Patent US3684158A successfully refreshed from Google Patents.
US4017889A
Expired / Lapsed
US
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Ternary barrier structure for conductive electrodes
Assignee: International Business Machines Corp
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Filing: 1974-12-23
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Granted: 1977-04-12
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Expires: 1994-12-23
Abstract
Abstract A ternary barrier structure and method for forming the structure to be used on a conductive electrode. In electronic structures, dielectric substrates are used which have a plurality of connecting conductive areas which are wettable by solder. The region surrounding these connecting conductive areas are not wettable by solder. Barrier structures are used to prevent the flow of the solder while the solder is liquid during the manufacture of these electronic products. The present barrier structure covers at least a portion of one of these connecting conductive electrodes wherein the electrode is composed predominantly of silver and a lesser quantity of one or more of the platinum metals. The barrier structure includes a gold bearing, non-wettable by solder, glaseous layer over a portion of the electrode. The portion of the conductive electrode under and adjacent to the barrier glasseous layer contains a gold-silver alloy which is produced during the formation of the barrier structure by diffusion of the gold from the glasseous layer into the conductive electrode. A particularly corrosion resistant barrier structure and conductive electrode combination is thereby produced at this rather critical point in the microminiature circuit structure.
Inventors
- 👤 Lewis F. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:21
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/24; H05K3/245; H05K3/247; H05K3/248; H05K3/30; H05K3/32; H05K3/34; H05K3/3452; H10; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/43; H10W90/00; H10W90/701; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H05K1/09; H05K1/092; H05K2201/00; H05K2201/01; H05K2201/0137; H05K2201/017; H05K2201/20; H05K2201/2081; H10W72/00; H10W72/071; H10W72/072; H10W72/07231; H10W72/07236; H10W72/07251; H10W72/20
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
124 words
A corrosion resistant microminiature circuit structure comprising: a substrate having a conductive electrode pattern with a plurality of connecting areas which are wettable by solder; said conductive electrode is composed predominently of silver and a lesser quantity of platinum group metal; regions surrounding said connecting areas not wettable by solder; at least a portion of said regions surrounding including a gold bearing, glasseous layer over a portion of a said conductive electrode including a silver and gold alloy; a chip of semiconductor material having a planar face with solder wettable terminal areas; and solder contacts establishing a unified joint between the terminal areas of said chip and said connecting areas, said solder contacts forming the means for physically supporting said chip from said substrate.
Claim 2
Dependent Claim
124 words
A corrosion resistant microminiature circuit structure comprising: a substrate having a conductive electrode pattern with a plurality of connecting areas which are wettable by solder; said conductive electrode is composed predominently of silver and a lesser quantity of platinum group metal; regions surrounding said connecting areas not wettable by solder; at least a portion of said regions surrounding including a gold bearing, glasseous layer over a portion of a said conductive electrode including a silver and gold alloy; a chip of semiconductor material having a planar face with solder wettable terminal areas; and solder contacts establishing a unified joint between the terminal areas of said chip and said connecting areas, said solder contacts forming the means for physically supporting said chip from said substrate.
Claim 3
Dependent Claim
19 words
The microminiature circuit structure of claim 1 wherein said solder contains greater than about 80 percent by weight lead.
Claim 4
Dependent Claim
22 words
The microminiature circuit structure of claim 1 wherein there is greater than about 20 percent by weight gold in said regions surrounding.
Claim 5
Dependent Claim
14 words
The microminiature circuit structure of claim 1 wherein said platinum group metal is palladium.
Claim 6
Dependent Claim
151 words
A corrosion resistant microminiature circuit structure comprising: a dielectric substrate having a conductive electrode pattern thereon which is composed of a material which is wettable with solder; said conductive pattern composed predominently of silver having a plurality of connecting areas; a pattern of a material which is not wetted by solder over said conductive pattern which isolates a small wettable with solder area at each of the said connecting areas from the remaining portions of said conductive pattern; said pattern of material including a gold bearing, glasseous layer and the portion of said conductive pattern under the said pattern of material including a gold-silver alloy; a chip of semiconductive material having a planar face with solder wettable terminal areas; solder contacts bonding said terminal areas to said connecting areas; and said chip being otherwise spaced and physically supported from said substrate by means of said solder at said preselected connecting areas.
Claim 7
Dependent Claim
151 words
A corrosion resistant microminiature circuit structure comprising: a dielectric substrate having a conductive electrode pattern thereon which is composed of a material which is wettable with solder; said conductive pattern composed predominently of silver having a plurality of connecting areas; a pattern of a material which is not wetted by solder over said conductive pattern which isolates a small wettable with solder area at each of the said connecting areas from the remaining portions of said conductive pattern; said pattern of material including a gold bearing, glasseous layer and the portion of said conductive pattern under the said pattern of material including a gold-silver alloy; a chip of semiconductive material having a planar face with solder wettable terminal areas; solder contacts bonding said terminal areas to said connecting areas; and said chip being otherwise spaced and physically supported from said substrate by means of said solder at said preselected connecting areas.
Claim 8
Dependent Claim
30 words
The microminiature circuit structure of claim 5 wherein said conductive pattern contains a quantity of a platinum group metal and said solder contains greater than 80 percent by weight lead.
Claim 9
Dependent Claim
14 words
The microminiature circuit structure of claim 6 wherein the platinum group metal is palladium.
Claim 10
Dependent Claim
25 words
The microminiature circuit structure of claim 5 wherein there is greater than about 20 percent by weight gold in said portion of said conductive pattern.
References Cited (Backward Citations)
US3597665A
Cited
US3809625A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-11 | 1980-10-11 | 1981-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-11 | 1984-10-11 | 1985-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-11 | 1988-10-11 | 1989-04-12 | $7700.00 | Window Closed / Lapsed |