oscillator

Abstract

Oscillator. The present invention provides an oscillator in which heat from the outside is less likely to be transmitted to a vibrating element and which has stable frequency characteristics. The oscillator has an outer package having a housing space, an inner package housed in the housing space, fixed to the outer package via a heat insulating member, a vibrating element housed in the inner package, a heat generating element housed in the housing space, fixed to the inner package, an oscillation circuit that oscillates the vibrating element, a control circuit disposed outside the housing space that controls the heat generating element, and a conductive lead that electrically connects the outer package and the inner package.

Description

Technical Field

[0001] This invention relates to oscillators. Background Technology

[0002] Patent Document 1 describes a quartz oscillator in which a package housing containing a heater IC and a vibration element is fixed within an outer package consisting of a base substrate and a protective shell. Furthermore, in this quartz oscillator, the package housing is fixed to the base substrate with multiple spacers between it.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2017-130861

[0004] However, in the quartz oscillator of Patent Document 1, through-holes with metal wiring or metal plating are formed on the spacer to achieve electrical connection between the package and the base substrate. Therefore, this creates a structure where heat can easily move between the base substrate and the package through the metal portion formed in the spacer. Consequently, there is a problem: external heat can easily be transferred to the vibrating element mounted in the package through the spacer, and the characteristics of the oscillation signal are easily affected by the ambient temperature. Furthermore, heat generated by the heater IC escapes from the package, so there is also the problem of inefficient heating of the vibrating element. Summary of the Invention

[0005] The oscillator of the present invention comprises: an outer package having a housing space; an inner package housed in the housing space and fixed to the outer package via a heat-insulating member; a vibration element housed in the inner package; a heating element housed in the housing space and fixed to the inner package; an oscillation circuit for oscillating the vibration element; a control circuit disposed outside the housing space for controlling the heating element; and conductive leads electrically connecting the outer package and the inner package. Attached Figure Description

[0006] Figure 1 This is a cross-sectional view showing the oscillator of the first embodiment.

[0007] Figure 2 It is shown Figure 1 The oscillator has a top view inside the inner package.

[0008] Figure 3 This is a cross-sectional view showing the oscillator of the second embodiment.

[0009] Figure 4 This is a cross-sectional view showing the oscillator of the third embodiment.

[0010] Figure 5 This is a cross-sectional view showing the oscillator of the fourth embodiment.

[0011] Figure 6 This is a cross-sectional view showing the oscillator of the fifth embodiment.

[0012] Figure 7 This is a cross-sectional view showing the oscillator of the sixth embodiment.

[0013] Figure 8 This is a cross-sectional view showing the oscillator of the seventh embodiment.

[0014] Figure 9 This is a cross-sectional view showing the oscillator of the eighth embodiment.

[0015] Label Explanation

[0016] 1 Oscillator; 2 External package; 3 Internal package; 4 Vibration element; 5 Heating element; 6 Circuit element; 6A First circuit element; 6B Second circuit element; 7, 8, 9 Thermal insulation components; 21 First base substrate; 21a Upper surface; 21b Lower surface; 22 First cover; 23 Connecting component; 31 Second base substrate; 31a Upper surface; 31b Lower surface; 32 Second cover; 33 Connecting component; 41 Quartz substrate; 51 Heating circuit; 52 Temperature sensor; 53 Electrode pad; 53a Electrode pad; 61 Temperature sensor; 62 Oscillating circuit; 64 Temperature control circuit; 71 Columnar portion; Recesses 211, 211a, 211b; Recesses 212, 212a, 212b; Internal terminal 241; Internal terminal 242; Mounting terminal 243; Recesses 311, 311a, 311b; Internal terminal 341; External terminal 342; First excitation electrode 421; First connecting electrode 422; First lead-out electrode 423; Second excitation electrode 431; Second connecting electrode 432; Second lead-out electrode 433; Bonding component B1; Bonding wires BW1, BW2, BW3, BW4, BW7; First storage space S1; Second storage space S2. Detailed Implementation

[0017] Hereinafter, preferred embodiments of the oscillator of the present invention will be described in detail with reference to the accompanying drawings.

[0018] <First Implementation>

[0019] Figure 1 This is a cross-sectional view showing the oscillator of the first embodiment. Figure 2 It is shown Figure 1 The oscillator has a top view inside its internal package. For clarity, the X, Y, and Z axes are shown in the figures. The direction along the X-axis is referred to as the X-axis direction, the direction along the Y-axis as the Y-axis direction, and the direction along the Z-axis as the Z-axis direction. The arrow side of the Z-axis direction is also referred to as "top," and the opposite side as "bottom." The top view from the Z-axis direction is simply referred to as "top view."

