US4945071A
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US
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Low softening point metallic oxide glasses suitable for use in electronic applications
Assignee: National Starch and Chemical Investment Holding Corp
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Filing: 1989-04-19
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Granted: 1990-07-31
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Expires: 2009-04-19
Abstract
Abstract This invention presents a series of glasses which possess low softening points, high resistance to recrystallization and good durability in the presence of moisture. The glasses are contained within oxides of silver, vanadium, tellurium, and lead and have glass transition temperatures below 260° C., and are useful in electronic applications such as die attach adhesives and sealing glasses.
Inventors
- 👤 G. Delbert Friesen
- 👤 Yun K. Shin
- 👤 Lewis Hoffman, deceased
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:53
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/12; C03C3/122; C03C8/00; C03C8/02; C03C8/10; C03C8/24; H; H10; H10W; H10W72/00; H10W72/30; H10W72/071; H10W72/073; H10W72/07331; H10W72/07337
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
42 words
A low softening point glass composition comprising 2 to 40% by wt. silver oxide, 12 to 40% by wt. vanadium oxide, and 35 to 75% by wt. tellurium oxide, and 2 to 30% by wt. lead oxide, wherein all percentages total 100.
Claim 2
Dependent Claim
42 words
A low softening point glass composition comprising 2 to 40% by wt. silver oxide, 12 to 40% by wt. vanadium oxide, and 35 to 75% by wt. tellurium oxide, and 2 to 30% by wt. lead oxide, wherein all percentages total 100.
Claim 3
Dependent Claim
21 words
The low softening point glass composition of claim 1, wherein the ratio of silver oxide/tellurium oxide is 0.1/1 to 0.5/1 (wt./wt.).
Claim 4
Dependent Claim
17 words
The low softening point glass composition of claim 1 having a glass transition temperature below 260° C.
Claim 5
Dependent Claim
59 words
The low softening point glass composition of claim 1, which further comprises up to a total of 10% (by wt.) of one or more oxide compounds selected from the group consisting of phosphorous oxide, tungsten oxide, silicon oxide, copper oxide, aluminum oxide, bismuth oxide, tin oxide, zinc oxide thallium oxide, arsenic oxide, molybdenum oxide, titanium oxide, and antimony oxide.
Claim 6
Dependent Claim
87 words
A die attach adhesive composition consisting essentially of an admixture of (a) a metal selected from the group consisting of silver, gold, and plantinum, and (b) a powdered, low softening point glass composition comprising 2 to 40% by wt. silver oxide, 12 to 40% by wt. vanadium oxide, 35 to 75% by wt. tellurium oxide, and 2 to 30% by wt. lead oxide, wherein all percentages total 100, having a peak firing temperature of 400° C. or lower, wherein the ratio of (a)/(b) is 4:1 to 100:1.
Claim 7
Dependent Claim
87 words
A die attach adhesive composition consisting essentially of an admixture of (a) a metal selected from the group consisting of silver, gold, and plantinum, and (b) a powdered, low softening point glass composition comprising 2 to 40% by wt. silver oxide, 12 to 40% by wt. vanadium oxide, 35 to 75% by wt. tellurium oxide, and 2 to 30% by wt. lead oxide, wherein all percentages total 100, having a peak firing temperature of 400° C. or lower, wherein the ratio of (a)/(b) is 4:1 to 100:1.
Claim 8
Dependent Claim
12 words
The die attach adhesive of claim 5 wherein the metal is silver.
Claim 9
Dependent Claim
36 words
The die attach adhesive of claim 5, wherein the metal is selected from the group consisting of flaked metal, powdered metal, mixtures of flaked metals, mixtures of powdered metals, and mixtures of flaked and powdered metals.
Claim 10
Dependent Claim
23 words
The die attach adhesive of claim 6, wherein the ratio of silver oxide/tellurium oxide in the glass composition is 0.1/1 to 0.5/1 (wt./wt.).
Claim 11
Dependent Claim
19 words
The die attach adhesive of claim 5, wherein the glass composition has a glass transition temperature below 260° C.
Claim 12
Dependent Claim
60 words
The die attach adhesive of claim 5, wherein the glass composition further comprises up to a total of 10% (by wt.) of one or more oxide compounds selected from the group consisting of phosphorous pentoxide, tungsten oxide, silicon oxide, copper oxide, aluminum oxide, bismuth oxide, tin oxide, zinc oxide thallium oxide, arsenic oxide, molybdenum oxide, titanium oxide, and antimony oxide.
Claim 13
Dependent Claim
12 words
A sealing glass comprising the low softening point composition of claim 1.
Claim 14
Dependent Claim
27 words
The sealing glass of claim 11 which further comprises an effective amount of an expansion-modifying filler, such that the thermal expansion coefficient of the glass is reduced.
Claim 15
Dependent Claim
21 words
The sealing glass of claim 12, wherein the expansion-modifying filler is selected from the group consisting of beta-eucryptite and amorphous silica.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-07-30 | 1994-01-29 | 1994-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-30 | 1998-01-29 | 1998-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-30 | 2002-01-29 | 2002-07-31 | $7700.00 | Window Closed / Lapsed |