Roll-to-roll pilot nanoimprinting process for backlight devices

• Published in: Microelectronic engineering Vol. 97; pp. 89 - 91
• Main Authors: Mäkelä, Tapio, Haatainen, Tomi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.09.2012; Elsevier
• Subjects: Applied sciences; Backlight; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electrical engineering. Electrical power engineering; Electronics; Exact sciences and technology; Hot embossing; Materials; Materials science; Methods of nanofabrication; Microelectronic fabrication (materials and surfaces technology); Nanoimprinting; Nanoscale pattern formation; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Physics; PMMA; Roll-to-roll; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Nanoimprinting; Roll-to-roll; PMMA; Hot embossing; Backlight; Atomic force microscopy; Backlighting; Luminescence; Methyl methacrylate polymer; Confocal microscopy; Integrated circuit bonding; Microelectronic fabrication; Optical microscopy; Optical properties; Optical characteristic; Illumination; Standard deviation; Manufacturing; Cost lowering; Trench; Hot process; Trench technology; Embossing; Polymer films; Nanolithography; Roll-to-roll process; Manufacturing process; Surface mount technology; Homogeneity; Replication
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2012.03.031

[Display omitted] ► We demonstrate a pilot scale roll-to-roll manufacturing process for backlight devices. ► Backlight device (28×28) mm2 consist more than 78,000 binary elements with different orientation. ► Each element has 40 trenches with 5μm width and 1.3μm thick, totally 3.1 million trenches in one device. ► Quality of printed devices are good and devices can be used for display illumination. A pilot scale roll-to-roll manufacturing process for backlight devices was demonstrated using Poly(methyl methacrylate) (PMMA) film. Backlight device (28×28) mm2 consist more than 78,000 binary elements with different orientation. Each element has 40 trenches with 5μm width and 1.3μm thick, totally 3.1 million trenches in one device. These devices can be used for display illumination in various applications when three LED is connected on the other end of the device. More than 1000 device was printed on 50mm wide 375μm thick PMMA web using custom made nanoimprinting equipment. These devices demonstrate a high throughput and a low cost production possibility for micron- and submicron optical structures. The printed patterns were analysed by using optical microscopy, atomic force microscopy (AFM) and confocal microscopy. The backlight device after LED integration was characterized using luminescence measurements. The three surface mounted LED is connect to the upper side of printed PMMA device to give light in the polymer film. To collect statistics, every 50th sample was analysed. The pattern replication is good and the depth of the imprinted structure is typically in the range of 1.2–1.4μm when limits for working device is ca. 1.0μm. The optical properties of the analysed devices show good homogeneity inside one device. The standard deviation for the measured luminescence values for all devices was within 17% which is still acceptable for final production. No drastic wearing of the stamp can be seen after pilot manufacturing.