Patent US4699888A successfully refreshed from Google Patents.
US4699888A
Expired / Lapsed
US
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Die/attach composition
Assignee: Evonik Operations GmbH
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Filing: 1985-09-16
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Granted: 1987-10-13
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Expires: 2005-09-16
Abstract
Abstract A silver-glass composition for use in attaching a semiconductor support and a method for making the attachment are disclosed. The glass component of the composition is a low melting point glass comprising about 75-85 wt. % lead oxide, about 8-15% boron oxide, about 0.75 to 2.5 wt. % silicon-dioxide, 0-10 wt. % zinc oxide, 0 to 3 wt. % alumina, 0.5 to 5.5 wt. % cuprousoxide and a non-volatile metal fluoride in amount such that the mol ratio of cuprous oxide to the fluoride content of the metal fluoride is in the range 1.0:0.25 to 1.0:10. The weight ratio of silver to glass in the composition is in the range about 2:1 to 9:1.
Inventors
- 👤 Maurice E. Dumesnil
- 👤 Karl Starz
- 👤 Leonid Finkelshteyn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:37
CPC Classifications
C; C03; C03C; C03C8/00; C03C8/24; C03C8/245; C04; C04B; C04B35/00; C04B35/622; C04B35/626; C04B35/62605; C04B35/62645; C04B35/62655; C04B35/63; C04B35/632; C04B35/634; C04B35/63404; C04B35/63424; C04B35/636; C04B35/6365; H; H10; H10W; H10W20/00; H10W20/40; C04B2237/00; C04B2237/02; C04B2237/04; C04B2237/06; C04B2237/062; C04B2237/064; C04B2237/12; C04B2237/122; C04B2237/125; C04B2237/126; C04B2237/30; C04B2237/32; C04B2237/34; C04B2237/343; C04B2237/50; C04B2237/70; C04B2237/708; C04B2237/72; H10W72/00; H10W72/071; H10W72/073; H10W72/07331; H10W72/07337; H10W72/30; H10W72/321; H10W72/325; H10W72/351; H10W72/352; H10W90/00; H10W90/701; H10W90/731; H10W90/734
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
133 words
A composition for use in bonding a semiconductor device to a ceramic support comprising a mixture of: (a) powdered silver metal; (b) powdered low melting glass consisting essentially of about 75-85 wt. % lead oxide, about 8-15 wt. % boron oxide, about 0.75 to 2.5 wt. % silicon dioxide, 0 to 10 wt. % zinc oxide, 0-5 wt. % bismuth oxide, 0 to 3 wt. % alumina, 0.5 to 5.5 wt. % cuprous oxide and a non-volatile metal fluoride in amount such that the mol ratio of cuprous oxide to the fluoride content of the metal fluoride is in the range of 1.0:0.25 to 1.0:10, and having a DTA softening point in the range about 260° C.-280° C., the weight ratio of (a) to (b) being in the range about 2:1 to 9:1.
Claim 2
Dependent Claim
133 words
A composition for use in bonding a semiconductor device to a ceramic support comprising a mixture of: (a) powdered silver metal; (b) powdered low melting glass consisting essentially of about 75-85 wt. % lead oxide, about 8-15 wt. % boron oxide, about 0.75 to 2.5 wt. % silicon dioxide, 0 to 10 wt. % zinc oxide, 0-5 wt. % bismuth oxide, 0 to 3 wt. % alumina, 0.5 to 5.5 wt. % cuprous oxide and a non-volatile metal fluoride in amount such that the mol ratio of cuprous oxide to the fluoride content of the metal fluoride is in the range of 1.0:0.25 to 1.0:10, and having a DTA softening point in the range about 260° C.-280° C., the weight ratio of (a) to (b) being in the range about 2:1 to 9:1.
References Cited (Backward Citations)
US2530217A
Cited
US3154503A
Cited
US4002799A
Cited
US4186023A
Cited
US4251595A
Cited
US4401767A
Cited
US4476090A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-10-12 | 1991-04-13 | 1991-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-12 | 1995-04-13 | 1995-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-12 | 1999-04-13 | 1999-10-13 | $7700.00 | Window Closed / Lapsed |