Lead Patents (Class 205/299)
  • Publication number: 20150027899
    Abstract: Provided is an anode for electroplating which uses an aqueous solution as an electrolytic solution, and the anode which is low in potential when compared with a conventional anode, able to decrease an electrolytic voltage and an electric energy consumption rate and may also be used as an anode for electroplating various types of metals, and which is low in cost. Also provided is a method for electroplating which uses an aqueous solution as an electrolytic solution, in which the anode is low in potential and electrolytic voltage, thereby making it possible to decrease the electric energy consumption rate. The anode for electroplating of the present invention is an anode for electroplating which uses an aqueous solution as an electrolytic solution, in which a catalytic layer containing amorphous ruthenium oxide and amorphous tantalum oxide is formed on a conductive substrate.
    Type: Application
    Filed: August 31, 2012
    Publication date: January 29, 2015
    Applicant: THE DOSHISHA
    Inventor: Masatsugu Morimitsu
  • Publication number: 20130264215
    Abstract: The present invention relates to an anode system for conventional electrolysis cells, a process for the production thereof and its use for the deposition of electrolytic coatings. The anode system is characterized in that the anode (2) is in direct contact with a membrane (3) which completely separates the anode space from the cathode space. This anode system is therefore a direct-contact membrane anode.
    Type: Application
    Filed: December 8, 2011
    Publication date: October 10, 2013
    Applicant: UMICORE GALVANOTECHNIK GMBH
    Inventors: Bernd Weyhmueller, Franz Kohl, Uwe Manz, Klaus Bronder, Frank Oberst, Mario Tomazzoni
  • Publication number: 20100044240
    Abstract: When depositing a metal or a compound of the metal from a liquid crystal phase comprising a metal compound, e.g. a metal salt, by electrochemical means, high concentrations of the salt may be employed by using an ionic surfactant in place of the commonly used non-ionic surfactant.
    Type: Application
    Filed: September 7, 2007
    Publication date: February 25, 2010
    Inventors: Jennifer Kimber, Daniel Peat
  • Publication number: 20090223830
    Abstract: A surface treatment method of cladding a Sn or Sn alloy coating with one or more metals selected from among Mn, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Ga, In, Ti, Ge, Pb, Sb and Bi continuously or discontinuously in such a way as to make the Sn or Sn alloy coating partially exposed, which method makes it possible to inhibit the generation of whiskers in an Sn or Sn alloy coating formed on the surface of a substrate to which other member is pressure-welded or the joint surface to be soldered. Cladding an Sn or Sn alloy coating with a prescribed metal continuously or discontinuously in such a way as to make the coating partially exposed inhibits the generation of whiskers by contact pressure in pressure welding, and further inhibits the generation of whiskers without impairing the solder wettability of the coating even when the cladding is not followed by heat treatment or reflowing.
    Type: Application
    Filed: October 2, 2006
    Publication date: September 10, 2009
    Applicants: C. UYEMURA & CO., LTD., OSAKA UNIVERSITY
    Inventors: Masanobu Tsujimoto, Isamu Yanada, Katsuaki Suganuma, Keunsoo Kim
  • Publication number: 20090123789
    Abstract: There is disclosed articles for and methods of confining volatile materials in the void volume defined by crystalline void materials. In one embodiment, the hydrogen isotopes are confined inside carbon nanotubes for storage and the production of energy. There is also disclosed a method of generating various reactions by confining the volatile materials inside the crystalline void structure and releasing the confined volatile material. In this embodiment, the released volatile material may be combined with a different material to initiate or sustain a chemical, thermal, nuclear, electrical, mechanical, or biological reaction.
    Type: Application
    Filed: May 9, 2008
    Publication date: May 14, 2009
    Inventors: William K. Cooper, James F. Loan, Christopher H. Cooper
  • Patent number: 7264704
    Abstract: It is described an electrolysis cell wherein the anodic dissolution of metals is carried out, in particular of metals characterised by a relatively high oxidation potential, such as copper, or metals with high hydrogen overpotential, for example tin, aimed at restoring both the concentration of said metals, and the pH in galvanic baths used in electroplating processes with insoluble anodes. The cell of the invention comprises an anodic compartment, wherein the metal to be dissolved acts as a consumable anode, and a cathodic compartment, containing a cathode for hydrogen evolution, separated by a cation-exchange membrane. The coupling of the cell of the invention with the electroplating cell allows a strong simplification of the overall process and a sensible reduction in the relevant costs.
