Molding of three dimensional microstructures by the LIGA process

Harmening, Marc; Bacher, W.; Bley, P.; El-Kholi, A.; Kalb, H.; Kowanz, B.; Menz, Wolfgang; Michel, A.; Mohr, J.

doi:10.1109/memsys.1992.187718

Cited by 31 publications

(16 citation statements)

References 1 publication

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“…Traditionally, x-ray lithography is a major technique for fabricating ultra-thick microstructures with millimeter-sized thickness. Very high aspect-ratio microstructures with vertical sidewalls and high resolution have been reported using the LIGA (lithographie, galvanoformung und abformung) technique [1][2][3][4]. However, the need for a synchrotron radiation source limits its application for researchers and the process is inherently timeconsuming and expensive.…”

Section: Introductionmentioning

confidence: 99%

A new fabrication process for ultra-thick microfluidic microstructures utilizing SU-8 photoresist

Lin

Lee

Chang

et al. 2002

J. Micromech. Microeng.

271

179

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In this paper we describe a new process for fabricating ultra-thick microfluidic devices utilizing SU-8 50 negative photoresist (PR) by standard UV lithography. Instead of using a conventional spin coater, a simple 'constant-volume-injection' method is used to create a thick SU-8 PR film up to 1.5 mm with a single coating. The SU-8 PR is self-planarized during the modified soft-baking process and forms a highly-uniform surface without any edge bead effect, which commonly occurs while using a spin coater. Photomasks can be in close contact with the PR and a better lithographic image can be generated. Experimental data show that the average thickness is 494.32 ± 17.13 µm for a 500 µm thick film (n = 7) and the uniformity is less than 3.1% over a 10 × 10 cm 2 area. In this study, the temperatures for the soft-baking process and post-exposure baking are 120 • C and 60 • C, respectively. These proved to be capable of reducing the processing time and of obtaining a better pattern definition of the SU-8 structures. We also report on an innovative photomask design for fabricating ultra-deep trenches, which prevents the structures from cracking and distorting during developing and hard-baking processes. In this paper, two microfluidic structures have been demonstrated using the developed novel methods, including a micronozzle for thruster applications and a microfluidic device with micropost arrays for bioanalytical applications.

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Section: Introductionmentioning

confidence: 99%

A new fabrication process for ultra-thick microfluidic microstructures utilizing SU-8 photoresist

Lin

Lee

Chang

et al. 2002

J. Micromech. Microeng.

271

179

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show abstract

“…This concept was demonstrated for a polyamide sheet with a thickness of 250 μm using a flexible, 200 μm‐thick electroformed nickel mold (tooling) containing 1 cm 2 arrays of microstructured circular holes with an average diameter ( D ) of 12.5 μm, depth ( H ) of 15.5 μm, and center‐to‐center spacing ( P ) of 30 μm. (The mold was fabricated by a conventional “LIGA” technique; details about the mold fabrication are presented in Figure ).…”

Section: Methodsmentioning

confidence: 99%

Continuous manufacturing of reentrant structures via roll‐to‐roll process

Shivaprakash

Zhang

Panwar

et al. 2018

J of Applied Polymer Sci

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Reentrant structures have been deemed necessary for repelling low‐surface‐tension liquids. In this article, a novel manufacturing methodology using the roll‐to‐roll process to enable continuous manufacturing of reentrant structures over large areas on a polymeric film was demonstrated. A two‐stage process, composed of embossing followed by post‐compression, allowed the fabrication of reentrant structures, which cannot be easily fabricated using other processes over large areas in a continuous manner. The treatment of the reentrant surface structures with an additional coating of 1H,1H,2H,2H‐perfluorooctyltrichlorosilane layer provided liquid repellency with contact angles of 155 and 140°, respectively, for water (Ylv = 72 mN m−1) and diiodomethane (Ylv = 50 mN m−1). © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 46980.

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“…Nevertheless, because of the difficulties in controlling the polymerization and the high shrinkage of the molded part, the hot embossing technique based on polymer foils was investigated. Besides fundamental tests with micro injection molding, basic experiments in 1989 by an embossing technique of PMMA material marked the start of the use of micro hot embossing for the production of LIGA structures [11] (Fig. 1.3).…”

Section: Development Of Micro Hot Embossingmentioning

confidence: 99%

“…These variants make this process unique for developments in micro and nano replication and for the development of micro-and nanosystems. 11 The aim of the book is to give the reader a fundamental knowledge about hot embossing. First, an overview of micro replication process will be given to understand the meaning of the hot embossing process compared to other micro replication processes.…”

Section: Development Of Micro Hot Embossingmentioning

confidence: 99%

Introduction

Worgull¹

2009

Hot Embossing

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Molding of three dimensional microstructures by the LIGA process

Cited by 31 publications

References 1 publication

A new fabrication process for ultra-thick microfluidic microstructures utilizing SU-8 photoresist

A new fabrication process for ultra-thick microfluidic microstructures utilizing SU-8 photoresist

Continuous manufacturing of reentrant structures via roll‐to‐roll process

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