CA1331325C - Electric power connectors - Google Patents
Electric power connectorsInfo
- Publication number
- CA1331325C CA1331325C CA000553333A CA553333A CA1331325C CA 1331325 C CA1331325 C CA 1331325C CA 000553333 A CA000553333 A CA 000553333A CA 553333 A CA553333 A CA 553333A CA 1331325 C CA1331325 C CA 1331325C
- Authority
- CA
- Canada
- Prior art keywords
- nickel
- electric power
- gold
- copper
- power connector
- 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 - Fee Related
Links
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 125
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 60
- 229910052737 gold Inorganic materials 0.000 claims abstract description 44
- 239000010931 gold Substances 0.000 claims abstract description 44
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims abstract description 43
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 20
- 239000000956 alloy Substances 0.000 claims abstract description 20
- 229910052751 metal Inorganic materials 0.000 claims abstract description 15
- 239000002184 metal Substances 0.000 claims abstract description 15
- 239000000463 material Substances 0.000 claims description 18
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 9
- 229910052802 copper Inorganic materials 0.000 claims description 9
- 239000010949 copper Substances 0.000 claims description 9
- 229910001020 Au alloy Inorganic materials 0.000 claims description 6
- DMFGNRRURHSENX-UHFFFAOYSA-N beryllium copper Chemical compound [Be].[Cu] DMFGNRRURHSENX-UHFFFAOYSA-N 0.000 claims description 6
- 239000000758 substrate Substances 0.000 claims description 6
- 229910001128 Sn alloy Inorganic materials 0.000 claims description 5
- VRUVRQYVUDCDMT-UHFFFAOYSA-N [Sn].[Ni].[Cu] Chemical compound [Sn].[Ni].[Cu] VRUVRQYVUDCDMT-UHFFFAOYSA-N 0.000 claims description 5
- 229910001369 Brass Inorganic materials 0.000 claims description 4
- 229910000570 Cupronickel Inorganic materials 0.000 claims description 4
- 239000010951 brass Substances 0.000 claims description 4
- -1 copper-nickel-aluminum Chemical compound 0.000 claims description 4
- 229910000838 Al alloy Inorganic materials 0.000 claims description 3
- 229910000906 Bronze Inorganic materials 0.000 claims description 3
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 3
- 239000010974 bronze Substances 0.000 claims description 3
- KUNSUQLRTQLHQQ-UHFFFAOYSA-N copper tin Chemical compound [Cu].[Sn] KUNSUQLRTQLHQQ-UHFFFAOYSA-N 0.000 claims description 3
- 239000002659 electrodeposit Substances 0.000 claims description 3
- MSNOMDLPLDYDME-UHFFFAOYSA-N gold nickel Chemical compound [Ni].[Au] MSNOMDLPLDYDME-UHFFFAOYSA-N 0.000 claims description 3
- 229910000990 Ni alloy Inorganic materials 0.000 claims description 2
- 239000010410 layer Substances 0.000 description 15
- 229910017052 cobalt Inorganic materials 0.000 description 6
- 239000010941 cobalt Substances 0.000 description 6
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 6
- 238000009792 diffusion process Methods 0.000 description 6
- 239000002131 composite material Substances 0.000 description 5
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 229910052709 silver Inorganic materials 0.000 description 4
- 239000004332 silver Substances 0.000 description 4
- 238000003483 aging Methods 0.000 description 3
- 238000000137 annealing Methods 0.000 description 3
- 238000009713 electroplating Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000003353 gold alloy Substances 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910000531 Co alloy Inorganic materials 0.000 description 2
- QXZUUHYBWMWJHK-UHFFFAOYSA-N [Co].[Ni] Chemical compound [Co].[Ni] QXZUUHYBWMWJHK-UHFFFAOYSA-N 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 239000004020 conductor Substances 0.000 description 2
- 230000001627 detrimental effect Effects 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- ZBTDWLVGWJNPQM-UHFFFAOYSA-N [Ni].[Cu].[Au] Chemical compound [Ni].[Cu].[Au] ZBTDWLVGWJNPQM-UHFFFAOYSA-N 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 229910052728 basic metal Inorganic materials 0.000 description 1
- 150000003818 basic metals Chemical class 0.000 description 1
- 229910052790 beryllium Inorganic materials 0.000 description 1
- ATBAMAFKBVZNFJ-UHFFFAOYSA-N beryllium atom Chemical compound [Be] ATBAMAFKBVZNFJ-UHFFFAOYSA-N 0.000 description 1
- 239000013590 bulk material Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005238 degreasing Methods 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 150000002343 gold Chemical class 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000013011 mating Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- XIKYYQJBTPYKSG-UHFFFAOYSA-N nickel Chemical compound [Ni].[Ni] XIKYYQJBTPYKSG-UHFFFAOYSA-N 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 238000005486 sulfidation Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
Classifications
-
- 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
- Contacts (AREA)
- Details Of Connecting Devices For Male And Female Coupling (AREA)
- Cable Accessories (AREA)
- Coupling Device And Connection With Printed Circuit (AREA)
Abstract
ABSTRACT
ELECTRIC POWER CONNECTORS
Electric power connectors made with at least one contacting component having a gold contacting surface wherein the gold contacting surface is metallurgically bonded to an underlying layer of nickel or nickel-rich alloy . At the contact surface the gold contains a total of about 1-10% by weight nickel with the amount of nickel generally increasing in the direction from the surface to the underlying metal the increase starting at a point inward of and remote from the contacting surface.
ELECTRIC POWER CONNECTORS
Electric power connectors made with at least one contacting component having a gold contacting surface wherein the gold contacting surface is metallurgically bonded to an underlying layer of nickel or nickel-rich alloy . At the contact surface the gold contains a total of about 1-10% by weight nickel with the amount of nickel generally increasing in the direction from the surface to the underlying metal the increase starting at a point inward of and remote from the contacting surface.
Description
133132~
ELECTRIC POWER CONNECTORS
- The present invention i8 concerned with electrical connectors or contacts and, more partlcularly, with electrical connectors useful in carrying substantial currents at voltages in excess of, perhaps, 10 volts.
It i6 known in electronic, particularly computer technology, to use electronic contacts of pure gold in order to reduce to the irreducible minimum value the contact resistance of faying, usually spring-loaded contact surfaces. Such contact surf~es having contact resistances of less than one milliohm when tested against a lightly weighted, polished gold probe are generally not designed for frequent make and break service. Thus, thin, pure -; gold contact surfaces on circuit boards and ~heir mating components are the standard means for providing electrical clrcuits in electronic and computer devices which often operate at voltages up to only 100 mV and with extremely low amperages. Such contacts are very resistant to corroding media and oxidatlon. However, if gold i8 used on certain metal bases, e.g. copper or silver, without an intermedlate layer of nickel, the electronic contacts tend to degrade 20 if exposed to temperatures elevated above 25C even as low as 100C.
~ ~k.~ , - .:; : .: ':
, , ; , - : , : : ,: ~ : :: : -133132a Gradually a~oms o f copper and silver migrate to the gold surface.
Mlgrated copper makes the contact surface sub~ect to sulfidation and oxldation while migrated silver i8 particularly detrimental when the contact surface is used in sulfidizing atmospheres as mild as ordinary room air. Accordingly, it is general]y standard practice to employ a layer of nickel (or perhaps cobalt or a nickel~ or cobalt-rich alloy~ between a base of copper or silver or copper- or ~ilver-base alloy and the gold in order to prevent copper or ailver migration and also to provide an exposed layer of relatively tarnish-resistant metal anywhere there may be breaks in the overlying layer of gold. A good description of electronic-type contact materials is contained in the article "Properties of Inlay Clad Wrought Gold Alloys", Robert J. Russell, Solid State Technology, 10 pages (8/76).
There is a need for electrical contact material~ which have a low contact resistance, but not necessarily the extremely low contact resistances required by the electronics industry, and which have sufficient abrasion resistance in order to survive multiple makes and breaks.
It is the object of the present invention to provide such electrical contacts adapted to carry reasonably high amperages at voltages in excess of perhaps 10 volt~.
It is a further ob~ect of the invention to provide an electrical contact material which can be employed in the electrical contacts of the present invention.
GENERAL DESCRIPTION OF THE INVENTION
The present invention contemplates an electric power connector adapted to provlde an interruptible conductive path for electrical current (for example, current of at least about 0.1 ampere) comprising at least two components adapted to be placed in surface contact one with another. At least one of the components has a fayable surface of contact made of an alloy of gold and nickel. At the fayable contact surface the alloy contains about 1 to about 10%
by weight of nickel. The amount of nickel in the gold generally increases with distance from the fayable contact surface to an " ,~,,,,, ' : ~ : ~ :' :
-~mderlying metallurgical bonded layer of essentially pure nickel.
