A porous adsorption substrate and a porous chuck structure

Abstract

The utility model discloses a kind of porous adsorption matrix and porous chuck structure, suitable for being communicated with vacuum system, a plurality of through holes are provided on porous adsorption matrix, one side of porous adsorption matrix is the contact surface for being contacted with the adsorbed object, the other side of porous adsorption matrix is the suction surface for being communicated with vacuum system;The porosity of porous adsorption matrix gradually increases in the direction of the suction surface pointing to the contact surface direction.The utility model passes through the design of the porous adsorption matrix of porosity gradient increasing from suction surface to contact surface direction, realizes the simultaneous consideration of adsorption performance and mechanical strength.Contact surface high porosity area realizes high adsorption force, suction surface low porosity area provides high structural strength, breaks through the performance contradiction of traditional homogeneous material.

Description

Technical Field

[0001] This utility model relates to the field of suction cup structure technology, specifically to a porous adsorption substrate and a porous suction cup structure. Background Technology

[0002] Porous ceramic chucks play a crucial role in semiconductor manufacturing, being installed on critical components of dicing machines or inspection equipment. The principle behind porous ceramic chucks is to utilize the porous structure of the stage surface and the negative pressure effect to maintain the high-precision planarity of thin silicon wafers.

[0003] The porosity of a suction cup is related to its adsorption force. When the porosity is high, the adsorption force is strong, but the material strength is low; conversely, when the porosity is low, the material strength is high, but the adsorption force is weak. Currently, the porosity of porous ceramic suction cups on the market exhibits a uniform distribution, meaning its internal porosity is homogeneous throughout the overall structure. This makes it impossible for commercially available porous ceramic suction cups to simultaneously achieve both material strength and adsorption force. Utility Model Content

[0004] In view of this, the present invention provides a porous adsorption substrate and a porous suction cup structure to solve the problem that current porous ceramic suction cups cannot simultaneously take into account material strength and adsorption force.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] In a first aspect, this utility model provides a porous adsorption matrix suitable for connection with a vacuum system. The porous adsorption matrix is ​​provided with a plurality of through holes. One side of the porous adsorption matrix is ​​a contact surface that contacts the adsorbate, and the other side of the porous adsorption matrix is ​​a suction surface that is connected to the vacuum system. The porosity of the porous adsorption matrix gradually increases in the direction from the suction surface to the contact surface.

[0007] The beneficial effects of the aforementioned porous suction cup structure are as follows: This invention achieves a balance between adsorption performance and mechanical strength by designing a porous adsorption matrix with a porosity gradient increasing from the suction surface to the contact surface. The high-porosity region of the contact surface provides high adsorption force, while the low-porosity region of the suction surface provides high structural strength, thus overcoming the performance contradictions of traditional homogeneous materials.

[0008] The high porosity of the contact surface enhances adsorption force. The side in contact with the adsorbate (the contact surface) has higher porosity, resulting in more pores per unit volume and a larger specific surface area. This provides more contact sites for adsorbate molecules during the adsorption process, directly improving adsorption capacity and stability. The porous structure with high porosity can closely conform to the microscopic undulations of the adsorbate surface, reducing air residue, enhancing vacuum sealing, and preventing adsorption failure due to localized air leakage.

[0009] The low porosity of the suction surface enhances the material's strength. The side of the suction surface connected to the vacuum system has lower porosity, resulting in a higher proportion of solid portion in the porous adsorption matrix, a denser structure, and significantly enhanced mechanical strength. This avoids the breakage problem caused by insufficient strength in traditional low-porosity suction cups.

[0010] To further optimize the technical solution, the porous adsorption matrix includes multiple structural layers stacked and connected in sequence. Each structural layer is provided with multiple through holes. The through holes of two adjacent structural layers are connected. The porosity of each structural layer is greater than that of the structural layer adjacent to it and closer to the suction surface.

[0011] The beneficial effects of the above technical solution are as follows: Compared with a single-layer arrangement of structural layers, this utility model forms a porous adsorption matrix by laminating multiple structural layers and controls the porosity of each structural layer. Each structural layer can be processed separately, which is very convenient for processing each structural layer and will not increase the processing difficulty. After lamination and sintering, each structural layer forms the final porous adsorption matrix.

