Vibration device

Abstract

To provide a vibration device capable of suppressing deterioration of the vibration characteristics of a vibration element.SOLUTION: A vibration device includes: a base substrate having an installation surface on which mounting terminals are arranged; and a mounting surface that is opposite to the installation surface; a package mounted on the mounting surface of the base substrate; and a vibration element housed in the package and having one end joined to a mount electrode arranged on the package. Therein when a direction in which the one end and the other end of the vibration element are aligned is defined as a first direction, in the first direction, a center of the base substrate is located within the mount electrode.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vibration device. [Background technology]

[0002] The oscillator described in Patent Document 1 has a packaged crystal unit arranged on the upper surface of a ceramic base, a temperature compensation circuit arranged on the upper surface of the crystal unit, a bypass capacitor arranged on the upper surface of the ceramic base, and a frequency control circuit arranged on the upper surface of the ceramic base. In this oscillator, the crystal unit and the frequency control circuit are arranged with the bypass capacitor in between, so that the crystal unit and the temperature compensation circuit are less susceptible to the heat of the frequency control circuit, and further, because the crystal unit and the temperature compensation circuit are in close contact with each other, the temperature compensation circuit operates in accordance with the temperature of the crystal unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-142899 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, when an oscillator such as the one described above is mounted on a circuit board, thermal stress caused by the difference in linear expansion coefficient between the ceramic base and the circuit board is applied to the crystal unit, which may result in deterioration of the vibration characteristics of the crystal unit. Furthermore, the thermal stress applied to the crystal unit varies depending on the mounting position of the crystal unit relative to the ceramic base, but the mounting position of the crystal unit in the oscillator of Patent Document 1 does not sufficiently alleviate the thermal stress. [Means for solving the problem]

[0005] The resonation device of the present invention includes a base substrate having a mounting surface on which mounting terminals are arranged and a mounting surface opposite to the mounting surface; a package mounted on the mounting surface of the base substrate; a vibration element housed in the package and having one end joined to a mount electrode disposed on the package; When the direction in which the one end and the other end of the vibration element are aligned is defined as a first direction, In the first direction, the mount electrode is located at the center of the base substrate. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a cross-sectional view showing a vibration device according to a first embodiment. [Figure 2] 2 is a cross-sectional view of a temperature compensated crystal oscillator included in the resonator device of FIG. 1. [Figure 3] 2 is a plan view showing the bottom surface of a recess in a base substrate of the temperature compensated crystal oscillator. FIG. [Figure 4] FIG. 2 is a plan view showing a vibration element included in the temperature compensated crystal oscillator. [Figure 5] 10 is a plan view showing the bottom surface of a recess in a base substrate of an outer package. FIG. [Figure 6] FIG. 2 is a cross-sectional view showing a state in which the vibration device is mounted on a mounting substrate. [Figure 7] FIG. 2 is a plan view showing the arrangement of mount electrodes with respect to a base substrate. [Figure 8] FIG. 2 is a plan view showing the arrangement of mount electrodes with respect to a base substrate. [Figure 9] FIG. 10 is a plan view showing a vibration element included in a vibration device according to a second embodiment. [Figure 10] FIG. 2 is a plan view showing the arrangement of mount electrodes with respect to a base substrate. DETAILED DESCRIPTION OF THE INVENTION

[0007] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the vibration device of the present invention will now be described in detail with reference to the accompanying drawings.

[0008] First Embodiment FIG. 1 is a cross-sectional view of a resonator device according to a first embodiment. FIG. 2 is a cross-sectional view of a temperature-compensated crystal oscillator included in the resonator device of FIG. 1. FIG. 3 is a plan view showing the bottom surface of a recess in a base substrate included in the temperature-compensated crystal oscillator. FIG. 4 is a plan view showing a resonator element included in the temperature-compensated crystal oscillator. FIG. 5 is a plan view showing the bottom surface of a recess in a base substrate included in an outer package. FIG. 6 is a cross-sectional view showing a state in which the resonator device is mounted on a mounting substrate. FIGS. 7 and 8 are plan views showing the arrangement of mount electrodes on the base substrate. For ease of explanation, each of FIGS. 2A to 2D illustrates an X-axis, a Y-axis, and a Z-axis, which are orthogonal to each other. The direction along the X-axis is also referred to as the X-axis direction, the direction along the Y-axis is also referred to as the Y-axis direction, and the direction along the Z-axis is also referred to as the Z-axis direction. The arrow side in the Z-axis direction, which is the thickness direction of the resonator device 1, is also referred to as the "upper" side, and the opposite side is also referred to as the "lower" side. The planar view from the Z-axis direction is also simply referred to as the "planar view."

