JP2010278712A - Piezoelectric oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric oscillator which eliminates a temperature difference between an oscillation circuit element and a piezoelectric vibration piece in a very short period of time and prevents the short circuit of the oscillation circuit element. <P>SOLUTION: The piezoelectric oscillator 1 includes: a vibration piece accommodation boy 20 that accommodates a crystal vibration piece 25; the oscillation circuit element 4 for controlling the vibrations of the crystal vibration piece 25; a heat conductive resin 5 arranged on outer surface of the oscillation circuit element 4; a heat conductive pad 37 located so as to hold the heat conductive resin 5 between itself and the oscillation circuit element 4; and first embedding poles 6 which has the characteristic of high heat conductivity, and whose one end is brought into contact with the heat conductive resin 5 and whose other end is brought into contact with the vibration piece accommodation body 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a piezoelectric oscillator having a piezoelectric vibrating piece and an oscillation circuit element.

  2. Description of the Related Art Conventionally, a piezoelectric oscillator having a configuration in which a first housing that houses a piezoelectric vibrating piece and a second housing that houses an oscillation circuit element that excites the piezoelectric vibrating piece are integrated. ing. These containers are each formed of ceramic or the like. The oscillation circuit element includes a temperature sensor and a circuit for compensating the temperature of the piezoelectric vibrating piece in accordance with the temperature detected by the temperature sensor. Accordingly, the piezoelectric oscillator can compensate the temperature of the resonance frequency of the piezoelectric vibrating piece in response to the environmental temperature change around the piezoelectric oscillator, and can output an oscillation frequency with a small frequency error.

  Furthermore, a piezoelectric oscillator as shown in Patent Document 1 is also disclosed. In this piezoelectric oscillator, a thermosetting paste having a higher thermal conductivity than each container (package body in Patent Document 1) is used as an oscillation circuit element. It has a configuration filled in the second container so as to cover (the integrated circuit element in Patent Document 1). According to this configuration, the heat generated by the oscillation circuit element can be efficiently transmitted to the piezoelectric vibrating piece, and the temperature difference between the surface temperature of the first container and the internal temperature of the second container can be reduced in a shorter time. It is possible to make it smaller.

JP 2007-158464 A

  However, in the piezoelectric oscillator disclosed in Patent Document 1, the heat generated by the oscillation circuit element is transmitted through the thermosetting paste, and is transmitted in a very short time to the portion where the container of the oscillation circuit element and the piezoelectric vibrating piece contacts. However, it is hard to be transmitted from there to the inside of the ceramic or the like that forms each container, as compared with the thermosetting paste. Therefore, it took some time for the temperature difference between the internal temperature of the first container and the internal temperature of the second container to be sufficiently small. Even in this slight time, for example, when a piezoelectric oscillator is used in a GPS (Global Positioning System) device, almost instantaneous vibration stability is required, and further improvement is necessary. Moreover, since the thermosetting paste is filled in the entire interior of the second container, there is a problem that only pastes having insulating properties that can prevent a short circuit of the oscillation circuit element can be used.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following application examples or forms.

  Application Example 1 A piezoelectric oscillator according to this application example includes an oscillation circuit element, a thermally conductive member disposed on the surface of the oscillation circuit element, and a vibration that houses a piezoelectric vibrating piece excited by the oscillation circuit element. The one piece container is disposed so as to overlap in a plan view, and one end is in contact with the heat conductive member, and is embedded in the vibrating piece container in a direction approaching the piezoelectric vibrating piece from the one end. A first embedded member is provided, wherein the first embedded member has a higher thermal conductivity than surrounding members.

  According to this piezoelectric oscillator, the heat generated by driving the oscillation circuit element is transmitted to the resonator element container via the heat conductive member and the first embedded member, so that the heat conductive member and the first Compared to the case where the vibration piece container is transmitted without passing through the embedded member, the vibration piece container is transmitted in a very short time. Due to the transmitted heat, the temperature of the piezoelectric vibrating piece inside the vibrating piece container quickly reaches a temperature substantially equal to the internal temperature of the oscillation circuit element. That is, the internal temperature of the resonator element housing changes quickly following the change in the internal temperature of the oscillation circuit element. As a result, the difference between the temperature sensed by the oscillation circuit element to correct the oscillation frequency of the piezoelectric vibrating piece and the internal temperature of the vibrating piece container affected by the corrected piezoelectric vibrating piece has occurred. Will be resolved as soon as possible. The piezoelectric oscillator having such a configuration can always maintain the internal temperature of the resonator element housing and the oscillation circuit element at substantially the same temperature, and the oscillation circuit element is in contact with the piezoelectric resonator element of the vibration element container. Therefore, vibration can be controlled by appropriate temperature correction. Therefore, the piezoelectric oscillator can always output a stable oscillation signal with high frequency accuracy.

  Application Example 2 A piezoelectric oscillator according to this application example includes an oscillation circuit element, a thermally conductive member disposed on the surface of the oscillation circuit element, and a vibration that houses a piezoelectric vibrating piece excited by the oscillation circuit element. The vibration piece container has a heat transfer member formed on a surface thereof, the heat transfer member is connected to the heat conductive member, and one end of the heat transfer member. A first embedded member that is in contact with the member and is embedded in the resonator element housing from the one end toward the piezoelectric resonator element, wherein the first embedded member is formed by surrounding members It has a high thermal conductivity.