[0012] To further optimize the technical solution, the pore diameter of each structural layer is smaller than that of the structural layer adjacent to it and closer to the contact surface, so that the pore diameter of the porous adsorption matrix gradually decreases in the direction from the suction surface to the contact surface.

[0013] The beneficial effects of the above technical solution are as follows: By gradually reducing the pore size, the flow rate of the suction port connected to the vacuum system is increased, allowing the porous adsorption matrix to quickly reach a vacuum. Simultaneously, the increased pore size at the suction surface enhances the channel flow rate, enabling the inclusion of larger particles and reducing the probability of end-stage clogging. The small-diameter through-holes on the contact surface act as a primary filter layer, preventing particles larger than this pore size from entering the internal channels. Even if particles close to the pore size on the contact surface enter the through-holes, the pore sizes of subsequent structural layers are all larger than the outer diameter of the particles, thus preventing cumulative clogging within the through-holes and extending the overall service life of the suction cup.

[0014] The aperture of the through-hole on the contact surface in contact with the atmosphere is reduced, which closely fits the micro-undulations of the workpiece surface and effectively prevents outside air from seeping in through the gap between the contact surface and the object being adsorbed, thus helping to reduce vacuum leakage.

[0015] To further optimize the technical solution, the structural layer is provided with at least five layers.

[0016] To further optimize the technical solution, when the structural layer has five layers, each of the structural layers is a first structural layer, a second structural layer, a third structural layer, a fourth structural layer, and a fifth structural layer stacked sequentially in the direction from the suction surface to the contact surface.

[0017] Further optimizing the technical solution, the porosity of the first structural layer is 40-55%, the porosity of the second structural layer is 45-55%, the porosity of the third structural layer is 50-60%, the porosity of the fourth structural layer is 50-65%, and the porosity of the fifth structural layer is 60-70%.

[0018] The technical solution is further optimized as follows: the through-hole diameter of the first structural layer is 35-45 μm, the through-hole diameter of the second structural layer is 30-40 μm, the through-hole diameter of the third structural layer is 25-35 μm, the through-hole diameter of the fourth structural layer is 20-30 μm, and the through-hole diameter of the fifth structural layer is 0-10 μm.

[0019] The technical solution is further optimized so that the thickness of the structural layer is 0.2-1mm.

[0020] To further optimize the technical solution, the structural layer is a ceramic sheet.

[0021] Secondly, this utility model provides a porous suction cup structure, including a porous adsorption substrate.

[0022] The aforementioned porous suction cup structure has the same beneficial effects as the porous adsorption substrate of the first aspect of this utility model, and will not be described in detail here. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a porous adsorption matrix provided by this utility model.

[0025] Figure label:

[0026] 1. First structural layer, 2. Second structural layer, 3. Third structural layer, 4. Fourth structural layer, 5. Fifth structural layer, 6. Through hole, 7. Contact surface, 8. Suction surface. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0028] Porous ceramic chucks play a crucial role in semiconductor manufacturing, being installed on critical components of dicing machines or inspection equipment. The principle behind porous ceramic chucks is to utilize the porous structure of the stage surface and the negative pressure effect to maintain the high-precision planarity of thin silicon wafers.

[0029] The porosity of a suction cup is related to its adsorption force. Higher porosity means more internal pores and lower density. While a high porosity results in strong adsorption, the material strength is low; conversely, a low porosity results in high material strength but weak adsorption. Currently, commercially available porous ceramic suction cups exhibit a uniform porosity distribution, meaning their internal porosity is consistent throughout the structure and does not change with location. This makes it impossible for commercially available porous ceramic suction cups to simultaneously achieve both material strength and adsorption force.

[0030] Therefore, this utility model provides a porous adsorption matrix. By changing the porosity distribution of the porous adsorption matrix, the porosity of the porous adsorption matrix gradually increases in the direction from the suction surface to the contact surface, thereby enabling the suction cup to simultaneously take into account both material strength and adsorption force.

