Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D3/00—Electroplating: Baths therefor
  • C25D3/02—Electroplating: Baths therefor from solutions
  • C25D3/38—Electroplating: Baths therefor from solutions of copper

Definitions

• the invention relates to an acid bath for the electrodeposition of shiny and leveled copper coatings and the use.
• DE-PS 1246347 organic thio compounds
• DE-AS 1521062 polyvinyl compounds
• DE-AS 1521062 also describes an acidic copper bath which, in addition to a polymeric acidic compound with a hydrophilic group, also contains at least one substituted phenazonium compound in solution.
• Baths containing polymeric phenazonium compounds have made progress and are mainly used in combination with nonionic wetting agents and organic sulfur compounds.
• ⁇ -naphthol polyglycol ether as an additive to a copper bath is disclosed in DE-OS 37 21 985 (example 2) and GB-A-2075063, but not in combination with polymeric phenazonium compounds.
• DE-PS 3104108 describes a fluoroborate bath which contains ⁇ -naphthol ethoxylate in combination with a phthalocyanine dye.
• the electrolyte itself shows only a moderate leveling in comparison to polymeric phenazonium compounds.
• a disadvantage of these baths is the high leveling of a fine roughness (pittings, nodules) on the layer, which sensitively disturbs the decorative appearance of particularly large parts.
• This roughness is not due to floating particles in the electrolyte, but is due to a disturbed deposition in the cathodic double layer. This occurs particularly with nitrogen-containing sulfur compounds (so-called thiourea derivatives) and with phenazonium compounds.
• the object of this invention is to avoid the disadvantages described and, moreover, not to worsen the advantageous leveling.
• Thiourea and thiourea derivatives and S- and N-containing heterocyclic compounds are used as nitrogen-containing thio compounds.
• Table 2 contains examples of nitrogen-containing thio compounds (so-called thiourea derivatives) or S- and N-containing heterocyclic compounds and Table 3 for polymeric phenazonium compounds.
• the preferred amount in which the ⁇ -naphthol ethoxylate must be added in order to achieve a significant improvement in copper deposition is approximately 0.005 to 3 g / liter, preferably 0.01 to 0.25 g / liter.
• ⁇ -naphthol ethoxylates are known or can be prepared by processes known per se by reacting ⁇ -naphthol with ethylene oxide and / or propylene oxide.
• the individual components of the copper bath according to the invention can in general advantageously be present in the ready-to-use bath within the following limit concentrations: Usual oxygen-containing, high-molecular compounds 0.005 - 20 g / liter preferably 0.01 - 5 g / liter Common organic thio compounds with hydrophilic groups 0.0005 - 0.2 g / liter preferably 0.001 - 0.03 g / liter Usual nitrogen-containing thio compounds (so-called thiourea derivatives) and / or polymeric phenazonium compounds 0.0001 - 0.50 g / liter preferably 0.0005 - 0.04 g / liter
• the basic composition of the bath according to the invention can vary within wide limits.
• An aqueous solution of the following composition is generally used: Copper sulfate (CuSO4. 5H2O) 20 - 250 g / liter preferably 60 - 80 g / liter or 180 - 220 g / liter sulfuric acid 50 - 350 g / liter preferably 180 - 220 g / liter or 50 - 90 g / liter Sodium chloride 0.02 - 0.25 g / liter, preferably 0.05-0.12 g / liter
• copper sulfate instead of copper sulfate, other copper salts can also be used, at least in part.
• Some or all of the sulfuric acid can be replaced by fluoroboric acid, methanesulfonic acid or other acids.
• the addition of sodium chloride can be omitted in whole or in part if the additives already contain halogen ions.
• customary brighteners, levelers or wetting agents can also be present in the bathroom.
• the working conditions of the bath are as follows: PH value: ⁇ 1 Temperature: 15 ° C - 45 ° C, preferably 20 ° C - 30 ° C cath. Current density: 0.5 - 12 A / dm2, preferably 2-4 A / dm2
• the electrolyte movement is achieved by blowing in air.
• Copper with a content of 0.02 to 0.067% phosphorus is used as the anode
• the invention also includes methods using the baths according to the invention according to the claims.
• CuSO4.5 H2O copper sulfate
• 0.2 g / liter sodium chloride are used as brighteners 0.2 g / liter polyethylene glycol, 0.01 g / liter bis (w-sulfopropyl) disulfide, disodium salt, and 0.02 g / liter polymeric 7-dimethylamino-5-phenyl-phenazonium chloride admitted.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Electroplating And Plating Baths Therefor (AREA)
• Electrolytic Production Of Metals (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=6416407

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (6)

Family Cites Families (13)

• 1990
  • 1990-10-13 DE DE4032864A patent/DE4032864A1/de active Granted
• 1991
  • 1991-10-11 EP EP91917496A patent/EP0554275B1/de not_active Expired - Lifetime
  • 1991-10-11 CA CA002093924A patent/CA2093924C/en not_active Expired - Lifetime
  • 1991-10-11 DE DE59103933T patent/DE59103933D1/de not_active Expired - Lifetime
  • 1991-10-11 ES ES91917496T patent/ES2066477T3/es not_active Expired - Lifetime
  • 1991-10-11 JP JP3516095A patent/JPH06501986A/ja active Pending
  • 1991-10-11 AT AT91917496T patent/ATE115651T1/de not_active IP Right Cessation
  • 1991-10-11 WO PCT/DE1991/000811 patent/WO1992007116A1/de active IP Right Grant

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