EP0168705B1 - Bath and process for electroplating hard gold - Google Patents
Bath and process for electroplating hard gold Download PDFInfo
- Publication number
- EP0168705B1 EP0168705B1 EP85108129A EP85108129A EP0168705B1 EP 0168705 B1 EP0168705 B1 EP 0168705B1 EP 85108129 A EP85108129 A EP 85108129A EP 85108129 A EP85108129 A EP 85108129A EP 0168705 B1 EP0168705 B1 EP 0168705B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- bath
- aqueous solution
- gold
- hard
- solution contains
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 229910052737 gold Inorganic materials 0.000 title claims description 62
- 239000010931 gold Substances 0.000 title claims description 62
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 title claims description 51
- 238000000034 method Methods 0.000 title claims description 12
- 238000009713 electroplating Methods 0.000 title claims 12
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 38
- 239000007864 aqueous solution Substances 0.000 claims description 33
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims description 30
- 238000007747 plating Methods 0.000 claims description 30
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 20
- 229910017052 cobalt Inorganic materials 0.000 claims description 19
- 239000010941 cobalt Substances 0.000 claims description 19
- 229910052759 nickel Inorganic materials 0.000 claims description 19
- 239000000654 additive Substances 0.000 claims description 16
- BJEPYKJPYRNKOW-REOHCLBHSA-N (S)-malic acid Chemical compound OC(=O)[C@@H](O)CC(O)=O BJEPYKJPYRNKOW-REOHCLBHSA-N 0.000 claims description 13
- BJEPYKJPYRNKOW-UHFFFAOYSA-N alpha-hydroxysuccinic acid Natural products OC(=O)C(O)CC(O)=O BJEPYKJPYRNKOW-UHFFFAOYSA-N 0.000 claims description 13
- 239000001630 malic acid Substances 0.000 claims description 13
- 235000011090 malic acid Nutrition 0.000 claims description 13
- XTFKWYDMKGAZKK-UHFFFAOYSA-N potassium;gold(1+);dicyanide Chemical compound [K+].[Au+].N#[C-].N#[C-] XTFKWYDMKGAZKK-UHFFFAOYSA-N 0.000 claims description 11
- 230000000996 additive effect Effects 0.000 claims description 10
- 150000003839 salts Chemical class 0.000 claims description 7
- 238000005507 spraying Methods 0.000 claims description 7
- XFXPMWWXUTWYJX-UHFFFAOYSA-N Cyanide Chemical compound N#[C-] XFXPMWWXUTWYJX-UHFFFAOYSA-N 0.000 claims description 4
- KTVIXTQDYHMGHF-UHFFFAOYSA-L cobalt(2+) sulfate Chemical compound [Co+2].[O-]S([O-])(=O)=O KTVIXTQDYHMGHF-UHFFFAOYSA-L 0.000 claims description 3
- 239000002253 acid Substances 0.000 claims description 2
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical compound [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 claims description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims 1
- 229940099690 malic acid Drugs 0.000 description 9
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 6
- 230000002378 acidificating effect Effects 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 239000002244 precipitate Substances 0.000 description 5
- 239000008139 complexing agent Substances 0.000 description 4
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 3
- 239000000470 constituent Substances 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 238000007545 Vickers hardness test Methods 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 239000010953 base metal Substances 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical compound OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 description 2
- 229910000361 cobalt sulfate Inorganic materials 0.000 description 2
- 229940044175 cobalt sulfate Drugs 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- IZLAVFWQHMDDGK-UHFFFAOYSA-N gold(1+);cyanide Chemical compound [Au+].N#[C-] IZLAVFWQHMDDGK-UHFFFAOYSA-N 0.000 description 2
- 229940116298 l- malic acid Drugs 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- MGFYIUFZLHCRTH-UHFFFAOYSA-N nitrilotriacetic acid Chemical compound OC(=O)CN(CC(O)=O)CC(O)=O MGFYIUFZLHCRTH-UHFFFAOYSA-N 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- VMDSWYDTKFSTQH-UHFFFAOYSA-N sodium;gold(1+);dicyanide Chemical compound [Na+].[Au+].N#[C-].N#[C-] VMDSWYDTKFSTQH-UHFFFAOYSA-N 0.000 description 2
- NWZSZGALRFJKBT-KNIFDHDWSA-N (2s)-2,6-diaminohexanoic acid;(2s)-2-hydroxybutanedioic acid Chemical compound OC(=O)[C@@H](O)CC(O)=O.NCCCC[C@H](N)C(O)=O NWZSZGALRFJKBT-KNIFDHDWSA-N 0.000 description 1
- 229910001020 Au alloy Inorganic materials 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- DSLZVSRJTYRBFB-LLEIAEIESA-N D-glucaric acid Chemical compound OC(=O)[C@@H](O)[C@@H](O)[C@H](O)[C@@H](O)C(O)=O DSLZVSRJTYRBFB-LLEIAEIESA-N 0.000 description 1
- 239000002841 Lewis acid Substances 0.000 description 1
- 229910021586 Nickel(II) chloride Inorganic materials 0.000 description 1
- DAHIGLYZUMACJM-RXMQYKEDSA-N O[C@](N(O)O)(CCC(=O)O)C(=O)O Chemical compound O[C@](N(O)O)(CCC(=O)O)C(=O)O DAHIGLYZUMACJM-RXMQYKEDSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- DUGNCICDIWXNSO-UHFFFAOYSA-K [OH-].[K+].S(=O)(=O)([O-])[O-].[Co+2] Chemical compound [OH-].[K+].S(=O)(=O)([O-])[O-].[Co+2] DUGNCICDIWXNSO-UHFFFAOYSA-K 0.000 description 1
- XOMDKRCFSBGDAM-UHFFFAOYSA-K [OH-].[K+].S(=O)(=O)([O-])[O-].[Ni+2] Chemical compound [OH-].[K+].S(=O)(=O)([O-])[O-].[Ni+2] XOMDKRCFSBGDAM-UHFFFAOYSA-K 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 125000001931 aliphatic group Chemical group 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 239000000872 buffer Substances 0.000 description 1
- 239000007853 buffer solution Substances 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 description 1
- 239000012876 carrier material Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- GVPFVAHMJGGAJG-UHFFFAOYSA-L cobalt dichloride Chemical compound [Cl-].[Cl-].[Co+2] GVPFVAHMJGGAJG-UHFFFAOYSA-L 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- MXZVHYUSLJAVOE-UHFFFAOYSA-N gold(3+);tricyanide Chemical compound [Au+3].N#[C-].N#[C-].N#[C-] MXZVHYUSLJAVOE-UHFFFAOYSA-N 0.000 description 1
- IKDUDTNKRLTJSI-UHFFFAOYSA-N hydrazine monohydrate Substances O.NN IKDUDTNKRLTJSI-UHFFFAOYSA-N 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 150000007517 lewis acids Chemical class 0.000 description 1
- 150000002681 magnesium compounds Chemical class 0.000 description 1
- -1 malic acid) Chemical compound 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910000402 monopotassium phosphate Inorganic materials 0.000 description 1
- 235000019796 monopotassium phosphate Nutrition 0.000 description 1