However, the alloy which 18 made by diffusing nickel from an underlayer into a gold overlaysr usually exhiblts a particular structure when examined by sputtering and Auger analysis. The immediate surface, perhaps 150 Angstrom units thick, exhibits a relatively high nlckel content. Immediately below this surface layer, the nickel content falls somewhat and remains relatively constant for perhaps up to two-thirds of the thickness of the gold layer which ranges from 0.3 to 2 micrometers. Over the remaining thickness of the gold-containing layer, the nickel content rises rapidly to the nickel content of the underlying metal. Those skilled in the art will appreciate that,this type of Auger analysi~ æome-times produces results at the surface of an object being examined which may be surface artifacts and may not represent or be signifi-cant with respect to properties of the bulk material. Accordingly,it appears safe to say that in the gold layer of the contact structure of the present invention, the nickel content near the - outer surface is at a relatively low level. It remains at that low level until, at some point remote from the surface the nickel con-tent of the gold rapidly increases.
The electrical power connector can be in any conventional contact form such afi male and female plug components, pins, threaded structures or the like. Advantageously, the connectors are of such configuration that they can be made from composite, electrical contact material in strip form. Such contact material which is also ~ithin the contemplation of the present invention comprises a strip-form structural base of electrically conductive material, e.g. metal having at least one major surface comprised of nickel nickel-rich alloy underlying a layer of gold about 0.1 to 2 micrometers thick metallurgically bonded to the nickel or nickel-rich alloy. This diffusion is such as to provide about 1 to about 10% by weigh~ of nickel at the outer major surface. In this connection, "nickel-rich alloy" means an alloy containing at least about 90% nickel advantageously at lea~t 95% or 99~ nickel and lncludes commercially pure n~ckel and nickel-cobalt alloys.
,, .
. ~
, ~: :
. '~
_4_ 133~325 PC-3127 Specific examples of contact materials of the present inventlon include copper, copper-base alloys such as brass, cupro-nickel, beryllium copper, copper-nickel-tin alloy and copper-nickel-aluminum alloy, nickel, cobalt or nickel-cobalt alloy particularly in strip form. In the cases of copper, copper-base alloys and cobalt the basic metal has an electrodeposited layer of nickel about 3 to 10 micrometers thick on at least one ma~or surface. The outer portion of that at least one major surface comprises a layer of electroplated gold or a gold alloy containing up to about 1% total nickel and/or cobalt about 0.1 to about 2 micrometers thick which layer of elec-troplated gold or gold alloy is heat bonded to the nickel so as to provide diffusion of nickel to the gold surface in an amount at or near the surface of about 1~ to abont 10% total nickel. The strip can be faced on all surfaces with gold or, on the two major surfaces, i.e. the top and bottom or on one ma~or surface.
Nickel and nickel-rich alloy strip can be made by conventional metallurgical melt technology wherein a charge of metal is melted, then caRt and then hot- and/or cold-worked to strip form.
A particularly advantageous method of making nickel, cobalt or nickel-rich alloy strip ~s to roll compact metal powder, sinter bond and interdiffuse the roll-compacted metal powder and thereafter or simultaneously roll the bonded powder product to strip form and thickness.
Strip of metal other than nickel or nickel-rich alloy which can form the principal structural element of the connectors of the present invention is generally made in a conventional manner and is commercially available from many sources. The present invention contemplates use of commercially available strip of copper, brass, aluminum bronze, cupro nickel, beryllium copper, copper-nickel-tin alloy and any other metal or other electrically conductive material useful in the electrical contact art. This strip is thoroughly cleaned by conventional means such as alkaline cleaning baths, solvent and vapor degreasing, etc. and then electroplated to provide a layer of nickel about 5 to about 10 micrometers thlck. One of the electroplating baths set forth in Electroplating Engineering Handbook, 3rd Ed., A. Kenneth Graham, Van Nostrand Reinhold Company, ,, ~ ;" ,'~
:, ~ , , , ~, ~
13 3132 a Copyright, 1971 at page 247 can be used to electroplate nickel.
Gold i8 electrodeposited over either the nickel strip or plated nickel from a cyanide-type, citrate-type or other type of bath adapted to produce a pure soft gold electro-deposit. The strip i8 then heat treated at about 350C to 600C for times ranging from 2 hours to 10 seconds so as to diffuse nickel into the gold to reach a level of from 1 to 10~ nickel at the gold outer surface.
The electrical connector materials and electrical contacts made therefrom as contemplated in the present invention are advantageous with respect to contacts made of base metals in that - they are and remain through their useful lives essentially free of corrosion products and thus give reliable, stable contact service.
Compared to pure gold contact surfaces, when high currents (e.g.
greater than 0.1 ampere) are passed through an electrical circuit, the contacts and contact materials of the present invention are advantageous when the contact must be broken periodically. In these situations, a pure gold surface becomes galled or roughened, gold-on-gold contacting fiurfaces tend to sinter or fuse together and the contact canno~ readily be separated. Conversely, the present invention i8 based upon the discovery that when gold contacting surfaces contain 1 to 10% nickel such modiied gold-on-modified gold contacts do not exhibit the fusing or sintering character of pure gold and thus the contacts can always be easily broken, provided of course, ~hat the circuit including the contact has not been over-loaded beyond design capacity.
In making the contact materials of the present invention,those of normal skill in the metallurgical art will appreciate that heat treatment time will normally vary with temperature such that longer times will be used at lower temperatures and vice versa with a given thlckness of gold. Lower temperatures and shorter times at a given temperature will be employed with thinner gold layers than with thicker gold layers. As disclosed in co-pending Canadian patent application Serial No. 534~009 diffusion of nickel into gold can be carried out simultaneously with age-hardening of an age-hardenable - 35 substrate. Normally this age-hardening of, for example, copper-base-alloys such as beryllium copper or a copper-nickel-tin alloy or a 1 3 3 1 3 2 ~
copper-nickel aluminum alloy will be carried out after the contact material is in final form as an electrical contact. For example, strip form of beryllium copper is blanked and shaped to contact con-figuration. The thus shaped contacts are then electroplated sequen-tially with nickel and gold and then heat treated at a temperatureand time combination selected in consideration of the thickness of electroplated gold so as to achieve both age-hardening of the substrate and proper gold-nickel interdiffusion at the same time.
Alternatively, contacts may be blanked out of composite gold-nickel-copper beryllium strip, formed and then heat treated.
The annealing heat treatment which produces diffusion ofnickel and gold can be carried out simultaneously with hot rerolling of plated strip material. For exam~le, nickel strip made by roll compacting and then sintering and rolling nlckel powder can be electroplated with gold and then rerolled at a temperature in the range of 350C to 500C to enhance the metallurgical bond between the nickel and gold and effectuate the diffusion of the nickel.
Alternatively, the metallurgical bond and diffusion can be ~ccomplished by the annealing heat treatment as described herein-before and the composlte can be cold rolled either before or after annealing so as to enhance mechanical characteristics.
In order to give those skilled in the art a greater appreciation of the advantages of the invention the following example is given:
A nickel strip made from roll compacted and sintered nickel powder about 0.5 mm thick, about 30 mm wide and about 70 meters long is thoroughly cleaned, mildly etched and electroplated with gold from a citrate-base electroplating bath to provide a uniform, pure gold deposit about 0.5 micrometer thick. The plated strip is thoroughly rinsed to remove any trace of electrolyte, dried and then heat treated by being passed through a furnace. The furnace is held at 480C and contains an atmosphere of 10 volume percent hydrogen, balance nitrogen. Cool strip is fed to the furnace and passes - through with a residence time of six minutes. As the strip exits the furnace it ia cooled under the same reducing conditlons and then coiled.
,~' .
.~; , ,~
'3,1', '.' ~''. . " .
133132~
The composite nickel-gold contact material made in this way gives excellent results in electric contact service composite material to composite material. The contacts exhibit essentlally no detrimental behavior over time when exposed to normal service. The contacts do not corrode, gall or pit in service and can be disconnected hundreds of times without difficulty even when exposed in use to temperatures up to about 200C.
While in accordance with the provisions of the statute, there is illustrated and described herein specific embodiments of the invention, those skilled in the art will understand that changes may be made in the form of the ~nvention covered by the claims and that certain features of the invention may sometimes be used to advantage without a corresponding use of the other features.
" ~", , ~ , ~
ELECTRIC POWER CONNECTORS
- The present invention i8 concerned with electrical connectors or contacts and, more partlcularly, with electrical connectors useful in carrying substantial currents at voltages in excess of, perhaps, 10 volts.
It i6 known in electronic, particularly computer technology, to use electronic contacts of pure gold in order to reduce to the irreducible minimum value the contact resistance of faying, usually spring-loaded contact surfaces. Such contact surf~es having contact resistances of less than one milliohm when tested against a lightly weighted, polished gold probe are generally not designed for frequent make and break service. Thus, thin, pure -; gold contact surfaces on circuit boards and ~heir mating components are the standard means for providing electrical clrcuits in electronic and computer devices which often operate at voltages up to only 100 mV and with extremely low amperages. Such contacts are very resistant to corroding media and oxidatlon. However, if gold i8 used on certain metal bases, e.g. copper or silver, without an intermedlate layer of nickel, the electronic contacts tend to degrade 20 if exposed to temperatures elevated above 25C even as low as 100C.
