JPH01180109A - Piezoelectric vibrator - Google Patents

Abstract

PURPOSE:To make the thickness remarkably thin by fixing a paper-tablet lead plate to both ends of a paper-tablet piezoelectric substance with an electrode formed onto both side plate faces and clipping the lead plate by a couple of paper-tablet shells having a recessed part at the center and applying airtight sealing. CONSTITUTION:Both ends of the piezoelectric substance 11 is fixed respectively to a lead plate 12 made of paper-tablet metallic plate respectively, prolonged externally with pressing and each lead plate 12 is connected electrically to a connection electrode 11b. Then a recessed part 13a is formed to the middle of the opposed face made of a thin metallic plate in opposite to both side plate faces of the lead plate 12, and a couple of paper-tablet shells 13 with equal width to that of the lead plate. Then a through hole 14a is made to the middle part corresponding to the recessed part of the shells between the shells 13 and the lead plate 12 and a sheet 14 made of fibers with an adhesive immersed thereto is interposed, the lead plate 12 is clipped from both sides by the shell 13 via the sheet 14 to apply airtight sealing. Thus, the thickness is made remarkably thin.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention provides a piezoelectric vibrator whose overall thickness can be significantly increased.

(Technical background of the invention and its problems) In general, piezoelectric FA1!1 elements are used in large quantities in the wide field of electronic technology, and in particular, crystal resonators using crystal pieces as piezoelectric bodies have high frequency stability. , communication AI device,
It is widely used as a time and frequency reference source for digital bullet control equipment, etc.

In particular, the miniaturization of electronic equipment in recent years 1. The demand for piezoelectric vibrators is increasing as they become more sophisticated, and reductions in price and size are progressing at a rapid pace.Also, as surface mounting technology advances, piezoelectric vibrators that are thin and can be surface mounted are desired.

For this reason, piezoelectric vibrators have been put into practical use, for example, in which a crystal piece is held on a plate-shaped base made of ceramic or the like, and a cover is placed over the crystal piece.

FIG. 4 is a side sectional view showing an example of such a piezoelectric vibrator, in which a metal holding piece 2 is fixed to a plate-shaped base l made of ceramic, and both ends of a crystal piece 3 are attached to this holding piece 2. hold.

Then, the electrodes formed on the crystal piece 3 are led out from the plate surface of the base 1 through a conductive pattern 4 formed by, for example, 4F metallization processing. A box-shaped ceramic lid 5 with an open bottom is placed over the base 1 to airtightly seal it.

In this way, the heat resistance of the ceramic used for the base 1 and the lid 5 is good, and the base 1 and the lid 5 are
If they are made of the same material, they have the same coefficient of thermal expansion, and even if they are heated for soldering when mounted on a printed circuit board, no damage such as cracks or chips will occur, and reliability can be improved.

However, as shown in FIG. 4, a container made of ceramic cannot be used for a card-type electronic device having a thickness of about 1 mm because the thickness is not very large.

For this purpose, a Utility Application filed in 1986 by the same applicant as the present invention.
- As in No. 161494, an idea is to connect electrodes to both ends of a piezoelectric body and connect them to a thin lead plate, and to sandwich this lead plate from both sides of the plate through a sheet impregnated with adhesive. It is being

By the way, in such a device, a lead plate is fixed in advance to both ends of a piezoelectric body with electrodes formed on the plate surface, and both sides of the plate surface of the lead plate are sandwiched between a pair of shells having recesses formed on the opposing surfaces. High precision is required to position the lead plate relative to the shell during chirping, which may cause problems such as poor appearance and, in extreme cases, deterioration of electrical characteristics due to contact between the piezoelectric body and the shell.

(Object of the Invention) The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a piezoelectric vibrator that can be made extremely thin in overall thickness and is easy to assemble. It is.

(Summary of the invention) The present invention applies to both side plate surfaces? A rectangular lead plate was fixed to both ends of a rectangular piezoelectric body that formed a pole, and a pair of rectangular shells with a recess formed in the center with the same width as the lead plate were impregnated with adhesive. The present invention is characterized in that the piezoelectric body is hermetically sealed by sandwiching the lead plate with a sheet interposed therebetween.

(Embodiment) The following is an assembled perspective view of an embodiment of the present invention shown in FIG.
This will be explained in detail with reference to the plan view shown in the figure and the sectional view of the main part shown in FIG.

In the figure, reference numeral 11 indicates a structure in which, for example, a quartz crystal is cut at a predetermined angle, formed into a rectangular plate shape, electrodes 11a are provided on both sides of the plate, and these electrodes 11a are led out to connection electrodes 11b at both ends in the elongated direction. It is a piezoelectric material.

Then, both ends of the piezoelectric body 11 are fixed to lead plates 12 formed into rectangular thin metal plates, such as nickel silver, to extend outward, and each lead plate 12 is connected to the connection electrode 11b. electrically connected.

Furthermore, cutouts 12a are provided on both sides of the portion of the lead plate 12 where the piezoelectric body 11 is fixed to the piezoelectric body in order to reduce the effect of external shocks on the piezoelectric body, and a through hole 12 is provided in the center of the lead plate 12.
b to increase the elasticity of the lead plate 12.

Then, facing each side of the lead plate 12, a recess 13a made of a thin metal plate such as 5O9304 is formed in the center of the opposing face, and a pair of rectangular plates having the same width as the lead plate are formed. A shell 13 is provided.

A through hole 14a is provided in the center between each shell 13 and the lead plate 12, corresponding to the recess 13a of the shell 13.
A sheet 14 impregnated with an adhesive, for example, made of glass A fiber, etc. is interposed, and the lead plate 12 is sandwiched between the shells 13 from both sides through the sheet 14 and bonded to make it airtight. Seal. The sheet 14 impregnated with adhesive in this manner is non-conductive, and serves to fix the lead plate 12 to the shell 13 and electrically insulate the two.

Since the shell 13 and the lead plate 12 have the same width, they can be easily positioned by aligning their edges in the width direction.

Further, in the above embodiment, the thickness of the lead plate 12 located outside the shell 13 is thicker than the thickness of the lead plate 12 at the inside of the shell 13 and the penetration portion. The (a1) determination of the lead plate 12 relative to the lead plate 12 can be easily determined, which has the advantage of significantly improving productivity.

In this way, for example, the thickness of the lead plate 12 and the sheet 14 can be set to 0.05 mm, and the thickness of the shell 13 can be set to 0.5 mm.
rnm, and the overall thickness after assembly can be made as thin as about 1 mtn.

Therefore, it can be used for card-type electronic devices, etc.
It is possible to provide a piezoelectric vibrator that is easy to assemble and is inexpensive.

Note that the present invention is not limited to the above embodiments,
For example, the shell 13 may be made of glass, ceramic, etc., and it goes without saying that these surfaces may be coated with metal to provide shielding.

(Effects of the Invention) As described in detail above, according to the present invention, it is possible to provide a piezoelectric vibrator that can be significantly thinned and can be used in card-type electronic equipment.

[Brief explanation of the drawing]

Fig. 1 is a vertical perspective view showing one embodiment of the present invention. Fig. 2 is a plan view showing the piezoelectric body shown in Fig. 1 fixed to a lead plate. Fig. 3 is a main part of the above embodiment. FIG. 4 is a side sectional view showing an example of a conventional thin pressure transducer. 11... Piezoelectric body 12... Lead plate 13... Shell 14... Sheet No. 21! ! Figure 3, 4th flash

Claims (3)

[Claims] (1) A rectangular piezoelectric body with electrodes formed on both side plate surfaces and led out to both ends in the longitudinal direction; a pair of rectangular shells having a width equal to that of the lead plates, and a pair of rectangular shells with a width equal to that of the lead plates, which form a recess in the center of opposing surfaces and sandwich the lead plates from both sides of the plate surfaces; a sheet made of fibers impregnated with an adhesive, which is interposed on both sides of the lead plate on the opposing surface of the shell and has a through hole in the center corresponding to the recess. piezoelectric vibrator. (2) A piezoelectric vibrator according to claim 1, characterized in that cuts are provided on both sides of the portion of the lead plate to which the piezoelectric body is fixed. (3) In the product described in claim 1, the thickness of the portion of the lead plate located outside the shell is thicker than the thickness of the portion inside the shell and the portion penetrating the shell. A piezoelectric vibrator characterized by: