JPS63182906A - Thin piezoelectric resonator and its manufacture - Google Patents

Abstract

PURPOSE:To easily form a piezoelectric resonator by providing a vibrating electrode at both end faces of a very thin piezoelectric ceramic element plate, forming a polarization electrode to both faces of a square block having a prescribed thickness made of a piezoelectric ceramic material, applying a DC high voltage to apply the polarization processing. CONSTITUTION:Polarization electrodes 11, 12 are formed to both faces of the square block 10 of a prescribed thickness made of a piezoelectric ceramic material and polarized by applying a DC high voltage. The block 10 subject to polarization processing is cut along notches 13 having an interval coincident with a side length l1 between vibrating electrodes 2, 3 of the piezoelectric ceramic element plate 1 being a finished component to form a rod 14. Moreover, electrode films 15, 16 left in the succeeding process are formed to a face of the rod 14 without electrodes provided yet to remove the electrodes 11, 12. Then the rod is cut very thinly along the notch 17 in the lateral face direction and also cut along the notch 18 in the longitudinal direction of the gap coincident with the side length l2 of the piezoelectric ceramic element plate 1 being a finished component along the face of vibrating electrodes 2, 3. Thus, the very thin piezoelectric resonator having a vibrating electrode at both side ridges is formed easily.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a thin piezoelectric resonator intended for use in IC cards, etc., and a method for manufacturing the same.

<Prior Art> An IC card requires a piezoelectric resonator to serve as a reference oscillation source, but this requires an extremely thin piezoelectric resonator with a thickness of, for example, 0.5 m. Also, the frequency is about 2
Something of the order of 00K t-1z is required.

<Problems to be Solved by the Invention> There are piezoelectric resonators such as those described above that utilize spreading vibration in the shape of a square plate, a disk, etc., but these conventional ones
There was a problem in that it was not possible to obtain something as thin as Jun.

<Means for Solving the Problems> The present invention was made in order to solve the problems of the conventional piezoelectric resonators as described above. An object of the present invention is to provide a thin piezoelectric resonator provided with a thin piezoelectric resonator and a method for manufacturing the same.

<Example> Fig. 1 shows an example of the thin piezoelectric resonator of the present invention, in which 1 is an extremely thin piezoelectric ceramic element plate, and vibrating electrodes 2.3 are provided on both end faces of the plate. .

As shown in FIGS. 2 and 3, this thin piezoelectric resonator 4 is fixed onto a printed circuit board 5 with a slight gap using solder 6, and 7.8 is mounted on the printed circuit board 5. (
It is a buta circuit electrode.

In this case, shake the circuit electrodes 7.8 of the printed circuit board 5! By soldering the middle point of the II electrode 2.3 as shown in Figure 3 and applying a high frequency voltage of, for example, 200 KHz to both vibrating electrodes 2.3, surface slippage will occur as shown by the chain line in Figure 3. vibration mode.

4 to 6 show an embodiment of the manufacturing method of the present invention, and numeral 10 in FIG. 4 is a rectangular block of constant thickness made of piezoelectric ceramic material. Form electrodes 11.12.

Thereafter, a high DC voltage is applied to both electrodes 11 and 12 to polarize them.

After polarization treatment is performed as described above, the lζ block 10 is turned into a completed piezoelectric ceramic element plate 1. A rod-shaped body 14 as shown in FIG. 5 is obtained by cutting along the cuts 13 at intervals corresponding to the side length I11 between the IJ electrodes 2.3.

Electrode films 15 and 16 to be left behind are formed on the surface of the rod-shaped body 14 obtained by performing the above steps on which no electrodes have been provided, and the electrodes 11 and 12 are removed.

Thereafter, as shown in FIG. !
:112), the membrane electrode films 15 and 16 are cut along the cuts 18 in the a cross-sectional direction with the interval corresponding to ! 11 electrodes 2.3, and a large number of thin piezoelectric resonators 4 as shown on the left side of FIGS. 1 and 6 are obtained.

<Effects of the Invention> As described above, the thin piezoelectric resonator of the present invention has vibrating electrodes on both end faces of an ultra-thin piezoelectric ceramic element plate. ,
By applying a high frequency voltage to the central portion of thin vibrating electrodes on both sides of this thin piezoelectric resonator, vibration in the plane sliding vibration mode can be obtained.

Further, in the manufacturing method of the present invention, since polarization electrodes are formed on both sides of a rectangular block of constant thickness formed from a piezoelectric ceramic material, polarization processing can be performed easily and efficiently.

Furthermore, the block that has been polarized in this way is cut in parallel at predetermined intervals so that the cut surface is in the direction intersecting the polarized electrode surface to form a rod-shaped body with a square cross section. Since the vibrating VJ electrode membrane is formed on both wide sides of the body where electrodes have not yet been provided, it is easy to form the vibrating electrode membrane. Since the piezoelectric resonator has many advantages, it is possible to easily manufacture an extremely thin piezoelectric resonator having vibrating electrodes on both side edges.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the thin piezoelectric resonator of the present invention, and FIG. 2 is a perspective view showing how the thin piezoelectric resonator of the present invention is mounted on a printed circuit board. Ii side view, FIG. 3 is a plan view of the same as above, and FIGS. 4 to 6 are perspective views showing the manufacturing process. 1... Piezoelectric ceramic element plate 2.3... Vibration 1 4... Thin piezoelectric resonator 11.12... Polarization electrode 1403. Rod-shaped body 15.16・
...Electrode membrane applicant patent attorney Kazu 1) Showai 1
rlA Figure 2 Figure 3 Figure 4

Claims (2)

[Claims] (1) A thin piezoelectric resonator characterized in that vibrating electrodes are provided on both end faces of an ultra-thin piezoelectric ceramic element plate. (2) Polarizing electrodes are formed on both sides of a rectangular block of constant thickness made of piezoelectric ceramic material, polarization is performed by applying a high DC voltage, and then the block is moved in a direction that intersects with the polarizing electrode surface. A rod-shaped body with a rectangular cross-section and polarization electrodes on both sides is formed by cutting parallel to each other at predetermined intervals so as to have cut surfaces, and on the side of the cut rod-shaped body on which the polarization electrodes are not formed. A method for manufacturing a thin piezoelectric resonator, characterized in that a thin piezoelectric resonator on which a vibrating electrode film is formed is further cut into predetermined dimensions in longitudinal and cross-sectional directions to obtain a thin piezoelectric resonator having vibrating electrodes on both end faces. .