Surface mount type crystal oscillator
AssigneeNihon Dempa Kogyo Co., Ltd.
InventorsKouichi Moriya, Tsutomu Yamakawa, Hidenori Harima
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Abstract
A surface mount crystal oscillator comprises a crystal blank, an IC chip having an oscillation circuit integrated thereon, and a hermetic package for accommodating the crystal blank and IC chip therein. The hermetic package comprises a substantially rectangular ceramic substrate formed with a metal film which makes a round on one main surface thereof, and a concave metal cover having an open end face bonded to the metal film. The IC chip is secured to the one main surface of the ceramic substrate through ultrasonic thermo-compression bonding using bumps, the crystal blank is disposed above the IC chip, and the ceramic substrate has the one main surface formed as a flat surface.
Claims4
A surface mount type crystal oscillator comprising a crystal blank, an IC chip having at least an oscillation circuit using said crystal blank, integrated thereon, and a hermetic package for accommodating said crystal blank and said IC chip therein, wherein:
- said hermetic package comprises a ceramic substrate having a substantially rectangular shape and formed with a metal film which makes a round on one main surface thereof, and a concave metal cover having an open end face bonded to said metal film,
- said ceramic substrate comprises mounting electrodes at corners on the other main surface of said ceramic substrate for use in mounting said crystal oscillator on a wiring board,
- said IC chip is secured to the one main surface of said ceramic substrate through ultrasonic thermo-compression bonding using bumps,
- said crystal blank is disposed above said IC chip, and
- said one main surface of said ceramic substrate is formed as a flat surface,
- wherein said ceramic substrate comprises a first ceramic layer formed with said mounting electrodes, and a second ceramic layer laminated on said first ceramic layer for securing said IC chip thereto,
- said first ceramic layer comprises a cutout portion in a central area of each side thereof, said cutout portion having an outer periphery open to said side,
- an adjustment terminal is formed on a laminated surface of said second ceramic layer exposed by each said cutout portion, and
- said adjustment terminals include a pair of write surface terminals used to write temperature compensation data into a temperature compensation mechanism within said IC chip, and a pair of crystal test terminals used to measure oscillation characteristics of said crystal blank.
A surface mount type crystal oscillator comprising a crystal blank, an IC chip having at least an oscillation circuit using said crystal blank, integrated thereon, and a package having at least a substantially rectangular ceramic substrate and adapted to accommodate said crystal blank and said IC chip therein, wherein:
- said ceramic substrate comprises mounting electrodes at corners on a surface thereof which is an outer bottom surface of said package for use in mounting said crystal oscillator on a wiring board,
- said ceramic substrate comprises a first ceramic layer formed with said mounting electrodes, and a second ceramic layer laminated on said first ceramic layer for securing said IC chip thereto,
- said first ceramic layer comprises a cutout portion in a central area on at least one side thereof, said cutout portion having an outer periphery open to said side, and
- an adjustment terminal is formed on a laminated surface of said second ceramic layer exposed by said cutout portion,
- wherein said first ceramic layer comprises said cutout portion in a central area of each side thereof, and said adjustment terminals include a pair of write surface terminals used to write temperature compensation data into a temperature compensation mechanism within said IC chip, and a pair of crystal test terminals used to measure oscillation characteristics of said crystal blank.
Dependencies are inferred from the claim text.