- QMMRZOWCJAIUJA-UHFFFAOYSA-L nickel dichloride Chemical compound Cl[Ni]Cl QMMRZOWCJAIUJA-UHFFFAOYSA-L 0.000 description 1
- 229910000363 nickel(II) sulfate Inorganic materials 0.000 description 1
- PJNZPQUBCPKICU-UHFFFAOYSA-N phosphoric acid;potassium Chemical compound [K].OP(O)(O)=O PJNZPQUBCPKICU-UHFFFAOYSA-N 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- LOAUVZALPPNFOQ-UHFFFAOYSA-N quinaldic acid Chemical compound C1=CC=CC2=NC(C(=O)O)=CC=C21 LOAUVZALPPNFOQ-UHFFFAOYSA-N 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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
- C25D3/56—Electroplating: Baths therefor from solutions of alloys
- C25D3/62—Electroplating: Baths therefor from solutions of alloys containing more than 50% by weight of gold
-
- 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
- C25D3/48—Electroplating: Baths therefor from solutions of gold
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H11/00—Apparatus or processes specially adapted for the manufacture of electric switches
- H01H11/04—Apparatus or processes specially adapted for the manufacture of electric switches of switch contacts
- H01H11/041—Apparatus or processes specially adapted for the manufacture of electric switches of switch contacts by bonding of a contact marking face to a contact body portion
- H01H2011/046—Apparatus or processes specially adapted for the manufacture of electric switches of switch contacts by bonding of a contact marking face to a contact body portion by plating
Definitions
- the invention relates to an acidic cyanide bath for the galvanic hard gold plating of electrical contact components according to the preamble of claim 1, and methods for the galvanic hard gold plating of electrical contact components using this bath.
- Galvanic gold deposits are characterized by their excellent corrosion resistance and their relatively good electrical properties. These two properties are of particular importance in the case of electrical contact components such as connectors, contacts for relays and switches and the like, since here the galvanically deposited gold layers have to take over the corrosion protection of the carrier material and the loss-free transmission of the energy. Great importance is attached to a low and constant contact resistance. With regard to the mechanical stress on the contact components, the hardness and wear resistance of the gold layers also play an important role. Corresponding abrasion-resistant hard gold layers are mostly produced from baths that contain so-called hardness additives, with the metals cobalt and nickel being used as hardness additives in particular.
- base metals such as cobalt and nickel
- other properties of the deposited layers can also be influenced.
- the base metals diffuse to the surface of the deposited layers and thereby lead to an undesirable increase in the contact resistance.
- the invention is based on an acidic cyanide bath known from DE-PS 3 121 509, which uses potassium gold cyanide as a gold source, malic acid as a conductive salt, nitrilotriacetic acid as a complexing agent, cobalt sulfate as a hardness additive and for adjusting a pH between 3.8 and 4.7 Contains potassium hydroxide.
- the gold layers deposited from this bath are hard and wear-resistant.
- Additive-free bath for galvanic hard gold plating which as the gold source is alkali gold cyanide. contains in particular potassium gold cyanide, potassium dihydrogen phosphate as a buffer system and possibly potassium hydroxide and hydrazine hydrate as a reducing agent.
- the term additive-free bath is intended to express that hardness additives such as cobalt or nickel can be dispensed with entirely or should only be present in small amounts of less than 10 mg / l.
- the gold layers deposited from this additive-free bath are hard, so-called adhesive wear occurs in electrical contact components such as connectors and the like. If there is friction between two such gold layers, they can weld to one another, which then leads to corresponding wear.
- an acidic cyanide gold bath which contains gold as sodium gold cyanide or potassium gold cyanide, cobalt or nickel in the form of a water-soluble salt of a hydroxycarboxylic acid and a mixture contains two hydroxycarboxylic acids - such as citric acid and trihydroxyglutamic acid or malic acid and tetrahydroxyadipic acid.
- pH values between 3.8 and 6.0 and bath temperatures between 20 and 50 ° C shiny gold layers are deposited with current densities between 0.1 and 1.5 A / dm 2 .
- galvanic hard gold plating of parts of mass production - such as electrical contact components - higher current densities or higher deposition rates are required for economical work.
- an acidic cyanide bath for galvanic hard gold plating which in aqueous solution alkali gold cyanide - such as.
- alkali gold cyanide - such as.
- potassium gold cyanide or sodium gold cyanide - a weak Lewis acid - such as. B. quinaldic acid or boric acid -, a weak polyfunctional water-soluble aliphatic acid - such.
- citric acid or malic acid - a non-separating metal compound - such as. B. an aluminum, barium or magnesium compound - and as a hardening additive contains a metal such as cobalt, nickel, cadmium, silver, copper, iron or platinum in the form of a water-soluble salt.
- the hard gold layers are deposited with current densities between 0.05 and 2.1 A / dm 2 .
- a simpler composition of the bath and the achievement of higher current densities would be desirable.
- the invention has for its object to provide a bath for the galvanic hard gold plating of contact components, which has a simple composition and an economy hard and wear-resistant gold layers with low and, above all, constant contact resistance. This object is achieved in a generic bath by the characterizing features of claim 1.
- the invention is based on the finding that in the bath known from DE-PS 3 121 509, the nitrilotriacetic acid provided as a complexing agent can be omitted without substitute, provided that the concentrations specified in the characterizing features of claim 1 are observed for the other constituents of the bath.
- the malic acid contained in the bath according to the invention thus acts simultaneously as a conductive salt, as a buffer and as a complexing agent.
- the gold layers deposited from the bath are hard and wear-resistant and have a low contact resistance.
- the aqueous solution can be free from additions of hardness, whereby matt precipitates are deposited which are hard and wear-resistant and have low contact resistances with a particularly good stability over time.
