Electroplating moulds using dry film thick negative photoresist

The emphasis of this paper lies in the fabrication of a three-layer polydimethylsiloxane chip for micro liquid sample operation. In this paper, the microchannels with a rectangular control layer cross section are fabricated based on a dry-film negative photoresist mold, while the microchannels with a rounded liquid layer cross section are fabricated by a positive photoresist reflow mold. The relationships between temperature and the time of reflow and the arc level of the liquid layer mold are discussed. Different ratios, curing temperatures, and curing times are used to fabricate the two PDMS layers to improve their toughness and plasticity separately. The PDMS slabs with microstructure networks are treated with oxygen plasma to improve their surface properties. The improved surface properties serve to reduce the temperature and time, and improve the sealing strength, which is as effective as adding PDMS in varying ratios. The micro liquid sample operation experiments show that high levels of pinching off and mixing performances on pneumatic microfluidic chips are obtained more easily.

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SUEX Flapping Wing Mechanisms for Pico Air Vehicles

Volume 2: Mechanics and Behavior of Active Materials; Integrated System Design and Implementation; Bio-Inspired Materials and Systems; Energy Harvesting ◽

10.1115/smasis2012-8092 ◽

2012 ◽

Cited By ~ 2

Author(s):

Kiron Mateti ◽

Rory A. Byrne-Dugan ◽

Srinivas A. Tadigadapa ◽

Christopher D. Rahn

Keyword(s):

Material Properties ◽

Processing Time ◽

Low Cost ◽

Precious Metals ◽

Flapping Wing ◽

Negative Photoresist ◽

Insect Wing ◽

Air Vehicle ◽

Flapping Mechanism ◽

Dry Film

This paper introduces a simple and low cost flapping wing mechanism fabricated monolithically from SUEX dry film, an epoxy based negative photoresist similar to SU-8. The developed process has fewer steps compared to other methods, does not use precious metals, and greatly reduces processing time and cost. It simultaneously defines the PAV airframe, compliant flapping mechanism, and artificial insect wing using photolithography. Rapid prototypes were fabricated with precisely defined features and material properties and geometry that are similar to insects. A linear model with simplified aerodynamics is developed with amplitude dependent damping and validated using experimental results in air and in vacuum. Angles up to 45° at a resonant frequency of 47 Hz are observed that demonstrate applicability of the developed fabrication process for flapping wing air vehicle applications.

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The Deep Etching Process Based on Parallel Laser Direct Writing System

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.426-427.265 ◽

2010 ◽

Vol 426-427 ◽

pp. 265-269

Author(s):

Jin Hu ◽

D.L. Pu ◽

Lin Sen Chen

Keyword(s):

Production Cycle ◽

Writing System ◽

Digital Micromirror Device ◽

Direct Writing ◽

Laser Direct Writing ◽

Negative Photoresist ◽

Deep Etching ◽

Whole Process ◽

Working Principle ◽

Dry Film

Due to the high cost-effectiveness, extra flexibility, and short production cycle, laser direct writing system as a kind of maskless lithography technology has been widely used in the fields of micro-nano-manufacturing. The working principle of the parallel laser direct writing system based on DMD(Digital Micromirror Device) is introduced. A novel negative photoresist -- dry film photoresist is adopted into the study of deep etching for the fabrication of the micro mold. The experimental results show that: the whole process is convenient, efficient and flexible; the precision of the 2-D patterning and the depth of etching is reliable.

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Whisker Formation in Copper Electroplating

ISTFA 2011: Conference Proceedings from the 37th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2011p0127 ◽

2011 ◽

Author(s):

Theresa Han ◽

Eunin Cho ◽

Jinwoo Heo ◽

Seoung Jae Lee

Keyword(s):

Copper Sulfate ◽

Surface Stress ◽

Whisker Formation ◽

Printed Wiring Boards ◽

Copper Electroplating ◽

Cu Electroplating ◽

Solution Surface ◽

Dry Film

Abstract In the manufacture of Printed Wiring Boards (PWB), unwelcome structures, such as nodules and whiskers can be formed during copper electroplating with copper sulfate. Copper (Cu) whiskers with lengths of up to a few hundred micrometers can lead to electrical shorts between layers or patterns. In this paper, we document factors that can affect the growth of Cu whiskers; decomposition of additives in the Cu electroplating solution, surface stress, acidic cleaner, and the ingredients of a dry film. Contaminants from outside of the electroplating bath and the ingredients of the dry film were shown as key components in the formation of Cu whiskers.

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Test method for dry film lubricants. Salt spray test

10.3403/00331297u ◽

2015 ◽

Keyword(s):

Salt Spray ◽

Salt Spray Test ◽

Test Method ◽

Dry Film

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Test method for dry film lubricants. Salt spray test

10.3403/00331297 ◽

1994 ◽

Keyword(s):

Salt Spray ◽

Salt Spray Test ◽

Test Method ◽

Dry Film

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Transient Three-Dimensional Flow Field Measurements by Means of 3D µPTV in Drying Poly(Vinyl Acetate)-Methanol Thin Films Subject to Short-Scale Marangoni Instabilities

Polymers ◽

10.3390/polym13081223 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1223

Author(s):

Max Tönsmann ◽

Philip Scharfer ◽

Wilhelm Schabel

Keyword(s):

Flow Field ◽

Vinyl Acetate ◽

Three Dimensional ◽

Field Measurements ◽

Initial Assessment ◽

Ambient Conditions ◽

Three Dimensional Flow ◽

Dimensional Flow ◽

Short Scale ◽

Dry Film

Convective Marangoni instabilities in drying polymer films may induce surface deformations, which persist in the dry film, deteriorating product performance. While theoretic stability analyses are abundantly available, experimental data are scarce. We report transient three-dimensional flow field measurements in thin poly(vinyl acetate)-methanol films, drying under ambient conditions with several films exhibiting short-scale Marangoni convection cells. An initial assessment of the upper limit of thermal and solutal Marangoni numbers reveals that the solutal effect is likely to be the dominant cause for the observed instabilities.

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