JP2005260727A - Piezo oscillating element supporting structure, and piezo oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezo oscillating element supporting structure for stably supporting a piezo oscillating element, even if the outer size of the piezo oscillating element changes, and for having little property variance, and to provide a piezo oscillator using the supporting structure. <P>SOLUTION: A crystal oscillator comprises a ceramic package 1 which is a package for electronic parts, an integrated circuit device 3 and a crystal vibration cone 2 contained within the ceramic package, an auxiliary support plate 4 located under the crystal vibration cone, and a lid 5 for hermetical sealing the ceramic package. The auxiliary support plate 4 is joined to a part of upper zone of electrode pads 12 and 13 at a supporting stand 1B by jointing material. During auxiliary support plate bonding, a cut 41 in the auxiliary support plate 4 is formed in a position where the electrode pad 12 is exposed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a support structure for a piezoelectric vibrator.

  In recent years, in information communication equipment such as a mobile computer and mobile communication equipment such as a mobile phone, a car phone, and a paging system, miniaturization of the device is rapidly progressing. For this reason, further miniaturization is required for electronic components such as crystal resonators and crystal oscillators used for these.

  As is well known, the crystal resonator is driven by an AC voltage supplied from excitation electrodes formed on the front and back surfaces of the crystal diaphragm. In other words, a mechanical vibration region due to the piezoelectric effect is required, but in order to secure the vibration region with the recent miniaturization, a configuration in which only one end side in the long side direction of the rectangular crystal diaphragm is cantilevered is supported. It has increased. However, in such a cantilever support structure, the side that is not supported by an external impact or the like, that is, the free end side is greatly bent, and the crystal diaphragm may be damaged. In order to eliminate such a problem, for example, as shown in Japanese Patent Application Laid-Open No. 3-88373, a structure in which a pillow material is provided on the free end side of the ceramic package to suppress bending is also considered.

  However, as the frequency of the quartz diaphragm increases, the outer dimensions of the quartz diaphragm also become smaller. With a uniform ceramic package configuration, the free end of the quartz diaphragm may come off the pillow material, and various ceramic packages are required. .

  The crystal oscillator has a configuration in which a crystal diaphragm and an integrated circuit element in which an oscillation circuit is built are housed in a ceramic package. For example, the crystal oscillator has a configuration shown in FIG. In FIG. 8, 1 is a ceramic package, 2 is a crystal diaphragm (piezoelectric vibration element) on which excitation electrodes are formed, 3 is an integrated circuit element, and 5 is a metal lid. The integrated circuit element 3 is installed below the concave opening of the ceramic package 1, and the crystal diaphragm 2 is positioned above the integrated circuit element 3. When the crystal diaphragm 2 is large, the free end is supplementarily supported by the auxiliary support base (pillow material) 1C. When the crystal diaphragm 2 is small, the auxiliary support effect by the auxiliary support base is obtained. Therefore, as shown in FIG. 8, the quartz diaphragm 2 may be tilted to the state 2a indicated by the dotted line due to an external impact, and the vibration of the quartz diaphragm may be hindered by contacting the integrated circuit element.

By the way, in the crystal oscillator, the upper surface of the integrated circuit element is grounded, and the lid may be grounded. In such a case, the frequency may fluctuate due to the inclination of the crystal diaphragm described above. That is, the capacitance formed by the excitation electrode-lid distance t1 formed on the quartz diaphragm or the excitation electrode-integrated circuit element distance t2 may change. Since this capacitance is one of the frequency determination parameters in the crystal oscillator, the distance t1 between the excitation electrode and the lid and the distance t2 between the excitation electrode and the integrated circuit element are set by tilting the crystal diaphragm as described above. There was a case where the frequency fluctuated from the value.
JP-A-3-88373

  The present invention has been made in view of the above points, and an object of the present invention is to provide a piezoelectric vibration element that is stably supported and has little characteristic change even when the outer size of the piezoelectric vibration element changes. It is an object of the present invention to provide a support structure and a piezoelectric oscillator using the support structure.

