| Zugriffsnummer | 12656 |
| Dokumenttyp | Konferenzartikel |
| Sprache | Englisch |
| Titel | Development of a special CMM for dimensional metrology on microsystem components |
| Autor(in); Institution |
Brand, Uwe; 5.101, Mikrosystem-Messtechnik, PTB-Braunschweig
Kleine-Besten, Thomas; 5.101, Mikrosystem-Messtechnik, PTB-Braunschweig
Schwenke, Heinrich; 5.32, Koordinatenmessgeräte, PTB-Braunschweig
|
| Quelle/Jahr | American Society of Precision Engineering: Proceedings of the fifteenth annual meeting:(2000), 542 - 546 |
| ISBN | 1-887706-24-0 |
| Verlag | Raleigh: American Society for Precision Engineering |
| Konferenzangaben | ASPE annual meeting 2000, Scottsdale, Arizona, 22-27, October, 2000, USA |
| Freie Schlagworte | CMM ; Micro Probe ; Piezo Resistive ; Opto-Tactile ; Depth Setting Standards ; Microsystems ; 3D probe ; Dimensional Metrology |
| Zusammenfassung | Further miniaturization and modularization are current trends in microsystem technology, which require 3D-coordinate measurements to be performed with measurement uncertainties in the range of 0.1 μm. With conventional coordinate measuring machines subcentimeter structures usually can be measured only optically, i.e. in two dimensions with measurement uncertainties of about 1 μm. Therefore activities were started to develop special measurement equipment which satisfies the described requirements. Moreover the equipment to be developed will also allow to perform measurements on other challenging objects, like e.g. small setting ring standards, small diameter wires etc. The PTB started a project to develop a special CMM for dimensional metrology on microsystem components with an uncertainty of < 0.1 μm. The measurement range will be 25 mm x 40 mm x 25 mm. The instrument is based on a commercial CMM with improved capabilities through the use of high resolution scales and optimised air bearings. The instrument will consist of an optical measurement system and a precision mechanical 3D-micro-sensing system. Both sensing systems will be mounted at different z-columns of the coordinate measuring machine. To improve the measurement uncertainty of the instrument the translational displacement and the guiding deviations of the CMM are measured by laser interferometry. Therefore the CMM-sensors are each enclosed by a zerodur cuboid which are fixed to the rams of the CMM. Compact double path laser interferometers for simultaneous measurement of displacement and angle are mounted within an aluminium frame. Inside this frame a second invar frame supports the reference mirrors of the interferometers and the specimen to be measured. The design principles of the instrument will be described. An opto-tactile 3D-sensor with an optical fibre as a "probe pin" will be used first. The 2D version of this sensor is commercially available with smallest probing ball diameters of 25 μm and probing forces down to 1 μN. 2D probing uncertainties of 0.15 μm were obtained with this system. Recently a modified 3D version has been realized and tested which is planned to be used on the special CMM for first measurements. Another completely different type of tactile 3D-sensor based on a silicon boss-membrane with piezo resistive transducers was also developed recently. First probing experiments have been carried out showing its resolution and 1D-reproducibility of the contacting points to be better than 10 nm. The special CMM and properties of its components will be presented. In parallel to the instrument development new precision diamond turned depth setting standards for topography measuring instruments with depths in the mm range have been developed. The standards are made of OFHC copper and are covered with a wear-reducing nickel coating. The calibration uncertainty of the deepest grooves (currently 900 µm) amounts to 54 nm. Under good conditions, these standards allow to perform traceable measurements with topography measuring instruments with a maximum uncertainty of 80 nm for the measurement range of 1 mm. |
