JPH10145177A - Piezoelectric vibrator and manufacture of piezoelectric vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the surface mount type piezoelectric vibrator in which no gas is intruded in the package at sealing. SOLUTION: A piezoelectric vibration chip 1 is contained in a package 2 with a bottom, whose one side is open, and a cap is fitted to a metabolized layer 7 provided to a circumferential ridge 2a at an opening via a solder 8. In the piezoelectric vibrator of above, an outer circumference of the metabolized layer 7 is smaller than the outer circumference of the circumferential ridge 2a of the opening, an inner circumference of the metalized layer 7 is equal to or larger than the inner circumference of the circumferential ridge 2a of the opening, an outer circumference of a cap 9 is smaller than the outer circumference of the metalized layer 7, and most parts of the solder 8 are soldered to parts at the outside of the outer circumferential part of the cap 9 and the outer circumference of the cap of the metalized layer 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a piezoelectric vibrator and a method for manufacturing a piezoelectric vibrator.

[0002]

2. Description of the Related Art FIG. 1 is an exploded perspective view of a conventional surface mount type piezoelectric vibrator. The main components are a piezoelectric vibrating reed 1, a bottomed cage 2 having a recess 2 b for accommodating the piezoelectric vibrating reed 1, a metal cap 3 for closing an opening of the bottomed cage 2, a bottomed holding A solder 4 for joining the container 2 and the metal cap 3. FIG. 2 is a cross-sectional view of a central portion in the longitudinal direction of a conventional piezoelectric vibrator. Bottomed cage 2
Is formed of ceramics, a metallized layer is formed on the entire surface of a peripheral edge 2 a of the opening of the bottomed cage 2, and the metal cap 3 is bonded and sealed with solder 4. Adhesive sealing is usually performed in a vacuum to improve the electrical characteristics of the piezoelectric vibrator.

[0003]

The metallization layer 6 is provided on the entire surface of the opening peripheral edge 2a.
During bonding and sealing, the gas generated when the solder 4 is melted enters the evacuated cage, increases the pressure inside the cage and adheres to the surface of the piezoelectric vibrator. This degrades the electrical characteristics (CI value, aging characteristics, etc.) of the piezoelectric vibrator.

When pressure is applied to bring the bottomed cage 2 and the metal cap 3 into close contact with each other, the solder 4 protrudes from the outer periphery and changes its outer shape. In addition, there is a possibility that the resin may protrude into the inside of the bottomed cage 2 and come into contact with a pattern (not shown) formed on the bottomed cage 2, the conductive adhesive 5, or the like to cause a short circuit.

If the metal cap 3 is made smaller than the outer periphery of the opening peripheral edge 2a in order to prevent the metal cap 3 from protruding to the outer periphery, it becomes difficult to position the metal cap 3 and the metal cap 3
And the leak at the sealing portion is likely to occur. An object of the present invention is to provide a structure and a manufacturing method of a piezoelectric vibrator that solve these problems.

[0006]

Means for Solving the Problems A piezoelectric vibrating reed is housed in a bottomed cage with one end opened, and a cap (preferably made of metal, preferably made of metal, is placed on a metallized layer provided on the periphery of the opening via solder. In a piezoelectric vibrator in which a metallized layer is provided on a sealing portion of a ceramic, a metal cap may be provided. Hereinafter, the metallized layer has an outer periphery smaller than an outer periphery of the opening peripheral portion and an inner periphery of the metallized layer has an opening peripheral portion. Having an inner circumference equal to or larger than the inner circumference of the portion, the outer circumference of the metal cap being smaller than the outer circumference of the metallization layer, and the solder being attached to the outer circumference of the metal cap and the outer portion of the metal cap outer circumference of the metallization layer. I do.

[0007] In a method of manufacturing a piezoelectric vibrator in which a metallized layer is provided on the periphery of an opening of a bottomed cage for accommodating a piezoelectric vibrating reed and a metal cap is heat-sealed with solder, at least the bottomed cage has A step of providing a metallization layer having an inner circumference smaller or larger than the outer circumference of the opening peripheral edge at the opening peripheral edge, and having an inner circumference equal to or larger than the inner circumference of the opening peripheral edge; and A step of positioning a flat donut-shaped solder having an outer periphery and having an inner periphery larger than the outer periphery of the metal cap at the opening and crimping the same; and a step of placing the metal cap on the metallized layer using the inner periphery of the solder as a guide. And a step of melting and sealing the solder.

[0008]

FIG. 3 is a sectional view showing each step for explaining a manufacturing method of the present invention. A shows a metallized layer 7 having an inner periphery whose outer periphery is smaller than the outer periphery of the opening periphery 2a and whose inner periphery is equal to or larger than the inner periphery of the opening periphery 2a at the opening periphery 2a of the bottomed cage 2. FIG.
B is a state diagram in which a flat donut-shaped solder 8 having an outer circumference equal to or smaller than the outer circumference of the opening peripheral edge 2a and having an inner circumference larger than the outer circumference of the metal cap 9 is positioned and crimped on the opening peripheral edge 2a. is there. FIG. 3C is a diagram showing a state in which the metal cap 9 is placed on the metallized layer 7 using the inner periphery of the solder 8 as a guide. D is a state diagram in which the solder 8 is melted and sealed. At the time of sealing, the metal cap 9 is heated while being pressed in a vacuum chamber.

The present invention is a manufacturing method having at least the above four steps. The step of attaching the piezoelectric vibrating reed 1 to the bottomed holder 2, the step of adjusting the frequency of the piezoelectric vibrating reed 1, and heating the whole in a vacuum. The annealing step or the like may be performed between step A and step C.

FIG. 4 is an enlarged sectional view of a sealing portion of the piezoelectric vibrator of the present invention. The bottomed cage 2 a and the metal cap 9 are sealed by the solder 8 with the side surface 9 a of the metal cap 9 and the metallized layer 7. There is little possibility that the solder 8 may enter the mating surface of the metallized layer 7 and the lower surface of the metal cap 9 depending on the pressing condition, but there is almost no possibility. (Although the metallized layer 7 is written with a considerable thickness in the figure, it is actually an extremely thin layer, and its surface is plated with solder.)

There is no metallized layer 7 on the outer peripheral portion of the opening peripheral portion 2a, and since the solder 8 does not adhere outside the outer periphery of the metallized layer 7, the sealing portion becomes larger than the outer shape of the bottomed cage 2. No overhang phenomenon occurs.

FIG. 5 shows another embodiment of the piezoelectric vibrator of the present invention, and is an enlarged sectional view of a sealing portion. Metal cap 10
The side surface 10a, which is the sealing portion, is formed in a stepped shape, and has more sealing surfaces than the sealing portion in FIG.

FIG. 6 shows still another embodiment of the present invention.
It is an expanded sectional view of a sealing part. The side surface 11a which is a sealing portion of the metal cap 11 is formed obliquely, and has a larger sealing surface than the sealing portion in FIG. In addition, metallization layer 1
Reference numeral 2 denotes an outer periphery smaller than the outer periphery of the opening peripheral portion 2a and an inner periphery larger than the inner periphery of the opening peripheral portion 12a.
Even if solder enters the mating surface between the metallized layer 12 and the lower surface of the metal cap 11, the solder does not easily enter the recess 2 b of the bottomed cage 2. 5 and 6, the manufacturing method is the same.

[0014]

The present invention has the above-described structure,
The gas generated when the solder is melted rarely penetrates into the evacuated bottomed holder, and does not deteriorate the electrical characteristics of the piezoelectric vibrator. Further, the solder does not protrude to the outer periphery of the bottomed cage.

By adopting the manufacturing method of the present invention, since the cap is positioned by the solder, even if the cap is smaller than the outer periphery of the bottomed cage, the positioning accuracy of the cap is improved, and the generation of a leak from the sealing portion is eliminated. .

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a conventional surface mount type piezoelectric vibrator.

2 is a longitudinal sectional view of FIG. 1;

FIG. 3 is a sectional view of each step for explaining the present invention.

FIG. 4 is an enlarged sectional view of a sealing portion of the piezoelectric vibrator of the present invention.

FIG. 5 is an enlarged sectional view of a sealing portion of another embodiment of the piezoelectric vibrator of the present invention.

FIG. 6 is an enlarged sectional view of a sealing portion of another embodiment of the piezoelectric vibrator of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric vibrating reed 2 Bottomed cage 2a Opening periphery 2b Depressed portion of bottomed cage 3 Metal cap 4 Solder 5 Conductive adhesive 6 Metallized layer 7 Metallized layer 8 Solder 9 Metal cap 9a Side face of metal cap 10 Metal cap 10a Side of metal cap 11 Metal cap 11a Side of metal cap 12 Metallized layer

Claims (2)

[Claims] 1. A piezoelectric vibrator in which a piezoelectric vibrating reed is housed in a bottomed cage having one open side, and a cap is attached via a solder to a metallized layer provided on the periphery of the opening.
The outer periphery of the metallized layer is smaller than the outer periphery of the peripheral portion of the opening, and the inner periphery of the metallized layer has an inner periphery equal to or larger than the inner periphery of the peripheral portion of the opening. The outer periphery of the cap is smaller than the outer periphery of the metallized layer, and the size of the solder is large. A piezoelectric vibrator characterized in that the portion is attached to an outer peripheral portion of the cap and to a portion of the metallized layer outside the outer periphery of the cap. 2. A method of manufacturing a piezoelectric vibrator in which a metallized layer is provided on a peripheral portion of an opening of a bottomed cage for accommodating a piezoelectric vibrating piece and a cap is heated and sealed with solder, at least in the bottomed cage. Providing a metallized layer having an inner periphery smaller or larger than the outer periphery of the opening periphery at the outer periphery of the opening, and having an inner periphery equal to or larger than the inner periphery of the opening periphery; A step of positioning a flat donut-shaped solder having an inner periphery larger than the outer periphery of the cap and having a small outer periphery at the opening and crimping the same, and a step of placing the cap on the metallized layer using the inner periphery of the solder as a guide, A method for manufacturing a piezoelectric vibrator, comprising a step of melting and sealing solder.