JPH05327385A - Electronic parts - Google Patents

Abstract

PURPOSE:To reduce the generating rate of defective products and the cost by applying ink for frequency adjustment to the surface of a vibration electrode over the specified multiple-fold diameter of the vibration electrode. CONSTITUTION:Vibration electrodes 3 are formed across from the two main surfaces of the front and the back of a rectangular piezoelectric substrate 2 respectively composed of electrostatic ceramic, and a leader electrode 6 is formed while being connected to the respective electrodes 3. Then, ink 6 for frequency adjustment is applied to the front surface of 1 or 1.2 times as large as the diameter of the electrodes 3. Thus, the quantity of the ink 6 applied by being protruded from the electrodes 3 is a little, ripple generated by the ink is decreased, and the generating rate of defective products and the cost is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component comprising a piezoelectric element utilizing energy trapping type thickness vibration by a rectangular piezoelectric substrate made of piezoelectric ceramics or the like,
For example, the defective rate due to the occurrence of ripples is reduced without lowering the productivity of the piezoelectric element using the third-order vibration in the thickness direction,
The present invention relates to an electronic component that improves resonance characteristics.

[0002]

2. Description of the Related Art Conventionally, as a piezoelectric element forming a ceramic piezoelectric resonator utilizing an energy trap type thickness longitudinal vibration using a piezoelectric substrate made of a piezoelectric ceramic, one shown in FIG. 3 is known. ing. In this piezoelectric element 1, a circular vibrating electrode 3 is formed on one main surface (front surface) of a piezoelectric substrate 2, and similarly, a circular vibration electrode 3 is formed on the other main surface (back surface) so as to face each other with the piezoelectric substrate 2 interposed therebetween. The electrodes 3 are formed, and the lead portions 4 respectively connected to the circular vibrating electrodes 3 facing each other on the front and back sides extend in opposite directions, and the lead electrodes 5 are formed on the opposing end portions on the front and back surfaces of the piezoelectric substrate 2. The lead portion 4 is connected and configured. These vibrating electrode 3, lead portion 4, extraction electrode 5, etc. are made of Ag,
The Cu material is formed by sputtering, vacuum deposition, plating, coating, or the like. Then, as shown in FIG. 3B, the frequency adjusting ink 6 having a diameter 1.8 times the diameter d of the vibrating electrode 3 is applied to the surface of the vibrating electrode 3. The vibration electrode of the electronic component becomes smaller as the frequency becomes higher. Further, the frequency adjusting ink applied to the surface of the vibrating electrode in order to set the resonance frequency to a predetermined value is diluted to an appropriate concentration, and the application position is applied according to the pattern. In order not to reduce the productivity due to the complexity of the work of exchanging the pattern, for example, the diameter of the vibrating electrode is 1.0 to
With respect to 1.4 mm, the diameter of the applied ink is kept constant at 1.8 mm for application.

[0003]

In the above-mentioned conventional electronic component, since the ink applied to the vibrating electrode surface is diluted and applied to a wide range on the vibrating electrode, variations in film thickness and density distribution are caused accordingly. It is easy and causes quality variations and many defective products. Also, although there is a difference depending on the material, as shown in FIG. 4, normally about 90% of the energy is confined under the vibrating electrode, but the remaining 1
The energy of 0% is 1.
It leaks to the outside at a distance of 1 to 1.2 times, and the energy leaked to the outside is suppressed by the frequency adjusting ink applied outside the vibrating electrode, which causes ripples. Further, the density is increased when the frequency adjustment amount (the amount that changes fo) is increased, but if the vibration electrode is applied in an excessively large size, the vibration is hindered and the resonance characteristic is deteriorated. Therefore, this electronic component has a high incidence of defective products and low reliability of quality.

The present invention has been made in view of the circumstances of the above-mentioned prior art, and it is an object of the present invention to provide an electronic component in which the rate of defective products is reduced and the cost is reduced without lowering the productivity. To aim.

[0005]

In the electronic component according to the present invention, vibrating electrodes are formed so as to face each other on two front and back main surfaces of a rectangular piezoelectric substrate made of piezoelectric ceramics. In the electronic component in which the extraction electrode is formed by connecting to each of the above, the frequency adjusting ink is applied to the surface of the vibrating electrode to a diameter of 1 to 1.2 times the diameter of the vibrating electrode. .

[0006]

According to the present invention, since the ink for frequency adjustment is applied to the surface of the vibrating electrode of the piezoelectric substrate in a diameter of 1 to 1.2 times the diameter of the vibrating electrode, it is applied unevenly beyond the vibrating electrode. The amount of ink that is applied is small, and the ripples that occur can be reduced, and since the work of replacing the coating pattern does not become too complicated, there is no reduction in productivity and there is no need to eliminate bias. Positioning of coating is not so difficult, and the rate of defective products can be reduced without increasing the cost. If the frequency adjustment ink is applied to a diameter that exceeds 1.2 times the diameter of the vibrating electrode, the amount of ink applied to parts other than the vibrating part will increase, and the damping amount will increase, resulting in a defect rate of 30% or more. And the resonance characteristics are deteriorated to the extent that it does not result in a defective product. When the ink is applied to less than 1 time the diameter of the vibrating electrode, the number of defective products whose frequency adjustment is incomplete increases, and the total defective rate increases. Therefore, the range of 1 to 1.2 times the diameter of the vibrating electrode is preferable.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating an electronic component according to an embodiment of the present invention, for example, an energy trap type thickness longitudinal vibration electronic component. Parts that are the same as or correspond to those in the conventional example will be described with the same reference numerals. In the figure, reference numeral 1 denotes a piezoelectric element forming an electronic component. In this piezoelectric element 1, a circular vibrating electrode 3 is formed on the front surface of a piezoelectric substrate 2 as in the conventional example, and a circular vibrating electrode 3 is formed on the rear surface so as to face the circular electrode. The vibrating electrode 3 is formed, the lead portions 4 respectively conducting to the opposing circular vibrating electrodes 3 on the front and back surfaces extend in opposite directions, and the extraction electrodes 5 are formed on the opposing end portions on the front and back surfaces of the piezoelectric substrate 2. Is connected to the lead portion 4. The frequency adjusting ink 6 is applied to the front and back surfaces of the respective vibrating electrodes 3 with a diameter 1.2 times the diameter d of the vibrating electrodes. As the ink for frequency adjustment, the same ink as the conventional one is used.

In the above embodiment of the present invention, the vibration electrode has a diameter of 1.0 in an electronic component using a 32 MHz thickness triple wave.
FIG. 2 shows the relationship between the ripple defect ratio (%) and the ratio of the diameter of the frequency adjusting ink applied to the diameter of the vibrating electrode of the electronic component outside the scope of the present invention in mm. According to FIG. 2, the relationship between the waveform defect caused by the ripple and the ink application diameter for frequency adjustment changes almost linearly, and the frequency adjustment is 1.8 times the diameter of the conventional vibrating electrode for frequency adjustment. It can be seen that the defective rate is improved by about 10% as compared with the case where the above ink is applied.

As described above, according to this embodiment, the production rate of defective products can be reduced, the cost can be reduced, and the coating amount can be increased so much without complicating the work and reducing the productivity. Since this is not done, it is possible to improve the reliability of the quality without disturbing the vibration and deteriorating the resonance characteristic. Further, according to the present invention, even in the case of producing electronic parts having different frequencies, it can be applied without changing the line, and the productivity can be improved. The present invention is not limited to the diameter examples of the vibrating electrode and the frequency adjusting ink in the above-described embodiment, and the same applies to electronic components formed in other dimensions.

[0010]

As described above, according to the electronic component of the present invention, since the amount of ink applied to the portion other than the vibrating portion is not increased, the damping amount is small and the resonance characteristic is not deteriorated. The reliability can be improved, the occurrence rate of defective products can be reduced without making the work so complicated, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an electronic component according to the present invention,
(A) is a plan view and (b) is a front view.

FIG. 2 is a graph showing a relationship between a coating diameter of a frequency adjusting ink and a defective product rate.

FIG. 3 is a view showing a conventional electronic component, (a) is a plan view,
(B) is a front view.

FIG. 4 is a graph showing a vibration energy distribution.

[Explanation of symbols]

 1 Piezoelectric element 2 Piezoelectric substrate 3 Vibration electrode 5 Extraction electrode 6 Ink

Claims (1)

[Claims] 1. An electronic device comprising vibrating electrodes formed on two front and back surfaces of a rectangular piezoelectric substrate made of piezoelectric ceramic so as to face each other, and extraction electrodes connected to the respective vibrating electrodes. The electronic component is characterized in that the frequency adjusting ink is applied to the surface of the vibrating electrode in a diameter of 1 to 1.2 times the diameter of the vibrating electrode.