International Business Machines Corporation

Edward Jay Frankoski

Jeffrey D Jones

Robert H Katyl

Lyn Braxton Ratcliff

Irving Memis

Michael J Canestaro

James Steven Kamperman

Steven L Bard

Jack M McCreary

Gerald A Bendz

Michael S Horan

John R Chapura

John R Kjelgaard, Jr

An apparatus, and a corresponding method, for chemically etching the copper foil of a copper foil-clad substrate are disclosed. Significantly, this apparatus includes fluid jet injectors which serve to produce jets of chemical etchant. These fluid jet injectors are arranged so as to simultaneously achieve a relatively high etch rate and a relatively high etch uniformity.

Apparatus, and corresponding method, for chemically etching substrates

The present invention provides printed circuit boards for mounting to a semiconductor integrated circuit die. In one embodiment the printed circuit boards comprise a rigid dielectric substrate having a planar face, a plurality of circuit lines affixed to the face of the substrate, and a plurality of conductive bumps affixed to the face of the substrate. Each conductive bump has an upper bonding surface that is substantially planar and a lateral surface which is essentially perpendicular to the face of the substrate. The conductive bumps and the circuit lines are formed from a single metallic layer. The conductive bumps and circuit lines constitute a unitary, integral structure, i.e., each conductive bump and connecting circuit line lack a physical interface therebetween. The upper surfaces of the conductive bumps extend to essentially the same height above the surface of the substrate, i.e., the upper surfaces of the conductive bumps are substantially coplanar relative to each other. In another embodiment, the printed circuit board further comprises a unitary solder dam or a plurality of unconnected solder dams that partially or completely surround the conductive bumps. The solder dam has an upper surface which lies below the upper bonding surface of the conductive bump. The solder dam is positioned to prevent the alloy, particularly solder, which is subsequently disposed on each conductive bump from flowing along the circuit lines that are integrally connected to the conductive bump. The present invention also relates to a microelectronic package that comprises a semiconductor integrated circuit die mounted to a printed circuit board made in accordance with the present invention.

Printed circuit boards for mounting a semiconductor integrated circuit

An apparatus for chemically etching the copper foil of a copper foil-clad substrate are disclosed. Significantly, this apparatus includes fluid jet injectors which serve to produce jets of chemical etchant. These fluid jet injectors are arranged so as to simultaneously achieve a relatively high etch rate and a relatively high etch uniformity.

Apparatus for chemically etching substrates

A fluid treatment apparatus and method for applying first and second fluids (e.g., etchant and water) to an article (e.g., circuit board) passing through the apparatus at a predetermined rate. The first fluid is impinged on a surface of the article and thereafter collected within the apparatus' common housing. The second fluid is impinged onto the surface of the article and collected within the same housing but at a location separate from the collected first fluid so as to at least partially prevent mixing thereof. The preferred means for effecting fluid impingement comprises separate fluid injecters, each including at least two rows of fluid jet injectors therein. The collected fluids are each returned to the respective impingement means. Replenishment of the second fluid is accomplished using a pump which supplies the second fluid, while the apparatus also includes means (e.g., a drain) to effectively remove the second fluid at a rate similar to the supply rate for the second fluid. The first fluid is also maintained at an established level above the article's surface using suitable means (e.g., dual rollers) located relative (e.g., on opposite sides of) the first fluid impingement means. Similar level retention for the second fluid is also possible. Cascading of the collected second fluid is also defined, this occurring within the same housing chamber which serves to collect the first fluid.

Fluid treatment apparatus

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Newark Valley, NY, United States of America

Edward Jay Frankoski