A calibration fixture for a wafer transfer apparatus
Patent Information
- Application Number
- CN202522275131.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-28
- Publication Date
- 2026-11-03
- Estimated Expiration
- 2035-10-28
AI Technical Summary
In existing wafer transfer equipment, the parallelism adjustment of the sensor light and the wafer relies on personnel experience, resulting in insufficient wafer thickness detection accuracy and affecting the accuracy of judging the presence, stacking, and tilting status of wafers.
A calibration fixture for a wafer transfer device is provided, including a base plate and a light-transmitting grid plate. The base plate is aligned with the stage surface, and a reference optical path is formed by using equal-height light-transmitting holes to achieve quantitative calibration of the parallelism between the sensor light and the wafer, reducing manual adjustment deviations.
It improves the accuracy of judging the presence, stacking, and tilting of wafers, reduces thickness detection deviation, adapts to the detection needs of wafers of different sizes, and reduces the difficulty of equipment debugging and maintenance costs.
Smart Images
Figure CN224936051U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of wafer inspection technology, and more specifically, to a calibration fixture for a wafer transmission device. Background Technology
[0002] In the wafer transfer equipment workflow, before the robotic arm transfers wafers, sensors automatically detect the wafers in the cassette. The detection items include wafer presence / absence, single / stacked status, and wafer tilt. The detection principle is as follows: the sensor moves up and down relative to the wafer cassette to scan each wafer individually. The presence / absence of a wafer is determined by whether the light emitted by the sensor is blocked by the wafer. Then, the wafer thickness is obtained based on the magnitude of the vertical displacement when the light is blocked, thereby determining the stacking and tilt status.
[0003] Since the parallelism between the sensor light and the wafer directly affects the measurement accuracy of the wafer thickness, it plays a crucial role in the final detection result. However, in existing technologies, the adjustment of the parallelism between the sensor light and the wafer relies on personnel experience, and the adjustment effect is greatly affected by the difference in personnel skill level. Furthermore, it is impossible to quantify the parallelism adjustment accuracy, which can easily lead to deviations in the wafer thickness measurement. This, in turn, affects the accuracy of judging the presence, stacking, and tilting status of the wafer, making it difficult to meet the detection accuracy requirements of wafer transmission equipment. Utility Model Content
[0004] In view of the shortcomings of the existing technology, this utility model innovatively provides a calibration fixture for wafer transfer equipment, which can solve the technical problem of large wafer thickness detection deviation in existing wafer transfer equipment.
[0005] To achieve the above-mentioned technical objectives, this utility model discloses a calibration fixture for a wafer transport device. The wafer transport device includes a stage for carrying a wafer cassette and a wafer inspection component for inspecting the wafers in the wafer cassette. The calibration fixture is used to calibrate the wafer inspection component. The calibration fixture includes: A base plate, wherein a reference surface is provided on the bottom side of the base plate, the reference surface being used to be parallel and aligned with the platform surface; The grid plate includes: a first light-transmitting grid plate and a second light-transmitting grid plate disposed opposite to each other at both ends of the base plate, wherein the first light-transmitting grid plate has a first light-transmitting hole and the second light-transmitting grid plate has a second light-transmitting hole; The first light-transmitting hole corresponds to the second light-transmitting hole and is at the same height from the reference surface, so as to transmit the emitted light of the sensor in the wafer inspection assembly.
[0006] Optionally, the relative distance between the first light-transmitting grating and the second light-transmitting grating is adjustable.
[0007] Optionally, the first light-transmitting grating plate and the second light-transmitting grating plate are slidably connected to the base plate; The bottom plate has a slide rail along its length on its top side, a first slider that cooperates with the slide rail on the first light-transmitting grid plate, and a second slider that cooperates with the slide rail on the second light-transmitting grid plate.
[0008] Optionally, the first light-transmitting grating and the second light-transmitting grating are detachably connected to the base plate; The base plate has multiple slots arranged along its length on its top side, the first light-transmitting grid plate has a first insert block that mates with the slots, and the second light-transmitting grid plate has a second insert block that mates with the slots.
[0009] Optionally, the first light-transmitting grating plate has a plurality of first light-transmitting holes, and the second light-transmitting grating plate has a plurality of second light-transmitting holes; The first light-transmitting hole and the second light-transmitting hole correspond one-to-one, and the corresponding first light-transmitting hole and the second light-transmitting hole are at the same height from the reference surface.
[0010] Optionally, both the first light-transmitting hole and the second light-transmitting hole are elongated holes.
[0011] Optionally, the length direction of the first light-transmitting hole and the length direction of the second light-transmitting hole are parallel, and are respectively parallel to the reference plane.
[0012] Optionally, the widths of the plurality of first light-transmitting holes are different, and the widths of the plurality of second light-transmitting holes are different; In the corresponding first and second light-transmitting holes, the width of the first light-transmitting hole and the width of the second light-transmitting hole are the same.
[0013] Optionally, along the height direction of the first light-transmitting grating, the width of the first light-transmitting hole on the first light-transmitting grating gradually increases or decreases.
[0014] The beneficial effects of this utility model are as follows: This invention provides a calibration fixture for a wafer transfer device. The calibration fixture aligns a reference plane with the stage surface and forms a reference optical path using first and second light-transmitting holes of equal height and light transmission. This enables quantitative calibration of the parallelism between the sensor light and the wafer, reducing thickness detection deviations caused by manual experience-based adjustments and improving the accuracy of determining the presence, stacking, and tilting of wafers. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the overall calibration fixture in an embodiment of the present invention; Figure 2 A schematic diagram of the light-transmitting grating plate in an embodiment of the present invention is shown; Figure 3 A schematic diagram showing the working state of the detection component, stage, and calibration fixture in an embodiment of this utility model; Figure 4 This is a schematic diagram of the transmitter sensor of the wafer inspection component in an embodiment of the present invention.
[0016] In the diagram: 10. Calibration fixture; 101. Base plate; 102. Grid plate; 1021. First light-transmitting grid plate; 1022. Second light-transmitting grid plate; 1023. Light-transmitting hole; 201. Stage; 202. Transmitter sensor assembly; 2021. Transmitter sensor; 2022. Rotation adjustment plate; 2023. Left and right adjustment plate; 2024. Up and down adjustment plate; 2025. Set screw; 2026. Fixing plate; 203. Receiver sensor assembly. Detailed Implementation
[0017] The following is a detailed explanation and description of the patient pants provided by this utility model, with reference to the accompanying drawings.
[0018] This utility model provides a calibration fixture for a wafer transmission device, such as... Figures 1-4 As shown, the wafer transfer device includes a stage 201 that carries a wafer cassette and a wafer inspection component that inspects the wafers in the wafer cassette. The calibration fixture 10 is used to calibrate the wafer inspection component.
[0019] like Figures 1-2 As shown, the calibration fixture 10 includes a base plate 101 and a grid plate 102.
[0020] Specifically, the bottom side of the base plate 101 is provided with a reference surface, which is used to align parallel to the table surface of the platform 201.
[0021] In this embodiment, a parallel reference to the stage 201 is established based on the datum plane positioning. The base plate 101 of the calibration fixture 10 has a datum plane on its bottom side. During use, the base plate 101 is first placed on the stage 201 of the wafer transfer device, ensuring the datum plane is fully aligned with the stage 201. Since the stage 201 serves as the datum plane for wafer placement (the wafer must remain parallel to the stage 201 during actual transfer), this allows the datum plane of the calibration fixture 10 to indirectly establish a parallel relationship with the "plane on which the wafer is to be inspected," providing a unified reference for subsequent parallelism calibration.
[0022] like Figures 1-2As shown, the grid plate 102 has light-transmitting holes 1023. Specifically, the grid plate 102 includes a first light-transmitting grid plate 1021 and a second light-transmitting grid plate 1022, which are disposed opposite to each other at both ends of the base plate 101. The first light-transmitting grid plate 1021 has a first light-transmitting hole, and the second light-transmitting grid plate 1022 has a second light-transmitting hole. The first light-transmitting hole and the second light-transmitting hole correspond to each other and are at the same height from the reference plane, so as to transmit the emitted light of the sensor in the wafer inspection assembly.
[0023] In this embodiment, a uniform light transmission reference is formed by constructing the optical path of the grid plate 102. The first light transmission grid plate 1021 and the second light transmission grid plate 1022 at both ends of the base plate 101 are arranged opposite each other, and the height of the first light transmission hole and the second light transmission hole of the two is completely consistent from the reference surface. After the calibration fixture 10 is positioned, the first light transmission hole and the second light transmission hole will form a horizontal optical path "parallel to the reference surface". The parallel reference of this optical path is directly derived from the stage surface of the stage 201 (i.e., parallel to the wafer plane in the wafer cassette), which is equivalent to simulating "the ideal optical path when the sensor light is completely parallel to the wafer".
