Micro-Hot Embossing of Fresnel Lens Using Precision Micro-Featured Mold

Abstract

Micro-hot embossing process has been widely used in the micromanufacturing. Development of a simple and cost-effective method for fabricating the micro-featured mold insert for micro-hot embossing molding is an important issue. Several techniques such as Si-based micromachining technology, lithographie galvanoformung abformung (LIGA), laser micromachining, micro-electro-discharge machining, micromachining, and deep reactive ion etching have been proposed for fabricating the micro-featured mold insert. However, these methods have some limitations including high cost, complex manufacturing processes, and long processing time. In this study, a simple and cost-effective method for fabricating micro-featured mold with micro-features for microfabrication of polymer was proposed. Effects of micro-hot embossing process parameters on the embossed accuracy of microfeatures were investigated. Results showed that the embossed accuracy of microgroove depth and width increased with both the embossing load and embossing temperature until a saturation value is reached. Based on both cycle time and green manufacturing, an approximately perfect Fresnel lens can be replicated under the embossing load of 50 Kgf and the embossing temperature of 170°C.

Keywords:

• Embossing
• Load
• Mold
• Temperature

ACKNOWLEDGMENTS

The authors gratefully acknowledge the financial support of the National Science Council of Taiwan under contract nos. NSC 102-2221-E-131-012 and NSC 101-2221-E-131-007.