Crystal vibrator with built-in temperature sensor

Abstract

To provide a crystal vibrator with a built-in temperature sensor having a new structure that can improve hysteresis of frequency-temperature characteristics of a crystal vibrator piece more than before.SOLUTION: A crystal vibrator 10 comprises a container 13, a recessed part 17, an AT-cut crystal vibrator piece 11 mounted in the container, and a temperature sensor 15 mounted in the recessed part. Two adhesive pads 13a and 13b are provided along a first direction (a) on a circumference portion of the recessed part of the container. The crystal vibrator further comprises a pedestal 23 made of crystals, arranged between the two adhesive pads and the crystal vibrator piece, one end of one surface of which is made to adhere to the two adhesive pads and in which the crystal vibrator piece is made to adhere to the other surface thereof, at two positions along an X-axis of the crystals or at two positions along a Z'-axis of the crystals. The pedestal has the X-axis or the Z'-axis, depending on whether the crystal vibrator piece is made to adhere thereto at the two positions along the X-axis or the piece is made to adhere thereto at the two positions along the Z'-axis, where the crystal vibrator piece is made to adhere to the two adhesive pads in a positional relation in which the axes are in parallel to the first direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a quartz crystal resonator having a structure in which a temperature sensor such as a thermistor is built in. [Background technology]

[0002] In recent years, crystal units with built-in temperature sensors, which have an AT-cut crystal element and a temperature sensor (typically a thermistor) built into a single container, have become popular. In these units, the oscillation frequency of the crystal element is corrected on the chipset side based on the temperature information detected by the temperature sensor, allowing the desired frequency to be obtained with greater precision.

[0003] Typical examples of crystal units with built-in temperature sensors are those with a so-called single-chamber structure and an H-shaped structure. The former has a crystal resonator element and a temperature sensor mounted in a single chamber and hermetically sealed (see, for example, paragraph 75, Figure 7, etc. of Patent Document 1). The latter has a first chamber mounting a crystal resonator element and a second chamber mounting a temperature sensor stacked back to back, with the first chamber being hermetically sealed (see, for example, the abstract, Figure 1, etc. of Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-70552 [Patent Document 2] Japanese Patent Publication No. 2022-140662 Summary of the Invention [Problem to be solved by the invention]

[0005] Further improvements in temperature compensation accuracy are desired for both single-chamber and H-shaped structures. One effective way to achieve this is to reduce the hysteresis of the frequency-temperature characteristics of the quartz crystal resonator blank. In other words, when the temperature of a quartz crystal resonator with a built-in temperature sensor is raised from t1 degrees to tn (tn>t1) degrees and then immediately lowered to t1 degrees, minimizing the difference between the frequency-temperature characteristics of the quartz crystal resonator blank during temperature rise and temperature fall is effective in improving temperature compensation accuracy. This application has been made in consideration of the above points, and therefore the purpose of this application is to provide a crystal unit with a built-in temperature sensor that has a new structure that can improve the hysteresis of the frequency-temperature characteristics of a crystal unit compared to conventional crystal units. [Means for solving the problem]

[0006] In order to achieve this object, according to the first invention of this application, a single-chamber structured temperature sensor built-in quartz crystal unit is provided with a container for mounting an AT-cut quartz crystal piece, a recessed portion provided on the bottom side of the container for mounting a temperature sensor, the quartz crystal piece having a rectangular shape in a plan view mounted within the container, and the temperature sensor mounted within the recessed portion, two adhesive pads provided along a first direction on a portion of the container that corresponds to the periphery of the recess; a quartz crystal base provided between the two bonding pads and the quartz crystal vibrating piece, the quartz crystal base being bonded to the two bonding pads at one end of one surface thereof, and the quartz crystal vibrating piece being bonded to the other surface thereof at two points along the X-axis of the quartz crystal or two points along the Z'-axis of the quartz crystal; The quartz crystal base has the quartz crystal's X-axis, Z'-axis, or Z-axis parallel to the surface, depending on whether the quartz crystal vibrating piece is bonded to the base at two points along the X-axis or two points along the Z'-axis, and is bonded to the two bonding pads in a positional relationship such that this axis is parallel to the first direction (however, the Z'-axis is an axis that is offset from the quartz crystal's true Z-axis due to the cutting angle of the AT-cut quartz crystal piece).

[0007] According to a second aspect of the present application, there is provided an H-structured temperature sensor built-in crystal unit including a first chamber in which an AT-cut crystal vibrating piece is mounted, a second chamber in which a temperature sensor is mounted and whose bottom surface is connected to the first chamber, the crystal vibrating piece having a rectangular shape in plan view mounted in the first chamber, and the temperature sensor mounted in the second chamber. two adhesive pads provided in the first chamber along a first direction; a quartz crystal base provided between the two bonding pads and the quartz crystal vibrating piece, the quartz crystal base being bonded to the two bonding pads at one end of one surface thereof, and the quartz crystal vibrating piece being bonded to the other surface thereof at two points along the X-axis of the quartz crystal or two points along the Z'-axis of the quartz crystal; The quartz crystal base has the quartz crystal's X-axis, Z'-axis, or Z-axis parallel to the surface, depending on whether the quartz crystal vibrating piece is bonded to the base at two points along the X-axis or two points along the Z'-axis, and is bonded to the two bonding pads in a positional relationship such that this axis is parallel to the first direction (however, the Z'-axis is an axis that is offset from the quartz crystal's true Z-axis due to the cutting angle of the AT-cut quartz crystal piece). [Effects of the Invention]

[0008] According to the first and second inventions of this application, a quartz crystal base is cantilevered and bonded to the adhesive pad of the container or the first chamber, and an AT-cut quartz crystal resonator piece is cantilevered and bonded to this quartz crystal base, thereby realizing a quartz crystal resonator with an integrated temperature sensor that makes extensive use of a cantilever support structure. Furthermore, depending on whether the quartz crystal blank is connected to the base at two points along the X-axis of the quartz crystal or at two points along the Z'-axis of the quartz crystal, a quartz crystal base with an axis corresponding to this axis in a direction parallel to the surface can be used, and the quartz crystal blank and the quartz crystal base can be bonded in a positional relationship such that the crystal axis of the quartz crystal blank and the crystal axis of the base are parallel. Therefore, the quartz crystal blank and the quartz crystal base can be positioned so that the crystallographic conditions of the portion between the two bonding points, which are said to be most susceptible to the effects of thermal stress, are similar to each other, thereby reducing the effects of the thermal expansion coefficient and the like compared to when this is not done. Therefore, the cantilever support structure and the structure using a specified quartz crystal base can reduce thermal stress, etc., and it is possible to provide a quartz crystal unit with a built-in temperature sensor having a new structure that can improve the hysteresis of the frequency-temperature characteristics of the quartz crystal resonator piece compared to conventional structures. [Brief explanation of the drawings]

