Piezoelectric devices

Abstract

To provide a piezoelectric device which can easily bring a measured temperature closer to the temperature of a piezoelectric body.SOLUTION: A crystal oscillator 1 has a crystal element 5, a mounting substrate 11, a lid 13, and a thermosensor 7. The mounting substrate 11 has a recess R1. The crystal element 5 is mounted on a bottom surface of the recess R1. The lid 13 closes the recess R1. The thermosensor 7 has a portion located further on the lid 13 side than the crystal element 5.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a piezoelectric device.

Background Art

[0002] Piezoelectric devices such as crystal oscillators and crystal resonators are known (see, for example, the following patent documents). Such a piezoelectric device has a piezoelectric element and a package holding the piezoelectric element. The piezoelectric element has a piezoelectric body (for example, a crystal blank), two excitation electrodes overlapping the piezoelectric body, and two lead-out electrodes drawn from the two excitation electrodes. The two lead-out electrodes contribute to the mounting of the piezoelectric element to the package, for example, by being joined to pads of the package with a conductive bonding material.

[0003] As such a piezoelectric device, one having a temperature-sensitive element such as a thermistor is known. The temperature detected by the temperature-sensitive element is used, for example, to compensate for a change in the characteristics of the piezoelectric element due to a temperature change.

[0004] The temperature-sensitive element is mounted on the package. For example, in Patent Document 1, the package has a first recess and a second recess opening on the side opposite to the first recess. The piezoelectric element is housed in the first recess and mounted on the bottom surface of the first recess. Further, the first recess is closed and sealed by a lid body. The temperature-sensitive element is a chip-type component, housed in the second recess, and mounted on the bottom surface of the second recess. Specifically, two terminals of the temperature-sensitive element and two pads located on the bottom surface of the second recess are joined by a conductive bonding material.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] For example, it is desirable to have piezoelectric devices that facilitate bringing the measured temperature closer to the temperature of the piezoelectric material. [Means for solving the problem]

[0007] A piezoelectric device according to one aspect of the present disclosure includes a piezoelectric element, a mounting substrate having a recess on which the piezoelectric element is mounted on the bottom surface of the recess, a cover that closes the recess, and a temperature-sensing element having a portion located on the cover side of the piezoelectric element. [Effects of the Invention]

[0008] According to the above configuration, for example, it becomes easier to bring the measured temperature closer to the temperature of the piezoelectric material. [Brief explanation of the drawing]

[0009] [Figure 1] An exploded perspective view showing a quartz crystal oscillator according to the first embodiment. [Figure 2] Another exploded perspective view showing the quartz crystal oscillator in Figure 1. [Figure 3] Cross-sectional view along line III-III in Figure 1. [Figure 4] Figures 4(a) and 4(b) are plan views showing modified examples of the external electrodes of the temperature-sensing element. [Figure 5] Figures 5(a), 5(b), and 5(c) are cross-sectional views showing modified examples related to the position of the temperature-sensing element. [Figure 6] A perspective view showing a modified example of the shape of the temperature-sensing element. [Figure 7] A cross-sectional view of a quartz crystal oscillator according to the second embodiment. [Figure 8] A cross-sectional view of a quartz crystal oscillator according to the third embodiment. [Figure 9] A perspective view showing a specific example of wiring in a package. [Figure 10] A perspective view showing another specific example of wiring in a package. [Figure 11]A plan view showing yet another specific example of wiring in a package. [Figure 12] A schematic diagram showing an example of the use of a quartz crystal oscillator according to the embodiment. [Modes for carrying out the invention]

[0010] Embodiments relating to this disclosure will be described below with reference to the drawings. The figures used in the following description are schematic. Therefore, for example, the dimensional ratios shown in the drawings do not necessarily match those of reality. The dimensional ratios of the same component do not necessarily match between drawings. In addition, details may be omitted, and some shapes may be exaggerated in the illustrations. However, the above does not negate the fact that the actual dimensional ratios may be as shown in the drawings, and that features such as shape and dimensional ratios may be extracted from the drawings.

[0011] For convenience, the drawings may include a Cartesian coordinate system D1-D2-D3. In the embodiment, the piezoelectric device may have either the vertical or horizontal direction. However, for convenience, the +D3 side may be represented as the upper direction. Unless otherwise specified, plan view or plan perspective refers to viewing parallel to the D3 direction.

[0012] In describing later embodiments (models and modifications), only the differences from the previously described embodiments will be noted. Unless otherwise specified, matters may be considered the same as or by analogy with the previously described embodiments. The descriptions of the previously described embodiments may be applied to the later described embodiments, provided that no contradictions arise. For convenience, corresponding components in multiple embodiments may be given the same reference numerals even if there are differences.

[0013] The term "side", which refers to the edge of a planar shape, generally refers to the edge of a polygon (in other words, a straight line). However, in the description of the embodiments, for convenience, it may be used for the edge of a shape that does not have to be a polygon (for example, an edge that may be curved). Similarly, "long side" and "short side" generally refer to the sides of a rectangle. However, in the description of the embodiments, for convenience, they may be used for the edge or a part similar to the edge of a shape that does not have to be a rectangle (however, a shape with four edges can be conceived). "Parallel" usually refers to the relationship where the distance between straight lines is constant. However, in the description of the embodiments, for convenience, it may be used for the relationship where the distance between lines that do not have to be straight lines (for example, curves) is constant. When referring to a rectangle or a rectangular shape, unless otherwise specified, it is not necessary to be a strictly square or a rectangle in the narrow sense, such as having chamfered corners. The same applies to polygons other than rectangles.

[0014] <First Embodiment> (Overview of Crystal Oscillator) FIG. 1 is an exploded perspective view showing the configuration of a crystal oscillator 1 (hereinafter, the term "crystal" may be omitted) according to the first embodiment. FIG. 2 is an exploded perspective view of the crystal oscillator 1 as viewed from the side opposite to FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1.

[0015] The oscillator 1 is, for example, a chip-type electronic component for surface mounting. Specifically, the shape of the oscillator 1 as a whole is generally a rectangular parallelepiped shape that is thin (the dimension in the D3 direction is smaller than the dimensions in the D1 direction and the D2 direction). And on the lower surface of the rectangular parallelepiped, four layered terminals 3 are provided at the four corners. By joining the four terminals 3 and pads (not shown) of a circuit board 53 (see FIG. 12 described later) with a conductive bonding material (for example, solder), the oscillator 1 is fixed to the circuit board 53 and electrically connected (that is, mounted).

[0016] The vibrator 1 has a crystal element 5, a temperature-sensitive element 7 (Figs. 2 and 3), and a package 9 (reference numeral in Fig. 3) that holds these elements (5 and 7). The crystal element 5 vibrates when an alternating voltage is applied through, for example, two of the four terminals 3. This vibration is utilized, for example, to generate an oscillation signal in which the intensity of a signal (e.g., voltage or current) vibrates at a constant frequency. The frequency of the oscillation signal is arbitrary. The temperature-sensitive element 7 outputs a signal corresponding to the temperature through the other two of the four terminals 3. This signal is utilized, for example, to compensate for a change in the characteristics of the crystal element 5 with respect to a temperature change.

[0017] The package 9 forms the outer contour of the vibrator 1 and has the above-described terminals 3. Further, the package 9 has, for example, a mounting substrate 11 having a recess R1 and a lid 13 that closes the recess R1. The crystal element 5 is housed in the recess R1. And, by closing the upper surface opening of the recess R1 with the lid 13, a sealed space is formed and the crystal element 5 is sealed. The sealed space is in a vacuum state or is filled with an appropriate gas (e.g., nitrogen). Also, the mounting substrate 11 has the above-described four terminals 3 on its lower surface. The crystal element 5 is mounted on the bottom surface of the recess R1. Thereby, the crystal element 5 is electrically connected to two of the terminals 3.

[0018] The temperature-sensitive element 7 has a portion located between the crystal element 5 and the lid 13. Specifically, in the illustrated example, the temperature-sensitive element 7 is constituted by a film-like element (e.g., a thin-film thermistor) that overlaps the lower surface of the lid 13 (lid lower surface 13b), and thereby is located between the crystal element 5 and the lid 13. The electrical connection between the temperature-sensitive element 7 and the two terminals 3 is realized, for example, by connecting the temperature-sensitive element 7 and the mounting substrate 11 around the upper surface opening of the recess R1.

[0019] Here, the package 9 is mounted on the circuit board 53 (Figure 12) by terminals 3 located on its lower surface. Therefore, heat from other devices mounted on the circuit board 53 is easily transferred from the lower side of the package 9 through the circuit board 53. As a result, for example, if the temperature sensing element 7 is located on the bottom side of the recess R1 relative to the crystal element 5, or on the lower surface of the package 9, the measured temperature may be excessively affected by external heat, causing the measured temperature to deviate from the temperature of the crystal element 5. By positioning the temperature sensing element 7 on the side of the cover 13 relative to the crystal element 5, as in this embodiment, it is possible to reduce the likelihood of the above-mentioned phenomenon occurring.

[0020] The above is an overview of the oscillator 1 according to the first embodiment. Below, the oscillator 1 will be described in general order as follows. 1. Crystal element 5 2. Package 9 (excluding the portion related to the temperature sensing element 7). 3. Temperature-sensing element 7 (including the portion of package 9 related to the temperature-sensing element 7). 4. Variations 5. Summary of the First Embodiment

[0021] (1. Crystal element) The crystal element 5 includes, for example, a crystal blank 15 (in other words, a piezoelectric material) and two or more (one pair in the illustrated example) conductor patterns 17 (in the illustrated example, two conductor patterns, a first conductor pattern 17A and a second conductor pattern 17B) overlapping the crystal blank 15. When a voltage is applied to the crystal blank 15 by the pair of conductor patterns 17, the crystal blank 15 vibrates. As a result, the crystal element 5 performs the functions described above. The specific configuration of the crystal element 5 can be various. For example, the configuration of the crystal element 5 can be various known configurations.

[0022] In embodiments where the quartz blank 15 is manufactured by etching, it may have inclined surfaces (or crystal faces, from another perspective) on its sides due to the anisotropy of quartz with respect to etching. In the description of the embodiments, the existence of such inclined surfaces will be generally ignored. In descriptions of dimensions, etc., where precision is required, the description may be made by ignoring the inclined surfaces, or by taking the inclined surfaces into consideration, as long as it does not lack rationality or create contradictions. For example, when referring to the length of the quartz blank 15 in the D1 direction, this length may be the length of the top or bottom surface of the quartz blank 15 (length excluding crystal faces), or it may be the maximum length in planar perspective (length considering crystal faces).

[0023] In the illustrated example, the quartz element 5 is a so-called AT-cut type quartz element. In the AT-cut type quartz element 5, the quartz blank 15 has a generally plate-like shape. The pair of conductor patterns 17 has a pair of excitation electrodes 19 that overlap both main surfaces (the widest surfaces of the plate shape; the front and back of the plate shape) of the plate-shaped quartz blank 15, and a pair of lead electrodes 21 that are drawn out from the pair of excitation electrodes 19.

[0024] A pair of excitation electrodes 19 contribute to applying a voltage to the crystal blank 15. In the AT-cut type, the application of an AC voltage to the crystal blank 15 causes so-called thickness-slip vibration. A pair of lead electrodes 21 contribute to mounting the crystal element 5. More specifically, in the illustrated example, a pair of lead electrodes 21 and a pair of pads 25 (described later) are joined by a pair of bonding materials 29 (Figure 3), thereby electrically connecting and fixing the crystal element 5 to the package 9, and further supporting it in a cantilevered manner.

[0025] Examples of quartz elements other than those shown in the illustration include: a tuning fork-type element that utilizes bending vibration; a CT-cut or DT-cut element that utilizes contour sliding vibration; an element with a cut angle other than AT-cut (e.g., BT-cut) that utilizes thickness sliding vibration; and an element that utilizes SAW (surface acoustic wave). Such elements also include, for example, a piezoelectric material (e.g., quartz), two or more excitation electrodes that excite the piezoelectric material, and two or more extraction electrodes drawn out from the two or more excitation electrodes. In elements that utilize SAW, the piezoelectric layer may overlap with a layer made of other materials.

[0026] In this description of the embodiment, for convenience, expressions may be used that assume the crystal element 5 is of the AT-cut type, without further explanation.

