Showing papers on "Surface micromachining published in 1976"

Omega-X micromachining system

Abstract: A micromachining tool system with X- and omega-axes is used to machine spherical, aspherical, and irregular surfaces with a maximum contour error of 100 nonometers (nm) and surface waviness of no more than 0.8 nm RMS. The omega axis, named for the angular measurement of the rotation of an eccentric mechanism supporting one end of a tool bar, enables the pulse increments of the tool toward the workpiece to be as little as 0 to 4.4 nm. A dedicated computer coordinates motion in the two axes to produce the workpiece contour. Inertia is reduced by reducing the mass pulsed toward the workpiece to about one-fifth of its former value. The tool system includes calibration instruments to calibrate the micromachining tool system. Backlash is reduced and flexing decreased by using a rotary table and servomotor to pulse the tool in the omega-axis instead of a ball screw mechanism. A thermally-stabilized spindle rotates the workpiece and is driven by a motor not mounted on the micromachining tool base through a torque-smoothing pulley and vibrationless rotary coupling. Abbe offset errors are almost eliminated by tool setting and calibration at spindle center height. Tool contour and workpiece contour are gaged on the machine; this enables the source of machining errors to be determined more readily, because the workpiece is gaged before its shape can be changed by removal from the machine.

The Mechanics Of Micromachining

Abstract: The current state of machining theory is examined for relevance to micromachining. Of particular interest are those features of the theory which are important to optical surface finishes and surface characteristics. The relation of transverse strain or side flow to the nature of the machining marks is one example of interest. Correlation with measurements of machining parameters and surface finishes is given.© (1976) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Micromachining using a laser beam and optical focussing train - suitable for adjusting resistances in integrated circuits

Abstract: Laser machining appts. comprises (a) a laser providing a parallel beam, (b) an optical train transmitting the beam,a nd (c) an objective receiving the beam and concentrating it on the zone being machined. The optical train (b) also contains a converging lens (1) for the initial focussing of the beam, followed by a second, adapter lens (2) leading to the objective (c) and the zone being machined. Lens (1) can pref. be displaced longitudinally so it concentrates the beam in a fixed plane and a diaphragm is pref. located between the two lenses (1,2) A dichroic mirror pref. deflects the beam onto the objective which possesses min. optical aberration. Machining extremely small areas, e.g. a cricle with a dia. of some tens of microns, e.g. micromachining for adjusting resistances in electronic integrated circuits. An accurate beam can be obtd. using optical elements normally employed in microscopes, and a beam with any desired shape of cross section can be achieved by using a diaphragm witha suitable shape.