  According to this piezoelectric oscillator, the heat generated by driving the oscillation circuit element is transferred to the resonator element container through the heat conductive member, the heat transfer member, and the first embedded member, thereby providing the heat conductivity. Compared to the case where the vibration piece container is transmitted without passing through the member, the heat transfer member, and the first embedded member, the vibration piece container is transmitted in a very short time. Due to this transmitted heat, the internal temperature of the resonator element housing quickly reaches a temperature substantially equal to the internal temperature of the oscillation circuit element. That is, the temperature of the piezoelectric vibrating reed inside the vibrating reed housing changes quickly following the change in the internal temperature of the oscillation circuit element. As a result, the difference between the temperature sensed by the oscillation circuit element to correct the oscillation frequency of the piezoelectric vibrating piece and the internal temperature of the vibrating piece container affected by the corrected piezoelectric vibrating piece has occurred. Will be resolved as soon as possible. The piezoelectric oscillator having such a configuration can always maintain the internal temperature of the resonator element housing and the oscillation circuit element at substantially the same temperature, and the oscillation circuit element is in contact with the piezoelectric resonator element of the vibration element container. Therefore, vibration can be controlled by appropriate temperature correction. Therefore, the piezoelectric oscillator can always output a stable oscillation signal with high frequency accuracy. In addition, since the heat conductive member is sandwiched between the oscillation circuit element and the heat transfer member, the flow that causes the oscillation circuit element to be short-circuited is regulated, such as a conductive paste. Etc., it can be used.

  Application Example 3 In the piezoelectric oscillator according to the application example described above, it is preferable that the resonator element housing includes a first heat radiating member in contact with the other end side of the first embedded member.

  According to this configuration, the heat transmitted from the oscillation circuit element to the first embedded member is transmitted to the piezoelectric vibrating piece side of the vibrating piece container through the first heat radiating member. Even if the first embedding member has various forms suitable for embedding into the resonator element housing due to heat conduction through the first heat radiating member, the first heat is transmitted regardless of the form. After being dispersed throughout the heat dissipating member, it is transmitted to the piezoelectric vibrating piece side of the vibrating piece container. Therefore, heat conduction is performed uniformly and more efficiently. And the 1st embedding member is the form which is a plurality of pillars which are scattered to face the 1st heat radiating member, or the single penetration provided in the central vicinity of the 1st radiating member The form which is a body etc. can be considered.

  Application Example 4 In the piezoelectric oscillator according to the application example described above, the resonator element housing is embedded in a position overlapping the first embedded member in plan view and has a higher thermal conductivity than the surrounding members. A second embedded member that is embedded in the vibration piece container in a direction in which one end is in contact with the first heat radiating member and approaches the piezoelectric vibrating piece from the one end; And a second heat dissipating member in contact with the other end of the embedding member.

  According to this configuration, in addition to the first embedded member, the vibration piece container further includes the second embedded member formed from the first heat radiating member toward the piezoelectric vibrating piece and the first embedded member. A second heat radiating member in contact with the two embedded members is provided. By providing the second embedded member and the second heat radiating member, the heat emitted from the oscillation circuit element and reaching the first heat radiating member is transferred to the side of the second heat radiating member via the second embedded member. It is transmitted to. Thereby, the heat that has reached the first heat radiating member is transmitted to the second heat radiating member in a shorter time compared to the case where the heat is transmitted through the inside of the resonator element housing without passing through the second embedded member. The heat transmitted to the second heat radiating member is dissipated inside the resonator element housing. As a result, the internal temperature of the resonator element housing reaches a temperature that is almost the same as the surface temperature of the oscillation circuit element even more quickly. That is, the internal temperature of the resonator element housing changes immediately following the change in the internal temperature of the oscillation circuit element. Therefore, the difference between the temperature sensed by the oscillation circuit element to correct the vibration of the piezoelectric vibrating piece and the internal temperature of the vibrating piece container that is affected by the corrected piezoelectric vibrating piece is more rapid, if any. Will be resolved. The piezoelectric oscillator having such a configuration can exhibit more stable and more accurate vibration characteristics.

  Application Example 5 In the piezoelectric oscillator according to the application example described above, it is preferable that the thermally conductive member is a resin containing metal powder.

  According to this configuration, the heat conductive member that is a resin can be flexibly set according to the shapes of the oscillation circuit element and the heat transfer member, and heat conduction between the oscillation circuit element and the heat transfer member is efficiently performed. Easy to arrange. In addition, since the resin contains metal powder, the thermal conductivity of the heat conductive member is higher than that of the resin alone, and heat can be transferred from the oscillation circuit element to the heat transfer member in a shorter time. is there. If the heat conductive member is a resin, it can be made into a paste or the like, and the arrangement work can be performed more easily regardless of the shapes of the oscillation circuit element and the heat transfer member. In this case, since the heat conductive resin is sandwiched between the oscillation circuit element and the heat transfer member, the flow of the oscillation circuit element to other than the outer surface is restricted, and even if the metal powder is contained, the oscillation circuit It is possible to prevent a short circuit of an element or the like.

  Application Example 6 In the piezoelectric oscillator according to the application example, it is preferable that the thermally conductive member is made of metal.

  According to this configuration, since the thermally conductive member is a metal itself, a member having high thermal conductivity can be selected, and options for the member are widened. Such a metal heat conductive member can transfer heat from the oscillation circuit element to the heat transfer member in almost the shortest time.

