Mechanical arm for adsorbing warped wafer

Abstract

The embodiment of the utility model provides a mechanical arm used for adsorbing a warped wafer. The mechanical arm comprises a hand structure, the plurality of vacuum chucks are uniformly distributed on the hand structure; the vacuum chuck comprises a supporting part and an adsorption part; a through hole is formed in the center of the supporting part and is used for extracting gas between the vacuum chuck and the wafer; the adsorption part is arranged around the supporting part, and the adsorption part is made of flexible ceramic; wherein the adsorption part is provided with a plurality of circles of protrusions, the outermost circle of protrusion is an annular continuous protrusion, the middle circle of protrusion and / or the inner circle of protrusion are / is a non-continuous protrusion, a recess between every two adjacent protrusions is communicated with the through hole, and the first height difference of part or all of the protrusions of the adsorption part relative to the surface of the hand structure is larger than the first height difference of the second height difference relative to the surface of the hand structure. And the height difference is greater than a second height difference of the supporting part relative to the hand structure. With the adoption of the technical scheme, the adsorption capacity of the warped wafer can be improved.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor manufacturing technology, and more particularly to a robotic arm for adsorbing warped wafers. Background Technology

[0002] During wafer manufacturing, the surface device layers accumulate high temperatures, causing the surface stress of the wafer to rise continuously. This leads to gradual deformation and warping of the wafer. When the warped wafer is transferred through most subsequent semiconductor manufacturing equipment, it may fail to fully adhere to the vacuum chuck of the robotic arm, triggering equipment alarms.

[0003] Therefore, how to provide technical solutions to improve the adsorption capacity of warped wafers has become an urgent technical problem to be solved. Utility Model Content

[0004] In view of this, embodiments of the present disclosure provide a robotic arm for adsorbing warped wafers, which can improve the adsorption capacity for warped wafers.

[0005] This disclosure provides a robotic arm for adsorbing warped wafers, comprising: a hand structure; a plurality of vacuum suction cups uniformly distributed on the hand structure; each vacuum suction cup includes a support portion and an adsorption portion; the support portion has a through hole at its center for extracting gas between the vacuum suction cup and the wafer; the adsorption portion is disposed around the support portion, and the adsorption portion is made of flexible ceramic; wherein, the adsorption portion includes multiple rings of protrusions, the outermost ring of protrusions being a continuous annular protrusion, the inner ring of protrusions being discontinuous protrusions, and the recesses between adjacent protrusions communicating with the through hole, and a first height difference between some or all of the protrusions of the adsorption portion and the surface of the hand structure being greater than a second height difference between the support portion and the hand structure.

[0006] Optionally, the hand structure has a plurality of support blocks, and the third height difference of the support blocks relative to the surface of the hand structure is consistent with the second height difference.

[0007] Optionally, the hand structure also has multiple vacuum channels inside, each vacuum channel being connected to a through hole in the support part, and the multiple vacuum channels are independent of each other; wherein, the vacuum channel is coupled to an external vacuum system, and responds to the opening of the vacuum system by a solenoid valve, the vacuum system provides an adsorption force to the vacuum channel.

[0008] Optionally, the hand structure is U-shaped, including a palm and two interdigitated fingers, and the number of vacuum suction cups is three, which are respectively distributed on the surface of the palm and the surface of the interdigitated fingers.

[0009] Optionally, one or more of the following conditions are met: the difference between the first height difference and the second height difference is selected from [0.1mm, 1mm]; the top height decreases ring by ring from the outermost ring protrusion of the adsorption part to the innermost ring protrusion.

[0010] Optionally, each ring of protrusions is annular, and the top height decreases progressively from the outermost ring of the adsorption portion to the innermost ring of the adsorption portion; the adsorption portion has a partition connecting each protrusion, and uniformly divides the adsorption portion into multiple independent adsorption regions; wherein, the partition is made of flexible ceramic, and the surface height of the partition continuously increases, and the surface height of the partition is consistent with the radial line connecting the top surfaces of each ring of protrusions.

