Vacuum suction cup combined ceramic fingers and their processing method

Abstract

This invention relates to the field of wafer manufacturing technology, and more particularly to a vacuum chuck-type ceramic finger and its processing method. The wafer is held by vacuum suction, and a ring structure is provided around the gas channel outlet. The wafer is vacuum-adsorbed onto the ring structure through the gas channel. The hardness of the ring structure is lower than that of the ceramic substrate. The ring structure is bonded and fixed to the ceramic substrate. Adhesive flows from the inside to the outside of the ring structure to form a fixed gap between the ring structure and the ceramic substrate at the bonding interface. After the bonding interface is formed, the adhesive overflows from the outer part of the ring structure. The bonding interface in this invention is formed by compression within the fixed gap, which eliminates air bubbles and voids at the bonding interface, strengthens the interface bonding force, and ensures a tighter, defect-free sealing layer between the ring structure and the ceramic substrate, enhancing the overall reliability and durability of the structure. The lower hardness of the ring structure compared to the ceramic substrate can mitigate the shortened lifespan and other derivative defects caused by wafer deformation.

Description

Technical Field

[0001] This invention relates to the field of wafer manufacturing technology, and in particular to a vacuum chuck-type ceramic finger and its processing method. Background Technology

[0002] In the current wafer manufacturing process, using ceramic substrate bosses to support the wafer can lead to poor boss flatness and roughness, which can affect wafer handling. The principle is that the static friction between the wafer and the ceramic substrate due to its own weight is converted into sliding friction when the transport arm moves, resulting in poor wafer sliding.

[0003] To avoid the above problems, vacuum suction for wafer mounting has become widely used. Specifically, air channels are created on the front side of the ceramic substrate, and a cover plate is glued to seal the entire air channel. On the back side, vents for wafer adsorption and steps for wafer support are created. The wafer is vacuum-adsorbed onto the three ceramic steps through the air channels. Provided the air channel sealing performance and step flatness are guaranteed, wafer slippage will not occur. However, in practical applications, when the adsorption force is strong, the high hardness of the ceramic substrate can cause wafer deformation, resulting in shortened lifespan and other derivative defects. Summary of the Invention

[0004] This invention provides a vacuum suction cup combined ceramic finger and its processing method, which can effectively solve the problems pointed out in the background art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A vacuum suction cup combined ceramic finger, which carries a wafer by vacuum suction, includes a ceramic substrate with internal air channels, the air channels having outlets on the surface of the ceramic substrate;

[0007] A ring structure is provided around the outlet. The wafer is vacuumed and adsorbed onto the ring structure through the air channel. The hardness of the ring structure is lower than that of the ceramic substrate.

[0008] The ring structure is bonded and fixed to the ceramic substrate. The bonding interface is formed by the flow of glue from the inside to the outside of the ring structure, thereby creating a fixed gap between the ring structure and the ceramic substrate.

[0009] After the bonding interface is formed, the adhesive overflows from the outer part of the ring structure.

[0010] Furthermore, the ring structure is a polyethyleneimine structure.

[0011] Furthermore, the outlet is located in the central region inside the ring structure.

[0012] Furthermore, on one side of the ring structure where it fits against the ceramic substrate, both the inner and outer rings of the ring structure are provided with rounded corners.

[0013] The processing method of the vacuum suction cup combined ceramic finger as described above includes:

[0014] The ring structure is pre-positioned relative to the ceramic matrix;

[0015] Glue is injected at the position where the inner ring of the pre-positioned annular structure is attached to the ceramic substrate to form an annular glue reservoir.

[0016] The ring structure is positioned twice by the cover structure. The second positioning realizes the positioning of the ring structure in the extension direction of the mating surface and the limitation of the gap height.

[0017] Gas is supplied from the outlet through the air passage to the space enclosed by the annular structure and the cover structure;

[0018] Within the space, the adhesive tape flows outward from the gap under the action of gas pressure;

[0019] After the glue partially overflows and forms a ring-shaped adhesive strip on the outside of the ring structure, the space is depressurized, and the cover structure is removed to allow the glue to solidify.

[0020] Furthermore, the cover structure includes a base and a power end, the power end being connected to an external power source to drive the base to move closer to or away from the ring structure;

[0021] The substrate is provided with a curved surface structure facing the outlet, and a first-level stepped structure that fits into the annular structure;

[0022] On the side of the ring structure away from the position where it is attached to the ceramic substrate, the bend of the stepped structure is attached to the outer ring of the ring structure.

