JPH0217708A - Composite part - Google Patents

Abstract

PURPOSE:To obtain a composite component without generating the cuttoff of a conductor film and with high reliability by coupling integrally a piezoelectric plate part and a dielectric plate part at a part where a piezoelecric material and a dielectric material are mixed. CONSTITUTION:Compacting and burning are applied on the piezoelectric plate part 31a and the dielectric plate part 31b on a substrate 31, and they are fused integrally by the mixing part 32 of the piezoelectric material and the dielectric material. Thereby, it is possible to prevent the disconnection of the piezoelectric plate part 31a from the dielectric plate part 31b on the substrate 31 from being generated, and furthermore, no sticking of them with a sticking agent is required. And since the substrate 31 is made of only an inorganic material, strong adhesion for a pattern can be expected, and the cutoff of the conductor film comprising part of the pattern can be prevented from being generated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a composite component in which a piezoelectric component and a capacitor are formed on a single substrate.

[Prior Art] Generally, some piezoelectric components such as ceramic filters and ceramic resonators have a capacitor integrally formed on a piezoelectric substrate.

As this type of piezoelectric component, for example, as shown in FIG. 3, three-terminal multimode filters 2 and 3 (hereinafter referred to as three-terminal filter) that utilize energy-trapped thickness longitudinal vibration of a piezoelectric plate 1 are used. Some are connected in cascade with a buffer capacitor C in between. Since piezoelectric materials are generally also dielectric materials, the buffer capacitor C is
Along with the set of 3-terminal filters 2 and 3, - piezoelectric plates! The three-terminal filter 2.3 and buffer capacitor C are integrally formed on the piezoelectric plate i, and as shown in FIG.
It is connected to the output terminal 5 and the ground terminal 6, respectively.

By the way, in this type of ceramic filter, since the capacitor C is formed on the piezoelectric plate 1, the portion of the piezoelectric plate 1 where the buffer capacitor C is formed also functions as a resonator, generating a resonance response, which changes the filter characteristics. This appears as an increase in ripple and insertion loss. In order to eliminate this resonance response, it has been attempted to attach solder or the like to the electrodes 7 and 8 of the buffer capacitor C to damp the vibrations in that area, but no significant improvement in insertion loss could be expected.

In order to eliminate the above-mentioned resonance response, conventionally, as shown in FIG. A ceramic filter in which a three-terminal filter 2.3 is formed and a buffer capacitor C is formed on the dielectric plate 12 is well known.

The piezoelectric plate 11 and dielectric plate 12 are formed by the steps shown in FIG. 5(a) to FIG. 5(e). That is,
Filling the female mold ■4 of the press machine with the material powder I3* (Fig. 5 (
a)), leveling components! 5 as shown by arrow A1 (FIG. 5(b)), and after lowering the lower mold 16 by a certain amount, lowering the upper mold 17 as shown by arrow A and starting the press. (FIG. 5(C)) and then firing to manufacture motherboards 18 and 19 (see FIG. 5(d)) of piezoelectric plate 11 and dielectric plate 12, respectively.

Of the motherboards 18 and 19, the motherboard 18 made of piezoelectric material powder was subjected to polarization treatment, as shown in FIG.
As shown in d), the motherboard 18 and the motherboard 19 are bonded together using an organic adhesive. And this,
As shown by the two-dot chain line in FIG. 5(d), it is cut to have the thickness of the piezoelectric plate 11 and dielectric plate 12 of the ceramic filter of FIG. 4. As a result, Fig. 5(e)
As shown in FIG. 2, a long substrate 21 is obtained in which the substrates made of the piezoelectric plate 11 and the dielectric plate 12 are continuous in a line.

After electrodes of a three-terminal filter 2.3 and a buffer capacitor C are formed on this long substrate 21, as shown in FIG. 5(e).
The ceramic filter described in FIG. 4 is obtained by cutting at the position indicated by the two-dot chain line.

[Problems to be Solved by the Invention] Incidentally, in the ceramic filter described above, since the piezoelectric plate 11 and the dielectric plate 12 are bonded to each other with an organic adhesive, an adhesion process is not required during manufacturing. There was a problem.

Moreover, when the adhesive layer 20 formed by this adhesive peels off, the piezoelectric plate! There was also the problem that the dielectric plate I2 came off from the l.

Furthermore, as can be seen from FIG. 4, the piezoelectric plate I! and a three-terminal filter 2.3 formed on the dielectric plate 12, respectively.
And the conductive film for connecting the buffer capacitor C is the adhesive layer 2.
It crosses 0. However, since the adhesive layer 20 is made of an organic adhesive, the adhesion strength of the conductive film to the adhesive layer is weak, and there is a problem in that the conductive film may be disconnected on the adhesive layer.

An object of the present invention is to provide a highly reliable composite component that does not require adhesion between a piezoelectric plate and a dielectric plate, the piezoelectric plate and the dielectric plate are integrally formed, and there is no disconnection of the conductive film. be.

[Means for Solving the Problems] Therefore, the present invention provides a piezoelectric plate portion made of a piezoelectric material on one side and a dielectric plate made of a dielectric material on the other side with a mixed portion of a piezoelectric material and a dielectric material in between. The piezoelectric plate part is provided with a single substrate that forms a piezoelectric component, and the piezoelectric plate part is formed with an electrode that forms a piezoelectric component, while the dielectric plate part is formed with a capacitor electrode that forms a capacitor. It is characterized by

[Function] The piezoelectric plate portion and the dielectric plate portion are integrally combined as a substrate of a composite component of a piezoelectric component and a capacitor at a mixed portion of piezoelectric material and dielectric material. The main surface of this substrate is a continuous surface made of ceramic material.

