Surface-mount type crystal oscillator

• US 6,229,249 B1
• Filed: 08/31/1999
• Issued: 05/08/2001
• Est. Priority Date: 08/31/1998
• Status: Expired due to Term

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Hayashi, Naoki, Yonemura, Hideomi, Sasagawa, Ryouma, Hatanaka, Hidefumi
• Primary Examiner(s): Dougherty, Thomas M.
• Application Number:
  US09/387,216
• Time in Patent Office: 616 Days
• Field of Search: 310/348, 310/349, 310/313 R
• US Class Current: 310/348
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H03B 5/04 Modifications of generator to compensate for variations in physical values, e.g. power supply, load, temperature
• CPC Class Codes: H03B 5/32 being a piezoelectric resonator selection of piezoelectric material H10N30/00
• CPC Class Codes: H03H 9/0509 consisting of adhesive elements
• CPC Class Codes: H03H 9/0547 consisting of a vertical arrangement H03H9/0566 takes precedence
• CPC Class Codes: H03H 9/0552 the device and the other elements being mounted on opposite sides of a common substrate
• CPC Class Codes: H03H 9/08 Holders with means for regulating temperature
• CPC Class Codes: H03H 9/1014 the enclosure being defined by a frame built on a substrate and a cap, the frame having no mechanical contact with the BAW device
• CPC Class Codes: H05K 1/0243 Printed circuits associated with mounted high frequency components
• CPC Class Codes: H05K 2201/09181 Notches in edge pads
• CPC Class Codes: H05K 2201/09381 Shape of non-curved single flat metallic pad, land or exposed part thereof; Shape of electrode of leadless component
• CPC Class Codes: H05K 2201/10075 Non-printed oscillator
• CPC Class Codes: H05K 2201/10727 Leadless chip carrier [LCC], e.g. chip-modules for cards
• CPC Class Codes: H05K 3/3442 having edge contacts, e.g. leadless chip capacitors, chip carriers
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

In a surface-mount type crystal oscillator according to the invention, a part of side surfaces of a lower cavity are formed into bulging space portions bulging into separating areas between adjacent ones of a plurality of terminal electrodes provided around the lower cavity. By accommodating an IC chip and an electronic device in the lower cavity including the bulging space portions, the crystal oscillator can be miniaturized without affecting the size of the plurality of terminal electrodes.

Claims

1. A surface-mount type crystal oscillator, comprising:

a main body formed with a cavity in a lower portion thereof, the cavity being partitioned from a top surface of the main body by a partition wall and surrounded by cavity walls;

a crystal oscillating element mounted on the top surface;

a plurality of terminal electrodes on the main body disposed around the cavity walls and spaced from each other by separating areas of the cavity walls;

extensions of the cavity protruding into the separating areas so that the terminal electrodes are separated by the extensions of the cavity; and

a controlling IC chip and an electronic device accommodated in the lower cavity with the electronic device accommodated within the extensions of the cavity.

2. A surface-mount type crystal oscillator according to claim 1, wherein the main body is generally rectangular in a plan view, four terminal electrodes are respectively provided at four corners of the main body, and the cavity has four bulging space portions bulging into the four separating areas defined by the terminal electrodes.

3. A surface-mount type crystal oscillator according to claim 2, wherein the electronic device is a chip-shaped capacitor.

4. A surface-mount type crystal oscillator according to claim 2, wherein the cavity is defined by a laterally extending surface and side surfaces, and a pair of electronic device mount electrodes are formed on the laterally extending surface.

5. A surface-mount type crystal oscillator according to claim 4, wherein the pair of electronic device mount electrodes is each formed with a notch at its outer side.

6. A surface-mount type crystal oscillator according to claim 1, wherein the main body is generally rectangular in a plan view, four terminal electrodes are respectively provided at four corners of the main body, and the cavity has three bulging space portions bulging into three of the four separating areas defined by the terminal electrodes.

7. A surface-mount type crystal oscillator according to claim 6, wherein the electronic device is a chip-shaped capacitor.

8. A surface-mount type crystal oscillator according to claim 6, wherein the cavity is defined by a laterally extending surface and side surfaces, and a pair of electronic device mount electrodes are formed on the laterally extending surface.

9. A surface-mount type crystal oscillator according to claim 8, wherein the pair of electronic device mount electrodes is each formed with a notch at its outer side.