[0011] Optionally, the support portion has multiple independent through holes, and the through holes are connected to the corresponding adsorption regions for transmitting air extracted between each adsorption region and the wafer; wherein, the through holes correspond one-to-one with the adsorption regions, and the through holes are connected to the recesses between each adjacent protrusion via vacuum grooves, and the vacuum grooves are the vacuum grooves of the support portion and the inner ring protrusions.

[0012] Optionally, in response to the wafer pressing the adsorption section onto the support, the tops of all the protrusions of the adsorption section abut against the wafer and are flush with the top surface of the support.

[0013] Optionally, each ring of protrusions is annular, and along the radial direction of each ring of protrusions, the cross-section of the outermost ring of protrusions is trapezoidal, and the cross-section of the inner ring of protrusions is semi-circular; wherein, the plane containing the long base of the trapezoid and the arc surface of the semi-circle are used to attach the wafer.

[0014] Optionally, the support is made of semiconductor ceramic, which is selected from one or more of the following: SrTiO3, BaTiO3, SiC, GaN, ZnO, AlN.

[0015] Compared with the prior art, the technical solution of the present disclosure has the following advantages:

[0016] In the robotic arm for adsorbing warped wafers provided in this embodiment, the warped wafer is adsorbed via a support portion and an adsorption portion of a vacuum suction cup. The adsorption portion, which surrounds the support portion, is made of flexible ceramic, allowing it to conform well to the warped wafer. Furthermore, a first height difference between some or all of the protrusions of the adsorption portion and the surface of the robotic arm is greater than a second height difference between the support portion and the robotic arm. Because the adsorption portion is flexible and deformable, under the influence of the wafer's gravity, the first height difference can be compressed to match the second height difference, thus allowing the adsorption portion to better conform to the warped portion of the wafer. Therefore, the adsorption capacity for warped wafers is improved. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this specification, the drawings used in the description of the embodiments of this specification or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A cross-sectional schematic diagram of a robotic arm and its vacuum chuck for adsorbing warped wafers is shown in an embodiment of the present disclosure.

[0019] Figure 2 A schematic diagram of a robotic arm for adsorbing warped wafers is shown in an embodiment of the present disclosure;

[0020] Figure 3 A cross-sectional schematic diagram of another robotic arm and its vacuum chuck for adsorbing warped wafers is shown in an embodiment of this disclosure.

[0021] Figure 4 A top view schematic diagram of a vacuum suction cup according to an embodiment of the present disclosure is shown.

[0022] Explanation of reference numerals in the attached figures:

[0023] Hand structure 100, vacuum tubing 110, palm 120, interdigitated fingers 130, support block 140;

[0024] Vacuum suction cup 200, support part 210, through hole 211, adsorption part 220, protrusion 221, outermost protrusion 221a, inner protrusion 221b, first height difference H1, second height difference H2, partition section 222, vacuum groove 230. Detailed Implementation

[0025] The technical solutions described herein will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of this disclosure and are used to illustrate the concept of this disclosure. These descriptions are illustrative and exemplary and should not be construed as limiting the implementation methods or the scope of protection of this disclosure. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0026] It should be noted that the accompanying drawings in this embodiment are schematic diagrams used to illustrate the concept of this disclosure, and to schematically show the shapes of the various parts and their interrelationships. It should be understood that, in order to clearly show the structure of the various components of this disclosure, the drawings are not drawn to the same scale, and the same reference numerals are used to indicate the same parts in the drawings.

[0027] As described in the background section, during wafer manufacturing, the surface device layer continuously accumulates high temperatures, causing the wafer surface stress to rise continuously, resulting in gradual deformation and warping. When the warped wafer is transferred in most subsequent semiconductor manufacturing equipment, it may fail to fully adhere to the vacuum chuck of the robotic arm, triggering equipment alarms.

[0028] To address the aforementioned technical problems, the robotic arm for adsorbing warped wafers provided in this disclosure utilizes a support portion and an adsorption portion of a vacuum suction cup to adsorb the warped wafer. The adsorption portion, surrounding the support portion, is made of flexible ceramic, allowing it to conform well to the warped wafer. Furthermore, a first height difference between some or all of the protrusions of the adsorption portion and the surface of the robotic arm is greater than a second height difference between the support portion and the robotic arm. Because the adsorption portion is flexible and deformable, under the influence of the wafer's gravity, the first height difference can be compressed to match the second height difference, thus enabling the adsorption portion to better conform to the warped portion of the wafer. Therefore, the adsorption capacity for warped wafers is improved.