[0009] [Figure 1] 1A and 1B are diagrams illustrating a quartz crystal resonator 10 according to a first embodiment of the first invention. [Figure 2] 1 is a diagram for explaining the relationship between the quartz crystal vibrating piece and the base in the present invention, and in particular, a diagram for explaining the relationship regarding the crystal axes of the quartz crystal. FIG. [Figure 3] 1 is an exploded view of the crystal unit 10 illustrating the connection relationship between the crystal unit 10, the base, and the container. FIG. [Figure 4] 10A and 10B are diagrams illustrating a crystal resonator 30 according to a second embodiment of the first invention. [Figure 5] 10A and 10B are diagrams for explaining a first embodiment and a second embodiment of the second invention. [Figure 6] 10A and 10B are diagrams for explaining the thickness of a quartz crystal base and the degree of stress relaxation. [Figure 7] 1 is a diagram illustrating the relationship between the distance h between the quartz crystal vibrating piece and the quartz crystal base, the angle θ between the quartz crystal vibrating piece and the quartz crystal base, and the crystal impedance. [Figure 8]10A and 10B are diagrams for explaining the dimensions of a quartz crystal base relative to a quartz crystal vibrating piece and an excitation electrode, and for explaining modified examples of the base structure. [Figure 9] 10A and 10B are diagrams for explaining a preferred example of the relationship between the depth of the recess for the temperature sensor and the thickness of the quartz crystal base. [Figure 10] 10A and 10B are diagrams for explaining specific examples of recesses for temperature sensors. [Figure 11] 1A and 1B are diagrams for explaining specific examples of quartz crystal vibrating pieces; [Figure 12] 1A and 1B are diagrams illustrating a preferred container and a preferred base. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the first and second inventions of this application will be described with reference to the drawings. Note that the drawings used for the description are merely schematic illustrations to enable understanding of these inventions. In addition, in the drawings used for the description, similar components are designated by the same numbers, and their description may be omitted. Furthermore, the structural examples, components used, etc. described in the following description are merely preferred examples within the scope of this invention. Therefore, the present invention is not limited to the following embodiments.

[0011] 1. First embodiment of the present invention 1-1. First embodiment 1 and 2 are diagrams illustrating a crystal unit 10 with an integrated temperature sensor (hereinafter sometimes abbreviated as crystal unit 10) according to a first embodiment of the first invention. In particular, FIG. 1(A) is a top view of crystal unit 10, FIG. 1(B) is a cross-sectional view taken along line PP in FIG. 1(A), and FIG. 1(C) is a bottom view. Note that FIG. 1(A) shows the crystal unit 10 with lid member 19 removed. In addition, FIG. 2 is a diagram particularly illustrating the relationship between crystal unit 11 and base 23.

[0012] This quartz crystal resonator 10 includes a container 13 for mounting an AT-cut quartz crystal vibrating piece 11, a recess 17 provided on the bottom side of the container 13 for mounting a temperature sensor 15, the quartz crystal vibrating piece 11 mounted in the container 13, and the temperature sensor 15 mounted in the recess 17. Furthermore, the quartz crystal unit 10 has two adhesive pads 13a and 13b provided at a predetermined distance along a first direction a (see FIG. 1(A)) in a portion that corresponds to the periphery of the recess 17 of the container 13. Here, in this example, the first direction a is the direction along the short side of the container 13. The recess 17 is formed in a state where it is biased toward one side of the long side of the container 13, and this bias widens a part of the periphery of the recess 17 of the container 13, and adhesive pads 13a and 13b are provided in this widened part.

[0013] The quartz crystal unit 10 further includes a quartz crystal base 23. This quartz crystal base 23 is provided between the two bonding pads 13a, 13b and the quartz crystal vibrating piece 11, and is bonded to the two bonding pads 13a, 13b at one end of one surface with a first conductive adhesive 21, while the quartz crystal vibrating piece 11 is bonded to the other surface with a second conductive adhesive 25 at two locations along the X-axis of the quartz crystal or two locations along the Z'-axis of the quartz crystal. Furthermore, depending on whether the quartz crystal vibrating piece 11 is bonded to the pedestal at two points along the quartz crystal's X axis or at two points along the quartz crystal's Z' axis, this axis (the quartz crystal's X axis, Z' axis, or Z axis) is parallel to the surface of the pedestal, and the quartz crystal is bonded to two bonding pads 13a, 13b in a positional relationship such that this axis is parallel to the first direction a. This will be described in detail later with reference to Figure 2. The Z' axis is an axis that is offset from the quartz crystal's true Z axis due to the cutting angle of the AT-cut quartz crystal piece. The quartz crystal vibrating piece 11 is adhered to the base 23 in a predetermined relationship with a second conductive adhesive 25. The quartz crystal vibrating piece 11 and the temperature sensor 15 are hermetically sealed, for example, vacuum sealed, with a lid member 19. Each of the components will be described in detail below.

[0014] As shown in FIG. 2, the AT-cut quartz crystal vibrating piece 11 has a square shape in plan view, in this example a rectangular shape, and has a predetermined thickness according to the oscillation frequency. The AT-cut quartz crystal vibrating piece 11 has excitation electrodes 11a on both the front and back main surfaces, and an extraction electrode 11b that is extracted from the excitation electrodes 11a to one of the short sides of the quartz crystal vibrating piece. The quartz crystal vibrating piece 11 is selected according to the design of the quartz crystal unit from among so-called X-long ones, in which the long sides are parallel to the X-axis, which is the crystal axis of the quartz crystal, and the short sides are parallel to the Z'-axis, which is the crystal axis of the quartz crystal, or so-called Z-long ones, in which the long sides are parallel to the Z'-axis of the quartz crystal and the short sides are parallel to the X-axis of the quartz crystal, or ones with a rectangular planar shape and one side parallel to either the X-axis or the Z'-axis of the quartz crystal.

[0015] In this case, the container 13 is a ceramic package having a square planar shape, specifically a rectangular shape. The container 13 has bank portions 13c along its edges, and the crystal vibrating piece 11 and temperature sensor 15 are mounted in the space surrounded by the bank portions 13c. Specifically, the container 13 has a recess 17 (also referred to as a second recess in the description of suitable containers, etc. in Section 7 below) that is square in plan view and in which the temperature sensor 15 is mounted on the bottom side, and two bonding pads 13a, 13b are provided around the recess 17. Furthermore, the container 13 has connection terminals 17a, 17b for mounting the temperature sensor 15 on the surface that corresponds to the bottom of the recess 17. A base 23 is mounted on the bonding pads 13a, 13b, and the temperature sensor 15 is mounted on the connection terminals 17a, 17b. In this example, the temperature sensor 15 is mounted in the recess 17 so that its longitudinal direction is perpendicular to the first direction a, and therefore the connection terminals 17a and 17b are arranged side by side along a direction perpendicular to the first direction a.

[0016] Furthermore, the four corners of the outer bottom surface of the container 13 are provided with external connection terminals 13d, 13e, 13f, and 13g for connecting the crystal unit 10 to an electronic device, such as an electronic board for a mobile phone (see FIG. 1(C)). The bonding pads 13a, 13b, connection terminals 17a, and connection terminals 17b are electrically connected to the external connection terminals 13d, 13e, 13f, and 13g in a predetermined relationship by via wiring or castellation wiring (not shown). The top surface of the bank portion 13c of the container 13 is treated according to the sealing method. In this example, a seam sealing method is used, and a seam ring (not shown) is provided on the top surface of the bank portion 13c. The sealing method may also be a soldering method using gold and tin. In this case, a metallized pattern for gold and tin sealing may be provided on the top surface of the bank portion 13c. The bank portion 13c is made of ceramic. As shown in FIG. 1B, a conductor 13m is embedded in a predetermined position on the bank portion 13c and the container 13 to electrically connect the lid member 19 to one terminal 13f of the external connection terminals for a temperature sensor. The external connection terminal 13f is connected to the ground of an electronic device (not shown) to which the crystal unit 10 is connected. This connection structure ensures an electromagnetic shielding structure for the crystal unit 10. The container 13 including the recess 17, the bonding pads 13a and 13b, the bank portion 13c, the conductor 13m, the connection terminals 17a and 17b, and the external connection terminals 13d, 13e, 13f, and 13g can be manufactured by, for example, ceramic package manufacturing technology.

[0017] The temperature sensor 15 is preferably configured with a thermistor. However, the temperature sensor 15 is not limited to a thermistor, and other elements, such as a diode, may also be used. This is because a temperature sensor can be realized by utilizing the temperature dependency of the PN junction of the diode. Any material may be used for the lid member 19 depending on the sealing method. When the sealing method is seam sealing, the lid member 19 may be made of, for example, a Kovar material plated with nickel. Although not limited to this, it is preferable to use a silicone-based conductive adhesive for the first conductive adhesive 21 and the second conductive adhesive 25. The first conductive adhesive 21 and the second conductive adhesive 25 may be the same or different, but it is preferable to use the same adhesive.

[0018] Although not limited to this, it is preferable to use a pedestal 23 that is rectangular in plan view because this makes it easier to process the pedestal. However, the planar shape of the pedestal 23 may be other shapes, such as a triangle or a trapezoid with a narrower tip. The size of the base 23 is not limited to this, but in the example shown in FIG. 1 etc., it is larger in plan view than the quartz crystal vibrating piece 11. In some cases, it is preferable for the size of the base to be smaller than the quartz crystal vibrating piece. This point will be discussed later. Furthermore, the inventors have found that there is a preferred value for the thickness of the base 23. This point will also be discussed later. The appropriate base 23 is used depending on whether the quartz crystal vibrating piece 11 is connected to the base at two points along the X-axis of the quartz crystal, or at two points along the Z'-axis of the quartz crystal. This will be explained in detail with reference to Figure 2. The coordinate axes indicated by X, Y', and Z' in Figure 2 are the crystal axes of the quartz crystal derived from the AT-cut. The Y' and Z' axes indicate that the axes are offset from the quartz crystal's original Y and Z axes depending on the cutting angle of the AT-cut.

[0019] FIG. 2A illustrates a pedestal in which the quartz crystal vibrating piece 11 is connected to the pedestal 23 at two locations along the X-axis of the quartz crystal. Specifically, two extraction electrodes 11b are located at two separate locations along the X-axis of the quartz crystal of the quartz crystal vibrating piece 11, and the quartz crystal vibrating piece 11 is bonded to the pedestal 23a or 23b at these locations. The pedestal 23 in this case includes the X-axis of the quartz crystal parallel to its surface, and the quartz crystal vibrating piece 11 can be connected to the pedestal 23a at two locations along the X-axis. Specifically, the pedestal 23a shown in the lower left of FIG. 2A is made of an AT-cut quartz crystal piece and is provided with adhesive wires 23a1 and 23a2 at two locations along the X-axis of the quartz crystal. Alternatively, the pedestal 23b shown in the lower right of FIG. 2A may be made of a Z-cut quartz crystal piece and is provided with adhesive wires 23a1 and 23a2 at two locations along the X-axis of the quartz crystal. The quartz crystal vibrating piece 11 and the base 23a or 23b are bonded to the adhesive pad and the quartz crystal vibrating piece 11 is bonded to the base so that the X axes of the respective crystals are parallel to the first direction a (see Figure 1(A)).

[0020] 2(B) is an explanatory diagram of a pedestal when the quartz crystal vibrating piece 11 is connected to the pedestal 23 at two points along the Z' axis of the quartz crystal. In this case, the pedestal 23c includes the Z axis or Z' axis of the quartz crystal within its plane, and the quartz crystal vibrating piece 11 can be connected to the pedestal at two points along the Z axis or Z' axis. Specifically, the pedestal 23c is made of an AT-cut quartz crystal piece, and is provided with adhesive wiring 23c1 and 23c2 along the Z' axis of the quartz crystal on the pedestal, corresponding to the extraction electrode 11b of the quartz crystal vibrating piece 11. The quartz crystal vibrating piece 11 and the pedestal 23c are bonded to the adhesive pad and the quartz crystal vibrating piece 11 is bonded to the pedestal so that the Z' axes of the respective quartz crystals are parallel to the first direction a (see Figure 1(A)). In each of the above-mentioned bases 23a, 23b, and 23c, the X-axis and Z'-axis of the base do not have to be exactly the same as the X-axis and Z'-axis of the quartz crystal vibrating piece. Within the scope of the object of the present invention, there may be some angular deviation between the two axes, or the two axes may not be parallel to each other.

[0021] As can be seen from the exploded view of the crystal unit 10 shown in FIG. 3, the crystal base 23 is connected and fixed to the case 13 at one short side at the position of the adhesive pads 13a and 13b of the case 13 in a cantilevered manner by the first conductive adhesive 21. The crystal resonator element 11 is also connected and fixed at one short side at the position of the adhesive wiring (23c1, 23c2) of the crystal base 23 in a cantilevered manner by the second conductive adhesive 25. Therefore, the crystal unit 10 has a structure in which the adhesive pads 13a, the first conductive adhesive 21, one end of the base 23, the second conductive adhesive 25, and one end of the crystal resonator element 11 overlap in the vertical direction, and the crystal base 23 and the crystal resonator element 11 are cantilevered at the same end. The effects of this structure will be described in detail later with reference to experimental results and analysis results using the finite element method.

[0022] 1-2. Second embodiment Next, a crystal resonator 30 according to a second embodiment of the first invention will be described. This will be explained with reference to FIG. 4. FIG. 4 is an explanatory diagram showing an exploded view of the crystal resonator 30. The difference between the crystal resonator 30 and the crystal resonator 10 is the position where the base and the crystal resonator piece are connected. 3 and described above, the crystal unit 10 of the first embodiment has a structure in which the bonding pads 13a and 13b, the first conductive adhesive 21, one end of the base 23, the second conductive adhesive 25, and one end of the crystal resonator element 11 are vertically overlapped, and the crystal base 23 and the crystal resonator element 11 are cantilevered at the same end. In contrast, the crystal unit 30 of the second embodiment has a structure in which one end of the base 23d is connected to the bonding pads 13a and 13b with the first conductive adhesive 21, and one end of the crystal resonator element 11 is connected to the other longitudinal end of the base 23d with the second conductive adhesive 25, as shown in FIG. 4. In other words, the bonding points of the first conductive adhesive 21 and the bonding points of the second conductive adhesive 26 are located at opposite longitudinal ends of the base 23d. Therefore, in this case, the adhesive wires 23d1 and 23d2 of the base 23d are elongated in the longitudinal direction of the base 23d. In the case of the quartz crystal resonator 30, since the quartz crystal resonator piece 11 is adhered to the free end of the base 23d, there are concerns about the tip of the base 23d shaking. However, the quartz crystal resonator 30 has the same or even greater effect in reducing thermal stress as the quartz crystal resonator 10.

