Piezoelectric device and fabricating method thereof
AssigneeNihon Dempa Kogyo Co., Ltd.
InventorHidenori Harima
Life of this patent
Estimating the term…
Abstract
A piezoelectric device and a fabricating method thereof are provided. Variation of output frequency is suppressed by forming an organic resin to protect an IC chip that is mounted in a cavity of a container body, and damage that may occur to the IC chip during the mounting process is prevented. The piezoelectric device includes a container body, a crystal resonator, an IC chip and a cover body. A surface of the IC chip, which is a mounting surface for mounting to the container body, has bumps thereon for connecting to terminal pads of a circuit wiring pattern configured on a bottom surface of a bottom cavity of the container body, and the other surface of the IC chip has an insulating protective sheet adhered and fixed thereon.
Claims11
A piezoelectric device, at least comprising:
- an IC chip;
- a container body, having insulativity and comprising a top cavity for receiving a crystal resonator and a bottom cavity for receiving the IC chip, wherein the IC chip is surface-mounted in the bottom cavity;
- the crystal resonator, disposed in the top cavity;
- and
- a cover body, covering and sealing the top cavity,
- wherein the IC chip comprises:
- a bump, configured on a mounting surface of the IC chip facing the container body and connected with terminal pads of a circuit wiring pattern configured on a bottom surface of the bottom cavity;
- and
- a protective sheet having insulativity and adhered to a back surface of the IC chip, opposite to the mounting surface, wherein the protective sheet adhered to the back surface of the IC chip is formed of a thermosetting resin.
A fabricating method of a piezoelectric device, wherein the piezoelectric device at least comprises a container body having insulativity and comprising a top cavity for receiving a crystal resonator and a bottom cavity for receiving an IC chip of a plurality of IC chips, the crystal resonator disposed in the top cavity, the IC chip surface-mounted in the bottom cavity, and a cover body covering and sealing the top cavity, the fabricating method comprising:
- polishing a back surface of a semiconductor wafer, which has the plurality of IC chips, to a predetermined thickness before the semiconductor wafer is cut into the separate plurality of IC chips, the back surface being a surface opposite to a laminated circuit forming surface of the semiconductor wafer;
- adhering an insulating sheet to the back surface that has been polished to completely cover the back surface after the polishing;
- cutting the semiconductor wafer into the separate plurality of IC chips based on each unit of the plurality of IC chips to form the plurality of IC chips with protective sheets;
- and
- connecting bumps configured on a mounting surface of the IC chip with terminal pads of a circuit wiring pattern configured on a bottom surface of the bottom cavity of the container body inside the bottom cavity;
- wherein a space exists between the IC chip and the container body, the space includes a gap between the mounting surface of the IC chip and the container body, the protective sheet of the IC chip is exposed to an external atmosphere of the container body, and the protective sheet adhered to the back surface of the IC chip is formed of a thermosetting resin.
Dependencies are inferred from the claim text.