EP0326077A2
Expired / Lapsed
EP
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Circuit board
Assignee: Toshiba Corp
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Filing: 1989-01-24
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Granted: —
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Expires: 2009-01-24
Abstract
Abstract Disclosed is an aluminum nitride thin film circuit board having an aluminum nitride substrate (1) and a conductive thin film pattern (3, 4) formed on the substrate (1). The conductive thin film pattern (3, 4) has a multi-layer structure selected from the group consisting of Ti/Ni/Au, Ti/Pd/Au, Ti/Pt/Au, Ni/Au, Cr/Au, and Cr/Cu/Au, and a boundary layer (2) of Aℓ-N-M-O (M is Ti, Ni, or Cr) is formed between the substrate (1) and the conductive thin film pattern (3, 4). Since the boundary layer (2) is formed, bonding properties between the substrate (1) and the conductive thin film pattern (3, 4) are improved. In particular, when the boundary layer (2) contains 0.02 to 30 atomic% of oxygen, a higher bonding strength can be obtained.
Inventors
- 👤 Takaaki Yasumoto
- 👤 Nobuo Iwase
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 04:45
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/38; H05K3/388; H10; H10W; H10W70/00; H10W70/60; H10W70/62; H10W70/66; H10W70/67; H10W70/69; H10W70/692; H05K1/00; H05K1/02; H05K1/03; H05K1/0306
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
77 words
An aluminum nitride thin film circuit board comprising an aluminum nitride substrate (1) and a conductive thin film pattern (3, 4) formed on said substrate, wherein said conductive thin film pattern (3, 4) has a multi-layer structure selected from the group consisting of Ti/Ni/Au, Ti/Pd/Au, Ti/Pt/Au, Ni/Au, Cr/Au, and Cr/Cu/Au, and a boundary layer (2) of Aℓ-N-M-O (M is Ti, Ni, or Cr) is formed between said substrate (1) and said conductive thin film pattern (3, 4).
Claim 2
Dependent Claim
77 words
An aluminum nitride thin film circuit board comprising an aluminum nitride substrate (1) and a conductive thin film pattern (3, 4) formed on said substrate, wherein said conductive thin film pattern (3, 4) has a multi-layer structure selected from the group consisting of Ti/Ni/Au, Ti/Pd/Au, Ti/Pt/Au, Ni/Au, Cr/Au, and Cr/Cu/Au, and a boundary layer (2) of Aℓ-N-M-O (M is Ti, Ni, or Cr) is formed between said substrate (1) and said conductive thin film pattern (3, 4).
Claim 3
Dependent Claim
21 words
A circuit board according to claim 1, characterized in that said boundary layer (2) contains 0.02 to 30 atomic% of oxygen.
Claim 4
Dependent Claim
22 words
A circuit board according to claim 1, characterized in that said boundary layer (2) has a thickness of 5 to 500 nm.
Claim 5
Dependent Claim
27 words
A circuit board according to claim 1, characterized in that said aluminum nitride substrate (1) has an average linear surface roughness of not more than 800 nm.
Claim 6
Dependent Claim
29 words
A circuit board according to claim 1, characterized in that said aluminum nitride substrate (1) comprises aluminum nitride crystals having an average particle size of 0.5 to 20 µm.
Claim 7
Dependent Claim
55 words
A circuit board according to claim 1, characterized in that said conductive thin film pattern (3, 4) comprises a bonding layer (3) having a thickness of 10 to 900 nm, a barrier layer (3) having a thickness of 50 to 1,000 nm, and a low-resistance layer (4) having a thickness of 50 to 9,000 nm.
Claim 8
Dependent Claim
43 words
A circuit board according to claim 1, characterized in that said conductive thin film pattern (3, 4) comprises a bonding layer (3) having a thickness of 10 to 900 nm and a low-resistance layer (4) having a thicknelss of 50 to 9,000 nm.
Claim 9
Dependent Claim
51 words
An aluminum nitride thin film circuit board comprising an aluminum nitride substrate (1) and a conductive thin film pattern (3, 4) formed on said substrate (1), characterized in that said conductive thin film pattern (3, 4) comprises a multi-layer structure selected from the group consisting of Ti/Ni/Au, Ni/Au, Cr/Au, and Cr/Cu/Au.
Claim 10
Dependent Claim
51 words
An aluminum nitride thin film circuit board comprising an aluminum nitride substrate (1) and a conductive thin film pattern (3, 4) formed on said substrate (1), characterized in that said conductive thin film pattern (3, 4) comprises a multi-layer structure selected from the group consisting of Ti/Ni/Au, Ni/Au, Cr/Au, and Cr/Cu/Au.
Claim 11
Dependent Claim
27 words
A circuit board according to claim 8, characterized in that said aluminum nitride substrate (1) has an average linear surface roughness of not more than 800 nm.
Claim 12
Dependent Claim
29 words
A circuit board according to claim 8, characterized in that said aluminum nitride substrate (1) comprises aluminum nitride crystals having an average particle size of 0.5 to 20 µm.
Claim 13
Dependent Claim
55 words
A circuit board according to claim 8, characterized in that said conductive thin film pattern (3, 4) comprises a bonding layer (3) having a thickness of 10 to 900 nm, a barrier layer (3) having a thickness of 50 to 1,000 nm, and a low-resistance layer (4) having a thickness of 50 to 9,000 nm.
Claim 14
Dependent Claim
43 words
A circuit board according to claim 8, characterized in that said conductive thin film pattern (3, 4) comprises a bonding layer (3) having a thickness of 10 to 900 nm and a low-resistance layer (4) having a thicknelss of 50 to 9,000 nm.
Claim 15
Independent Claim
83 words
A method for producing an aluminum nitride thin film circuit board, comprising the steps of: (a) polishing one surface of an aluminum nitride substrate (1) to have an average linear roughness of not more than 300 nm; (b) polishing the polished surface of the aluminum nitride substrate (1) by aluminum nitride ceramic particles to have an average linear roughness of not more than 150 nm; and (c) forming a conductive thin film pattern on the polished surface of the aluminum nitride substrate (1).
Claim 16
Independent Claim
83 words
A method for producing an aluminum nitride thin film circuit board, comprising the steps of: (a) polishing one surface of an aluminum nitride substrate (1) to have an average linear roughness of not more than 300 nm; (b) polishing the polished surface of the aluminum nitride substrate (1) by aluminum nitride ceramic particles to have an average linear roughness of not more than 150 nm; and (c) forming a conductive thin film pattern on the polished surface of the aluminum nitride substrate (1).
Claim 17
Dependent Claim
28 words
A method according to claim 13, characterized in that said aluminum nitride substrate (1) comprises aluminum nitride crystals having an average particle size of 0.5 to 20 µm.
Claim 18
Dependent Claim
23 words
A method according to claim 13, characterized in that said aluminum nitride ceramic particles have a diameter of not more than 2.0 µm.
Claim 19
Dependent Claim
42 words
A method according to claim 13, characterized in that said conductive thin film pattern (3, 4) has a multi-layer structure and a lowermost layer thereof is formed of at least one metal selected from the group consisting of Ti, Ni and Cr.
Claim 20
Dependent Claim
25 words
A method according to claim 16, characterized in that said multi-layer structure is selected from the group consisting of Ti/Ni/Au, Ti/Pt/Au, Ni/Au, Cr/Au, and Cr/Cu/Au.
Claim 21
Dependent Claim
52 words
A method according to claim 17, characterized in that said conductive thin film pattern comprises a bonding layer (3) having a thickness of 10 to 900 nm, a barrier layer (3) having a thickness of 50 to 1,000 nm, and a low-resistance layer (4) having a thickness of 50 to 9,000 nm.
Claim 22
Dependent Claim
42 words
A method according to claim 17, characterized in that said conductive thin film pattern (3, 4) comprises a bonding layer (3) having a thickness of 10 to 900 nm and a low-resistance layer (4) having a thickness of 50 to 9,000 nm.
Claim 23
Dependent Claim
29 words
A method according to claim 13, characterized in that said polishing in step (b) is carried out to have an average linear roughness of not more than 60 nm.
References Cited (Backward Citations)
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