CA1143260A - Conditioning of polyamides for electroless plating - Google Patents
Conditioning of polyamides for electroless platingInfo
- Publication number
- CA1143260A CA1143260A CA000342112A CA342112A CA1143260A CA 1143260 A CA1143260 A CA 1143260A CA 000342112 A CA000342112 A CA 000342112A CA 342112 A CA342112 A CA 342112A CA 1143260 A CA1143260 A CA 1143260A
- Authority
- CA
- Canada
- Prior art keywords
- solution
- polyamide
- substrate
- polyamide substrate
- conditioning
- 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
- 229920002647 polyamide Polymers 0.000 title claims abstract description 114
- 239000004952 Polyamide Substances 0.000 title claims abstract description 113
- 238000007772 electroless plating Methods 0.000 title claims abstract description 31
- 230000003750 conditioning effect Effects 0.000 title claims description 42
- 239000000243 solution Substances 0.000 claims abstract description 168
- 239000000758 substrate Substances 0.000 claims abstract description 105
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Natural products CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims abstract description 60
- 239000002253 acid Substances 0.000 claims abstract description 36
- -1 acetic acid compound Chemical class 0.000 claims abstract description 23
- 230000001143 conditioned effect Effects 0.000 claims abstract description 22
- 239000007864 aqueous solution Substances 0.000 claims abstract description 17
- 150000007524 organic acids Chemical class 0.000 claims abstract description 10
- 125000004432 carbon atom Chemical group C* 0.000 claims abstract description 7
- YNJBWRMUSHSURL-UHFFFAOYSA-N trichloroacetic acid Chemical compound OC(=O)C(Cl)(Cl)Cl YNJBWRMUSHSURL-UHFFFAOYSA-N 0.000 claims abstract description 7
- 229960004319 trichloroacetic acid Drugs 0.000 claims abstract description 7
- 238000000034 method Methods 0.000 claims description 52
- 229910052751 metal Inorganic materials 0.000 claims description 30
- 239000002184 metal Substances 0.000 claims description 30
- 150000008044 alkali metal hydroxides Chemical class 0.000 claims description 24
- 239000003054 catalyst Substances 0.000 claims description 24
- 239000003960 organic solvent Substances 0.000 claims description 20
- 238000005530 etching Methods 0.000 claims description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 14
- 238000009835 boiling Methods 0.000 claims description 11
- 230000002378 acidificating effect Effects 0.000 claims description 7
- 238000004519 manufacturing process Methods 0.000 claims description 6
- 229910052736 halogen Inorganic materials 0.000 claims description 5
- 150000002367 halogens Chemical class 0.000 claims description 5
- 229910052739 hydrogen Inorganic materials 0.000 claims description 4
- 239000001257 hydrogen Substances 0.000 claims description 4
- 125000002887 hydroxy group Chemical group [H]O* 0.000 claims description 4
- 239000003513 alkali Substances 0.000 claims description 3
- 239000011260 aqueous acid Substances 0.000 claims description 3
- JXTHNDFMNIQAHM-UHFFFAOYSA-N dichloroacetic acid Chemical compound OC(=O)C(Cl)Cl JXTHNDFMNIQAHM-UHFFFAOYSA-N 0.000 claims description 3
- 229960005215 dichloroacetic acid Drugs 0.000 claims description 3
- 125000004435 hydrogen atom Chemical class [H]* 0.000 claims 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 16
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 16
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 16
- 229910052802 copper Inorganic materials 0.000 description 16
- 239000010949 copper Substances 0.000 description 16
- 239000012670 alkaline solution Substances 0.000 description 14
- 239000002904 solvent Substances 0.000 description 13
- 229960000583 acetic acid Drugs 0.000 description 12
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 11
- 238000007654 immersion Methods 0.000 description 11
- 229910000510 noble metal Inorganic materials 0.000 description 9
- 238000010899 nucleation Methods 0.000 description 9
- 238000012360 testing method Methods 0.000 description 9
- 229910001854 alkali hydroxide Inorganic materials 0.000 description 8
- 229910052759 nickel Inorganic materials 0.000 description 8
- HEMHJVSKTPXQMS-UHFFFAOYSA-M sodium hydroxide Inorganic materials [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 8
- 239000003518 caustics Substances 0.000 description 7
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 6
- 229920006100 Vydyne® Polymers 0.000 description 6
- 229910052763 palladium Inorganic materials 0.000 description 6
- 239000000725 suspension Substances 0.000 description 6
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 5
- 239000000084 colloidal system Substances 0.000 description 5
- 150000001875 compounds Chemical class 0.000 description 5
- 239000004033 plastic Substances 0.000 description 5
- 229920002292 Nylon 6 Polymers 0.000 description 4
- 230000001464 adherent effect Effects 0.000 description 4
- 150000002739 metals Chemical class 0.000 description 4
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 239000008367 deionised water Substances 0.000 description 3
- 229910021641 deionized water Inorganic materials 0.000 description 3
- 230000008021 deposition Effects 0.000 description 3
- PIBWKRNGBLPSSY-UHFFFAOYSA-L palladium(II) chloride Chemical compound Cl[Pd]Cl PIBWKRNGBLPSSY-UHFFFAOYSA-L 0.000 description 3
- 238000007747 plating Methods 0.000 description 3
- ISPYQTSUDJAMAB-UHFFFAOYSA-N 2-chlorophenol Chemical compound OC1=CC=CC=C1Cl ISPYQTSUDJAMAB-UHFFFAOYSA-N 0.000 description 2
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 2
- 229920006051 Capron® Polymers 0.000 description 2
- JPVYNHNXODAKFH-UHFFFAOYSA-N Cu2+ Chemical compound [Cu+2] JPVYNHNXODAKFH-UHFFFAOYSA-N 0.000 description 2
- 239000004677 Nylon Substances 0.000 description 2
- 229920002302 Nylon 6,6 Polymers 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- 239000012736 aqueous medium Substances 0.000 description 2
- 239000002585 base Substances 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- FOCAUTSVDIKZOP-UHFFFAOYSA-N chloroacetic acid Chemical compound OC(=O)CCl FOCAUTSVDIKZOP-UHFFFAOYSA-N 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 150000001896 cresols Chemical class 0.000 description 2
- 238000009713 electroplating Methods 0.000 description 2
- JBKVHLHDHHXQEQ-UHFFFAOYSA-N epsilon-caprolactam Chemical compound O=C1CCCCCN1 JBKVHLHDHHXQEQ-UHFFFAOYSA-N 0.000 description 2
- 235000019253 formic acid Nutrition 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- 229910021645 metal ion Inorganic materials 0.000 description 2
- 239000002923 metal particle Substances 0.000 description 2
- 229920001778 nylon Polymers 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 230000002035 prolonged effect Effects 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- TXUICONDJPYNPY-UHFFFAOYSA-N (1,10,13-trimethyl-3-oxo-4,5,6,7,8,9,11,12,14,15,16,17-dodecahydrocyclopenta[a]phenanthren-17-yl) heptanoate Chemical compound C1CC2CC(=O)C=C(C)C2(C)C2C1C1CCC(OC(=O)CCCCCC)C1(C)CC2 TXUICONDJPYNPY-UHFFFAOYSA-N 0.000 description 1
- XEPXTKKIWBPAEG-UHFFFAOYSA-N 1,1-dichloropropan-1-ol Chemical compound CCC(O)(Cl)Cl XEPXTKKIWBPAEG-UHFFFAOYSA-N 0.000 description 1
- QTWJRLJHJPIABL-UHFFFAOYSA-N 2-methylphenol;3-methylphenol;4-methylphenol Chemical compound CC1=CC=C(O)C=C1.CC1=CC=CC(O)=C1.CC1=CC=CC=C1O QTWJRLJHJPIABL-UHFFFAOYSA-N 0.000 description 1
- MIMUSZHMZBJBPO-UHFFFAOYSA-N 6-methoxy-8-nitroquinoline Chemical compound N1=CC=CC2=CC(OC)=CC([N+]([O-])=O)=C21 MIMUSZHMZBJBPO-UHFFFAOYSA-N 0.000 description 1
- 241000905957 Channa melasoma Species 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical group [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 229920006068 Minlon® Polymers 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 239000004115 Sodium Silicate Substances 0.000 description 1
- 229910021626 Tin(II) chloride Inorganic materials 0.000 description 1
- DTQVDTLACAAQTR-UHFFFAOYSA-N Trifluoroacetic acid Chemical compound OC(=O)C(F)(F)F DTQVDTLACAAQTR-UHFFFAOYSA-N 0.000 description 1
- 125000000218 acetic acid group Chemical class C(C)(=O)* 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 239000012190 activator Substances 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 239000003637 basic solution Substances 0.000 description 1
- 229910021538 borax Inorganic materials 0.000 description 1
- RJTANRZEWTUVMA-UHFFFAOYSA-N boron;n-methylmethanamine Chemical compound [B].CNC RJTANRZEWTUVMA-UHFFFAOYSA-N 0.000 description 1
- KDPAWGWELVVRCH-UHFFFAOYSA-N bromoacetic acid Chemical compound OC(=O)CBr KDPAWGWELVVRCH-UHFFFAOYSA-N 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000008139 complexing agent Substances 0.000 description 1
- 150000001879 copper Chemical class 0.000 description 1
- 229910000365 copper sulfate Inorganic materials 0.000 description 1
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 description 1
- PBWZKZYHONABLN-UHFFFAOYSA-N difluoroacetic acid Chemical compound OC(=O)C(F)F PBWZKZYHONABLN-UHFFFAOYSA-N 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- QEWYKACRFQMRMB-UHFFFAOYSA-N fluoroacetic acid Chemical compound OC(=O)CF QEWYKACRFQMRMB-UHFFFAOYSA-N 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 239000012362 glacial acetic acid Substances 0.000 description 1
- 229940093915 gynecological organic acid Drugs 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910000000 metal hydroxide Inorganic materials 0.000 description 1
- 150000004692 metal hydroxides Chemical class 0.000 description 1
- 150000007522 mineralic acids Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 235000005985 organic acids Nutrition 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 150000002989 phenols Chemical class 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- LJCNRYVRMXRIQR-OLXYHTOASA-L potassium sodium L-tartrate Chemical compound [Na+].[K+].[O-]C(=O)[C@H](O)[C@@H](O)C([O-])=O LJCNRYVRMXRIQR-OLXYHTOASA-L 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 230000001235 sensitizing effect Effects 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 235000017550 sodium carbonate Nutrition 0.000 description 1
- 235000019795 sodium metasilicate Nutrition 0.000 description 1
