GB2186597A - Electrical contact surface coating - Google Patents
Electrical contact surface coating Download PDFInfo
- Publication number
- GB2186597A GB2186597A GB08603900A GB8603900A GB2186597A GB 2186597 A GB2186597 A GB 2186597A GB 08603900 A GB08603900 A GB 08603900A GB 8603900 A GB8603900 A GB 8603900A GB 2186597 A GB2186597 A GB 2186597A
- Authority
- GB
- United Kingdom
- Prior art keywords
- nickel
- layer
- gold
- surface coating
- palladium
- 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.)
- Granted
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D7/00—Electroplating characterised by the article coated
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/10—Electroplating with more than one layer of the same or of different metals
- C25D5/12—Electroplating with more than one layer of the same or of different metals at least one layer being of nickel or chromium
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/60—Electroplating characterised by the structure or texture of the layers
- C25D5/623—Porosity of the layers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
- H01R13/00—Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
- H01R13/02—Contact members
- H01R13/03—Contact members characterised by the material, e.g. plating, or coating materials
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electroplating Methods And Accessories (AREA)
- Contacts (AREA)
Abstract
A process for providing an electrically conductive surface coating on an electrical contact body, the process comprising the steps of depositing upon the body (1) surface in sequence, (a) a nickel layer (2), (b) a first gold layer (3), (c) a palladium/nickel alloy layer (4) which may be an alloy containing nickel up to a proportion of 50% by weight, and (d) a second gold layer (5). All the layers may be deposited by an electrodeposition process. The resulting surface coating has excellent corrosion and wear resistance properties.
Description
SPECIFICATION
Electrical contact surface coating
This invention relates to an electrical contact surface coating. It relates particularly to a process for providing a surface coating on an electrical contact body which will have good corrosion and wear resistance properties.
In the construction of electrical connectors for linking the separate parts of electrical equipment it is necessary to provide contact bodies which are capable of making good electrical contact with one another and will be able to do this even after the contact surfaces have been exposed to atmospheric conditions likely to cause surface corrosion of the bodies. The products of any surface corrosion are likely to include the formation of an electrically insulating film on the contact body and the occurence of this will cause an unacceptably high electrical resistance between a pair of the contact surfaces. In addition the contact bodies may need to be brought into contact with one another very many times over the lifetime of the equipment so that the contactmaking surface will need to be resistant to mechanical wear.
Some of these problems can be reduced by the use of gold as the contact surface coating. Whilst gold generally has good corrosion resistance, use of this element can lead to an increased cost of manufacture of the contactmaking bodies. The provision of an alternative suitable coating material would therefore be advantageous.
According to the invention, there is provided a process for forming an electrically conductive surface coating on an electrical contact body, the process comprising the steps of depositing upon the body surface in sequence (a) a nickel layer, (b) a first gold layer, (c) a palladium/nickel alloy layer which may be an alloy containing nickel up to a proportion of 50% by weight, and (d) a second gold layer.
Preferably, the separate layers are laid down by an electro-deposition process such as electroplating.
The nickel layer may be laid down so as to give a deposit of pure, soft, low stress nickel.
The relevant plating bath should be free of organic impurities and traces of metals other than nickel.
The first gold layer may be deposited from a conventional commercially available gold plating solution. A gold thickness of between 0.05 to 0.1 micrometres is laid down.
The palladium/nickel alloy layer may be deposited from a conventional commercial electroplating solution. The composition of the layer is satisfactory with palladium in the range of 50 to 100% by weight, balance nickei.
The second gold layer may be a pure gold metal or one containing metal hardening additives, such as cobalt, nickel or iron in amounts of approximately 0.2 to 0.5% by weight. One preferred composition for the second gold layer is similar to that used for the said first gold layer.
The invention also comprises an electrical contact body when manufactured with an electrically conductive surface coating having layers deposited in sequence of nickel, gold, palladium/nickel alloy and gold. The electrical contact body may be intended for use in applications such as electrical and electronic connector contacts, sliding contacts for electrical slip-rings and for printed circuit boards.
By way of example, a particular embodiment of the invention will now be described with reference to the accompanying drawing, the single figure of which shows a flow chart of the surface deposition process.
As shown in the drawing, an electrical contact body 1 after suitable cleaning and possibly a surface smoothing treatment is passed through a first electroplating bath 2 where it is given a coating of pure, soft, low stress nickel deposit. The nickel plating solution composition should be free of organic impurities and traces of metals other than nickel. In order to achieve this, the nickel plating solution may have been given a preliminary carbon treatment to remove organic impurities and been subject to a low current plating-out stage to remove any metal impurities.
The nickel plating solution should therefore preferably contain only nickel salts and possibly an additive such as boric acid. The thickness of nickel deposited is within the range of 0.5 to 3.0 micrometres.