[0020] Figure 1 The oscillator 1 shown is a thermostatic quartz oscillator (OCXO). Such an oscillator 1 has: an outer package 2; an inner package 3 housed within the outer package 2; a vibrating element 4 and a heating element 5 housed within the inner package 3; a circuit element 6 fixed to the outer package 2; a heat-insulating component 7 between the outer package 2 and the inner package 3; and a bonding wire BW3, which is a conductive lead electrically connecting the outer package 2 and the inner package 3. This oscillator 1 utilizes the heat from the heating element 5 to heat the vibrating element 4, maintaining the vibrating element 4 at a desired temperature, thereby suppressing frequency variations in the oscillation signal and achieving excellent oscillation characteristics.

[0021] The external package 2 has a first base substrate 21. The first base substrate 21 has an upper surface 21a and a lower surface 21b that are opposite to each other. Furthermore, the first base substrate 21 has a first recess 211 with a bottom that opens onto the upper surface 21a and a third recess 212 with a bottom that opens onto the lower surface 21b. Therefore, the first base substrate 21 has an H-shaped cross-sectional shape. Additionally, the recess 211 is composed of multiple recesses, including a recess 211a that opens onto the upper surface 21a and a recess 211b that opens onto the bottom surface of the recess 211a but has an opening smaller than that of the recess 211a. Similarly, the recess 212 is composed of multiple recesses, including a recess 212a that opens onto the lower surface 21b and a recess 212b that opens onto the bottom surface of the recess 212a but has an opening smaller than that of the recess 212a. Furthermore, the inner package 3 is fixed to the bottom surface of the recess 211b via the heat insulation component 7, and the circuit element 6 is fixed to the bottom surface of the recess 212b.

[0022] Furthermore, a plurality of internal terminals 241 are disposed on the bottom surface of recess 211a, a plurality of internal terminals 242 are disposed on the bottom surface of recess 212a, and a plurality of mounting terminals 243 are disposed on the lower surface 21b. These terminals 241, 242, and 243 are electrically connected via internal wiring (not shown) formed within the first base substrate 21. As described later, each internal terminal 241 is electrically connected to an external terminal 342 of the inner package 3 via bonding wire BW3, and each internal terminal 242 is electrically connected to a circuit element 6 via bonding wire BW4. Moreover, the oscillator 1 is electrically connected to an external device (not shown) via the plurality of mounting terminals 243.

[0023] Additionally, the outer package 2 has a first cover 22. The first cover 22 is engaged with the upper surface 21a of the first base substrate 21 by means of a coupling member 23, thereby closing the opening of the recess 211. By closing the opening of the recess 211 with the first cover 22 in this way, an airtight first storage space S1 is formed inside the outer package 2. The inner package 3 is then stored in the first storage space S1.

[0024] The first storage space S1 is in a depressurized state, preferably closer to a vacuum. This provides excellent thermal insulation, preventing external heat from the oscillator 1 from easily transferring to the inner enclosure 3. Therefore, the vibrating element 4 is less susceptible to external heat, and the heat from the heating element 5 can easily maintain it at the desired temperature. However, the atmosphere of the first storage space S1 is not particularly limited; for example, it can be an atmosphere filled with inert gases such as nitrogen, argon, or helium, or it can be in an atmospheric pressure or pressurized state instead of a depressurized state. Furthermore, as described in the embodiments below, the first storage space S1 can also be filled with a thermal insulation component 7.

[0025] In addition, although there are no particular limitations, the first base substrate 21 can be made of ceramic such as alumina, and the first cover 22 can be made of metal materials such as Kovar alloy.

[0026] 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 that are in a front-to-back relationship. In addition, the second base substrate 31 has a second recess with a bottom, which is an opening on the lower surface 31b. Furthermore, the recess 311 is composed of multiple recesses, including a recess 311a that opens on the lower surface 31b and a recess 311b that opens on the bottom surface of the recess 311a but has an opening smaller than that of the recess 311a. Furthermore, the heating 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 heating element 5.

[0027] Furthermore, a plurality of internal terminals 341 are disposed on the bottom surface of the recess 311a, and a plurality of external terminals 342 are disposed on the upper surface 31a. These terminals 341, 342 are electrically connected via internal wiring (not shown) formed in the second base substrate 31.