~ ~k.~ , - .:; : .: ':
, , ; , - : , : : ,: ~ : :: : -133132a Gradually a~oms o f copper and silver migrate to the gold surface.
Mlgrated copper makes the contact surface sub~ect to sulfidation and oxldation while migrated silver i8 particularly detrimental when the contact surface is used in sulfidizing atmospheres as mild as ordinary room air. Accordingly, it is general]y standard practice to employ a layer of nickel (or perhaps cobalt or a nickel~ or cobalt-rich alloy~ between a base of copper or silver or copper- or ~ilver-base alloy and the gold in order to prevent copper or ailver migration and also to provide an exposed layer of relatively tarnish-resistant metal anywhere there may be breaks in the overlying layer of gold. A good description of electronic-type contact materials is contained in the article "Properties of Inlay Clad Wrought Gold Alloys", Robert J. Russell, Solid State Technology, 10 pages (8/76).
There is a need for electrical contact material~ which have a low contact resistance, but not necessarily the extremely low contact resistances required by the electronics industry, and which have sufficient abrasion resistance in order to survive multiple makes and breaks.
It is the object of the present invention to provide such electrical contacts adapted to carry reasonably high amperages at voltages in excess of perhaps 10 volt~.
It is a further ob~ect of the invention to provide an electrical contact material which can be employed in the electrical contacts of the present invention.
GENERAL DESCRIPTION OF THE INVENTION
The present invention contemplates an electric power connector adapted to provlde an interruptible conductive path for electrical current (for example, current of at least about 0.1 ampere) comprising at least two components adapted to be placed in surface contact one with another. At least one of the components has a fayable surface of contact made of an alloy of gold and nickel. At the fayable contact surface the alloy contains about 1 to about 10%
by weight of nickel. The amount of nickel in the gold generally increases with distance from the fayable contact surface to an " ,~,,,,, ' : ~ : ~ :' :
-~mderlying metallurgical bonded layer of essentially pure nickel.
However, the alloy which 18 made by diffusing nickel from an underlayer into a gold overlaysr usually exhiblts a particular structure when examined by sputtering and Auger analysis. The immediate surface, perhaps 150 Angstrom units thick, exhibits a relatively high nlckel content. Immediately below this surface layer, the nickel content falls somewhat and remains relatively constant for perhaps up to two-thirds of the thickness of the gold layer which ranges from 0.3 to 2 micrometers. Over the remaining thickness of the gold-containing layer, the nickel content rises rapidly to the nickel content of the underlying metal. Those skilled in the art will appreciate that,this type of Auger analysi~ æome-times produces results at the surface of an object being examined which may be surface artifacts and may not represent or be signifi-cant with respect to properties of the bulk material. Accordingly,it appears safe to say that in the gold layer of the contact structure of the present invention, the nickel content near the - outer surface is at a relatively low level. It remains at that low level until, at some point remote from the surface the nickel con-tent of the gold rapidly increases.
The electrical power connector can be in any conventional contact form such afi male and female plug components, pins, threaded structures or the like. Advantageously, the connectors are of such configuration that they can be made from composite, electrical contact material in strip form. Such contact material which is also ~ithin the contemplation of the present invention comprises a strip-form structural base of electrically conductive material, e.g. metal having at least one major surface comprised of nickel nickel-rich alloy underlying a layer of gold about 0.1 to 2 micrometers thick metallurgically bonded to the nickel or nickel-rich alloy. This diffusion is such as to provide about 1 to about 10% by weigh~ of nickel at the outer major surface. In this connection, "nickel-rich alloy" means an alloy containing at least about 90% nickel advantageously at lea~t 95% or 99~ nickel and lncludes commercially pure n~ckel and nickel-cobalt alloys.
,, .
. ~
, ~: :
. '~
_4_ 133~325 PC-3127 Specific examples of contact materials of the present inventlon include copper, copper-base alloys such as brass, cupro-nickel, beryllium copper, copper-nickel-tin alloy and copper-nickel-aluminum alloy, nickel, cobalt or nickel-cobalt alloy particularly in strip form. In the cases of copper, copper-base alloys and cobalt the basic metal has an electrodeposited layer of nickel about 3 to 10 micrometers thick on at least one ma~or surface. The outer portion of that at least one major surface comprises a layer of electroplated gold or a gold alloy containing up to about 1% total nickel and/or cobalt about 0.1 to about 2 micrometers thick which layer of elec-troplated gold or gold alloy is heat bonded to the nickel so as to provide diffusion of nickel to the gold surface in an amount at or near the surface of about 1~ to abont 10% total nickel. The strip can be faced on all surfaces with gold or, on the two major surfaces, i.e. the top and bottom or on one ma~or surface.
Nickel and nickel-rich alloy strip can be made by conventional metallurgical melt technology wherein a charge of metal is melted, then caRt and then hot- and/or cold-worked to strip form.
A particularly advantageous method of making nickel, cobalt or nickel-rich alloy strip ~s to roll compact metal powder, sinter bond and interdiffuse the roll-compacted metal powder and thereafter or simultaneously roll the bonded powder product to strip form and thickness.
Strip of metal other than nickel or nickel-rich alloy which can form the principal structural element of the connectors of the present invention is generally made in a conventional manner and is commercially available from many sources. The present invention contemplates use of commercially available strip of copper, brass, aluminum bronze, cupro nickel, beryllium copper, copper-nickel-tin alloy and any other metal or other electrically conductive material useful in the electrical contact art. This strip is thoroughly cleaned by conventional means such as alkaline cleaning baths, solvent and vapor degreasing, etc. and then electroplated to provide a layer of nickel about 5 to about 10 micrometers thlck. One of the electroplating baths set forth in Electroplating Engineering Handbook, 3rd Ed., A. Kenneth Graham, Van Nostrand Reinhold Company, ,, ~ ;" ,'~
:, ~ , , , ~, ~
13 3132 a Copyright, 1971 at page 247 can be used to electroplate nickel.
Gold i8 electrodeposited over either the nickel strip or plated nickel from a cyanide-type, citrate-type or other type of bath adapted to produce a pure soft gold electro-deposit. The strip i8 then heat treated at about 350C to 600C for times ranging from 2 hours to 10 seconds so as to diffuse nickel into the gold to reach a level of from 1 to 10~ nickel at the gold outer surface.
The electrical connector materials and electrical contacts made therefrom as contemplated in the present invention are advantageous with respect to contacts made of base metals in that - they are and remain through their useful lives essentially free of corrosion products and thus give reliable, stable contact service.
Compared to pure gold contact surfaces, when high currents (e.g.
greater than 0.1 ampere) are passed through an electrical circuit, the contacts and contact materials of the present invention are advantageous when the contact must be broken periodically. In these situations, a pure gold surface becomes galled or roughened, gold-on-gold contacting fiurfaces tend to sinter or fuse together and the contact canno~ readily be separated. Conversely, the present invention i8 based upon the discovery that when gold contacting surfaces contain 1 to 10% nickel such modiied gold-on-modified gold contacts do not exhibit the fusing or sintering character of pure gold and thus the contacts can always be easily broken, provided of course, ~hat the circuit including the contact has not been over-loaded beyond design capacity.
In making the contact materials of the present invention,those of normal skill in the metallurgical art will appreciate that heat treatment time will normally vary with temperature such that longer times will be used at lower temperatures and vice versa with a given thlckness of gold. Lower temperatures and shorter times at a given temperature will be employed with thinner gold layers than with thicker gold layers. As disclosed in co-pending Canadian patent application Serial No. 534~009 diffusion of nickel into gold can be carried out simultaneously with age-hardening of an age-hardenable - 35 substrate. Normally this age-hardening of, for example, copper-base-alloys such as beryllium copper or a copper-nickel-tin alloy or a 1 3 3 1 3 2 ~
copper-nickel aluminum alloy will be carried out after the contact material is in final form as an electrical contact. For example, strip form of beryllium copper is blanked and shaped to contact con-figuration. The thus shaped contacts are then electroplated sequen-tially with nickel and gold and then heat treated at a temperatureand time combination selected in consideration of the thickness of electroplated gold so as to achieve both age-hardening of the substrate and proper gold-nickel interdiffusion at the same time.
Alternatively, contacts may be blanked out of composite gold-nickel-copper beryllium strip, formed and then heat treated.
The annealing heat treatment which produces diffusion ofnickel and gold can be carried out simultaneously with hot rerolling of plated strip material. For exam~le, nickel strip made by roll compacting and then sintering and rolling nlckel powder can be electroplated with gold and then rerolled at a temperature in the range of 350C to 500C to enhance the metallurgical bond between the nickel and gold and effectuate the diffusion of the nickel.
Alternatively, the metallurgical bond and diffusion can be ~ccomplished by the annealing heat treatment as described herein-before and the composlte can be cold rolled either before or after annealing so as to enhance mechanical characteristics.
