Rapid laser fabrication of microlens array using colorless liquid photopolymer for AMOLED devices

• Published in: Optics communications Vol. 284; no. 1; pp. 405 - 410
• Main Authors: Kim, Kwang-Ryul, Jeong, Han-Wook, Lee, Kong-Soo, Yi, Junsin, Yoo, Jae-Chern, Cho, Myung-Woo, Cho, Sung-Hak, Choi, Byoungdeog
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2011; Elsevier
• Subjects: Applied sciences; Arrays; Colorless liquid photopolymer; Density; Devices; Display devices; Electronics; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Gaussian; Lasers; Light-sensitive materials; Liquids; Local thermal expansion; MLA; OLED; Optical materials; Optics; Optoelectronic devices; Photopolymers; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; UV laser; OLED; UV laser; MLA; Local thermal expansion; Colorless liquid photopolymer; Violet lasers; Display devices; Microlens arrays; Experimental study; Micro-optics; Thermal expansion; Manufacturing processes; Light sensitive polymer; Optical adhesives; Organic light emitting diodes; Organic light-emitting devices
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2010.08.074

Microlens array (MLA) is microfabricated using Ultra Violet (UV) laser for display device applications. A colorless liquid photopolymer, Norland Optical Adhesive (NOA) 60, is spin-coated and pre-cured via UV light for completing the laser process. The laser energy controlled by a galvano scanner is radiated on the surface of the NOA 60. A rapid thermal volume expansion inside the material creates microlens array when the Gaussian laser energy is absorbed. The fabrication process conditions for various shapes and densities of MLA using a non-contact surface profiler are investigated. Furthermore, we analyze the optical and display characteristics for the Organic Light Emitting Diode (OLED) devices. Optimized condition furnishes the OLED with the enhancement of light emission by 15%. We show that UV laser technique, which is installed with NOA 60 MLA layer, is eligible for improving the performance of the next generation display devices.