Patent US5541145A successfully refreshed from Google Patents.
US5541145A
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Low temperature sintering route for aluminum nitride ceramics
Assignee: CMC INTERCONNECT TECHNOLOGIES Inc
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Filing: 1995-06-12
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Granted: 1996-07-30
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Expires: 2015-06-12
Abstract
Abstract An aluminum nitride ceramic having desired properties suitable for electronic packaging applications can be prepared from a novel aluminum nitride powder/sintering aid mixture. The sintering aid comprises a glassy component formed from alumina, calcia and boria, and a non-vitreous component comprising an element or compound of a metal of Group IIa, IIIa, or the lanthanides, preferably crystalline oxides, reactibis with the crystallized glass component and the alumina from the Al N grains. Alternatively, the sintering aid comprises a multi-component glass composition capable of forming the above components upon melting and thereafter crystallizing upon reaction.
Inventors
- 👤 Jonathan H. Harris
- 👤 Subhash L. Shinde
- 👤 Takeshi Takamori
- 👤 Robert A. Youngman
- 👤 Lester W. Herron
- 👤 Benjamin V. Fasano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:37
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/581; Y; Y10; Y10S; Y10S428/00; Y10S428/901
Claims Analysis
Total Claims: 65
Claim 1
Independent Claim
123 words
A resistive sintered aluminum nitride ceramic body, prepared from a presintering aluminum nitride powder/sintering aid mixture wherein the aluminum nitride contains alumina and wherein the sintering aid comprises a) an element or compound of a metal selected from the group consisting of Group IIa, IIIa, lanthanide metals and mixtures thereof, and b) a glassy component formed from alumina, calcia, and boria, said metal element or compound being reactible with the glassy component and the alumina from the AlN to form a second phase containing a calcium containing component upon sintering, said calcium containing component of said second phase being in contact with aluminum nitride at a dihedral angle sufficient to provide a resistivity of at least about 10 8 Ω-cm upon heat treatment.
Claim 2
Dependent Claim
123 words
A resistive sintered aluminum nitride ceramic body, prepared from a presintering aluminum nitride powder/sintering aid mixture wherein the aluminum nitride contains alumina and wherein the sintering aid comprises a) an element or compound of a metal selected from the group consisting of Group IIa, IIIa, lanthanide metals and mixtures thereof, and b) a glassy component formed from alumina, calcia, and boria, said metal element or compound being reactible with the glassy component and the alumina from the AlN to form a second phase containing a calcium containing component upon sintering, said calcium containing component of said second phase being in contact with aluminum nitride at a dihedral angle sufficient to provide a resistivity of at least about 10 8 Ω-cm upon heat treatment.
Claim 3
Dependent Claim
18 words
The resistive, sintered aluminum nitride ceramic body of claim 1 wherein said dihedral angle is greater than 30°.
Claim 4
Dependent Claim
22 words
The resistive, sintered aluminum nitride ceramic body of claim 1 wherein said dihedral angle is greater than or equal to about 80°.
Claim 5
Dependent Claim
19 words
The resistive sintered aluminum nitride ceramic body of claim 1 wherein said second phase has a substantially dewetted microstructure.
Claim 6
Dependent Claim
34 words
The resistive, sintered aluminum nitride ceramic body of claim 1 wherein said second phase contains a quaternary or pseudo-quaternary compound containing Ca, Y, Al, and O and having substitutional boron contained within said compound.
Claim 7
Dependent Claim
22 words
The resistive, Sintered aluminum nitride ceramic body of claim 1 wherein said second phase includes CaYAl 3 O 7 having substitutional boron.
Claim 8
Dependent Claim
20 words
The resistive, sintered aluminum nitride ceramic body of claim 1 wherein said second phase includes CaYAlO 4 having substitutional boron.
