Inspection Tools for Inspecting Micro LED Array Panels
The inspection tool with rotatable optical collectors addresses the challenge of detecting pixel defects in micro LED array panels by allowing separate and efficient light collection and measurement, improving detection accuracy and efficiency.
Patent Information
- Application Number
- JP2024535974
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2021-12-16
- Publication Date
- 2025-01-23
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Traditional methods struggle to accurately detect pixel defects in micro LED array panels due to their small light emitting areas and the limitations of optical collectors, leading to reduced image accuracy and simultaneous light and image collection issues.
An inspection tool with a group of optical collectors, including a first and second optical collector, where the first collector is vertically aligned with the micro LED array and directs light to an image detector, while the second collector is aligned with a light measurement device, allowing for separate collection and measurement of light from different areas of the panel, with the collectors being rotatable and adjustable.
Enhances detection efficiency and accuracy by enabling simultaneous light and image collection without interference, facilitating precise inspection of micro LED array panels.
Smart Images
Figure 2025501725000001_ABST
Abstract
Description
[Technical field]
[0001] The present disclosure relates generally to the field of light emitting diodes, and more particularly to an inspection tool for inspecting micro light emitting diode (LED) array panels. [Background technology]
[0002] Micro LED, with its much smaller area and higher resolution, is becoming more and more popular around the world. Micro LED array panels can be used to form various kinds of devices, such as camera modules, light projection modules, display modules, VR / AR optical modules, etc.
[0003] However, pixel defects in the micro LED array panel are not easy to detect and identify by traditional methods since the light emitting area and the image displayed by the micro LED array panel are much smaller than before, which requires operators to scan the wafer, chip, and mask through a graphical user interface that displays various pattern images of the micro LED panel to identify pattern defects.
[0004] In addition, the light-emitting area of the micro LED array panel is extremely small, such as 3mm*5mm. However, the light-collecting area of the optical collector for collecting the light emitted by the micro LED array included in the micro LED array panel cannot be as small as the light-emitting area of the micro LED array panel due to various optical components in the optical collector. Therefore, the image collecting process and the light collecting process cannot be performed simultaneously. Moreover, when the light collecting process and the image collecting process are performed simultaneously, the light entering the optical collector will be weakened, thereby reducing the image accuracy.
[0005] The above contents are only used to help understand the technical solutions of the present application, and are not admitted to be prior art. Summary of the Invention
[0006] To overcome the above stated shortcomings, the present disclosure provides an inspection tool for inspecting micro LED array panels to improve detection efficiency and detection accuracy.
[0007] In order to achieve the above object, an inspection tool for inspecting a micro light emitting diode (LED) array panel according to the present disclosure includes: a collector optics configured to collect light emitted from the micro LED array included in the micro LED array panel; an image detector coupled to the collector optics to receive light collected by the collector optics and configured to capture an image of the micro LED array; a light measurement device electrically connected to the collector group optics to receive light collected by the collector group optics and configured to measure light emitted from one or more portions of the micro LED array; Equipped with An optical collector group is disposed above the micro LED array panel to collect light emitted from any position of the micro LED array, the optical collector group includes a first optical collector and a second optical collector, the first optical collector is connected to an image detector, the second optical collector is electrically connected to a light measurement device, the first optical collector group and the second optical collector group are configured on a fixed element, and the fixed element is rotatable in any direction.
[0008] In some embodiments, the first collector optics is disposed above and vertically aligned with the micro LED array via rotating the fixing element, and the first collector optics is configured to direct light emitted from the micro LED array to the image detector.
[0009] In some embodiments, a second collector optics is disposed above and facing the micro LED array via rotating the fixing element, the second collector optics configured to collect light emitted from one or more portions of the micro LED array.
[0010] In some embodiments, the detection area of the first collector optics is equal to or greater than the light emitting area of the microLED array.
[0011] In some embodiments, the detection area of the second collector optics is larger than the light emitting area of the micro LED array.
[0012] In some embodiments, the detection area of the second collector optics is smaller than or equal to the light emitting area of the micro LED array.
[0013] To achieve the above objective, an inspection system for inspecting a micro LED array panel includes at least the inspection tool mentioned above.
[0014] In some embodiments, the inspection system further comprises a sample stage for supporting the micro LED array panel.