[0031] Currently, porous ceramic suction cups on the market generally employ direct molding technology, typically resulting in a single-layer structure with internal pores concentrated around a specific size. If the internal pore size of the suction cup is too large, vacuum leakage is more likely, reducing its suction power. Simultaneously, while larger pores provide stronger suction, they can also easily become clogged by dust or particles from the suction components. Conversely, if the ceramic pore size is too small, the flow rate within the internal channels will be limited, similarly weakening the suction power.

[0032] Therefore, this invention distributes the pore size of the porous adsorption matrix in a gradually decreasing manner in the direction from the suction surface to the contact surface, thereby reducing vacuum leakage and the probability of clogging.

[0033] The following is combined Figure 1 As shown, the porous adsorption substrate of the first aspect of the present invention and the porous suction cup structure of the second aspect of the present invention are described in detail.

[0034] According to an embodiment of the present invention, in a first aspect, a porous adsorption matrix is ​​provided, suitable for connection with a vacuum system. The porous adsorption matrix has multiple through holes 6. One side of the porous adsorption matrix is ​​a contact surface 7 that contacts the adsorbate, and the other side is a suction surface 8 that connects to the vacuum system. The through holes 6 extend from the suction surface 8 through the contact surface 7. The porosity of the porous adsorption matrix gradually increases in the direction from the suction surface 8 to the contact surface 7.

[0035] In this embodiment, by designing a porous adsorption matrix with a porosity gradient increasing from the suction surface to the contact surface, both adsorption performance and mechanical strength are simultaneously achieved. The high porosity region of the contact surface provides high adsorption force, while the low porosity region of the suction surface provides high structural strength, overcoming the performance contradictions of traditional homogeneous materials.

[0036] The high porosity of the contact surface enhances adsorption force. The side in contact with the adsorbate (the contact surface) has higher porosity, resulting in more pores per unit volume and a larger specific surface area. This provides more contact sites for adsorbate molecules during the adsorption process, directly improving adsorption capacity and stability. The porous structure with high porosity can closely conform to the microscopic undulations of the adsorbate surface, reducing air residue, enhancing vacuum sealing, and preventing adsorption failure due to localized air leakage.

[0037] The low porosity of the suction surface enhances the material's strength. The side of the suction surface connected to the vacuum system has lower porosity, resulting in a higher proportion of solid portion in the porous adsorption matrix, a denser structure, and significantly enhanced mechanical strength. This avoids the breakage problem caused by insufficient strength in traditional low-porosity suction cups.

[0038] In some embodiments, the porous adsorption matrix includes a plurality of structural layers stacked in sequence, each structural layer having a plurality of through holes 6, the through holes of two adjacent structural layers being interconnected, and the porosity of each structural layer being greater than the porosity of the structural layer adjacent to it and closer to the suction surface 8.

[0039] In this embodiment, the porosity of each structural layer is greater than that of the adjacent layer near the suction surface. That is, from the contact surface in contact with the adsorbate to the suction surface connected to the vacuum system, the porosity decreases layer by layer. The outer structural layer, which directly contacts the adsorbate, has the highest porosity, with a large number of pores per unit volume, a large specific surface area, and abundant adsorption sites, enabling more efficient adsorption of the adsorbate through negative pressure. The inner structural layer, which is close to the vacuum system, has the lowest porosity, a denser matrix, and significantly improved mechanical strength. It can withstand the stress generated by the vacuum negative pressure and equipment vibration, avoiding suction cup breakage or deformation due to insufficient strength.

[0040] Compared to a single-layer arrangement of structural layers, this embodiment forms a porous adsorption matrix by laminating multiple structural layers, and controls the porosity of each structural layer individually. Each structural layer can be processed separately, making processing very convenient and not increasing the processing difficulty. After lamination and sintering, each structural layer forms the final porous adsorption matrix, and the porosity of the final porous adsorption matrix gradually increases in the direction from the suction surface 8 to the contact surface 7. In this embodiment, the inner structural layer has a strong supporting effect, and the outer structural layer has a strong adsorption effect, breaking through the performance limits of single-layer materials and achieving a two-way improvement in adsorption force and strength.

[0041] In some embodiments, the pore diameter of each structural layer is smaller than that of the structural layer adjacent to it and closer to the contact surface 7, so that the pore diameter of the porous adsorption matrix gradually decreases in the direction from the suction surface 8 to the contact surface 7.

