JPH088677A - Piezoelectric parts - Google Patents

Abstract

PURPOSE:To prevent a hindrance to oscillation and to enhance degree of freedom of assembling by adhering about the center part of an electrode on a substrate side face of a piezoelectric resonator to a first electrode of the substrate with a conductive adhesive and connecting a second electrode on the substrate to an electrode on the other face by a bonding wire. CONSTITUTION:A piezoelectric resonator 1 is adhered and held to a first electrode 21 of a substrate 2 in about the center part of one principal face on the side of a driving electrode 13 by a flexible conductive adhesive 4. Since this flexible conductive adhesive 4 less attenuates a transverse wave (oscillation in the lengthwise direction), its influence upon the resonance response is small, and the resonance frequency and the resonance level are hardly changed by adhesion to the substrate 2. A driving electrode 12 of the piezoelectric resonator 1 and a second electrode 22 of the substrate 2 are electrically connected with a bonding wire 5 by an ultrasonic wave. A cap 3 made of alumina or the like is adhered to the substrate 2 in the outer peripheral part to seal up the piezoelectric resonator 1, thus constituting the chip type piezoelectric parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric component containing a piezoelectric resonator.

[0002]

2. Description of the Related Art In a conventional piezoelectric component of this type, a piezoelectric resonator is mounted on a substrate and sealed with a cap.

Further, the electrodes on the substrate and the electrodes of the piezoelectric resonator are connected by spring terminals having a plate thickness of several mm.

[0004]

The problem with the above construction is that the spring terminal has a large plate thickness of several mm.
This means that if the spring terminal is pressed into contact with a point displaced from the center of the piezoelectric resonator, the vibration of the piezoelectric resonator will be hindered.

Therefore, the present invention prevents the vibration inhibition of the piezoelectric resonator.

[0006]

In order to achieve this object, according to the present invention, a substantially central portion of an electrode on one main surface of the piezoelectric resonator is used as a first electrode on the substrate and a conductive adhesive is used. Adhesive bonding and fixing, and the substantially central portion of the electrode on the other main surface of the piezoelectric resonator and the second electrode on the substrate are connected by a bonding wire.

[0007]

According to the above structure, the first electrode of the rectangular piezoelectric resonator and the first electrode formed on the substrate are electrically connected and fixed and held by the conductive adhesive. Further, the second electrode of the rectangular piezoelectric resonator and the second electrode formed on the substrate have a very small effect on the length vibration of the resonator, and are electrically connected by ultrasonic fusion with a bonding wire. Connected. Therefore, vibration inhibition of the piezoelectric resonator does not occur.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the piezoelectric component according to the present invention will be described below with reference to the accompanying drawings. The piezoelectric component shown in FIG.
It is composed of a piezoelectric resonator 1, an insulating substrate 2 made of alumina or the like, and a cap 3 made of alumina or the like.

The piezoelectric resonator 1 has a rectangular shape, and the drive electrodes 12 and 13 are provided on the upper and lower main planes by a method such as vapor deposition, plating and sputtering. The material of the piezoelectric resonator 1 is piezoelectric ceramic or piezoelectric single crystal, and when an electric signal is applied between the drive electrodes 12 and 13, the piezoelectric resonator 1 has a vibration mode in which it vibrates in the longitudinal direction. Occurs.

A first electrode 21 and a second electrode 22 are provided on the main plane of the substrate 2 by means such as printing or printing. In this embodiment, Ag-Pd is formed by printing and baking. The electrically separated first electrode 21 and second electrode 22 also serve as electrodes for extracting signals to the outside, and are extended to both side surfaces of the substrate 2, respectively.

The piezoelectric resonator 1 has a flexible conductive adhesive (in this embodiment, a silicon-based silver powder-containing conductive material) with the first electrode 21 of the substrate 2 at approximately the center of one main surface on the drive electrode 13 side. Adhesive adhesive was used.) 4. Since the flexible conductive adhesive 4 has a small attenuation with respect to transverse waves (longitudinal vibration), its influence on the resonance response is extremely small, and the resonance frequency and the resonance level are hardly changed by the adhesion to the substrate 2. Since there is a vibration node at the central portion of the piezoelectric resonator 1 in the longitudinal vibration, only this central portion has a width sufficiently smaller than the length of the piezoelectric resonator 1 (the length of the piezoelectric resonator 1 is approximately 1). / 10 or less), it is not always necessary to use a flexible conductive adhesive.

The electrical connection between the drive electrode 12 of the piezoelectric resonator 1 and the second electrode 22 of the substrate 2 is made by the ultrasonic bonding wire 5. As the bonding wire 5, an aluminum wire having a diameter of 20 μm was used. Since such a thin bonding wire 5 is used and it is extremely lightweight, even if the wire connection point on the drive electrode 12 deviates from the central portion of the piezoelectric resonator 1, the influence on the resonance response is extremely small and the assembly is free. The degree increases.

A cap 3 made of alumina or the like is adhered to the substrate 2 at the outer peripheral portion, and the piezoelectric resonator 1 is sealed to form a chip type piezoelectric component.

2 and 3 show another embodiment, and a ladder filter using a plurality of rectangular piezoelectric resonators will be described. The eight rectangular piezoelectric resonators S1 to S4 and P1 to P4 are mounted on the substrate 2 having the electrodes 21 to 24 formed on the main plane. The electrodes 21, 22, 24 of the substrate 2 also serve as electrodes for extracting signals to the outside. Piezoelectric resonator S1 to S
4, P1 to P4 are connected to and held by the electrodes 21, 22, 24 of the substrate 2 with a flexible conductive adhesive at the central portion of the lower drive electrode, as in the above embodiment. In addition, substantially the central portions of the electrodes on the upper surfaces of the piezoelectric resonators S1 to S4 and P1 to P4 and the electrodes 21, 22 and 24 on the substrate 2 or the electrodes on the upper surfaces of the other piezoelectric resonators S1 to S4 and P1 to P4 are omitted. By connecting the central portion with the bonding wires 51 to 56, the electrical connection shown in FIG. 3 becomes possible.

[0015]

As is apparent from the above description, according to the present invention, the substantially central portion of the electrode on the side surface of the substrate of the piezoelectric resonator is adhered to the first electrode of the substrate with a conductive adhesive, and Since the second electrode on the substrate is connected to the electrode with a bonding wire, vibration is not obstructed, and the accuracy of the bonding position with the flexible conductive adhesive can be made rough, allowing a great degree of freedom in assembly. Become.

[Brief description of drawings]

FIG. 1 is a perspective view of an electronic component showing an embodiment of the present invention.

FIG. 2 is a top view of an electronic component showing another embodiment of the present invention.

FIG. 3 is a diagram showing electrical connection of another embodiment of the present invention.

[Explanation of symbols]

 1 Piezoelectric resonator 2 Substrate 3 Cap 4 Flexible conductive adhesive 5 Bonding wire

Claims (2)

[Claims] 1. A substrate, a rectangular piezoelectric resonator mounted on the substrate, having one or more rectangular vibrations as a main vibration mode, and a cap sealing the piezoelectric resonator on the substrate. , A substantially central portion of an electrode provided on one main surface of the piezoelectric resonator is adhered and fixed to the first electrode of the substrate with a conductive adhesive, and an electrode provided on the other main surface of the piezoelectric resonator is substantially A piezoelectric component in which a central portion and a second electrode of the substrate are connected by a bonding wire. 2. The piezoelectric component according to claim 1, wherein the piezoelectric resonator and the substrate are fixedly adhered to each other with a flexible conductive adhesive.