- Email: [email protected]
Masks for microelectronics
PE¢=S techniques". Positioning or registering of patterns must be accomplished to tenths of a micron. For optical systems, the precLsion X - Y positioning stages employ linear bearings, either air or hydrostatic, which are free from wear and have minimal pitch and yaw. The displacement measurement systems available based on laser interferometry give a resolution of better than 0.1/~m even at stage velocities of the order of 100mm/s. The Philips Electron Beam Pattern Generator, however, has a registration accuracy of +0.1/zm; the mechanical table used in the system uses ball bearings in vacuum.
Previews Optical radiation measurement
Alan Richardson automatic facing machine which has given a high quality finish with increased productivity and increased tool life
Face turning In traditional face turning operations, cutting speed varies substantially between the outer diameter and the centre of the work-piece. A compromise between floor-to-floor times, tool life, and surface finish normally has to be found. At constant traverse rates, pitch of the cut also varies across the diameter of the workpiece. These problems can be avoided by using a cnc machine with a dc drive. Alan Richardson Machine Services, however, have developed what they claim is a more cost effective solution. On their new machine, tool motion is towards' the centre, and by driving the chuck through an infinitely variable hydraulic motor and linking this hydraulically to the tool traverse, then mechanically back to the motor swash plate, a closed loop is formed and the two motions, rotation and traverse, are maintained in exact relationship at an ever increasing speed. The;result is a constant, optimum cut speed which can be set to any requirement. In one application floor to floor times were reduced by almo=t 50%, a high quality finish achieved and tool life (~oubled. Pitch of cut is set by altering delivery to the toolslide hydraulic feed cylinder, while a by-pass valve
PRECISION ENGINEERING
in the pressure line to the main hydraulic drive motor can be adjusted to enable a wide range of cutting speeds to be obtained. The tool depth is controlled by a hydraulic copy beam which enables the edge radius to be machined. A 75mm (3in) stroke is available which will permit high speed face contour turning to that depth. The manufacturers stress that due to the modular construction of the machine, variations can easily be made in detailed design to tailor the machine to specific ranges of workniece. Alan Richardson Machine Services, Sedburgh Road, Halifax, UK
Masks for microelectronics For a 256K random access memory (ram) to be included on one chip, line widths of the order of 1-1.5/Jm will be required.At the British Association for the Advancement of Science Annual Meeting held 3 - 7 September 1979 in Glasgow, J.C. Walling outlined mask fabrication for microelectronic circuits and stated " I t is likely that optical techniques will be able to define patterns of geometries down to 1.5#m. The long term future of the ic industry depends on the use of electron beam
New developments and applications in optical radiation measurement will be discussed at a two day international seminar at the National Physical Laboratory on 7 - 8 May 1980. The programme will comprise state-of-the-art summaries, covering radiometric standards and techniques of radiation measurement, novel measurement techniques and instrumentation, and applications of precise radiation measurements in science and technology. It will cover the spectrum range from vacuum ultraviolet through to submillimetre wavelengths: ionising, microwave and X-ray radiations are excluded. Further information from Sira Institute Ltd, South Hill, Chislehurst, Kent BR7 5EH, UK
Precision machine design High precision machine tools and production machinery require special considerations in their design. An intensive 5-day course on precision engineering at the University o f . Wisconsin (April 21-25, 1980) will review these design concepts and present some of the latest techniques and developments in the design of such machines. The course is intended for experienced engineers involved either in the design and manufacture or the specification and operation of high precision machine tools and machinery. Further information from James E. Nichols, Department of Engineering, University of Wisconsin - Extension, 432 North Lake Street, Madison, Wl 53706, USA
113
Previews Optical radiation measurement
Alan Richardson automatic facing machine which has given a high quality finish with increased productivity and increased tool life
Face turning In traditional face turning operations, cutting speed varies substantially between the outer diameter and the centre of the work-piece. A compromise between floor-to-floor times, tool life, and surface finish normally has to be found. At constant traverse rates, pitch of the cut also varies across the diameter of the workpiece. These problems can be avoided by using a cnc machine with a dc drive. Alan Richardson Machine Services, however, have developed what they claim is a more cost effective solution. On their new machine, tool motion is towards' the centre, and by driving the chuck through an infinitely variable hydraulic motor and linking this hydraulically to the tool traverse, then mechanically back to the motor swash plate, a closed loop is formed and the two motions, rotation and traverse, are maintained in exact relationship at an ever increasing speed. The;result is a constant, optimum cut speed which can be set to any requirement. In one application floor to floor times were reduced by almo=t 50%, a high quality finish achieved and tool life (~oubled. Pitch of cut is set by altering delivery to the toolslide hydraulic feed cylinder, while a by-pass valve
PRECISION ENGINEERING
in the pressure line to the main hydraulic drive motor can be adjusted to enable a wide range of cutting speeds to be obtained. The tool depth is controlled by a hydraulic copy beam which enables the edge radius to be machined. A 75mm (3in) stroke is available which will permit high speed face contour turning to that depth. The manufacturers stress that due to the modular construction of the machine, variations can easily be made in detailed design to tailor the machine to specific ranges of workniece. Alan Richardson Machine Services, Sedburgh Road, Halifax, UK
Masks for microelectronics For a 256K random access memory (ram) to be included on one chip, line widths of the order of 1-1.5/Jm will be required.At the British Association for the Advancement of Science Annual Meeting held 3 - 7 September 1979 in Glasgow, J.C. Walling outlined mask fabrication for microelectronic circuits and stated " I t is likely that optical techniques will be able to define patterns of geometries down to 1.5#m. The long term future of the ic industry depends on the use of electron beam
New developments and applications in optical radiation measurement will be discussed at a two day international seminar at the National Physical Laboratory on 7 - 8 May 1980. The programme will comprise state-of-the-art summaries, covering radiometric standards and techniques of radiation measurement, novel measurement techniques and instrumentation, and applications of precise radiation measurements in science and technology. It will cover the spectrum range from vacuum ultraviolet through to submillimetre wavelengths: ionising, microwave and X-ray radiations are excluded. Further information from Sira Institute Ltd, South Hill, Chislehurst, Kent BR7 5EH, UK
Precision machine design High precision machine tools and production machinery require special considerations in their design. An intensive 5-day course on precision engineering at the University o f . Wisconsin (April 21-25, 1980) will review these design concepts and present some of the latest techniques and developments in the design of such machines. The course is intended for experienced engineers involved either in the design and manufacture or the specification and operation of high precision machine tools and machinery. Further information from James E. Nichols, Department of Engineering, University of Wisconsin - Extension, 432 North Lake Street, Madison, Wl 53706, USA
113