# US 9,439,279 B2 · Ceramic circuit board and electronic device

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- Number: US 9,439,279 B2
- Document ID: US9439279B2
- Status: Granted
- Kind: B2
- Application number: 14/457,429
- Filed: 2014-08-12
- Published: 2015-02-19
- Granted: 2016-09-06
- Earliest claimed: 2013-08-16
- Assignees: NGK Insulators, Ltd.
- Applicants: Ngk Insulators, Ltd.
- Inventors: Makoto Tani; Yoshihiro Tanaka; Takashi Ebigase
- Web page: https://patentgrep.com/patent/US9439279B2

## CPC

- H05K 1/0204: {using means for thermal conduction connection in the thickness direction of the substrate (H05K1/0207 takes precedence)}
- C04B 37/026: {consisting of metals or metal salts}
- H05K 1/111: {Pads for surface mounting, e.g. lay-out}
- H10W 40/22: characterised by their shape, e.g. having conical or cylindrical projections
- H10W 40/255: {having a laminate or multilayered structure, e.g. direct bond copper [DBC] ceramic substrates}
- C04B 2237/124: based on copper
- C04B 2237/125: based on noble metals, e.g. silver
- C04B 2237/127: The active component for bonding being a refractory metal
- C04B 2237/368: Silicon nitride
- C04B 2237/407: Copper
- C04B 2237/704: of one or more of the ceramic layers or articles
- C04B 2237/706: of one or more of the metallic layers or articles
- C04B 2237/708: of one or more of the interlayers
- C04B 2237/86: Joining of two substrates at their largest surfaces, one surface being complete joined and covered, the other surface not, e.g. a small plate joined at it's largest surface on top of a larger plate
- H05K 1/0306: {Inorganic insulating substrates, e.g. ceramic, glass}
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

A ceramic circuit board includes a ceramic substrate, and a first metal plate bonded to a front surface of the ceramic substrate. A size of the front surface of the ceramic substrate is smaller than a size of a surface, i.e., a first facing surface, on a side of the first metal plate that faces the ceramic substrate.

## Claims

### Claim 1

A ceramic circuit board comprising:
a ceramic substrate; and
a metal plate bonded to a front surface of the ceramic substrate,
wherein a size of the front surface of the ceramic substrate is smaller than a size of a surface on a side of the metal plate that faces the ceramic substrate,
wherein:
a second metal plate is bonded to a rear surface of the ceramic substrate; and
a size of the rear surface of the ceramic substrate is larger than a size of a surface on a side of the second metal plate that faces the ceramic substrate, and
wherein the inequality
t2<ta <t1
is satisfied, where ta represents a thickness of the ceramic substrate, t1 represents a thickness of the metal plate, and t2 represents a thickness of the second metal plate.

### Claim 2 (depends on 1)

The ceramic circuit board according to claim 1, wherein the ceramic substrate and the metal plate are bonded together, such that an entirety of the front surface of the ceramic substrate is included within the surface on the side of the metal plate that faces the ceramic substrate.

### Claim 3 (depends on 1)

The ceramic substrate according to claim 1, wherein the second metal plate is bonded within the rear surface of the ceramic substrate at a position where the entire surface of the second metal plate that faces the ceramic substrate is included.

### Claim 4 (depends on 1)

An electronic device comprising:
the ceramic circuit board according to claim 1; and
a power semiconductor, which is mounted on a surface of the metal plate of the ceramic circuit board.