JPH1127079A - Piezoelectric vibrator - Google Patents

Abstract

(57) [Abstract] [Object] To reduce the size of the entire container by embedding a piezoelectric vibrator in a part of a concave portion of the container in which a multilayer ceramic substrate (plate) is bonded (laminated). Further, when the piezoelectric vibrator is mounted and fixed in the concave portion, stress is forcibly applied to the piezoelectric vibrator due to the warpage of the ceramic substrate due to heating during the fixing. [Structure] When a conductive part of a piezoelectric vibrator of a multilayer ceramic container and an electrode part of the piezoelectric vibrator are fixed to each other with solder or a conductive adhesive and conductive, unnecessary stress is applied to the piezoelectric vibrator in a subsequent heating process. Before mounting the piezoelectric vibrator, before mounting the piezoelectric vibrator, an adhesive is applied to at least two places on the piezoelectric vibrator housing portion (concave portion) of the ceramic container other than the conductive portion of the piezoelectric vibrator, or the piezoelectric vibrator is in contact with the piezoelectric vibrator in the concave portion. By forming at least two convex portions on the surface, and providing a slight gap between the piezoelectric vibrator and the surface of the concave portion in contact with the piezoelectric vibrator, the amount of heat applied to the entire piezoelectric vibrator can be reduced. Solve.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric vibrator for a ceramic container in which unnecessary stress is not applied to the piezoelectric vibrator when the piezoelectric vibrator is mounted and fixed on a multilayer ceramic container.

[0002]

2. Description of the Related Art In recent years, with the miniaturization and high performance of equipment, the material of a container for a piezoelectric vibrator or a piezoelectric oscillator has also been required to have a ceramic substrate layer on which piezoelectric components and mounted electronic components can be efficiently mounted at high density. Multi-layered containers are used.

As shown in FIG. 4, a multilayer ceramic substrate (plate) is bonded (laminated), a doughnut-shaped substrate is bonded to a part of the ceramic substrate to form a concave portion, and a piezoelectric vibrator is formed in the concave portion. By embedding, the entire container can be further miniaturized.

A piezoelectric vibrator is housed in a concave portion of a ceramic container, and an electrode portion of the piezoelectric vibrator and a conductor portion routed to the ceramic container are fixed to each other with a solder or a conductive adhesive to establish conduction. .

[0005]

However, the piezoelectric vibrator is mounted almost directly on the multilayer ceramic container, and the conductor portion on the ceramic substrate and the electrode portion of the piezoelectric vibrator are fixed with solder or a conductive adhesive. Therefore, after mounting the piezoelectric vibrator, the entire multilayer ceramic container must be heated.

At this time, due to the difference in the coefficient of thermal expansion between the multilayer ceramic container and the piezoelectric vibrator, the conductive portion of the piezoelectric vibrator of the multilayer ceramic container (the portion that secures and conducts)
Unnecessary stress is applied to the electrode part of the piezoelectric vibrator and it is fixed as it is.Therefore, there is a problem that it is difficult to maintain the quality in the process of mounting the piezoelectric vibrator on the multilayer ceramic container and to improve the production yield. Was.

[0007]

In order to solve this problem, the conductive portion of the piezoelectric vibrator of the multilayer ceramic container and the electrode portion of the piezoelectric vibrator are fixed by soldering or a conductive adhesive, and when the conductive portion is conductive, the subsequent heating is performed. Before mounting the piezoelectric vibrator, apply an adhesive to at least two portions of the piezoelectric vibrator accommodating portion (concave portion) of the ceramic container other than the conducting portion of the piezoelectric vibrator so that unnecessary stress is not applied to the piezoelectric vibrator in the process. By applying or forming at least two convex portions on the surface of the concave portion in contact with the piezoelectric vibrator, by providing a slight gap between the surface of the concave portion in contact with the piezoelectric vibrator and the piezoelectric vibrator, the piezoelectric vibration The problem was solved by reducing the amount of heat applied to the whole child.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In each drawing, the same reference numeral indicates the same object. FIG. 1 shows a partial sectional view of an embodiment of the present invention. Although the external terminals are not shown, the external terminals are arranged on the bottom surface of the ceramic container 2. The entire ceramic container 2 has a structure in which at least two or more multilayer ceramic substrates 1 are bonded (laminated).

[0009] From the bottom of the ceramic container 2, that is, from the ceramic substrate 1 mounted on the printed board, the piezoelectric vibrator
A flat ceramic substrate 1 is used up to the ceramic substrate 1 on which the piezoelectric vibrator 3 is mounted, and a donut-shaped ceramic substrate 5 is arranged so that the ceramic substrate 1 is disposed only around the piezoelectric vibrator 3 above the mounting surface of the piezoelectric vibrator 3. Has become. FIG. 2 shows a perspective view of the structure of the multilayer ceramic container 2 of the present invention in order to make this shape easy to understand.

As can be seen from FIG. 2, the ceramic container 2 has a structure in which a multilayer ceramic substrate 1 is bonded. In this embodiment, the structure of a ceramic container 2 in which three layers of ceramic substrates 1 are bonded will be described. A ceramic container (a) mounted on a printed circuit board, a ceramic substrate (b) mounting a piezoelectric vibrator, and a donut-shaped ceramic substrate (c) forming an edge recess of the ceramic container are all bonded together to form a ceramic container 2. The ceramic substrate (a) and the ceramic substrate (b) are flat plates, and the piezoelectric vibrator 3
And a doughnut-shaped ceramic substrate (c) is adhered on the ceramic substrate (b) so as to cover the ceramic substrate (b).

Accordingly, when viewed from the entire ceramic container 2,
The recess 4 is formed in the ceramic container by the donut-shaped ceramic substrate (c), and the piezoelectric vibrator 3 is mounted in the recess 4. In the present invention, the method of mounting the piezoelectric vibrator 3 on the ceramic substrate (b) to secure adhesion and conduction is not limited to soldering or a conductive adhesive. In FIG. 2, the conduction pattern of the ceramic container 2 on which the piezoelectric vibrator 3 is mounted and which is electrically connected to the fixing is not shown.

FIG. 3 is an enlarged view of a mounting portion of the piezoelectric vibrator 3 which is a feature of the present invention. Unlike the conventional method of mounting the piezoelectric vibrator 3 shown in FIG. 4, when the piezoelectric vibrator 3 is mounted on the ceramic substrate 1, the ceramic substrate 1 and the piezoelectric vibrator 3
The piezoelectric vibrator 3 is mounted in such a manner that the piezoelectric vibrator 3 is floated by the adhesive 7 and the convex portion 6 on the ceramic substrate 1 so that a slight gap (t) is formed between the piezoelectric vibrator 3 and the piezoelectric vibrator 3.

FIG. 3A shows a structure in which a convex portion 6 is formed on a ceramic substrate 1 on which a piezoelectric vibrator 3 is to be floated. The protrusion 6 is formed of a ceramic material,
The piezoelectric vibrator 3 is floated by the convex portion 6 so that the piezoelectric vibrator 3 does not directly contact the ceramic substrate 1 to form a slight gap. The height (t) of the convex portion 6 is equal to or more than の of the thickness of the piezoelectric vibrator 3, and the contact area (w) with the piezoelectric vibrator 3 is equal to or more than the thickness of the piezoelectric vibrator 3. It is arranged at two places above.

FIG. 3B shows a method of mounting the piezoelectric vibrator 3 on which an adhesive 7 is applied to lift the piezoelectric vibrator 3.
As shown in FIG. 3A, a small gap is provided using an adhesive 7 so that the piezoelectric vibrator 3 does not directly contact the ceramic substrate 1. The adhesive 7 is applied. The adhesive 7 is applied to at least two or more places avoiding the electrode position of the piezoelectric vibrator 3. Although the present embodiment mainly describes a piezoelectric vibrator, it goes without saying that the present invention can also be applied to a method of mounting a piezoelectric vibrator incorporated in a piezoelectric oscillator or the like to which a peripheral circuit is added.

[0015]

According to the present invention, even when the piezoelectric vibrator is mounted on the multilayer ceramic container and heated for curing the solder or conductive adhesive for fixing and conducting the piezoelectric vibrator, the piezoelectric vibrator can be used. Manufacturing was possible without applying unnecessary stress to the vibrator, and maintenance and improvement of reliability and improvement of manufacturing yield were realized.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing a structure of a piezoelectric vibrator of the present invention.

FIG. 2 is a perspective view showing a multilayer ceramic container structure of the present invention.

FIG. 3 is an enlarged view of a mounting portion of a piezoelectric vibrator according to the present invention.

FIG. 4 is a partial sectional view showing a structure of a piezoelectric vibrator according to a conventional mounting method.

[Explanation of symbols]

 Reference Signs List 1 ceramic substrate 2 ceramic container 3 piezoelectric vibrator 4 concave portion 5 donut-shaped ceramic substrate 6 convex portion 7 adhesive

Claims (3)

[Claims] 1. A ceramic container comprising at least two or more multilayer ceramic substrates, wherein at least one layer of the multilayer ceramic substrate uses a donut-shaped ceramic substrate so that a concave portion can be formed in a portion where a piezoelectric vibrator is mounted. A piezoelectric vibrator characterized in that a convex portion is formed on the surface of the ceramic substrate in contact with the piezoelectric vibrator in the concave portion and the piezoelectric vibrator is mounted. 2. The height of a convex portion disposed on a surface of the concave portion in contact with the piezoelectric vibrator is at least half the plate thickness of the piezoelectric vibrator, and the contact area is at least the plate thickness of the piezoelectric vibrator. The piezoelectric vibrator according to claim 1, wherein: 3. The piezoelectric vibrator according to claim 1, wherein an adhesive is applied to the concave portion before mounting the piezoelectric vibrator on the convex portion.