Surface mounted piezoelectric vibrator

Patent metadata

Field	Value
Publication number	US-9831414-B2
Application number	US-201314406317-A
Country	US
Kind code	B2
Filing date	Mar 27, 2013
Priority date	Jun 19, 2012
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

A piezoelectric vibrator according to the invention has a base, an integrated circuit element, and a piezoelectric vibration element. The base has internal terminal pads, and external terminals including an AC output terminal. The base includes rectangular ceramic substrate layers stacked in at least three layers, each of which has castellations formed at four corners. Among the internal terminal pads, internal terminal pads for the integrated circuit element and internal terminal pads for the piezoelectric vibration element are connected to each other by externally exposed wiring patterns formed on upper surfaces of the castellations at the corners of the ceramic substrate constituting a middle layer.

First claim

The invention claimed is:

1. A piezoelectric vibrator, comprising:
a base with insulating properties, having a rectangular outer shape in plan view, the base including a plurality of ceramic substrate layers stacked in at least three layers and castellations extending in vertical directions and respectively formed at four corners of the rectangular shapes of the plurality of ceramic substrate layers, the base further including a housing portion having a plurality of internal terminal pads formed therein, and an exterior portion having at least four external terminals formed on an outer bottom surface thereof;
an integrated circuit element electrically connected to a part of the plurality of internal terminal pads; and
a piezoelectric vibration element electrically connected to another part of the plurality of internal terminal pads and further electrically connected to the integrated circuit element, wherein
the four external terminals are formed proximate to and in non-contact with the castellations formed at the four corners, and one of the four external terminals constitutes an external terminal for output of alternating current,
the part and the another part of the plurality of internal terminal pads are formed on respective surfaces of the ceramic substrate layers which are different layers (hereinafter, different layer surfaces),
externally exposed wiring patterns that provide connection between the part of the plurality of internal terminal pads and the another part of the plurality of internal terminal pads are formed on upper surfaces of first and second castellations alone, the first and second castellations being provided at one of pairs of corners among the four corners of the rectangular shape of the ceramic substrate layer constituting a middle layer between the ceramic substrate layers respectively constituting uppermost and lowermost layers of the ceramic substrate layers stacked in at least three layers,
the first castellation is a castellation located opposite to a third castellation in a long-side direction of the base, the third castellation being provided at one of the four corners of the rectangular shape proximate to the external terminal for output of alternating current, and
the second castellation is a castellation provided at one of the four corners diagonally opposite to the third castellation on the rectangular shape of the base in plan view.

2. The piezoelectric vibrator as claimed in claim 1 , wherein the piezoelectric vibration element mounted in the housing portion of the base is hermetically sealed with a cover attached to a joint area on an upper surface of the ceramic substrate layer constituting the uppermost layer and formed as a rectangular frame surrounding a rectangular space centrally located,
the castellations of the ceramic substrate layer constituting the uppermost layer are formed at only four corners on an outer side of the rectangular frame of the ceramic substrate layer constituting the uppermost layer, and
a chamfer or a curvature is formed at each of four corners on an inner side of the rectangular frame of the ceramic substrate layer constituting the uppermost layer.

3. The piezoelectric vibrator as claimed in claim 1 , wherein
the integrated circuit element has a rectangular shape and includes pads formed on a main surface thereof, the pads being flip-chip bonded to the part of the plurality of internal terminal pads by means of bumps,
the pads of the integrated circuit element include:
two opposing first pads formed proximate to a first side of the integrated circuit element;
two opposing second pads formed proximate to a second side opposite to the first side of the integrated circuit element; and
two opposing third pads respectively formed between the first pads and the second pads, one of the two opposing second pads outputting alternating current,
the plurality of internal terminal pads of the base include:
two opposing first internal terminal pads electrically connected to the piezoelectric vibration element and joined to the two opposing first pads of the integrated circuit element;
two opposing second internal terminal pads joined to the two opposing second pads; and
two opposing third internal terminal pads joined to the two opposing third pads and interposed between the two opposing first internal terminal pads and the two opposing second internal terminal pads,
the two opposing third internal terminal pads and two wiring patterns that respectively extend the two opposing third internal terminal pads are formed on the same surface along a part of perimeter of the two opposing first internal terminal pads to respectively form conducive paths for blocking radiation noise, and
the two opposing first internal terminal pads and the two opposing second internal terminal pads are spaced apart with the conducive paths for blocking radiation noise interposed therebetween.

4. The piezoelectric vibrator as claimed in claim 1 , wherein the piezoelectric vibration element is an AT-cut crystal piece.

5. The piezoelectric vibrator as claimed in claim 1 , wherein
the base includes a bottom portion constituting a lowermost layer, a first bank portion constituting a middle layer, and a second bank portion constituting an uppermost layer, the bottom portion constituting the lowermost layer is constructed of a single plate made of a ceramic material and having a rectangular shape in plan view, the first bank portion constituting the middle layer is made of a ceramic material and formed in a frame shape in plan view on the bottom portion constituting the lowermost layer, the second bank portion constituting the uppermost layer is made of a ceramic material and formed in a frame shape in plan view on the first bank portion constituting the middle layer,
the housing portion of the base corresponding to the lowermost layer includes:
a first housing portion formed by the first bank portion constituting the middle layer to house therein the integrated circuit element; and
a second housing portion formed by the second bank portion constituting the uppermost layer to house therein the piezoelectric vibration element, and
the plurality of internal terminal pads are formed on an inner bottom surface of the first housing portion.

6. The piezoelectric vibrator as claimed in claim 1 , wherein
the base includes an intermediate plate portion constituting a middle layer, a third bank portion constituting an upper layer, and a fourth bank portion constituting a lower layer,
the intermediate plate portion constituting the middle layer is constructed of a single plate made of a ceramic material and having a rectangular shape in plan view,
the third bank portion constituting the upper layer is made of a ceramic material and formed on the intermediate plate portion constituting the middle layer,
the fourth bank portion constituting the lower layer is made of a ceramic material and formed in a frame shape in plan view below the intermediate plate portion constituting the middle layer,
the housing portion of the base includes:
a third housing portion formed by the third bank portion constituting the upper layer to house therein the piezoelectric vibration element; and
a fourth housing portion formed by the fourth bank portion constituting the lower layer to house therein the integrated circuit element, and
the first to third internal terminal pads are formed on an inner bottom surface of the fourth housing portion.

7. The piezoelectric vibrator as claimed in claim 3 , further comprising:
two first wiring patterns that respectively extend the two opposing first internal terminal pads to first and second castellations of the four castellations provided at the four corners of the rectangular shape of the base;
two secon

Assignees

• Daishinku Corp

Inventors

• Kojo Takuya

Classifications

• H03H9/1021

  the BAW device being of the cantilever type · CPC title

• H03H9/17

  having a single resonator (crystal tuning forks H03H9/21) · CPC title

• H03H9/171

  implemented with thin-film techniques, i.e. of the film bulk acoustic resonator [FBAR] type · CPC title

• H03H9/0561

  consisting of a multilayered structure · CPC title

• H03H9/0547

  consisting of a vertical arrangement (H03H9/0566 takes precedence) · CPC title