Surface mount type crystal device

Abstract

A crystal device for surface mounting is provided with at least: a container body having a substantially rectangular outer shape and mounting electrodes formed in the four corners of the outside bottom surface of the container body; and a crystal blank hermetically sealed within the container body. The spacing of mounting electrodes on at least one side of the outside bottom surface is less than the length of the mounting electrodes in the direction along that side. A jetty having a height greater than the thickness of the mounting electrodes is provided in the cross-shaped area interposed between the mounting electrodes on the outside bottom surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are a sectional view and a bottom plan view, respectively, showing the configuration of a surface mount type crystal unit of the prior art;

FIG. 2 is a plan view showing a crystal blank;

FIG. 3 is a sectional view showing the surface mount type crystal unit when mounted on a wiring board;

FIG. 4 is a view for explaining the size of the mounting electrodes and the dimensions of the bottom surface of a surface mount type crystal oscillator;

FIGS. 5A and 5B are a sectional view and a bottom plan view, respectively, showing the configuration of a surface mount type crystal unit according to an embodiment of the present invention;

FIG. 6 is a sectional view showing the surface mount type crystal unit when mounted on a wiring board;

FIG. 7 is a bottom plan view showing a surface mount type crystal unit according to another embodiment of the present invention; and

FIG. 8 is a sectional view showing the configuration of a surface mount type crystal oscillator according to a further embodiment of the present invention.

Claims

1. A crystal device for surface mounting provided with at least: a container body having a substantially rectangular outer shape and mounting electrodes formed at four corners of a outside bottom surface of the container body; and a crystal blank hermetically sealed within said container body; wherein: spacing between mounting electrodes on at least one side of said outside bottom surface is smaller than a length of said mounting electrodes in a direction along said side; anda jetty having a height greater than a thickness of said mounting electrodes is provided in a cross-shaped area interposed between said mounting electrodes on said outside bottom surface.

2. The crystal device according to claim 1, wherein said container body is composed of laminated ceramics.

3. The crystal device according to claim 2, wherein said jetty is formed as a single unit with said container body by applying ceramic paste to a ceramic green sheet that corresponds to said outside bottom surface and then burning.

4. The crystal device according to claim 1, wherein a planar shape of said container body has a length no greater than 2.0 mm on a long sides thereof and no greater than 1.6 mm on short sides thereof.

5. The crystal device according to claim 1, wherein said crystal device is configured as a crystal unit.

6. The crystal device according to claim 1, wherein said crystal device is configured as a crystal oscillator.

7. The crystal device according to claim 6, wherein an IC chip in which an oscillation circuit that uses said crystal blank is integrated is provided within said container body.