Other

Siltronic Corporation

David E Gore

Roland R Vandamme

Wesley Harrison

A loudspeaker having a cylindrical sound-producing membrane includes an acoustic lens which radially surrounds the membrane. The membrane is composed of wire mesh formed into a cylinder. The cylindrical membrane is positioned on the magnet structure by an inner supporting cylindrical core column. Sound from the membrane is fractionally redirected by the lens which is centered along the axis of the membrane. The lens includes a plurality of radially disposed petals that reflect a portion of the sound. The base of the lens supports and mounts the loudspeaker magnet and driver assembly.

Loudspeaker with sound dispersion lens

A method is provided for processing the back side of a semiconductor wafer after the wafer has been lapped. The process includes grinding the back side of the wafer to remove wafer material, to substantially eliminate lap damage from the back side of the wafer. The back side of the wafer may then be cleaned, etched, and polished, after which the front side of the wafer is polished. The back side grinding may be accomplished after the lapping without any other step of substantial removal of wafer material. The polishing of the back side of the wafer may be performed with a CMP machine and may produce a specular surface, visually free of damage under haze lamp inspection, with removal of about 0.5 microns of wafer material. After polishing the front side of the wafer, an epitaxial layer may be produced on the front side of the wafer.

Method for processing a semiconductor wafer including back side grinding

The present invention comprises a radially pulsating cylindrical surface operating as a wave transmission-line. The device is responsive to electrical means and may be practically utilized to generate pressure waves. A conventional electromagnetic driving system is employed with the novel cylindrical surface. A cylindrical voice coil is affixed to the cylindrical surface co-axially. The surface may comprise a matrix of helically oriented fibers suspended in an elastomeric impregnant. Damping means may be provided both internally and terminally. The radiation produced is omnidirectional.

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Santa Ana, CA, United States of America

David E Gore