GB2089374A - Electrodeposition of palladium and palladium alloys - Google Patents
Electrodeposition of palladium and palladium alloys Download PDFInfo
- Publication number
- GB2089374A GB2089374A GB8137456A GB8137456A GB2089374A GB 2089374 A GB2089374 A GB 2089374A GB 8137456 A GB8137456 A GB 8137456A GB 8137456 A GB8137456 A GB 8137456A GB 2089374 A GB2089374 A GB 2089374A
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- United Kingdom
- Prior art keywords
- palladium
- electroplating bath
- bath
- metal
- present
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- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical group [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 title claims abstract description 89
- 229910052763 palladium Inorganic materials 0.000 title claims abstract description 45
- 229910001252 Pd alloy Inorganic materials 0.000 title claims abstract description 9
- 238000004070 electrodeposition Methods 0.000 title description 4
- 238000009713 electroplating Methods 0.000 claims abstract description 31
- -1 palladium amine compounds Chemical class 0.000 claims abstract description 23
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 20
- 150000001412 amines Chemical class 0.000 claims abstract description 13
- 239000000203 mixture Substances 0.000 claims abstract description 12
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 claims abstract description 11
- 239000004327 boric acid Substances 0.000 claims abstract description 11
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims abstract description 8
- 239000000908 ammonium hydroxide Substances 0.000 claims abstract description 8
- 239000000872 buffer Substances 0.000 claims abstract description 8
- 229910021529 ammonia Inorganic materials 0.000 claims abstract description 6
- 238000000034 method Methods 0.000 claims abstract description 6
- 229910052751 metal Inorganic materials 0.000 claims description 38
- 239000002184 metal Substances 0.000 claims description 38
- 238000005275 alloying Methods 0.000 claims description 18
- 150000003839 salts Chemical class 0.000 claims description 15
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 9
- 229910052783 alkali metal Inorganic materials 0.000 claims description 9
- 125000003118 aryl group Chemical group 0.000 claims description 7
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 claims description 5
- 229910002651 NO3 Inorganic materials 0.000 claims description 5
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 claims description 5
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 5
- 150000001340 alkali metals Chemical class 0.000 claims description 5
- 239000000758 substrate Substances 0.000 claims description 5
- 229910021653 sulphate ion Inorganic materials 0.000 claims description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 4
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 4
- 229910052759 nickel Inorganic materials 0.000 claims description 4
- 229910052709 silver Inorganic materials 0.000 claims description 4
- 239000004332 silver Substances 0.000 claims description 4
- 229910052725 zinc Inorganic materials 0.000 claims description 4
- 239000011701 zinc Substances 0.000 claims description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 3
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 3
- 150000001732 carboxylic acid derivatives Chemical class 0.000 claims description 3
- 229910052802 copper Inorganic materials 0.000 claims description 3
- 239000010949 copper Substances 0.000 claims description 3
- 125000002924 primary amino group Chemical class [H]N([H])* 0.000 claims description 3
- IOVCWXUNBOPUCH-UHFFFAOYSA-M Nitrite anion Chemical compound [O-]N=O IOVCWXUNBOPUCH-UHFFFAOYSA-M 0.000 claims description 2
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 2
- 150000001408 amides Chemical class 0.000 claims description 2
