JPS6328114A - Piezoelectric vibrating component - Google Patents

Abstract

PURPOSE:To eliminate the projection of a piezoelectric vibration component from other electronic components and to reduce its size by providing a vibration space between the 2nd counter electrode and an earth plate and connecting the earth electrode which projects from the 2nd counter electrode to the earth plate. CONSTITUTION:A ceramic trap 10 consists of two energy confined type thickness shear vibration resonator 11 and the earth plate 12 interposed between the both. Further, the 1st counter electrode 14 is formed at the center part of the outside main surface 13a of a piezoelectric substrate 13 and the 2nd counter electrode 16 is formed on the inside main surface 13b opposite the 1st counter electrode 14 across a piezoelectric substrate 13 to constitute a resonance element. An earth electrode 17 extended from the counter electrode 16 is arranged at one side part of the 2nd counter electrode 16. Then, the vibration space S is provided between the 2nd counter electrode 16 and earth plate 12 formed on each thickness shear vibration resonator 11 and the respective earth electrodes 17 are fixed to the earth plate 12. Consequently, this piezoelectric vibration component never projects higher than any other electronic component even when incorporated in a printed board.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a pressure i-vibrating component having two sets of resonant elements.

<Prior Art> Conventionally, a three-terminal ceramic trap 30 as shown in FIG. 3 has been known as an example of this type of piezoelectric vibrating component. This ceramic trap 30 includes a single rectangular flat piezoelectric substrate 31, on which two sets of resonant elements 32 and 32 are formed.

Each of such resonant elements 32.32 includes a first opposing electrode 33 formed on one main surface of the piezoelectric substrate 31, and
This pressure 1 is applied to the first opposing electrode with the substrate 31 in between;
It is constituted by a counter electrode 34. Note that terminal electrodes 35.35 extend from each of the first opposing electrodes 33.33 through lead portions, and the second opposing electrodes 34.34
is connected to the ground electrode 36 by a lead portion.

Corresponding lead terminals (not shown) are connected to each terminal electrode 35, 35 and ground electrode 36, respectively.

<Problems to be solved by the invention> By the way, the ceramic trap 30 as described above has the following features:
There were the following problems. That is, in this ceramic trap 30, one pressure is applied to two substrates 31.
Since a set of resonant elements is configured, the space required for the piezoelectric substrate 31 becomes large, and there is a limit to reducing the vertical and horizontal dimensions of the piezoelectric substrate 31. Therefore, when this ceramic trap 30 is assembled into a printed circuit board (not shown) in an upright position, it protrudes higher than other electronic components.

To deal with this, the protrusion height is reduced by bending each lead terminal of the ceramic trap 30 and incorporating the ceramic trap 30 into a printed circuit board in a lying position.

However, this bending work must be done while taking into account the surroundings of the ceramic trap 30 incorporated in the printed circuit board, and it is time-consuming and cannot be done automatically, so it must be done manually. There wasn't. Therefore, the cost has increased.

In view of such conventional problems, the present invention aims to reduce the height of a piezoelectric vibrating component incorporated in a printed circuit board without having to perform troublesome manual work such as bending lead terminals, thereby achieving miniaturization. The purpose is to provide piezoelectric vibrating parts that can.

<Means for Solving the Problems> In order to solve these problems, the present invention provides two thickness-traversing vibration resonators, a ground plate interposed between the two thickness-travel vibration resonators, A piezoelectric vibrating component comprising: a first opposing electrode having a terminal ii formed on the outer main surface of the piezoelectric substrate in each resonator; forming a second counter electrode that constitutes a resonant element by opposing the first counter electrode;
The feature is that a vibration space is provided between the second opposing electrode and the ground plate, and the ground electrode extending from the second opposing electrode and the ground plate are connected. 6 <Operation> Above. According to the structure, the vertical and horizontal dimensions of the vibrating component are approximately the same as the dimensions of one resonant element in a conventional piezoelectric vibrating component, and the height thereof is also reduced.

Therefore, even if this pressure tg: dynamic component is incorporated into a printed circuit board, it will not protrude higher than other electronic components.

<Example> Hereinafter, the present invention will be described in detail based on an example shown in the drawings. In this embodiment, the present invention will be explained by applying it to a three-terminal ceramic trap (hereinafter referred to as a ceramic trap) as a piezoelectric vibrating component.