[0009] 1 includes an outer package 2 and a temperature compensated crystal oscillator (TCXO) 3 housed in the outer package 2. Such a resonator device 1 is used as an oscillator.

[0010] First, we will explain the temperature compensated crystal oscillator 3. As shown in Figure 2, the temperature compensated crystal oscillator 3 has an inner package 5 as a package, and a resonator element 6 and a circuit element 7 housed in the inner package 5.

[0011] The inner package 5 includes a base substrate 51. The base substrate 51 has an upper surface 51a and a lower surface 51b, which are opposite surfaces. The lower surface 51b faces the mounting surface 21a (described later). The base substrate 51 also includes a recess 511 with a bottom that opens to the upper surface 51a. The recess 511 includes a first recess 511a that opens to the upper surface 51a and a second recess 511b that opens to the bottom of the first recess 511a and has a smaller opening than the first recess 511a. In other words, the recess 511 is configured as a two-tiered recess. The circuit element 7 is fixed to the bottom surface of the second recess 511b, and the resonator element 6 is fixed to the bottom surface of the first recess 511a. This arrangement allows the resonator element 6 and the circuit element 7 to be stacked in the Z-axis direction within the inner package 5. This allows them to be housed compactly within the inner package 5, thereby enabling the temperature-compensated crystal oscillator 3 to be miniaturized. However, the arrangement of the vibration element 6 and the circuit element 7 is not particularly limited.

[0012] As shown in FIG. 3, a pair of mount electrodes 541 and 542 are arranged on the bottom surface of the first recess 511a. The pair of mount electrodes 541 and 542 are aligned in the Y-axis direction and spaced apart from each other. The vibration element 6 is bonded to the mount electrodes 541 and 542 via bonding members B1 and B2, and the mount electrodes 541 and 542 are electrically connected to the vibration element 6 via the bonding members B1 and B2. A plurality of internal terminals 543 are arranged on the bottom surface of the second recess 511b. The circuit element 7 is bonded to the plurality of internal terminals 543 via a plurality of bonding members B3, and the internal terminals 543 and the circuit element 7 are electrically connected via the bonding member B3. Four external terminals 544 are arranged on the lower surface 51b of the base substrate 51. The temperature-compensated crystal oscillator 3 is electrically connected to the outer package 2 via the four external terminals 544. The housing space S1 may be under atmospheric pressure, a reduced pressure, or preferably a state closer to a vacuum. In a reduced pressure state, the CI (crystal impedance) value of the vibration element 6 decreases, improving the oscillation characteristics of the vibration element 6. However, the atmosphere of the accommodation space S1 is not particularly limited.

[0013] As shown in FIG. 2, the inner package 5 has a plate-shaped lid 52. The lid 52 is bonded to the upper surface 51a of the base substrate 51 via a bonding member and closes the opening of the recess 511. By closing the opening of the recess 511 with the lid 52 in this way, an airtight storage space S1 is formed inside the inner package 5. The resonator element 6 and the circuit element 7 are housed in the storage space S1. The storage space S1 is in a reduced pressure state, preferably a state closer to a vacuum. This reduces the CI (crystal impedance) value of the resonator element 6 and improves the oscillation characteristics of the resonator element 6. However, the atmosphere of the storage space S1 is not particularly limited.

[0014] The inner package 5 has been described above. Although not particularly limited, the base substrate 51 can be made of a ceramic such as alumina, and the lid 52 can be made of a metal material such as kovar. This makes it possible to sufficiently increase the mechanical strength of the inner package 5 while aligning the linear expansion coefficients of the base substrate 51 and the lid 52 to approximately the same value. This makes it possible to minimize thermal stress that occurs in the inner package 5 due to the difference in linear expansion coefficients between the base substrate 51 and the lid 52. This makes it difficult for thermal stress to be applied to the vibration element 6 arranged in the inner package 5, thereby effectively suppressing deterioration of the vibration characteristics of the vibration element 6.

[0015] The vibration element 6 is an AT-cut quartz crystal vibration element. AT-cut quartz crystal vibration elements have third-order frequency-temperature characteristics and therefore excellent frequency stability. As shown in FIG. 4, the vibration element 6 is arranged along the X-axis direction, with the base end (one end) on the negative side in the X-axis direction and the tip end (the other end) on the positive side in the X-axis direction. This vibration element 6 includes a rectangular quartz crystal substrate 61 cut out by AT cut and electrodes arranged on the surface of the quartz crystal substrate 61. The electrodes include a pair of excitation electrodes 621 and 622 arranged opposite each other on the top and bottom surfaces of the quartz crystal substrate 61, and a pair of pad electrodes 623 and 624 arranged on the bottom surface of the quartz crystal substrate 61. The excitation electrode 621 and the pad electrode 623 are electrically connected, and the excitation electrode 622 and the pad electrode 624 are electrically connected. The pad electrodes 623 and 624 are located at the base end of the quartz crystal substrate 61, i.e., the end on the negative side in the X-axis direction, and are arranged side by side in the Y-axis direction.

[0016] However, there is no particular limitation on the configuration of the vibration element 6. For example, the planar shape of the quartz crystal substrate 61 is not limited to a rectangle and may be a circle. Furthermore, as the vibration element 6, in addition to an AT-cut quartz crystal vibration element, an SC-cut quartz crystal vibration element, a BT-cut quartz crystal vibration element, a tuning fork-type quartz crystal vibration element, a surface acoustic wave resonator, other piezoelectric vibration elements, a MEMS (Micro Electro Mechanical Systems) resonator element, etc. may also be used.

[0017] The vibrating element 6 has its base end joined to the bottom surface of the first recess 511a by a pair of conductive bonding members B1 and B2. The bonding members B1 and B2 are spaced apart and arranged side by side in the Y-axis direction. The bonding member B1 contacts the pad electrode 623 and the mount electrode 541, electrically connecting them. Similarly, the bonding member B2 contacts the pad electrode 624 and the mount electrode 542, electrically connecting them. The bonding members B1 and B2 are not particularly limited, and may be, for example, conductive bonding members such as metal bumps, solder, brazing material, metal paste, and conductive resin adhesive.

[0018] 2, the circuit element 7 is bonded to the bottom surface of the second recess 511b by a bonding member B3 and is electrically connected to the internal terminal 543. The circuit element 7 also has a temperature sensor 71 and an oscillation circuit 72. The oscillation circuit 72 has a function of oscillating the vibration element 6 and generating a temperature-compensated clock signal (frequency signal) based on the temperature detected by the temperature sensor 71. Specifically, the oscillation circuit 72 is electrically connected to the vibration element 6 and has an oscillation circuit unit that amplifies the output signal of the vibration element 6 and causes the vibration element 6 to oscillate by feeding back the amplified signal to the vibration element 6, and a temperature compensation circuit unit that performs temperature compensation based on temperature information output from the temperature sensor 71 so that frequency fluctuations of the clock signal are smaller than the frequency-temperature characteristics of the vibration element 6 itself.

[0019] The oscillator circuit 72 may be, for example, a Pierce oscillator circuit, an inverter oscillator circuit, a Colpitts oscillator circuit, a Hartley oscillator circuit, etc. The temperature compensation circuit may be, for example, one that adjusts the oscillation frequency of the oscillator circuit by adjusting the capacitance of a variable capacitance circuit connected to the oscillator circuit, or one that adjusts the frequency of the output signal of the oscillator circuit by a PLL circuit or a direct digital synthesizer circuit.

[0020] In this way, by housing both the temperature sensor 71 and the vibration element 6 in the inner package 5, it is possible to arrange the temperature sensor 71 in the same space as the vibration element 6 and in the vicinity of the vibration element 6. Therefore, there is little discrepancy between the actual temperature of the vibration element 6 and the temperature detected by the temperature sensor 71, and the temperature sensor 71 can detect the temperature of the vibration element 6 with higher accuracy. Therefore, temperature compensation by the oscillation circuit 72 becomes more accurate.

[0021] In this embodiment, the temperature sensor 71 is configured as an IC temperature sensor and is built into the circuit element 7, which is a single integrated circuit, but this is not limiting. That is, the circuit element 7 may be configured with an integrated circuit that incorporates the oscillation circuit 72 and a discrete component that is the temperature sensor 71. In this case, the temperature sensor 71 may be configured with, for example, a thermistor, a thermocouple, or the like. Furthermore, the location of the temperature sensor 71 is not particularly limited as long as it is within the accommodation space S1 and can detect the temperature of the vibration element 6, and it may be located on the base substrate 51 or the circuit element 7, for example.

[0022] The four external terminals 544 arranged on the lower surface 51b of the base substrate 51 are electrically connected to the circuit elements 7 via the corresponding internal terminals 543. As shown in Fig. 3, these four external terminals 544 include a VDD external terminal 544a for supplying power to the circuit element 7, an OUT external terminal 544b for outputting a clock signal from the circuit element 7, a GND external terminal 544c for connecting the circuit element 7 to GND, and an NC external terminal 544d for frequency adjustment.

