International Business Machines Corporation

Daniel S Mackin

John Ulrich Knickerbocker

Candace A Sullivan

David Clifford Long

Jon Alfred Casey

Glenn A Pomerantz

Krishna Gandhi Sachdev

Keith C O'Neil

Michael E Cropp

Donald W Diangelo

James C Utter

John F Harmuth

Cynthia J Calli

Bruce E Tripp

David E Speed

Mark J LaPlante

David B Goland

Kevin M Prettyman

Kathleen Mary McGuire

Darren T Cook

Joseph Christopher Saltarelli

Michael Thomas Puchalski

James N Humenik

Robert J Sullivan

John T Butler

James G Balz

Brenda Lee Peterson

An aqueous alkaline cleaning composition for efficient removal of Mo, Cu, W, or Cu/Ni-based conductive paste residue from screening masks, associated screening equipment and the like by using alkali metal salt and/or tetramethyl ammonium salt of polyacrylic acid, acrylic acid-methacrylic acid co-polymer, polyaspartic acid, polylactic acid, poly(acrylic acid-co-maleic anhydride), poly(maleic acid), with excess alkali for pH adjustment in the range of about 11.5-13.5, and a surfactant which may be a medium foam, low foam or no-foam surfactant, and is preferably an amphoteric and/or non-ionic and/or ionic surfactant.

Polycarboxylates-based aqueous compositions for cleaning of screening apparatus

This invention relates to the cleaning of objects that relate to semiconductor printing, such as, for example, screening masks. This invention is basically directed to removing, for example, an organic polymer-metal composite paste from screening masks used in printing conductive metal patterns onto ceramic green sheets in the fabrication of semiconductor packaging substrates. More particularly, this invention is concerned with the automated in-line cleaning of paste screening masks with an aqueous alkaline solution of a quaternary ammonium hydroxide as a more environmentally friendly alternative to non-aqueous organic solvents-based cleaning in screening operations for the production multilayer ceramic (MLC) substrates.

Aqueous quaternary ammonium hydroxide as a screening mask cleaner

A cleaning method and related apparatus for cleaning semiconductor screening masks using an aqueous alkali detergent solution applied under high pressure simultaneously from both sides of the mask, followed by a drying step that uses air knives to blow off the mask surface any residual cleaner solution.

System for cleaning residual paste from a mask

An apparatus and method is provided for vacuum screen printing a greensheet having vias and both vias and open areas whereby vacuum leakage in the apparatus is minimized and avoids bowing of the screen over the open area of the greensheet. An interposer apparatus is provided comprising at least two layers having vertical through openings in registration with the via openings of the greensheet and screen. The interposer also comprises vertical through openings communicating with the open area of the greensheet and with vent channels of the interposer. A porous membrane is also used either alone or in conjunction with the interposer to provide enhanced screening results.

Process for via fill

Optimized in-line mask cleaning system

The present invention relates generally to a new apparatus and method for screening using electrostatic adhesion. More particularly, the invention encompasses an apparatus that uses an electrostatic charge during the screening process for a semiconductor substrate. Basically, a backing layer is adhered to a green ceramic sheet using an electrostatic charge, while the green ceramic sheet is processed.

Apparatus and method for screening using electrostatic adhesion

The present invention relates generally to a new apparatus and method for screening using porous backing material. More particularly, the invention encompasses an apparatus that uses a porous backing material which is adhered to a green sheet during the screening process. Basically, a backing layer having a very high porosity is adhered to a green sheet, while the green sheet is screened. During the drying process of the green sheet some of the screening fluids are absorbed by the porous backing layer, which allows the screened vias of the green sheet to have a smooth surface.

Apparatus and method for screening green sheet with via hole using

Method for screening using electrostatic adhesion

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Pleasant Valley, NY, United States of America

Daniel S Mackin