[Source: "High-tech LED - Technology and Applications" November issue]
Lighting, display and light source are the three major application areas of LED. Among them, LED display is the most mature one in technology, product and market application. Under the circumstance of industrial development and technological development with reduced technology, LED display The industrial chain is fully operational under market conditions. In the past two years, as funds have entered the upstream of the LED industry chain, the effect has shown that the capital is madly vying for LED application market resources, and sales activities below cost have occurred. In the LED display market, although a number of screen factories with display-oriented business started to appear on the market, there has also been a phenomenon in which large-scale screen factories have closed down. This shows that with the intensification of competition for market resources, cost and technical competition have reached a feverish level. Most enterprises with no technical characteristics in the market choose to fight for cost, which poses hidden dangers for the collapse of large-scale enterprises. In the face of this fierce competition, there are basically three kinds of corporate countermeasures: one is to seek scale operation and enhance the ability to resist risks; the second is to seek business models to be surprisingly successful; the third is to make products have characteristics to enhance core competitiveness. The huge temptation of emerging industry market opportunities has caused some of the LED industry practitioners to have impetuous and speculative psychology, and are reluctant to spend time and energy on new technologies and product development, resulting in a large instability in the LED display industry and enterprises. . What kind of countermeasures should be taken in this game? To be or not to be? The problem with Shakespeare has reappeared.
In the LED display industry, LED chips should be the most important link. Improving the quality of LED chips and using chips correctly is the most important part of the effort.
1. LED chip detection and corporate profitability improvement
The technological characteristics of LEDs determine the testing throughout the entire LED industry chain, and the downstream inspections occupy a more important role. Downstream enterprises use good testing links to ensure continuous good products.
During the operation of the actual LED display factory, due to factors such as cognition, equipment and cost, many companies abandoned the quality inspection of the chip, resulting in frequent problem screens.
Cognition: LED chip processing and packaging process, according to a variety of indicators such as wavelength (color), brightness, reverse voltage, leakage current, etc., the electrical indicator detection of LED lights is the same as the ordinary diode detection method, but for wavelength and The detection of brightness photoelectric index is relatively complicated. For the chip and packaging factory, professional sorting machine is needed. The display factory should use the detection equipment such as illuminance colorimeter to test the unevenness of the wavelength and brightness of the LED chip. All of the above devices have problems with accuracy and calibration. For the ordinary illuminance colorimeter of the screen factory, such as BM-7 and CL-100, the test display accuracy reaches three decimal places, the precision is not enough, and the chip wavelength cannot be accurately tested, so the mixing of different batches of chips becomes a problem.
Test standard for chip processing and packaging: For ordinary LED display, the chip is not easy to detect brightness change within 10% of the human eye at the pixel level, but it is difficult to identify within 4 nm for color change, so the common binning standard for LED chips is The brightness difference is within 20%, and the color difference is within 5nm (if the accuracy of the sorter or test equipment can be guaranteed), the screen display effect is ideal. The same binning standard is not ideal for small pixel pitch screens such as P4 or P3. The problem of solving the screen within P4 is usually 10% brightness, 2.5nm color binning or point-by-point chromaticity and brightness correction control. Plug-in lights used in outdoor screens, in addition to the inconsistencies in color and brightness discussed above, also have angular inconsistencies. These problems should mainly be solved by the packaging factory in terms of materials and processes.
The human eye is not easily aware of the brightness of the module level in the range of 3%, and the color is within 2 nm. Once the LED chips are combined into a module, the human eye can perceive the difference. Therefore, the screen factory should not mix the different batches of chip modules as much as possible. If mixed, the chroma and brightness correction should be performed.
For chip factories, packaging plants and even display factories, there are calibration problems for sorting and testing equipment. The more feasible methods are usually compared with standard light sources. In actual operation, in order to reduce costs and ensure a certain precision, it is usually used with considerable precision. The light source replaces the standard light source to calibrate the test equipment.
