Micro-led detection method, system and electronic device for photoluminescence detection

Abstract

A micro-LED detection method, system and electronic device for photoluminescence detection, comprising: 1) scanning a micro-LED module to obtain position data of each chip in the module; 2) positioning the center of an excitation light circle at a certain position of a single chip to be measured, obtaining PL light intensity data in the excitation light circle region, and calculating the PL light intensity of the chip to be measured according to the ratio of the area of the chip to be measured to the total area in the excitation light circle region; 3) moving the excitation light circle to other positions of the chip to be measured in turn, and repeating step 2) to obtain multiple PL light intensities of the chip to be measured, and averaging to obtain a PL light intensity average value; 4) adjusting the size of the excitation light circle, repeating steps 2-3) to obtain multiple PL light intensity average values, and averaging to obtain the PL light intensity data of the chip to be measured. The present application effectively separates and obtains accurate data of a single chip, and improves the precision of the PL detection method.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photoluminescence detection, in particular to a photoluminescence detection micro-LED detection method, system and electronic equipment. BACKGROUND

[0002] In recent years, with the increasing demand for high-definition, color vividness and other visual experience, new display technologies have been widely used in various fields. Because micro-LED display technology has many advantages such as high brightness, high contrast, wide color gamut, fast response speed and long service life, it has become one of the popular candidates for the next generation of new display technology.

[0003] Photoluminescence detection is a non-contact detection technology, which has the advantages of non-contact, non-damage and high efficiency. Its principle is to excite the multi-quantum well layer in the micro-LED chip by short-wavelength laser to realize light emission, and then analyze the photoluminescence spectrum to evaluate the quality of the LED. The PL detection technology can quickly and non-contactly detect the appearance, brightness and light emitting wavelength of the micro-LED on the wafer.

[0004] Micro-LED display applications have very high requirements for chip yield, so it is urgent to realize large-scale, high-efficiency and high-precision detection of micro-LED arrays on wafers. The size of micro-LED is gradually reduced, and due to the limitation of excitation light lens precision, the traditional PL detection method can only excite the chips in a certain area by the aperture, and cannot accurately test a single chip, so only the performance data of a small area of micro-LED can be obtained. At the same time, the light emitted by adjacent chips will interfere with each other, which cannot meet the demand of high-precision detection of single chips.

[0005] In addition, the data processing algorithm in the traditional PL detection instrument cannot be well adapted to different sizes and types of micro-LED chips, and has poor generalization ability, so it cannot truly realize detection automation. The previous PL tester usually uses an external industrial computer to process the collected data, which requires additional space to store the computer, and more complex software testing process to adapt to different computers. SUMMARY

[0006] The main purpose of the present application is to overcome the above-mentioned defects in the prior art, and to provide a photoluminescence detection micro-LED detection method, system and electronic equipment, which can effectively separate and obtain accurate data of a single chip, improve the precision of the PL detection method, and accurately evaluate the performance indicators of a single chip.

[0007] The present application adopts the following technical solutions:

[0008] A micro-LED detection method for photoluminescence detection, comprising:

[0009] 1) scanning a micro-LED module to obtain position data of each chip in the micro-LED module, and determining a plurality of positioning points of each chip according to the position data of each chip;

[0010] 2) positioning the center of an excitation light circle at a certain positioning point of a single chip to be measured, obtaining PL light intensity data in the excitation light circle region, and calculating the PL light intensity of the chip to be measured according to the ratio of the area of the chip to be measured to the total area in the excitation light circle region;

[0011] 3) moving the excitation light circle to other positioning points of the chip to be measured in turn, and repeating step 2) to obtain a plurality of PL light intensities of the chip to be measured, and averaging all the PL light intensities of the chip to be measured to obtain a PL light intensity average value;

[0012] 4) adjusting the size of the excitation light circle, repeating steps 2-3) to obtain a plurality of PL light intensity average values, and averaging all the PL light intensity average values of the chip to be measured to obtain PL light intensity data of the chip to be measured.

[0013] The plurality of positioning points of each chip at least include a center point of the chip, a center point of the left edge of the chip, a center point of the upper edge of the chip, a center point of the right edge of the chip, and a center point of the lower edge of the chip.

[0014] The PL light intensity of the chip to be measured is calculated according to the ratio of the area of the single chip to be measured to the total area in the excitation light circle region, specifically comprising the following:

[0015] All chip edges contained in the region of the excitation light circle are detected and the total area is calculated by a deep learning edge detection algorithm, and the ratio of the area of the chip to be measured to the total area is calculated, and the PL light intensity of the chip to be measured is calculated according to the ratio.