[0015] Numerous other advantages and features of the present disclosure will become better understood from the following detailed description and the accompanying drawings. [Brief description of the drawings]
[0016] [Figure 1] FIG. 1 is a schematic diagram illustrating a configuration of an inspection tool according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] Reference will now be made in detail to preferred embodiments of the invention in order to provide a further understanding of the present disclosure. The specific embodiments discussed and the accompanying drawings are merely illustrative of specific ways to make and use the disclosure and do not limit the scope of the disclosure or the appended claims.
[0018] Referring to FIG. 1, an inspection tool for inspecting a micro LED array panel 00 according to one embodiment of the present disclosure includes: a collector optics group 01 configured to collect light emitted from the micro LED array included in the micro LED array panel 00; an image detector 02 coupled to the optical collector group 01 for receiving light collected by the optical collector group 01 and configured to capture an image of the micro LED array; a light measurement device 03 electrically connected to the optical collector group 01 for receiving light collected by the optical collector group 01 and configured to measure light emitted from one or more portions of the micro LED array; Equipped with.
[0019] Here, an optical collector group 01 is disposed above the micro LED array panel 00 to collect light emitted from any position of the micro LED array, the optical collector group 01 includes a first optical collector 101 and a second optical collector 102, the first optical collector 101 is connected to an image detector 02, and the second optical collector 102 is electrically connected to a light measurement device 03, where the first optical collector 101 and the second optical collector 102 are configured on a fixed element 104, and the fixed element 104 is rotatable in any direction. An optical transmission channel 103 passes through the fixed element 103 and is connected to the first optical collector 101 or the second optical collector 102. When the fixing element 104 is rotated such that the first optical collector 101 is located above the micro LED array panel 00 and vertically aligned with the micro LED array panel 00, the light transmission channel 103 is connected to the first optical collector 101, and the image detector 02 is in an active state to acquire the light collected by the first optical collector 101. When the fixing element 104 is rotated such that the second optical collector 102 is located above the micro LED array panel 00 and vertically aligned with the micro LED array panel 00, the light transmission channel 103 is connected to the second optical collector 102, and the light measurement device 03 is in an active state to acquire the light collected by the second optical collector 102. It is noted that the position of the micro LED array panel 00 is adjusted to align with the light transmission channel 103 by moving the sample stage 04 on which the micro LED array panel 00 is disposed.
[0020] Additionally, the image detector 02 may include, but is not limited to, a charge-coupled device detector, a photomultiplier tube detector, etc. The light measurement device 03 may include, but is not limited to, a spectrometer. The light measurement device 03 may measure any optical parameter of the emitted light, such as half-maximum peak width, peak width, etc.
[0021] The first optical collector 101 is disposed above and vertically aligned with the micro LED array via rotating the fixing element 104, and the first optical collector 101 directs light emitted from the micro LED array to the image detector 02.
[0022] Here, the first collector optics 101 comprises various optical components for collecting and directing the light emitted from the micro LED array. The optical elements may comprise lenses, mirrors, filters, beam splitters, etc. For example, a filter may be placed in the light path between the first collector optics and the image detector to filter out unexpected light or attenuate the light intensity.
[0023] A second collector optics 102 is disposed above and vertically aligned with the micro LED array via rotating the fixing element 104, and the second collector optics 102 collects light from one or more portions of the micro LED array.
[0024] It should be noted that in an embodiment, the detection area of the first collector optics 101 is larger than the light emitting area of the micro LED array. In another embodiment, the detection area of the first collector optics 101 may be equal to the light emitting area of the micro LED array panel 00.
[0025] Additionally, the detection area of the second collector optics 102 is larger than the light emitting area of the micro LED array in accordance with the embodiment. In another embodiment, the detection area of the second collector optics 102 may be smaller than or equal to the light emitting area of the micro LED array panel 00.
[0026] It should be noted that the second optical collector 102 may be electrically connected to the light measurement device 03 via a conductive line. For example, the conductive line may be an optical fiber.
[0027] The above-mentioned inspection tool can be used for any system to detect the micro LED array panel, such as pixel defect inspection system, optical inspection system, etc. Additionally, the micro LED array panel can be one piece, or more pieces arranged on one wafer. The micro LED array panel is supported on a sample stage. The sample stage can move in any direction and / or rotate to any angle to align the micro LED array panel with the first optical collector.
[0028] During operation, the first collector optics 01 may be adjusted to an optimized position for acquiring one or more portions of a clear image of the micro LED array. When the micro LED array panel 00 is aligned with the first collector optics 01, the inspection process may begin without adjusting the position of the second collector optics 02.