[0023] The lower surface 51b on which these four external terminals 544 are arranged has a generally rectangular shape elongated in the X-axis direction in a plan view from the Z-axis direction. The lower surface 51b has a pair of sides L11 and L12 arranged side by side in the X-axis direction and extending in the Y-axis direction, and a pair of sides L13 and L14 arranged side by side in the Y-axis direction and extending in the X-axis direction. Of the pair of sides L11 and L12, the side L11 serving as the third side is located on the positive side in the X-axis direction, i.e., toward the tip end of the vibration element 6, and the side L12 serving as the fourth side is located on the negative side in the X-axis direction, i.e., toward the base end of the vibration element 6. The OUT external terminal 544b and the GND external terminal 544c are arranged side by side in the Y-axis direction on the side L11, and the VDD external terminal 544a and the NC external terminal 544d are arranged side by side in the Y-axis direction on the side L12. In particular, in this embodiment, these four external terminals 544 are arranged at the four corners of the lower surface 51b. In this way, by arranging the GND external terminal 544c next to the OUT external terminal 544b, the GND external terminal 544c functions as a shield, and it is possible to effectively suppress the intrusion of noise into the clock signal.

[0024] The above describes the temperature compensated crystal oscillator 3. Next, the outer package 2 will be described.

[0025] As shown in Fig. 1, the outer package 2 has a base substrate 21. The base substrate 21 has an upper surface and a lower surface. The base substrate 21 also has a bottomed recess 211 that opens to the upper surface. In such a base substrate 21, the bottom surface of the recess 211 is the mounting surface 21a, and the lower surface is the mounting surface 21b. The mounting surface 21a and the mounting surface 21b are opposite each other.

[0026] 5, four internal terminals 241 corresponding to the four external terminals 544 of the temperature compensated crystal oscillator 3 are arranged on the mounting surface 21a. These four internal terminals 241 are electrically connected to the corresponding external terminals 544 via the bonding members B4. That is, the four internal terminals 241 include a VDD internal terminal 241a electrically connected to the VDD external terminal 544a, an OUT internal terminal 241b electrically connected to the OUT external terminal 544b, a GND internal terminal 241c electrically connected to the GND external terminal 544c, and an NC internal terminal 241d electrically connected to the NC external terminal 544d.

[0027] Furthermore, four mounting terminals 242 are arranged on the mounting surface 21b. Each mounting terminal 242 is electrically connected to a corresponding internal terminal 241 via wiring (not shown) formed on the base substrate 21. These four mounting terminals 242 include a VDD mounting terminal 242a electrically connected to the VDD internal terminal 241a, an OUT mounting terminal 242b electrically connected to the OUT internal terminal 241b, a GND mounting terminal 242c electrically connected to the GND internal terminal 241c, and an NC mounting terminal 242d electrically connected to the NC internal terminal 241d.

[0028] The mounting surface 21b on which these four mounting terminals 242 are arranged has a generally rectangular shape elongated in the X-axis direction in a plan view from the Z-axis direction. The mounting surface 21b has a pair of sides L21, L22 arranged side by side in the X-axis direction and extending in the Y-axis direction, and a pair of sides L23, L24 arranged side by side in the Y-axis direction and extending in the X-axis direction. Of the pair of sides L21, L22, the side L21 serving as the first side is located on the positive side in the X-axis direction, i.e., the tip side of the vibration element 6, and the side L22 serving as the second side is located on the negative side in the X-axis direction, i.e., the base end side of the vibration element 6. The OUT mounting terminal 242b and the GND mounting terminal 242c are arranged side by side in the Y-axis direction on the side L21, and the VDD mounting terminal 242a and the NC mounting terminal 242d are arranged side by side in the Y-axis direction on the side L22. In particular, in this embodiment, these four mounting terminals 242 are arranged at the four corners of the mounting surface 21b. In this way, by arranging the GND mounting terminal 242c next to the OUT mounting terminal 242b, the GND mounting terminal 242c functions as a shield, and it is possible to effectively suppress the intrusion of noise into the clock signal.

