Manufacturing Systems

Industrial companies as well as small and medium sized enterprises engage themselves more and more in international production networks. Each networkpartner aims on building and maintaining business relationships to the best partner for any specific task. This leads to an increasing amount of goods being transported from partner to partner and leads to an immense logistics effort. These logistics tasks are responsible for major cost blocks in most companies. Organisations will have to react to the increasing demand for on time delivery with organisational as well as technological solutions to maintain their competitive advantage.

For micro assembly processes, assembly accuracy in the range of one micron is required. In the following some strategies for enhancement of accuracy in micro assembly are shown by means of two different assembly systems. First, a self-developed assembly system consisting out of a parallel robot for micro assembly, a 3D vision sensor, grippers, magazines and fixtures is presented. Second, a cartesian robot that endues over a 2D vision sensor, a force sensor and a confocal laser scanning microscope is described. On the basis of examples for micro assembly processes the application limitations of both systems are depicted.

The continuous attempt to miniaturize components and structures demands increasing improvements in the field of micromachining technologies. A big challenge for the production technology is to manufacture microsystems and micro parts made of different materials. Processes well suited for three-dimensional machining of many materials are mechanical production technologies. A practicable production technology that is able to structure hard and brittle materials with high surface qualities is micro-grinding. The following article should give an overview about the current state of the technology of micro grinding of hardened steels.

Fast ions produced in so-called broad beam ion sources are established as highly deterministic tools in ultra-precision surface finishing processing. The driving force for this kind of technology is the requirement for highest quality surfaces with ultimate roughness and accuracy in topology. High performance optics which need such surfaces with fabrication tolerances below one nanometer are used for lithography, laser, x-ray or optical satellite communication as well as highly integrated electronics for processors and memory circuits and surface acoustic wave filters. New physical effects of ion beam induced smoothing of surface and nanostructure give rise for new research and development with a high potential of technology exploitation. Scientists and technicians from the Leibniz Institute for Surface Modification do intensive research work in this field and develop ion beam technologies and components mature for application in industry.

The latest developments in the field of nano technology must not mislead to the impression that all challenges in the micro system technology (MST) are solved. As a matter of fact, right now new applications are causing novel technological challenges. In addition, the market of MST is still one of the most dynamic and will continue its growth within the next years. It is expected that the worldwide annual turnover will increase from 3.9 billion US$ (2002) to 8.3 billion US$ (2007) [1].

The development of faster and more powerful computers has led to virtual flood of digital data. Over the decades capacity of data storage devices has continued to multiply. At the same time the dimensions of these digital silos have even become smaller. Year after year better devices and finer write-read-heads are developed. The magnetic bit domains became smaller and smaller. Until one day - they are no bigger than an atom. By using spin-polarized scanning tunnelling microscopy - a method of nanotechnology - it is possible today to determine the individual magnetic orientation of single atoms on surfaces, which means to read magnetic information atom by atom. If the same instrument could be used to write magnetic information in adjacent atoms, it would be possible to store the entire world literature on a space of a postage stamp. This is in the focus of research at the University of Hamburg.

Micro-forming presses are barely to find at the market, especially if it comes apart from high precision and high dynamic to free stroke and force control. The Bremer Institut für angewandte Strahltechnik has developed and built such a press, which is additionally featured with double axis, high stroke and air bearings for high precision force measurement and control.

By Micro Metal Injection Molding (Micro MIM) the manufacturing of miniature parts and parts with microstructured surfaces out of nearly all metallic materials is possible. Single injected parts with dimensions of 300 µm and microsturctured surfaces with details in the range of 20 µm could be achieved. Targeted material selection and process control allow the production of parts consisting of different materials without additional joining techniques. Functionality of parts can be increased by structural properties as micro channels for fluidic applications. On the other hand special material properties as the use of magnetic, bio-active or corrosion resistant materials contribute to further functionalisation. Regarding the trend to smaller components and devices micro MIM offers a cost-effective production technology for the necessary parts.

The microstructuring of embossing rollers offers an economic and productive production tool for molding of large-area plastic films with functional and optical properties. Due to ultraprecision diamond machining processes a wide spectrum of microstructures in combination with a high manufacturing flexibility can be produced for optical, fluidic and mechanical applications. Both, the microstructuring of embossing rollers by ultraprecision diamond machining as well as the following molding process of plastic films exhibit a high potential for innovative applications in industrial and consumer products.

The assembly of fragile microsystem or semiconductor components poses a challenge on handling technologies as damage by gripping forces must be avoided. Non-contact handling solutions are being developed at the Institute for Machine Tools and Industrial Management that facilitate a gentle gripping of sensitive dies and highly thinned wafers using fluid dynamic effects. The advantages of this technology are reduced damages during handling, a higher yield per wafer as well as a reduction of particle contamination.