  In order to achieve the above object, the present invention has been made in view of stabilizing the support state of the piezoelectric vibration element by providing an auxiliary support plate on the cantilever support side for electrode connection. This can be realized by the configuration.

  That is, as shown in claim 1, the piezoelectric vibration in which an electrode pad is provided on the upper part of the support base and a part of the plate-like piezoelectric vibration element having the excitation electrode formed on the support base is cantilevered. A support structure for an element, wherein an auxiliary support plate is formed between the support base and the piezoelectric vibration element, the auxiliary support plate is mounted in a state of partially protruding from the support base, and includes the protruding region. A piezoelectric vibration element supporting structure in which a piezoelectric vibration element is mounted and an excitation electrode of the piezoelectric vibration element and the electrode pad are electrically connected by a conductive bonding material.

  As a specific configuration of the ceramic package, a ceramic package having a support base with an opening at the top and a plurality of electrode pads formed on the upper surface, and a cantilever mounted on the support base, excitation electrodes are formed on the front and back sides. In addition, the excitation electrode is drawn out to the outer periphery, a rectangular piezoelectric vibration element having an extraction electrode connected to each of the electrode pads, and between the support base and the piezoelectric vibration element, a part of the support base, A support structure for a piezoelectric vibration element comprising an auxiliary support plate that is mounted in a state where the other part protrudes from the support base and supports the piezoelectric vibration element including the protruding area can be given.

The above-mentioned auxiliary support plate needs to use an insulating material when a plurality of electrode pads having different polarities are formed on the support base, but is not limited thereto, and has conductivity only in a specific direction, for example. It is also possible to use an auxiliary support plate made of an anisotropic conductive material. Further, when the auxiliary support plate is an insulating material, the auxiliary support plate may be used as it is, or an electrode film corresponding to an electrode pattern such as an extraction electrode formed on the piezoelectric vibration element on the surface thereof. It may be formed to assist the connection between the excitation electrode of the piezoelectric vibration element and the electrode pad of the support base.

According to the above configuration, the auxiliary support plate is positioned below the cantilevered support portion of the piezoelectric vibration element, and the joining area of the cantilevered support portion can be widened. Therefore, when external impact or the like is applied, impact absorption can be performed over a relatively large area. Further, shock absorption can also be performed by a buffering function due to bending of the auxiliary support plate itself.

By the way, it is preferable that the auxiliary support plate has a configuration wider than the width of the piezoelectric vibration element mounted on the upper part of the auxiliary support plate in a region protruding from the support base. Accordingly, even when an impact or the like is applied from the outside after the piezoelectric vibration element is supported and fixed, the buffer function is further strengthened to alleviate the impact on the entire auxiliary support plate.

The present invention also proposes a configuration in which the support structure is applied to a piezoelectric oscillator having a configuration in which a piezoelectric vibration element and an integrated circuit element are housed in the same chamber. That is, as shown in claim 3, a ceramic package having a support base having an upper opening and a plurality of electrode pads formed on the upper surface thereof, an integrated circuit element installed on the bottom surface inside the package, and the integration A piezoelectric vibration element formed of a plate-like piezoelectric vibration element which is positioned above the circuit element and is cantilevered by the support base; an auxiliary support plate disposed between the support base and the piezoelectric vibration element; and the ceramic package A piezoelectric oscillator comprising a metal lid that hermetically seals the integrated circuit element and the piezoelectric vibration element, wherein the piezoelectric vibration element has a rectangular shape and excitation electrodes are formed on the front and back sides. In addition, the excitation electrode is led to the outer periphery and has a lead electrode connected to the electrode pad, and the auxiliary support plate includes the support base and the piezoelectric vibration element. A piezoelectric oscillator characterized in that a part of the piezoelectric oscillator is mounted on the support base in a state where the other part protrudes from the support base and supports the piezoelectric vibration element even in the protruding area. .

  According to the configuration of the third aspect, the auxiliary support plate is positioned below the cantilever support portion of the piezoelectric vibration element, and the joining area of the cantilever support portion can be widened. Therefore, when an external impact or the like is applied, the impact can be absorbed over a relatively large area, and the impact can also be absorbed by a buffering function due to bending of the auxiliary support plate itself. For this reason, the piezoelectric vibration element is not supported obliquely, and accordingly, the capacitance does not change due to the change in the positional relationship with other components.