[0016] A high-precision camera is used to scan the micro-LED module to obtain the position data of each chip in the micro-LED module.

[0017] For each chip in the micro-LED module, steps 2)-4) are used to calculate the PL light intensity data of each chip.

[0018] Adjusting the size of the excitation light circle includes pre-setting a plurality of different threshold values, and adjusting the excitation light circle to the corresponding threshold value.

[0019] A micro-LED detection system for photoluminescence detection, comprising:

[0020] A scanning module scans the micro-LED module to obtain position data of each chip in the micro-LED module, and determines a plurality of positioning points of each chip according to the position data of each chip;

[0021] A light source module is configured to position the center of the excitation light circle at the positioning point of the single chip to be measured;

[0022] An industrial computer is configured to execute the steps of the micro-LED detection method for photoluminescence detection to obtain PL light intensity data of the single chip.

[0023] An electronic device comprises a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the micro-LED detection method for photoluminescence detection.

[0024] As can be seen from the above description of the present application, compared with the prior art, the present application has the following beneficial effects:

[0025] The present application provides a method for obtaining the light intensity proportion of each chip in a region, thereby effectively separating and obtaining accurate data of a single chip, ensuring detection efficiency while improving the accuracy of the PL detection method, enabling accurate evaluation of the performance indicators of a single chip, improving the integration of the system, reducing the size of the equipment, and reducing maintenance difficulty. At the same time, the method has excellent generalization ability.

[0026] The present application can complete rapid detection of the performance data of each chip in a micro-LED chip array in a short time by optimizing the detection process, using machine learning algorithms, and using parallel processing and high-speed data transmission technology, thereby realizing accurate evaluation of the overall performance parameters of a single micro-LED chip and improving the detection accuracy. By using a deep learning large model algorithm, the interference of adjacent chip light emission can be effectively eliminated or reduced, ensuring the accuracy of the detection results of a single chip. By obtaining data at a plurality of different aperture positions for a single chip and processing the obtained multiple sets of results to obtain the final result, the accuracy is higher than that of using only a single data.

[0027] The present application method can adapt to large-scale rapid detection requirements, and is not only suitable for high-precision detection of a single chip, but also can adapt to large-scale rapid detection requirements of a micro-LED array, thereby meeting the requirements of detection efficiency in actual applications.

[0028] The application has strong generalization ability. It can be applied to micro-LED chips of different sizes and types. Due to the flexible and adjustable optical system design, the technical scheme of the application can be applied to the detection of micro-LED chips of different sizes and types, and has wide applicability. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 chip position data for each chip of the micro-LED module;

[0030] Figure 2 schematic diagram of a plurality of positioning points of the chip to be measured;

[0031] Figure 3 schematic diagram of light emission mutual interference of chips in the excitation light circle area;

[0032] Figure 4 PL value of chip A2-2 measured before and after adjustment of the laser light circle.

[0033] The application will be further described below in combination with the drawings and specific embodiments. DETAILED DESCRIPTION

[0034] The application will be further described below through specific embodiments.

[0035] Reference Figure 2 (a), due to the small size of the micro-LED, the distance between the single chip and the chip is close, and the lens precision of the current excitation light source does not allow the photo-induced excitation of the single micro-LED chip. Only the chips in a certain area can be excited by light, and a single chip cannot be excited by light. Only the chips in the circle range can be excited by light, and the light emission of the adjacent chips in the light excitation range exists mutual interference problem. In combination with Figure 3 , the PL value measured at A2-2 by the existing method is actually a result of superposition of photo-induced excitation of A1-2, A2-1, A3-2, A2-3 and A2-2 itself. Therefore, the overall performance of a certain chip cannot be accurately obtained.

[0036] The application provides a micro-LED detection method for photoluminescence detection. A deep learning algorithm is used to reduce the influence of surrounding chips on the PL value of the chip to be measured. The method comprises the following steps:

[0037] 1) Scanning the micro-LED module to obtain the position data of each chip in the micro-LED module, and determining a plurality of positioning points of each chip according to the position data of each chip.

[0038] In this step, a high-precision camera is used to scan the micro-LED module to obtain the position data of each chip in the micro-LED module. Referring to Figure 1 , the position data A 1-1 to A n-n of each chip in the micro-LED module.

[0039] Specifically, the positioning points of each chip include at least the center point of the chip, the center point of the left edge of the chip, the center point of the upper edge of the chip, the center point of the right edge of the chip, and the center point of the lower edge of the chip, but are not limited thereto. Referring to Figure 2 , the positioning points of the chip are shown in the figure, wherein A1 is the center point of the chip, A2 is the center point of the left edge of the chip, A3 is the center point of the upper edge of the chip, A4 is the center point of the right edge of the chip, and A5 is the center point of the lower edge of the chip. Then, the center of the excitation light circle can be positioned at the positioning point A1, the positioning point A2, the positioning point A3, the positioning point A4, and the like of the chip.

