# US 12,114,417 B2 · Circuit board

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- Number: US 12,114,417 B2
- Document ID: US12114417B2
- Status: Granted
- Kind: B2
- Application number: 17/912,989
- Filed: 2021-02-19
- Published: 2023-05-18
- Granted: 2024-10-08
- Earliest claimed: 2020-03-23
- Assignees: Sumitomo Bakelite Co., Ltd.
- Applicants: Sumitomo Bakelite Co., Ltd.
- Inventors: Nobuo Tagashira
- Web page: https://patentgrep.com/patent/US12114417B2

## CPC

- H05K 1/0209: {External configuration of printed circuit board adapted for heat dissipation, e.g. lay-out of conductors, coatings}
- H10W 40/255: {having a laminate or multilayered structure, e.g. direct bond copper [DBC] ceramic substrates}
- H05K 1/09: Use of materials for the {conductive, e.g. } metallic pattern
- H05K 2201/0355: Metal foils
- H05K 2201/09154: Bevelled, chamferred or tapered edge
- H05K 2201/09272: Layout details of angles or corners
- H05K 2201/09281: Layout details of a single conductor
- H10W 70/6875: {being on a metallic substrate, e.g. insulated metal substrates [IMS]}
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

A heat radiating substrate (10) includes an insulating layer (11) and a circuit pattern (20) of a metal formed on the insulating layer (11) in direct contact with the insulating layer (11), in which a side surface (that is, metal layer side surface (23)) of the circuit pattern (20) has a region in which an angle θ formed by a surface (insulating layer upper surface (11a)) of the insulating layer (11) (insulating substrate) and a tangential line L at a middle portion (X1) in a height direction in a cross-sectional view perpendicular to an extending direction of the metal is 80 degrees or more and 100 degrees or less.

## Claims

### Claim 1

A circuit board comprising:
an insulating substrate; and
a circuit pattern of a metal formed on the insulating substrate in direct contact with the insulating substrate,
wherein a side surface of the circuit pattern has a region in which an angle formed by a surface of the insulating substrate and a tangential line at a middle portion in a height direction in a cross-sectional view perpendicular to an extending direction of the metal is 80 degrees or more and 100 degrees or less,
wherein in a case where a height of the circuit pattern is denoted by D, the side surface of the circuit pattern exhibits a straight line in the cross-sectional view perpendicular to the extending direction of the metal, in a height range of 0.4D or more and 0.6D or less in a perpendicular direction from the insulating substrate, and
wherein the side surface of the circuit pattern exhibits a trailing-tailed shape at an interface with the insulating substrate.

### Claim 2 (depends on 1)

The circuit board according to claim 1,
wherein the insulating substrate is configured to be a resin substrate.

### Claim 3 (depends on 1)

The circuit board according to claim 1,
wherein the metal is configured to be rolled copper.

### Claim 4 (depends on 1)

The circuit board according to claim 1,
wherein in a case where a height of the circuit pattern is denoted by b and a distance from an adjacent circuit pattern in a middle portion of the height of the circuit pattern is denoted by a, a region in which an aspect ratio b/a is 0.2 or more and 5 or less is provided.

### Claim 5

A circuit board comprising:
an insulating substrate; and
a circuit pattern of a metal formed on the insulating substrate in direct contact with the insulating substrate,
wherein a side surface of the circuit pattern has a region in which an angle formed by a surface of the insulating substrate and a tangential line at a middle portion in a height direction in a cross-sectional view perpendicular to an extending direction of the metal is 80 degrees or more and 100 degrees or less,
wherein the side surface of the circuit pattern exhibits a trailing-tailed shape at an interface with the insulating substrate, and
wherein in a case where a height of the circuit pattern is denoted by b and a distance from an adjacent circuit pattern in a middle portion of the height of the circuit pattern is denoted by a, a region in which an aspect ratio b/a is 0.2 or more and 5 or less is provided.