The present invention also proposes a configuration in which the auxiliary support plate is disposed above the piezoelectric vibration element. That is, as shown in claim 2, an electrode pad is provided on an upper portion of a support base, and a piezoelectric element that cantileverly holds a part of a plate-like piezoelectric vibration element having an excitation electrode formed on the surface of the support base. A support structure of a vibration element, wherein an auxiliary support plate is mounted on the piezoelectric vibration element and above the support base, and the auxiliary support plate is disposed in a state of partially protruding from the support base in a plan view, The piezoelectric vibration element may be supplementarily supported including the protruding region, and the excitation electrode of the piezoelectric vibration element and the electrode pad may be electrically connected by a conductive bonding material.

According to the above configuration, the auxiliary support plate is positioned above the cantilever support portion of the piezoelectric vibration element, so that the joining region of the cantilever support portion can be widened. Therefore, when external impact or the like is applied, impact absorption can be performed over a relatively large area. Further, the weight distribution on the cantilever support side increases in the piezoelectric vibration element due to the weight effect of the auxiliary support plate. Therefore, even when an external impact or the like is applied, the free end side is prevented from being inclined and stable support can be performed.

The present invention also proposes a configuration in which the support structure is applied to a piezoelectric oscillator having a configuration in which the piezoelectric vibration element and the integrated circuit element are accommodated in the same chamber in the above-described configuration. According to another aspect of the present invention, there is provided a ceramic package having a support base in which an upper portion is opened and a plurality of electrode pads are formed on an upper surface, an integrated circuit element installed on a bottom surface inside the package, and the integration A piezoelectric vibration element formed of a plate-shaped piezoelectric vibration element that is positioned above the circuit element and cantilevered on the support base; and an auxiliary support plate mounted on the piezoelectric vibration element and above the support base; A piezoelectric oscillator comprising a metal lid that closes the opening and hermetically seals the integrated circuit element and the piezoelectric vibration element, wherein the piezoelectric vibration element is rectangular and excitation electrodes are formed on the front and back sides. In addition, the excitation electrode is led to the outer periphery and has a lead electrode connected to the electrode pad, and the auxiliary support plate partially protrudes from the support base in a plan view. Disposed state, the piezoelectric vibrating element may have a structure that the auxiliary support includes the overrunning region.

According to the above configuration, the auxiliary support plate is positioned above the cantilever support portion of the piezoelectric vibration element, and the joining area of the cantilever support portion can be widened. Therefore, when external impact or the like is applied, impact absorption can be performed over a relatively large area. Further, the weight distribution on the cantilever support side increases in the piezoelectric vibration element due to the weight effect of the auxiliary support plate. Therefore, even when an external impact or the like is applied, the free end side is prevented from being inclined and stable support can be performed. Further, the capacitance does not change due to a change in the positional relationship with other components.

  According to the present invention, when an external impact or the like is applied, the impact can be absorbed over a relatively large area, and the impact can also be absorbed by a buffering function due to the deflection of the auxiliary support plate itself. For this reason, the piezoelectric vibration element is not supported obliquely, and accordingly, the capacitance does not change due to the change in the positional relationship with other components. Therefore, even if the external size of the piezoelectric vibration element changes, the support structure can be stably provided and the piezoelectric vibration element supporting structure with little characteristic change and the piezoelectric oscillator using the support structure can be obtained.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
A first embodiment of the present invention will be described with reference to the drawings, taking a crystal oscillator as an example of a piezoelectric vibration device. 1 is a perspective view of the crystal oscillator in the opened state, FIG. 2 is a sectional view of the crystal oscillator in the closed state in FIG. 1, and FIG. 3 is a state in which each component is incorporated in FIG. FIG.

  The crystal oscillator applied to the present invention is a ceramic package 1 which is a package for electronic components, an integrated circuit element 3 and a crystal diaphragm 2 housed in the ceramic package, and an auxiliary support plate located below the crystal diaphragm. 4 and a lid 5 for hermetically sealing the ceramic package.