Claim 9
Dependent Claim
165 words
A resistive sintered aluminum nitride ceramic body prepared from a presintering aluminum nitride powder/sintering aid mixture wherein the aluminum nitride contains alumina and wherein the sintering aid comprises a) an element or compound of a metal selected from the group consisting of Group Ha, IIIa, lanthanide metals and mixtures thereof, and b) a glassy component formed from alumina, calcia, and boria, wherein the presintering mixture is sintered, at a sintering temperature between 1550° C. and 1800° C., to form a sintered body having a second phase containing a calcium containing component; said sintered body being cooled to at least below 1500° C.; and heat treated at a temperature of at least 1300° C. but below the sintering temperature for a period of time sufficient to cause said calcium containing component of said second phase to at least partially dewet from the aluminum nitride so as to contact the aluminum nitride at a dihedral angle sufficient to provide a resistivity of at least 10 8 Ω-cm.
Claim 10
Dependent Claim
165 words
A resistive sintered aluminum nitride ceramic body prepared from a presintering aluminum nitride powder/sintering aid mixture wherein the aluminum nitride contains alumina and wherein the sintering aid comprises a) an element or compound of a metal selected from the group consisting of Group Ha, IIIa, lanthanide metals and mixtures thereof, and b) a glassy component formed from alumina, calcia, and boria, wherein the presintering mixture is sintered, at a sintering temperature between 1550° C. and 1800° C., to form a sintered body having a second phase containing a calcium containing component; said sintered body being cooled to at least below 1500° C.; and heat treated at a temperature of at least 1300° C. but below the sintering temperature for a period of time sufficient to cause said calcium containing component of said second phase to at least partially dewet from the aluminum nitride so as to contact the aluminum nitride at a dihedral angle sufficient to provide a resistivity of at least 10 8 Ω-cm.
Claim 11
Dependent Claim
18 words
The resistive, sintered aluminum nitride ceramic body of claim 8 wherein said dihedral angle is greater than 30°.
Claim 12
Dependent Claim
22 words
The resistive, sintered aluminum nitride ceramic body of claim 8 wherein said dihedral angle is greater than or equal to about 80°.
Claim 13
Dependent Claim
19 words
The resistive, sintered aluminum nitride ceramic body of claim 8 wherein said second phase has a substantially dewetted microstructure.
Claim 14
Dependent Claim
34 words
The resistive, sintered aluminum nitride ceramic body of claim 8 wherein said second phase contains a quaternary or pseudo-quaternary compound containing Ca, Y, Al, and O and having substitutional boron contained within said compound.
Claim 15
Dependent Claim
22 words
The resistive, sintered aluminum nitride ceramic body of claim 8 wherein said second phase includes CaYAl 3 O 7 having substitutional boron.
Claim 16
Dependent Claim
20 words
The resistive, sintered aluminum nitride ceramic body of claim 8 wherein said second phase includes CayAlO 4 having substitutional boron.
Claim 17
Dependent Claim
115 words
A resistive, sintered aluminum nitride ceramic body formed from a presintering aluminum nitride powder/sintering aid mixture wherein the aluminum nitride contains alumina and wherein the sintering aid comprises a glassy component formed from a) an oxide of at least one metal selected from the group consisting of Group Ilia, lanthanide metals and mixtures thereof, and b) alumina, calcia, and boria, said glassy component being reactable with the alumina from the AlN to form a second phase containing a calcium containing component upon sintering, said calcium containing component of second phase being in contact with aluminum nitride at a dihedral angle sufficient to provide a resistivity of at least about 10 8 Ω-cm upon heat treatment.
Claim 18
Dependent Claim
115 words
A resistive, sintered aluminum nitride ceramic body formed from a presintering aluminum nitride powder/sintering aid mixture wherein the aluminum nitride contains alumina and wherein the sintering aid comprises a glassy component formed from a) an oxide of at least one metal selected from the group consisting of Group Ilia, lanthanide metals and mixtures thereof, and b) alumina, calcia, and boria, said glassy component being reactable with the alumina from the AlN to form a second phase containing a calcium containing component upon sintering, said calcium containing component of second phase being in contact with aluminum nitride at a dihedral angle sufficient to provide a resistivity of at least about 10 8 Ω-cm upon heat treatment.
Claim 19
Dependent Claim
18 words
The resistive, sintered aluminum nitride ceramic body of claim 15 wherein said dihedral angle is greater than 30°.
