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 present invention relates to an aqueous acidic galvanic copper bath for the deposition of fine-grained ductile copper containing polymers from bifunctional propane derivatives and, if appropriate, other bath additives, and to the process for producing the same.
• DE-PS 9 75 247 DE-AS 1 086 508, DE-AS 1 921 845 and DE-AS 2 003 539.
• DE-AS 1 521 061 also discloses copper baths with to produce a content of polymers, a 1,3-dioxolane polymer having terminal hydroxyl groups being described as the polymer.
• the copper baths according to DE-OS 15 21 062 can also contain other polyether polymers.
• the object of the invention is therefore to develop an acidic galvanic copper bath which, in addition to improved scattering power, provides fine crystalline, ductile copper deposits, with high elongation at break values and better shock test behavior.
• an acidic galvanic copper bath for the deposition of fine-grained ductile copper containing polymers from bifunctional propane derivatives and optionally other bath additives characterized in that it contains polymers as polymers which in the presence of 1 to 50 mol% one or more unsaturated alcohols having 3 to 10 carbon atoms and one or more double and / or triple bonds have been polymerized.
• the molar ratio of polymers from bifunctional propane derivatives to alcohol should be in the range from 2: 1 to 100: 1, preferably 10: 1 to 80: 1.
• the present invention furthermore relates to a process for producing an acidic galvanic copper bath for the deposition of fine-grained ductile copper containing polymers from bifunctional propane derivatives and, if appropriate, other bath additives, characterized in that the bifunctional propane derivatives are present in the presence of 1 to 50 mol%. one or more unsaturated alcohols with 3 to 10 carbon atoms and one or more double and / or triple bonds at a temperature of 100 to 260 ° C. polymerized, the polymer at temperatures below 100 ° C with water and possibly small amounts of a lower Al diluted alcohol and then added to the acid copper bath.
• Substances of the general formulas I and II are particularly suitable as bifunctional propane derivatives. in which X and Y is a hydroxyl group or halogen, but X must not be Y and Z is oxygen, sulfur or a methylene group.
• Typical examples of these substances are monochlorohydrin, epichlorohydrin and glycid (glycidol).
• the bifunctional propane derivatives can be polymerized in a manner known per se by adding catalysts such as protonic acids and Lewis acids.
• catalysts such as protonic acids and Lewis acids.
• Boron trifluoride etherate has proven particularly useful as Lewis acid, but other catalysts are also suitable for the preparation of the polymers used according to the invention.
• the polymers used according to the invention are copolymers of the bifunctional propane derivatives, the end groups of which contain unsaturated alcohols.
• Polymers of glycide are, for example, polyethers with primary or secondary OH groups and terminal groups which belong to an unsaturated alcohol. These polymers are viscous in their pure form and can be used in hot water or in hot water with the addition of lower alcohols. They are added to the copper bath in the form of such aqueous or aqueous-alcoholic solutions. If necessary, the undissolved material is filtered off beforehand.
• the amount of additive according to the invention is not critical. It has been shown that amounts of 0.1 to 1 g of polymer per liter of copper bath are completely sufficient to achieve the desired effect. If the solutions of the polymer are adjusted to a concentration of approximately 2.5% by weight, 4 to 40 ml of this solution per liter of copper bath are sufficient.
• the copper baths according to the invention can be used at current densities between 0.5 and 10 A / dm 2 .
• the copper plating of conductor tracks shows that layer thicknesses are also achieved in the boreholes, which are over 90% of the thickness of the layer thicknesses otherwise achieved.
• circuit boards produced with the copper bath according to the invention with copper coatings of 20 to 30 ⁇ m are subjected to a temperature shock test by heating to 250 ° C. in an oil bath and then cooling again to room temperature, no defects and edge breaks in the copper layer are observed even after 10 cycles .
• Copper foils of 50 ⁇ m thickness produced with the aid of the copper bath according to the invention show measured values in the range from 6 to 20% in the test for elongation at break. These elongation at break values are achieved even after the electrolyte has been in operation for a long time, and therefore no disruptive degradation products are formed in the electrolyte, which lead to a reduced bath service life or reduced quality of the copper coatings.
• Another advantage of the copper baths according to the invention is that instead of the usual concentration of 10 to 20 g / l copper and 100 to 250 g / 1 sulfuric acid, now also at concentrations of 40 to 80 g / l copper and 30 to 80 g / 1 Sulfuric acid can work.
• the copper baths according to the invention can be moved in the usual way by blowing in air.
• the bath temperature is generally 15 to 40 ° C.
• a copper bath of the following composition is produced:
• the copper coatings (20 - 30 ⁇ m) deposited in the above electrolytes on printed circuit boards are subjected to a temperature shock test (ie the material is heated in an oil bath to 250 ° C and then cooled back to room temperature), no defects will occur after 10 cycles (edge breaks) in the copper layer.
• the elongation at break is determined on copper foils (50 ⁇ m) produced in the electrolytes according to the invention, measurement values are obtained which are in the range of 6-20%. It is essential that the elongation at break values remain constant even after a long period of operation of the electrolyte, that is to say that no disruptive degradation products are formed.

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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)

Applications Claiming Priority (2)

Publications (3)

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ID=6210272

Family Applications (1)

Country Status (2)

Cited By (4)

Citations (1)

• 1984
  • 1984-09-25 DE DE8484111402T patent/DE3483078D1/de not_active Expired - Fee Related
  • 1984-09-25 EP EP84111402A patent/EP0137397B1/fr not_active Expired - Lifetime

Patent Citations (1)

Non-Patent Citations (1)

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