  The ceramic package 1 has a rectangular parallelepiped shape as a whole, is composed of ceramics such as alumina as a main material, has a conductor wiring pattern formed therein, and has a housing portion 10 that opens at the top and has a concave section. It is a configuration. A metal layer 11 made of metallization or plating is provided on the upper portion of the bank portion 1A of the ceramic package, and the metal layer 4 is connected to a ground electrode (not shown) provided on the lower surface of the ceramic package. A support base 1B is formed at one end in the long side direction inside the package, and an auxiliary support base (pillow material) 1C is provided at the other end. The support base 1B and the auxiliary support base 1C are substantially the same height, or the support base 1B is formed slightly higher. Electrode pads 12 and 13 are formed on the upper surface of the support base 1B at a predetermined interval in the short side direction.

The storage unit 10 includes a lower storage unit 10a and an upper storage unit 10b. The two storage units are spatially connected, but the electronic component elements are different from each other. The integrated circuit element 3 is disposed in the lower storage unit 10a, and the crystal diaphragm 2 is disposed in the upper storage unit 10b. ing. A plurality of electrode pads 14 are formed by predetermined electrode wiring on the bottom surface of the lower housing portion 10a, and the integrated circuit element 3 is mounted on the electrode pads.

The integrated circuit element 3 has a rectangular parallelepiped shape as a whole, a plurality of electrode pads 31 are formed on the lower surface, and a conductive layer (not shown) is formed on the upper surface. The conductive layer is drawn out to one of the electrode pads on the lower surface and is grounded. The plurality of electrode pads 14 and the electrode pads 31 of the integrated circuit element 3 are joined by electromechanical bonding by a well-known face-down bonding technique. The integrated circuit element 3 and the lower housing portion 10a are bonded as necessary. An underfill made of an insulating resin material may be formed between the bottom surfaces of these. By forming the underfill, the mechanical joint strength of the integrated circuit element 3 can be improved.

The integrated circuit element 3 is a one-chip integrated circuit element in which a circuit configuration that constitutes an oscillation circuit together with the crystal diaphragm 1 is integrated. Further, the integrated circuit element 3 incorporates a circuit such as a temperature compensation circuit, a voltage control circuit, or a PLL output circuit as necessary.

The upper storage portion 10b is an area in which the crystal diaphragm 2 is arranged, and shows an area near the upper surface of the support base 1B in the height direction. The electrode pads 12 and 13 are formed on the support base 1B as described above. The electrode pads 12 and 13 are appropriately connected to the integrated circuit element 3 and external connection electrodes (not shown) formed on the lower surface of the ceramic package by wiring in the ceramic package. The electrode pads 12 and 13 are formed by the same method as the electrode pad 14 for connecting an integrated circuit element formed on the bottom surface. For example, a nickel layer and a gold layer are plated in this order on a tungsten layer formed by metallization. It is formed by such means. The total height of the support base 1B and the electrode pad 12 or 13 is preferably higher than the height in a state where the integrated circuit element 3 disposed below is installed.

  Further, the auxiliary support plate 4 is bonded to the upper part of the electrode pads 12 and 13 of the support base 1B by a bonding material. The auxiliary support plate 4 is made of, for example, ceramic or quartz and has a notch 41. The notch 41 is formed at a position where the electrode pad 12 is exposed when the auxiliary support plate is joined. The auxiliary support plate 1 </ b> C side of the auxiliary support plate has a protruding region 4 a that protrudes from the support table, and at least the protruding region 4 a is formed wider than the width of the quartz crystal plate 2. The outer shape and dimensions of the auxiliary support plate 4 may be determined as appropriate depending on the shape and dimensions of the quartz crystal plate to be mounted, and are not limited to the above configuration. Further, the bonding material for bonding the auxiliary support plate 4 to the support base 1B may be an insulating bonding material or a conductive bonding material. In the case of using a conductive bonding material, it is necessary to supply the bonding material so as to prevent a short circuit with an adjacent electrode pad.

