Etchant Contains Acid Patents (Class 216/106)
  • Patent number: 5759427
    Abstract: A technique for chemically planarizing an exposed surface of metal on a substrate to a pre-determined thickness is provided. The substrate has an exposed metal surface such as copper circuitry on a dielectric substrate which is to be planarized. Typically, this will be circuitization extending above a photoresist layer. A planarizing head is rotated against the substrate, with the planarizing head in contact with the metal surface on the substrate. A chemical etchant, essentially free of abrasive material, is continuously supplied to the interface between the metal surface and the planarizing head. The planarizing continues until a predetermined thickness of the metal has been reached. In circuit board manufacturing, this will form a surface co-planar with the photoresist. In some instances where significant height reduction is required, thus requiring significant metal removal, several passes of the substrate may be required or a device with multiple heads may be used.
    Type: Grant
    Filed: August 28, 1996
    Date of Patent: June 2, 1998
    Assignee: International Business Machines Corporation
    Inventors: Edward Cibulsky, Gerald Andrew Kiballa, Voya Rista Markovich, Gary Leigh Newman, John Francis Prikazsky, Michael Wozniak
  • Patent number: 5755950
    Abstract: An improved method for stripping or removing tin or tin/lead plating materials from copper-based alloys is provided. This method is essentially a two-stage process whereby the bulk of the plating layer is removed in the first stage and the remaining intermetallic layer (i.e., the interface between the copper-based substrate and the plating materials) is removed in the second stage. The first stage uses an aqueous etchant solution containing either sulfuric acid and nitric or an alkane sulfonic acid and nitric acid. An aqueous immersion solution containing either sulfuric acid and copper (II) ions or an alkane sulfonic acid and copper (II) ions (which can form complexes with the alkane sulfonic acid such as copper mesylate) is used in the second stage to remove the remaining intermetallic layer. The copper-based substrate, after rinsing with water and is drying (if appropriate), can then be treated using conventional metal-recycling procedures.
    Type: Grant
    Filed: February 13, 1997
    Date of Patent: May 26, 1998
    Assignee: Dulin Metals Company
    Inventor: Nick J. Bell
  • Patent number: 5741432
    Abstract: A composition that includes an aqueous solution of nitric acid and an additive having the formula ##STR1## or a salt thereof, in an amount sufficient to improve the oxidative stability of the aqueous nitric acid solution relative to the oxidative stability of that aqueous solution in the absence of the additive.
    Type: Grant
    Filed: January 17, 1995
    Date of Patent: April 21, 1998
    Assignee: The Dexter Corporation
    Inventor: Kwee C. Wong
  • Patent number: 5635084
    Abstract: A method for treating the surface of aluminum alloys hang a relatively high copper content is provided which includes the steps of removing substantially all of the copper from the surface, contacting the surface with a first solution containing cerium, electrically charging the surface while contacting the surface in an aqueous molybdate solution, and contacting the surface with a second solution containing cerium. The copper is substantially removed from the surface in the first step either by (i) contacting the surface with an acidic chromate solution or by (ii) contacting the surface with an acidic nitrate solution while subjecting the surface to an electric potential. The corrosion-resistant surface resulting from the invention is excellent, consistent and uniform throughout the surface. Surfaces treated by the invention may often be certified for use in salt-water services.
    Type: Grant
    Filed: May 22, 1995
    Date of Patent: June 3, 1997
    Assignee: University of Southern California
    Inventors: Florian B. Mansfeld, You Wang, Simon H. Lin
  • Patent number: 5630950
    Abstract: A process and aqueous bath for bright dipping of a copper containing substrate. The bath includes: an acid, hydrogen peroxide and a bath soluble, peroxide stable constituent effective for creation and stabilization of a dissolution inhibiting film over the brightened substrate.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: May 20, 1997
    Assignee: Enthone-OMI, Inc.
    Inventor: Anthony R. Cangelosi
  • Patent number: 5601658
    Abstract: A method for treating bronze or brass fixtures containing lead with a cupric acetate solution is described. The treatment results in decreased amounts of lead in subsequent use. A preferred embodiment uses about 0.01 M cupric acetate at pH4.
    Type: Grant
    Filed: June 30, 1995
    Date of Patent: February 11, 1997
    Assignee: Purdue Research Foundation
    Inventors: Benito J. Marinas, Connie Bogard, Yi Jiang, Hsin-Ting Lan
  • Patent number: 5527766
    Abstract: Novel structures and methods utilize layered copper oxide release materials to separate oxide films from growth substrates. Generally, the method comprises the steps of: first, forming a layered copper oxide sacrificial release material on a growth substrate, in the preferred embodiment being the high temperature superconductor YBCO grown on a compatible substrate such as LaAlO3, second, forming an oxide film on the layered copper oxide release material, in the preferred embodiment, a ferroelectric, an optical material or a oxide film compatible with further high temperature superconductor growth, such as SrTiO3 or CeO2, and third, etching the layered copper oxide release material so as to separate the oxide film from the growth substrate. Optionally, additional layers may be grown on the oxide film prior to etching.