  Application Example 7 In the piezoelectric oscillator according to the application example, it is preferable that the thermally conductive member is a thermally conductive sheet.

  According to this configuration, a heat conductive sheet as a heat conductive member can be attached to the oscillation circuit element or the heat transfer member, and the heat conductive member is interposed between the oscillation circuit element and the heat transfer member. , Arranged freely. Further, since the heat conductive member is in the form of a sheet, it can be handled flexibly by cutting it in accordance with the shape of the oscillation circuit element or the heat transfer member, and is easy to handle.

  Application Example 8 In the piezoelectric oscillator according to the application example described above, it is preferable that the resonator element housing, the oscillation circuit element, and the thermal conductive member are covered with a covering member.

  According to this configuration, the piezoelectric oscillator has a configuration in which the resonator element housing, the oscillation circuit element, and the heat conductive member are covered and integrated with a covering member such as a resin. The piezoelectric oscillator covered with the covering member is less susceptible to external temperature changes, and has an effect of preventing the internal temperature of the resonator element housing and the oscillation circuit element from changing suddenly. Thereby, the piezoelectric oscillator can easily maintain the internal temperature of the resonator element housing and the oscillation circuit element at substantially the same temperature via the heat conductive member, the heat transfer member, the first embedded member, and the like. Become.

  Application Example 9 In the piezoelectric oscillator according to the application example described above, it is preferable that at least one of the oscillation circuit element and the heat transfer member has a groove on a surface in contact with the heat conductive member.

  According to this configuration, if the groove portion is formed in the oscillation circuit element, the contact area between the oscillation circuit element and the heat conductive member is widened, and heat conduction from the oscillation circuit element to the heat conductive member is performed quickly. Is called. Similarly, if a groove is formed in the heat transfer member, the contact area between the heat conductive member and the heat transfer member is widened, and heat conduction from the heat conductive member to the heat transfer member is performed quickly. As described above, if a groove is formed in either or both of the oscillation circuit element and the heat transfer member, the heat generated by the oscillation circuit element is transmitted more quickly and efficiently than in the case where there is no groove.

FIG. 3 is a cross-sectional view showing the configuration of the piezoelectric oscillator according to the first embodiment. The top view which shows the structure of the piezoelectric oscillator seen from the crystal oscillator side. FIG. 4 is a cross-sectional view illustrating a configuration of a piezoelectric oscillator according to a second embodiment. FIG. 6 is a cross-sectional view illustrating a configuration of a piezoelectric oscillator according to a third embodiment. FIG. 6 is a cross-sectional view showing a modification of the piezoelectric oscillator according to the first embodiment. FIG. 6 is a cross-sectional view showing a modification of the piezoelectric oscillator according to the second embodiment.

Hereinafter, specific embodiments of the piezoelectric oscillator will be described with reference to the drawings. The piezoelectric oscillator in the embodiment has a configuration including a crystal resonator including a crystal resonator element as a piezoelectric resonator element, and a circuit element unit including an oscillation circuit element for exciting the crystal resonator element.
(Embodiment 1)

  FIG. 1 is a cross-sectional view illustrating the configuration of the piezoelectric oscillator according to the first embodiment. FIG. 2 is a plan view showing the configuration of the piezoelectric oscillator viewed from the quartz resonator side. As shown in FIGS. 1 and 2, the piezoelectric oscillator 1 according to the present embodiment includes a crystal resonator element 2 in which a crystal resonator element (piezoelectric resonator element) 25 made of crystal, which is a piezoelectric single crystal material, is stored in a resonator element container 20. And the circuit element portion 3 in which the oscillation circuit element 4 is accommodated in the element housing 30, and the crystal resonator 2 and the circuit element portion 3 are integrated so as to cover a part of the crystal resonator 2 and the circuit element portion 3. And a resin mold (covering member) 9.

  The quartz crystal vibrating piece 25 is provided with a vibrating piece electrode 28 (FIG. 2) on a quartz crystal substrate in which quartz is formed in a substantially rectangular parallelepiped thin plate shape. The resonator element electrode 28 is a metal film having chromium (Cr) as a base and gold (Au) formed thereon, and is independent on each of two counter electrode surfaces that are parallel and form counter electrodes in a thin plate portion of the quartz substrate. Is formed. In this case, these metal films are formed by sputtering. In addition, the resonator element electrode 28 extends from the corner of the excitation electrode 28a to the end of the quartz substrate along the longitudinal direction of the quartz substrate, and is formed at a substantially central portion of the counter electrode surface. And an extraction electrode 28b that wraps around to the counter electrode surface on the opposite side. The resonator element electrodes 28 respectively formed on the counter electrode surfaces are arranged so as to have the same shape when viewed from the same direction when rotated in the longitudinal direction of the quartz crystal substrate.

  The quartz crystal resonator element 25 according to the embodiment is further cut out from a crystal wafer cut along an XZ ′ plane inclined about 35 degrees around the X axis in the XZ plane of a crystal column that is a piezoelectric single crystal material. Crystal board is used. The quartz crystal vibrating piece 25 cut out from the quartz crystal column in this way is a thin plate shape along the X-Z ′ plane and has a thickness in the Y ′ direction which is the front and back direction. The quartz crystal vibrating piece 25 is excited when an alternating voltage is applied between the excitation electrodes 28a formed on the two counter electrodes, and can maintain regular vibration.