- the aqueous solution can also contain 30 to 250 mg / l, preferably 40 to 100 mg / l as a hardness additive and approximately 50 mg / l cobalt or 50 to 300 mg / l as an optimum and approximately 100 mg / l as an optimum Contain nickel.
- shiny precipitates are deposited, which are hard and wear-resistant and have low, constant contact resistances over time.
- the current density window in which acceptable precipitation is achieved, is considerably larger than in an additive-free bath.
- the aqueous solution preferably contains the cobalt in the form of cobalt sulfate or the nickel preferably in the form of nickel sulfate.
- the aqueous solution contains 10 to 25 g / l gold, optimal results being achieved at approximately 15 g / l gold.
- the aqueous solution contains 150 to 250 g / l malic acid.
- An optimal quality of the precipitates is achieved when the aqueous solution contains approximately 200 g / l malic acid.
- the aqueous solution contains potassium hydroxide for adjusting a pH between 4.2 and 4.7, preferably for adjusting a pH of approximately 4.5.
- the invention also specifies a preferred method for the galvanic hard gold plating of electrical contact components using an additive-free bath according to the invention. It is provided that the hard gold plating is carried out in a jet plating system at a current density between 2 and 20 A / dm 2 and at a spraying speed of the aqueous solution between 1 and 10 m / s. A particularly good quality of the deposited precipitates is achieved if the hard gold plating is carried out at a current density between 2 and 13 A / dm 2 .
- the invention further specifies a preferred method for the galvanic hard gold plating of electrical contact components using a bath according to the invention containing cobalt or nickel as a hardness additive. It is provided that the hard gold plating is carried out in a jet plating system at a current density between 2 and 45 A / dm 2 and at a spraying speed of the aqueous solution between 1 and 10 m / s. A particularly good quality of the deposited layers is achieved when the hard gold plating with a current density between 2 and. 35 A / dm 2 is carried out.
- the hard gold plating is carried out at a spraying speed of the aqueous solution of approximately 2 m / s. In both cases it is also particularly favorable if the hard gold plating is carried out at a bath temperature between 40 and 65 ° C., preferably between 50 and 60 ° C., a bath temperature of approximately 55 ° C. being regarded as optimal.
- the bath temperature was set to 55 ° C when the jet plating system was in operation.
- the aqueous bath solution with Spr i was tz Oberen of about 2 m / s on the areas to be plated of the plug contacts directed and plating at current densities 2-13 ALDM 2 pre- taken, the cathodic current yield was 90 to 95%.
- Matte_hard gold layers with a layer thickness of approx. 2.5 ⁇ m were deposited, which had very good wear resistance, excellent ductility and a low contact resistance. After storing the plug contacts at an elevated temperature, there was no noticeable increase in the contact resistance.
- the hardness HV (50) was always in the range between 170 and 180 kp / mm 2 .
- the bath temperature was set to 55 ° C and the spraying speed to approx. 2 m / s.
- cathodic current yields between 40 and 70% shining hard gold layers with a layer thickness of approx. 2.5 ⁇ m were deposited, which had very good wear resistance, good ductility and a low contact resistance.
- the measured hardness HV (50) was always in the range between 120 and 180 kp / mm 2 .
- the baths described in Examples 1, 2 and 3 contained no further constituents or additives apart from the constituents indicated.
- similarly good results can be achieved if the cobalt or nickel used as the hardness additive is added in the form of other water-soluble salts, for example in the form of cobalt chloride or nickel chloride.
Landscapes
- 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)
Description
Die Erfindung betrifft ein saures cyanidisches Bad zur galvanischen Hartvergoldung von elektrischen Kontaktbauteilen nach dem Oberbegriff des Anspruchs 1, sowie Verfahren zur galvanischen Hartvergoldung von elektrischen Kontaktbauteilen unter Verwendung dieses Bades.The invention relates to an acidic cyanide bath for the galvanic hard gold plating of electrical contact components according to the preamble of claim 1, and methods for the galvanic hard gold plating of electrical contact components using this bath.
Galvanische Goldniederschläge zeichnen sich durch ihre ausgezeichnete Korrosionsbeständigkeit und ihre relativ guten elektrischen Eigenschaften aus. Diesen beiden Eigenschaften kommt insbesondere bei elektrischen Kontaktbauteilen wie Steckverbindern, Kontakten für Relais und Schalter und dg eine erhöhte Bedeutung zu, da hier die galvanisch abgeschiedenen Goldschichten zum einen den Korrosionsschutz des Trägermaterials und zum andern die verlustfreie Übertragung der Energie übernehmen müssen. Dabei wird auf einen niedrigen und zeitlich konstanten Übergangswiderstand größter Wert gelegt. Im Hinblick auf die mechanische Beanspruchung der Kontaktbauteile spielen aber auch die Härte und Verschleißfestigkeit der Goldschichten eine wesentliche Rolle. Entsprechende abriebbeständige Hartgoldschichten werden meist aus Bädern hergestellt, die sog. Härtezusätze enthalten, wobei in sauren Bädern als Härtezusätze insbesondere die Metalle Kobalt und Nickel verwendet werden. Durch das Zu legieren von Unedelmetallen wie Kobalt und Nickel können neben der erwünschten Steigerung der Härte des Niederschlages aber auch andere Eigenschaften der abgeschiedenen Schichten mit beeinflußt werden. Insbesondere nach einer Lagerung der Kontaktbauteile bei erhöhter Temperatur diffundieren die Unedelmetalle an die Oberfläche der abgeschiedenen Schichten und führen dadurch zu einer unerwünschten Erhöhung des Übergangswiderstandes.Galvanic gold deposits are characterized by their excellent corrosion resistance and their relatively good electrical properties. These two properties are of particular importance in the case of electrical contact components such as connectors, contacts for relays and switches and the like, since here the galvanically deposited gold layers have to take over the corrosion protection of the carrier material and the loss-free transmission of the energy. Great importance is attached to a low and constant contact resistance. With regard to the mechanical stress on the contact components, the hardness and wear resistance of the gold layers also play an important role. Corresponding abrasion-resistant hard gold layers are mostly produced from baths that contain so-called hardness additives, with the metals cobalt and nickel being used as hardness additives in particular. By alloying base metals such as cobalt and nickel, in addition to the desired increase in the hardness of the precipitation, other properties of the deposited layers can also be influenced. In particular after the contact components have been stored at elevated temperature, the base metals diffuse to the surface of the deposited layers and thereby lead to an undesirable increase in the contact resistance.
