiments, the vacuum table further includes a gasket disposed on the top surface of the vacuum plate at the periphery of the vacuum plate. Accordingly, when the substrate is placed on the top surface of the vacuum plate, the gasket at least partially seals the space between the substrate and the top surface of the vacuum plate.

[0050] In step 230, at least one vacuum source is controlled to apply a negative pressure in the space between the substrate and the top 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 top surface of the vacuum plate and at least one vacuum source applies a negative pressure, the plurality of suction cups can be compressed into a compressed state, thereby flattening the substrate against the top surface of the vacuum plate. By flattening at least a portion of the substrate against the top surface of the top plate, the warpage can be reduced to substantially 0 mm.

[0051] Using the method 200 of the present disclosure, a severely warped substrate can be flattened by applying a negative pressure in the space between the substrate and the top surface of the vacuum plate and in the space between the substrate and the plurality of suction cups. The plurality of suction cups can protrude to engage even the most warped portions of the substrate and be compressed to completely flatten the substrate against the top surface of the vacuum table, and the arrangement of the suction cups can be configured for local flattening in areas of the substrate that may be difficult to flatten.

[0052] As Figures 5 to 9 shown, another embodiment of the present disclosure provides another vacuum table 300. The vacuum table 300 can include a vacuum plate 310. The vacuum plate 310 can be of various shapes. For example, the vacuum plate 310 can be circular, rectangular, or any other polygonal shape. The length and width of the vacuum plate 310 can vary depending on the size of the substrate to be flattened. For example, for a 510 mm × 515 mm substrate, the vacuum plate 310 can be greater than or equal to 510 mm × 515 mm. To flatten a smaller substrate, a smaller vacuum plate 310 can be used.

[0053] The vacuum plate 310 can have a top surface 311 on which the substrate 301 to be flattened can be placed. The substrate 301 can be an organic substrate panel, a glass carrier panel, a glass core panel, or other workpiece to be flattened. The substrate 301 can have a thickness of 0.2 mm to 4 mm. The substrate 301 can be warped into a convex shape, a concave shape, or other complex shapes, such as a saddle shape or a potato chip shape, an example of which is shown in Figure 5 shown. The warpage of the substrate 301 can be defined by the maximum distance from the substrate 301 to a horizontal plane. The warpage of the substrate 301 can be up to 6 mm, but other values are also possible.

[0054] The top surface 311 of the vacuum plate 310 may have openings 312. The openings may be distributed across the top surface 311 of the vacuum plate 310 and may be connected by a main distribution channel 314 inside the vacuum plate 310. The top surface 311 of the vacuum plate 310 may further include surface features 313. The surface features 313 may be depressions or protrusions in the top surface 311 of the vacuum plate. For example, the surface features 313 may be a network of grooves, a porous structure, or a pin structure defined in the top surface 311 of the vacuum plate 310. In Figure 4 and 5 In the embodiment shown, the surface features 313 are defined as a plurality of rectangular protrusions on the top surface 311 of the vacuum plate. For example, the rectangular protrusions may be 10 mm × 10 mm blocks or 5 mm × 5 mm blocks arranged in an array. The openings 312 may be defined in the spaces between the rectangular protrusions. With the surface features 313, the openings 312 can communicate with a larger area of the substrate 301 because air can travel between the surface features 313.

[0055] Referring Figures 5 to 7 , the vacuum table 300 may further include a gasket 320. The gasket 320 may be placed on a sealing surface 317 on the side of the vacuum plate 310. The sealing surface 317 may be arranged around the periphery of the top surface 311 of the vacuum plate 310, radially outward from the openings 312 and the surface features 313. By being placed at the periphery of the vacuum plate 310, the gasket 320 can engage the edge of the substrate 301 for local leveling. The corners 321 of the gasket 320 may form notches and / or slits (as Figure 7 shown) to fit the substrate 301 more freely.

