Patent ID: 8035454

Claim:
A crystal oscillator device, comprising: an air-tight case forming a vacuum chamber; a piezoelectric resonator element; oscillation circuitry; a temperature sensor; and a heating unit implemented in an integrated-circuit chip having an active surface, wherein the piezoelectric resonator element and the oscillation circuitry are connected together to form an oscillation circuit, and the temperature sensor and the heating unit are enclosed in the vacuum chamber with the piezoelectric resonator element, wherein the piezoelectric resonator element is attached in a heat conductive manner to the active surface of the integrated-circuit chip so that the integrated-circuit chip supports the piezoelectric resonator element, wherein the oscillation circuit is implemented in said integrated-circuit chip along with the heating unit, and wherein the piezoelectric resonator element is attached to the active surface of the integrated-circuit chip in such a way as to be directly connected to the oscillation circuitry.