JP2010124347A - Piezoelectric oscillation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric oscillation device wherein a bad effect due to foreign matters or sealing gas at the time of hermetic sealing is eliminated to reduce the effect of stress of a conductive bump. <P>SOLUTION: The piezoelectric oscillation device includes a piezoelectric oscillation piece 2 having an oscillation part 23 and a holding part 24, a base 3 which holds the piezoelectric oscillation piece, and a lid 4 which is joined at the sealing part of the base for hermetically sealing the piezoelectric oscillation piece held by the base. The holding part of the piezoelectric oscillation piece is joined by ultrasonic waves to a mounting part of the base using a conductive bump B. A shield plate 5 is interposed between an oscillation part 23 of the piezoelectric oscillation piece and a sealing part 321 of the base. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a piezoelectric vibration device.

Currently, examples of the piezoelectric vibration device include a crystal resonator, a crystal filter, and a crystal oscillator. In this type of piezoelectric vibration device, the casing is a rectangular parallelepiped package and includes a base and a lid. The base and the lid are joined to hermetically seal the piezoelectric vibrating piece inside the package. In recent years, with the miniaturization of piezoelectric vibration devices, as shown in Patent Document 1, a piezoelectric vibration piece is electrically and mechanically bonded and held on a mounting portion of a base via a conductive bump by an FCB method. .
JP 2001-85966 A

  As a problem with piezoelectric vibration devices, sealing gas or foreign matter generated by splash during hermetic sealing may adhere to the vibration part of the piezoelectric vibration piece and adversely affect the characteristics of the piezoelectric vibration device. . In particular, a so-called reverse mesa type piezoelectric vibrating piece has been adopted along with the recent increase in frequency, but in such a reverse mesa type piezoelectric vibrating piece, the thickness of the vibrating part is very thin relative to the holding part. Adverse effects of deposits are easily manifested.

  SUMMARY OF THE INVENTION In order to solve the above-described problems, an object of the present invention is to provide a piezoelectric vibration device that eliminates the adverse effects of sealing gas and foreign matters during hermetic sealing.

  In order to achieve the above object, a piezoelectric vibrating device according to the present invention includes a piezoelectric vibrating piece having a vibrating portion and a holding portion, a base holding the piezoelectric vibrating piece, and the piezoelectric vibrating piece held on the base. In the piezoelectric vibration device in which a lid that is bonded at a sealing portion of a base is provided for hermetic sealing, and the holding portion of the piezoelectric vibrating piece is bonded to the mounting portion of the base with a conductive bonding material, the piezoelectric vibration A shielding plate having a partition between the vibrating portion of the piece and the sealing portion of the base is interposed.

  According to the present invention, since the shielding plate partitions the space between the vibrating portion of the piezoelectric vibrating piece and the sealing portion of the base, the sealing gas generated in the sealing portion, the outgas generated in the annealing process, the contamination, etc. By suppressing the adhesion to the vibration part, the deterioration of the characteristics of the piezoelectric vibration device is eliminated.

  Further, in addition to the above-described configuration, the shielding plate is arranged to overlap the piezoelectric vibrating piece in a state where a part of the shielding plate covers the vibrating portion of the piezoelectric vibrating piece, and the conductive bonding material is attached to the holding portion of the piezoelectric vibrating piece. May be joined. With this configuration, in addition to the above-described effects, the sealing gas generated in the sealing portion can more effectively adhere to the vibrating portion without completely covering the shielding plate with respect to the entire piezoelectric vibrating piece. Can be suppressed. Further, since it is not necessary to increase the size of the shielding plate and the shielding plate can be attached without increasing the storage space of the base, it is possible to cope with downsizing of the piezoelectric vibration device.

  According to the invention, the piezoelectric vibrating piece having the vibrating portion and the holding portion, the support holding the piezoelectric vibrating piece, the base holding the piezoelectric vibrating piece via the support, and the base are held by the base. A lid that is joined at a base sealing portion to hermetically seal the piezoelectric vibrating piece is provided, and the support is joined to the mounting portion of the base by a conductive bonding material, and the mounting portion of the support is In the piezoelectric vibration device in which the holding portion of the piezoelectric vibrating piece is bonded with the conductive bonding material, a part of the support serves as a shielding plate to partition the vibrating portion of the piezoelectric vibrating piece and the sealing portion of the base The support is disposed on the piezoelectric vibrating piece in a state where a part of the support covers the vibrating portion of the piezoelectric vibrating piece, and is joined to the holding portion of the piezoelectric vibrating piece with a conductive bonding material. Naruko The features.

