JP6538310B2 - Piezoelectric device with thermostat - Google Patents

Description

  The present invention relates to a thermostat-equipped piezoelectric device.

  Piezoelectric devices having a thermostat are known. For example, in Patent Document 1, a mounting substrate, a temperature compensated crystal oscillator (TCXO) mounted on one main surface of the mounting substrate, and a heater mounted on the other main surface of the mounting substrate There is disclosed an oven controlled crystal oscillator (OCXO) having a case for containing them. The heater and the case constitute a constant temperature bath. The temperature around the TCXO is kept constant by the thermostat. As a result, the frequency of the oscillation signal of the TCXO is reduced due to the temperature.

  In Patent Document 1, TCXO has a so-called H-type package. That is, the TCXO includes an element mounting member having a first concave portion and a second concave portion located on the back surface, a vibration element accommodated in the first concave portion, and an integrated circuit element (IC) accommodated in the second concave portion. Have. The first recess is sealed by joining the lid to the element mounting member. The TCXO is mounted on the mounting substrate with the second recess side facing the mounting substrate.

Unexamined-Japanese-Patent No. 2013-211752

  In the technology of Patent Document 1, a second recess (IC) and a mounting substrate are interposed between the transducer of the TCXO and the heater. Therefore, it is difficult for the heat of the heater to be transmitted to the atmosphere around the vibrating element (the atmosphere of the first recess). As a result, for example, when the OCXO is activated, it takes time for the temperature of the vibrating element to reach a constant temperature, and it may take time until the frequency of the oscillation signal is stabilized.

  Therefore, it is desirable to provide a thermostat-equipped piezoelectric device that can quickly bring the temperature of the vibrating element to a constant temperature.

  A piezoelectric device with a thermostat according to an aspect of the present invention comprises a mounting base having a first mounting surface and a second mounting surface on the back surface, a piezoelectric device mounted on the first mounting surface, and the second mounting surface. A substrate portion having a first mounting surface and a second mounting surface on the back surface of the piezoelectric device, the piezoelectric device, the mounting base, and a case for housing the heater; A first frame portion that is located on the first mounting surface side of the substrate portion and that forms a first recess with the first mounting surface as a bottom surface, and is located on the second mounting surface side of the substrate portion, An element mounting member including an insulating member having a second frame portion forming a second concave portion having a second mounting surface as a bottom surface, a vibration element accommodated in the first concave portion, and an accumulation accommodated in the second concave portion A top surface of the second frame portion opposite to the substrate portion; Is mounted facing the first mounting surface, the element mounting member is made of a material having a thermal conductivity higher than that of the material of the insulating member, and the top surface of the second frame portion A first conductor exposed to the outside, a part of which is located in the insulating member, and electrically disconnected from the vibrating element, the integrated circuit element, and other electronic elements of the piezoelectric device Have.

  Preferably, the first conductor has a portion overlapping the first recess inside the substrate portion.

  Preferably, the first conductor has a portion exposed in the first recess.

  Preferably, the first conductor has a portion joined to a mounting pad provided on the first mounting surface by a bump.

  Preferably, the mounting substrate is made of an insulating substrate having the first mounting surface and the second mounting surface, and a material having a thermal conductivity higher than the material of the insulating substrate, and the mounting substrate overlaps the heater. And a second conductor which penetrates the insulating base from a first mounting surface to the second mounting surface and is connected to the first conductor by a bump.

  Preferably, the first conductor is in an electrically floating state.

  Preferably, the first conductor is applied with a reference potential.

  According to the above configuration, the temperature of the vibrating element can be quickly made constant.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which fractures | ruptures and shows schematic structure of the crystal oscillator with a thermostat which concerns on the 1st Embodiment of this invention. Sectional drawing in the II-II line of FIG. The elements on larger scale of FIG. FIG. 2 is a block diagram showing a schematic configuration of a signal processing system of OCXO of FIG. 1; The partially expanded sectional view of the crystal oscillator with a thermostat which concerns on the 2nd Embodiment of this invention.