Claim 20
Dependent Claim
22 words
The resistive, sintered aluminum nitride ceramic body of claim 15 wherein said dihedral angle is greater than or equal to about 80°.
Claim 21
Dependent Claim
19 words
The resistive, sintered aluminum nitride ceramic body of claim 15 wherein said second phase has a substantially dewetted microstructure.
Claim 22
Dependent Claim
34 words
The resistive, sintered aluminum nitride ceramic body of claim 15 wherein said second phase contains a quaternary or pseudo-quaternary compound containing Ca, Y, Al, and O and having substitutional boron contained within said compound.
Claim 23
Dependent Claim
22 words
The resistive, sintered aluminum nitride ceramic body of claim 15 wherein said second phase includes CaYAl 3 O 7 having substitutional boron.
Claim 24
Dependent Claim
20 words
The resistive, sintered aluminum nitride ceramic body of claim 15 wherein said second phase includes CayAlO 4 having substitutional boron.
Claim 25
Dependent Claim
165 words
A resistive, sintered aluminum nitride ceramic body prepared from a presintering aluminum nitride powder/sintering aid mixture wherein the aluminum nitride contains alumina and wherein the sintering aid comprises a glassy component formed from a) an oxide of at least one metal selected from the group consisting of Group IIIa, lanthanide metals and mixtures thereof, and b) alumina, calcia, and boria, and wherein the presintering mixture is sintered, at a sintering temperature between 1550° C. and 1800° C., to form a sintered body having a second phase having a calcium containing component; said sintered body being cooled to at least below 1500° C.; and heat treated at a temperature of at least 1300° C. but below the sintering temperature for a period of time sufficient to cause said calcium containing component of said second phase to at least partially dewet from the aluminum nitride so as to contact the aluminum nitride at a dihedral angle sufficient to provide a resistivity of at least 10 8 Ω-cm.
Claim 26
Dependent Claim
165 words
A resistive, sintered aluminum nitride ceramic body prepared from a presintering aluminum nitride powder/sintering aid mixture wherein the aluminum nitride contains alumina and wherein the sintering aid comprises a glassy component formed from a) an oxide of at least one metal selected from the group consisting of Group IIIa, lanthanide metals and mixtures thereof, and b) alumina, calcia, and boria, and wherein the presintering mixture is sintered, at a sintering temperature between 1550° C. and 1800° C., to form a sintered body having a second phase having a calcium containing component; said sintered body being cooled to at least below 1500° C.; and heat treated at a temperature of at least 1300° C. but below the sintering temperature for a period of time sufficient to cause said calcium containing component of said second phase to at least partially dewet from the aluminum nitride so as to contact the aluminum nitride at a dihedral angle sufficient to provide a resistivity of at least 10 8 Ω-cm.
Claim 27
Dependent Claim
18 words
The resistive, sintered aluminum nitride ceramic body of claim 22 wherein said dihedral angle is greater than 30°.
Claim 28
Dependent Claim
22 words
The resistive, sintered aluminum nitride ceramic body of claim 22 wherein said dihedral angle is greater than or equal to about 80°.
Claim 29
Dependent Claim
19 words
The resistive, sintered aluminum nitride ceramic body of claim 22 wherein said second phase has a substantially dewetted microstructure.
Claim 30
Dependent Claim
24 words
The resistive, sintered aluminum nitride ceramic body of claim 22 wherein said second phase contains a pseudo-quaternary compound containing Ca, Y, Al, and O.
Claim 31
Dependent Claim
22 words
The resistive, sintered aluminum nitride ceramic body of claim 22 wherein said second phase includes CaYAl 3 O.sub. 7 having substitutional boron.
Claim 32
Dependent Claim
20 words
The resistive, sintered aluminum nitride ceramic body of claim 22 wherein said second phase includes CayAlO 4 having substitutional boron.