[0056] The gasket 320 may include a flexible material. For example, the gasket 320 may be a soft silicone foam. In other words, the gasket 320 can be compressed between an uncompressed state and a compressed state. In the uncompressed state, the gasket 320 may protrude from the top surface 311 of the vacuum plate 310. For example, in the uncompressed state, the gasket 320 may protrude from the top surface 311 of the vacuum plate 310 by at least 6 mm (as Figure 5 shown). Thus, even in the case of a maximum warpage of 6 mm, the gasket 320 can still contact the surface of the substrate 301. It should be understood that the gasket 320 may protrude more or less from the top surface 311 of the vacuum plate 310 in order to level a substrate 301 with more or less warpage. In the compressed state ( Figure 6As shown in [reference], the gasket 320 can be substantially coplanar with the top surface 311 of the vacuum plate 310. When the gasket 320 is compressed from the uncompressed state to the compressed state, the gasket 320 can maintain contact with the substrate 301. Therefore, when the gasket 320 is in the compressed state, the substrate 301 can be flattened against the top surface 311 of the vacuum plate 110. It should be understood that the gasket 320 can be deformed to be coplanar with the top surface 311 of the vacuum plate 310 to completely flatten the substrate 301 against the top surface 311 of the vacuum plate 310.

[0057] In some embodiments, the gasket 320 can protrude from the top surface 311 of the vacuum plate 310 at an angle θ. For example, the angle θ can be 45 degrees. Therefore, the gasket 320 can accommodate a wider range of substrates 301 because the substrate 301 can contact the inclined surface of the gasket 340.

[0058] In some embodiments, the gasket 320 can be Figures 8 to 9 the bellows-shaped gasket 320a shown in [reference]. The bellows-shaped gasket 320a can be disposed in the sealing groove 317a on the top surface 311 of the vacuum plate 310. The bellows-shaped gasket 320a is shown in Figure 8 the uncompressed state and can be compressed downward into the compressed state ( Figure 9 as shown in [reference]) to flatten the substrate 301 against the top surface 311 of the vacuum plate 310.

[0059] The gasket 320 can be configured to seal the space between the substrate 301 and the top surface 311 of the vacuum plate 310. Therefore, when a negative pressure is applied by the vacuum source 330, the gasket 320 can reduce leakage and more effectively flatten the substrate 301.

[0060] The vacuum table 300 can further include a vacuum source 330. The vacuum source 330 can be a vacuum pump with a power of 0.3 to 9.0 KPa. The vacuum source 330 can be in fluid communication with the main distribution channel 314. Therefore, the vacuum source 330 can be configured to apply a negative pressure through the opening 312. When the substrate 301 is placed on the top surface 311 of the vacuum plate 310 and the vacuum source 330 applies a negative pressure, the gasket 320 can be compressed into the compressed state, thereby flattening the substrate 301 against the top surface 311 of the vacuum plate 310.

[0061] With the vacuum table 300 of the present disclosure, a severely warped substrate 301 can be flattened by applying a negative pressure in the space between the substrate 301 sealed by the gasket 320 and the top surface 311 of the vacuum plate 310. The gasket 320 can protrude to engage even the most warped part of the substrate 301 and be compressed to completely flatten the substrate 301 against the top surface 311 of the vacuum table 310, and by sealing the edge of the substrate 301, the gasket 320 can be configured to reduce leakage in the area of the substrate 301 where it may be difficult to flatten.

[0062] Another embodiment of the present disclosure provides a method 400 for flattening a substrate. As shown in Figure 10 , method 400 may include the following steps.

[0063] In step 410, a vacuum table is provided. The vacuum table may correspond to the vacuum table 300 described herein, and its details are not repeated herein.

[0064] In step 420, the substrate is placed on the top surface of the vacuum plate in contact with the gasket. The substrate may be an organic substrate panel, a glass carrier panel, a glass core panel, or other workpiece to be flattened. The substrate may have a thickness of 0.2 mm to 4 mm. The substrate may be warped into a convex shape, a concave shape, or other complex shapes, such as a saddle shape or a potato chip shape, an example of which is shown in Figure 5 . The warpage of the substrate may be defined by the maximum distance from the substrate to a horizontal plane. In some embodiments, the warpage of the substrate may be up to 6 mm.

[0065] When the substrate is placed on the top surface of the vacuum plate, the substrate may contact and at least partially compress the gasket. Thus, the gasket may at least partially seal the space between the substrate and the top surface of the vacuum plate.

