JPH08237066A - Piezoelectric resonator and its manufacture - Google Patents

Abstract

PURPOSE: To attain a piezoelectric resonator and a manufacturing method in which high connection reliability is realized for electrodes on the front and rear sides. CONSTITUTION: On the front and rear sides of a piezoelectric ceramic substrate 10, 1st and 2nd electrodes 11, 12 opposed to each other are formed, 3rd and 4th electrodes 13, 14 are formed to both end faces of the substrate and 1st and 2nd protection films 15, 16 are formed to cover the 3rd and 4th electrodes. An extension 11a of the 1st electrode 11 and a 5th electrode 17 are formed to the front and rear side of one end of the substrate to be in continuity with the 3rd electrode 13 and an extension 12a of the 2nd electrode 12 and a 6th electrode 18 are formed to the front and rear side of the other end of the stbstrate to be in continuity with the 4th electrode 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric resonator and a manufacturing method thereof, and more particularly to a structure and a manufacturing method for ensuring electrical continuity of electrodes on front and back sides formed at end portions of the resonator.

[0002]

2. Description of the Related Art Conventionally, as a thickness-shear vibration mode piezoelectric resonator, as shown in FIG. 1, a first electrode 2 is formed on a front main surface of a strip-shaped piezoelectric substrate 1 from one end side to a central part, and It is known that the second electrode 3 is formed on the main surface from the other end side to the central portion. The electrodes 2 and 3 face each other at the central portion of the piezoelectric substrate 1 and generate thickness shear vibration.
When connecting this type of piezoelectric resonator to another electronic component, circuit board, or the like, the first and second electrodes 2 and 3 are formed only on one surface of each end of the piezoelectric substrate 1, and It was necessary to apply a large amount of a conductive adhesive to the end portions and to raise the conductive adhesive agent to ensure conduction between the two. Therefore, the connection reliability was low.

[0003]

Therefore, in order to increase the conduction area between the electrodes 2 and 3 and the outside, as shown in FIG. 2, the main surface side facing the electrodes 2 and 3 with the end face of the piezoelectric substrate 1 facing the side. Providing extensions 2a, 3a extending up to
However, in this case, the corner portion 1 of the piezoelectric substrate 1
The thickness of the electrodes 2 and 3 at a is very thin, and edge peeling easily occurs, and the electrodes 2 and 3 and the extension portions 2a and 3 are likely to occur.
The conduction reliability with a is low.

Therefore, an object of the present invention is to provide a piezoelectric resonator in which the connection reliability of the electrodes on the front and back surfaces is high. Another object of the present invention is to provide a manufacturing method which can inexpensively manufacture a piezoelectric resonator having high connection reliability of electrodes on the front and back surfaces.

[0005]

In order to achieve the above object, a piezoelectric resonator of the present invention is a piezoelectric resonator in which first and second electrodes facing each other are formed on the front and back surfaces of a piezoelectric ceramic substrate. The third and fourth electrodes are formed on the end surfaces of both ends of the piezoelectric ceramic substrate, respectively, and the first and second protective films that cover the outer surfaces of the third and fourth electrodes are formed. Has an extension part that is electrically connected to the third electrode
Of the second electrode, and the second electrode is formed with an extended portion which is electrically connected to the fourth electrode up to the second protective film. In the above piezoelectric resonator, a fifth electrode that is electrically connected to the third electrode is formed on the back surface of one end of the piezoelectric ceramic substrate up to the first protective film, and a fourth electrode is formed on the surface of the other end of the piezoelectric ceramic substrate. The conductive sixth electrode may be formed over the second protective film.

Further, the manufacturing method of the present invention comprises the steps of forming third and fourth electrodes on the front and back surfaces of the piezoelectric ceramic block, and applying a voltage between the third and fourth electrodes to form the piezoelectric ceramic block. A step of performing polarization treatment in the thickness direction, a step of forming first and second protective films for covering the third and fourth electrodes on the front and back surfaces of the piezoelectric ceramic block, and piezoelectric processing for which polarization treatment and protective film formation have been completed. A step of cutting the ceramic block in the thickness direction to obtain a thin plate-shaped mother substrate, and a step of forming a first electrode on the front main surface of the mother substrate so that one end of the first electrode is electrically connected to the third electrode The step of forming up to the protective film and the second main electrode on the back main surface of the mother substrate are arranged so that one end of the second electrode faces the first electrode and the other end conducts with the fourth electrode. The process of forming up to the protective film and cutting the mother substrate into one element width And that step, is intended to include. In the above manufacturing method, a step of forming a sixth electrode on the front main surface of the mother substrate up to the second protective film so as to be electrically connected to the fourth electrode, and a fifth electrode on the back main surface of the mother substrate. A step of forming up to the first protective film so as to be electrically connected to the third electrode may be added.

As the material of the protective film, as long as it has a function of protecting the third and fourth electrodes, it may be an insulating material such as resin or ceramics, or a conductive material such as a conductive adhesive or a metal material. But it's okay. The protective film may be a thin film formed by sputtering or the like, or may be a thick film formed by printing or the like. Furthermore, the step of forming the protective film may be either before or after the polarization treatment.
The piezoelectric resonator of the present invention is used not only as a piezoelectric resonator alone, but also as a surface-mount type composite electronic component mounted on an insulating substrate and sealed with a cap, or as a composite electronic component containing a capacitor. Can be used as

[0008]

According to the piezoelectric resonator of the first aspect, the third electrode formed on one end surface of the piezoelectric ceramic substrate is connected to the first electrode extending to above the protective film, and the third electrode is formed on the other end surface. The formed fourth electrode is connected to the second electrode extending to above the protective film. Moreover, these connections are connected in a so-called T-shape, rather than being conducted in an L-shape through the corners of the piezoelectric substrate. Therefore, there is no thinning of the electrode film at the corners or peeling of edges, and the connection reliability of the electrodes on the front and back surfaces is high. Further, according to the piezoelectric resonator of the second aspect, by adding the fifth and sixth electrodes,
The third and fifth electrodes and the second, fourth, and sixth electrodes become H-shaped, so to speak, and the connection reliability is further improved.

According to the manufacturing method of the third aspect, a protective film is formed on the third and fourth electrodes for polarization,
Cut the piezoceramic block into a mother board. After cutting into a mother substrate, lapping is performed in order to adjust the thickness, but edge peeling of the third and fourth electrodes and chipping of the edges are likely to occur during cutting or lapping. However, since the third and fourth electrodes are covered with the protective film, peeling or chipping is prevented. A first electrode and a second electrode are formed on the front and back surfaces of the mother substrate so as to intersect the third and fourth electrodes. At this time, the third electrode and the first electrode are electrically connected in a T shape, and the fourth electrode and the second electrode are also electrically connected in a T shape, so that the conduction reliability is high. In this way, the polarization electrode can also be used as a connection electrode for connecting the electrodes on the front and back surfaces of the piezoelectric substrate, so that the processing steps for electrode formation can be reduced. Furthermore, according to the manufacturing method of the fourth aspect, the piezoelectric resonator of the second aspect can be easily manufactured.

[0010]

EXAMPLE FIG. 3 shows an example of a piezoelectric resonator A according to the present invention. In the figure, 10 is a strip-shaped piezoelectric ceramic substrate made of a piezoelectric ceramic material such as Pb (Ti, Zr) O ₃ , and the first electrode 11 and the second electrode 12 are located in the central portion on the front and back main surfaces. It is formed so as to face each other. The first electrode 11 extends to one end of the piezoelectric substrate 10, and the second electrode 12 extends to the other end of the piezoelectric substrate 10. The third electrodes 13 are formed on the end faces of both ends of the piezoelectric substrate 10.
And a fourth electrode 14 are formed, and these electrodes 13,
Each of 14 is covered with a first protective film 15 and a second protective film 16.

The third and fourth electrodes 13 and 14 are, for example, 3 μm
It is preferable to form the metal film layer having the following thickness, and to form the protective films 15 and 16 with a thicker material, for example, a material having a viscosity of about 3 to 60 μm and having no viscosity. The reason why the third and fourth electrodes 13 and 14 are made thin is to prevent the curling due to the viscosity of the metal. The material of the protective films 15 and 16 may be either insulating or conductive, and for example, a resin adhesive, a conductive adhesive, ceramic or the like can be used. Use of a conductive adhesive further improves the conduction reliability.
When ceramic is used, it is necessary to select one that does not react with the third and fourth electrodes 13 and 14 during formation.

As shown in FIG. 4, the extended portion 11 a of the first electrode 11 extended to one end of the piezoelectric substrate 10 has a first protective film 15 formed thereon.
And extends to the upper side, and intersects with the side edge of the third electrode 13 exposed on the surface side of the piezoelectric substrate 10 in a T-shape to establish electrical connection.
Similarly, the second electrode 1 extended to the other end of the piezoelectric substrate 10.
The second extended portion 12 a extends to above the second protective film 16 and is electrically connected to the side edge of the fourth electrode 14 exposed on the back surface side of the piezoelectric substrate 10 in a T-shape. Furthermore, a fifth electrode 17 extending to above the first protective film 15 is formed on the back main surface of one end of the piezoelectric substrate 10, and a second protective film 16 is formed on the front main surface of the other end of the piezoelectric substrate 10. A sixth electrode 18 extending to the top is formed. The fifth electrode 17 and the third electrode 13 intersect with each other in a T shape and are electrically connected, and the sixth electrode 18 and the fourth electrode 1
4 also intersects in a T shape and is conductive. Therefore, the first
The electrode 11 is electrically connected to the fifth electrode 17 via the third electrode 13, and the second electrode 12 is connected to the sixth electrode 18 via the fourth electrode 14.
It is conducting.

As described above, the first electrode 11 and the third electrode 1
Since the third and fifth electrodes 17 are connected in a T shape, unlike the conventional connection by the corner portion, there is no edge peeling or thinning of the film thickness, and reliable connection reliability can be secured. Similarly, since the second electrode 12, the fourth electrode 14, and the sixth electrode 18 are also connected in a T shape, the conduction reliability is high. And
At both ends of the surface of the piezoelectric substrate 10, the first terminal 11 and the sixth terminal 11 are provided.
The electrode 18 is formed, and the second electrode 12 is formed on both ends of the back surface.
Since the fifth electrode 17 is formed, even if either the front surface or the back surface of the piezoelectric resonator A is bonded to the external conductive portion, the piezoelectric resonator A can be reliably connected to the outside.

Next, an example of a method of manufacturing the piezoelectric resonator A will be described with reference to FIGS. FIG. 5 shows the piezoelectric ceramic block 20. The block 20 is a thick plate made of a piezoelectric ceramic material, and third and fourth electrodes 13 and 14 for polarization are formed on the entire surface by a known method such as printing, sputtering, vapor deposition, and thermal spraying on the front and back surfaces. ing. A DC voltage 21 is applied to the third and fourth electrodes 13 and 14, and the block 20 is polarized in the thickness direction.

As shown in FIG. 6, protective films 15 and 16 for covering the third and fourth electrodes 13 and 14 are formed on the front and back surfaces of the block 20 after polarization or before polarization by a method such as printing or sputtering. In this embodiment, the insulating resin is the third
By printing on the fourth electrodes 13 and 14, thick protective films 15 and 16 were formed. After that, the block 20 is cut at a constant width in the thickness direction along a cut line CL ₁ shown by a chain line in FIG. 6A, and the mother substrate 2 as shown in FIG.
2 was obtained.

After cutting, the mother substrate 22 is lapped so that its thickness t becomes a predetermined value. At this time, since the front and back surfaces of the mother substrate 22 slide with the lapping device, the edge portions of the third and fourth electrodes 13 and 14 are easily peeled off,
Since the electrodes 13 and 14 are covered with the protective films 15 and 16, edge peeling is prevented.

As shown in FIG. 8, the mother substrate 22 adjusted to have a constant thickness t has the first and second electrodes 11,
The 12th and fifth and sixth electrodes 17 and 18 are formed by a known method such as printing, sputtering, vapor deposition, or thermal spraying. As a result, the first electrode 11 and the fifth electrode 17 become the third electrode 13
The second electrode 12 and the sixth electrode 18 are electrically connected via the
It conducts through the electrode 14. The first and sixth electrodes 11 and 18 on the front side can be formed simultaneously, and the second and fifth electrodes on the back side can be formed.
The electrodes 12 and 17 can be formed at the same time. After that, the mother substrate 22 is cut element by element along the cut line CL ₂ in FIG. 8 to obtain the piezoelectric resonator A as shown in FIG. As described above, since the third and fourth electrodes 13 and 14 which are polarization electrodes also serve as connection electrodes, it is possible to reduce the number of electrode forming steps and the material cost. In particular, the third and fourth electrodes 1
Since 3 and 14 are covered with the protective films 15 and 16,
There is no peeling during cutting or lapping, and high conduction reliability can be secured.

FIG. 9 shows another example of the piezoelectric resonator according to the present invention. The piezoelectric resonator B is the same as the piezoelectric resonator A in FIG. 3 except that the electrode patterns of the first electrode 11 and the second electrode 12 are changed. The electrodes 11 and 12 are composed of the vibrating electrodes 11b and 12b facing the central portion of the substrate 10 and the substrate 10
It is composed of terminal electrodes 11c and 12c formed at the end portions of, and thin lead electrodes 11d and 12d connecting both electrodes.

FIG. 10 shows an example in which the piezoelectric resonator A of the present invention is applied to a surface mount type oscillator. This oscillator is a substrate 3
0, the oscillator element A, and the cap 34. The substrate 30 is a thin plate of alumina ceramics sheet-formed or tablet-formed and has a thickness of 0.3 to 0.7 mm. In this embodiment, a thin plate having a thickness of 0.5 mm was used.
Two attachment electrodes 31 and 32 are formed on the front and back surfaces of the substrate 30. The ends of the electrodes 31 and 32 are drawn to the concave through-hole portions 30a formed on both side edges of the substrate 30, and the attachment electrodes 31 on the front and back sides are inserted through the electrodes formed on the inner surface of the through-hole portion 30a. 32 is conducting. The oscillator element A is adhered and fixed on the electrodes 31 and 32 by a material 33 having a conductive and adhesive function, such as a conductive adhesive or solder, and depending on the thickness of the material 33, the resonator element A is bonded to the substrate 30. A certain vibration space is secured in.

The cap 34 is adhered onto the substrate 30 with an adhesive 35 so as to cover the oscillator element A. Although the cap 34 is formed by deep drawing a metal plate in a U-shaped vertical cross section, coining or die casting may be used. As the material of the cap 30, nickel white (Ni / Cu alloy) having a thickness of 0.15 mm was used in terms of moldability and strength, but other materials may be used. As the adhesive 35,
Epoxy-based, epoxy-acrylate-based, and silicone-based adhesives are conceivable from the viewpoint of heat resistance and chemical resistance, but epoxy-based adhesives are preferable from the viewpoint of adhesiveness with the metal cap 34 and cost. Although the oscillator element A made of a piezoelectric ceramic material has a property of depolarizing at a high temperature, since the epoxy-based adhesive is usually cured at 200 ° C. or lower, there is no fear of depolarizing the oscillator element A.

The oscillator element A is attached to the mounting electrode 3 of the substrate 30.
In order to connect with the electrodes 1 and 32, a conductive adhesive 33 is applied to a certain thickness by means of printing or the like, and the oscillator element A is adhered thereon, so that the electrodes 11, 12 of the element A and the mounting electrodes 31, 32
And can be surely conducted. When the conventional oscillator element (see FIG. 1) is connected to the mounting electrodes 31 and 32 of the substrate 30, the electrodes 2 and 3 are formed on only one side of the element, so that the conductive adhesive is applied to the element. It was necessary to inject it into the end portion with a dispenser or the like and cover it with a conductive adhesive from the top of the element to the end surface. Therefore, the tact time for injecting the conductive adhesive becomes long, and the damping state of the resonator element changes depending on how the conductive adhesive is attached, resulting in unstable characteristics. Further, since the conductive adhesive is injected, the coating variation becomes large, so that it is necessary to increase the size of the cap 34 in advance with a margin. On the other hand, when the resonator element A of the present invention is used, it is not necessary to cover the end portion of the element A with the conductive adhesive, so that the above-mentioned drawbacks can be solved.

FIG. 11 shows an example of a composite electronic component to which the piezoelectric resonator A according to the present invention is applied. This electronic component is a surface-mounted oscillator with a built-in load capacitance that is used in a Colpitts oscillator circuit, and includes one oscillator element A and two capacitors C ₁ and C ₂ . FIG. 12 shows the electric circuit.

The substrate 40 is made of alumina ceramics, a first capacitance electrode 41 is formed at the center of the upper surface of the substrate 40, and two mounting electrodes 42 and 43 are formed at both ends of the upper surface. Terminal portions 41a to 43 of the electrodes 41 to 43
The a is drawn to the concave through-hole portions 40a formed on both side edge portions of the substrate 40, and is electrically connected to the electrodes formed on the inner surface of the through-hole portion 40a. Although not shown in FIG. 11, the electrodes 41 to 4 are also formed on the lower surface of the substrate 40.
The strip-shaped electrode that is electrically connected to 3 is formed in the shape of a headband.

A dielectric layer 45 is formed on the first capacitance electrode 41 of the substrate 40 and on the portion corresponding to the cap bonding portion.
Are formed with a constant thickness. Examples of the material of the dielectric layer 45 include resin-based and glass-based pastes,
In this example, a glass-based paste was used in consideration of insulation, moisture resistance, and the like. The method of forming the dielectric layer 45 includes printing, transfer, dispensing, etc., but it is preferable to use a pattern printing method capable of accurately controlling the layer thickness. Although the thickness of the dielectric layer 45 varies depending on the target load capacitance value, the unevenness due to the electrodes 41 to 43 is mitigated, and sufficient insulation between the cap 55 and the electrodes 41 to 43 described later is secured. Like, for example, 20-
It was set to about 100 μm. After printing, a drying process was performed, and a baking process was further performed at 700 to 850 ° C./10 minutes.

In the dielectric layer 45 of this embodiment, a capacitance portion 45a covering the first capacitance electrode 41 and a frame-shaped adhesive portion 45b corresponding to the cap adhesive portion are continuously formed, and mounting electrodes are provided near both ends. Two window holes 45c exposing a part of 42, 43
Although the capacitor portion 45a and the adhesive portion 45b are formed,
It may be a separated version. In this case, the amount of dielectric paste used can be saved.

Two second capacitance electrodes 46 and 47 are formed on the dielectric layer 45 by a known method such as sputtering, vapor deposition, printing or thermal spraying. These capacitance electrodes 46, 4
7, the main part of the capacitor 7 faces the first capacitance electrode 41 with the capacitance part 45a in between, and a part of the attachment electrode 42,
43 and the window hole 45c are electrically connected.

On the second capacitance electrodes 46 and 47, a material 4 having both conductive and adhesive functions such as a conductive adhesive is used.
The oscillator element A is adhesively fixed by 8. The adhesive material 48 is applied to the second capacitance electrodes 46 and 47 by printing or the like to a constant thickness, and both ends of the oscillator element A are adhered on the second capacitance electrodes 46 and 47 so that the vibrating portion of the oscillator element A and the second capacitance are formed. A constant vibration space is secured between the electrodes 46 and 47 by the thickness of the conductive adhesive 48. Also in this embodiment, since the electrode 17 and the electrode 12 which are electrically connected to the electrode 11 are formed on the lower surface side of the oscillator element A, the electrodes 11 and 12 of the oscillator element A are respectively bonded by the second capacitance electrode by adhesion. Four
6 and 47 are electrically connected.

The cap 55 is adhered to the substrate 40 by an adhesive 56 so as to cover the oscillator element A. As the material of the cap 55, nickel silver (Ni / Cu alloy), 42
A metal material such as Ni—Fe alloy, aluminum alloy, or aluminum is used. An epoxy-based adhesive was used as the adhesive 56, which was transferred and applied to the bottom surface of the opening of the cap 55, and then adhered and cured on the adhesive 45b of the dielectric layer 45.

FIG. 13 shows another example of a composite electronic component to which the piezoelectric resonator A according to the present invention is applied. Similar to the embodiment of FIG. 11, this embodiment is also a surface-mounted oscillator with a built-in load capacitance used in a Colpitts oscillator circuit.
The electric circuit is similar to that shown in FIG. In this embodiment, instead of the paste-like dielectric layer 45, a separate capacitor element 80 is used.

The substrate 60 is made of alumina ceramics, and three attachment electrodes 61 to 63 are formed on the front and back surfaces of the central portion and both ends of the substrate 60. The electrodes 61 to 63
Of the mounting electrodes 61 to 63 on the front and back sides through the electrodes formed on the inner surfaces of the through-hole portions 61a to 63a, which are recessed to the through-hole portions 61a to 63a formed on both side edges of the substrate 60. Are in conduction with each other. On the upper surface of the substrate 60 and above the electrodes 61 to 63, a frame-shaped insulator layer 64 corresponding to a cap bonding portion is formed with a constant thickness. As a material of the insulator layer 64, a resin base, a glass base, or the like is used, and a known method such as printing, transfer, or dispensing may be used as a method of forming the material.

On the substrate 60, a material in which the oscillator element A and the capacitor element 80 are laminated and integrated by means of materials 65 to 67 having both conductive and adhesive functions such as a conductive adhesive is fixed by adhesion. Has been done.

As shown in FIG. 14, the capacitor element 80 includes two individual capacitors extending from both ends toward the center on the surface of a dielectric substrate (for example, a ceramic substrate) 81 having the same length and width as the oscillator element A. The electrodes 82 and 83 are formed, and one counter electrode 84 that faces the individual electrodes 82 and 83 is formed in the center of the back surface. Two electrodes are provided at the facing portions of the individual electrodes 82 and 83 and the counter electrode 84. Capacitance parts are formed.

As in the case of the oscillator element A, the end face electrodes 85 and 86 and the protective film 8 are provided on both ends of the capacitor element 80.
7a, 87b and back electrodes 88, 89 are formed. That is, end face electrodes 85 and 86 that are electrically connected to the individual electrodes 82 and 83, respectively, are formed on both end faces of the capacitor element 80, and these end face electrodes 85 and 86 are protective films 87a and 87.
It is covered with b. The material of the protective films 87a and 87b is the same as that of the oscillator element A. On the back surfaces of both ends of the capacitor element 80, the back surface electrodes 8 that are electrically connected to the end surface electrodes 85 and 86 are provided.
8, 89 are formed up to the protective films 87a, 87b. As a result, the connection reliability of the electrodes on the front and back of the capacitor element 80 is improved.

The back surface of the oscillator element A and the capacitor element 80
The surface of the is adhered and fixed at both ends by materials 90 and 91 having a conductive and adhesive function such as a conductive adhesive. That is, the lower electrode 1 of the oscillator element A
7, 12a are upper electrodes 82, 8 of the capacitor element 80.
3 is electrically connected. At this time, a predetermined vibration space is formed between the vibrating portion of the oscillator element A and the capacitor element 80 due to the thickness of the materials 90 and 91. Damping materials 92, 93 made of resin or the like for frequency adjustment are applied to both ends of the surface of the oscillator element A.

The resonator element A and the capacitor element 80, which are laminated and integrated as described above, are adhered on the substrate 60 with the conductive materials 65 to 67, and the individual electrode 8 of the capacitor element 80 is bonded.
2, 83 are connected to the attachment electrodes 61, 63, and the counter electrode 84 is connected to the attachment electrode 62, respectively. At this time, the capacitor element 8
Since the back surface electrodes 88 and 89 that are electrically connected to the individual electrodes 82 and 83 are formed on the back surfaces of both ends of 0, the individual electrodes 82 and 83 and the mounting electrodes 61 and 81 are formed by the conductive materials 65 and 67 applied in a film shape. 63 can be surely connected.
When the oscillator element A and the capacitor element 80 are integrated, for example, after the mother substrate of the oscillator element A (see FIG. 8) and the mother substrate of the capacitor element 80 are bonded by the materials 90 and 91, one element It can be easily manufactured by cutting it into width.

After the oscillator element A and the capacitor element 80 are integrally bonded, the back surface side of the capacitor element 80 is made of the material 6
When bonded to the substrate 60 by 5 to 67, the end portion 82a of one individual electrode 82 of the capacitor element 80 becomes the electrode 61.
The end portion 83 a of the other individual electrode 83 is connected to the electrode 63, and the common electrode 84 is connected to the electrode 62.

The cap 100 has an adhesive 10 on the substrate 60 so as to cover the oscillator element A and the capacitor element 80.
Glued by 1. As the material of the cap 100, the same material as that of the embodiment of FIG. 11 was used. Adhesive 10
1 also uses the same material as that of the embodiment of FIG.
00 is applied to the bottom surface of the opening by transfer, and then the insulating layer 6
4 was glued on and cured.

FIG. 15 shows an example of a composite electronic component with lead terminals using the piezoelectric resonator A according to the present invention, and this embodiment also has a circuit structure similar to that of FIG. In the figure, 1
Reference numeral 10 is a capacitor element, and 120 to 122 are hoop-shaped lead terminals. In the capacitor element 110, two individual electrodes 112 and 113 are formed at both ends of one main surface of a dielectric substrate 111 such as ceramics, and a counter electrode 114 facing the individual electrodes 112 and 113 at the center of the other main surface. Are formed.

Of the lead terminals 120 to 122,
Holding portions 120a and 121a having a U-shaped cross section into which both ends of the piezoelectric resonator A are inserted are formed at the tips of the two lead terminals 120 and 121 on both sides, and one holding portion 120a is formed.
The second electrode 12 of the piezoelectric resonator is attached to the other holding portion 121.
The first electrodes 11 are soldered to a. In addition, the capacitor element 110 is formed on the outer surfaces of the holding portions 120a and 121a.
Both end portions of the individual electrodes 112 are soldered to each other,
113 is connected to the holding portions 120a and 121a, respectively.
An intermediate lead terminal 122 is soldered to the counter electrode 114 of the capacitor element 110.

The piezoelectric resonator A and the capacitor element 110
Further, the tip portions of the lead terminals 120 to 122 are made of resin 13
0 is dip coated. Also in this embodiment, since the fifth and sixth electrodes 17 and 18 are formed on the front and back surfaces of both ends of the piezoelectric resonator A, the holding portion 120a,
The conduction reliability with 121a is very high.

FIG. 16 shows another example of the composite electronic component using the piezoelectric resonator A according to the present invention, and this embodiment is also shown in FIG.
It has the same circuit structure as. In the figure, 140 is a capacitor element, and 150 to 152 are round bar-shaped lead terminals.

The capacitor element 140 has the same structure as the capacitor element 110 shown in FIG. 15, and has two individual electrodes 142, 1 at both ends of one main surface of the dielectric substrate 141.
43 is formed, and the individual electrodes 142, 1 are formed at the center of the other main surface.
A counter electrode 144 that faces 43 is formed. The capacitor element 140 is longer than the piezoelectric resonator A, and the piezoelectric resonator A is bonded to the central portion of the side surface of the capacitor element 140 on the individual electrode side with a conductive adhesive (not shown). Therefore, the second electrode 12 of the piezoelectric resonator A is separated from the individual electrode 143.
In addition, the fifth electrodes 17 are connected to the individual electrodes 142, respectively.

