JPH06164302A - Pizoelectric parts - Google Patents

Abstract

PURPOSE:To prevent the degradation of electric characteristics caused by a residual wax on one of a main surface side and a resin flash attached to the surface of a vibrating electrode by forming a void on the other main surface side of piezoelectric parts by melting and impregnating the wax in the sealing resin. CONSTITUTION:The void 15a on one of the main surface side of the resonator element 2 of the piezoelectric parts 10 is formed by melting and impregnating the wax 15 in a sealing resin 16 and the void 15a of the other main surface side is formed by a recessed part provided on a planar member or the thickness of an adhesive (jointing member) 11 of a reinforcing plate and the capacitor of the planar member, etc., arranged on the other main surface side and the resonator element 2. In such a manner, the void on the other main surface side for which a gap for arranging the planar member is narrow is formed by the recessed part provided on the planar member or the thickness of the jointing member 11 without using the wax 15. Thus, the wax 15 can be prevented from remaining on a vibrating electrode surfaces 4, 5, the resin 16 flash is prevented from being attached and thus the degradation of the electric characteristics can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-sealed piezoelectric component in which a resonator element and a plate member are integrally formed by forming a cavity in a vibrating portion of the resonator element. The present invention relates to a piezoelectric component of a type in which wax is applied to a desired vibrating portion and then resin dipping is performed to cover the resonator element and the plate-shaped member with an exterior resin so as to be integrated.

[0002]

2. Description of the Related Art As a resonator element that constitutes a piezoelectric component,
There is a piezoelectric substrate in which vibration electrodes are formed on both main surfaces of the piezoelectric substrate so as to face each other, thereby generating an energy trapping vibration mode. In the piezoelectric component, when the outer surface of the resonator element is resin-dipped or is housed in a case for exterior packaging, a cavity should be formed in this electrode part in order not to disturb the vibration of the vibrating electrode part. I have to. Then, as a conventional piezoelectric component formed by resin dipping this resonator element integrally with a capacitor,
There is a resonator with a built-in load capacitance having the structure shown in FIG. Figure 8
1 is a piezoelectric component. This piezoelectric component 1 is shown in FIG.
As shown in, the electrode 4 is provided on one main surface (front surface) of the piezoelectric substrate 3 extending from one end side to the center, and the electrode 5 is provided on the other main surface (back surface) extending from the other end side to the center. Part 4
The resonator element 2 is formed so that a and 5a face each other. Then, as shown in FIG. 8, this resonator element 2 is sandwiched by cup-shaped terminals 6 and 6 from both sides, a capacitor 7 is installed between the terminals 6 and 6 on the back surface side, and electrodes 4 and 5 face each other. Wax 8 is applied to the vibrating portion, and then resonator element 2 is applied.
The outer surface of the resin 9 is covered with a dip and baked to form an exterior resin to seal the resonator element 2, and at the same time, the wax 8 is melt-impregnated into the resin 9 to thereby form the electrode 4 , 5 are formed with vibrating cavities 8a in opposing vibrating portions and sealed with resin.

[0003]

However, in the above-mentioned conventional resin dip-type piezoelectric component, plate-like members such as capacitors are attached to the resonator element with a space between them. Does not enter the gap, and when baking the resin, the resin is not in sufficient quantity to completely absorb the wax, so the wax cannot dissolve in the resin and the wax remains on the vibrating electrode surface.
There is a problem that the resin flashes and adheres to the surface of the vibrating electrode, deteriorating the electrical characteristics.

The present invention has been made to solve the above-mentioned problems of the prior art, and prevents deterioration of electrical characteristics caused by sticking to the surface of the vibrating electrode due to wax residue or resin flash. It is an object of the present invention to provide a piezoelectric component that reduces the generation of non-defective products and improves the product reliability.

[0005]

SUMMARY OF THE INVENTION Therefore, according to the present invention, an electrode extending from one end of one main surface and an electrode extending from the other end of the other main surface are formed in a strip shape or a rectangular shape. A resonator element in the shape of a plate, a plate-shaped member disposed substantially parallel to the other main surface side of the resonator element at a predetermined interval, and a cavity formed in at least a vibrating portion of the resonator element. In a piezoelectric component having an exterior resin that covers the resonator element and the periphery of the plate-shaped member, the cavity on the one main surface side is melt-impregnated with wax in the exterior resin,
The piezoelectric component is formed by forming the cavity on the other main surface side by the thickness of the joining member for disposing the resonator element and the plate-shaped member or the recess provided in the plate-shaped member.

[0006]

According to the piezoelectric component of the present invention, as described above, the cavity on the one main surface side of the resonator element is formed by melt impregnating wax into the exterior resin, and the cavity on the other main surface side is formed. A resonator element and a capacitor arranged on the other main surface side,
It is formed by the thickness of a joining member for disposing a plate-shaped member such as a reinforcing plate or a recess provided in the plate-shaped member.
As described above, since the other main surface side in which the plate-shaped members are arranged at a narrow interval is formed with the thickness of the bonding member or the concave portion provided in the plate-shaped member without using the wax, the vibration electrode surface is formed. It is possible to prevent the wax from remaining and the resin from adhering due to flash, and prevent the deterioration of the electrical characteristics.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings by taking a capacitor-integrated piezoelectric component as an example. 1 to 5 are views for explaining a first embodiment of the piezoelectric component according to the present invention. In the figure, reference numeral 10 denotes a piezoelectric component. In this piezoelectric component 10, a cavity is formed in a vibrating portion formed by a portion of an electrode 5 on the other main surface facing each other by a thickness of a bonding member (adhesive) 11. Then capacitor 1
2 is adhered, wax 15 is applied to the electrode 4 on the one main surface, and a side electrode is provided by connecting to the portion 4b or 5b extending to the ends of the electrodes 4 and 5 on both main surfaces to form a side electrode. Terminal 1
It is sandwiched between 3 and 13 and soldered, and the terminal 14 is also soldered to the capacitor electrode of the capacitor 12,
A resin 16 is coated on the outer surface of the resonator element 2 with a dip and baked to evaporate the wax 15 and melt-impregnate it into the resin 16, thereby forming a vibration cavity 15a on one main surface. At the same time, resin 1
6 forms an exterior part, and a resonator element 2 and a capacitor 1 are formed.
And 2 are sealed.

As in the conventional resonator element 2, the resonator element 2 partially opposes both main surfaces of the front and back surfaces of the piezoelectric substrate 3 made of strip-shaped or rectangular piezoelectric ceramics with the piezoelectric substrate 3 interposed therebetween. The electrodes 4 and 5 are provided so as to extend to the ends opposite to each other. In this embodiment, the resonator element 2 is a plate-shaped capacitor 1 which is arranged with a space.
2, the capacitor electrode 18 is provided on the surface of the strip-shaped or rectangular-shaped dielectric substrate 17, and the attachment electrode 18a is formed at the center thereof, as shown in FIG. On the back surface of the substrate 17, the capacitor electrode 1 facing the capacitor electrode 18
9 and 19 are provided. Further, the terminal 14 is soldered to the mounting electrode 18a. As shown in FIG. 3, the joining member 11 of this embodiment is provided with a recess or a through hole 11a at a portion facing the vibrating portion. When the capacitor 12 is arranged and adhered on the back surface of the resonator element 2, as shown in FIG.
As shown in FIG. 5, a cavity is formed in the vibrating portion formed in the opposing portion 5a of the electrode 5 on the back surface of the resonator element 2.

Next, a method of manufacturing the piezoelectric component 10 of this embodiment will be described. First, the resonator element 2 is manufactured. further,
As shown in FIG. 4, the through hole 11a is made to face the facing portion 5a of the electrode 5 on the back surface of the resonator element 2, and the adhesive 11
And the capacitor 12 is adhered to the back surface of the resonator element 2, and the thickness of the adhesive 11 (the concave portion or the through hole 11a) is used.
As shown in (1), a cavity is formed and the resonator element 2 and the capacitor 12 are adhered to each other to produce a capacitor integrated element. Front and back electrodes 4, which extend to the side surface of this capacitor-integrated element
The electrodes 20 and 20 are formed by conducting to 5 and by sputtering, vapor deposition, coating, firing and the like. Then, it is sandwiched between the cup-shaped terminals 13 and 13 and soldered, the terminal 14 is also soldered to the mounting electrode 18a of the capacitor 12, the wax 15 is applied to the portion of the electrode 4 on the other surface, and then the resonator element. By coating the epoxy resin 16 on the outer surface of 2 with a dip and baking it,
The wax 15 is melted and impregnated in the resin 16 to form a cavity 15a for vibration in the electrode 4 portion.
In the vibrating portion of the electrode 5 on the back surface of the resonator element 2, a cavity is formed by the through hole 11a as described above. In the piezoelectric component 10 configured as in this embodiment, the vibrating portion of the electrode 5 having a small distance from the capacitor forms a cavity with the thickness of the adhesive 11 (through hole 11a). Since the wax 15 on the surface of the vibrating portion of the electrode 4 on the surface is surrounded by a sufficient amount of the resin 16, even if the resin 16 is baked and the wax 15 is melt-impregnated, it diffuses into the resin 16 and the vibrating portion of the electrode 4 is absorbed. It can eliminate wax and resin flash.

FIG. 6 is a sectional view for explaining another embodiment in which a cavity is formed between the resonator element and the plate-shaped member in a form different from that of the above embodiment. As shown in the figure, a recess 21 is provided in a portion of the plate-shaped capacitor 12 facing the other main surface of the resonator element 2. When the capacitor 12 is arranged and adhered substantially parallel to the other main surface of the resonator element 2, the cavity is formed by the recess 21 in the vibrating portion of the vibrating electrode 5.
In this case, the joining member 22 and the recess 21 may form a cavity.

In the above embodiment, an example of using a cup-shaped terminal with a built-in load capacitance in which a resonator element and a capacitor are integrated has been described, but other electronic parts such as a chip type may be used. The plate member is not limited to the capacitor, and may be a simple reinforcing plate. Further, the shape of the joining member is not limited to the above-mentioned embodiment, but may be one having only an edge portion or one provided with a gap between the terminal and an adhesive or the like. In short,
A cavity is provided on one side of the resonator element at a small interval to dispose a plate-like material, and the other side has a sufficient interval to seal the energy trap type resonator element by resin dipping. It can be applied to things.

[0011]

As described above, according to the piezoelectric component of the present invention, the surface where the distance between the resonator element and the plate-shaped member is small secures a cavity in the vibrating portion due to the thickness of the bonding member and does not use wax. Therefore, wax is not left on the surface of the vibrating portion of the electrode having a small gap, and the resin is not attached, so that the defective rate due to defective vibration can be reduced and the reliability of the product can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a piezoelectric component according to the present invention.

FIG. 2 is a perspective view illustrating a capacitor having the configuration of the above embodiment.

FIG. 3 is a perspective view illustrating a joining member having the configuration of the above embodiment.

FIG. 4 is a perspective view of an intermediate component for explaining the above embodiment.

FIG. 5 is a cross-sectional view of an essential part for explaining a cavity of the above embodiment.

FIG. 6 is a cross-sectional view of main parts for explaining a cavity of another embodiment.

FIG. 7 is a perspective view showing a resonator element.

FIG. 8 is a perspective view of a conventional piezoelectric component.

[Simple explanation of symbols]

2 Resonator element 4, 5 Electrode 10 Piezoelectric component 11 Adhesive (joining member) 12 Capacitor (plate member) 15 Wax 15a Cavity 16 Resin (exterior part)

Claims (1)

[Claims] 1. A strip-shaped or rectangular-shaped resonator element in which an electrode extending from one end of one main surface and an electrode extending from the other end of the other main surface are partially opposed to each other, and the resonance element. A plate-shaped member disposed substantially parallel to the other main surface side of the child element, and a cavity is formed at least in the vibrating portion of the resonator element, and the resonator element and the plate-shaped member. In a piezoelectric component having an exterior resin covering the periphery of, the cavity on the one main surface side is melt-impregnated with wax in the exterior resin to form the cavity on the other main surface side with a resonator element and a plate member. A piezoelectric component formed by a thickness of a joining member to be arranged or a recess provided in the plate member.