[0028] In addition, multiple external terminals 342 are electrically connected to the internal terminals 241 of the first base substrate 21 via bonding wires BW3. In this way, by providing external terminals 342 facing the outside of the inner package 3, the electrical connection between the inner package 3 and the outer package 2 becomes easy.

[0029] Here, since the conductive component electrically connecting the inner package 3 and the outer package 2 has high thermal conductivity, it readily functions as a heat transfer path between the inner package 3 and the outer package 2. Therefore, by using the thin, linear bonding wire BW3 as the conductive component, heat transfer between the inner package 3 and the outer package 2 can be effectively suppressed. Consequently, external heat from the oscillator 1 is not easily transferred to the inner package 3. Therefore, the vibrating element 4 is almost unaffected by external heat, and the vibrating element 4 is easily maintained at the desired temperature by the heat from the heating element 5. Conversely, the heat from the heating element 5 does not easily escape to the outer package 2 via the bonding wire BW3, and the heat from the heating element 5 can be effectively transferred to the vibrating element 4. Therefore, the heating element 5 can be effectively driven, and the temperature of the vibrating element 4 can be more stable.

[0030] Additionally, the inner package 3 has a second cover 32. The second cover 32 engages with the lower surface 31b of the second base substrate 31 via a coupling member 33, sealing the opening of the recess 311. Thus, by sealing the opening of the recess 311 with the second cover 32, an airtight second storage space S2 is formed inside the inner package 3. The vibration element 4 and the heating element 5 are housed in this second storage space S2.

[0031] The second storage space S2 is in a depressurized state, preferably closer to a vacuum. This reduces the CI (quartz resistance) value of the vibrating element 4 and improves its oscillation characteristics. However, the atmosphere of the second storage space S2 is not particularly limited; for example, it can be atmospheric pressure or pressurized.

[0032] In addition, although there are no particular limitations, the second base substrate 31 can be made of ceramic such as alumina, and the second cover 32 can be made of metal materials such as Kovar alloy.

[0033] The inner package 3 is configured such that the second cover 32 faces the bottom surface of the recess 211, and the second cover 32 is fixed to the bottom surface of the recess 211 via the heat insulation member 7. Thus, by placing the heat insulation member 7 between the inner package 3 and the outer package 2, external heat, especially the heat from the circuit element 6, is not easily transferred to the inner package 3 via the outer package 2. Therefore, the vibrating element 4 is less susceptible to external heat, and the heat from the heating element 5 can be easily used to maintain the vibrating element 4 at the desired temperature. Furthermore, conversely, the heat from the heating element 5 is less likely to escape from the inner package 3 to the outer package 2, enabling efficient transfer of heat from the heating element 5 to the vibrating element 4. Therefore, effective driving of the heating element 5 is possible, and the temperature of the vibrating element 4 can be more stable.

[0034] In particular, by fixing the second cover 32, which is not used to fix the vibration element 4 in the components constituting the inner package 3, to the outer package 2, the heat transfer path from the heat insulation component 7 to the vibration element 4 can be extended. Therefore, even if external heat is transferred to the inner package 3 via the heat insulation component 7, the heat is not easily transferred to the vibration element 4. Therefore, the vibration element 4 is less susceptible to external heat, and the heat from the heating element 5 can easily maintain the vibration element 4 at the desired temperature. However, it is not limited to this; the second base plate 31 can also be fixed to the first base plate 21 via the heat insulation component 7.

[0035] The heat insulation component 7 is made of a material with a lower thermal conductivity than the second cover 32. There are no particular limitations on the type of heat insulation component 7; various resin materials can be used, with porous resin materials such as porous polyimide being particularly preferred. Besides resin materials, various glass materials, inorganic porous materials such as silica aerogel, etc., can also be used. Furthermore, the thermal conductivity of the heat insulation component 7 is not particularly limited, but is preferably 1.0 W / m·K or less. This results in a heat insulation component 7 with sufficiently low thermal conductivity.

[0036] Furthermore, the heat insulation component 7 has multiple columnar portions 71 arranged separately from each other, which are configured in an island shape throughout the entire area of ​​the second cover 32. This allows the inner package 3 to be stably fixed to the outer package 2. Additionally, it reduces the contact area between the heat insulation component 7 and the outer package 2, making it less likely for external heat to be transferred to the inner package 3 via the heat insulation component 7. However, this is not a limitation; the heat insulation component 7 can also be arranged across the entire lower surface of the second cover 32. This increases the bonding area between the inner package 3 and the outer package 2, thereby increasing the adhesive strength. Consequently, the mechanical strength of the oscillator 1 is improved.

