JP2007067777A - Support structure for crystal resonator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a support structure for a crystal blank plate which reduces stress that the crystal blank plate receives by improving joining property of a jointing material for the crystal blank plate. <P>SOLUTION: This support structure for the crystal resonatot is characterized in that: exciting electrodes are formed on the top and reverse surfaces of the crystal blank plate; lead-out electrodes led around from the exciting electrodes are held and fixed by a support plate and the jointing material connecting with two metal terminals extending from a metal base; one of the lead-out electrodes led around from the exciting electrodes is held by the metal terminals and support plate; and the other lead-out electrode has a narrow part partially at the metal terminal and support plate along the width of the support plate. Further, disclosed is a support structure of a crystal resonatot characterized in that a through hole is bored in a portion of a support plate instead of the narrow part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention, as an example, uses AuGe (gold-germanium) as an example, when the crystal element plate is held by a support plate connected to two metal terminals extending from the base of the hermetic structure and a bonding material, stress distortion applied to the crystal element plate The present invention relates to a support structure for a quartz base plate that reduces the above-mentioned problem.

  With the rapid growth of the mobile communication market in recent years, the demand for communication equipment has increased dramatically. At present, crystal oscillators that are used as a clock source for generating a reference frequency in communication equipment are used in the surroundings. There is also a demand for ensuring that a frequency signal serving as a desired reference is stably output even under a severer environment.

  As a typical example of a structure for holding a quartz plate, a quartz resonator having a round plate shape shown in FIG. 4 is shown. The above-described quartz crystal holding structure is formed by forming excitation electrodes on the front and back sides of the quartz base plate, and connecting with a support plate connected to the extraction electrode routed from the excitation electrode and the two metal terminals extending from the metal base with a bonding material And hold it. The holding part has a so-called clip-type structure, and holds the crystal element plate in a fashionable manner, holds the crystal element plate directly between a pair of flat support plates, or a metal terminal In addition, there are various forms such as a shape in which a slit is formed at a place where the crystal base plate is held on the support plate to hold the crystal base plate.

  In addition, as a method of connecting the extraction electrode routed from the excitation electrode, there are a case where a metal having a relatively low melting point such as solder is used and a case where a conductive adhesive is used.

  The above-described round plate-shaped quartz base plate is in a rare presence in the shape of a mainstream quartz base plate having a strip shape in recent years. This is because the round plate-shaped quartz base plate is a quartz base plate specially manufactured to obtain a highly stable frequency output. The rectangular shape of the recent quartz base plate has a rectangular outer shape with a long side dimension of 2 to 6 mm and a short side of 2 mm or less, whereas the round plate shape has a diameter of around 10 mm compared to the rectangular shape. Have large external dimensions. As for the thickness of the quartz base plate, high-order overtone oscillation is often used, and the round-plate-shaped quartz base plate is much thicker than the strip-shaped quartz base plate.

  Now, as a typical example of the purpose of use of the crystal unit shown in FIG. 4, the frequency output characteristics are obtained by using a thermostat inside a crystal oscillator called an oven controlled crystal oscillator (OCXO). There is a form of an oscillator that can maintain a stable state.

  A crystal resonator having a high stability characteristic that is mounted and used in a thermostat crystal oscillator called OCXO is roughly one point between 70 ° C. and 90 ° C. (temperature deviation ± 0.3). In order to obtain stable frequency characteristics (aging characteristics), it is used in a temperature environment maintained at a temperature of (° C) and the output frequency fluctuation due to secular change is suppressed. The material used is AuGe (gold-germanium alloy) or a highly heat-resistant polyimide conductive paste that generates less internal gas, is stable against changes in thermal expansion, and has little effect on the quartz base plate. Often done.

Japanese Patent Laid-Open No. 7-240656 Japanese Patent Laid-Open No. 11-214949 In addition, the applicant has not found any prior art documents related to the present invention by the time of the filing of the application other than the prior art documents specified by the prior art document information described above. It was.

An object of the present invention is to reduce stress generated in a quartz base plate by firmly joining at least two places of the quartz base plate and the support using a hard joint material such as AuGe and polyimide having high heat resistance. It is in providing the support structure of a crystal base plate.
In short, one of the factors that influence the aging characteristics shown in the prior art is the stress on the quartz base plate from the support part, also called the support plate. For example, the stress due to the difference in thermal expansion coefficient of each material and the shrinkage at the time of joining the quartz base plates, or the weld pressure deforms the metal base of the crystal unit during the welding in the sealing process, and the stress accompanying the deformation Is transmitted to the crystal base plate through the metal terminal and the support plate, so that asymmetrical twist and torsional force is applied to the crystal base plate and the holding portion from the support (holding) portion to the crystal base plate, This greatly affects the characteristics of the crystal unit, impairs the highly stable frequency output characteristics inherent to the crystal base plate, and may significantly deteriorate the aging characteristics of the crystal unit.

  Therefore, it is possible to reduce the stress and strain components applied from the support part to the crystal base plate by the structure of the holding part that electrically and mechanically joins the support part and the crystal base plate. However, the present situation is that no effective means can be found, although a supporting method and a bonding material for the holding portion for the purpose have been proposed.

  On the other hand, an invention for holding a piezoelectric element with a thin metal wire as shown in Patent Document 3 has been made. It is difficult to obtain stable aging characteristics.

In order to solve the above-described problem, the present invention provides a support plate in which excitation electrodes are formed on the front and back surfaces of a quartz base plate, and the extraction electrode routed from the excitation electrode is connected to two metal terminals extending from a metal base. In the support structure of the crystal resonator that is held and fixed by the bonding material, one of the extraction electrodes routed from the excitation electrode is held by the metal terminal and the support plate, and the other of the extraction electrodes is the metal terminal and the support plate.
This is a support structure for a crystal resonator in which a narrow portion exists in at least a part in the width direction of the support plate. In addition, the support structure for a crystal resonator is characterized in that a through hole is formed in a part of the support plate instead of the narrow portion.

  In short, the crystal base plate is a support structure of a crystal resonator supported by a support plate fixed to two metal terminals extending from a metal base, and one support portion is a support plate and a crystal connected to the metal terminal as in the prior art. Part of the crystal base plate, which is the lead-out electrode routed from the excitation electrode on the front and back of the base plate, is bonded using a bonding material (for example, AuGe, solder or conductive adhesive) to firmly hold the crystal base plate From the other lead electrode, the metal terminal and the support plate were drawn from the excitation electrodes on the front and back of the quartz base plate to the support plate having a narrow part or a through hole in at least a part of the width direction of the support plate. Although a part of the crystal element plate, which is the extraction electrode, is bonded with a bonding material, the support is flexible so that the crystal element plate is not fixed and the same effect as when the crystal element plate is supported in one place. Produced by water It solves the problem by realizing a holding structure stress without added against workpieces.

  By using a support structure for a crystal unit having a holding method by a combination of a support structure with a strong support plate according to the present invention and a support structure with a flexible support plate of the same type, two or more points are used. The stress relief to the quartz base plate, which could not be achieved with the conventional structure with a strong support part, can be realized, and a stable and stable frequency output can be obtained even in the form of a crystal resonator mounted on a hermetic base be able to. As a result, the yield of the manufacturing process can be improved and the manufacturing cost can be reduced.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In addition, the same code | symbol in each figure shall show the same object. Note that the place in FIG. 2 is designated as the width direction of the support plate that appears in the following description. FIG. 1 is a partial cross-sectional view showing the concept of the support structure of the crystal resonator 5 of the present invention. 1A is a front view, FIG. 1B is one partial side view, and FIG. 1C is the other partial side view. Excitation electrodes 8 are formed on the front and back of the quartz base plate 1, and an extraction electrode 9 routed from the excitation electrode 8 is fixed to a support plate 4 connected to two metal terminals 3 extending from the metal base 2 with a bonding material. By doing so, the quartz base plate 1 is held and the electrical conduction is obtained. In the figure, a lid and a cap for configuring the sealed container are not shown.

  Accordingly, as an example, the quartz base plate 1 is fixed to the tip portion of the metal terminal 3 made of a material that penetrates the metal base 2 while the metal base 2 is hermetically sealed by a hermetic container made of glass. In general, a support plate 4 or the like may be arranged at the tip portion of the metal terminal 3 so that the crystal base plate 1 can be reliably mounted.

  In one example shown in FIG. 1, one holding structure of the crystal base plate 1 is configured such that the support base 41 is disposed at the tip of a support portion (metal terminal) that extends through the holding metal base 2. The form of the supported crystal resonator 5 is shown. In this case, the support plate 41 and the tip of the crystal base plate 1 side are joined with a joint material such as AuGe, solder, or conductive adhesive, On the other hand, the support plate 42 has a narrow portion 6 at least in the width direction of the support plate, or is joined with a support plate 42 in which a through hole 7 is formed in a part thereof. The extracted electrode 9 and one to be rotated are firmly connected and the other is connected flexibly to reduce the stress applied to the quartz base plate 1. Here, as long as the support plate 42 has a flexibility that does not firmly support the crystal base plate 1, there is no restriction on the size of the narrow portion 6 or the size of the through hole 7.

FIG. 2 is a partially enlarged view focusing on the support plate 4 portion of the crystal resonator 5 of the present invention, as viewed from the direction of the arrow in FIG. 1 and depicting the concept of the support plate described above. As a form of the support plate 4, FIGS. 2A and 2B show a case where the narrow portion 6 is present in at least a part of the width direction of the support plate, and FIG. The state where the through-hole 7 is formed in a part is shown. 2 (a) and 2 (b) may have a shape as illustrated here, but a shape other than the one shown here may be effective as long as it has the same effect. There are no restrictions.

  Further, the through hole 7 formed in the support plate 4 shown in FIG. 2B is not limited to the shape of the round hole or the square hole, and there is no restriction on the size of the through hole.

  In short, the crystal base plate 1 is a support structure of the crystal resonator 5 supported by the support plate 4 fixed to the two metal terminals extending from the metal metal base 2, and one support portion has the support structure 4 having a conventional structure. A portion of the quartz base plate 1 that is the lead electrode 9 routed from the excitation electrode 8 on the front and back of the quartz base plate 1 is joined to the tip of the base plate 1 using a joining material (eg, AuGe, solder or conductive adhesive), From the other extraction electrode 9, the same kind of support plate 4 is processed to have flexibility, and by making an electrical connection, the crystal base plate 1 is firmly fixed on the extraction electrode 9 side at one end thereof. By holding and securing the flexible holding means at the other end of the quartz base plate 1, it is possible to realize a holding structure that does not apply stress to the quartz base plate 1.

It is a fragmentary sectional view which shows the concept of the support structure of the crystal oscillator of this invention. It is a conceptual diagram explaining the support structure of the crystal oscillator of this invention. It is a fragmentary sectional view of a crystal oscillator with a form which holds a crystal blank using a support plate as a conventional example.

Explanation of symbols

1 ... Crystal base plate 2 ... Metal base 3 ... Metal terminal 4 (41, 42) ... Support plate 5 ...・ ・ ・ Quartz crystal 6 ・ ・ ・ ・ ・ ・ ・ ・ Narrow part (in width direction) 7 ・ ・ ・ ・ ・ ・ ・ ・ Through hole 8 ・ ・ ・ Excitation electrode 9 ・ ・ ・... Extraction electrodes

Claims (2)

In a support structure of a crystal resonator in which excitation electrodes are formed on the front and back surfaces of a quartz base plate, and a lead electrode routed from the excitation electrode is held and fixed with a support plate connected to two metal terminals extending from a metal base and a bonding material ,
One of the extraction electrodes routed from the excitation electrode is held by the metal terminal and the support plate, and the other of the extraction electrodes has a narrow portion in at least part of the width direction of the support plate of the metal terminal and the support plate. A quartz crystal support structure characterized by the existence. A support structure for a crystal resonator, wherein a through hole is formed in a part of the support plate instead of the narrow portion according to claim 1.

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