CA1248780A - Nickel-based electrical contact - Google Patents

Nickel-based electrical contact

Info

Publication number
CA1248780A
CA1248780A CA000489652A CA489652A CA1248780A CA 1248780 A CA1248780 A CA 1248780A CA 000489652 A CA000489652 A CA 000489652A CA 489652 A CA489652 A CA 489652A CA 1248780 A CA1248780 A CA 1248780A
Authority
CA
Canada
Prior art keywords
contact
glass
nickel
contact material
forming additive
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
Application number
CA000489652A
Other languages
French (fr)
Inventor
Joachim J. Hauser
John T. Plewes
Murray Robbins
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AT&T Corp
Original Assignee
American Telephone and Telegraph Co Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by American Telephone and Telegraph Co Inc filed Critical American Telephone and Telegraph Co Inc
Application granted granted Critical
Publication of CA1248780A publication Critical patent/CA1248780A/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H1/00Contacts
    • H01H1/02Contacts characterised by the material thereof
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H1/00Contacts
    • H01H1/02Contacts characterised by the material thereof
    • H01H1/021Composite material

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Composite Materials (AREA)
  • Materials Engineering (AREA)
  • Contacts (AREA)
  • Conductive Materials (AREA)

Abstract

NICKEL-BASED ELECTRICAL CONTACT
Abstract Contacts comprising nickel and having a crystallographically disordered structure having electrical contact properties which render them suitable as replacements for gold contacts; disclosed contacts have low contact resistance even after prolonged exposure to an oxidizing ambient. Contacts comprising nickel and at least one glass-forming additive selected from boron, silicon, germanium, phosphorus, arsenic, antimony, or bismuth, are readily formed, e.g., as layers on substrates. A
crystallographically disordered structure is produced in a contact surface layer at least upon exposure to an oxidizing ambient; alternatively, such desired structure can be produced by ion bombardment and even in the absence of glass-forming additives.

Description

~2~71~

NICKEL-BASED ELECTRIC~L CONTACT
Technical Field _____________.__ The invention is concerned with electrical contact surfaces and, more specifically, with nickel-based contact surface materials.
_ ckground of the Invention_ _ _______ _ _ ____ _ __ Typically, the manufacture of high-quality electrical contacts has involved the use of gold whose ~roperties o~ low contact resistance and high chemical stability are key advantages in such usage. However, as the price oE gold remains high, efforts continue at finding alternative materials for contact manuEacture.
Prominent among such alternatives are precious metals other than gold; e.g., silver-palladium alloys have been found suitable for certain applications. While such alternate alloys are less expensive than gold, still Eurther cost reduction is desired, and nonprecious metal alloys such as, eAg., copper-nickel alloys have also been investigated for contact resistance and stability over time. See S. ~. Garte et al., "Contact Properties of Nickel-Containing Alloys", Electrlcal_Con_acts, 1972, Illinois Institute of Technology.
Summary of the Invention ____ _____ _ It has been discovered that certain nickel alloys have contact properties of high stability and low contact resistance comparable to those of gold.
In accordance with an aspect of the invention there is provided apparatus comprising an electrical contact, said contact comprising a surface of a body of contact material, said contact material comprising nickel and at least one glass forming additive selected from the group consisting of boron, germanium, phosphorus, arsenic, antimony, and bismuth, said at least one glass ~orming additive bein~ present in said contact material in an amount in the range ~rom 2 to 10 atom percent of the combined amount of nickel and said at least one glass Eorming additive, said combined amount being greater than ~2~

or equal to 70 atom percent of said contact material, whereby at least a surface portion of said contact material is crystallographically disordered at least upon exposure to an oxidizing ambient.
The addi-tion of one or several glass-forming elements results in a crystallographically disordered structure at least upon exposure of the layer to an oxidizing ambient, this as contrasted with the formation of crystalline nickel oxide in the absence of preferred addition of a glass-forming element. Alternatively, crystallographically disordered structure can be produced by ion bombardment, alpha particles being conveniently used for this purpose.
Surface contact resistance less than 100 milliohms is typically maintained even after prolonged exposure to an oxidizing ambient.
Brief Descri~tion of the Drawin~
____________ _______________ _ _ FIG. 1 is a perspective view of an electrical connector device in accordance with the invention; and FIG. 2 is a schematic cross-sectional view of a portion of a device in accordance with the invention.
Detailed Descr~tion __.________ ____ The electrical connector device shown in ~IG. 1 comprises housing 11 and contact pins 1~. Housing 11 is made of an electrically insulating material, and contact pins 12 have contact surfaces in accordance with the invention.
Shown in FIG. 2 are, in cross section, an electrically conducting member 21 on which a surface layer ~2 is situated. In accordance with the invention surface layer 22 is made of an alloy of nickel and at least one glass-forming additional element. Upon e~posure to an oxidizing atmosphere, portion 23 of layer 22 further comprises oxygen.
Preferred glass-forming additive elements are boron, silicon, germanium, phosphorus, arsenic, antimonyr and bismuth, and their presence in the contact layer is in a preferred amount in the range of from 1 to 40 and preferably 2 to 10 atom percent relative to the combined .

878~

amount of nickel and the additive element; preEerred al.so in the range of from 25 to 35 a~om percent where thermodynamically stable, stoichiometric compounds are formed.
In combination, nickel and the ~lass-forming additive element or elements constitute a preferred amount of at least 70 atom percent of the contact layer material.
In the interest of enhanced electrically and mechanical contact properties, the addition of cobalt is desirable, elements other than cobalt preferably being limited to amounts less than S atom percent in combination and preferably less than 1 atom percent. Particularly undesirable is the presence of Group VI elements such as sulfur, selenium, and tellurium, and their combined amount is preferably limited to less than 0.5 atom percent.
. In the case of non-stoichiometric aggregates, glass-forming additives to nickel are considered to inhibit the formation of semiconducting nickel oxide in an oxidizing ambient. Instead of such semiconducting nickel oxide, in the presence of the glass-forming additive, a surface layer of an aggregation including nickel, oxygen~
and the glass-forming additive is believed to be formed in sufficiently large regions of the layer, such aggregation having essentially metallic conduction properties. Based on experimental evidence the thickness of the oxygen-containing surface layer is estimated to be on the order of
2.5 nm.
Crystallographically disordered structure in nickel-containing layers is produced also upon ion bombardment which results in a crystallographically disordered structure even before exposure to an oxidizing ambient. Still, it is the disordered, quasi-amorphous, glass-like nature of an oxidized surface portion which is considered to be conducive to desired low contact resistance of a contact laver for use in an oxidizing ambient. A crystallographically disordered nickel aggregate preferably comprises nickel in an amount of at least 50 atom percent.
The following examples specifically illustrate the suitability of contacts in accordance with the invention.
Example 1. A layer consisting essentially of 95 atomic percent nickel and 5 atomic percent antimony was deposited by getter-sputtering approximately 3 micrometers thick on a copper substrate. Standard four-point probes were used to determine surface contact resistance; such resistance was found to be in the range of from 5 to 7 milliohms. The deposited film was then subjected to a test for stability at elevated temperature and humidity ~65 hours at a temperature of 75 degrees C, relative humidity of 95 percent), and contact resistance was then found to be in the range of from 15 to 20 milliohms.
Example 2. An experiment was carried out, analogous to Example 1, on a layer consisting essentially of 95 atomic percent nickel and 5 atomic percent phosphorus. Contact resistance was 1.8 milliohm before the test and 4~4 to 5 milliohms after the test.
Example 3. An experiment was carried out, analogous to Example 1, on a layer consisting essentially of 95 atomic percent nickel and 5 atomic percent boron. Contact resistance was in the range of from 2.9 to 3.5 milliohms before the test and in the range of from 10 to 14 milliohms after the test.
Example 4. An experimen~ was carried out, analogous to Example 1, on a layer consisting essentially of 95 atomic percent nickel and 5 atomic percent silicon. Contact resistance was in the range of from 1.6 to 2.1 milliohms before the test and in the range of from 4.5 to 6 milliohms after the test.
Example 5. An experiment was carried out f analogous to ~xample 1, on a layer consisting essentially of 95 atomic percent nickel and 5 atomic percent germanium. Con~act resistance was in the range oE from 1.5 to 1.85 milliohms before She test and 10 to 14 milliohms af~er the ~es~.