    Type: Grant
    Filed: June 28, 2002
    Date of Patent: September 4, 2007
    Assignee: De Nora Elettrodi S.p.A.
    Inventors: Ulderico Nevosi, Paolo Rossi
  • Patent number: 7235165
    Abstract: An electroplating solution may be formulated as an aqueous solution of oxalic acid, trisodium phosphate and ammonium sulfate. Such solutions may be used for both brush plating and bath plating, and are suitable for use with a variety of plating metals and substrate metals without the need to add plating metal ions to the solution in the form of metal salts, chelates or complexes.
    Type: Grant
    Filed: January 27, 2005
    Date of Patent: June 26, 2007
    Inventor: Richard Lacey
  • Patent number: 6852210
    Abstract: To provide a plating method, which enables wide industrial use of the redox system electroless plating method having excellent characteristics, and a plating bath precursor which is preferable for the plating method. The plating method comprises a process oxidizing first metal ions of a redox system of a plating bath from a lower oxidation state to a high oxidation state, and second metal ions of said redox system are reduced and deposited onto the surface of an object to be plated, wherein a process is provided in which by supplying the electrical current to the plating bath, the first metal ions are reduced from said lower oxidation state to thereby activate the plating bath. The plating bath precursor is formed stabilizing the plating bath so that reduction and deposition of the second metal ions substantially do not occur in order to improve its storing performance.
    Type: Grant
    Filed: January 7, 2002
    Date of Patent: February 8, 2005
    Assignees: Daiwa Fine Chemicals Co., Ltd., Sumitomo Electric Industries, Ltd.
    Inventors: Keigo Obata, Dong-Hyun Kim, Takao Takeuchi, Seiichiro Nakao, Shinji Inazawa, Ayao Kariya, Masatoshi Majima, Shigeyoshi Nakayama
  • Publication number: 20040089556
    Abstract: In the low-lead-content plating process of the present invention, tens to hundreds ppms of lead, thallium and iron ions, which are much lower than the international “non-lead” standard, are added into a pure tin plating liquid to change the crystal phase orientation during infrared-ray reflow, thereby reducing the melting point of the plated layer.
    Type: Application
    Filed: October 31, 2003
    Publication date: May 13, 2004
    Inventor: Philip Chung-Hwei Chen
  • Patent number: 6730209
    Abstract: In accordance with the invention, the volatility of a solder plating bath with volatile brighteners such as aldehydes has its volatility reduced by the addition of diols to the bath. The diols are advantageously 1,3 propanediol or 1,2 propanediol and are accompanied by lower molecular weight alcohols. In a preferred embodiment, a diol along with low alcohol is added to a bath comprising sulfonic acid, surfactant, grain refiner and brightening agents comprising an aromatic aldehyde and a carboxylic acid.
    Type: Grant
    Filed: February 22, 2002
    Date of Patent: May 4, 2004
    Assignee: Lucent Technologies Inc.
    Inventors: Joseph A. Abys, Frank Stanley Humiec, Kenneth J. Murski, Yun Zhang
  • Patent number: 6685820
    Abstract: The present invention relates to a method for treating spent tin or tin/lead stripping solution used in the electronic industry, particularly in the manufacture of printed circuit boards or a lead frames. Said method comprises (i) electrolytically reducing copper ions in the solution to copper at a low temperature; (ii) electrolytically oxidizing Sn2+ and Pb2+ in the solution at a high temperature to form solid tin and lead oxides and hydroxides; (iii) separating solid tin and lead oxides and hydroxides from the solution; (iv) dissolving tin and lead oxides and hydroxides obtained in step (iii) in a strong alkali or acidic solution; and (v) electrolytically reducing the alkali or acidic solution obtained in step (iv) at a high temperature to recover metallic tin and lead. Also, the filtrate obtained in step (iii) above is useful for preparing fresh tin or tin/lead stripping solution.
    Type: Grant
    Filed: April 26, 2002
    Date of Patent: February 3, 2004
    Assignees: Amia Co., Ltd., Persee Chemical Co., Ltd.