[0023] 2. Second Embodiment of the Invention Next, an embodiment of the second invention (crystal resonator with an H-shaped structure and built-in temperature sensor) will be described with reference to FIGS. 5(A) and 5(B). FIG. 5A is a cross-sectional view of a quartz crystal resonator 50 according to a first embodiment of the second invention, and corresponds to FIG. 1A. The difference between the first and second aspects of the present invention is that the chamber 13x is formed by stacking a first chamber 13x1 in which an AT-cut quartz crystal vibrating piece is mounted and a second chamber 13x2 whose bottom is connected to the first chamber and in which a temperature sensor 15 is mounted, so that the chamber 13x has an H-shaped cross section cut in the thickness direction, and the quartz crystal vibrating piece 11 and the temperature sensor 15 are mounted in the corresponding chambers. Therefore, the rest of the configuration is substantially the same as the configuration of the first embodiment described with reference to Figures 1 and 2, so a description thereof will be omitted. 5(B) is a cross-sectional view of a quartz crystal resonator 60 according to a second embodiment of the second invention, corresponding to the cross-sectional view in FIG. 4. This quartz crystal resonator 60 differs from the quartz crystal resonator 50 in that one end of the base 23 is bonded to the bonding pad 13a or the like, and the quartz crystal resonator piece 11 is bonded to the base 23 at the other end in the longitudinal direction of the base 23. In other words, the structure described with reference to FIG. 4 is applied to the second invention. The effect of this application can be obtained even with the H-shaped structure shown in FIGS. 5(A) and 5(B).

[0024] 3. Experimental results and finite element analysis results illustrating the features of the present invention 3-1.About the base One of the features of the present invention is that a predetermined pedestal made of quartz crystal is used as the pedestal, and the results of the investigation that led to this will be explained below. 3-1-1. Frequency hysteresis with and without base The inventors of this application fabricated multiple crystal resonators (Example) 10 described with reference to Figures 1 and 2, as well as multiple crystal resonators (Comparative Example) without a base, i.e., a crystal resonator blank 11 directly bonded at one end to bonding pads 13a and 13b with a silicone conductive adhesive. Both the Example and Comparative Example were prototyped using a so-called 1612-size ceramic package. The AT-cut crystal resonator blank used in both the Example and Comparative Example experiments was an X-long crystal resonator blank, sized to fit in a 1612-size ceramic package, with an oscillation frequency of 76.8 MHz (crystal resonator blank thickness of approximately 22 μm), and equipped with a specified excitation electrode. The external dimensions of the crystal resonator blank used were, specifically, an X dimension of approximately 0.75 mm and a Z' dimension of approximately 0.51 mm. The base used in the Example was an AT-cut crystal resonator blank with an X dimension of 1.0 mm, a Z' dimension of 0.8 mm, and a thickness of 40 μm. Here, the 1612 size ceramic package is a package whose external long side dimension is approximately 1.6 mm and short side dimension is approximately 1.2 mm, and whose internal structure is as explained with reference to FIG.

[0025] Next, the hysteresis characteristics of the frequency-temperature characteristics of each of the samples of the example and comparative example were measured. The measurements were performed using a temperature control device (not shown) that had a substrate with a Peltier element and a temperature control unit that controlled the temperature of the Peltier element, a frequency measurement device, and a temperature measurement device. Specifically, the samples of the example and comparative examples are connected to a substrate having a Peltier element. Of the external connection terminals (13d to 13g in FIG. 1(C)) of the sample, terminals 13e and 13g connected to quartz crystal vibrating piece 11 are connected to a frequency measuring device, and terminals 13d and 13f connected to temperature sensor 15 are connected to a temperature measuring device. Next, the temperature of the Peltier element is raised from t1 to tn (tn>t1) degrees using a temperature control device at predetermined temperature intervals and under predetermined temperature rise conditions, and then immediately lowered to t1 under the same temperature change conditions as during the temperature rise. The actual temperatures of the quartz crystal resonator 10 during this temperature rise and fall were measured using the temperature sensor 15 and temperature measurement device, and the frequency of the quartz crystal resonator piece 11 was measured using a frequency measurement device. Based on these measurement results, the frequency-temperature characteristics during temperature rise and temperature fall were extracted. Next, the frequency difference between the frequency-temperature characteristics during temperature rise and the frequency-temperature characteristics during temperature fall at the same temperature, that is, frequency hysteresis information, was determined, and the average value of the frequency difference was calculated for each evaluation sample. These average values ​​were then used to determine the average, maximum, and minimum values ​​of the frequency difference for the sample group of the example and the sample group of the comparative example. These results are shown in Table 1. The frequency difference is shown in ppm, which is the ratio of the frequency difference divided by the oscillation frequency. From Table 1, it can be seen that when comparing the average values ​​of the frequency difference during temperature rise and fall defined above, the example has a value of 0.06 / 0.026 ≒ 0.23, which is approximately one-fifth of the comparative example. The maximum value of the example also has a value of 0.09 / 0.96 ≒ 0.09, which is approximately one-eleventh of the comparative example. TIFF2025168235000002.tif36140

[0026] 3-1-2. Base material and crystal axis of the base Additionally, as another evaluation, the following evaluation was performed using the finite element method. Four types of analytical models were created using the finite element method, imitating the quartz crystal resonator 10 described with reference to Figure 1. The quartz crystal axis conditions for the direction in which the two bonding points of the AT-cut quartz crystal resonator element are aligned, as well as the base material and crystal axis conditions, were set as shown in Table 2 below. The von Mises stress generated at the center point of the quartz crystal resonator element in each analytical model was then determined when the temperature of each analytical model was changed from 25°C to 105°C. The results are shown in Table 2. TIFF2025168235000003.tif79154

[0027] Table 2 shows that the stress generated at the center of the quartz crystal vibrating piece due to the above temperature changes is approximately 366 to 386 kPa in analytical models 1 and 2, but is approximately 10 kPa in analytical models 3 and 4, which is about 1 / 37th of the normal value. It can be seen that stress can be reduced by using a quartz crystal base with a crystal axis that matches the crystal axis corresponding to the line segment connecting the two bonding points of the quartz crystal vibrating piece, with the appropriate axial relationship. Therefore, from the results in Tables 1 and 2, it can be seen that taking into consideration the bonding direction of the two points of the AT-cut quartz crystal piece, and appropriately selecting and using an AT-cut quartz crystal base or a Z-cut quartz crystal base as the base is effective in reducing thermal stress in the bonding structure of the quartz crystal unit.

[0028] 3-1-3. Base thickness and stress on the crystal element In another evaluation using the finite element method, we investigated how the thickness of the quartz crystal pedestal affects stress in the quartz crystal resonator blank. Specifically, we created eight analytical models, each of which corresponds to analytical model 4 in Table 2, with the thickness T of the AT-cut quartz crystal pedestal varying in 10-μm increments between 10 μm and 80 μm. We then measured the von Mises stress generated at the center of each analytical model's quartz crystal resonator blank when the temperature was changed from 25°C to 105°C. Figure 6(A) shows the results, with the horizontal axis representing the pedestal thickness and the vertical axis representing the stress value (relative value). Figure 6(B) also shows the definitions of the thickness T of the pedestal 23 and the thickness t of the quartz crystal resonator blank 11. From Figure 6(A), it can be seen that, if we consider the stress when the base thickness T is 10 μm as the standard, the stress is about one-third when the base thickness T is 20 μm, and about one-sixth when the base thickness T is 30 μm. Up to a base thickness T of 60 μm, the stress rises to about one-fifth of the standard, and as the base thickness T increases further, the stress tends to decrease. Therefore, it can be said that a thicker base thickness T is better, but if it is too thick, the base will not fit inside the crystal unit's container, so there is a limit. Taking this into consideration, when considering the optimum value for the base thickness, the following can be said.

