SBIR Phase II: Diamagnetically Directed Self-Assembly of Light Emitting Diodes for Fabricating Large Area, Direct View Displays

这个小企业创新研究（SBIR）二期项目的更广泛的影响/商业潜力是，如果成功，这个项目的结果将彻底改变大面积LED阵列组装制造，导致LED显示屏市场前所未有的增长。直接观看LED显示屏或视频墙在日常生活中变得越来越普遍。它们最初只出现在体育场馆，后来逐渐开始出现在零售广告中，现在也开始出现在电影院和控制室。这些类型的显示器更亮，具有更好的对比度，更快的刷新率，并且比其他竞争显示技术更节能。尽管有这些优点，但受制造这些显示器所需的成本和时间的限制，采用的速度非常缓慢。随着显示器分辨率的提高，目前的制造工具正面临瓶颈。大规模并行装配技术可以大幅提高生产速度，同时降低产品成本。此外，研究这种自组装技术所获得的知识有可能为半导体封装（包括照明和聚光太阳能）带来新的机遇。该项目旨在通过利用定向自组装的平行特性来加速LED的安装过程。这种技术不像现在那样将单个led放置在网格阵列中，而是利用有限的磁场快速而简单地将数百或数千个led排列成整齐有序的网格阵列。其目标是实现比传统工具至少快5倍的装配速度。研究将集中在LED尺寸和几何形状对精度、速率和良率的影响。此外，将开发新的磁场级以提高装配精度。关键的预期结果是：(1)一个能够快速组装数千个LED芯片的系统，具有高分辨率显示器所需的精度；(2)一个完全可操作的LED显示面板，用该技术构建，以展示该技术的制造潜力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase II project is that if successful, the results of this project will revolutionize large area LED array assembly manufacturing, leading to unprecedented growth of the direct view LED display market. Direct view LED displays, or video walls, are becoming more ubiquitous in everyday life. First only appearing in sports stadiums, they have gradually started appearing in retail advertising, and now are starting to appear in cinemas and control rooms. These types of displays are much brighter, have better contrast ratios, faster refresh rates, and are more energy efficient than other competing display technologies. Despite these advantages, rate of adoption is very slow, limited by the cost and time required to make these displays. Current manufacturing tools are facing a bottleneck as display resolutions increase. A massively parallel assembly technology could drastically increase production speeds while reducing cost-of-goods. Additionally, the knowledge gained by the research into this self-assembly technology has the potential to unlock new opportunities in semiconductor packaging including lighting and concentrated solar.The proposed project seeks to speed-up the LED placement process by leveraging the parallel nature of directed self-assembly. Rather than placing individual LEDs into a grid-array as it is done today, this technology utilizes confining magnetic fields to quickly and simply arrange hundreds or thousands of LEDs into a neat and ordered grid-array. The objective is to achieve assembly speeds at least 5 times faster than conventional tools. The research will focus on the effects of LED size and geometry on accuracy, rate, and yield. Additionally,  new magnetic field stages to enhance assembly precision will be developed. The key anticipated results are (1) a system that will be able to rapidly assemble thousands of LED die with the precision necessary for high-resolution displays and (2) a fully operational LED display panel constructed with this technology to demonstrate the manufacturing potential of this technology.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.