[0023] Furthermore, the substrate is configured in two parts, including processing a first part of the stepped structure and processing a second part of the curved surface structure;

[0024] The coefficient of thermal expansion of the first part is lower than that of the second part.

[0025] Furthermore, the temperature of the gas supplied through the airway is higher than the ambient temperature.

[0026] Furthermore, it also includes:

[0027] Obtain an image of the excess adhesive tape and evaluate the bonding effect of the ring structure based on the image.

[0028] Further, an image of the excess adhesive tape is obtained, and the bonding effect of the ring structure is evaluated based on the image, including:

[0029] Images are captured at equal intervals along the outline of the ring structure at various points on the overflow tape.

[0030] Identify the total length and total area of ​​the excess adhesive tape in the acquired images;

[0031] When both the total length and total area meet the set threshold range, the bonding is deemed qualified.

[0032] The technical solution of this invention can achieve the following technical effects:

[0033] In this invention, adhesive flows through the gap between the ring structure and the ceramic substrate to form a bonding interface. During this process, the relative positional relationship between the ring structure and the ceramic substrate remains stable, and the bonding interface is formed by compression within the gap. This method effectively eliminates air bubbles and voids at the bonding interface, strengthens the interfacial bonding force, and ensures a tighter, defect-free sealing layer between the ring structure and the ceramic substrate, thereby enhancing the reliability and durability of the overall structure. During implementation, it avoids the problems of excessive or insufficient adhesive accumulation, ensuring a uniform adhesive layer thickness while reducing adhesive waste and lowering costs. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 A schematic diagram of a vacuum suction cup combined ceramic finger;

[0036] Figure 2 This is a schematic diagram illustrating the process of change from the adhesive storage belt to the adhesive overflow belt;

[0037] Figure 3 This is a schematic diagram showing the installation of the cover structure relative to the vacuum suction cup combined ceramic fingers;

[0038] Figure 4 for Figure 3 A magnified view of a section at point A in the middle;

[0039] Figure 5 This is a sectional view of the installation location of the cover structure;

[0040] Figure 6 for Figure 5A magnified view of a section at point C;

[0041] Figure 7 for Figure 3 A magnified view of a section at point B (including the direction of pressure);

[0042] Figure 8 This is a schematic diagram of the split structure of the cover;

[0043] Figure 9 A flowchart illustrating the processing method of vacuum suction cup combined ceramic fingers;

[0044] Figure 10 A flowchart for evaluating the bonding effect of a ring structure based on an image of the excess adhesive tape.

[0045] Reference numerals: 1. Ceramic substrate; 11. Air passage; 12. Outlet; 2. Ring structure; 3. Adhesive storage strip; 4. Gap; 5. Adhesive overflow strip; 6. Cover structure; 61. Curved surface structure; 62. Stepped structure; 63. First part; 64. Second part; 7. Power end. Detailed Implementation

[0046] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0047] Example 1

[0048] like Figure 1 and 2 As shown, the vacuum suction cup combined ceramic finger carries a wafer through vacuum suction. It includes a ceramic substrate 1 with internal air channels 11, and outlets 12 on the surface of the ceramic substrate 1. A ring structure 2 is arranged around the outlets 12. The wafer is vacuum-adsorbed onto the ring structure 2 through the air channels 11. The hardness of the ring structure 2 is lower than that of the ceramic substrate 1. The ring structure 2 is bonded and fixed to the ceramic substrate 1. Adhesive flows from the inside to the outside of the ring structure 2 at the bonding interface, forming a fixed gap 4 between the ring structure 2 and the ceramic substrate 1. After the bonding interface is formed, adhesive overflows from the outer part of the ring structure 2, participating in… Figure 2 The state.

[0049] In this invention, adhesive flows through the gap 4 between the ring structure 2 and the ceramic substrate 1 to form an adhesive interface. During this process, the relative positional relationship between the ring structure 2 and the ceramic substrate 1 remains stable, and the adhesive interface is formed by compression within the gap 4. This method effectively eliminates air bubbles and voids at the adhesive interface, strengthens the interfacial bonding force, and ensures a tighter, defect-free sealing layer between the ring structure 2 and the ceramic substrate 1, thereby enhancing the reliability and durability of the overall structure. During implementation, it avoids the problems of excessive or insufficient adhesive accumulation, ensures uniform adhesive layer thickness, reduces adhesive waste, and lowers costs.

[0050] The ring structure 2 has a lower hardness than the ceramic matrix 1, which can improve the shortened lifespan and other derivative defects caused by crystal deformation. The specific material of the ring structure 2 can be selected according to actual needs. As a preferred embodiment, the ring structure 2 can be specifically selected as a polyethyleneimine structure.

[0051] Polyethyleneimine material possesses a certain degree of deformation capability, which can buffer the deformation of the wafer during adsorption. Furthermore, under controlled coplanarity, surface roughness can be reduced to decrease dicing defects. Of course, the polyethyleneimine used in this embodiment is merely a preferred implementation method; other usable materials and structures are also within the scope of protection of this invention.

[0052] As a preferred embodiment of the above, the outlet 12 is located in the central region inside the annular structure 2; in this way, the force from the gas acting on the annular structure 2 during operation can be more uniform and stable.

[0053] As a preferred embodiment of the above, see below. Figure 2 On one side of the ring structure 2 where it is attached to the ceramic substrate 1, both the inner and outer rings of the ring structure 2 are rounded, which allows the adhesive to flow more smoothly.

[0054] Example 2

[0055] The processing method of the vacuum suction cup combined ceramic finger as described in Example 1, such as Figure 9 As shown, it includes:

[0056] S1: The ring structure 2 is pre-positioned relative to the ceramic substrate 1 to complete the initial alignment of the ring structure 2 and the ceramic substrate 1. During the pre-positioning, a ring-shaped extrusion structure can be used to apply pressure to the ring structure 2. The inner ring of the extrusion structure can provide operating space for the subsequent glue injection action. During the implementation process, the ring structure 2 is precisely placed on the surface of the ceramic substrate 1, so that its inner ring covers the outer periphery of the outlet 12 of the air channel 11, and the bonding interface between the ring structure 2 and the ceramic substrate 1 is kept parallel.

[0057] S2: Apply adhesive at the position where the inner ring of the pre-positioned annular structure 2 adheres to the ceramic substrate 1, forming an annular adhesive reservoir 3; the adhesive, as the bonding medium, is initially concentrated on the inner side, and continues to the next step. Figure 2 The top left side of the figure shows the glue storage strip 3 in this step. At this position, the glue supply is required to be stable. The amount of glue stored is set according to the actual product size and glue condition. The glue injection must be carried out continuously to form a closed and uniform glue storage strip 3.

[0058] S3: The ring structure 2 is repositioned secondaryally using the cover structure 6. This secondary positioning achieves the positioning of the ring structure 2 in the extension direction of the mating surface, and limits the height of the gap 4 between the ring structure 2 and the mating surface. The cover structure 6 in this step, as shown... Figures 3-6 As shown; the secondary positioning in this step is different from the pre-positioning. This positioning cannot be done by pressing the ring structure 2 and the ceramic substrate 1 together. In this invention, the gap 4 between the ring structure 2 and the ceramic substrate 1 is the key to obtaining the bonding interface. After the secondary positioning is completed, the adhesive tape 3 achieves the sealing function on the inside of the gap 4.

[0059] S4: Gas is supplied from outlet 12 through air passage 11 into the space enclosed by ring structure 2 and cover structure 6; during implementation, air passage 11 becomes multifunctional in this step, and compared with the vacuum passage in operation, it is used as a positive pressure passage in the production process, and the gas forms a uniform static pressure in the closed space.

[0060] S5: Within the space, the adhesive tape 3 flows outward from the gap 4 under the action of gas pressure, and the direction of the gas pressure is as follows: Figure 7 As shown; under pressure, the glue will flow under pressure in the restricted gap 4, thereby eliminating air bubbles and forming a complete sealing ring. The glue is squeezed outward to expel air and avoid sealing voids.

[0061] S6: After the adhesive partially overflows and forms a ring-shaped adhesive strip 5 on the outside of the ring structure 2, the space is depressurized, and the cover structure 6 is removed to allow the adhesive to solidify. The adhesive strip 5 is as follows: Figure 2 As shown at the bottom center, the overflow tape 5 serves as a marker for the completion of the bonding interface. Waiting for the adhesive to solidify completes the bonding of the ring structure 2. During implementation, the air supply can be stopped after observing a continuous and uniform annular adhesive line overflowing from the outer ring of the ring structure 2, or the timing of stopping the air supply can be adjusted according to the production rhythm. During the removal of the cover structure 6, collisions and displacement of the ring structure 2 must be avoided. The adhesive can be cured by allowing it to stand or by heating.

[0062] The processing method in this embodiment can precisely control the flow path of the adhesive through air pressure, and can visualize the bonding process through the adhesive overflow tape 5. During the bonding interface formation process, active air degassing eliminates air bubbles, the adhesive layer is continuous without breaks, and gas pressurization simultaneously completes positioning, degassing, and adhesive extrusion. This process can be directly integrated into the production line and is suitable for the precision bonding of the ring structure 2, ensuring that surface roughness control is maintained under the coplanarity requirement, and reducing the risk of scratch defects.

[0063] As a preferred embodiment of the above, the cover structure 6 includes a base and a power end 7. The power end 7 is connected to an external power source to drive the base to move closer to or away from the ring structure 2. The base is provided with a curved surface structure 61 facing the outlet 12 and a first-level step structure 62 that fits into the ring structure 2. On the side of the ring structure 2 away from the position where it fits into the ceramic base 1, the bend of the step structure 62 fits into the outer ring of the ring structure 2.

[0064] See Figure 5 and Figure 6 The curved structure 61 transforms the injected gas from vertical impact to multi-directional diffusion. This method can eliminate local turbulence and form a relatively uniform static pressure field in the circumference, ensuring that the glue is extruded synchronously and at a uniform speed in the annular gap 4, and avoiding the occurrence of breakpoints or width differences in the overflow tape 5 due to pressure fluctuations.

[0065] The vertical surface of the stepped structure 62 is tightly fitted to the outer ring of the ring structure 2. On the one hand, it can resist the lateral shear force on the ring structure 2 during gas injection and prevent the ring structure 2 from shifting. On the other hand, the horizontal bottom surface of the stepped structure 62 covers the non-adhesive area on the upper surface of the ring structure 2, which can suppress the micro-deformation of the ring caused by gas pressure, maintain the stability of the gap 4 height, and ensure the uniformity of the adhesive layer thickness.

[0066] During implementation, the corner of the stepped structure 62 is fully fitted with the outer circumference of the ring structure 2 to form a dynamic sealing boundary. During the glue extrusion stage, it prevents gas from escaping along the upper surface of the ring structure 2, forcing the airflow to act completely on the glue storage belt 3, thus achieving protection during the production process. By restricting the glue to overflow only from the gap 4 on the outside of the ring structure 2, a straight-edged annular overflow belt 5 is formed.

[0067] As a preferred embodiment of the above, the substrate is configured in two parts, including a first part 63 of the processed stepped structure 62 and a second part 64 of the processed curved surface structure 61; the coefficient of thermal expansion of the first part 63 is lower than that of the second part 64.

[0068] like Figure 8As shown, the split structure design allows for the selection of different materials for different parts based on their different functions; for example, the stepped structure 62 uses a low-expansion alloy, while the curved structure 61 uses a high thermal conductivity copper alloy, physically isolating the thermal expansion difference between the two materials, and the two can be connected by a screw structure.

[0069] Based on the above-mentioned separate configuration, as a further preferred method, the gas supplied through air channel 11 is at a temperature higher than the ambient temperature. This appropriately increased gas temperature allows the viscosity of the adhesive to decrease after heating, enhancing molecular activity and simultaneously inducing thermal expansion to synergistically promote interfacial adhesion. With the viscosity appropriately reduced, the flow resistance of the adhesive in the gap 4 decreases, allowing for faster filling of the entire annular path. The increased thermal energy increases the spreading coefficient of the adhesive at the interface between the ceramic matrix 1 and the annular structure 2, forcing the adhesive into the surface micropores of both, forming a dual structure of micromechanical interlocking and chemical bonding.

[0070] In this embodiment, the processing method of the vacuum suction cup combined ceramic finger further includes: acquiring an appearance image of the excess adhesive tape 5, and evaluating the bonding effect of the ring structure 2 based on the appearance image. This process can be performed after the cover structure 6 is removed, thereby ensuring the accuracy and convenience of appearance image acquisition.

[0071] As a preferred embodiment of the above, and as a relatively simple implementation, an image of the appearance of the excess adhesive tape 5 is obtained, such as... Figure 10 As shown, it includes:

[0072] A1: Along the outline of the ring structure 2, images are collected at equal intervals at various points on the overflow tape 5.

[0073] A2: Identify the total length and total area of ​​the overflow tape 5 in the acquired images;

[0074] A3: When both the total length and total area meet the set threshold range, the bonding is deemed qualified.

[0075] In a specific implementation, when the total length of the excess adhesive tape 5 is greater than or equal to 98% of the set length, the adhesive is considered to have formed a closed annular seal, thereby preventing linear leakage channels caused by adhesive breakage. If the length does not meet the standard, it indicates the presence of unfilled sections, increasing the risk of wafer adsorption failure under vacuum suction, and therefore the product must be deemed unqualified.

[0076] In addition, when the total area of ​​the overflow tape 5 is 95% to 105% of the set area, the overflow amount is considered appropriate. This can prevent interface pores caused by insufficient adhesive and avoid excessive adhesive contamination of the functional surface of the ring.

[0077] In continuous production, equipment calibration can be triggered immediately when drift in total length or total area data is detected: for length fluctuations, check for nozzle blockages or uneven air pressure; for area fluctuations, detect changes in adhesive viscosity or abnormal temperature. During implementation, this preferred solution only requires contour extraction and pixel statistics, eliminating the need for complex edge gradient analysis. The determination can be completed within 5 seconds after removing the cover structure, ensuring product production efficiency.

[0078] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A vacuum chuck combined ceramic finger for carrying a wafer by vacuum suction, comprising a ceramic base body having an internal air passage, and an outlet of the air passage being arranged on a surface of the ceramic base body; characterized in that: an annular structure is arranged around the outlet, and the wafer is adsorbed on the annular structure by vacuum suction through the air passage, and the hardness of the annular structure is lower than that of the ceramic base body; the annular structure is fixedly connected with the ceramic base body, and a glue flow interface is formed from the inside to the outside of the annular structure, so as to form a gap between the annular structure and the ceramic base body; after the glue flow interface is formed, the glue flows out from the outside of the annular structure. 2.The annular structure is a polyethylene imine structure. 3.The outlet is located in a central region inside the annular structure. 4.On one side of a position where the annular structure is attached with the ceramic base body, the inner circle and the outer circle of the annular structure are both provided with a round corner. 5.Comprising: pre-positioning the annular structure relative to the ceramic base body; injecting glue at a position where the inner circle of the pre-positioned annular structure is attached with the ceramic base body, so as to form an annular glue storage belt; and second positioning the annular structure by a cover structure, so as to realize positioning of the annular structure in a direction of extension of an attached surface and limitation of a height of the gap.

2. The vacuum cup modular ceramic finger according to claim 1, wherein, 6.Through the air passage, gas is supplied from the outlet to a space surrounded by the annular structure and the cover structure.

3. The vacuum cup modular ceramic finger according to claim 1, wherein, 7.In the space, the glue storage belt flows from the gap to the outside under the action of gas pressure.

4. The vacuum cup modular ceramic finger according to claim 1, wherein, 8.After the annular overflow glue belt is formed on the outside of the annular structure by the glue overflow, the space is depressurized, and the cover structure is removed to wait for the glue to solidify.

5. The method of claim 1 to 4, wherein the vacuum chuck assembly is a ceramic finger. 9.The cover structure comprises a base body and a power end, the power end is connected with an external power source, and the base body is driven to move close to or away from the annular structure. 10.The base body is provided with a curved surface structure facing the outlet and a first step structure attached with the annular structure. 11.On a side of the annular structure away from the position attached with the ceramic base body, a bending corner of the step structure is attached with an outer circle of the annular structure. 12.The base body is divided into two parts, including a first part for processing the step structure and a second part for processing the curved surface structure. 13.The first part has a lower thermal expansion coefficient than the second part. 14.The gas supplied through the air passage has a higher temperature than the ambient temperature. 15.Further comprising: obtaining an appearance image of the overflow glue belt, and evaluating the adhesion effect of the annular structure through the appearance image.

6. The method of claim 5, wherein the vacuum chuck assembly ceramic finger is processed by, 16.Obtaining an appearance image of the overflow glue belt, and evaluating the adhesion effect of the annular structure through the appearance image, comprising: image acquisition at equal distances along the outline of the annular structure; identifying a total length and a total area of the overflow glue belt in the acquired image; and determining that the adhesion is qualified when the total length and the total area both satisfy a set threshold range. ​ ​ 7. The method of claim 6, wherein the vacuum chuck assembly ceramic finger is processed by, ​ ​ 8. The method of claim 7, wherein the vacuum chuck assembly ceramic finger is processed by, ​ 9. The method of claim 5, wherein the ceramic finger is formed by a combination of vacuum chucking and a ceramic finger machining method. ​ ​ 10. The method of claim 9, wherein the vacuum chuck assembly ceramic finger is processed by, ​ ​ ​ ​

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