Quartz crystal vibrator, oscillator and electronic apparatus
To provide a quartz crystal vibrator, an oscillator and an electronic apparatus capable of preventing a bonding electrode from being corroded and easily maintaining soundness of the bonding electrode over a long period of time, a quartz crystal vibrator is provided with a quartz crystal vibrating plate formed by surrounding a quartz crystal vibrating piece by a frame-like portion, a hermetically closed vessel including a lid member and a base member in a plate-like shape for interposing the quartz crystal vibrating plate in a thickness direction, bonding electrodes provided between the lid member and the quartz crystal vibrating plate and between the base member and the quartz crystal vibrating plate and electrically connected to an inner electrode, and a protecting film for protecting the bonding electrode, provided with a recess portion recessed to an inner side of the hermetically closed vessel from an outer edge portion between the lid member and the quartz crystal vibrating plate and an outer edge portion between the base member and the quartz crystal vibrating plate, the protecting film is provided at the recess portion and the bonding electrode is disposed on the inner side of the recess portion.
1. A quartz crystal vibrator comprising:
a quartz crystal vibrating plate formed by surrounding a quartz crystal vibrating piece by a frame-like portion;
an inner electrode provided at the quartz crystal vibrating piece for applying a voltage to the quartz crystal vibrating piece;
a hermetically closed vessel including a lid member and a base member in a plate-like shape for interposing the quartz crystal vibrating plate in a thickness direction thereof;
bonding electrodes for bonding provided between the lid member and the quartz crystal vibrating plate and between the base member and the quartz crystal vibrating plate and electrically connected to the inner electrode; and
a protecting film provided at an outer face of the hermetically closed vessel for protecting the bonding electrode;
wherein recess portions recessed to inner sides of the hermetically closed vessel are provided at an outer edge portion between the lid member and the quartz crystal vibrating plate and between the base member and the quartz crystal vibrating plate, the protecting film is provided at the recess portion; and
wherein the bonding electrode is disposed on the inner side of the recess portion,
the quartz crystal vibrator further comprising:
an auxiliary electrode electrically connected to the bonding electrode and having a corrosion resistance higher than a corrosion resistance of the bonding electrode;
wherein the auxiliary electrode is extended to the outer edge portion between the lid member and the quartz crystal vibrating plate and the outer edge portion between the base member and the quartz crystal vibrating plate.
2. The quartz crystal vibrator according to claim 1 , wherein an opening diameter of the recess portion is set to be larger than a diameter of an inner portion of the recess portion.
3. An oscillator, wherein the quartz crystal vibrator according to claim 1 is electrically connected to an integrated circuit as an oscillation piece.
4. An electronic apparatus including the quartz crystal vibrator according to claim 1 .
5. A quartz crystal vibrator comprising:
a quartz piece responsive to application of an electrical signal to vibrate;
an enclosure configured with two halves which sandwich a part of the quartz piece therebetween to hermetically enclose the quartz piece inside thereof;
main electrodes patterned over the quartz piece to supply the electrical signal to the quartz piece, the main electrodes extending over the quartz piece and terminating with peripheral portions inside a periphery of the quartz piece, wherein the peripheral portions are sandwiched between the two halves and the quartz piece and each have a thickness sufficiently thick to form a gap between the two halves and the quartz piece; and
a protective material covering in film at least a part of the enclosure and the quartz piece and filling the gap to prevent exposure of the main electrodes to air, wherein the gap is sufficiently wide and deep such that a self-reinforcing amount of protective material fills the gap, and further wherein the protective material comprises 0.1 wt % fluorocarbon of a fluorine species coating agent having trimethyl siloxane at a terminus thereof.
6. A quartz crystal vibrator according to claim 5 , wherein the main electrodes are made of aluminum.
7. A quartz crystal vibrator according to claim 5 , further comprising auxiliary electrodes being laid between the two halves and the quartz piece.
8. A quartz crystal vibrator according to claim 7 , wherein the auxiliary electrodes are made of a material selected from the group consisting of Cr, Ti, Ni and W.
9. A quartz crystal vibrator according to claim 5 , wherein the protective material comprises OPTOOL DSX.
10. A quartz crystal vibrator according to claim 5 , wherein the enclosure comprises soda lime glass.
11. A quartz crystal vibrator according to claim 5 , wherein the quartz piece comprises a frame and a vibrating piece surrounded by the frame.
12. A quartz crystal vibrator according to claim 11 , wherein the two halves sandwich at least a part of the frame.
13. A quartz crystal vibrator according to claim 5 , wherein a periphery of at least one of the two halves is formed with a cut-off to increase a volume of the gap.