Oscillator

Abstract

To provide an oscillator that prevents external heat from being easily transferred to a vibration element and has stable frequency characteristics.SOLUTION: An oscillator has: an outside package that has an accommodation space; an inside package that is accommodated in the accommodation space and is fixed to the outside package with a heat insulating member therebetween; a vibration element that is accommodated in the inside package; a heater element that is accommodated in the accommodation space and fixed to the inside package; an oscillation circuit that oscillates the vibration element; a control circuit that is accommodated in the accommodation space and controls the drive of the heater element; and conductive wires that electrically connect the outside package and the inside package with each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an oscillator. [Background technology]

[0002] Patent Document 1 describes a crystal oscillator in which a package body mounting a heater IC and a vibration element is fixed inside an outer package made up of a base substrate and a cover case. In this crystal oscillator, the package body is fixed to the base substrate via a number of spacers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-130861 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the crystal oscillator of Patent Document 1, metal wiring and metal-plated through holes are formed in the spacer to electrically connect the package body and the base substrate. Therefore, the structure is such that heat is easily transferred between the base substrate and the package body via the metal part formed in the spacer. Therefore, there is a problem that heat from the outside is easily transferred to the vibration element mounted on the package body via the spacer, and the characteristics of the oscillation signal are easily affected by the ambient temperature. In addition, there is a problem that the heat generated by the heater IC escapes from the package body to the outside, making it difficult to efficiently heat the vibration element. [Means for solving the problem]

[0005] The oscillator of the present invention comprises an outer package having an accommodating space; an inner package accommodated in the accommodation space and fixed to the outer package via a heat insulating member; A vibration element housed in the inner package; a heat generating element accommodated in the accommodation space and fixed to the inner package; An oscillation circuit that oscillates the vibration element; A control circuit that is accommodated in the accommodation space and controls the driving of the heating element; and a conductive wire electrically connecting the outer package and the inner package. [Brief description of the drawings]

[0006] [Figure 1] 1 is a cross-sectional view showing an oscillator according to a first embodiment. [Diagram 2] 2 is a plan view showing the inside of an internal package of the oscillator of FIG. 1. [Diagram 3] FIG. 4 is a cross-sectional view showing an oscillator according to a second embodiment. [Figure 4] FIG. 11 is a cross-sectional view showing an oscillator according to a third embodiment. [Diagram 5] FIG. 11 is a cross-sectional view showing an oscillator according to a fourth embodiment. [Figure 6] FIG. 13 is a cross-sectional view showing an oscillator according to a fifth embodiment. [Figure 7] FIG. 13 is a cross-sectional view showing an oscillator according to a sixth embodiment. [Figure 8] FIG. 13 is a cross-sectional view showing an oscillator according to a seventh embodiment. [Figure 9] FIG. 13 is a cross-sectional view showing an oscillator according to an eighth embodiment. [Figure 10] FIG. 13 is a cross-sectional view showing an oscillator according to a ninth embodiment. [Figure 11] FIG. 23 is a cross-sectional view showing an oscillator according to a tenth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of an oscillator according to the present invention will be described in detail with reference to the accompanying drawings.

[0008] For ease of explanation, each figure shows an X-axis, a Y-axis, and a Z-axis that are perpendicular to each other. The direction along the X-axis is also called the X-axis direction, the direction along the Y-axis is also called the Y-axis direction, and the direction along the Z-axis is also called the Z-axis direction. The arrow side in the Z-axis direction is also called "upper" and the opposite side is also called "lower." A planar view from the Z-axis direction is also simply called a "planar view."

[0009] First Embodiment Fig. 1 is a cross-sectional view showing an oscillator according to a first embodiment of the present invention, Fig. 2 is a plan view showing the inside of an internal package of the oscillator shown in Fig. 1.

[0010] The oscillator 1 shown in Fig. 1 is an oven-controlled crystal oscillator (OCXO). Such oscillator 1 has an outer package 2, an inner package 3 and a circuit element 6 housed in the outer package 2, a vibration element 4 and a heat generating element 5 housed in the inner package 3, a heat insulating member 7 interposed between the outer package 2 and the inner package 3, and a bonding wire BW3 which is a conductive wire electrically connecting the outer package 2 and the inner package 3. Such oscillator 1 heats the vibration element 4 with the heat of the heat generating element 5 and maintains the vibration element 4 at a desired temperature, thereby suppressing frequency fluctuations of the oscillation signal and realizing excellent oscillation characteristics.

[0011] The outer package 2 has a first base substrate 21. The first base substrate 21 has an upper surface 21a and a lower surface 21b which are opposite surfaces. The first base substrate 21 also has a bottomed recess 211 which is a first recess opening on the upper surface 21a. The recess 211 is composed of a plurality of recesses, and has a recess 211a which opens on the upper surface 21a, a recess 211b which opens on the bottom surface of the recess 211a and has a smaller opening than the recess 211a, a recess 211c which opens on the bottom surface of the recess 211b and has a smaller opening than the recess 211b, and a recess 211d which opens on the bottom surface of the recess 211c and has a smaller opening than the recess 211c. The circuit element 6 is fixed on the bottom surface of the recess 211b, and the inner package 3 is fixed on the bottom surface of the recess 211d via a heat insulating member 7.