In order to give those skilled in the art a greater appreciation of the advantages of the invention the following example is given:
A nickel strip made from roll compacted and sintered nickel powder about 0.5 mm thick, about 30 mm wide and about 70 meters long is thoroughly cleaned, mildly etched and electroplated with gold from a citrate-base electroplating bath to provide a uniform, pure gold deposit about 0.5 micrometer thick. The plated strip is thoroughly rinsed to remove any trace of electrolyte, dried and then heat treated by being passed through a furnace. The furnace is held at 480C and contains an atmosphere of 10 volume percent hydrogen, balance nitrogen. Cool strip is fed to the furnace and passes - through with a residence time of six minutes. As the strip exits the furnace it ia cooled under the same reducing conditlons and then coiled.
,~' .
.~; , ,~
'3,1', '.' ~''. . " .
133132~
The composite nickel-gold contact material made in this way gives excellent results in electric contact service composite material to composite material. The contacts exhibit essentlally no detrimental behavior over time when exposed to normal service. The contacts do not corrode, gall or pit in service and can be disconnected hundreds of times without difficulty even when exposed in use to temperatures up to about 200C.
While in accordance with the provisions of the statute, there is illustrated and described herein specific embodiments of the invention, those skilled in the art will understand that changes may be made in the form of the ~nvention covered by the claims and that certain features of the invention may sometimes be used to advantage without a corresponding use of the other features.
" ~", , ~ , ~
Claims (14)
1. An electric power connector adapted to provide an inter-ruptible conductive path for electric current comprising at least two components adapted to be placed in surface contact, one with another, at least one of said components having a fayable surface of contact made of an alloy of gold and nickel, said alloy containing about 1 to about 10% by weight of nickel near said fayable surface of contact, said amount of said nickel remaining essentially constant through some distance from the surface and then starting at a point interior of said fayable surface to increase with distance from said fayable surface of contact toward the interface of gold-containing metal with an underlying, metallurgically bonded layer of metal from the group of nickel and alloys rich in nickel.
2. An electric power connector as in claim 1 wherein said underlying metallurgically bonded layer is a layer of essentially pure nickel.
3. An electric power connector as in claim 2 wherein said layer of essentially pure nickel is the principle structural element of said connector.
4. An electric power connector as in claim 1 wherein said underlying metallurgically bonded layer is an electrodeposit of nickel about 3 to about 10 micrometers thick on an electroconductive substrate.
5. An electric power connector as in claim 4 wherein said electroconductive substrate is selected from the group of copper, brass, aluminum bronze, copper-nickel-aluminum alloy, cupro-nickel, beryllium copper and copper-nickel-tin alloy.
6. An electric power connector as in claim 5 wherein said electroconductive substrate is selected from the group of age-hardened copper-base alloys.
7. An electric power connector as in claim 1 wherein two or more components of said connector have fayable surfaces of said alloy of gold nickel.
8. An electric connector as in claim 1 having mateable male and female components.
9. An electric power connector material comprising an electro-conductive base having at least one surface made of a metal from the group of nickel and nickel-rich alloys and having overlying and metallurgically bonded thereto a layer of gold about 0.1 to about 2 micrometers thick, said layer of gold containing near its outer surface about 1 to 10% by weight of nickel the content of nickel remaining essentially constant over some distance interior of said outer surface and starting to increase at a point remote from said outer surface and continuing to increase as the distance from said outer surface increases.
10. An electric power connector material as in claim 9 wherein the underlying metal is nickel.
11. An electric power connector material as in claim 10 wherein said nickel is an electrodeposit on an electroconductive base.
12. An electric power connector material as in claim 11 wherein said electroconductive base is a metal from the group of copper, brass, aluminum bronze, copper-nickel-aluminum, cupro-nickel, beryllium copper and copper-nickel-tin alloy.
13. An electric power connector material as in claim 12 wherein said electroconductive substrate is an age-hardened and copper-base alloy.