Die Erfindung geht aus von einem aus der DE-PS 3 121 509 bekannten sauren cyanidischen Bad, welches als Goldquelle Kaliumgoldcyanid, als Leitsalz Apfelsäure, als Komplexbildner Nitrilotriessigsäure, als Härtezusatz Kobaltsulfat und zur Einstellung eines pH-Wertes zwischen 3,8 und 4,7 Kaliumhydroxid enthält. Die aus diesem Bad abgeschiedenen Goldschichten sind hart und verschleißfest.The invention is based on an acidic cyanide bath known from DE-PS 3 121 509, which uses potassium gold cyanide as a gold source, malic acid as a conductive salt, nitrilotriacetic acid as a complexing agent, cobalt sulfate as a hardness additive and for adjusting a pH between 3.8 and 4.7 Contains potassium hydroxide. The gold layers deposited from this bath are hard and wear-resistant.
Aus der EP-OS 0 025 220 ist ein sog. zusatzfreies Bad zur galvanischen Hartvergoldung bekannt, welches als Goldquelle Alkaligoldcyanid. insbesondere Kaliumgoldcyanid, als Puffersystem Kaliumdihydrogenphosphat und ggf. Kaliumhydroxid und als Reduktionsmittel Hydrazinhydrat enthält. Durch die Bezeichnung zusatzfreies Bad soll dabei ausgedrückt werden, daß Härtezusätze wie Kobalt oder Nickel ganz entfallen können bzw. nur in geringen Mengen von weniger als 10 mg/I enthalten sein sollen. Obwohl die aus diesem zusatzfreien Bad abgeschiedenen Goldschichten hart sind, tritt bei elektrischen Kontaktbauteilen wie Steckverbindern und dgl. ein sog. adhäsiver Verschleiß auf. Bei einer Reibung zwischen zwei derartigen Goldschichten können diese miteinander verschweißen, was dann zu einem entsprechenden Verschleiß führt.From EP-OS 0 025 220 a so-called. Additive-free bath for galvanic hard gold plating is known, which as the gold source is alkali gold cyanide. contains in particular potassium gold cyanide, potassium dihydrogen phosphate as a buffer system and possibly potassium hydroxide and hydrazine hydrate as a reducing agent. The term additive-free bath is intended to express that hardness additives such as cobalt or nickel can be dispensed with entirely or should only be present in small amounts of less than 10 mg / l. Although the gold layers deposited from this additive-free bath are hard, so-called adhesive wear occurs in electrical contact components such as connectors and the like. If there is friction between two such gold layers, they can weld to one another, which then leads to corresponding wear.
Aus Chemical Abstracts •, Bd.90, Nr.10, 5. März 1979, Seite 418, Zusammenfassung 78466j ist ein saures cyanidisches Goldbad bekannt, welches Gold als Natriumgoldcyanid oder Kaliumgoldcyanid, Kobalt oder Nickel in Form eines wasserlöslichen Salzes einer Hydroxycarboxylsäure und eine Mischung aus zwei Hydroxycarboxylsäuren - wie Zitronensäure und Trihydroxyglutaminsäure oder Apfelsäure und Tetrahydroxyadipinsäure enthält. Bei pH-Werten zwischen 3,8 und 6,0 und Badtemperaturen zwischen 20 und 50 °C werden mit Stromdichten zwischen 0,1 und 1,5 A/dm2 glänzende Goldschichten abgeschieden. Für eine galvanische Hartvergoldung von Teilen der Massenfertigung - wie elektrischen Kontaktbauteilen - werden für ein wirtschaftliches Arbeiten jedoch höhere Stromdichten bzw. höhere Abscheideraten verlangt.From Chemical Abstracts •, Vol. 90, No. 10, March 5, 1979, page 418, abstract 78466j, an acidic cyanide gold bath is known which contains gold as sodium gold cyanide or potassium gold cyanide, cobalt or nickel in the form of a water-soluble salt of a hydroxycarboxylic acid and a mixture contains two hydroxycarboxylic acids - such as citric acid and trihydroxyglutamic acid or malic acid and tetrahydroxyadipic acid. At pH values between 3.8 and 6.0 and bath temperatures between 20 and 50 ° C, shiny gold layers are deposited with current densities between 0.1 and 1.5 A / dm 2 . For galvanic hard gold plating of parts of mass production - such as electrical contact components - higher current densities or higher deposition rates are required for economical work.
Aus der US-PS 4 075 065 ist ein saures cyanidisches Bad für die galvanische Hartvergoldung bekannt, welches in wäßriger Lösung Alkaligoldcyanid - wie z. B. Kaliumgoldcyanid oder Natriumgoldcyanid - eine schwache Lewis-Säure - wie z. B. Chinaldinsäure oder Borsäure -, eine schwache polyfunktionelle wasserlösliche aliphatische Säure - wie z. B. Zitronensäure oder Apfelsäure -, eine nichtabscheidende Metallverbindung - wie z. B. eine Aluminium-, Barium-oder Magnesiumverbindung - und als Härtezusatz ein Metall wie Kobalt, Nickel, Cadmium, Silber, Kupfer, Eisen oder Platin in Form eines wasserlöslichen Salzes enthält. Bei pH-Werten zwischen 3,7 und 4,8 und Badtemperaturen zwischen 30 und 50 °C werden die Hartgoldschichten mit Stromdichten zwischen 0.05 und 2,1 A/dm2 abgeschieden. Für eine wirtschaftliche galvanische Hartvergoldung von elektrischen Kontaktbauteilen wären jedoch eine einfachere Zusammensetzung des Bades und die Erzielung höherer Stromdichten erwünscht.From US-PS 4 075 065 an acidic cyanide bath for galvanic hard gold plating is known, which in aqueous solution alkali gold cyanide - such as. As potassium gold cyanide or sodium gold cyanide - a weak Lewis acid - such as. B. quinaldic acid or boric acid -, a weak polyfunctional water-soluble aliphatic acid - such. As citric acid or malic acid -, a non-separating metal compound - such as. B. an aluminum, barium or magnesium compound - and as a hardening additive contains a metal such as cobalt, nickel, cadmium, silver, copper, iron or platinum in the form of a water-soluble salt. At pH values between 3.7 and 4.8 and bath temperatures between 30 and 50 ° C, the hard gold layers are deposited with current densities between 0.05 and 2.1 A / dm 2 . For economical galvanic hard gold plating of electrical contact components, however, a simpler composition of the bath and the achievement of higher current densities would be desirable.