[0027] As shown in the illustrated example, in a quartz element 5 (not necessarily of the AT-cut type) having a plate-shaped quartz blank 15, a pair of excitation electrodes 19 overlapping both main surfaces of the quartz blank 15, and a pair of lead electrodes 21 drawn out from the pair of excitation electrodes 19, the more specific configurations (planar shape, etc.) of the quartz blank 15, excitation electrodes 19, and lead electrodes 21 may be set as appropriate.

[0028] For example, the shapes of the crystal blank 15, excitation electrode 19, and extraction electrode 21 may be configured such that either side of the crystal element 5 is the mounting side (-D3 side), or they may not be configured in such a way (see illustrated example). For example, the crystal element 5 may be configured to be approximately 180° rotationally symmetric with respect to an unillustrated center line extending in the D1 direction (the longitudinal direction of the crystal element 5 in the illustrated example), or they may not be configured in such a way (see illustrated example).

[0029] Furthermore, the planar shape of the crystal blank 15 may be rectangular (as shown in the example), circular, elliptical, or a polygon other than a rectangle. The planar shape of the crystal blank 15 may also be a shape in which any number of sides of a polygon (for example, one, two, three, or four sides of a rectangle) are curved outwards. The planar shape of the crystal blank 15 may also have protrusions or notches in part. Furthermore, the planar shape of the crystal blank 15 may be a shape where the D1 direction is the longitudinal direction (a shape where the maximum length in the D1 direction is longer than the maximum length in the D2 direction), or it may be a shape where such distinction is not possible.

[0030] Furthermore, for example, the thickness of the quartz blank 15 may be constant (as shown in the illustration) or not. Examples of the latter include the following, although not specifically shown in the illustration: A so-called mesa type in which the central region (mesa portion) excited in conjunction with a pair of excitation electrodes 19 is thicker than the outer peripheral region. Conversely, a so-called inverse mesa type in which the central region excited in conjunction with a pair of excitation electrodes 19 is thinner than the outer peripheral region. A type having a vibrating portion excited in conjunction with a pair of excitation electrodes 19, and a fixed portion adjacent to a part of the edge of the vibrating portion (for example, one side, two sides, or three sides), which is thicker than the vibrating portion, and in which a pair of lead electrodes 21 are located. A bevel type in which the outer peripheral portion becomes thinner as it approaches the outer edge.

[0031] Furthermore, for example, the planar shape of the excitation electrode 19 may be similar to the planar shape of the crystal blank 15 (or the planar shape of the mesa portion, inverse mesa portion, or vibrating portion described above; the same applies hereafter in this paragraph) (as illustrated in the example), or it may not be such a shape. As an example of the former, an example can be given of a configuration in which the planar shape of the crystal blank 15 and the planar shape of the excitation electrode 19 are rectangular-rectangular, circular-circular, or elliptical-elliptical. As an example of the latter, an example can be given of a configuration in which the planar shape of the crystal blank 15 and the planar shape of the excitation electrode 19 are rectangular-circular, rectangular-elliptical, or elliptical-rectangular. Regardless of whether the planar shape of the excitation electrode 19 is similar to the planar shape of the crystal blank 15 or not, the previously described explanation of the planar shape of the crystal blank 15 may be applied to the planar shape of the excitation electrode 19, provided that no contradictions arise.

[0032] Furthermore, for example, a pair of lead electrodes 21 are led out from the excitation electrode 19 to one end of the crystal blank 15. More specifically, as already mentioned, although not specifically indicated by reference numerals, each lead electrode 21 has a wiring portion extending from the excitation electrode 19 and a pad-shaped terminal portion connected to the excitation electrode 19 via the wiring portion. The terminal portion is the part that is joined to the pad 25.

[0033] In the quartz element 5 that utilizes thickness-sliding vibration, the thickness of the quartz blank 15 (in this paragraph, unless otherwise specified, the thickness in the portion where the excitation electrodes 19 overlap) is a factor that determines the frequency of the oscillation signal. For example, as is well known, in an AT-cut quartz element, the relationship f = 1.67 × n / t basically holds, where f is the frequency (MHz), n is the order of the vibration used, and t (mm) is the thickness. The quartz element 5 may utilize the fundamental wave mode or the overtone mode. As previously stated, the frequency of the oscillation signal is arbitrary, and consequently, the thickness of the quartz blank 15 is also arbitrary. For example, the thickness of the quartz blank 15 may be 5 μm or more, 10 μm or more, 30 μm or more, or 50 μm or more, and may also be 200 μm or less, 100 μm or less, 50 μm or less, or 30 μm or less. The above lower and upper limits may be combined in any way so as not to cause contradiction.

[0034] The maximum thickness of the AT-cut type crystal blank 15 may be the same as or different from the thickness that defines the above frequencies, as can be understood from the explanation above. In any case, the maximum thickness of the crystal blank 15 is arbitrary. The maximum thickness of the AT-cut type or other type of crystal blank (or crystal element) may be, for example, 30 μm or more, 50 μm or more, or 100 μm or more, and may also be 300 μm or less, 200 μm or less, 100 μm or less, or 50 μm or less. The above lower and upper limits may be combined in any way so as not to cause any contradiction.

[0035] The material of the conductor pattern 17 may be, for example, a metal. Examples of metals include nickel (Ni), chromium (Cr), titanium (Ti), gold (Au), or silver (Ag), or alloys in which at least one of these is the main component. The conductor pattern 17 may consist of a single conductor layer made of a single material, or it may consist of multiple conductor layers made of different materials stacked together. The conductor pattern 17 may have the same material composition throughout its entire area, or the material composition may differ in different regions.

[0036] (2. Package (excluding parts related to the temperature sensing element)) Package 9 constitutes the outer casing of the oscillator 1, and its external shape is generally that of a thin rectangular parallelepiped. The dimensions of package 9 (oscillator 1) are arbitrary. For example, if the oscillator 1 is relatively small, the length in the longitudinal or transverse direction (D1 or D2 direction) in a plan view is 0.6 mm or more and 2.0 mm or less. The thickness (length in the D3 direction) is 0.2 mm or more and 1.5 mm or less.

[0037] Package 9, as previously described, comprises a mounting base 11 and a cover 13. The mounting base 11 includes, for example, an insulating base 23 and various conductors located on the insulating base 23. The various conductors include, for example, the terminals 3 described above, two pads 25 on which the crystal element 5 is mounted (Figures 1 and 3), and a plurality of wires 27 (Figure 3) that contribute to the electrical connections within package 9. The plurality of wires 27 include, for example, two wires 27 connecting the two pads 25 and the two terminals 3.

[0038] The following description of Package 9 will be roughly as follows: 2.1. Insulating substrate 23 2.2. Conductors of the mounting substrate 11 (excluding those related to the connection between the mounting substrate 11 and the cover 13) 2.3. Bonding material 29 2.4. Lid 13 2.5. Joining the mounting base 11 and the lid 13

[0039] (2.1. Insulating substrate) The shape, dimensions, and material of the insulating substrate 23 are arbitrary. The insulating substrate 23 constitutes the majority of the mounting substrate 11, and its outer shape (shape ignoring the recess R1) is generally that of a thin rectangular parallelepiped. The recess R1 opens on the upper surface of the insulating substrate 23 (the surface on the +D3 side). Although not specifically shown in the figures, in a plan view, the corners of the insulating substrate 23 may be chamfered by a flat or curved surface, or may have recesses (castellations).

[0040] Since the insulating substrate 23 has a recess R1, it can be considered to have a substrate portion 23a that constitutes the bottom surface of the recess R1 and a frame portion 23b that constitutes the wall portion of the recess R1. The insulating substrate 23 may be manufactured by laminating the substrate portion 23a and the frame portion 23b, or it may be manufactured by a manufacturing method different from such a method. As an example of the former, an opening that will become the recess R1 is formed in one layer (or two or more layers) of ceramic green sheet that will become the frame portion 23b, and the ceramic green sheet with the opening formed therein is laminated with one layer (or two or more layers) of ceramic green sheet that will become the substrate portion 23a and fired. As an example of the latter manufacturing method, an example of the latter is a method in which the recess R1 is formed in one layer (or two or more layers) of ceramic green sheet by pressing and then fired.

[0041] The substrate portion 23a is, for example, generally flat. In other words, the substrate portion 23a has a first substrate surface 23c and a second substrate surface 23d facing the opposite side, and both surfaces are planar and parallel to each other. The first substrate surface 23c constitutes the bottom surface of the recess R1. The second substrate surface 23d constitutes the bottom surface of the package 9. The planar shape of the substrate portion 23a is rectangular, for example, corresponding to the fact that the outer shape of the insulating substrate 23 is a rectangular parallelepiped. That is, in a plan view, the substrate portion 23a has a pair of opposing long sides and a pair of opposing short sides. The ratio of the lengths of the long sides to the short sides is arbitrary. The thickness of the substrate portion 23a is also arbitrary.

[0042] The frame portion 23b extends, for example, along the edge of the upper surface of the substrate portion 23a. The shape of the outer edge of the frame portion 23b in plan view is, for example, a shape that generally coincides with the outer edge of the substrate portion 23a. The shape of the inner edge of the frame portion 23b (the shape of the recess R1 in plan view) is, for example, a rectangle with four sides that are generally parallel to the four sides of the outer edge of the frame portion 23b. The frame portion 23b has, for example, a certain thickness. The outer and inner surfaces of the frame portion 23b are, for example, generally parallel to the D3 direction. However, unlike the illustrated example, the inner surface of the frame portion 23b may be inclined such that the diameter of the recess R1 increases towards the top (+D3 side). Regardless of whether or not such inclination is present, the shape and dimensions of the recess R1 in plan view mentioned in the description of the embodiment may be the upper opening of the recess R1 (the inner edge of the upper surface of the frame portion 23b (frame portion upper surface 23e)) or the bottom surface of the recess R1, unless otherwise specified and unless there is a contradiction.

[0043] The thickness of the frame portion 23b (depth of the recess R1) may be set appropriately according to, for example, the thickness of the crystal element 5 and the temperature sensing element 7. For example, the depth of the recess R1 (or the height from the first substrate surface 23c to the bottom surface 13b of the lid; the same applies hereinafter in this paragraph) may be 1.2 times or more, 1.5 times or more, 2 times or more, or 3 times or more the total thickness of the crystal element 5 and the temperature sensing element 7 (excluding the space between them; if the thickness is not constant, for example, the maximum thickness), or it may be 10 times or less, 5 times or less, 3 times or less, or 2 times or less. The above lower and upper limits may be combined in any way so as not to cause any contradiction. The above lower and / or upper limits may be used in comparison to the depth of the recess R1 with the thickness of the crystal element 5 alone.

[0044] The width of the frame portion 23b (length from the inner surface to the outer surface) is arbitrary. In this embodiment, as will be described in detail later, a connecting electrode 31 (Figures 1 and 3) electrically connected to the temperature sensing element 7 is provided on the upper surface of the frame portion 23b (frame upper surface 23e). Therefore, the width of the frame portion 23b (and / or frame upper surface 23e) may be wider than that of conventional packages. Alternatively, the width may be the same as that of conventional packages. In this case, for example, by making the width of the sealing material 33 (reference numeral 3 in Figure 3) that overlaps the frame upper surface 23e narrower than in conventional packages, an area for arranging the connecting electrode 31 on the frame upper surface 23e may be secured.

[0045] The width of the frame portion 23b and / or the upper surface 23e of the frame portion (if not constant, the maximum width or the width of the side on which the connecting electrode 31 is located) may be, for example, 1 / 20 or more, 1 / 10 or more, or 1 / 5 or more of the length of the substrate portion 23a in the longitudinal or transverse direction, and may also be 1 / 3 or less, 1 / 4 or less, or 1 / 5 or less. The above lower and upper limits may be combined in any way so as not to cause any contradiction.

[0046] The size of the recess R1 in plan view may be appropriately set, for example, by considering the size of the crystal element 5 in plan view. If necessary, the size of the temperature sensing element 7 in plan view may also be considered. For example, in plan view, the diameter of the recess R1 in the longitudinal direction (D1 direction) (for example, the maximum diameter if it differs depending on the position in the height direction, etc.) may be 1.05 times or more, 1.1 times or more, 1.2 times or more, or 1.5 times or more, or 2 times or less, 1.5 times or less, or 1.3 times or less, relative to the longitudinal diameter (for example, the maximum diameter) of the crystal element 5. The above lower and upper limits may be combined in any way so as not to cause any contradiction.