  The resonator element housing 20 that accommodates such a crystal resonator element 25 is made of ceramic and has two base parts 23 and 24 that are opposed to each other in the form of a plate, and is also made of ceramic along the entire circumference of the edge of the base part 23. And a concave portion that is formed by the base body 23 and the frame wall 22 and is a rectangle that is substantially similar to the crystal vibrating piece 25 in plan view in order to accommodate the crystal vibrating piece 25, Although omitted in FIG. 2, the lid 21 for closing the opening of the concave portion is provided between the base body 23 and the base body 24 located on the concave portion side with respect to the base body 24, and has a high thermal conductivity characteristic. And a heat dissipating pad (first heat dissipating member) 38 which is a metal material such as tungsten (W) or molybdenum (Mo). Furthermore, the resonator element housing body 20 includes two electrode portions 26 that are formed on the short side corners of the base portion 23 on the concave portion side and are metal films similar to the resonator element electrode 28. The extraction electrode 28 b of each of the two vibrating piece electrodes 28 formed on the crystal vibrating piece 25 is bonded and fixed to the electrode portion 26 with a conductive adhesive 27. That is, the crystal vibrating piece 25 is cantilevered at the position of the extraction electrode 28 b at the end of the crystal substrate, and is held substantially parallel to the base body 23. In this case, the conductive adhesive 27 is obtained by dispersing an elastic silicon resin as a base material and dispersing nickel fine powder, silver fine powder or the like as conductive particles in the base material. Therefore, in the crystal vibrating piece 25, the stress to the crystal vibrating piece 25 is relaxed by the elasticity of the silicon resin, and the impact resistance is improved.

  The lid 21 is for hermetically sealing the crystal vibrating piece 25 in a vacuum state. Therefore, a Kovar seam ring (not shown) is fixed to the opening end face of the frame wall 22 with a silver brazing material, and the surface of this seam ring is plated with nickel (Ni). The lid 21 has the same Kovar plate shape as the seam ring, and the surface of the plate portion is nickel (Ni) plated. According to this configuration, first, the seam ring and the lid 21 are seam welded at atmospheric pressure to close the opening (lid sealing step), so that the crystal vibrating piece 25 is hermetically sealed to the vibrating piece container 20. The crystal resonator 2 is configured. A sealing hole penetrating the plate-like portion of the lid 21 is formed, and after the lid sealing step, heating is performed in a chamber whose pressure is reduced to a vacuum, and a spherical gold germanium (AuGe larger than the sealing hole diameter) is formed in the sealing hole. ) Is placed as a sealing material and heated and melted, whereby the crystal resonator 2 can be hermetically sealed. According to this method, since the impure gas generated in the lid sealing step is discharged from the internal space of the resonator element housing 20, the influence of the impure gas on the frequency of the crystal unit 2 can be suppressed.

  The element housing 30 that houses the oscillation circuit element 4 is disposed on the edge of the element substrate 33 made of polyimide or glass epoxy and formed between the element substrate 33 and the resonator element housing 20. 33 and a conductive spacer 32 for holding the resonator element housing 20 at a constant interval. Further, the element substrate 33 is provided on the surface located on the inner side of the element housing 30 and is in contact with the conductive spacer 32, and the electrode portion 36 provided on the surface located on the outer side of the element housing 30 is illustrated. The base body 24 has an electrode portion 35 in contact with the conductive spacer 32 on the surface located on the inner side of the element housing 30.

  The element housing 30 configured as described above is a substrate that engages with the element-side terminal 40 of the oscillation circuit element 4 at a substantially central position on the inner surface side of the element substrate 33 in order to accommodate the oscillation circuit element 4 therein. A side terminal 39 is provided. The element side terminal 40 and the substrate side terminal 39 are so-called flip chip terminals, and the oscillation circuit element 4 is fixed to the element substrate 33 by engaging both terminals. Further, the board-side terminal 39 is electrically connected to the electrode portion 36 through a wiring (not shown). The base body 24 facing the element housing 30 is provided with a heat conduction pad (heat transfer member) 37 that faces the oscillation circuit element 4. The heat conduction pad 37 belongs to the resonator element housing 20 and has a rectangular shape substantially the same as that of the oscillation circuit element 4. The oscillation circuit element 4 includes a temperature sensor and a temperature compensation circuit that adjusts the oscillation frequency based on the temperature detected by the temperature sensor, and the frequency-temperature characteristics of the crystal vibrating piece 25 that changes according to the environmental temperature. It plays a role to compensate.

  Then, a paste-like heat conductive resin (heat conductive member) 5 is applied to almost the entire outer surface, which is the surface opposite to the element side terminal 40, on the oscillation circuit element 4 accommodated in the element container 30. Has been. The heat conductive resin 5 is filled so as to be sandwiched between the outer surface of the oscillation circuit element 4 and the heat conductive pad 37. Further, the base body 24 of the resonator element container 20 is formed with six circular holes penetrating the base body 24, and the first embedded pillar (first) of tungsten (W) embedded in each circular hole. 1 embedded member) 6 is provided. In this case, tungsten (W) is used as a thermal conductive material having a higher thermal conductivity than the ceramic forming the base body 24. These first embedded columns 6 are equally arranged in two rows of three (FIG. 2) so as to be located in the inner region of the excitation electrode 28a of the resonator element electrode 28 in plan view. The first embedded column 6 has one end on the element housing 30 side of the base body 24 in contact with the heat conduction pad 37 and the other end in contact with the heat dissipation pad 38 on the crystal vibrating piece 25 side. . In this case, the heat conductive resin 5 is a paste-like material containing silver (Ag) as a metal powder having high heat conductivity in an epoxy resin. The thermal conductive pad 37 is made of a metal plate such as tungsten, molybdenum, or copper having a high thermal conductivity characteristic like silver.

