JPH0397314A - Laminated type piezoelectric resonator component - Google Patents

Abstract

PURPOSE:To eliminate the electric coupling between resonators by forming a conductor shield layer between at least piezoelectric bases so as to allow the conductor shield layer to apply electromagnetic shield to a resonator provided to the piezoelectric base. CONSTITUTION:A shield base is inserted between piezoelectric bases 2, 3. A conductor shield layer 11 is formed to the upper face of the shield base 4. A capacitor C1 consists of capacitor electrodes 12a, 12b formed opposite to upper and lower faces of the center of the dielectric base 5. The piezoelectric bases 2, 3, the dielectric base 5 and the shield base 4 prepared in such a way are stacked in the broadwise direction and insulation seal bases 6, 6 are stacked to the bottom and the top respectively. They are fixed by using an adhesives with a distance so as not to be in direct contact with each other to form a integrated laminate structure having an enclosed vibration space.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laminated piezoelectric resonant component used in filters, oscillators, etc.

Laminated piezoelectric resonant components have been proposed as a solution to the drawback that arranging various functional elements on a single substrate increases the size of the component.

As this type of piezoelectric resonant component, an energy trapping filter 30 shown in FIGS. 6 to 8 is conventionally known. This filter 30 has two resonant F11. This is a chip type filter equipped with F12 and one capacitor CIO. The resonance filter is generated by two input/output vibrating electrodes 35a. 35b and one common vibrating electrode 36 formed on the lower surface of the substrate 31 in opposition to these. Similarly, resonance 1,000 F12
There are two input/output vibration electrodes 3 on the top center surface of the piezoelectric substrate 32.
7a. 37b and one common vibrating electrode 38 placed opposite to these.

The capacitor CIO has capacitor electrodes 39a . It consists of 39b. The piezoelectric substrates 31, 32 and the dielectric substrate 33 are stacked in the thickness direction as shown in FIG. 6, and the insulator sealing substrates 34. 34 are stacked on top of each other. These are fixed with adhesive and form a monolithic structure with a sealed vibration space inside.

FIG. 7 shows the appearance of the filter 30. The filter 30 has an external input/output terminal (A) at the left end, an external input/output terminal (B) at the rear end, and an external common terminal (C) at the front end.
) is formed. A vibrating electrode 35b is connected to the input/output terminal (A). A vibrating electrode 37b is connected to the other input/output terminal (B).

Further, the common terminal (C) is connected to a vibrating electrode 36. 38 and a capacitor electrode 39b are connected.

Note that the vibrating electrode 35a. 37a and the capacitive electrode 39a are electrically connected via an external relay terminal (D) formed at the right end of the filter 30.

The electrical equivalent circuit of the filter 30 having the above structure is shown in the eighth section.
As shown in the figure. Resonators Fil and F12 are inserted in parallel between the input/output signal line and the common signal line with the capacitor CIO interposed therebetween.

By the way, when piezoelectric substrates equipped with resonators are stacked, the level difference between the input and output signal voltages of each resonator is large, and therefore electrical coupling occurs between the resonators due to the potential difference.
There was a problem that the characteristics of each resonator were not fully exhibited.

Therefore, an object of the present invention is to prevent electrical coupling between the resonators of a laminated piezoelectric resonant component.

Means for Solving the Problems In order to solve the above problems, a multilayer piezoelectric resonant component according to the present invention is characterized in that a conductor shield layer is formed at least between piezoelectric substrates.

Since the working conductor shield layer is formed between the piezoelectric substrates, the resonator provided on the piezoelectric substrate is electromagnetically shielded by the shield layer, and even if the level difference between the input and output signal voltages of the resonator is large, No electrical coupling occurs between the resonators due to potential difference.

EXAMPLE Hereinafter, an example of a laminated piezoelectric resonant component according to the present invention will be described together with a manufacturing method thereof.

In this embodiment, an energy trapping filter will be described as a layered piezoelectric resonant component.

[The first embodiment shows a laminated energy trap type filter in Fig. 1.] FIG. 1 shows an exploded perspective view of No. 1. This filter 1 has two resonant F1.
This is a chip type filter that includes F2 and one capacitor C1.

The resonator F1 is composed of two input/output vibrating electrodes 7a and 7b formed on the upper center surface of the piezoelectric substrate 2, and one common vibrating electrode 8 formed on the lower surface of the substrate 2 in opposition to these electrodes. There is. Similarly, resonance 1,000F2 is the piezoelectric substrate 3
It consists of two input/output vibrating electrodes 9a, 9b on the upper center surface of the input/output vibrating electrode and one common vibrating electrode 10 opposite to these. The piezoelectric substrates 2 and 3 are Pb(zrTi)OBaTi
A ceramic substrate of Om or the like is used. Vibrating electrode 7a
．． 7b. 8, 9a, 9b. 10 is formed by vapor deposition of Ag or the like.

The shield substrate 4 is inserted between the piezoelectric substrates 2 and 3. A conductive shield layer 11 is formed on the upper surface of this shield substrate 4. Although an insulator is generally used as the material for the shield substrate 4, it may also be an insulating magnetic material such as ferrite. The conductor shield layer 11 is formed by vapor deposition of Ag or the like.