[0047] Furthermore, the shape of the recess R1 in plan view does not have to be rectangular, unlike the illustrated example. From another viewpoint, the inner edge of the upper surface 23e of the frame does not have to be parallel to the outer edge. For example, consider a configuration in which the quartz element has an arm for vibration or an arm for mounting. In this case, in plan view, the upper surface 23e of the frame may have a protrusion that is inserted between the arm and other parts of the quartz element. Such a protrusion can contribute, for example, to securing a placement area for the connecting electrode 31 connected to the temperature sensing element 7.

[0048] The material of the insulating substrate 23 (substrate portion 23a and frame portion 23b) is arbitrary and may be, for example, ceramic. The specific type of ceramic is arbitrary and examples include aluminum oxide (alumina, Al2O3), aluminum nitride (AlN), and LTCC (Low Temperature Co-fired Ceramics). Of course, the material of the insulating substrate 23 may be a material other than ceramic, or it may be a composite material containing multiple types of materials.

[0049] (2.2. Conductors of the mounting substrate (excluding those related to the connection between the mounting substrate and the cover)) As previously described, the mounting substrate 11 has four terminals 3, two pads 25, and wiring 27.

[0050] The four terminals 3 are composed of layered (pad-shaped) conductors (e.g., metal) that overlap the second substrate surface 23d of the substrate portion 23a. The position, shape, and dimensions of the terminals 3 are arbitrary. For example, the four terminals 3 are located at the four corners of the second substrate surface 23d. In this case, in a plan view, each terminal 3 may or may not be separated from the two intersecting edges (long side and short side) of the second substrate surface 23d (as shown in the illustration). Whether or not they are located at the four corners can be reasonably determined based on the dimensions of the substrate portion 23a, the dimensions of the terminals 3, the distance between the edge of the substrate portion 23a and the edge of the terminals 3, etc. The same applies to the pads 25, etc., which will be described later.

[0051] The positional relationship between the two terminals 3 connected to the crystal element 5 and the two terminals 3 connected to the temperature sensing element 7 is arbitrary. For example, the former two terminals 3 may be located on one side (-D1 side) in the longitudinal direction of the substrate portion 23a, and the latter two terminals 3 may be located on the other side (+D1 side) in the longitudinal direction of the substrate portion 23a. Alternatively, for example, the former two terminals 3 may be located at one diagonal, and the latter two terminals 3 may be located at the other diagonal.

[0052] The two pads 25 are composed of layered (pad-shaped) conductors (e.g., metal) that overlap the first substrate surface 23c of the substrate portion 23a. The position, shape, and dimensions of the pads 25 are arbitrary. For example, the two pads 25 are located on one end (-D1 side) of the substrate portion 23a in the longitudinal direction rather than the center of the substrate portion 23a, and are aligned in the short direction of the substrate portion 23a. More specifically, the two pads 25 are located at two corners of the bottom surface of the recess R1, on one side in the longitudinal direction.

[0053] Each of the multiple wirings 27 may have an appropriate configuration. For example, each wiring 27 may include one of the following: a via conductor that penetrates the insulating substrate 23 (substrate portion 23a and / or frame portion 23b) in the thickness direction (D3 direction); a layered conductor (layered wiring) that overlaps the surface (top surface, bottom surface and / or side surface) of the insulating substrate 23 (substrate portion 23a and / or frame portion 23b); or a layered conductor located inside the insulating substrate 23 (e.g., at the boundary between the substrate portion 23a and the frame portion 23b) and aligning with the D1-D2 plane (first substrate surface 23c) (e.g., parallel). Note that the layered conductor overlapping the side surface of the insulating substrate 23 includes a layered conductor arranged on the inner surface of a castellation (recess).

[0054] The wiring 27 connecting the pad 25 and terminal 3, as illustrated in Figure 3, is composed solely of via conductors that penetrate the substrate portion 23a. In a configuration where both terminals 3 connected to the crystal element 5 (two pads 25) are located on one side in the longitudinal direction of the substrate portion 23a, the wiring 27 connecting the pads 25 and terminal 3, which are not shown in Figure 3, may be configured similarly. Furthermore, regardless of whether the two terminals 3 connected to the crystal element 5 are located on opposite diagonals of the substrate portion 23a, the two wirings 27 connected to the crystal element 5 may be configured in ways other than those shown.

[0055] Furthermore, at the connection point between the via conductor and the conductor layer (including not only those constituting the wiring 27, but also the pads 25, terminals 3, connecting electrodes 31, etc.), from the standpoint of materials, the upper or lower surface of the conductor layer and the lower or upper end surface of the via conductor may be joined, the via conductor may penetrate the conductor layer, or such distinction may be impossible. For convenience, in the following, expressions may be made assuming that the via conductor is joined to the upper or lower surface of the conductor layer in any of these configurations.

[0056] The conductor layer (terminal 3, pad 25, and wiring 27) may consist of a single conductor layer made of a single material, or it may consist of multiple conductor layers made of different materials stacked together. Furthermore, the conductor layer may have different material compositions in different regions.

[0057] The specific configuration of the via conductor (wiring 27) can be varied. For example, the via conductor may be solid (without internal cavities) (as shown in the illustration) or hollow. The via conductor may be made entirely of the same material, or its interior and outer surface may be made of different materials. Furthermore, for example, the via conductor may be in the shape of a straight column, tapered, or have flanges at appropriate positions.

[0058] The materials of the various conductors described above (conductor layer, via conductor, terminal 3, pad 25, and wiring 27) may be, for example, metals. Examples of metals include nickel (Ni), tungsten (W), copper (Cu), aluminum (Al), gold (Au), silver (Ag), or platinum (Pt), or alloys in which at least one of these is the main component.

[0059] (2.3. Bonding material) The conductive bonding material 29 that joins the crystal element 5 and the pad 25 is, for example, a conductive adhesive. The conductive adhesive, although not specifically shown, has an insulating binder and a conductive filler (conductive powder) dispersed in the binder. The binder may be an organic material (e.g., a resin, more specifically a thermosetting resin) or an inorganic material. The resin may be, for example, a silicone resin, an epoxy resin, a polyimide resin, or a bismaleimide resin. The material of the conductive filler may be, for example, a metal. The metal may be, for example, aluminum, molybdenum, tungsten, platinum, palladium, silver, titanium, nickel, or iron, or an alloy mainly composed of one or more of these.

[0060] (2.4. Lid) The shape, dimensions, and material of the cover 13 are arbitrary, as long as they can close the recess R1. In the illustrated example, the cover 13 is generally a flat member. Its planar shape is generally the same as that of the frame 23b, i.e., rectangular. In another view, the outer edge of the cover 13 extends along (for example, parallel to) the frame 23b. In planar perspective, the outer edge of the cover 13 is, for example, located outside the inner edge of the frame 23b (more specifically, the upper surface 23e). Also in planar perspective, part or all of the outer edge of the cover 13 may coincide with the outer edge of the frame 23b (as in the illustrated example), be located inside, or be located outside.

[0061] The material of the lid 13 may be a conductive material (e.g., metal), an insulating material, or a combination of both. The metal may be, for example, iron, nickel, or cobalt, or an alloy (e.g., Kovar) mainly composed of at least one of these. In the description of the embodiments, for convenience, expressions may be made assuming that the material of the lid 13 is metal. The insulating material may be an inorganic material (e.g., ceramic) or an organic material (e.g., resin).

[0062] (2.5. Joining the mounting base and the lid) The method of joining the mounting base 11 (frame portion 23b) and the lid 13 can be various, as long as the recess R1 is sealed. In the illustrated example, a sealing material 33 (reference numeral 3 in Figure 3) is interposed between the mounting base 11 and the lid 13 to join them. More specifically, the illustrated example shows a configuration in which seam welding is performed. In this configuration, the sealing material 33 has, for example, a first metal layer 35 that overlaps the upper surface of the frame portion 23b and a second metal layer 37 that overlaps the lower surface of the conductive lid 13. With the first metal layer 35 and the second metal layer 37 overlapping each other, voltage and pressure are applied to these metal layers (in other words, the metal layers are heated and pressurized) to weld them together.

[0063] Furthermore, the sealing material 33 may be considered, in whole or in part, as part of the mounting substrate 11 or the cover 13. For example, the first metal layer 35 may be considered as part of the mounting substrate 11. The second metal layer 37 may be considered as part of the cover 13. However, for convenience in describing the embodiments, the sealing material 33 may be described as a separate component from the mounting substrate 11 and the cover 13.

[0064] The conductive cover 13 (and / or sealing material 33 (first metal layer 35 and / or second metal layer 37); the same applies hereafter in this paragraph) may be connected via wiring 27 to a terminal 3 to which a reference potential is applied, although this is not specifically shown. The terminal 3 to which a reference potential is applied may be, for example, one of two terminals 3 connected to a temperature sensing element 7. The path connecting the cover 13 and the terminal 3 and the path connecting the temperature sensing element 7 and the terminal 3 may be shared by at least a portion of each other. The temperature sensing element 7 may not utilize a reference potential. In this case, the conductive cover 13 may be electrically floating, or a reference potential may be applied by adding an unshown terminal 3 for the reference potential.

[0065] The materials of the first metal layer 35 and the second metal layer 37 are arbitrary. For example, the material of the second metal layer 37 may be brazing material, and the first metal layer 35 may be a material that improves the wettability of the second metal layer 37. The specific materials in such embodiments are also arbitrary. For example, the material of the second metal layer 37 may be silver brazing material or gold tin. The material of the first metal layer 35 may be, for example, a layer made of tungsten or molybdenum on which nickel plating and gold plating are sequentially applied. In embodiments where brazing material is used as the material of the second metal layer 37, seam welding here may be considered as brazing.

[0066] The method of joining the mounting base 11 and the lid 13 may be any of the methods other than those described above.

[0067] For example, the sealing material 33 is not limited to a metal (or, from another perspective, a conductive material), but may also be an insulating material. Examples of such materials include glass. In other words, glass sealing may be performed. Specific types of glass include, for example, lead-based or lead-free low-melting-point glass. Examples of lead-free glass include bismuth-based or tin-based glass. The glass transition temperature of low-melting-point glass is, for example, 200°C to 500°C.

[0068] Furthermore, unlike welding and brazing, the joining may be performed without melting. From another perspective, the second metal layer 37 does not have to be a brazing material. For example, the joining of the first metal layer 35 and the second metal layer 37 may be diffusion bonding (or, in other words, direct intermetallic bonding). More specifically, for example, the overlapping surfaces of the first metal layer 35 and the second metal layer 37 may be subjected to a predetermined treatment (e.g., polishing and / or activation treatment), and these metal layers may be pressurized under conditions of a temperature below their melting point. Heating may or may not be performed, and unlike seam welding, current is not required.

[0069] Furthermore, in embodiments where seam welding (or other welding) is performed, the brazing material (second metal layer 37 in the above description) does not necessarily have to be used. For example, the metallic cover 13 may be directly welded to the first metal layer 35. Alternatively, the second metal layer 37 may be made of a material different from the material (brazing material) exemplified above.

[0070] Furthermore, for example, the method for heating the conductive or insulating sealing material 33 may be various methods other than applying electricity. For example, heating may be performed by placing the transducer 1 in a furnace, by irradiating with ultrasonic waves, by irradiating with laser light, or by a combination of these.

[0071] The shape and dimensions of the sealing material 33 (or, in other words, the first metal layer 35 and / or the second metal layer 37; hereafter, unless otherwise specified, the same applies in this paragraph and the next paragraph) in plan view are set such that the overlapping area with the upper surface 23e of the frame portion forms a frame shape (ring) in plan perspective. For example, the sealing material 33 has a shape and dimensions that fit within the upper surface 23e of the frame portion in plan perspective. In the illustrated example, the outer edge of the sealing material 33 (or, in other words, the first metal layer 35) coincides with the outer edge of the upper surface 23e of the frame portion. Also, the outer edge of the sealing material 33 (or, in other words, the second metal layer 37) coincides with the outer edge of the lower surface 13b of the lid. However, part or all of the outer edge of the sealing material 33 does not have to coincide with the outer edges of the upper surface 23e of the frame portion and / or the lower surface 13b of the lid.

[0072] As previously described, a connecting electrode 31 connected to the temperature-sensing element 7 is provided on the upper surface 23e of the frame. Therefore, at least at the location where the connecting electrode 31 is positioned, the sealing material 33 is separated from the inner edge of the upper surface 23e of the frame. From another perspective, for example, at least at the location where the connecting electrode 31 is positioned, the width of the sealing material 33 (length from the inner edge to the outer edge) is narrower than the width of the upper surface 23e of the frame. Outside the location where the connecting electrode 31 is positioned, the inner edge of the sealing material 33 may be separated from the inner edge of the upper surface 23e of the frame (as shown in the illustration), or it may coincide with the inner edge of the upper surface 23e of the frame. In other words, outside the location where the connecting electrode 31 is positioned, the width of the sealing material 33 may be narrower than or equal to the width of the upper surface 23e of the frame.