    Type: Grant
    Filed: December 13, 1993
    Date of Patent: June 18, 1996
    Assignee: Superconductor Technologies, Inc.
    Inventor: Michael M. Eddy
  • Patent number: 5509557
    Abstract: A method for depositing a conductive metal onto a dielectric substrate is provided. The method includes obtaining a metal sheet having a roughened surface that has the following parameters:R.sub.a =0.05-0.08 mil,R.sub.max =0.20-0.55 mil,S.sub.m =1.00-3.00 mil,R.sub.p =0.20-0.35 mil, andsurface area=0.90-1.20 square milswherein R.sub.a is the average roughness and the arithmetic mean of the departures from horizontal mean line profile;R.sub.max is the maximum peak-to-valley height;S.sub.m is the mean spacing between high spots at the mean line;R.sub.p is the maximum profile height from the mean line; andsurface area is the area under the surface profile from each measurement using a Talysurf S-120 profilometer;The sheet is laminated to the dielectric substrate surface by pressing the roughened surface of the metal sheet against the surface of the substrate and then removed from the substrate.
    Type: Grant
    Filed: January 24, 1994
    Date of Patent: April 23, 1996
    Assignee: International Business Machines Corporation
    Inventors: Lisa J. Jimarez, William H. Lawrence, Voya R. Markovich, Robert J. Owen, Carlos J. Sambucetti
  • Patent number: 5505872
    Abstract: This invention relates to the removal of lead from spent ferric nitrate based solder strippers, the regeneration of the spent ferric nitrate based solder strippers, and the reuse of these solutions at least one time. It comprises a method and process for precipitating lead salts from used acidic solder strippers which are employed to strip solder coatings, including the underlying tin-copper alloy, from the copper substrate of a printed circuit board. The method includes the use of sulfate ions which are directly added to an aqueous solution of spent solder stripper, without neutralization of the spent solder stripper, optionally in combination with nitric or methylsulfonic acid addition. After precipitation and removal of the lead salts, additional components of the solder stripper composition may be added to substantially restore the initial functioning of the solder stripper.
    Type: Grant
    Filed: May 23, 1995
    Date of Patent: April 9, 1996
    Assignee: Applied Electroless Concepts, Inc.
    Inventors: Gerald A. Krulik, Nenad V. Mandich, Rajwant Singh
  • Patent number: 5501350
    Abstract: A process for producing a printed wiring board, comprising the steps of forming a photosensitive resist layer on a copper layer provided on an insulating substrate, patterning the photosensitive resist layer, and etching the copper layer made bare from the photosensitive resist layer to form a copper wiring layer, wherein the surface of the copper layer is subjected to pretreatment comprising the steps of black-oxide treating the surface by the use of an alkaline oxidizing solution and subsequently finely surface-roughening the black-oxide treated surface by the use of an acidic treating solution comprised of phosphoric acid or an organic acid, followed by drying in the presence of oxygen, and thereafter the photosensitive resist layer is formed thereon. Such pretreatment enables formation of fine and uniform roughness on the copper layer surface to bring about an improvement in its adhesion to the resist layer, so that ethcing solutions can be prevented from penetrating the interface between these layers.
    Type: Grant
    Filed: January 5, 1995
    Date of Patent: March 26, 1996
    Assignee: Toppan Printing Co., Ltd.
    Inventors: Risaburo Yoshida, Kiyotomo Nakamura, Akitsu Ota, Mitsuaki Taguchi
  • Patent number: 5492235
    Abstract: A method for removing Ball Limiting Metallurgy (BLM) layers from the surface of a wafer in the presence of Pb/Sn solder bumps. In one embodiment, the BLM comprises two layers: titanium and copper. After Pb/Sn solder bumps have been formed over the electrical contact pads of the wafer, the BLM copper layer is etched with a H.sub.2 SO.sub.4 +H.sub.2 O.sub.2 +H.sub.2 O solution. While removing the copper layer, the H.sub.2 SO.sub.4 +H.sub.2 O.sub.2 +H.sub.2 O etchant also reacts with the Pb/Sn solder bumps to form a thin PbO protective layer over the surface of the bumps. When the copper layer has been etched away, the titanium layer is etched with a CH.sub.3 COOH+NH.sub.4 F+H.sub.2 O solution. The PbO layer formed over the surface of the Pb/Sn solder bumps remain insoluble when exposed to the CH.sub.3 COOH+NH.sub.4 F+H.sub.2 O etchant, thereby preventing the solder bumps from being etched in the presence of the CH.sub.3 COOH+NH.sub.4 F+H.sub.2 O etchant.
