Double-sintered gold-nickel electrical contact for compression-bonded electrical devices

Claim 2

The electrical contact of claim 1 in which an electrical lead is electrically connected to said body.

Claim 3

The electrical contaCt of claim 3 in which said electrical lead is an integral part of said electrical contact.

Claim 4

The electrical contact of claim 3 in which said body is comprised of molybdenum, and said electrical lead is comprised of braided copper wire.

Claim 5

The electrical contact of claim 4 in which said body and said electrical lead is comprised of a copper-based alloy.

Claim 6

An electrical device comprised of: a. an electrically and thermally conductive support member; b. a semiconductor element disposed on said support member, said element having at least two regions of alternate type semiconductivity and at least one PN junction formed at the interface of said two regions of different type semiconductivity and at least a first electrical contact electrically affixed to at least one region of semiconductivity, and a second electrical contact electrically connected to the other region of semiconductivity; and c. a third electrical contact disposed on, and electrically connected to one of said first and said second electrical contacts, said electrical contact being comprised of a body of electrically and thermally conductive material having at least two major opposed surfaces, one of the at least two major opposed surfaces being an electrical contact surface, a layer of nickel disposed on at least that portion of said body disposed on at least said contact surface and metallurgically bonded to said body, the layer of nickel of said third electrical contact being initially from 0.0002 inch to 0.0003 inch in thickness said body and said layer of nickel heated to an elevated temperature of approximately 800* C. to 850* C. for a sufficient time to sinter them whereby to metallurgically bond the gold to the metallurgically bonded nickel layer, and a layer of gold disposed on and metallurgically bonded to said layer of nickel said layer of gold being initially from 0.000050 inch to 0.000200 inch in thickness said layers having been sintered together.

Claim 7

The electrical device of claim 7 in which said electrically and thermally conductive material is one selected from the group consisting of molybdenum, tungsten, tantalum, copper, aluminum and combinations and base alloys thereof.

Claim 8

The electrical device of claim 7 in which an electrical lead is electrically connected to said body of said third electrical contact.

Claim 9

The electrical device of claim 9 in which said electrical lead is an integral part of said third electrical contact.

Claim 10

The electrical device of claim 10 in which said body and said electrical lead of said third electrical contact are integral with one another and are each comprised of a copper based alloy.

Claim 11

The electrical device of claim 8 in which each of said first and said second electrical contacts each are comprised of a metal selected from a group consisting of molybdenum, tungsten, tantalum and combinations and base alloys thereof.

Claim 12

The electrical device of claim 12 in which: said fIrst electrical contact consists of an alloy of from 12 to 17 percent by weight silver and the remainder is tungsten; and said second and said third electrical contacts are each consisted of molybdenum.

Claim 13

The electrical device of claim 13 in which a hermetic enclosure seals therein said semiconductor element.

Claim 14

The electrical device of claim 7 in which said support member has an upwardly extending pedestal, said pedestal having a peripheral side surface, at least a portion of which is beveled and forms an included angle of approximately 135* with the top surface of said pedestal.

Claim 15

The electrical device of claim 15 in which: said first electrical contact is comprised of an alloy of 12 to 17 percent by weight silver and the remainder is tungsten; and said second electrical contact is comprised of molybdenum.

Claim 16

The electrical device of claim 15 in which the top surface of said pedestal has at least the physical dimensions as the bottom surface of said first electrical contact.

Claim 17

The electrical device of claim 7 in which: said semiconductor element has at least tree regions of alternate type semiconductivity; a fourth electrical contact electrically connected to a third region of semiconductivity of said element; an electrical lead electrically connected to said fourth electrical contact; and said force means acts on said fourth electrical contact.

Claim 18

In a process for making an electrical contact, the steps comprising: a. disposing a layer of nickel of a thickness of from 0.0002 to 0.0003 inch on at least the electrical contact surfaces of a body of electrically and thermally conductive material; b. heating said body and said layer of nickel to an elevated temperature of approximately 800* C. to 850* C. for a sufficient time to metallurgically bond the nickel to the body; c. disposing a layer of gold of a thickness of from 0.00005 to 0.0002 inch on at least the layer of metallurgically bonded nickel; and d. heating said body, said metallurgically bonded nickel, and said gold to an elevated temperature of approximately 800* C. to 850* C. for a sufficient time to sinter them whereby to metallurgically bond the gold to the metallurgically bonded nickel layer.

Claim 19

The process of claim 19 in which each of said heating steps is practiced at an elevated temperature of at least 800* C. + or - 15* C.

Claim 20

The process of claim 19 in which each of said heating steps is practiced by heating said contact to a temperature of 800* C. + or - 15* C. for a period of approximately 6 1/2 minutes.

Claim 21

The process of claim 21 in which said contacts are preheated during each heating step to a temperature of 800* C. + or - 15* C. in approximately 5 minutes; and said contacts are furnace cooled during each heating step to 605* C. + or - 15* C. in approximately 5 minutes.

Claim 22

The process of claim 22 in which the furnace atmosphere is hydrogen.