[0073] When the sealing material 33 is conductive, the sealing material 33 is, for example, separated from the two connecting electrodes 31 (as shown in the illustration). However, the sealing material 33 may be connected to one of the two connecting electrodes 31 on the upper surface 23e of the frame. In this case, one of the two connecting electrodes 31 (or, from another viewpoint, one of the two external electrodes 7b of the temperature sensing element 7) may be, for example, to which a reference potential is applied. In addition, an insulating sealing material 33 may be in contact with one or both of the two connecting electrodes 31.

[0074] In an embodiment in which a single connecting electrode 31 is connected to a conductive sealing material 33 (e.g., a first metal layer 35), the two may be made of different materials or may be integrally formed from the same material. In the latter embodiment, the single connecting electrode 31 and the first metal layer 35 may not be distinguishable by their thickness and planar shape. For example, the first metal layer 35 may overlap the entire length and width of one side of the upper surface 23e of the frame in a planar perspective view, and a portion of its area may be used as a single connecting electrode 31.

[0075] As can be understood from the above explanation, the sealing material 33 may extend with a constant width around the entire circumference (as shown in the illustration), or it may extend with a varying width. An example of the latter is a configuration in which, among the four sides of the upper surface 23e of the frame, the width is constant on each side, and the widths differ from side to side. In this case, for example, the width of the sealing material 33 on the side where the connecting electrode 31 is placed may be narrower than the width of the sealing material 33 on the side where the connecting electrode 31 is not placed. Another configuration in which the sealing material 33 extends with a varying width is a configuration in which the width changes on each side. More specifically, for example, a configuration in which the width is narrowed only in the area where the connecting electrode 31 is placed and its periphery.

[0076] The specific width of the sealing material 33 is arbitrary. For example, the width of the sealing material 33 (e.g., minimum width) may be 1 / 10 or more, 1 / 5 or more, 1 / 3 or more, or 1 / 2 or more of the width of the upper surface 23e of the frame (width at the same position as the width of the sealing material 33 in the circumferential direction), or it may be 4 / 5 or less, 3 / 4 or less, 2 / 3 or less, or 1 / 2 or less. The above lower and upper limits may be combined in any way so as not to cause any contradiction. Furthermore, any of the lower and / or upper limits exemplified above regarding the width of the upper surface 23e of the frame may be combined with any of the above lower and / or upper limits regarding the width of the sealing material 33.

[0077] The thickness of the sealing material 33 is, for example, constant around its entire circumference. The specific value of the thickness of the sealing material 33 is arbitrary. For example, the thickness of the sealing material 33 may be thinner than, equal to, or thicker than the thickness (minimum or maximum) of the quartz element 5 (or quartz blank 15). The thickness of the first metal layer 35 may be, for example, 10 μm or more and 30 μm or less, and may also be thicker than that range. The thickness of the second metal layer 37 may be, for example, 10 μm or more and 40 μm or less, and may also be thicker than that range.

[0078] (3. Temperature-sensing element (including the portion of the package related to the temperature-sensing element)) In the following, the temperature-sensing element 7 will be described in general order as follows. 3.1. Overview of the configuration of the temperature sensing element 7 3.2. Correspondence between the configuration of the temperature sensing element 7 and the drawing. 3.3. Position, shape, and dimensions of the temperature sensing element 7 3.4. Position, shape, and dimensions of the external electrode 7b (described later) 3.5. Part of package 9 relating to the temperature sensing element 7

[0079] (3.1. Overview of the temperature sensing element configuration) As previously described, in this embodiment, the temperature sensing element 7 is composed of a film-like element. The type of such film-like temperature sensing element 7 (or, from another perspective, the temperature detection principle) is arbitrary. For example, the temperature sensing element 7 may be a thermistor, a resistance thermometer, a thermocouple, or a diode. The specific configuration of the various temperature sensors is also arbitrary. In the description of the embodiment, for convenience, expressions may be used as an example where the temperature sensing element 7 is a thermistor, without further explanation.

[0080] It can be reasonably determined, based on common technical knowledge, that the temperature-sensing element 7 is a film-like element and not a chip-type temperature-sensing element. For example, the temperature-sensing element 7 is composed of one or more layers that overlap the object to be film-formed (cover 13), while a chip-type temperature-sensing element is mounted using a bonding material (e.g., bumps) for packaging. From another perspective, the absolute thickness of the temperature-sensing element 7, or its relative thickness to the thickness of the cover 13, etc., does not necessarily need to be extremely thin.

[0081] Although not specifically illustrated, we will take the example of a configuration where the temperature-sensing element 7 is a thermistor and explain that its specific configuration can vary.

[0082] A thermistor, for example, has a resistive film as a basic component whose resistance changes with temperature. The material of the resistive film may be, for example, an oxide (e.g., a composite oxide) or a nitride (e.g., a composite nitride). The oxide or nitride may contain one or more of the following: nickel (Ni), manganese (Mn), cobalt (Co), aluminum (Al), iron (Fe), and chromium (Cr). The resistive film may consist of only one layer made of a single material, or it may consist of two or more layers made of different materials. Furthermore, the resistive film may have the same material composition throughout in a plan view, or the material composition may differ in different regions.

[0083] The resistive film described above may overlap the conductive or insulating lower surface 13b of the lid via an insulating film, or it may overlap the insulating lower surface 13b of the lid directly. The insulating film has, for example, a resistivity higher than that of the resistive film. The material of the insulating film is arbitrary and may be, for example, an inorganic material, an organic material, or a combination of both. Examples of inorganic materials include silicon dioxide (SiO2) and silicon nitride (Si3N4). Examples of organic materials include various resins (e.g., epoxy resins or silicone resins). The insulating film may have, for example, only one layer made of a single material, or it may have two or more layers made of different materials. Furthermore, in a plan view, the insulating film may have the same material composition throughout, or the material composition may differ in different regions.

[0084] Furthermore, the resistive film may be exposed in the space formed by the package 9 (or, from another perspective, inside the recess R1), or it may be covered by an insulating coating. The coating has, for example, a resistivity higher than that of the resistive film. The coating may contribute to protecting the resistive film or the electrodes described later. The material of the coating is arbitrary. For example, the description of the insulating film material in the previous paragraph may be applied to the coating.

[0085] A voltage may be applied to the resistive film by a pair of application electrodes of an appropriate arrangement and shape. For example, the pair of application electrodes may be located at both ends of the resistive film in the longitudinal (or short-length) direction in a plan view, and a voltage may be applied to the resistive film in the longitudinal (or short-length) direction. In this embodiment, at least the portion of the pair of application electrodes connected to the resistive film may overlap the lower surface (cover 13 side) of the resistive film or overlap the upper surface of the resistive film. Alternatively, the pair of application electrodes may face each other across the resistive film in the thickness direction, and a voltage may be applied to the resistive film in the thickness direction. The pair of application electrodes may overlap the upper or lower surface of the resistive film and may be a pair of comb-shaped electrodes that mesh with each other.

[0086] If there is a portion of the applied electrode that does not overlap the upper surface of the resistive film (the surface opposite to the cover 13), that portion may overlap, for example, the conductive or insulating lower surface 13b of the cover via the aforementioned insulating film (or other insulating film), or it may directly overlap the insulating lower surface 13b of the cover. The same applies to the external electrode 7b and the relay conductor described later. The conductive cover 13 can be used as an applied electrode. The conductive cover 13 can also be used as wiring to apply voltage to the applied electrode, either directly overlapping it or indirectly overlapping it via another conductive layer. However, in the description of the embodiments, for convenience, expressions may be used that assume that the cover 13 is not used as an applied electrode or wiring.

[0087] The material of the applied electrode is arbitrary. For example, at least a portion of the material of the applied electrode may be the same as, or different from, at least a portion of the material of the various conductors (3, 25, 27, 31, and 35, etc.) of the conductor pattern 17 and the mounting substrate 11. In any case, the descriptions of the materials of the various conductors of the conductor pattern 17 and the mounting substrate 11 described above (specific examples of metals, presence or absence of layers of different materials, presence or absence of regions of different materials, etc.) may be used to describe the material of the applied electrode. The same applies to the materials of the external electrode 7b and the intermediate conductor described later.

[0088] (3.2. Correspondence between the structure of the thermosensitive film and the drawings) As can be understood from the above description, the temperature-sensing element 7 may have various configurations (for example, a resistive film, an insulating film, a coating film, and an applied electrode). In Figures 2 and 3 (and other drawings), the configuration of the temperature-sensing element 7 is shown as follows.

[0089] In Figures 2 and 3 (and other drawings), the thermosensitive element 7 comprises a thermosensitive film 7a and a pair of external electrodes 7b. A voltage is applied to the thermosensitive film 7a, for example, via the pair of external electrodes 7b. In another view, the thermosensitive film 7a outputs a signal of intensity corresponding to temperature from at least one of the pair of external electrodes 7b.

[0090] The temperature-sensitive film 7a may have only a functional part that directly contributes to temperature detection (for example, a resistive film in the case of a thermistor), as can be understood from the explanation using the thermistor as an example above, or it may have an insulating film, a coating film, an applied electrode and / or a relay conductor that overlaps the functional part, as described in the next paragraph.

[0091] The external electrode 7b may, for example, be part or all of the application electrode that directly applies a voltage to the resistive film (is in direct contact with the resistive film), or it may be an electrode electrically connected to the application electrode, taking the example where the temperature sensing element 7 is a thermistor. In the latter embodiment, the external electrode 7b may be directly connected to the application electrode, for example, by overlapping parts of each other, or it may be indirectly connected to the application electrode via an intermediate conductor (for example, a conductor layer different from both the application electrode and the external electrode 7b).

[0092] From another perspective, the pair of external electrodes 7b may be seen as being shown in their entirety in Figures 1 and 2, or as being shown only in part. In the latter case, the part may be, for example, the portion of the pair of external electrodes 7b that is covered by a coating film and is exposed from the coating film. Alternatively, the part may be seen as the portion of the pair of external electrodes 7b that contributes to the connection with the package 9 (although other parts of the pair of external electrodes 7b are also exposed, they are omitted from the illustration).

[0093] To give a specific example, the temperature sensing element 7 may have, as previously described, a pair of application electrodes that overlap the functional part on both sides of a predetermined direction in a plan view (for example, the direction in which the functional part (resistive film) extends). In this case, the pair of external electrodes 7b illustrated in Figure 2 may be, for example, a part of the pair of application electrodes (an exposed portion or an extracted portion), or a pair of terminals that are directly or indirectly connected to the pair of application electrodes.

[0094] Furthermore, for example, the temperature sensing element 7 may have a pair of application electrodes sandwiching the resistive film in the thickness direction, as described above. In this case, the pair of external electrodes 7b exemplified in Figure 2 may be a part (exposed or extracted portion) of the pair of application electrodes, or a pair of terminals directly or indirectly connected to the pair of application electrodes. In the former embodiment, the pair of external electrodes 7b may be the end of one application electrode in a plan view and the end of the other application electrode in a plan view.

[0095] Furthermore, for example, the temperature sensing element 7 may have a pair of comb-shaped electrodes as a pair of applied electrodes, as described above. The pair of external electrodes 7b illustrated in Figure 2 may be a part (exposed or extracted portion) of a pair of conductive patterns including a pair of comb-shaped electrodes, or a pair of terminals directly or indirectly connected to the pair of comb-shaped electrodes. More specifically, the pair of comb-shaped electrodes may have, for example, a pair of busbars facing each other and a plurality of electrode fingers extending from each busbar to the other busbar. The part of the pair of conductive patterns described above may be, for example, a portion extending from a pair of busbars. The pair of terminals described above may be, for example, directly or indirectly connected to a pair of busbars.

[0096] In plan view, the relationship between the shape of the temperature-sensing element 7 and the arrangement of one pair (or more than two pairs) of comb-tooth electrodes is arbitrary. For example, in the case where at least a part (all in the case of Figure 2) of the temperature-sensing element 7 has a shape having a longitudinal direction and a transverse direction (referred to as the first shape in this paragraph), as in the example in Figure 2, a pair of comb-tooth electrodes may be arranged such that a pair of busbars extends in the longitudinal direction and multiple electrode fingers extend in the transverse direction. In embodiments in which the temperature-sensing element 7 has multiple first shapes, a pair of comb-tooth electrodes may be provided for each first shape.