Figure 1 is an exploded perspective view of the ceramic trap, and Figure 2 is an exploded perspective view of the ceramic trap.
The figure is an assembled sectional view taken along the line ■-■ in FIG. 1. Reference numeral 10 in these figures is a ceramic trap,
It is composed of two energy-trapped thickness-sliding vibration resonators 11 and a ground plate 12 interposed between them.

Each of the thickness-stretching vibration resonators 11 includes a piezoelectric substrate 13 in the shape of a rectangular flat plate. A first counter electrode 14 is formed at the center of the outer main surface 13a of the piezoelectric substrate 13,
This first counter electrode 14 is connected to the same main surface 13 by a lead portion.
It is connected to a terminal electrode 15 formed at one end of a. Also, pressure! A second counter electrode 16 is formed on the inner main surface 13b of the substrate 13, and forms a resonant element by opposing the first counter electrode 14 with the piezoelectric base Vi, 13 in between. On one side of this second counter electrode 16, the counter electrode 1
A ground electrode 17 extending from 6 is arranged.

The main part 12a of the grounding plate 12 is made of a rectangular metal plate having almost the same external shape as the piezoelectric substrate 13, and a lead terminal serving as a grounding terminal is connected from the center of the -long side (lower side in the figure). L2b is coupled together. Note that this lead terminal 12b may be formed separately from the earth part 12a of the ground Fi 12 and connected to the main part 12a.

This ground plate 12 is interposed between both thickness-stretching vibration resonators 11.11 arranged so that the inner main surfaces 13b, 13b of the piezoelectric substrate 13.13 face each other. As shown in FIG. 2, each thickness-stretching vibration resonator 11 . They are sequentially shifted in the lateral direction (in the figure, in the left-right direction) so as not to face the ground plate 12 on both sides. A second opposing tF formed in each thickness-stretching vibration resonator 11
A vibration space S is provided between the fA 16 and the ground plate 12, and each ground electrode 17 is fixed to the ground plate 12 using cream solder, R-electrode adhesive, or the like. In addition, the ground plate 12
The ends of both piezoelectric substrates 1 are located outside of each counter electrode FfA16.
3.13 is adhesively fixed to the inner main surfaces 13b, 13b.

The dual-thickness sliding vibration resonator 11 constructed in this way
．． 11 terminal electrodes 15 and 15 each have a lead terminal 1.
8.18 is connected, and both thickness sliding resonators 11.
A resin outer device 9 made of epoxy resin or the like is provided around the ground plate 11 and the ground plate 12 via an elastic material such as silicone rubber.

<Effects of the Invention> As described above, according to the present invention, a piezoelectric vibrating component is constructed by interposing a ground plate between two thickness-stretching vibration resonators arranged to face each other. The vertical and horizontal dimensions can be made comparable to that of one resonant element in the conventional example,
And its height can also be reduced. Therefore, even if this piezoelectric vibrating component is incorporated into a printed circuit board, it will not protrude higher than other electronic components, and miniaturization can be achieved.

Furthermore, since the ground plate is interposed between the two thickness-stripping vibration resonators like a core material, there is an effect that the piezoelectric vibrating component is strengthened against external stresses such as drop impact.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, FIG. 1 is an exploded perspective view of a ceramic trap, and FIG. 2 is an exploded perspective view of a ceramic trap.
It is an assembled sectional view taken along the line ■-■ in the figure. Further, FIG. 3 shows a perspective view of a conventional example. DESCRIPTION OF SYMBOLS 10... Piezoelectric vibrating component, 11... Thickness sliding vibration resonator, 12... Ground plate, 13... Piezoelectric substrate, 13a... Outer main surface, 13b... Inner main surface, 14. ...First counter electrode, 15...Terminal electrode, 16...Second counter electrode, 17...Ground electrode, S...Vibration space.

Claims (1)

[Claims] (1) A piezoelectric vibrating component consisting of two thickness-traversing vibration resonators and a ground plate interposed between the two thickness-traversing vibration resonators, wherein the piezoelectric substrate in each of the resonators has an outer main surface on the piezoelectric substrate. forms a first counter electrode having a terminal electrode, and also forms a second counter electrode on the inner main surface thereof, which faces the first counter electrode with the piezoelectric substrate in between, thereby configuring a resonant element; A piezoelectric vibrating component, characterized in that a vibration space is provided between the second opposing electrode and the ground plate, and the ground electrode extending from the second opposing electrode is connected to the ground plate.