[0029] The micro LED array panel is a micro self-luminous panel. The LEDs in the panel can be organic or inorganic LEDs. The light-emitting area of the micro LED array panel 00 is extremely small, such as 3mm*5mm. Please note that the light-emitting area is the area of the micro LED array. The micro LED array panel comprises a micro LED array forming a pixel array, such as 1600x1200, 680x480, 1920x1080, etc. The diameter of the micro LED is in the range of 200nm to 2μm. However, the light-collecting area of the first optical collector 101 cannot be as small as the light-emitting area of the micro LED array panel due to various optical components in the first optical collector 101, which prevents the light from reaching the second optical collector 02 directly when the first optical collector 01 is arranged vertically. Thus, the configuration of the first optical collector 01 and the second optical collector in the embodiment of the present disclosure can solve this problem. An IC backplane is formed on the back surface of the micro LED array and electrically connected with the micro LED array. The IC backplane acquires signals such as image data from the outside through signal lines to control corresponding micro LEDs to emit light. The IC backplane generally adopts an 8-bit digital-to-analog converter (DAC). The 8-bit DAC has 256 levels of display, each level corresponds to one gray level, that is, the 8-bit DAC can provide 256 different gray levels. Any one of the 256 gray levels can be applied to the micro LED, so that gray levels ranging from 0 to 255 can be displayed by one pixel. Optionally, the luminance value of the micro LED can be controlled by the voltage amplitude or current amplitude of a signal acquired by the IC backplane, and the gray level can be indicated by the time interval, e.g., pulse width, of the signal.
[0030] It should be noted that the first optical collector and the second optical collector are disposed separately in the embodiment. However, in another embodiment, the first optical collector and the second optical collector may be configured together to form one light collection area, for example, the first optical collector is in an active state and the second optical collector is in an inactive state, or the first optical collector is in an inactive state and the second optical collector is in an active state. Thus, the optical transmission paths for the first optical collector and the second optical collector may share one optical transmission path or various transmission paths according to the scope of the present disclosure.
[0031] The above description is only the embodiment of the present disclosure, and the present disclosure is not limited thereto. Any modifications, equivalent replacements, and improvements made without departing from the concept and principle of the present disclosure shall be within the protection scope of the present disclosure.
Claims
1. 1. An inspection tool for inspecting a micro light emitting diode (LED) array panel, comprising: a collector optics configured to collect light emitted from the micro LED array included in the micro LED array panel; an image detector coupled to the group of collector optics to receive the light collected by the group of collector optics and configured to capture an image of the micro LED array; a light measurement device electrically connected to the group of collector optics to receive the light collected by the group of collector optics and configured to measure the light emitted from one or more portions of the micro LED array; Equipped with the optical collector group is disposed above the micro LED array panel to collect the light emitted from any position of the micro LED array, the optical collector group comprises a first optical collector and a second optical collector, the first optical collector is connected to the image detector, the second optical collector is electrically connected to the light measurement device, the first optical collector group and the second optical collector group are configured on a fixed element, the fixed element is rotatable in any direction; Inspection tool.
2. 2. An inspection tool for inspecting a micro LED array panel as described in claim 1, wherein the first optical collector is disposed above and vertically aligned with the micro LED array via rotating the fixing element, the first optical collector configured to direct the light emitted from the micro LED array to the image detector.
3. 3. An inspection tool for inspecting a micro LED array panel as claimed in claim 2, wherein the second collector optics is disposed above and facing the micro LED array via rotating the fixing element, the second collector optics configured to collect the light emitted from one or more portions of the micro LED array.
4. 4. The inspection tool for inspecting a micro LED array panel of claim 3, wherein a detection area of the first optical collector is equal to or greater than a light emitting area of the micro LED array.
5. 5. The inspection tool for inspecting a micro LED array panel of claim 4, wherein a detection area of the second collector optical is larger than the light emitting area of the micro LED array.
6. 5. An inspection tool for inspecting a micro LED array panel as claimed in claim 4, wherein the detection area of the second collector optical is less than or equal to the light emitting area of the micro LED array.
7. 13. An inspection system for inspecting a micro LED array panel comprising at least the inspection tool of claim 1.
8. 10. The inspection system of claim 7, further comprising a sample stage for supporting the micro LED array panel.
Citation Information
Patent Citations
Micro display chip production detection system and method
CN105182209A