  Further, one end in the long side direction of the crystal vibrating plate 2 is joined to the upper portion of the auxiliary support plate 4. The quartz crystal plate 2 is formed of a rectangular AT-cut crystal plate, and excitation electrodes 21 and 22 (the back side excitation electrode 22 is not shown) facing the front and back surfaces are formed in the center portion. The excitation electrodes 21 and 22 are drawn out by the extraction electrodes 211 and 221 to one end in the long side direction of the quartz crystal plate 2 and to both end portions in the short side direction, respectively. These electrode formations can be obtained by covering the quartz crystal vibrating plate with a film formation mask having an opening pattern shape corresponding to the excitation electrode and the extraction electrode, and forming an electrode film by a vacuum deposition method or a sputtering method.

  When the quartz crystal plate 2 is bonded, the conductive bonding material S is applied to each extraction electrode portion of the quartz plate to be mounted on the auxiliary support base 4, and the quartz plate is mounted in a cantilevered state. To do. At this time, when the conductive bonding material S is applied so as to straddle the extraction electrode 211 and the electrode pad 12, and the extraction electrode 221 and the electrode pad 13, the respective groups are electrically independent, and the electric bonding is surely performed. This is preferable. In addition, if necessary, a conductive bonding material may be overcoated on the bonded portion after mounting the quartz crystal plate, whereby reliable electromechanical joining of the quartz plate can be performed. The conductive bonding material S uses, for example, a silicone-based resin adhesive containing a conductive material, but a urethane-based or epoxy-based conductive bonding material may be used.

Thereafter, the opening of the ceramic package is closed with the lid 5 in an inert gas atmosphere or a vacuum atmosphere, and hermetic sealing is performed. The lid 5 is made of metal. For example, the core 5 is made of Kovar, a nickel layer is formed on the upper part, and a silver brazing layer is formed on the lower part, that is, on the joint surface side with the ceramic package via a copper layer. is there. By joining such a lid by a seam welding method, hermetic sealing can be performed. The lid is drawn from the metal layer 11 to an external connection electrode (not shown) formed on the lower surface of the package by internal wiring (not shown) provided inside the ceramic package.

  The mounting and joining of the auxiliary support plate 4 and the crystal diaphragm 2 to the support base can be performed in a continuous process using an automatic machine, for example. That is, first, a conductive bonding material is supplied to each of the electrode pads 12 and 13 of the support base with a dispenser or the like, and then the auxiliary support plate 4 is mounted. At this time, the conductive bonding material may be supplied to a position close to the end portion (step portion) of the support base. Subsequently, a conductive bonding material is supplied and applied by a dispenser or the like so as to straddle the extraction electrode 211 and the electrode pad 12, and the extraction electrode 221 and the electrode pad 13, respectively. After that, the crystal diaphragm 2 is mounted, and electrical bonding with each extraction electrode is performed, and a conductive bonding material for overcoating is applied to the bonding portion. Thereafter, the adhesive is cured to complete conductive bonding.

  With the above configuration, since the auxiliary support plate 4 is firmly fixed to the support base 1B, the crystal diaphragm 2 that is conductively bonded to the upper portion of the auxiliary support plate 4 is inclined downward even when stress due to external impact is applied. The initial support state can be stably maintained without any problems. Therefore, even if the external size of the crystal diaphragm changes, a crystal oscillator that is stably supported and has little characteristic change can be obtained.

  The present invention is not limited to that shown in the above embodiment, and auxiliary support plates having various configurations can be used. FIG. 4 is a plan view showing another configuration of the auxiliary support plate formed on the support base. The crystal diaphragm 2 is configured by a dotted line. FIG. 4A shows an example in which an electrode film (conductive film) is formed on the auxiliary support plate 6. The electrode film 62 corresponds to the electrode pad 12, and the electrode film 63 corresponds to the electrode pad 13. Is formed. In this example, the auxiliary support plate 6 is not provided with a notch as in the above-described embodiment, but the electrode connection can be reliably performed by the electrode films 62 and 63. In addition, you may form an electrode film like this example in the auxiliary | assistant support plate structure which has a notch. Further, the electrode films 62 and 63 are formed widely as long as there is no fear of short-circuit between them, or are formed up to the end of the auxiliary support plate also in the long side direction of the quartz crystal vibration plate. The stability of the joint can be improved.