[0066] In step 430, the vacuum source is controlled to apply a negative pressure in the space between the substrate sealed by the gasket and the top surface of the substrate. When the substrate is placed on the top surface of the vacuum plate and the vacuum source applies a negative pressure, the gasket may be compressed into a compressed state, thereby flattening the substrate against the top surface of the vacuum plate. By flattening at least a portion of the substrate against the top surface of the top plate, the warpage may be reduced to substantially 0 mm.

[0067] Using the method 400 of the present disclosure, a severely warped substrate can be flattened by applying a negative pressure in the space between the substrate sealed by the gasket and the top surface of the vacuum plate. The gasket may protrude to engage even the most warped portions of the substrate, and be compressed to completely flatten the substrate against the top surface of the vacuum table, and by sealing the edges of the substrate, the gasket may be configured to reduce leakage in areas of the substrate that may be difficult to flatten.

[0068] Although the present disclosure has been described with reference to one or more specific embodiments, it will be understood that other embodiments of the present disclosure may be made without departing from the scope of the present disclosure. Accordingly, the present disclosure is considered to be limited only by the appended claims and their reasonable interpretation.

Claims

1. A vacuum table, comprising: A vacuum plate having an opening on a top surface thereof; A plurality of suction cups disposed on the top surface of the vacuum plate and having a bellows shape, wherein the plurality of suction cups protrude from the top surface of the vacuum plate in an uncompressed state and are substantially coplanar with the top surface of the vacuum plate in a compressed state; And At least one vacuum source in fluid communication with the opening of 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. The vacuum table according to claim 1, further comprising: A gasket disposed on the top surface of the vacuum plate at a periphery of the vacuum plate.

3. The vacuum table according to claim 2, wherein the gasket is disposed in a sealing groove on the top surface of the vacuum plate and protrudes from the top surface of the vacuum plate.

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

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

6. The vacuum table according to claim 1, wherein the plurality of suction cups comprises: A first group of suction cups arranged near an edge of the top surface of the vacuum plate; And A second group of suction cups disposed near a corner of the top surface of the vacuum plate.

7. The vacuum table according to claim 6, wherein the first group of suction cups is arranged parallel to each edge of the top surface of the vacuum plate.

8. The vacuum table according to claim 6, wherein the second group of suction cups is radially symmetrically arranged in the corners of the top surface of the vacuum plate.

9. The vacuum table according to claim 1, wherein the at least one vacuum source comprises: A first vacuum source in fluid communication with the opening of the vacuum plate; And 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. The vacuum table according to claim 9, wherein the opening is connected to a main distribution channel in the vacuum plate, and the first vacuum source is in fluid communication with the opening via the main distribution channel.

11. The vacuum table according to claim 9, wherein the plurality of suction cups are connected to an auxiliary distribution channel in the vacuum plate, and the second vacuum source is in fluid communication with the auxiliary distribution channel.

12. The vacuum table according to claim 1, wherein the opening is defined between surface features on the top surface of the vacuum plate.

13. A method of leveling a substrate, comprising: Providing a vacuum table, comprising: A vacuum plate having an opening on a top surface thereof; A plurality of suction cups, which are disposed on the top surface of the vacuum plate and have a bellows shape, wherein the plurality of suction cups protrude from the top surface of the vacuum plate in an uncompressed state and are substantially coplanar with the top surface of the vacuum plate in a compressed state; and At least one vacuum source, which is in fluid communication with the opening of the vacuum plate and the plurality of suction cups; Placing the substrate on the top 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 the space between the substrate and the top surface of the vacuum plate and in the 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 top surface of the vacuum plate.

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

15. The method according to claim 13, wherein the substrate disposed on the top surface of the vacuum plate is warped such that there is a deflection of up to 6 mm, and by flattening the substrate against at least a portion of the top surface of the top plate, the deflection is reduced to substantially 0 mm.

16. A vacuum table, comprising: A vacuum plate having an opening on its top surface; A gasket disposed on the top surface of the vacuum plate at the periphery of the vacuum plate; And A vacuum source in fluid communication with the opening of 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. The 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. The vacuum table according to claim 16, wherein the gasket protrudes from the top surface of the vacuum plate at an angle.

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

20. The vacuum table according to claim 16, wherein the gasket has a bellows shape.

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