JP2003218662A - Piezoelectric component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric component which can securely prevent a dielectric substrate from thermally damaging during soldering. <P>SOLUTION: A piezoelectric substrate 12 has vibration electrode films 141 and 142 on both its surfaces and also has its one surface bonded to one surface of a base substrate 11 across a vibration space with an adhesive 15. The dielectric substrate 13 is bonded to the other surface side of the piezoelectric substrate 12 across a vibration space with an adhesive 16. Terminal electrode films 21 to 23 are stuck on at least flanks of the base substrate 11, piezoelectric substrate 12, and dielectric substrate 13. A solder nonsticking film 3 is a film where no solder sticks and stuck on a region for preventing solder from sticking on terminal electrode films 21 to 23 stuck on the flanks of the piezoelectric substrate 12 and dielectric substrate 13 on at least the terminal electrode films 21 to 23. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a resonator, an oscillator,
Alternatively, it relates to a piezoelectric component used for a filter or the like.

[0002]

2. Description of the Related Art A piezoelectric substrate is used as a piezoelectric component of this type.
There is known a piezoelectric component having a laminated structure in which a dielectric substrate and a support substrate are sandwiched. The piezoelectric substrate has vibrating electrode films on both sides, and one surface has a vibrating space and is bonded to one surface of the supporting substrate. The electrode films formed on both sides of the piezoelectric substrate are
One end is led out to the side surface of the piezoelectric substrate.

Since the piezoelectric substrate is for obtaining piezoelectric characteristics, it is formed by using a piezoelectric ceramic or the like which has excellent piezoelectric characteristics rather than a material having high mechanical strength.

The dielectric substrate is bonded to the other surface of the piezoelectric substrate with a vibration space. The dielectric substrate is used to form a load capacitance for the piezoelectric vibrating component,
Electrodes for obtaining load capacitance are formed at appropriate positions on the substrate surface or the like. Since the dielectric substrate is for obtaining the load capacitance, it is configured by using a dielectric ceramic or the like having a higher dielectric constant than a material having a high mechanical strength.

The supporting substrate supports the piezoelectric substrate and the dielectric substrate and is directly attached to a mounting substrate such as a circuit substrate. Therefore, a ceramic material having high mechanical strength such as alumina or It is composed of a ceramic material such as forsterite.

A terminal electrode film for connecting to the outside is provided on the side surface and the bottom surface of the laminate composed of the supporting substrate, the piezoelectric substrate and the dielectric substrate. This terminal electrode film needs to be connected not only to the electrode film provided on the piezoelectric substrate but also to the electrode for capacitance acquisition formed on the dielectric substrate.

When the above-described piezoelectric component is mounted on a mounting board such as a circuit board, the terminal electrode film is soldered to a conductor pattern provided on the mounting board.

However, this terminal electrode film is
Since the laminated body composed of the piezoelectric substrate and the dielectric substrate is formed in a strip shape, when the laminated body is soldered to the mounting substrate, the molten solder causes the surface of the terminal electrode film from the side of the supporting substrate. , Rises in a certain direction of the piezoelectric substrate and the dielectric substrate, and adheres also to the upper part of the terminal electrode film covering the side surfaces of the dielectric substrate and the piezoelectric substrate.

As described above, since the piezoelectric substrate is for obtaining the piezoelectric characteristic and the dielectric substrate is for obtaining the load capacitance, the piezoelectric characteristic is more important than the material having high mechanical strength. It is configured by using high piezoelectric ceramics and dielectric ceramics having a high dielectric constant. Therefore, the piezoelectric substrate and the dielectric substrate, which have relatively weak mechanical strength, may crack at the contact portion with the terminal electrode film due to thermal stress caused by thermal expansion due to molten solder and thermal contraction during cooling and solidification of the solder. However, problems such as damage due to electrode peeling may occur.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a piezoelectric component that can reliably prevent thermal damage to the piezoelectric substrate and the dielectric substrate caused by soldering.