[0012] Further, a plurality of internal terminals 241 are arranged on the bottom surface of the recess 211a, a plurality of internal terminals 242 are arranged on the bottom surface of the recess 211c, and a plurality of mounting terminals 243 are arranged on the lower surface 21b. These terminals 241, 242, and 243 are electrically connected via internal wiring (not shown) formed in the first base substrate 21. As described later, each internal terminal 242 is electrically connected to an external terminal 342 of the inner package 3 via a bonding wire BW3, and each internal terminal 241 is electrically connected to a circuit element 6 via a bonding wire BW4. The oscillator 1 is electrically connected to an external device (not shown) via the plurality of mounting terminals 243.

[0013] The outer package 2 also has a first lid 22. The first lid 22 is bonded to the upper surface 21a of the first base substrate 21 via a bonding member 23, and closes the opening of the recess 211. By closing the opening of the recess 211 with the first lid 22 in this manner, an airtight first housing space S1 is formed inside the outer package 2. The inner package 3 and the circuit element 6 are housed in the first housing space S1.

[0014] The first housing space S1 is in a reduced pressure state, preferably in a state closer to a vacuum. This allows excellent thermal insulation, and makes it difficult for heat from outside the oscillator 1 to be transmitted to the inner package 3. Therefore, the vibration element 4 is less susceptible to the effects of external heat, and the vibration element 4 is easily kept at a desired temperature by the heat of the heating element 5. However, the atmosphere of the first housing space S1 is not particularly limited, and may be, for example, an atmosphere filled with an inert gas such as nitrogen, argon, or helium, and may be in an atmospheric pressure state or a pressurized state instead of a reduced pressure state. In addition, as in an embodiment described later, the first housing space S1 may be filled with a thermal insulation member 7.

[0015] Although not particularly limited, the first base substrate 21 can be made of ceramics such as alumina, and the first lid 22 can be made of a metal material such as Kovar.

[0016] The inner package 3 has a second base substrate 31. The second base substrate 31 has an upper surface 31a and a lower surface 31b which are opposite surfaces. The second base substrate 31 also has a bottomed recess 311 which is a second recess that opens to the lower surface 31b. The recess 311 is composed of a plurality of recesses, and has a recess 311a which opens to the lower surface 31b, and a recess 311b which opens to the bottom surface of the recess 311a and has a smaller opening than the recess 311a. The heat generating element 5 is fixed to the bottom surface of the recess 311b, and the vibration element 4 is fixed to the lower surface of the heat generating element 5.

[0017] Further, a plurality of internal terminals 341 are arranged on the bottom surface of the recess 311a, and a plurality of external terminals 342 are arranged on the top surface 31a. These terminals 341, 342 are electrically connected via internal wiring (not shown) formed in the second base substrate 31.

[0018] Further, each of the multiple external terminals 342 is electrically connected to the internal terminals 242 of the first base substrate 21 via a bonding wire BW3. By providing the external terminals 342 facing the outside of the inner package 3 in this manner, electrical connection between the inner package 3 and the outer package 2 is facilitated.

[0019] Here, the conductive member electrically connecting the inner package 3 and the outer package 2 has a high thermal conductivity and therefore easily functions as a heat transfer path between the inner package 3 and the outer package 2. Therefore, by using a long and thin linear bonding wire BW3 as the conductive member, the transfer of heat between the inner package 3 and the outer package 2 can be effectively suppressed. Therefore, the heat outside the oscillator 1 is less likely to be transferred to the inner package 3. Therefore, the vibration element 4 is less likely to be affected by external heat, and the vibration element 4 can be easily kept at a desired temperature by the heat of the heat generating element 5. On the other hand, the heat of the heat generating element 5 is less likely to escape to the outer package 2 via the bonding wire BW3, and the heat of the heat generating element 5 can be efficiently transferred to the vibration element 4. Therefore, the heat generating element 5 can be efficiently driven and the temperature of the vibration element 4 can be more stabilized.

[0020] The inner package 3 also has a second lid 32. The second lid 32 is joined to the lower surface 31b of the second base substrate 31 via a joining member 33, and closes the opening of the recess 311. By closing the opening of the recess 311 with the second lid 32 in this manner, an airtight second housing space S2 is formed inside the inner package 3. The vibration element 4 and the heat generating element 5 are housed in this second housing space S2.

[0021] The second housing space S2 is in a reduced pressure state, preferably a state closer to a vacuum. This reduces the CI (crystal impedance) value of the vibration element 4, improving the oscillation characteristics. However, the atmosphere of the second housing space S2 is not particularly limited, and may be, for example, atmospheric pressure or pressurized.

[0022] Although not particularly limited, the second base substrate 31 can be made of ceramics such as alumina, and the second lid 32 can be made of a metal material such as Kovar.

[0023] Such an inner package 3 is disposed with the second lid 32 facing the bottom side of the recess 211, and the second lid 32 is fixed to the bottom surface of the recess 211d via the heat insulating member 7. In this way, by interposing the heat insulating member 7 between the inner package 3 and the outer package 2, external heat is less likely to be transmitted to the inner package 3 via the outer package 2. Therefore, the vibration element 4 is less likely to be affected by external heat, and the vibration element 4 can be easily kept at a desired temperature by the heat of the heat generating element 5. Conversely, the heat of the heat generating element 5 is less likely to escape to the outer package 2 via the inner package 3, and the heat of the heat generating element 5 can be efficiently transmitted to the vibration element 4. Therefore, the heat generating element 5 can be efficiently driven, and the temperature of the vibration element 4 can be more stabilized.

[0024] In particular, by fixing the second lid 32, which is not fixed to the vibration element 4, among the members constituting the inner package 3, to the outer package 2, it is possible to lengthen the heat transfer path from the heat insulating member 7 to the vibration element 4. Therefore, even if external heat is transferred to the inner package 3 via the heat insulating member 7, the heat is less likely to be transferred to the vibration element 4. Therefore, the vibration element 4 is further less susceptible to the effects of external heat, and it becomes easier to keep the vibration element 4 at a desired temperature by the heat of the heating element 5. However, this is not limited thereto, and the second base substrate 31 may be fixed to the first base substrate 21 via the heat insulating member 7.

[0025] The heat insulating member 7 is made of a material having a lower thermal conductivity than the second lid 32. Such a heat insulating member 7 is not particularly limited, and for example, various resin materials, particularly porous resin materials such as porous polyimide, can be used. In addition to resin materials, for example, various glass materials and inorganic porous materials such as silica aerogel can be used. The thermal conductivity of the heat insulating member 7 is not particularly limited, but is preferably 1.0 W / m·K or less. This results in a heat insulating member 7 with a sufficiently low thermal conductivity.

[0026] Moreover, the heat insulating member 7 has a plurality of pillar-shaped parts 71 arranged at a distance from each other, and these pillar-shaped parts 71 are arranged in an island shape spreading over the entire area of ​​the second lid 32. This allows the inner package 3 to be fixed to the outer package 2 in a stable position. Also, the contact area between the heat insulating member 7 and the outer package 2 can be reduced, making it difficult for external heat to be transmitted to the inner package 3 via the heat insulating member 7. However, this is not limited thereto, and the heat insulating member 7 may be arranged in a solid manner spreading over the entire lower surface of the second lid 32. This increases the bonding area between the inner package 3 and the outer package 2, increasing the adhesive strength. As a result, the mechanical strength of the oscillator 1 is increased.

[0027] If the heat insulating member 7 has an adhesive force, the second lid 32 and the first base substrate 21 may be bonded to each other via the heat insulating member 7. On the other hand, if the heat insulating member 7 does not have an adhesive force, the heat insulating member 7 and the second lid 32, and the heat insulating member 7 and the first base substrate 21 may be bonded to each other via a bonding member such as an adhesive. The heat insulating member 7 may also contain a gap material such as silica gel having a sufficiently low thermal conductivity. This allows the thickness of the heat insulating member 7 to be controlled, and the heat insulating effect to be more reliably exhibited.

[0028] The vibration element 4 is an SC-cut quartz crystal vibration element. This results in a vibration element 4 with excellent frequency stability. As shown in FIG. 2, the vibration element 4 has a disk-shaped quartz crystal substrate 41 cut out by the above-mentioned SC cut, and an electrode provided on the surface of the quartz crystal substrate 41. The electrode also has a first excitation electrode 421 arranged in the center of the lower surface of the quartz crystal substrate 41, and a second excitation electrode 431 arranged in the center of the upper surface of the quartz crystal substrate 41 so as to face the first excitation electrode 421. The electrode also has a first connection electrode 422 arranged on the outer edge of the lower surface, a first extraction electrode 423 connecting the first excitation electrode 421 and the first connection electrode 422, a second connection electrode 432 arranged on the outer edge of the upper surface, and a second extraction electrode 433 connecting the second excitation electrode 431 and the second connection electrode 432.

[0029] However, the configuration of the vibration element 4 is not limited to this. For example, the planar shape of the quartz substrate 41 is not limited to a circle, and may be, for example, a rectangle. In addition, the vibration element 4 may be an AT-cut quartz crystal vibration element, a BT-cut quartz crystal vibration element, a tuning fork-type quartz crystal vibration element, a surface acoustic wave resonator, other piezoelectric vibration elements, a MEMS (Micro Electro Mechanical Systems) resonator element, or the like.

[0030] Such a vibration element 4 is disposed with its upper surface facing the heating element 5, and its outer edge is fixed via a conductive bonding member B1 to the lower surface of the heating element 5. The bonding member B1 is not particularly limited as long as it is conductive, and for example, a metal bump, solder, metal paste, conductive resin adhesive, etc. can be used.

[0031] The heating element 5 is housed in the inner package 3 together with the vibration element 4. This allows the heating element 5 to be disposed in the vicinity of the vibration element 4, and allows the heat of the heating element 5 to be efficiently transferred to the vibration element 4.