    Inventors: Kuo-Chin Chen, Ching-Hwa Chang, Yu-Feng Lin, Tai-Sheng Yuan, Hung-Ming Wang, Jenn-Fang Wu, Huei-Yin Cheng
  • Publication number: 20030159939
    Abstract: In accordance with the invention, the volatility of a solder plating bath with volatile brighteners such as aldehydes has its volatility reduced by the addition of diols to the bath. The diols to the bath. The diols are advantageously 1,3 propanediol or 1,2 propanediol and are accompanied by lower molecular weight alcohols. In a preferred embodiment, a diol along with low alcohol is added to a bath comprising sulfonic acid, surfactant, grain refiner and brightening agents comprising an aromatic aldehyde and a carboxylic acid.
    Type: Application
    Filed: February 22, 2002
    Publication date: August 28, 2003
    Applicant: Lucent Technologies
    Inventors: Joseph A. Abys, Frank Stanley Humiec, Kenneth J. Murski, Yun Zhang
  • Publication number: 20030150740
    Abstract: A complex porous structure of a reticulated foam, felt or fabric types, wherein their metallisation over their entire developed surface, by electrolysis of lead or lead alloys, is made possible by a specific preliminary conductive activation treatment obtained by using two consecutive phases of coating the developed surface of the structures, comprising a first deposition of a conductive polymer, which provides the structures with the required conductivity, and a second thin deposition of conductive lacquer or varnish which ensures the surface protection of the conductive polymer against the deactivating effect of the conductive nature of the latter, due to the cathodic polarisation of the said structures in the electrolytic lead-coating bath.
    Type: Application
    Filed: January 30, 2003
    Publication date: August 14, 2003
    Inventors: Bernard Bugnet, Denis Doniat
  • Publication number: 20030070934
    Abstract: A metal plating bath and method of plating a metal on a substrate where the metal plating bath contains heteroatom compounds that prevent or inhibit the consumption of metal plating bath additives. The metal plating bath additives improve the brightness of plated metal as well as the ductility, micro-throwing power and macro-throwing power of the plating bath. The addition of the additive consumption inhibiting heteroatom organic compounds improves the physical properties of the plated metal as well as the efficiency of the plating process. The heteroatom organic compounds may contain sulfur, oxygen or nitrogen heteroatoms.
    Type: Application
    Filed: October 2, 2001
    Publication date: April 17, 2003
    Applicant: Shipley Company, L.L.C.
    Inventors: Andrew J. Cobley, Mark J. Kapeckas, Erik Reddington, Wade Sonnenberg, Leon R. Barstad, Thomas Buckley
  • Publication number: 20030066756
    Abstract: A metal plating bath and method for plating a metal on a substrate. The metal plating bath contains hydroxylamines that inhibit the consumption of additive bath components to improve the efficiency of metal plating processes. The additive bath components are added to metal plating baths to improve brightness of plated metal as well as the micro-throwing and macro-throwing power of the bath. In addition to brighteners, the additive bath components may include levelers, suppressors, hardeners, and the like. The hydroxylamines that inhibit additive consumption may be employed in metal plating baths for plating copper, gold, silver, platinum, palladium, cobalt, cadmium, nickel, bismuth, indium, tin, rhodium, iridium, ruthenium and alloys thereof.
    Type: Application
    Filed: October 4, 2001
    Publication date: April 10, 2003
    Applicant: Shipley Company, L.L.C.
    Inventors: David R. Gabe, Andrew J. Cobley, Leon R. Barstad, Mark J. Kapeckas, Erik Reddington, Wade Sonnenberg, Thomas Buckley
  • Publication number: 20020079232
    Abstract: Disclosed are methods for depositing a conductive layer on a substrate having a barrier layer and/or a dielectric layer. Such methods are particularly suitable for depositing an electroplated copper layer on a substrate having small apertures, and preferably very small apertures.
    Type: Application
    Filed: October 25, 2001
    Publication date: June 27, 2002
    Applicant: Shipley Company, L.L.C.
    Inventor: James G. Shelnut
  • Publication number: 20020038764
    Abstract: A continuous layer of a metal is electrodeposited onto a substrate having both hydrodynamically inaccessible recesses and hydrodynamically accessible recesses on its surface by a twostep process in which the hydrodynamically inaccessible recesses are plated using a pulsed reversing current with cathodic pulses having a duty cycle of less than about 50% and anodic pulses having a duty cycle of greater than about 50% and the hydrodynamically accessible recesses are then plated using a pulsed reversing current with cathodic pulses having a duty cycle of greater than about 50% and anodic pulses having a duty cycle of less than about 50%.