- ONBDEXUUNGGFRN-UHFFFAOYSA-N amino nitrite Chemical compound NON=O.NON=O ONBDEXUUNGGFRN-UHFFFAOYSA-N 0.000 claims description 2
- JXLHNMVSKXFWAO-UHFFFAOYSA-N azane;7-fluoro-2,1,3-benzoxadiazole-4-sulfonic acid Chemical compound N.OS(=O)(=O)C1=CC=C(F)C2=NON=C12 JXLHNMVSKXFWAO-UHFFFAOYSA-N 0.000 claims description 2
- 229910052793 cadmium Inorganic materials 0.000 claims description 2
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 claims description 2
- 229910017052 cobalt Inorganic materials 0.000 claims description 2
- 239000010941 cobalt Substances 0.000 claims description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 2
- 229910052737 gold Inorganic materials 0.000 claims description 2
- 239000010931 gold Substances 0.000 claims description 2
- 150000004820 halides Chemical group 0.000 claims description 2
- 150000003949 imides Chemical class 0.000 claims description 2
- 229910052738 indium Inorganic materials 0.000 claims description 2
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 claims description 2
- 229910052742 iron Inorganic materials 0.000 claims description 2
- IIACRCGMVDHOTQ-UHFFFAOYSA-M sulfamate Chemical compound NS([O-])(=O)=O IIACRCGMVDHOTQ-UHFFFAOYSA-M 0.000 claims description 2
- 239000011135 tin Substances 0.000 claims description 2
- 229910052718 tin Inorganic materials 0.000 claims description 2
- 239000002659 electrodeposit Substances 0.000 claims 1
- IIACRCGMVDHOTQ-UHFFFAOYSA-N sulfamic acid Chemical class NS(O)(=O)=O IIACRCGMVDHOTQ-UHFFFAOYSA-N 0.000 claims 1
- BDHFUVZGWQCTTF-UHFFFAOYSA-N sulfonic acid Chemical compound OS(=O)=O BDHFUVZGWQCTTF-UHFFFAOYSA-N 0.000 claims 1
- BTBUEUYNUDRHOZ-UHFFFAOYSA-N Borate Chemical compound [O-]B([O-])[O-] BTBUEUYNUDRHOZ-UHFFFAOYSA-N 0.000 abstract description 7
- 238000006386 neutralization reaction Methods 0.000 abstract description 4
- 150000008044 alkali metal hydroxides Chemical class 0.000 abstract 1
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 8
- 238000001556 precipitation Methods 0.000 description 7
- 230000002028 premature Effects 0.000 description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 4
- 235000019270 ammonium chloride Nutrition 0.000 description 4
- 150000001642 boronic acid derivatives Chemical class 0.000 description 4
- 150000002739 metals Chemical class 0.000 description 4
- 229910000069 nitrogen hydride Inorganic materials 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- LPXPTNMVRIOKMN-UHFFFAOYSA-M sodium nitrite Chemical compound [Na+].[O-]N=O LPXPTNMVRIOKMN-UHFFFAOYSA-M 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 238000009472 formulation Methods 0.000 description 3
- YWYZEGXAUVWDED-UHFFFAOYSA-N triammonium citrate Chemical compound [NH4+].[NH4+].[NH4+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O YWYZEGXAUVWDED-UHFFFAOYSA-N 0.000 description 3
- PAWQVTBBRAZDMG-UHFFFAOYSA-N 2-(3-bromo-2-fluorophenyl)acetic acid Chemical compound OC(=O)CC1=CC=CC(Br)=C1F PAWQVTBBRAZDMG-UHFFFAOYSA-N 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 238000011065 in-situ storage Methods 0.000 description 2
- LVIYYTJTOKJJOC-UHFFFAOYSA-N nickel phthalocyanine Chemical compound [Ni+2].C12=CC=CC=C2C(N=C2[N-]C(C3=CC=CC=C32)=N2)=NC1=NC([C]1C=CC=CC1=1)=NC=1N=C1[C]3C=CC=CC3=C2[N-]1 LVIYYTJTOKJJOC-UHFFFAOYSA-N 0.000 description 2
- 235000021317 phosphate Nutrition 0.000 description 2
- 150000003013 phosphoric acid derivatives Chemical class 0.000 description 2
- 238000007747 plating Methods 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- FGIUAXJPYTZDNR-UHFFFAOYSA-N potassium nitrate Chemical compound [K+].[O-][N+]([O-])=O FGIUAXJPYTZDNR-UHFFFAOYSA-N 0.000 description 2
- VWDWKYIASSYTQR-UHFFFAOYSA-N sodium nitrate Chemical compound [Na+].[O-][N+]([O-])=O VWDWKYIASSYTQR-UHFFFAOYSA-N 0.000 description 2
- 235000010288 sodium nitrite Nutrition 0.000 description 2
- HMRJQTZQGGNCCJ-UHFFFAOYSA-M zinc azanide acetate Chemical compound C(C)(=O)[O-].N[Zn+] HMRJQTZQGGNCCJ-UHFFFAOYSA-M 0.000 description 2
