Roll-to-roll (R2R) printing technologies have been widely adopted in a variety of engineering fields, e.g., organic photovoltaics and flexible electronics, owing to the advantages of cost and throughput. Although a minimum feature size of 100 nm has been demonstrated on R2R systems, the layer to layer registration accuracy (i.e., overlay accuracy) still remains as low as tens of microns, which prevents the fabrication of common electronic and functional devices, such as transistors. To realize the full potential of R2R technologies, the registration accuracy must be improved to match the printing resolution, i.e., 100s nm. To address the issue, we have developed a multi-layer R2R system with multiple-input multiple-output (MIMO) closed-loop control that achieves submicron level alignment precision for large-scale continuous printing processes. The enabling elements in the multi-layer R2R system include: (1) new vision-based alignment algorithm/method, which provides 100s nm position detection capability based on low-cost cameras; and (2) custom-built five-axis compliant roller positioner. Experimental results show that the compliant roller positioner has a ±1 mm range with 100s nm precision in X, Y, and Z axes respectively. For correcting in-plane web errors, the roller positioner can achieve a range of 1 mm with < 1 μm precision, realizing multi-layer R2R printing with submicron overlay accuracy. Based on the new methods, a gate/source-drain multi-layer electrode structure for field-effect transistors (FETs) has been designed and fabricated on a 4-inch PET web, demonstrating better than 1 μm overlay precision in fabricating flexible electronics on a R2R platform for the first time.

卷到卷（R2R）打印技术由于成本和生产量的优势而被广泛用于各种工程领域，例如有机光伏和柔性电子产品。尽管在R2R系统上已证明最小特征尺寸为100 nm，但层到层配准精度（即重叠精度）仍保持低至数十微米，这妨碍了常见电子和功能器件（例如晶体管）的制造。为了充分发挥R2R技术的潜力，必须提高套准精度以匹配打印分辨率，即100s nm。为了解决该问题，我们开发了具有多输入多输出（MIMO）闭环控制的多层R2R系统，该系统可为大规模连续打印过程实现亚微米级的对准精度。多层R2R系统中的使能元素包括：（1）新的基于视觉的对齐算法/方法，它基于低成本相机提供100s nm的位置检测能力；（2）定制的五轴兼容滚子定位器。实验结果表明，该柔性滚子定位器的精度为±1 mm，在100s nm的精度范围内。X，Y和Z轴。为了校正面内卷筒纸错误，辊定位器可以达到1 mm的范围，精确度小于1μm，从而实现亚微米覆盖精度的多层R2R打印。基于新方法，已在4英寸PET网上设计并制造了用于场效应晶体管（FET）的栅极/源极/漏极多层电极结构，证明在其上制造柔性电子产品时的叠层精度优于1μm。首次使用R2R平台。