[0032] Such a heating element 5 has a heating circuit 51 having a function as a heating part for heating the vibration element 4, and a temperature sensor 52. The lower surface of the heating element 5 serves as a fixing surface for fixing the vibration element 4, and as shown in Fig. 2, a plurality of electrode pads 53 are provided on the lower surface. Each electrode pad 53 is electrically connected to an internal terminal 341 via a bonding wire BW1.

[0033] The electrode pad 53a included in the plurality of electrode pads 53 is not electrically connected to the heat generating circuit 51, and functions as a relay electrode that electrically connects the internal terminal 341 and the vibration element 4. The electrode pad 53a is electrically connected to the second connection electrode 432 of the vibration element 4 via a conductive bonding member B1. On the other hand, the first connection electrode 422 of the vibration element 4 is electrically connected to the internal terminal 341 via a bonding wire BW2 without going through the electrode pad 53. However, the method of electrically connecting the vibration element 4 and the internal terminal 341 is not particularly limited.

[0034] 1, the circuit element 6 is accommodated in the first accommodation space S1 and fixed to the bottom surface of the recess 211b. The circuit element 6 is also electrically connected to the internal terminal 241 of the first base substrate 21 via a bonding wire BW4. This electrically connects the circuit element 6 to the vibration element 4 and the heating element 5.

[0035] The circuit element 6 has a temperature sensor 61, an oscillation circuit 62, and a temperature control circuit 64. The oscillation circuit 62 has a function of oscillating the vibration element 4 and generating a temperature-compensated oscillation signal based on the temperature detected by the temperature sensor 61. That is, the oscillation circuit 62 has an oscillation circuit section that is electrically connected to the vibration element 4, amplifies the output signal of the vibration element 4, and causes the vibration element 4 to oscillate by feeding back the amplified signal to the vibration element 4, and a temperature compensation circuit section that performs temperature compensation based on the temperature information output from the temperature sensor 61 so that the frequency fluctuation of the oscillation signal is smaller than the frequency-temperature characteristics of the vibration element 4 itself.

[0036] The temperature control circuit 64 is a control circuit that controls the driving of the heating element 5, and is a circuit for controlling the amount of current flowing through the resistor of the heating circuit 51 based on the output signal of the temperature sensor 52, and for maintaining the vibration element 4 at a constant temperature. For example, the temperature control circuit 64 controls so that a desired current flows through the resistor of the heating circuit 51 when the current temperature determined from the output signal of the temperature sensor 52 is lower than a set reference temperature, and so that no current flows through the resistor of the heating circuit 51 when the current temperature is higher than the reference temperature. Also, for example, the temperature control circuit 64 may control so that the amount of current flowing through the resistor of the heating circuit 51 is increased or decreased depending on the difference between the current temperature and the reference temperature.

[0037] Such a circuit element 6 is disposed at a distance from the inner package 3 in the Z-axis direction. That is, a gap G is formed between the circuit element 6 and the inner package 3, and they are not in contact with each other. This makes it difficult for heat from the circuit element 6 to be transmitted to the inner package 3, for example, compared to when they are in contact with each other. Therefore, the vibration element 4 is less susceptible to the heat of the circuit element 6, and it is easier to keep the vibration element 4 at a desired temperature by the heat of the heating element 5. In particular, as described above, the inside of the first housing space S1 is in a reduced pressure state, so that the transfer of heat due to gas convection in the gap G is suppressed, and the above-mentioned effect becomes more prominent.

[0038] The width of the gap G, i.e., the distance D between the circuit element 6 and the inner package 3, is not particularly limited, but is preferably set to, for example, 0.1 mm or more and 1.0 mm or less. This makes it possible to fully achieve the above-mentioned effects while avoiding excessive increase in size of the oscillator 1.

[0039] Moreover, the circuit element 6 is located above the inner package 3 and between the inner package 3 and the first lid 22. As described above, since the lower surface of the inner package 3 is fixed to the bottom surface of the recess 211d, it can also be said that the circuit element 6 is located on the opposite side to the side of the inner package 3 joined to the first base substrate 21. With this arrangement, it is possible to sufficiently lengthen the heat transfer path between the joint between the circuit element 6 and the first base substrate 21 and the joint between the inner package 3 and the first base substrate 21. Therefore, the vibration element 4 is less susceptible to the heat of the circuit element 6, and it is easier to keep the vibration element 4 at a desired temperature by the heat of the heating element 5.

[0040] Moreover, the circuit element 6 is disposed so as to overlap, in a plan view, at least a portion of the inner package 3. This prevents the oscillator 1 from expanding in the X-axis and Y-axis directions, allowing the oscillator 1 to be made more compact.

[0041] The above describes the oscillator 1. As described above, the oscillator 1 includes the outer package 2 having the first housing space S1 as a housing space, the inner package 3 housed in the first housing space S1 and fixed to the outer package 2 via a heat insulating member 7, the vibration element 4 housed in the inner package 3, the heat generating element 5 housed in the first housing space S1 and fixed to the inner package 3, an oscillation circuit 62 that causes the vibration element 4 to oscillate, a temperature control circuit 64 that is housed in the first housing space S1 and is a control circuit that controls the driving of the heat generating element 5, and a bonding wire BW3 that is a conductive wire that electrically connects the outer package 2 and the inner package 3.

