US5122930A
Expired / Lapsed
US
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High heat-conductive, thick film multi-layered circuit board
Assignee: Niterra Co Ltd
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Filing: 1990-01-04
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Granted: 1992-06-16
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Expires: 2010-01-04
Abstract
Abstract High heat-conductive, thick film multilayered circuit board for high speed signal transmission in a high frequency region, the circuit board comprising: a substrate having high heat conductivity; an oxidized layer formed on a surface of said substrate; an electrically conductive layer formed of a printed paste containing therein crystallized glass; and an insulating layer formed of a printed insulating paste comprised of crystallized glass as a principal constitutent, wherein at least one of said conductive layer and at least one of said insulating layer are alternately disposed by printing on the oxidized layer of said substrate, and said conductive and insulating layers have been heated to form solid layers. The substrate is AlN, SiC/BeO, SiC, Cu/W and/or ZrB2 having a heat conductively of 40-140 W/mxk at room temperature. The layers have high adhesion strength to the substrate and the insulating layer has a low dielectric constant.
Inventors
- 👤 Kazuo Kondo
- 👤 Asao Morikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:46
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/60; H10W70/67; H10W70/68; H10W70/6875; H10W40/00; H10W40/20; H10W40/25; H10W40/259; H10W70/69; H10W70/692; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H05K3/00; H05K3/46; H05K3/4644; H05K3/4664; H05K3/4667
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
122 words
A high heat-conductive, thick film multilayered circuit board comprising: a substrate having high heat conductivity selected from the group consisting of AlN, SiC/BeO, SiC, ZrB 2 , and Cu/W having a heat conductivity of at least 40 W/m·K at room temperature; an oxidized layer formed on a surface of said substrate; an electrically conductive layer formed of a printed paste containing crystallized glass; and an insulating layer formed of a printed insulating paste comprised of crystallized glass as a principal constituent, wherein at least one of said conductive layer and at least one of said insulating layer are alternately disposed by printing on the oxidized layer of said substrate, and said conductive and insulating layers have been heated to form solid layers.
Claim 2
Dependent Claim
122 words
A high heat-conductive, thick film multilayered circuit board comprising: a substrate having high heat conductivity selected from the group consisting of AlN, SiC/BeO, SiC, ZrB 2 , and Cu/W having a heat conductivity of at least 40 W/m·K at room temperature; an oxidized layer formed on a surface of said substrate; an electrically conductive layer formed of a printed paste containing crystallized glass; and an insulating layer formed of a printed insulating paste comprised of crystallized glass as a principal constituent, wherein at least one of said conductive layer and at least one of said insulating layer are alternately disposed by printing on the oxidized layer of said substrate, and said conductive and insulating layers have been heated to form solid layers.
Claim 3
Dependent Claim
14 words
The circuit board as set forth in claim 1, wherein said substrate is AlN.
Claim 4
Dependent Claim
36 words
The circuit board as set forth in claim 1, wherein said crystallized glass has a coefficient of thermal expansion of 1.5 to 4.5×10 -6 /° C. at a temperature range between room temperature and 400° C.
Claim 5
Dependent Claim
25 words
The circuit board as set forth in claim 3, wherein said crystallized glass has a coefficient of thermal expansion of 2.5 to 4.5×10 -6 /°C.
Claim 6
Dependent Claim
31 words
The circuit board as set forth in claim 3, wherein said crystallized glass has a heating temperature for consolidation from a paste thereof at a temperature of 1,100° C. or less.
Claim 7
Dependent Claim
27 words
The circuit board as set forth in claim 5, wherein said crystallized glass has said heating temperature for consolidation between about 900° C. and about 1,000° C.
Claim 8
Dependent Claim
34 words
The circuit board as set forth in claim 1, wherein said electrically conductive layer comprises an electrically conductive metal component which can be metallized at a heating temperature for consolidation of the crystallized glass.
Claim 9
Dependent Claim
44 words
The circuit board as set forth in claim 7, wherein said metal component is one or more selected from the group consisting of Au, Cu, Cu-Au alloy, Ni, Ni-Au alloy, Ni-Cu alloy, Pt-Cu alloy, Pt-Au alloy, Pd, Pd-Cu alloy, Pd-Au alloy and Pd-Pt alloy.
Claim 10
Dependent Claim
30 words
The circuit board as set forth in claim 7, wherein said electrically conductive layer comprises 1 to 5 parts by weight of the crystallized glass per 100 parts of Au.
Claim 11
Dependent Claim
43 words
The circuit board as set forth in claim 9, wherein said electrically conductive layer further comprises 0.1 to 1 parts by weight of CuO and up to 3 parts by weight of Ag, respectively, per 100 parts by weight of said metal component.
Claim 12
Dependent Claim
73 words
The circuit board as set forth in claim 1, wherein said thick film conductive paste is consisting essentially of: 100 parts by weight of Au, 2 to 5 parts by weight fo crystallized glass having a coefficient of thermal expansion of 2.5 to 4.5×10 -6 /°C. between room temperature and 400° C., 0.1 to 1 part by weight of copper oxide (CuO) powder, and 3 parts by weight or less of Ag powder.
Claim 13
Dependent Claim
30 words
The circuit board as set forth in claim 1, wherein said insulating paste consists essentially of crystallized glass having a coefficient of thermal expansion of 2.5 to 4.5×10 -6 /°C.
Claim 14
Dependent Claim
134 words
A high heat-conductive, thick film multilayered circuit board comprising: a substrate having high heat conductivity selected from the group consisting of AlN, SiC/BeO, SiC, ZrB 2 and Cu/W having a heat conductivity of at least 40 W/m·K at room temperature; an oxidized layer formed on a surface of said substrate by surface treatment of said substrate in a humidified reducing atmosphere at a temperature of from 1,000° C. to 1,500° C.; an electrically conductive layer formed of a printed paste containing crystallized glass; and an insulating layer formed of a printed insulating paste; wherein at least one of said conductive layer and at least one of said insulating layer are alternately disposed by printing on the oxidized layer of said substrate, and said conductive and insulating layers have been heated to form solid layers.
Claim 15
Dependent Claim
134 words
A high heat-conductive, thick film multilayered circuit board comprising: a substrate having high heat conductivity selected from the group consisting of AlN, SiC/BeO, SiC, ZrB 2 and Cu/W having a heat conductivity of at least 40 W/m·K at room temperature; an oxidized layer formed on a surface of said substrate by surface treatment of said substrate in a humidified reducing atmosphere at a temperature of from 1,000° C. to 1,500° C.; an electrically conductive layer formed of a printed paste containing crystallized glass; and an insulating layer formed of a printed insulating paste; wherein at least one of said conductive layer and at least one of said insulating layer are alternately disposed by printing on the oxidized layer of said substrate, and said conductive and insulating layers have been heated to form solid layers.
Claim 16
Dependent Claim
36 words
The circuit board as set forth in claim 13, wherein said oxidized layer has been formed by surface treatment of said substrate in a humidified reducing atmosphere with a dew point of -30° to +15° C.
Claim 17
Dependent Claim
24 words
The circuit board as set forth in claim 13, wherein said substrate is AlN having a dielectric constant of about 5.5 (at 1 MHz).
Claim 18
Dependent Claim
22 words
The circuit board as set forth in claim 1, wherein said substrate has a dielectric constant of about 5.5 (at 1 MHz).
Claim 19
Dependent Claim
20 words
The circuit board as set forth in claim 1, wherein said crystallized glass has a water absorbance of nearly zero.
Claim 20
Dependent Claim
31 words
The circuit board as set forth in claim 17, wherein said crystallized glass has a coefficient of thermal expansion of 1.5 to 3.5×10 -6 /°C. between room temperature and 400° C.
Claim 21
Dependent Claim
57 words
The circuit board as set forth in claim 18, wherein said crystallized glass is selected from the group generally expressed by a formula RO--Al 2 O 3 --SiO 2 where RO represents ZnO, MgO, Li 2 O, Y 2 O 3 , ZrO 2 , CaO, BaO, B 2 O 3 or P 2 O 5 .
Claim 22
Dependent Claim
65 words
The circuit board as set forth in claim 19, wherein said crystallized glass is selected from the group consisting of ZnO--MgO--Al 2 O 3 --SiO 2 , CaO--B 2 O 3 --MgO--Al 2 O 3 --SiO 2 , Y 2 O 3 --MgO--Al 2 O 3 --SiO 2 , Li 2 O--Al 2 O 3 --SiO 2 and BaO--Al 2 O 3 --SiO 2 .
Claim 23
Dependent Claim
49 words
The circuit board as set forth in claim 19, wherein said crystallized glass is composed of, by weight, 57-63% SiO 2 , 20-28% Al 2 O 3 , 10-18% MgO, 2-6% ZnO, and 0.1-6% of at least one of B 2 O 3 and P 2 O 5 .
Claim 24
Dependent Claim
43 words
The circuit board as set forth in claim 19, wherein said crystallized glass is composed of, by weight, 40-52% SiO 2 , 27-37% Al 2 O 3 , 10-20% MgO, 2-8% B 2 O 3 , 2-8% CaO, and 0.1-3% ZrO 2 .
Claim 25
Dependent Claim
53 words
The circuit board as set forth in claim 19, wherein said crystallized glass is composed of, by weight, 55-63% SiO 2 , 20-28% Al 2 O 3 , 1-8% Y 2 O 3 , 10-20% MgO and 0.1-5% of at least one of B 2 O 3 and P 2 O 5 .
Claim 26
Dependent Claim
33 words
The circuit board as set forth in claim 19, wherein said crystallized glass is of a ZnO--MgO--Al 2 O 3 --SiO 2 system and, when crystallized, has a major crystallites phase of cordierite.
Claim 27
Dependent Claim
30 words
The circuit board as set forth in claim 19, wherein said crystallized glass contains up to 60% by volume of fine ceramic particles coated with a thin SiO 2 film.
Claim 28
Dependent Claim
32 words
The circuit board as set forth in cliam 25, wherein said ceramic particles are selected from the group consisting of Al 2 O 3 , Bn and Si 3 N 4 .
Claim 29
Dependent Claim
32 words
The circuit board as set forth in cliam 25, wherein said ceramic particles are selected from the group consisting of Al 2 O 3 , Bn and Si 3 N 4 .
Claim 30
Dependent Claim
41 words
The circuit board as set forth in claim 1, wherein each of said electrically conductive layer and insulating layer has been heated for metallization or consolidation to form either one of said layers each after a respective paste has been applied.
Claim 31
Dependent Claim
23 words
The circuit board as set forth in claim 1, wherein said oxidized layer has a thickness of up to about a few microns.
Claim 32
Dependent Claim
21 words
The circuit board as set forth in claim 1, wherein said oxidized layers has a thickness of at least 0.1 microns.
Claim 33
Dependent Claim
20 words
The circuit board as set forth in claim 28, wherein said oxidized layer has a thickness of about one microns.
Claim 34
Dependent Claim
28 words
The circuit board as set forth in claim 1, wherein said substrate is electrically insulating material and the electrically conductive layer is first applied onto said oxidized layer.
Claim 35
Dependent Claim
26 words
The circuit board as set forth in claim 1, wherein said substrate is electrically conductive and the insulating layer is first applied onto said oxidized layer.
Claim 36
Dependent Claim
14 words
The circuit board as set forth in claim 32, wherein said substrate is Cu/W.
Claim 37
Dependent Claim
39 words
The circuit board as set forth in claim 1, wherein said electrically conductive layer and the insulating layer are alternately laminated to form a multilayer circuit board comprising at least several circuit layers formed of said electrically conductive layer.
Claim 38
Dependent Claim
36 words
The circuit board as set forth in claim 34, wherein one of said electrically conductive layers is formed of a conductor paste containing no crystallized glass when this conductive layer is disposed between two insulating layers.
Claim 39
Dependent Claim
24 words
The circuit board as set forth in claim 1, wherein said electrically conductive layer has a thickness of about 5 to about 40 μm.
Claim 40
Dependent Claim
24 words
The circuit board as set forth in claim 36, wherein said electrically conductive layer has a thickness of about 10 to about 20 μm.
Claim 41
Dependent Claim
23 words
The circuit board as set forth in claim 1, wherein said insulating layer has a thickness of about 10 to about 250 μm.
Claim 42
Dependent Claim
20 words
The circuit board as set forth in claim 38, wherein said insulating layer has a thickness of about 30 μm.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-06-16 | 1995-12-16 | 1996-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-16 | 1999-12-16 | 2000-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-16 | 2003-12-16 | 2004-06-16 | $7700.00 | Window Closed / Lapsed |