Patent US4098452A successfully refreshed from Google Patents.
US4098452A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lead bonding method
Assignee: General Electric Co
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Filing: 1976-10-07
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Granted: 1978-07-04
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Expires: 1996-10-07
Abstract
Abstract A bond between a refractory metal or semiconductor and a ductile metal and a method for making the same includes forming a layer of a refractory metal wetting agent such as titanium on the refractory metal before bonding to allow wetting of the refractory metal by the ductile metal.
Inventors
- 👤 Harold F. Webster
- 👤 Dominic A. Cusano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:40
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/01; H10W72/013; B; B23; B23K; B23K1/00; B23K1/20; B23K35/00; B23K35/001; B23K35/005; H10W72/30; B23K2035/008; B23K2101/00; B23K2101/36; B23K2101/40; H10W72/071; H10W72/073; H10W72/07331; H10W72/07336; H10W72/351; H10W72/352; H10W72/381
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
146 words
A method for forming a bond between a suitable metal and a semiconductor selected from the group consisting of silicon, germanium and group III-V compounds comprising: coating the surfaces to be bonded with a substantially uniform layer of refractory metal wetting agent selected from the group consisting of titanium, zirconium and hafnium, providing a source of bonding metal selected from the group consisting of substantially pure lead, tin, bismuth and indium between said coated surfaces, said coated surfaces having a thickness which substantially prevents interaction between said bonding metal and said semiconductor, heating the bonding metal and the surfaces to be bonded to a temperature sufficiently high to cause melting of the bonding metal and wetting of the surfaces by the bonding metal in the presence of the refractory metal wetting agent, whereby a bond is formed having a low melting point and low residual strain.
Claim 2
Independent Claim
146 words
A method for forming a bond between a suitable metal and a semiconductor selected from the group consisting of silicon, germanium and group III-V compounds comprising: coating the surfaces to be bonded with a substantially uniform layer of refractory metal wetting agent selected from the group consisting of titanium, zirconium and hafnium, providing a source of bonding metal selected from the group consisting of substantially pure lead, tin, bismuth and indium between said coated surfaces, said coated surfaces having a thickness which substantially prevents interaction between said bonding metal and said semiconductor, heating the bonding metal and the surfaces to be bonded to a temperature sufficiently high to cause melting of the bonding metal and wetting of the surfaces by the bonding metal in the presence of the refractory metal wetting agent, whereby a bond is formed having a low melting point and low residual strain.
Claim 3
Dependent Claim
39 words
The method of claim 1 wherein coating said surfaces to be bonded with a layer of refractory metal wetting agent comprises coating said surfaces with finely divided refractory metal having a thickness between approximately 300 angstroms and 1 mil.
Claim 4
Dependent Claim
28 words
The method of claim 2 wherein coating said surfaces to be bonded with a layer of refractory metal wetting agent comprises sputtering said refractory metal onto said surfaces.
Claim 5
Dependent Claim
22 words
The method of claim 2 wherein coating said surfaces with a refractory metal wetting agent comprises evaporating said metal onto said surface.
Claim 6
Dependent Claim
25 words
The method of claim 1 wherein providing a source of substantially pure bonding metal comprises disposing a thin sheet of bonding metal between said surfaces.
Claim 7
Dependent Claim
37 words
The method of claim 1 wherein providing a source of substantially pure bonding metal comprises inserting a metal filled stand pipe through one of said surfaces so that upon melting, said metal will flow between said surfaces.
Claim 8
Dependent Claim
19 words
The method of claim 1 wherein said heating step comprises heating to a temperature in excess of 550° C.
Claim 9
Dependent Claim
19 words
The method of claim 1 wherein said heating step comprises heating to a temperature between 500° and 700° C.
Claim 10
Dependent Claim
31 words
The method of claim 1 wherein said heating step includes placing said refractory metal coated semiconductor and metal along with said bonding metal into a graphite boat and heating said boat.
Claim 11
Dependent Claim
21 words
The method of claim 1 wherein said suitable metal is chosen from the group consisting of tungsten, molybdenum, tantalum, and niobium.
Claim 12
Dependent Claim
14 words
The method of claim 1 wherein said heating step comprises heating in a vacuum.
Claim 13
Dependent Claim
15 words
The method of claim 1 wherein said heating step comprises heating in an inert gas.
Claim 14
Independent Claim
121 words
A method for forming a lead bond between a suitable metal and a semiconductor selected from the group consisting of silicon, germanium and group III-V compounds comprising: coating the surfaces to be bonded with a layer of approximately 300 Angstroms to 10 mils thickness from a source of titanium; providing a source of substantially pure lead between said titanium coated surfaces; and heating the lead and the surfaces to be bonded to a temperature sufficiently high to cause melting of the lead and wetting of the surfaces by the lead in the presence of the titanium, the thickness of said source of titanium layer substantially preventing interaction between said semiconductor and said lead thereby producing a bond having low residual strain.
Claim 15
Independent Claim
121 words
A method for forming a lead bond between a suitable metal and a semiconductor selected from the group consisting of silicon, germanium and group III-V compounds comprising: coating the surfaces to be bonded with a layer of approximately 300 Angstroms to 10 mils thickness from a source of titanium; providing a source of substantially pure lead between said titanium coated surfaces; and heating the lead and the surfaces to be bonded to a temperature sufficiently high to cause melting of the lead and wetting of the surfaces by the lead in the presence of the titanium, the thickness of said source of titanium layer substantially preventing interaction between said semiconductor and said lead thereby producing a bond having low residual strain.
Claim 16
Dependent Claim
33 words
The method for forming a bond of claim 13 wherein coating said surfaces to be bonded with a layer of a source of titanium comprises coating said surfaces with finely divided titanium hydride.