Gleiches gilt für die US-PS 3 764 489, worin beschrieben wird, daß eine Legierung aus Gold mit Zinn oder Blei auf eine leitfähige Oberfläche in einem wäßrigen sauren Plattierungsbad abgeschieden wird, welches zwischen 1 und 30 g/l Gold in Form von Kaliumgoldcyanid, 1 bis 100 g/1 Zinn als eine wasserlösliche Komponente, 0,01 bis 1,0 g/I Blei als eine wasserlösliche Komponente und zwischen 5 und 500 g/1 eines Komplexbildners für Zinn (z. B. Apfelsäure), gleichzeitig Elektrolyt für das besagte Bad, enthält. Hierbei wird die besagte leitfähige Oberfläche als Kathode verwendet. Die einsetzbaren Stromstärken liegen zwischen 0,3 und 2,0 A/dm2. Der pH-Wert wird zwischen 3,5 und 5,5 eingestellt.The same applies to US Pat. No. 3,764,489, which describes that an alloy of gold with tin or lead is deposited on a conductive surface in an aqueous acidic plating bath which contains between 1 and 30 g / l gold in the form of potassium gold cyanide, 1 to 100 g / 1 tin as a water-soluble component, 0.01 to 1.0 g / l lead as a water-soluble component and between 5 and 500 g / 1 of a complexing agent for tin (e.g. malic acid), at the same time electrolyte for said bath contains. The said conductive surface is used as the cathode. The current strengths that can be used are between 0.3 and 2.0 A / dm 2 . The pH is adjusted between 3.5 and 5.5.
Der Erfindung liegt die Aufgabe zugrunde, ein Bad zur galvanischen Hartvergoldung von Kontaktbauteilen zu schaffen, welches eine einfache Zusammensetzung aufweist und eine wirtschaftliche Abscheidung harter und verschleißfester Goldschichten mit niedrigem und vor allem zeitlich konstanten Übergangswiderstand ermöglicht. Diese Aufgabe wird bei einem gattungsgemäßen Bad durch die kennzeichnenden Merkmale des Anspruchs 1 gelöst.The invention has for its object to provide a bath for the galvanic hard gold plating of contact components, which has a simple composition and an economy hard and wear-resistant gold layers with low and, above all, constant contact resistance. This object is achieved in a generic bath by the characterizing features of claim 1.
Der Erfindung liegt die Erkenntnis zugrunde, daß bei dem aus der DE-PS 3 121 509 bekannten Bad die als Komplexbildner vorgesehene Nitrilotriessigsäure ersatzlos entfallen kann, sofern für die übrigen Bestandteile des Bades die in den kennzeichnenden Merkmalen des Anspruchs 1 angegebenen Konzentrationen eingehalten werden. Die in dem erfindungsgemäßen Bad enthaltene Apfelsäure wirkt also entsprechend dieser Erkenntnis gleichzeitig als Leitsalz, als Puffer und als Komplexbildner. Hierdurch ergibt sich eine besonders einfache Zusammensetzung des Bades, welches nur noch Kaliumgoldcyanid, Apfelsäure, Kaliumhydroxid und ggf. Kobalt oder Nickel in Form von wasserlöslichen Salzen enthält. Die aus dem Bad abgeschiedenen Goldschichten sind hart und verschleißfest und weisen einen geringen Übergangswiderstand auf. Da Kobalt oder Nickel als Härtezusatz allenfalls in geringen Mengen vorhanden ist und auch auf andere Zusätze verzichtet wird, tritt selbst nach einer Lagerung der hartvergoldeten Kontaktbauteile bei erhöhter Temperatur keine merkliche Erhöhung des Übergangswiderstandes auf. Die äußerst günstigen mechanischen und elektrischen Eigenschaften der Hartgoldschichten sind also auf die einfache Badzusammensetzung bzw. auf das Weglassen bisher üblicher Badbestandteile zurückzuführen.The invention is based on the finding that in the bath known from DE-PS 3 121 509, the nitrilotriacetic acid provided as a complexing agent can be omitted without substitute, provided that the concentrations specified in the characterizing features of claim 1 are observed for the other constituents of the bath. According to this finding, the malic acid contained in the bath according to the invention thus acts simultaneously as a conductive salt, as a buffer and as a complexing agent. This results in a particularly simple composition of the bath, which only contains potassium gold cyanide, malic acid, potassium hydroxide and possibly cobalt or nickel in the form of water-soluble salts. The gold layers deposited from the bath are hard and wear-resistant and have a low contact resistance. Since cobalt or nickel as a hardness additive is only present in small quantities and no other additives are used, there is no noticeable increase in contact resistance even after the hard gold-plated contact components have been stored at elevated temperatures. The extremely favorable mechanical and electrical properties of the hard gold layers can therefore be attributed to the simple bath composition or the omission of previously common bath components.
Bei dem erfindungsgemäßen Bad kann die wäßrige Lösung frei von Härtezusätzen sein, wobei matte Niederschläge abgeschieden werden, die hart und verschleißfest sind und niedrige Übergangswiderstände mit einer besonders guten zeitlichen Konstanz aufweisen.In the bath according to the invention, the aqueous solution can be free from additions of hardness, whereby matt precipitates are deposited which are hard and wear-resistant and have low contact resistances with a particularly good stability over time.
Bei dem erfindungsgemäßen Bad kann die wäßrige Lösung aber auch als Härtezusatz 30 bis 250 mg/l, vorzugsweise 40 bis 100 mg/I und als Optimum ungefähr 50 mg/I Kobalt oder 50 bis 300 mg/1 und als Optimum ungefähr 100 mg/I Nickel enthalten. In diesem Fall werden glänzende Niederschläge abgeschieden, die hart und verschleißfest sind und niedrige, zeitlich konstante Übergangswiderstände aufweisen. Außerdem ist hier das Stromdichtefenster, in dem annehmbare Niederschläge erzielt werden, wesentlich größer als bei einem zusatzfreien Bad.In the bath according to the invention, however, the aqueous solution can also contain 30 to 250 mg / l, preferably 40 to 100 mg / l as a hardness additive and approximately 50 mg / l cobalt or 50 to 300 mg / l as an optimum and approximately 100 mg / l as an optimum Contain nickel. In this case, shiny precipitates are deposited, which are hard and wear-resistant and have low, constant contact resistances over time. In addition, the current density window, in which acceptable precipitation is achieved, is considerably larger than in an additive-free bath.