  As described above, the crystal resonator 2 and the circuit element unit 3 configured as described above are overlapped so that the base body 24 of the resonator element housing 20 and the element housing 30 are in contact with each other, and the outer surface of the frame wall 22 The element housing 30 including the entire circumference of the side surface where the conductive spacer 32 is located is covered with the resin mold 9. Thereby, the crystal unit 2 and the circuit element unit 3 are integrated and function as the piezoelectric oscillator 1. In the piezoelectric oscillator 1, the electrode portion 26 of the base body 23 and the electrode portion 35 of the base body 24 are electrically connected by a conduction line (not shown), and the crystal vibrating piece 25 and the oscillation circuit element 4 are connected. Can be connected to the outside via the external terminal 41, the electrode portions 26, 35, 36 and the conductive spacer 32.

  In addition, the excitation electrode 28a of the crystal vibrating piece 25 is in a state of overlapping with the formation region of the first embedded column 6, the heat conductive resin 5, and the oscillation circuit element 4 in a plan view (FIG. 2). More specifically, the formation region of the first embedded pillar 6 overlaps the excitation electrode 28 a, the heat conductive resin 5, and the oscillation circuit element 4 in plan view. By doing so, the heat conduction path through which the heat generated in the oscillation circuit element 4 is transmitted to the crystal vibrating piece 25 is shortened, and the oscillation frequency can be quickly stabilized against a temperature change. In the first embodiment, even in a structure in which the heat conductive resin 5 and one end of the first embedded column 6 are in direct contact without providing the heat conductive pad 37, the temperature in the concave portion of the resonator element housing 20 is as follows. Following the change in the internal temperature of the element housing 30, the same temperature is quickly reached.

  The effects of the piezoelectric oscillator 1 according to the first embodiment will be collectively described below.

  (1) In the piezoelectric oscillator 1, the heat conductive resin 5, the heat conductive pad 37, and the first embedded pillar 6 are provided on the element container 30 side, and the heat radiation pad 38 is provided on the vibration piece container 20 side. . As a result, the heat generated by driving the oscillation circuit element 4 increases the internal temperature of the element housing 30 and is also transmitted to the vibration piece housing 20. The heat conduction to the vibration piece housing 20 is the heat conduction. Compared with the case where the resin 5, the heat conduction pad 37, the first embedded pillar 6, and the heat radiation pad 38 are not provided, the process can be performed in a very short time. Therefore, the temperature of the crystal vibrating piece 25 in the concave portion of the vibrating piece container 20 follows the change in the internal temperature of the element container 30 and quickly reaches the same temperature. Thereby, even if the oscillation circuit element 4 controls the vibration of the quartz crystal vibrating piece 25 accommodated in the resonator element accommodating body 20 in accordance with the internal temperature of the element accommodating body 30, the element accommodating body 30 and the resonator element accommodating body. Since the internal temperature with respect to 20 is always substantially the same, the crystal vibrating piece 25 is controlled by appropriate temperature correction. Therefore, the crystal vibrating piece 25 can quickly stabilize the vibration accuracy against a temperature change.

  (2) The first embedded pillar 6 can be embedded in the ceramic counter substrate 31 sintered at a high temperature by using heat-resistant tungsten (W). Can be formed.

  (3) Since the thermal conductive resin 5 is sandwiched between the oscillation circuit element 4 and the thermal conduction pad 37, the thermal conductive resin 5 is applied to the element side terminal 40 of the oscillation circuit element 4 or the like even in a paste form. Flow can be regulated. Therefore, even when the conductive heat conductive resin 5 is used, a short circuit of the oscillation circuit element 4 or the like can be prevented, and a conductive material such as silver (Ag) is contained in order to make the heat conductive resin 5 have high thermal conductivity. It is possible to make it.

  (4) Since the crystal oscillator 2 and the circuit element unit 3 are covered with the resin mold 9, the piezoelectric oscillator 1 has a configuration in which the crystal vibrating piece 25 and the oscillation circuit element 4 are not easily affected by the external temperature. Yes. Therefore, an extreme temperature change hardly occurs with respect to the crystal vibrating piece 25 and the oscillation circuit element 4, and an environment in which stable vibration can be easily maintained for the crystal vibrating piece 25 is maintained.

(5) The piezoelectric oscillator 1 is configured to transmit the heat from the other end of the first embedded column 6 to the resonator element housing 20 by the heat dissipation pad 38. Therefore, even at the other end having a columnar shape and a small area, the heat can be radiated to the base body 23 through the heat radiation pad 38 and then heat can be radiated to the base body 23, and quick heat conduction to the resonator element housing 20 is possible. is there.
(Embodiment 2)

  Next, another embodiment of the piezoelectric oscillator will be described. FIG. 3 is a cross-sectional view showing the configuration of the piezoelectric oscillator according to the second embodiment. The difference between the piezoelectric oscillator 10 according to the present embodiment and the piezoelectric oscillator 1 according to the first embodiment is that the piezoelectric oscillator 10 further includes a second embedded pillar (second embedded member) 7. Therefore, the same components as those of the piezoelectric oscillator 1 are denoted by the same reference numerals and detailed description thereof is omitted.

  As shown in FIG. 3, the piezoelectric oscillator 10 of the present embodiment includes a crystal resonator 2 in which a crystal resonator element 25 is accommodated in a resonator element container 20, and a circuit element portion in which an oscillation circuit element 4 is accommodated in an element container 30. 3 is provided. Further, in order to transmit the heat generated by driving the oscillation circuit element 4 to the resonator element housing 20, the piezoelectric oscillator 10 is provided between the heat conductive resin 5 applied to the outer surface of the oscillation circuit element 4 and the outer surface. A heat conductive pad 37 disposed so as to sandwich the heat conductive resin 5 therebetween, six first embedded columns 6 embedded in the base body 24 of the resonator element housing 20 and having one end in contact with the heat conductive pad 37, And a heat dissipating pad 38 for dissipating heat to the base body 23 of the resonator element housing 20 disposed in contact with the other end of the first embedded column 6.

  In addition to such a configuration, the piezoelectric oscillator 10 includes the second embedded column 7 provided on the base body 23 of the resonator element housing 20 and the heat transmitted from the second embedded column 7 to the crystal resonator element 25. In order to dissipate heat, a copper plate heat dissipating pad (second heat dissipating member) 29 provided on the concave portion side of the base body 23 is further provided. The second embedded pillar 7 is one in which tungsten (W) is embedded in each of six circular holes formed through the base body 23. In this case, tungsten (W) is used as a material having a higher thermal conductivity than the ceramic forming the base body 23. These second embedded pillars 7 are arranged in two rows of three in plan view, facing the first embedded pillar 6 with the heat dissipation pad 38 interposed therebetween. The second embedded pillar 7 has one end in contact with the heat dissipation pad 38 and the other end in contact with the heat dissipation pad 29.

According to this configuration, the speed of heat conduction from the heat dissipating pad 38 to the concave portion side of the resonator element housing 20 is higher when transmitted through the second embedded column 7 than when transmitted through the base body 23 itself. , In a shorter time. As described above, the piezoelectric oscillator 10 in which the second embedded column 7 is provided in the base body 23 is the temperature sensed by the oscillation circuit element 4 to correct the vibration of the crystal vibrating piece 25, that is, the internal temperature of the element housing 30. , And the internal temperature of the resonator element housing 20 affected by the crystal resonator element 25 to be corrected, even if a difference occurs, it can be resolved more quickly. Therefore, the piezoelectric oscillator 10 has an effect of being able to exhibit more stable and more accurate vibration characteristics.
(Embodiment 3)

  Next, another embodiment of the piezoelectric oscillator will be described. FIG. 4 is a cross-sectional view illustrating the configuration of the piezoelectric oscillator according to the third embodiment. The difference between the piezoelectric oscillator 50 of the present embodiment and the piezoelectric oscillator 1 of the first embodiment or the piezoelectric oscillator 10 of the second embodiment is that the forms of the surfaces of the oscillation circuit element 4 and the heat conduction pad 37 are different. is there. Therefore, since the configuration other than the oscillation circuit element 4 and the heat conduction pad 37 is the same as that of the piezoelectric oscillator 1 or the piezoelectric oscillator 10, the same reference numerals are given and detailed description thereof is omitted.

  As shown in FIG. 4, the piezoelectric oscillator 50 includes the oscillation circuit element 4, the heat conductive resin 5, and the heat conductive pad 37 between the base body 24 of the resonator element housing 20 and the element substrate 33 from the element substrate 33 side. The heat generated by the oscillation circuit element 4 is transmitted to the first embedded pillar 6 side. Here, in the oscillation circuit element 4 according to the present embodiment, a plurality of groove portions 45 are formed on the outer surface to which the heat conductive resin 5 is applied, and the groove portions 45 extend from the edge portion of the outer surface to another edge. Each part extends linearly and in parallel. As a result, the surface area of the outer surface of the oscillation circuit element 4 is larger than when the groove portion 45 is not provided.

  Similarly, a plurality of groove portions 46 are formed on the heat conduction pad 37 on the holding surface side for holding the heat conductive resin 5 between the outer surface of the oscillation circuit element 4 and the groove portions 46 are formed in the oscillation circuit element 4. Following the groove 45 of the element 4, each extends linearly and in parallel. Thereby, the surface area of the sandwiching surface of the heat conductive pad 37 is larger than that in the case where there is no groove 46.

  Due to the formation of the groove portions 45 and 46, the contact area between the oscillation circuit element 4 and the heat conduction resin 5 and the contact area between the heat conduction resin 5 and the heat conduction pad 37 are both larger than the contact area before the groove formation. It has increased. That is, the heat generated by driving the oscillation circuit element 4 is quickly transferred to the heat conducting resin 5 through the groove 45, and the heat transferred to the heat conducting resin 5 is transferred to the heat conducting resin 5 through the groove 46. It is quickly transmitted from the conductive resin 5 to the heat conductive pad 37.