[0029] In this analysis model, the thickness of the quartz crystal blank is approximately 22 μm (derived from the oscillation frequency of 76.8 MHz). Taking the quartz crystal blank thickness of 22 μm as the standard, the base thickness T should be 20 μm≦T, or thicker than the quartz crystal blank. Considering the ability to fit it into a container, 20 μm≦T≦70 μm, or even better, the thickness of the quartz crystal blank≦T≦70 μm, is preferable. Furthermore, stress is smaller when the base thickness T is in the range from approximately 20 μm, slightly thinner than the quartz crystal blank, to 60 μm, so the base thickness T should be 20 μm≦T≦60 μm, and even better, 30 μm≦T≦60 μm. Generalizing the above findings, the following can be said. When the thickness of the crystal vibrating piece is t and the thickness of the base is T, T≧0.9t is preferable. 0.9t≦T≦3.1t or t≦T≦3.1t is preferable, 0.9t≦T≦2.7t or t≦T≦2.7t is more preferable, and 1.3t≦T≦2.7t is even more preferable. Here, the value 0.9 is based on the above lower values, 20 / 22≒0.9. The value 3.1 is based on 70 / 22≒3.18. The value 2.7 is based on 60 / 22≒2.7. The value 1.3 is based on 30 / 22≒1.36.

[0030] 3-1-4. Distance between the crystal element and the base, and the angle between them In addition, the following evaluation was performed as another evaluation. FIG. 7 is an explanatory diagram. The crystal impedance (CI) of each of the samples of the example fabricated in Section 3-1-1 above was measured. Then, for each sample, the distance h between the tip of the quartz crystal vibrating piece 11 and the base 23, and the angle θ between the quartz crystal vibrating piece 11 and the base 23 were measured, as shown in FIG. 7(A). 7B is a diagram showing the relationship between CI and the distance h between the tip of quartz crystal vibrating piece 11 and base 23, based on the above measurement results. From FIG. 7B, it can be said that CI improves when distance h is relatively large. Furthermore, if distance h is small, there is a concern that the tip of quartz crystal vibrating piece 11 may come into contact with base 23 when the quartz crystal unit is subjected to an impact, resulting in damage or other problems. Therefore, from this perspective, it is better to have distance h relatively large. In this example, from Figure 7(B), it can be said that the distance h should be 20 μm or more, a reasonable value that takes into account restrictions on the container height, etc. Considering this point in light of the thickness of the quartz crystal resonator blank prototyped here, which is 22 μm, it can also be said that the distance h should be a reasonable value of 20 / 22 ≒ 0.9t or more, where t is the thickness of the quartz crystal resonator blank. FIG. 7C is a diagram showing the relationship between CI and the angle θ between the quartz crystal vibrating piece 11 and the base 23, based on the above measurement results. From FIG. 7C, it can be said that the CI improves when the angle θ is set to a certain degree. Furthermore, as mentioned above, it can be said that a certain degree of angle θ is better from the perspective of improving shock resistance. In this example, from FIG. 7C, it can be said that the angle θ should be set to a reasonable angle of 0.5 degrees or more. Furthermore, if the distance h or angle θ is increased to a certain extent, it is believed that the conductive adhesive 25 will be less likely to flow toward the center of the quartz vibrating piece 11, which is believed to reduce the impact of the conductive adhesive on the vibrating part and prevent deterioration of the CI. Furthermore, if the distance h is small, the stray capacitance from the base to the excitation electrode may have an adverse effect, so taking this into consideration, it is better to make the distance h somewhat large.

[0031] 3-1-5. Size and shape of base In the above-described embodiment, an example was described in which the base was larger than the quartz crystal vibrating piece. However, the base does not need to be so large as long as it can reduce the effects of thermal stress on the quartz crystal vibrating piece and does not pose any problems in terms of adhesive strength, and also for reasons such as avoiding contact between the quartz crystal vibrating piece and the base. Even when considering the effects of the distance h and angle θ described above, the base does not need to be so large. Therefore, a consideration regarding the size of the base will be explained below with reference to FIG. 8(A). 8A is a diagram showing a cross-sectional view of the quartz crystal resonator 10 corresponding to FIG. 1B, a plan view of the base 23, and a plan view of the quartz crystal resonator piece 11. The long side dimension of the quartz crystal resonator piece 11 is denoted by Lb, and various examples of the long side dimension of the base are shown. 8(A) shows four examples (La1, Lx, Ly, Lz) in which the tip position of the base 23 is different from the tip position of the crystal vibrating piece 11 and the tip position of the excitation electrode 11a. In other words, these are four examples in which the longitudinal dimension of the base is shorter than the longitudinal dimension of the crystal vibrating piece.

[0032] In the first example, the long side dimension of the base is set to La1 so that the tip position of the base 23 is located between the tip position of the quartz crystal vibrating piece and the tip position of the excitation electrode. In the second example, the long side dimension of the pedestal is set to Lx so that the tip position of the pedestal 23 is located between the tip position of the excitation electrode and the center position of the excitation electrode. In the third example, the long side dimension of the base 23 is set to Ly so that the tip position of the base 23 is located between the center position of the excitation electrode and the end position of the excitation electrode on the conductive adhesive 25 side. In the fourth example, the long side dimension of the base is set to Lz so that the tip position of the base 23 is located between the conductive adhesive 25 and the end of the excitation electrode on the conductive adhesive 25 side. Whether the long side dimension of the pedestal is La1, Lx, Ly, or Lz can be determined depending on the design of the quartz crystal unit 10. However, considering that the pedestal can reduce the effects of thermal stress on the quartz crystal unit and is good enough in terms of adhesive strength, it is considered best to set the long side dimension of the pedestal to the above-mentioned Lz. In other words, it is considered best to position the tip of the pedestal between the conductive adhesive 25 and the end of the excitation electrode 11a on the conductive adhesive 25 side so that the pedestal does not face the excitation electrode 11a.

[0033] As for the three-dimensional structure of the base, as shown in Figures 8(B) and 8(C), the base may be a base 23x (Figure 8(B)) in which the thickness of the base is thinned from the middle of the longitudinal direction to the other end, for example, from just before the area facing the excitation electrode to the other end, or a base 23y (Figure 8(C)) in which the thickness of the base is thinned in the central region in the longitudinal direction, for example, in an area slightly wider than the area facing the excitation electrode.

[0034] 4. Relationship between the depth of the recess where the temperature sensor is mounted and the thickness of the crystal base Next, a preferred example of the relationship between the depth of the recess (sometimes abbreviated as recess) for mounting the temperature sensor and the thickness of the crystal base (sometimes abbreviated as base) will be described. This description will be made with reference to FIGS. 9(A) to 9(C). Here, FIGS. 9(A) and 9(B) are cross-sectional views of crystal units 10x and 10y at the same positions as in FIG. 1(B). Also, FIG. 9(C) is a diagram for explaining the ranges for defining the base thickness tx and the height hs of the temperature sensor 15 for the crystal unit 10y shown in FIG. 9(B). In the crystal unit 10x shown in FIG. 9A, when the depth of the recess for mounting the temperature sensor is represented as d1 and the height of the temperature sensor is represented as hs, the relationship d1>hs is satisfied. In the case of this quartz crystal unit 10x, since d1>hs, there is more space above the temperature sensor 15 than in other cases. Therefore, even if the base 23 extends between the quartz crystal vibrating piece 11 and the temperature sensor 15 (such as in the case of Ly in FIG. 9A), there is little risk of the base and the temperature sensor coming into contact. In the case of this quartz crystal unit 10x, when the thickness of the base 23 is represented as tx1, the thickness tx1 of the base 23 can be set to any suitable value. Note that when the thickness of the bottom plate of the container 13 is represented as t, the thickness t is set to a thickness that ensures the mechanical strength of the container 13.