Bei einem Bad mit Härtezusatz enthält die wäßrige Lösung das Kobalt vorzugsweise in Form von Kobaltsulfat oder das Nickel vorzugsweise in Form von Nickelsulfat.In the case of a bath with added hardness, the aqueous solution preferably contains the cobalt in the form of cobalt sulfate or the nickel preferably in the form of nickel sulfate.
Gemäß einer weiteren bevorzugten Ausgestaltung der Erfindung enthält die wäßrige Lösung 10 bis 25 g/l Gold, wobei optimale Ergebnisse bei ungefähr 15 g/I Gold erzielt werden.According to a further preferred embodiment of the invention, the aqueous solution contains 10 to 25 g / l gold, optimal results being achieved at approximately 15 g / l gold.
Weiterhin ist es vorteilhaft, wenn die wäßrige Lösung 150 bis 250 g/l Apfelsäure enthält. Eine optimale Qualität der Niederschläge wird dabei dann erreicht, wenn die wäßrige Lösung ungefähr 200 g/I Apfelsäure enthält.It is also advantageous if the aqueous solution contains 150 to 250 g / l malic acid. An optimal quality of the precipitates is achieved when the aqueous solution contains approximately 200 g / l malic acid.
Im Hinblick auf die Qualität der abgeschiedenen Niederschläge ist es besonders vorteilhaft, wenn die wäßrige Lösung Kaliumhydroxid zur Einstellung eines pH-Wertes zwischen 4,2 und 4,7, vorzugsweise zur Einstellung eines pH-Wertes von ungefähr 4,5 enthält.With regard to the quality of the deposited precipitates, it is particularly advantageous if the aqueous solution contains potassium hydroxide for adjusting a pH between 4.2 and 4.7, preferably for adjusting a pH of approximately 4.5.
Die Erfindung gibt auch ein bevorzugtes Verfahren zur galvanischen Hartvergoldung von elektrischen Kontaktbauteilen unter Verwendung eines zusatzfreien erfindungsgemäßen Bades an. Dabei ist vorgesehen, daß die Hartvergoldung in einer Jet-Plating-Anlage bei einer Stromdichte zwischen 2 und 20 A/dm2 und bei einer Spritzgeschwindigkeit der wäßrigen Lösung zwischen 1 und 10 m/s durchgeführt wird. Eine besonders gute Qualität der abgeschiedenen Niederschläge wird dabei dann erzielt, wenn die Hartvergoldung bei einer Stromdichte zwischen 2 und 13 A/dm2 durchgeführt wird.The invention also specifies a preferred method for the galvanic hard gold plating of electrical contact components using an additive-free bath according to the invention. It is provided that the hard gold plating is carried out in a jet plating system at a current density between 2 and 20 A / dm 2 and at a spraying speed of the aqueous solution between 1 and 10 m / s. A particularly good quality of the deposited precipitates is achieved if the hard gold plating is carried out at a current density between 2 and 13 A / dm 2 .
Die Erfindung gibt ferner ein bevorzugtes Verfahren zur galvanischen Hartvergoldung von elektrischen Kontaktbauteilen unter Verwendung eines Kobalt oder Nickel als Härtezusatz enthaltenden erfindungsgemäßen Bades an. Dabei ist vorgesehen, daß die Hartvergoldung in einer Jet-Plating-Anlage bei einer Stromdichte zwischen 2 und 45 A/dm2 und bei einer Spritzgeschwindigkeit der wäßrigen Lösung zwischen 1 und 10 m/s durchgeführt wird. Eine besonders gute Qualität der abgeschiedenen Schichten wird dabei dann erzielt, wenn die Hartvergoldung bei einer Stromdichte zwischen 2 und. 35 A/dm2 durchgeführt wird. Bei dem zusatzfreien Bad und bei dem Kobalt oder Nickel als Härtezusatz enthaltenden Bad werden optimale Ergebnisse erzielt, wenn die Hartvergoldung bei einer Spritzgeschwindigkeit der wäßrigen Lösung von ungefähr 2 m/s durchgeführt wird. lri beiden Fällen ist es auch besonders günstig, wenn die Hartvergoldung bei einer Badtemperatur zwischen 40 und 65 °C, vorzugsweise zwischen 50 und 60 °C, durchgeführt wird, wobei eine Badtemperatur von ungefähr 55 °C als optimal angesehen wird.The invention further specifies a preferred method for the galvanic hard gold plating of electrical contact components using a bath according to the invention containing cobalt or nickel as a hardness additive. It is provided that the hard gold plating is carried out in a jet plating system at a current density between 2 and 45 A / dm 2 and at a spraying speed of the aqueous solution between 1 and 10 m / s. A particularly good quality of the deposited layers is achieved when the hard gold plating with a current density between 2 and. 35 A / dm 2 is carried out. In the case of the additive-free bath and the bath containing cobalt or nickel as hardness additive, optimal results are achieved if the hard gold plating is carried out at a spraying speed of the aqueous solution of approximately 2 m / s. In both cases it is also particularly favorable if the hard gold plating is carried out at a bath temperature between 40 and 65 ° C., preferably between 50 and 60 ° C., a bath temperature of approximately 55 ° C. being regarded as optimal.
Die folgenden Beispiele dienen zur weiteren Erläuterung der Erfindung.The following examples serve to further explain the invention.
In einer Jet-Plating-Anlage wurde zur galvanischen Hartvergoldung von Steckkontakten ein zusatzfreies Bad eingesetzt, das folgende Bestandteile in wäßriger Lösung enthielt :
- 15 gll ... reines Gold in Form von Kaliumgoldcyanid
- 200 g/l ... Apfelsäure Kaliumhydroxid in der zur Einstellung eines pH-Wertes von 4,5 erforderlichen Menge.
- 15 gll ... pure gold in the form of potassium gold cyanide
- 200 g / l ... malic acid potassium hydroxide in the amount required to adjust the pH to 4.5.