[0097] (3.3. Position, shape, and dimensions of the temperature-sensing element) The position (position on the cover 13; the same applies hereafter unless otherwise specified), shape, and dimensions of the temperature-sensing element 7 are arbitrary. The description of the position, shape, and dimensions of the temperature-sensing element 7 may be applied to the position, shape, and dimensions of the temperature-sensing film 7a, provided that no contradictions arise. As can be understood from the above example of the thermistor, the position, shape, and dimensions of the temperature-sensing film 7a are those of the functional part (resistive film in the case of a thermistor) in embodiments where the temperature-sensing film 7a consists only of the functional part, and those of the functional part and the other parts as a whole in embodiments where the temperature-sensing film 7a includes other parts (insulating film, coating film, applied electrode, and / or relay conductor). However, the description of the position, shape, and dimensions of the temperature-sensing element 7 may be applied to the position, shape, and dimensions of the functional part, or a combination of the functional part and the other part directly above it, in embodiments where the temperature-sensing film 7a includes parts other than the functional part, provided that no contradictions arise.

[0098] As can be seen from the modified examples described later, the temperature-sensing element 7 may be located in any region of the lower surface 13b of the lid. For example, when viewed from above, the temperature-sensing element 7 may be contained within the recess R1 (or, from another viewpoint, inside the upper surface 23e of the frame) (as in the examples in Figures 2 and 3), located outside the recess R1 (as in the example in Figure 6 described later), or straddle the recess R1 and the area outside it. In other words, in a planar view, the temperature-sensing element 7 may or may not have a portion overlapping the recess R1, and may or may not have a portion overlapping the area outside the recess R1.

[0099] Furthermore, in a planar perspective view, in an embodiment where the temperature-sensing element 7 overlaps with the recess R1, the temperature-sensing element 7 may or may not overlap with the geometric center of the recess R1. Also, regardless of whether the temperature-sensing element 7 overlaps with the recess R1 or the geometric center of the recess R1, the geometric center of the temperature-sensing element 7 may or may not coincide with the geometric center of the recess R1. For example, if the distance between the geometric centers is 1 / 5 or less of the minimum diameter of the recess R1, they may be considered to coincide.

[0100] In a planar perspective view, the thermosensing element 7 has a portion that overlaps with the recess R1, and the extent of this overlap is arbitrary. For example, the area of ​​the thermosensing element 7 that overlaps with the recess R1 may be 1 / 5 or more, 1 / 3 or more, 1 / 2 or more, 2 / 3 or more, 4 / 5 or more, or 1x or less, 4 / 5 or less, 2 / 3 or less, 1 / 2 or less, 1 / 3 or less, or 1 / 5 or less of the area of ​​the recess R1. The above lower and upper limits may be combined in any way so as not to cause any contradiction. Furthermore, the thermosensing element 7 may overlap the entire recess R1. Also, the lower and / or upper limits of this paragraph may be applied in a planar perspective view to the length (e.g., maximum length) of the thermosensing element 7 that overlaps with the length (e.g., maximum length) of the recess R1 in any direction (e.g., longitudinal or transverse direction) of the recess R1.

[0101] The above explanation of the position and size of the temperature-sensing element 7 in comparison with the recess R1 (whether or not it overlaps with the recess R1, whether or not the geometric centers coincide, and the overlapping area relative to the area of ​​the recess R1, etc.) may be used to explain the position and size of the temperature-sensing element 7 in comparison with the crystal element 5 or the excitation electrode 19, by replacing the term "recess R1" with the term "crystal element 5" or the term "excitation electrode 19".

[0102] In the illustrated example, the thermosensing element 7, in plan view, generally overlaps with the entire recess R1. That is, in plan view, the thermosensing element 7 (more specifically, the thermosensing film 7a) has the same shape and dimensions as the recess R1. Therefore, the previously stated explanation regarding the shape and dimensions of the recess R1 in plan view can be applied to the planar shape of the thermosensing film 7a. Furthermore, since the thermosensing element 7 overlaps with the entire recess R1 in plan view, it also overlaps with the entire quartz element 5 and the entire excitation electrode 19. Moreover, in plan view, the geometric center of the thermosensing element 7 is roughly coincidental with, or relatively close to, the geometric center of the recess R1, the geometric center of the quartz element 5, and the geometric center of the excitation electrode 19.

[0103] Of course, unlike the illustrated example, the shape and dimensions of the temperature-sensing element 7 may differ from those of the recess R1 in a planar perspective view. For example, the temperature-sensing element 7 may be rectangular in shape, smaller than the recess R1, in a planar perspective view. In this case, the longitudinal direction of the rectangle may be the same as either the longitudinal or short longitudinal direction of the recess R1. The rectangle may also be square. Furthermore, in a planar perspective view, the temperature-sensing film 7a may be separated from the upper surface 23e of the frame around its entire circumference.

[0104] Furthermore, in planar perspective, the shape of the temperature-sensing element 7 may be other than rectangular, regardless of whether it is the same as the shape of the recess R1. Examples of shapes other than rectangular include circles, ellipses, and polygons other than rectangles. These shapes can be described as the boundary lines of a convex set in mathematics. In addition, the shape of the temperature-sensing element 7 may be an L-shape or a U-shape, or any other shape that deviates from the boundary lines of a convex set.

[0105] The temperature-sensing element 7 may have a generally constant thickness throughout its entire region, or it may have multiple regions with different thicknesses. The upper surface of the temperature-sensing element 7 may be, for example, flat, curved, or have an uneven shape. An example of an uneven shape is a shape having multiple planes with different heights. An example of such a shape is a shape in which the presence or absence of a resistive film and / or relay conductors is visible on the upper surface of the coating film covering them.

[0106] The specific thickness of the temperature sensing element 7 is arbitrary. For example, the maximum or average thickness of the temperature sensing element 7 may be 1 / 300 or more, 1 / 200 or more, 1 / 100 or more, 1 / 50 or more, 1 / 30 or more, 1 / 10 or more, 1 / 5 or more, or 1 / 2 or more relative to the minimum, average, or maximum thickness of the crystal blank 15, or it may be 2 times or less, 1 time or less, 1 / 5 or less, 1 / 10 or less, or 1 / 100 or less. The above lower and upper limits may be combined in any way so as not to cause contradictions. Furthermore, the thickness of the temperature sensing element 7 may be, for example, 0.05 μm or more, 0.1 μm or more, 1 μm or more, 5 μm or more, or 10 μm or more, or it may be 100 μm or less, 50 μm or less, or 10 μm or less. The above lower and upper limits may be combined in any way so as not to cause contradictions.

[0107] The value of the first distance (e.g., shortest distance or average distance) between the temperature sensing element 7 and the crystal element 5 is arbitrary. For example, this first distance may be smaller than, equal to, or larger than the thickness of the crystal element 5 or the distance (e.g., shortest distance or average distance) between the crystal element 5 and the bottom surface of the recess R1.

[0108] As previously described, the quartz element is not limited to a plate shape, but may be of various types, such as a tuning fork shape. In this case, the position, shape, and dimensions of the temperature-sensing element may be set so as to face a specific part of the quartz element. For example, in a configuration in which the quartz element has a base and vibrating arms extending from the base, the temperature-sensing element may have an elongated shape that faces the vibrating arms but does not face the base.

[0109] (3.4. Position, shape, and dimensions of external electrodes) The pair of external electrodes 7b are located, for example, in a region of the lid 13 that overlaps with the upper surface 23e of the frame in a planar perspective view. As a result, when the lid 13 is placed over the recess R1, the pair of external electrodes 7b and the pair of connecting electrodes 31 located on the upper surface 23e of the frame face each other and are connected.

[0110] In planar perspective, a pair of external electrodes 7b may be located in any region within the upper surface 23e of the frame. For example, each external electrode 7b may be contained within one of the four sides of the upper surface 23e of the frame (as shown in the illustration), or it may extend across two or more sides. In the following explanation, unless otherwise specified, and unless contradictions arise, one external electrode 7b may be considered to be contained within one side.

[0111] Furthermore, for example, one external electrode 7b may be located on either the long side or the short side of the four sides of the upper surface 23e of the frame. Also, two external electrodes 7b may be located on the same side (example in Figure 2), or on two different sides (see Figures 4(a) and 4(b) described later). The two different sides may be opposite sides or intersecting sides.

[0112] Furthermore, for example, one external electrode 7b that fits within one side of the upper surface 23e of the frame portion may be located in any region along the length of that side. For example, one external electrode 7b may be located along the entire side (see Figure 4(b) described later), or it may be located in part of that side (examples in Figure 2 and Figure 4(a) described later). In the latter embodiment, one external electrode 7b may be located at the end of one side (illustrated example), or it may be located towards the center of one side.

[0113] When viewed from above, the pair of external electrodes 7b are located inside the sealing material 33 (or, in other words, the second metal layer 37). More specifically, the pair of external electrodes 7b are separated from the conductive sealing material 33 (or, in other words, the first metal layer 35 and / or the second metal layer 37) (as shown in the illustration). However, one of the pair of external electrodes 7b may be connected to the conductive sealing material 33 at the lower surface 13b of the lid (upper surface 23e of the frame). In this case, the one external electrode 7b may be, for example, to which a reference potential is applied. Also, one or both of the pair of external electrodes 7b may be in contact with or not in contact with the insulating sealing material 33.

[0114] In an embodiment in which one external electrode 7b and a conductive sealing material 33 (e.g., a second metal layer 37) are connected, the two may be made of different materials or may be integrally formed from the same material. In the latter embodiment, the one external electrode 7b and the second metal layer 37 may not be distinguishable by their thickness and planar shape. For example, the second metal layer 37 may have an area that spans the entire length and width of one side of the upper surface 23e of the frame in a planar perspective, and a portion of its area may be used as one external electrode 7b.

[0115] When viewed from above, the pair of external electrodes 7b may be located in any region in the width direction (from the inner edge to the outer edge) within the upper surface 23e of the frame, as long as they are located inside the sealing material 33 as described above. For example, the pair of external electrodes 7b may be located inside the center of the upper surface 23e in the width direction, may overlap with the center in the width direction, may overlap with the inner edge of the upper surface 23e of the frame, or may be located outside the inner edge of the upper surface 23e of the frame. The external electrodes 7b may have a portion located inside the inner edge of the upper surface 23e of the frame.

[0116] As can be understood from the positional description above, the shape and dimensions of the external electrode 7b in plan view are arbitrary. For example, the planar shape of the external electrode 7b may be rectangular, located on one side of the upper surface 23e of the frame (as shown in the illustration), or roughly L-shaped, following two of the four sides of the upper surface 23e of the frame, or roughly U-shaped, following three of the four sides of the upper surface 23e of the frame. Furthermore, the shape of the external electrode 7b located on one side is not limited to rectangular, but may be other shapes (for example, circular, elliptical, or polygonal shapes other than rectangles).

[0117] Furthermore, for example, the length of one external electrode 7b relative to the length of one side of the inner edge of the upper frame surface 23e may be less than 1 / 2 or greater than 1 / 2. Also, for example, the width of the external electrode 7b relative to the width of the upper frame surface 23e may be less than 1 / 3 or greater than 1 / 3.

[0118] As previously described, the structure of the temperature-sensitive film 7a can be varied. For example, a relay conductor may be interposed between the application electrode, which applies voltage to the functional part (resistive film in the case of a thermistor), and the external electrode 7b to electrically connect them. Furthermore, at least two of the application electrode, the relay conductor, and the external electrode 7b may intersect in three dimensions via an insulator, or two or more (e.g., two or more layers) of relay conductors may be interposed between the application electrode and the external electrode 7b. As can be understood from this, the position, shape, and dimensions of the external electrode 7b can be any position, shape, and dimensions, regardless of the position, shape, and dimensions of the temperature-sensitive film 7a (functional part).

[0119] For example, each external electrode 7b may or may not be located within the arrangement area of ​​the thermosensing film 7a (functional part). In the former embodiment, the specific position of the external electrode 7b relative to the thermosensing film 7a is also arbitrary. For example, the external electrode 7b may be located in an area adjacent to the edge of the thermosensing film 7a, or in an area away from the edge of the thermosensing film 7a (see Figure 5(a) described later). Furthermore, in an embodiment in which the external electrode 7b has a portion located outside the arrangement area of ​​the thermosensing film 7a, the external electrode 7b may extend from a position overlapping the thermosensing film 7a to an arbitrary position, or be located in an arbitrary area and connected to the thermosensing film 7a via a relay conductor. In such an embodiment, the thermosensing film 7a may be located in an area away from the upper surface 23e of the frame (for example, an area overlapping with the quartz element 5 or the excitation electrode 19) in a planar perspective view.

[0120] In the examples shown in Figures 1 to 3, when viewed from above, the two external electrodes 7b are located on the opposite side (+D1 side) from the side where the two pads 25 are located, relative to the center of the package 9 in the longitudinal direction of the package 9. More specifically, the two external electrodes 7b are both located on the short side on the +D1 side of the four sides of the upper surface 23e of the frame. Furthermore, the two external electrodes 7b are located apart from each other on both sides of the short side on the +D1 side, in the direction in which that short side extends. In addition, the two external electrodes 7b overlap the inner edge of the upper surface 23e of the frame.

[0121] The thickness of the external electrode 7b is arbitrary. However, in the examples of Figures 1 to 3, the connecting electrode 31 and the external electrode 7b are joined facing each other between the planar lower surface 13b of the lid and the planar upper surface 23e of the frame, so the thickness of the external electrode 7b is less than the thickness of the sealing material 33. It is also possible to make the thickness of the external electrode 7b greater than or equal to the thickness of the sealing material 33 by making the area where the connecting electrode 31 is placed lower than the area where the first metal layer 35 is placed on the upper surface 23e of the frame. The thickness of the external electrode 7b may be thinner than, equal to, or thicker than the thickness of the second metal layer 37. The explanation of the thickness of the external electrode 7b in this paragraph may be applied to the thickness of the connecting electrode 31. In this case, the term "second metal layer 37" may be replaced with the term "first metal layer 35".

[0122] (3.5. Part of the package related to the temperature sensing element) As already mentioned, package 9 (mounting substrate 11) has connecting electrodes 31 that are connected to two external electrodes 7b. The connecting electrodes 31 and the external electrodes 7b are joined facing each other. When viewed from a plane perspective, the connecting electrodes 31 and the external electrodes 7b may coincide in general, or they may overlap but be offset from each other. In any case, the previously described position, shape, and dimensions of the external electrodes 7b in a plane perspective may be applied to the position, shape, and dimensions of the connecting electrodes 31 in a plane perspective, as long as no inconsistencies arise.

[0123] The two connecting electrodes 31 are electrically connected to the two terminals 3 via two wires 27. As has already been mentioned, the wires 27 may have various configurations. The wires 27 connecting the connecting electrodes 31 and the terminals 3 as illustrated in Figure 3 consist only of via conductors that penetrate the frame portion 23b and the substrate portion 23a. In a configuration in which both of the two terminals 3 connected to the two connecting electrodes 31 are located on one side in the longitudinal direction of the substrate portion 23a, the wires 27 connecting the connecting electrodes 31 and the terminals 3, which are not shown in Figure 3, may be configured similarly. Furthermore, regardless of whether the two terminals 3 connected to the two connecting electrodes 31 are located on a pair of diagonal corners of the substrate portion 23a or not, the two wires 27 connected to the two connecting electrodes 31 may be configured in ways other than those shown.

[0124] The material of the connecting electrode 31 is also arbitrary. For example, the material of the connecting electrode 31 may be the same as the material of the various conductors (3, 25 and / or 27) of the package 9, or it may be the same as the material of the sealing material 33 (e.g., the first metal layer 35). In any case, the descriptions of the materials of the various conductors of the package 9 and / or the sealing material 33 may be applied to the material of the connecting electrode 31.

[0125] Various methods can be used to join the external electrode 7b and the connecting electrode 31. For example, they may be joined by a conductive bonding material (not shown) interposed between them. The conductive bonding material may be a conductive adhesive or a metallic material. The metallic material may be solder (including lead-free solder; the same applies hereinafter) or a brazing material. Alternatively, the external electrode 7b and the connecting electrode 31 may be joined by direct metal-to-metal bonding. The joining method of the connecting electrode 31 and the external electrode 7b may be the same as or different from the joining method of the first metal layer 35 and the second metal layer 37.

[0126] The joining of the external electrode 7b and the connecting electrode 31 may be performed, for example, before the sealing step in which the mounting substrate 11 and the lid 13 are joined by the sealing material 33. In the sealing step, the temperature of the external electrode 7b and the connecting electrode 31 (and the bonding material if one is interposed) is set, for example, below the heat resistance temperature of the conductive adhesive used to join them, or below the melting temperature of the metal material connecting them (solder or brazing material; this may be the external electrode 7b itself and / or the connecting electrode 31 itself; the same applies in the next paragraph). However, the metal material may melt and be re-bonded.

[0127] Contrary to the above, the joining of the external electrode 7b and the connecting electrode 31 may be performed simultaneously with the sealing process in which the mounting substrate 11 and the lid 13 are joined by the sealing material 33. For example, the heat generated during the sealing process may cause the conductive adhesive between the external electrode 7b and the connecting electrode 31 to harden, or the metal material between the external electrode 7b and the connecting electrode 31 (that is not joined to at least one of the external electrode 7b and the connecting electrode 31) to melt. It is also clear that the external electrode 7b, which is formed integrally with the second metal layer 37 using the same material as the second metal layer 37, may be joined to the connecting electrode 31 during the sealing process.

[0128] It is also possible to join the external electrode 7b and the connecting electrode 31 after the sealing process. For example, in the sealing process, the temperatures of the external electrode 7b and the connecting electrode 31 are set below the melting point of the metal material connecting them. After that, the external electrode 7b and the connecting electrode 31 may be heated by ultrasonic irradiation or the like, or the lid 13 may be locally pressurized with an appropriate device.

[0129] (4. Variant) The following describes some modifications of the first embodiment in the order outlined below. 4.1. Modified examples relating to the external electrode 7b (Figures 4(a) and 4(b)) 4.2. Modified examples related to the thermosensitive film 7a (Figures 5(a) to 5(c) and Figure 6)

[0130] (4.1. Modified examples related to external electrodes) Figures 4(a) and 4(b) are plan views showing the lower surface 13b of the cover where the temperature-sensing element 7A or 7B according to the modified example is located.

[0131] As previously described, the position, shape, and dimensions of the external electrode 7b (or connecting electrode 31, from another perspective) can vary. Figures 4(a) and 4(b) show examples of external electrode 7b with positions, shapes, and dimensions different from those illustrated in Figures 1 to 3. Specifically, they are as follows. Although not specifically shown, the position, shape, and dimensions of the connecting electrode 31 connected to the external electrode 7b in the modified example are generally the same as those of the external electrode 7b in the modified example.

[0132] In the example shown in Figure 4(a), the two external electrodes 7b are adjacent to two different edges (sides) of the rectangular (in other words, a shape that can be conceptualized as having four edges) thermosensing film 7a. From another viewpoint, when viewed from above, the two external electrodes 7b overlap two different sides of the rectangular (in other words, a shape that can be conceptualized as having four segments (sides)) upper surface 23e of the frame. More specifically, the two external electrodes 7b are located on two short sides of the thermosensing film 7a or the upper surface 23e of the frame. Furthermore, the two external electrodes 7b are located on opposite sides of each other in the direction in which the short sides extend (direction D2).

[0133] In the example shown in Figure 4(b), the two external electrodes 7b are located on two different sides (more specifically, two short sides) of the thermosensitive film 7a (or, from another viewpoint, the upper surface 23e of the frame), similar to the example shown in Figure 4(a). However, each external electrode 7b extends over most of the length of each side (in the case of the upper surface 23e of the frame, the length relative to the inner circumference) (for example, more than 80%; in the illustrated example, the entire length).

[0134] (4.2. Modified examples related to thermosensitive films) Figures 5(a), 5(b), and 5(c) are cross-sectional views showing parts of modified quartz oscillators 1C, 1D, and 1E. These figures correspond to the upper portion of Figure 3.

[0135] As previously described, the position, shape, and dimensions of the thermosensitive film 7a can vary. Figures 5(a) to 5(c) show examples with positions, shapes, and dimensions different from those exemplified in Figures 1 to 3. Specifically, these are as follows:

[0136] In Figures 5(a) to 5(c), the position of the two external electrodes 7b is shown as an example, similar to the embodiment, where the two external electrodes 7b are located on the +D1 side of the upper surface 23e of the frame. However, as can be understood from the above explanation, the position of the two external electrodes 7b is arbitrary, and may be, for example, the positions exemplified in Figures 4(a) and 4(b), or similar positions.

[0137] In the example shown in Figure 5(a), the temperature-sensitive film 7a of the temperature-sensitive element 7C has a portion located outside the recess R1 when viewed from above. More specifically, the temperature-sensitive film 7a overlaps the entire surface of the lower surface 13b of the lid. Accordingly, the sealing material 33C of the package 9C is bonded to the lower surface 13b of the lid via the temperature-sensitive film 7a.

[0138] In embodiments in which the temperature-sensitive film 7a has a portion located outside the recess R1 (including the modified forms shown in Figures 5(b) and 6 described later), the size of the portion is arbitrary. For example, in a planar perspective view, the area of ​​the portion located outside the recess R1 (and / or the portion overlapping the upper surface 23e of the frame) may be 1 / 5 or more, 1 / 3 or more, 1 / 2 or more, 2 / 3 or more, 4 / 5 or more, or 1 times the area of ​​the upper surface 23e of the frame. In the above description, the word "area" may be replaced with the word "length in the width direction of the upper surface 23e of the frame.

[0139] In the description in the previous paragraph, the term "recess R1" may be replaced with the term "crystal element 5". In this case, the term "frame upper surface 23e" may be replaced with the term "region from the outer edge of the crystal element 5 to the inner or outer edge of the frame upper surface 23e". Furthermore, in the description in the previous paragraph, the term "recess R1" may be replaced with the term "excitation electrode 19". In this case, the term "frame upper surface 23e" may be replaced with the term "region from the outer edge of the excitation electrode 19 to the outer edge of the crystal element 5", or the term "region from the outer edge of the excitation electrode 19 to the inner or outer edge of the frame upper surface 23e".

[0140] The sealing material 33C may be a conductive material (e.g., metal) or an insulating material (e.g., glass). In the former embodiment, the temperature-sensitive film 7a may have an insulating coating film between the functional part (resistive film in the case of a thermistor) and the sealing material 33C. In the latter embodiment, the temperature-sensitive film 7a may or may not have a coating film. In Figure 5(a), the sealing material 33C is represented as a single layer of material. However, the sealing material 33C may include a first metal layer 35 and a second metal layer 37, as in the embodiment.

[0141] In the example shown in Figure 5(b), the thermosensitive film 7a of the thermosensitive element 7D has a portion located outside the recess R1 when viewed from above, similar to the example shown in Figure 5(a). However, in the thermosensitive element 7D, the thermosensitive film 7a does not overlap the entire lower surface 13b of the lid, but overlaps only a portion of it. More specifically, the outer edge (for example, the entire) of the thermosensitive film 7a is located inside the outer edge of the lower surface 13b of the lid (or, in other words, the upper surface 23e of the frame). In the package 9D shown in Figure 5(b), the bonding between the mounting substrate 11D and the lid 13 may be performed on the outer circumference of the thermosensitive film 7a (thermosensitive element 7D), similar to the embodiment (illustrated example), or it may be performed via the thermosensitive film 7a, similar to the example in Figure 5(a).

[0142] The temperature-sensing element 7D shown in Figure 5(b) is an example of a configuration in which the thickness of the temperature-sensing film 7a is greater than the thickness of the sealing material 33. In this configuration, the upper surface 23e of the frame may have a lower area for the placement of the connecting electrode 31 than the area for the placement of the sealing material 33 (it may be located on the bottom side of the recess R1). This reduces the likelihood that the sealing performance of the recess R1 will be reduced due to the thickness of the temperature-sensing film 7a.

[0143] Furthermore, there are various methods for making the area where the connecting electrodes 31 are placed lower than the area where the sealing material 33 is placed on the upper surface 23e of the frame. For example, similar to the formation of the recess R1, the area where the sealing material 33 is placed may be made relatively higher by laminating a ceramic green sheet over the area where the sealing material 33 is placed, or the area where the connecting electrodes 31 are placed may be made relatively lower by pressing. Alternatively, the area where the connecting electrodes 31 are placed may be made relatively lower by polishing, grinding, cutting, or laser processing.

[0144] In the example shown in Figure 5(c), the thermosensitive film 7a of the thermosensitive element 7E, when viewed from above, is almost entirely superimposed on the entire recess R1, similar to the embodiment. However, the thermosensitive film 7a is housed in a recess (not shown) in the lower surface 13b of the lid. The thickness of the thermosensitive film 7a may be less than, equal to (as in the illustrated example) or thicker than the depth of the recess in the lower surface 13b of the lid. This modification is applicable not only to thermosensitive films 7a having an area that covers the entire recess R1, but also to thermosensitive films 7a of various sizes where the entire film is located on the inner circumference side of the outer edge of the lid 13.

[0145] In package 9E, the joining of the lid 13E and the mounting substrate 11 may be performed, for example, in the same manner as in the embodiment or other modifications. However, for example, by housing the temperature-sensitive film 7a in the recess of the lid 13E, the -D3 side of the temperature-sensitive film 7a is positioned on the +D3 side compared to the embodiment. As a result, for example, as in the example of Figure 5(b), the probability of the arrangement area of ​​the connecting electrode 31 on the upper surface 23e of the frame being lower than the arrangement area of ​​the sealing material 33 is reduced.

[0146] Figure 6 is a perspective view showing a modified example of the temperature-sensing element 7F.

[0147] As previously described, the planar shape of the thermosensitive film 7a can be various shapes and is not limited to a rectangular shape. In the thermosensing element 7F, the planar shape of the thermosensitive film 7a is frame-shaped (annular). In other words, the thermosensitive film 7a is a shape that extends along (for example, parallel to) one or more edges of the cover 13 (or, from another viewpoint, one or more sides of the upper surface 23e of the frame). The shape that extends along the edge does not necessarily have to be annular. For example, the thermosensitive film 7a may extend along only one side of the rectangular cover 13, or along only two sides (it may be L-shaped), or along only three sides (it may be U-shaped), or along all four sides but interrupted midway (it may be C-shaped).

[0148] The temperature-sensing film 7a of the temperature-sensing element 7F may be considered to have one or more segments (reference numerals omitted) extending along one or more edges of the cover 13. Each segment is generally rectangular in shape. From another viewpoint, each segment extends with a constant width. Also, each segment extends over approximately the entire length of one edge (for example, 80% or more of the length). Of course, as can be understood from the above explanation, the planar shape of each segment may not be rectangular, the width may vary, and the length may be shorter than the length of one edge. The shapes and dimensions of multiple segments may be the same or different from one another.

[0149] The thermosensitive film 7a extending along one or more edges of the lid 13 may or may not overlap with the recess R1 in a planar view. In the example of Figure 6, an embodiment is assumed in which the thermosensitive film 7a does not overlap with the recess R1 (or the overlapping area is relatively small). For example, the inner edge of the thermosensitive film 7a roughly coincides with the edge of the recess R1 in a planar view. Note that the thermosensitive film 7a in Figure 6 is an example of an embodiment that has a portion located outside the recess R1 in a planar view, similar to the examples in Figures 5(a) and 5(b).

[0150] When viewing the thermosensitive film 7a, which is shaped to follow the edge of the lid 13, from a planar perspective, the area of ​​the recess R1 that does not overlap with the thermosensitive film 7a (the area surrounded by the thermosensitive film 7a), the area of ​​the area where the thermosensitive film 7a and the recess R1 overlap, and the area of ​​the thermosensitive film 7a that does not overlap with the recess R1 (the area outside the recess R1) are arbitrary. For example, when viewed from a planar perspective, the area of ​​the region of the thermosensitive film 7a outside the recess R1 may be 1 / 2 or more, 2 / 3 or more, 4 / 5 or more, or 1 times the total area of ​​the thermosensitive film 7a. In this explanation, the word area may be replaced with the word width of the thermosensitive film 7a (segment). Also, for example, when viewed from a planar perspective, the area of ​​the region of the recess R1 surrounded by the thermosensitive film 7a may be 1 / 2 or more, 2 / 3 or more, 4 / 5 or more, or 1 times the total area of ​​the recess R1. In this description, the term "area" may be replaced with the term "length (e.g., maximum length) of the recess R1 in any direction (e.g., longitudinal or transverse) when viewed from a plane. In the description in this paragraph, the term "recess R1" may be replaced with the term "crystal element 5" or the term "excitation electrode 19".

[0151] As previously described, the configuration of the thermosensitive film 7a (e.g., the shape of the applied electrodes) can be varied. The same applies to the thermosensitive element 7F. For example, the thermosensitive element 7 may have a voltage applied at both ends in the direction in which one or more segments (sides) included in the thermosensitive film 7a extend, or a voltage applied in the thickness direction of the thermosensitive film 7a, or a voltage applied by one or more pairs of comb-tooth electrodes. In the embodiment in which comb-tooth electrodes are provided, for example, one pair of comb-tooth electrodes may be provided for each segment. In this case, for example, one pair of comb-tooth electrodes may be arranged so that one pair of busbars extends in the longitudinal direction of the segment.

[0152] As previously described, the position, shape, and dimensions of the two external electrodes 7b can be arbitrary, as long as they overlap with the upper surface 23e of the frame in plan view. In the example of Figure 6, the two external electrodes 7b are located at one diagonal corner of the rectangular frame-shaped thermosensitive film 7a. Their shape is a square with a length similar to the width of the segments (sides) of the thermosensitive film 7a. Of course, the two external electrodes 7b may be located in areas other than the pair of diagonals (see, for example, Figure 2 or Figure 4(b)), or they may have a shape other than a square (for example, a rectangle or circle other than a square).

[0153] When viewed from above, the temperature-sensitive film 7a extending along one or more edges of the lid 13 may overlap with the sealing material 33, as in the example in Figure 5(a), or it may not overlap with the sealing material 33, as in the example in Figure 5(b). Figure 6 illustrates the former configuration. For convenience, the configuration in which the second metal layer 37 is located on the lid 13 is shown here. As can be understood from the above explanation, the sealing material 33 may be an insulating material (e.g., glass), or it may be located only on the mounting substrate 11 before the lid 13 is joined to the mounting substrate 11.

[0154] (5. Summary of the First Embodiment) As described above, the piezoelectric device (quartz oscillator 1) comprises a piezoelectric element (quartz element 5), a mounting substrate 11, a cover 13, and a temperature sensing element 7. The mounting substrate 11 has a recess R1. The quartz element 5 is mounted on the bottom surface of the recess R1. The cover 13 covers the recess R1. The temperature sensing element 7 has a portion that is located closer to the cover 13 than the quartz element 5.

[0155] Therefore, as previously described, for example, the likelihood of the temperature-sensing element 7 being excessively affected by heat from the bottom side of the recess R1 is reduced. As a result, the measured temperature is expected to follow the temperature of the crystal element 5.

[0156] The temperature-sensing element 7 may have a temperature-sensing film 7a that overlaps the first surface (lower surface 13b of the cover) of the cover 13 on the side facing the mounting substrate 11.

[0157] In this case, for example, since the temperature-sensing element 7 is fixed to the cover 13, after mounting the crystal element 5 to the mounting substrate 11 and before fixing the temperature-sensing element 7 to the mounting substrate 11 (via the cover 13), it is possible to inspect the crystal element 5 via the mounting substrate 11 or to shave the excitation electrode 19 with laser light to adjust the frequency characteristics. Therefore, for example, even if the crystal element 5 and the mounting substrate 11 are determined to be defective by the above inspection, the temperature-sensing element 7 will not be wasted. Also, for example, the temperature-sensing element 7 will not be shaved by laser light. If the temperature-sensing element 7 and the cover 13 are separate, the frequency characteristics may change when the temperature-sensing element 7 is fixed to the mounting substrate 11 after frequency adjustment with laser light, etc., and when the cover 13 is fixed to the mounting substrate 11, and consequently, the change in frequency characteristics may become large. However, since both are fixed together, it is expected that the change in frequency characteristics will be reduced. As described above, by making frequency adjustment easier, productivity can be improved, for example. Furthermore, since the temperature-sensing element 7 has a temperature-sensing film 7a, it is easier to make the oscillator 1 thinner compared to an embodiment in which the temperature-sensing element 7 is chip-type (such embodiments are also included in the technology of this disclosure). In addition, the probability of unintended contact between the side surface of the temperature-sensing element 7 and the mounting substrate 11 is reduced during the process of joining the cover 13 to the mounting substrate 11. In an embodiment in which a reference potential is applied to the cover 13 and the temperature-sensing element 7, since the temperature-sensing element 7 is provided on the cover 13, it is easy to make the terminals 3 and wiring 27 for applying the reference potential to both common.

[0158] The thermosensitive film 7a may have a portion that overlaps with the recess R1 (or the quartz element 5 or the excitation electrode 19) in planar view. For example, the thermosensitive film 7a may overlap with 1 / 3 or more, 1 / 2 or more, or all of the area of ​​the recess R1 (or the quartz element 5 or the excitation electrode 19) in planar view (see Figures 1 to 5(c)).

[0159] In this case, for example, in an embodiment in which the temperature-sensitive film 7a can detect the temperature of the quartz element 5 via the gas in the recess R1, the measured temperature can more easily track the temperature of the quartz element 5. Also, for example, the need to secure an area for the temperature-sensitive film 7a on the upper surface 23e of the frame is reduced, making it easier to avoid structural interference between the sealing structure of the recess R1 (e.g., sealing material 33) and the temperature-sensitive film 7a. As a result, for example, the structure of the temperature-sensitive film 7a is simplified.

[0160] The thermosensitive film 7a may have a portion located outside the recess R1 (or the crystal element 5 or excitation electrode 19) in planar view. For example, in planar view, the thermosensitive film 7a may overlap with 1 / 5 or more, 1 / 3 or more, 1 / 2 or more, or all of the area of ​​the upper surface 23e of the frame (see Figures 5(a), 5(b), and 6).

[0161] In this case, for example, in the embodiment shown in Figures 5(a) and 5(b), where the temperature-sensitive film 7a extends outward from the region overlapping the recess R1, it is easier to secure the area of ​​the temperature-sensitive film 7a. As a result, for example, it is advantageous for miniaturizing the oscillator 1 in plan view. Also, for example, in the embodiment shown in Figure 6, where the temperature-sensitive film 7a does not overlap the recess R1 (or the quartz element 5 or excitation electrode 19), for example, contact between the temperature-sensitive film 7a and the quartz element 5 can be avoided. From another viewpoint, it is advantageous for thinning the oscillator 1. Furthermore, in the embodiment where the space between the quartz element 5 and the temperature-sensitive film 7a has high thermal insulation, such as when the inside of the recess R1 is a vacuum, the temperature of the quartz element 5 and the temperature of the temperature-sensitive film 7a tend to become equal via the frame portion 23b. Consequently, the measured temperature tends to follow the temperature of the quartz element 5 more easily.

[0162] <Second Embodiment> Figure 7 is a cross-sectional view showing the crystal oscillator 201 according to the second embodiment. This figure corresponds to Figure 3 of the first embodiment.

[0163] In the first embodiment, the temperature-sensing element 7 was a film-type element, whereas in the second embodiment, the temperature-sensing element 207 is a chip-type element. The temperature-sensing element 207 is mounted on the cover 13 by a conductive bonding material 41. In this embodiment as well, similar to the first embodiment, the temperature-sensing element 207 is located closer to the cover 13 than the crystal element 5. Therefore, the same effects as in the first embodiment are achieved. For example, the influence of heat from the circuit board 53 on which the oscillator 1 is mounted on the temperature-sensing element 207 is reduced. Specifically, for example, it is as follows.

[0164] The specific configuration of the temperature sensing element 207 is arbitrary. For example, the temperature sensing element 207 may be based on various principles, such as a thermistor, resistance thermometer, thermocouple, or diode, similar to the temperature sensing element 7. Also, for example, the functional part of the temperature sensing element 207 (e.g., the resistor in the case of a thermistor) may be exposed to the outside (the space in the recess R1) or covered by a sealing part. The material of the sealing part is arbitrary and may be an insulating material such as glass, ceramic, or resin.

[0165] In the illustrated example, the temperature-sensing element 207 has an element body 207a and two element terminals 207b (only one is shown). As can be understood from the previous paragraph, the element body 207a may include, for example, at least a functional part and may further have a sealing part that covers the functional part. The shape of the element body 207a may be, for example, generally a thin rectangular parallelepiped (more specifically, a plate shape in the illustrated example). The two element terminals 207b are located, for example, on the lid 13 side (+D3 side) of the element body 207a. In this sense, the element terminals 207b may be, for example, layered conductors that overlap the +D3 side surface of the element body 207a, or they may be conductors (not necessarily layered conductors) that have an exposed portion on the +D3 side surface of the element body 207a.