- FTLYMKDSHNWQKD-UHFFFAOYSA-N (2,4,5-trichlorophenyl)boronic acid Chemical class OB(O)C1=CC(Cl)=C(Cl)C=C1Cl FTLYMKDSHNWQKD-UHFFFAOYSA-N 0.000 description 1
- XVWFIMLHNWYMKY-UHFFFAOYSA-N 2-[2-[bis(carboxymethyl)amino]ethyl-(carboxymethyl)amino]acetic acid;cobalt Chemical compound [Co].OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O XVWFIMLHNWYMKY-UHFFFAOYSA-N 0.000 description 1
- FMYBFLOWKQRBST-UHFFFAOYSA-N 2-[bis(carboxymethyl)amino]acetic acid;nickel Chemical compound [Ni].OC(=O)CN(CC(O)=O)CC(O)=O FMYBFLOWKQRBST-UHFFFAOYSA-N 0.000 description 1
- GEHMBYLTCISYNY-UHFFFAOYSA-N Ammonium sulfamate Chemical compound [NH4+].NS([O-])(=O)=O GEHMBYLTCISYNY-UHFFFAOYSA-N 0.000 description 1
- 229910001369 Brass Inorganic materials 0.000 description 1
- 229910000906 Bronze Inorganic materials 0.000 description 1
- RPNUMPOLZDHAAY-UHFFFAOYSA-N Diethylenetriamine Chemical compound NCCNCCN RPNUMPOLZDHAAY-UHFFFAOYSA-N 0.000 description 1
- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical compound NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 description 1
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- WINXNKPZLFISPD-UHFFFAOYSA-M Saccharin sodium Chemical compound [Na+].C1=CC=C2C(=O)[N-]S(=O)(=O)C2=C1 WINXNKPZLFISPD-UHFFFAOYSA-M 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 150000001339 alkali metal compounds Chemical class 0.000 description 1
- 229910001508 alkali metal halide Inorganic materials 0.000 description 1
- 150000008045 alkali metal halides Chemical class 0.000 description 1
- 229910000318 alkali metal phosphate Inorganic materials 0.000 description 1
- 150000001341 alkaline earth metal compounds Chemical class 0.000 description 1
- CAMXVZOXBADHNJ-UHFFFAOYSA-N ammonium nitrite Chemical compound [NH4+].[O-]N=O CAMXVZOXBADHNJ-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910021538 borax Inorganic materials 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 239000010974 bronze Substances 0.000 description 1
- 150000001860 citric acid derivatives Chemical class 0.000 description 1
- KUNSUQLRTQLHQQ-UHFFFAOYSA-N copper tin Chemical compound [Cu].[Sn] KUNSUQLRTQLHQQ-UHFFFAOYSA-N 0.000 description 1
- 150000004985 diamines Chemical class 0.000 description 1
- UQGFMSUEHSUPRD-UHFFFAOYSA-N disodium;3,7-dioxido-2,4,6,8,9-pentaoxa-1,3,5,7-tetraborabicyclo[3.3.1]nonane Chemical compound [Na+].[Na+].O1B([O-])OB2OB([O-])OB1O2 UQGFMSUEHSUPRD-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 229910001092 metal group alloy Inorganic materials 0.000 description 1
- PSZYNBSKGUBXEH-UHFFFAOYSA-N naphthalene-1-sulfonic acid Chemical compound C1=CC=C2C(S(=O)(=O)O)=CC=CC2=C1 PSZYNBSKGUBXEH-UHFFFAOYSA-N 0.000 description 1
- BSIDXUHWUKTRQL-UHFFFAOYSA-N nickel palladium Chemical compound [Ni].[Pd] BSIDXUHWUKTRQL-UHFFFAOYSA-N 0.000 description 1
- 239000010955 niobium Substances 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 150000002826 nitrites Chemical class 0.000 description 1
- 238000010979 pH adjustment Methods 0.000 description 1
- 150000002940 palladium Chemical class 0.000 description 1
- PIBWKRNGBLPSSY-UHFFFAOYSA-L palladium(II) chloride Chemical compound Cl[Pd]Cl PIBWKRNGBLPSSY-UHFFFAOYSA-L 0.000 description 1
- 239000001508 potassium citrate Substances 0.000 description 1
- 229960002635 potassium citrate Drugs 0.000 description 1
- QEEAPRPFLLJWCF-UHFFFAOYSA-K potassium citrate (anhydrous) Chemical compound [K+].[K+].[K+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O QEEAPRPFLLJWCF-UHFFFAOYSA-K 0.000 description 1
- 235000011082 potassium citrates Nutrition 0.000 description 1
- 239000004323 potassium nitrate Substances 0.000 description 1
- 235000010333 potassium nitrate Nutrition 0.000 description 1
- OTYBMLCTZGSZBG-UHFFFAOYSA-L potassium sulfate Chemical compound [K+].[K+].[O-]S([O-])(=O)=O OTYBMLCTZGSZBG-UHFFFAOYSA-L 0.000 description 1
- 229910052939 potassium sulfate Inorganic materials 0.000 description 1