  FIG. 4B is an auxiliary support plate 7 showing another configuration. In this example, a notch 71 is formed in the auxiliary support plate 7 and chamfered portions 72 and 73 are provided on the other side in the long side direction. With such a configuration, the stress of the external impact is applied to the quartz diaphragm, and even when the quartz diaphragm is bent, damage to the support portion of the quartz diaphragm can be minimized. The chamfering configuration may be a chamfering configuration having a curvature. Further, a chamfering configuration in which the thickness gradually decreases on the other end portion in the long side direction of the auxiliary support plate, that is, on the auxiliary support stand 1C side, may be employed.

  Next, a second embodiment of the present invention will be described with reference to the drawings, taking a crystal oscillator as an example of a piezoelectric vibration device. 5 is a cross-sectional view of the crystal oscillator with the lid closed, and FIG. 6 is a plan view of the crystal oscillator with the lid open in FIG.

  The crystal oscillator applied to the present invention is a ceramic package 1 which is a package for electronic components, an integrated circuit element 3 and a crystal diaphragm 2 housed in the ceramic package, and an auxiliary support plate located above the crystal diaphragm. 6 and a lid 5 for hermetically sealing the ceramic package.

  The ceramic package 1 has a rectangular parallelepiped shape as a whole, is composed of ceramics such as alumina as a main material, has a conductor wiring pattern formed therein, and has a housing portion 10 that opens at the top and has a concave section. It is a configuration. A metal layer 11 made of metallization or plating is provided on the upper portion of the bank portion 1A of the ceramic package, and the metal layer 4 is connected to a ground electrode (not shown) provided on the lower surface of the ceramic package. A support base 1B is formed at one end in the long side direction inside the package, and an auxiliary support base (pillow material) 1C is provided at the other end. The support base 1B and the auxiliary support base 1C are substantially the same height, or the support base 1B is formed slightly higher. Electrode pads 12 and 13 are formed on the upper surface of the support base 1B at a predetermined interval in the short side direction.

The storage unit 10 includes a lower storage unit 10a and an upper storage unit 10b. The two storage units are spatially connected, but the electronic component elements are different from each other. The integrated circuit element 3 is disposed in the lower storage unit 10a, and the crystal diaphragm 2 is disposed in the upper storage unit 10b. ing. A plurality of electrode pads 14 are formed by predetermined electrode wiring on the bottom surface of the lower housing portion 10a, and the integrated circuit element 3 is mounted on the electrode pads.

The integrated circuit element 3 has a rectangular parallelepiped shape as a whole, a plurality of electrode pads 31 are formed on the lower surface, and a conductive layer (not shown) is formed on the upper surface. The conductive layer is drawn out to one of the electrode pads on the lower surface and is grounded. The plurality of electrode pads 14 and the electrode pads 31 of the integrated circuit element 3 are joined by electromechanical bonding by a well-known face-down bonding technique. The integrated circuit element 3 and the lower housing portion 10a are bonded as necessary. An underfill made of an insulating resin material may be formed between the bottom surfaces of these. By forming the underfill, the mechanical joint strength of the integrated circuit element 3 can be improved.

The integrated circuit element 3 is a one-chip integrated circuit element in which a circuit configuration that constitutes an oscillation circuit together with the crystal diaphragm 1 is integrated. Further, the integrated circuit element 3 incorporates a circuit such as a temperature compensation circuit, a voltage control circuit, or a PLL output circuit as necessary.

The upper storage portion 10b is an area in which the crystal diaphragm 2 is arranged, and shows an area near the upper surface of the support base 1B in the height direction. The electrode pads 12 and 13 are formed on the support base 1B as described above. The electrode pads 12 and 13 are appropriately connected to the integrated circuit element 3 and external connection electrodes (not shown) formed on the lower surface of the ceramic package by wiring in the ceramic package. The electrode pads 12 and 13 are formed by the same method as the electrode pad 14 for connecting an integrated circuit element formed on the bottom surface. For example, a nickel layer and a gold layer are plated in this order on a tungsten layer formed by metallization. It is formed by such means. The total height of the support base 1B and the electrode pad 12 or 13 is preferably higher than the height in a state where the integrated circuit element 3 disposed below is installed.