The capacitor C1 has capacitive electrodes 12a. It consists of 12b. The piezoelectric substrates 2, 3, dielectric substrate 5, and shield substrate 4 thus prepared are stacked in the thickness direction as shown in FIG. 6 is stacked.

These are fixed with an adhesive at a distance so that they do not come into direct contact with each other, forming a laminated structure having a sealed vibration space. In addition, these substrates 2, 3, 4, 5
．． In the actual mass production process, a wide-area product is used for No. 6, and after being fixed, it is cut into a predetermined size.

FIG. 2 shows the appearance of the filter 1. There is an external input/output terminal (A) at the end of filter 1, and an external input/output terminal (A) at the rear end.
B), and an external common terminal (C) is formed at the front end. A vibrating electrode 7b is connected to the input/output terminal (A). A vibrating electrode 9 is connected to the other input/output terminal (B).
b is connected. Furthermore, the common terminal (C) includes vibration electrodes 8, 10, a capacitive electrode 12b, and a conductor shield layer 1.
1 is connected. Note that the vibrating electrode 7a. 9a and the capacitive electrode 12a are electrically connected via an external relay terminal (D) formed at the right end of the filter 1.

FIG. 3 shows an electrical equivalent circuit of the filter 1 having the above configuration. Resonators F1 and F2 are inserted in parallel between the input/output signal line and the common signal line with a capacitor C1 between them, and a conductive shield layer 11 is inserted between the resonator F1 and the capacitor C1.
is formed.

In the thus obtained filter 1, since the conductor shield layer 1l is formed between the resonators Fl and F2, the resonators Fl and F2 are electromagnetically shielded by the conductor shield layer 11, and there is no fear of electrical coupling.

[Second Embodiment] In place of the shield substrate 4 in FIG. 1, a metal plate 13 shown in FIG. 4 may be used. The metal plate 13 has cutouts 14a, 14a, 14b, 14b, 14b, 14b, 14b, 14b, 14b, 14b, 14b, 14a, 13b to prevent contact with external input/output terminals (A), (B) and external relay terminal (D). 14b. 14c,
It is designed to be connected only to the external common terminal (C).

[In the third embodiment shown in FIG. 1, the shield board 4 and the capacitor board 5 are
Instead, a dielectric substrate 15 shown in FIG. 5 may be used. The dielectric substrate 15 has capacitive electrodes 16a on its upper and lower surfaces.
．． 16b is formed. Capacitive electrode 16a. A capacitor C1 is formed at the opposite portion of 16b. Moreover, since the capacitor electrode 16b is formed almost entirely on the lower surface of the substrate 15, the resonance 1,000 F1. F2 is electrically shielded by the capacitive electrode 16b, so there is no fear of electrical coupling.

[Other Embodiments] The laminated piezoelectric resonant component according to the present invention is not limited to the embodiments described above, and can be modified in various ways within the scope of the gist.

In FIG. 1, a shield substrate 4 includes a piezoelectric substrate 2 and a dielectric substrate 5.
Although shown as being inserted between the piezoelectric substrate 3 and the dielectric substrate 5, a shield substrate 4 may be additionally inserted between the piezoelectric substrate 3 and the dielectric substrate 5.

Further, in FIG. 1, a conductor shield layer may be formed on the upper or lower surface of the upper and lower sealing substrates 6.

In the present invention, since the conductor shield layer is formed between the piezoelectric substrates, the resonator provided on the piezoelectric substrate is electromagnetically shielded by the conductor shield layer. As a result, there is no electrical coupling between the resonators, and a laminated piezoelectric resonant component with excellent input/output characteristics can be obtained.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of a laminated piezoelectric resonant component according to a first embodiment of the present invention, FIG. 2 is a perspective view showing the external appearance of the laminated piezoelectric resonant component, and FIG. 3 is an electrical equivalent circuit diagram thereof. . FIG. 4 is a perspective view of a metal plate used in a second embodiment of the invention, and FIG. 5 is a perspective view of a dielectric substrate used in a third embodiment of the invention. 6, 7, and 8 show conventional laminated piezoelectric resonant components, FIG. 6 is an exploded perspective view of the piezoelectric resonant component, FIG. 7 is a perspective view showing the external appearance of the piezoelectric resonant component, and FIG. The figure is an electrical equivalent circuit diagram. 1... Laminated piezoelectric resonant component (energy trapping filter), 2. 3-...piezoelectric substrate, 7a. 7b.
8 +9a. 9b. 10... Vibrating electrode, 11...
- Conductor shield layer, 13... Conductor shield layer (metal plate), 16b... Conductor shield layer (capacitive electrode).

Claims (1)

[Claims] 1. A piezoelectric resonant component having a structure in which two or more piezoelectric substrates having vibrating electrodes provided on the front and back surfaces are stacked in the thickness direction, characterized in that a conductive shield layer is formed at least between the piezoelectric substrates. Laminated piezoelectric resonant component.