  According to the present invention, since the support partitions the space between the vibrating portion of the piezoelectric vibrating piece and the sealing portion of the base, the sealing gas generated in the sealing portion, the outgas generated in the annealing process, contamination, and the like vibrate. By suppressing the adhesion to the part, the deterioration of the characteristics of the piezoelectric vibration device is eliminated. Further, since the support is disposed so as to overlap the piezoelectric vibrating piece with a part of the support covering the vibrating portion of the piezoelectric vibrating piece, and is bonded to the holding portion of the piezoelectric vibrating piece with a conductive bonding material, the piezoelectric vibrating piece However, the support does not adversely affect the piezoelectric vibrating piece because the support absorbs the adverse effects of the restraining force during bonding by various conductive bonding materials and the influence of stress distortion of the base. It is possible to more effectively suppress the sealing gas generated in the sealing portion from adhering to the vibrating portion without completely covering the support with respect to the entire piezoelectric vibrating piece. Since it is not necessary to increase the size of the support and the support can be attached without increasing the storage space of the base, the piezoelectric vibration device can be reduced in size.

  When the piezoelectric vibrating piece is quartz, the shielding plate and the support may be an insulating brittle material such as quartz, glass, or ceramic. This is because even if the shielding plate and support are placed close to the excitation electrode of the piezoelectric vibrating piece, the adverse effect of the stray capacitance is less likely to occur, and the necessary wiring and pad portions are formed by the same method as the electrode formation of the piezoelectric vibrating piece. Easy to do. By selecting glass or quartz that has a thermal expansion coefficient of the shielding plate or support close to that of the piezoelectric vibrating piece, the support only absorbs the adverse effects of external thermal mechanical stress on the piezoelectric vibrating piece. In addition, the adverse effect of the thermal mechanical stress on the piezoelectric vibrating piece from the shielding plate and the support is eliminated, and as a result, the electrical characteristics of the piezoelectric vibrating device are less likely to change over time, which is suitable for improving the electrical characteristics. is there.

  Further, in addition to the above-described configuration, the support is configured such that two supports are superposed on both main surfaces of the piezoelectric vibrating piece with a part of the support covering the vibrating portion of the piezoelectric vibrating piece. It may be joined to the holding portion with a conductive bonding material, and may be joined to the mounting portion of the base with a conductive bonding material by a support on the bottom side. With this configuration, in addition to the above-described effects, it is possible to more effectively suppress the sealing gas generated in the sealing portion, the outgas generated in the annealing process, contamination, and the like from adhering to the vibration portion.

  The above configuration is particularly effective for a reverse mesa type piezoelectric vibrating piece having a thin vibrating portion and a thick holding portion (thick portion), and the vibrating portion having a very thin thickness, Can handle high frequency. In the case of an inverted mesa type piezoelectric vibrating piece, the shielding plate and a part of the support cover the thin vibrating portion of the piezoelectric vibrating piece so as to be superposed on the piezoelectric vibrating piece, thereby maintaining the thick thickness of the piezoelectric vibrating piece. Since the side wall portion is present in the thick-walled holding portion by bonding to the portion with the conductive bonding material, the sealing gas generated in the sealing portion and the outgas generated in the annealing process with respect to the thin-walled vibration portion, It is possible to more effectively suppress contamination and the like from adhering to the vibration part.

  In the above-described configuration, the conductive bonding material may be a conductive bump, and ultrasonic bonding may be performed by the conductive bump. With this configuration, in addition to the above-described operational effects, the holding portion of the piezoelectric vibrating piece is ultrasonically bonded to the mounting portion of the base by means of conductive bumps. The bonding gas adheres to the vibrating part of the vibrating piece, and the deterioration of the characteristics can be eliminated.

  ADVANTAGE OF THE INVENTION According to this invention, the piezoelectric vibration device which eliminated the bad influence by sealing gas at the time of airtight sealing and a foreign material can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. In each example shown below, a case where the present invention is applied to a crystal resonator as a piezoelectric vibration device is shown. FIG. 1 is a cross-sectional view showing a schematic configuration of a crystal resonator according to a first embodiment of the present invention. 2 and 3 are schematic cross-sectional views according to other examples of the first embodiment.

