Polycarboxylates-based aqueous compositions for cleaning of screening apparatus
AssigneeInternational Business Machines Corporation
InventorsKrishna G. Sachdev, Glenn A. Pomerantz, Daniel S. Mackin
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Abstract
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.
Claims32
An aqueous alkaline cleaning composition for removing paste residue from screening apparatus in the fabrication of ceramic substrates comprising a water soluble polycarboxylate salt in excess alkali, wherein the polycarboxylate salt is derived from the reaction of an alkali with a component selected from the group consisting of polyacrylic acid, polymethacrylic acid, poly (acrylic acid-co-methacrylic acid), polyacrylic-maleic acid copolymer, acrylic acid-maleic anhydride co-polymer, poly (maleic acid), poly (maleic acid-co-olefin), polyaspartic acid, poly (dl-lactic acid), and combinations thereof, and wherein the alkali is an organic quaternary ammonium hydroxide.
A method of cleaning paste residue from screening apparatus comprising the step of contacting the screening mask having a paste residue with an aqueous alkaline cleaning composition comprising a water soluble polycarboxylate salt in excess alkali.
Dependencies are inferred from the claim text.