- 239000001120 potassium sulphate Substances 0.000 description 1
- 235000011151 potassium sulphates Nutrition 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000004317 sodium nitrate Substances 0.000 description 1
- 235000010344 sodium nitrate Nutrition 0.000 description 1
- 159000000000 sodium salts Chemical class 0.000 description 1
- 239000004328 sodium tetraborate Substances 0.000 description 1
- 235000010339 sodium tetraborate Nutrition 0.000 description 1
- HIEHAIZHJZLEPQ-UHFFFAOYSA-M sodium;naphthalene-1-sulfonate Chemical compound [Na+].C1=CC=C2C(S(=O)(=O)[O-])=CC=CC2=C1 HIEHAIZHJZLEPQ-UHFFFAOYSA-M 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- 150000003892 tartrate salts Chemical class 0.000 description 1
- AGGKEGLBGGJEBZ-UHFFFAOYSA-N tetramethylenedisulfotetramine Chemical compound C1N(S2(=O)=O)CN3S(=O)(=O)N1CN2C3 AGGKEGLBGGJEBZ-UHFFFAOYSA-N 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
- C25D3/50—Electroplating: Baths therefor from solutions of platinum group metals
-
- 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
- C25D3/567—Electroplating: Baths therefor from solutions of alloys containing more than 50% by weight of platinum group metals
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)
Abstract
Improved compositions and method for electrodepositing palladium and palladium alloys utilizing palladium amine compounds are described. The improvement comprises maintaining the electroplating bath at a pH ranging from about 6.5 to 9.5 during operations with a borate buffer resulting from the neutralization of boric acid with ammonia, ammonium hydroxide, and alkali metal hydroxide or an amine.
Description
SPECIFICATION Electrodeposition of palladium and palladium alloys
The present invention relates to compositions and methods for the electrodeposition of palladium metal or alloys on substrates from baths utilizing palladium in the form of palladium amine compounds such as pailadous amine chloride, i.e. Pd(NH3)2CI3.
There is a considerable body of prior art dealing with the electrodeposition of palladium metal and its alloys on substrates. This art is represented by the following U.S. Patents: 3,530,050 -- Hill et al.
3,580,820 -- Yamamura et al.
3,677,909 -- Yamamura et al.
4,066,517 -- Stevens et al.
4,098,656 -- Deuber It is apparent from these references that the palladium metal component of the electroplating bath, whether employed alone or in conjunction with an alloying metal, is advantageously in the form of amine complex salts such as, for example, palladous amine chloride and palladium diamine dinitrite.
The amine palladium and palladium alloy electrolytes or electroplating baths disclosed in the prior art are normally operated at a pH within the range of about 6.5 and 10.0. Unfortunately these baths with use become difficult to operate when heated to temperatures of from about 200 to 700C because the pH tends to drop to pH 5 or lower. Once the pH drops to these levels premature precipitation of the palladium metal salt as well as the alloying metal salt occurs. It has been suggested previously that this undesirable drop in pH might be avoided by utilizing buffers such as ammonium or alkali metal phosphates. However, the use of such buffers had the untoward effect of causing undesirable precipitation of these metals as phosphates.Consequently, the main problem associated with use of amine palladium complex electrolytes is the necessity of frequent pH adjustment and premature precipitation of the palladium and/or its alloying metal.
This invention aims to provide electroplating baths containing palladium amine complexes alone or with an alloying metal compound which are less liable to an undesirable drop of the pH during operation.
This invention also aims te provide a palladium amine complex-containing electroplating bath wherein the tendency to premature precipitation of the palladium or alloying metal salts is lessened.