[0042] In this embodiment, by gradually decreasing the pore size, the flow rate of the suction port connected to the vacuum system is increased, allowing the porous adsorption matrix to quickly reach a vacuum. Simultaneously, the increased pore size at position 8 on the suction surface enhances the channel flow rate, enabling the inclusion of larger particles and reducing the probability of clogging at the end (closer to the suction surface). The small-diameter through-holes on the contact surface act as a primary filter layer, preventing particles larger than this pore size from entering the internal channels. Even if particles close to the pore size on the contact surface enter the through-holes, the pore sizes of subsequent structural layers are all larger than the outer diameter of the particles, thus preventing cumulative clogging within the through-holes and extending the overall service life of the suction cup.

[0043] The aperture of the through-hole on the contact surface in contact with the atmosphere is reduced, which closely fits the micro-undulations of the workpiece surface and effectively prevents outside air from seeping in through the gap between the contact surface and the object being adsorbed, thus helping to reduce vacuum leakage.

[0044] In some embodiments, the structural layer has at least five layers.

[0045] Taking a five-layer structure as an example, each layer consists of a first structural layer 1, a second structural layer 2, a third structural layer 3, a fourth structural layer 4, and a fifth structural layer 5, sequentially stacked from the suction surface 8 towards the contact surface 7. In this embodiment, the porous adsorption matrix employs a gradually decreasing pore size distribution and a gradually increasing porosity distribution in the direction from the suction surface 8 to the contact surface 7. Through casting and lamination processes, ceramic sheets made from slurries with different particle size formulations are sintered together using a lamination process to form a gradually decreasing pore size distribution and a gradually increasing porosity distribution.

[0046] The porous adsorption matrix in this embodiment is supported by five ceramic slurries, which are ultimately formed into a multi-level distribution structure through casting, lamination, debinding, and sintering. The porosity of the first structural layer 1 is 40-55%, the second structural layer 2 is 45-55%, the third structural layer 3 is 50-60%, the fourth structural layer 4 is 50-65%, and the fifth structural layer 5 is 60-70%. The pore size of the first structural layer 1 is 35-45 μm, the second structural layer 2 is 30-40 μm, the third structural layer 3 is 25-35 μm, the fourth structural layer 4 is 20-30 μm, and the fifth structural layer 5 is 0-10 μm. In this embodiment, the adsorption efficiency and adsorption force can be effectively improved while maintaining good air permeability and flowability. From the suction surface to the contact surface, the pore size gradually decreases, allowing for layer-by-layer filtration and blocking of particles, preventing clogging and maintaining the suction cup's continuous and efficient operation. Furthermore, the gradually expanding porosity distribution helps increase the adsorption area, improving the adsorption effect, while also reducing vacuum leakage, further enhancing the suction cup's adsorption performance.

[0047] The structural layer is a ceramic sheet. The thickness of the structural layer is 0.2-1mm. By controlling the thickness of each structural layer, the overall thickness of the porous adsorption matrix is ​​controlled to meet the application requirements.

[0048] The above-mentioned method for preparing porous adsorption matrix includes the following steps:

[0049] S1. Prepare casting slurries with different pore sizes and porosities according to the aggregate particle size.

[0050] S2. The casting slurry prepared in step S1 is cast on a small casting machine to obtain ceramic sheets. The cast ceramic sheets are dried at a certain temperature to obtain multiple ceramic green sheets with gradually increasing average pore size and gradually decreasing porosity.

[0051] S3. Stack the obtained ceramic pieces.

[0052] S4. Then, isostatic pressing is performed to obtain ceramic green bodies.

[0053] S5. The ceramic green body is debinded and sintered to obtain multi-level porous ceramic.

[0054] According to an embodiment of the present invention, in a second aspect, a porous suction cup structure is provided, comprising a porous adsorption substrate. The surface or interior of the porous adsorption substrate has numerous tiny pores, which can increase the adsorption area and generate adsorption force through principles such as air pressure difference, and can be used to adsorb objects.