10. A surface-mount type crystal oscillator according to claim 1, wherein the main body includes:

an upper unit having a top surface and a bottom surface, the top surface defining the top surface of the main body;

a lower unit formed with the cavity, the cavity being top opened, and the opening of the cavity being closed by the bottom surface of the upper unit.

11. A surface-mount type crystal oscillator according to claim 10, wherein:

the lower unit is provided with a plurality of lower connection electrodes on a top surface around the opening of the cavity, and provided with the terminal electrodes, the terminal electrodes being electrically connected with the IC chip and the electronic device;

the upper unit is provided with a plurality of upper connection electrodes on the bottom surface thereof at positions corresponding to the plurality of lower connection electrodes, respectively, at least two of the plurality of upper connection electrodes being electrically connected with the crystal oscillating element on the top surface thereof.

12. A surface-mount type crystal oscillator according to claim 11, wherein the upper unit is formed by a plurality of insulating layers, and further provided with a viahole conductor extending in a thickness direction of the upper unit and an internal wiring conductor between the insulating layers for connecting the crystal oscillating element with the at least two upper connection electrodes.

13. A surface-mount type crystal oscillator comprising:

a main body formed with a cavity in a lower portion thereof, the cavity being partitioned from a top surface of the main body by a partition wall and surrounded by cavity walls;

a crystal oscillating element mounted on the top surface;

a plurality of terminal electrodes on the main body disposed around the cavity walls and spaced from each other by separating areas of the cavity walls;

extensions of the cavity protruding into the separating areas so that the terminal electrodes are separated by the extensions of the cavity;

a controlling IC chip and an electronic device accommodated in the lower cavity; and

a thermosetting resin filling the cavity with a thickness of resin covering a lower surface of the IC chip being less than a thickness of resin between an inner surface of the IC chip and an inner laterally extending surface of the cavity, and a thickness of resin between a side surface of the IC chip and a side surface of the cavity being less than a thickness of the IC chip.

14. A surface-mount type crystal oscillator comprising:

a main body formed with a cavity in a lower portion thereof, the cavity being partitioned from a top surface of the main body by a partition wall and surrounded by cavity walls, each cavity wall having a step adjacent to the cavity;

a crystal oscillating element mounted on the top surface;

a plurality of terminal electrodes on the main body disposed around the cavity walls and spaced from each other by separating areas of the cavity walls;

extensions of the cavity protruding into the separating areas so that the terminal electrodes are separated by the extensions of the cavity;

a controlling IC chip and an electronic device accommodated in the lower cavity; and

a layer of thermosetting resin disposed within the cavity with the step serving to retain the resin within the cavity.

15. A surface-mount type crystal oscillator comprising:

a main body formed with a cavity in a lower portion thereof, the cavity being partitioned from a top surface of the main body by a partition wall and surrounded by cavity walls;

a crystal oscillating element mounted on the top surface;

a plurality of terminal electrodes on the main body disposed around the cavity walls and spaced from each other by separating areas of the cavity walls;

extensions of the cavity protruding into the separating areas so that the terminal electrodes are separated by the extensions of the cavity;

a controlling IC chip and an electronic device accommodated in the lower cavity; and

resin filling the cavity, the resin comprising;

a first resin layer filling both a space between the cavity and a bottom surface of the IC chip and a space between the cavity and side surfaces of the IC chip; and

a second resin layer covering top surfaces of the IC chip and the first resin layer.

16. A surface-mount type crystal oscillator comprising:

a main body formed with a cavity in a lower portion thereof, the cavity being partitioned from a top surface of the main body by a partition wall and surrounded by cavity walls, each cavity wall having a step adjacent to the cavity;

a crystal oscillating element mounted on the top surface by a mount electrode pad with a groove formed in the top surface around the mount electrode pad;

a plurality of terminal electrodes on the main body disposed around the cavity walls and spaced from each other by separating areas of the cavity walls;

extensions of the cavity protruding into the separating areas so that the terminal electrodes are separated by the extensions of the cavity; and

a controlling IC chip and an electronic device accommodated in the lower cavity.

17. A surface-mount type crystal oscillator according to claim 16, wherein two mount electrode pads are arranged side by side, and the groove is formed in an area between the two mount electrode pads.

18. A surface-mount type crystal oscillator according to claim 16, wherein the groove is formed in an area between the mount electrode pad and a free end of the crystal oscillating element.