In accordance with the present invention it has now been found that pH stability can be improved, while lessening the tendency to premature precipitation of palladium metal or alloying metal salts, by utilizing a borate buffer in formulating the electroplating bath. The borate buffer is used in an amount sufficient to bring the bath to a pH within the range of about 6.5 to 9.5. This pH will not drop to pH 5 or lower under actual operating conditions utilizing conventional palladium metal plating temperatures of from about 20" to 750C and current densities ranging from about 1 to 100 ASF (0.1 1 to 11 ASD), preferably 3 to 50 ASF (0.32 to 5.4 ASD).Consequently, the premature precipitation of palladium or alloying metal salt is avoided through the maintenance of the desired pH range in the bath; and, in addition, the special borates employed in the practice of the present invention do not have the tendency to form metal salts which would undesirably precipitate and interfere with the normal functioning of the electroplating bath.
The borates employed for the present purposes are formed by the neutralization of boric acid with an alkali metal, ammonia, ammonium hydroxide, or an amine. The neutralization can be conducted either in situ, i.e. during formation of the bath, or as a separate step with the thus formed borate used as a component of the bath. The neutralization of the boric acid can be carried out, as described above, with the following substances, ammonia; ammonium hydroxide; alkali or alkaline earth metal compounds such as sodium hydroxide or potassium hydroxide; or an amine such as ethylene diamine or diethylene triamine. Preferred borates are sodium tetraborate and ammonium biborate.
Preferably the borate is formed in situ where the allcaline reactant is used in an amount not only sufficient to convert the boric acid, usually about 10 to 50 g/l, to the corresponding borate but also sufficient to raise or adjust the initial pH of the newly formulated electroplating bath to about 6.5 to 9.5.
The palladium amine complex can either be the halide, nitrite, nitrate, sulphate, or sulphamate.
Illustrativs complexes include the following
Palladous diamine chloride [Pd(NH3)2C13] Palladium diamine dinitrite [Pd(NH3)2(NO2)21 Palladium tetramine nitrate [Pd(NH )4(NO)2] Palladium diamine sulphate [Pd(NH3)2S04] Other palladium salts may be utilized for example dichlorodiamine palladium chloride.
The palladium metal in the amine complex is preferably used in an amount ranging from about 1 to 50 g/l, and preferably about 5 to 35 g/l.
It is often desirable to plate the viorkpiece or substrate with a palladium alloy, and alloying metals which may be employed in this invention include copper, cobalt, cadmium, gold, iron, indium, nickel, silver, tin and zinc which conveniently may be added to the bath as amino salts. Illustrative alloying metal components include nickelous amine chloride, aminozinc acetate, ethylene diamine tetracetic acid cobalt complex, and nitrilotriacetic acid nickel complex.
The alloying metal component may be present in the electroplating bath in an amount ranging from about 0 to 50 g/l, and when present preferably in amounts of from about 5 to 20 g/l.
The bath will also preferably contain from about 5 to 1 50 gIl, preferably from 10 to 100 g/l, of a conducting salt. The conducting salt may be an ammonium or alkali metal halide, carboxylic acid, sulphate, nitrate, or sulphate salt. Examples of such salts include ammonium chloride, ammonium citrate, ammonium nitrate, sodium nitrate, ammonium sulphamate, and potassium sulphate, and mixtures thereof. The especially preferred conducting salts are ammonium chloride, ammonium citrate, potassium citrate, and mixtures thereof.
In formulating the electroplating baths of this invention it is also useful for certain applications to utilize a brightener. The brighteners most useful for the present purposes are aromatic sulphonated amides, aromatic suiphonated imides, alkali metal aromatic sulphonates, and aromatic sulphonic acids and mixtures thereof. Specific preferred brighteners are naphthalene sulphonate sodium salt, saccharin sodium salt, and mixture thereof. In general, the brighteners will be used in amounts ranging from about 0.1 to 5 g/l, preferably from about 0.5 to 4 g/l.
In some instances it is desirable to provide a source of "free" or uncomplexed nitrite ions in the bath. The source of the free nitrite ions is preferably a water soluble inorganic nitrite compound such as an alkali metal nitrite. Especially preferred nitrites are sodium nitrite, potassium nitrate, and ammonium nitrite. The amount of nitrite ions employed may vary widely and is preferably at least about 0.05% by weight relative to the palladium ions in the bath. Initially the concentration of the nitrite ions may range from about 0.1 to about 50 X0 by weight, based on the weight of the palladium ions.
The baths of this invention have been used in conjunction with insoluble platinum, platinum clad, tantalum, or columbium anodes. In general, rack plating is employed and the workpieces, e.g. box and pin contacts, printed circuit board contacts, or decorative jewelry, have surfaces of metals such as copper, brass, bronze, nickel, silver, or steel. Palladium metal or palladium metal alloy deposits of high quality can be produced.