[0024] During sensor parallelism calibration, deviations are verified using a standard optical path. The sensor in the wafer inspection assembly is activated, aligning its emitted light with the first transparent aperture. If the sensor light is parallel to the wafer, it will precisely pass through the first and second transparent apertures, forming a stable transmitted beam. If the sensor light is not parallel to the wafer (it is tilted), the light will be blocked by the grid plate 102 and cannot completely penetrate the two transparent apertures 1023. Operators can determine the parallelism deviation of the sensor light by observing whether the light is transmitted and the position of the light spot during transmission. Adjustments are made according to the reference optical path of the transparent apertures 1023 until the light can stably penetrate both apertures, completing the parallelism calibration.
[0025] Based on the size of the light-transmitting hole 1023 on the calibration fixture 10, quantitative calibration of the parallelism between the sensor light and the wafer can be achieved, reducing thickness detection deviations caused by manual experience-based adjustments and improving the accuracy of judging the presence, stacking, and tilting of wafers.
[0026] In some alternative configurations, the relative distance between the first light-transmitting grid plate 1021 and the second light-transmitting grid plate 1022 is adjustable. In this embodiment, by designing the relative distance between the first light-transmitting grid plate 1021 and the second light-transmitting grid plate 1022 to be adjustable, it is possible to adapt to the inspection requirements of wafers of different sizes.
[0027] For example, for smaller wafers, the relative distance between the two grid plates 102 can be adjusted to reduce the spacing to the same as the diameter of the wafer being tested, thereby optimizing the detection conditions, effectively reducing interference factors when detecting small wafers, and further improving the accuracy of detecting the presence, stacking, and tilting of wafers.
[0028] Optionally, the first light-transmitting grating plate 1021 and the second light-transmitting grating plate 1022 are slidably connected to the base plate 101. The base plate 101 has a slide rail along its length on its top side, the first light-transmitting grating plate 1021 has a first slider that cooperates with the slide rail, and the second light-transmitting grating plate 1022 has a second slider that cooperates with the slide rail.
[0029] In this embodiment, by slidingly connecting the first and second transparent grid plates 1022 to the base plate 101, and utilizing the sliding track on the top side of the base plate 101 in conjunction with the slider on the grid plate 102, a stable and smooth adjustment of the relative distance between the two grid plates 102 is achieved, avoiding jamming or offset during the adjustment process. The sliding connection structure is simple and its precision is easy to control, ensuring the positional stability of the two grid plates 102 after adjustment, reducing detection deviations caused by loose connections, and further ensuring the accuracy of detection for wafers of different sizes (especially small wafers). In addition, this structure does not require complex driving components, is easy to operate, reduces the difficulty of equipment debugging and maintenance costs, and has strong adaptability, flexibly meeting the detection needs of wafers of various sizes.
[0030] In another alternative, the first light-transmitting grating plate 1021 and the second light-transmitting grating plate 1022 are detachably connected to the base plate 101. The base plate 101 has multiple slots arranged along its length on its top side, the first light-transmitting grating plate 1021 has a first insert that mates with the slots, and the second light-transmitting grating plate 1022 has a second insert that mates with the slots.
[0031] In this embodiment, a detachable connection structure is adopted. Multiple slots on the top side of the base plate 101 engage with inserts on the grid plate 102, enabling rapid assembly, disassembly, and position adjustment of the first transparent grid plate 1021 and the second transparent grid plate 1022, significantly improving the efficiency of equipment debugging and maintenance. Multiple slots are arranged along the length of the base plate 101, providing multiple distance adjustment options to precisely adapt to the testing needs of wafers of different sizes. This is especially true for small wafers, where distance control is more flexible, further ensuring testing accuracy. The engagement structure of the inserts and slots is simple and reliable, preventing loosening or displacement after connection. It stably maintains the relative position of the two grid plates 102, reducing testing deviations caused by structural vibration, while also reducing component wear and failure risks, and extending equipment lifespan.
[0032] In some alternative methods, such as Figure 2As shown, a plurality of first light-transmitting holes are formed on the first light-transmitting grid plate 1021, and a plurality of second light-transmitting holes are formed on the second light-transmitting grid plate 1022. The first light-transmitting holes and second light-transmitting holes correspond one-to-one, and the corresponding first and second light-transmitting holes are at the same height from the reference surface.
[0033] In this embodiment, the first and second light-transmitting holes are arranged in a one-to-one correspondence, ensuring that the sensor light accurately passes through the two grid plates 102 along a preset path, avoiding light deviation or obstruction due to hole misalignment, and providing a stable optical path foundation for wafer thickness and status detection. The corresponding two light-transmitting holes 1023 are at the same height from the reference plane, ensuring that the light remains horizontal (or parallel to the reference plane) when passing through the two grid plates 102. The installation position of the sensor in the wafer inspection component of different wafer transfer devices may be different. By adopting a standardized hole correspondence and height setting, the calibration requirements of the wafer inspection component in the wafer transfer device can be met.
[0034] In some alternative methods, such as Figures 1-2 As shown, both the first and second light-transmitting holes are elongated holes. In this embodiment, by designing the light-transmitting hole 1023 as an elongated hole, it can better match and correspond with the light beam of the sensor in the wafer inspection assembly, making it easier for operators to use.
[0035] Optionally, the length direction of the first light-transmitting hole and the length direction of the second light-transmitting hole are parallel, and are respectively parallel to the reference plane.
[0036] The length directions of the first and second light-transmitting holes are parallel to each other and both are parallel to the reference plane. This ensures that when the sensor light passes through the light-transmitting holes 1023 of the two grid plates 102, it always propagates in a direction parallel to the reference plane. From the optical path structure, this guarantees the parallelism between the light and the wafer, directly reducing wafer thickness detection deviations caused by optical path tilt. In addition, the uniform design of the light-transmitting hole 1023 reduces the risk of directional deviation during grid plate 102 processing, and facilitates quick calibration of the hole orientation during assembly, making it easier for operators to operate.
[0037] Optionally, the widths of the multiple first light-transmitting holes are different, and the widths of the multiple second light-transmitting holes are also different. However, in the corresponding first and second light-transmitting holes, the widths of the first and second light-transmitting holes are the same.
[0038] Multiple first and second light-transmitting holes are designed with different aperture widths to improve the equipment's compatibility with different types of wafers. At the same time, the aperture widths of the corresponding first and second light-transmitting holes are kept the same, ensuring that light in the same optical path always passes through the two grid plates 102 with a consistent width, avoiding light interception or scattering due to aperture width differences, and ensuring the accuracy of wafer obstruction displacement detection.
[0039] Furthermore, the combination of differentiated aperture widths and corresponding unified aperture widths not only provides flexibility in sensor light selection but also reduces detection errors from the perspective of optical path consistency. Especially in the detection of small-sized or thin wafers, it can more accurately capture thickness changes and further improve the reliability of stacking and tilting state judgment.
[0040] Alternatively, along the height direction of the first light-transmitting grid plate 1021, the width of the first light-transmitting hole on the first light-transmitting grid plate 1021 gradually increases or decreases. This design allows staff to easily select the corresponding light-transmitting hole 1023.
[0041] Furthermore, in some alternative embodiments, the first and second light-transmitting gratings 1021 and 1022 can be improved to make the height of the respective light-transmitting gratings 102 adjustable perpendicular to the reference plane. Based on this, without replacing the light-transmitting gratings 102, different aperture widths can be used to match and simulate wafers of different sizes through height adjustment, thereby calibrating the wafer inspection assembly.
[0042] It should be noted that the distance between the two grid plates 102 of the calibration fixture 10 in this embodiment can be adjusted or kept fixed. The width of the light-transmitting holes 1023 in a row of corresponding grid plates can have multiple specifications or only one size specification. Furthermore, the shape of the light-transmitting holes can be designed in various styles, such as oblong holes, rectangular holes, etc.
[0043] The working principle of the calibration fixture 10 will be explained below in conjunction with the wafer inspection component in the wafer transfer equipment.
[0044] To ensure the reliability of wafer inspection results, the accuracy of wafer thickness measurement must be guaranteed. Therefore, the parallelism between the sensor's emitted light and the wafer must be ensured. During sensor debugging, calibration fixture 10 is used to adjust and calibrate the parallelism between the emitted light of the transmitter sensor in the wafer inspection assembly and the stage 201, thereby ensuring the parallelism between the emitted light of the transmitter sensor and the wafer.
[0045] like Figures 3-4 As shown, the sensor includes a transmitting sensor assembly 202 and a receiving sensor assembly 203. The transmitting sensor assembly 202 includes a transmitting sensor 2021, a rotation adjustment plate 2022, a left-right adjustment plate 2023, a right-up adjustment plate 2024, a set screw 2025, and a fixing plate 2026. The transmitting sensor assembly 202 can adjust the angle and position of the light emitted by the transmitting sensor 2021. Specifically, the rotation adjustment plate 2022 can adjust the angle in the θ direction, the left-right adjustment plate 2023 can adjust the position in the x direction, the right-up adjustment plate 2024 can adjust the position in the y direction, and the set screw 2025 can adjust the angle in the α direction. The receiving sensor assembly 203 includes a receiving sensor.
[0046] Select the appropriate size of the light-transmitting hole 1023 according to the requirements of wafer precision and size (e.g., the width of the light-transmitting hole 1023 is d), and determine that the size of the light-transmitting holes 1023 at the same height of the two grid plates 102 is the same. Adjust the distance D between the two grid plates 102 to a suitable distance (generally the distance is adjusted to be the same as the diameter of the wafer being inspected).
[0047] The calibration fixture 10 is placed on the stage 201. The stage 201 and the sensor can move up and down relative to each other. The transmitting sensor 2021 is adjusted so that the emitted light passes through the light-transmitting holes of the two grid plates 102 at the same height and with a hole width of d, and is projected onto the receiving sensor. It can be assumed that the parallelism between the emitted light of the sensor and the stage 201 is d. That is, the calibration ensures the parallelism between the emitted light of the wafer and the sensor, and ensures the reliability of the wafer detection results.
[0048] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0049] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0050] In the description of this specification, the references to terms such as "this embodiment," "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any at least one embodiment or example. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0052] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and simple improvements made on the substantive content of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A calibration fixture for a wafer transport device, the wafer transport device comprising a stage for carrying a wafer cassette and a wafer inspection component for inspecting wafers in the wafer cassette, characterized in that, The calibration fixture is used to calibrate the wafer inspection assembly, and the calibration fixture includes: A base plate, wherein a reference surface is provided on the bottom side of the base plate, the reference surface being used to align parallel to the table surface of the platform; The grid plate includes: a first light-transmitting grid plate and a second light-transmitting grid plate disposed opposite to each other at both ends of the base plate, wherein the first light-transmitting grid plate has a first light-transmitting hole and the second light-transmitting grid plate has a second light-transmitting hole; The first light-transmitting hole corresponds to the second light-transmitting hole and is at the same height from the reference surface, so as to transmit the emitted light of the sensor in the wafer inspection assembly.
2. The calibration fixture for the wafer transmission equipment according to claim 1, characterized in that, The relative distance between the first light-transmitting grating and the second light-transmitting grating is adjustable.
3. The calibration fixture for the wafer transmission equipment according to claim 2, characterized in that, The first light-transmitting grating plate and the second light-transmitting grating plate are slidably connected to the base plate, respectively; The bottom plate has a slide rail along its length on its top side, a first slider that cooperates with the slide rail on the first light-transmitting grid plate, and a second slider that cooperates with the slide rail on the second light-transmitting grid plate.
4. The calibration fixture for the wafer transmission device according to claim 2, characterized in that, The first light-transmitting grating plate and the second light-transmitting grating plate are detachably connected to the base plate, respectively; The base plate has multiple slots arranged along its length on its top side, the first light-transmitting grid plate has a first insert block that mates with the slots, and the second light-transmitting grid plate has a second insert block that mates with the slots.
5. The calibration fixture for the wafer transmission device according to any one of claims 1-4, characterized in that, The first light-transmitting grating plate has a plurality of first light-transmitting holes, and the second light-transmitting grating plate has a plurality of second light-transmitting holes; The first light-transmitting hole and the second light-transmitting hole correspond one-to-one, and the corresponding first light-transmitting hole and the second light-transmitting hole are at the same height from the reference surface.
6. The calibration fixture for the wafer transmission device according to claim 5, characterized in that, Both the first light-transmitting hole and the second light-transmitting hole are elongated holes.
7. The calibration fixture for the wafer transmission device according to claim 6, characterized in that, The length directions of the first light-transmitting hole and the second light-transmitting hole are parallel, and are also parallel to the reference plane.
8. The calibration fixture for the wafer transmission device according to claim 6, characterized in that, The widths of the multiple first light-transmitting holes are different, and the widths of the multiple second light-transmitting holes are different; In the corresponding first and second light-transmitting holes, the width of the first light-transmitting hole and the width of the second light-transmitting hole are the same.
9. The calibration fixture for the wafer transmission device according to claim 8, characterized in that, Along the height direction of the first light-transmitting grating, the width of the first light-transmitting hole on the first light-transmitting grating gradually increases or decreases.