# US 4,399,320 A · Conductor inks

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- Number: US 4,399,320 A
- Document ID: US4399320A
- Status: Granted
- Kind: A
- Application number: 06/396,662
- Filed: 1982-07-09
- Granted: 1983-08-16
- Earliest claimed: 1980-10-17
- Assignees: RCA Corporation
- Inventors: Ashok N. Prabhu; Kenneth W. Hang
- Web page: https://patentgrep.com/patent/US4399320A

## CPC

- H05K 1/092: {Dispersed materials, e.g. conductive pastes or inks}
- C03C 8/02: Frit compositions, i.e. in a powdered or comminuted form
- C03C 8/18: containing free metals
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS

## Abstract

Improved conductor inks useful in constructing multilayer circuits, particularly on porcelain-coated metal substrates, are provided. The subject inks comprise: copper powder, a barium calcium borosilicate glass frit, a suitable organic vehicle and bismuth oxide, which is present either in admixture with the copper powder or as a component of the glass frit.

## Claims

### Claim 1

A circuit board having on a portion of the surface thereof a coating of a conductor ink comprising:
(a) from about 70 to about 90 percent by weight of copper powder;
(b) from about 1 to about 15 percent by weight of a barium calcium borosilicate glass frit;
(c) from about 0.5 to about 3 percent by weight of bismuth oxide, wherein bismuth oxide is present in admixture with the copper powder or as a component of the glass frit; and
(d) from about 6 to about 25 percent by weight of a suitable organic vehicle.

### Claim 2 (depends on 1)

A circuit board in accordance with claim 1, wherein said board is porcelain-coated metal.

### Claim 3

A process for forming a conductor film as part of a circuit on a suitable circuit board comprising applying and firing onto said board an ink composition comprising:
(a) from about 70 to about 90 percent by weight of copper powder;
(b) from about 1 to about 15 percent by weight of a barium calcium borosilicate glass frit;
(c) from about 0.5 to about 3 percent by weight of bismuth oxide, wherein bismuth oxide is present in admixture with the copper powder or as a component of the glass frit; and
(d) from about 6 to about 25 percent by weight of a suitable organic vehicle.

### Claim 4

An electronic assembly comprising a circuit board having a circuit thereon, said circuit containing a conductor film formed by applying and firing a conductor ink comprising:
(a) from about 70 to about 90 percent by weight of copper powder;
(b) from about 1 to about 15 percent by weight of a barium calcium borosilicate glass frit;
(c) from about 0.5 to about 3 percent by weight of bismuth oxide, wherein bismuth oxide is present in admixture with the copper powder or as a component of the glass frit; and
(d) from about 6 to about 25 percent by weight of a suitable organic vehicle.

### Claim 5 (depends on 4)

An electronic assembly in accordance with claim 4, wherein said circuit board is a procelain-coated metal circuit board.