類LIGA製程製作微小模仁應用於繞/折射微透鏡之研究

The Study of LIGA Like Fabrication Process for Refractive/Diffractive Microlens

楊詔中(Jauh-Jung Yang)

指導教授 ： 廖運炫

國立臺灣大學/工學院/機械工程學研究所/博士(2007年)

https://doi.org/10.6342/NTU.2007.10167

摘要

在高分子微光學元件中，微光學模仁大幅影響微光學元件之品質。在微光學元件中最常用的是折射微透鏡與繞射微透鏡，本篇論文主要以改良之類LIGA製程改善傳統微透鏡製程之缺點，製作高精度、高品質之微小光學模仁，並將製作完成之折射與繞射微透鏡應用於不同之光線調制領域。本篇論文研究主題分為兩大部分：
在折射微透鏡部份，本研究提出以灰階光罩製程突破傳統製程限制，製作單一曲率、外形非對稱、填充率接近100%之微透鏡母模，製程中以精密灰階光罩校正避免微影製程中表面硬化層對微透鏡表面形狀之干擾。接下來將光阻母模翻製成鎳金屬模仁，並以滾軸以及UV成形製程將微透鏡轉印到可撓性PET薄膜上。本研究以無間隙長六角微透鏡為例驗證改良之類LIGA製程，無間隙長六角微透鏡長軸長度L為50 μm，短軸長度W 為15 μm，曲率半徑為26 μm，實驗結果發現完成微透鏡之幾何形狀與設計值非常接近，除中心高度外，幾何尺寸誤差都在5%以下，表面粗糙度達到光學鏡面等級， Ra為28 nm，填充率達到95.4%，結果驗證改良之製程可以製作出單一曲率、無間隙、外形長扁形且高精度之微透鏡陣列。無間隙長六角微透鏡陣列可將入射光束調制不對稱之發散光源，根據光學檢測之結果發現長六角微透鏡陣列可將發光角度角10

關鍵字

折射微透鏡 ； 繞射微透鏡 ； 類LIGA製程 ； 微成形

並列摘要

Polymer micro-optics has been widely used for various applications such as imaging systems, digital display systems, digital optical processors, and optical interconnection, etc. In micro-optics fabrication process, the precision mold is foundation to achieve ideal performance of micro-optics. Refractive and diffractive microlens are mosytly used in micro-optics system. To improved fabrication quality of refractive and diffractive microlens, modified mold fabrication processes are proposed. The study was divided into two parts:
The first part is to develop an asymmetrical hexagonal microlens (HML) used for light emitting purpose. To obtain ideal spherical lens profile and near 100% filling factor, accurate optical density (OD) was employed in gray-scale lithography process. By applying precision micro-replication process, a high quality HML array was duplicated on flexible polyethylene terphthalate (PET) film. The fabrication quality was inspected and compared with the designed specifications. A hexagonal microlens array with long aspect ratio of 3.3:1 designed for beam shaping was fabricated by applying gray-scale lithography micro-replication process. The gray-scale lithography process was employed in this study to obtain unity curvature and to maximize filling factor of the lens array. Precision micro-replication process was applied to duplicate HML on a flexible polyethylene terphthalate (PET) substrate by UV-forming process. The geometry character of obtained HML was inspected and the shape errors of HML are below 5% which is very close to the designed specification. The optical performance was also investigated. It was found that the incident beam of white LED was diversified differently at short and long axis. The diversified view angles (FWHM) at long and at short axis directions through HML are 29.2

並列關鍵字

Diffraction Microlens ； Refractive Microlens ； LIGA-Like Fabrication ； Micro-Replication

參考文獻

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