The invention can be put into practice in various ways and a number of specific embodiments will be described to illustrate the invention with reference to the accompanying examples.
EXAMPLE I
An aqueous palladium metal electroplating bath was prepared with the following formulation.
Component g/l Palladous Amine Chloride 10 (Pd metal)
Ammonium Chloride 50
Boric Acid 30
Ammonium Hydroxide to pH 8.2
Water Remainder
The bath was operated at a temperature of from about 200 to 700C and at a current density of 10 ASF (1.1 ASD). After 4 hours of operation, the pH had not dropped below 7.5.
EXAMPLE II
An aqueous palladium metal electroplating bath was prepared with the following formulation:
Component g/l Palladium Diamino Dinitrite 10-30 (Pd metal)
Sodium Nitrite 10
Ammonium Nitrate 30
Boric Acid 20
Ammonia to pH 7.5
Water Remainder
The bath was operated at a temperature of from about 500 to 700C and at a current density of from 100 to 1000 ASF (11 to 108 ASD). The pH had not dropped below 7.5 after 4 hours of operation.
EXAMPLE Ill An aqueous, palladium-nickel metal alloy electroplating bath was prepared with the following formulation:
Component s/l Palladous Amine Chloride 10 (Pd metal)
Nickelous Amine Chloride 12 (Ni metal)
Ammonium Chloride 30
Ammonium Citrate 10
Boric Acid 15
Ammonium Hydroxide to pH 9.0
Water Remainder
The bath was operated at a temperature of from about 200 to 500C and at a current density of about 20 ASF (2.2 ASD). After 4 hours of operation the pH had not dropped below 7.5.
EXAMPLES IV A to IV D
Example IV A
Example II was repeated, with the exception that the palladium metal content was reduced to 24 g/l and 5 g/l of silver metal was present in the form of silver dinitrite alkali metal salt. The temperature of the bath was maintained at between 200 and 250C.
Example IV B
Example II was repeated, with the exception that palladium metal content was reduced to 5 g/l and alloying zinc metal (1 g/l) was present in the form of aminozinc acetate.
Example IV C
Example lli was repeated with the exception that 3 g/l of benzaldehyde-o-sodium sulphonate and 0.1 g/l of sodium salt of naphthalene sulphonate were added. This bath was operated at 300C and between 10 and 50 ASF (1.1 and 5.4 ASD).
Example IV D
Example lli was repeated, with the exception that from 0.1 to 10 g/l of sodium saccharin were added. This bath was electrolyzed at 350C and at current densities between 5 and 50 ASF (0.54 and 5.4 ASD) to give low stress nickel-palladium deposits.
None of the baths of Example iV A to D showed an excessive pH drop, i.e. from 7.5 to 5 over a 4 hour operating period. On the other hand, when these baths as well as the baths of Examples I through Ill were operated without the prescribed borate buffer, i.e. alkali metal or ammonium hydroxide neutralized boric acid, or when other buffers such as citrates, phosphates, or tartrates were used in place of the borates, the pH dropped in 4 hours or less to pH 5 undesirably resulting in a concomitant precipitation of the palladium and/or the second or alloying metals.
Claims (21)
1. An aqueous palladium or palladium alloy electroplating bath containing an ammonium, amine, or alkali metal borate buffer whereby the bath has a pH of from about 6.5 to 9.5.
2. An aqueous palladium electroplating bath containing 1 to 50 g/l of palladium metal, 0 to 20 g/l of an alloying metal 5 to 1 50 g/l of a conductivity salt, 0 to 5 g/l of a brightener, and 10 to 50 g/l of boric acid neutralized with an alkali metal or ammonium hydroxide, ammonia or an amine whereby the pH of the bath is in the range 6.5 to 9.5.
3. An electroplating bath as claimed in Claim 1 or Claim 2 containing an alloying metal component comprising copper, cobalt, cadmium, gold, iron, indium, nickel, silver, tin or zinc or mixtures thereof.
4. An electroplating bath as claimed in Claim 2 or Claim 3 in which the alloying metal component is present in the bath in the form of an amino complex or salt.
