The Large Chamber SEM: A New Tool for Non-Destructive Testing
Thursday, October 23, 2008, 10:40 am, Room 310
Although conventional SEMs are limiting the size of objects or production equipment to be inspected scanning-electron-microscopes (SEM) are well known instruments for the use in nearly any micro¬technology. A more flexible tool to allow a visual control of micro¬mechanical manu¬facturing, assembling, and testing process is not yet described. Analyzing human behaviour during the visual investigation of objects and adapting this behaviour, lead to a new concept of electron microscopes called Large Chamber Scanning Electron Microscope (LC-SEM) In this case the electron optics is installed within the vacuum chamber and can be positioned freely inside this chamber. This change of kinematics combines conventional SEM´s advantages of high resolution and high depth of focus with the possibility to observe and test micro¬mechanical handling and assembly equipment. Using the LC-SEM allows a new understanding of these processes. The paper describes development, functionality, and applications of this LC-SEM. There are fields of application within the microtechnology and macro¬technology as well. The paper is focused on the use of the LC-SEM within microtechnology, microassembly and micromecha¬tronics. For nearly any process of manufacturing in the microworld a transmission of information to the human macroworld is necessary. For this purpose especially a visual control is important. Optical microscopes are of limited use due to their small magnification and depth of focus (e.g. an optical microscope offers just a depth of focus of 2 μm at an enlargement of 100). Conventional scanning-electron-microscopes (SEM) offer a much better resolution and a better depth of focus but are limited in the size and weight of objects to be inspected because of the usually small vacuum-chambers. Conventional goniometer tables are constructed with a very high precision and for a load carrying capacity up to 20 kg. The load carrying capacity is greatly restricted in that in conventional goniometer tables it is necessary to provide numerous moving guide elements and slide carriages, which for cost reasons are only designed for a moderate load. Therefore an Large Chamber- Scanning Electron Microscope as a tool to support the investigation of microproduction has been developed which opens new fields of application to electron microscopy. Key to the functionality of this microscope is the adaption of human behaviour during the investigation of objects.