JPH0388509A - Piezoelectric vibrator - Google Patents

Abstract

PURPOSE:To improve shock resistance by making a holding arm abut on the outer periphery of a piezoelectric piece, making the outer peripheral part of the piezoelectric piece, which abuts on the extension start end part of the holding arm, free, and fixing the outer peripheral part of the piezoelectric piece, which abuts on the extension end part of the holding arm, at right angles to a straight line connecting a support shaft part. CONSTITUTION:The holding arm 11 is made arcuate so that its length does not exceed the half of the outer periphery of a crystal piece 1. Then the parts of the outer peripheral parts of both ends of the crystal piece 1 are matched with each other in a direction which crosses the straight line connecting the support shaft part 6 almost at right angles. Then the outer peripheral parts which abut on both the end sides of the holding arm 11 are fixed. Further, the outer peripheral part of the crystal piece 1 which abuts on the center part of the holding arm 11 is made almost free to an external force. Consequently, the external force of the curvature, etc., of a substrate at the time of a shock is transmitted to the fixed end of the crystal piece 1 through the holding arm 11. Then the external force is absorbed by the elasticity and oscillation of the holding arm 11 and weakened to reduce the stress generated in the crystal piece.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a field of application of piezoelectric vibrators, and relates to, for example, a holding method for improving the impact resistance of a surface-mounted crystal vibrator.

(Background of the Invention) Due to their excellent resonance characteristics, crystal resonators are often used as oscillators and filter elements, and in particular, surface-mounted types are becoming useful like other components due to the miniaturization and automation of various electronic devices. . In recent years, there has been a desire for something that can prevent oscillation stop (damage to the crystal piece) and frequency changes due to shocks caused by frequent movement.

(Prior Art) Figure 1 shows the factors of a crystal oscillator illustrating a conventional example of this type, Figure (a) is an exploded view, and Figure (b) is a plan view of the main parts.

The crystal resonator is, for example, a disk-shaped crystal piece with an AT cut.
is held on the substrate 3 by the holding member 2. crystal piece 1
Excitation electrodes 5 extend from the excitation electrodes 4 formed on both main surfaces to the outer periphery of both ends. The holding member 2 has an L-shaped support shaft 6.
An arc-shaped holding arm 7 is provided on the tip side of the holding arm 7. And L
The lower end portion 2-8 of the letter shape is attached to a conductive path (not shown) of the board. In addition, the outer circumferential portions of both ends of the crystal piece 1 are made to approximately coincide with the center of the holding arm 7 (the starting end of extension from the support shaft portion 6), and conductive adhesive 9 is applied to three locations at the center and both ends. The configuration shall be electrically and mechanically connected. Note that the conductive path of the substrate 3 extends to the back surface side and becomes an external terminal. Further, the substrate 3 is covered with a cover (not shown), and the crystal piece 1 is hermetically sealed.

(Problems with the Prior Art) However, in the crystal resonator having the above configuration, the outer periphery of both ends of the crystal piece 1 is the central part (extending start end) of the holding arm 7, respectively.
It is fixed in place. The starting end of the extension becomes both ends on a straight line connecting the respective support shafts 6, and also serves as a fixed end. Therefore, in such a device, deformation, for example, warping of the substrate during an impact or the like generates direct stress on the crystal piece 1 via the support shaft. Then, the crystal blank 1 is damaged or detached from the holding member, and oscillation is stopped. Further, even if the crystal blank 1 is not damaged, the frequency is changed depending on the stress sensitivity characteristics of the crystal blank 1. In particular, in the case of deformation due to heat, there is a problem that the overall impact resistance is inferior, such as deterioration of frequency temperature characteristics.

(Objective of the Invention) An object of the present invention is to provide a crystal resonator having a holding structure with good impact resistance.

(Solution Means) In the present invention, a holding arm extending from a support shaft of a holding member is brought into contact with the outer periphery of a piezoelectric piece, and the outer periphery of the piezoelectric piece that comes into contact with the extension start end of the holding arm is set at a free end. The solution is that the outer periphery of the piezoelectric piece that comes into contact with the extension terminal end of the holding arm is made to be a fixed end perpendicular to the straight line connecting the support shaft. An embodiment of the present invention will be described below.

(Embodiment) FIG. 1 is a diagram of a crystal resonator illustrating an embodiment of the present invention, in which (a) is an exploded view, and (b) is a plan view of the main part. In addition, the same numbers are given to the same parts as in the previous conventional example diagram, and the explanation thereof will be simplified.

The crystal resonator is made up of a crystal piece 1 held on a substrate 3 by a holding member 10 in the same manner as described above. The holding member is an L-shaped support shaft 6
and a holding arm 11 extending equally from the tip to both sides and abutting along the outer circumference of the crystal piece 1. In this embodiment, the length of the holding arm 11 is longer than that of the conventional example, and has an arcuate shape that does not exceed half of the outer circumference of the crystal piece 1. And the crystal piece l draw-out power! ! ! The outer periphery of both extended ends of the holding arm 9 is connected to the extending terminal end of one side of each holding arm 9 and the conductive adhesive 1.
1 to connect electrically and mechanically. Further, each of the two ends is mechanically connected to the other end of the extension.

In this case, it goes without saying that the conductive adhesive 11 may be replaced with an insulating adhesive.

That is, the outer periphery portions at both ends of the crystal piece 1 are aligned in a direction substantially perpendicular to the straight line connecting the support shaft portions 6.

The outer circumferential portion that comes into contact with both ends (terminus of extension) of the holding arm 11 is a fixed end. Further, the outer circumferential portion of the crystal piece 1 that comes into contact with the central portion (starting end of extension) of the holding arm 11 is made to be a substantially free end against external force.

With such a configuration, external force such as warping of the substrate at the time of impact or the like is transmitted to the fixed end of the crystal piece 1 via the holding arm 11. Then, the external force is absorbed and weakened by the elasticity and swinging of the holding arm 11.

The stress generated in the crystal piece is reduced. Therefore, it is possible to prevent damage to the crystal piece 1, maintain frequency change due to stress sensitivity characteristics and frequency temperature characteristics, and improve overall impact resistance.

(Other matters) In the above embodiment, the holding arm 11 is arcuate, but
The shape is not limited to this, and can be determined depending on the shape of the crystal piece 1. In addition, the length of the holding arm 11 was set to a length not exceeding half the circumference of the crystal piece 1, but basically, the effect can be obtained by setting the extending start end of the holding arm 11 as a free end and the extending end as a fixed end. can be expected. However, since the longer the holding arm 11 is, the more elastic it becomes and the more it absorbs external force, it is considered practical if the holding arm 11 has an outer circumference of 174 mm or more.

Further, although the support shaft portion of the holding member 10 is L-shaped and its lower end is attached to the substrate, it may be formed into an inverted T-shape, for example, to improve stability. Further, the support arm 11 may be extended in the same plane as the holding arm 11 and directly led out of the container as an external terminal. refers to something that supports

(Effects of the Invention) According to the present invention, the holding arm extending from the support shaft portion of the holding member is brought into contact with the outer periphery of the piezoelectric piece, and the outer periphery of the piezoelectric piece that comes into contact with the extending start end of the holding arm is whitened. A crystal resonator with good shock resistance is provided because the outer circumferential portion of the piezoelectric piece that contacts the extending terminal end of the holding arm is made perpendicular to the straight line connecting the support shaft portion and is a fixed end. can.

[Brief explanation of drawings]

FIG. 1 is a diagram of a crystal resonator illustrating an embodiment of the present invention, in which FIG. 1(a) is an exploded view and FIG. 1(b) is a plan view of a main part. Figure 2 is a diagram of a crystal oscillator explaining a conventional example.
) is an exploded view, and (b) is a plan view of the main parts. Suzu

Claims (1)

[Claims] In a piezoelectric vibrator in which the plate surface is set horizontally to the base by a pair of holding members, and the outer periphery of both ends of a piezoelectric piece extending from an excitation electrode to an extraction electrode is electrically and mechanically connected. , a support shaft portion that attaches the holding member to a base; and a holding arm that extends in both directions from the tip side (starting end of extension) of the support shaft portion and abuts along the outer periphery of the piezoelectric piece; The outer circumferential portion of the piezoelectric piece that comes into contact with the extending start end of the holding arm is a free end, and the outer circumferential portion of the piezoelectric piece that makes contact with the extending end of the holding arm is a straight line connecting the support shaft portion. A piezoelectric vibrator characterized by fixed ends that are orthogonal to each other.