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CN-122028557-A - Processing method of laser direct-engraving gray scale micro-nano structure, microLED chip and MicroLED brightness calibration system

CN122028557ACN 122028557 ACN122028557 ACN 122028557ACN-122028557-A

Abstract

The invention discloses a processing method of a laser direct-engraving gray-scale micro-nano structure, a MicroLED chip and a MicroLED brightness calibration system, which relate to the technical field of MicroLED manufacturing, wherein the processing method of the laser direct-engraving gray-scale micro-nano structure comprises the steps of detecting pixel-by-pixel brightness of a MicroLED array after macro transfer, obtaining an actual measurement brightness value of each pixel, calculating a brightness deviation value delta based on a target brightness value, and generating a brightness deviation map; the method comprises the steps of calculating the required microstructure height according to the mapping relation between the prestored microstructure height h and the brightness attenuation rate alpha, performing direct engraving processing on the surface corresponding to MicroLED pixels to form a gray scale micro-nano structure with the microstructure height, performing secondary brightness detection on the processed MicroLED array, and realizing pixel-by-pixel brightness calibration on the MicroLED array through a non-contact and high-precision physical processing mode to replace the traditional low-efficiency method relying on screening and electrical adjustment.

Inventors

  • Zheng tianqi
  • ZHANG YARONG
  • LI JINBANG

Assignees

  • 合肥泰沃达智能装备有限公司

Dates

Publication Date
20260512
Application Date
20260126

Claims (10)

  1. 1. A processing method of a laser direct-engraving gray scale micro-nano structure is used for MicroLED brightness calibration and is characterized by comprising the following steps: S1, brightness detection and map generation, namely performing pixel-by-pixel brightness detection on a MicroLED array subjected to huge transfer to obtain an actual measurement brightness value of each pixel And based on the target brightness value Calculating the brightness deviation value delta Generating a brightness deviation map; s2, calculating gray scale processing parameters, namely according to a mapping relation alpha=f (h) between a prestored microstructure height h and a brightness attenuation rate alpha, aiming at delta in the brightness deviation mapping diagram A pixel of >0, calculating the desired microstructure height ; S3, laser direct engraving forming based on calculated Directly engraving the surface corresponding to MicroLED pixels by adopting ultraviolet laser to form the microstructure height A gray scale micro-nano structure of (a); S4, performing secondary brightness detection on the machined MicroLED array, and adjusting laser machining parameters for performing secondary brightness adjustment on pixels with brightness deviation still exceeding a preset tolerance range until the brightness consistency of the whole array meets the target requirement.
  2. 2. The method for processing a laser direct structuring gray scale micro-nano structure according to claim 1, wherein the MicroLED pixels in the step S1 have a size of 1 μm-10 μm and an array resolution of not less than 4K.
  3. 3. The method for processing a laser direct structuring gray scale micro-nano structure according to claim 1, wherein in the step S2, the mapping relation α=f (h) is a linear relation α=k×h+b; wherein, the value range of k is 0.05 to 0.12, and the value range of b is 0 to 0.05.
  4. 4. The method for processing the laser direct structuring gray scale micro-nano structure according to claim 1, wherein the height of the microstructure is as follows The range of the value of the luminance attenuation factor alpha is 1-2.5 mu m, and the corresponding range of the value of the luminance attenuation factor alpha is 10-22%.
  5. 5. The method for processing a gray scale micro-nano structure according to claim 1, wherein in step S3, the laser direct structuring is performed in an inert gas atmosphere.
  6. 6. The method for processing a gray scale micro-nano structure by direct laser etching according to claim 1, wherein in the step S3, the wavelength of the ultraviolet laser is 266nm, 355nm or 405nm; The laser pulse width is nanosecond, the energy density of the laser during processing ranges from 5X 10 5 W/cm2 to 1X 10 6 W/cm2, and the residence time is 2 mu s to 5 mu s.
  7. 7. The method for processing a gray scale micro-nano structure by laser direct structuring according to claim 1, wherein in step S4, the preset tolerance range is that the brightness deviation is not more than ±1%; the compensation is realized by finely adjusting the laser pulse energy, and the compensation rate of the array after compensation is less than or equal to 0.5 percent.
  8. 8. A MicroLED chip, characterized in that its light-emitting surface has a gray-scale micro-nano structure formed by processing according to any one of claims 1 to 7.
  9. 9. MicroLED brightness calibration system for implementing the method of any one of claims 1 to 7, comprising: the brightness detection module is used for detecting pixel-by-pixel brightness of the MicroLED array and generating a brightness deviation map; The data processing and control module is pre-stored with the mapping relation alpha=f (h) and is used for calculating the microstructure height required by each pixel according to the brightness deviation mapping diagram Generating a laser processing control instruction; And the laser direct etching processing module comprises an ultraviolet laser source and a high-precision scanning device and is used for receiving the control instruction and selectively etching the surface of the MicroLED chip to form the gray scale micro-nano structure.
  10. 10. The system of claim 9, wherein the laser direct structuring processing module further comprises an environment control unit for providing an inert gas environment during processing.

