In a significant advancement for next-generation display manufacturing, a research team at Tianjin University has developed a non-destructive testing (NDT) method for micro-LED wafers, offering a breakthrough in electroluminescence inspection that could accelerate mass production of high-end flexible and large-area displays.
Micro-LED technology is widely viewed as critical to future display systems due to its high brightness, efficiency, and long lifespan. However, precise testing during wafer fabrication has remained a bottleneck, as traditional inspection methods either damage the wafer surface or fall short in detection accuracy, leading to higher defect rates and increased production costs.
Led by Professor Huang Xian, the Tianjin University team introduced a flexible three-dimensional probe array that conforms to the surface topography of micro-LED wafers while applying ultra-low contact pressure—measured at just 0.9 megapascals, or the equivalent of a soft breath. The technique enables high-throughput electrical testing with minimal physical contact, preserving the wafer's integrity.
“The contact pressure exerted by our flexible probes is just one ten-thousandth that of conventional rigid probes,” said Huang. “This not only preserves the wafer surface but also significantly extends the probe's service life. Even after one million contact cycles, probes retain their original condition.”
The innovation, published in Nature Electronics, also includes a custom-developed measurement system that pairs with the soft-contact probe array to enable precise process control and improved yield screening in micro-LED production.
“This breakthrough establishes a new foundation in the field,” Huang noted. “It closes a major technical gap in micro-LED electroluminescence testing and paves the way for broader applications in advanced wafer inspection and biophotonics.”
Currently, efforts are underway to commercialize the technology at the Tiankai Higher Education Innovation Park in Tianjin. The solution is expected to bolster China's micro-LED industry with a scalable, damage-free, and cost-effective inspection platform, while advancing the use of flexible electronics across high-tech domains including biomedical devices and photonics.
Reference: https://english.news.cn/20250616/45133864056947df8a46c0e313fbab06/c.html