Beim Betrieb der Jet-Plating-Anlage wurde die Badtemperatur auf 55 °C eingestellt. Über die Spritzdüsen der Jet-Plating-Anlage wurde die wäßrige Badlösung mit Spritzgeschwindigkeiten von ca. 2 m/s auf die zu galvanisierenden Bereiche der Steckkontakte gerichtet und die Plattierung bei Stromdichten zwischen 2 und 13 Aldm2 vorgenommen, wobei die kathodische Stromausbeute bei 90 bis 95% lag. Es wurden matte_Hartgoldschichten mit einer Schichtstärke von ca. 2,5 µm abgeschieden, die eine sehr gute Verschleißfestigkeit, eine ausgezeichnete Duktilität und einen niedrigen Übergangswiderstand aufwiesen. Nach einer Lagerung der Steckkontakte bei erhöhter Temperatur konnte keine merkliche Erhöhung des Übergangswiderstandes festgestellt werden. Bei der Vickers-Härteprüfung der abgeschiedenen Hartgoldschichten mit einem Gewicht des Eindringkörpers von 50 g lag die Härte HV (50) stets im Bereich zwischen 170 und 180 kp/mm2.The bath temperature was set to 55 ° C when the jet plating system was in operation. Via the spray nozzles of the jet-plating plant, the aqueous bath solution with Spr i was tzgeschwindigkeiten of about 2 m / s on the areas to be plated of the plug contacts directed and plating at current densities 2-13 ALDM 2 pre- taken, the cathodic current yield was 90 to 95%. Matte_hard gold layers with a layer thickness of approx. 2.5 µm were deposited, which had very good wear resistance, excellent ductility and a low contact resistance. After storing the plug contacts at an elevated temperature, there was no noticeable increase in the contact resistance. In the Vickers hardness test of the deposited hard gold layers with a weight of the indenter of 50 g, the hardness HV (50) was always in the range between 170 and 180 kp / mm 2 .
In einer Jet-Plating-Anlage wurde zur galvanischen Hartvergoldung von Steckkontakten ein Bad eingesetzt, das folgende Bestandteile in wäßriger Lösung enthielt :
- 15 g/l ... reines Gold in Form von Kaliumgoldcyanid
- 200 g/l ... Apfelsäure
- 50 mg/l reines Kobalt in Form von Kobaltsulfat Kaliumhydroxid in der zur Einstellung eines pH-Wertes von 4.5 erforderlichen Menge.
- 15 g / l ... pure gold in the form of potassium gold cyanide
- 200 g / l ... malic acid
- 50 mg / l pure cobalt in the form of cobalt sulfate potassium hydroxide in the amount required to adjust the pH to 4.5.
Beim Betrieb der Jet-Plating-Anlage wurde die Badtemperatur auf 55 °C und die Spritzgeschwindigkeit auf ca. 2 m/s eingestellt. In einem Stromdichtebereich zwischen 2 und 35 A/dm2 wurden bei kathodischen Stromausbeuten zwischen 40 und 70 % glänzende Hartgoldschichten mit einer Schichtstärke von ca. 2,5 µm abgeschieden, die eine sehr gute Verschleißfestigkeit, eine gute Duktilität und einen niedrigen Übergangswiderstand aufwiesen. Nach einer Lagerung der Steckkontakte bei erhöhter Temperatur konnte keine merkliche Erhöhung des Übergangswiderstandes festgestellt werden. Bei der Vickers-Härteprüfung lag die gemessene Härte HV (50) stets im Bereich zwischen 120 und 180 kp/mm2.When operating the jet plating system, the bath temperature was set to 55 ° C and the spraying speed to approx. 2 m / s. In a current density range between 2 and 35 A / dm 2 , cathodic current yields between 40 and 70% shining hard gold layers with a layer thickness of approx. 2.5 µm were deposited, which had very good wear resistance, good ductility and a low contact resistance. After storing the plug contacts at an elevated temperature, there was no noticeable increase in the contact resistance. In the Vickers hardness test, the measured hardness HV (50) was always in the range between 120 and 180 kp / mm 2 .
In einer Jet-Plating-Anlage wurde zur galvanischen Hartvergoldung von Steckkontakten ein Bad eingesetzt, das folgende Bestandteile in wäßriger Lösung enthielt :
- 15 g/l ... reines Gold in Form von Kaliumgoldcyanid
- 200 g/l ... Apfelsäure
- 100 mg/I ... reines Nickel in Form von Nickelsulfat Kaliumhydroxid in der zur Einstellung eines pH-Wertes von 4,5 erforderlichen Menge.
- 15 g / l ... pure gold in the form of potassium gold cyanide
- 200 g / l ... malic acid
- 100 mg / I ... pure nickel in the form of nickel sulfate potassium hydroxide in the amount required to set a pH value of 4.5.
Die galvanische Abscheidung glänzender Hartgoldschichten erfolgt mit den im Beispiel 2 angegebenen Parametern. Im Hinblick auf die Verschleißfestigkeit, die Duktilität, den Übergangswiderstand und die Härte der Hartgoldschichten konnten die im Beispiel 2 angegebenen Ergebnisse nahezu erreicht werden.The galvanic deposition of shiny hard gold layers takes place with the parameters given in example 2. With regard to wear resistance, ductility, contact resistance and hardness of the hard gold layers, the results given in Example 2 could almost be achieved.
Die in den Beispielen 1, 2 und 3 beschriebenen Bäder enthielten außer den angegebenen Bestandteilen keine weiteren Bestandteile oder Zusätze. Bei den in den Beispielen 2 und 3 geschilderten Bädern können ähnlich gute Ergebnisse erzielt werden, wenn das als Härtezusatz verwendete Kobalt oder Nickel in Form anderer wasserlöslicher Salze, beispielsweise in Form von Kobaltchlorid oder Nickelchlorid zugegeben wird.The baths described in Examples 1, 2 and 3 contained no further constituents or additives apart from the constituents indicated. In the baths described in Examples 2 and 3, similarly good results can be achieved if the cobalt or nickel used as the hardness additive is added in the form of other water-soluble salts, for example in the form of cobalt chloride or nickel chloride.
