What is Micro-LED?
Micro-LED, the full English name being Micro Light Emitting Diode, is also written as μLED in Chinese. It generally refers to the technology of using LED emitting units with dimensions ranging from 1 to 60μm to form a display array. The size of these units is about 1/10th the diameter of a human hair. Micro-LED technology has characteristics such as not requiring backlighting, high photoelectric conversion efficiency, and response times in the nanosecond range. It involves thinning, miniaturizing, and arraying LEDs, reducing their volume to only 1% of mainstream LEDs, and achieving pixel spacing from millimeters to micrometers.
A Micro LED display is created by manufacturing LED display driver circuits using standard CMOS integrated circuit fabrication processes. Afterward, an LED array is fabricated on the integrated circuit using MOCVD machines, resulting in a miniature display screen, often referred to as a downsized version of an LED display. It is considered the next-generation display technology after OLED.
Micro-LED technology is still constrained by production capacity and cost, so it will take some time for it to become commercialized. However, major manufacturers are actively investing in this field, and rapid progress in key technologies is expected to drive the commercialization process in the coming years.
The Display Principle of Micro-LED
Each pixel of a Micro-LED display is composed of sub-pixels in red, green, and blue. Each sub-pixel is individually controlled, allowing precise control of brightness, color, and contrast in the display. The light emitted by each LED passes through a set of lenses and mirrors to form a pixel on the screen. Then, the light is guided through a set of filters to create the desired colors. This type of display is capable of achieving very high brightness, contrast, and color accuracy.
The Micro-LED array connects the positive and negative poles of each Micro LED through vertically interleaved grid-like electrodes. By sequentially applying power through the electrode lines, Micro LEDs are illuminated in a scanning manner to display images.
The Manufacturing Process of Micro-LED
Micro-LED involves the design of LED structures with thin-film, miniaturization, and array-based technologies, resulting in dimensions at the level of approximately 1-100μm. The Micro-LEDs are then batch-transferred onto circuit substrates, which can be either rigid or flexible, transparent or opaque. Subsequently, a protective layer and upper electrode are created using physical deposition processes, allowing for the encapsulation of the upper substrate, thus completing the structure of a simple Micro-LED display.
- Wafer Formation: Micro LEDs are initially created from semiconductor materials like Gallium Nitride (GaN) to form thin wafers.
- Template: A layer of template photoresist is applied to the wafer, serving as a mask for etching the wafer.
- Etching: The wafer is then etched to create individual Micro LEDs.
- Mask Removal: The photoresist mask is removed, leaving individual Micro LEDs on the wafer.
- Bonding: The Micro LEDs are then bonded to a substrate, such as an IC or PCB.
- Assembly: The Micro LEDs are assembled into their final form, such as an array or display.
- Testing: The Micro LEDs undergo testing and calibration to ensure their proper functionality.
Compared to traditional LED displays, Micro-LED differs significantly in several aspects:
- Precision has been improved by tens of times.
The integration process has shifted from methods like through-hole, surface mount, and Chip-on-Board (COB) packaging to “massive micro-transfer.”
- Virtually zero defect repairability.
The backplane has evolved from printed circuit boards to TFT substrates used in liquid crystal and OLED displays or single-crystal silicon substrates used in CPUs and memory. In every aspect, including chip, packaging, integration process, backplane, and driving, Micro-LED differs from traditional LED displays.
The Future Outlook of the Micro-LED Display Market Is Highly Promising
Today, LED displays are gradually moving towards smaller pixel pitch sizes. After all, smaller pixel pitch leads to higher resolution, resulting in better display quality, which aligns with users’ ever-increasing demand for personalized displays. The industry widely believes that Micro-LED display technology will be the direction for this trend. Micro-LED technology has a wide range of applications, suitable for small-sized displays such as smartwatches and VR glasses. It can also be applied to large-sized displays like LED conference screens, LED stage screens, LED cinema screens, LED storefront displays, remote shopping screens, interactive screens, and more.
Due to the advantage of smaller pixel pitch in Micro-LED displays, it also means energy savings and improved display performance. In future scenarios, Micro-LED displays will serve as carriers for ultra-high-definition displays such as 4K and 8K, truly delivering an immersive experience to users.
Today, Micro-LED display manufacturers are actively working on optimizing their production processes and techniques to reduce production costs. This will significantly enhance the competitive advantage of Micro-LED when competing with other display technologies. Industry experts generally believe that in such a vast market with rapid growth, the future prospects of Micro-LED displays are promising.
LEDKUL has introduced the Black Diamond series of Micro-LED displays, along with new products and technologies. This series addresses the challenges related to pixel pitch size limitations caused by the technical difficulties, pricing, and supply chain constraints of Micro-LED display technology. The Black Diamond series of Micro-LED display products has made continuous breakthroughs in technology research and development, yield rate, and production automation processes. Moreover, these displays offer excellent energy efficiency and heat radiation performance, which has the potential to impact various industries positively.
According to a research report from authoritative organizations, the revenue from Micro-LED displays is expected to grow from approximately $40 million in 2023 to over $1.3 billion in 2027. Micro-LED displays are expected to be applied as a material adhered to walls, enabling applications such as human-computer interaction, video conferencing, remote shopping, and interactive communication.
LEDKUL is a specialized manufacturer of high-quality LED displays, offering a range of products including LED transparent screens, naked-eye 3D displays, LED conformal screens, LED grid screens, LED floor tile screens, LED creative screens, LED film screens, LED narrow-pixel-pitch screens, and all-in-one conference machines. These displays find wide applications in areas such as stage design, advertising and media, sports events, entertainment venues, broadcasting, exhibition centers, large product launches, automotive showrooms, canopies, as well as creative and innovative setups, helping clients achieve effective brand promotion, product showcasing, and eye-catching presentations.