[0029] To make the above-described objects, features and advantages of this disclosure more apparent and understandable, a clear and complete illustrative description of this disclosure is provided below in conjunction with the accompanying drawings.

[0030] See Figure 1 , Figure 1 A cross-sectional schematic diagram of a robotic arm worktable for adsorbing warped wafers is shown in an embodiment of this disclosure. The cross-sectional schematic diagram is divided into upper and lower parts, with the same structure outlined by a dashed line. The lower part is a cross-sectional view of the robotic arm's hand structure and the vacuum suction cup, while the upper part, outlined by the dashed line, is a top view of the vacuum suction cup.

[0031] In this embodiment, see reference Figure 2 , Figure 2 A schematic diagram of a robotic arm for adsorbing warped wafers is shown in an embodiment of this disclosure. The robotic arm for adsorbing warped wafers may include: a hand structure 100, a support block 140, and a vacuum suction cup 200.

[0032] The hand structure 100 includes a palm 120 and interdigitated fingers 130, and the side of the hand structure 100 used for adsorbing the wafer has a plurality of support blocks 140 for supporting the wafer.

[0033] The hand structure 100 is a U-shape composed of the palm 120 and the two interdigitated fingers 130.

[0034] The number of support blocks 140 is four. Each of the two interdigitated fingers 130 has one support block 140, and the palm part 120 has two support blocks 140. They are symmetrically distributed about the axis of symmetry of the U-shaped hand structure 100, so that the wafer is subjected to uniform force on the support blocks 140.

[0035] The number of vacuum suction cups 200 is three, and they are respectively distributed on the surface of the palm 120 and the surface of the interdigital fingers 130.

[0036] In this embodiment, a vacuum suction cup 200 is distributed on the surface of the palm 120 and the surfaces of the two interdigitated fingers 130.

[0037] The hand structure 100 also has multiple vacuum tubes 110 inside, each of which is connected to the vacuum suction cup 200 in a one-to-one correspondence, and the multiple vacuum tubes 110 are independent of each other.

[0038] The vacuum line 110 is coupled to an external vacuum system and responds to the opening of the vacuum system by the solenoid valve, wherein the vacuum system provides an adsorption force to the vacuum line 110.

[0039] In some embodiments, the vacuum line 110 is coupled to a vacuum pump located on the machine tool where the robotic arm is located, and the machine tool controls the start and stop of the vacuum pump.

[0040] It should be noted that the above example is intended to illustrate the structure in the accompanying drawings, and not to limit the number of the support block 140 and the vacuum suction cup 200. That is, the number of support blocks 140 can be 3 or more, and the number of vacuum suction cups 200 can be 4 or more, depending on the actual needs.

[0041] Furthermore, multiple vacuum suction cups 200 are evenly distributed on one side of the surface of the hand structure 100 for adsorbing wafers. The vacuum suction cups 200 are snapped into the hand structure 100, meaning they are connected via matching snap-fit ​​mechanisms. Alternatively, they can be connected using detachable methods such as threaded connections, pins, or magnetic attachments to facilitate maintenance and replacement of the vacuum suction cups.

[0042] The vacuum chuck 200 includes a support portion 210 and an adsorption portion 220. The two work together to achieve stable adsorption and deformation compensation of the wafer.

[0043] The support 210 is a rigid frame made of aerospace-grade aluminum alloy (such as 6061-T6) or ceramic-reinforced composite material, possessing high rigidity (elastic modulus ≥70GPa) and low coefficient of thermal expansion (CTE≤8×10). -6 / ℃), to ensure that no plastic deformation occurs during the vacuum adsorption process.

[0044] In this embodiment, the support portion 210 is made of semiconductor ceramic, which is selected from one or more of the following: SrTiO3, BaTiO3, SiC, GaN, ZnO, AlN.

