Process for attaching a lead member to a semiconductor device

Claim 2

A process for attaching a lead member to a semiconductor device comprising the steps of A. providing a lead member formed substantially of a thermally and electrically conductive metal and terminating at one end in a joining surface; and a semiconductor device comprising a semiconductor body and a contact member formed of a refractory metal extending outwardly from said body and terminating in a joining surface of said refractory metal spaced from said body; B. placing said joining surfaces of said members in contact with a brazing alloy comprising on a weight basis about 80-89 percent copper, about 5-15 percent silver, and about 4-6 percent phosphorus; C. heating the brazing alloy at least to its wetting point for a period of time sufficient to melt the brazing alloy; and D. allowing the molten brazing alloy to cool and solidify in contact with said joining surfaces of said members, thereby to join said contact member and said lead member into a unitary structure.

Claim 3

The process of claim 1 including the additional step of subsequently applying and fusing a passivating layer of a passivating material about said body and about said contact member between said joining surface thereof and said body.

Claim 4

The process of claim 1 wherein the refractory metal is selected from the group consisting of tungsten, molybdenum, tantalum, and alloys thereof.

Claim 5

The process of claim 3 wherein said refractory metal is molybdenum.

Claim 6

The process of claim 1 wherein the conductive metal is selected from the group consisting of silver and copper and alloys thereof.

Claim 7

The process of claim 5 wherein said conductive metal is copper.

Claim 8

The process of claim 2 wherein the passivating material is selected from the group consisting of glass and plastic.

Claim 9

The process of claim 7 wherein the passivating material is glass.

Claim 10

The process of claim 1 wherein said semiconductor body is formed substantially of silicon.

Claim 11

The process of claim 2 wherein said refractory metal is molybdenum, said conductive metal is copper, said passivating material is glass, and said semiconductor body is formed substantially of silicon.

Claim 12

The process of claim 1 wherein the heating of step (C) is performed in an inert atmosphere.

Claim 13

The process of claim 1 wherein said joining surfaces of said members are of substantially the same configuration and size, and wherein the brazing alloy is provided as a preform with joining surfaces of substantially similar configuration and size abutting said joining surfaces of said members.

Claim 14

The process according to claim 2 wherein said refractory metal is selected from the group consisting of tungsten, molybdenum, tantalum, and alloys thereof; said thermally and electrically conductive metal is selected from the group consisting of silver, copper and alloys thereof; said brazing alloy comprises on a weight basis about 80 percent copper, about 15 percent silver and about 5 percent phosphorus; and said passivating material is selected from the group consisting of glass and plastic.

Claim 15

A process for attaching a lead member to a semiconductor body comprises the steps of A. providing (i) a semiconductor body having a joining surface; (ii) a contact member formed substantially of a refractory metal and having a joining surface of said refractory metal at each end thereof; (iii) a lead member formed substantially of a thermally and electrically conductive metal and having at one end a joining surface; and (iv) a brazing preform formed substantially of a brazing alloy comprising on a weight basis about 80-89 percent copper, about 5-15 percent silver, and about 4-6 percent phosphorus, and having a joining surface at each end thereof. B. forming an assembly by simultaneously contacting (i) said joining surface of said semiconductor body to one of said refractory metal joining surfaces of said contact member; (ii) the other of said refractory metal joining surfaces of said contact member to one of said brazing alloy joining surfaces of said preform; and (iii) the other of said brazing alloy joining surfaces of said preform to said conductive metal joining surface of said lead member; C. heating said assembly in an inert atmosphere at least to the alloy wetting point to cause brazing of contacting joining surfaces; and D. allowing said assembly to cool, thereby to join said semiconductor body, said contact member, said preform, and said lead member into a unitary structure.

Claim 16

A process for attaching a lead member to a semiconductor body comprises the steps of A. providing (i) a semiconductor body having a joining surface; (ii) a contact member formed substantially of a refractory metal and having a joining surface of said refractory metal at each end thereof; (iii) a lead member formed substantially of a thermally and electrically conductive metal and having at one end a joining surface; and (iv) a brazing preform formed substantially of a brazing alloy comprising on a weight basis about 80-89 percent copper, about 5-15 percent silver, and about 4-6 percent phosphorus, and having a joining surface at each end thereof. B. forming an assembly by simultaneously contacting (i) said joining surface of said semiconductor body to one of said refractory metal joining surfaces of said contact member; (ii) the other of said refractory metal joining surfaces of said contact member to one of said brazing alloy joining surfaces of said preform; and (iii) the other of said brazing alloy joining surfaces of said preform to said conductive metal joining surface of said lead member; C. heating said assembly in an inert atmosphere at least to the alloy wetting point to cause brazing of contacting joining surfaces; and D. allowing said assembly to cool, thereby to join said semiconductor body, said contact member, said preform, and said lead member into a unitary structure.

Claim 17

The process of claim 14 wherein said refractory metal is selected from the group consisting of molybdenum, tungsten, tantalum and alloys thereof.

Claim 18

The process of claim 15 wherein said refractory metal is molybdenum.

Claim 19

The process of claim 14 wherein said conductive metal is selected from the group consisting of copper and silver and alloys thereof.

Claim 20

The process of claim 17 wherein said conductive metal is copper.

Claim 21

The process of claim 14 wherein said semiconductor body is formed substantially of silicon and has an electrically conductive layer of metal selected from the group consisting of aluminum and gold disposed thereon to define said joining surface thereof.

Claim 22

The process of claim 14 wherein said refractory metal is molybdenum, said conductive metal is copper, and said semiconductor body is formed substantially of silicon with a layer of aluminum disposed thereon to define said joining surface thereof.

Claim 23

The process of claim 14 including the additional step of subsequently applying and fusing a passivating layer of a passivating material about said semiconductor body and about said contact member between said refractory metal joining surfaces.

Claim 24

The process of claim 21 wherein said passivating material is selected from the group consisting of glass and plastic.

Claim 25

The process of claim 22 wherein said passivating material is glass.

Claim 26

The process of claim 21 wherein said refractory material is molybdenum, said conductive metal is copper, said passivating material is glass, and said semiconductor body is formed substantially of silicon and has an electrically conductive layer of aluminum disposed thereon to define said joining surface thereof.

Claim 27

The process according to claim 14 wherein said semiconductor body is formed substantially of silicon and has an electrically conductive layer of a metal selected from the group consisting of aluminum and gold disposed thereon to define said joining surface thereof; said refractory metal is selected from the group consisting of molybdenum, tungsten, tantalum, and alloys thereof; said thermally and electrically conductive metal is selected from the group consisting of copper, silver and alloys thereof; and said brazing alloy comprises on a weight basis about 80 percent copper, about 15 percent silver, and about 5 percent phosphorus.

Claim 28

The process of claim 25 including the additional step of subsequently applying and fusing a passivating layer of a passivating material selected from the group consisting of glass and plastic about said semiconductor body and about said contact member between said refractory joining surfaces.

Claim 29

The process of claim 14 wherein said assembly is heated in an inert atmosphere at substantially atmospheric pressure.