The tip portions of the three lead terminals 150 to 152 are crushed to be flat, and the tip portions of the two lead terminals 150 and 151 on both sides form the both ends of the piezoelectric resonator A and the capacitor element 140. It is arranged in a concave step part composed of
It is soldered. At this time, one solder covers the lead terminal 150, the first electrode 11 of the piezoelectric resonator A, and the individual electrode 142 of the capacitor element 140, so that the three can be reliably connected. Also, the other solder is used for the lead terminal 151.
And the sixth electrode 18 of the piezoelectric resonator A and the capacitor element 140
Since it covers the individual electrodes 143, the three parties can be reliably connected. In addition, the counter electrode 14 of the capacitor element 140
An intermediate lead terminal 152 is connected to 4 by soldering. The tips of the piezoelectric resonator A, the capacitor element 140, and the lead terminals 150 to 152 are dip-coated with resin 160.

Also in this embodiment, since the fifth and sixth electrodes 17 and 18 are formed on the front and back surfaces of both ends of the piezoelectric resonator A, the capacitor element 140 and the lead terminal 15 are formed.
The connection reliability with 0, 151 is very high. In this embodiment, a round lead can be used as the lead terminal, and since it is not necessary to form a cup-shaped holding portion at the tip of the lead terminal, it can be formed at a lower cost than the embodiment of FIG. Further, since the leading end portions of the lead terminals on both sides are arranged in the concave step portion formed by both ends of the piezoelectric resonator A and the capacitor element, the lead terminal and the piezoelectric resonator A can be arranged on the same plane. Thus, it is possible to obtain a thin composite electronic component as a whole.

The present invention is not limited to the above embodiment, but can be applied to any type such as a chip type piezoelectric resonator used by being enclosed in a cylindrical case. Further, the present invention is not limited to the thickness-shear vibration mode piezoelectric resonator, but can be applied to the thickness-longitudinal vibration mode piezoelectric resonator. Therefore, the electrode pattern is not limited to that shown in FIGS.

[0046]

As is apparent from the above description, claim 1
According to the invention described in (1), the first electrode formed on the surface of one end of the piezoelectric substrate is connected to the back surface side by the third electrode covered with the protective film, and the second electrode formed on the back surface of the other end. Is connected to the surface side by a fourth electrode covered with a protective film, and these connections are so-called T-shaped connections, so there is no thinning or edge peeling of the electrode film at the corners. The connection reliability of the electrodes on the front and back surfaces is high. In particular, when the fifth electrode that is electrically connected to the third electrode is formed on the back surface of one end of the piezoelectric substrate and the sixth electrode that is electrically connected to the fourth electrode is formed on the surface of the other end, the electrodes on the front and back sides are called H It is connected in a letter shape, and the connection reliability is further improved. Further, according to the manufacturing method of the present invention, since the polarization electrodes can be used as the third and fourth electrodes, it is not necessary to form the connection electrodes particularly,
A piezoelectric resonator with high connection reliability of electrodes on the front and back surfaces can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an example of a conventional piezoelectric resonator.

FIG. 2 is a perspective view of another example of a conventional piezoelectric resonator.

FIG. 3 is a perspective view of an example of a piezoelectric resonator according to the present invention.

4 is a partially enlarged sectional view of the piezoelectric resonator shown in FIG.

FIG. 5 is a perspective view of a piezoelectric block during polarization processing.

6A and 6B are a perspective view and a partial sectional view of a state where a protective film is formed on a piezoelectric block.

FIG. 7 is a perspective view of a mother substrate and a cross-sectional view thereof.

FIG. 8 is a perspective view and a cross-sectional view of a state where an electrode is formed on a mother substrate.

FIG. 9 is a front and back view of another example of the piezoelectric resonator according to the present invention.

FIG. 10 is an exploded perspective view of an example in which the piezoelectric resonator according to the present invention is used as an oscillator.

FIG. 11 is an exploded perspective view of an example of a surface mount composite electronic component using the piezoelectric resonator according to the present invention.

12 is an electric circuit diagram of the oscillator shown in FIG.

FIG. 13 is an exploded perspective view of another example of the surface mount composite electronic component using the piezoelectric resonator according to the present invention.

14 is a perspective view of a capacitor element used in the oscillator of FIG.

FIG. 15 is a perspective view of an example in which the piezoelectric resonator according to the present invention is used in a composite electronic component with lead terminals.

FIG. 16 is a perspective view of another example in which the piezoelectric resonator according to the present invention is used in a composite electronic component with lead terminals.

[Explanation of symbols]

 Reference Signs List 10 piezoelectric ceramic substrate 11 first electrode 11a extension 12 second electrode 12a extension 13 third electrode 14 fourth electrode 15 first protective film 16 second protective film 17 fifth electrode 18 sixth electrode

Claims (9)

[Claims] 1. A piezoelectric resonator in which first and second electrodes facing each other are formed on the front and back surfaces of a piezoelectric ceramic substrate, and the end faces of both ends of the piezoelectric ceramic substrate have third and fourth electrodes, respectively.
Electrode is formed, first and second protective films are formed to cover the outer surfaces of the third and fourth electrodes, and the first electrode has an extension portion that is electrically connected to the third electrode. A piezoelectric resonator, wherein the extension is formed up to the protective film, and the second electrode is formed up to the second protective film so as to extend to the fourth electrode. 2. The piezoelectric resonator according to claim 1, wherein a fifth electrode electrically connected to the third electrode is formed on the back surface of one end of the piezoelectric ceramic substrate up to the first protective film. A piezoelectric resonator in which a sixth electrode which is electrically connected to the fourth electrode is formed on the surface of the other end of the substrate up to the second protective film. 3. A step of forming third and fourth electrodes on front and back surfaces of a piezoelectric ceramic block, and a voltage is applied between the third and fourth electrodes to perform polarization treatment in the thickness direction of the piezoelectric ceramic block. A step of forming first and second protective films for covering the third and fourth electrodes on the front and back surfaces of the piezoelectric ceramic block, and a piezoelectric ceramic block for which polarization processing and protective film formation have been completed, in the thickness direction thereof. To obtain a thin plate-shaped mother substrate, and a first electrode is provided on the front main surface of the mother substrate with one end of the third electrode
Forming a second electrode on the main surface of the mother substrate so that it is electrically connected to the first electrode, and one end of the second electrode is the first electrode.
Of the piezoelectric resonator including the step of forming up to the second protective film so that the other end is electrically connected to the fourth electrode so as to be opposed to the electrode and the step of cutting the mother substrate into one element width. Method. 4. The manufacturing method according to claim 3, wherein a step of forming a sixth electrode on the front main surface of the mother substrate up to the second protective film so as to be electrically connected to the fourth electrode, And a step of forming a fifth electrode on the back main surface of the mother substrate up to the first protective film so as to be electrically connected to the third electrode. 5. An insulating substrate, the piezoelectric resonator according to claim 1, and a cap, wherein two mounting electrodes are formed on at least an upper surface of the substrate, and the mounting electrodes have piezoelectric resonance. A piezoelectric resonator, wherein first and second electrodes of a child are connected, and a cap is adhered on the substrate so as to cover the piezoelectric resonator. 6. An insulating substrate, a piezoelectric resonator according to claim 1 or 2, and a cap, wherein at least an upper surface of the substrate has first and second attachment electrodes and a first capacitor between them. An electrode is formed, a dielectric layer is formed on the first capacitance electrode, and two second capacitances facing the first capacitance electrode on the dielectric layer and conducting to the first and second attachment electrodes. An electrode is formed, the first and second electrodes of the piezoelectric resonator are connected on the second capacitor electrode, and a cap is adhered on the substrate so as to cover the piezoelectric resonator. Electronic components. 7. An insulating substrate, a piezoelectric resonator according to claim 1 or 2, a capacitor element, and a cap, wherein first to third mounting electrodes are formed on at least an upper surface of the substrate. In the above capacitor element, two individual electrodes are formed at both ends of one main surface of the dielectric substrate, and a counter electrode facing the individual electrode is formed in the central portion of the other main surface. The counter electrode is connected to the second mounting electrode of the substrate, the individual electrodes are connected to the first and third mounting electrodes of the substrate and the first and second electrodes of the piezoelectric resonator, and the piezoelectric resonator is provided on the substrate. A composite electronic component, wherein a cap is adhered so as to cover the capacitor element. 8. A piezoelectric resonator according to claim 1 or 2,
A capacitor element and three lead terminals are provided. In the capacitor element, two individual electrodes are formed at both ends of one main surface of the dielectric substrate, and the individual electrodes are opposed to the center electrode of the other main surface. A counter electrode is formed, and a holding portion having a U-shaped cross section into which both ends of the piezoelectric resonator are inserted is formed at the tip portions of the two lead terminals on both sides. The first and second electrodes are connected, the individual electrodes of the capacitor element are laid across and connected to the outer surface of the holding portion, and the intermediate lead terminal is connected to the counter electrode of the capacitor element. Electronic components. 9. A piezoelectric resonator according to claim 1 or 2,
A capacitor element and three lead terminals are provided. In the capacitor element, two individual electrodes are formed at both ends of one main surface of a dielectric substrate longer than a piezoelectric resonator, and the center of the other main surface. A counter electrode facing the individual electrode is formed in the portion, and the piezoelectric resonator is bonded to the middle portion of the capacitor element so that the first and second electrodes of the piezoelectric resonator are connected to the individual electrodes of the capacitor element. The two lead terminals are arranged in a concave step formed by both ends of the piezoelectric resonator and the side surface of the capacitor element, and are connected to the first and second electrodes of the piezoelectric resonator and the individual electrodes of the capacitor element, A composite electronic component, wherein an intermediate lead terminal is connected to a counter electrode of a capacitor element.