International Business Machines Corporation

Leonard J Gardecki

Adolf E Wirsing

Harry David Cox

Kibby B Horsford

Doris P Pulaski

Charles R Ramsey

James R Palmer

Erik M Probstfield

David L Smith

Brian K Burnor

David J Specht

Mary A Schaffer

William L Hammond

Thomas A Dotolo

David P Daniel

Albert J Gregoritsch, Iii

Duane E Allen

Ruth A Machell Julianelle

Charles H Keeler

David C Linnell

Robert P Westerfield, Jr

Dennis Albert Covert

Brian J Stark

David M Waligunda

William Wayne Witmer

A system for of aligning a mask to a substrate comprising: a fixture for holding the mask and the substrate in fixed positions relative to each other; means for holding the substrate, the means for holding the substrate protruding through openings in a table and the fixture, the means for holding fixedly mounted on a stage, the stage moveable in first and second directions and rotatable about an axis relative to the table; means for affixing the fixture containing the mask and the substrate to the table; means for controlling the means for temporarily affixing so as to generate a uniform force around a perimeter of the fixture to effectuate the temporarily affixing; means for aligning the mask to the substrate, the means for aligning controlling movement of the stage in the first and second directions and rotation about the axis; and means for fastening the fixture together.

Mask and substrate alignment for solder bump process

A method of forming a semiconductor interconnect including, in the order recited: (a) providing a semiconductor wafer; (b) forming bonding pads in a terminal wiring level on the frontside of the wafer; (c) reducing the thickness of the wafer; (d) forming solder bumps on the bonding pads; and (e) dicing the wafer into bumped semiconductor chips.

Method for forming interconnects on thin wafers

A shadow mask for depositing solder bumps includes additional dummy holes located adjacent holes corresponding to most of the perimeter chips of the wafer. The additional dummy provide more uniform plasma etching of contacts of the wafer, improve etching of contacts of perimeter chips, and lower contact resistance of contacts of perimeter chips. The extra holes also provide solder bumps outside the perimeter chips that can be used to support a second shadow mask for deposition of an additional material, such as tin, on the reflowed solder bumps for mounting the chips on a plastic substrate at low temperature. An improved mask to wafer alignment aid is formed from standard solder bumps. The improved alignment aid avoids damage to test probes and provides improved course alignment.

Wafer integrated rigid support ring

An apparatus for removing surface irregularities from a flat workpiece includes one or more abrading assemblies through which the workpiece passes sequentially. Each abrading assembly has a lower contact assembly and an upper contact assembly. The upper contact assembly is precisely spaced above the lower contact assembly in opposing parallel relation to the lower assembly. The lower and upper contact assemblies reciprocate in opposing directions to provide abrading action to the workpiece.

Apparatus for removing surface irregularities from a flat workpiece

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Essex, VT, United States of America

Leonard J Gardecki