    Type: Application
    Filed: April 3, 2001
    Publication date: April 4, 2002
    Inventors: E. Jennings Taylor, Jenny J. Sun, Maria E. Inman
  • Publication number: 20020027083
    Abstract: A cathode is made of an electrically conducting support with a coating ot electrochemically deposited lead with a density between 0.001 and 2 g/cm3.
    Type: Application
    Filed: August 10, 2001
    Publication date: March 7, 2002
    Applicant: Consortium Fur Elektrochemische Industrie GmbH
    Inventor: Elke Fritz-Langhals
  • Patent number: 6287433
    Abstract: An insoluble anode for sulfate electrolytes composed of, generally, from 1 to 99 wt % titanium or titanium alloy and the remainder lead or lead alloy, comprising a titanium-lead active layer, or a titanium-lead active layer covering and a core being made from titanium or lead. The anode is produced by infiltration of porous titanium with lead, either by consolidation of the mixture of titanium and lead powders. The anode formed of the active layer, or of the active layer covering and a sheet core is fabricated in the shape of a plate. The anode formed of the active layer covering and a rod or tube core is fabricated in the shape of a lattice. Advantageously, the titanium-lead active layer is dispersion-strengthened by zirconium carbide or titanium carbide particles, and it's surface is released of a portion of lead.
    Type: Grant
    Filed: May 15, 2000
    Date of Patent: September 11, 2001
    Inventor: Alla Sapozhnikova
  • Patent number: 6183545
    Abstract: An aqueous solution for the reductive deposition of metals comprising, besides water, (A) a phosphine of the general formula (1)  in which R1, R2, and R3 denote lower alkyl groups, at least one of which being hydroxy-or amino-substituted lower alkyl group, and (B) a soluble compound of a metal or a compound of a metal solubilized through the formation of a soluble complex by said phosphine.
    Type: Grant
    Filed: June 28, 1999
    Date of Patent: February 6, 2001
    Assignee: Daiwa Fine Chemicals Co., Ltd.
    Inventors: Yoshiaki Okuhama, Takao Takeuchi, Masakazu Yoshimoto, Shigeru Takatani, Emiko Tanaka, Masayuki Nishino, Yuji Kato, Yasuhito Kohashi, Kyoko Kuba, Tetsuya Kondo, Keiji Shiomi, Keigo Obata, Mitsuo Komatsu, Hidemi Nawafune
  • Patent number: 6179985
    Abstract: The use of alkali metal, alkaline earth metal, ammonium and substituted ammonium salts of alkyl and alkanol sulfonic acids as additives in pure metal and metal alloy fluoroborate electroplating baths has a number of unexpected benefits including wider useful current density range and improved appearance. The metals and metal alloys include but are not limited to tin, lead, copper, cadmium, indium, iron, tin/lead and tin/lead copper.
    Type: Grant
    Filed: March 19, 1999
    Date of Patent: January 30, 2001
    Assignees: Technic, Inc., Specialty Chemical Systems, Inc.
    Inventors: Hyman D. Gillman, Brenda Fernandes, Kazimierz Wikiel
  • Patent number: 5853557
    Abstract: The present invention relates to composite articles including a surface layer of tin, lead, silver or an alloy thereof that contains co-deposited non-ionic polymeric particles to provide a reduced-friction deposit that has an initially low coefficient of friction and low insertion force and fretting corrosion in separable electronic connectors, and to methods for preparing the plated articles. The polymeric particles have a size between about 0.1 to 0.45 .mu.m in diameter to reduce the coefficient of friction of the resultant deposit to about 0.45 or below. Also, the deposit has excellent electrical properties and can be successfully soldered. The invention also relates to a solution for plating the surface layer of the composite articles, which surface layer reduces insertion force and fretting corrosion of separable electronic connectors.