Description

Processing method of laser direct-engraving gray scale micro-nano structure, microLED chip and MicroLED brightness calibration system Technical Field The invention relates to the technical field of MicroLED manufacturing, in particular to a laser direct-engraving gray scale micro-nano structure processing method, a MicroLED chip and a MicroLED brightness calibration system. Background MicroLED (micro light emitting diode) display technology is regarded as a core direction of next generation display technology because of advantages of high brightness, high contrast, low power consumption, long lifetime, and the like. In high-end application fields, such as near-eye display, oversized 8K/16K screen and high-end vehicle display, extremely severe requirements are placed on display uniformity, and brightness non-uniformity among millions of pixels is usually required to be controlled within +/-1.5% or even +/-1%. However, achieving such high brightness uniformity during the MicroLED manufacturing process presents a significant challenge, and the prior art has mainly presented the following bottlenecks: Due to the non-uniformity of epitaxial wafer growth and inherent precision limitations of mass transfer processes, there is a significant difference in luminous efficiency even for MicroLED chips produced on the same wafer and transferred to the same backplate. The actual measurement shows that the brightness deviation of the untreated pixel array can reach +/-10% to +/-15%, so that 'bright spots' or 'dark spots' which can be distinguished by naked eyes are formed in a display picture, and the visual experience and the product grade are seriously influenced. To cope with the above-mentioned differences, conventional solutions rely mainly on electrical testing and optical sorting. That is, before or after large-scale transfer, a large number MicroLED of chips are tested, and the chips are classified into tens or even hundreds of grades according to parameters such as brightness, wavelength and the like, and then the chips of the same grade are assembled together. The method has the obvious defects that firstly, the sorting process is complex, the process time and the equipment cost are greatly increased, secondly, the sorting cannot create consistency, only the existing deviation is classified, the system-level yield is usually only 90% -95%, and about 5% -10% of chips are discarded due to the fact that the chips cannot be matched, and according to industry estimation, the overall manufacturing cost can be increased by more than 20%. In view of the foregoing, there is a need in the art for a pixel-by-pixel brightness calibration method that enables non-contact, high precision, high efficiency and no impact on optoelectronic performance and reliability of MicroLED arrays integrated on a backplane after mass transfer. Disclosure of Invention The invention provides a processing method of a laser direct-engraving gray scale micro-nano structure, microLED chips and a MicroLED brightness calibration system, which can realize the pixel-by-pixel brightness calibration of a MicroLED array by a non-contact and high-precision physical processing mode after massive transfer so as to replace the traditional low-efficiency method relying on screening and electrical adjustment. In order to solve the above problems, the present invention provides a method for processing a laser direct-engraving gray scale micro-nano structure for MicroLED brightness calibration, comprising: S1, brightness detection and map generation, namely performing pixel-by-pixel brightness detection on a MicroLED array subjected to huge transfer to obtain an actual measurement brightness value of each pixel And based on the target brightness valueCalculating the brightness deviation value deltaGenerating a brightness deviation map; s2, calculating gray scale processing parameters, namely according to a mapping relation alpha=f (h) between a prestored microstructure height h and a brightness attenuation rate alpha, aiming at delta in the brightness deviation mapping diagram A pixel of >0, calculating the desired microstructure height; S3, laser direct engraving forming based on calculatedDirectly engraving the surface corresponding to MicroLED pixels by adopting ultraviolet laser to form the microstructure heightA gray scale micro-nano structure of (a); S4, performing secondary brightness detection on the machined MicroLED array, and adjusting laser machining parameters for performing secondary brightness adjustment on pixels with brightness deviation still exceeding a preset tolerance range until the brightness consistency of the whole array meets the target requirement. Compared with the prior art, the laser direct-engraving gray scale micro-nano structure processing method for MicroLED brightness calibration has the following beneficial effects: And (3) independently processing each pixel with the brightness exceeding the standard through a detection-calcul