Claim 33
Dependent Claim
127 words
A process for producing sintered aluminum nitride bodies comprising preparing a presintered mixture as set forth in claim 1; sintering, in a sintering atmosphere to a sintering temperature between about 1550° C. and 1800° C. to form a sintered body having a second phase containing a calcium containing component; cooling said sintered body to a temperature at least below 1500° C.; and heat treating said sintered body at a temperature of at least 1300° C. but below the sintering temperature for a period of time sufficient to cause said calcium containing component of said second phase to at least partially dewet from the aluminum nitride so as to contact the aluminum nitride at a dihedral angle sufficient to provide a resistivity of at least 10 8 Ω-cm.
Claim 34
Dependent Claim
125 words
A process for producing sintered aluminum nitride bodies comprising preparing a presintered mixture as set forth in claim 15; sintering, in a sintering atmosphere to a sintering temperature between about 1550° C. and 1800° C. to form a sintered body having a second phase containing a calcium containing component; cooling said sintered body to a temperature at least below 1500° C.; and heat treating said sintered body at a temperature of at least 1300° C. but below the sintering temperature for a period of time sufficient to cause said calcium containing component second phase to at least partially dewet from the aluminum nitride so as to contact the aluminum nitride at a dihedral angle sufficient to provide a resistivity of at least 10 8 Ω-cm.
Claim 35
Dependent Claim
78 words
A sintered aluminum nitride body having low camber, high dimensional stability, at least 95% theoretical density and a thermal conductivity of at least 120 W/m-K comprising aluminum nitride and a calcium containing second phase containing a pseudo-quaternary compound containing Ca, Y, Al, and O and having substitutional boron contained within said compound, said second phase being in contact with said aluminum nitride at a dihedral angle sufficient to provide a resistivity of at least about 10 8 Ω-cm.
Claim 36
Dependent Claim
78 words
A sintered aluminum nitride body having low camber, high dimensional stability, at least 95% theoretical density and a thermal conductivity of at least 120 W/m-K comprising aluminum nitride and a calcium containing second phase containing a pseudo-quaternary compound containing Ca, Y, Al, and O and having substitutional boron contained within said compound, said second phase being in contact with said aluminum nitride at a dihedral angle sufficient to provide a resistivity of at least about 10 8 Ω-cm.
Claim 37
Dependent Claim
16 words
The sintered aluminum nitride body of claim 31 wherein said dihedral angle is greater than 30°.
Claim 38
Dependent Claim
20 words
The sintered aluminum nitride body of claim 31 wherein said dihedral angle is greater than or equal to about 80°.
Claim 39
Dependent Claim
17 words
The sintered aluminum nitride body of claim 31 wherein said second phase has a substantially dewetted microstructure.
Claim 40
Dependent Claim
20 words
The sintered aluminum nitride body of claim 31 wherein said second phase contains CaYAl 3 O 7 having substitutional boron.
Claim 41
Dependent Claim
18 words
The sintered aluminum nitride body of claim 31 wherein said second phase contains CaYAlO 4 having substituted boron.
Claim 42
Dependent Claim
21 words
The sintered aluminum nitride body of claim 31 with a dielectric loss at 1 kHz of less than 10 -2 .
Claim 43
Dependent Claim
32 words
A co-sintered multilayer laminate comprising at least one ceramic layer and at least one metal layer wherein the at least one ceramic layer comprises the sintered aluminum nitride body of claim 31.
Claim 44
Dependent Claim
18 words
The co-sintered multilayer laminate of claim 38, wherein said metal comprises at least one of tungsten and molybdenum.
Claim 45
Dependent Claim
22 words
The co-sintered multilayer laminate of claim 39, wherein the metal resistivity is less than 3 times the value of the bulk metal.
Claim 46
Dependent Claim
28 words
The resistive, sintered aluminum nitride ceramic body of claim 1 wherein said Group Ha metals are selected from the group consisting of Ca, St, Ba and mixtures thereof.
Claim 47
Dependent Claim
41 words
The resistive, sintered aluminum nitride ceramic body of claim 1 wherein said Group IIIa and lanthanide metals are selected from the group consisting of Y, La, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and mixtures thereof.
Claim 48
Dependent Claim
22 words
The resistive, sintered aluminum nitride ceramic body of claim 1 wherein the metal element or compound is yttrium or a yttrium compound.
Claim 49
Dependent Claim
16 words
The resistive, sintered aluminum nitride ceramic body of claim 43 wherein the yttrium compound is yttria.
Claim 50
Dependent Claim
21 words
The resistive, sintered aluminum nitride ceramic body of claim 1 wherein the presintering mixture additionally comprises added alumina as metal oxide.
Claim 51
Dependent Claim
28 words
The resistive, sintered aluminum nitride ceramic body of claim 8 wherein said Group Ha metals are selected from the group consisting of Ca, St, Ba and mixtures thereof.
Claim 52
Dependent Claim
41 words
The resistive, sintered aluminum nitride ceramic body of claim 8 wherein said Group lIIa and lanthanide metals are selected from the group consisting of Y, La, Ce, Nd, Sin, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and mixtures thereof.
Claim 53
Dependent Claim
22 words
The resistive, sintered aluminum nitride ceramic body of claim 8 wherein the metal element or compound is yttrium or a yttrium compound.
Claim 54
Dependent Claim
16 words
The resistive, sintered aluminum nitride ceramic body of claim 48 wherein the yttrium compound is yttria.
Claim 55
Dependent Claim
21 words
The resistive, sintered aluminum nitride ceramic body of claim 8 wherein the presintering mixture additionally comprises added alumina as metal oxide.
Claim 56
Dependent Claim
41 words
The resistive, sintered aluminum nitride ceramic body of claim 15 wherein said Group IIIa and lanthanide metals are selected from the group consisting of Y, La, Ce, Nd, Sin, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and mixtures thereof.
Claim 57
Dependent Claim
21 words
The resistive, sintered aluminum nitride ceramic body of claim 15 wherein the presintering mixture additionally comprises added alumina as metal oxide.
Claim 58
Dependent Claim
43 words
The resistive, sintered aluminum nitride ceramic body of claim 15 wherein the sintering aid contains an additional non-vitreous component comprising at least one element or compound of a metal selected from the group consisting of Group IIa, IIIa, lanthanide metals and mixtures thereof.
Claim 59
Dependent Claim
60 words
The resistive, sintered aluminum nitride ceramic body of claim 53 wherein said Group IIa metals are selected from the group consisting of Ca, St, Ba and mixtures thereof, and wherein said Group IIIa and lanthanide metals are selected from the group consisting of Y, La, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tin, Yb, Lu, and mixtures thereof.
Claim 60
Dependent Claim
21 words
The resistive, sintered aluminum nitride ceramic body of claim 53 wherein the presintering mixture additionally comprises added alumina as metal oxide.
Claim 61
Dependent Claim
41 words
The resistive, sintered aluminum nitride ceramic body of claim 22 wherein said Group IIIa and lanthanide metals are selected from the group consisting of Y, La, Ce, Nd, Sin, Eu, Gd, Tb, Dy, Ho, Er, Tin, Yb, Lu, and mixtures thereof.
Claim 62
Dependent Claim
21 words
The resistive, sintered aluminum nitride ceramic body of claim 22 wherein the presintering mixture additionally comprises added alumina as metal oxide.
Claim 63
Dependent Claim
43 words
The resistive, sintered aluminum nitride ceramic body of claim 22 wherein the sintering aid contains an additional non-vitreous component comprising at least one element or compound of a metal selected from the group consisting of Group Ha, IIIa, lanthanide metals and mixtures thereof.
Claim 64
Dependent Claim
60 words
The resistive, sintered aluminum nitride ceramic body of claim 58 wherein said Group Ha metals are selected from the group consisting of Ca, Sr, Ba and mixtures thereof, and wherein said Group IIIa and lanthanide metals are selected from the group consisting of Y, La, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and mixtures thereof.
Claim 65
Dependent Claim
21 words
The resistive, sintered aluminum nitride ceramic body of claim 58 wherein the presintering mixture additionally comprises added alumina as metal oxide.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-07-30 | 2000-01-29 | 2000-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-07-30 | 2004-01-29 | 2004-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-07-30 | 2008-01-29 | 2008-07-30 | $7700.00 | Window Closed / Lapsed |