  Hereinafter, an OCXO according to an embodiment of the present invention will be described with reference to the drawings. Note that the drawings used in the following description are schematic, and dimensional ratios and the like in the drawings do not necessarily coincide with actual ones.

  In OCXO, any direction may be upward or downward, but hereinafter, for convenience, the orthogonal coordinate system xyz is defined and the positive side of the z direction is upward, and the terms such as the upper surface and the lower surface Shall be used.

First Embodiment
FIG. 1 is a partially broken perspective view showing a schematic configuration of an OCXO 1 according to a first embodiment of the present invention. 2 is a cross-sectional view taken along line II-II of FIG.

  The OCXO 1 has, for example, TCXO 3 and a thermostatic chamber 5 for maintaining the atmosphere around the TCXO 3 at a predetermined temperature and for mediating the electrical connection between the TCXO 3 and an external device.

  The TCXO 3 has, for example, an element mounting member 7, a vibrating element 9 (FIG. 2) and an IC 11 (FIG. 2) mounted on the element mounting member 7, and a lid 13 for sealing the vibrating element 9. ing.

  The element mounting member 7 includes, for example, an insulating member 15 and various conductors (conductors, hereinafter the same) provided on the surface or inside of the insulating member 15. As shown in FIG. 2, the insulating member 15 has a first recess 15 a which opens upward and accommodates the vibration element 9, and a second recess 15 b which opens downward and accommodates the IC 11. In another viewpoint, the insulating member 15 includes the substrate portion 15c, a first frame portion 15d positioned on one main surface (first mounting surface 15ca) of the substrate portion 15c, and the other main surface (substrate portion 15c) of the substrate portion 15c. And a second frame portion 15e located on the second mounting surface 15cb).

  The vibrating element 9 includes, for example, a flat plate-like piezoelectric base plate 10 (FIG. 2) and a pair of excitation electrodes 32 (see FIG. 4) provided on both main surfaces of the piezoelectric base plate 10. The piezoelectric base plate 10 is made of, for example, a quartz material such as quartz, is cut at a predetermined angle with respect to the crystal axis, and has a rectangular shape in plan view. The vibrating element 9 generates thickness shear vibration at a predetermined frequency by applying a voltage to the pair of excitation electrodes 32.

  The lid 13 is joined to the upper surface of the first frame portion 15d to seal the first recess 15a. The lid 13 may be made of a conductive material such as metal, may be made of an insulating material, or may be made of a composite material in which an insulating layer and a conductive layer are laminated. For example, the lid 13 is formed of a metal plate, and the metal plate is joined to the first frame portion 15d by seam welding or the like.

  For example, the thermostatic chamber 5 mounts the mounting substrate 17 on which TCXO3 is mounted, the case 19 accommodating the TCXO3, the heater 21 (FIG. 2) for heating the atmosphere in the case 19, and the OCXO 1 to an external device. And a plurality of (four in the present embodiment) external terminals 23. In addition to the TCXO 3 and the heater 21, various electronic components (for example, a power supply IC) may be mounted on the mounting substrate 17.

  The mounting substrate 17 is formed of, for example, a printed wiring board, and includes an insulating substrate 24 and various conductors provided on the insulating substrate 24. The insulating base 24 (mounting base 17) has a first mounting surface 24a and a second mounting surface 24b on the back surface thereof. The TCXO 3 is mounted on the first mounting surface 24a, and the heater 21 is mounted on the second mounting surface 24b. That is, the mounting substrate 17 is interposed between the TCXO 3 and the heater 21. The insulating base 24 is made of, for example, a glass epoxy material.

