G.J. Burger

High-resolution shadow-mask patterning in deep holes and its application to an electrical wafer feed-through

The paper presents a technique to pattern materials in deep holes and/or on non-planar substrate surfaces. A rather old technique, namely, electron-beam evaporation of metals through a shadow mask, is used. The realization of high-resolution shadow masks using micromachining techniques is described. Further, a low ohmic electrical wafer foed-through with a small parasitic capacitance to the substrate and a high placing density is presented.

A thin-film piezoelectric impact sensor array fabricated on a Si slider for measuring head-disk interaction

A new type of acoustic emission sensor using a thin film piezoelectric material (sputtered ZnO) was developed for measuring head-disk interaction in a rigid magnetic disk system. The sensor is mounted on a Si slider (length: 3 mm) and was fabricated using micro-machining techniques in our on-going efforts to downsize sliders. Some fundamental tests of the sensor were conducted: sensitivity and frequency characteristics, and a flying test over a rotating bump disk.

Piezoelectric impact force sensor array for tribological research on rigid disk storage media

This paper presents a method to measure impact forces on a surface by means of a piezoelectric thin film sensor array. The output signals of the sensor array provide information about the position, magnitude and wave form of the impact force. The sensor array may be used for tribological studies to the slider disk interface of a rigid disk storage device. In such a device a slider head assembly is flying above the rotating disk with a typical spacing of 100nm. Possible mechanical interactions between the slider and the disk are expected to produce impact forces in the order of 0.1N with a frequency range from 100kHz to 100MHz [1].

Characterization of Silicon-Based Insulated Channels for Capillary Electrophoresis

A new fabrication method to produce miniaturized Transparent Insulating Channels (μTICs) is presented. The process involves Deep Reactive Ion Etching (DRIE), insulating film deposition, anodic bonding and back etching of the silicon. The μTIC process leaves optically transparent channels that can be cooled very easily due to the thin walls, thus in principle enabling higher electric field strengths. Because the fragile nature of thin walls limits the practical application of the μTICs, a polymer film is added to reinforce the microstructures. A μTIC design with an injection- and separation channel and containing a 100 μm long injection loop is realized and evaluated. EOF was confirmed by the use of fluorescently labeled, 3 μm diameter beads observed by a CCD camera coupled to a fluorescence microscope. Current/voltage curves were linear up to applied fields of 700 V/cm. For the first time, siliconbased microchannels have been realized that are suitable for CE. Thus, μTICs allow for high flexibility in the design of insulated channels with respect to dimensions and cross-sectional shapes for analytical techniques where insulating materials are required, such as CE.

High Resolution Shadow Mask Patterning In Deep Holes And Its Application To An Electrical Wafer Feed-through

This paper presents a technique to pattern materials in deep holes and/or on non-planar substrate surfaces. A rather old technique, E-beam evaporation of metals through a shadow mask, is used [1]. The realisation of high resolution shadow masks using micromachining techniques is described. Further, a low ohmic electrical wafer feed through with a small parasitic capacitance to the substrate and a high placing density is presented.

Fundamental study on a thin-film AE sensor for measurement of behavior of a multi-pad contact slider

To study the fundamental dynamic characteristics of a multi-pad slider for contact recording, we developed a thin-film piezoelectric acoustic emission array sensor on an Si-suspension with an array pattern similar to that of contact pads. Experiments showed that the sensitivity of the sensor is about 0.11 V/N (slider thickness: 0.2 mm) and that each array sensor designed here is not influenced by the acoustic waves which occur due to contact with other contact pads, so the contact or non-contact condition of each pad can be measured.

Glass channels and capillary injectors for capillary zone electrophoresis

Novel glass and silicon microstructures and their application in chemical analysis are presented. The micro technologies comprise (deep) dry etching, thin layer growth and anodic bonding. With this combination it is possible to create high resolution electrically isolating silicon dioxide structures with aspect ratio’s similar to those possible in silicon. Main applications are chemical separation methods such as High Performance Liquid Chromatography (HPLC) or Capillary Zone Electrophoresis (CZE). Beside these channel structures, a capillary connector with very low dead and mixing volume has been designed and fabricated for use in correlation CZE, and demonstrated by determining the precision of consecutive single injections.