[0029] As shown in FIG. 1 , the outer package 2 has a plate-shaped lid 22. The lid 22 is bonded to the upper surface of the base substrate 21 via a bonding member and closes the opening of the recess 211. By closing the opening of the recess 211 with the lid 22, an airtight storage space S2 is formed inside the outer package 2, i.e., between the base substrate 21 and the lid 22. The temperature-compensated crystal oscillator 3 is housed in the storage space S2. This protects the temperature-compensated crystal oscillator 3. The storage space S2 may be at atmospheric pressure, a reduced pressure, or preferably a state closer to a vacuum. In a reduced pressure state, the insulation properties of the outer package 2 are enhanced, making the temperature-compensated crystal oscillator 3 less susceptible to external environmental influences such as wind. This stabilizes the temperature of the vibration element 6, thereby suppressing fluctuations in the vibration characteristics of the vibration element 6. However, the atmosphere of the storage space S2 is not particularly limited.

[0030] The outer package 2 has been described above. Similar to the inner package 5, the base substrate 21 can be made of ceramics such as alumina, and the lid 22 can be made of a metal material such as kovar, although this is not a limitation. This allows the linear expansion coefficients of the base substrate 21 and the lid 22 to be roughly the same while sufficiently increasing the mechanical strength of the outer package 2. Therefore, it is possible to minimize the thermal stress that occurs in the outer package 2 due to the difference in the linear expansion coefficients between the base substrate 21 and the lid 22. This makes it difficult for thermal stress to be applied to the vibration element 6 disposed in the inner package 5, effectively suppressing deterioration of the vibration characteristics of the vibration element 6.

[0031] The above briefly describes the configuration of the resonator device 1. As shown in FIG. 6 , the resonator device 1 is mounted on the mounting substrate 100 via a conductive bonding member B5. Furthermore, each mounting terminal 242 is electrically connected to a terminal 110 disposed on the mounting substrate 100 via the bonding member B5. When the resonator device 1 is mounted on the mounting substrate 100, thermal stress due to the difference in linear expansion coefficient between the base substrate 21 and the mounting substrate 100 occurs in the base substrate 21. This thermal stress may be transmitted to the temperature-compensated crystal oscillator 3, degrading the vibration characteristics of the resonator element 6. Therefore, in the resonator device 1 of this embodiment, the fixing position of the temperature-compensated crystal oscillator 3 relative to the base substrate 21 is carefully considered to prevent the thermal stress from being transmitted to the resonator element 6. This effectively suppresses the deterioration of the vibration characteristics of the resonator element 6.

[0032] 7, the temperature-compensated crystal oscillator 3 is fixed to the base substrate 21 so that the center O of the base substrate 21 is located within the mount electrodes 541 and 542 in the X-axis direction. In other words, when an axis that intersects with the center O and extends in the Y-axis direction is defined as a central axis Jy, the temperature-compensated crystal oscillator 3 is fixed to the base substrate 21 so that the central axis Jy passes through the mount electrodes 541 and 542 in a plan view from the Z-axis direction. Since the thermal stress decreases closer to the center O of the base substrate 21, by fixing the temperature-compensated crystal oscillator 3 to the base substrate 21 in this positional relationship, the thermal stress generated in the base substrate 21 is less likely to be transmitted to the temperature-compensated crystal oscillator 3, and deterioration of the vibration characteristics of the vibration element 6 can be effectively suppressed.

[0033] In particular, in this embodiment, the temperature compensated crystal oscillator 3 is fixed to the base substrate 21 so that the central axis Jy passes through the bonding members B1 and B2 on the mount electrodes 541 and 542 in a plan view from the Z-axis direction. Since thermal stress generated in the base substrate 21 is ultimately transmitted to the vibration element 6 via the bonding members B1 and B2, by positioning the bonding members B1 and B2 on the central axis Jy, the thermal stress generated in the base substrate 21 is less likely to be transmitted to the vibration element 6. Therefore, deterioration of the vibration characteristics of the vibration element 6 can be more effectively suppressed.

[0034] In this way, to align the mount electrodes 541 and 542 with the central axis Jy, the temperature-compensated crystal oscillator 3 in the resonator device 1 is positioned offset toward the positive side of the X-axis direction relative to the base substrate 21. That is, the distance D1 between the sides L11 and L21 is smaller than the distance D2 between the sides L12 and L22. Therefore, in the resonator device, the OUT external terminal 544b is positioned on the side L11 of the bottom surface 51b, and the OUT mounting terminal 242b is positioned on the side L21 of the mounting surface 21b. This allows the OUT external terminal 544b and the OUT mounting terminal 242b to be positioned closer to each other. This shortens the wiring length between the OUT external terminal 544b and the OUT mounting terminal 242b, effectively suppressing noise from entering the clock signal.