  The case 19 is made of, for example, a metal material, and accommodates the TCXO 3, the mounting base 17 and the heater 21. Although the case 19 is not particularly illustrated, for example, a member constituting the lower surface of the case 19 and a member constituting the upper surface and the outer peripheral surface of the case 19 are fixed. It is preferable that the two members be joined airtightly (the inside of the case 19 is sealed).

  The heater 21 is joined to, for example, the second mounting surface 24 b of the mounting substrate 17 at a position overlapping with the TCXO 3. More specifically, for example, in plan view, the heater 21 is larger than the TCXO 3, and the TCXO 3 is within the arrangement range of the heater 21. The heater 21 is configured, for example, by sealing a conductor (resistor) extending in a predetermined pattern with an insulating material, and generates heat according to a voltage applied through the mounting substrate 17. The heater 21 may be electrically connected and fixed to the mounting substrate 17 by bumps (not shown), and may be fixed to the mounting substrate 17 by an adhesive having a relatively high heat conductivity and by bonding wires. It may be electrically connected to the mounting base 17. When the heater 21 is mounted on the mounting substrate 17 by bumps, an underfill may be disposed between the heater 21 and the mounting substrate 17 or the like.

  The plurality of external terminals 23 are, for example, pin-shaped terminals, one end side of which is inserted into a hole formed in the mounting base 17, fixed to the mounting base 17 by solder or the like, and electrically connected. The other end sides of the plurality of external terminals 23 extend from, for example, the lower surface of the case 19. The plurality of external terminals 23 may be fixed to the case 19 and contribute to fixing the mounting substrate 17 and the case 19 while securing a distance between the mounting substrate 17 and the lower surface of the case 19. .

  FIG. 3 is a partially enlarged view of FIG.

  The element mounting member 7 has a conductor for electrically connecting the mounting base 17 and the IC 11 as a conductor (a pad or a wire), and a conductor for electrically connecting the IC 11 to the vibrating element 9. ing. In addition to this, the element mounting member 7 is provided to improve the heat conductivity from the heater 21 to the first concave portion 15a (the vibrating element 9), and with respect to other electronic elements of the IC 11, the vibrating element 9 and the TCXO3. It has a non-connected conductor (first conductor 61). Specifically, it is as follows.

  The insulating member 15 is formed, for example, by stacking a plurality of layered members made of ceramic such as alumina. In the example of FIG. 3, the insulating member 15 includes two layered members 15f and 15g constituting the substrate portion 15c, a layered member constituting the first frame portion 15d, and a layered member constituting the second frame portion 15e. Four sheets are piled up and formed.

  The element mounting member 7 has a plurality of mounting pads 25 provided on the lower surface of the second frame 15 e and a plurality of mounting member wirings 26 extending from the plurality of mounting pads 25.

  The plurality of mounting pads 25 (except 25H described later) are basically for inputting and outputting signals to and from the TCXO 3, and the bottom surface of the second recess 15 b (the plurality of mounting member wirings 26) The second mounting surface 15cb) is connected to any of a plurality of pads (not shown) for mounting the IC 11.

  Although not particularly shown, any two of the plurality of pads for mounting the IC 11 are provided on the bottom surface (first mounting surface 15 ca) of the first recess 15 a via the two mounting member wires 26. It is connected to a pair of pads for mounting the vibration element 9.

  The arrangement position, the planar shape, and the area of the plurality of mounting pads 25 in the lower surface of the second frame 15 e may be set as appropriate. For example, the plurality of mounting pads 25 are provided at an intermediate position of the four corners or the four corners of the second frame 15 e and the long side.

  The mounting member wiring 26 is constituted of, for example, a via conductor which vertically penetrates at least a part of the insulating member 15 and a layered conductor which extends the inside of the substrate portion 15c in parallel to the substrate portion 15c. The mounting member wiring 26 may include a layered conductor provided on the first mounting surface 15 ca or the second mounting surface 15 cb.

  The plurality of mounting pads 25 include heat transfer mounting pads 25 H for transferring the heat of the heater 21. In addition, the plurality of mounting member wirings 26 include a heat transfer mounting member wiring 26 H for transmitting the heat of the heater 21. The heat transfer mounting pad 25H and the heat transfer mounting member wiring 26H are not connected to the IC 11, the vibrating element 9 and the other electronic elements of the TCXO 3 and constitute the first conductor 61 described above.

  Basically, the other mounting pads 25 and the other mounting member wiring 26 are the same except that the mounting pad for heat transfer 25 H and the mounting member wiring for heat transfer 26 H are not connected to the electronic element such as the IC 11. The same configuration as that of FIG.

  For example, the heat transfer mounting pad 25 H is made of the same material as the other mounting pads 25. For example, the mounting pad 25 (including 25H) is formed of one or more metal layers. The heat transfer mounting member wiring 26 H is made of the same material as the other mounting member wiring 26. For example, the mounting member wiring 26 is made of metal. The metal which comprises the mounting pad 25 or the mounting member wiring 26 is Cu, Ag, Au, Al, Ti, Ni, Cr, or these alloys, for example.

  In general, a conductor such as metal has high thermal conductivity as compared to an insulator. Therefore, the material of the mounting pad 25 (including 25H) and the mounting member wiring 26 (including 26H) has a thermal conductivity higher than that of the material of the insulating member 15.

  For example, the heat transfer mounting member wiring 26H penetrates the second frame portion 15e from the heat transfer mounting pad 25H to reach the inside (between the layered members 15f and 15g) of the substrate portion 15c, and the inside of the substrate portion 15c. Extends to a position overlapping the first recess 15a and the second recess 15b. The heat transfer mounting member wiring 26 H may extend to a position overlapping the vibrating element 9.

  The TCXO 3 is disposed with the lower surface of the second frame portion 15 e facing the first mounting surface 24 a of the mounting substrate 17. Then, for example, the plurality of mounting pads 25 (including 25H) are joined by the plurality of bumps 28 to the plurality of mounting pads 27 (including 27H) provided on the first mounting surface 24a. Thus, the TCXO 3 is fixed to the mounting substrate 17 and electrically connected. The bumps 28 are made of, for example, solder (including lead-free solder) or a conductive adhesive.

  The plurality of mounting pads 27 (except for 27H) are connected to a plurality of base wirings 29 provided on the mounting base 17. The plurality of base wirings 29 are connected to the plurality of external terminals 23 directly or indirectly via an appropriate electric element. The base wiring 29 is constituted by, for example, a via conductor which penetrates at least a part of the insulating base 24 in the vertical direction, and a layered conductor which extends the inside or the surface of the insulating base 24 parallel to the insulating base 24.

  Among the plurality of mounting pads 27, the heat transfer mounting pad 27H connected to the heat transfer mounting pad 25H is not connected to the base wiring 29, and is in an electrically floating state. Therefore, not only is the first conductor 61 not connected to the TCXO3 electronic element (the vibrating element 9 and the IC 11), but an electric signal (including drive power and GND etc.) is applied also on the mounting substrate 17 side. It is not electrically floating.

  The heat transfer mounting pad 27H may have the same configuration as the other mounting pads 27. For example, the heat transfer mounting pad 27 H is made of the same material as the other mounting pads 27. For example, the heat transfer mounting pad 27 (including 27H) is formed of one or more metal layers. As described above, in general, since the conductor such as metal has higher thermal conductivity than the insulator, the materials of the plurality of mounting pads 27 and bumps 28 have higher thermal conductivity than the material of the insulating substrate 24.

  FIG. 4 is a block diagram showing a schematic configuration of a signal processing system of OCXO 1.

  As described above, OCXO 1 has TCXO 3 and thermostatic chamber 5, both of which are connected with a plurality of mounting pads 25 (excluding 25H) and a plurality of mounting pads 27 (excluding 27H). Are electrically connected. In addition, various signals are input to the plurality of mounting pads 25 of the TCXO 3 through the plurality of external terminals 23 of the thermostatic chamber 5, or various signals are output.

  The signals applied to the plurality of external terminals 23 are, for example, power supply voltage Vcc for driving TCXO 3 and thermostatic chamber 5, reference potential GND, and control voltage Vcon for controlling the frequency of the oscillation signal generated by TCXO3. . The signals output from the plurality of external terminals 23 are, for example, the oscillation signal Vout generated by TCXO3. Note that which role is to be assigned to which position of the external terminal 23 may be set as appropriate. The same applies to the mounting pad 25 and the mounting pad 27.

  As described above, the TCXO 3 includes the vibrating element 9 and the IC 11 connected to the vibrating element 9. For example, the IC 11 applies a voltage to the vibration element 9 to generate an oscillation signal, a temperature compensation circuit 35 for compensating for a temperature change of the oscillation signal, and a temperature compensation held by the temperature compensation circuit 35. And a rewriting circuit (not shown) for rewriting the content of the data related to. The configuration of these circuits may be the same as known configurations.

  For example, although the oscillation circuit 33 is not particularly illustrated, an inverter whose input side and output side are connected to the vibration element 9, a feedback resistor connected to the input side and output side of the inverter, and between the input side of the inverter and the ground portion And a variable capacitance element disposed between the output side of the inverter and the ground portion.

  Further, for example, the temperature compensation circuit 35 includes a variable capacitance element 39 disposed between the vibration element 9 and the ground portion, a compensation signal generation circuit 41 connected to the variable capacitance element 39, and a compensation signal generation circuit 41. It has a ROM 43, a RAM 45 and a first temperature sensor 47 connected.

  The variable capacitance element 39 included in the oscillation circuit 33 may be used as the variable capacitance element 39 of the temperature compensation circuit 35 in order to change the frequency of the oscillation signal according to the control voltage Vcon. Further, the ROM 43 and the RAM 45 may be used also as the ROM and the RAM that hold information used by the oscillation circuit 33. The first temperature sensor 47 may be provided separately from the IC 11.

  The compensation signal generation circuit 41 applies a voltage corresponding to the temperature detected by the first temperature sensor 47 to the variable capacitance element 39 based on the information stored in the ROM 43 or the RAM 45. As a result, the load capacity of the vibrating element 9 changes according to the temperature, and the frequency of the oscillation signal is temperature compensated.

  The thermostatic chamber 5 controls the heater 21 based on the temperature detected by the second temperature sensor 49 and the second temperature sensor 49, for example, in addition to the heater 21 described above, which detects the temperature at an appropriate position in the case 19. And a temperature control circuit 51. The temperature control circuit 51 feedback-controls the heater 21 so that, for example, the temperature detected by the second temperature sensor 49 is maintained at a preset temperature.

  Some TCXOs can output the temperature detected by the first temperature sensor 47 from the mounting pad 25. When such a TCXO is selected as TCXO3, the heater 21 may be controlled based on the temperature detected by the first temperature sensor 47 without providing the second temperature sensor 49.

  The plurality of external terminals 23 exposed from the thermostatic chamber 5 and the plurality of mounting pads 25 (except 25H) of the TCXO 3 are directly connected via the base wiring 29 of the mounting base 17. However, an appropriate electronic element may be interposed between the plurality of external terminals 23 and the plurality of mounting pads 25. For example, an amplifier or an element for impedance matching may be interposed.

  Further, as described above, the heat transfer mounting pad 27H is not connected to the base wiring 29, and the first conductor 61 is in an electrically floating state.

  Note that, as indicated by an imaginary line (two-dot chain line), a reference potential may be applied to the heat transfer mounting pad 27H.

  As described above, in the OCXO 1 of the present embodiment, the element mounting member 7 of TCXO 3 is exposed to the outside of the insulating member 15 at the top surface (surface on the mounting base 17 side) of the second frame 15 e It has a first conductor 61 located in the member 15 and electrically disconnected from the vibrating element 9, the IC 11 and the other electronic elements of TCXO3.

  Therefore, the heat of the heater 21 is easily conducted to the inside of the insulating member 15, and as a result, the atmosphere of the first recess 15a is easily heated. As a result, the temperature of the vibrating element can be quickly brought to a constant temperature, and the time until the frequency of the oscillation signal stabilizes can be shortened. Since the first conductor 61 is not for connecting electronic elements, it can be a suitable path for heat transfer. On the other hand, the first conductor 61 can be formed together with the connection target mounting pad 25 (excluding 25H) and the mounting member wiring 26 (excluding 26H), which can suppress an increase in manufacturing cost.

  Further, in the present embodiment, the first conductor 61 (heat transfer mounting member wiring 26H) has a portion overlapping the first recess 15a inside the substrate portion 15c. Therefore, the heat of the heater 21 can be rapidly transmitted to the first recess 15 a separated from the heater 21 by the second recess 15 b.

  Further, in the present embodiment, the first conductor 61 is a portion joined to the mounting pad 27 (heat transfer mounting pad 27H) provided on the first mounting surface 24a by the bumps 28 (heat transfer mounting pad 25H )have.

  Therefore, the first conductor 61 can contribute to the rigid mounting of the TCXO3. Furthermore, since the heat of the heater 21 is transmitted to the first conductor 61 through the heat transfer mounting pad 27H and the bumps 28, the atmosphere of the first recess 15a can be heated more efficiently. In another aspect, the TCXO 3 may have a mounting pad 25 that is not used for input / output of an electrical signal, and such mounting pad 25 may be effectively used as a part of the first conductor 61. Can.

  Further, in the present embodiment, the first conductor 61 is in an electrically floating state. Therefore, for example, it is not necessary to provide the base wiring 29 for applying the reference potential to the first conductor 61, and the configuration of the OCXO 1 is simplified. Further, in another aspect, since the first conductor 61 does not constitute a shield, it is not necessary to be provided in an arrangement that functions as a shield, and it is preferable to be provided for heat transfer. It is possible. For example, the mounting member wiring 26 does not have to surround the vibrating element 9 or the IC 11 in a plan view.

  When the reference potential is applied to the first conductor 61, the first conductor 61 can be electrically stabilized. As a result, for example, the risk of spurious emissions is reduced. In addition, the shielding effect can be expected by setting the arrangement range of the first conductor 61 to an appropriate one (for example, a shape provided in the substrate portion 15c and surrounding the vibrating element 9 or the IC 11 in plan view) .

Second Embodiment
FIG. 5 is a partially enlarged cross-sectional view showing the OCXO 201 according to the second embodiment of the present invention, which corresponds to FIG. 2 of the first embodiment. In addition, about the matter which does not mention in particular below, it is the same as that of 1st Embodiment.

  The second embodiment is different from the first embodiment in the shape of the first conductor. That is, the heat transfer mounting member wiring 226H of the first conductor 261 of the present embodiment has the exposed portion 261a exposed in the first concave portion 15a. The exposed portion 261a is formed of, for example, a via conductor which penetrates at least a part of the substrate portion 15c (layered member 15f).

  The exposed portion 261a may be provided on the first mounting surface 15ca (and on the via conductor), and may be configured to include a layered conductor having an area larger than the cross-sectional area of the via conductor. Also, depending on various thermal conditions, the first conductor (for example, a via conductor penetrating through the substrate portion 15c) is exposed to both the first recess 15a and the second recess 15b, and the heat of the second recess 15b is May be transmitted to the first recess 15a.

  In such a configuration, since the first conductor 261 is in direct contact with the atmosphere of the first recess 15a, the heat of the heater 21 is more efficiently transmitted to the atmosphere of the first recess 15a, and the temperature is raised. be able to.