Claim 17
Dependent Claim
16 words
The method of claim 14 wherein said finely divided titanium hydride is carried by amyl acetate.
Claim 18
Dependent Claim
15 words
The method of claim 15 wherein said finely divided titanium further includes a nitro-cellulose binder.
Claim 19
Dependent Claim
29 words
The method of claim 13 wherein coating said surfaces with a layer of titanium comprises sputtering said titanium onto said surfaces to a thickness in excess of 300 A.
Claim 20
Dependent Claim
25 words
The method of claim 13 wherein coating said surfaces with titanium comprises evaporating titanium onto said surfaces to a thickness in excess of 300 A.
Claim 21
Dependent Claim
21 words
The method of claim 13 wherein providing a source of lead comprises disposing a thin sheet of lead between said surfaces.
Claim 22
Dependent Claim
34 words
The method of claim 13 wherein providing a source of lead comprises inserting a lead filled stand pipe through one of said surfaces so that upon melting, said lead will flow between said surfaces.
Claim 23
Dependent Claim
19 words
The method of claim 13 wherein said heating step comprises heating to a temperature in excess of 550° Centigrade.
Claim 24
Dependent Claim
19 words
The method of claim 13 wherein said heating step comprises heating to a temperature between 500° and 700° Centigrade.
Claim 25
Dependent Claim
29 words
The method of claim 13 wherein said heating step includes placing said titanium coated semiconductor and metal along with said lead in a graphite boat and heating the boat.
Claim 26
Dependent Claim
10 words
The method of claim 13 wherein said semiconductor is silicon.
Claim 27
Dependent Claim
20 words
The method of claim 13 wherein said suitable metal is chosen from the group comprising tungsten, molybdenum, tantalum and niobium.
Claim 28
Dependent Claim
14 words
The method of claim 13 wherein said heating step comprises heating in a vacuum.
Claim 29
Dependent Claim
15 words
The method of claim 13 wherein said heating step comprises heating in an inert gas.
Claim 30
Dependent Claim
38 words
The method of claim 13 wherein coating said surfaces to be bonded with a thin layer of a source of titanium comprises coating said surfaces with a layer of titanium hydride overlying a layer of substantially pure titanium.
Claim 31
Dependent Claim
61 words
The method of claim 28 wherein coating the surfaces to be bonded with a thin layer of titanium hydride overlying a layer of substantially pure titanium comprises coating said surfaces with a layer of substantially pure titanium; and exposing the titanium surfaces to a hydrogen atmosphere so that at least some of said substantially pure titanium is converted to titanium hydride.
Claim 32
Independent Claim
137 words
A method for forming a bond between a suitable metal and a semiconductor selected from the group consisting of silicon, germanium and group III-V compounds comprising: coating the surfaces to be bonded with a layer of between 1000 and 10,000 Angstroms of a refractory metal wetting agent selected from the group consisting of a source of titanium, zirconium and hafnium; coating said coated surfaces with a further layer of bonding metal selected from the group consisting of substantially pure lead, tin, bismuth and indium; heating the bonding metal and the surfaces to be bonded to a temperature sufficiently high to cause melting of the bonding metal and wetting of the surfaces by the bonding metal in the presence of the refractory metal wetting agent; and rapidly cooling the resulting structure to minimize residual strain in the structure.
Claim 33
Independent Claim
137 words
A method for forming a bond between a suitable metal and a semiconductor selected from the group consisting of silicon, germanium and group III-V compounds comprising: coating the surfaces to be bonded with a layer of between 1000 and 10,000 Angstroms of a refractory metal wetting agent selected from the group consisting of a source of titanium, zirconium and hafnium; coating said coated surfaces with a further layer of bonding metal selected from the group consisting of substantially pure lead, tin, bismuth and indium; heating the bonding metal and the surfaces to be bonded to a temperature sufficiently high to cause melting of the bonding metal and wetting of the surfaces by the bonding metal in the presence of the refractory metal wetting agent; and rapidly cooling the resulting structure to minimize residual strain in the structure.
Claim 34
Dependent Claim
17 words
The method of claim 30 wherein said coating steps are performed by sputtering in an inert atmosphere.
Claim 35
Dependent Claim
24 words
The method of claim 30 wherein coating said surfaces with said further layer of bonding metal comprises sputtering said bonding metal onto said surfaces.
Claim 36
Dependent Claim
32 words
The method of claim 32 wherein sputtering said bonding metal onto said surfaces comprises sputtering a layer of bonding metal having a thickness between approximately 1000 and 10,000 Angstrom onto said surface.
Claim 37
Dependent Claim
25 words
The method of claim 30 wherein coating said surfaces with a layer of refractory metal wetting agent comprises sputtering said wetting agent onto said surfaces.
Claim 38
Dependent Claim
24 words
The method of claim 34 wherein coating said surfaces with said further layer of bonding metal comprises sputtering said bonding metal onto said surfaces.
Claim 39
Dependent Claim
14 words
The method of claim 35 wherein said sputtering is performed in an inert atmosphere.
Claim 40
Dependent Claim
11 words
The method of claim 36 wherein said inert atmosphere comprises argon.
Claim 41
Dependent Claim
27 words
The method of claim 34 wherein sputtering said wetting agent onto said surfaces comprises sputtering a layer having a thickness of between approximately 1000 and 5000 Angstroms.
Claim 42
Dependent Claim
32 words
The method of claim 38 wherein sputtering said bonding metal onto said surfaces comprises sputtering a layer of bonding metal having a thickness between approximately 1000 and 10,000 Angstrom onto said surface.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-03 | 1982-01-02 | 1982-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-03 | 1986-01-02 | 1986-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-03 | 1990-01-02 | 1990-07-04 | $7700.00 | Window Closed / Lapsed |