Views: 0 Author: Site Editor Publish Time: 2025-01-07 Origin: Site
Although Mini LED technology brings higher resolution and image quality, it also faces many challenges in the production and manufacturing process. For example, issues such as PCB substrate PAD consistency, soldering effect, solder paste printing uniformity, precision and efficiency matching of die bonding equipment, and defect detection need to be addressed in the packaging process.
In order to address these challenges, the important role of inspection and repair equipment is becoming increasingly prominent. At present, domestic intelligent equipment enterprise Mengtuo Intelligence has launched a series of detection and repair equipment for Mini LED. At the 2024 TrendForce Consulting Self luminous Display Industry Seminar, Tang Yangshu, CEO of Mengtuo Intelligence, shared how to bridge the gap between Mini/Micro LED measurement and repair technology and demand around process control.
Quality Control and Solutions for Mini LED
At present, typical Mini LED production lines cover expansion and contraction measurement/pad inspection, printing machines SPI、 There are many links, such as solidification machine, pre furnace AOI, reflow oven, post furnace AOI, lighting test, colloid test, laser marking, repair equipment, etc., each of which is related to the yield and cost of Mini LED.
In the substrate process, surface inspection of solder pads involves defects such as copper leakage, gold infiltration, narrow spacing between solder pads, scratches, uneven hole filling, small and missing solder pads, and foreign objects, which need to be controlled. On this basis, attention should also be paid to data such as pad length, width, spacing, row column collinearity, and overall expansion and contraction. Among them, the pad expansion and contraction detection is to match the best steel mesh. For the detection of pad expansion and contraction, Mengtuo Intelligent has launched the Mini LED Expansion and Shrinkage Measurement AOI device M2020MM.
In the solder paste printing process, there may be issues such as solder continuity, insufficient solder, missing prints, poor solder pads, and offset. Mengtuo Intelligent combines three-dimensional height and two-dimensional RGB color information to analyze the volume, height, area, perimeter, and other information of the solder paste, achieving impartiality and not too much or too little, laying a solid foundation for the next step of solidification. For the solder paste process, Mengtuo Intelligence has launched the Mini LED 3D SPI device M3212.
In the solidification process, there may be various problems such as missed solidification, monument standing, lateral standing, offset, solid flipping, solid weight, tilt, foreign objects, etc. Mengtuo Intelligence has launched the Mini LED furnace front AOI device M2020 based on sub-pixel positioning algorithm to accurately identify error points.
In the lighting test phase, there may also be many problems, including red, blue, and green not lighting up, dark lighting, and over lighting. To address these issues, Mengtuo Intelligence has launched testing methods including color coordinate analysis algorithm, static imaging (multi view), and dynamic lighting imaging, each with its own advantages and disadvantages, which can be matched with different combinations of solutions according to customer needs. For the lighting testing process, Mengtuo Intelligence has launched the Mini LED lighting AOI device M2012EL and Mini LED lighting appearance all-in-one machine M2020-2012EL series products, which can meet both static and dynamic imaging needs.
At present, AI technology has been widely applied in various industries, and Mengtuo Intelligence has introduced AI technology in the testing process, forming a re evaluation system that can not only save manpower and reduce costs, but also improve accuracy.
For Mini LED to achieve normal shipment, defect repair is an inevitable part. In terms of direct display repair, the first step is to remove bad chips, then tidy up the solder pads, followed by solidification, dot printing, and then soldering the chips to achieve the goal of direct display repair. The backlight repair process is also the same. After membrane pressing, the membrane is first removed before wafer removal, and finally dot printing and solidification are performed to achieve the maintenance goal.
Mengtuo Intelligence has strong anti-interference pad positioning capabilities and has laid a further foundation for successful repair at the bottom level, including the function of repairing at any angle and positioning at any angle of the pad. Due to the need for repeated corrections, the ability to locate the entire pad is particularly important for locating the repaired points.
Mengtuo Intelligence has launched the fully automatic direct display Mini LED rework machine RD30L, RD30K, and fully automatic backlight Mini LED rework machine RB30L for direct display and backlight rework, as well as rework after film pressing, all of which have achieved mass production applications.
Universal and flexible software architecture
In March of this year, Mengtuo Intelligence released the world's first integrated visual inspection platform ideaPi, which integrates the capabilities of target positioning, defect detection, size measurement, artificial intelligence, and visual guidance. Based on this, Mengtuo Intelligence has completed the research and development of a series of equipment for inspection, repair, and other purposes.
During the research and development process, Mengtuo Intelligence made the ideaPi system platform based, modular, and versatile, with strong versatility and personalization, suitable for various scenarios such as Mini/Micro LED new displays, SMT integrated circuits, SiP semiconductor advanced packaging, etc.
Mengtuo Intelligence has a self-developed industrial machine vision software system, and Mini/Micro LED is one of the most systematic and in-depth scenarios for its inspection and repair.
Innovative technological capability
Although Mengtuo Intelligence only entered the Mini LED/Micro LED field in 2018, it has been deeply involved in software systems and optical solutions around industrial machine vision and image processing software for 15 years, continuously iterating and developing in technology.
In terms of visual algorithms, Mengtuo Intelligence uses Blob analysis for foreign object detection; Applying AI to WB quality inspection, device missing and offset detection, and scratch detection can improve the accuracy of recognition and judgment.
Mengtuo intelligent related equipment can not only make qualitative judgments, but also locate, identify, and measure the absolute values of wafer size, spacing, offset trends and collinearity, including area and angle offset issues.
In the Mini/Micro LED detection scenario, it is necessary to consider how to achieve measurement accuracy under environmental influences (temperature, humidity, vibration, etc.), which puts higher requirements on software systems and measurement capabilities. Mengtuo Intelligent has extended its measurement capabilities in a targeted manner, including whole board expansion and contraction measurement.
To ensure the smooth implementation of measurements, Mengtuo Intelligent has developed measurement mechanisms such as field of view correction and lens distortion correction, which make the corrected images closer to objectivity and lay a better foundation for visual inspection.
In addition, Mengtuo Intelligent sub-pixel positioning is a technology for better identifying problem points, which can identify and judge problem points smaller than 1 pixel, achieving better positioning capabilities.
brief summary
While developing a diverse range of Mini LED production line equipment, Mengtuo Intelligent utilizes industrial machine vision and AI technology to assist in foreign object detection, WB quality detection, device missing and offset detection, scratch detection, field of view correction, lens distortion correction, sub-pixel positioning and other detection work. Through the combination of hardware and software, it comprehensively improves the quality of Mini LED products and helps the Mini/Micro LED industry overcome the development gap.