  The second embodiment is different from the second embodiment in that a second conductor 271 for transmitting the heat of the heater 21 to the first conductor 61 is provided. Specifically, the mounting substrate 217 of the second embodiment has, for example, a heat transfer base wiring 29H connected to the heat transfer mounting pad 27H. A second conductor 271 is configured by the heat transfer mounting pad 27H and the heat transfer base wiring 29H.

  The heat transfer base wiring 29 H is configured by via conductors and layered wirings as the other base wirings 29. In the example of FIG. 5, the heat transfer base wiring 29H is configured by a via conductor which linearly penetrates the insulating base 24 from the second mounting surface 24b side to the first mounting surface 24a side. The heat transfer mounting pad 27 H and the heat transfer base wiring 29 H are disposed at positions overlapping the TCXO 3 and the heater 21. The heat transfer base wiring 29H is not connected to the external terminal 23 or the electronic element mounted on the mounting base 17, and is in an electrically floating state.

  The material of the heat transfer base wiring 29 H may be the same as the material of the other base wiring 29. For example, the base wiring 29 (29H) is made of a conductor such as metal. The material of the heat transfer base wiring 29 H has a thermal conductivity higher than that of the material of the insulating base 24.

  Thus, the second conductor 271 is provided which penetrates the insulating base 24 from the first mounting surface 24 a to the second mounting surface 24 b at a position overlapping the heater 21 and is connected to the first conductor 61 by the bumps 28. Thus, the heat of the heater 21 can be more suitably transmitted to the atmosphere of the first recess 15a.

  In the above embodiment, OCXO 1 and 201 are an example of a piezoelectric device with a thermostat, TCXO 3 and 203 are an example of a piezoelectric device, and IC 11 is an example of an integrated circuit element.

  The present invention is not limited to the above embodiments, and may be implemented in various aspects.

  The first embodiment and the second embodiment may be combined as appropriate. That is, the configuration in which the first metal is not exposed in the first recess and the configuration in which the second conductor is provided may be combined, or the configuration in which the first conductor is exposed in the first recess and the second conductor may be combined. A configuration not provided may be combined.

  The piezoelectric device may not have a temperature compensation function. Also, the piezoelectric device is not limited to the oscillator, and may be, for example, a filter such as a SAW filter.

  The oscillator may input and output signals other than those exemplified in the embodiment. For example, the oscillator may be one to which the control voltage is not input (that which outputs an oscillation signal of a predetermined constant frequency), or may be one to which the enable / disable signal is input. Alternatively, two oscillation signals having different frequencies or the same frequency may be output.

  The vibrating element is not limited to the one in which the pair of electrodes is provided on both main surfaces of the piezoelectric body, and the pair of electrodes is provided on one main surface of the piezoelectric body as in the SAW type vibrating element It is also good. The cut angle of the piezoelectric body may be set appropriately. The piezoelectric body is not limited to quartz, and may be, for example, ceramic.

  The structure of OCXO may be changed as appropriate. For example, a circuit substrate facing the mounting substrate via the spacer is provided on the heater side of the mounting substrate, and a case covering the surface of the piezoelectric device (TCXO), the mounting substrate, and the circuit substrate on the mounting substrate side is provided. The surface of the circuit board opposite to the mounting substrate may be exposed outside the case. A pad-like external terminal may be provided on the surface of the circuit board exposed to the outside of the case.

  A plurality of first conductors may be provided on the element mounting member. In addition, a plurality of heat transfer mounting pads may be provided. In this case, the number of the heat transfer mounting member wires may be the same as the number of the plurality of mounting pads, or by connecting two or more heat transfer mounting member wires to one another It may be less. The heat transfer mounting member wiring extending from one heat transfer mounting pad may be branched as appropriate. By branching, it is expected that heat can be efficiently and evenly transferred to the plurality of positions of the first recess.

  The shape and arrangement position of the first conductor can be set as appropriate, and are not limited to those exemplified in the embodiment. For example, the first conductor may not have the heat transfer mounting pad, and the via conductor penetrating the second frame may be directly exposed from the top surface of the second frame. Also, for example, the first conductor may penetrate the first frame portion and the substrate portion, extend along the surface on the second frame portion side of the substrate portion, and be exposed in the first recess. Also, for example, the first conductor is not limited to the shape similar to the other mounting member wiring, and may include, for example, a portion facing the vibration element in a relatively large area.

  The invention of OCXO whose element mounting member is not H-type can be extracted from the present application. For example, a mounting base having a first mounting surface and a second mounting surface on the back surface, a piezoelectric device mounted on the first mounting surface, a heater mounted on the second mounting surface, the piezoelectric device, A mounting base and a case for housing the heater, wherein the piezoelectric device has a first mounting surface and a substrate portion having a second mounting surface on the back surface, and the first mounting surface side of the substrate portion An element mounting member including an insulating member having a first frame portion positioned to form a first concave portion having the first mounting surface as a bottom surface, and a vibration element accommodated in the first concave portion, The element mounting member is mounted with the side opposite to the first frame facing the first mounting surface, the element mounting member is made of a material having a thermal conductivity higher than that of the material of the insulating member, and the first frame It is exposed to the outside of the insulating member on the opposite side, and a part is inside the insulating member Extract the invention of a thermostatic piezoelectric device having a first conductor positioned and electrically disconnected from the vibration element, the integrated circuit element, and other electronic elements of the piezoelectric device. It is possible. Also in the present invention, the heat conductivity from the heater to the first recess can be improved, and the temperature rise of the first recess separated from the heater by the substrate portion and the mounting substrate can be efficiently performed.

  DESCRIPTION OF SYMBOLS 1 ... crystal oscillator with thermostat (OCXO, piezoelectric device with thermostat), 3 ... temperature compensation type crystal oscillator (TCXO, piezoelectric device), 7 ... element mounting member, 9 ... vibration element, 11 ... IC (integrated circuit element) 15: insulating member, 15a: first concave portion, 15b: second concave portion, 15c: substrate portion, 15ca: first mounting surface, 15cb: second mounting surface, 15d: first frame portion, 15e: second frame portion , 17: mounting base, 19: case, 21: heater, 24a: first mounting surface, 24b: second mounting surface, 61: first conductor.

Claims (3)

A mounting substrate having a first mounting surface and a second mounting surface on the back surface thereof;
A piezoelectric device mounted on the first mounting surface;
A heater mounted on the second mounting surface;
A case for housing the piezoelectric device, the mounting base, and the heater;
Have
The piezoelectric device is
A first frame portion comprising a substrate portion having a first mounting surface and a second mounting surface on the back surface thereof, and a first frame portion located on the first mounting surface side of the substrate portion and having the first mounting surface as a bottom surface And an element mounting member including an insulating member having a second frame portion positioned on the second mounting surface side of the substrate portion and having a second recess whose bottom surface is the second mounting surface;
A vibrating element accommodated in the first recess;
An integrated circuit element housed in the second recess,
The top surface of the second frame portion opposite to the substrate portion is mounted so as to face the first mounting surface,
The element mounting member is made of a material having a thermal conductivity higher than that of the material of the insulating member, is exposed to the outside of the insulating member at the top surface of the second frame portion, and a part is in the insulating member. A first electrical conductor positioned and electrically disconnected from the vibrating element, the integrated circuit element and other electronic elements of the piezoelectric device;
The first conductor is electrically disconnected from all the external terminals exposed from the case and is in an electrically floating state. The thermostatic oven-equipped piezoelectric device according to claim 1 , wherein the first conductor has a portion overlapping the first concave portion in a plan view inside the substrate portion. It said first conductor is a thermostatic piezoelectric device with tank according to claim 1 or 2 having a part exposed within the first recess.

Images