7~

Example 6. An aqueous solution was prepared containing 208 gm/1 NiC12.6H20, 49 gm/1 H3PO4 85 percent, and 5 gm/1 H3PO3. The solution was used to electroplate onto a copper electrode; plating bath temperature was 75 degrees C, current density was 150 mA/cm2, and plating rate was approximately 3 micrometers per minute. The deposited layer had a thickness of approximately 4,5 micrometers. Contact resistance of the deposited layer was less than 10 milliohms after exposure to the testing ambient.
Example 7. An aqueous solution of 0.087 molar of As2Os and 0.5 molar of NiCl2.6H2O was prepared~ A copper electrode was plated with nickel arsenide by pulse-plating from the solution at a temperature of 75 degrees C; current pulses of 200 mA/cm2 were on for 1.5 seconds and off for 0.5 seconds. Deposited layer thickness was approximately 4.5 micrometers. Contact resistance of the deposited layer was less than 10 milliohms after exposure to the testiny ambient.
Example 8. To a solution of 5 gm GeO2 in 50 c~ water plus 4 cc ammonium hydroxide and 0.5 molar of NiCl~.6H20, ~50 gm/l ammonium citrate were ~dded~ The solution was filtered, and ammonium hydroxide ~as added until pH was 8.5u A layer of nickel-germanium was plated 25 from the solution at a temperature of 75 degrees C onto a copper electrode; current density was 150 mA/cm2 and plating rate was approximately 2.5 micrometers per minute.
Deposited layer thickness was approximately 4.5 micrometers. Contact resistance of the deposited layer was less than 10 milliohms after exposure to the testing ambient.
Example 9~ A layer o nickel having a thickness of approximately 350 nm was deposited on a polished copper foil. A portion oE the nickel layer was covered wi~h an aluminum foil, and alpha-particles were implanted in the uncovered portion of the nick~l layer. Alpha-particles had an energy of approximately 1.8 MeV, and a dose of approximately 1.6x1016 particles per cm2 was found to be optimal or near-optimal for minimized contact resistance (less than 10 milliohms) after exposure to humid air at elevated temperature as described in Example 1 above. (This test is considered to be an approximate equivalent of exposure to ordinary atmospheric conditions for a duration of 5 years.) Also, visual inspection of the implanted portion after the test as compared with the portion which had been covered with aluminum foil, showed the latter to be dull and brownish while the former appeared bright and shiny.
3~

~z~l~7~

SUPPLEMENTARY DISCLOSURE

Contacts of the invention may receive a final coating or "Elash" comprising a significant amount of a coating material such as gold, one or several platinum-group elements, or gold and one or several platinum-group elements, the amount being sufficient to impart to the coated surface the appearance of such coating material.
The structure of such coating may be essentially homogeneous or layered, and coating thickness typically is in a range o~ from 0.01 to O.Oi micrometer. For example, a cobalt-hardened gold coating may be electro-deposited from a slightly acidic solution (pH 5) comprising potassium gold cyanide, cobalt citride, and a cltric buffer. (The presence of cobalt, nominally in a range of from 0.2 to 0.5 percent by weight, enhances surface hardness especially in the case of thicker coatings.) Preferred temperature of the plating bath is approximately 35 degrees C, and a plating current of approximately 5 milliamperes per cm2 is convenient. Typical plating times are of the order of half a minute Prior to plating, a surface may be cleaned, e.g., by electrolytic scrubbing in an alkaline solution, rinsing in de-ioni2ed water, and dipping in dilute hydrochloric acid at elevated temperature.