  The piezoelectric oscillator 50 provided with the groove portions 45 and 46 rapidly conducts heat from the oscillation circuit element 4 to the heat conduction pad 37 via the heat conduction resin 5, and is more stable and more accurate vibration characteristics. It has the effect that it is possible to exhibit.

  Further, the piezoelectric oscillators 1, 10, 50 described above are not limited to the forms exemplified in the above-described embodiments, and even in the form of the following modifications, the same as in the embodiments. Effects can be obtained.

  (Modification 1) The piezoelectric oscillator 1 according to the first embodiment has a configuration in which six first embedded pillars 6 (FIG. 1) having a cylindrical shape are formed on the base body 24 to improve heat conduction. It is not limited to this configuration. For example, the first embedded pillar 6 may be a pillar such as a rectangle or an ellipse, or may be a plurality of pillars other than six. Similarly, in the piezoelectric oscillator 10 according to the second embodiment, the first embedded pillar 6 of the base body 24 and the second embedded pillar 7 of the base body 23 may be rectangular or elliptical pillars, and other than six. It may be a plurality of pillars. Thus, flexible setting is possible in accordance with the shape and size of the oscillation circuit element 4 and the like.

  (Modification 2) Further, the first embedded pillar 6 of the piezoelectric oscillator 1 according to the first embodiment may be a single embedded body having one end having substantially the same shape as the outer surface of the oscillation circuit element 4. FIG. 5 is a cross-sectional view illustrating a modification of the piezoelectric oscillator according to the first embodiment. As an example shown in FIG. 5, the piezoelectric oscillator 60 includes a first embedded pillar that is disposed so as to penetrate the base body 24 and have one end sandwiching the heat conductive resin 5 between the outer surface of the oscillation circuit element 4. 65 is provided as the embedded body. The first embedded pillar 65 is tungsten (W) embedded in one rectangular hole formed through the base body 24, and the rectangular hole has substantially the same shape as the outer surface of the oscillation circuit element 4. It is. The first embedded column 65 has one end on the element housing 30 side of the base body 24 in contact with the heat conductive resin 5 and the other end in contact with the base body 23 of the vibrating piece housing 20. The configuration of the piezoelectric oscillator 60 other than the first embedded pillar 65 arranged in place of the first embedded pillar 6 is the same as that of the piezoelectric oscillator 1 of the first embodiment. In the piezoelectric oscillator 60 having such a configuration, since the first embedded pillar 65 has one end having substantially the same shape as the outer surface of the oscillation circuit element 4, the heat conduction through the first embedded pillar 65 is an embodiment. As compared with the case of the first embedded pillar 6 in FIG. 1, the process is performed more quickly than equivalent, and the difference between the internal temperature of the element housing 30 and the internal temperature of the resonator element housing 20 can be eliminated. In the piezoelectric oscillator 60, the shape of the first embedded column 65 is not limited to a rectangular shape, but may be a circular shape or the like. In addition, one end of the first embedded column 65 and the outside of the oscillation circuit element 4 may be used. A groove for expanding the contact area with the heat conductive resin 5 may be formed on either or both of the surfaces. More preferably, for the heat conduction, the base body 23 is desirably provided with an embedded column similar to the first embedded column 65 so as to be in contact with the first embedded column 65.

  (Modification 3) FIG. 6 is a sectional view showing a modification of the piezoelectric oscillator according to the second embodiment. As shown in FIG. 6, this piezoelectric oscillator 70 is provided with a substrate opening 75 in the region of the base body 24 where the first embedded pillar 6 (FIG. 3) is formed in the second embodiment. The opening 75 is a through hole larger than the shape of the outer surface of the oscillation circuit element 4. A portion of the oscillation circuit element 4 and the heat conductive resin 5 is inserted into the substrate opening 75, and the surface of the heat conductive resin 5 opposite to the outer surface of the oscillation circuit element 4 is a heat radiation pad of the resonator element housing 20. 38. The configuration of the piezoelectric oscillator 70 other than the substrate opening 75 provided in the base body 24 instead of the first embedded pillar 6 is the same as that of the piezoelectric oscillator 10 of the second embodiment. According to such a configuration, the heat generated in the oscillation circuit element 4 is directly transmitted to the heat radiating pad 38 of the resonator element housing 20 only through the heat conductive resin 5, and therefore, compared with the case of the second embodiment. Thus, the vibration is transmitted to the vibrating piece container 20 more quickly, and the difference between the internal temperature of the element container 30 and the internal temperature of the vibrating piece container 20 can be eliminated. In the piezoelectric oscillator 70, a groove for expanding the contact area with the heat conductive resin 5 is formed on one or both of the heat conductive resin 5 side of the heat radiation pad 38 and the outer surface of the oscillation circuit element 4. May be.

  (Modification 4) Tungsten (W) is used for the first embedded columns 6 and 65 and the second embedded column 7, but if it is a heat-resistant heat conductive material that can withstand the sintering temperature of the ceramic, tungsten Molybdenum (Mo) other than (W) may be used.

