oscillator

Abstract

Oscillator. An oscillator is provided which is less susceptible to wind and has a good noise characteristic of an output signal. The oscillator has a first vibration element, a circuit element which generates an oscillation signal by oscillating the first vibration element, a first package having a substrate, a housing space which houses the first vibration element and the circuit element on one main surface side of the substrate, a second vibration element which is disposed on the other main surface side of the substrate, the oscillation frequency of the second vibration element being controlled in accordance with the oscillation signal, and a leg portion which is disposed on the other main surface side of the substrate and is configured to surround the periphery of the second vibration element when the substrate is viewed in plan.

Description

Technical Field

[0001] This invention relates to oscillators. Background Technology

[0002] Patent Document 1 describes a quartz oscillator (OCXO) with a thermostatic bath, comprising a first container housing a first vibrating element and a first circuit element that oscillates the first vibrating element to generate a first oscillation signal. A second container is mounted on the lower surface of the first container, housing a second vibrating element, the oscillation frequency of which is controlled according to the first oscillation signal. Furthermore, the quartz oscillator with a thermostatic bath also includes a third container, which consists of a base plate supporting the first container via a lead frame and a cover joined to the base plate in such a way that it houses both the first and second containers.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2020-120159

[0004] However, in the quartz oscillator with a thermostatic bath in Patent Document 1, when the third container is omitted to achieve miniaturization, the second container is exposed to the outside and is susceptible to wind. Therefore, it is easily affected by temperature fluctuations caused by wind, and the noise characteristics of the output signal may deteriorate. Summary of the Invention

[0005] The oscillator of the present invention comprises: a first vibrating element; a circuit element that causes the first vibrating element to oscillate to generate an oscillation signal; a first package having a substrate having a receiving space for receiving the first vibrating element and the circuit element on one main surface side of the substrate; a second vibrating element disposed on another main surface side of the substrate, the oscillation frequency of the second vibrating element being controlled according to the oscillation signal; and legs disposed on another main surface side of the substrate, configured to surround the second vibrating element when viewed from above. Attached Figure Description

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

[0007] Figure 2 This is a top view of the oscillator viewed from the top surface side.

[0008] Figure 3 This is a cross-sectional view showing the inner package of the oscillator and its interior.

[0009] Figure 4 This is a top view of the inner package as seen from the bottom surface.

[0010] Figure 5 This is a cross-sectional view showing a voltage-controlled quartz oscillator.

[0011] Figure 6 This is a top view of a voltage-controlled quartz oscillator viewed from the bottom surface.

[0012] Figure 7 This is a circuit diagram showing the PLL circuit included in the first circuit element of the oscillator.

[0013] Figure 8 This is a top view of the oscillator viewed from the bottom surface side.

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

[0015] Figure 10 This is a circuit diagram showing the PLL circuit included in the first circuit element of the oscillator.

[0016] Figure 11 This is a cross-sectional view showing the oscillator of the third embodiment.

[0017] Figure 12 This is a cross-sectional view showing the oscillator of the fourth embodiment.

[0018] Figure 13 This is a top view of the oscillator viewed from the bottom surface side.

[0019] Figure 14 This is a cross-sectional view showing the oscillator of the fifth embodiment.

[0020] Figure 15 It is shown Figure 14 A cross-sectional view of a modified example of the oscillator shown.

[0021] Figure 16 This is a cross-sectional view showing the oscillator of the sixth embodiment.

[0022] Figure 17 It is shown Figure 16 A cross-sectional view of a modified example of the oscillator shown.

[0023] Figure 18 This is a cross-sectional view showing the oscillator of the seventh embodiment.

[0024] Label Explanation

[0025] 1 Oscillator; 10 Circuit element; 100 External device; 2 Outer package; 21 Outer base; 21a Upper surface; 21b Lower surface; 211 Upper recess; 211a First upper recess; 211b Second upper recess; 211c Third upper recess; 211d Fourth upper recess; 212 Lower recess; 22 Outer cover; 23 Sealing component; 241 Internal terminal; 242 Internal terminal; 243 Internal terminal; 244 External terminal; 245 Side terminal; 246 Connection terminal; 25 Internal wiring; 27 Substrate; 28 Wall; 29 Leg; 29A Unit leg; 29B Unit leg; 3 Inner package; 31 Inner base; 31a Upper surface; 31b Lower surface; 311 Recess; 311a First recess; 311b Second recess; 311c Third recess; 32 Inner cover; 33 Sealing component; 341 Internal terminal; 342 Internal terminal; 343 Internal terminal; 344 External terminal; 4 First circuit element; 41 Temperature control circuit; 42 PLL circuit; 421 First phase comparator; 422 First low-pass filter; 423 Voltage-controlled oscillator; 424 First frequency divider; 425 Second phase comparator; 426 Second low-pass filter; 427 Second frequency divider; 43 Output buffer circuit; 5 Voltage-controlled quartz oscillator; 50 Oscillator; 51 Package; 52 Base; 52a Upper surface; 52b Lower surface; 521 Recess; 521a First recess; 521b Second recess; 521c Third recess; 53 Cover; 54 Sealing component; 55 Vibration element; 551 Quartz substrate; 553a Excitation electrode; 553b Pad electrode; 553c Lead electrode; 554a Excitation electrode; 554b Pad electrode; 554c Lead electrode; 561 Internal terminal; 562 Internal terminal; 564 External terminal; 59 Circuit element; 591 Oscillation circuit; 6 Vibration element; 61 Quartz substrate; 621 Excitation electrode; 622 Pad electrode; 631 Excitation electrode; 632 Pad electrode; 7 Temperature Control element; 71 Temperature sensor; 72 Heating circuit; 8 Second circuit element; 81 Oscillating circuit; 9 Leg base plate; 9a Upper surface; 9b Lower surface; 91 Recess; 921 Connecting terminal; 922 External terminal; 923 Side terminal; 924 Internal terminal; 93 Recess; B1 Joining component; B2 Joining component; B3 Joining component; B4 Joining component; B7 Joining component; BW1 Bonding wire; BW2 Bonding wire; BW3 Bonding wire; BW4 Bonding wire; BW5 Bonding wire; BW6 Bonding wire; H Solder; H1 Height; H2 Height; M Resin material; S2 Outer storage space; S3 Inner storage space; S5 Storage space; S9 Storage space. Detailed Implementation

[0026] Hereinafter, preferred embodiments of the oscillator of the present invention will be described in detail with reference to the accompanying drawings. For ease of explanation, the X-axis, Y-axis, and Z-axis are illustrated as mutually orthogonal in each figure. The direction along the X-axis will be 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 each axis will also be referred to as the "positive side," and the opposite side as the "negative side." The positive side of the Z-axis direction will also be referred to as "up," and the negative side of the Z-axis direction as "down." The top view from the Z-axis direction will also be simply referred to as "top view."

