Research on optimization of the hot embossing process

• Published in: Journal of micromechanics and microengineering 2007-12, Vol.17 (12), p.2420-2425
• Main Authors: He, Yong, Fu, Jian-Zhong, Chen, Zi-Chen
• Format: Article
• Language: English
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Machinery and processing; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Microelectronic fabrication (materials and surfaces technology); Micromechanical devices and systems; Moulding; Physics; Plastics; Polymer industry, paints, wood; Precision engineering, watch making; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Technology of polymers
• ISSN: 0960-1317; 1361-6439
• DOI: 10.1088/0960-1317/17/12/005

The hot embossing of polymer was studied to improve product quality. The finite element method (FEM) was used to analyze the embossing step, the cooling step and the demolding step with respect to product quality. The numerical simulation results show that profile precision is largely influenced by the topological structure of the mold during the embossing step. Inadequate holding time will result in low pattern fidelity. Inappropriate demolding temperature could induce a large thermal stress at the bottom of the micro pattern, while keeping imprint pressure during the cooling step will aggravate this phenomenon. Fracture, necking and pattern distortion can easily be induced by adhesion between the polymer and the mold when high aspect ratio patterns are demolded. The hot embossing process was optimized and an improved hot embossing system with an automatic demolding device was designed based on the simulation analysis. Successful fabrication of fine patterns with a high aspect ratio verified the improvements.