[0042] In this way, by interposing the heat insulating member 7 between the inner package 3 and the outer package 2, external heat is less likely to be transmitted to the inner package 3 through the outer package 2. Therefore, the vibration element 4 is less likely to be affected by external heat, and the heat of the heat generating element 5 makes it easier to keep the vibration element 4 at a desired temperature. Conversely, the heat of the heat generating element 5 is less likely to escape to the outer package 2 through the inner package 3, and the heat of the heat generating element 5 can be efficiently transmitted to the vibration element 4. Therefore, the heat generating element 5 can be efficiently driven, and the temperature of the vibration element 4 can be more stabilized. In addition, the conductive member electrically connecting the inner package 3 and the outer package 2 has a high thermal conductivity, and therefore easily functions as a heat transfer path between the inner package 3 and the outer package 2. In this regard, since the long and thin linear bonding wire BW3 is used as the conductive member, the transfer of heat between the inner package 3 and the outer package 2 can be effectively suppressed. Therefore, the heat outside the oscillator 1 is less likely to be transmitted to the inner package 3. Therefore, also in this respect, the vibration element 4 is less susceptible to the effects of external heat, and the vibration element 4 can be easily maintained at a desired temperature by the heat of the heating element 5. Therefore, the oscillator 1 has high frequency characteristics and can be driven with low power consumption.

[0043] As described above, the outer package 2 has the first base substrate 21 having the recess 211, which is a first recess for accommodating the inner package 3, and the first lid 22 joined to the first base substrate 21 so as to close the opening of the recess 211, and a first accommodating space S1 is formed by the recess 211 and the first lid 22. The inner package 3 is fixed to the first base substrate 21 via the heat insulating member 7. With this configuration, the outer package 2 has a simple configuration.

[0044] As described above, the inner package 3 has the second base substrate 31 having the recess 311, which is the second recess for accommodating the vibration element 4, and the second lid 32 bonded to the second base substrate 31 so as to close the opening of the recess 311, and the vibration element 4 is fixed to the second base substrate 31. The second lid 32 is fixed to the outer package 2 via the heat insulating member 7. In this way, by fixing the second lid 32 to which the vibration element 4 is not fixed to the outer package 2, the heat transfer path from the heat insulating member 7 to the vibration element 4 can be lengthened. Therefore, the heat transferred from the outer package 2 to the inner package 3 via the heat insulating member 7 is less likely to be transferred by the vibration element 4. Therefore, the vibration element 4 is less susceptible to the influence of external heat, and the heat of the heating element 5 makes it easier to keep the vibration element 4 at a desired temperature.

[0045] As described above, the inner package 3 has the external terminals 342 arranged on the upper surface 31a, which is the surface opposite to the lower surface 31b, which is the surface to which the second lid 32 of the second base substrate 31 is bonded. The external terminals 342 and the outer package 2 are electrically connected via bonding wires BW3. This facilitates electrical connection between the inner package 3 and the outer package 2.

[0046] As described above, the oscillator 1 also includes the temperature sensor 52. This makes it easy to keep the vibration element 4 at a desired temperature.

[0047] As described above, the first housing space S1 is in a reduced pressure state. This allows excellent thermal insulation, and makes it difficult for heat from outside the oscillator 1 to be transmitted to the inner package 3. Therefore, the vibration element 4 is less susceptible to the effects of external heat, and the heat from the heating element 5 makes it easier to keep the vibration element 4 at a desired temperature.

[0048] As described above, the heating element 5 is housed in the inner package 3. This allows the heating element 5 to be disposed in the vicinity of the vibration element 4, and allows the heat of the heating element 5 to be efficiently transferred to the vibration element 4. This allows the heating element 5 to be driven efficiently.

[0049] As described above, the oscillator 1 has a circuit element 6 including a temperature control circuit 64. The circuit element 6 and the inner package 3 are spaced apart from each other and arranged to overlap each other in a plan view. This prevents the oscillator 1 from expanding in the X-axis and Y-axis directions, making it possible to miniaturize the oscillator 1.

[0050] The configuration of the oscillator 1 is not particularly limited, and for example, the first housing space S1 may house a circuit component other than the circuit element 6. This circuit component is not particularly limited, but for example, when the circuit element 6 includes a PLL circuit (phase-locked loop), the oscillator can be used for the PLL circuit.

[0051] <Second embodiment> FIG. 3 is a cross-sectional view showing an oscillator according to the second embodiment.

[0052] This embodiment is similar to the first embodiment described above, except that a heat insulating member 8 is also interposed between the heat generating element 5 and the inner package 3. In the following description, the present embodiment will be described focusing on the differences from the previous embodiment, and the description of the similarities will be omitted. In addition, in FIG. 3, the same reference numerals are used for the same configurations as the previous embodiment.

