glass

R.M. Minev (a), S.S. Dimov (b), S.R. Koev (c), G.Lalev (b), N.H. Festchiev (a)

(a) Department of Materials and Manufacturing Engineering, Rousse University, 8 Studentska, 7017 Rousse, Bulgaria
(b) Manufacturing Engineering Center, Cardiff University, Cardiff, CF24 3AA, UK
(c) BOM Ltd, Basarbovo, 7071 Rousse, Bulgaria

Abstract

In spite of the commercial advantages the available engineering materials for IC and MEMS processes are not able to meet the manufacturing demands for 3D high-aspect-ratio nano/micro structures and high precision. There is a group of energy assisted processes, such as laser ablation, e-beam and ion beam machining that could provide the needed high specific processing energy to create 3D microstructures. However, the required surface integrity of the manufactured nano/micro structures cannot be achieved without developing appropriate materials with adequate processing response. Thus, to broaden the range of micro-engineering products and multiply their capabilities the introduction of “novel” compatible amorphous or composite materials is required.
The study presents the capability of the explosive welding technology to create a bimetallic sandwich with amorphous Ni-based alloys foils (40 μm thick) without affecting the structure of the materials. Direct patterning by Focused Ion Beam (FIB) was used to produce masters from these materials for injection moulding and hot embossing tools. It was demonstrated that high feature resolution and surface quality of the manufactured nano/micro structures can be easily achieved by employing this technological chain.

Samuel Queste, Gwenn Ulliac, Jean-Claude Jeannot and Chantal Khan Malek
Institute FEMTO-ST/Dpt. MN2S, CNRS UMR 6174, 32 Av. de l’Observatoire, 25044 Besançon, FRANCE

Abstract

High speed directional etching of non conventional materials is still insufficiently developed for producing high aspect ratio microstructures. Compared to deep silicon etching, the plasma etching of these materials has suffered from limitations in achievable depth, aspect ratio, verticality and smoothness of surfaces. Inductively coupled plasma (ICP) reactive ion etching (RIE) of quartz crystal, lithium niobate and glass was conducted using fluorine and fluorocarbon based plasma-chemical etching processes. Optimization of etched depth, verticality of the walls, etch rate, etch selectivity towards the etch mask, and surface smoothness was investigated and compared to results of the literature. Deep etching with nearly vertical walls was successfully demonstrated for all three materials.

S. G. Serra(a), A. Schneider(a), K. Malecki(b), S. E. Huq(a), W. Brenner(b)
a: Science and Technology Facilities Council, Rutherford Appleton Laboratory,Technology – Central Microstructure Facility, Harwell Science and Innovation Campus, Didcot, OX11 0QX, UK
b: Institute of Sensor and Actuator Systems Vienna University of Technology, Floragasse Str./E366 MST, Vienna 1040, Austria

Abstract

This paper describes a simple process of adhesive bonding between a glass lid and a SU-8 microfluidic device. The bonding is made by applying pressure, between 1.24 MPa – 3.72 MPa, and heat, above the SU-8 glass transition temperature (Tg). The advantages of this process are low cost, simplicity and no need of extra adhesive material, which could block microchannels and inlets. The SU-8 microchannels are fabricated on a glass substrate by UV photolithography. The resist thickness is 30 μm and the smallest channels are 5 μm in width. The bonding process was performed using a simple uniaxial press, a torque wrench and a convection oven as an alternative to the complex and expensive bonding machines with a vacuum chamber and alignment tools. To identify a suitable bonding temperature, a Tg of 175°C for the patterned SU-8 was obtained by Dynamic Mechanical Analysis (DMA). The bonding strength was 1.15MPa, measured by a pull-out test, and a bonding area of 90% was achieved, which was observed by visual inspection. It was also investigated the effect of an O2 plasma cleaning process on the bonding quality.