Unfinished
For more information, please refer to the November issue of "High-tech LED - Technology and Applications"
Lighting, display and light source are the three major application areas of LED. Among them, LED display is the most mature one in technology, product and market application. Under the circumstance of industrial development and technological development with reduced technology, LED display The industrial chain is fully operational under market conditions. In the past two years, as funds have entered the upstream of the LED industry chain, the effect has shown that the capital is madly vying for LED application market resources, and sales activities below cost have occurred. In the LED display market, although a number of screen factories with display-oriented business started to appear on the market, there has also been a phenomenon in which large-scale screen factories have closed down. This shows that with the intensification of competition for market resources, cost and technical competition have reached a feverish level. Most enterprises with no technical characteristics in the market choose to fight for cost, which poses hidden dangers for the collapse of large-scale enterprises. In the face of this fierce competition, there are basically three kinds of corporate countermeasures: one is to seek scale operation and enhance the ability to resist risks; the second is to seek business models to be surprisingly successful; the third is to make products have characteristics to enhance core competitiveness. The huge temptation of emerging industry market opportunities has caused some of the LED industry practitioners to have impetuous and speculative psychology, and are reluctant to spend time and energy on new technologies and product development, resulting in a large instability in the LED display industry and enterprises. . What kind of countermeasures should be taken in this game? To be or not to be? The problem with Shakespeare has reappeared.
In the LED display industry, LED chips should be the most important link. Improving the quality of LED chips and using chips correctly is the most important part of the effort.
1. LED chip detection and corporate profitability improvement
The technological characteristics of LEDs determine the testing throughout the entire LED industry chain, and the downstream inspections occupy a more important role. Downstream enterprises use good testing links to ensure continuous good products.
During the operation of the actual LED display factory, due to factors such as cognition, equipment and cost, many companies abandoned the quality inspection of the chip, resulting in frequent problem screens.
Cognition: LED chip processing and packaging process, according to a variety of indicators such as wavelength (color), brightness, reverse voltage, leakage current, etc., the electrical indicator detection of LED lights is the same as the ordinary diode detection method, but for wavelength and The detection of brightness photoelectric index is relatively complicated. For the chip and packaging factory, professional sorting machine is needed. The display factory should use the detection equipment such as illuminance colorimeter to test the unevenness of the wavelength and brightness of the LED chip. All of the above devices have problems with accuracy and calibration. For the ordinary illuminance colorimeter of the screen factory, such as BM-7 and CL-100, the test display accuracy reaches three decimal places, the precision is not enough, and the chip wavelength cannot be accurately tested, so the mixing of different batches of chips becomes a problem.
Test standard for chip processing and packaging: For ordinary LED display, the chip is not easy to detect brightness change within 10% of the human eye at the pixel level, but it is difficult to identify within 4 nm for color change, so the common binning standard for LED chips is The brightness difference is within 20%, and the color difference is within 5nm (if the accuracy of the sorter or test equipment can be guaranteed), the screen display effect is ideal. The same binning standard is not ideal for small pixel pitch screens such as P4 or P3. The problem of solving the screen within P4 is usually 10% brightness, 2.5nm color binning or point-by-point chromaticity and brightness correction control. Plug-in lights used in outdoor screens, in addition to the inconsistencies in color and brightness discussed above, also have angular inconsistencies. These problems should mainly be solved by the packaging factory in terms of materials and processes.
The human eye is not easily aware of the brightness of the module level in the range of 3%, and the color is within 2 nm. Once the LED chips are combined into a module, the human eye can perceive the difference. Therefore, the screen factory should not mix the different batches of chip modules as much as possible. If mixed, the chroma and brightness correction should be performed.
For chip factories, packaging plants and even display factories, there are calibration problems for sorting and testing equipment. The more feasible methods are usually compared with standard light sources. In actual operation, in order to reduce costs and ensure a certain precision, it is usually used with considerable precision. The light source replaces the standard light source to calibrate the test equipment.
Unfinished
For more information, please refer to the November issue of "High-tech LED - Technology and Applications"
Fan Motor,Micro Stepper Motor,Unipolar Stepper Motor,Linear Stepper Motor
Shenzhen Maintex Intelligent Control Co., Ltd. , https://www.maintexmotor.com