[0027] <First Implementation>

[0028] Figure 1 This is a cross-sectional view showing the oscillator of the first embodiment. Figure 2 This is a top view of the oscillator viewed from the top surface side. Figure 3 This is a cross-sectional view showing the inner package of the oscillator and its interior. Figure 4 This is a top view of the inner package as seen from the bottom surface. Figure 5 This is a cross-sectional view showing a voltage-controlled quartz oscillator. Figure 6 This is a top view of a voltage-controlled quartz oscillator viewed from the bottom surface. Figure 7 This is a circuit diagram showing the PLL circuit included in the first circuit element of the oscillator. Figure 8 This is a top view of the oscillator viewed from the bottom surface side.

[0029] Figure 1 and Figure 2 The oscillator 1 shown is a quartz oscillator (OCXO) with a thermostatic bath, including: a vibrating element 6 as a first vibrating element; a second circuit element 8 as a circuit element; a temperature control element 7 as a heater; an inner package 3 as a second package housing the vibrating element 6, the second circuit element 8, and the temperature control element 7; a first circuit element 4; an outer package 2 as a first package housing the inner package 3 and the first circuit element 4; and a voltage-controlled quartz oscillator 5 disposed in the outer package 2, which includes a vibrating element 55 as a second vibrating element. These components will be described in turn below.

[0030] <<Outer Packaging 2>>

[0031] like Figure 1As shown, the outer package 2 has an outer base 21 and an outer cover 22. The outer base 21 is box-shaped, having an upper recess 211 opening on the upper surface 21a and a lower recess 212 opening on the lower surface 21b. Therefore, the outer base 21 is generally H-shaped in longitudinal sectional view. In other words, the outer base 21 can be described as having a substrate 27, a frame-shaped wall 28 erected vertically from the edge of the upper surface of the substrate 27 toward the upper side, and a frame-shaped leg 29 erected vertically from the edge of the lower surface of the substrate 27 toward the lower side.

[0032] Furthermore, the outer cover 22 is plate-shaped and is joined to the upper surface 21a of the outer base 21 via a sealing ring, low-melting-point glass, or other sealing components 23 to block the opening of the upper recess 211. Thus, the upper recess 211 is hermetically sealed, forming an outer storage space S2 within the outer package 2. On the other hand, the opening of the lower recess 212 is not sealed and faces the outside of the outer package 2. Moreover, the inner package 3 and the first circuit element 4 are housed in the outer storage space S2, and a voltage-controlled quartz oscillator 5 is disposed in the lower recess 212.

[0033] Furthermore, the materials used to construct the outer base 21 and the outer cover 22 are not particularly limited. For example, the outer base 21 can be made of various ceramic materials such as alumina and titanium dioxide, and the outer cover 22 can be made of various metal materials such as Kovar alloy. This results in a robust outer package 2 with excellent mechanical strength. Additionally, by making the coefficients of linear expansion of both approximately equal, thermal stress generated on the outer package 2 can be reduced. Therefore, stress is less likely to be applied to the vibrating elements 6 and 55, and the vibration characteristics of the vibrating elements 6 and 55 are stable.

[0034] The outer storage space S2 is described in detail. The upper recess 211 has a first upper recess 211a that opens onto the upper surface 21a, a second upper recess 211b that opens onto the bottom surface of the first upper recess 211a but the opening is smaller than that of the first upper recess 211a, and a third upper recess 211c that opens onto the bottom surface of the second upper recess 211b but the opening is smaller than that of the second upper recess 211b. Furthermore, a first circuit element 4 is disposed on the bottom surface of the first upper recess 211a, and an inner package 3 is disposed on the bottom surface of the third upper recess 211c.

[0035] The outer storage space S2 is airtight and in a depressurized state, preferably closer to a vacuum. This improves the thermal insulation of the outer enclosure 2, making the oscillator 1 less susceptible to external temperature influences. Furthermore, heat from the temperature control element 7 is less likely to escape, improving the heating efficiency of the vibration element 6. Therefore, the temperature of the vibration element 6 is more stable, and energy saving is achieved. The environment of the outer storage space S2 is not particularly limited.

[0036] Additionally, the outer base 21 is provided with: a plurality of internal terminals 241 disposed on the bottom surface of the first upper recess 211a; a plurality of internal terminals 242 disposed on the bottom surface of the second upper recess 211b; a plurality of internal terminals 243 disposed on the bottom surface of the lower recess 212; and a plurality of external terminals 244 disposed on the top surface of the lower surface 21b, i.e., the leg 29. Each internal terminal 241 is electrically connected to the first circuit element 4 via bonding wire BW1, each internal terminal 242 is electrically connected to the inner package 3 via bonding wire BW2, and each internal terminal 243 is electrically connected to the voltage-controlled quartz oscillator 5 via a conductive bonding member B1.

[0037] Furthermore, these terminals 241, 242, 243, and 244 are appropriately electrically connected via internal wiring 25 formed within the outer base 21, electrically connecting the first circuit element 4, the inner package 3, the voltage-controlled quartz oscillator 5, and the external terminal 244. In such an oscillator 1, the connection to the external device 100 is made on the external terminal 244. In particular, in this embodiment, a side terminal 245 for connecting to the external terminal 244 is disposed on the side of the leg 29. The side terminal 245 has a castellation structure. Therefore, the solder H wets and spreads on the side terminal 245 to form a fillet, making the mechanical and electrical connection with the external device 100 more robust. However, this is not a limitation; for example, the side terminal 245 may be omitted.