[0011]

In order to solve the above problems, a piezoelectric component according to the present invention includes a support substrate, a piezoelectric substrate, a dielectric substrate, a terminal electrode film, and a solder non-adhesion film.

The piezoelectric substrate has vibrating electrode films on both sides, and one surface has a vibrating space and is bonded to one surface of the supporting substrate. The dielectric substrate is bonded to the other surface of the piezoelectric substrate with a vibration space.

The terminal electrode film is attached at least to the side surfaces of the supporting substrate, the piezoelectric substrate and the dielectric substrate, and is electrically connected to the vibrating electrode film.

The solder non-adhesion film is a film to which solder does not adhere, and is at least on the terminal electrode film,
It is attached to a region that prevents solder from attaching to the terminal electrode films attached to the side surfaces of the piezoelectric substrate and the dielectric substrate.

As described above, the piezoelectric component according to the present invention includes the supporting substrate, the piezoelectric substrate, and the dielectric substrate. One surface of the piezoelectric substrate is bonded to one surface of the supporting substrate, Since the body substrate is adhered to the other surface side of the piezoelectric substrate, a piezoelectric component having a laminated structure in which the support substrate, the piezoelectric substrate and the dielectric substrate are laminated can be obtained.

The piezoelectric substrate has vibrating electrode films on both sides, one surface has a vibrating space and is bonded to one surface of the support substrate, and the dielectric substrate has a vibrating space on the other surface side of the piezoelectric substrate. When the piezoelectric substrate is excited by supplying a signal to the vibrating electrode films formed on both surfaces of the piezoelectric substrate, the piezoelectric substrate can vibrate in the vibrating space.

The piezoelectric component includes a terminal electrode film, and the terminal electrode film is attached to at least a side surface of the piezoelectric substrate,
It is electrically connected to the vibrating electrode film. Therefore, the vibrating electrode film of the piezoelectric substrate can be guided to the outside through the terminal electrode film and a signal for excitation can be supplied.

The terminal electrode film is also attached at least to the side surface of the supporting substrate. Therefore, the supporting substrate can be made to face the mounting substrate, and the terminal electrode film of the supporting substrate can be soldered to the conductor pattern or the like of the mounting substrate.

Further, the terminal electrode film is attached at least to the side surface of the dielectric substrate. According to this structure, the load capacitance electrode film formed at an appropriate position such as the surface of the dielectric substrate is electrically and mechanically connected to the terminal electrode film on the side surface of the dielectric substrate, and is connected to the outside. can do.

The piezoelectric component according to the present invention includes a solder non-adhesion film as its characteristic portion. The solder non-adhesion film is a film to which solder does not adhere, and is an area that is at least on the terminal electrode film and prevents the solder from adhering to the terminal electrode film adhered to the side surfaces of the piezoelectric substrate and the dielectric substrate. Is attached to.

According to such a solder non-adhesion film, when the piezoelectric component is soldered to the mounting substrate, the molten solder causes the surface of the terminal electrode film to come into contact with the piezoelectric substrate and the dielectric substrate from the side of the supporting substrate. Even if it goes up in a certain direction, it can be prevented from adhering to the terminal electrode film covering the side surfaces of the piezoelectric substrate and the dielectric substrate.

For this reason, a piezoelectric ceramic having a high piezoelectric characteristic or the like is used, and a piezoelectric substrate having a low mechanical strength or a dielectric ceramic having a high dielectric constant is used. Dielectric substrate and piezoelectric substrate with weak strength are less susceptible to thermal stress due to thermal expansion due to molten solder and thermal contraction during cooling and solidification of solder, and piezoelectric substrate and dielectric substrate come into contact with the terminal electrode film. Problems such as cracking at the part and damage due to electrode peeling will not occur.

Furthermore, the piezoelectric component according to the present invention can have the following aspects. (A) The solder non-adhesion film can be composed of one kind selected from a metal oxide film or an insulating resin film. (B) The non-soldered film can be attached only to the side surfaces of the piezoelectric substrate and the dielectric substrate and the terminal electrode films of the piezoelectric substrate and the dielectric substrate. (C) The solder non-adhesive film may be attached only to the terminal electrode films on the piezoelectric substrate and the dielectric substrate and not attached to the surfaces of the piezoelectric substrate and the dielectric substrate. (D) The solder non-adhesion film may be adhered only to the terminal electrode film on the piezoelectric substrate.

[0024]

1 is an exploded perspective view of a piezoelectric component according to the present invention, FIG. 2 is a perspective view showing an assembled state of the piezoelectric component shown in FIG. 1, and FIG. 3 is a line 3-3 of FIG. Sectional view along Figure 4,
FIG. 4 is a sectional view taken along line 4-4 of FIG. The illustrated piezoelectric component includes a support substrate 11, a piezoelectric substrate 12, a dielectric substrate 13, terminal electrode films 21 to 23, and a solder non-adhesive film 3.
Including and

The piezoelectric substrate 12 has vibrating electrode films 14 on both sides.
1, 142, and one surface thereof is bonded to the one surface of the support substrate 11 with an adhesive 15 having a vibration space. The piezoelectric substrate 12 may have any polarization direction, vibration mode, and the like as long as it is in the energy confinement vibration mode, and a piezoelectric material known in piezoelectric components can be used.

The vibrating electrode films 141 and 142 can have any pattern such as a circular shape and a square shape. The vibrating electrode films 141 and 142 can be formed by printing, sputtering, ion plating, plating, or a combination thereof. The vibrating electrode films 141 and 142 are an example, but can be made of a two-layer metal of Cr and Ag.

The adhesive 15 is formed by laminating a first adhesive layer 151 and a second adhesive layer 152. In FIG. 1, the first adhesive layer 151 and the second adhesive layer 152 are shown separately from the support substrate 11 and the piezoelectric substrate 12, but the first adhesive layer 151 covers the periphery of the support substrate 11. The second adhesive layer 152 is attached to the periphery of the lower surface of the piezoelectric substrate 12 so as to form the edge, and the second adhesive layer 152 is attached to the periphery of the piezoelectric substrate 12 so as to surround the lower surface of the piezoelectric substrate 12.
As the adhesive 15, for example, an epoxy adhesive can be used.

For the supporting substrate 11, a ceramic material having high mechanical strength or another structural insulating material can be used. Alumina, forsterite, or the like can be given as a typical example of the material forming the support substrate 11.

The dielectric substrate 13 is bonded to the other surface side of the piezoelectric substrate 12 with an adhesive 16 having a vibration space. The dielectric substrate 13 is made of a high dielectric constant material. Such a material can be selected and used from the ceramic materials used as a capacitor material.

The adhesive 16 is formed by laminating a third adhesive layer 161 and a fourth adhesive layer 162. In FIG. 1, the third adhesive layer 161 and the fourth adhesive layer 162 are shown separately from the piezoelectric substrate 12 and the dielectric substrate 13, but the third adhesive layer 161 is the periphery of the piezoelectric substrate 12. Is adhered to the upper surface of the piezoelectric substrate 12 so as to have an edge, and the fourth adhesive layer 162 is attached to the periphery of the dielectric substrate 13 so as to have an edge around the lower surface of the dielectric substrate 13. It is a thing. As the adhesive 16, for example, an epoxy adhesive can be used.

The terminal electrode films 21 to 23 are attached to at least the side surfaces of the support substrate 11, the piezoelectric substrate 12 and the dielectric substrate 13. In the illustrated embodiment, the terminal electrode film 21
23 to 23 are arranged so as to be continuous with each other through the side surfaces of the support substrate 11, the piezoelectric substrate 12 and the dielectric substrate 13, the bottom surface of the support substrate 11 and the top surface of the dielectric substrate 13 at intervals. The terminal electrode films 21 to 23 may be partially cut off at the bottom surface of the support substrate. The terminal electrode film 21 is the piezoelectric substrate 12
Is electrically connected to the vibrating electrode film 141 provided in the terminal electrode film 2
3 is a vibrating electrode film 142 provided on the lower surface of the piezoelectric substrate 12.
Is connected to. The terminal electrode film 22 serves as a ground terminal, and on the surface of the dielectric substrate 13, the terminal electrode film 22 causes a load capacitance between the terminal electrode film 21 and the terminal electrode film 23.

The terminal electrode films 21 to 23 may have the same film structure made of the same material over the entire length thereof, or the portions formed on the surfaces of the dielectric substrate 13 and the support substrate 11 may be changed to other portions. It is also possible to use a material or a film structure different from the above. For example, in the portions formed on the surfaces of the dielectric substrate 13 and the support substrate 11, a 5 μm Ag film is formed, a 2 μm Cu film is formed on the Ag film, and a 1.5 μm Ni film is formed on the Cu film. The film structure is such that a 4 μm Sn film is formed, and the other part is a 2 μm Cu film with 1.5 μm above it.
It is possible to have a film structure in which a Ni film of μm and a Sn film of 4 μm are further formed thereon. Terminal electrode films 21-23
Can be formed by sputtering, ion plating, plating, or a combination thereof.

The solder non-adhesion film 3 is a film to which solder does not adhere, and is at least on the terminal electrode films 21 to 23, and the terminal electrode films 21 to 21 attached to the side surfaces of the piezoelectric substrate 12 and the dielectric substrate 13. 23 is attached to the area that prevents solder from adhering. The solder non-adhesion film 3 can be composed of one kind selected from a metal oxide film or an insulating resin film.

In the embodiment shown in FIGS. 1 to 4, the solder non-adhesive film 3 is made of an insulating resin film, and the side surfaces of the piezoelectric substrate 12 and the dielectric substrate 13 except the side surface of the support substrate 11 are connected to the terminal electrode film 21. It is attached so as to cover with the surfaces of ~ 23.

As described above, in the piezoelectric component according to the present invention, one surface of the piezoelectric substrate 12 is bonded to one surface of the support substrate 11, and the dielectric substrate 13 is bonded to the other surface side of the piezoelectric substrate 12. Therefore, the support substrate 11 and the piezoelectric substrate 12
A piezoelectric component having a structure in which the dielectric substrate 13 is laminated is obtained.

The piezoelectric substrate 12 has a vibrating electrode film 14 on both sides.
1 and 142, one side of which has a vibrating space, and the supporting substrate 1
1 is bonded to one surface of the piezoelectric substrate 12, and the dielectric substrate 13 is bonded to the other surface of the piezoelectric substrate 12 with a vibration space.
Vibrating electrode films 141, 1 formed on both surfaces of the piezoelectric substrate 12.
When a signal is supplied to 42 to excite the piezoelectric substrate 12,
The piezoelectric substrate 12 can vibrate in the vibrating space.

The piezoelectric component generally includes terminal electrode films 21 to 23, and the terminal electrode films 21 to 23 are included.
Is attached to at least the side surface of the piezoelectric substrate 12, and the terminal electrode films 21 and 23 are electrically connected to the vibrating electrode films 141 and 142. Therefore, the vibrating electrode films 141 and 142 of the piezoelectric substrate 12 can be guided to the outside through the terminal electrode films 21 and 22, and a signal for excitation can be supplied.

The terminal electrode films 21 to 23 are also attached at least to the bottom surface and side surfaces of the support substrate 11.
Therefore, the supporting substrate 11 can be made to face the mounting substrate, and the terminal electrode films 21 to 23 in the portion of the supporting substrate 11 can be soldered to the conductor pattern or the like of the mounting substrate.

Further, the terminal electrode films 21 to 23 are attached at least to the side surface of the dielectric substrate 13. According to this structure, the load capacitance electrode film formed at an appropriate position on the surface of the dielectric substrate 13 is electrically and mechanically connected to the terminal electrode films 21 to 23 on the side surface of the dielectric substrate 13. And can be connected to the outside.

The piezoelectric component according to the present invention includes the solder non-adhesion film 3 as its characteristic portion. The non-soldered film 3 is
A film to which solder does not adhere, and at least the terminal electrode film 2
1 to 23, the piezoelectric substrate 12 and the dielectric substrate 1
3 is attached to a region that prevents the solder from attaching to the terminal electrode film attached to the side surface of No. 3. Next, the function and effect of the solder non-adhesion film 3 will be described with reference to FIG. 5 showing the usage state of the piezoelectric component. FIG. 5 shows FIGS.
FIG. 9 is a cross-sectional view showing a state in which the piezoelectric component shown in FIG.

As shown in FIG. 5, when the piezoelectric component is soldered 60 to the conductor pattern 75 of the mounting substrate 70, the molten solder is applied to the surface of the terminal electrode films 21 to 23 from the support substrate 11 side. , Piezoelectric substrate 12 and dielectric substrate 13
Try to rise in a certain direction.

However, the piezoelectric component according to the present invention includes the solder non-adhesive film 3, and the solder non-adhesive film 3 is at least on the terminal electrode films 21 to 23, and the piezoelectric substrate 1
2 and the terminal electrode film 2 attached to the side surface of the dielectric substrate 13.
1 to 23 are attached to the areas that prevent the solder from attaching. Specifically, the solder non-adhesion film 3 is formed on the piezoelectric substrate 12 and the dielectric substrate 13 except for the side surface of the support substrate 11.
Is attached so as to cover the side surfaces of the terminal electrode films 21 to 23 together with the surfaces thereof.

Therefore, the solder 60 adheres only to the terminal electrode films 21 to 23 on the side surface of the support substrate 11 where the solder non-adhesion film 3 is not adhered, and covers the side surface of the dielectric substrate 13. It does not adhere to the terminal electrode films 21 to 23.

Therefore, the piezoelectric substrate 12 having a high piezoelectric property is used, and the piezoelectric substrate 12 having a low mechanical strength and the dielectric ceramic having a high dielectric constant are used. The weak dielectric substrate 13
It becomes less susceptible to the thermal expansion due to the molten solder and the thermal stress due to the thermal contraction when the solder is cooled and solidified, and the piezoelectric substrate 12 and the dielectric substrate 13 are cracked at the contact portions with the terminal electrode films 21 to 23. In addition, problems such as damage due to electrode peeling will not occur.

FIG. 6 is a sectional view showing another embodiment of the piezoelectric component according to the present invention. The cross-sectional position is on the line 4-4 in FIG. In this embodiment, the non-soldered film 3 is formed on the upper surface of the dielectric substrate 13, the side surface of the dielectric substrate 13, and the piezoelectric substrate 12.
Is attached so as to continuously cover the terminal electrode films 21 to 23 on the side surface of the. The solder non-adhesion film 3 is not attached to the terminal electrode films 21 to 23 located on the side surface of the support substrate 11.

FIG. 7 is a front view showing still another embodiment of the piezoelectric component according to the present invention, and FIG. 8 is a sectional view taken along line 8-8 of FIG. In this embodiment, the non-soldered film 3 is formed on the side surface of the piezoelectric substrate 12 and the terminal electrode films 21 to 21 on the side surface.
It covers only 23. The non-soldered film 3 is formed on the upper surface of the dielectric substrate 13, the side surface of the dielectric substrate 13, and the support substrate 11.
Is not attached to the surfaces of the terminal electrode films 21 to 23 located on the side surfaces and the bottom surface of the.

FIG. 9 is a front view showing still another embodiment of the piezoelectric component according to the present invention. In this embodiment, the non-soldered films 31 to 33 are divided. Non-soldered film 31
Covers only the terminal electrode film 21 on the side surfaces of the dielectric substrate 13 and the piezoelectric substrate 12. The solder non-adhesion film 32 covers only the terminal electrode film 22 on the side surfaces of the dielectric substrate 13 and the piezoelectric substrate 12. The solder non-adhesion film 33 covers only the terminal electrode film 23 on the side surfaces of the dielectric substrate 13 and the piezoelectric substrate 12. The solder non-adhesion films 31 to 33 are hardly adhered to the surfaces of the piezoelectric substrate 12 and the dielectric substrate 13.

FIG. 10 is a front view showing still another embodiment of the piezoelectric component according to the present invention. Also in this embodiment, the non-soldered films 31 to 33 are divided. Non-soldered film 31
Covers only the terminal electrode film 21 on the side surface of the piezoelectric substrate 12. The non-soldered film 32 is formed on the piezoelectric substrate 12.
On the side surface of, only the terminal electrode film 22 is covered.
The non-soldered film 33 is formed on the side surface of the piezoelectric substrate 12,
Only the terminal electrode film 23 is covered. Non-soldered film 31
On the surface of the piezoelectric substrate 12 and the dielectric substrate 13,
Almost no adhesion.

Also in the embodiment shown in FIGS. 6 to 10, the function of the solder non-adhesive films 3, 31 to 33 is shown in FIG.
~ It is possible to obtain the same effects as those of the piezoelectric component shown in Fig. 4.

The piezoelectric component according to the present invention is not limited to the illustrated structure. INDUSTRIAL APPLICABILITY The present invention can be applied to all piezoelectric components modified into a structure suitable for a resonator, an oscillator, a filter, or the like.

[0051]

As described above, according to the present invention, it is possible to provide a piezoelectric component which can reliably prevent thermal damage to the dielectric substrate due to soldering.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a piezoelectric component according to the present invention.

2 is a perspective view showing an assembled state of the piezoelectric component shown in FIG. 1. FIG.

FIG. 3 is a sectional view taken along line 3-3 of FIG.

4 is a cross-sectional view taken along line 4-4 of FIG.

FIG. 5 is a cross-sectional view showing a state where the piezoelectric component shown in FIGS. 1 to 4 is soldered and mounted on a mounting substrate.

FIG. 6 is a sectional view showing another embodiment of the piezoelectric component according to the present invention.

FIG. 7 is a front view showing still another embodiment of the piezoelectric component according to the present invention.

8 is a cross-sectional view taken along line 8-8 of FIG.

FIG. 9 is a front view showing still another embodiment of the piezoelectric component according to the present invention.

FIG. 10 is a front view showing still another embodiment of the piezoelectric component according to the present invention.

[Explanation of symbols]

11 Support substrate 12 Piezoelectric substrate 13 Dielectric substrate 21-23 Terminal electrode film 3 Non-soldered film

Claims (6)

[Claims] 1. A piezoelectric component including a support substrate, a piezoelectric substrate, a dielectric substrate, a terminal electrode film, and a solder non-adhesive film, wherein the piezoelectric substrate has vibrating electrode films on both surfaces, One surface has a vibration space and is bonded to one surface of the support substrate, the dielectric substrate is bonded to the other surface side of the piezoelectric substrate with a vibration space, the terminal electrode film, At least, the support substrate, the piezoelectric substrate and the side surface of the dielectric substrate, which is attached to the side surface of the vibrating electrode film, the solder non-adhesion film is a film to which the solder does not adhere,
A piezoelectric component, which is attached at least on the terminal electrode film and in a region that prevents solder from attaching to the terminal electrode film attached to the side surfaces of the dielectric and the piezoelectric substrate. 2. The piezoelectric component according to claim 1, wherein the solder non-adhesion film is one kind selected from a metal oxide film and an insulating resin film. 3. The piezoelectric component according to claim 1, wherein the solder non-adhesive film is adhered to at least the side surfaces of the dielectric and the piezoelectric substrate and the terminal electrode film thereon. Piezoelectric parts. 4. The piezoelectric component according to claim 1, wherein the solder non-adhesion film is attached only to the terminal electrode film. 5. The piezoelectric component according to claim 1, wherein the solder non-adhesion film is attached to a side surface of the piezoelectric substrate and the terminal electrode film of the piezoelectric substrate. 6. The piezoelectric component according to claim 5, wherein the solder non-adhesion film is attached only to the terminal electrode film.