  (Modification 5) The heat conductive resin 5 of the heat conductive member is not limited to a resin containing silver (Ag) metal powder in an epoxy resin, but may be copper (Cu) or aluminum (Al) in a silicon resin or the like. It may contain fine powders such as. In addition, the heat conductive member is not limited to a paste-like resin, but is a metal such as solder, gold (Au) tin (Sn) alloy, gold (Au) germanium (Ge) alloy, polyamide, fluororesin, etc. This sheet may be a so-called heat conductive sheet containing alumina, carbon fiber, or the like. If the heat conductive member is a metal, a member having a high heat conductivity can be widely selected, and heat can be transferred from the oscillation circuit element 4 to the heat conductive pad 37 in the shortest time. If the heat conductive member is a heat conductive sheet, the heat conductive member can be cut out according to the shape of the oscillation circuit element 4 or the heat conductive pad 37 to be flexible and easy to handle.

(Modification 6) The piezoelectric vibrating piece is not limited to the one using a quartz crystal such as the quartz vibrating piece 25, but is a piezoelectric such as lithium niobate (LiNbO ₃ ) or zircon lead titanate (PZT) other than quartz. Or a semiconductor such as silicon. Further, the shape is not limited to a substantially rectangular parallelepiped thin plate shape such as the crystal vibrating piece 25, and may have a shape having a plurality of vibrating arms such as a tuning fork type.

  (Modification 7) The resin mold 9 of the covering member is not limited to the covering with the resin as long as it is possible to integrate the vibrating piece container 20 and the element container 30, and is an integrally fixed structure with a metal plate or the like It may be.

  (Modification 8) The grooves 45 and 46 in the third embodiment have a configuration in which each groove extends linearly and in parallel. There may be. In this way, the groove portions 45 and 46 that are optimal for heat conduction can be formed in a flexible manner corresponding to the shape of the oscillation circuit element 4 and the like.

  The piezoelectric oscillators 1, 10, 50, 60, and 70 eliminate the temperature difference between the crystal vibrating piece 25, which is an example of a piezoelectric vibrating piece, and the oscillation circuit element 4 that controls the vibration of the crystal vibrating piece 25. Since accurate temperature correction can be performed, the accuracy of vibration characteristics can be improved. Due to this feature, piezoelectric oscillators equipped with piezoelectric resonator elements are widely used as electronic devices such as digital mobile phones, personal computers, electronic watches, video recorders, and televisions as timing devices. Can contribute.

  DESCRIPTION OF SYMBOLS 1,10,50,60,70 ... Piezoelectric oscillator, 2 ... Crystal oscillator, 3 ... Circuit element part, 4 ... Oscillation circuit element, 5 ... Thermal conductive resin as a heat conductive member, 6 ... 1st embedding 1st embedded column as member, 7 ... 2nd embedded column as 2nd embedded member, 20 ... Vibrating piece container as 1st container, 21 ... Lid, 22 ... Frame wall, 23 ... Reference body, 24 ... Base body, 25 ... Quartz vibrating piece as piezoelectric vibrating piece, 29 ... Heat radiation pad as second heat radiating member, 32 ... Conductive spacer, 33 ... Element substrate, 37 ... Heat conduction as heat transfer member Pads 38... Heat radiation pads as first heat radiation members 45, 46.

Claims (9)

An oscillation circuit element;
A thermally conductive member disposed on the surface of the oscillation circuit element;
A resonator element containing a piezoelectric resonator element excited by the oscillation circuit element;
Are arranged so as to overlap in plan view,
One end is in contact with the thermally conductive member, and includes a first embedded member embedded in the vibrating piece container from the one end toward the piezoelectric vibrating piece.
The piezoelectric oscillator according to claim 1, wherein the first embedded member has higher thermal conductivity than surrounding members. An oscillation circuit element;
A thermally conductive member disposed on the surface of the oscillation circuit element;
A resonator element containing a piezoelectric resonator element excited by the oscillation circuit element;
Are arranged so as to overlap in plan view,
The vibration piece container has a heat transfer member formed on a surface thereof, and the heat transfer member is connected to the heat conductive member.
One end is in contact with the heat transfer member, and includes a first embedded member embedded in the vibration piece container toward the direction from the one end toward the piezoelectric vibration piece,
The piezoelectric oscillator according to claim 1, wherein the first embedded member has higher thermal conductivity than surrounding members. The piezoelectric oscillator according to claim 1 or 2,
The piezoelectric resonator includes a first heat radiating member in contact with the other end of the first embedded member. The piezoelectric oscillator according to claim 3, wherein
The vibrating piece container is
The first embedded member is embedded in a position overlapping with the first embedded member in plan view, has a higher thermal conductivity than the surrounding members, has one end in contact with the first heat radiating member, and the piezoelectric vibrating piece from the one end. A second embedded member embedded in the resonator element housing in the approaching direction;
A second heat dissipation member in contact with the other end of the second embedded member;
A piezoelectric oscillator comprising: The piezoelectric oscillator according to any one of claims 1 to 4,
The piezoelectric oscillator, wherein the heat conductive member is a resin containing metal powder. The piezoelectric oscillator according to any one of claims 1 to 4,
The piezoelectric oscillator, wherein the heat conductive member is made of metal. The piezoelectric oscillator according to any one of claims 1 to 4,
The piezoelectric oscillator, wherein the thermally conductive member is a thermally conductive sheet. The piezoelectric oscillator according to any one of claims 1 to 7,
The piezoelectric oscillator, wherein the resonator element container, the oscillation circuit element, and the thermal conductive member are covered with a covering member. The piezoelectric oscillator according to any one of claims 1 to 8,
At least one of the oscillation circuit element and the heat transfer member has a groove on a surface in contact with the heat conductive member.

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