# US 8,541,694 B2 · Multilayer wiring board

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- Number: US 8,541,694 B2
- Document ID: US8541694B2
- Status: Granted
- Kind: B2
- Application number: 12/542,736
- Filed: 2009-08-18
- Published: 2009-12-03
- Granted: 2013-09-24
- Earliest claimed: 2007-03-01
- Assignees: Murata Manufacturing Co., Ltd.
- Applicants: Masato Nomiya
- Inventors: Masato Nomiya
- Web page: https://patentgrep.com/patent/US8541694B2

## CPC

- H05K 1/115: {Via connections; Lands around holes or via connections (H05K1/112 takes precedence)}
- H05K 1/0271: {Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion}
- H05K 3/4611: {by laminating two or more circuit boards (H05K3/4652 takes precedence)}
- H05K 3/4629: {laminating inorganic sheets comprising printed circuits, e.g. green ceramic sheets}
- H05K 1/0306: {Inorganic insulating substrates, e.g. ceramic, glass}
- H05K 2201/0195: Dielectric or adhesive layers comprising a plurality of layers, e.g. in a multilayer structure
- H05K 2201/09781: Dummy conductors, i.e. not used for normal transport of current; Dummy electrodes of components
- H05K 2201/10378: Interposers
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS

## Abstract

A multilayer wiring board is capable of preventing the occurrence of cracking in the vicinity of a connection portion of a conductor pattern disposed inside a basic material layer and a via-hole conductor even when the conductor pattern is connected to the via-hole conductor. A multilayer wiring board includes basic material layers and the constraining layers that are alternately stacked. In the material layer, a via-hole conductor is connected to an intermediate conductor pattern. An extended portion is defined by extending an end of the via-hole conductor beyond the intermediate conductor pattern inside the basic material layer.

## Claims

### Claim 1

A multilayer wiring board comprising:
at least one basic material layer and at least one constraining layer stacked on each other;
a conductor pattern disposed on or inside at least one of the at least one basic material layer or the at least one constraining layer, the conductor pattern extending in a surface direction in which the at least one basic material layer and the at least one constraining layer extend; and
a via-hole conductor extending inside at least the at least one basic material layer in a direction in which the at least one basic material layer and the at least one constraining layer are stacked, the via-hole conductor being connected to the conductor pattern; wherein
the via-hole conductor includes a via body and an extended portion, the via body is connected to an intermediate conductor pattern disposed inside the at least one basic material layer such that portions of a single one of the at least one basic material layer are disposed on both sides of the intermediate conductor pattern in a stacking direction of the at least one basic material layer and the at least one constraining layer, and the extended portion is defined by the via body being extended in a direction towards the at least one constraining layer and away from the via body, and the extended portion is connected to the intermediate conductor pattern; and
an end of the extended portion of the via-hole conductor is not directly electrically or physically connected to any conductor pattern and is in direct contact with a surface of the at least one constraining layer.

### Claim 2 (depends on 1)

The multilayer wiring board according to claim 1, wherein the extended portion of the via-hole conductor extends completely through the at least one constraining layer.

### Claim 3 (depends on 1)

The multilayer wiring board according to claim 1, wherein an end surface of the extended portion of the via-hole conductor is in contact with the at least one constraining layer.

### Claim 4 (depends on 1)

The multilayer wiring board according to claim 1, wherein the extended portion of the via-hole conductor is arranged to be substantially coaxial with the via body.

### Claim 5 (depends on 4)

The multilayer wiring board according to claim 4, wherein a diameter of the extended portion of the via-hole conductor is substantially the same as a diameter of the via body.

### Claim 6 (depends on 1)

The multilayer wiring board according to claim 1, further comprising a plurality of basic material layers, wherein a thickness of at least one of the basic materials layer having the intermediate conductor pattern therein is greater than thicknesses of other ones of the basic material layers.

### Claim 7 (depends on 1)

The multilayer wiring board according to claim 1, further comprising a plurality of basic material layers and a plurality of constraining layers that are alternately stacked on each other.