Laminate type piezoelectric vibrator, piezoelectric vibration device, and thermostatic chamber type piezoelectric oscillator

Abstract

To provide a laminate type piezoelectric vibrator capable of improving a heat transmission in an OCXO.SOLUTION: A laminate type piezoelectric vibrator includes a crystal diaphragm 10, a first sealing member 20, and a second sealing member 30. A third terminal 23 of the first sealing member 20 is bonded to an oscillation IC 51 by a bonding material. The third terminal 23 is overlapped with a one part of an outer frame part 12 of the crystal diaphragm 10 in a plan view. An area in the plan view of the third terminal 23 is formed by 50% or larger of an area in the plan view of the first sealing member 20. An external terminal 32 of the second sealing member 30 is bonded to a heater IC 52 by the bonding material. The external terminal 32 is overlapped with the one part of the outer frame part 12 of the crystal diaphragm 10 in the plan view. The area in the plan view of the external terminal 32 is formed by 50% or larger of the area in the plan view of the second sealing member 30. The third terminal 23 and the external terminal 32, and seal passes 41 and 42 are thermally coupled.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a stacked piezoelectric vibrator, a piezoelectric vibrating device, and an oven-controlled piezoelectric oscillator. [Background technology]

[0002] Piezoelectric oscillators such as quartz crystal oscillators change their oscillation frequency depending on the temperature based on their inherent frequency-temperature characteristics. Therefore, oven-controlled piezoelectric oscillators (hereinafter also referred to as "OCXOs") are known in which the piezoelectric oscillator is enclosed in a thermostatic oven to maintain a constant temperature around the piezoelectric oscillator (see, for example, Patent Document 1).

[0003] The OCXO described in Patent Document 1 has a core section, which is made up of a stack of an oscillation IC, a piezoelectric vibrator, and a heater IC, supported inside a heat-insulating package via a flexible core substrate, with the necessary wiring performed using wire bonding. An OCXO with this configuration achieves a compact size while improving the heat insulation effect of the core section. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 097132 Summary of the Invention [Problem to be solved by the invention]

[0005] The OCXO described above uses a three-layer (laminated) piezoelectric vibrator with four external terminals on the bottom surface of the piezoelectric vibrator, which can cause problems such as short circuits caused by the bonding material during die bonding and poor heat transfer from heated external components.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a stacked piezoelectric vibrator that can improve the heat transfer in an OCXO. Another aim of the present invention is to provide a piezoelectric vibrating device and an OCXO that include such a stacked piezoelectric vibrator. [Means for solving the problem]

[0007] The present invention provides the means for solving the above-mentioned problems as follows. That is, the present invention is a stacked piezoelectric vibrator having a piezoelectric diaphragm in which an outer frame portion, a holding portion, and a vibrating portion on which an excitation electrode is formed are integrally formed, a first sealing member covering the upper surface of the vibrating portion, and a second sealing member covering the lower surface of the vibrating portion, wherein a heat transfer electrode is formed on the outer surface of the first sealing member or the outer surface of the second sealing member, the heat transfer electrode being joined to an external heating member with a bonding material and overlapping with a part of the outer frame portion that is not connected to the excitation electrode, the area of ​​the heat transfer electrode in a planar view being 50% or more of the area of ​​the first sealing member or the second sealing member in a planar view, a first annular sealing electrode is formed between the first sealing member and the piezoelectric diaphragm, and a second annular sealing electrode is formed between the second sealing member and the piezoelectric diaphragm, the first sealing electrode and the second sealing electrode overlap in an annular shape at the outer frame portion, and the heat transfer electrode, the first sealing electrode, and the second sealing electrode are thermally coupled via connecting electrodes.

[0008] According to the above configuration, the heat-transfer electrode heated by the external heating member is thermally coupled to the first and second sealing electrodes, and the first and second sealing electrodes are annularly overlapped in the outer frame portion. Therefore, heat from the heat-transfer electrode is transferred to the outer frame portion via the first and second sealing electrodes, and further transferred from the outer frame portion via the holding portion to the vibrating portion. This improves heat transfer from the external heating member to the vibrating portion via the outer frame portion and holding portion. Therefore, it is possible to provide a stacked piezoelectric vibrator that can improve heat transfer in an OCXO.

[0009] In the above configuration, it is preferable that the heat-transfer electrodes include a top heat-transfer electrode formed on the outer surface of the first sealing member and a bottom heat-transfer electrode formed on the outer surface of the second sealing member. As a result, heat transfer electrodes (top heat transfer electrode, bottom heat transfer electrode) are provided on both the outer surface of the first sealing member and the outer surface of the second sealing member, thereby further improving heat transfer from the external heating member to the vibration part of the piezoelectric vibration plate.

[0010] The present invention also provides a piezoelectric resonator device including the stacked piezoelectric resonator having the above-described configuration, wherein the external heating member is an oscillation IC or a heater IC, and is bonded to the heat transfer electrodes on the outer surface of the stacked piezoelectric resonator with a bonding material. This improves heat transfer from the oscillation IC and the heater IC to the vibration part of the stacked quartz crystal resonator plate in the piezoelectric resonator device.

[0011] In the above configuration, it is preferable that the multilayer piezoelectric vibrator is stacked and disposed in a state sandwiched between the oscillation IC and the heater IC. This allows the oscillation IC and heater IC to transfer heat from both sides of the stacked piezoelectric vibrator to the vibration part of the piezoelectric diaphragm, further improving heat transfer from the oscillation IC and heater IC to the vibration part of the piezoelectric diaphragm.

[0012] The present invention also provides an oven-controlled piezoelectric oscillator including a piezoelectric resonator device having the above-described configuration, wherein the piezoelectric resonator device is hermetically sealed inside a heat-insulating package, a core unit includes at least the oscillation IC, the stacked piezoelectric resonator, and the heater IC, and at least one of the oscillation IC and the heater IC is stacked on the outer surface of the stacked piezoelectric resonator, the core unit is mounted on the package via a substrate, and a space is provided between the substrate and the inner bottom surface of the package. This space improves the insulation of the core unit, reduces the amount of heat generated by the heater required to maintain the temperature of the core unit, and further reduces power consumption.

