JPH04126420U - piezoelectric vibrator - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a piezoelectric vibrator having a structure that suppresses peeling at the center of a flexible printed circuit board bonded to a disc-shaped piezoelectric vibrator. [Structure] A piezoelectric vibrator element 6 having a through hole 5 with an E-shaped cross section is provided in the center of the piezoelectric vibrator element 6 in the form of a disk. This piezoelectric vibrator has a structure in which holes 6 are also filled with adhesive 4 and flexible printed circuit boards are bonded to both sides. [Effects] The flexible printed circuit board bonded to both sides of the disc-shaped piezoelectric vibrator is directly bonded to the center of the piezoelectric vibrator with adhesive in the through hole, providing reliability with less risk of peeling off during operation. A piezoelectric vibrator with high quality can be provided.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to a disc-shaped piezoelectric vibrator with a flexible printed circuit board bonded to it. It is.

0002

[Conventional technology]

Conventionally, this type of thin disc-shaped piezoelectric vibrator has a piezoelectric vibrator element 6 shown in FIG. Adhesive with a uniform thickness is applied to one surface of the electrode on both the top and bottom sides in the thickness direction using a screen printing method. The copper foil 3 of the flexible printed circuit (hereinafter referred to as FPC) board 8 shown in FIG. It is made by pasting the parts together, applying pressure, heating and curing to bond them, and is used as a piezoelectric vibrator. was. However, the adhesion strength between the copper foil 3 and the electrode 1 of the piezoelectric vibrator element is low and the piezoelectric While the vibrator is being driven, boundary separation between the copper foil and the piezoelectric vibrator element occurs in the center of the disk. There is a problem that this happens due to the problem that it becomes unusable.

0003

[Problem that the idea aims to solve]

The present invention solves the above-mentioned problems and uses a thin disc-shaped piezoelectric vibrator. By changing the shape of the vibrator element, peeling of the FPC board from the piezoelectric vibrator element can be prevented. An object of the present invention is to provide a highly reliable piezoelectric vibrator that prevents the above problems.

0004

[Means to solve the problem]

In the present invention, the central part of the disk-shaped piezoelectric vibrator element in the plane direction has an E-shaped shape in the thickness direction. By adhering an FPC board to an element with through holes, the adhesive in the through holes With a structure in which the upper and lower FPC boards are directly bonded, the piezoelectric vibrator element and the FPC board are bonded directly. This is a piezoelectric vibrator that maintains close contact.

[0005] In other words, the present invention provides a piezoelectric vibrator element with electrodes on both sides of a disk. The copper foil side of a flexible printed circuit board made of copper foil and flexible film is placed on the bottom side. In a piezoelectric vibrator formed by bonding, a thickness is Assembled using a piezoelectric vibrator element with a through hole with an E-shaped cross section in the viewing direction. A piezoelectric vibrator featuring:

[0006]

[Effect]

A through hole where the adhesive connects to the FPC board on both sides at the center of the piezoelectric vibrator, The layer of adhesive should be thicker around it to increase the adhesive strength with the FPC board. A through hole with an E-shaped cross section was created with a step around the through hole. Assembling with piezoelectric vibrator elements may cause the FPC board in the center to peel off. A piezoelectric vibrator with low resistance to corrosion can be obtained.

[0007]

【Example】

Embodiments of the piezoelectric vibrator of the present invention will be described below with reference to the drawings. Figure 1 is , shows a piezoelectric vibrator element used in a piezoelectric vibrator according to an embodiment of the present invention, and (a) of FIG. FIG. 1B is a plan view, and FIG. 1B is a front sectional view. Figure 2 shows the piezoelectric vibrator element in Figure 1. FIG. 2 is a front cross-sectional view showing a piezoelectric vibrator according to an embodiment of the present invention assembled using FIG. Figure 3 is , shows a conventional piezoelectric vibrator element, in which FIG. 3(a) is a plan view and FIG. 3(b) is a front cross-section. It is a front view. FIG. 4 shows a flexible printed circuit board, and FIG. 4(a) is a plan view. FIG. 4(b) is a front sectional view. Figure 5 shows a conventional piezoelectric vibrator element and a flexible 1 is a front sectional view showing a conventional piezoelectric vibrator assembled with a flexible printed circuit board; FIG.

[0008] As shown in FIG. 3, the conventional disk-shaped piezoelectric vibrator element 6 has electrodes 1 on its upper and lower surfaces. As shown in FIG. 4, the FPC board 8 has a A polyimide film or the like to which a copper foil 3 of approximately the same size as the electrode is adhered. It is made of a flexible insulating film 2. Conventional piezoelectric vibrators are piezoelectric vibrator elements. Adhesive 4 is printed and coated on one surface of electrode 6 by screen printing method, and the copper foil of FPC board 8 is applied. The three sides are pasted together and heated under pressure to harden and adhere, creating the shape shown in Figure 5. was.

[0009] The piezoelectric vibrator according to the present invention has a disc-shaped piezoelectric vibrator element 6 as shown in FIG. A piezoelectric vibrator element is used, which has a through hole 5 having an E-shaped cross section in the center. That is, As shown in Figure 1, a circular depression is provided on both sides in the center of the disk-shaped disk, and The part has a small hole penetrating both sides. Electrode 1 on both sides is the outer annular part It has been processed only in minutes. Adhesive 4 is printed on one side of the annular electrode by screen printing. Apply the adhesive, paste the FPC board 8 shown in Figure 4, and then print and apply adhesive on the opposite side. Adhesive is injected into the through-hole 5 in the center of the cloth and the cloth is bonded to form the state shown in FIG. 2.

0010 As mentioned above, the conventional piezoelectric vibrator is simply a flat piezoelectric vibrator element and an FPC. Previously, the substrate was bonded, but according to the present invention, an E-shaped through hole is formed in the center of the piezoelectric vibrator. It is firmly attached because it is fixed by the adhesive in the hole. Therefore, In piezoelectric vibrators with a conventional structure, peeling occurred at the center of the copper foil surface during driving, but this With the invented piezoelectric vibrator, there was no peeling from the center.

[0011]

[Effect of the idea]

As described above in the embodiments, the present invention provides a disc-shaped piezoelectric vibrator with an FP It is possible to provide a highly reliable piezoelectric vibrator in which peeling does not easily occur at the center of the C substrate.

[Brief explanation of drawings]

FIG. 1 shows a piezoelectric vibrator element used in a piezoelectric vibrator according to an embodiment of the present invention, with FIG. 1(a) being a plan view and FIG. 1(b) being a front sectional view.

FIG. 2 is a front sectional view showing a piezoelectric vibrator according to an embodiment of the present invention assembled using the piezoelectric vibrator element of FIG. 1;

FIG. 3 shows a conventional piezoelectric vibrator element, (a)
is a plan view, and (b) is a front sectional view.

FIG. 4 shows a flexible printed circuit board, with FIG. 4(a) being a plan view and FIG. 4(b) being a front sectional view.

FIG. 5 is a front sectional view showing a conventional piezoelectric vibrator assembled with a conventional piezoelectric vibrator element and a flexible printed circuit board.

[Explanation of symbols]

1 electrode 2 Flexible insulation film 3 Copper foil 4 Adhesive 5 Through hole 6 Piezoelectric vibrator element 7 Piezoelectric ceramics 8 FPC board

Claims (1)

[Scope of utility model registration request] [Claim 1] A piezoelectric device in which the copper foil surface of a flexible printed circuit board made of copper foil and a flexible film is adhered to the upper and lower surfaces in the thickness direction of a piezoelectric vibrator element having electrodes on both sides of a disk shape. 1. A piezoelectric vibrator, characterized in that the vibrator is assembled using a piezoelectric vibrator element having a through hole having an E-shaped cross section in the thickness direction in the central part of the piezoelectric vibrator element in the planar direction.