JP3139139B2 - Chip type piezoelectric resonator and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip-type piezoelectric resonator used as, for example, a chip-type filter or discriminator, and a method of manufacturing the same.

[0002]

2. Description of the Related Art FIG. 4 is an exploded perspective view showing an example of a conventional chip type piezoelectric resonator. This chip-type piezoelectric resonator is an example of a chip-type piezoelectric filter, and uses an energy-trapping dual-mode piezoelectric resonance element 2 using a thickness-shear vibration mode as a filter element.

In this piezoelectric resonance element 2, two divided vibrating electrodes 6, 7 are formed on one main surface of a strip-shaped piezoelectric substrate 4, and each vibrating electrode is formed on the other main surface as shown in FIG. 6,
The vibrating electrodes 8 and 9 are formed so as to be opposed to 7, respectively.
In addition, the vibration electrodes 6 to 9 are connected to the terminal electrodes 10 to 12, respectively.

Conventionally, such a piezoelectric resonance element 2
Are housed in a case 14 made of ceramics, both of which are composed of a lower case 16 and an upper lid 18 as follows, to produce a chip-type piezoelectric resonator.

That is, the lower case 16 includes the piezoelectric resonance element 2
Is formed, and the piezoelectric resonance element 2
Extraction electrodes 2 at positions corresponding to the respective terminal electrodes 10 to 12
Nos. 0 to 22 are formed by sputtering or the like. First, portions on the extraction electrodes 20 to 22 in the concave portions (E to E in the drawing)
A conductive adhesive (also referred to as a conductive paste; the same applies hereinafter) is applied to the portion indicated by G, and the piezoelectric resonance element 2 is inserted from above.

Next, a conductive adhesive is further applied to the terminal electrodes 10 and 11 on both sides of the piezoelectric resonance element 2 so that the connection between the terminal electrodes 10 and 11 and the extraction electrodes 20 and 21 is further ensured. To Thereafter, the conductive adhesive is cured by heating.

Next, in order to dampen unnecessary vibrations of the piezoelectric resonance element 2, the vibration electrodes 6, 7 of the piezoelectric resonance element 2 are provided.
Is applied with silicone rubber, and is cured by heating.

Next, each extraction electrode 20 of the lower case 16 is
The upper cover 18 in which the external electrodes 23 to 25 have been formed in advance at positions corresponding to
Put on and glue. Even so, each of the extraction electrodes 20 to 22 has its end exposed on the side surface of the case 14.

Thereafter, the side electrodes 26 to 22 are connected to the side surfaces of the case 14 so as to connect the exposed extraction electrodes 20 to 22 and the external electrodes 23 to 25 of the upper cover 18 respectively.
28 is provided by sputtering or the like. Further, usually, plating on the surface electrode is performed.

[0010] Through the above steps, a chip-type piezoelectric resonator can be obtained.

[0011]

However, in the above-described chip type piezoelectric resonator, the lower case 16 and the upper lid 18 are made of ceramics, and the lower case 16 has a concave portion, so that it is a molded product of ceramics. For this reason, the cost of the case 14 is high, the extraction electrodes 20 to 22 also have a complicated shape and must be formed by sputtering or vacuum deposition, so that the cost of electrode formation is high, and the number of manufacturing steps is large. There is a problem that it is very expensive.

Further, since the case 14 is used,
There is also a problem that the shape is large and heavy.

Further, damping of unnecessary vibration of the piezoelectric resonance element 2 is performed with silicone rubber. However, with silicone rubber, vibrations leaking to portions other than the vibrating electrode portion cannot be damped, so that ripples and large spurs appear in the characteristic waveform. There is also a problem that the characteristics are not good.

SUMMARY OF THE INVENTION Accordingly, it is a main object of the present invention to provide a chip-type piezoelectric resonator which is small and lightweight, has good characteristics, and is inexpensive, and a method of manufacturing the same.

[0015]

In order to achieve the above object, a chip-type piezoelectric resonator according to the present invention includes a piezoelectric resonator having a vibration electrode and a plurality of terminal electrodes connected to the vibration electrode. Are placed on an insulating substrate having an extraction electrode at a position corresponding to, and each terminal electrode of the piezoelectric resonance element and each extraction electrode of the insulation substrate are electrically conductively bonded by a conductive bonding material, respectively, and a vibration electrode portion of the piezoelectric resonance element. A chip-shaped part is formed by molding a rubber-like elastic body so as to cover the chip part with an electrically insulating exterior resin, and further on the surface of the chip part and at a position corresponding to each lead electrode of the internal insulating substrate. And a side electrode is provided on the side surface of the chip component so as to connect each external electrode on the surface and each extraction electrode of the internal insulating substrate. Characterized in that it a.

Further, according to the manufacturing method of the present invention, a plurality of piezoelectric resonance elements having a vibration electrode and a plurality of terminal electrodes connected to the vibration electrode and having the same structure are provided at positions corresponding to the respective terminal electrodes of the piezoelectric resonance element. Each terminal electrode of each piezoelectric resonance element is placed on an insulating substrate having an extraction electrode, and each terminal electrode of each piezoelectric resonance element is electrically conductively bonded to each extraction electrode of the insulating substrate by a conductive bonding material, and further covers the vibration electrode portion of each piezoelectric resonance element. A rubber-like elastic body is applied to the molded product, and the resulting product is molded with an electrically insulating exterior resin, and then externally placed on the surface of the molded product at a position corresponding to each lead electrode of the internal insulating substrate. Electrodes are applied, and the molded product is cut into a plurality of chip components by each piezoelectric resonance element. Characterized by the insulating substrate and each lead electrode impart side electrodes so as to connect respectively.

[0017]

The chip-type piezoelectric resonator has a structure in which a piezoelectric resonance element or the like is molded with an exterior resin without using a ceramic case as in the related art, so that it is small and light.

In addition, the above-mentioned structure is better than the case where a conventional ceramic case is used.
, The cost of forming the electrodes, and the cost of assembling are reduced, and thus the overall cost is very low.

Further, in the above structure, the exterior resin can be sufficiently adhered to a portion of the internal piezoelectric resonance element other than the vibration electrode portion provided with the rubber-like elastic body to sufficiently dampen, thereby suppressing unnecessary vibration. As a result, good characteristics with little ripple and sufficient suppression of spurious can be obtained.

Further, according to the above-described manufacturing method, a large number of chip-type piezoelectric resonators having the above-described excellent characteristics can be manufactured at a time with high efficiency. Down can be planned.

[0021]

FIG. 1 is a schematic perspective view showing an example of a chip-type piezoelectric resonator according to the present invention. The internal structure of this chip-type piezoelectric resonator will be described later with reference to FIGS. 2 and 3.
Is placed on an insulating substrate (for example, a ceramic substrate) 30 having extraction electrodes 32 to 34 at positions corresponding to the respective terminal electrodes 10 to 12, and the respective terminal electrodes 10 to 10 of the piezoelectric resonance element 2 are placed. 12 and the lead electrodes 32 to 34 of the insulating substrate 30 are conductively bonded by a conductive bonding material such as a conductive adhesive or solder, and silicone rubber or the like is formed so as to cover the vibrating electrodes 6 and 7 of the piezoelectric resonance element 2. The rubber-like elastic body is molded with an electrically insulating exterior resin 40 such as an epoxy resin to form a chip component. External electrodes 42 to 44 are provided at positions corresponding to the electrodes 32 to 34, and the lead electrodes 32 to 3 of the internal insulating substrate 30 are provided on the surface of the chip component.
4 and side electrodes 52 to 54 so as to connect the external electrodes 42 to 44 on the surface, respectively.

Next, an example of a method of manufacturing the above-described chip-type piezoelectric resonator will be described with reference to FIGS.

First, a plurality of piezoelectric resonance elements 2 having the same structure as each other having the vibrating electrodes 6 to 9 and the plurality of terminal electrodes 10 to 12 connected thereto, as described with reference to FIGS. 4 and 5, for example, are prepared. .

Further, as shown in FIG. 2A, the extraction electrodes 32 to 34 are elongated at positions corresponding to the terminal electrodes 10 to 12 of the piezoelectric resonance element 2, for example, by printing a conductive paste.
An insulating substrate (for example, a ceramic substrate) 30 formed by baking or the like is prepared.

Then, as shown in FIG. 2B, a plurality of piezoelectric resonance elements 2 are placed side by side on the insulating substrate 30. 2B and 2C, illustration of the piezoelectric resonance element 2 in the middle portion is omitted.

