Electrical contacts and methods of making contacts by electrodeposition
AssigneeLeaRonal, Inc.
InventorsFred I. Nobel, James L. Martin, Michael P. Toben
Life of this patent
Estimating the term…
Abstract
Methods for increasing the ductility and reducing the porosity and cracking tendency of a palladium or palladium-silver electrodeposit which comprises providing an underlayer of a palladium/nickel or palladium/cobalt alloy electrodeposit. Also dual layer composite electroplated deposits and their use in electrical contacts or connectors.
Claims21
A method for increasing the ductility and reducing the porosity or tendency for cracking in a dual layer palladium alloy electrodeposit upon a substrate which comprises:
- electrodepositing a first layer of a palladium/nickel or palladium/cobalt alloy comprising between about 20 and 95 weight percent palladium and between about 5 and 80 weight percent nickel or cobalt upon the substrate in a thickness of at least about 0.5 microinches to increase the ductility and reduce the porosity and tendency for cracking of the dual layer electrodeposit;
- and
- electrodepositing a second layer of palladium or a palladium/silver alloy upon said first layer in a thickness of greater than about 5 microinches for use as an electrical contact, said second layer having a thickness greater than said first layer.
A palladium or palladium/silver electrical contact comprising a substrate and a dual layer electrodeposit comprising at least about 0.5 microinches of a first layer of a palladium/nickel or palladium/cobalt alloy comprising between about 20 and 95 weight percent palladium and between about 5 and 80 weight percent nickel or cobalt and greater than about 5 microinches of a second layer of palladium or a palladium/silver alloy;
- said second layer being thicker than said frist layer and providing the electrical characteristics of the electrical contact.
A method for reducing corrosion of a copper, nickel or copper/nickel alloy basis metal substrate during electroplating of palladium/silver alloys from an acidic, high chloride electroplating bath which comprises electroplating at least 0.5 microinches of a first layer of a palladium/nickel or palladium/cobalt alloy comprising between about 20 and 95 weight percent palladium and between about 5 and 80 weight percent nickel or cobalt upon the substrate prior to electroplating the palladium/silver alloy to reduce or prevent corrosion of the basis metal during electroplating of the palladium/silver alloy.
A method for electroplating a dual layer palladium alloy deposit which comprises:
- electrodepositing a first layer of a palladium/nickel or palladium/cobalt alloy comprising between about 20 and 95 weight percent palladium and between about 5 and 80 weight percent nickel or cobalt upon a substrate in a thickness greater than about 0.5 microinches to increase the ductility and reduce the porosity and tendency for cracking in the dual layer electrodeposit;
- and
- electrodepositing a second layer of palladium or a palladium/silver alloy comprising between about 20 and 95 weight percent palladium and between about 5 and 80 weight percent silver upon said first layer in a thickness of at least about 5 microinches for use as an electrical contact;
- the thickness of said second layer being greater than the thickness of said first layer.
A palladium/silver electrical contact comprising a substrate and a composite electrodeposit comprising greater than about 0.5 microinches of a first layer of a palladium/nickel or palladium/cobalt alloy comprising between about 20 and 95 weight percent palladium and between about 5 and 80 weight percent nickel or cobalt upon said substrate and at least about 5 microinches of a second layer of a palladium/silver alloy comprising between about 20 and 95 weight percent palladium and between about 5 and 80 weight percent silver upon said first layer.
A method for making an electrical contact having a contact surface of palladium which comprises initially electrodepositing a first layer of a palladium/nickel or palladium/cobalt alloy comprising between about 20 and 95 weight percent palladium and between about 5 and 80 weight percent nickel or cobalt upon a substrate in a thickness of greater than 0.5 microinches before electroplating the palladium layer to increase the ductility and reduce the porosity and tendency for cracking in the dual layer electrodeposit;
- and
- electrodepositing a second layer of palladium upon said first layer in a thickness of at least about 5 microinches;
- the thickness of said second layer being greater than the thickness of said first layer, said second layer providing the electrical characteristics of the contact.
A palladium electrical contact comprising a substrate and a composite electrodeposit comprising a first layer of greater than 5 microinches of a palladium/nickel or palladium/cobalt alloy comprising between about 20 and 95 weight percent palladium and between about 5 and 80 weight percent nickel or cobalt and greate than 20 microinches and a second layer of palladium;
- the thickness of the second layer being greater than that of the first layer and providing the electrical characteristics of the contact.
Dependencies are inferred from the claim text.