After deposition of the nickel layer, the contact body is washed and it is then passed through a second electroplating bath 3 for the formation of a gold layer. The gold plating solution was a conventional commercial gold plating solution and a thickness of gold of between 0.05 and 0.1 micrometres was formed.
One gold plating solution that was found to be particularly suitable was that produced by
Degussa (West Germany) under the name of "Auruna 553 Solution".
The object of the nickel coating followed by the gold coating was partly to promote the formation of a low porosity coating in the palladium/nickel alloy layer that was to be applied subsequently and thus the gold enhanced the eventual corrosion resistance. In addition, the nickel and gold coatings served to reduce the possibility of a chemical contamination of the palladium/nickel electroplating solution used in the next stage by the accidental dissolution of metals such as copper, zinc or lead from the substrate material.
After deposition of the gold layer, the contact body 1 is washed and it is then passed through a third electroplating bath 4 for the formation of a palladium/nickel alloy layer. The palladium/nickel alloy deposition bath was a commercially available bath selected from a group comprising: Degussa (West Germa ny)-' 'Palladium Nickel 462 Solution", Englehard Industries--"Palnic Solution", Lea Ro nal-' 'Pallamet 30 Solution" and Sel-Rex (Oxymetal Industries)-' 'Palladex Solution". The conditions of deposition used were those recommended by the supplier of the relevant electroplating solution.
The composition of the palladium/nickel alloy layer was found to be satisfactory with palladium in the range of 50 to 100% by weight, balance nickel.
After deposition of the alloy layer, the contact body is washed and it is then passed through a fourth electroplating bath 5 to be given a thin plating of gold. The object of this step was to give a satisfactory wear resistance to the completed contact body and the type of gold deposit laid down was not found to be critical. The type of gold used may be either a pure gold metal or one containing metal-hardening additives, such as cobalt, nickel or iron in an amount of approximately 0.2 to 0.5% by weight.
A particularly suitable gold deposition bath 5 for the second gold layer is a similar bath to that used for the first gold layer.
After removing the plated contact body from the final bath and washing and drying the body, it was able to be tested to determine the wear and corrosion resistance of the resulting multi-layer surface coating.
As a result of the testing processes carried out, the coating was found to have improved corrosion resistance and good wear resistance properties as compared with an electrical contact body having a conventional surface coating.
The method of application of the electroplated layers to the contact body was found to be able to be carried out by any suitable electroplating technique such as barrel plating, vat plating or selective plating.
The foregoing description of an embodiment of the invention has been given by way of example only and a number of modifications may be made without departing from the scope of the invention as defined in the appended claims. For instance, instead of the electrical contact surface coating being laid down by an electrodeposition process, it might be possible to use a suitable alternative process such as an inlaid coating where the materials required for the different surface coatings are rolled into contact with one another.
Claims (8)
1. A process for providing an electrically conductive surface coating on an electrical contact body, the process comprising the steps of depositing upon the body surface in sequence, (a) a nickel layer, (b) a first gold layer, (c) a palladium/nickel alloy layer which may be an alloy containing nickel up to a proportion of 50% by weight, and (d) a second gold layer.
2. A process as claimed in Claim 1, in which at least one of the said layers is deposited by an electrodeposition process.
3. A process as claimed in Claim 1 or 2, in which the said nickel layer is a deposit of a pure, soft, low stress nickel coating.
4. A process as claimed in any one of
Claims 1 to 3, in which the said first gold layer has a thickness of between 0.05 to 0.1 micrometres.
5. A process as claimed in any one of
Claims 1 to 4, in which the said palladium/ nickel alloy layer has a composition with palladium in the range of 50 to 100% by weight, balance nickel.
6. A process as claimed in any one of
Claims 1 to 5, in which the said second gold layer is of a pure gold metal or a gold containing metal hardening additives such as cobalt, nickel or iron.
7. A process for providing an electrical conductive surface coating on an electrically contact body substantially as hereinbefore described with reference to the accompanying drawing.
8. An electrical contact body including a surface coating, when manufactured by a process as claimed in any one of Claims 1 to 7.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8603900A GB2186597B (en) | 1986-02-17 | 1986-02-17 | Electrical contact surface coating |
PCT/GB1987/000114 WO1987005057A1 (en) | 1986-02-17 | 1987-02-17 | Electrical contact surface coating |
EP87901534A EP0258365A1 (en) | 1986-02-17 | 1987-02-17 | Electrical contact surface coating |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8603900A GB2186597B (en) | 1986-02-17 | 1986-02-17 | Electrical contact surface coating |
Publications (3)
Publication Number | Publication Date |
---|---|
GB8603900D0 GB8603900D0 (en) | 1986-03-26 |
GB2186597A true GB2186597A (en) | 1987-08-19 |
GB2186597B GB2186597B (en) | 1990-04-04 |
Family
ID=10593200
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB8603900A Expired - Lifetime GB2186597B (en) | 1986-02-17 | 1986-02-17 | Electrical contact surface coating |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0258365A1 (en) |
GB (1) | GB2186597B (en) |
WO (1) | WO1987005057A1 (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0234487A2 (en) * | 1986-02-20 | 1987-09-02 | Alcatel SEL Aktiengesellschaft | Thin film circuit and method for manufacturing the same |
US4895771A (en) * | 1988-06-14 | 1990-01-23 | Ab Electronic Components Limited | Electrical contact surface coating |
US5066550A (en) * | 1989-07-27 | 1991-11-19 | Yazaki Corporation | Electric contact |
US5294486A (en) * | 1990-10-22 | 1994-03-15 | International Business Machines Corporation | Barrier improvement in thin films |
GB2305188A (en) * | 1995-09-16 | 1997-04-02 | Sung Soo Moon | Process for plating palladium or palladium alloy onto iron-nickel alloy substrate |
WO2007078799A2 (en) * | 2005-12-28 | 2007-07-12 | Intel Corporation | Low resistivity package substrate and its manufacturing method |
US20140234663A1 (en) * | 2009-07-10 | 2014-08-21 | Xtalic Corporation | Coated articles and methods |
EP3417089A4 (en) * | 2016-02-16 | 2020-01-15 | Xtalic Corporation | Articles including a multi-layer coating and methods |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE4431847C5 (en) * | 1994-09-07 | 2011-01-27 | Atotech Deutschland Gmbh | Substrate with bondable coating |
DE102005047799A1 (en) * | 2005-10-05 | 2007-05-24 | W.C. Heraeus Gmbh | Slip ring body for continuous power transmission |
WO2021188674A1 (en) * | 2020-03-18 | 2021-09-23 | Xtalic Corporation | Nanostructured palladium-based alloys and related methods |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60248892A (en) * | 1984-05-24 | 1985-12-09 | Electroplating Eng Of Japan Co | High-purity palladium-nickel alloy plating liquid and method thereof and alloy coated parts thereof and gold or gold alloy coated parts thereof |
-
1986
- 1986-02-17 GB GB8603900A patent/GB2186597B/en not_active Expired - Lifetime
-
1987
- 1987-02-17 WO PCT/GB1987/000114 patent/WO1987005057A1/en not_active Application Discontinuation
- 1987-02-17 EP EP87901534A patent/EP0258365A1/en not_active Ceased
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0234487A2 (en) * | 1986-02-20 | 1987-09-02 | Alcatel SEL Aktiengesellschaft | Thin film circuit and method for manufacturing the same |
EP0234487A3 (en) * | 1986-02-20 | 1990-03-07 | Standard Elektrik Lorenz Aktiengesellschaft | Thin film circuit and method for manufacturing the same |
US4895771A (en) * | 1988-06-14 | 1990-01-23 | Ab Electronic Components Limited | Electrical contact surface coating |
US5066550A (en) * | 1989-07-27 | 1991-11-19 | Yazaki Corporation | Electric contact |
US5294486A (en) * | 1990-10-22 | 1994-03-15 | International Business Machines Corporation | Barrier improvement in thin films |
GB2305188B (en) * | 1995-09-16 | 1997-11-12 | Sung Soo Moon | Process for plating palladium or palladium alloy onto iron-nickel alloy substrate |
GB2305188A (en) * | 1995-09-16 | 1997-04-02 | Sung Soo Moon | Process for plating palladium or palladium alloy onto iron-nickel alloy substrate |
WO2007078799A2 (en) * | 2005-12-28 | 2007-07-12 | Intel Corporation | Low resistivity package substrate and its manufacturing method |
WO2007078799A3 (en) * | 2005-12-28 | 2007-08-30 | Intel Corp | Low resistivity package substrate and its manufacturing method |
US7432202B2 (en) | 2005-12-28 | 2008-10-07 | Intel Corporation | Method of substrate manufacture that decreases the package resistance |
US20140234663A1 (en) * | 2009-07-10 | 2014-08-21 | Xtalic Corporation | Coated articles and methods |
US9765438B2 (en) * | 2009-07-10 | 2017-09-19 | Xtalic Corporation | Coated articles and methods |
EP3417089A4 (en) * | 2016-02-16 | 2020-01-15 | Xtalic Corporation | Articles including a multi-layer coating and methods |
Also Published As
Publication number | Publication date |
---|---|
GB2186597B (en) | 1990-04-04 |
WO1987005057A1 (en) | 1987-08-27 |
GB8603900D0 (en) | 1986-03-26 |
EP0258365A1 (en) | 1988-03-09 |
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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 |