[0035] 7, in the vibration device 1, when a central axis Jx is an axis that intersects with the center O and extends in the X-axis direction, the temperature-compensated crystal oscillator 3 is fixed to the base substrate 21 so that, in a plan view from the Z-axis direction, point Q, which is equidistant from the centers of the mount electrodes 541 and 542, overlaps with the central axis Jx. With this configuration, thermal stress generated in the base substrate 21 is less likely to be transmitted by the vibration element 6. Therefore, deterioration of the vibration characteristics of the vibration element 6 can be more effectively suppressed.

[0036] Note that the term "equal" used herein not only means that the distance from the center of the mount electrode 541 to point Q is the same as the distance from the center of the mount electrode 542 to point Q, but also includes a case where there is a slight error, for example, an error of 5% or less, between these two distances due to, for example, errors that may occur during manufacturing. Furthermore, in this embodiment, point Q is defined as a point that is equidistant from the centers of the mount electrodes 541 and 542, but this is not limiting, and point Q may also be defined as a point that is equidistant from an arbitrary point on the mount electrode 541 to an arbitrary point on the mount electrode 542.

[0037] In particular, in this embodiment, point Q coincides with a point on the mount electrodes 541 and 542 that is equidistant from the centers of the bonding members B1 and B2. In other words, the distance from the center of the bonding member B1 to point Q is equal to the distance from the center of the bonding member B2 to point Q. As described above, thermal stress generated in the base substrate 21 is ultimately transmitted to the vibration element 6 via the bonding members B1 and B2. Therefore, by positioning point Q, which is equidistant from the centers of the bonding members B1 and B2, on the central axis Jx, the thermal stress generated in the base substrate 21 is less likely to be transmitted to the vibration element 6. Therefore, deterioration of the vibration characteristics of the vibration element 6 can be more effectively suppressed.

[0038] Furthermore, in the base substrate 21, large thermal stress occurs near the mounting terminals 242, which are the joints with the mounting substrate 100. Therefore, as shown in FIG. 8, in the resonation device 1, the temperature-compensated crystal oscillator 3 is fixed to the base substrate 21 so that the external terminals 544 do not overlap the mounting terminals 242 in a plan view from the Z-axis direction. With this configuration, the temperature-compensated crystal oscillator 3 can be positioned to avoid locations where large thermal stress occurs. Therefore, the thermal stress generated in the base substrate 21 is further inhibited from being transmitted to the resonator element 6, and deterioration of the vibration characteristics of the resonator element 6 can be more effectively suppressed.

[0039] Furthermore, in plan view from the Z-axis direction, the area of ​​the inner package 5 is 20% or less, and preferably 10% or less, of the area of ​​the base substrate 21. This allows the temperature-compensated crystal oscillator 3 to be compactly arranged in the center of the base substrate 21, avoiding the outer periphery of the base substrate 21. This makes it even more difficult for thermal stress generated in the base substrate 21 to be transmitted to the vibration element 6. This makes it possible to more effectively suppress deterioration of the vibration characteristics of the vibration element 6.

[0040] As an example, if the area of ​​the inner package 5 is 2.0 mm × 1.6 mm and the area of ​​the base substrate is 5.0 mm × 3.2 mm, the area of ​​the inner package 5 is 20% or less of the area of ​​the base substrate 21. Also, if the area of ​​the inner package 5 is 2.0 mm × 1.6 mm and the area of ​​the base substrate is 7.0 mm × 5.0 mm, the area of ​​the inner package 5 is 10% or less of the area of ​​the base substrate 21.

[0041] The above describes the resonator device 1. As described above, the resonator device 1 includes the base substrate 21 having the mounting surface 21b on which the mounting terminals 242 are arranged and the mounting surface 21a opposite to the mounting surface 21b, the inner package 5 mounted on the mounting surface 21a of the base substrate 21, and the resonator element 6 housed in the inner package 5 and having one end, i.e., a base end, joined to mount electrodes 541 and 542 arranged on the inner package 5. When the direction in which both ends of the resonator element 6 are aligned is defined as the X-axis direction as a first direction, the center O of the base substrate 21 is located within the mount electrodes 541 and 542 in the X-axis direction. This configuration makes it difficult for thermal stress generated in the base substrate 21 to be transmitted to the resonator element 6. Therefore, deterioration of the vibration characteristics of the resonator element 6 can be effectively suppressed.

[0042] As described above, the inner package 5 has a pair of mount electrodes 541, 542 arranged along the Y-axis direction, which is a second direction orthogonal to the X-axis direction, and a point Q equidistant from each of the mount electrodes 541, 542 is located at the center O of the base substrate 21 in the Y-axis direction. With this configuration, thermal stress generated in the base substrate 21 is less likely to be transmitted by the vibration element 6. Therefore, deterioration of the vibration characteristics of the vibration element 6 can be more effectively suppressed.