    Type: Grant
    Filed: April 4, 1997
    Date of Patent: December 29, 1998
    Assignee: Handy & Harman
    Inventors: Theresa R. Souza, Allen E. Molvar
  • Patent number: 5720867
    Abstract: An electrolytic cell comprising bipolar electrodes is employed for electrochemical deposition of copper, zinc, lead, nickel or cobalt. An interior space is provided between the cathode side and the anode side of a bipolar electrode. The electrolyte can flow substantially without an obstruction through the interelectrode space between adjacent electrodes. The current densities in the interelectrode space amount to 800 to 8000 A/m.sup.2. Gas is evolved on the anode side of the bipolar electrodes and causes liquid to flow along the anode side. In the middle of the height of the anode side that liquid flow has a vertical component having a velocity of 5 to 100 cm/second. Electrolyte solution flows from the upper edge portion of the anode side to a return flow space, in which the solution flows downwardly. From the return flow space the solution is returned to the lower portion of the interelectrode space.
    Type: Grant
    Filed: October 27, 1995
    Date of Patent: February 24, 1998
    Assignee: Metallgesellschaft AG
    Inventors: Nikola Anastasijevic, Gerhard Jedlicka, Karl Lohrberg
  • Patent number: 5698087
    Abstract: It now has been found that a smooth and level deposit of tin, lead or tin-lead alloy can be deposited on a substrate from an aqueous plating bath which comprises (A) at least one bath-soluble metal salt selected from the group consisting of a stannous salt, a lead salt, or a mixture of stannous and lead salts, (B) an acid selected from the group consisting of sulfuric or fluoboric acid; and (C) an effective amount of at least one soluble bismuth salt of an alkane sulfonic acid or an alkanol sulfonic acid. Optionally, the aqueous plating bath may further comprise (D) at least one surfactant.
    Type: Grant
    Filed: March 11, 1992
    Date of Patent: December 16, 1997
    Assignee: McGean-Rohco, Inc.
    Inventor: George S. Bokisa
  • Patent number: 5672181
    Abstract: A method for manufacturing a hardened lead storage battery electrode wherein fine, particulate solids, that are insoluble in lead, are incorporated into a lead matrix. The method includes the steps of incorporating solids, dissolved or suspended in an electrolyte, into a lead matrix such that shaping simultaneously occurs during the deposition of lead due to a suitable fashioning of a plurality of electrically conductive surface regions; vigorously agitating the electrolyte by introducing air through an apertured plate in the bottom of an electrolyte vessel providing an electro-chemical cell including a cathode and a Cu/Ta/Pt anode and an electrolyte solution including HBF.sub.4 and an electrolyte selected from PbO, Pb(OH).sub.2 and PbCO.sub.3 or including a graphite anode and an electrolyte solution of Fe(BF.sub.4).sub.2 and Fe(BF.sub.4).sub.3. The electrolyte is prepared from a raw material selected from lead, waste material containing lead and desulfured lead storage battery electrolyte paste.
    Type: Grant
    Filed: April 22, 1996
    Date of Patent: September 30, 1997
    Assignee: Hans Warlimont
    Inventors: Hans Warlimont, Marco Olper, Armin Ueberschaer, Klaus Drefahl
  • Patent number: 5667659
    Abstract: The present invention relates to a solution and method for plating tin, lead, or tin-lead alloy deposits which contain a co-deposit of fluorocarbon particles to provide a lower-friction solder-type deposit which reduces insertion force and fretting corrosion in separable electronic connectors. The fluorocarbon particles have a size between about 0.1 to 1 .mu.m in diameter, and reduce the coefficient of friction of the resultant deposit to 0.8 or less. Also, the deposit has excellent mechanical properties and can be successfully soldered.
    Type: Grant
    Filed: April 4, 1996
    Date of Patent: September 16, 1997
    Assignee: Handy & Harman
    Inventors: Therese R. Souza, Allen E. Molvar
  • Patent number: 5651873
    Abstract: An electroplating solution (A), comprises an aqueous solution consisting essentially of lead phenolsulfonate: 1 to 250 g/liter in terms of Pb content; tin phenolsulfonate: 0.1 to 250 g/liter in terms of Sn content; phenolsulfonic acid: 20 to 300 g/liter; polyoxyethylene polyoxypropylene alkylamine: 1 to 50 g/liter; a 1-naphthaldehyde derivative: 0.001 to 1 g/liter; and an aldol sulfanilic acid derivative: 0.1 to 30 g/liter; or an aqueous solution (B) consisting essentially of lead methanesulfonate: 1 to 250 g/liter in terms of Pb content; tin methanesulfonate: 0.1 to 250 g/liter in terms of Sn content; methanesulfonic acid: 20 to 300 g/liter; polyoxyethylene polyoxypropylene alkylamine: 1 to 50 g/liter; and an aldol sulfanilic acid derivative: 0.1 to 30 g/liter.
