JPH10242784A - Production of piezoelectric resonator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily decide the quality of a piezoelectric resonator by separating the electrode pads from each other on a piezoelectric substrate of a large size and cutting every electrode pad into pieces. SOLUTION: Plural pairs of vibration containment electrodes 2 are provided opposite to each other on both sides of a piezoelectric substrate 1 of a large size, and an electrode pad 4 is connected to each electrode 2 to connect it to an external terminal via a draw-out electrode 3. These pads 4 are separated from each other, and the width of the pad 4 is set longer than the width or diameter of each electrode 2 by 100μ or more. Then the substrate 1 is cut into pieces among the pads 4 for a group of piezoelectric resonators. In such a production method of piezoelectric resonators, a non-defective resonator is decided as long as it's cut into pieces among the pads 4. Meanwhile, the quality is decided according to the presence or absence of the slip electrodes 5 for a piezoelectric resonator that has plural electrodes 5 among its separated pads 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a piezoelectric resonator used for a ceramic filter, an oscillator and the like.

[0002]

2. Description of the Related Art FIG. 7 is a plan view showing a piezoelectric resonator group in which a plurality of conventional piezoelectric resonators are connected. The piezoelectric resonator group includes a plurality of piezoelectric resonators.

That is, a plurality of vibration confinement electrodes 12, extraction electrodes 13 extracted therefrom, and electrode pads 14 for connecting to external terminals (not shown) are formed on both front and back surfaces of the piezoelectric substrate 11, When each is cut, it is separated into the individual piezoelectric resonators 18 shown in FIG. The electrode pad 14 is designed to have an area necessary for connecting to an external terminal.

In each piezoelectric resonator 18, 1
Reference numeral 6 denotes a non-electrode forming portion provided to reduce the influence from the end face. The non-electrode forming part 16 is necessary for sufficiently increasing the distance from the vibration confining electrode 12 to the end face so that unnecessary resonance response due to the influence from the end face does not occur near the resonance frequency.

[0005]

In the above-described conventional structure, it is necessary to increase the precision of cutting the piezoelectric resonator into 18 pieces in order to secure the non-electrode forming portion 16 reduced to the limit. When an abnormality occurs in the forming process and the non-electrode forming portion 16 is expected to have a size smaller than the limit,
The piezoelectric resonator 18 whose non-electrode forming portion 16 is below the limit needs to be sorted out. However, the critical dimension of the distance between the vibration confinement electrode 12 and the end face of the resonator differs depending on the resonance frequency. For this reason, all processing lots that are expected to contain defective products have to be discarded, which has the problem of lowering the yield.

The present invention solves the above-mentioned conventional problems, and provides a method of manufacturing a piezoelectric resonator which does not cause a reduction in yield when forming a small and high-performance resonator. is there.

[0007]

According to the present invention, a plurality of pairs of vibration confinement electrodes are provided on both sides of a large-plate-shaped piezoelectric substrate. An electrode pad for connection to an external terminal is connected via an extraction electrode, and the plurality of electrode pads are separated from each other, and the width of each electrode pad is at least 100 μm larger than the width or diameter of the vibration confinement electrode. The piezoelectric substrate is divided into individual pieces between the electrode pads of the elongated piezoelectric resonator group.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to a first aspect of the present invention, a plurality of pairs of vibration confinement electrodes are provided on both front and back surfaces of a large-sized piezoelectric substrate, and each of the vibration confinement electrodes has an extraction electrode. An electrode pad for connecting to an external terminal through the piezoelectric element, wherein the plurality of electrode pads are separated from each other, and the width of each electrode pad is at least 100 μm longer than the width or diameter of the vibration confinement electrode. A method of manufacturing a piezoelectric resonator in which a piezoelectric substrate is divided into individual pieces between the electrode pads of a resonator group, and if the piezoelectric resonator is divided between the electrode pads, a good product can be obtained.

According to a second aspect of the present invention, a plurality of slit electrodes are provided between the separated electrode pads.
In the method for manufacturing a piezoelectric resonator described above, the quality can be determined based on the presence of the slit electrode.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of a piezoelectric resonator having a resonance frequency of 45 MHz. In this case, the diameter of the vibration confining electrode 2 is selected to be a = 0.6 mm so that unnecessary resonance does not occur. The distance from the vibration confining electrode 2 to the end face of the piezoelectric resonator 8 after cutting in FIG. 2 is required to be at least 100 μm in the non-electrode forming part 6 in order to prevent unnecessary resonance from occurring. 4 is 100 μm (= 100 μ) on one side of the diameter a of the vibration confinement electrode 2, that is, 20 μm as a whole.
0μ longer. 2 and 3 show a state in which individual piezoelectric resonators 8 are cut out from the large piezoelectric substrate 1 in FIG.
FIG. 2 shows a state in which the resonator forming process has been performed normally, and has non-electrode pad forming portions 7 on both sides of the electrode pads 4 up to the end faces. That is, if the electrode pad 4 is cut without chipping, it can be easily recognized that the lower limit of 100 μ necessary for preventing unnecessary resonance from occurring is secured. The distance between the non-electrode pad formation portions 7 is determined based on the cutting blade thickness, blade runout, and the tolerance of each step of the resonator forming process. FIG. 3 shows a state in which an abnormality has occurred in the resonator formation process. The vibration confinement electrode 2, the extraction electrode 3, and the electrode pad 4 are all shifted to the left, and the non-electrode pad formation part 7 does not exist on the left. Thus, it can be easily recognized that the distance to the resonator end face is not required, and the lower limit 100 μ necessary for preventing unnecessary resonance from being generated is not secured. That is, selection by visual inspection is possible, and image recognition can be easily performed by recognizing the presence / absence of the non-electrode pad forming portion 7. FIG. 4 shows a piezoelectric substrate having a plurality of slit electrodes 5 between the electrode pads 4. FIG. 5 shows a case where the resonator forming process has been performed normally, and FIG. 6 shows a case where an abnormality has occurred. ing. In the case of FIG. 6, similarly to the case of FIG. 3, it can be easily recognized that the distance to the end face of the resonator is not ensured so that unnecessary resonance does not occur. That is, in this case, it can be more easily determined from the number of the slit electrodes 5 existing in the non-electrode pad formation portions 7 on both sides of the cut-out piezoelectric resonator 8 on the electrode pad 4. More specifically, in FIG. 5, which is normal, the number of slit electrodes 5 on both sides of the electrode pad portion 4 is one, and the distance to the end face of the resonator is sufficient to prevent unnecessary resonance from occurring. I have. In FIG. 9, the impedance characteristics when the necessary distance (100 μm for 45 MHz) is secured are shown by solid lines A, and the impedance characteristics when the required distance is not secured are shown by broken lines B and C.

[0011]

As is clear from the above description of the embodiment, the present invention separates the electrode pads from each other and separates the electrode pads into individual pieces between the separated electrode pads, thereby eliminating defective products and defective products. It is possible to easily determine.

[Brief description of the drawings]

FIG. 1 is a plan view of a group of piezoelectric resonators according to an embodiment of the present invention.

FIG. 2 is a plan view of a piezoelectric resonator formed by a processing process more ordinary than the piezoelectric resonator group.

FIG. 3 is a plan view of a piezoelectric resonator formed in a state where an abnormality has occurred in a processing process from the piezoelectric resonator group.

FIG. 4 is a plan view of a group of piezoelectric resonators according to another embodiment of the present invention.

FIG. 5 is a plan view of a piezoelectric resonator formed by a processing process more ordinary than the piezoelectric resonator group.

FIG. 6 is a plan view of a piezoelectric resonator formed in a state where an abnormality has occurred in a processing process from the piezoelectric resonator group.

FIG. 7 is a plan view of a conventional piezoelectric resonator group.

FIG. 8 is a plan view of a piezoelectric resonator formed from the piezoelectric resonator group.

FIG. 9 is a diagram illustrating frequency characteristics of a resonator when a non-electrode forming portion is secured and when the non-electrode forming portion is below a limit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric substrate 2 Vibration confinement electrode 3 Leader electrode 4 Electrode pad 8 Piezoelectric resonator

Claims (2)

[Claims] A large-sized piezoelectric substrate is provided with a plurality of pairs of vibration confinement electrodes facing each other on both sides thereof, and each of the vibration confinement electrodes has an electrode pad for connecting to an external terminal via a lead-out electrode. Connected, the plurality of electrode pads are separated from each other, and the width dimension of each electrode pad is set to 100 μm more than the width or diameter of the vibration confinement electrode.
A method of manufacturing a piezoelectric resonator of a group of piezoelectric resonators having a length as described above, wherein the piezoelectric substrate is divided into individual pieces between the electrode pads. 2. The method according to claim 1, wherein a plurality of slit electrodes are provided between the separated electrode pads.