US4505418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of direct bonding copper foils to oxide-ceramic substrates
Assignee: BBC Brown Boveri AG Germany
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Filing: 1983-12-12
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Granted: 1985-03-19
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Expires: 2003-12-12
Abstract
Abstract Method for directly bonding copper foils having a copper oxide layer to oxide-ceramic substrates by heating the ceramic substrate covered with the copper foil in an oxygen-containing atmosphere to a temperature above the eutectic temperature of Cu and Cu 2 O, but below the melting temperature of copper in a vacuum furnace at a pressure of not more than 1 mbar while maintaining a furnace atmosphere with a partial oxygen pressure between 0.001 and 0.1 mbar.
Inventors
- 👤 Arno Neidig
- 👤 Dietmar Berndt
- 👤 Georg Wahl
- 👤 Mark Wittmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:04
CPC Classifications
C; C04; C04B; C04B37/00; C04B37/02; C04B37/021; B; B23; B23K; B23K35/00; B23K35/22; B23K35/38; C04B37/023; C04B37/026; H; H05; H05K; H05K3/00; H05K3/38; H05K3/40; H05K3/4007; H05K3/4015; C04B2235/00; C04B2235/65; C04B2235/658; C04B2235/6581; C04B2237/00; C04B2237/02; C04B2237/12; C04B2237/124; C04B2237/126; C04B2237/30; C04B2237/32; C04B2237/34; C04B2237/343; C04B2237/40; C04B2237/407; C04B2237/50; C04B2237/54
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
129 words
Method for the direct bonding of copper foils which carry a copper oxide layer on the surface, to oxide ceramic substrates which comprises disposing a copper foil having a copper oxide layer on the surface on a ceramic substrate with the copper oxide layer in contact with the ceramic substrate, heating the ceramic substrate covered with the copper foil in an oxygen-containing atmosphere to a temperature above the eutectic temperature of Cu and Cu 2 O but below the melting temperature of Cu, in a vacuum furnace at a pressure not more than 1 mbar and maintaining a furnace atmosphere with a partial oxygen pressure between 0.001 and 0.1 mbar, and cooling down the heated ceramic substrate during which cooling-down the partial oxygen pressure is kept below 0.005 mbar.
Claim 2
Dependent Claim
129 words
Method for the direct bonding of copper foils which carry a copper oxide layer on the surface, to oxide ceramic substrates which comprises disposing a copper foil having a copper oxide layer on the surface on a ceramic substrate with the copper oxide layer in contact with the ceramic substrate, heating the ceramic substrate covered with the copper foil in an oxygen-containing atmosphere to a temperature above the eutectic temperature of Cu and Cu 2 O but below the melting temperature of Cu, in a vacuum furnace at a pressure not more than 1 mbar and maintaining a furnace atmosphere with a partial oxygen pressure between 0.001 and 0.1 mbar, and cooling down the heated ceramic substrate during which cooling-down the partial oxygen pressure is kept below 0.005 mbar.
Claim 3
Dependent Claim
16 words
Method according to claim 1, wherein the oxide-ceramic is high-purity aluminum-oxide ceramic with a smooth surface.
Claim 4
Dependent Claim
26 words
Method according to claim 1, wherein the oxide-ceramic substrates are moved into the vacuum furnace through a lock and removed from the furnace through a lock.
Claim 5
Dependent Claim
17 words
Method according to claim 1, wherein the pressure in the vacuum furnace is at most 0.1 mbar.
Claim 6
Dependent Claim
17 words
Method according to claim 2, wherein the pressure in the vacuum furnace is at most 0.1 mbar.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-03-18 | 1988-09-17 | 1989-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-03-18 | 1992-09-17 | 1993-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-03-18 | 1996-09-17 | 1997-03-19 | $7700.00 | Window Closed / Lapsed |