[0035] In the crystal unit 10y shown in FIG. 9B, when the depth of the recess for mounting the temperature sensor is d, the height of the temperature sensor is hs, and the thickness of the base 23 is tx,<hsかつ(d+tx)> It is written as hs. In the case of this crystal unit 10y, the depth of the recess 17 can be made shallower than that of the crystal unit 10x in FIG. 9A, which is preferable as a means for reducing the overall thickness of the crystal unit. In other words, this is advantageous for making the crystal unit thinner. Furthermore, if the depth d of the recess can be made shallower, it becomes easier to mount the temperature sensor in the recess. However, it is necessary to determine the dimension Lz of the base 23 so that the base 23 does not come into contact with the temperature sensor 15.

[0036] The crystal unit 10z shown in Fig. 9(C) illustrates that the thickness tx of the base may be a thickness including the thickness of the bonding pad 13a and the thickness of the first conductive adhesive 21, and that the height hs of the temperature sensor 15 may be a thickness including the thickness of the connection terminal 17a and the thickness of the first conductive adhesive 21. The fact that the height hs of the temperature sensor 15 may be a thickness including the thickness of the connection terminal 17a and the thickness of the first conductive adhesive 21 also applies to the crystal unit 10x shown in Fig. 9(A).

[0037] 5. Recess for temperature sensor Next, a specific example of the recess 17 for the temperature sensor will be described. This description will be made with reference to Figures 10(A) and 10(B). Here, Figure 10(A) is a plan view of the container 13 similar to Figure 1(A), and Figure 10(B) is a cross-sectional view of the container 13 along line RR in addition to the plan view of Figure 1(A). An example of the recess 17 referred to in this invention is a recess that is closed in plan view and has a predetermined depth (depth d1 or depth d shown in FIG. 9), as shown in FIG. 10(A). Another example of the recess 17 is a recess that is closed in plan view and has a predetermined depth (depth d1 or depth d shown in FIG. 9), as shown in FIG. 10(B). Another example of the recess 17 is a recess that is closed in plan view and has protrusions 13h and 13i at the portions of the container 13 where the bonding pads 13a and 13b for bonding the crystal vibrating piece are provided, and the portions other than the protrusions 13h and 13i are lower and function as recesses. In the former (FIG. 10(a)), the recess 17 is closed in plan view, which makes it easier to increase the strength of the container compared to cases where the recess 17 is not closed. In the latter (FIG. 10(b)), the planar area for mounting the temperature sensor 15 can be larger than in the former.

[0038] 6. Crystal Resonator Blank The quartz crystal vibrating piece 11 described with reference to FIGS. 1 and 2 has a uniform thickness and a rectangular planar shape, but the shape of the quartz crystal vibrator is not limited to the above example. For example, as shown in FIG. 11(A), the crystal vibrating piece may have a so-called one-sided frame structure, which includes a vibrating portion 11c having a thickness corresponding to the frequency and a supporting portion 11d that is thicker than the vibrating portion 11c. Alternatively, as shown in FIG. 11(B), the crystal vibrating piece may have a notch 11e between the vibrating portion and the supporting portion. Alternatively, as shown in FIG. 11(C), the crystal vibrating piece may have a through-hole 11f between the vibrating portion and the supporting portion. The notch 11e or the through-hole 17f may be provided in a crystal vibrating piece with a uniform thickness, or may be provided in the crystal vibrating piece with the one-sided frame structure shown in FIG. 11(A).

[0039] Although the above-described embodiment shows an example in which the oscillation frequency is 76.8 MHz, the present invention can be applied to other frequencies. For example, the present invention is also useful for 50 MHz band crystal resonators, which have a proven track record as crystal resonators with built-in temperature sensors. Furthermore, the present invention is increasingly useful for even higher frequencies that will be used in the future, such as 153 MHz band and 306 MHz band. Furthermore, while the above-described embodiment has been described as an example of a 1612 type package in terms of external dimensions, the present invention can also be applied to other sizes. It can also be applied to package external dimensions of 1210, 1008, even smaller ones, and ones larger than the 1612 size. In particular, in the case of small packages, the crystal resonator element becomes even smaller, so the effect of thermal stress becomes greater. Therefore, it is believed that applying the present invention makes it easier to reduce thermal stress. Furthermore, in the above-described embodiment, the temperature sensor is mounted in the recess so that the longitudinal direction of the temperature sensor is parallel to the longitudinal direction of the container, but the arrangement direction of the temperature sensor is not limited to this, and for example, the temperature sensor may be mounted in the recess so that the longitudinal direction of the temperature sensor is parallel to the short direction of the container.

[0040] 7. Other preferred containers and other preferred pedestals In the above embodiment, the container 13 described with reference to Figures 1(A) and 1(B), etc., was exemplified as an example of the container. That is, the container has a recess 17 for the temperature sensor 15, a ceramic bank portion 13c surrounding a space for accommodating the quartz crystal vibrating piece 11, and a seal ring (not shown) on the top surface of the bank portion 13c. Also, the pedestal 23 described with reference to Figures 3, 8, etc. was exemplified as an example of the pedestal. That is, the pedestal 23 is rectangular in plan view, and the wiring 23a1, etc. is routed around the side surface of the container 13 on the bank portion 13c side. However, when further improving the characteristics and miniaturizing the piezoelectric device, a container and base having the following structure are preferable. These will be described below with reference to Figures 12(A) and 12(B). Here, Figure 12(A) is a cross-sectional view corresponding to Figure 1(B) to explain a preferable container 70. Figure 12(B) is a side view, top view, and rear view (perspective view) to explain a preferable base 80.

[0041] A preferred container 70 includes a ceramic main body 70a having a recess 17 (also referred to as a second recess 17) for mounting a temperature sensor 15, and a metal ring-shaped member 70c serving as a sidewall for forming a first recess 70b connected to the main body 70a and having a square planar shape and a larger area than the second recess 17 for accommodating a quartz crystal vibrating piece 11. Specifically, the main body 70a has a square planar shape, specifically a rectangular shape, and the second recess 17 is positioned slightly off-center from the longitudinal center. The metal ring-shaped member 70c is connected to the main body 70a by, for example, brazing material along the edge of the surface of the main body 70a facing the second recess 17. Therefore, the metal ring-shaped member 70c forms the sidewall of the first recess 70b. The planar shape of the metal ring-shaped member 70c is similar to that of the bank portion 13c shown in FIG. 1(A). The metal ring-shaped member 70c is typically made of Kovar material. As shown in Figure 12(A), a conductor 13m is embedded in a predetermined position in the ceramic body 70a to electrically connect the metal ring-shaped member 70c to one of the external connection terminals, terminal 13f. The external connection terminal 13f is connected to the ground of an electronic device (not shown) to which the crystal unit 10 is connected. This connection structure ensures an electromagnetic shielding structure for the crystal unit 10. Two adhesive pads 13a, 13b (see FIG. 1) are provided along a portion of the main body 70a on the first side wall 70ca side, which corresponds to the first side of the ring-shaped member 70c. In the case of this preferred container 70, the recess 70b for mounting the quartz crystal vibrating piece 11, i.e., the first recess 70b, is surrounded by a metal ring-shaped member 70c. This, in combination with the metal lid member 19, provides advantages such as stronger electromagnetic shielding. This increases the electromagnetic shielding resistance of the quartz crystal unit. Furthermore, since the recess 70b (cavity) area for mounting the quartz crystal vibrating piece 11 can be defined by a metal ring, the desired recess can be easily formed. Furthermore, while the quartz crystal unit 10 of the embodiment uses the bank portion 13c and a seal ring (not shown) as shown in FIG. 1A, the container 70 uses a metal ring-shaped member instead of the bank portion 13c, making it easier to reduce the height of the quartz crystal unit.