- 239000001488 sodium phosphate Substances 0.000 description 1
- 235000011006 sodium potassium tartrate Nutrition 0.000 description 1
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 1
- 229910052911 sodium silicate Inorganic materials 0.000 description 1
- 239000004328 sodium tetraborate Substances 0.000 description 1
- 235000010339 sodium tetraborate Nutrition 0.000 description 1
- 239000001119 stannous chloride Substances 0.000 description 1
- 235000011150 stannous chloride Nutrition 0.000 description 1
- 239000012085 test solution Substances 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
- RYFMWSXOAZQYPI-UHFFFAOYSA-K trisodium phosphate Chemical compound [Na+].[Na+].[Na+].[O-]P([O-])([O-])=O RYFMWSXOAZQYPI-UHFFFAOYSA-K 0.000 description 1
- 229910000406 trisodium phosphate Inorganic materials 0.000 description 1
- 235000019801 trisodium phosphate Nutrition 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
- C08J7/12—Chemical modification
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
- C08G69/46—Post-polymerisation treatment
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
- C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
- C23C18/18—Pretreatment of the material to be coated
- C23C18/20—Pretreatment of the material to be coated of organic surfaces, e.g. resins
- C23C18/22—Roughening, e.g. by etching
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2377/00—Characterised by the use of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Derivatives of such polymers
- C08J2377/02—Polyamides derived from omega-amino carboxylic acids or from lactams thereof
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/02—Details
- H05K1/03—Use of materials for the substrate
- H05K1/0313—Organic insulating material
- H05K1/032—Organic insulating material consisting of one material
- H05K1/0346—Organic insulating material consisting of one material containing N
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/02—Details
- H05K1/03—Use of materials for the substrate
- H05K1/0313—Organic insulating material
- H05K1/0353—Organic insulating material consisting of two or more materials, e.g. two or more polymers, polymer + filler, + reinforcement
- H05K1/0373—Organic insulating material consisting of two or more materials, e.g. two or more polymers, polymer + filler, + reinforcement containing additives, e.g. fillers
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/10—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
- H05K3/18—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using precipitation techniques to apply the conductive material
- H05K3/181—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using precipitation techniques to apply the conductive material by electroless plating
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/38—Improvement of the adhesion between the insulating substrate and the metal
- H05K3/381—Improvement of the adhesion between the insulating substrate and the metal by special treatment of the substrate
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- General Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Chemically Coating (AREA)
- Coating Of Shaped Articles Made Of Macromolecular Substances (AREA)
- Treatments Of Macromolecular Shaped Articles (AREA)
- Polyamides (AREA)
Abstract
Abstract of the Invention Polyamide substrates are pre-conditioned for electroless plating by contact with an alkaline aqueous solution having a pH of at least about 10 and etched with an acid solution.
The acid solution is preferably an aqueous solution of an organic acid containing at least two carbon atoms, particularly an acetic acid compound, such as trichloracetic acid.
The acid solution is preferably an aqueous solution of an organic acid containing at least two carbon atoms, particularly an acetic acid compound, such as trichloracetic acid.
Description
11~3~:60 .,~.. I ~ ~
12161:JPG 1 CONDITIONING OF POLYAMIDES FOR ELECTROLESS PLATING
~.
Background of the Invention The present invention relates to electroless plating of polyamides, in particular, to providing a surface uniformly receptive to metals which catalyze electroless deposition of 1 nickel and copper.
The benefits of electroless plated, non-conductive articles, particularly plastic articles, are well known.
In the finished product, the desirable characteristics of the plastic and the metal are combined to offer thereby the technical and aesthetic advantages of each.
Polymeric substrates are conventionally plated by pre-conditioning the surface by contact with an aqueous solution of at least one organic compound active for conditioning the surface of the plastic, etching with
12161:JPG 1 CONDITIONING OF POLYAMIDES FOR ELECTROLESS PLATING
~.
Background of the Invention The present invention relates to electroless plating of polyamides, in particular, to providing a surface uniformly receptive to metals which catalyze electroless deposition of 1 nickel and copper.
The benefits of electroless plated, non-conductive articles, particularly plastic articles, are well known.
In the finished product, the desirable characteristics of the plastic and the metal are combined to offer thereby the technical and aesthetic advantages of each.
Polymeric substrates are conventionally plated by pre-conditioning the surface by contact with an aqueous solution of at least one organic compound active for conditioning the surface of the plastic, etching with
2 a strong oxidizing acid or base, seeding the surface with a noble metal catalyst, e.g., a palladium chloride solution, then immersing the seeded surface in an autocatalytic electroless solution where an initial coatinq of a conductive metal, e.g., copper or nickel, is established by chemical 1~3-1 l .
:' ~.
11~3Z60 `~ deposition. The metal deposit acts as a buss to allow a thicker coating of metal to be built up electrolytically.
Attempts to adapt conventional procedures for electroless plating of polymers to polyamides by us have resulted in a failure to achieve a uniform adherent coat of metal. Having found conventional electroless plating procedures ineffective, a quest was initiated to discover a procedure to enable uniform coating of polyamides with electroless deposited metals.
Summary of the Invention In accordance with the present invention there is ; provided in a process for ~lectroless plating of polyamide substrate wherein the substrate is etched with an acid prior to electroless plating, the improvement which comprises conditioning the substrate prior to etch by contact with an aqueous alkaline conditioning solution having a pH of at least about 10 and !; maintained at a temperature of from about 150F to the lesser of , the boiling point of the solution and the softening temperature of the polyamide substrate for a time sufficient to enhance acid etch of the polyamide substrate.
Also in accordance with the invention there is provided a process for preparing the surface of polyamide substrates for electroless plating which comprises:
(a) forming a conditioned polyamide substrate for etching by contacting the polyamide substrate with an aqueous alkaline conditioning solution having a pH of at least about 10 and maintained at a temperature from about 150F to the lesser of the boiling point of the solution and the softening temperature of the polyamide substrate for a time sufficient to render the substrate receptive to etch by an organic acid;
(b) etching the conditioned polyamide substrate by ,:
11~3Z~;O
contacting the conditioned polyamide s.ubstrate with an aqueous etch solution comprising at least one water soluble organic acid containing from 2 to about 10 carbon atoms in the molecule and present in the aqueous solution in a concentrati.on of at least about 3 percent by weight of the solution and sufficient to render the conditioned polyamide substrate substantially uniformly receptive to a metal electroless plating catalyst.
Further in accordance with.the invention there is provided a process for preparing the surface of polyamide substrates for ; 10 electroless plating which comprises:
(a) forming a conditioned polyamide substrate for etching by contacting the polyamide substrate with an aqueous conditioning solution of at least one a.lkali metal hydroxide in .: which the alkali metal hydroxide concentrati.on of thR solution is .. 15 from about 2 percent by weight of the solution to solution saturation and maintained at a temperature of from about 150F
to the lesser of the boiling point of the solution and the softening temperature of the polyamide surface for a time sufficient . to render surface polyamide s:ubstrate receptive to etch by an acetic acid compound;
(b) etching the conditioned polyamide substrate by contacting the conditi.oned polyamide substrate with an aqueous acid etch solution comprising at least one acetic acid compound having the formula:
~ O
X C - C
wherein each X is independently selected from the group consisting of hydrogen, hydroxyl and halogen and in which the acetic acid compound concentration is sufficient to render the conditioned ~olyamide substrate receptive to a metal electroless plating catalyst.
-- 2a 1~3260 Further in accordance with the invention there is provided a process for preparing the surface of polyamide sub-strates for electroless plating ~hich comprises:
(a) forming a conditioned polyamide substrate by contacting the polyamide substrate with an aqueous conditioning solution of at least one alkali metal hydroxide in which the total alkali metal hydroxide concentration is from about 10 per cent by weight of the solution to solution saturation and maintained at a temperature of from about 150F to the lesser of the boiling point of the solution and the softening temperature of the poly-amide surface for a period of from about 0.5 to about 20 minutes;
(b) forming an etched polyamide substrate by contacting the conditioned polyamide substrate with an aqueous etch solution comprising at least one acetic acid compound selected from the group consisting of trichloracetic acid, dichoracetic acid and acetic acid in which the acetic acid compound concentration is sufficient to render the conditioned polyamide substrate receptive to a metal electroless plating catalyst.
Thus, it has now been found that electroless plating of polyamides, particularly filled polyamides, can be enhanced by first contacting the polyamide substrate with an aqueous alkaline solution having a pH of at least about 10, preferably a solution of at least one alkali metal hydroxide in which the alkali metal hydroxide content is from about 2 percent by weight to solution saturation, more preferably from about 10 to about 50 percent by weight. The alkaline solution is maintained at a temperature from about 150F to the lesser of the boiling point of the solution and the softening point of the plastic. Contact is for a time sufficient to enable etching by an acid solution.
The substrate is then contacted with an acid etch at - 2b .. ..
. .
.
ll143Z60 ambient temperature or above. The concentration of the acid is sufficient to render the polyamide surface uniformly receptive to seeding by a metal catalyst. A preferred acid solution is a solution comprising at least one organic acid containing from two carbon atoms to about 10 carbon atoms and having a solubility in water of at least about 3 percent by weight of solution.
- 2c ., .
11~3Z60 12161:JPG
l The present1y preferred acid solutions are solutions comprising at least one acetic acid compound of the formula:
wherein each X is independently selected from the group consisting of hydrogen, hydroxyl and halogen.
Contact with the acid etch may be directly followed by seeding the surface with a metal electroless plating catalyst which are solutions of metal ions or suspensions of metal particles.
Following seeding and activation of the metal catalyst by conventional means, the surface can be uniformly plated with electroless copper or nickel.
Etching may be followed by rinsing debris from the surface of the substrate with an acid to alkaline rinse solution.
In carrying out the process of this invention in its preferred embodiment, an alkali metal hydroxide solution is used as the conditioner and is preferably employed at a ; 2 temperature from about 170 to about 200F at contact times ranging from about 0.5 to about 20 minutes or more, depending on temperature and caustic concentration. No damage has been found from prolonged contact.
Contact time in the aqueous acid solution etch is normally 2 from about lO seconds to lS minutes at room temperature.
When, as is presently preferred, a solution of an acetic acid compound is employed for etching the substrate, concentration is normally at least about 3 percent by weight up to solution saturation, preferably from about 5 to about 60 percent by
:' ~.
11~3Z60 `~ deposition. The metal deposit acts as a buss to allow a thicker coating of metal to be built up electrolytically.
Attempts to adapt conventional procedures for electroless plating of polymers to polyamides by us have resulted in a failure to achieve a uniform adherent coat of metal. Having found conventional electroless plating procedures ineffective, a quest was initiated to discover a procedure to enable uniform coating of polyamides with electroless deposited metals.
Summary of the Invention In accordance with the present invention there is ; provided in a process for ~lectroless plating of polyamide substrate wherein the substrate is etched with an acid prior to electroless plating, the improvement which comprises conditioning the substrate prior to etch by contact with an aqueous alkaline conditioning solution having a pH of at least about 10 and !; maintained at a temperature of from about 150F to the lesser of , the boiling point of the solution and the softening temperature of the polyamide substrate for a time sufficient to enhance acid etch of the polyamide substrate.
Also in accordance with the invention there is provided a process for preparing the surface of polyamide substrates for electroless plating which comprises:
(a) forming a conditioned polyamide substrate for etching by contacting the polyamide substrate with an aqueous alkaline conditioning solution having a pH of at least about 10 and maintained at a temperature from about 150F to the lesser of the boiling point of the solution and the softening temperature of the polyamide substrate for a time sufficient to render the substrate receptive to etch by an organic acid;
(b) etching the conditioned polyamide substrate by ,:
11~3Z~;O
contacting the conditioned polyamide s.ubstrate with an aqueous etch solution comprising at least one water soluble organic acid containing from 2 to about 10 carbon atoms in the molecule and present in the aqueous solution in a concentrati.on of at least about 3 percent by weight of the solution and sufficient to render the conditioned polyamide substrate substantially uniformly receptive to a metal electroless plating catalyst.
Further in accordance with.the invention there is provided a process for preparing the surface of polyamide substrates for ; 10 electroless plating which comprises:
(a) forming a conditioned polyamide substrate for etching by contacting the polyamide substrate with an aqueous conditioning solution of at least one a.lkali metal hydroxide in .: which the alkali metal hydroxide concentrati.on of thR solution is .. 15 from about 2 percent by weight of the solution to solution saturation and maintained at a temperature of from about 150F
to the lesser of the boiling point of the solution and the softening temperature of the polyamide surface for a time sufficient . to render surface polyamide s:ubstrate receptive to etch by an acetic acid compound;
(b) etching the conditioned polyamide substrate by contacting the conditi.oned polyamide substrate with an aqueous acid etch solution comprising at least one acetic acid compound having the formula:
~ O
X C - C
wherein each X is independently selected from the group consisting of hydrogen, hydroxyl and halogen and in which the acetic acid compound concentration is sufficient to render the conditioned ~olyamide substrate receptive to a metal electroless plating catalyst.
-- 2a 1~3260 Further in accordance with the invention there is provided a process for preparing the surface of polyamide sub-strates for electroless plating ~hich comprises:
(a) forming a conditioned polyamide substrate by contacting the polyamide substrate with an aqueous conditioning solution of at least one alkali metal hydroxide in which the total alkali metal hydroxide concentration is from about 10 per cent by weight of the solution to solution saturation and maintained at a temperature of from about 150F to the lesser of the boiling point of the solution and the softening temperature of the poly-amide surface for a period of from about 0.5 to about 20 minutes;
(b) forming an etched polyamide substrate by contacting the conditioned polyamide substrate with an aqueous etch solution comprising at least one acetic acid compound selected from the group consisting of trichloracetic acid, dichoracetic acid and acetic acid in which the acetic acid compound concentration is sufficient to render the conditioned polyamide substrate receptive to a metal electroless plating catalyst.
Thus, it has now been found that electroless plating of polyamides, particularly filled polyamides, can be enhanced by first contacting the polyamide substrate with an aqueous alkaline solution having a pH of at least about 10, preferably a solution of at least one alkali metal hydroxide in which the alkali metal hydroxide content is from about 2 percent by weight to solution saturation, more preferably from about 10 to about 50 percent by weight. The alkaline solution is maintained at a temperature from about 150F to the lesser of the boiling point of the solution and the softening point of the plastic. Contact is for a time sufficient to enable etching by an acid solution.
The substrate is then contacted with an acid etch at - 2b .. ..
. .
.
ll143Z60 ambient temperature or above. The concentration of the acid is sufficient to render the polyamide surface uniformly receptive to seeding by a metal catalyst. A preferred acid solution is a solution comprising at least one organic acid containing from two carbon atoms to about 10 carbon atoms and having a solubility in water of at least about 3 percent by weight of solution.
- 2c ., .
11~3Z60 12161:JPG
l The present1y preferred acid solutions are solutions comprising at least one acetic acid compound of the formula:
wherein each X is independently selected from the group consisting of hydrogen, hydroxyl and halogen.
Contact with the acid etch may be directly followed by seeding the surface with a metal electroless plating catalyst which are solutions of metal ions or suspensions of metal particles.
Following seeding and activation of the metal catalyst by conventional means, the surface can be uniformly plated with electroless copper or nickel.
Etching may be followed by rinsing debris from the surface of the substrate with an acid to alkaline rinse solution.
In carrying out the process of this invention in its preferred embodiment, an alkali metal hydroxide solution is used as the conditioner and is preferably employed at a ; 2 temperature from about 170 to about 200F at contact times ranging from about 0.5 to about 20 minutes or more, depending on temperature and caustic concentration. No damage has been found from prolonged contact.
Contact time in the aqueous acid solution etch is normally 2 from about lO seconds to lS minutes at room temperature.
When, as is presently preferred, a solution of an acetic acid compound is employed for etching the substrate, concentration is normally at least about 3 percent by weight up to solution saturation, preferably from about 5 to about 60 percent by
3 weight.
113-~
~ 3Z60 In conducting the process of the invention, the article may he treated by contacting the article in an aqueous solution of an organic solvent for the polyamide, prior to or following contact with the alkaline solution. Alternatively, the organic solvent can be contained in the alkaline solution.
j The solvent in its solution is normally employed in a concen-tration up to about 2 percent by weight, preferably up to about 1 percent by weight. Ethylene glycol, phenolic compounds such as chlorophenol, cresols and salts thereof are presently I 10 preferred. As indicated, solvent may be contained in its own ! bath or included in the alkaline solution so long as the organic solvent is not hydrolyzed or degraded. The solvent serves to soften plastic to aid attack by the alkaline conditioner or acid etch.
¦ 15 As indicated, the substrate after etching may be further processed to remove the debris of etching by contact with acidic to basic wash.
! Detailed Description ¦ The present invention provides a process which enables ¦ 20 uniform electroless deposition of metals onto polyamide substrates. In particular, the processes of the present invention are directed to improvements in electroless plating of filled and unfilled polyamides such as Nylon 6 and Nylon 6,6.
In its broadest aspects, the invention is directed to conditioning the surface of a polyamide substrate with an ; aqueous alkaline solution having a p~I of at least about 10 to render the surface receptive to attack by an acid etch.
~ 4 -~` - ~ ( 1~3260 12161:JPG
l Although solutions of alkali hydroxide are preferab1y employed, there may also be used alkaline compounds such as sodium metasilicate, trisodium phosphate, sodium carbonate and the like, used alone, in admixture and/or in combination with an alkali metal hydroxide.
When a conditioning solution of at least one alkali metal hydroxide is employed, the solution has an alkali metal hydroxide content of from about 2 percent by weight of solution to solution saturation, preferably about 10 to about 50 per cent by weight.
~ ¦ The alkali conditioning solutions are, as presently v- ¦ employed, maintained at a temperature from about 150F to ¦ the lesser of the boiling point of the solution and the ¦ softening temperature of the polyamide.
15 ¦ Contact is for a time sufficient to render the substrate ¦ receptive to attack by the acid etch; and after rinsing, ¦ is followed by contact of the polyamide substance with an ¦ acid etch solution. The preferred acid solutions are solutions ¦ comprising at least one soluble organic acid containing at 20 ¦ least two carbon atoms, and contact is for a time sufficient ¦ to render the surface receptive to a metal catalyst. The ¦ metal catalyst may be in the form of a solution of functional ¦ metal ions or as a dispersion of metal particles. It is ¦ presently preferred that the organic acid be an acetic 25 ¦ acid compound as defined below.
¦ As part of the process measures, water rinsing with ¦ deionized water is performed for good housekeeping between ¦ each step. The substrate may be treated with a dilute ¦ solution of solvent for the polyamide to soften the surface 30 l .
-~ ~ ~
1~3260 12l61:JPG
l of the polyamide to promote conditioning and/or etch.
Contact. with the solvent may be prior to or after contact with the alkaline solution or contained in the alkaline solution. It is presently preferred to contact the substrate with the solvent following contact with the alkaline solution.
If desired, a solution of the solvent may be employed prior to and following contact with the alkaline conditioner. The solvent softens the surface of the substrate to promote conditioning or etching. The solvent for the polyamide may be contained in a separate bath or part of the alkaline solution.
In addition, the substrates may be contacted with an acidic to basic solution subsequent to etch to remove debris present on the surface of the substrate.
The procedure of contact with the aqueous alkaline solution prior to contact with an acid etch is critical to the process of the invention and the reverse of steps normally conducted in electroless plating operations.
While reception of electroless plating onto the surface of any polyamide may be enhanced, the polyamides to be normally treated are filled polyamides as are conventionally used in molding operations. Typical of such materials are filled Nylon 6, Nylon 6,6 and the like.
The first essential step of the process is contacting the polyamide substrate with an aqueous alkaline solution.
2 The presently preferred solutions are solutions of at least one alkali metal hydroxide, such as sodium and/or potassium hydroxide, present in a concentration from about 3 percent by weight of solution to solution saturation, preferably from about lO to about 50 percent by weight. Solution temperature :~ ~ (- (-~1~a3~60 12161:JPG
1 is maintained from about 150F to the lesser of the boiling point of the solution and the softe~ing temperature of the polyamide substrate, preferably from a temperature of about 170 to about 200F.
S Contact time may vary from about 0.5 to 20 minutes or more, depending upon temperature and the alkaline compound concentration, although it has been found that prolonged immersions will not damage the substrate. The object is to condition the surface of the substrate to make it receptive 0 to attack by the acid etch.
Following water rinsing to remove the alkaline ; conditioning solution, the article is passed to an acid etch, preferably one based on organic acids containing from 2 to ;; about 10 carbon atoms and having a water solubility of at least about 3 percent by weight of solution. The presently preferred etch is one comprising from about 5 percent by weight to about 65 percent by weight of solution and more preferably, from about 10 to about 25 percent.by weight of solution of at least one acetic compound of the formula:
~' X C C ~
where each X is independently hydroxyl, hydrogen or halogen 2 with halogen preferred.
Contact is at ambient or room temperature although elevated temperatures may be employed. Contact times range from about . 10 seconds to lS minutes or more and are for a time sufficient to etch the surface of the polyamide to a degree that it becomes uniformly receptive to seeding by a metal catalyst.
`~! 3 ,. 9 ;'' ' 11~3~60 12161:JPG
Among the acetic acid compounds which may be used there may be mentioned trichloracetic acid, acetic acid, hydroxy-aceti^ acid, dichloracetic acid, chloracetic acid, fluoracetic acid, difluoracetic acid, trifluoracetic acid, bromacetic acid, dibromacetic acid and the like. Trichloroacetic acid is presently preferred.
Optionally, there may be employed as part of the process, contact with an organic solvent for the polyamide. The solvent may be in a separate bath used preceding and/or following the alkaline conditioning solution or included in the alkaline con-ditioning solutionr The organic solvent softens the surface of the substrate to aid attack by the conditioning and/or etching solutions. Typically, concentration of the solvent in its solution is up to about 2 percent by weight, preferably up to about l percent by weight. A wide variety of solvents for polyamides may be used. The presently preferred solvents are , ethylene glycol, chlorophenol, cresols and salts thereof. If employed in the alkaline conditioner as its solution, the sol-; vent should not be hydrolyzed or degraded by the alkaline batch.
~ 20 In addition, subsequent to contact with the acid etch, : the substrate may be brought into contact with an acid to ~, alkaline solution of either an organic or inorganic acid or base to cleanse the surface of debris, i.e., filler and/or degradated resin. Such solutions are normally maintained at room temperature, although elevated temperatures may be ¦ employed. Although solutions used as the conditioner may be r'; ¦ employed, solutions having an acidic or alkaline compound , ¦ in concentration in the range up to about 20 percent by weight, : ¦ preferably up to about l0 percent by weight may also be 30 ¦ employed. Functional acids include hydrochloric acid, sulfuric ~ acid, phosphoric acid, nitric acid, formic acid, acetic acid 113-l 1 8 .' I
' ~1~3,''260 and the like. As indicated, there may also be used as a convenience to minimize the number of baths involved, the alkaline solution used for conditioning the substrate.
- Alternative solutions include such as solutions of borax,ammonium bifluoride and the like. The concentration is that - which will enhance surface finish without detracting fromthe ability of etched surface to accept a metal catalyst.
Whether or not the cleansing treatment is employed, the article is rinsed in water, usually deionized water, and seeded with a metal electroless plating catalyst.
The electroless plating catalysts employed may be nob~e metal or non-noble metal based. Non-noble metal catalysts are described in United States Patent 3,958,048 to the same assignee as this application.
A noble metal catalyst in an aqueous medium is presently preferred. By a "noble metal catalyst contained in an aqueous medium" there is meant an ionic solution or colloidal suspension of the free metals. Colloidal suspensions are preferred. The noble metals include gold, platinum and palladium, with palladium preferred.
A suitable ionic bath is one containing palladium chloride in a concentration of about 0~2 grams per liter solution and 3 ml of concentrated hydrochloric acid per liter of solution. Following seeding, the palladium can be reduced to the free metal state by immersion in a bath of a reducing agent such as dimethyl amine borane.
Colloidal suspensions of noble metals are described in United States Patent 3,011,920 to C.R. Shipley, Jr. Such -- suspensions are colloidal in nature in which the noble metal ~ 30 colloid is maintained in suspension . _ g _.
. ~
'~
.
3~60 by a protective colloid, i.e., stannic acid colloids. Following seeding, the colloid is removed by immersion in an acidic or alkaline accelerator solution to remove the protective colloid and expose the absorbed noble metal.
- 5 Although less preferred, there may also be employed a seeding method which involves contacting the etched article with a sensitizing solution containing stannous chloride followed by immersion in an activator solution such as a palladium chloride solution where the ionic palladium is reduced to the free metal on the surface of the substrate.
Suitably activated, the article may be electrolessly plated by conventional means. Electroless copper and nickel formulations, such as those described in United States Patents 3,011,920 and 3,874,072, may be employed. Electroless copper solutions are typically based on a soluble copper salt, such as copper sulfate, a complexing agent for the cupric ion such as Rochelle salt, an alkali hydroxide for adjustment of pH, a carbonate radical as a buffer and a reducing agent for the cupric ion such as formaldehyde.
Following electroless plating, the substrate may be electrolytically plated by conventional means, with nickel, gold, silver, chromium and the like to provide the desired finish on the article. It has been observed that adhesion will increase with age of the plate.
In the following Examples and Controls where the article or substrate was contacted with an alkali hydroxide solution, the bath was about 35 percent weight to volume sodium hydroxide solution maintained at 200~F. Where contacted with a _ ln 1143;Z60 ` 12161:JPG
l hydrochloric acid solution, the solution was a 28.5 percent (volume by volume) of concentrated hydrochloric acid in water.
The solution of trichloracetic acid (TCA solution) employed was a 20 percent by weight to volume aqueous solution maintained at room temperature. Seeding of the etched substrate was with a proprietary colloidal tin-palladium catalyst as described in U.S. Patent 3,011,920 at an acid molarity of about 1.7.
An alkaline accelerator was used to expose the palladium metal.
The catalyst was maintained at about 120F and the accelerator at about 105F. The electroless copper solution employed was Cuposit(TM) PM-990 manufactured and sold by the Shipley Company.
The electroless copper solution was maintained at ambient temperature.
Following electroless plating, the article was electrolytically plated when possible. In this operation, the substrate was rinsed in deionized water, soaked in an alkaline cleaner, then passed to a reverse current cleaner, an acid dip, bright acid copper and nickel electrolytic plating solutions and finally to a chromium plating solution.
Some plated articles were subjected to cycle testing to determine adhesion performance under thermal stress conditions.
In this test the plated article was maintained at a temper-ature of at least 180 F for l hour, then cooled to room temperature and maintained at room temperature for 30 min-; 25 utes then cooled to -20 F and maintained at that temperature for l hour.
113-1 ll ~ ~ 3;~1i0 lExample l A p1ating grade of filled Nylon 6,~ known as Vydyne(TM) RP-260, manufactured and sold by the Monsanto Company, was - immersed for lO minutes in the alkali hydroxide solution then water rinsed and immersed for l minute in the TCA solution.
The article was then rinsed in water, catalyzed, rinsed, electrolessly plated with copper and electrolytically plated.
Initial plate adhesion ranged from l.0 to l.5 lb/in with an average of 1.3 lb/in. The cycle test was successful.
Control l The procedure of Example l was reversed in that the article was immersed in the TCA solution prior to contact with the alkali hydroxide solution. This resulted in skip - plating and blistering of the electroless plate.
Control 2 ; Control l was repeated except that immersion time in the TCA solution was increased to 5 minutes. The electrolessly deposited plate blistered.
Control 3 Example l was repeated except that immersion in the TCA solution was omitted. This also resulted in blistering ; of the electroless plate.
, Example 2 Example l was repeated except that the article after contact with the TCA solution was reimmersed in the caustic solu~ion for lO minutes to cleanse the surface. There was ~.' ,,- (-~1~3Z60 ':
12161:JPG
obtained uniform coverage of the electroless and electrolytic plate. Initial adhesion ranged from l.S to 1.8 Ib/in with an average of 1.7 Ib/in. The cycle test was successful.
:
Example 3 - Example 1 was repeated except that immersion in the TCA
solution was for 2 minutes followed by immersion in a hydrochloric acid solution for 1 minute. The article uni-; formly plated with electroless copper and was electrolytically ;~ 10 plated. Initial adhesion of the plate ranged from 1.3 to ' 1.8 lb/in with an average of 1.5 lb/in. The cycle test was successful.
Control 4 In this test Example 1 was repeated except that the Vydyne article was immersed in the hydrochloric acid solution for 1 minute, rinsed, then immersed for 1 minute in the TCA
solution and again for one minute in the hydrochloric acid solution. Small blisters developed in the electroless plating operation with extensive blistering occurring in the 2 reverse current cleaning step preceding electrolytic plating such that the article could not be electrolytically plated.
Control 5 ; 2 An article molded of Vydyne(TM) RP-260 was immersed in the hydrochloric acid solution for 1 minute, rinsed for 1 minute in the TCA solution, followed by 10 minutes in the caustic solution but at a reduced temperature of 160F. The electro-less plate exhibited small blisters with large blistering occurring in the reverse current cleaner.
'"'''`
`-~ ~ 3'~60 12161:JPG
1Example 4 An article molded of Vydyne(TM) RP-260 was immersed for lO
minu~es in the caustic solution, rinsed, immersed for l minute in the TCA solution and for 5 minutes in a cleaner - 5 which was a 50 percent volume by volume solution of glacial acetic acid in water at room temperature. The article accepted the electroless and the electrolytic plates.
Initial adhesion averaged 1.2 Ibs/in.
Example 5 10 An article molded of Capron(TM) XPN-1030, a filled Nylon 6 manufactured and sold by Allied Chemical Corporation, was immersed in the caustic solution for lO minutes, rinsed, then immersed in a 10 percent volume by volume solution of dichloracetic acid for 5 minutes. The article accepted uniform electroless and electrolytic plates.
Example 6 Example 5 was repeated except that immersion in the dichloracetic solution was for 2 minutes at 120F. The same results were obtained.
.' Example 7 An article molded of Vydyne(TM) RP-260, following immersion in the alkali hydroxide solution as described in Example 1, was immersed for 15 seconds in a 90 percent aqueous acetic acid solution at room temperature. The etched article accepted an adherent deposit of electroless copper, then adherent electrolytic pLates of copper, nlckel and chrome.
11~3Z60 :' 12161:JPG
1 Example 8 The procedure of-Example 1, was repeated except that the trichloracetic acid concentration was reduced to 10 percent by weight to volume. Immersion was for I minute.
The etched article accepted uniform adherent deposit of electroless copper, an electrolytic plate of copper, nickel then chrome.
Example 9 The procedure of Example 8, was repeated except that the polyamide substrate was Capran(TM) XPN-1030. The results were equally successful.
~' Example 10 A substrate molded Minlon(TM) ll-C-40, a nylon manu~
factured and sold by DuPont, was immersed in a 2 percent by volume solution of cresylic acid in a 5 percent by weight volume aqueous solution of sodium hydroxide, maintained at I 130 F for 5 minutes, then immersed in the alkali hydroxide ; ¦ solution maintained at 200F for lO minutes and for l minute ¦ in a 15 percent weight by volume aqueous solution of tri-¦ chloracetic acid. The etched article accepted upon catalysation ¦ a uniform electroless plate of copper and an electrolytic ¦ plate of copper, nickel then chrome and passed the cycle test.
¦ Adhesion ranged from 2 to 3 pounds per inch.
¦ Example 11 ¦ There was employed an unfilled nylon substrate formed of Capron(TM) 8202F - Type 6 manufactured and sold by Allied Chemical Corporation. The substrate was contacted with the ~1~3;260 1216l:JPG
1 caustic solution for 5 minutes at 200 F, then with the TCA
solution for 1 minute at ambient temperature, followed by c re-contact with the caustic solution for 5 minutes. The etched substrate accepted uniform electroless and electrolytic plates.
Controls 7 to 9 In tests on Vydyne where contact with the alkali hydroxide solution was used for 5 or 10 minutes contact, failues occurred in the organic solutions and conditions identified below.
Control Test Solution Nature of (Conc, Temp, Contact Time) Failure 7 dichloropropanol(l5% v/v, Massive blistering ; 15 150F, 1.5 min.) in cycle test 8 do Blistered severely in reverse current : 9 Formic acid (45% v/v, Blistered in pre-R.T., 1 min.) plate ,.:' 30 l
113-~
~ 3Z60 In conducting the process of the invention, the article may he treated by contacting the article in an aqueous solution of an organic solvent for the polyamide, prior to or following contact with the alkaline solution. Alternatively, the organic solvent can be contained in the alkaline solution.
j The solvent in its solution is normally employed in a concen-tration up to about 2 percent by weight, preferably up to about 1 percent by weight. Ethylene glycol, phenolic compounds such as chlorophenol, cresols and salts thereof are presently I 10 preferred. As indicated, solvent may be contained in its own ! bath or included in the alkaline solution so long as the organic solvent is not hydrolyzed or degraded. The solvent serves to soften plastic to aid attack by the alkaline conditioner or acid etch.
¦ 15 As indicated, the substrate after etching may be further processed to remove the debris of etching by contact with acidic to basic wash.
! Detailed Description ¦ The present invention provides a process which enables ¦ 20 uniform electroless deposition of metals onto polyamide substrates. In particular, the processes of the present invention are directed to improvements in electroless plating of filled and unfilled polyamides such as Nylon 6 and Nylon 6,6.
In its broadest aspects, the invention is directed to conditioning the surface of a polyamide substrate with an ; aqueous alkaline solution having a p~I of at least about 10 to render the surface receptive to attack by an acid etch.
~ 4 -~` - ~ ( 1~3260 12161:JPG
l Although solutions of alkali hydroxide are preferab1y employed, there may also be used alkaline compounds such as sodium metasilicate, trisodium phosphate, sodium carbonate and the like, used alone, in admixture and/or in combination with an alkali metal hydroxide.
When a conditioning solution of at least one alkali metal hydroxide is employed, the solution has an alkali metal hydroxide content of from about 2 percent by weight of solution to solution saturation, preferably about 10 to about 50 per cent by weight.
~ ¦ The alkali conditioning solutions are, as presently v- ¦ employed, maintained at a temperature from about 150F to ¦ the lesser of the boiling point of the solution and the ¦ softening temperature of the polyamide.
15 ¦ Contact is for a time sufficient to render the substrate ¦ receptive to attack by the acid etch; and after rinsing, ¦ is followed by contact of the polyamide substance with an ¦ acid etch solution. The preferred acid solutions are solutions ¦ comprising at least one soluble organic acid containing at 20 ¦ least two carbon atoms, and contact is for a time sufficient ¦ to render the surface receptive to a metal catalyst. The ¦ metal catalyst may be in the form of a solution of functional ¦ metal ions or as a dispersion of metal particles. It is ¦ presently preferred that the organic acid be an acetic 25 ¦ acid compound as defined below.
¦ As part of the process measures, water rinsing with ¦ deionized water is performed for good housekeeping between ¦ each step. The substrate may be treated with a dilute ¦ solution of solvent for the polyamide to soften the surface 30 l .
-~ ~ ~
1~3260 12l61:JPG
l of the polyamide to promote conditioning and/or etch.
Contact. with the solvent may be prior to or after contact with the alkaline solution or contained in the alkaline solution. It is presently preferred to contact the substrate with the solvent following contact with the alkaline solution.
If desired, a solution of the solvent may be employed prior to and following contact with the alkaline conditioner. The solvent softens the surface of the substrate to promote conditioning or etching. The solvent for the polyamide may be contained in a separate bath or part of the alkaline solution.
In addition, the substrates may be contacted with an acidic to basic solution subsequent to etch to remove debris present on the surface of the substrate.
The procedure of contact with the aqueous alkaline solution prior to contact with an acid etch is critical to the process of the invention and the reverse of steps normally conducted in electroless plating operations.
While reception of electroless plating onto the surface of any polyamide may be enhanced, the polyamides to be normally treated are filled polyamides as are conventionally used in molding operations. Typical of such materials are filled Nylon 6, Nylon 6,6 and the like.
The first essential step of the process is contacting the polyamide substrate with an aqueous alkaline solution.
2 The presently preferred solutions are solutions of at least one alkali metal hydroxide, such as sodium and/or potassium hydroxide, present in a concentration from about 3 percent by weight of solution to solution saturation, preferably from about lO to about 50 percent by weight. Solution temperature :~ ~ (- (-~1~a3~60 12161:JPG
1 is maintained from about 150F to the lesser of the boiling point of the solution and the softe~ing temperature of the polyamide substrate, preferably from a temperature of about 170 to about 200F.
S Contact time may vary from about 0.5 to 20 minutes or more, depending upon temperature and the alkaline compound concentration, although it has been found that prolonged immersions will not damage the substrate. The object is to condition the surface of the substrate to make it receptive 0 to attack by the acid etch.
Following water rinsing to remove the alkaline ; conditioning solution, the article is passed to an acid etch, preferably one based on organic acids containing from 2 to ;; about 10 carbon atoms and having a water solubility of at least about 3 percent by weight of solution. The presently preferred etch is one comprising from about 5 percent by weight to about 65 percent by weight of solution and more preferably, from about 10 to about 25 percent.by weight of solution of at least one acetic compound of the formula:
~' X C C ~
where each X is independently hydroxyl, hydrogen or halogen 2 with halogen preferred.
Contact is at ambient or room temperature although elevated temperatures may be employed. Contact times range from about . 10 seconds to lS minutes or more and are for a time sufficient to etch the surface of the polyamide to a degree that it becomes uniformly receptive to seeding by a metal catalyst.
`~! 3 ,. 9 ;'' ' 11~3~60 12161:JPG
Among the acetic acid compounds which may be used there may be mentioned trichloracetic acid, acetic acid, hydroxy-aceti^ acid, dichloracetic acid, chloracetic acid, fluoracetic acid, difluoracetic acid, trifluoracetic acid, bromacetic acid, dibromacetic acid and the like. Trichloroacetic acid is presently preferred.
Optionally, there may be employed as part of the process, contact with an organic solvent for the polyamide. The solvent may be in a separate bath used preceding and/or following the alkaline conditioning solution or included in the alkaline con-ditioning solutionr The organic solvent softens the surface of the substrate to aid attack by the conditioning and/or etching solutions. Typically, concentration of the solvent in its solution is up to about 2 percent by weight, preferably up to about l percent by weight. A wide variety of solvents for polyamides may be used. The presently preferred solvents are , ethylene glycol, chlorophenol, cresols and salts thereof. If employed in the alkaline conditioner as its solution, the sol-; vent should not be hydrolyzed or degraded by the alkaline batch.
~ 20 In addition, subsequent to contact with the acid etch, : the substrate may be brought into contact with an acid to ~, alkaline solution of either an organic or inorganic acid or base to cleanse the surface of debris, i.e., filler and/or degradated resin. Such solutions are normally maintained at room temperature, although elevated temperatures may be ¦ employed. Although solutions used as the conditioner may be r'; ¦ employed, solutions having an acidic or alkaline compound , ¦ in concentration in the range up to about 20 percent by weight, : ¦ preferably up to about l0 percent by weight may also be 30 ¦ employed. Functional acids include hydrochloric acid, sulfuric ~ acid, phosphoric acid, nitric acid, formic acid, acetic acid 113-l 1 8 .' I
' ~1~3,''260 and the like. As indicated, there may also be used as a convenience to minimize the number of baths involved, the alkaline solution used for conditioning the substrate.
- Alternative solutions include such as solutions of borax,ammonium bifluoride and the like. The concentration is that - which will enhance surface finish without detracting fromthe ability of etched surface to accept a metal catalyst.
Whether or not the cleansing treatment is employed, the article is rinsed in water, usually deionized water, and seeded with a metal electroless plating catalyst.
The electroless plating catalysts employed may be nob~e metal or non-noble metal based. Non-noble metal catalysts are described in United States Patent 3,958,048 to the same assignee as this application.
A noble metal catalyst in an aqueous medium is presently preferred. By a "noble metal catalyst contained in an aqueous medium" there is meant an ionic solution or colloidal suspension of the free metals. Colloidal suspensions are preferred. The noble metals include gold, platinum and palladium, with palladium preferred.
A suitable ionic bath is one containing palladium chloride in a concentration of about 0~2 grams per liter solution and 3 ml of concentrated hydrochloric acid per liter of solution. Following seeding, the palladium can be reduced to the free metal state by immersion in a bath of a reducing agent such as dimethyl amine borane.
Colloidal suspensions of noble metals are described in United States Patent 3,011,920 to C.R. Shipley, Jr. Such -- suspensions are colloidal in nature in which the noble metal ~ 30 colloid is maintained in suspension . _ g _.
. ~
'~
.
3~60 by a protective colloid, i.e., stannic acid colloids. Following seeding, the colloid is removed by immersion in an acidic or alkaline accelerator solution to remove the protective colloid and expose the absorbed noble metal.
- 5 Although less preferred, there may also be employed a seeding method which involves contacting the etched article with a sensitizing solution containing stannous chloride followed by immersion in an activator solution such as a palladium chloride solution where the ionic palladium is reduced to the free metal on the surface of the substrate.
Suitably activated, the article may be electrolessly plated by conventional means. Electroless copper and nickel formulations, such as those described in United States Patents 3,011,920 and 3,874,072, may be employed. Electroless copper solutions are typically based on a soluble copper salt, such as copper sulfate, a complexing agent for the cupric ion such as Rochelle salt, an alkali hydroxide for adjustment of pH, a carbonate radical as a buffer and a reducing agent for the cupric ion such as formaldehyde.
Following electroless plating, the substrate may be electrolytically plated by conventional means, with nickel, gold, silver, chromium and the like to provide the desired finish on the article. It has been observed that adhesion will increase with age of the plate.
In the following Examples and Controls where the article or substrate was contacted with an alkali hydroxide solution, the bath was about 35 percent weight to volume sodium hydroxide solution maintained at 200~F. Where contacted with a _ ln 1143;Z60 ` 12161:JPG
l hydrochloric acid solution, the solution was a 28.5 percent (volume by volume) of concentrated hydrochloric acid in water.
The solution of trichloracetic acid (TCA solution) employed was a 20 percent by weight to volume aqueous solution maintained at room temperature. Seeding of the etched substrate was with a proprietary colloidal tin-palladium catalyst as described in U.S. Patent 3,011,920 at an acid molarity of about 1.7.
An alkaline accelerator was used to expose the palladium metal.
The catalyst was maintained at about 120F and the accelerator at about 105F. The electroless copper solution employed was Cuposit(TM) PM-990 manufactured and sold by the Shipley Company.
The electroless copper solution was maintained at ambient temperature.
Following electroless plating, the article was electrolytically plated when possible. In this operation, the substrate was rinsed in deionized water, soaked in an alkaline cleaner, then passed to a reverse current cleaner, an acid dip, bright acid copper and nickel electrolytic plating solutions and finally to a chromium plating solution.
Some plated articles were subjected to cycle testing to determine adhesion performance under thermal stress conditions.
In this test the plated article was maintained at a temper-ature of at least 180 F for l hour, then cooled to room temperature and maintained at room temperature for 30 min-; 25 utes then cooled to -20 F and maintained at that temperature for l hour.
113-1 ll ~ ~ 3;~1i0 lExample l A p1ating grade of filled Nylon 6,~ known as Vydyne(TM) RP-260, manufactured and sold by the Monsanto Company, was - immersed for lO minutes in the alkali hydroxide solution then water rinsed and immersed for l minute in the TCA solution.
The article was then rinsed in water, catalyzed, rinsed, electrolessly plated with copper and electrolytically plated.
Initial plate adhesion ranged from l.0 to l.5 lb/in with an average of 1.3 lb/in. The cycle test was successful.
Control l The procedure of Example l was reversed in that the article was immersed in the TCA solution prior to contact with the alkali hydroxide solution. This resulted in skip - plating and blistering of the electroless plate.
Control 2 ; Control l was repeated except that immersion time in the TCA solution was increased to 5 minutes. The electrolessly deposited plate blistered.
Control 3 Example l was repeated except that immersion in the TCA solution was omitted. This also resulted in blistering ; of the electroless plate.
, Example 2 Example l was repeated except that the article after contact with the TCA solution was reimmersed in the caustic solu~ion for lO minutes to cleanse the surface. There was ~.' ,,- (-~1~3Z60 ':
12161:JPG
obtained uniform coverage of the electroless and electrolytic plate. Initial adhesion ranged from l.S to 1.8 Ib/in with an average of 1.7 Ib/in. The cycle test was successful.
:
Example 3 - Example 1 was repeated except that immersion in the TCA
solution was for 2 minutes followed by immersion in a hydrochloric acid solution for 1 minute. The article uni-; formly plated with electroless copper and was electrolytically ;~ 10 plated. Initial adhesion of the plate ranged from 1.3 to ' 1.8 lb/in with an average of 1.5 lb/in. The cycle test was successful.
Control 4 In this test Example 1 was repeated except that the Vydyne article was immersed in the hydrochloric acid solution for 1 minute, rinsed, then immersed for 1 minute in the TCA
solution and again for one minute in the hydrochloric acid solution. Small blisters developed in the electroless plating operation with extensive blistering occurring in the 2 reverse current cleaning step preceding electrolytic plating such that the article could not be electrolytically plated.
Control 5 ; 2 An article molded of Vydyne(TM) RP-260 was immersed in the hydrochloric acid solution for 1 minute, rinsed for 1 minute in the TCA solution, followed by 10 minutes in the caustic solution but at a reduced temperature of 160F. The electro-less plate exhibited small blisters with large blistering occurring in the reverse current cleaner.
'"'''`
`-~ ~ 3'~60 12161:JPG
1Example 4 An article molded of Vydyne(TM) RP-260 was immersed for lO
minu~es in the caustic solution, rinsed, immersed for l minute in the TCA solution and for 5 minutes in a cleaner - 5 which was a 50 percent volume by volume solution of glacial acetic acid in water at room temperature. The article accepted the electroless and the electrolytic plates.
Initial adhesion averaged 1.2 Ibs/in.
Example 5 10 An article molded of Capron(TM) XPN-1030, a filled Nylon 6 manufactured and sold by Allied Chemical Corporation, was immersed in the caustic solution for lO minutes, rinsed, then immersed in a 10 percent volume by volume solution of dichloracetic acid for 5 minutes. The article accepted uniform electroless and electrolytic plates.
Example 6 Example 5 was repeated except that immersion in the dichloracetic solution was for 2 minutes at 120F. The same results were obtained.
.' Example 7 An article molded of Vydyne(TM) RP-260, following immersion in the alkali hydroxide solution as described in Example 1, was immersed for 15 seconds in a 90 percent aqueous acetic acid solution at room temperature. The etched article accepted an adherent deposit of electroless copper, then adherent electrolytic pLates of copper, nlckel and chrome.
11~3Z60 :' 12161:JPG
1 Example 8 The procedure of-Example 1, was repeated except that the trichloracetic acid concentration was reduced to 10 percent by weight to volume. Immersion was for I minute.
The etched article accepted uniform adherent deposit of electroless copper, an electrolytic plate of copper, nickel then chrome.
Example 9 The procedure of Example 8, was repeated except that the polyamide substrate was Capran(TM) XPN-1030. The results were equally successful.
~' Example 10 A substrate molded Minlon(TM) ll-C-40, a nylon manu~
factured and sold by DuPont, was immersed in a 2 percent by volume solution of cresylic acid in a 5 percent by weight volume aqueous solution of sodium hydroxide, maintained at I 130 F for 5 minutes, then immersed in the alkali hydroxide ; ¦ solution maintained at 200F for lO minutes and for l minute ¦ in a 15 percent weight by volume aqueous solution of tri-¦ chloracetic acid. The etched article accepted upon catalysation ¦ a uniform electroless plate of copper and an electrolytic ¦ plate of copper, nickel then chrome and passed the cycle test.
¦ Adhesion ranged from 2 to 3 pounds per inch.
¦ Example 11 ¦ There was employed an unfilled nylon substrate formed of Capron(TM) 8202F - Type 6 manufactured and sold by Allied Chemical Corporation. The substrate was contacted with the ~1~3;260 1216l:JPG
1 caustic solution for 5 minutes at 200 F, then with the TCA
solution for 1 minute at ambient temperature, followed by c re-contact with the caustic solution for 5 minutes. The etched substrate accepted uniform electroless and electrolytic plates.
Controls 7 to 9 In tests on Vydyne where contact with the alkali hydroxide solution was used for 5 or 10 minutes contact, failues occurred in the organic solutions and conditions identified below.
Control Test Solution Nature of (Conc, Temp, Contact Time) Failure 7 dichloropropanol(l5% v/v, Massive blistering ; 15 150F, 1.5 min.) in cycle test 8 do Blistered severely in reverse current : 9 Formic acid (45% v/v, Blistered in pre-R.T., 1 min.) plate ,.:' 30 l
Claims (38)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a process for electroless plating of polyamide substrate wherein the substrate is etched with an acid prior to electroless plating, the improvement which comprises conditioning the substrate prior to etch by contact with an aqueous alkaline conditioning solution having a pH of at least about 10 and maintained at a temperature of from about 150°F
to the lesser of the boiling point of the solution and the softening temperature of the polyamide substrate for a time sufficient to enhance acid etch of the polyamide substrate.
to the lesser of the boiling point of the solution and the softening temperature of the polyamide substrate for a time sufficient to enhance acid etch of the polyamide substrate.
2. A process as claimed in claim 1, in which the polyamide substrate is contacted with the conditioning solution for a period of from about 0.5 to about 20 minutes.
3. A process as claimed in claim 1, in which the polyamide substrate is contacted, prior to contact with the conditioning solution, with a dilute aqueous solution of an organic solvent for the polyamide for a time sufficient to soften the surface of the polyamide substrate.
4. A process as claimed in claim 1, in which the polyamide substrate is contacted following contact with the conditioning solution, with a dilute aqueous solution of an organic solvent for the polyamide for a time sufficient to soften the surface of the polyamide substrate.
12161:
12161:
5. A process as claimed in claim 1 in which the conditioning solution contains an organic solvent for the polyamide.
6. A process for preparing the surface of polyamide substratres for electroless plating which comprises:
(a) forming a conditioned polyamide substrate for etching by contacting the polyamide substrate with an aqueous alkaline conditioning solution having a pH of at least about 10 and maintained at a temperature from about 150°F to the lesser of the boiling point of the solution and the softening temperature of the polyamide substrate for a time sufficient to render the substrate receptive to etch by an organic acid;
(b) etching the conditioned polyamide substrate by contacting the conditioned polyamide substrate with an aqueous etch solution comprising at least one water soluble organic acid containing from 2 to about 10 carbon atoms in the molecule and present in the aqueous solution in a con-centration of at least about 3 percent by weight of the solution and sufficient to render the conditioned polyamide substrate substantially uniformly receptive to a metal electroless plating catalyst.
(a) forming a conditioned polyamide substrate for etching by contacting the polyamide substrate with an aqueous alkaline conditioning solution having a pH of at least about 10 and maintained at a temperature from about 150°F to the lesser of the boiling point of the solution and the softening temperature of the polyamide substrate for a time sufficient to render the substrate receptive to etch by an organic acid;
(b) etching the conditioned polyamide substrate by contacting the conditioned polyamide substrate with an aqueous etch solution comprising at least one water soluble organic acid containing from 2 to about 10 carbon atoms in the molecule and present in the aqueous solution in a con-centration of at least about 3 percent by weight of the solution and sufficient to render the conditioned polyamide substrate substantially uniformly receptive to a metal electroless plating catalyst.
7. A process as claimed in claim 6 in which the polyamide substrate is cleansed prior to contact with the metal catalyst by contact with an aqueous acidic or basic cleansing solution.
8. A process as claimed in claim 6 in which the polyamide substrate is contacted, prior to contact with the conditioning solution, with a dilute aqueous solution of an organic solvent for the polyamide for a time sufficient to soften the surface of the polyamide substrate.
9. A process as claimed in claim 6 in which the polyamide substrate is contacted following contact with the conditioning solution, with a dilute aqueous solution of an organic solvent for the polyamide for a time sufficient to soften the surface of the polyamide substrate.
10. A process as claimed in claim 6 in which the conditioning solution contains an organic solvent for the polyamide.
11. A process for preparing the surface of polyamide substrates for electroless plating which comprises:
(a) forming a conditioned polyamide substrate for etching by contacting the polyamide substrate with an aqueous conditioning solution of at least one alkali metal hydroxide in which the alkali metal hydroxide concentration of the solution is from about 2 percent by weight of the solution to solution saturation and maintained at a temperature of from about 150°F to the lesser of the boiling point of the solution and the softening temperature of the polyamide surface for a time sufficient to render surface polyamide substrate receptive to etch by an acetic acid compound;
(Claim 11 cont.) (b) etching the conditioned polyamide substrate by contacting the conditioned polyamide substrate with an aqueous acid etch solution comprising at least one acetic acid compound having the formula:
wherein each X is independently selected from the group consisting of hydrogen, hydroxyl and halogen and in which the acetic acid compound concentration is sufficient to render the conditioned polyamide substrate receptive to a metal electroless plating catalyst.
(a) forming a conditioned polyamide substrate for etching by contacting the polyamide substrate with an aqueous conditioning solution of at least one alkali metal hydroxide in which the alkali metal hydroxide concentration of the solution is from about 2 percent by weight of the solution to solution saturation and maintained at a temperature of from about 150°F to the lesser of the boiling point of the solution and the softening temperature of the polyamide surface for a time sufficient to render surface polyamide substrate receptive to etch by an acetic acid compound;
(Claim 11 cont.) (b) etching the conditioned polyamide substrate by contacting the conditioned polyamide substrate with an aqueous acid etch solution comprising at least one acetic acid compound having the formula:
wherein each X is independently selected from the group consisting of hydrogen, hydroxyl and halogen and in which the acetic acid compound concentration is sufficient to render the conditioned polyamide substrate receptive to a metal electroless plating catalyst.
12. A process as claimed in claim 11 in which the polyamide substrate is cleansed prior to contact with the metal catalyst by contact with an aqueous acidic or basic cleansing solution.
13. A process as claimed in claim 11 in which the polyamide substrate is contacted, prior to contact with the conditioning solution, with a dilute aqueous solution of an organic solvent for the polyamide for a time sufficient to soften the surface of the polyamide substrate.
2161:
2161:
14. A process as claimed in claim 11 in which the polyamide substrate is contacted following contact with the conditioning solution, with a dilute aqueous solution of an organic solvent for the polyamide for a time sufficient to soften the surface of the polyamide substrate.
15. A process as claimed in claim 11 in which the conditioning solution contains an organic solvent for the polyamide.
16. A process as claimed in claim 15 in which the organic solvent is an alkali soluble organic solvent.
17. A process as claimed in claim 11 in which the polyamide substrate is formed of a filled polyamide.
18. A process as claimed in claim 11 in which the total alkali metal hydroxide content of the conditioning solution is from about 10 to about 50 percent by weight of the solution.
19. A process as claimed in claim 11 in which the conditioning solution is maintained at a temperature from about 170 to about 200°F.
20. A process as claimed in claim 11 in which the contact time in the conditioning solution is from about 0.5 to about 20 minutes.
12161:
12161:
21. A process as claimed in claim 11 in which the total acetic acid compound concentration of the etch solution is from about 3 percent by weight to solution saturation.
22. A process as claimed in claim 11 in which the total acetic acid compound concentration of the etch solution is from about 5 to about 60 percent by weight of the solution.
23. A process as claimed in claim 11 in which the polyamide substrate is contacted with the etch solution for a period of from about 10 seconds to about 15 minutes.
24. A process as claimed in claim 11 in which the acetic acid compound is trichoracetic acid.
25. A process as claimed in claim 11 in which the acetic acid compound is dichloracetic acid.
26. A process as claimed in claim 11 in which the acetic acid compound is acetic acid.
27. A process for preparing the surface of polyamide substrates for electroless plating which comprises:
(a) forming a conditioned polyamide substrate by contacting the polyamide substrate with an aqueous condition-ing solution of at least one alkali metal hydroxide in which the total alkali metal hydroxide concentration is from about 10 per cent by weight of the solution to solution saturation 12161:
(Claim 27 cont.) and maintained at a temperature of from about 150°F to the lesser of the boiling point of the solution and the softening temperature of the polyamide surface for a period of from about 0.5 to about 20 minutes;
(b) forming an etched polyamide substrate by contacting the conditioned polyamide substrate with an aqueous etch solution comprising at least one acetic acid compound selected from the group consisting of trichloracetic acid, dichoracetic acid and acetic acid in which the acetic acid compound concentration is sufficient to render the conditioned polyamide substrate receptive to a metal electroless plating catalyst.
(a) forming a conditioned polyamide substrate by contacting the polyamide substrate with an aqueous condition-ing solution of at least one alkali metal hydroxide in which the total alkali metal hydroxide concentration is from about 10 per cent by weight of the solution to solution saturation 12161:
(Claim 27 cont.) and maintained at a temperature of from about 150°F to the lesser of the boiling point of the solution and the softening temperature of the polyamide surface for a period of from about 0.5 to about 20 minutes;
(b) forming an etched polyamide substrate by contacting the conditioned polyamide substrate with an aqueous etch solution comprising at least one acetic acid compound selected from the group consisting of trichloracetic acid, dichoracetic acid and acetic acid in which the acetic acid compound concentration is sufficient to render the conditioned polyamide substrate receptive to a metal electroless plating catalyst.
28. A process as claimed in claim 27 in which the polyamide substrate is cleansed prior to contact with the metal catalyst by contact with an aqueous acidic or basic cleansing solution.
29. A process as claimed in claim 27 in which the polyamide substrate is contacted, prior to contact with the conditioning solution, with a dilute aqueous solution of an organic solvent for the polyamide for a time sufficient to soften the surface of the polyamide substrate.
12161:
12161:
30. A process as claimed in claim 27 in which the polyamide substrate is contacted following contact with the conditioning solution, with a dilute aqueous solution of an organic solvent for the polyamide for a time sufficient to soften the surface of the polyamide substrate.
31. A process as claimed in claim 27 in which the conditioning solution contains an organic solvent for the polyamide.
32. A process as claimed in claim 31 in which the organic solvent is alkali soluble.
33. A process as claimed in claim 21 in which the polyamide substrate is formed of a filled polyamide.
34. A process as claimed in claim 27 in which the total alkali metal hydroxide content of the conditioning solution is from 10 to about 50 percent by weight of the solution.
35. A process as claimed in claim 27 in which the conditioning solution is maintained at a temperature from about 170 to about 200°F.
36. A process as claimed in claim 27 in which the total acetic acid compound concentration of the etch solution is from about 5 percent by weight of the solution to solution saturation.
1.3-1 ?161:
1.3-1 ?161:
37. A process as claimed in claim 27 in which the total acetic acid compound concentration of the etch solution is from about 5 to about 60 percent by weight of the solution.
38. A process as claimed in claim 27 in which the polyamide substrate is contacted with the etch solution for a period of from about 10 seconds to about 15 minutes.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US97092378A | 1978-12-19 | 1978-12-19 | |
US970,923 | 1978-12-19 |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1143260A true CA1143260A (en) | 1983-03-22 |
Family
ID=25517714
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA000342112A Expired CA1143260A (en) | 1978-12-19 | 1979-12-12 | Conditioning of polyamides for electroless plating |
Country Status (6)
Country | Link |
---|---|
JP (1) | JPS55112238A (en) |
CA (1) | CA1143260A (en) |
DE (1) | DE2946343C2 (en) |
FR (1) | FR2444691A1 (en) |
GB (1) | GB2040969B (en) |
IT (1) | IT1164546B (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4325991A (en) * | 1981-01-05 | 1982-04-20 | Crown City Plating Co. | Electroless plating of polyesters |
DE3137587A1 (en) * | 1981-09-22 | 1983-04-14 | Schering Ag, 1000 Berlin Und 4619 Bergkamen | Process for the pretreatment of polyamide mouldings for the application of strongly adherent, chemically deposited metal coatings |
JPH0427472A (en) * | 1990-05-21 | 1992-01-30 | Nippon Parkerizing Co Ltd | Washing method for resin molding |
DE4328883C2 (en) * | 1993-08-27 | 1996-08-14 | Bayer Ag | Process for the preparation of molded polyamide parts for the subsequent electroless metallization |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1042816A (en) * | 1964-06-15 | 1966-09-14 | Ibm | Improvements in or relating to the production of metallic coatings upon the surfacesof other materials |
US3595761A (en) * | 1965-02-18 | 1971-07-27 | Enthone | Chemical reduction metal plated diallylphthalate polymer and preparation process |
US3370974A (en) * | 1965-10-20 | 1968-02-27 | Ivan C. Hepfer | Electroless plating on non-conductive materials |
US3377187A (en) * | 1967-02-21 | 1968-04-09 | American Cyanamid Co | Glossy, transparent nylon film having an ionically reacted content of a strongly acidic material and method of making same |
DE1920238A1 (en) * | 1969-04-22 | 1970-11-12 | Du Pont Deutschland | Surface pre-treatment of mouldings made of - polyoxymethylene homopolymers |
US3686017A (en) * | 1970-10-05 | 1972-08-22 | Monsanto Co | Surface treatment of nylon shaped articles with aqueous reducing agents |
BE792310A (en) * | 1971-12-08 | 1973-06-05 | Kalle Ag | PROCESS FOR DEPOSITING COPPER COATS ON MOLDED PARTS OF POLYIMIDES |
FR2131563A7 (en) * | 1972-03-23 | 1972-11-10 | Dynachim Sarl | Metal coating - of non-metallic substrates |
FR2199012A1 (en) * | 1972-09-11 | 1974-04-05 | Aries Robert | Etching compsn. for metallisation process - contg alkali hydroxide, org. solvent and surfactant |
US4125649A (en) * | 1975-05-27 | 1978-11-14 | Crown City Plating | Pre-etch conditioning of polysulfone and other polymers for electroless plating |
-
1979
- 1979-11-07 GB GB7938564A patent/GB2040969B/en not_active Expired
- 1979-11-16 DE DE2946343A patent/DE2946343C2/en not_active Expired
- 1979-12-12 CA CA000342112A patent/CA1143260A/en not_active Expired
- 1979-12-17 IT IT28067/79A patent/IT1164546B/en active
- 1979-12-18 FR FR7930961A patent/FR2444691A1/en active Granted
- 1979-12-19 JP JP16548379A patent/JPS55112238A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS55112238A (en) | 1980-08-29 |
IT1164546B (en) | 1987-04-15 |
IT7928067A0 (en) | 1979-12-17 |
DE2946343C2 (en) | 1983-03-24 |
JPS633950B2 (en) | 1988-01-26 |
FR2444691B1 (en) | 1983-11-04 |
GB2040969A (en) | 1980-09-03 |
FR2444691A1 (en) | 1980-07-18 |
DE2946343A1 (en) | 1980-06-26 |
GB2040969B (en) | 1983-04-13 |
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