[0045] The support portion 210 has a through hole 211 at its center. Multiple vacuum channels 110 inside the hand structure 100 are connected one-to-one with the through hole 211 of the support portion 210 to extract gas between the vacuum chuck 200 and the wafer.

[0046] The adsorption section 220 is a flexible contact layer. In some embodiments, fluororubber (FKM) or hydrogenated nitrile rubber (HNBR) is used, with a Shore hardness of 40±5A and a surface roughness Ra≤0.2μm.

[0047] In this embodiment, the adsorption part 220 is arranged around the support part 210, and the adsorption part 220 is made of flexible ceramic. Flexible ceramic is a new type of high-strength ceramic material with characteristics such as high strength, light weight, flexibility, wear resistance, and corrosion resistance. Its special structure and material composition give it impact resistance, pressure resistance, and high temperature resistance, enabling it to withstand a large amount of energy when impacted, effectively mitigating damage caused by external impacts.

[0048] Flexible ceramics are primarily composed of two materials: ceramics and polymers. The ceramics are the main constituent material, while the polymers act as binders and prevent breakage. During manufacturing, ceramic particles are first coated with polymers, forming a multi-layered structure. This layered structure not only endows the flexible ceramics with high strength and flexibility but also allows it to effectively absorb and disperse impact forces, thus avoiding brittle fracture caused by the properties of a single material. The adsorption part 220, due to its flexibility, can be engaged with the hand structure 100.

[0049] Furthermore, the support portion 210 and the adsorption portion 220 of the vacuum suction cup 200 are connected by non-removable methods such as welding or bonding. In this embodiment, the support portion 210 and the adsorption portion 220 are connected by high-temperature sintering to improve the stability and sealing of the vacuum suction cup 200.

[0050] See also Figure 1 and Figure 3 , Figure 3 A cross-sectional schematic diagram of another robotic arm and its vacuum chuck for adsorbing warped wafers, as shown in an embodiment of this disclosure, is illustrated.

[0051] The adsorption part 220 includes multiple rings of protrusions 221, with the outermost ring of protrusions 221a being a continuous annular protrusion, so that the adsorption part 220 and the wafer form a sealed space.

[0052] The inner ring protrusion 221b is a discontinuous protrusion. That is, the inner ring protrusion 221b within the same ring is interrupted by the vacuum groove 230.

[0053] Specifically, the recesses between adjacent protrusions 221 are connected by the vacuum groove 230, and the vacuum groove 230 of the support is connected to the through hole 211, so that the robotic arm can extract the air between the recesses between each protrusion 221 and the wafer through the through hole 211 to form a vacuum and adsorb the wafer.

[0054] The first height difference H1 of some or all of the protrusions 221 of the adsorption portion 220 relative to the surface of the hand structure 100 is greater than the second height difference H2 of the support portion 210 relative to the hand structure 100. This arrangement allows the adsorption portion 220 to better adhere to the wafer, even if the wafer warps.

[0055] The difference between the first height difference H1 and the second height difference H2 is selected from [0.1mm, 1mm], and in this embodiment, it is preferably 0.2mm.

[0056] Furthermore, the third height difference between the support block 140 and the surface of the hand structure 100 is consistent with the second height difference H2. Thus, the top surface of the support block 140 and the support portion 210 are in the same plane, resulting in uniform stress on the wafer and making it less prone to damage.

[0057] Continue to refer to Figure 3 The height of the top of the protrusion 221 of the adsorption part 220 relative to the height of the hand structure 100 decreases progressively from the outermost protrusion 221 to the innermost protrusion 221.

[0058] Specifically, the protrusions 221 of the adsorption section 220 are designed with a gradient height, so that the height of the protrusions 221 decreases progressively from the outer ring to the inner ring (e.g., the outermost ring protrusion height is 0.5 mm, and the innermost ring protrusion height is 0.3 mm), forming an adaptive contact gradient that allows the outer ring protrusions to make contact first. When the wafer edge warps, the higher outer ring protrusions adhere first, establishing an initial seal. The lower inner ring protrusions are gradually flattened under the influence of wafer gravity and the increasing adsorption force, and this gradual pressing avoids local stress concentration.