[0040] 2) Position the center of the excitation light circle at a certain positioning point of the single chip to be measured, obtain the PL light intensity data in the excitation light circle region, and calculate the PL light intensity of the chip to be measured according to the ratio of the area of the single chip to be measured to the total area in the excitation light circle region.

[0041] In this step, the PL light intensity of the chip to be measured is calculated according to the ratio of the area of the single chip to be measured to the total area in the excitation light circle region, which specifically includes the following:

[0042] All chip edges contained in the excitation light circle region are detected and the total area is calculated by using a deep learning edge detection algorithm, and the ratio of the area of the chip to be measured to the total area is calculated, and the PL light intensity β of the chip to be measured is calculated according to the ratio.

[0043] This step is used to calculate the PL light intensity of the chip to be measured when the center of the excitation light circle is positioned at a certain positioning point of the chip to be measured. Assuming that the positioning point is A1, the PL light intensity β1 is obtained.

[0044] 3) Move the excitation light circle to other positioning points of the chip to be measured in turn, and repeat step 2) to obtain multiple PL light intensities of the chip to be measured, and average all the PL light intensities of the chip to be measured to obtain the average PL light intensity.

[0045] This step is used to calculate the PL light intensity of the chip when the center of the excitation light circle is positioned at other positioning points of the chip to be measured. For the positioning points A1-A4 of the chip, single chip measurement needs to move the excitation light circle to the corresponding position for measurement, a total of five measurements are needed, and the obtained light intensities are β1, β2, β3, β4 and β5. The PL light intensity average value α is obtained by averaging β1, β2, β3, β4 and β5, and the PL light intensity average value α is the more accurate single chip light intensity value.

[0046] 4) Adjust the size of the excitation light circle, repeat steps 2-3) to obtain a plurality of PL light intensity average values, and average all PL light intensity average values of the chip to be measured to obtain the PL light intensity data of the chip to be measured.

[0047] Adjusting the size of the excitation light circle includes pre-setting a plurality of different thresholds, and adjusting the size of the excitation light circle to the corresponding threshold. In this step, by adjusting the size of the light circle, all PL light intensity average values of the chip to be measured under different excitation light circle sizes are calculated, α1……αn is obtained, and the average light intensity data B is obtained by averaging the PL light intensity average values. Through several groups of data, the accurate data of a single chip is finally obtained.

[0048] Through steps 2)-3), the performance of a specific chip under a single light source condition is predicted. Since the algorithm cannot accurately eliminate the influence of other chips on the to-be-measured chip, there is still some error with the actual performance. To further eliminate this error, the excitation light circle range of the light source can be modified, and the PL value after adjusting the excitation light circle is predicted again, combined with Figure 4 It is illustrated that the left side is the PL value α1 of chip A2-2 obtained by prediction for the first time in the excitation range of the light source, and the right side is the PL value α2 of chip A2-2 obtained by prediction for the second time after adjusting the excitation of the light source. The final result is obtained by averaging the two, that is, the accurate performance of chip A2-2.

[0049] The present application obtains the final result by obtaining data of a single chip under several different light circle positions and processing the obtained multiple sets of data results, which is more accurate than using only single data in the past.

[0050] The method of the present application calculates the PL light intensity data of each chip in the micro-LED module by steps 2)-4).

[0051] The application can increase the accuracy of chip performance prediction by adjusting the light source multiple times and calculating the alpha value of photo-induced excitation under the light source condition, and finally increasing the accuracy of chip performance prediction by taking the average method, thereby effectively improving the detection precision. Through optimization of the detection process and adoption of machine learning algorithms, as well as adoption of parallel processing and high-speed data transmission technology, the performance data of each chip in the micro-LED chip array can be quickly detected in a short time, the accurate evaluation of the overall performance parameters of a single micro-LED chip is realized, and the detection precision is improved; through the deep learning large model algorithm processing, the interference of adjacent chips can be effectively eliminated or reduced, and the accuracy of the detection result of a single chip is ensured.

[0052] A micro-LED detection system for photoluminescence detection, comprising:

[0053] A scanning module scans the micro-LED module to obtain the position data of each chip in the micro-LED module, and determines a plurality of positioning points of each chip according to the position data of each chip. The scanning module can use a high-precision camera.

[0054] A light source module is used to position the center of the excitation light circle at the positioning point of the single chip to be measured. The light source module can be a light source of a PL tester or a separate light source.

[0055] An industrial computer is used to cooperate with the scanning module and the light source module, and execute the above-mentioned micro-LED detection method for photoluminescence detection, which comprises obtaining the PL light circle data in the excitation light circle area, calculating the PL light intensity of the single chip to be measured according to the ratio of the area of the single chip to be measured to the total area in the excitation light circle area. The light source module is controlled to move the excitation light circle to other positioning points of the chip to be measured in turn, and the PL light intensity of the chip to be measured is repeatedly calculated to obtain a plurality of PL light intensities of the chip to be measured. All the PL light intensities of the chip to be measured are averaged to obtain the PL light intensity average value. The size of the excitation light circle is adjusted by the light source module, and the PL light intensity average value of the chip to be measured is repeatedly calculated to obtain a plurality of PL light intensity average values of the chip to be measured. All the PL light intensity average values of the chip to be measured are averaged to obtain the PL light intensity data of the chip to be measured.

[0056] The traditional PL tester often needs an external computer, which is usually purchased by the user or provided by the manufacturer. The additional computer often has a performance far exceeding the minimum performance requirement for running the PL test software, and the manufacturer needs to consider the software adaptation problems between different operating systems or computer hardware, resulting in waste of computer resources and increase of software development cost. At the same time, since the scheme of the present application needs to use offline deep learning algorithm, the external computer may encounter problems such as incompatible running environment. In order to solve such problems and reduce resource waste and production cost, the present application proposes a method of integrating an industrial computer with offline deep learning edge detection algorithm and the PL detection algorithm mentioned in the present application and a series of required components such as light source and chip placement platform of the PL tester together, which effectively avoids the above-mentioned problems and makes the control of the equipment more centralized and efficient.

[0057] The present application also provides an electronic device, which includes a memory, a processor and a computer program stored in the memory. The processor executes the computer program to implement the steps of the micro-LED detection method for photoluminescence detection.

[0058] The above is only a specific embodiment of the present application, but the design concept of the present application is not limited thereto. Any non-essential modification of the present application using this concept shall be deemed to infringe the protection scope of the present application.

Claims

1. A micro-LED detection method of photoluminescence detection, characterized in that, Comprising: 1) scanning the micro-LED module to obtain the position data of each chip in the micro-LED module, and determining a plurality of positioning points of each chip according to the position data of each chip; the plurality of positioning points of each chip at least include the center point of the chip, the center point of the left edge of the chip, the center point of the upper edge of the chip, the center point of the right edge of the chip, and the center point of the lower edge of the chip; 2) positioning the center of the excitation light circle at a certain positioning point of a single chip to be measured, obtaining the PL light intensity data in the excitation light circle region, and calculating the PL light intensity of the chip to be measured according to the ratio of the area of the chip to be measured to the total area in the excitation light circle region; specifically comprising the following: detecting all chip edges contained in the region of the excitation light circle by a deep learning edge detection algorithm and calculating the total area, then calculating the ratio of the area of the chip to be measured to the total area, and calculating the PL light intensity of the chip to be measured according to the ratio; 3) moving the excitation light circle to other positioning points of the chip to be measured in turn, and repeating step 2) to obtain a plurality of PL light intensities of the chip to be measured, and averaging all the PL light intensities of the chip to be measured to obtain a PL light intensity average value; 4) adjusting the size of the excitation light circle, repeating steps 2-3) to obtain a plurality of PL light intensity average values, and averaging all the PL light intensity average values of the chip to be measured to obtain the PL light intensity data of the chip to be measured.

2. The photoluminescence detection micro-LED detection method of claim 1, wherein, A high-precision camera is used to scan the micro-LED module to obtain the position data of each chip in the micro-LED module.

3. The photoluminescence detection micro-LED detection method of claim 1, wherein, For each chip in the micro-LED module, steps 2)-4) are used to calculate the PL light intensity data of each chip.

4. The photoluminescence detection micro-LED detection method of claim 1, wherein, Adjusting the size of the excitation light circle includes pre-setting a plurality of different thresholds, and adjusting the excitation light circle to the corresponding threshold.

5. A photoluminescence detection micro-LED detection system, comprising: Comprising: a scanning module for scanning the micro-LED module to obtain the position data of each chip in the micro-LED module, and determining a plurality of positioning points of each chip according to the position data of each chip; a light source module for positioning the center of the excitation light circle at a positioning point of a single chip to be measured; an industrial computer for performing the steps of the photoluminescence detection micro-LED detection method according to any one of claims 1 to 4 to obtain the PL light intensity data of a single chip.

6. An electronic device comprising a memory and a processor, i.e., a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the photoluminescence detection micro-LED detection method according to any one of claims 1 to 4.

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