[Effects of the Invention] According to the present invention, the piezoelectric plate portion and the dielectric plate portion are integrally joined at the mixed portion of the piezoelectric material and the dielectric material, so that the main surface of the substrate is made of a continuous ceramic material. The conductive film has the same adhesion force in the mixed part of the piezoelectric plate part and the dielectric plate part as in other parts, and there is no disconnection of the conductive film, making it possible to create highly reliable composite parts. Obtainable.

Further, according to the present invention, there is no need for adhesion between the piezoelectric plate portion and the dielectric plate portion, and there is no possibility that the two may come off.

[Example code] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

An embodiment of the composite component according to the present invention is shown in FIG.

The above composite component is one in which the present invention is applied to the ceramic filter explained in FIG.
A piezoelectric plate portion 31a made of a piezoelectric material on one side with
The other side is a dielectric plate portion atb made of a dielectric material. As the piezoelectric material of the piezoelectric plate portion 31a, for example, PbZr0-pb'rlo5cpZT)-based solid solution porcelain is used. Further, as the dielectric material for the dielectric plate portion I2, a material classified as YY or YZ according to the Japanese Industrial Standards (115) is used.

Note that in FIG. 1, parts corresponding to those in FIG. 4 are designated by corresponding reference numerals, and redundant explanations will be omitted.

In addition, although the mixed portion 32 of the piezoelectric material and the dielectric material is shown in a slightly exaggerated manner in FIG. Continuous.

The bipedal ceramic filter is manufactured as shown in FIGS. 2(a) to 2(i).

First, as shown in FIG. 2(a), the female mold I of the press
The piezoelectric material powder 33 is filled onto the lower mold 16 that is fitted into the lower mold 16, and leveling is performed. Thereafter, the lower mold 16 is lowered one step, and as shown in FIG. 2(b), the piezoelectric material powder 33 is further filled with dielectric material powder 34 for leveling.

Thereafter, as shown in FIG. 2(C), the upper mold 17 is lowered onto the dielectric material powder 34 as shown by arrow A3, and the piezoelectric material 33 and the dielectric material powder 34 are compression-molded. . After this compression molding, a block-shaped molded body 37 consisting of a piezoelectric material portion 35 and a dielectric material portion 36 is obtained, as shown in FIG. 2(d). This molded body 37 is fired in a firing furnace.

After firing, electrodes 38 and 39 are formed on a pair of opposing side surfaces of the molded body 37, as shown in FIG. 2(e). Then, as shown in FIG. 2(f), the electrode 38.3
A high voltage E is applied between 9 and 9 to polarize the piezoelectric material portion 35 of the molded body 37.

As shown in FIG. 2(g), the molded body 37 subjected to the polarization treatment as described above is placed parallel to the polarization electrodes 38 and 39 to the thickness of the ceramic filter substrate 31 explained in FIG. Cut at equal pitches. As a result, Figure 2 (h
), a long substrate 4 in which a piezoelectric plate portion 31a and a dielectric plate portion 31b are integrated! get.

After forming the electrode patterns 42 of the three-terminal filter 2.3 and the buffer capacitor C as shown in FIG. 2 (+) on the elongated substrate 4I, the elongated substrate 4! If it is separated at the two-dot chain line position, the ceramic filter explained in FIG. 1 can be obtained.

In the above ceramic filter, the piezoelectric plate portion 31 of the substrate 31
a and the dielectric plate portion 31b, the piezoelectric material and the dielectric material are fused together at the mixed portion 32 by compression molding and firing of the molded body 37 shown in FIG. 2(d). This results in
The piezoelectric plate portion 3Ia and the dielectric plate portion 31b of the substrate 31 do not come apart, and the need for bonding with the adhesive described above is eliminated. Since the substrate 3J is entirely made of inorganic materials, the adhesion of the pattern 42 is strong, and the pattern 4
There is also no cutting of the conductive film that constitutes part of 2.

The present invention is not limited to the ceramic filter described in FIG. 1, but can generally be applied to composite components of piezoelectric resonators and capacitors.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment of a composite component according to the present invention. Figure 2 (a), Figure 2 (b), Figure 2 (C), Figure 2 (
d), FIG. 2(e), FIG. 2(r), FIG. 2(g), FIG. 2(h), and FIG. 2(+) are explanations of the manufacturing process of the composite part in FIG. 1, respectively. Figure 3 is a circuit diagram of a ceramic filter, which is an example of a conventional composite component, Figure 4 is a perspective view of another conventional ceramic filter, Figure 5 (a), Figure 5 (b), Figure 5 (C), Figure 5 (
d) and FIG. 5(e) are explanatory views of the manufacturing process of the ceramic filter shown in FIG. 4, respectively. 2.3... Multimode filter, 4... Input terminal, 5... Output terminal, 6... Earth terminal, 7.8... Electrode, 31... Board, 31a.
...Piezoelectric plate part, 31b...Dielectric plate part, 32...Mixing part, C...Buffer capacitor. 1st U! J Patent Applicant Murata Manufacturing Co., Ltd. Representative Patent Attorney Aohaku Ao and 1 person Figure 2 (c) As Figure 2 (i) Figure 3 Section 2 (d) Figure 4 Figure 5 (0) Figure 5 :, :(b) Do A1 ]-2- Figure 5(d) Figure 5(e)

Claims (1)

[Claims] (1) A single substrate is provided with a piezoelectric plate part made of a piezoelectric material on one side and a dielectric plate part made of a dielectric material on the other side with a mixed part of a piezoelectric material and a dielectric material in between, A composite component characterized in that the piezoelectric plate portion is formed with an electrode constituting a piezoelectric component, and the dielectric plate portion is formed with a capacitor electrode constituting a capacitor.