    Type: Grant
    Filed: December 1, 1994
    Date of Patent: February 20, 1996
    Assignee: Intel Corporation
    Inventors: Douglas E. Crafts, Venkatesan Murali, Caroline S. Lee
  • Patent number: 5492595
    Abstract: The present invention is directed to an improved method for treating an oxidized surface of a copper film for bonding to a resinous layer such as in the formation of a single-sided, double-sided, or multi-layered circuit board and to a layered product produced by the method. In particular, the method of the present invention comprises the steps of: contacting the oxidized surface of a copper film, having cupric oxide whiskers protruding therefrom, with an acidic reducing solution having a pH of 1 to 6.5 and having an effective amount of a water soluble thiosulfate reducing agent dissolved therein to provide a reduced copper surface; and rinsing the reduced copper surface with an acidic solution to produce a rinsed and reduced copper surface having reduced whiskers protruding therefrom, said reduced whiskers each being a mix of cuprous oxide and metallic copper. Preferably, the reduced surface is treated with a passivating agent to minimize any reoxidation prior to laminate formation.
    Type: Grant
    Filed: April 11, 1994
    Date of Patent: February 20, 1996
    Assignee: Electrochemicals, Inc.
    Inventors: Michael V. Carano, Therese M. Harryhill
  • Patent number: 5486234
    Abstract: A process of removing both the field metal, such as copper, and a metal, such as copper, embedded into a dielectric or substrate at substantially the same rate by dripping or spraying a suitable metal etchant onto a spinning wafer to etch the metal evenly on the entire surface of the wafer. By this process the field metal is etched away completely while etching of the metal inside patterned features in the dielectric at the same or a lesser rate. This process is dependent on the type of chemical etchant used, the concentration and the temperature of the solution, and also the rate of spin speed of the wafer during the etching. The process substantially reduces the metal removal time compared to mechanical polishing, for example, and can be carried out using significantly less expensive equipment.
    Type: Grant
    Filed: January 19, 1995
    Date of Patent: January 23, 1996
    Assignee: The United States of America as represented by The United States Department of Energy
    Inventors: Robert J. Contolini, Steven T. Mayer, Lisa A. Tarte
  • Patent number: 5482174
    Abstract: A method for removing copper oxide on a surface of a copper film is comprising the steps of treating the surface of the copper film with acid, neutralizing the surface of the copper film treated with acid, and washing the neutralized surface of the copper film.
    Type: Grant
    Filed: June 3, 1994
    Date of Patent: January 9, 1996
    Assignee: Fujitsu Limited
    Inventors: Takahisa Namiki, Yasuo Yamagishi, Ei Yano
  • Patent number: 5439783
    Abstract: A composition suitable for the treatment of surfaces of copper and copper alloys is disclosed. It comprises, (a) a cupric complex of an azole compound, (b) an organic acid having a boiling point or a decomposition point of 230.degree. C or lower, (c) a difficultly volatile complexing agent, (d) a complexing agent having a complexing power which is weaker than that of the azole compound, and (e) water. The treatment of copper or copper alloys with the composition produces abraded surface with moderate irregularities, thereby ensuring better adhesion of various resists thereto and increased solderability. The composition is particularly useful for the manufacture of printed-wiring boards.
    Type: Grant
    Filed: March 25, 1994
    Date of Patent: August 8, 1995
    Assignee: MEC Co., Ltd.
    Inventors: Daisaku Akiyama, Yoshiro Maki
  • Patent number: 5429715
    Abstract: A method of rendering nonreflective an imaging member substrate, preferably a photoreceptor substrate, involves etching the substrate with(a) an effective amount of an etching agent at a temperature sufficient to effect etching of the substrate, wherein the etching agent comprises (i) high purity deionized water, (ii) a mixture of high purity deionized water and a mild acid or (iii) a mixture of high purity deionized water and a base; or(b) a combination of the etching agent (a) and modulating ultrasonic energy.This method renders the substrate clean, spotless, and pristine, and provides it with uniform surface roughness.
    Type: Grant
    Filed: November 1, 1993
    Date of Patent: July 4, 1995
    Assignee: Xerox Corporation
    Inventors: Mark S. Thomas, Phillip G. Perry, David J. Maty, Richard J. Manzolati, Gene W. O'Dell