    Type: Grant
    Filed: June 26, 1995
    Date of Patent: July 29, 1997
    Assignees: Mitsubishi Materials Corporation, Daiwa Fine Chemicals Co., Ltd.
    Inventors: Naoki Uchiyama, Masayoshi Kohinata, Akihiro Masuda, Yoshiaki Okuhama, Seishi Masaki, Masakazu Yoshimoto
  • Patent number: 5562814
    Abstract: A novel electroplating bath is described which comprises an alkane or alkanol sulfonic acid, tin, lead or tin-lead metal alloy and either an alkali carbonate or alkali bicarbonate salt. The addition of the alkali carbonate or bicarbonate salts reduces tin oxidation and thus decreases the amount of sludge formation in the bath.
    Type: Grant
    Filed: September 1, 1995
    Date of Patent: October 8, 1996
    Assignee: Dale Electronics, Inc.
    Inventor: John Kirby
  • Patent number: 5521029
    Abstract: The present invention is directed to a substrate with a coating of titanium suboxide thereon. The coating protects the substrate from corrosion. Typically, the substrate is a current collector for a lead acid battery. The present invention is also directed to a process for forming the coating of titanium suboxide coating on the substrate. A colloidal dispersion of titanium suboxide particles in water is formed. The pH of the colloidal dispersion is brought within the range of 3 or less. The substrate to be coated is then placed in the colloidal dispersion. A positive electrode is also placed in the colloidal dispersion. An electric field is then introduced into the colloidal dispersion to effect electrophoretic deposition of the titanium suboxide on the substrate.
    Type: Grant
    Filed: February 22, 1995
    Date of Patent: May 28, 1996
    Assignee: AT&T Corp.
    Inventors: Mary E. Fiorino, Jorge L. Valdes
  • Patent number: 5443714
    Abstract: A process for acidic electrolytical deposition of lead layers and predominantly lead-containing layers onto surfaces using an electrolyte containing lead salts and acids, in particular alkanesulfonic acid, borofluoric acid or silicofluoric acid, with non-ionic surfactants and cationic or amphoteric surfactants being added to the electrolyte. The process can be operated at current densities of from 0.5 to 20 A/dm.sup.2 and at a pH value below 1.
    Type: Grant
    Filed: May 29, 1992
    Date of Patent: August 22, 1995
    Assignee: Blasberg Oberflachentechnik, GmbH
    Inventors: Karl-Jurgen Schmidt, Eberhard Knaak
  • Patent number: 5316632
    Abstract: A method for improving the efficiency of electrolytic fuel cells and the like, and more particularly aluminum-air fuel cells, is described. The efficiency of the fuel cell is controlled by the rate of dissolution of Aluminum in an alkaline electrolyte and this rate can be increased dramatically by activating the surface of the anode with an activator such as Tin which is precipitated thereon. Self corrosion of the Aluminum anode, when the battery is not in use is a problem which is usually solved by using ultra pure Aluminum which is very expensive. The problem may be reduced by passivating the surface of the anode by electro-deposition of a passivating layer such as Pb. The passivating layer can be electrolytically removed to reactivate the battery before the activating layer is precipitated.
    Type: Grant
    Filed: April 22, 1993
    Date of Patent: May 31, 1994
    Inventor: Dieter Remppel
  • Patent number: 5174887
    Abstract: A process for depositing tin upon a steel strip by high speed electroplating to produce tinplate, which includes a basis solution of an alkyl sulfonic acid, a solution soluble tin compound and a surfactant, preferably of an alkylene oxide condensation compound of 1) an aliphatic hydrocarbon having seven, preferably six or less, carbon atoms and at least one hydroxy group, or 2) an organic compound having no more than a total of twenty carbon atoms in one or two independent or joined rings optionally substituted with an alkyl moeity of six carbon atoms or less. After electroplating, the tinplate is rinsed and the rinse water only needs to be treated for removal of tin ions prior to discharge by normal procedures.
    Type: Grant
    Filed: May 2, 1990
    Date of Patent: December 29, 1992
    Assignee: Learonal, Inc.
    Inventors: George A. Federman, Donald W. Thomson, Michael P. Toben, Neil D. Brown