[0043] As described above, the resonator device 1 has the lid 22 that is bonded to the base substrate 21 and forms an accommodation space S2 between the lid 22 and the base substrate 21 to accommodate the resonator element 6. With this configuration, the resonator element 6 can be protected.

[0044] As described above, the resonator device 1 includes a circuit element 7 that is housed in the inner package 5 and includes an oscillator circuit 72 that oscillates the resonator element 6 to output a clock signal. This allows the resonator device to be used as an oscillator.

[0045] As described above, the mounting surface 21b of the base substrate 21 has a side L21 as a first side and a side L22 as a second side, which are spaced apart in the X-axis direction. The inner package 5 has an external terminal 544 located on the bottom surface 51b, which is an opposing surface facing the mounting surface 21a and biased toward the side L21. The bottom surface 51b also has a side L11 as a third side located on the side L21 side and a side L12 as a fourth side located on the side L22 side, which are spaced apart in the X-axis direction. The external terminal 544 is located on the side L11 of the bottom surface 51b and has an OUT external terminal 544b that outputs a clock signal. The mounting terminal 242 is located on the side L21 of the mounting surface 21b and has an OUT mounting terminal 242b that is electrically connected to the OUT external terminal 544b. This configuration allows the OUT external terminal 544b and the OUT mounting terminal 242b to be positioned closer to each other. Therefore, the wiring length between the OUT external terminal 544b and the OUT mounting terminal 242b can be shortened, and the inclusion of noise in the clock signal can be effectively suppressed.

[0046] As described above, the external terminal 544 is disposed adjacent to the OUT external terminal 544b on the lower surface 51b and has a GND external terminal 544c connected to ground, and the mounting terminal 242 is disposed adjacent to the OUT mounting terminal 242b on the mounting surface 21b and has a GND mounting terminal 242c electrically connected to the GND external terminal 544c. With this configuration, the GND external terminal 544c and the GND mounting terminal 242c function as shields, effectively suppressing noise from entering the clock signal. Note that "the mounting terminals are disposed adjacent to each other" means that they are disposed side by side with no other mounting terminals between them in a plan view of the base substrate 21.

[0047] Furthermore, as described above, in the resonation device 1, the external terminals 544 and the mounting terminals 242 do not overlap in a plan view of the base substrate 21, that is, in a plan view from the Z-axis direction. With this configuration, thermal stress generated in the base substrate 21 is less likely to be transmitted by the resonator element 6. Therefore, deterioration of the vibration characteristics of the resonator element 6 can be more effectively suppressed.

[0048] Furthermore, as described above, the area of ​​the inner package 5 in a plan view of the base substrate 21, that is, in a plan view from the Z-axis direction, is 20% or less of the area of ​​the base substrate 21. With this configuration, thermal stress generated in the base substrate 21 is less likely to be transmitted by the vibration element 6. Therefore, deterioration of the vibration characteristics of the vibration element 6 can be more effectively suppressed.

[0049] Furthermore, as described above, the area of ​​the inner package 5 in a plan view of the base substrate 21, that is, in a plan view from the Z-axis direction, is 10% or less of the area of ​​the base substrate 21. With this configuration, thermal stress generated in the base substrate 21 is less likely to be transmitted by the vibration element 6. Therefore, deterioration of the vibration characteristics of the vibration element 6 can be more effectively suppressed.

[0050] Second Embodiment Fig. 9 is a plan view showing a vibration element included in a vibration device according to a second embodiment of the present invention, Fig. 10 is a plan view showing the arrangement of mount electrodes with respect to a base substrate.

[0051] This embodiment is similar to the resonator device of the first embodiment described above, except for the configuration of the temperature compensated crystal oscillator 3. In the following explanation, the differences between this embodiment and the previous embodiment will be mainly described, and explanations of similar points will be omitted. Furthermore, in each drawing of this embodiment, the same components as those in the previous embodiment are denoted by the same reference numerals.

[0052] 9, in the temperature compensated crystal oscillator 3 of this embodiment, pad electrodes 623, 624 of the vibration element 6 are arranged opposite to each other on the upper and lower surfaces of the crystal substrate 61. The vibration element 6 is bonded to the mount electrode 542 via one bonding member B2, and the pad electrode 624 is electrically connected to the mount electrode 542 via the bonding member B2. Meanwhile, the pad electrode 623 is electrically connected to the mount electrode 541 via a bonding wire BW.