[0038] Furthermore, the internal wiring 25 is connected to the external terminal 244 through the interior of the leg 29. Thus, by forming the internal wiring 25 so that it does not expose to the exterior of the outer package 2, the oscillator 1 becomes less susceptible to interference from radiated noise, electromagnetic fields, etc. Therefore, the oscillator 1 can exhibit excellent phase noise characteristics. However, it is not limited to this; a portion of the internal wiring 25 may also be exposed to the exterior of the outer package 2.

[0039] <<Inner Packaging 3>>

[0040] like Figure 1 As shown, the inner package 3 is housed within the outer storage space S2 of the outer package 2. Figure 3 As shown, the inner package 3 has an inner base 31 and an inner cover 32. The inner base 31 is box-shaped and has a recess 311 with an opening on its lower surface 31b. The inner cover 32 is plate-shaped and is joined to the lower surface 31b of the inner base 31 via a sealing ring, a low-melting-point glass, or other sealing member 33 to block the opening of the recess 311. Thus, the recess 311 is hermetically sealed, forming an inner storage space S3 within the inner package 3. Furthermore, the inner storage space S3 houses a vibration element 6, a temperature control element 7, and a second circuit element 8.

[0041] Furthermore, the materials used to construct the inner base 31 and the inner cover 32 are not particularly limited. For example, the inner base 31 can be made of various ceramic materials such as alumina and titanium dioxide, and the inner cover 32 can be made of various metal materials such as Kovar alloy. This results in a robust inner package 3 with excellent mechanical strength. Additionally, by making the coefficients of linear expansion of both approximately equal, thermal stress generated on the inner package 3 can be reduced. Therefore, stress is less likely to be applied to the vibrating element 6, and the vibration characteristics of the vibrating element 6 are stable.

[0042] The inner storage space S3 is described in detail. The recess 311 has a first recess 311a that opens onto the lower surface 31b, a second recess 311b that opens onto the bottom surface of the first recess 311a but has an opening smaller than that of the first recess 311a, and a third recess 311c that opens onto the bottom surface of the second recess 311b but has an opening smaller than that of the second recess 311b. Furthermore, a vibration element 6 is disposed on the bottom surface of the first recess 311a, and a temperature control element 7 and a second circuit element 8 are arranged along the X-axis direction on the bottom surface of the third recess 311c.

[0043] The inner storage space S3 is airtight and in a depressurized state, preferably closer to a vacuum. This reduces the viscous resistance of the inner storage space S3 and improves the vibration characteristics of the vibrating element 6. However, the environment of the inner storage space S3 is not particularly limited.

[0044] Additionally, the inner base 31 is provided with: a plurality of internal terminals 341 disposed on the bottom surface of the first recess 311a; a plurality of internal terminals 342 and 343 disposed on the bottom surface of the second recess 311b; and a plurality of external terminals 344 disposed on the upper surface 31a of the inner base 31. Each internal terminal 341 is electrically connected to the vibration element 6 via a conductive bonding member B2 and a bonding wire BW3, each internal terminal 342 is electrically connected to the temperature control element 7 via a bonding wire BW4, and each internal terminal 343 is electrically connected to the second circuit element 8 via a bonding wire BW5.

[0045] Furthermore, these terminals 341, 342, 343, and 344 are appropriately electrically connected via internal wiring (not shown) formed within the inner package 3, thereby electrically connecting the vibration element 6, the temperature control element 7, the second circuit element 8, and the external terminal 344. In such an inner package 3, the internal and external components are electrically connected via the external terminal 344.

[0046] The aforementioned inner package 3 is fixed at the inner cover 32 to the bottom surface of the third upper recess 211c by a bonding member B3 with sufficiently low thermal conductivity. Furthermore, the bonding member B3 is not particularly limited; for example, various insulating resin materials such as silicone resin and epoxy resin can be used. By using an insulating material, the thermal conductivity of the bonding member B3 can be sufficiently reduced with a simple structure.

[0047] With this structure, the inner package 3 and the outer package 2 are insulated by the joining member B3, so the heat from the temperature control element 7 is less likely to escape to the outside via the outer package 2. Therefore, the vibration element 6 can be heated stably and effectively by the temperature control element 7. In particular, in this embodiment, the inner cover 32 is fixed to the bottom surface of the third upper recess 211c. Therefore, it can be ensured that the heat conduction distance between the fixing part fixed to the third upper recess 211c and the temperature control element 7 is longer, and the heat from the temperature control element 7 is less likely to escape to the outside via the outer package 2. The method of fixing the inner package 3 to the outer package 2 is not particularly limited.

[0048] <<Vibration Element 6>>

[0049] Vibrating element 6 is an SC-cut quartz vibrating element. For example... Figure 4 As shown, the vibration element 6 has a quartz substrate 61 cut out by SC and viewed as a rectangle, an excitation electrode 621 disposed in the center of the upper surface, a pad electrode 622 led out from the excitation electrode 621 and disposed in the edge of the upper surface, an excitation electrode 631 disposed in the center of the lower surface opposite to the excitation electrode 621, and a pad electrode 632 led out from the excitation electrode 631 and disposed in the edge of the lower surface.

[0050] The above description of the vibrating element 6 is not particularly limited in its structure. For example, the top view shape of the quartz substrate 61 is not limited to a rectangle; it can also be circular, elliptical, semi-circular, or other polygonal. Furthermore, it is possible to perform bevel machining on the outer edge of the quartz substrate 61, or convex machining to make the upper and lower surfaces of the quartz substrate 61 convex curved surfaces. Additionally, the vibrating element 6 may not use an SC-cut quartz vibrating element, but rather 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 resonating elements, etc.

[0051] The vibrating element 6 is fixed at its end to the bottom surface of the first recess 311a via the connecting member B2. Furthermore, the pad electrodes 622 and 632 are electrically connected to each internal terminal 341 via the connecting member B2 and the bonding wire BW3. However, the method of fixing and electrically connecting the vibrating element 6 is not particularly limited. For example, two pad electrodes, respectively electrically connected to the excitation electrode 621 and the excitation electrode 631, may be provided on the upper surface, and these two pad electrodes are fixed to the bottom surface of the first recess 311a via the connecting member.

[0052] <<Temperature Control Element 7>>

[0053] like Figure 3As shown, the temperature control element 7 includes a temperature sensor 71 and a heating circuit 72. The temperature sensor 71 functions as a temperature detection unit that detects the ambient temperature, particularly the temperature of the vibrating element 6, while the heating circuit 72 functions as a heating unit that heats the vibrating element 6. This temperature control element 7 is positioned on the bottom surface of the third recess 311c with its active surface facing downwards (towards the inner cover 32), and is electrically connected to multiple internal terminals 342 via bonding wires BW4. In this embodiment, the vibrating element 6 and the temperature control element 7 are housed in the same space, thus reducing the difference between the temperature sensor 71's detection result and the actual temperature of the vibrating element 6, resulting in an oscillator 1 with excellent frequency-temperature characteristics. Furthermore, the heating circuit 72 can be controlled without relying on the detection result of the temperature sensor 71. For example, another temperature sensor can be provided within the second circuit element 8 (described later), and the heating circuit 72 can be controlled based on the detection result of that temperature sensor.

[0054] <<Circuit Element 8>>

[0055] like Figure 3 As shown, the second circuit element 8 has an oscillation circuit 81 that causes the vibrating element 6 to oscillate. This oscillation circuit 81 amplifies the signal output from the vibrating element 6 and feeds it back to the vibrating element 6, thereby causing the vibrating element 6 to oscillate and generate an oscillation signal. Such a second circuit element 8 is disposed on the bottom surface of the third recess 311c with the active surface facing downward (towards the inner cover 32 side), and is electrically connected to a plurality of internal terminals 343 via bonding wire BW5.

[0056] <<Voltage-Controlled Quartz Oscillators 5>>

[0057] The voltage-controlled quartz oscillator 5 is the oscillator included in the PLL circuit 42 described later. For example... Figure 5 As shown, this voltage-controlled quartz oscillator 5 includes a package 51 and an oscillating element 55 and a circuit element 59 housed in the package 51.

[0058] The package 51 includes a base 52 and a cover 53. The base 52 is box-shaped and has a recess 521 with an opening on its lower surface 52b. The cover 53 is plate-shaped and is joined to the lower surface 52b of the base 52 via a sealing ring, a low-melting-point glass, or other sealing member 54 to block the opening of the recess 521. Thus, the recess 521 is hermetically sealed, forming a storage space S5 within the package 51. Furthermore, a vibration element 55 and a circuit element 59 are housed within the storage space S5.

[0059] Furthermore, the materials used to construct the base 52 and the cover 53 are not particularly limited. For example, the base 52 can be made of various ceramic materials such as alumina and titanium dioxide, and the cover 53 can be made of various metal materials such as Kovar alloy. This results in a robust package 51 with excellent mechanical strength. Additionally, by making the coefficients of linear expansion of both components approximately equal, thermal stress generated on the package 51 can be reduced. Therefore, it is less likely to apply stress to the vibrating element 55, and the vibration characteristics of the vibrating element 55 are stable.

[0060] The storage space S5 is described in detail. The recess 521 has a first recess 521a opening on its lower surface 52b, a second recess 521b opening on the bottom surface of the first recess 521a but smaller than the opening of the first recess 521a, and a third recess 521c opening on the bottom surface of the second recess 521b but smaller than the opening of the second recess 521b. Furthermore, a vibration element 55 is disposed on the bottom surface of the first recess 521a, and a circuit element 59 is disposed on the bottom surface of the third recess 521c. The storage space S5 is airtight, in a depressurized state, preferably closer to a vacuum. This reduces the viscous resistance of the storage space S5 and improves the vibration characteristics of the vibration element 55. The environment of the storage space S5 is not particularly limited.

[0061] Additionally, the base 52 is provided with: a plurality of internal terminals 561 disposed on the bottom surface of the first recess 521a; a plurality of internal terminals 562 disposed on the bottom surface of the second recess 521b; and a plurality of external terminals 564 disposed on the upper surface 52a of the base 52. Furthermore, each internal terminal 561 is electrically connected to the vibrating element 55 via a conductive bonding member B4, and each internal terminal 562 is electrically connected to the circuit element 59 via a bonding wire BW6. These terminals 561, 562, and 564 are appropriately electrically connected via internal wiring (not shown) formed within the base 52, electrically connecting the vibrating element 55, the circuit element 59, and the external terminals 564. In this package 51, the internal and external components are electrically connected via the external terminals 564.

[0062] Vibrating element 55 is an AT-cut quartz vibrating element. For example... Figure 6 As shown, the vibration element 55 has a rectangular quartz substrate 551 cut by AT cutting, excitation electrodes 553a and 554a arranged opposite to the upper and lower surfaces of the quartz substrate 551, pad electrodes 553b and 554b arranged on the upper surface of the quartz substrate 551, and lead-out electrodes 553c and 554c connecting the excitation electrodes 553a and 554a and the pad electrodes 553b and 554b.

[0063] The above description of the vibrating element 55 is not particularly limited in its structure. For example, the top view shape of the quartz substrate 551 is not limited to a rectangle; it can also be a circle, a rectangle other than a rectangle, or other polygons. Furthermore, it is possible to perform bevel machining on the outer edge of the quartz substrate 551 or convex machining to make the upper and lower surfaces of the quartz substrate 551 convex curved surfaces. Additionally, the vibrating element 55 may not use an AT-cut quartz vibrating element, but rather an SC-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 resonating elements, etc.

[0064] The vibrating element 55 is fixed at its end to the bottom surface of the first recess 521a via a pair of connecting members B4. Additionally, the pad electrodes 553b and 554b and each internal terminal 561 are electrically connected via the connecting members B4. However, the method of fixing the vibrating element 55 and the method of electrical connection are not particularly limited.

[0065] The circuit element 59 has an oscillation circuit 591 that causes the oscillating element 55 to oscillate. Such a circuit element 59 is disposed on the bottom surface of the third recess 521c with the active surface facing downward, and is electrically connected to a plurality of internal terminals 562 via bonding wire BW6.

[0066] like Figure 5 As shown, the voltage-controlled quartz oscillator 5 is fixed to the bottom surface of the lower recess 212 via a conductive connecting member B1. Furthermore, the external terminal 564 and the internal terminal 243 are electrically connected via the connecting member B1.

[0067] <<Circuit Element 4>>

[0068] like Figure 1 As shown, the first circuit element 4 has a temperature control circuit 41 for controlling the drive of the temperature control element 7, a part of the PLL circuit 42, and an output buffer circuit 43.

[0069] The temperature control circuit 41 controls the amount of current flowing through the resistor of the heating circuit 72 based on the output signal of the temperature sensor 71, thereby maintaining the vibrating element 6 at a constant temperature. For example, the temperature control circuit 41 controls the flow of a desired current through the resistor of the heating circuit 72 when the current temperature, as determined by the output signal of the temperature sensor 71, is lower than a set reference temperature, and prevents current from flowing through the resistor of the heating circuit 72 when the current temperature is higher than the reference temperature. Alternatively, the temperature control circuit 41 can also control the amount of current flowing through the resistor of the heating circuit 72 to increase or decrease based on the difference between the current temperature and the reference temperature. Furthermore, as mentioned above, the temperature control circuit 41 can also control the heating circuit 72 based on the detection result of the temperature sensor installed in the second circuit element 8.

[0070] like Figure 7 As shown, the PLL circuit 42 includes a first phase comparator 421 that receives the oscillation signal (i.e., the reference frequency signal) output from the oscillation circuit 81, a first low-pass filter 422, a voltage-controlled oscillator 423 that receives the DC signal from the first low-pass filter 422, and a first frequency divider 424 that receives the frequency signal output from the voltage-controlled oscillator 423. Furthermore, the frequency signal divided by the first frequency divider 424 is input to the first phase comparator 421. The first phase comparator 421 detects the phase difference between the reference frequency signal and the frequency signal and outputs it to the first low-pass filter 422. The first low-pass filter 422 removes high-frequency components from the output signal from the first phase comparator 421, converting it into a voltage, which is then output as the DC signal to control the voltage-controlled oscillator 423.

[0071] Furthermore, the first frequency divider 424 can be set to a fractional frequency division ratio by switching the integer division ratio, for example. Thus, the pre-stage PLL circuit section, composed of the first phase comparator 421, the first low-pass filter 422, the voltage-controlled oscillator 423, and the first frequency divider 424, functions as a fractional PLL circuit. As a result, the fractional PLL circuit can output a signal of any frequency.

[0072] Additionally, the PLL circuit 42 includes: a second phase comparator 425 that receives the frequency signal output from the voltage-controlled oscillator 423; a second low-pass filter 426; a voltage-controlled quartz oscillator 5; and a second frequency divider 427 that receives the frequency signal output from the voltage-controlled quartz oscillator 5. Furthermore, the frequency signal divided by the second frequency divider 427 is input to the second phase comparator 425. The second phase comparator 425 detects the phase difference between the frequency signal output from the voltage-controlled oscillator 423 and the frequency signal divided by the second frequency divider 427, and outputs it to the second low-pass filter 426. The second low-pass filter 426 removes high-frequency components from the output signal from the second phase comparator 425, converting it into a voltage, which is then output as a DC signal (frequency control signal) to control the voltage-controlled quartz oscillator 5.

[0073] Furthermore, the second frequency divider 427 is, for example, an integer frequency divider that performs an integer division on the input signal. Thus, the subsequent PLL circuit section, composed of the second phase comparator 425, the second low-pass filter 426, the voltage-controlled quartz oscillator 5, and the second frequency divider 427, functions as an integer frequency divider PLL circuit. Integer frequency divider PLL circuits can be circuits with less phase noise and simpler circuit structure.

[0074] Furthermore, the voltage-controlled quartz oscillator 5 outputs a frequency signal corresponding to the voltage of the DC signal to the output buffer circuit 43. That is, the oscillation frequency of the voltage-controlled quartz oscillator 5 is controlled according to the reference frequency signal output from the oscillation circuit 81.

[0075] The voltage-controlled quartz oscillator 5 and the first circuit element 4 are separately configured among the various circuit elements constituting the PLL circuit 42, but other elements can also be separately configured with the first circuit element 4. For example, the first low-pass filter 422 and the second low-pass filter 426 can also be separately configured with the first circuit element 4 and arranged side by side with the voltage-controlled quartz oscillator 5 on the bottom surface of the lower recess 212.

[0076] Here, as Figure 8 As shown, the voltage-controlled quartz oscillator 5 is disposed on the bottom surface of the lower recess 212 and is surrounded by legs 29. Therefore, the legs 29 function as windbreaks, preventing wind from easily blowing onto the voltage-controlled quartz oscillator 5. Thus, temperature fluctuations of the voltage-controlled quartz oscillator 5 caused by wind can be suppressed, effectively suppressing the deterioration of the phase noise characteristics of the output signal output from the output buffer circuit 43.

[0077] In particular, in this embodiment, the leg 29 is frame-shaped, surrounding the entire circumference of the pressure-controlled quartz oscillator 5 when viewed from above. Therefore, the aforementioned effects are more pronounced. Furthermore, as... Figure 1 As shown, the height H1 of the leg 29 from the bottom surface of the recess 212 is greater than the height H2 of the voltage-controlled quartz oscillator 5 from the bottom surface of the recess 212. Therefore, the entire area of ​​the voltage-controlled quartz oscillator 5 is contained within the lower recess 212, thus making the aforementioned effect more significant.

[0078] Furthermore, the leg 29 is integrally formed with the substrate 27; in other words, the leg 29 and the substrate 27 are formed together as part of the outer base 21. Therefore, the formation of the leg 29 becomes easy.

[0079] The oscillator 1 has been described above. As described above, this oscillator 1 includes: a vibrating element 6 as a first vibrating element; a second circuit element 8 as a circuit element that causes the vibrating element 6 to oscillate and generate an oscillation signal; an outer package 2 as a first package, which has a substrate 27, and an outer storage space S2 on the upper surface side, i.e., one main surface side, of the substrate 27 for housing the vibrating element 6 and the second circuit element 8; a vibrating element 55 as a second vibrating element, which is disposed on the lower surface side, i.e., another main surface side, of the substrate 27, and the oscillation frequency of the vibrating element 55 is controlled according to the oscillation signal; and legs 29 disposed on the lower surface side of the substrate 27 and arranged to surround the vibrating element 55 when viewed from above. According to this structure, the legs 29 function as windproof walls, suppressing temperature fluctuations of the vibrating element 55 caused by wind, and effectively suppressing the deterioration of the noise characteristics of the output signal.

[0080] In particular, in this embodiment, the leg 29 forms a frame that surrounds the entire circumference of the vibrating element 55 when viewed from above the substrate 27. Therefore, the aforementioned effects are more pronounced. That is, wind is less likely to reach the vibrating element 55, further suppressing temperature fluctuations in the vibrating element 55 caused by wind. Therefore, the deterioration of the noise characteristics of the output signal can be suppressed more effectively.

[0081] Furthermore, as described above, the oscillator 1 has an external terminal 244 disposed on the lower surface 21b of the top surface of the leg 29, and an internal wiring 25 disposed inside the leg 29 and electrically connected to the external terminal 244. Thus, by disposing of the external terminal 244 on the top surface of the leg 29, connection between the oscillator 1 and the external device 100 becomes easier. Additionally, by forming the internal wiring 25 inside the leg 29, it is less susceptible to interference.

[0082] Furthermore, as described above, the oscillator 1 has a side terminal 245 disposed on the side of the leg 29 and connected to the external terminal 244. Thus, when the oscillator 1 is connected to the external device 100, the side terminal 245 functions as a toothed structure. Consequently, solder H wets and spreads on the side terminal 245 to form solder legs, resulting in a stronger connection with the external device 100.

[0083] Furthermore, as described above, the leg 29 is integrally formed with the substrate 27. As a result, the formation of the leg 29 becomes easier.

[0084] Furthermore, as described above, the oscillator 1 has a temperature control element 7 that acts as a heater to heat the vibrating element 6. As a result, the temperature of the vibrating element 6 is stable, enabling it to exhibit superior frequency-temperature characteristics.

[0085] Furthermore, as described above, the oscillator 1 has an inner package 3 as a second package that houses the vibrating element 6 and the temperature control element 7. Moreover, the inner package 3 is bonded to the substrate 27 (the bottom surface of the third upper recess 211c) via an insulating bonding member B3. Thus, the inner package 3 and the outer package 2 are insulated from heat by the bonding member B3, preventing heat from the temperature control element 7 from easily escaping to the outside via the outer package 2. Therefore, the vibrating element 6 can be stably and effectively heated by the temperature control element 7.

[0086] <Second Implementation Method>

[0087] Figure 9 This is a cross-sectional view showing the oscillator of the second embodiment. Figure 10 This is a circuit diagram showing the PLL circuit included in the first circuit element of the oscillator.

[0088] In the oscillator 1 of this embodiment, except that an oscillator 50 is used instead of a voltage-controlled quartz oscillator 5, it is the same as in the first embodiment described above. Therefore, in the following description, this embodiment will be described mainly in terms of its differences from the first embodiment described above, and descriptions of the same matters will be omitted. In addition, in the figures of this embodiment, the same reference numerals are used to denote the same structures as in the embodiments described above.

[0089] like Figure 9 As shown, in the oscillator 1 of this embodiment, instead of the voltage-controlled quartz oscillator 5, an oscillator 50 in which the vibrating element 55 is housed in a package 51 is used. Furthermore, as... Figure 10 As shown, an oscillation circuit 591 that causes the vibrating element 55 to oscillate is formed in the first circuit element 4.

[0090] According to the second embodiment described above, the same effect as the first embodiment described above can also be achieved.

[0091] <Third Implementation Method>

[0092] Figure 11 This is a cross-sectional view showing the oscillator of the third embodiment.

[0093] In the oscillator 1 of this embodiment, except that the voltage-controlled quartz oscillator 5 is molded, it is the same as in the first embodiment described above. Therefore, in the following description, this embodiment will be described mainly in terms of its differences from the first embodiment described above, and descriptions of the same matters will be omitted. In addition, in the figures of this embodiment, the same reference numerals are used to denote the same structures as in the above embodiments.

[0094] like Figure 11As shown, in the oscillator 1 of this embodiment, the lower recess 212 is filled with resin material M, and the pressure-controlled quartz oscillator 5 is molded using this resin material M. According to this structure, the pressure-controlled quartz oscillator 5 is less susceptible to wind influence.

[0095] According to the third embodiment described above, the same effect as the first embodiment described above can also be achieved.

[0096] <Fourth Implementation>

[0097] Figure 12 This is a cross-sectional view showing the oscillator of the fourth embodiment. Figure 13 This is a top view of the oscillator viewed from the bottom surface side.

[0098] In the oscillator 1 of this embodiment, except for the structure of the leg 29, it is the same as that of the first embodiment described above. Therefore, in the following description, this embodiment will be described mainly for the differences from the first embodiment described above, and descriptions of the same matters will be omitted. In addition, in the figures of this embodiment, the same reference numerals are used to denote the same structures as in the above embodiment.

[0099] like Figure 12 and Figure 13 As shown, in the oscillator 1 of this embodiment, the leg 29 has a pair of unit legs 29A and 29B arranged in such a way that the voltage-controlled quartz oscillator 5 is sandwiched in the middle. In the illustrated arrangement, unit leg 29A is located on the positive side of the voltage-controlled quartz oscillator 5 in the X-axis direction, and unit leg 29B is located on the negative side of the X-axis direction.

[0100] Furthermore, each of the unit legs 29A and 29B extends along the Y-axis direction, which is orthogonal to their arrangement direction (X-axis), when viewed from above on the substrate 27. This structure prevents wind from the X-axis direction from reaching the voltage-controlled quartz oscillator 5. Therefore, temperature variations in the voltage-controlled quartz oscillator 5 caused by wind can be suppressed, and the deterioration of the noise characteristics of the output signal can be effectively suppressed.

[0101] Thus, in the oscillator 1 of this embodiment, the leg 29 has a pair of unit legs 29A and 29B arranged to sandwich the vibrating element 55 in the middle. The pair of unit legs 29A and 29B extend along the Y-axis direction, which is orthogonal to the arrangement direction of the pair of unit legs 29A and 29B, i.e., the X-axis direction, when viewed from above the substrate 27. With this structure, wind from the X-axis direction can be prevented by the unit legs 29A and 29B, suppressing temperature fluctuations of the vibrating element 55 caused by wind. Therefore, the deterioration of the noise characteristics of the output signal can be effectively suppressed.

[0102] According to the fourth embodiment described above, the same effect as the first embodiment described above can also be achieved.

[0103] <Fifth Implementation>

[0104] Figure 14 This is a cross-sectional view showing the oscillator of the fifth embodiment. Figure 15 It is shown Figure 14 A cross-sectional view of a modified example of the oscillator shown.

[0105] In the oscillator 1 of this embodiment, except that the leg 29 and the outer package 2 are separately constructed, it is the same as that of the first embodiment described above. Therefore, in the following description, this embodiment will be described mainly in terms of the differences from the first embodiment described above, and descriptions of the same matters will be omitted. In addition, in the figures of this embodiment, the same reference numerals are used to denote the same structures as in the above embodiment.

[0106] like Figure 14 As shown, in the oscillator 1 of this embodiment, the leg 29 and the outer casing 2 are separate components. This increases the design freedom of the leg 29 in terms of shape, material, etc., resulting in a leg 29 that can provide superior windproof performance.

[0107] This oscillator 1 has a leg substrate 9 disposed on the lower side of the outer package 2 and having legs 29 formed thereon. The lower recess 212 is omitted from the outer package 2, and the lower surface of the substrate 27 forms the lower surface 21b of the outer base 21. Furthermore, a plurality of connection terminals 246 electrically connected to various parts within the outer package 2 are disposed on the lower surface 21b.

[0108] On the other hand, the leg substrate 9 has a recess 91 with an opening on its lower surface 9b, thereby forming a frame-shaped leg 29 erected around the recess 91. Furthermore, a voltage-controlled quartz oscillator 5 is disposed on the bottom surface of the recess 91. Additionally, a plurality of connection terminals 921 are disposed on the upper surface 9a of the leg substrate 9, a plurality of internal terminals 924 electrically connected to the voltage-controlled quartz oscillator 5 are disposed on the bottom surface of the recess 91, and a plurality of external terminals 922 are disposed on the lower surface 9b of the leg substrate 9, i.e., the top surface of the leg 29. These terminals 921, 922, and 924 are connected via internal wiring (not shown) formed inside the leg substrate 9. Furthermore, a plurality of side terminals 923 connected to the external terminals 922 are disposed on the sides of the leg 29.

[0109] Furthermore, the material of the leg substrate 9 is not particularly limited; for example, it can be the same ceramic material as the outer base 21. This results in a leg substrate 9 that is robust and possesses excellent mechanical strength. Additionally, by making the coefficients of linear expansion of both components approximately equal, thermal stress can be reduced. Therefore, it is less likely to apply stress to the vibrating elements 6 and 55, and the oscillation characteristics of the vibrating elements 6 and 55 are stable. Furthermore, the leg substrate 9 can also be, for example, a printed circuit board (PCB). This allows for the manufacture of the leg substrate 9 at a lower cost.

[0110] The outer package 2 and the leg substrate 9 are joined by multiple conductive bonding members B7. Furthermore, the connection terminal 246 on the outer package 2 side and the connection terminal 921 on the leg substrate 9 side are electrically connected via the bonding members B7. In this oscillator 1, a connection to an external device 100 is made at the external terminal 922.

[0111] With this structure, the lower surface 21b of the outer base 21 and the upper surface 9a of the leg substrate 9 are both flat. Therefore, the processing characteristics in the manufacturing process are excellent, and the manufacturing of the oscillator 1 becomes easy.

[0112] Thus, in the oscillator 1 of this embodiment, the leg 29 and the substrate 27 are formed separately. As a result, the design freedom of the leg 29, such as its shape and material, is increased, resulting in a leg 29 that can exert a better windproof effect.

[0113] Furthermore, as mentioned above, the leg 29 can be a printed circuit board. This allows for the manufacture of the leg 29 at a lower cost.

[0114] According to the fifth embodiment described above, the same effects as those of the first embodiment can be achieved. Furthermore, as a variation of this embodiment, for example, ... Figure 15 As shown, the recess 91 can also extend through the upper surface 9a, and a pressure-controlled quartz oscillator 5 can be disposed on the lower surface 21b of the outer base 21. Therefore, compared to this embodiment, the oscillator 1 can be made thinner.

[0115] <Sixth Implementation>

[0116] Figure 16 This is a cross-sectional view showing the oscillator of the sixth embodiment. Figure 17 It is shown Figure 16 A cross-sectional view of a modified example of the oscillator shown.

[0117] In the oscillator 1 of this embodiment, except for the different structure of the leg substrate 9, it is similar to the one described above. Figure 15 The structure shown is the same. Therefore, in the following description, this embodiment will be described in the same way as described above. Figure 15The differences in the structures shown will be explained primarily, while descriptions of the same items will be omitted. Furthermore, in the figures of this embodiment, structures identical to those in the above embodiment are labeled with the same reference numerals.

[0118] like Figure 16 As shown, in the oscillator 1 of this embodiment, the leg substrate 9 has a recess 93 with an opening on its upper surface 9a. Furthermore, the leg substrate 9 is joined at its upper surface 9a to the lower surface 21b of the outer base 21 so as to house the pressure-controlled quartz oscillator 5 within the recess 93. Therefore, in the oscillator 1, a storage space S9 is formed on the lower surface 21b side of the substrate 27, serving as a second storage space for housing the pressure-controlled quartz oscillator 5. As a result, the pressure-controlled quartz oscillator 5 is less susceptible to wind influence.

[0119] Thus, the oscillator 1 of this embodiment has a storage space S9 on the lower surface side of the substrate 27, which serves as a second storage space for housing the vibration element 55. As a result, the vibration element 55 is less susceptible to the influence of wind.

[0120] According to the sixth embodiment described above, the same effects as those of the first embodiment can also be achieved. Furthermore, as a variation of this embodiment, for example, such as... Figure 17 As shown, the voltage-controlled quartz oscillator 5 can also be configured on the bottom surface of the recess 93.