5. An electroplating bath as claimed in Claim 3 in which the alloying metal is present as a nickel amino complex.
6. An electroplating bath as claimed in Claim 3 in which the alloying metal is present as a silver amino complex.
7. An electroplating bath as claimed in Claim 2 in which the alloying metal is present as a zinc amino complex.
8. An electroplating bath as claimed in any one of Claims 1 to 7 containing a conductivity salt.
9. An electroplating bath as claimed in Claim 8 in which the conductivity salt is a halide, carboxylic acid, sulphate, nitrate or sulphamate salt of ammonium or an alkali metal or a mixture thereof.
10. An electroplating bath as claimed in any one of Claims 1 to 9 containing a brightener.
11. An electroplating bath as claimed in Claim 10 in which the brightener is an aromatic sulphonated imide, an aromatic sulphonated amide, an alkali metal aromatic sulphonate, or an aromatic sulphonic acid, or a mixture thereof.
12. An electroplating bath as claimed in any one of Claims 1 to 11 in which the palladium metal is present as an amine palladium halide, nitrite, nitrate, sulphate, sulphamate, or carboxylic acid derivative.
13. An electroplating bath as claimed in Claim 12 in which the palladium is present as palladous amine chloride.
14. An electroplating bath as claimed in Claim 12 in which the palladium is present as palladium diamino dinitrite.
1 5. An electroplating bath as claimed in any one of Claims 2 to 14 in which the boric acid is neutralized with ammonium hydroxide.
1 6. An electroplating bath as claimed in any one of Claims 2 to 1 4 in which the boric acid is neutralized with ammonia.
17. An electroplating bath as claimed in Claim 1 substantially as specifically described herein with reference to any one of Examples I to Ill or IV A to IV D.
1 8. A method of electrodepositing metallic palladium or palladium alloys on a substrate which comprises passing an electric current between a cathode and an anode through an electroplating bath as claimed in any one of Claims 1 to 17 for a period of time sufficient to deposit the desired thickness of palladium or palladium alloy.
19. A method as claimed in Claim 1 8 in which the bath is at a temperature of from about 200 to 750C and the current density of from about 1 to 1000 ASF (0.1 to 108 ASD).
20. A method as claimed in Claim 1 8 substantially as specifically described herein with reference to any one of Examples I to Ill or IV A to IV D.
21. A substrate whenever provided with a palladium or palladium alloy electrodeposit by a method as claimed in Claim 1 8, 19 or 20.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US21521280A | 1980-12-11 | 1980-12-11 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2089374A true GB2089374A (en) | 1982-06-23 |
| GB2089374B GB2089374B (en) | 1983-11-30 |
Family
ID=22802107
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8137456A Expired GB2089374B (en) | 1980-12-11 | 1981-12-11 | Electrodeposition of palladium and palladium alloys |
Country Status (13)
| Country | Link |
|---|---|
| JP (1) | JPS609116B2 (en) |
| BE (1) | BE891319A (en) |
| BR (1) | BR8108038A (en) |
| CH (1) | CH649582A5 (en) |
| DE (1) | DE3147823A1 (en) |
| DK (1) | DK548881A (en) |
| ES (1) | ES507865A0 (en) |
| FR (1) | FR2496130A1 (en) |
| GB (1) | GB2089374B (en) |
| HK (1) | HK67186A (en) |
| IT (1) | IT8149859A0 (en) |
| NL (1) | NL8105601A (en) |
| SE (1) | SE8106867L (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4512963A (en) * | 1982-12-10 | 1985-04-23 | At&T Bell Laboratories | Palladium compound synthesis procedure |
| US4938851A (en) * | 1984-12-14 | 1990-07-03 | De Nora Permelec S.P.A. | Method for preparing an electrode and use thereof in electrochemical processes |
| EP0921212A1 (en) * | 1997-11-19 | 1999-06-09 | Lucent Technologies Inc. | Composition for electroplating palladium alloys and electroplating process using that composition |
| EP1852525A1 (en) * | 2006-03-03 | 2007-11-07 | Electroplating Engineers of Japan Limited | Palladium plating solution |