[0037] Furthermore, if the heat insulation component 7 has adhesive strength, the second cover 32 and the first base substrate 21 can be joined using the heat insulation component 7. On the other hand, if the heat insulation component 7 does not have adhesive strength, the heat insulation component 7 and the second cover 32, as well as the heat insulation component 7 and the first base substrate 21, can be joined using adhesives or other joining components. Additionally, the heat insulation component 7 may contain a gap material with sufficiently low thermal conductivity, such as silicone. This allows for control of the thickness of the heat insulation component 7, resulting in more reliable heat insulation performance.

[0038] Vibrating element 4 is an SC-cut quartz vibrating element. Therefore, it becomes a vibrating element 4 with excellent frequency stability. For example... Figure 2As shown, the vibrating element 4 has a circular quartz substrate 41 cut by the SC cutter and electrodes disposed on the surface of the quartz substrate 41. The electrodes include: a first excitation electrode 421 disposed at the center of the lower surface of the quartz substrate 41; and a second excitation electrode 431 disposed opposite to the first excitation electrode 421 at the center of the upper surface of the quartz substrate 41. Furthermore, the electrodes include: a first connecting electrode 422 disposed at the outer edge of the lower surface; a first lead-out electrode 423 connecting the first excitation electrode 421 and the first connecting electrode 422; a second connecting electrode 432 disposed at the outer edge of the upper surface; and a second lead-out electrode 433 connecting the second excitation electrode 431 and the second connecting electrode 432.

[0039] However, the structure of the vibrating element 4 is not limited to this. For example, the top view shape of the quartz substrate 41 is not limited to a circle; it can also be rectangular. Furthermore, the vibrating element 4 can also be an AT-cut quartz vibrating element, a BT-cut quartz vibrating element, a tuning fork-type quartz vibrating element, a surface acoustic wave resonator, other piezoelectric vibrating elements, MEMS (Micro ElectroMechanical Systems) resonating elements, etc.

[0040] The vibrating element 4 is positioned with its upper surface facing the heating element 5, and its outer edge is fixed to the lower surface of the heating element 5 by means of a conductive bonding member B1. Furthermore, the bonding member B1 is not particularly limited as long as it is conductive; for example, metal bumps, solder, metal paste, conductive resin adhesives, etc., can be used.

[0041] The heating element 5 and the vibration element 4 are housed together in the inner package 3. This allows the heating element 5 to be positioned near the vibration element 4, enabling efficient heat transfer from the heating element 5 to the vibration element 4.

[0042] Such a heating element 5 has a heating circuit 51 and a temperature sensor 52. The heating circuit 51 functions as a heating part for heating the vibrating element 4. Furthermore, the lower surface of the heating element 5 serves as a fixing surface for fixing the vibrating element 4, such as... Figure 2 As shown, 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.

[0043] The electrode pads 53a included in these multiple electrode pads 53 are not electrically connected to the heating circuit 51, but function as relay electrodes for electrically connecting the internal terminal 341 to the vibrating element 4. The electrode pad 53a is electrically connected to the second connecting electrode 432 of the vibrating element 4 via a conductive bonding member B1. On the other hand, the first connecting electrode 422 of the vibrating element 4 is electrically connected to the internal terminal 341 via a bonding wire BW2, not via the electrode pads 53. However, the method of electrically connecting the vibrating element 4 to the internal terminal 341 is not particularly limited.

[0044] like Figure 1 As shown, circuit element 6 is disposed within the recess 212 of the first base substrate 21 and fixed to the bottom surface of the recess 212. That is, circuit element 6 is located outside the first storage space S1. As a result, the heat of circuit element 6 is not easily transferred to the inner package 3. Therefore, the vibration element 4 is not easily affected by the heat of circuit element 6, and the heat of heating element 5 can be used to maintain the vibration element 4 at the desired temperature. In addition, since the inner package 3 and circuit element 6 can be overlapped in the Z-axis direction, the expansion of oscillator 1 in the X-axis and Y-axis directions can be suppressed, and miniaturization of oscillator 1 can be achieved.

[0045] In addition, circuit element 6 is electrically connected to the internal terminal 242 of the first base substrate 21 via bonding wire BW4. Thus, circuit element 6 is electrically connected to vibration element 4 and heating element 5.

[0046] Circuit element 6 includes a temperature sensor 61, an oscillation circuit 62, and a temperature control circuit 64. The oscillation circuit 62 functions to cause the vibrating element 4 to oscillate, generating an oscillation signal after temperature compensation based on the temperature detected by the temperature sensor 61. Specifically, the oscillation circuit 62 includes: an oscillation circuit section electrically connected to the vibrating element 4, which amplifies the output signal of the vibrating element 4 and feeds the amplified signal back to the vibrating element 4, thereby causing the vibrating element 4 to oscillate; 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 variation of the oscillation signal is less than the frequency-temperature characteristics of the vibrating element 4 itself.

[0047] Temperature control circuit 64 is a control circuit for controlling the heating element 5. Specifically, temperature control circuit 64 controls the amount of current flowing through the resistor of heating circuit 51 based on the output signal of temperature sensor 52, thereby maintaining the vibrating element 4 at a constant temperature. For example, if the current temperature, as determined by the output signal of temperature sensor 52, is lower than a set reference temperature, temperature control circuit 64 allows the desired current to flow through the resistor of heating circuit 51; if the current temperature is higher than the reference temperature, it controls the flow so that no current flows through the resistor of heating circuit 51. Furthermore, for example, temperature control circuit 64 can also control the flow by increasing or decreasing the amount of current flowing through the resistor of heating circuit 51 based on the difference between the current temperature and the reference temperature.

[0048] The oscillator 1 has been described above. As described above, this oscillator 1 includes: an outer package 2 having a first storage space S1 as a storage space; an inner package 3 housed in the first storage space S1 and fixed to the outer package 2 with a heat insulation member 7 in between; a vibration element 4 housed in the inner package 3; a heating element 5 housed in the first storage 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 disposed outside the first storage space S1 as a control circuit for controlling the heating element 5; and a bonding wire BW3, which is a conductive lead that electrically connects the outer package 2 and the inner package 3.

[0049] Thus, by installing a heat insulation component 7 between the inner package 3 and the outer package 2, external heat is not easily transferred to the inner package 3 via the outer package 2. Therefore, the vibrating element 4 is less affected by external heat, and the heat from the heating element 5 can easily maintain the vibrating element 4 at the desired temperature. Conversely, the heat from the heating element 5 is less likely to escape from the inner package 3 to the outer package 2, and the heat from the heating element 5 can be efficiently transferred to the vibrating element 4. Therefore, efficient driving of the heating element 5 is possible, and the temperature of the vibrating element 4 can be more stable. Furthermore, since the conductive component that electrically connects the inner package 3 and the outer package 2 has high thermal conductivity, it easily functions as a heat transfer path between the inner package 3 and the outer package 2. In this regard, since a thin, linear bonding wire BW3 is used as the conductive component, heat transfer between the inner package 3 and the outer package 2 can be effectively suppressed. Therefore, external heat from the oscillator 1 is less likely to be transferred to the inner package 3. Therefore, in this respect, the vibrating element 4 is also less affected by external heat, and the heat from the heating element 5 can easily maintain the vibrating element 4 at the desired temperature. Therefore, it becomes an oscillator 1 with high frequency characteristics and capable of power-saving drive.

[0050] Furthermore, as described above, the outer package 2 includes: a first base substrate 21 having a recess 211, which is a first recess for receiving the inner package 3; and a first cover 22, which engages with the first base substrate 21 to close the opening of the recess 211, forming a first receiving space S1 through the recess 211 and the first cover 22. Moreover, the inner package 3 is fixed to the first base substrate 21 via a heat insulation member 7. With this structure, the structure of the outer package 2 becomes simple.

[0051] Furthermore, as described above, the inner package 3 includes: a second base substrate 31 having a recess 311 for receiving the vibration element 4; and a second cover 32 that engages with the second base substrate 31 to close the opening of the recess 311, with the vibration element 4 fixed to the second base substrate 31. The second cover 32 is fixed to the outer package 2 via the heat insulation member 7. Thus, by fixing the second cover 32, which does not hold the vibration element 4, to the outer package 2, the heat transfer path from the heat insulation member 7 to the vibration element 4 can be extended. Therefore, heat transferred from the outer package 2 to the inner package 3 via the heat insulation member 7 is less likely to be transferred to the vibration element 4. Consequently, the vibration element 4 is less susceptible to external heat, and the heat from the heating element 5 can easily maintain the vibration element 4 at the desired temperature.

[0052] Furthermore, as described above, the inner package 3 has an external terminal 342 disposed on the upper surface 31a of the second base substrate 31, opposite to the lower surface 31b to which the second cover 32 is attached. The external terminal 342 is electrically connected to the outer package 2 via a bonding wire BW3. This facilitates the electrical connection between the inner package 3 and the outer package 2.

[0053] Additionally, as described above, the oscillator 1 includes a temperature sensor 52. This makes it easy to maintain the vibrating element 4 at the desired temperature.

[0054] Furthermore, as described above, the first storage space S1 is in a depressurized state. This provides excellent thermal insulation, preventing external heat from the oscillator 1 from easily transferring to the inner package 3. Consequently, the vibrating element 4 is less susceptible to external heat, and the heat from the heating element 5 can easily maintain the vibrating element 4 at the desired temperature.

[0055] Furthermore, as described above, the heating element 5 is housed within the inner package 3. This allows the heating element 5 to be positioned near the vibration element 4, enabling efficient heat transfer from the heating element 5 to the vibration element 4. Consequently, the heating element 5 can be driven effectively.

[0056] Furthermore, the structure of the oscillator 1 is not particularly limited. For example, a circuit component different from the circuit element 6 may be disposed in the recess 212 of the first base substrate 21. This circuit component is not particularly limited; for example, if a PLL circuit (phase synchronization circuit) is formed in the circuit element 6, it can serve as an oscillator for that PLL circuit. Alternatively, the circuit element 6 may be molded by filling the recess 212 with a filler material.

[0057] <Second Implementation Method>

[0058] Figure 3 This is a cross-sectional view showing the oscillator of the second embodiment.

[0059] This embodiment is the same as the first embodiment, except that a heat insulation component 8 is also present between the heating element 5 and the inner package 3. Furthermore, in the following description, this embodiment will be described primarily for its differences from the first embodiment; identical items will be omitted. Figure 3 In this document, structures that are the same as those in the aforementioned embodiments are marked with the same reference numerals.

[0060] like Figure 3 As shown, in the oscillator 1 of this embodiment, the heating element 5 is fixed to the bottom surface of the recess 311b via the heat insulation member 8. Therefore, the heat from the heating element 5 is less likely to escape to the second base substrate 31, and the heat from the heating element 5 can be efficiently transferred to the vibrating element 4. Thus, efficient driving of the heating element 5 is possible, and the temperature of the vibrating element 4 can be more stable. The heat insulation member 8 is made of a material with a lower thermal conductivity than the second base substrate 31. Such a heat insulation member 8 is not particularly limited; for example, the same material as the heat insulation member 7 can be used.

[0061] According to the second embodiment described above, the same effect as the first embodiment described above can also be achieved.

[0062] <Third Implementation Method>

[0063] Figure 4 This is a cross-sectional view showing the oscillator of the third embodiment.

[0064] This embodiment is identical to the second embodiment described above, except for the size of the heating element 5. In the following description, this embodiment will be described primarily for its differences from the embodiments described above; identical aspects will be omitted. Figure 4 In this document, the same reference numerals are used for configurations that are the same as those in the aforementioned embodiments.

[0065] like Figure 4As shown, in the oscillator 1 of this embodiment, the heating element 5 is configured to be larger than the vibrating element 4 when viewed from above, and is arranged to overlap the entire area of ​​the vibrating element 4. Therefore, more heat can be generated from the heating element 5, and this heat can be transferred more efficiently and evenly to the entire area of ​​the vibrating element 4. Consequently, the temperature of the vibrating element 4 can be made more stable.

[0066] According to the third embodiment described above, the same effect as the first embodiment described above can also be achieved.

[0067] <Fourth Implementation>

[0068] Figure 5 This is a cross-sectional view showing the oscillator of the fourth embodiment.

[0069] This embodiment is the same as the first embodiment, except that a heat insulation component 9 exists between the circuit element 6 and the outer package 2. In the following description, this embodiment will be described primarily for its differences from the above embodiments, and descriptions of identical items will be omitted. Figure 5 In this document, structures that are the same as those described in the above embodiments are marked with the same reference numerals.

[0070] like Figure 5 As shown, in the oscillator 1 of this embodiment, the circuit element 6 is fixed to the bottom surface of the recess 212b via the heat insulation member 9. Therefore, the heat from the circuit element 6 is not easily transferred to the first base substrate 21. Consequently, the vibrating element 4 is less susceptible to external heat, especially the heat from the circuit element 6, and the heat from the heating element 5 can easily maintain the vibrating element 4 at the desired temperature. The heat insulation member 9 is made of a material with a lower thermal conductivity than the first base substrate 21. Such a heat insulation member 9 is not particularly limited; for example, the same material as the heat insulation member 7 described above can be used.

[0071] According to the fourth embodiment described above, the same effect as the first embodiment described above can also be achieved.

[0072] <Fifth Implementation>

[0073] Figure 6 This is a cross-sectional view showing the oscillator of the fifth embodiment.

[0074] This embodiment is the same as the first embodiment except that the heating element 5 is located outside the inner package 3, and the oscillation circuit 62 and temperature sensor 61 in the circuit element 6 are housed in the inner package 3. In the following description, this embodiment will be described focusing on the differences from the above embodiments, and descriptions of identical items will be omitted. Figure 6 In this document, structures that are the same as those described in the above embodiments are marked with the same reference numerals.

[0075] like Figure 6 As shown, the heating element 5 is located on the outside of the inner package 3 and housed in the first storage space S1. Furthermore, the heating element 5 is fixed to the upper surface 31a of the second base substrate 31. Therefore, the heat from the heating element 5 is transferred to the vibration element 4 via the second base substrate 31. Additionally, the heating element 5 is electrically connected to the internal terminal 241 via a bonding wire BW7. Thus, by arranging the heating element 5 on the outer peripheral surface of the inner package 3, the number of components housed within the inner package 3 can be reduced. Therefore, miniaturization of the inner package 3 is possible, and contamination and disturbance of the second storage space S2 caused by exhaust gases, etc., can be suppressed.

[0076] Furthermore, in the oscillator 1 of this embodiment, the circuit element 6 is divided into a first circuit element 6A, which includes a temperature sensor 61 and an oscillation circuit 62, and a second circuit element 6B, which includes a temperature control circuit 64. The second circuit element 6B is fixed to the bottom surface of the recess 212. On the other hand, the first circuit element 6A is housed together with the vibration element 4 in the inner package 3. In this way, by housing the first circuit element 6A in the inner package 3, the wiring length connecting the oscillation circuit 62 and the vibration element 4 can be shortened, noise is less likely to enter from the wiring, and a high-precision oscillation signal can be generated. Moreover, since the temperature sensor 61 can be placed near the vibration element 4, the temperature of the vibration element 4 can be detected with higher precision using the temperature sensor 61.

[0077] As described above, in the oscillator 1 of this embodiment, the oscillation circuit 62 is housed in the inner package 3. This shortens the wiring length connecting the oscillation circuit 62 and the vibration element 4, making it less susceptible to noise intrusion and enabling the generation of a high-precision oscillation signal.

[0078] Furthermore, as described above, the heating element 5 is disposed on the upper surface 31a of the second base substrate 31, opposite to the lower surface 31b to which the second cover 32 is joined. Thus, by disposing the heating element 5 on the outer peripheral surface of the inner package 3, the number of components housed within the inner package 3 can be reduced. Therefore, miniaturization of the inner package 3 is possible, and contamination and displacement of the second storage space S2 caused by exhaust gases, 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, enabling efficient heat transfer from the heating element 5 to the vibration element 4.

[0079] According to the fifth embodiment described above, the same effect as the first embodiment described above can also be achieved.

[0080] <Sixth Implementation>

[0081] Figure 7 This is a cross-sectional view showing the oscillator of the sixth embodiment.

[0082] This embodiment is the same as the fifth embodiment, except that the first circuit element 6A is located outside the inner package 3. In the following description, this embodiment will be described primarily for its differences from the aforementioned embodiments, and descriptions of identical items will be omitted. Figure 7 In this document, structures that are the same as those in the aforementioned embodiments are marked with the same reference numerals.

[0083] like Figure 7 As shown, in the oscillator 1 of this embodiment, the first circuit element 6A, which includes the oscillation circuit 62, is located outside the inner package 3 and housed in the first storage space S1. Furthermore, the first circuit element 6A is fixed together with the heating element 5 to the upper surface 31a of the second base substrate 31. The first circuit element 6A is electrically connected to the vibration element 4 and the external terminal 342 via internal wiring (not shown) formed within the second base substrate 31. Thus, by placing the first circuit element 6A outside the inner package 3, the number of components housed within the inner package 3 can be reduced. Therefore, miniaturization of the inner package 3 is possible, and contamination and deformation of the second storage space S2 caused by exhaust gases, etc., can be suppressed.

[0084] According to the sixth embodiment described above, the same effect as the first embodiment described above can also be achieved.

[0085] <Seventh Implementation>

[0086] Figure 8 This is a cross-sectional view showing the oscillator of the seventh embodiment.

[0087] This embodiment is identical to the fifth embodiment except for the configuration of the heating element 5. In the following description, this embodiment will be described primarily for its differences from the aforementioned embodiments; identical details will be omitted. Figure 8 In this document, structures that are the same as those in the aforementioned embodiments are marked with the same reference numerals.

[0088] like Figure 8 As shown, in the oscillator 1 of this embodiment, the heating element 5 is disposed between the second cover 32 and the heat insulation member 7. Therefore, heat transferred from the outside to the inner enclosure 3 via the heat insulation member 7 is absorbed by the heating element 5 and used as part of the heat of the heating element 5. Thus, temperature changes in the vibration element 4 caused by heat other than the heating element 5 can be suppressed, and the temperature of the vibration element 4 becomes more stable.

[0089] The same effect as the first embodiment can be achieved through the seventh embodiment described above.

[0090] <Eighth Implementation>

[0091] Figure 9 This is a cross-sectional view showing the oscillator of the eighth embodiment.

[0092] This embodiment is identical to the first embodiment except for the configuration of the heat insulation component 7. In the following description, this embodiment will be described primarily for its differences from the aforementioned embodiments, and descriptions of identical items will be omitted. Figure 9 In this document, structures that are the same as those in the aforementioned embodiments are marked with the same reference numerals.

[0093] like Figure 9 As shown, in the oscillator 1 of this embodiment, the heat insulation member 7 is filled in the first storage space S1. That is, the heat insulation member 7 is disposed in the first storage space S1 substantially without gaps. Moreover, the entire circumference of the inner package 3 is covered by the heat insulation member 7. As a result, the inner package 3 can be more firmly fixed to the outer package 2, and the mechanical strength of the oscillator 1 is improved.

[0094] According to the eighth embodiment described above, the same effect as the first embodiment described above can also be achieved.

[0095] The oscillator of the present invention has been described above based on the illustrated embodiments, but the present invention is not limited thereto, and the structure of each part can be replaced with any structure having the same function. Furthermore, other arbitrary components can be added to the present invention. Additionally, the described embodiments can be appropriately combined.

Claims

1. An oscillator, characterized in that, It has the following characteristics: The outer casing has a storage space, includes a first recess on the upper surface, and a second recess on the bottom surface; and The inner enclosure is housed within the storage space and is fixed to the bottom surface of the first recess of the outer enclosure via a heat-insulating component. The inner package has an inner cover. The inner enclosure is positioned such that the inner cover is opposite to the bottom surface of the first recess. The thermal insulation component has a lower thermal conductivity than the inner cover. The oscillator also has: The vibrating element is housed within the inner enclosure. The heating element is housed in the storage space and fixed to the outer surface of the inner encapsulation. An oscillation circuit, housed within the inner package, causes the vibrating element to oscillate. A control circuit, disposed outside the storage space, controls the heating element; and Conductive leads electrically connect the outer package and the inner package.

2. The oscillator according to claim 1, wherein, The outer package includes: a first base substrate having a first recess for receiving the inner package; and an outer cover that engages with the first base substrate to close the opening of the first recess. The storage space is formed by the first recess and the outer cover. The inner encapsulation is fixed to the first base substrate through the heat insulation component.

3. The oscillator according to claim 1 or 2, wherein, The inner package includes: a second base substrate having a recess for receiving the vibrating element; and an inner cover that engages with the second base substrate to close the opening of the recess in the inner package. The vibration element is fixed to the second base plate. The inner cover is fixed to the outer enclosure via the heat insulation component.

4. The oscillator according to claim 3, wherein, The inner enclosure has an external terminal disposed on the side of the second base substrate opposite to the side to which the inner cover is joined. The external terminals and the outer package are electrically connected via the conductive leads.

5. The oscillator according to claim 1 or 2, wherein, The oscillation circuit is housed within the inner package.

6. The oscillator according to claim 1 or 2, wherein, The oscillator includes a temperature sensor.

7. The oscillator according to claim 1 or 2, wherein, The storage space is in a depressurized state.

8. The oscillator according to claim 1 or 2, wherein, The heat insulation component is filled in the storage space.

9. The oscillator according to claim 1 or 2, wherein, The heating element is housed in the inner package.

10. The oscillator according to claim 3, wherein, The heating element is disposed on the side of the second base substrate opposite to the side where the inner cover is joined.

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