  In the crystal resonator 1 according to this example, as shown in FIG. 1, a crystal vibrating piece 2 (a piezoelectric vibrating piece referred to in the present invention), a base 3 that holds the crystal vibrating piece 2 in one piece, and a base 3. A lid 4 and a shielding plate 5 are provided for hermetically sealing the quartz crystal vibrating piece 2.

  In this crystal unit 1, a package is constituted by a base 3 and a lid 4, and the base 3 and the lid 4 are joined to form an internal space of the package, and a crystal is formed on the base 3 in the internal space of the package. While the vibration piece 2 is held, the internal space of the package is hermetically sealed. At this time, as shown in FIG. 1, the base 3 and the quartz crystal vibrating piece 2 are electromechanically ultrasonically bonded (diffusion bonded) by the FCB method using conductive bumps B made of a metal material.

  As shown in FIG. 1, the base 3 is formed in a box-like body including a bottom portion 31 and a wall portion 32 extending upward from the bottom portion 31. The base 3 is formed by laminating a rectangular parallelepiped of a ceramic material on a single plate having a rectangular shape in a plan view made of a ceramic material, and integrally firing in a concave shape.

  The wall portion 32 is formed along the outer periphery of the surface of the bottom portion 31. The upper surface of the wall portion 32 is a joining region (sealing portion 321) with the lid 4, and a sealing member (not shown) for joining with the lid 4 (for example, a metallized layer or a metal ring material) ) Is provided.

  A plurality of electrode pads 33 and 33 (base mounting portions) are formed on the bottom 31 of the base 3 for electromechanical bonding with an excitation electrode (not shown) of the crystal vibrating piece 2. These electrode pads are respectively electrically connected to terminal electrodes (not shown) formed on the outer peripheral back surface of the base 3. These terminal electrodes are connected to external parts and external devices. These terminal electrodes and electrode pads are formed by printing integrally with a base 3 after printing a metallized material such as tungsten or molybdenum. Some of these terminal electrodes and electrode pads are formed by forming nickel plating on the metallized upper portion and forming gold plating on the upper portion thereof.

  The lid 4 is made of, for example, a metal material or a ceramic material, and is formed into a single plate. The lid 4 has a sealing material (a brazing material, a plating material, a glass material, etc.) (not shown) formed on the lower surface, a welding technique such as a seam or a beam, an atmosphere heating technique using a glass sealing material, a metallic brazing material, or the like. Is bonded to the base 3 and hermetically sealed, and a package of the crystal unit 1 is formed by the lid 4 and the base 3.

  As shown in FIG. 1, the quartz crystal vibrating piece 2 is formed of an AT-cut quartz substrate, for example, is formed into a single-plate rectangular parallelepiped, and the outer peripheral shape of the substrate is a rectangular parallelepiped shape. Concave portions 21 and 22 are formed on both main surfaces of the substrate of the crystal resonator element 2 in order to cope with the high frequency of the crystal resonator element 2, and excitation electrodes (not shown) are formed near the center inside the recesses 21 and 22, respectively. Has been. These excitation electrodes are joined to an external electrode (in this embodiment, electrode pads 33 and 33 of the base 3) and an extraction electrode (not shown) drawn from the excitation electrode and an after-mentioned shielding plate for electromechanical joining. A shielding plate bonding pad portion for this purpose is formed in the vicinity of the corner of the holding portion, which is both ends of one end portion of the crystal vibrating piece 2. In other words, the quartz crystal resonator element 2 has a thin-walled vibration part 23 constituted by the recesses 21 and 22 and the excitation electrode, and a thick-walled part (holding part) 24 formed with a lead electrode and a pad part for shielding plate bonding. is doing.

  The excitation electrode, the extraction electrode, and the shielding plate bonding pad portion are formed by photolithography, for example, in the order of chromium and gold (Cr—Au) from the substrate side, or nickel and gold (Ni—Au). ) In this order.

  Only one end of the thick portion 24 of the quartz crystal vibrating piece 2 is ultrasonically bonded to the electrode pads 33 and 33 which are the mounting portions of the base 3 by the conductive bumps B for base bonding. The conductive bump B is composed of a metal bump made of gold or the like or a metal plating bump. The conductive bump B for base bonding is preferably a metal bump, and the conductive bump B for crystal vibrating piece bonding is preferably a metal plating bump, but is not limited thereto.