Each terminal electrode 1 of each piezoelectric resonance element 2
A conductive adhesive 36 is applied to portions 0 to 12 and baked and hardened, and the terminal electrodes 10 to 12 and the extraction electrodes 32 to 34 of the insulating substrate 30 are conductively bonded by the conductive adhesive 36, respectively. Note that the conductive adhesive 34 in the central terminal electrode 12 portion is actually applied on the extraction electrode 34 before the piezoelectric resonance element 2 is mounted. These may be connected by soldering with a solder paste.

Further, as shown in FIG. 2C, a rubber-like elastic body 38 such as silicone rubber is applied and cured so as to cover the vibrating electrodes 6 and 7 of each piezoelectric resonance element 2 respectively.

Then, the product made as described above is
As shown in FIG. 3A, for example, molding is performed with an electrically insulating exterior resin 40 such as an epoxy resin.

Thereafter, the external electrodes 42 to 44 are elongated at positions on the surface of the molded product corresponding to the respective extraction electrodes 32 to 34 of the insulating substrate 30 by, for example, printing or baking of a conductive paste. Form. In this example, the external electrodes 42 to 44 are formed only on one main surface of the molded product, but may be formed on the other main surface as needed. In addition, the external electrodes 42 to
The conductive paste used for 44 is, for example, 150 to 160
Baking and hardening can be performed at a temperature of about ° C, and after hardening, solderable. By doing so, heat at the time of baking of the external electrodes 42 to 44 does not adversely affect the exterior resin 40, and it is not particularly necessary to perform plating or the like.

Further, the molded product is cut into a plurality of chip parts by dividing the piezoelectric resonance element 2 into pieces. More specifically, the cutting is performed along the line 48 in FIG. 3A. If the left and right ends are inconvenient due to remaining roundness, the portion is drawn by a line 46.
May be cut and removed along. This is the case in this embodiment.

Through the above steps, a plurality of chip components as shown in FIG. 3B are obtained collectively. The extraction electrodes 32 to 34 on the internal insulating substrate 30 are exposed on the side surface, which is the cut surface of the chip component.

Further, as shown in FIG. 1, each of the extraction electrodes 32 to 34 of the internal insulating substrate 30 and each of the external electrodes 42 to 34 on the surface are provided on the cut surfaces (both cut surfaces in this example) of the chip components. 44 to connect the side electrodes 52 to 5 respectively.
4 is applied by, for example, printing or baking of a conductive paste.

Through the steps described above, a plurality of chip-type piezoelectric resonators as shown in FIG. 1 can be manufactured at once.

In the conventional chip type piezoelectric resonator using the ceramic case 14, the case 14 must have a certain thickness in terms of mechanical strength and the like, and the piezoelectric resonance element 2 However, the chip-type piezoelectric resonator of the present invention does not use a ceramic case, but uses the exterior resin 40 to provide a piezoelectric resonator. It has a structure in which the element 2 and the insulating substrate 30 are molded, and the thickness of the exterior resin 40 does not need to be so large. Further, since the exterior resin 40 is much lighter than the case made of ceramics, the weight is also reduced.

The conventional case 14, especially the lower case 16, is expensive because it is a molded product of ceramics. However, the exterior resin 40 is inexpensive and easy to process. Also, regarding the formation of the internal extraction electrode,
In the conventional example, the lower case 16 had a complicated shape, so that it was necessary to use sputtering or vacuum deposition. However, in the present invention, since the lower case 16 can be formed on the flat insulating substrate 30 by printing or the like, the cost of electrode formation is reduced. Therefore, a significant cost reduction can be achieved even as a whole of the chip-type piezoelectric resonator.

In the chip-type piezoelectric resonator of the present invention, since the internal piezoelectric resonance element 2 can be damped by the exterior resin 40, that is, the vibration electrode having the rubber-like elastic body 38 of the piezoelectric resonance element 2 is provided. Since the exterior resin 40 is in close contact with portions other than the portion and can be sufficiently damped, vibrations leaking to portions other than the vibrating electrode portion can be prevented.
0 provides sufficient damping, whereby unnecessary vibration of the piezoelectric resonance element 2 is suppressed, and good characteristics with little ripple and sufficient suppression of spurious can be obtained.

Further, according to the above-described manufacturing method, a large number of chip-type piezoelectric resonators having the above-described excellent characteristics can be manufactured at a time with high efficiency. Further cost reduction can be achieved.

It should be noted that the piezoelectric resonance element housed inside may have a structure other than the piezoelectric resonance element 2 described above.

As the above-mentioned exterior resin 40, a thermosetting resin liquidized with a solvent, which is widely used as a dipping resin for electronic parts, is preferable. Such a material has a sufficient adhesive force to the piezoelectric resonance element 2, and also reduces stress to the piezoelectric resonance element 2 by appropriately kneading a resin component with a stress relaxation agent, for example, a filler such as silica or talc. And designed to be problem-free. Furthermore,
The resin component is an epoxy resin, which has high heat resistance, and the coefficient of thermal expansion is kept low depending on the quality and quantity of each material constituting the resin.

[0040]

As described above, this chip-type piezoelectric resonator has a structure in which a piezoelectric resonance element or the like is molded with an exterior resin without using a ceramic case as in the prior art. Becomes

Further, as compared with the case where a conventional ceramic case is used, the cost of the exterior material, the cost of forming the electrodes and the cost of assembling are reduced, so that the cost as a whole is very low.

Further, since the internal piezoelectric resonance element can be sufficiently damped not only with the rubber-like elastic body but also with the exterior resin, unnecessary vibration is suppressed, ripples are reduced, and spurious is suppressed. Sufficient and good properties can be obtained.

Further, according to the manufacturing method of the present invention, a large number of chip-type piezoelectric resonators having the above-mentioned excellent characteristics can be manufactured at a time with high efficiency. Cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an example of a chip-type piezoelectric resonator according to the present invention.

FIG. 2 is a diagram showing steps of a manufacturing method according to the present invention.

FIG. 3 is a view showing a step of a manufacturing method according to the present invention, which is a continuation of FIG. 2;

FIG. 4 is an exploded perspective view showing an example of a conventional chip-type piezoelectric resonator.

FIG. 5 is a rear view of the piezoelectric resonance element in FIG. 4;

[Explanation of symbols]

 Reference Signs List 2 piezoelectric resonance element 4 piezoelectric substrate 6-9 vibrating electrode 10-12 terminal electrode 30 insulating substrate 32-34 extraction electrode 36 conductive adhesive 38 rubbery elastic body 40 exterior resin 42-44 external electrode 52-54 side electrode

Continuation of the front page (56) References JP-A-4-77011 (JP, A) JP-A-63-104508 (JP, A) JP-A-4-91510 (JP, A) JP-A-1-228310 (JP) , A) Japanese Utility Model 4-43018 (JP, U) Japanese Utility Model 4-34013 (JP, U) Japanese Utility Model 3-120119 (JP, U) Japanese Utility Model 2-5923 (JP, U) Japanese Utility Model Akira Japanese Utility Model 62-141213 (JP, U) Japanese Utility Model Showa 62-26924 (JP, U) Japanese Utility Model Application 2-134734 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H03H 9/00 -9/215 H03H 9/54-9/60 H03H 3/00-3/04

Claims (2)

(57) [Claims] A piezoelectric resonance element having a vibration electrode and a plurality of terminal electrodes connected thereto is placed on an insulating substrate having a lead electrode at a position corresponding to each terminal electrode of the piezoelectric resonance element. A terminal electrode and each lead electrode of the insulating substrate are conductively bonded by a conductive bonding material, respectively, and a rubber-like elastic body is provided so as to cover a vibrating electrode portion of the piezoelectric resonance element. An external electrode is provided at a position corresponding to each extraction electrode of the internal insulating substrate on the surface of the chip component, and each external electrode on the surface is provided on a side surface of the chip component. A chip-type piezoelectric resonator having a structure in which side electrodes are provided so as to connect to respective extraction electrodes of an internal insulating substrate. 2. An insulating substrate having a plurality of piezoelectric resonance elements each having a vibration electrode and a plurality of terminal electrodes connected to the vibration electrode and having the same structure and having a lead electrode at a position corresponding to each terminal electrode of the piezoelectric resonance element. And each terminal electrode of each piezoelectric resonance element and each lead electrode of this insulating substrate are conductively bonded by a conductive bonding material, and a rubber-like elastic body is provided so as to cover the vibration electrode portion of each piezoelectric resonance element. Then, the resulting product is molded with an electrically insulating exterior resin, and then external electrodes are provided on the surface of the molded product at positions corresponding to the respective extraction electrodes of the internal insulating substrate. The molded product is cut into a plurality of chip components for each piezoelectric resonance element. Characterized in that side electrodes are provided so as to connect the piezoelectric resonators to each other.