[0053] As shown in FIG. 3, in the oscillator 1 of this embodiment, the heat generating element 5 is fixed to the bottom surface of the recess 311b via the heat insulating member 8. This makes it difficult for the heat of the heat generating element 5 to escape to the second base substrate 31, and the heat of the heat generating element 5 can be efficiently transferred to the vibration element 4. Therefore, the heat generating element 5 can be efficiently driven, and the temperature of the vibration element 4 can be more stabilized. The heat insulating member 8 is made of a material having a lower thermal conductivity than the second base substrate 31. Such a heat insulating member 8 is not particularly limited, and can be, for example, the same material as the heat insulating member 7 described above.

[0054] The second embodiment as described above can also achieve the same effects as the first embodiment.

[0055] <Third embodiment> FIG. 4 is a cross-sectional view showing an oscillator according to the third embodiment.

[0056] This embodiment is similar to the second embodiment described above, except for the size of the heating element 5. In the following description, the present embodiment will be described with a focus on the differences from the previous embodiment, and the description of the similarities will be omitted. In addition, in FIG. 4, the same reference numerals are used for the same configurations as the previous embodiment.

[0057] 4, in the oscillator 1 of this embodiment, the heating element 5 is configured to be larger than the vibration element 4 in a plan view, and is arranged so as to overlap the entire area of ​​the vibration element 4. This allows more heat to be generated from the heating element 5, and the heat can be more efficiently and evenly transferred to the entire area of ​​the vibration element 4. Therefore, the temperature of the vibration element 4 can be more stabilized.

[0058] The third embodiment as described above can also achieve the same effects as the first embodiment.

[0059] <Fourth embodiment> FIG. 5 is a cross-sectional view showing an oscillator according to the fourth embodiment.

[0060] This embodiment is similar to the first embodiment described above, except that a heat insulating member 9 is interposed between the circuit element 6 and the outer package 2. In the following description, the present embodiment will be described focusing on the differences from the previous embodiment, and a description of the similarities will be omitted. In addition, in FIG. 5, the same reference numerals are used for the same configurations as the previous embodiment.

[0061] As shown in FIG. 5, in the oscillator 1 of this embodiment, the circuit element 6 is fixed to the bottom surface of the recess 211b via the heat insulating member 9. This makes it difficult for the heat of the circuit element 6 to be transmitted to the first base substrate 21. Therefore, the vibration element 4 is less susceptible to the heat of the circuit element 6, and it becomes easier to keep the vibration element 4 at a desired temperature by the heat of the heating element 5. The heat insulating member 9 is made of a material having a lower thermal conductivity than the first base substrate 21. Such a heat insulating member 9 is not particularly limited, and can be made of the same material as the heat insulating member 7 described above, for example.

[0062] The fourth embodiment as described above can also achieve the same effects as the first embodiment.

[0063] <Fifth embodiment> FIG. 6 is a cross-sectional view showing an oscillator according to a fifth embodiment.

[0064] This embodiment is similar to the first embodiment described above, except that the heat generating element 5 is located outside the inner package 3, and the oscillator circuit 62 and the temperature sensor 61 of the circuit element 6 are housed in the inner package 3. In the following description, the present embodiment will be described focusing on the differences from the previous embodiment, and a description of the similarities will be omitted. Also, in FIG. 6, the same reference numerals are used for the same configurations as the previous embodiment.

[0065] As shown in FIG. 6, the heating element 5 is accommodated in the first accommodation space S1, but is located outside the inner package 3. The heating element 5 is fixed to the upper surface 31a of the second base substrate 31. Therefore, heat from the heating element 5 is transferred to the vibration element 4 via the second base substrate 31. The heating element 5 is electrically connected to the internal terminal 242 via the bonding wire BW7. In this way, by disposing the heating element 5 on the outer peripheral surface of the inner package 3, the number of components accommodated in the inner package 3 can be reduced. Therefore, the inner package 3 can be made smaller, and contamination and fluctuation of the second accommodation space S2 due to outgassing, etc. can be suppressed.

[0066] In the oscillator 1 of this embodiment, the circuit element 6 is divided into a first circuit element 6A including a temperature sensor 61 and an oscillation circuit 62, and a second circuit element 6B including a temperature control circuit 64. The second circuit element 6B is fixed to the bottom surface of the recess 211b. Meanwhile, the first circuit element 6A is housed in the inner package 3 together with the vibration element 4. By housing the first circuit element 6A in the inner package 3 in this way, the length of the wiring connecting the oscillation circuit 62 and the vibration element 4 can be shortened, and noise is less likely to be mixed in from the wiring, making it possible to generate an oscillation signal with high accuracy. In addition, since the temperature sensor 61 can be disposed in the vicinity of the vibration element 4, the temperature of the vibration element 4 can be detected by the temperature sensor 61 with higher accuracy.

[0067] As described above, in the oscillator 1 of this embodiment, the oscillation circuit 62 is housed in the inner package 3. This allows the length of the wiring connecting the oscillation circuit 62 and the vibration element 4 to be shortened, making it difficult for noise to be mixed in from the wiring, and allowing for the generation of an oscillation signal with high accuracy.