  The first embodiment of the present invention is characterized in that a shielding plate 5 having a partition between the vibrating portion 23 of the quartz crystal vibrating piece 2 and the sealing portion 321 of the base 3 is interposed. Will be explained.

  For example, a Z-cut quartz substrate is used as the shielding plate 5 and is formed into a single-plate rectangular parallelepiped. The outer peripheral shape of the substrate is a rectangular parallelepiped shape, and is configured to have substantially the same shape and the same plane area as the quartz crystal vibrating piece 2. In this embodiment, a Z-cut quartz substrate is used, but other cut angles such as an AT-cut may be used, or an insulating brittle material other than a quartz substrate such as glass may be used. At both ends of one end portion of the shielding plate 5 on the substrate bottom side, pad portions for crystal resonator element bonding (not shown) for bonding the crystal resonator element 2 are formed. The pad for crystal resonator element bonding is formed by photolithography in the same manner as the above-described electrodes and the like. For example, chromium, gold (Cr—Au) in this order from the substrate side, or nickel, gold (Ni— Au) are stacked in this order.

  Then, a shielding plate 5 is arranged on top of the crystal vibrating piece 2 mounted on the base 3, and a shielding plate bonding pad portion formed at one end of the thick portion 24 of the crystal vibrating piece 2; Ultrasonic bonding is carried out with a quartz crystal vibrating piece bonding conductive bump B interposed between a pad portion for crystal vibrating piece bonding formed at one end of the shielding plate 5. As a result, it is possible to completely partition the sealing plate 5 from the sealing portion 321 of the base 3 with a part of the shielding plate 5 covering the vibrating portion 23 of the crystal vibrating piece 2. Further, in this embodiment, the base 3, the crystal vibrating piece 3, and the shielding plate 5 are held (cantilevered) only at one end, and the adverse effect due to the restraining force of the conductive bump B after the bonding is exerted on the crystal vibrating piece 3. It is a holding structure that is difficult to join. Note that the present invention is not limited to this embodiment, and an integrated body in which the crystal vibrating piece 2 and the shielding plate 5 are bonded in advance by the conductive bump B for bonding the crystal vibrating piece is mounted on the base 3. B may be joined.

  It should be noted that the first embodiment of the present invention is not limited to the shielding plate 5 as shown in FIG. 1, and the shape, the number, the joining configuration and the like are not specified. For example, as shown in FIG. 2, a reverse concave shielding plate 51 is used to mount on the base in a state independent of the crystal vibrating piece 2 and to cover the upper part of the crystal vibrating piece 2 completely. A configuration in which the conductive bumps B are joined to the base 3 may be employed. Further, as shown in FIG. 3, the base 3 is provided with a middle step portion 35, and the crystal resonator element 2 is electrically and mechanically joined to the base 3 by the conductive bumps B for joining the base in the storage portion below the middle step portion 35. In addition, the shielding plate 52 may be joined by the base joint conductive bumps B at the middle stage portion 35. With these configurations, a partition can be provided between the vibrating portion 23 of the quartz crystal vibrating piece 2 and the sealing portion 321 of the base 3.

  As described above, according to the first embodiment of the present invention, the shielding plate 5, the shielding plate 51, and the shielding plate 52 form a partition between the vibrating portion 23 of the crystal vibrating piece 2 and the sealing portion 321 of the base 3. Therefore, the deterioration of the characteristics of the crystal unit 1 is eliminated by suppressing the sealing gas generated in the sealing part 321 from adhering to the vibration part 23. Further, a holding portion 24 at one end of the crystal vibrating piece is ultrasonically bonded to the base electrode pads 33 and 33 (base mounting portion) by a conductive bump B for base bonding, and a holding portion at one end of the crystal vibrating piece. 24, one end of the shielding plate is ultrasonically bonded by the conductive bump B for bonding the crystal vibrating piece, so that the influence of gas generation during bonding is reduced, and bonding to the vibrating portion 23 of the crystal vibrating piece is performed. It is possible to eliminate the deterioration of characteristics due to the adhesion of gas.