[0055] In addition, the porous suction cup structure also includes a suction cup shell, on which the porous adsorption substrate can be positioned to provide overall support for the suction cup. The porous suction cup structure also includes an air channel, which connects the vacuum source of the vacuum system to the porous adsorption substrate, transferring the suction force generated by the vacuum to the substrate surface, enabling the porous adsorption substrate to adsorb objects.

[0056] Example 1

[0057] This embodiment discloses a method for preparing a porous adsorption matrix, including the following steps:

[0058] Casting slurries with different pore sizes and porosities are prepared according to the aggregate particle size.

[0059] The prepared casting slurry was cast on a small casting machine to obtain ceramic sheets at a casting speed of 0.8 m / min and a casting thickness of 0.5 mm. The cast ceramic sheets were dried at 120°C to obtain ceramic green sheets with average pore sizes of 5 μm, 20.1 μm, 28.3 μm, 33 μm, and 40.1 μm, and porosities of 62%, 58%, 52%, 46%, and 38%, respectively.

[0060] The obtained ceramic sheets were stacked (pressure 5 g kf, temperature 120°).

[0061] Subsequently, isostatic pressing was performed at 150 MPa to obtain ceramic green bodies.

[0062] Multi-layered porous ceramics are obtained by debinding and sintering the ceramic green body.

[0063] Comparison of performance between multi-layer porous ceramics and third-layer porous ceramics of the same thickness produced by injection molding

[0064] name strength suction vacuum degree Surface roughness Example 1 21MPa 0.297 N / cm -0.1MPa 0.135um Comparative Example 11MPa 0.177 N / cm 0.08MPa 0.31um

[0065] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A porous adsorption matrix, suitable for communication with a vacuum system, characterized in that, The porous adsorption matrix is ​​provided with multiple through holes (6), one side of the porous adsorption matrix is ​​a contact surface (7) that contacts the adsorbate, and the other side of the porous adsorption matrix is ​​a suction surface (8) that is connected to the vacuum system; the porosity of the porous adsorption matrix gradually increases in the direction from the suction surface (8) to the contact surface (7).

2. The porous adsorption matrix according to claim 1, characterized in that, The porous adsorption matrix includes multiple structural layers stacked in sequence. Each structural layer is provided with multiple through holes (6). The through holes of two adjacent structural layers are connected. The porosity of each structural layer is greater than that of the structural layer adjacent to it and closer to the suction surface (8).

3. The porous adsorption matrix according to claim 2, characterized in that, The pore diameter of each of the structural layers is smaller than that of the structural layer adjacent to it and closer to the contact surface (7), so that the pore diameter of the porous adsorption matrix gradually decreases in the direction from the suction surface (8) to the contact surface (7).

4. The porous adsorption matrix according to claim 3, characterized in that, The structure has at least five layers.

5. The porous adsorption matrix according to claim 4, characterized in that, When the structure layer has five layers, each of the structure layers is a first structure layer (1), a second structure layer (2), a third structure layer (3), a fourth structure layer (4), and a fifth structure layer (5) that are stacked sequentially in the direction from the suction surface (8) to the contact surface (7).

6. The porous adsorption matrix according to claim 5, characterized in that, The porosity of the first structural layer (1) is 40-55%, the porosity of the second structural layer (2) is 45-55%, the porosity of the third structural layer (3) is 50-60%, the porosity of the fourth structural layer (4) is 50-65%, and the porosity of the fifth structural layer (5) is 60-70%.

7. The porous adsorption matrix according to claim 6, characterized in that, The through-hole diameter of the first structural layer (1) is 35-45 μm, the through-hole diameter of the second structural layer (2) is 30-40 μm, the through-hole diameter of the third structural layer (3) is 25-35 μm, the through-hole diameter of the fourth structural layer (4) is 20-30 μm, and the through-hole diameter of the fifth structural layer (5) is 0-10 μm.

8. The porous adsorption matrix according to any one of claims 2-7, characterized in that, The thickness of the structural layer is 0.2-1 mm.

9. The porous adsorption matrix according to any one of claims 2-7, characterized in that, The structural layer is a ceramic sheet.

10. A porous suction cup structure, characterized in that, The porous adsorption matrix includes any one of claims 1-9.

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