[ Best Paper of This Month ]

Journal of the Korean Society of Manufacturing Technology Engineers - Vol. 33, No. 3, pp.119-125

ISSN: 2508-5107 (Online)

Print publication date 15 Jun 2024

Received 16 Apr 2024 Revised 25 May 2024 Accepted 27 May 2024

DOI: https://doi.org/10.7735/ksmte.2024.33.3.119

열 재유동 공정을 통해 제작된 마이크로렌즈 배열의 곡률 및 높이 변화에 대한 가해지는 열 에너지의 영향에 관한 연구

김명서^a ; 신승우^b ; 김우영^a ; 박서림^a ; 이상훈^a ; 조영태^a

; 김석^a^{, *}

Effect of Thermal Energy on Change in Curvature and Height of Fabricated Microlens Array using Thermal Reflow Process

Myung Seo Kim^a ; Seungwoo Shin^b ; Woo Young Kim^a ; Seo Rim Park^a ; Sang Hoon Lee^a ; Young Tae Cho^a

; Seok Kim^a^{, *}

aDepartment of Smart Manufacturing Engineering, Changwon National University
bDepartment of Advanced Battery Manufacturing Systems, Korea Institute of Machinery & Materials

Correspondence to: ^*Tel.: +82-55-213-3604 E-mail address: kimseok@changwon.ac.kr (Seok Kim).

Abstract

Micro Lens Arrays (MLAs) are modeled after insect eyes and comprise a (50–150) micrometer-sized array of lenses with multiple applications. We used photoresists (PR) in MLA construction to improve cost-efficiency over conventional methods. Reflow processes at temperatures beyond the glass- transition (glassy to rubbery state temperature) are used to mold lens shapes, making reflow ideal for shape reassembly. PR reflow in MLA production is rapidly adaptable, cost-effective and ensures uniform lens shapes in large-scale production. Experimental results show that, at constant temperatures, the lens curvature and height vary with reflow time. We empirically analyzed the influence of temperature and time on MLA curvature and height characteristics during reflow and proposed an approach to manipulate lens shape for desired focal lengths. Precise MLA fabrication offers insights into optimal process selection based on desired lens shapes in MLA production.

Keywords:

MLA(microlens array), Thermal reflow process, Glass transition temperature, Curvature

Acknowledgments

이 논문은 2023-2024년도 창원대학교 자율연구과제 연구비 지원으로 수행된 연구결과임.

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Myung Seo Kim

M. S. Students in the Department of Smart Manufacturing Engineering, Changwon National University. His research interest is Nano-micro Technology.

E-mail: 20215000@gs.cwnu.ac.kr

Seungwoo Shin

Postdoctoral Researcher in the Department of Advanced Battery Manufacturing Systems, Korea Institute of Machinery and Materials(KIMM). His research interests are Manufacturing system for Nano-imprintlithography and DLP 3D Printing.

E-mail: swshin@kimm.re.kr

Woo Young Kim

Ph. D. Candidate in the Department of Smart Manufacturing Engineering, Changwon National University. His research interests are Surface Engineering and Nano-micro Technology.

E-mail: wooyoung0329@changwon.ac.kr

Seo Rim Park

Ph. D. Student in the Department of Smart Manufacturing Engineering, Changwon National University. Her research interests are 3D Printing and Nano-micro Technology.

E-mail: qkrtjflakr@changwon.ac.kr

Sang Hoon Lee

M. Sc. Candidate in the Department of Smart Manufacturing Engineering, Changwon National University. His research interests are Surface Engineering and Nano-micro Technology.

E-mail: netsh2@changwon.ac.kr

Young Tae Cho

Professor in the Department of Mechanical Engineering in Changwon National University. His research interests are Welding/Joining, Additive Manufacturing, Laser applied Material Processing, Nano-Micro Fabrication, Imprint Process, Super-Hydrophobic Surface Fabrication, Printed Electronics, and Precision Manufacturing System.

E-mail: ytcho@changwon.ac.kr

ORCID: http://orcid.org/0000-0001-7545-4646

Seok Kim

Associate Professor in the Department of Mechanical Engineering in Changwon National University. His research interests are Multiscale Manufacturing with Functional Materials for Energy, Environmental, and Biological Applications.

E-mail: kimseok@changwon.ac.kr

ORCID: https://orcid.org/0000-0002-6049-6461