Claims (23)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT85108129T ATE38061T1 (en) | 1984-07-05 | 1985-07-01 | BATH AND PROCESS FOR ELECTROPLATING HARD GOLD. |
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3424757 | 1984-07-05 | ||
| DE3424757 | 1984-07-05 | ||
| DE3509245 | 1985-03-14 | ||
| DE19853509245 DE3509245A1 (en) | 1985-03-14 | 1985-03-14 | Bath and process for hard gold electroplating |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0168705A1 EP0168705A1 (en) | 1986-01-22 |
| EP0168705B1 true EP0168705B1 (en) | 1988-10-19 |
Family
ID=25822654
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP85108129A Expired EP0168705B1 (en) | 1984-07-05 | 1985-07-01 | Bath and process for electroplating hard gold |
Country Status (2)
| Country | Link |
|---|---|
| EP (1) | EP0168705B1 (en) |
| DE (1) | DE3565697D1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN120666187B (en) * | 2025-08-21 | 2025-11-25 | 长春黄金研究院有限公司 | Low cyanide gold leaching agent system and heap leaching process thereof |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH494284A (en) * | 1968-11-28 | 1970-07-31 | Sel Rex Corp | Process for the electrolytic deposition of a gold alloy with at least one other common metal and aqueous plating bath for carrying out this process |
| PL86754B1 (en) * | 1974-12-11 | 1977-12-15 | ||
| US4075065A (en) * | 1975-07-07 | 1978-02-21 | Handy & Harman | Gold plating bath and process |
| DE3121509C2 (en) * | 1981-05-29 | 1983-04-14 | Siemens AG, 1000 Berlin und 8000 München | Bath for galvanic hard gold plating |
-
1985
- 1985-07-01 DE DE8585108129T patent/DE3565697D1/en not_active Expired
- 1985-07-01 EP EP85108129A patent/EP0168705B1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE3565697D1 (en) | 1988-11-24 |
| EP0168705A1 (en) | 1986-01-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE2355581C3 (en) | Galvanic bright gold bath with high deposition rate | |
| AT514818B1 (en) | Deposition of Cu, Sn, Zn coatings on metallic substrates | |
| DE1233693B (en) | Process for the electroless deposition of firmly adhering tin coatings on aluminum | |
| EP1413646A2 (en) | Process for electroless plating of metals | |
| DE102008033174B3 (en) | Cyanide-free electrolyte composition for the electrodeposition of a copper layer and method for the deposition of a copper-containing layer | |
| DE3821073A1 (en) | Method for electroplating objects made of aluminium or aluminium alloys with a preferably solderable metal coating | |
| DE60202378T2 (en) | ELECTROLYTIC BATH FOR THE ELECTROCHEMICAL SEPARATION OF GOLD AND GOLD ALLOYS | |
| DE3012999C2 (en) | Bath and process for the galvanic deposition of high-gloss and ductile gold alloy coatings | |
| DE60111727T2 (en) | COMPLEX PALLADIUM SALT AND ITS USE FOR ADAPTING THE PALLADIUM CONCENTRATION IN ELECTROLYTIC BATHS DETERMINED FOR THE DISPOSAL OF PALLADIUM OR ONE OF ITS ALLOYS | |
| AT514427B1 (en) | Electrolyte bath and thus available objects or articles | |
| DE3013191A1 (en) | IN THE ESSENTIAL CYANIDE-FREE BATH FOR THE ELECTROLYTIC DEPOSITION OF SILVER OR SILVER ALLOY | |
| DE3147823A1 (en) | "BATH FOR GALVANIC DEPOSITION OF PALLADIUM OR PALLADIUM ALLOYS AND A METHOD FOR DEPOSITING PALLADIUM OR PALLADIUM ALLOYS WITH THIS BATH" | |
| DE3244092A1 (en) | AQUEOUS BATH FOR GALVANIC DEPOSITION OF GOLD AND METHOD FOR GALVANIC DEPOSIT OF HARD GOLD USING ITS USE | |
| EP3067444B1 (en) | Deposition of decorative palladium iron alloy coatings on metallic substances | |
| CH717790B1 (en) | Process for galvanically silver-plating contact elements for connectors and contact elements silver-plated using this process. | |
| EP0149029A1 (en) | Palladium bath | |
| EP0168705B1 (en) | Bath and process for electroplating hard gold | |
| DE2930035A1 (en) | AQUEOUS GALVANIC BATH | |
| DE3139815A1 (en) | "METHOD FOR MAINTAINING A GOLD COATING WITH IMPROVED CORROSION RESISTANCE ON A SUBSTRATE" | |
| DE2002836A1 (en) | Process for the continuous production of wire-shaped material which is coated with a single layer of nickel or a double layer of nickel and gold | |
| DE102020133188B4 (en) | Use of a silver-bismuth electrolyte for the deposition of hard silver layers | |
| DE3509245A1 (en) | Bath and process for hard gold electroplating | |
| DE69011549T2 (en) | Electroplating alloys containing gold. | |
| DE2439656C2 (en) | Aqueous acid bath for the electrodeposition of a tin-nickel alloy | |
| CH680449A5 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
| AK | Designated contracting states |
Designated state(s): AT BE CH DE FR GB IT LI NL SE |
|
| 17P | Request for examination filed |
Effective date: 19860709 |
|
| 17Q | First examination report despatched |
Effective date: 19870610 |
|
| R17C | First examination report despatched (corrected) |
Effective date: 19870610 |
|
| GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
| AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT BE CH DE FR GB IT LI NL SE |
|
| REF | Corresponds to: |
Ref document number: 38061 Country of ref document: AT Date of ref document: 19881115 Kind code of ref document: T |
|
| GBT | Gb: translation of ep patent filed (gb section 77(6)(a)/1977) | ||
| REF | Corresponds to: |
Ref document number: 3565697 Country of ref document: DE Date of ref document: 19881124 |
|
| ET | Fr: translation filed | ||
| ITF | It: translation for a ep patent filed | ||
| PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
| STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
| 26N | No opposition filed | ||
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 19900614 Year of fee payment: 6 |
|
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: AT Payment date: 19900704 Year of fee payment: 6 |
|
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: BE Payment date: 19900719 Year of fee payment: 6 |
|
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 19900724 Year of fee payment: 6 |
|
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: SE Payment date: 19900727 Year of fee payment: 6 |
|
| ITTA | It: last paid annual fee | ||
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: NL Payment date: 19900731 Year of fee payment: 6 |
|
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 19900919 Year of fee payment: 6 |
|
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: CH Payment date: 19901024 Year of fee payment: 6 |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Effective date: 19910701 Ref country code: AT Effective date: 19910701 |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Effective date: 19910702 |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LI Effective date: 19910731 Ref country code: CH Effective date: 19910731 Ref country code: BE Effective date: 19910731 |
|
| BERE | Be: lapsed |
Owner name: SIEMENS A.G. BERLIN UND MUNCHEN Effective date: 19910731 |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Effective date: 19920201 |
|
| GBPC | Gb: european patent ceased through non-payment of renewal fee | ||
| NLV4 | Nl: lapsed or anulled due to non-payment of the annual fee | ||
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Effective date: 19920331 |
|
| REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Effective date: 19920401 |
|
| REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST |
|
| EUG | Se: european patent has lapsed |
Ref document number: 85108129.9 Effective date: 19920210 |