| CN104040032A (en) * | 2012-01-12 | 2014-09-10 | 庄信万丰股份有限公司 | Improvements in coating technology |
| IT202000000391A1 (en) * | 2020-01-13 | 2021-07-13 | Italfimet Srl | Galvanic process, and relative bath, of electrodeposition of palladium with high corrosion resistance. |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2171721B (en) * | 1985-01-25 | 1989-06-07 | Omi Int Corp | Palladium and palladium alloy plating |
| US4628165A (en) * | 1985-09-11 | 1986-12-09 | Learonal, Inc. | Electrical contacts and methods of making contacts by electrodeposition |
| DE3935664C1 (en) * | 1989-10-26 | 1991-03-28 | W.C. Heraeus Gmbh, 6450 Hanau, De | Palladium-silver alloys for electrical contacts - deposited from ammoniacal bath contg. palladium tetramine complex, silver di:amine complex and organic sulphur cpd. |
| DE4444232C1 (en) * | 1994-07-21 | 1996-05-09 | Heraeus Gmbh W C | Bath for the galvanic deposition of palladium-silver alloys |
| DE19528800C2 (en) * | 1995-08-04 | 1999-05-06 | Ami Doduco Gmbh | Alkaline or neutral bath for the galvanic deposition of palladium or alloys of palladium |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2839360C2 (en) * | 1978-09-09 | 1982-11-04 | Oxy Metal Industries Corp., Detroit, Mich. | Aqueous bath for the galvanic deposition of shiny coatings made of palladium or its alloys |
-
1981
- 1981-11-18 SE SE8106867A patent/SE8106867L/en not_active Application Discontinuation
- 1981-12-01 BE BE0/206712A patent/BE891319A/en not_active IP Right Cessation
- 1981-12-03 DE DE19813147823 patent/DE3147823A1/en not_active Ceased
- 1981-12-09 JP JP56198322A patent/JPS609116B2/en not_active Expired
- 1981-12-09 IT IT8149859A patent/IT8149859A0/en unknown
- 1981-12-10 DK DK548881A patent/DK548881A/en unknown
- 1981-12-10 CH CH7901/81A patent/CH649582A5/en not_active IP Right Cessation
- 1981-12-10 FR FR8123097A patent/FR2496130A1/en not_active Withdrawn
- 1981-12-10 ES ES507865A patent/ES507865A0/en active Granted
- 1981-12-10 BR BR8108038A patent/BR8108038A/en unknown
- 1981-12-11 GB GB8137456A patent/GB2089374B/en not_active Expired
- 1981-12-11 NL NL8105601A patent/NL8105601A/en not_active Application Discontinuation
-
1986
- 1986-09-11 HK HK671/86A patent/HK67186A/en unknown
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4512963A (en) * | 1982-12-10 | 1985-04-23 | At&T Bell Laboratories | Palladium compound synthesis procedure |
| US4938851A (en) * | 1984-12-14 | 1990-07-03 | De Nora Permelec S.P.A. | Method for preparing an electrode and use thereof in electrochemical processes |
| US5976344A (en) * | 1996-05-10 | 1999-11-02 | Lucent Technologies Inc. | Composition for electroplating palladium alloys and electroplating process using that composition |
| EP0921212A1 (en) * | 1997-11-19 | 1999-06-09 | Lucent Technologies Inc. | Composition for electroplating palladium alloys and electroplating process using that composition |
| EP1852525A1 (en) * | 2006-03-03 | 2007-11-07 | Electroplating Engineers of Japan Limited | Palladium plating solution |
| US7887692B2 (en) | 2006-03-03 | 2011-02-15 | Electroplating Engineers Of Japan Limited | Palladium plating solution |
| CN104040032A (en) * | 2012-01-12 | 2014-09-10 | 庄信万丰股份有限公司 | Improvements in coating technology |
| IT202000000391A1 (en) * | 2020-01-13 | 2021-07-13 | Italfimet Srl | Galvanic process, and relative bath, of electrodeposition of palladium with high corrosion resistance. |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2089374B (en) | 1983-11-30 |
| CH649582A5 (en) | 1985-05-31 |
| JPS609116B2 (en) | 1985-03-07 |
| HK67186A (en) | 1986-09-18 |
| JPS57123992A (en) | 1982-08-02 |
| NL8105601A (en) | 1982-07-01 |
| FR2496130A1 (en) | 1982-06-18 |
| ES8304617A1 (en) | 1983-03-01 |
| IT8149859A0 (en) | 1981-12-09 |
| BE891319A (en) | 1982-06-01 |
| BR8108038A (en) | 1982-09-21 |
| ES507865A0 (en) | 1983-03-01 |
| SE8106867L (en) | 1982-06-12 |
| DE3147823A1 (en) | 1982-06-24 |
| DK548881A (en) | 1982-06-12 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |