JP2006186839A - Support structure for crystal vibrator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a support structure for a crystal raw plate of a crystal vibrator which has excellent joining property between a joining material and the crystal raw plate, reduces a twisting force applied to the crystal raw plate, and has two metal terminals. <P>SOLUTION: In the present invention to solve the problem, the support structure for the crystal vibrator such that the crystal raw plate is supported by a support plate fixed to the two metal terminals airtightly penetrating a metal base is characterized in that a joining material is held in a recessed portion on a plate-thickness inside surface of the tip portion of the support plate on the side of the crystal raw plate and the recessed portion has a corner portion abutting against the crystal raw material plate. Further, the support structure is characterized in that a joining material is held in a recessed portion on the plate thickness inside surface of the tip portion of the support portion on the side of the crystal raw plate, a first recessed portion abuts against the crystal raw plate at two points of the corner portion, and a second recessed portion connects with the first recessed portion perpendicularly across a wall and is recessed from the plate thickness inside surface side of the support plate to a plate-thickness outside surface side on the plate thickness inside surface side of the support plate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

          The present invention relates to a support structure for a crystal base plate in a crystal unit having two metal terminals, which improves the bondability of a bonding material such as AuGe with the crystal base plate and reduces the twisting force applied to the crystal base plate. Is.

          With the rapid growth of mobile communication market in recent years, the demand for communication equipment has increased dramatically. As a result, quartz resonators used as a source of frequency as a reference in communication equipment are used in the surrounding environment. However, even under more severe conditions, it is currently required to secure a more stable operation with a specified frequency output.

          There are roughly two types of support structures for quartz plates. A support plate support structure mold using a metal such as solder as a bonding material between the crystal element plate as shown in FIG. 4 and the support plate as a support structure, and a crystal element plate as shown in FIG. There are two types of support structures for the slit support plate having a slit-like hole in the support plate in which a conductive adhesive is used as a bonding material with the support plate. Among crystal resonators, a thermostat crystal oscillator, which is mounted inside a crystal oscillator called OCXO (Oven Controlled Crystal Oscillator) and has high stability characteristics, an electrode made of a metal thin film The crystal base plate formed on the two main surfaces is supported by the metal support structure, and the crystal base plate and the metal support structure are fixed by the bonding material, so that the physical support of the crystal base plate and electrical conduction are achieved. The state shown in FIG. 4 is taken.

          A crystal resonator having a high stability characteristic, which is mounted and used in the above-mentioned constant temperature chamber type crystal oscillator called OCXO, is generally used in a temperature environment of 70 ° C. to 90 ° C. and depends on aging. In order to obtain good aging characteristics with reduced fluctuations in frequency output, the quartz base plate is less likely to be affected by thermal and temporal changes as a bonding material between the quartz base plate of the crystal unit and the metal support structure. AuGe (gold-germanium) is often used. However, AuGe has a high melting point of about 380 ° C., and if the melting time at the time of bonding is long, it causes a phenomenon (called gold erosion) that gold (Au) forming the electrode of the crystal base plate of the bonded portion is struck. As a result, there is a risk of poor conduction between the quartz base plate and the support plate. Therefore, in the joining operation, it is necessary to rapidly heat AuGe and finish the joining in a short time.

          Further, one of the factors that influence the aging characteristics described above is the stress on the crystal base plate from the metal support structure, which is also a support for the crystal base plate and is also called a support plate. For example, the metal support of the type shown in FIG. When manufacturing a crystal unit that uses a structure, the weld pressure deforms the metal base of the crystal unit during welding, and the stress accompanying the deformation is transmitted to the crystal base plate through the metal terminal and metal support structure. There is stress. Among these stresses, especially when asymmetrical twisting or twisting force is applied to the quartz base plate from the metal support structure, it has a significant effect on the characteristics of the quartz crystal unit, and in some cases, it must be highly stable. There is a risk that the aging characteristics of a quartz crystal having a certain level will be remarkably deteriorated. Therefore, the bonding length and bonding area of the bonding material for electrically and mechanically bonding the support plate and the crystal base plate are determined by the amount of the bonding material used for bonding and the force applied to the crystal base plate on the left and right sides of the crystal base plate. It is necessary to be symmetric at the joint.

          However, when using a bonding material such as AuGe that requires rapid heating and finishes the bonding operation in a short period of time as described above, the conventional quartz crystal support structure has the right and left sides of the quartz base plate. The bonding length and the bonding area described above, which is the bonding state of the crystal base plate and the support plate, are not symmetric at the bonding portion, and as a result, there is a problem that the aging characteristics of the crystal unit may be greatly deteriorated. there were.

Japanese Patent Laid-Open No. 7-240656 Japanese Patent Laid-Open No. 11-214949

          The applicant has not found any prior art documents related to the present invention other than the prior art documents specified by the prior art document information described above by the time of filing of the present application.

          An object of the present invention is to improve the bonding property of a bonding material such as AuGe with a crystal element plate, and reduce the generation of twisting force applied to the crystal element plate. It is to provide a support structure.

          In the support structure of a crystal unit supported by a support plate fixed to two metal terminals that penetrate the metal base in an airtight manner, the crystal base plate is bonded to the inner surface of the support plate at the tip of the crystal base plate side. The material is characterized by having a recess that is held in a recess and whose corners abut against the quartz base plate.

          In addition, a bonding material is accumulated and held in the concave portion on the inner surface of the tip of the support plate on the side of the crystal base plate, and has a first concave portion that contacts the crystal base plate at two corners. The second concave shape is connected to the first concave portion in the vertical direction across the wall, and is recessed on the inner thickness side surface of the support plate and on the outer thickness side surface side of the support plate from the inner thickness side surface side of the support plate. It has the part.

          By using the quartz crystal support structure according to the present invention, the bonding material can be stored in the concave portion of the support plate even if the melting time or melting temperature of the bonding material varies, Assuming that the joining length and joining area of the joining part are constant along with the amount of joining material used for joining, the stress applied to the crystal base plate from the left and right support plates of the crystal base plate is made symmetrical, and as a result, the crystal resonator The aging characteristics can be made extremely stable.

          Further, not only in the crystal unit of the present embodiment alone, but also in the crystal oscillator constituting the crystal unit of the present invention, the effect of remarkably suppressing changes in characteristics such as frequency and aging characteristics can be obtained. As a result, the manufacturing yield of the crystal oscillator can be significantly increased.

          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.

          FIG. 1 is a schematic front view of a support structure for a crystal resonator 5 according to the present invention. In the support structure of the crystal resonator 5 supported by the support plate 4 in which the crystal base plate 1 is fixed to the two metal terminals 3 hermetically penetrating the metal base 2, the tip of the support plate 4 on the crystal base plate 1 side. The bonding material 8 is accumulated and held in the concave portion on the inner surface 7 of the plate thickness 6 and has the concave portion 9 in which the corner portion comes into contact with the quartz base plate. Therefore, the bonding is completed in a short time by heating rapidly, for example, AuGe. Even in the case of using the bonding material 8 that is strict in the required use conditions, the bonding portion of the bonding material is the same amount in the recesses of the support plate 4 having the same shape on both the left and right sides while the corner portions are in contact with the crystal base plate 1. Since the bonding material 8 can be stored in the concave portion with the length and area of the crystal element plate 1 and the support plate 4 can be bonded to each other, the bondability between the crystal element plate 1 and the crystal element plate 1 is improved. Against the stress applied to the quartz base plate 1 from the support plate 4 As a result, the twisting force applied to the crystal base plate 1 from the left and right sides of the crystal base plate 1 is suppressed, and the fluctuation of the aging characteristics of the crystal resonator 5 is suppressed, so that the crystal base plate 1 is extremely stable. I can do it. In this embodiment, the corner portion of the recess of one support plate 4 abuts on the crystal base plate 1. However, because of the structure of this embodiment, the position where the crystal base plate 1 abuts on the support plate 4 is defined as the recess corner. The crystal plate 1 and the support plate 4 can be joined to the right and left sides of the crystal plate 1 when the bonding material 8 is actually used. Here, the concave portion and the concave portion indicate both the L-shaped structure and the U-shaped structure.

          FIG. 2 shows a state in which the crystal base plate 1 is supported via a bonding material 8 using a support plate 4 having a concave portion 9 whose corners abut against the crystal base plate of the support structure of the crystal resonator 5 of the present invention. It is the schematic figure seen from the main surface direction of the quartz base plate 1, and the schematic diagram seen from the side surface direction. The diagram in the dotted circle is a schematic diagram in which the support plate 4 is enlarged. Even if there is a variation in the melting time or melting temperature of the bonding material 8, the bonding material 8 dissolved in the concave portion 9 is fixed in a shape that is drooped downward by the weight of the bonding material 8 because the concave portion 9 is provided. In this case, the bonding length and the bonding area of the bonding portion between the crystal element plate 1 and the support plate 4 are constant, and the stress applied to the crystal element plate 1 from the left and right sides of the crystal element plate 1 is symmetrical. Can be given. 2 is an enlarged view around the concave portion 9 of one support plate 4, and the left and right support plates 4 of the quartz base plate 1 have the same shape. That is, the bonding material 8 is accumulated in the concave portion with the same amount, the length and the area of the bonding portion of the bonding material in the concave portion of the support plate 4 having the same shape on both the left and right sides while the corner portion is in contact with the crystal base plate 1. In order to join the base plate 1 and the support plate 4, the bondability between the crystal base plate 1 is improved and the stress applied to the crystal base plate 1 from the left and right support plates 4 of the crystal base plate 1 is symmetrical. As a result, the generation of a twisting force applied to the quartz base plate 1 can be suppressed, and the fluctuation of the aging characteristics of the quartz resonator 5 can be suppressed, so that it can be made extremely stable.

          FIG. 3 shows the main surface direction of the crystal base plate 1 showing a state in which the crystal base plate 1 is supported through the bonding material 8 using the support plate 4 of the support structure of the crystal resonator 5 according to another embodiment of the present invention. It is the schematic figure seen from the side, and the schematic diagram seen from the side surface direction. The diagram in the dotted circle is an enlarged schematic view of the portion of the support plate 4 where the first concave portion 10 and the second concave portion 12 are present. A first concave shape that holds and holds the bonding material 8 in the concave portion on the inner thickness surface 7 of the tip portion 6 of the support plate 4 on the side of the crystal base plate 1 and abuts the crystal base plate at two corners. And has a portion 10, which is connected to the first concave portion 10 in the vertical direction, and is recessed from the plate thickness inner surface 7 of the support plate 4 to the plate thickness outer surface 11 side from the plate thickness inner surface 7 side of the support plate 4. However, since the second concave portion 12 is provided, the melting time of the bonding material 8 to be used is long, and the bonding material 8 protruding from the first concave portion 10 is hardened while being in contact with the quartz base plate 1. In addition, since the bonding material 8 that protrudes from the first concave portion 10 has the second concave portion 12 that flows away from the quartz base plate 1, the same shape on the left and right is also obtained in this embodiment. The bonding material 8 is accumulated in the concave portion with the same amount in the concave portion 10 of the support plate 4 and the length and area of the bonding portion of the bonding material 8 and bonded. Since the bondability with the plate 1 can be improved and the stress applied to the crystal plate 1 from the left and right sides of the crystal plate 1 can be symmetrical, the crystal plate 1 can be viewed from the left and right sides of the crystal plate. It is possible to suppress the generation of the applied twisting force and suppress the fluctuation of the aging characteristic of the crystal unit 5 to make it extremely stable. In FIG. 3 as well, the dotted circle is an enlarged view around the first recess 10 of one support plate 4, and the left and right support plates 4 of the crystal base plate 1 have the same shape. That is, even in this case, the same amount of the first concave portion 10 of the support plate 4 having the same shape on both the left and right sides while contacting the crystal base plate 1 at two corners, and the length of the joining portion of the joining material In order to join the crystal element plate 1 and the support plate 4 by collecting the bonding material 8 in the recesses by area, the stress applied to the crystal element plate 1 from the left and right support plates 4 is made symmetrical. As a result, the generation of the twisting force applied to the crystal base plate 1 can be suppressed, and the fluctuation of the aging characteristic of the crystal resonator 5 can be suppressed, so that it can be made extremely stable.

          FIG. 4 is a schematic view of the crystal base plate 1 as viewed from the direction of one main surface, showing a state in which the crystal base plate 1 is held using the conventional plate support plate 4. In such a support structure of the crystal unit 5, the bonding length and the bonding area, which are the bonding state of the crystal element plate 1 and the support plate 4, are not symmetrical at the left and right bonding portions of the crystal element plate 1, and as a result There is a problem that the aging characteristics of the crystal unit 5 may be extremely deteriorated.

          FIG. 5 is a schematic view seen from the main surface direction of the crystal base plate 1 showing how the crystal base plate 1 is held using a conventional slit support plate.

          FIG. 6 is a schematic view of a conventional support structure using the support plate 4 as viewed from the front. In the conventional support plate 4, the bonding length and the bonding area in the bonded state of the crystal base plate 1 and the support plate 4 do not collect the bonding material 8, and the length of the splayed joint portion is left and right of the crystal base plate 1. There is a problem in that the aging characteristics of the crystal unit 5 may be extremely deteriorated because it is not symmetric at the joint.

It is a schematic front view of the support structure of the crystal unit of the present invention. From the main surface direction of the crystal element plate showing a state in which the crystal element plate of the support structure of the present invention has a concave portion with which a corner portion abuts and supports the crystal element plate via a bonding material It is the schematic figure seen, and the schematic diagram seen from the side surface direction. The diagram in the dotted circle is a schematic diagram enlarging the concave portion of one support plate. Schematic view seen from the main surface direction of the crystal base plate showing a state of supporting the crystal base plate through the bonding material using the support plate of the support structure of the crystal resonator which is another embodiment of the present invention, and its It is the schematic diagram seen from the side surface direction. The diagram in the dotted circle is an enlarged schematic view of a portion near the tip of one support plate where the first concave portion and the second concave portion are present. It is the schematic seen from the main surface direction of the crystal base plate which shows a mode that a crystal base plate is hold | maintained using the conventional plate support plate. It is the schematic seen from the main surface direction of the crystal base plate which shows a mode that a crystal base plate is hold | maintained using the conventional slit support plate. It is the schematic which looked at the support structure using the conventional support plate from the front direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crystal base plate 2 Metal base 3 Metal terminal 4 Support plate 5 Crystal oscillator 6 Tip part 7 Thickness inner side surface 8 Bonding material 9 Recess 10 where a corner | angular part contact | connects a crystal base plate 1st concave part 11 which contact | abuts Thickness outer side surface 12 2nd concave part

Claims (2)

In the support structure of the crystal resonator, the crystal base plate is supported by a support plate fixed to two metal terminals hermetically penetrating the metal base.
A quartz resonator having a concave portion in which a bonding material is accumulated and held in a concave portion on the inner surface of a thickness portion of a tip portion of the support plate on the quartz base plate side, and a corner portion is in contact with the quartz base plate Support structure.           On the inner surface of the thickness of the support plate at the tip of the quartz base plate side, a first concave portion that holds the bonding material in a concave portion and is in contact with the quartz base plate at two corners is provided. A second concave portion extending in a vertical direction across a wall from the first concave portion and recessed from the inner thickness side of the support plate on the inner thickness side of the support plate and on the outer thickness side of the support plate. The support structure for a crystal resonator according to claim 1, comprising: a concave portion.

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