JPH033412A - Piezoelectric vibrator and its manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a piezoelectric vibrator for which frequency stability is not strictly required, and a method for manufacturing the same.

[Prior Art] Generally, piezoelectric vibrators are used in places where high frequency stability is required. In many cases, this is manufactured by first connecting a stem or the like to the vibrator to mechanically support it, covering it with a metal case, and hermetically sealing the metal case.

[Problems to be Solved by the Invention] On the other hand, with the rapid spread of electronic devices in recent years, demands for improved reliability standards have become stricter, and along with this, standards for frequency stability have also become stricter. For this reason, although the frequency stability of signals generated by LC oscillation circuits was conventionally sufficient, the standards are no longer able to satisfy the requirements. A solution to this problem is to use a piezoelectric vibrator, but since this element is manufactured using the method described above, there is a limit to its mass production. There was a problem that it was too uneconomical to use it instead.

[Means for Solving the Problems] In order to solve these problems, the present invention continuously constructs piezoelectric vibrators using band-shaped flexible printed circuit boards.

[Operation] Electrodes for attaching components are successively provided adjacent to each other in the longitudinal direction of a strip-shaped flexible printed circuit board, and piezoelectric vibrators and lead wires are sequentially connected to predetermined locations on the electrodes, and the piezoelectric vibrator element is connected to the piezoelectric vibrator element. The entire piezoelectric vibrator element is covered with a film-like cap in a non-contact state, and the parts except for a part of the lead wire are coated with hard resin.

[Embodiment] FIG. 1 is a diagram showing an embodiment of the present invention, in which 1 is a strip-shaped and long flexible printed circuit board made of a material such as polyester or polyimide; 21.
Reference numerals 22 denote electrodes provided adjacent to each other in the longitudinal direction of the flexible printed circuit board 1. This electrode is usually formed by attaching a foil metal such as copper to a film plate using the flexible plant board manufacturing method and etching it, but it is also possible to attach a foil electrode that has been formed into an electrode shape in advance. Also good. Such a flexible printed circuit board 1 is wound up as shown in the figure, and is moved to the right at a predetermined speed while being unwound by a device (not shown). When the flexible printed circuit board 1 moves to the right and reaches the position indicated by symbol A, the electrodes 2 □, 2
A piezoelectric vibrator element 3 is connected to a predetermined location of 2.

When the flexible printed circuit board 1 further moves to the right and reaches the position indicated by symbol B, the lead line 4
1.4□ is connected to the lead wire connection portion of the electrode 21.2□.

In this way, the piezoelectric vibrator element 3 and the lead wire 41
．． Flexible print I/board 1 with 42 attached
When it moves further to the right, it is covered with a film-like cap 5 as shown at the right end in FIG.

This cap 5 maintains the vibration space of the piezoelectric vibrator element 3, and is configured to cover the piezoelectric vibrator element 3 from above without contacting the piezoelectric vibrator element 3. The cap 5 may be a single piece, but in this embodiment, portions corresponding to the cap are continuously formed on a long film at intervals at which piezoelectric vibrator elements are attached using a diaphragm device (not shown). something is being used. That is, a strip-shaped film made of polyester or the like, on which the cap 5 is formed, is placed on the piezoelectric vibrator element 3 in accordance with the moving speed of the flexible printed circuit board l.Then, the cap 5 is removed by a device (not shown). It is fixed to the flexible printed circuit board 1 by a method such as adhesion or thermocompression bonding. The cap 5 is provided with an adhesive layer coated or pasted on the adhesive surface in advance, and can be easily adhered by applying a knife or pressure. In addition,
In this example, an example is given in which a cap with a concave portion formed in advance is used, but when a flat film is placed over a piezoelectric vibrator element and heated by thermocompression, etc., the cap inside expands, creating a space inside. It is also possible to make one. cap 5
Once the fixation has been completed, the pieces are separated individually, resulting in the state shown in Figure 2.

A hard resin coating is applied to this to complete the piezoelectric vibrator in the shape shown in FIG.

Since the circuit constructed in this way is sealed with resin, the frequency stability is worse than that of conventional hermetic seals, but the stability is orders of magnitude better than that of an LC oscillation circuit, and it is easy to use in assembly lines. Since it can be manufactured easily, the price can be made comparable to that of an LC oscillation circuit.

Note that, since there is a part where heat is applied during the work process, if the flexible printed circuit board 1 and the cap 5 are deformed by the heat, the cap 5 may come into contact with the piezoelectric vibrator element, making it impossible to secure a desired vibration space. For this reason,
The flexible printed circuit board 1 and the cap 5 must be selected from materials that are not easily deformed by heat, or the cap 5 must be structured so that it does not come into contact with the piezoelectric vibrator element 3 even if it is slightly deformed. In the example, an example of a thin piezoelectric vibrator was shown, but in the case of a thick piezoelectric vibrator (low frequency piezoelectric vibrator), the main surface of the piezoelectric vibrator comes into contact with the flexible printed circuit board, so the gap between the electrodes is This can be achieved by making a through hole in the flexible printed circuit board in advance, fixing the piezoelectric vibrator thereon, and then covering the flexible printed circuit board with a cap from the upper and lower surfaces.

[Effects of the Invention] As explained above, the first invention provides a method for attaching a piezoelectric vibrator element and a lead wire to a flexible printed circuit board,
Since the piezoelectric vibrator element is covered with a film-like cap,
The lead wire portion has flexibility, and even if some force is exerted during the manufacturing process, it can absorb that force and is less likely to be mechanically damaged, which has the effect of improving yield.

The second invention is one in which piezoelectric vibrator elements are sequentially attached to a long flexible printed circuit board, a cap is placed on the piezoelectric vibrator elements, and the piezoelectric vibrator elements are individually cut out and coated with hard resin, so that continuous production is possible. Since mass production is now possible, it has the effect of being able to be configured economically.

[Brief explanation of the drawing]

Figure 1 is a perspective view for explaining the invention in detail, Figure 2 is a perspective view for explaining the invention in detail;
The figure is a perspective view showing a state in which the first part is individually separated, and FIG. 3 is a perspective view showing a state in which the first part is coated with a resin. 1...Flexible printed circuit board, 2...Electrode, 3...Piezoelectric vibrator element, 4...Leader line,
5...Cap.

Claims (2)

[Claims] (1) An electrode for attaching components provided on a flexible printed circuit board, a piezoelectric vibrator element and a lead wire connected to a predetermined location of the electrode, and a piezoelectric vibrator that does not touch the piezoelectric vibrator element. A piezoelectric vibrator consisting of a film-like cap that covers the entire body, and a hard resin coated over the entire body except for some of the lead wires. (2) Electrodes for attaching components are provided adjacent to each other in the longitudinal direction of a strip-shaped flexible printed circuit board, and piezoelectric vibrator elements and lead wires are sequentially connected to predetermined locations on the electrodes, and piezoelectric vibrator elements are connected to the piezoelectric vibrator elements. A method of manufacturing a piezoelectric vibrator, in which the entire piezoelectric vibrator element is covered with a film-like cap without contact, and a hard resin is applied except for a part of the lead wire.