14. An electric power connector material as in claim 9 in strip form.
Priority Applications (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000553333A CA1331325C (en) | 1987-12-02 | 1987-12-02 | Electric power connectors |
| EP88119564A EP0318831B1 (en) | 1987-12-02 | 1988-11-24 | Electric power connectors |
| DE8888119564T DE3874492T2 (en) | 1987-12-02 | 1988-11-24 | ELECTRICAL POWER CONNECTORS. |
| ES198888119564T ES2034127T3 (en) | 1987-12-02 | 1988-11-24 | ELECTRICAL POWER CONNECTORS. |
| AT88119564T ATE80501T1 (en) | 1987-12-02 | 1988-11-24 | ELECTRICAL POWER CONNECTORS. |
| JP63305126A JPH067452B2 (en) | 1987-12-02 | 1988-12-01 | Power connector |
| GR920402051T GR3005728T3 (en) | 1987-12-02 | 1992-09-17 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000553333A CA1331325C (en) | 1987-12-02 | 1987-12-02 | Electric power connectors |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1331325C true CA1331325C (en) | 1994-08-09 |
Family
ID=4136987
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000553333A Expired - Fee Related CA1331325C (en) | 1987-12-02 | 1987-12-02 | Electric power connectors |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0318831B1 (en) |
| JP (1) | JPH067452B2 (en) |
| AT (1) | ATE80501T1 (en) |
| CA (1) | CA1331325C (en) |
| DE (1) | DE3874492T2 (en) |
| ES (1) | ES2034127T3 (en) |
| GR (1) | GR3005728T3 (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2069390A1 (en) * | 1991-09-05 | 1993-03-06 | James Alexander Evert Bell | Corrosion resistant high temperature contacts or electrical connectors and method of fabrication thereof |
| US5533915A (en) * | 1993-09-23 | 1996-07-09 | Deans; William S. | Electrical connector assembly |
| JP2002017073A (en) * | 2000-02-11 | 2002-01-18 | Litton Systems Inc | Noble metal clad brush wire and slip ring assembly |
| DE112007000210T5 (en) | 2006-01-19 | 2008-11-06 | Advantest Corp. | Contact device and method of making the same |
| JP2008078061A (en) * | 2006-09-25 | 2008-04-03 | Alps Electric Co Ltd | Elastic contactor and its manufacturing method, and connecting device and its manufacturing method using the above-elastic contactor |
| USD573536S1 (en) | 2007-04-17 | 2008-07-22 | Traxxas Lp | Electrical connector |
| US7374460B1 (en) | 2007-04-17 | 2008-05-20 | Traxxas Lp | Electrical connector assembly |
| USD939442S1 (en) | 2020-03-16 | 2021-12-28 | Traxxas Lp | Electrical connector for a model vehicle |
| USD933014S1 (en) | 2020-03-16 | 2021-10-12 | Traxxas Lp | Electrical connector for a model vehicle |
| US11569589B2 (en) | 2020-04-07 | 2023-01-31 | Traxxas, L.P. | Electrical power tap connector |
| USD1054383S1 (en) | 2022-09-07 | 2024-12-17 | Traxxas, L.P. | Electrical connector |
| USD1054382S1 (en) | 2022-09-07 | 2024-12-17 | Traxxas, L.P. | Electrical connector |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3214989A1 (en) * | 1982-04-22 | 1983-11-10 | Doduco KG Dr. Eugen Dürrwächter, 7530 Pforzheim | ELECTRIC CONTACT PIECE COATED WITH PRECIOUS METAL OR A PRECIOUS METAL ALLOY |
| JPS61233912A (en) * | 1985-04-09 | 1986-10-18 | 田中貴金属工業株式会社 | electrical contact material |
| CA1270408A (en) * | 1987-04-07 | 1990-06-19 | James Alexander Evert Bell | Coated article having a base of age-hardened metal |
-
1987
- 1987-12-02 CA CA000553333A patent/CA1331325C/en not_active Expired - Fee Related
-
1988
- 1988-11-24 ES ES198888119564T patent/ES2034127T3/en not_active Expired - Lifetime
- 1988-11-24 DE DE8888119564T patent/DE3874492T2/en not_active Expired - Fee Related
- 1988-11-24 EP EP88119564A patent/EP0318831B1/en not_active Expired - Lifetime
- 1988-11-24 AT AT88119564T patent/ATE80501T1/en not_active IP Right Cessation
- 1988-12-01 JP JP63305126A patent/JPH067452B2/en not_active Expired - Fee Related
-
1992
- 1992-09-17 GR GR920402051T patent/GR3005728T3/el unknown
Also Published As
| Publication number | Publication date |
|---|---|
| JPH067452B2 (en) | 1994-01-26 |
| DE3874492D1 (en) | 1992-10-15 |
| ATE80501T1 (en) | 1992-09-15 |
| GR3005728T3 (en) | 1993-06-07 |
| EP0318831B1 (en) | 1992-09-09 |
| EP0318831A3 (en) | 1990-09-26 |
| JPH01194218A (en) | 1989-08-04 |
| DE3874492T2 (en) | 1993-02-25 |
| EP0318831A2 (en) | 1989-06-07 |
| ES2034127T3 (en) | 1993-04-01 |
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| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |