US4806725A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit substrate and thermal printing head using the same
Assignee: Hitachi Ltd
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Filing: 1987-07-09
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Granted: 1989-02-21
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Expires: 2007-07-09
Abstract
Abstract A circuit substrate, such as a thermal printing head, having electrodes made of a material suitable for soldering. The electrode to be soldered, at least in part, is composed of an alloy of Ni and Cu, whose composition ranges from 65 mol % Ni - 35 mol % Cu to 75 mol % Ni - 25 mol % Cu.
Inventors
- 👤 Yasunori Narizuka
- 👤 Keiji Mori
- 👤 Akira Yabushita
- 👤 Tsuneaki Kamei
- 👤 Mamoru Morita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:36
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/22; H05K3/24; H05K3/244; B; B41; B41J; B41J2/00; B41J2/315; B41J2/32; B41J2/335; B41J2/33505; B41J2/3351; B41J2/3352; B41J2/3355; B41J2/33555; B41J2/3357; B41J2/33575; H10; H10W; H10W72/00; H10W72/071; H10W72/072
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
77 words
A circuit substrate having an electrical circuit, which comprises at least a part of an electrode to be soldered being composed of an alloy of Ni and Cu, whose composition ranges from 65 mol % Ni--35 mol % Cu to 75 mol % Ni--25 mol % Cu so that diffusion of solder into said electrode can be substantially avoided while a protective inorganic material layer, and the solder, have sufficient adhesion to the electrode to be soldered.
Claim 2
Dependent Claim
77 words
A circuit substrate having an electrical circuit, which comprises at least a part of an electrode to be soldered being composed of an alloy of Ni and Cu, whose composition ranges from 65 mol % Ni--35 mol % Cu to 75 mol % Ni--25 mol % Cu so that diffusion of solder into said electrode can be substantially avoided while a protective inorganic material layer, and the solder, have sufficient adhesion to the electrode to be soldered.
Claim 3
Dependent Claim
73 words
A thermal printing head having an electrical circuit, which comprises a part to be soldered being composed of an alloy of Ni and Cu, whose composition ranges from 65 mol % Ni--35 mol % Cu to 75 mol % Ni--25 mole % Cu so that diffusion of solder into said part can be substantially avoided while a protective inorganic material layer, and the solder, have sufficient adhesion to the part to be soldered.
Claim 4
Dependent Claim
73 words
A thermal printing head having an electrical circuit, which comprises a part to be soldered being composed of an alloy of Ni and Cu, whose composition ranges from 65 mol % Ni--35 mol % Cu to 75 mol % Ni--25 mole % Cu so that diffusion of solder into said part can be substantially avoided while a protective inorganic material layer, and the solder, have sufficient adhesion to the part to be soldered.
Claim 5
Dependent Claim
112 words
A circuit substrate comprising an electrical circuit having an electrode electrically connected to the electrical circuit, and a solder in electrical contact with the electrode, the electrode constituting a barrier metal layer between the solder and the electrical circuit, and a protective inorganic material layer in contact with the electrode, the electrode, at least in part, being composed of an alloy of Ni and Cu, whose composition ranges from 65 mol % Ni--35 mol % Cu to 75 mol % Ni--25 mol % Cu so that diffusion of the solder into said electrode can be substantially avoided while said protective inorganic material layer, and said solder, have sufficient adhesion to the electrode.
Claim 6
Dependent Claim
112 words
A circuit substrate comprising an electrical circuit having an electrode electrically connected to the electrical circuit, and a solder in electrical contact with the electrode, the electrode constituting a barrier metal layer between the solder and the electrical circuit, and a protective inorganic material layer in contact with the electrode, the electrode, at least in part, being composed of an alloy of Ni and Cu, whose composition ranges from 65 mol % Ni--35 mol % Cu to 75 mol % Ni--25 mol % Cu so that diffusion of the solder into said electrode can be substantially avoided while said protective inorganic material layer, and said solder, have sufficient adhesion to the electrode.
Claim 7
Dependent Claim
32 words
A circuit substrate according to claim 3, wherein a layer of chromium is interposed between the electrode and the electrical circuit so as to avoid diffusion of Ni into the electrical circuit.
Claim 8
Dependent Claim
23 words
A circuit substrate according to claim 3, wherein said electrode is provided only at locations interposed between the electrical circuit and the solder.
Claim 9
Dependent Claim
15 words
A circuit substrte according to claim 3, wherein the electrical circuit is formed of copper.
Claim 10
Dependent Claim
32 words
A circuit substrate according to claim 6, wherein a layer of chromium is interposed between the electrode and the electrical circuit so as to avoid diffusion of Ni into the electrical circuit.
Claim 11
Dependent Claim
17 words
A circuit substrate according to claim 3, wherein said circuit substrate is for a thermal printing head.
Claim 12
Dependent Claim
19 words
A circuit substrate according to claim 3, wherein the protective inorganic material layer is made of SiO 2 .
Claim 13
Dependent Claim
32 words
A circuit substrate according to claim 3, wherein the alloy of Ni and Cu is a layer, interposed between the solder and electrical circuit, having a thickness of 0.3 to 0.5 μm.
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) | 1992-02-21 | 1992-08-22 | 1993-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-21 | 1996-08-22 | 1997-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-21 | 2000-08-22 | 2001-02-21 | $7700.00 | Window Closed / Lapsed |