[0121] <Seventh Implementation>

[0122] Figure 18 This is a cross-sectional view showing the oscillator of the seventh embodiment.

[0123] In the oscillator 1 of this embodiment, except that the inner package 3 is omitted, it is the same as in the first embodiment described above. Therefore, in the following description, this embodiment will be described mainly in terms of the differences from the first embodiment described above, and descriptions of the same matters will be omitted. In addition, in the figures of this embodiment, the same reference numerals are used for structures that are the same as those in the above embodiment. Furthermore, the electrical connections of each part are the same as in the first embodiment described above, therefore, descriptions of the terminals or bonding wires that electrically connect the parts to each other will be omitted hereafter.

[0124] like Figure 18As shown, in the oscillator 1 of this embodiment, the upper recess 211 has: a first upper recess 211a that opens on the upper surface 21a; a second upper recess 211b that opens on the bottom surface of the first upper recess 211a and has an opening smaller than that of the first upper recess 211a; a third upper recess 211c that opens on the bottom surface of the second upper recess 211b and has an opening smaller than that of the second upper recess 211b; and a fourth upper recess 211d that opens on the bottom surface of the third upper recess 211c and has an opening smaller than that of the third upper recess 211c. Furthermore, a temperature control element 7 is disposed on the bottom surface of the second upper recess 211b, a vibration element 6 is disposed on the temperature control element 7, and a circuit element 10 is disposed on the bottom surface of the fourth upper recess 211d. In addition, in circuit element 10, the first circuit element 4 and the second circuit element 8 are integrated, including an oscillation circuit 81, a temperature control circuit 41, a PLL circuit 42, and an output buffer circuit 43.

[0125] With this structure, the inner package 3 is omitted, and the oscillator 1 can be miniaturized compared to the first embodiment described above.

[0126] According to the seventh embodiment described above, the same effect as the first embodiment described above can also be achieved.

[0127] 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 may be added to the present invention. Additionally, the various embodiments may be appropriately combined.

Claims

1. An oscillator having: The first vibrating element; The second circuit element causes the first vibration element to oscillate, thereby generating an oscillation signal; The first package has a substrate, and a first receiving space for receiving the first vibrating element and the second circuit element is provided on a main surface side of the substrate; A temperature sensor that detects the temperature of the first vibrating element; The heating element heats the first vibrating element based on the detection result of the temperature sensor. The second package, housed in the first storage space, includes a base with a first recess and a cover that blocks the first recess, and houses the first vibration element, the second circuit element, the temperature sensor, and the heating element within the first recess; The second vibrating element has its oscillation frequency controlled according to the oscillation signal; A third circuit element causes the second vibrating element to oscillate; The third package houses the second vibrating element and the third circuit element; The second storage space houses the third package on the other main side of the substrate; Legs, which are disposed on the other main surface side of the substrate, are configured to surround the third package when viewed from above. The heating element is disposed on the bottom surface of the first recess. The cover is joined to the substrate via an insulating bonding member.

2. The oscillator according to claim 1, wherein, The oscillator has: External terminals, which are disposed on the top surface of the legs; and Internal wiring, which is disposed inside the leg, is electrically connected to the external terminals.

3. The oscillator according to claim 2, wherein, The oscillator has side terminals disposed on the side of the leg and connected to the external terminals.

4. The oscillator according to any one of claims 1 to 3, wherein, When viewed from above, the legs form a frame that surrounds the entire circumference of the third package.

5. The oscillator according to any one of claims 1 to 3, wherein, The legs have a pair of unit legs configured to sandwich the third package between them. When viewed from above, the pair of unit legs extend in directions orthogonal to the arrangement direction of the pair of unit legs.

6. The oscillator according to any one of claims 1 to 3, wherein, The leg is integrally formed with the substrate.

7. The oscillator according to any one of claims 1 to 3, wherein, The leg portion is formed separately from the substrate.

8. The oscillator according to claim 7, wherein, The legs are printed circuit boards.

9. The oscillator according to any one of claims 1 to 3, wherein, The oscillator has a leg substrate, which has a second recess that opens toward a main surface and receives the third package. One of the main surfaces of the base plate for the leg is bonded to the base plate.

10. The oscillator according to any one of claims 1 to 3, wherein, The first storage space has a first upper recess that opens toward one of the main surfaces of the substrate, and a second upper recess that opens toward the bottom surface of the first upper recess and is smaller than the first upper recess. The second package is disposed in the second upper recess. The oscillator also has a first circuit element, which, when viewed from above the substrate, overlaps with the second package and is disposed in the first upper recess. The first circuit element has: A temperature control circuit that controls the heating element; The PLL circuit is input with the oscillation signal; as well as An output buffer circuit is input with the frequency signal of the second vibrating element.

11. An oscillator having: The first vibrating element; The second circuit element causes the first vibration element to oscillate, thereby generating an oscillation signal; The first package has a substrate, and a first receiving space for receiving the first vibrating element and the second circuit element is provided on a main surface side of the substrate; A temperature sensor that detects the temperature of the first vibrating element; The heating element heats the first vibrating element based on the detection result of the temperature sensor. The second package, housed in the first storage space, includes a base with a first recess and a cover that blocks the first recess, and houses the first vibration element, the second circuit element, the temperature sensor, and the heating element within the first recess; The second vibrating element has its oscillation frequency controlled according to the oscillation signal; The third package houses the second vibrating element; The second storage space houses the third package on the other main side of the substrate; Legs, which are disposed on the other main surface side of the substrate, are configured to surround the third package when viewed from above. The heating element is disposed on the bottom surface of the first recess. The cover is joined to the substrate via an insulating bonding member.

12. The oscillator according to claim 11, wherein, The first storage space has a first upper recess that opens toward one of the main surfaces of the substrate, and a second upper recess that opens toward the bottom surface of the first upper recess and is smaller than the first upper recess. The second package is disposed in the second upper recess. The oscillator also has a first circuit element, which, when viewed from above the substrate, overlaps with the second package and is disposed in the first upper recess. The first circuit element has: A temperature control circuit that controls the heating element; The PLL circuit is input with the oscillation signal; as well as The output buffer circuit is input with the frequency signal of the second vibrating element; and An oscillating circuit that causes the second vibrating element to oscillate.

Images