  Further, in addition to the above-described effects, the shielding plate 5 is configured to have the same shape and the same flat area as the crystal vibrating plate 2, and a portion of the shielding plate 5 covers the vibrating portion 23 of the crystal vibrating piece 2. Since the integrated member is superposed on the resonator element 2 and ultrasonically bonded by the conductive bumps B for bonding the crystal resonator element to the holding part 24 of the crystal resonator element 2, the shielding plate 5 is enlarged. In addition, it is possible to more effectively suppress the sealing gas generated in the sealing portion 321 from adhering to the vibration portion 23 and to attach the shielding plate 5 without expanding the storage space of the base 3. Therefore, it is possible to cope with downsizing of the crystal unit 1.

  Since the shielding plate 5 is made of the same crystal as the crystal vibrating piece 2, it absorbs the adverse effect of stress during ultrasonic bonding of the conductive bump B for crystal vibrating piece bonding, and bonds the conductive bump B. It is suitable for improving the property, and the adverse effect of the thermal mechanical stress on the quartz crystal vibrating piece 2 from the shielding plate is also eliminated. As a result, the electrical characteristics of the crystal unit 1 are less likely to change over time, and a configuration suitable for improving the electrical characteristics can be obtained. Further, even if the shielding plate 5 made of an insulating material crystal is disposed close to the excitation electrode of the crystal vibrating piece 2, the stray capacitance is hardly adversely affected. The formation of the pad portion for bonding the crystal vibrating piece can be easily performed by photolithography as in the case of forming each electrode of the crystal vibrating piece. In addition, by using a Z-cut quartz substrate, since it is a material that is not easily affected by anisotropy, it is less susceptible to anisotropy during etching when forming the shielding plate, and the shape accuracy is good. The shape of the shielding plate can be easily formed into an arbitrary shape. This is because, in the case of a material that is easily affected by anisotropy, the shape of the shielding plate is arbitrarily set because the etching is performed obliquely with respect to a preset axial direction when the shielding plate is formed. This is because it becomes difficult to form the shape, size, and area. Further, since the shielding plate is a material that is not easily affected by anisotropy, it is not affected by the vibration of the quartz crystal vibrating piece, and the assembly accuracy and the holding position accuracy are improved. As a result, it is possible to prevent the characteristics of the quartz crystal vibrating piece from being deteriorated by the installation of the shielding plate.

  The above configuration particularly includes the inverted mesa type crystal vibrating piece 2 having the thin vibrating portion 23 and the thick holding portion (thick portion) 24, and the vibrating portion 23 is very thin. It is effective and can cope with high frequency. Since the base 3 and the shielding plate 5 can be bonded to the thick holding portion 24 of the crystal vibrating piece by various conductive bumps B, the strength in the thickness direction of the crystal vibrating piece 2 at the time of bonding the conductive bump is increased. This is suitable for eliminating cracks in the inverted mesa-type crystal vibrating piece 2 having a small thickness and a relatively weak strength. In addition, a part of the shielding plate 5 covers the thin vibrating portion 23 of the crystal vibrating piece 2 and is superposed on the quartz vibrating piece 2 and joined to the thick holding portion 24 of the crystal vibrating piece 2. Since the thick holding portion 24 has the side wall portion 241, the sealing gas generated in the sealing portion 321 is more effectively suppressed from adhering to the vibrating portion 23 with respect to the thin vibrating portion 23. be able to.

  Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a cross-sectional view showing a schematic configuration of a crystal resonator according to a second embodiment of the present invention. 5 and 6 are schematic cross-sectional views according to other examples of the second embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and different points will be mainly described.

  In the second embodiment of the present invention, as shown in FIG. 4, a quartz crystal vibrating piece 2 (a piezoelectric vibrating piece referred to in the present invention), a support 6 that cantilever the quartz crystal vibrating piece 2 on both main surfaces, and a support 60, a base 3 to which the support 6 is joined, and a lid 4 for hermetically sealing the quartz crystal vibrating piece 2 held on the base 3 are provided. Among these, the support 60 is interposed in a state where a part of the support is a shielding plate and a partition is formed between the vibrating portion 23 of the crystal vibrating piece 2 and the sealing portion 321 of the base 3. Is characterized in that a part of the support covers the vibrating part 23 of the crystal vibrating piece 2 and is superposed on the crystal vibrating piece 2 and joined to the holding part 24 of the crystal vibrating piece 2. Will be explained.

  The supports 6 and 60 are, for example, Z-cut quartz substrates and are formed into a single-plate rectangular parallelepiped. The outer peripheral shape of the substrate is a rectangular parallelepiped shape, and has the same shape and the same plane area as the quartz crystal resonator element 2. . In this embodiment, a Z-cut quartz substrate is used, but other cut angles such as an AT-cut may be used, or an insulating brittle material other than a quartz substrate such as glass may be used. At both ends of one end on the upper surface side of the support 6 and at both ends of one end on the bottom surface side of the support 60, a crystal vibrating piece (not shown) for bonding with the lead electrode of the crystal vibrating piece 2 is connected. A pad portion is formed, and the both ends of one end portion on the bottom side of the support 6 are not shown for joining the pad portion for joining the crystal vibrating piece and the base 3 connected by a via or a drawing pattern not shown. A base bonding pad portion is formed. The crystal vibrating piece bonding pad portion, the base bonding pad portion, the routing pattern, and the like are formed by a photolithography method in the same manner as the above-described electrodes. For example, chromium, gold (Cr- Au) or nickel and gold (Ni—Au) in this order.

  Then, only one end of the support 6 is ultrasonically bonded to the electrode pads 33 and 33 which are the mounting portions of the base 3 by base-bonding conductive bumps B. The quartz crystal vibrating piece 2 is placed on top of the support 6 mounted on the base 3, and the support 60 is placed on the top of the quartz crystal vibrating piece 2, and one end of the thick portion 24 of the quartz crystal vibrating piece 2 is arranged. Conductive bumps B for crystal vibrating piece bonding between the pad portions for supporting bonding formed on both main surfaces and the pad portions for crystal vibrating piece bonding formed at one end of each of the supports 6, 60. Are ultrasonically bonded in a state of interposing each. That is, the two supports 6, 60 are superimposed on both main surfaces of the crystal vibrating piece 2 and are joined to only one end of the holding portion 24 of the crystal vibrating piece 2 by the conductive bump B. The base pads are ultrasonically bonded to electrode pads 33, 33, which are base mounting portions, by means of conductive bumps B for base bonding. With such a configuration, the support 60 can be completely separated from the sealing portion 321 of the base 3 in a state where a part of the support 60 covers the vibration portion 23 of the crystal vibrating piece 2. In this embodiment, the base 3, the support 6, the crystal vibrating piece 3, and the support 60 are held (cantilevered) only at one end, and the adverse effect due to the restraining force of the conductive bumps B after bonding is the crystal vibrating piece 3. The holding structure is difficult to add to. Note that the present invention is not limited to this embodiment, and an integrated body in which the crystal vibrating piece 2, the support 6, and the support 60 are bonded in advance by the conductive bumps B for bonding the crystal vibrating piece is mounted on the base 3. Bonding may be performed with the property bump B. Further, a pad portion for base bonding is provided on the support 60 instead of the support 6, and the pad portion is electrically and mechanically bonded to the base 3 via the conductive bumps B for base bonding, and is mounted on the base 3. Also good.

  Note that the second embodiment of the present invention is not limited to the combination of the support 6 and the support 60 as shown in FIG. 4, and the shape, the number, the bonding configuration, and the like are specified. is not. For example, as shown in FIG. 5, a reverse-recessed support 61 is used, and the crystal vibrating piece 2 is electrically and mechanically joined to the support housing 611 by a conductive bump B for joining the crystal vibrating piece. A configuration may be adopted in which the opening end 612 of the side wall is electrically and mechanically bonded to the base 3 by the conductive bumps B for base bonding. As shown in FIG. 6, the base 3 is provided with a middle step portion 35 to use a plate-like support 62, and the crystal vibrating piece 2 is electrically connected to the bottom surface of the support 62 by conductive bumps B for bonding the crystal vibrating piece. It may be configured to be mechanically joined and to be electrically and mechanically joined to the middle step portion 35 of the base by the conductive bump B for base joining at the end of the support 62. With these configurations, not only can the partition between the vibrating portion 23 of the crystal vibrating piece 2 and the sealing portion 321 of the base 3 be partitioned, but the crystal vibrating piece 2 can be electrically and mechanically attached to the base 3 via a support. Can be joined.

  As described above, according to the second embodiment of the present invention, the support 60, the support 61, and the support 62 partition the space between the vibrating portion 23 of the crystal vibrating piece 2 and the sealing portion 321 of the base 3. Therefore, the deterioration of the characteristics of the crystal unit 1 is eliminated by suppressing the sealing gas generated in the sealing part 321 from adhering to the vibration part 23. Further, the support 6, the support 61, and the support 62 are ultrasonically bonded to the base electrode pads 33 and 33 (base mounting portion) by the conductive bumps B for base bonding, and the support 6 and the support 60, the support 61, and Since the crystal vibrating piece holder 24 is ultrasonically bonded to the mounting portion of the support 62 by the conductive bump B for bonding the crystal vibrating piece, the influence of gas generation during bonding is reduced, and the vibration of the crystal vibrating piece is reduced. The bonding gas adheres to the portion 23 to eliminate the deterioration of characteristics. The crystal vibrating piece 2 may adversely affect the crystal vibrating piece 2 by the support 6, the support 61, and the support 62 absorbing the adverse effect of the binding force at the time of bonding by the conductive bumps B and the influence of the stress distortion of the base 3. Absent. In addition, the support 6 and the support 60 are configured to have the same shape and the same plane area as the crystal vibrating plate 2 and are arranged so as to overlap the crystal vibrating piece 2, and the conductive part for bonding the crystal vibrating piece to the holding portion 24 of the crystal vibrating piece 2. Since the integrated object is ultrasonically bonded by the conductive bump B, the entire support 6 and the support 60 can be wrapped around the crystal vibrating piece 2 without increasing the size of the support 6 and the support 60. Become. As a result, it is possible not only to more effectively suppress the sealing gas generated in the sealing portion 321 from adhering to the vibration portion 23, but also to attach the support without expanding the base 3 storage space. It can cope with the miniaturization of the crystal unit 1.

  Since the support 6, the support 60, the support 61, and the support 62 are made of the same crystal as the crystal vibrating piece 2, the adverse effect of stress during ultrasonic bonding of the conductive bump B for crystal vibrating piece bonding is absorbed. Therefore, it is suitable for improving the bondability of the conductive bump B, and the adverse effect of the thermal mechanical stress from the support to the crystal vibrating piece 2 is eliminated. As a result, the electrical characteristics of the crystal unit 1 are less likely to change over time, and a configuration suitable for improving the electrical characteristics can be obtained. Further, even if the support 6 made of an insulating material crystal, the support 60, the support 61, and the support 62 are disposed close to the excitation electrode of the crystal vibrating piece 2, the stray capacitance is hardly adversely affected. The formation of the pad portion for bonding the crystal vibrating piece can be easily performed by photolithography as in the case of forming each electrode of the crystal vibrating piece. In addition, by using a Z-cut quartz substrate, because it is a material that is not easily affected by anisotropy, the shape accuracy is good when etching the support, because it is less susceptible to anisotropy, The shape of the support can be easily formed into an arbitrary shape. This is because, in the case of a material that is easily affected by anisotropy, the shape of the support material is set to an arbitrary shape because etching is performed in an oblique direction with respect to a preset axial direction when etching the support. This is because it becomes difficult to form, size and area. In addition, since the support material is not easily affected by anisotropy, it is not affected by the vibration of the quartz crystal vibrating piece, and the assembly accuracy and the holding position accuracy are improved. As a result, it is possible to prevent the characteristics of the quartz crystal vibrating piece from being deteriorated by installing the support material.

  The above configuration particularly includes the inverted mesa type crystal vibrating piece 2 having the thin vibrating portion 23 and the thick holding portion (thick portion) 24, and the vibrating portion 23 is very thin. It is effective and can cope with high frequency. Since the base 3, the support 6, the support 60, the support 61, and the support 62 can be bonded to the thick holding portion 24 of the crystal vibrating piece by the conductive bump B for bonding the crystal vibrating piece, the conductive bump The strength in the thickness direction of the crystal vibrating piece 2 at the time of bonding can be ensured, which is suitable for eliminating the crack of the inverted mesa type crystal vibrating piece 2 in which the thickness of the vibrating portion 23 is thin and the strength is relatively weak. In addition, a part of the support is disposed so as to overlap the crystal vibrating piece 2 with the vibrating portion 23 of the crystal vibrating piece 2 covered. By connecting the support 62 and the thick wall holding portion 24, the side wall portion 241 exists, so that the sealing gas generated in the sealing portion 321 adheres to the vibration portion 23 with respect to the thin vibration portion 23. It can suppress even more effectively.

  In the above embodiment, an example in which only an inverted mesa type quartz diaphragm is used has been described. However, the present invention is also applicable to other quartz diaphragms having a vibrating portion such as a flat plate-like quartz diaphragm and a holding portion. it can. Further, as shown in FIG. 7, a quartz diaphragm 2 having an outer frame 26 formed through a through-groove 24 is used as the quartz diaphragm 2, and a shielding plate is formed by conductive bumps B on the outer frame 26 of the quartz diaphragm. 5 or the support 6, 60, 61, 62 may be joined. This embodiment is particularly effective for the configuration using the conductive bump B as the conductive bonding material, which can eliminate the adverse effect of the restraining force and the influence of the stress distortion of the base when the conductive bump B is bonded. It is preferable because the sealing gas generated at the stop portion 321 can be more effectively suppressed from adhering to the vibration portion 23.

  In the above embodiment, the conductive bump is described as an example of the conductive bonding material, but a silicone resin-based or epoxy resin-based conductive resin adhesive may be used, solder, lead-free solder, gold A metal brazing material such as tin or gold gel material may be used. Further, in the outer surfaces of the shielding plates 5, 51, 52 and the supports 6, 60, 61, 62 described above, at least a region close to the sealing portion 321 of the base 3 is an unnecessary object (gas or foreign matter) due to splash. It is more preferable to apply a structure that makes it easy to adhere. As such a configuration example, when a rough surface portion is formed, a thin film made of an oxide film such as Si, Ti, Cr, Al, or NiCr is formed, or a getter material such as Ti, Mg, Ba, or Zr is formed. Good.

  It should be noted that the present invention can be implemented in various other forms without departing from the spirit, gist, or main features. For this reason, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  The present invention can be applied to piezoelectric vibration devices such as a crystal resonator, a crystal filter, and a crystal oscillator.

1 is a cross-sectional view showing a schematic configuration of a crystal resonator according to a first embodiment of the present invention. FIG. 6 is a schematic cross-sectional view according to another example of the first embodiment. FIG. 6 is a schematic cross-sectional view according to another example of the first embodiment. Sectional drawing which showed schematic structure of the crystal oscillator concerning the 2nd Embodiment of this invention. The schematic sectional drawing concerning the other Example of 2nd Embodiment. The schematic sectional drawing concerning the other Example of 2nd Embodiment. The schematic sectional drawing concerning another Example.

Explanation of symbols

1 Crystal resonator 2 Crystal resonator element 3 Base 4 Lid 5, 51, 52 Shield plate 6, 60, 61, 62 Support B Conductive bump

Claims (2)

A piezoelectric vibrating piece having a vibrating portion and a holding portion; a base holding the piezoelectric vibrating piece; and a lid joined at a sealing portion of the base to hermetically seal the piezoelectric vibrating piece held on the base. In the piezoelectric vibration device provided, the holding portion of the piezoelectric vibrating piece is bonded to the mounting portion of the base by a conductive bonding material,
A piezoelectric vibration device comprising a shielding plate having a partition between a vibrating portion of the piezoelectric vibrating piece and a sealing portion of the base. A piezoelectric vibrating piece having a vibrating portion and a holding portion, a support holding the piezoelectric vibrating piece, a base holding the piezoelectric vibrating piece via the support, and the piezoelectric vibrating piece held on the base are hermetically sealed. In order to achieve this, a lid that is joined at the sealing portion of the base is provided, and the support is joined to the mounting portion of the base by a conductive bonding material, and the holding portion of the piezoelectric vibrating piece is electrically conductive to the mounting portion of the support In the piezoelectric vibration device bonded by the conductive bonding material,
A part of the support serves as a shielding plate and is interposed in a state where a partition is formed between the vibrating part of the piezoelectric vibrating piece and the sealing part of the base, and the part of the support is part of the piezoelectric vibrating piece. A piezoelectric vibration device, wherein the piezoelectric vibration device is arranged so as to be superimposed on the piezoelectric vibrating piece and is bonded to the holding portion of the piezoelectric vibrating piece with a conductive bonding material.

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