JP3023366U - Surface mount crystal unit - Google Patents

Abstract

(57) [Abstract] [Problem] A cylinder-type crystal unit, which is housed in a cylindrical metal container and has a pair of terminals led out from one end, can be surface-mounted with a simple structure, and is excellent. Obtains excellent impact resistance. [Solution] A cylindrical crystal resonator 1 is housed in a housing 2a of a base 2, and a pair of lead terminals 1b extending from one end of the cylinder are connected to a mounting electrode 2e for surface mounting formed on the bottom surface of the base. In this structure, a vertically elongated through hole 2c is provided at one end of the base body 2 so as to communicate with the housing portion 2a and allow the pair of lead terminals 1b to be penetrated only in a state of being vertically positioned. Mounting electrodes 2 on both sides
A holding electrode 2 electrically connected to each of the lead terminals 1e and electrically connected to the lead terminal 1b so as to be electrically connected and mechanically held
d is provided.

Description

[Detailed description of the device]

[0001]

[Technical field to which the device belongs]

 The present invention relates to a surface-mounted crystal oscillator in which a cylinder-type crystal oscillator is housed in a base body to be surface-mounted.

[0002]

[Prior art]

 Recently, in various electronic devices, a crystal oscillator that uses a crystal oscillator as a reference frequency as a time or frequency reference is widely used. On the other hand, electronic devices using such crystal oscillators are required to have smaller shapes and automated assembly. For this reason, electronic parts used are also required to be so-called chip type, which are small in shape and capable of surface mounting.

Since the conventional crystal unit is sealed in an inert gas, a vacuum atmosphere, etc., it is generally housed in a metal container so as to obtain reliable airtightness. That is, the electrodes are led out to the outside through a hermetic terminal or the like. For this reason, the outer circumference of the container is made of a conductive metal, and if the terminals are simply bent along the container, the terminals will contact the outside of the container and conduct electricity. Could not be surface mounted.

Further, a mounting electrode for performing surface mounting is formed on the bottom surface side of the plate-shaped insulating material, a holding electrode is provided on the surface side so as to be electrically connected to the mounting electrode, and a crystal vibration housed in a cylinder container is provided there. It is also considered to connect the lead terminals of the child. However, in such a device, when the lead terminal is connected to the holding electrode at the shortest distance, the lead terminal is mounted in a state of being arranged parallel to the plate surface of the insulating material, that is, horizontally. Therefore, the crystal piece held in the cylinder container in parallel with the arrangement direction of the lead terminals is held in parallel with the plate surface of the insulating material, and is greatly damaged by the stress acting in the direction perpendicular to the plate surface. There was a problem.

[0005]

[Problems to be solved by the device]

 The present invention has been made in view of the above circumstances, and a cylinder type crystal unit in which a pair of terminals are led out from one end of the cylinder type crystal unit is converted into a surface mount type by a simple structure. It is an object of the present invention to provide a surface-mount type crystal unit that can achieve high impact resistance.

[0006]

[Means for Solving the Problems]

 According to the present invention, a cylindrical crystal unit is housed in a housing space of a base and a pair of lead terminals extending from one end of a cylinder are connected to a mounting electrode for surface mounting formed on the bottom surface of the base. A vertical through hole is provided at one end of the base body, which communicates with the storage space and allows the pair of lead terminals to be penetrated only when positioned vertically. The present invention is characterized in that a holding electrode is provided which is electrically connected to connect the lead terminal to electrically connect the lead terminal and mechanically holds the electrode.

[0007]

【Example】

 Hereinafter, an embodiment of the present invention will be described in detail with reference to the perspective view shown in FIG. In the figure, reference numeral 1 is a crystal unit housed in a metal cylinder container 1a. The crystal oscillator 1 has a pair of lead terminals 1b extending from one end of a cylinder container 1a. A strip-shaped crystal piece 1c is housed in the cylinder container 1a, and the end of the crystal piece 1c in the longitudinal direction is fixed to the tip of the lead terminal 1b with a conductive adhesive or the like.

The plate surface of the crystal piece 1c is held parallel to the arrangement direction of the lead terminals 1b, and the excitation electrode formed on the plate surface of the crystal piece 1c is led out. Reference numeral 2 denotes a base formed by molding, and has a substantially rectangular parallelepiped outer shape, and forms a bottomed cylindrical storage portion 2a for storing the crystal unit 1 from one end thereof along the longitudinal direction. ing.

Then, a recess 2b is formed at the other end of the base body 2 in the horizontal direction through substantially the center of the height dimension, and a vertically long transparent member communicating with the housing 2a is formed in the center of the recess 2b. A hole 2c is formed to allow the pair of lead terminals 1b of the crystal unit 1 to pass through the through hole 2c only in a state in which the pair of lead terminals 1b is positioned vertically to the bottom surface of the substrate 2. ing.

Then, the crystal unit 1 is inserted from the lead terminal 1b side into the storage portion 2a of the base body 2 and stored. The lead terminals 1b penetrating the through holes 2c are bent outward at a substantially right angle and fixed to the holding electrodes 2d formed on both sides of the through holes 2c on the other end surface of the base 2 with, for example, a conductive adhesive. It is electrically connected and mechanically held. The holding electrode 2d is electrically connected to the mounting electrode 2e formed on the bottom surface of the base 2 for surface mounting.

With such a configuration, surface mounting can be performed by soldering the mounting electrode 2e of the crystal unit 1 to the conductive pattern of the printed board. In this case, since the crystal piece 1c of the crystal resonator 1 is held in parallel with the arrangement direction of the lead terminals 1b, the crystal piece 1c is held perpendicular to the plate surface of the printed board.

However, in the case of the crystal unit 1 housed in such a cylinder-type container, the structure is such that the end of the crystal piece 1c in the longitudinal direction is held by the tip of the lead terminal 1b. Therefore, the external force acting in the direction perpendicular to the plate surface of the crystal piece 1c acts in the direction perpendicular to the bonding surface between the crystal piece 1c and the lead terminal 1b, so that the bonding surface and the crystal piece 1c are greatly damaged. On the other hand, the printed circuit board is apt to be displaced and deformed in the direction perpendicular to the plate surface regardless of the material, and a large stress acts on the mounted electronic components in the direction perpendicular to the plate surface.

Therefore, when the crystal unit 1 is surface-mounted on a printed circuit board and the crystal piece 1c is held so as to be positioned horizontally on the plate surface of the printed circuit board, stress due to external vibration, impact, etc. Mainly acts in the direction perpendicular to the plate surface of the crystal piece 1c, and a large amount of stress acts to easily damage it. For example, suppose that an electronic device mounted with a printed circuit board receives an impulse of 3000 G for 0.3 ms.

In this case, an impact of 3000 G and 0.3 ms only acts parallel to the plate surface of the printed circuit board. On the other hand, the stress in the direction perpendicular to the board surface of the printed circuit board vibrates with a maximum value of about 2000 G due to the bending of the board and is attenuated over a period of about 1 ms, so a large stress acts as an impulse. To do. For example, a structure in which the crystal piece is held perpendicular to the mounting surface and a structure in which the crystal piece is held parallel to the mounting surface are manufactured by the structure as in the above-described example, and samples mounted on a printed circuit board are manufactured. .

When a drop test is performed using these samples, a crystal plate held vertically to the former mounting surface does not cause damage up to a height of 170 cm, but the latter mounting surface does not. If the crystal pieces are held in parallel, they will be damaged at a height of 75 cm. Therefore, when the crystal piece 1c is held vertically to the plate surface of the printed circuit board, it is possible to obtain overwhelmingly good vibration and shock resistance as compared with the case where it is held horizontally.

Therefore, according to the above-described embodiment, the crystal piece of the crystal unit is held perpendicular to the bottom surface of the base, that is, the mounting surface. Therefore, if this crystal oscillator is mounted on a printed circuit board, the crystal element can be held perpendicular to the plate surface of the printed circuit board, and good vibration and shock resistance can be obtained.

Further, the crystal resonator housed in the cylinder container can be made a surface mount type by a simple process of bending the lead terminals of the crystal resonator housed in the housing part of the base body 2 to the outside and fixing them to the holding electrodes. Easy to assemble and low cost. In addition, the cylinder type crystal unit has a small shape, and moreover, the round trapezoidal base with the lead terminals implanted can be fitted into the opening of the cylinder type cover to seal it. Therefore, there is an advantage that high reliability can be obtained.

[0018]

[Effect of device]

 As described in detail above, according to the present invention, it is possible to provide a surface-mount type crystal unit which is easy to assemble and which can obtain good vibration resistance and impact resistance.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a front view seen from the other end side of the substrate of the crystal unit of the embodiment shown in FIG.

[Explanation of symbols]

 1 ·· Crystal oscillator 1a ·· Cylinder container 1b · · Lead terminal 1c · · Crystal piece 2 · · Base 2a · · Storage 2b · · Recess 2c · · Through hole 2d · · Holding electrode 2e · · Mounting electrode

Claims (2)

[Scope of utility model registration request] 1. A pair of lead terminals are led out from one end of a metal cylinder container, and longitudinal ends of a crystal piece housed in the container are connected to the lead terminals to lead out electrodes formed on a plate surface. Along with the crystal unit, which holds the plate surface of the crystal unit parallel to the arrangement direction of the lead terminals, and the cylindrical unit with a bottom, which has the external shape of a rectangular parallelepiped and accommodates the crystal unit from one end along the longitudinal direction. The arrangement direction of the base body having the storage portion formed therein and the pair of lead terminals of the crystal unit, which is formed at the other end in the longitudinal direction and communicates with the storage portion of the base body and is stored in the storage portion, is perpendicular to the bottom surface of the base body. And a vertically elongated through hole that allows the lead terminal to pass through only in the direction, and a pair of lead terminals formed on both sides of the through hole at the other end of the base body for connecting and holding the pair of lead terminals, and a bottom surface of the base body. Mounting electrodes for surface mounting formed on Surface-mount crystal resonator which is characterized by comprising a holding electrode electrically connected to. 2. The surface mount type crystal resonator according to claim 1, wherein the base is formed by molding a molding material.