[0042] On the other hand, a preferred base 80 has a first wiring pattern 80a on a first surface for connecting to a quartz vibrating piece, a second wiring pattern 80b on a second surface opposite the first surface for connecting to a container, specifically for connecting to two adhesive pads 13a, 13b, and a third wiring pattern 80c connecting the first wiring pattern 80a and the second wiring pattern 80b to the side wall, and the third wiring pattern 80c is provided on the side wall of the base 80 opposite the side wall facing the first side wall 70ca. A preferred pedestal 80 further includes cutouts 80x at both ends of the side wall facing the first side wall 70ca. The cutouts 80x are preferably configured as C-chamfered portions. The size of the cutouts 80x is not limited to this, but is preferably 20 to 70 μm, and more preferably 30 to 50 μm in C dimension, for example.

[0043] Furthermore, each of the first wiring pattern 80a and the second wiring pattern 80b has a recessed portion 80d, recessed from the edge of the pedestal 80 toward the center, at least on the side of the first sidewall 70ca of the pedestal 80. The recessed dimension S1 of the recessed portion 80d may be a dimension that prevents the first wiring pattern 80a from contacting (short-circuiting with) the metal ring-shaped member 70c even when the pedestal 80 comes into contact with the metal ring-shaped member 70c. If the recessed dimension S1 is too large, the area of ​​the wiring pattern becomes small, which is undesirable. Although not limited to this, the recessed dimension S1 is preferably, for example, about 30 to 50 μm. Each of the first wiring pattern 80a and the second wiring pattern 80b further includes recessed portions 80e on the two side walls of the base 80 that intersect with the side wall opposite the first side wall 70ca of the container. The recessed dimension S2 of the recessed portion 80e may be determined similarly to the dimension S1. S1 and S2 may be the same or different. In addition to the recessed portion 80d, the second wiring pattern 80b includes a recessed portion 80f, which has a recessed dimension S3 larger than the recessed dimension of the recessed portion 80d, located near the center of the side of the base 80 where the recessed portion 80d is provided, extending from the edge of the base 80 toward the center of the base 80. This recessed portion 80f is designed to prevent damage to the second wiring pattern 80b by a breaking jig used to break off each base from the wafer after a large number of bases 80 are manufactured in wafer form. The width of the recessed portion 80f and the recessed dimension S3 are determined taking into account the size of the breaking jig. However, if the width of the recessed portion 80f or the recessed dimension S3 is too large, the area of ​​the second wiring pattern 80b will become small, which is undesirable in terms of electrical continuity, so it is advisable to take this into consideration when determining these dimensions.

[0044] The above-described preferable base 80 allows the base 80 to be positioned close to the wall of the container 70, even when the container 70 has a first recess 70b whose sidewall is formed of a metal ring-shaped member 70c. This is because the base 80 is provided with the predetermined recessed portion 80d and / or cutout portion 80x, so that even when the base is positioned close to the wall of the container 70, the first wiring pattern 80a, the second wiring pattern 80b, and the third wiring pattern 80c of the base 80 do not short-circuit with the metal ring-shaped member 70c. Therefore, even when crystal units are becoming increasingly smaller and the mounting margin for the base 80 in the container 70 becomes narrower, mounting is easy.

[0045] The preferred container 70 and the preferred base 80 may be used in place of the first chamber 13X1 and base 23 of the H-shaped temperature sensor-less crystal unit 50 described with reference to FIG. 5, and may also be used in place of the container 13 and base 23 of various crystal units described with reference to FIG. 9. [Explanation of symbols]

[0046] 10, 30, 50, 60: Crystal oscillator with built-in temperature sensor according to an embodiment; 11: AT-cut crystal element 13: Container 13a, 13b: two adhesive pads arranged along a first direction 13x1: First room 13x2: Second room 15: Temperature sensor 17: Recess for mounting the temperature sensor (second recess) 19: Lid member 21: Conductive adhesive (first conductive adhesive) 23: Crystal base 25: Conductive adhesive (second conductive adhesive) d: Depth of the recess hs: Height of the temperature sensor tx: Thickness of the base 70: Preferred container 70a: Ceramic body 70b: Recess for mounting a crystal vibrating piece (first recess) 70c: Metal ring-shaped member 70ca: First side wall 80: Preferred base 80a: First wiring pattern 80b: Second wiring pattern 80c: Third wiring pattern 80d, 80e, 80f: Retracted section 80x: Notched section

Claims

1. A single-chamber structured temperature sensor built-in quartz crystal unit includes a container for mounting an AT-cut quartz crystal piece, a recessed portion provided on the bottom side of the container for mounting a temperature sensor, the quartz crystal piece having a square shape in a plan view mounted in the container, and the temperature sensor mounted in the recessed portion, two adhesive pads provided along a first direction on a portion of the container that contacts the periphery of the recess; a quartz crystal base provided between the two bonding pads and the quartz crystal vibrating piece, the quartz crystal base being bonded to the two bonding pads at one end of one surface thereof, and the quartz crystal vibrating piece being bonded to the other surface thereof at two points along the X-axis of the quartz crystal or two points along the Z'-axis of the quartz crystal; The quartz crystal base has the X-axis, the Z'-axis, or the Z-axis of the quartz crystal parallel to the surface, depending on whether the quartz crystal piece is bonded to the base at two points along the X-axis or at two points along the Z'-axis, and is bonded to the two bonding pads in a positional relationship such that this axis is parallel to the first direction (however, the Z'-axis is an axis that is offset from the true Z-axis of the quartz crystal due to the cutting angle of the AT-cut quartz crystal piece).

2. A crystal unit with a built-in temperature sensor and an H-shaped structure includes a first chamber in which an AT-cut crystal vibrating piece is mounted, a second chamber whose bottom surface is connected to the first chamber and in which a temperature sensor is mounted, the crystal vibrating piece having a square shape in a plan view mounted in the first chamber, and the temperature sensor mounted in the second chamber, two adhesive pads provided in the first chamber along a first direction; a quartz crystal base provided between the two bonding pads and the quartz crystal vibrating piece, the quartz crystal base being bonded to the two bonding pads at one end of one surface thereof, and the quartz crystal vibrating piece being bonded to the other surface thereof at two points along the X-axis of the quartz crystal or two points along the Z'-axis of the quartz crystal; The quartz crystal base has an X-axis, a Z'-axis, or a Z-axis parallel to the surface, depending on whether the quartz crystal piece is bonded to the base at two points along the X-axis or at two points along the Z'-axis, and is bonded to the two bonding pads in a positional relationship such that this axis is parallel to the first direction (however, the Z'-axis is an axis that is offset from the true Z-axis of the quartz crystal due to the cutting angle of the AT-cut quartz crystal piece).