[0068] As described above, the heating element 5 is disposed on the upper surface 31a, which is the surface opposite to the lower surface 31b, which is the surface to which the second lid 32 of the second base substrate 31 is bonded. In this way, by disposing the heating element 5 on the outer peripheral surface of the inner package 3, the number of parts housed in the inner package 3 can be reduced. Therefore, the inner package 3 can be made smaller, and contamination and fluctuation of the second housing space S2 due to outgassing, etc. can be suppressed. In particular, by disposing the heating element 5 on the upper surface 31a, the heat transfer path to the vibration element 4 can be sufficiently shortened, and the heat of the heating element 5 can be efficiently transferred to the vibration element 4.

[0069] The fifth embodiment as described above can also achieve the same effects as the first embodiment.

[0070] Sixth Embodiment FIG. 7 is a cross-sectional view showing an oscillator according to the sixth embodiment.

[0071] This embodiment is similar to the above-described fifth embodiment except that the first circuit element 6A is located outside the inner package 3. In the following description, the present embodiment will be described focusing on the differences from the above-described embodiment, and the description of the similarities will be omitted. In addition, in FIG. 7, the same reference numerals are used for the same configurations as the above-described embodiment.

[0072] As shown in FIG. 7, in the oscillator 1 of this embodiment, the first circuit element 6A including the oscillation circuit 62 and the temperature sensor 61 is located outside the inner package 3 and is accommodated in the first accommodation space S1. The second circuit element 6B is fixed to the upper surface 31a of the second base substrate 31 together with the heat generating element 5. The first circuit element 6A is electrically connected to the vibration element 4 and the external terminal 342 via internal wiring (not shown) formed in the second base substrate 31. In this way, by arranging the first circuit element 6A outside the inner package 3, the number of components accommodated in the inner package 3 can be reduced. Therefore, the inner package 3 can be made smaller, and contamination and fluctuation of the second accommodation space S2 due to outgassing, etc. can be suppressed.

[0073] The sixth embodiment as described above can also achieve the same effects as the first embodiment.

[0074] Seventh embodiment FIG. 8 is a cross-sectional view showing an oscillator according to the seventh embodiment.

[0075] This embodiment is similar to the above-described fifth embodiment except for the arrangement of the heating element 5. In the following description, the present embodiment will be described focusing on the differences from the above-described embodiment, and the description of the similarities will be omitted. In addition, in FIG. 8, the same reference numerals are used for the same configurations as the above-described embodiment.

[0076] As shown in Fig. 8, in the oscillator 1 of this embodiment, the heating element 5 is disposed between the inner package 3 and the heat insulating member 7. More specifically, the heating element 5 is disposed between the second lid 32 and the heat insulating member 7. As a result, heat transferred from the outside to the inner package 3 via the heat insulating member 7 is absorbed by the heating element 5 and used as part of the heat of the heating element 5. Therefore, it is possible to suppress temperature changes in the vibration element 4 caused by heat other than that from the heating element 5, and the temperature of the vibration element 4 becomes more stable.

[0077] The seventh embodiment as described above can also achieve the same effects as the first embodiment.

[0078] Eighth embodiment FIG. 9 is a cross-sectional view showing an oscillator according to the eighth embodiment.

[0079] This embodiment is similar to the first embodiment described above, except for the arrangement of the heat insulating member 7. In the following description, the present embodiment will be described focusing on the differences from the previous embodiment, and the description of the similarities will be omitted. In addition, in FIG. 9, the same reference numerals are used for the same configurations as the previous embodiment.

[0080] 9, in the oscillator 1 of this embodiment, the heat insulating member 7 fills the first housing space S1. That is, the heat insulating member 7 is disposed in the first housing space S1 with substantially no gaps. The inner package 3 is covered all around with the heat insulating member 7. This allows the inner package 3 to be more firmly fixed to the outer package 2, and the mechanical strength of the oscillator 1 is increased.

[0081] The eighth embodiment as described above can also achieve the same effects as the first embodiment.

[0082] <Ninth embodiment> FIG. 10 is a cross-sectional view showing an oscillator according to the ninth embodiment.

[0083] This embodiment is similar to the first embodiment described above, except for the arrangement of the circuit elements 6. In the following description, the present embodiment will be described focusing on the differences from the previous embodiment, and the description of the similarities will be omitted. In addition, in FIG. 10, the same reference numerals are used for the same configurations as the previous embodiment.

[0084] 10, in the oscillator 1 of this embodiment, the recess 211 has a recess 211a that opens to the upper surface 21a, and a recess 211b that opens to the bottom surface of the recess 211a and has a smaller opening than the recess 211a. The circuit element 6 is fixed to the bottom surface of the recess 211b, and the inner package 3 is fixed to the upper surface of the circuit element 6 via the heat insulating member 7. With this configuration, for example, it is possible to reduce the height of the oscillator 1 compared to the first embodiment in which a gap G is formed between the inner package 3 and the circuit element 6.

[0085] The ninth embodiment as described above can also achieve the same effect as the first embodiment. The oscillator 1 is not particularly limited, and for example, the circuit element 6 may be fixed to the bottom surface of the recess 211a, and the inner package 3 may be fixed to the lower surface of the circuit element 6 via the heat insulating member 7. With such a configuration, the same effect as the present embodiment can also be achieved.

