JPH02185197A - Lead extraction structure for piezoelectric body - Google Patents

Abstract

PURPOSE:To obtain a stable conduction state, to widen the range of an adhering position and to facilitate the assembling by adhering a tip flat part of a spring terminal to a flexible conductive adhesives applied to an electrode of a piezoelectric body so as to connect the electrode and the spring terminal. CONSTITUTION:The piezoelectric body 3 is formed by providing an electrode 2 made of a conductive material on the surface of a piezoelectric element 1 made of a piezoelectric ceramic or the like and a tip of a spring terminal 11 connecting to the electrode 2 is formed to a flat part 12. To connect the electrode 2 and the spring terminal 11, a flexible conductive adhesives 13 is thinly printed and applied near a node on the electrode 2 of the piezoelectric body 3. and the tip flat part 12 of the fixed spring terminal 11 is pressed onto the adhesives 13. When the flexible conductive adhesives 13 is cured by forced drying or natural drying to fix the electrode 12 and the spring terminal 11 via the adhesives 13 and bonded electrically at the same time. Even when the adhered part between the electrode and the spring terminal 11 is deviated somewhat from the node point of the piezoelectric body 3, the vibration is absorbed because of flexibility of the adhesives 13.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a piezoelectric lead lead-out structure, more specifically,
The present invention relates to a lead extraction structure for connecting a spring terminal to an electrode formed on the surface of a piezoelectric body.

<Prior Art> Conventionally, as one structure for leading out leads from electrodes in piezoelectric bodies such as piezoelectric buzzers, a type in which a spring terminal is pressed into contact with an electrode has been used.

Figure 2 shows the above-mentioned conventional pull-out structure, in which electrodes 2 of a piezoelectric body 3 are formed by providing electrodes 2 on the surface of a piezoelectric element 1 made of piezoelectric ceramic, etc., and are fixed to a case, a wiring board, etc. The spring pressure on the tip protrusion 5 of the spring terminal 4 is several tens of grams.
They were pressed together to a weight of about 300 g, and the electrode leads were taken out using the spring terminals 4.

<Problems to be Solved by the Invention> By the way, the position where the tip projection 5 of the spring terminal 4 comes into contact with the electrode 2 must be set at a node point where the vibration of the piezoelectric body 3 is small. In addition to being limited to narrow areas, vibrations are damped if the position shifts,
Moreover, there is a problem in that the electrode 2 is scraped due to the vibration of the connecting portion.

Furthermore, in order to reliably press the spring terminal into contact with the electrode, it is difficult to design and manage the shape and spring pressure of the spring terminal.

Further, since the spring terminal 4 only has its tip projection 5 in pressure contact with the electrode 2, there is a problem in that if foreign matter such as an insulator gets into the connection part, a connection failure will occur.

This invention has been made to solve the above-mentioned problems, and it is possible to reliably connect the electrode barb terminal regardless of the spring pressure of the spring terminal, and it is possible to select a wide range of connection positions with respect to the piezoelectric body. It is an object of the present invention to provide a piezoelectric lead lead-out structure that does not cause vibration damping or electrode scraping.

Means for Solving the Problems> In order to solve the above problems, the present invention applies and adheres a flexible conductive adhesive onto the electrodes provided on the surface of the piezoelectric element, and attaches a flat end of the spring terminal to this adhesive. After the parts are joined, the flexible conductive adhesive is cured.

Effect> Apply a thin layer of flexible conductive adhesive to the electrodes provided on the surface of the piezoelectric element near the node points of the piezoelectric body, and bond the flat end of the spring terminal to this adhesive. If the adhesive is forced or air-dried to harden, the electrode barb terminal can be electrically connected, and the flexibility of the adhesive allows vibrations to be absorbed even if the joint of the spring terminal is offset to some extent from the node point. The spring terminal is less likely to resonate or damp vibration, and the occurrence of electrode scraping can also be prevented.

<Example> Hereinafter, an example of the present invention will be described based on FIG. 1 of the accompanying drawings.

As shown in the figure, the piezoelectric body 3 is formed by providing an electrode 2 made of a conductive material such as Ag, Cu, or Ni on the surface of a piezoelectric element 1 made of piezoelectric ceramic or the like, and a spring connected to the electrode 2. The terminal 11 has a flat portion 12 at its tip.

The flexible conductive adhesive 13 used to connect the spring terminal 11 to the electrode 2 may be epoxy-based, silicon-based, or urethane-based.

To connect the electrode 2 and the spring terminal 11, apply a flexible conductive adhesive 1 on the electrode 2 of the piezoelectric body 3 near the node point.
3 is printed and applied thinly, and the flat end portion 12 of the spring terminal 11 fixed to the case or the wiring board is pressed into contact with the adhesive 13 by a hardening agent having flexibility.

Thereafter, the flexible conductive adhesive 13 is hardened by forced drying with hot air or the like or natural drying, and the electrode 2 and the spring terminal 11 are fixed and electrically connected via the adhesive 13.

At the joint portion of the electrode barbed terminal 11, due to the flexibility of the adhesive 13, vibrations are absorbed even if the electrode deviates from the node point of the piezoelectric body 3 to some extent, causing the spring terminal 11 to resonate or damping the vibration of the piezoelectric body 3. is reduced, and the flexible conductive adhesive 13 between the electrode 2 and the spring terminal 11 acts as a buffer, preventing the spring terminal 11 from scraping the electrode 2, and reliably maintaining the bonded state between the two.

<Effects of the Invention> As described above, according to the present invention, the electrode and the spring terminal are connected by bonding the flat end of the spring terminal to the flexible conductive adhesive applied to the piezoelectric electrode. It has the effect of enumerating.

(D) The electrode and the spring terminal can be reliably joined,
A stable conduction state similar to soldering can be obtained.

■ Due to the flexibility of the adhesive, it absorbs vibrations even if it deviates to some extent from the node point position of the piezoelectric body, and there is less chance of the spring terminal resonating or damping the vibration of the piezoelectric body (,
The range of joining positions is wide (which makes assembly work easier).

(2) The flexible conductive adhesive prevents the electrode from being scraped off by the spring terminal (and the bonded state can be reliably maintained).

(ll) Since the flat end portion of the spring terminal is adhesively fixed to the electrode, the spring pressure of the spring terminal can be reduced, and design conditions such as the spring pressure and shape of the spring terminal can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a lead extraction structure for a piezoelectric body according to the present invention, and FIG. 2 is a front view showing a conventional lead extraction structure. 1... Piezoelectric element 2... Electrode 3... Piezoelectric body 11... Spring terminal 12... Flat tip portion 13... Flexible conductive adhesive

Claims (1)

[Claims] (1) A piezoelectric lead made by coating and bonding a flexible conductive adhesive onto the electrode provided on the surface of the piezoelectric element, bonding the flat end of the spring terminal to this adhesive, and then curing the flexible conductive adhesive. Drawer structure.