  On one of these electrode pads, one end in the long side direction of the crystal diaphragm 2 is joined and cantilevered. The quartz crystal plate 2 is formed of a rectangular AT-cut crystal plate, and excitation electrodes 21 and 22 (the back side excitation electrode 22 is not shown) facing the front and back surfaces are formed in the center portion. The excitation electrodes 21 and 22 are drawn out by the extraction electrodes 211 and 221 to one end in the long side direction of the quartz crystal plate 2 and to both end portions in the short side direction, respectively. In bonding the crystal diaphragm 2, the conductive bonding material S is applied onto the electrode pads 12 and 13 of the support base, respectively, and the extraction electrodes 211 and 221 are positioned on the conductive bonding material S so that the crystal Cantilever support the diaphragm. Further, if necessary, a conductive bonding material may be overcoated on the bonding portion after the quartz diaphragm is mounted, so that the extraction electrode 211 and the electrode pad 12, and the extraction electrode 221 and the electrode pad 13 can be reliably electrically connected. Can be mechanically joined.

  An auxiliary support plate 6 is installed on the upper part of the cantilever support portion of the crystal diaphragm 2 with a bonding material. The auxiliary support plate 6 is made of, for example, ceramic or quartz and has a notch 61. The notch 41 is formed at a position where the electrode pad 12 is exposed when the auxiliary support plate is joined. The auxiliary support plate 1 </ b> C side of the auxiliary support plate has a protruding region 6 a that protrudes from the support table, and at least the protruding region 6 a has a width wider than that of the quartz crystal plate 2. Note that the bonding material for bonding the auxiliary support plate 6 to the support base 1B may be an insulating bonding material or a conductive bonding material. In the case of using a conductive bonding material, it is necessary to supply the bonding material so as to prevent a short circuit with an adjacent electrode pad.

Thereafter, the opening of the ceramic package is closed with the lid 5 in an inert gas atmosphere or a vacuum atmosphere, and hermetic sealing is performed. The lid 5 is made of metal. For example, the core 5 is made of Kovar, a nickel layer is formed on the upper part, and a silver brazing layer is formed on the lower part, that is, on the joint surface side with the ceramic package via a copper layer. is there. By joining such a lid by a seam welding method, hermetic sealing can be performed. The lid is drawn from the metal layer 11 to an external connection electrode (not shown) formed on the lower surface of the package by internal wiring (not shown) provided inside the ceramic package.

  With the above configuration, since the auxiliary support plate 6 is installed in the cantilever support portion of the crystal diaphragm, the weight distribution on the cantilever support side increases in the crystal diaphragm due to the weight effect of the auxiliary support plate. Moreover, the joining area | region of a cantilever support part can be taken widely, and when external impact etc. are added, impact absorption can be performed in a comparatively wide area. Even when an external impact or the like is applied due to the above action, the free end side is prevented from being inclined and stable support can be performed. Further, the capacitance does not change due to a change in the positional relationship with other components. Therefore, even if the external size of the crystal diaphragm changes, a crystal oscillator that is stably supported and has little characteristic change can be obtained.

  Furthermore, the present invention also discloses a configuration in which the electrode pad on the support base is devised when the auxiliary support plate 7 is used. That is, as shown in FIG. 7, two electrode pads 15 and 16 (16 is not shown) formed on the support base 1B are thick portions 15a and 16a (16a is not shown) and thin portions 15b, respectively. 16b (16a is not shown), and the auxiliary support plate 7 is installed in the thin portion. With such a configuration, the auxiliary support plate increases the bonding area with the electrode pad, so that the bonding strength is improved and positioning in bonding can be easily performed. Note that FIG. 7 illustrates a crystal resonator configuration that does not include an oscillation circuit or the like.

  In the examples of the above embodiments, a surface mount type crystal oscillator using an AT cut crystal diaphragm is exemplified, but a crystal oscillator using an AT cut crystal diaphragm or a tuning fork type crystal diaphragm is used. Alternatively, it may be a piezoelectric ceramic vibrator, and is not limited to the example of the above embodiment.

  It can be applied to mass production of piezoelectric vibration devices such as crystal oscillators and crystal oscillators.

The perspective view of the open state of the crystal oscillator which shows 1st Embodiment. Sectional drawing of the closed state which shows 1st Embodiment. The top view of the open state which shows 1st Embodiment. The top view which shows the other example of an auxiliary support plate. Sectional drawing of the closed state which shows 2nd Embodiment. The top view of the open state which shows 2nd Embodiment. Sectional drawing of the closed state which shows the other example of a support structure. The figure which shows a prior art example.

Explanation of symbols

1 Ceramic package 2 Quartz diaphragm (piezoelectric transducer)
3 Integrated circuit elements
4, 6, 7 Auxiliary support plate 5 Lid

Claims (4)

An electrode pad is provided on the upper part of the support base, and a piezoelectric vibration element support structure for cantilevering a part of the plate-like piezoelectric vibration element on which the excitation electrode is formed on the support base,
An auxiliary support plate is formed between the support base and the piezoelectric vibration element, the auxiliary support plate is mounted in a state of partially protruding from the support base, and the piezoelectric vibration element including the protruding area is mounted. A support structure for a piezoelectric vibration element, wherein the excitation electrode of the piezoelectric vibration element and the electrode pad are electrically connected by a conductive bonding material. An electrode pad is provided on the upper part of the support base, and a piezoelectric vibration element support structure for cantilevering a part of the plate-like piezoelectric vibration element on which the excitation electrode is formed on the support base,
An auxiliary support plate is mounted on the piezoelectric vibration element and above the support base, and the auxiliary support plate is arranged in a state of partially protruding from the support base in a plan view, and includes the protruding region and the piezoelectric element. A support structure for a piezoelectric vibration element, wherein the vibration element is supported and supported, and the excitation electrode of the piezoelectric vibration element and the electrode pad are electrically connected by a conductive bonding material. A ceramic package having an opening at the top and a support base having a plurality of electrode pads formed on the upper surface thereof, an integrated circuit element installed on the bottom surface inside the package, and an upper part of the integrated circuit element, the support A piezoelectric vibration element composed of a plate-like piezoelectric vibration element that is cantilevered by a table, an auxiliary support plate disposed between the support table and the piezoelectric vibration element, the opening being closed, and the integrated circuit element and the piezoelectric vibration A piezoelectric oscillator comprising a metal lid that hermetically seals the element,
The piezoelectric vibration element has a rectangular shape, and excitation electrodes are formed on the front and back sides, the excitation electrode is led out to the outer periphery, and has an extraction electrode connected to the electrode pad, and the auxiliary support plate Between the support base and the piezoelectric vibration element, a part is mounted on the support base in a state where the other part protrudes from the support base, and the piezoelectric vibration element is supported even in the protruding region. Piezoelectric oscillator. A ceramic package having an opening at the top and a support base having a plurality of electrode pads formed on the upper surface thereof, an integrated circuit element installed on the bottom surface inside the package, and an upper part of the integrated circuit element, the support A piezoelectric vibration element comprising a plate-like piezoelectric vibration element that is cantilevered by a table; an auxiliary support plate mounted on the piezoelectric vibration element and above the support; and the opening is closed; And a piezoelectric oscillator comprising a metal lid for hermetically sealing the piezoelectric vibration element,
The piezoelectric vibration element has a rectangular shape, and excitation electrodes are formed on the front and back, the excitation electrode is led to the outer periphery, and has a lead electrode connected to the electrode pad, and the auxiliary support plate is a flat surface. A piezoelectric oscillator, wherein the piezoelectric oscillator is disposed so as to partially protrude from the support base when viewed from the outside, and supports the piezoelectric vibration element in an auxiliary manner including the protruding region.

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