[0086] Tenth embodiment FIG. 11 is a cross-sectional view showing an oscillator according to a tenth embodiment.

[0087] This embodiment is similar to the ninth embodiment described above, except for the configuration of the circuit element 6. In the following description, the present embodiment will be described focusing on the differences from the previous embodiment, and the description of the similarities will be omitted. In addition, in FIG. 11, the same reference numerals are used for the same configurations as the previous embodiment.

[0088] 11, in the oscillator 1 of this embodiment, similarly to the above-described fifth embodiment, the circuit element 6 is divided into a first circuit element 6A including a temperature sensor 61 and an oscillation circuit 62, and a second circuit element 6B including a temperature control circuit 64. The second circuit element 6B is fixed to the bottom surface of the recess 211b, and the inner package 3 is fixed to the upper surface of the second circuit element 6B via a heat insulating member 7. The second base substrate 31 has a recess 312 that opens to its upper surface 31a. The first circuit element 6A is fixed to the bottom surface of this recess 312.

[0089] The above-described tenth embodiment can also achieve the same effects as the above-described first embodiment.

[0090] Although the oscillator of the present invention has been described above based on the illustrated embodiment, the present invention is not limited thereto, and the configuration of each part can be replaced with any configuration having a similar function. Any other configuration may be added to the present invention. The above-mentioned embodiments may be appropriately combined. In particular, the above-mentioned ninth embodiment can be suitably combined with the first to seventh embodiments. [Explanation of symbols]

[0091] 1...oscillator, 2...outer package, 3...inner package, 4...vibration element, 5...heat generating element, 6...circuit element, 6A...first circuit element, 6B...second circuit element, 7, 8, 9...thermal insulation member, 21...first base substrate, 21a...upper surface, 21b...lower surface, 22...first lid, 23...jointing member, 31...second base substrate, 31a...upper surface, 31b...lower surface, 32...second lid, 33...jointing member, 41...quartz substrate, 51...heat generating circuit, 52...temperature sensor, 53...electrode pad, 53a...electrode pad, 61...temperature sensor, 62...oscillating circuit, 64...temperature control Control circuit, 71... columnar portion, 211, 211a, 211b, 211c, 211d... recessed portion, 241, 242... internal terminal, 243... mounting terminal, 311, 311a, 311b... recessed portion, 312... recessed portion, 341... internal terminal, 342... external terminal, 421... first excitation electrode, 422... first connection electrode, 423... first extraction electrode, 431... second excitation electrode, 432... second connection electrode, 433... second extraction electrode, B1... bonding member, BW1, BW2, BW3, BW4, BW7... bonding wire, G... gap, S1... first housing space, S2... second housing space

Claims

1. An outer package; an inner package fixed to the outer package via a heat insulating member and having an external terminal; 、 A vibration element housed in the inner package; a heating element secured to the inner package; An oscillation circuit that oscillates the vibration element; A control circuit for controlling the driving of the heating element; a conductive wire electrically connecting the outer package and the inner package; Has The outer package comprises: a first recess, the first recess having an opening at a bottom surface thereof and configured to accommodate the entire inner package; a first base substrate including a first recess having a plurality of recesses including a second recess having a first recess; a first lid joined to the first base substrate so as to close an opening of the first recess; , the inner package is fixed to a bottom surface of the second recess via the heat insulating member; The external terminal and the bottom surface of the first recess are connected by the conductive wire. An oscillator characterized by:

2. The inner package includes a second base substrate having a second recess for accommodating the vibration element; a second lid joined to the second base substrate so as to close the opening of the second recess; Has The vibration element is fixed to the second base substrate, 2. The method of claim 1, wherein the second lid is fixed to the outer package via the insulating member.

2. The oscillator according to claim 1 .

3. The external terminals are provided on a surface of the second base substrate opposite to a surface to which the second lid is bonded. The oscillator of claim 2 disposed on a surface.

4. 4. The semiconductor device according to claim 1, wherein the oscillator circuit is housed in the inner package. Item 3. An oscillator according to item 2.

5. 5. An oscillator as claimed in any preceding claim, including a temperature sensor.

6. A storage space formed by the first recess and the first lid is in a reduced pressure state.

6. The oscillator according to any one of items 1 to 5.

7. The heat insulating member is filled in an accommodation space formed by the first recess and the first lid.

6. The oscillator according to claim 1, wherein

8. 8. The heating element according to claim 1, wherein the heating element is housed in the inner package. Item 3. An oscillator according to item 2.

9. The heat generating element is disposed on the opposite side of the second base substrate to the side to which the second lid is bonded. The oscillator of claim 2 disposed on a surface.

10. 2. The heat generating element according to claim 1, wherein the heat generating element is disposed between the inner package and the insulating member.

7. An oscillator according to any one of claims 1 to 6.

11. A circuit element including the control circuit, The circuit element and the inner package are disposed apart from each other and overlap each other in a plan view.

11. The oscillator according to claim 1, wherein

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