3. 3. The quartz crystal resonator according to claim 1, wherein the thickness of the quartz crystal resonator piece is represented as t and the thickness of the base is represented as T, and the thickness T of the base satisfies the relationship 0.9t≦T≦3.1t.

4. 3. The quartz crystal resonator according to claim 1, wherein the thickness of the quartz crystal resonator element is t and the thickness of the base is T, and the thickness T of the base satisfies the relationship 1.3t≦T≦2.

7.

5. 3. The quartz crystal resonator according to claim 1, wherein the base is provided closer to the bonding pad than the excitation electrode provided on the quartz crystal resonator element.

6. When the thickness of the crystal vibrating piece is represented as t and the thickness of the base is represented as T, the thickness T of the base is in the range of 0.9t≦T≦3.1t, 3. The quartz crystal resonator according to claim 1, wherein the base is provided closer to the bonding pad than the excitation electrode provided on the quartz crystal resonator element.

7. 3. The quartz crystal resonator according to claim 1, wherein the base has a thickness selected from the range of 30 to 60 μm.

8. 3. The quartz crystal unit according to claim 1, wherein the base is an AT-cut quartz crystal piece and is bonded to the two bonding pads at two points along the X-axis of the quartz crystal.

9. 3. The quartz crystal unit according to claim 1, wherein the base is an AT-cut quartz crystal piece and is bonded to the two bonding pads at two points along the Z' axis of the quartz crystal.

10. 3. The quartz crystal unit according to claim 1, wherein the base is a Z-cut quartz crystal piece and is bonded to the two bonding pads at two points along the X-axis of the quartz crystal.

11. 4. The quartz crystal unit according to claim 3, wherein the base is an AT-cut quartz crystal piece and is bonded to the two bonding pads at two points along the X-axis of the quartz crystal.

12. 4. The quartz crystal unit according to claim 3, wherein the base is an AT-cut quartz crystal piece and is bonded to the two bonding pads at two points along the Z' axis of the quartz crystal.

13. 4. The quartz crystal unit according to claim 3, wherein the base is a Z-cut quartz crystal piece and is bonded to the two bonding pads at two points along the X-axis of the quartz crystal.

14. The quartz crystal resonator according to claim 1 or 2, characterized in that the quartz crystal resonator piece has an oscillation frequency in the 76 MHz band, which includes 76.8 MHz, and the base has a thickness selected from the range of 30 to 60 μm.

15. The quartz crystal resonator according to claim 5, wherein the quartz crystal resonator element has an oscillation frequency in the 76 MHz band, which includes 76.8 MHz, and the base has a thickness selected from the range of 30 to 60 μm.

16. When the depth of the recess is represented by d, the height of the temperature sensor is represented by hs, and the thickness of the base is represented by tx, d<hs and (d+tx)>hs are satisfied, 2. The quartz crystal unit according to claim 1, wherein the dimension of the base in a direction perpendicular to the first direction is such that the base does not come into contact with a temperature sensor.

17. When the depth of the recess is represented by d, the height of the temperature sensor is represented by hs, and the thickness of the base is represented by tx, d<hs and (d+tx)>hs are satisfied, 2. The quartz crystal resonator according to claim 1, wherein a dimension of the base in a direction perpendicular to the first direction is such that the base does not come into contact with a temperature sensor, the quartz crystal resonator element has an oscillation frequency in the 76 MHz band that includes 76.8 MHz, and the quartz crystal resonator has a thickness selected from the range of 30 to 60 μm.

18. When the depth of the recess is represented by d, the height of the temperature sensor is represented by hs, and the thickness of the base is represented by tx, d<hs and (d+tx)>hs are satisfied, a dimension of the base in a direction perpendicular to the first direction such that the base does not come into contact with a temperature sensor, and the quartz crystal resonator element has an oscillation frequency in the 76 MHz band, which includes 76.8 MHz; 2. The quartz crystal unit according to claim 1, wherein the base has a thickness selected from the range of 30 to 60 μm and is an AT-cut quartz crystal piece or a Z-cut quartz crystal piece.

19. When the depth of the recess is represented as d and the height of the temperature sensor is represented as hs, d>hs; 2. The quartz crystal unit according to claim 1, wherein the base has a thickness selected from the range of 30 to 60 μm and is an AT-cut quartz crystal piece or a Z-cut quartz crystal piece.

20. When the depth of the recess is represented as d and the height of the temperature sensor is represented as hs, d>hs; The crystal vibrating piece has an oscillation frequency in the 76 MHz band, which includes 76.8 MHz, 2. The quartz crystal unit according to claim 1, wherein the base has a thickness selected from the range of 30 to 60 μm and is an AT-cut quartz crystal piece or a Z-cut quartz crystal piece.

21. The container includes a ceramic body having a second recess, which is the recess for mounting a temperature sensor, and a metal ring-shaped member as a side wall that is connected to the body and forms a first recess, which is a rectangular shape in plan view and has an area larger than that of the second recess, for accommodating the crystal vibrating piece; The two adhesive pads are provided on a portion of the main body on a first side wall side corresponding to a first side of the ring-shaped member.

2. The quartz crystal resonator according to claim 1,

22. the first chamber includes a metal ring-shaped member as a side wall that forms a recess having a rectangular planar shape for accommodating the crystal vibrating piece; The two adhesive pads are provided on a portion of the first chamber on a first side wall side corresponding to a first side of the ring-shaped member.

3. The quartz crystal resonator according to claim 2,

23. The container includes a ceramic body having a second recess, which is the recess for mounting a temperature sensor, and a metal ring-shaped member as a side wall that is connected to the body and forms a first recess, which is a rectangular shape in plan view and has an area larger than that of the second recess, for accommodating the crystal vibrating piece; the two adhesive pads are provided on a portion of the main body on a first side wall side corresponding to a first side of the ring-shaped member, 2. The quartz crystal unit according to claim 1, wherein the base has a first wiring pattern for connection to the quartz crystal vibrating piece on a first surface, a second wiring pattern for connection to the container on a second surface opposite the first surface, and a third wiring pattern connecting the first wiring pattern and the second wiring pattern to a side wall, and the third wiring pattern is provided on a side wall of the base opposite to the side wall facing the first side wall.

24. the first chamber includes a metal ring-shaped member as a side wall that forms a recess having a rectangular planar shape for accommodating the crystal vibrating piece; the two adhesive pads are provided on a portion of the first chamber on a first side wall side corresponding to a first side of the ring-shaped member; 3. The quartz crystal unit according to claim 2, wherein the base has a first wiring pattern for connection to the quartz crystal vibrating piece on a first surface, a second wiring pattern for connection to the container on a second surface opposite the first surface, and a third wiring pattern for connecting the first wiring pattern and the second wiring pattern to a side wall, and the third wiring pattern is provided on a side wall of the base opposite to the side wall facing the first side wall.

25. 25. The crystal unit according to claim 23, wherein the side wall of the base facing the first side wall has a notch at each end.

26. 25. The quartz crystal resonator according to claim 23, wherein each of the first wiring pattern and the second wiring pattern has a recessed portion that recesses from the edge of the base toward the center, at least on the first side wall side of the base.

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