[0059] In some embodiments, the height of the top of the protrusion 221 of the adsorption portion 220 relative to the height of the hand structure 100 decreases by 0.1 mm per ring from the outermost protrusion 221 to the innermost protrusion 221.

[0060] In response to the wafer pressing down, the adsorption portion 220 falls onto the support portion 210, the top of the protrusion 221 of the adsorption portion 220 abuts against the wafer and is flush with the top surface of the support portion 210.

[0061] like Figure 3 In the diagram, dashed lines A1-A2 represent the connection between the outermost protrusion 221a and the support portion 210, and the inner protrusion 221b is tangent to dashed lines A1-A2. This allows the adsorption portion 220 to be gradually flattened under the influence of wafer gravity and increasing adsorption force. In other words, dashed lines A1-A2 are pressed to a horizontal state, ensuring sufficient contact at the edge regions when adsorbing warped wafers, reducing the risk of vacuum leakage and improving adsorption stability.

[0062] Each ring of protrusions 221 is annular, and along the radial direction of each ring of protrusions 221, the cross-section of the outermost ring protrusion 221a is trapezoidal, and the cross-section of the inner ring protrusion 221b is semi-elliptical and / or semi-circular.

[0063] The long base plane of the trapezoid and the semi-circular arc surface are used to attach the wafer.

[0064] Specifically, the outermost protrusion 221a has a trapezoidal cross-section, and its long bottom plane (width 0.3-0.5mm) ensures the maximum contact area with the wafer and improves edge sealing.

[0065] In some embodiments, the outermost protrusion 221a has a trapezoidal cross section, and its long base plane is designed with an inwardly inclined slope (angle of 5 to 30 degrees) to achieve progressive contact and avoid sudden stress changes.

[0066] In addition, the outermost protrusion 221a has a rounded corner design at the acute angle of its trapezoidal cross-section to reduce stress and prevent damage to the wafer.

[0067] The inner ring protrusion 221b adopts a semi-elliptical / semi-circular cross-section, which ensures uniform distribution of contact stress. In addition, the flexible contact design can control the maximum contact stress below 0.15MPa.

[0068] See Figure 4 , Figure 4 A top view schematic diagram of a vacuum suction cup according to an embodiment of the present disclosure is shown.

[0069] The adsorption section 220 has a partition section 222 that connects each of the protrusions 221. The partition section 222 protrudes from the surface of the adsorption section 220 and uniformly divides the adsorption section 220 into multiple independent adsorption regions.

[0070] Specifically, the dividing segment 222 connects each of the protrusions 221, uniformly dividing the adsorption part 220 into multiple independent adsorption regions. Preferably, there are four adsorption regions.

[0071] Furthermore, the material of the partition segment 222 is flexible ceramic, and along the radial direction of each ring of protrusions 221, the surface height of the partition segment 222 is consistent with the height of each ring of protrusions 221. (See also...) Figure 3 The surface height of the dividing segment 222 coincides with the dashed lines A1-A2. This design effectively improves the independence and sealing of each adsorption region.

[0072] In some embodiments, the support portion 210 has a plurality of independent through holes 211, and the through holes 211 communicate with the adsorption regions for extracting air between each adsorption region and the wafer. Preferably, there are four through holes 211, each corresponding to one of the adsorption regions. The through holes 211 communicate with the vacuum grooves 230 of the support portion 210 and the inner ring protrusions 221b, and with the recesses between adjacent protrusions 221.

[0073] It is understood that the above describes multiple embodiments of a robotic arm for adsorbing warped wafers. The various alternatives described in each embodiment can be combined and cross-referenced without conflict, thereby extending to a variety of possible embodiments. These can all be considered as disclosed embodiments of this utility model.

[0074] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article indicates that the preceding and following related objects have an "or" relationship.

[0075] In the embodiments of this application, "multiple" refers to two or more.

[0076] The descriptions of "first," "second," etc., appearing in the embodiments of this application are for illustrative purposes and to distinguish the objects being described. They have no order and do not indicate any special limitation on the number of devices in the embodiments of this application, nor do they constitute any limitation on the embodiments of this application.