[0013] In the above configuration, it is preferable that the substrate is mechanically joined at both ends to the inner bottom surface of the package by a bonding material, and the core is electrically joined to the package by a wire, thereby preventing heat from escaping to the outside by directly mechanically joining the core to the package and realizing the necessary electrical connection from the core to the outside. [Effects of the Invention]

[0014] According to the present invention, since the heat transfer electrode joined to the external heating member is thermally coupled to the first and second sealing electrodes, it is possible to improve heat transfer from the external heating member to the vibration portion of the piezoelectric diaphragm, and therefore it is possible to provide a stacked piezoelectric vibrator that can improve heat transfer in an OCXO. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of an OCXO according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view of the OCXO of FIG. [Figure 3] FIG. 2 is a bottom view of the OCXO of FIG. 1. [Figure 4] 2 is a cross-sectional view showing a schematic configuration of a core section and a core substrate of the OCXO of FIG. 1. [Figure 5] FIG. 6 is a schematic diagram showing the configuration of a crystal oscillator in the core section of FIG. 5. [Figure 6] 2 is a schematic plan view of a first main surface side of a first sealing member of a quartz crystal resonator according to an embodiment of the present invention. FIG. [Figure 7] 3 is a schematic plan view of the second main surface side of the first sealing member of the quartz crystal resonator. FIG. [Figure 8] 2 is a schematic plan view of a first main surface side of a quartz crystal plate of a quartz crystal resonator. FIG. [Figure 9] 2 is a schematic plan view of the second main surface side of the quartz crystal plate of the quartz crystal resonator. FIG. [Figure 10]3 is a schematic plan view of the first main surface side of the second sealing member of the quartz crystal resonator. FIG. [Figure 11] 4 is a schematic plan view of the second main surface side of the second sealing member of the quartz crystal resonator. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0017] 1 to 3, the OCXO 1 according to this embodiment has a structure in which a core part 5 is disposed inside a recessed part 2a of a package (housing) 2 made of ceramic or the like and having a substantially H-shaped cross section, and the core part 5 is hermetically sealed by a lid 3. Fig. 2 shows the OCXO 1 with the lid 3 removed, and illustrates the internal structure of the recessed part 2a of the package 2.

[0018] Specifically, as shown in FIGS. 1 and 2, the OCXO 1 has a package 2 with a substantially H-shaped cross section, including a recess 2a that opens upward and a recess 2e that opens downward. A core 5 is hermetically sealed within the recess 2a of the package 2. A lid 3 is fixed to the upper surface of a peripheral wall 2b surrounding the recess 2a by seam welding via a sealing material 8, sealing the interior of the recess 2a in an airtight state. The sealing material 8 is preferably a metal-based sealing material such as an Au-Sn alloy or solder, but low-melting-point glass or other sealing material may also be used. Furthermore, other sealing methods, such as seam sealing using a metal ring, direct seam sealing without a metal ring, or beam sealing, may also be used (seam sealing is preferred to avoid reducing the degree of vacuum). The interior space of the recess 2a is preferably filled with a high vacuum (e.g., a vacuum of 10 Pa or less) or a low-vacuum atmosphere, or a low-pressure atmosphere with low thermal conductivity, such as nitrogen or argon.

[0019] As shown in FIGS. 1 and 3 , a recess 2e is formed on the main surface of the package 2 opposite the main surface (the main surface on which the recess 2a is formed) that serves as the mounting area for the core unit 5. Circuit components such as a capacitor 9 are disposed in the recess 2e as adjustment electronic components used in combination with the heater IC 52 of the core unit 5. Unlike the recess 2a, the recess 2e does not need to be sealed with the lid 3. By disposing the circuit components outside the space that houses the core unit 5 of the package 2, it is possible to achieve low-power temperature control of the core unit 5 and improve the temperature tracking ability of the core unit 5. Furthermore, it is possible to prevent subsequent gas generation due to solder, flux, etc. in the atmosphere inside the hermetically sealed recess 2a. This prevents the core unit 5 from being adversely affected by gas, which is desirable for further stabilizing its electrical characteristics.

[0020] In this embodiment, three capacitors 9 are mounted on the other principal surface of the package 2 opposite the one principal surface (in this case, the bottom surface of the recess 2e). The capacitors 9 are soldered to mounting pads 9a formed on the bottom surface of the recess 2e of the package 2. The arrangement area of ​​the capacitors 9 is indicated by a dashed line in FIG. 3. A pair of mounting pads 9a, 9a are arranged opposite each other along the short side of the package 2, and both ends of each of the three capacitors 9 in the short side direction of the package 2 are bonded to the mounting pads 9a, 9a. The bottom surface of the package 2 also has a plurality of external connection terminals 2g (eight in FIG. 3) formed thereon for electrically connecting the OCXO 1 to an external circuit board (not shown) provided externally via solder or the like. The number of capacitors 9 mounted on the other principal surface of the package 2 is not particularly limited, and the number of capacitors 9 may be other than three. Furthermore, circuit components other than the capacitors 9 may be mounted on the other principal surface of the package 2. Furthermore, the sizes (volumes, surface areas) of all the circuit components do not need to be the same.

[0021] As shown in FIGS. 1 and 2, a stepped portion 2c is formed on the inner wall surface of the peripheral wall portion 2b of the recess 2a of the package 2 along an arrangement of multiple connection terminals (wire pads) 2h. The core portion 5 is disposed on the bottom surface (inner bottom surface) of the recess 2a between a pair of opposing stepped portions 2c, 2c, via a core substrate (flexible substrate) 4 made of a plate-shaped flexible material. Alternatively, the stepped portion 2c may be formed so as to surround the bottom surface of the recess 2a on all four sides. The wire pads 2h formed on the stepped surface of the stepped portion 2c are connected by wire bonding to wire pads formed on each component of the core portion 5 via wires 6a and 6b. Specifically, the wire pads 2h on the stepped portion 2c are connected via wire 6a to a wire pad (see FIG. 2) formed on the oscillation IC 51 of the core portion 5. The wire pads 2h on the stepped portion 2c are connected via wire 6b to a wire pad (see FIG. 2) formed on the heater IC 52 of the core portion 5. In addition, the first and second terminals 21, 22 (see FIG. 5) formed on the crystal resonator 50 of the core portion 5 are connected by wire bonding to wire pads (see FIG. 2) formed on the oscillation IC 51 via wires 6c.

[0022] The core substrate 4 is bonded to the bottom surface of the recess 2a with a non-conductive adhesive (bonding material) 7, and a space (gap) 2d is formed in the lower portion of the core substrate 4. Specifically, a pair of spacer members 2f are provided on the bottom surface of the package 2 at a predetermined interval, and a non-conductive adhesive 7 is applied to each spacer member 2f. The non-conductive adhesive 7 mechanically bonds the core substrate 4 to the bottom surface of the package 2 at both ends of the core substrate 4. The spacer members 2f and the non-conductive adhesive 7 are provided linearly along the short-side direction of the core substrate 4 (the direction perpendicular to the plane of the paper in FIG. 1).

[0023] Furthermore, the bonding area (the area where the non-conductive adhesive 7 is applied) for bonding the core substrate 4 to the package 2 is arranged so as not to overlap the area where the core portion 5 is arranged on the upper surface of the core substrate 4 in a plan view. The core substrate 4 is made of a heat-resistant and flexible resin material such as polyimide. The spacer member 2f is made of a paste material (metallization material) such as molybdenum or tungsten. The non-conductive adhesive 7 may be, for example, a polyimide-based adhesive or an epoxy-based adhesive. The core substrate 4 may also be made of quartz crystal.

[0024] Next, the core unit 5 will be described with reference to FIG. 4. FIG. 4 illustrates the core unit 5 mounted on the core substrate 4. The core unit 5 is a package containing various electronic components used in the OCXO 1. It has a three-layer structure (laminated structure) in which an oscillation IC 51, a crystal unit (piezoelectric unit) 50, and a heater IC 52 are stacked in this order from top to bottom. The areas of the oscillation IC 51, the crystal unit 50, and the heater IC 52 in a plan view gradually decrease upward. The core unit 5 is configured to stabilize the oscillation frequency of the OCXO 1 by adjusting the temperatures of the crystal unit 50, the oscillation IC 51, and the heater IC 52, which have particularly strong temperature characteristics. Although the various electronic components in the core unit 5 are not sealed with sealing resin, sealing with sealing resin may be used depending on the sealing atmosphere.

[0025] The crystal oscillator 100 is composed of the crystal resonator 50 and the oscillation IC 51. For example, a VCXO IC can be used as the oscillation IC 51, in which case the crystal oscillator 100 is configured as a VCXO. The oscillation frequency of the OCXO 1 is controlled by controlling the piezoelectric vibration of the crystal resonator 50 using the oscillation IC 51.

[0026] A non-conductive adhesive 53 is interposed between the opposing surfaces of the crystal unit 50 and the oscillation IC 51, and the opposing surfaces of the crystal unit 50 and the oscillation IC 51 are fixed together by the non-conductive adhesive 53. In this case, the top surface of the crystal unit 50 (the first main surface of the first sealing member 20) and the bottom surface of the oscillation IC 51 are joined together via the non-conductive adhesive 53.

[0027] The area of ​​the oscillation IC 51 in a plan view is smaller than that of the crystal unit 50, and the entire oscillation IC 51 is located within the range of the crystal unit 50 in a plan view. The entire bottom surface of the oscillation IC 51 is bonded to the top surface of the crystal unit 50 (the first main surface of the first sealing member 20).

[0028] The heater IC 52 is configured to integrate, for example, a heating element (heat source), a control circuit (current control circuit) for controlling the temperature of the heating element, and a temperature sensor for detecting the temperature of the heating element. By controlling the temperature of the core unit 5 using the heater IC 52, the temperature of the core unit 5 is maintained at a substantially constant temperature, thereby stabilizing the oscillation frequency of the OCXO 1. Note that the temperature sensor may be provided as a separate member from the heater IC 52.

[0029] A conductive adhesive 54 is interposed between the opposing surfaces of the crystal unit 50 and the heater IC 52, and the opposing surfaces of the crystal unit 50 and the heater IC 52 are fixed together by the conductive adhesive 54. In this case, the bottom surface of the crystal unit 50 (the second main surface of the second sealing member 30) and the top surface of the heater IC 52 are joined via the conductive adhesive 54.

[0030] The crystal unit 50 has a smaller area in plan view than the heater IC 52, and the entire crystal unit 50 is located within the range of the heater IC 52 in plan view. The entire lower surface of the crystal unit 50 (the second main surface of the second sealing member 30) is bonded to the upper surface of the heater IC 52.

[0031] A non-conductive adhesive 55 is interposed between the opposing surfaces of the heater IC 52 and the core substrate 4, and the opposing surfaces of the heater IC 52 and the core substrate 4 are fixed together by the non-conductive adhesive 55. Examples of the non-conductive adhesives 53 and 55 and the conductive adhesive 54 that can be used include a polyimide adhesive and an epoxy adhesive.

[0032] In the core unit 5 shown in FIG. 5, wire pads for wire bonding (see FIG. 2) are formed on the top surfaces of the oscillation IC 51, the crystal unit 50, and the heater IC 52. Wire bonding of the oscillation IC 51, the crystal unit 50, and the heater IC 52 is not performed before mounting the core unit 5 in the package 2, but is performed after mounting the core unit 5 (core substrate 4) in the package 2. That is, as shown in FIGS. 1 and 2, after mounting the core unit 5 (core substrate 4) in the package 2, the wire pad formed on the top surface of the crystal unit 50 is connected to the wire pad formed on the oscillation IC 51 via wire 6c. The wire pad formed on the oscillation IC 51 is connected to the wire pad 2h formed on the step surface of the step portion 2c via wire 6a. The wire pad formed on the top surface of the heater IC 52 is connected to the wire pad 2h formed on the step surface of the step portion 2c via wire 6b. In this way, by performing wire bonding after mounting the core unit 5 on the package 2, wire bonding can be performed efficiently, and an OCXO 1 that is suitable for mass production can be provided.

[0033] As described above, in this embodiment, the core unit 5 is supported by the package 2 via the core substrate 4, and the core unit 5 has at least the oscillation IC 51, the crystal unit 50, and the heater IC 52, and is configured so that the oscillation IC 51, the crystal unit 50, and the heater IC 52 are stacked in this order. The heater IC 52 controls the current supplied to the heating element to adjust the temperature of the core unit 5, thereby maintaining the temperature of the core unit 5 at a substantially constant temperature.

[0034] Although there are no particular limitations on the type of quartz crystal unit 50 used in the core portion 5, a stacked quartz crystal unit can be preferably used, which allows for easy thinning of the device. A stacked quartz crystal unit is a three-layer structure device that is composed of first and second sealing members made of glass or quartz crystal, and a piezoelectric diaphragm made of, for example, quartz crystal and having a vibrating portion with excitation electrodes formed on both main surfaces, in which the first sealing member and the second sealing member are stacked and bonded via the piezoelectric diaphragm, and the vibrating portion of the piezoelectric diaphragm arranged inside is hermetically sealed.

[0035] An example of a crystal oscillator 100 in which a crystal resonator 50 as such a stacked crystal resonator and an oscillation IC (for example, a VCXO IC) 51 are integrally provided will be described with reference to FIGS.

[0036] 5, the crystal oscillator 100 is configured to include a crystal diaphragm (piezoelectric diaphragm) 10, a first sealing member 20, a second sealing member 30, and an oscillation IC 51. In this crystal oscillator 100, the crystal diaphragm 10 is bonded to the first sealing member 20, and the crystal diaphragm 10 is bonded to the second sealing member 30 to form a package with a substantially rectangular parallelepiped sandwich structure. That is, in the crystal oscillator 100, the first sealing member 20 and the second sealing member 30 are bonded to each of the two main surfaces of the crystal diaphragm 10 to form an internal space (cavity) of the package, and the vibrating unit 11 (see FIGS. 8 and 9) is hermetically sealed in this internal space.

[0037] The crystal oscillator 100 has a package size of, for example, 1.0 x 0.8 mm, and is designed to be compact and low-profile. To accommodate the miniaturization, the package does not have castellations but instead uses through-holes for electrode continuity. The oscillation IC 51 mounted on the first sealing member 20 is a one-chip integrated circuit element that, together with the crystal diaphragm 10, forms an oscillation circuit. The crystal oscillator 100 is mounted on the heater IC 52 described above via a conductive adhesive 54.

[0038] As shown in FIGS. 8 and 9, the quartz crystal vibrating plate 10 is a piezoelectric substrate made of quartz crystal, and both of its main surfaces (first main surface 101, second main surface 102) are formed as flat, smooth surfaces (mirror-finished). An AT-cut quartz crystal plate that vibrates in thickness-shear mode is used as the quartz crystal vibrating plate 10. In the quartz crystal vibrating plate 10 shown in FIGS. 8 and 9, both main surfaces 101, 102 of the quartz crystal vibrating plate 10 are in the XZ' plane. In this XZ' plane, the direction parallel to the lateral direction (short side direction) of the quartz crystal vibrating plate 10 is the X-axis direction, and the direction parallel to the longitudinal direction (long side direction) of the quartz crystal vibrating plate 10 is the Z'-axis direction.

[0039] A pair of excitation electrodes (first excitation electrode 111 and second excitation electrode 112) are formed on both main surfaces 101, 102 of the quartz crystal vibrating plate 10. The quartz crystal vibrating plate 10 has a substantially rectangular vibrating portion 11, an outer frame portion 12 that surrounds the outer periphery of the vibrating portion 11, and a holding portion (connecting portion) 13 that holds the vibrating portion 11 by connecting the vibrating portion 11 and the outer frame portion 12. In other words, the quartz crystal vibrating plate 10 is configured such that the vibrating portion 11, outer frame portion 12, and holding portion 13 are integrally provided. The holding portion 13 extends (protrudes) in the -Z' direction from only one corner of the vibrating portion 11 that is located in the +X direction and the -Z' direction.

[0040] The first excitation electrode 111 is provided on the first main surface 101 side of the vibrating section 11, and the second excitation electrode 112 is provided on the second main surface 102 side of the vibrating section 11. The first excitation electrode 111 and the second excitation electrode 112 are connected with lead-out wiring (first lead-out wiring 113, second lead-out wiring 114) for connecting these excitation electrodes to external electrode terminals. The first lead-out wiring 113 is led out from the first excitation electrode 111 and connected to a connection bonding pattern 14 formed on the outer frame section 12 via a holding section 13. The second lead-out wiring 114 is led out from the second excitation electrode 112 and connected to a connection bonding pattern 15 formed on the outer frame section 12 via the holding section 13.

[0041] Both main surfaces (first main surface 101, second main surface 102) of the quartz crystal plate 10 are provided with vibration-side sealing portions for bonding the quartz crystal plate 10 to the first sealing member 20 and the second sealing member 30. A vibration-side first bonding pattern 121 is formed as the vibration-side sealing portion on the first main surface 101, and a vibration-side second bonding pattern 122 is formed as the vibration-side sealing portion on the second main surface 102. The vibration-side first bonding pattern 121 and the vibration-side second bonding pattern 122 are provided on the outer frame portion 12 and are formed in an annular shape in a plan view.

[0042] 8 and 9, five through holes are formed in the quartz-crystal vibrating plate 10, penetrating between the first main surface 101 and the second main surface 102. Specifically, the four first through holes 161 are provided in the four corner regions of the outer frame portion 12. The second through hole 162 is provided in the outer frame portion 12 on one side of the vibrating portion 11 in the Z′-axis direction (the −Z′ direction side in FIGS. 8 and 9). Around the first through hole 161, a vibration-side first bonding pattern 121 is formed on the first main surface 101 side, and a vibration-side second bonding pattern 122 is formed on the second main surface 102 side. Around the second through hole 162, a connection bonding pattern 124 is formed on the first main surface 101 side, and a connection bonding pattern 15 is formed on the second main surface 102 side.

[0043] In the first through-hole 161 and the second through-hole 162, a through electrode for achieving electrical continuity between the electrodes formed on the first main surface 101 and the second main surface 102 is formed along the inner wall surface of each through-hole. In addition, the central portion of each of the first through-hole 161 and the second through-hole 162 is a hollow through portion that penetrates between the first main surface 101 and the second main surface 102.

[0044] 6 and 7, the first sealing member 20 is a rectangular parallelepiped substrate formed from a single AT-cut quartz crystal plate, and the second main surface 202 of this first sealing member 20 (the surface that bonds to the quartz crystal vibrating plate 10) is formed as a flat, smooth surface (mirror-finished). Although the first sealing member 20 does not have a vibrating part, by using an AT-cut quartz crystal plate like the quartz crystal vibrating plate 10, the thermal expansion coefficients of the quartz crystal vibrating plate 10 and the first sealing member 20 can be made the same, thereby suppressing thermal deformation in the quartz crystal oscillator 100. The X-axis, Y-axis, and Z'-axis of the first sealing member 20 are also oriented in the same directions as those of the quartz crystal vibrating plate 10.

[0045] As shown in FIG. 6, first and second terminals 21 and 22 for wiring formed on the outer surface of the package and a third terminal 23 for shielding (ground connection) are formed on the first main surface 201 (the main surface not facing the quartz-crystal vibrating plate 10) of the first sealing member 20. The first and second terminals 21 and 22 are connected to wire pads (see FIG. 2) formed on the oscillation IC 51 via wires 6c by wire bonding. The first terminal 21 is electrically connected to the first excitation electrode 111 of the quartz-crystal vibrating plate 10. The second terminal 22 is electrically connected to the second excitation electrode 112 of the quartz-crystal vibrating plate 10. The first and second terminals 21 and 22 are provided at both ends in the Z′-axis direction, with the first terminal 21 on the +Z′-direction side and the second terminal 22 on the −Z′-direction side.

[0046] The third terminals 23 are provided at the four corners (corners) and in the central region of the first main surface 201 of the first sealing member 20, and are generally H-shaped. The third terminals 23 are disposed at a predetermined distance from the first and second terminals 21 and 22, and are provided in almost all of the regions of the first main surface 201 of the first sealing member 20 where the first and second terminals 21 and 22 are not formed. An oscillation IC 51 is mounted on the upper side of the third terminals 23 via a non-conductive adhesive 53. The third terminals 23 are electrically connected to and grounded by external terminals 32 formed on the second main surface 302 of the second sealing member 30. Note that the third terminals 23 do not necessarily have to be grounded; in other words, the third terminals do not necessarily have to have an electrical connection function.

[0047] 6 and 7, six through holes are formed in the first sealing member 20, penetrating between the first main surface 201 and the second main surface 202. Specifically, four third through holes 211 are provided in the four corner (corner) regions of the first sealing member 20. Fourth and fifth through holes 212, 213 are provided in the +Z' direction and -Z' direction in FIGS. 6 and 7, respectively.

[0048] In the third through-hole 211 and the fourth and fifth through-holes 212, 213, through-electrodes for achieving electrical continuity between the electrodes formed on the first main surface 201 and the second main surface 202 are formed along the inner wall surfaces of the respective through-holes. In addition, the central portions of the third through-hole 211 and the fourth and fifth through-holes 212, 213 form hollow through-holes that penetrate between the first main surface 201 and the second main surface 202.

[0049] A first sealing-side bonding pattern 24 is formed on the second main surface 202 of the first sealing member 20 as a first sealing-side sealing portion for bonding to the quartz-crystal vibrating plate 10. The first sealing-side bonding pattern 24 is formed in a ring shape in a plan view. The first sealing-side bonding pattern 24 is also formed around each third through-hole 211. A connection bonding pattern 262 is formed around the fourth through-hole 212, and a connection bonding pattern 261 is formed around the fifth through-hole 213. Furthermore, a connection bonding pattern 263 is formed on the opposite side of the connection bonding pattern 261 in the long axis direction of the first sealing member 20 (the -Z' direction side), and the connection bonding pattern 261 and the connection bonding pattern 263 are connected by a wiring pattern 27.

[0050] 10 and 11, the second sealing member 30 is a rectangular parallelepiped substrate formed from a single AT-cut quartz crystal plate, and the first main surface 301 of this second sealing member 30 (the surface that bonds to the quartz crystal vibrating plate 10) is formed as a flat, smooth surface (mirror-finished). Note that the second sealing member 30 also uses an AT-cut quartz crystal plate like the quartz crystal vibrating plate 10, and it is desirable that the orientations of the X-axis, Y-axis, and Z'-axis are the same as those of the quartz crystal vibrating plate 10.

[0051] A second sealing-side bonding pattern 31 is formed on the first main surface 301 of the second sealing member 30 as a second sealing portion for bonding to the quartz-crystal vibrating plate 10. The second sealing-side bonding pattern 31 is formed in a ring shape in a plan view. The second sealing-side bonding pattern 31 is also formed around a sixth through-hole 33, which will be described later.

[0052] External terminals 32 are formed over substantially the entire surface of the second main surface 302 of the second sealing member 30. The external terminals 32 are also formed around sixth through holes 33, which will be described later.

[0053] As shown in FIGS. 10 and 11 , the second sealing member 30 has one sixth through hole 33 formed therein, penetrating between the first main surface 301 and the second main surface 302. The sixth through hole 33 is provided in the four corner regions (corner portions) of the second sealing member 30. In the sixth through hole 33, a through electrode for ensuring electrical connection between the electrodes formed on the first main surface 301 and the second main surface 302 is formed along the inner wall surface of each sixth through hole 33. The center portion of each sixth through hole 33 is a hollow through portion that penetrates between the first main surface 301 and the second main surface 302. Note that if the third terminal 23 of the first sealing member 20 is not connected to earth, the second sealing member 30 may not have the sixth through hole 33.

[0054] In the crystal oscillator 100 including the crystal vibrating plate 10, first sealing member 20, and second sealing member 30 configured as described above, the crystal vibrating plate 10 and the first sealing member 20 are diffusion bonded together with the first vibration-side bonding pattern 121 and the first sealing-side bonding pattern 24 overlapping each other, and the crystal vibrating plate 10 and the second sealing member 30 are diffusion bonded together with the second vibration-side bonding pattern 122 and the second sealing-side bonding pattern 31 overlapping each other, thereby producing a sandwich-structured package as shown in Fig. 5. This hermetically seals the internal space of the package, i.e., the space housing the vibrating portion 11.

[0055] At this time, the above-mentioned connection bonding patterns are also diffusion bonded while overlapping each other. The bonding of the connection bonding patterns ensures electrical continuity in the crystal oscillator 100. Specifically, the first excitation electrode 111 is connected to the oscillation IC 51 via the first escape wiring 113, the wiring pattern 27, the fourth through-hole 212, the first terminal 21, and the wire 6c in this order. The second excitation electrode 112 is connected to the oscillation IC 51 via the second escape wiring 114, the second through-hole 162, the fifth through-hole 213, the second terminal 22, and the wire 6c in this order.

[0056] In the crystal oscillator 100, the various bonding patterns are preferably formed by stacking multiple layers on the crystal plate, with a Ti (titanium) layer and an Au (gold) layer formed from the bottom layer onwards by vapor deposition or sputtering. It is also preferable that the other wiring and electrodes formed on the crystal oscillator 100 have the same configuration as the bonding patterns, allowing the bonding patterns, wiring and electrodes to be patterned simultaneously.

[0057] In the crystal oscillator 100 configured as described above, the sealing electrodes (seal paths) 41, 42 that hermetically seal the vibrating portion 11 of the crystal vibrating plate 10 are formed in an annular shape in a plan view. The seal path 41, which serves as a first sealing electrode, is formed by diffusion bonding the above-mentioned vibration-side first bonding pattern 121 and the sealing-side first bonding pattern 24, and the outer and inner edge shapes of the seal path 41 are formed in a substantially rectangular shape. Similarly, the seal path 42, which serves as a second sealing electrode, is formed by diffusion bonding the above-mentioned vibration-side second bonding pattern 122 and the sealing-side second bonding pattern 31, and the outer and inner edge shapes of the seal path 42 are formed in a substantially rectangular shape. The seal paths 41, 42 are not electrically connected to the wiring connected to the above-mentioned first and second excitation electrodes 111, 112. Meanwhile, the seal paths 41 and 42 are electrically connected to the third terminal 23 of the first sealing member 20 and the external terminal 32 of the second sealing member 30 via the through electrodes in the first through holes 161, the third through holes 211, and the sixth through holes 33. The external terminal 32 is connected to the heater IC 52 via a conductive adhesive 54, so that the seal paths 41 and 42 and the third terminal 23 are grounded.

[0058] In this embodiment, the quartz crystal resonator 50 is a stacked quartz crystal resonator formed by stacking a first sealing member 20, a quartz crystal plate 10, and a second sealing member 30. The first sealing member 20 has a third terminal 23 formed on its outer surface as a top heat transfer electrode that is bonded to an external heating member (oscillation IC 51) with a bonding material, and the second sealing member 30 has a third terminal 32 formed on its outer surface as a bottom heat transfer electrode that is bonded to an external heating member (heater IC 52) with a bonding material. The third terminal 23 and the external terminal 32 are thermally coupled to sealing paths 41 and 42 that serve as sealing electrodes via connection electrodes. This will be described below with reference to FIGS. 5 to 11.

[0059] A third terminal 23 serving as an upper surface heat transfer electrode formed on the first main surface 201 of the first sealing member 20 is bonded to the oscillation IC 51 serving as an external heating member with a bonding material (non-conductive adhesive 53). The third terminal 23 overlaps a portion of the outer frame 12 of the quartz crystal vibrating plate 10 in a planar view. The area of ​​the third terminal 23 in a planar view is 50% or more of the area of ​​the first sealing member 20 in a planar view. The third terminal 23 and the seal paths 41 and 42 are electrically connected via the through electrodes in the first through holes 161, the third through holes 211, and the sixth through holes 33 serving as connection electrodes, and the third terminal 23 and the seal paths 41 and 42 are thermally coupled.

[0060] Additionally, an external terminal 32 serving as a bottom heat transfer electrode formed on the second main surface 302 of the second sealing member 30 is bonded to a heater IC 52 serving as an external heating member with a bonding material (conductive adhesive 54). The external terminal 32 overlaps a portion of the outer frame 12 of the quartz crystal vibrating plate 10 in a planar view. The area of ​​the external terminal 32 in a planar view is formed to be 50% or more of the area of ​​the second sealing member 30 in a planar view. The external terminal 32 and the seal paths 41 and 42 are electrically connected via the through electrodes in the third through hole 211 and the sixth through hole 33 serving as connection electrodes, and the external terminal 32 and the seal paths 41 and 42 are thermally coupled. Here, the electrode configuration on the outer surface of the quartz crystal unit 50 (the third terminal 23 as a top heating electrode, the external terminal 32 as a bottom heating electrode, etc.) is a laminated configuration including, for example, a Ti film, a NiTi film, and an Au film, and the electrode configuration of the quartz crystal vibrating plate 10 and the first and second sealing members 20, 30 inside the quartz crystal unit 50 is a laminated configuration including, for example, a Ti film and an Au film. Furthermore, the Ti film of the electrode configuration of the quartz crystal vibrating plate 10 is thinner than the Ti film of the electrode configuration of the first and second sealing members 20, 30. Note that other film materials or laminated layers may be used for the electrode configuration.

[0061] According to this embodiment, the oscillation IC 51 heats the third terminal 23 of the first sealing member 20, and the heater IC 52 heats the external terminal 32 of the second sealing member 30. The third terminal 23 and external terminal 32, heated by the oscillation IC 51 and heater IC 52, are thermally coupled to the seal paths 41 and 42. The seal paths 41 and 42 are annularly overlapped on the outer frame 12. Therefore, heat from the third terminal 23 and external terminal 32 is transferred to the outer frame 12 via the seal paths 41 and 42, and then from the outer frame 12 via the holder 13 to the vibrating unit 11. This improves heat transfer from the oscillation IC 51 and heater IC 52 to the vibrating unit 11 via the outer frame 12 and holder 13 of the quartz crystal vibrating plate 10. Therefore, a stacked piezoelectric resonator capable of improving heat transfer in the OCXO 1 can be provided.

[0062] In this embodiment, the third terminal 23 and the external terminal 32 are provided on both the first main surface 201 of the first sealing member 20 and the second main surface 302 of the second sealing member 30, further improving heat transfer from the oscillation IC 51 and the heater IC 52 to the vibrating portion 11 of the quartz crystal vibrating plate 10. In addition, the external terminals 32 and the heater IC 52 are bonded together with a conductive adhesive 54, improving heat transfer from the heater IC 52 to the vibrating portion 11 of the quartz crystal vibrating plate 10 compared to when a non-conductive adhesive is used.

[0063] In this embodiment, the third terminal 23 overlaps, in plan view, portions of the sealing paths 41, 42 that are formed on at least two sides of the outer frame portion 12. Specifically, the third terminal 23 overlaps, in plan view, portions of the sealing paths 41, 42 that are formed on two sides that face each other in the X-axis direction. Furthermore, the external terminal 32 overlaps, in plan view, portions of the sealing paths 41, 42 that are formed on at least two sides of the outer frame portion 12. Specifically, the external terminal 32 overlaps, in plan view, the entire periphery of the sealing paths 41, 42 (two sides that face each other in the X-axis direction and two sides that face each other in the Z′-axis direction). This positional relationship improves heat transfer from the oscillation IC 51 and the heater IC 52 to the vibrating portion 11 of the quartz crystal vibrating plate 10.

[0064] Additionally, the third terminal 23 and the external terminal 32 are connected to the heater IC 52 via a conductive adhesive 54 and to a ground power supply, thereby ensuring the shielding function of the third terminal 23 and the external terminal 32 and reducing the influence of external noise.

[0065] In this embodiment, the center of gravity (center) of the third terminal 23 is approximately aligned with the center of gravity (center) of the first sealing member 20. Furthermore, the center of gravity (center) of the external terminal 32 is approximately aligned with the center of gravity (center) of the second sealing member 30. This positional relationship allows for efficient heat transfer from the oscillation IC 51 and the heater IC 52 to the vibration portion 11 of the quartz crystal vibrating plate 10.

[0066] Furthermore, because the area of ​​the third terminal 23 in a plan view is 50% or more of the area of ​​the first sealing member 20 in a plan view, and the area of ​​the external terminal 32 in a plan view is 50% or more of the area of ​​the second sealing member 30 in a plan view, heat transfer from the oscillation IC 51 and the heater IC 52 to the vibrating portion 11 of the quartz-crystal vibrating plate 10 can be further improved. By setting the area ratio at 50% or more, heat transfer to the first and second sealing members 20, 30 is improved while reducing variations in temperature change due to heating of the first and second sealing members 20, 30. Furthermore, while the thermal conduction and heating of the first and second sealing members 20, 30 are stable, heat transfer from the outer frame 12 of the quartz-crystal vibrating plate 10 sandwiched between the first and second sealing members 20, 30 to the vibrating portion 11 can also be stabilized, improving heat transfer efficiency.

[0067] In a crystal oscillator (piezoelectric vibration device) 100 equipped with the crystal resonator 50 configured as described above, the external heating components are the oscillation IC 51 and the heater IC 52, which are bonded to the heat transfer electrodes (third terminal 23, external terminal 32) on the outer surface of the crystal resonator 50 with a bonding material. Specifically, the oscillation IC 51 is bonded to the third terminal 23 of the first sealing member 20 of the crystal resonator 50 with a non-conductive adhesive 53. The heater IC 52 is bonded to the external terminal 32 of the second sealing member 30 of the crystal resonator 50 with a conductive adhesive 54. This improves heat transfer from the oscillation IC 51 and the heater IC 52 to the vibration portion 11 of the crystal vibrating plate 10 in the crystal oscillator 10.

[0068] In this embodiment, the crystal unit 50 is stacked and sandwiched between the oscillation IC 51 and the heater IC 52. This allows the oscillation IC 51 and the heater IC 52 to transfer heat from both sides of the crystal unit 50 to the vibrating portion 11 of the crystal plate 10, further improving heat transfer from the oscillation IC 51 and the heater IC 52 to the vibrating portion 11 of the crystal plate 10.

[0069] In the OCXO 1 equipped with the crystal oscillator 100 configured as described above, the crystal oscillator 100 is hermetically sealed inside a heat-insulating package 2, the core unit 5 includes at least an oscillation IC 51, a crystal unit 50, and a heater IC 52, and at least one of the oscillation IC 51 and the heater IC 52 is laminated on the outer surface of the crystal unit 50, the core unit 5 is mounted on the package 2 via a core substrate 4, and a space 2d is provided between the core substrate 4 and the inner bottom surface of the package 2. This space 2d can improve the heat insulation of the core unit 5 and further reduce the amount of heat generated by the heater required to maintain the temperature of the core unit 5, thereby further reducing the power consumption of the OCXO 1.

[0070] In the present embodiment, in the OCXO 1, the core substrate 4 is mechanically joined at both ends of the core substrate 4 to the inner bottom surface of the package 2 by a bonding material, and the core unit 5 is electrically joined to the package 2 by wires 6a and 6b. This makes it possible to prevent heat from escaping to the outside by directly mechanically joining the core unit 5 to the package 2, and also to realize the necessary electrical connection from the core unit 5 to the outside.

[0071] In this embodiment, the crystal unit 50 is only connected to the oscillation IC 51 via the wire 6c, and is not directly wire-connected to the package 2. This configuration prevents heat from escaping from the crystal unit 50 to the package 2 via the wire. As a result, there are advantages such as improved thermal insulation for the crystal unit 50 and improved temperature controllability for the crystal unit 50. By making the diameter of the wire 6c connected to the crystal unit 50 smaller than the diameter of the wires 6a and 6b not connected to the crystal unit 50, heat from the crystal unit 50 can be prevented from escaping to the outside. Furthermore, by making the thickness of the second sealing member 30 on the heater IC 52 side of the crystal unit 50 larger than the thicknesses of the crystal vibrating plate 10 and the first sealing member 20, heat from the crystal unit 50 can be prevented from escaping to the outside.

[0072] In the present embodiment, in the OCXO 1, the bonding region of the core substrate 4 that is bonded by the non-conductive adhesive 7 (the region that is mechanically bonded to the inner bottom surface of the recess 2a of the package 2) does not overlap with the arrangement region of the core unit 5 on the core substrate 4 in a plan view. As a result, the arrangement region of the core unit 5 and the bonding region are not provided contiguously across the core substrate 4, and therefore, it is possible to prevent heat from the core unit 5 from escaping to the outside via the bonding region (non-conductive adhesive 7). Furthermore, the core unit 5 is vacuum-sealed inside the package 2, which makes it easier to prevent heat from escaping from the core unit 5.

[0073] Furthermore, in the OCXO 1, the spacer member 2f and the non-conductive adhesive 7 are arranged one above the other, which makes it easier to ensure a space 2d between the core substrate 4 and the inner bottom surface of the package 2. The spacer member 2f and the non-conductive adhesive 7 may be arranged side by side, or the spacer member 2f may be arranged in two layers, one above the other.

[0074] The embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present invention should not be interpreted solely by the above-described embodiments, but should be defined by the claims. Furthermore, all modifications within the scope and meaning equivalent to the claims are included.

[0075] In the above embodiment, heat transfer electrodes (third terminal 23, external terminal 32) are provided on both the outer surface of the first sealing member 20 and the outer surface of the second sealing member 30, but this is not limited to this, and heat transfer electrodes may be provided on only one of the outer surface of the first sealing member 20 and the outer surface of the second sealing member 30.

[0076] The shapes and sizes of the third terminal 23 and the external terminal 32 described above are merely examples, and are not particularly limited as long as they are superimposable in a planar view with the annular seal paths 41, 42, and can be modified in various ways. For example, the third terminal 23 may be formed on substantially the entire first main surface 201 of the first sealing member 20. Although the third terminal 23 has a substantially H-shape including two opposing sides and a center of gravity, the third terminal 23 may be T-shaped, Z-shaped, annular, figure-8 shaped, or the like. Although the external terminal 32 has been formed on substantially the entire second main surface 301 of the second sealing member 30, the external terminal 32 may be formed in an annular shape having a non-electrode region in the center.

[0077] In the above embodiment, the core unit 5 has a configuration in which at least the oscillation IC 51, the crystal unit 50, and the heater IC 52 are stacked in this order from the top, but conversely, the core unit 5 may have a configuration in which at least the heater IC 52, the crystal unit 50, and the oscillation IC 51 are stacked in this order from the top. Note that the core unit 5 may have a configuration in which at least the oscillation IC 51, the heater IC 52, and the crystal unit 50 are stacked in this order from the top, and with this configuration, a relatively large crystal unit 50 can be used, and the characteristics required for the crystal unit 50 can be easily ensured.

[0078] The core unit 5 only needs to have a configuration in which at least the oscillation IC 51, the crystal unit 50, and the heater IC 52 are stacked in this order, and may also have a configuration in which, for example, a heater substrate or the like is added to the stacked structure of the oscillation IC 51, the crystal unit 50, and the heater IC 52. For example, a four-layer structure in which the heater substrate, oscillation IC 51, the crystal unit 50, and the heater IC 52 are stacked in this order from the top may be used, or a four-layer structure in which the heater IC 52, the crystal unit 50, the oscillation IC 51, and the heater substrate are stacked in this order from the top may be used. In these cases, stacking the heater substrate, which is a heating element, on the oscillation IC 51 can make the temperature of the core unit 5 more uniform.

[0079] Furthermore, the core unit 5 need not have the above-described laminated structure as long as it has at least the oscillation IC 51, the crystal unit 50, and the heater IC 52. For example, the core unit 5 may have a heater substrate, multiple chip capacitors (bypass capacitors), and the like in addition to the oscillation IC 51, the crystal unit 50, and the heater IC 52. In this case, the bonding area between the core substrate 4 and a component (e.g., the heater substrate) directly bonded to the core substrate 4 is the area where the core unit 5 is provided.

[0080] In the above embodiment, the core unit 5 and the package 2 are electrically connected without passing through the core substrate 4, but the core unit 5 and the package 2 may be electrically connected through the core substrate 4.

[0081] In the above embodiment, the core unit 5 is configured such that the crystal unit 50 is mounted on the heater IC 52, and the oscillation IC 51 is mounted on the crystal unit 50. However, the core unit 5 is not limited to this, and may be configured such that the crystal unit 50 and the oscillation IC 51 are mounted horizontally on the heater IC 52.

[0082] In the above embodiment, an AT-cut quartz crystal plate is used as the quartz crystal plate 10, but other quartz crystal plates (for example, an SC-cut quartz crystal plate, a quartz crystal Z-plate, etc.) may also be used. Furthermore, while the first sealing member 20 and the second sealing member 30 are formed from quartz crystal plates, this is not limiting, and the first sealing member 20 and the second sealing member 30 may also be formed from, for example, glass or resin.

[0083] In the above embodiment, the crystal unit 50 as a stacked piezoelectric resonator is described as being applied to an OCXO 1. However, the stacked piezoelectric resonator is not limited to this. For example, the stacked piezoelectric resonator may be applied to a piezoelectric resonator with a temperature sensor (such as a TSX) that is equipped with a temperature sensor such as a thermistor, or may be applied to a temperature-compensated piezoelectric oscillator (such as a TCXO) that is equipped with a temperature compensation circuit. In these piezoelectric resonators with a temperature sensor or temperature-compensated piezoelectric oscillator, the improved thermal conductivity between the stacked piezoelectric resonator and the temperature sensor or IC reduces the temperature difference between them, contributing to improved electrical characteristics. [Explanation of symbols]

[0084] 1 OCXO (oven-controlled piezoelectric oscillator) 2 packages 4-core board 5 Core 10 Crystal diaphragm 11 Vibration unit 12 Outer frame 13 Holding part 20 First sealing member 23 Third terminal (top heat transfer electrode) 30 Second sealing member 32 External terminal (bottom heat transfer electrode) 41 seal path (first sealing electrode) 42 Seal path (second sealing electrode) 50 Quartz crystal unit (multilayer piezoelectric unit) 51 Oscillation IC (heating external component) 52 Heater IC (external heating component) 100 Crystal oscillator (piezoelectric vibration device) 111 1st excitation electrode 112 2nd excitation electrode

Claims

1. a piezoelectric diaphragm having an outer frame, a holding portion, and a vibration portion having an excitation electrode formed thereon, which are integrally formed; A first sealing member covering an upper surface side of the vibration portion; a second sealing member covering a lower surface side of the vibration portion, A heat transfer electrode is formed on an outer surface of the first sealing member or an outer surface of the second sealing member, the heat transfer electrode being joined to an external heating member by a joining material and overlapping a part of the outer frame portion not connected to the excitation electrode; The area of ​​the heat transfer electrode in a plan view is 50% or more of the area of ​​the first sealing member or the second sealing member in a plan view, a first annular sealing electrode is formed between the first sealing member and the piezoelectric diaphragm; a second annular sealing electrode is formed between the second sealing member and the piezoelectric diaphragm; the first sealing electrode and the second sealing electrode are annularly overlapped on the outer frame portion, a first sealing electrode and a second sealing electrode, the first sealing electrode and the second sealing electrode being thermally coupled to each other via a connecting electrode;

2. 2. The laminated piezoelectric vibrator according to claim 1, a bottom heat transfer electrode formed on the outer surface of the second sealing member; and a top heat transfer electrode formed on the outer surface of the second sealing member.

3. A piezoelectric vibrator device comprising the stacked piezoelectric vibrator according to claim 1, A piezoelectric vibration device characterized in that the external heating member comprises an oscillation IC or a heater IC, and is joined to the heat transfer electrode on the outer surface of the laminated piezoelectric vibrator by a bonding material.

4. 4. The piezoelectric vibration device according to claim 3, A piezoelectric vibration device, characterized in that the laminated piezoelectric vibrator is laminated and sandwiched between the oscillation IC and the heater IC.

5. 4. An oven-controlled piezoelectric oscillator comprising the piezoelectric vibration device according to claim 3, The piezoelectric vibration device is hermetically sealed inside a heat-insulating package, a core portion including at least the oscillation IC, the laminated piezoelectric vibrator, and the heater IC, and at least one of the oscillation IC and the heater IC is laminated on an outer surface of the laminated piezoelectric vibrator; 2. The oven-controlled piezoelectric oscillator according to claim 1, wherein the core portion is mounted on the package via a substrate, and a space is provided between the substrate and an inner bottom surface of the package.

6. 6. The oven-controlled piezoelectric oscillator according to claim 5, the substrate is mechanically bonded to the inner bottom surface of the package by a bonding material at both ends of the substrate; 4. The oven-controlled piezoelectric oscillator according to claim 1, wherein the core portion is electrically connected to the package by a wire.

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