Claims (16)

Claims:
1. Apparatus comprising an electrical contact, said contact comprising a surface of a body of contact material, said contact material comprising nickel and at least one glass forming additive selected from the group consisting of boron, germanium, phosphorus, arsenic, antimony, and bismuth, said at least one glass forming additive being present in said contact material in an amount in the range from 2 to 10 atom percent of the combined amount of nickel and said at least one glass forming additive, said combined amount being greater than or equal to 70 atom percent of said contact material, whereby at least a surface portion of said contact material is crystallographically disordered at least upon exposure to an oxidizing ambient.
2. Apparatus of claim 1, the presence of sulfur, selenium, and tellurium in combination being limited in said contact material to less than 0.5 atomic percent.
3. Apparatus of claim 1, said contact material further comprising cobalt.
4. Apparatus of claim 1, in which said at least one glass-forming additive is boron.
5. Apparatus of claim 1 in which said at least one glass-forming additive is germanium.
6. Apparatus of claim 1 in which said at least one glass-forming additive is phosphorus.
7. Apparatus of claim 1 in which said at least one glass-forming additive is arsenic.
8. Apparatus of claim 1 in which said at least one glass-forming additive is antimony.
9. Apparatus of claim 1 in which said at least one glass-forming additive is bismuth.
10. Apparatus of claim 1, said surface having a contact resistance which is less than 100 milliohms.
11. Apparatus of claim 1, said body of contact material being in the form of a layer deposited on a substrate.
12. Apparatus comprising an electrical contact, said contact comprising a surface of a body of contact material, said contact material comprising at least 50 atom percent nickel, and said contact material being crystallographically disordered by ion bombardment.

CLAIMS SUPPORTED BY SUPPLEMENTARY DISCLOSURE
13. Apparatus of claim 1, said contact material having a surface coating which consists essentially of a coating material selected from the group consisting of gold, one or several platinum-group elements, and gold and one or several platinum-group elements.
14. Apparatus of claim 12, said contact material having a surface coating which consists essentially of a coating material selected from the group consisting of gold, one or several platinum-group elements, and gold and one or several platinum-group elements.
15. Apparatus of claim 13 or 14, the amount of said coating material being sufficient to produce a surface appearance of said coating material.
16. Apparatus of claim 13 or 14, said surface coating having a thickness in the range from 0.01 to 0.05 micrometer.
CA000489652A 1984-08-31 1985-08-29 Nickel-based electrical contact Expired CA1248780A (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US64670784A 1984-08-31 1984-08-31
US646,707 1984-08-31
US76140285A 1985-08-01 1985-08-01
US761,402 1985-08-01

Publications (1)

Publication Number Publication Date
CA1248780A true CA1248780A (en) 1989-01-17

Family

ID=27094992

Family Applications (1)

Application Number Title Priority Date Filing Date
CA000489652A Expired CA1248780A (en) 1984-08-31 1985-08-29 Nickel-based electrical contact

Country Status (7)

Country Link
EP (1) EP0192703B1 (en)
JP (1) JPH08306256A (en)
KR (1) KR930009233B1 (en)
CA (1) CA1248780A (en)
DE (1) DE3574075D1 (en)
ES (1) ES8704042A1 (en)
WO (1) WO1986001636A1 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6481130A (en) * 1987-09-21 1989-03-27 Omron Tateisi Electronics Co Electrical contact
JPH0359972A (en) * 1989-07-27 1991-03-14 Yazaki Corp Electrical contact
JP3467527B2 (en) * 1992-12-17 2003-11-17 株式会社山王 Contact material and method of manufacturing the same
FI113912B (en) * 2001-12-13 2004-06-30 Outokumpu Oy Connector terminal with additive coating

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1769229A (en) * 1925-05-19 1930-07-01 Ambrose J Mandell Electrode and contact element
US3017532A (en) * 1956-02-27 1962-01-16 Gen Am Transport Electrical elements
US3856513A (en) * 1972-12-26 1974-12-24 Allied Chem Novel amorphous metals and amorphous metal articles
NL7513557A (en) * 1974-11-29 1976-06-01 Allied Chem PRECISION RESISTANCE.
JPS543010A (en) * 1977-06-06 1979-01-11 Ajinomoto Co Inc Stabilization of glutamic acid-gamma-semialdehyde or delta1-pyrroline-5- carboxylic acid
JPS57132615A (en) * 1981-02-10 1982-08-17 Tokyo Shibaura Electric Co Composite contact
IT1190842B (en) * 1981-06-30 1988-02-24 Erba Farmitalia SUMMARY ROUTE OF OPTICALLY ACTIVE DERIVATIVES OF 2-PENEM-3-CARBOXYLIC ACID
JPS59229428A (en) * 1984-04-27 1984-12-22 Toshiba Corp Production of two-stage hysteresis loop soft magnetic alloy
ATE40721T1 (en) * 1984-05-11 1989-02-15 Burlington Industries Inc ELECTRICAL CONTACT COATED WITH AN AMORPHOUS TRANSITION ALLOY WHICH IS ITSELF COATED WITH A GOLD FILM.

Also Published As

Publication number Publication date
KR930009233B1 (en) 1993-09-24
ES546448A0 (en) 1987-03-01
DE3574075D1 (en) 1989-12-07
EP0192703B1 (en) 1989-11-02
JPH08306256A (en) 1996-11-22
WO1986001636A1 (en) 1986-03-13
ES8704042A1 (en) 1987-03-01
KR860700310A (en) 1986-08-01
EP0192703A1 (en) 1986-09-03

Similar Documents

Publication Publication Date Title
EP0410472B1 (en) Electric contact
KR100783847B1 (en) Metal article coated with multilayer surface finish for porosity reduction
CN1318647C (en) Metal-plated material and method for preparation, and electric and electronic parts using same
JP3465876B2 (en) Wear-resistant copper or copper-based alloy, method for producing the same, and electric component comprising the wear-resistant copper or copper-based alloy
US20040038072A1 (en) Terminal with ruthenium layer and part having the same
JP2002339097A (en) Metallic product coated on surface with doped tin or tin alloy
EP0160761B1 (en) Amorphous transition metal alloy, thin gold coated, electrical contact
CA1248780A (en) Nickel-based electrical contact
US4925407A (en) Nickel-based electrical contact
KR102509377B1 (en) Tin-plated copper terminal material and terminal and wire termination structure
JPH0855521A (en) Conductive member and its manufacture
US5560812A (en) Method for producing a metal film resistor
Lindborg et al. Intermetallic growth and contact resistance of tin contacts after aging
US4732821A (en) Nickel-based electrical contact
WO1986007205A1 (en) Nickel-based electrical contact device
JPH043041B2 (en)
CN112151991A (en) Electric contact material, terminal fitting, connector, wire harness, and method for manufacturing electric contact material
JPS61288384A (en) Electric contact
CA2069390A1 (en) Corrosion resistant high temperature contacts or electrical connectors and method of fabrication thereof
GB1596493A (en) Additive method of manufacturing wiring patterns
EP4365329A1 (en) Composite material, composite material production method, terminal, and terminal production method
JP2002180260A (en) Method of forming nickel film by electroless nickel plating
CA1245259A (en) Amorphous transition metal alloy, thin gold coated, electrical contact
JPH0640458B2 (en) Switching contacts for low power and its manufacturing method
JPS62503061A (en) Nickel-based electrical contact devices

Legal Events

Date Code Title Description
MKEX Expiry