[0077] It should be noted that the sequence number of each step in this embodiment does not represent a limitation on the execution order of each step.

[0078] While the embodiments disclosed herein are as described above, this disclosure is not limited thereto. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this disclosure; therefore, the scope of protection of this disclosure should be determined by the scope defined in the claims.

Claims

1. A robotic arm for adsorbing warped wafers, characterized in that, include: Hand structure; Multiple vacuum suction cups are evenly distributed on the hand structure; The vacuum suction cup includes a support part and an adsorption part; The support portion has a through hole at its center for extracting gas between the vacuum chuck and the wafer. The adsorption part is arranged around the support part, and the material of the adsorption part is flexible ceramic; The adsorption part includes multiple rings of protrusions. The outermost ring of protrusions is a continuous annular protrusion, while the inner ring of protrusions is a discontinuous protrusion. The depressions between adjacent protrusions are connected to the through holes. Furthermore, the first height difference between some or all of the protrusions of the adsorption part and the surface of the hand structure is greater than the second height difference between the support part and the hand structure.

2. The robotic arm for adsorbing warped wafers according to claim 1, characterized in that, The hand structure has multiple support blocks, and the third height difference between the support blocks and the surface of the hand structure is consistent with the second height difference.

3. The robotic arm for adsorbing warped wafers according to claim 1, characterized in that, The hand structure also has multiple vacuum tubes inside, each of which is connected to a through hole in the support part, and the multiple vacuum tubes are independent of each other. The vacuum pipeline is coupled to an external vacuum system and responds to the opening of the vacuum system by a solenoid valve, wherein the vacuum system provides an adsorption force to the vacuum pipeline.

4. The robotic arm for adsorbing warped wafers according to claim 1, characterized in that, The hand structure is U-shaped, including a palm and two interdigitated fingers, and the number of vacuum suction cups is three, which are respectively distributed on the surface of the palm and the surface of the interdigitated fingers.

5. The robotic arm for adsorbing warped wafers according to claim 1, characterized in that, Meet one or more of the following: The difference between the first height difference and the second height difference is selected from [0.1mm, 1mm]; The height of the top of the adsorption section decreases with each ring from the outermost to the innermost ring.

6. The robotic arm for adsorbing warped wafers according to claim 1, characterized in that, Each ring of protrusions is annular, and the top height decreases with each ring from the outermost ring to the innermost ring of the adsorption part. The adsorption section has a partition segment connecting each protrusion, and the adsorption section is uniformly divided into multiple independent adsorption regions. The material of the dividing segment is flexible ceramic, and the surface height of the dividing segment continuously increases. The surface height of the dividing segment is consistent with the radial line connecting the top surfaces of each ring of protrusions.

7. The robotic arm for adsorbing warped wafers according to claim 6, characterized in that, The support has multiple independent through holes, and the through holes are connected to the corresponding adsorption regions for transmitting the air extracted between each adsorption region and the wafer. The through holes correspond one-to-one with the adsorption areas, and the through holes are connected to the recesses between each adjacent protrusion via vacuum grooves. The vacuum grooves are the vacuum grooves of the support portion and the inner ring protrusions.

8. The robotic arm for adsorbing warped wafers according to claim 1, characterized in that, In response to the wafer pressing down, the adsorption section is pressed against the support, and the tops of all the protrusions of the adsorption section abut against the wafer and are flush with the top surface of the support.

9. The robotic arm for adsorbing warped wafers according to claim 8, characterized in that, Each ring of protrusions is annular, and along the radial direction of each ring of protrusions, the cross-section of the outermost ring of protrusions is trapezoidal, and the cross-section of the inner ring of protrusions is semi-circular. The long base plane of the trapezoid and the semi-circular arc surface are used to attach the wafer.

10. The robotic arm for adsorbing warped wafers according to claim 1, characterized in that, The support is made of semiconductor ceramic, which is selected from one or more of the following: SrTiO3, BaTiO3, SiC, GaN, ZnO, AlN.

Images