[0053] As shown in FIG. 10, the temperature compensated crystal oscillator 3 is fixed to the base substrate 21 so that the mount electrode 542 is positioned at the center O of the base substrate 21.

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

[0055] While the vibration device of the present invention has been described above based on the illustrated embodiment, the present invention is not limited thereto, and the configuration of each part can be replaced with any configuration having a similar function. Furthermore, any other components may be added to the present invention. Furthermore, the above-described embodiments may be combined as appropriate.

[0056] In the above-described embodiment, the temperature compensated crystal oscillator 3 is housed in the outer package 2, but this is not limiting, and for example, the circuit element 7 may be an oscillator that does not include a temperature compensation circuit unit. Also, the circuit element 7 may be omitted from the resonator device. [Explanation of symbols]

[0057] 1... resonator device, 100... mounting substrate, 110... terminal, 2... outer package, 21... base substrate, 21a... mounting surface, 21b... mounting surface, 211... recess, 22... lid, 241... internal terminal, 241a... VDD internal terminal, 241b... OUT internal terminal, 241c... GND internal terminal, 241d... NC internal terminal, 242... mounting terminal, 242a... VDD mounting terminal, 242b... OUT mounting terminal, 242c... GND mounting terminal, 242d... NC mounting terminal, 3... temperature compensated crystal oscillator, 5... inner package, 51... base substrate, 51a... upper surface, 51b... lower surface, 511... recess, 511a... first recess, 511b... second recess, 52... lid, 541... mount electrode, 542... mount electrode, 543 ...internal terminal, 544...external terminal, 544a...VDD external terminal, 544b...OUT external terminal, 544c...GND external terminal, 544d...NC external terminal, 6...vibration element, 61...quartz crystal substrate, 621...excitation electrode, 622...excitation electrode, 623...pad electrode, 624...pad electrode, 7...circuit element, 71...temperature sensor, 72...oscillating circuit, B1...bonding member, B2...bonding member, B3...bonding member, B4...bonding member, B5...bonding member, BW...bonding wire, D1...separation distance, D2...separation distance, Jx...central axis, Jy...central axis, L11...side, L12...side, L13...side, L14...side, L21...side, L22...side, L23...side, L24...side, O...center, Q...point, S1...accommodation space, S2...accommodation space

Claims

1. a base substrate having a mounting surface on which mounting terminals are arranged and a mounting surface opposite to the mounting surface; a package mounted on the mounting surface of the base substrate; a vibration element housed in the package and having one end joined to a mount electrode disposed on the package; When the direction in which the one end and the other end of the vibration element are aligned is defined as a first direction, A vibration device characterized in that, in the first direction, the center of the base substrate is located within the mount electrode.

2. the package has a pair of the mount electrodes arranged along a second direction perpendicular to the first direction, The vibrating device according to claim 1 , wherein the points equidistant from the mount electrodes are located at the center of the base substrate in the second direction.

3. The vibration device according to claim 1 , further comprising a lid joined to the base substrate, forming an accommodation space between the lid and the base substrate for accommodating the vibration element.

4. The vibrating device according to claim 1 , further comprising a circuit element housed in the package and including an oscillation circuit that oscillates the vibrating element to output a clock signal.

5. the mounting surface of the base substrate has a first side and a second side spaced apart in the first direction, the package has external terminals arranged biased toward the first side and arranged on an opposing surface facing the mounting surface, the opposing surfaces are spaced apart in the first direction and have a third side located on the first side and a fourth side located on the second side, the external terminal is disposed on the third side of the opposing surface and includes an OUT external terminal that outputs the clock signal; The resonator device according to claim 4 , wherein the mounting terminal includes an OUT mounting terminal that is disposed on the first side of the mounting surface and is electrically connected to the OUT external terminal.

6. the external terminal has a GND external terminal that is arranged adjacent to the OUT external terminal on the opposing surface and is connected to ground; The resonator device according to claim 5 , wherein the mounting terminals include a GND mounting terminal that is disposed adjacent to the OUT mounting terminal on the mounting surface and is electrically connected to the GND external terminal.

7. The resonation device according to claim 5 , wherein the external terminals and the mounting terminals do not overlap in a plan view of the base substrate.

8. The resonation device according to claim 1 , wherein the area of ​​the package is 20% or less of the area of ​​the base substrate in a plan view of the base substrate.

9. The resonation device according to claim 1 , wherein the area of ​​the package is 10% or less of the area of ​​the base substrate in a plan view of the base substrate.

Images