[0166] Regarding the position, shape, and dimensions of the element body 207a (temperature-sensing element 7) in a planar perspective view, the explanation of the position, shape, and dimensions of the temperature-sensing film 7a that fits within the recess R1 in a planar perspective view may be used, as long as no inconsistencies arise. For example, the element body 207a may overlap the entire recess R1 (or the quartz element 5 or excitation electrode 19) or overlap only a part of it. The geometric center of the element body 207a may or may not coincide with the geometric center of the recess R1 (or the quartz element 5 or excitation electrode 19).

[0167] The thickness and position of the element body 207a in the thickness direction (D3 direction) are arbitrary. For example, the thickness of the element body 207a may be thinner, the same as, or thicker than the thickness of the crystal element 5 (or crystal blank 15). Also, the distance between the element body 207a and the crystal element 5, and the distance between the element body 207a and the cover 13, may be shorter, the same as, or longer than the distance between the crystal element 5 and the bottom surface of the recess R1 (first substrate surface 23c).

[0168] The position, shape, and dimensions of the element terminal 207b may be arbitrary, as long as the element terminal 207b and the lower surface 13b of the cover (more specifically, the area facing the recess R1) can be joined by the bonding material 41. For example, a typical chip-type temperature sensing element has two element terminals at both ends in the longitudinal direction. The element terminals at each end either overlap only on the lower surface (in this case, the +D3 side) or overlap on the entire surface of each end (five surfaces excluding the other end). The element terminal 207b may be configured in such a way.

[0169] In the illustrated example, the two element terminals 207b are adjacent to one side (+D1 side) of the longitudinal (or possibly short side) edge (the edge extending in the D2 direction; the short side) of the element body 207a, and are arranged along that edge (for example, parallel to it). The element body 207a is supported in a cantilevered manner by the two element terminals 207b being joined to the lower surface 13b of the cover by two joining members 41 (only one is shown). In the illustrated example, the element terminals 207b have only a first portion that overlaps the surface of the element body 207a on the cover 13 side (+D3 side). In addition to the first portion, the element terminals 207b may have portions that overlap the other surfaces (+D1 side, +D2 side, -D2 side and / or -D3 side).

[0170] The positions of the two element terminals 207b relative to the mounting substrate 11 are arbitrary. For example, in a planar perspective view, the two element terminals 207b may be located at the ends of the recess R1 in a predetermined direction (e.g., the longitudinal or transverse direction), or they may be located relatively far from the ends (e.g., in the center of the predetermined direction). In the former case, the two element terminals 207b may be located at any two of the four corners, or they may be located away from the four corners.

[0171] In the illustrated example, the two element terminals 207b are located on the opposite side (+D1 side) of the geometric center of the recess R1 from the side where the lead electrode 21 (pad 25) is located (+D1 side) in a planar perspective view, and more specifically, they are located at the two corners on the +D1 side of the recess R1. Of course, unlike the illustrated example, the two element terminals 207b may also be located on the side (-D1 side) of the geometric center of the recess R1 (-D1 side) in a planar perspective view, or further, they may be located at the two corners on the -D1 side of the recess R1.

[0172] Package 209 is configured to allow mounting of the temperature sensing element 207 on the lower surface 13b of the cover. Its specific configuration is arbitrary. In the illustrated example, the cover 13 is made of insulating material at least on its lower surface 13b (for example, the entire cover 13). A conductor pattern 39 is superimposed on the lower surface 13b of the cover. The conductor pattern 39 may have, for example, a first portion to which a bonding material 41 is bonded, a second portion to which a connecting electrode 31 is bonded, and a wiring portion connecting the two. The specific shape, dimensions, and material of the conductor pattern 39 are arbitrary.

[0173] The material of the bonding material 41 is arbitrary. For example, the material of the bonding material 41 may be the same as that of the bonding material 29, or it may be a different material. The bonding material 41 may be a conductive adhesive or solder. For the joining of the conductor pattern 39 and the connecting electrode 31, the explanation for the joining of the external electrode 7b and the connecting electrode 31 may be used as a reference.

[0174] In Figure 7, the sealing material that joins the lid 13 and the mounting substrate 11 is indicated by the same reference numeral as the sealing material 33C shown in Figure 5(a). However, the sealing material may be either a conductive material or an insulating material, or it may have a material on the mounting substrate 11 side and a material on the lid 13 side (for example, a first metal layer 35 and a second metal layer 37).

[0175] As described above, the piezoelectric device (quartz oscillator 201) comprises a piezoelectric element (quartz element 5), a mounting substrate 11, a cover 13, and a temperature sensing element 207. The temperature sensing element 207 has a portion located on the cover 13 side of the quartz element 5 (the entire temperature sensing element 207 in the illustrated example). Therefore, for example, as previously mentioned, the likelihood of the temperature sensing element 207 being excessively affected by heat from the bottom side of the recess R1 is reduced. As a result, the measured temperature is expected to follow the temperature of the quartz element 5.

[0176] Furthermore, the temperature-sensing element 207 may be a chip-type element mounted on the side of the cover 13 that faces the mounting substrate 11 (the lower surface 13b of the cover).

[0177] In this case, for example, it becomes possible to use an already available temperature-sensing element 207 as the oscillator 201. Also, similar to the embodiment in which a film-shaped temperature-sensing element 7 is held in the cover 13, if the crystal element 5 and the mounting substrate 11 are determined to be defective during inspection after the crystal element 5 is mounted on the mounting substrate 11 and before the cover 13 is joined to the mounting substrate 11, the cover 13 and the temperature-sensing element 207 will not be wasted.

[0178] <Third Embodiment> Figure 8 is a cross-sectional view showing the quartz oscillator 301 according to the third embodiment. This figure corresponds to Figure 7 of the second embodiment.

[0179] In the third embodiment, similar to the second embodiment, the chip-type temperature-sensing element 207 is located closer to the cover 13 than the crystal element 5. However, while in the second embodiment the temperature-sensing element 207 was mounted on the cover 13, in the third embodiment the temperature-sensing element 207 is mounted on the wall portion (frame portion 23b) of the recess R1. Specifically, for example, it is as follows.

[0180] In the package 309 of the third embodiment, the mounting base 311 has a stepped portion on the wall of the recess R1. In other words, the frame portion 23b has a surface (not shown in reference numerals) facing the lid 13 at a position lower than the upper surface to which the lid 13 is joined. The connecting electrode 31 is located on this surface. The temperature sensing element 207 is mounted on the wall of the recess R1 by joining the element terminal 207b and the connecting electrode 31 with a bonding material 41.

[0181] The frame portion 23b may be considered to have a first frame portion 23ba that overlaps the substrate portion 23a, and a second frame portion 23bb that overlaps the first frame portion 23ba. The second frame portion 23bb has a reduced width on its inner edge side in at least a portion of the circumferential direction compared to the first frame portion 23ba. As can be understood from the description of the substrate portion 23a and the frame portion 23b in the first embodiment, the first frame portion 23ba and the second frame portion 23bb may be manufactured by overlapping each other, or they may be manufactured by a different manufacturing method (e.g., pressing).

[0182] Regarding the position, shape, and dimensions of the element body 207a (temperature-sensing element 7) in a planar view, the description of the position, shape, and dimensions of the temperature-sensing film 7a that fits within the recess R1 in a planar view may be used as in the second embodiment, unless inconsistencies arise. Regarding the thickness and position of the element body 207a in the thickness direction (D3 direction), the description in the second embodiment may be used as in the second embodiment.

[0183] The position, shape, and dimensions of the element terminal 207b in a plan view may be described, for example, by reference to the description of the position, shape, and dimensions of the external electrode 7b in a plan view in the first embodiment. However, in this reference, for example, in a plan perspective view, the position of the inner edge of the upper surface of the first frame portion 23ba may be considered to correspond to the position of the inner edge of the upper surface 23e of the frame portion in the description of the first embodiment.

[0184] As described above, the piezoelectric device (quartz oscillator 301) comprises a piezoelectric element (quartz element 5), a mounting substrate 311, a cover 13, and a temperature sensing element 207. The temperature sensing element 207 has a portion located on the cover 13 side of the quartz element 5 (the entire temperature sensing element 207 in the illustrated example). Therefore, for example, as previously mentioned, the likelihood of the temperature sensing element 207 being excessively affected by heat from the bottom side of the recess R1 is reduced. As a result, the measured temperature is expected to follow the temperature of the quartz element 5.

[0185] Furthermore, the temperature-sensing element 207 may be a chip-type element mounted on the wall portion (frame portion 23b) of the recess R1.

[0186] In this case, for example, similar to the second embodiment, a commercially available temperature-sensing element 207 can be used as the oscillator 201. Furthermore, the configuration of the cover 13 can be the same as in the conventional design.

[0187] <Specific examples of wiring in packages> As described above, the positional arrangement of the pad 25 and the connecting electrode 31 in a plan view is arbitrary, and the positional relationship between the terminal 3 connected to the pad 25 and the terminal 3 connected to the connecting electrode 31 in a plan view is also arbitrary. The wiring 27 can have various configurations depending on the arrangement of the pad 25, the connecting electrode 31 and the terminal 3, and even when the arrangement of the pad 25, the connecting electrode 31 and the terminal 3 is specific, it can still have various configurations. Below, specific examples of the configuration of the wiring 27 when the arrangement of the pad 25, the connecting electrode 31 and the terminal 3 is specific are shown. Note that in the drawings referenced in the following explanation, for convenience, via conductors that are hidden and not visible by the layered conductor may be shown with solid lines instead of dotted lines.

[0188] Figure 9 is a perspective view showing a specific example of wiring 27. This figure corresponds to a part of Figure 1.

[0189] In the example in Figure 9, the two terminals 3 connected to the two pads 25 are located at two diagonal corners of the second substrate surface 23d, and the two terminals 3 connected to the two connecting electrodes 31 are located at the other two diagonal corners. Also, in the example in Figure 9, similar to the example in Figure 1, the two pads 25 are located on one side (-D1 side) in the longitudinal direction of the first substrate surface 23c and are aligned in the short direction (D2 direction). The two connecting electrodes 31 are located on the other side (+D1 side) in the longitudinal direction of the first substrate surface 23c and are aligned in the short direction (D2 direction).

[0190] The wiring 27A connecting one of the two pads 25 (the pad 25A on the -D1 and -D2 side in the example of Figure 9) to terminal 3 is composed of a via conductor 27b that penetrates the substrate portion 23a in the thickness direction. One end of the via conductor 27b is connected to pad 25A, and the other end is connected to terminal 3 located on the -D1 and -D2 side. The wiring 27B connecting the other of the two pads 25 (the pad 25B on the -D1 and +D2 side in the example of Figure 9) to terminal 3 is composed of a layered conductor 27a extending from pad 25B to the other side in the longitudinal direction (+D1 side) and a via conductor 27b that penetrates the substrate portion 23a in the thickness direction at a position overlapping the layered conductor 27a. The layered conductor 27a overlaps the first substrate surface 23c. One end of the via conductor 27b is connected to the layered conductor 27a, and the other end is connected to terminal 3 located on both the +D1 and +D2 sides. Through these two wires 27, the two pads 25 are connected to two diagonally located terminals 3.

[0191] The wiring 27C connecting one of the two connection electrodes 31 (connection electrode 31A on the +D1 and -D2 side in the example of Figure 9) to terminal 3 is composed of a via conductor 27d that penetrates the substrate portion 23a and the frame portion 23b in the thickness direction. One end of this via conductor 27d is connected to connection electrode 31A, and the other end is connected to terminal 3 located on the +D1 and -D2 side. The wiring 27D connecting the other of the two connection electrodes 31 (connection electrode 31B on the +D1 and +D2 side in the example of Figure 9) to terminal 3 is composed of a layered conductor 27c extending from connection electrode 31 to the first metal layer 35 (or sealing material 33 in another view; the same applies hereafter in the explanation of Figures 9 to 11 unless inconsistencies arise), the first metal layer 35, and a via conductor 27d that penetrates the substrate portion 23a and the frame portion 23b in the thickness direction at a position overlapping the first metal layer 35. The layered conductor 27c overlaps the upper surface 23e of the frame. One end of the via conductor 27d is connected to the first metal layer 35, and the other end is connected to terminal 3 located on both the -D1 and +D2 sides. Through these two wires 27, the two connecting electrodes 31 are connected to two diagonally opposite terminals 3.

[0192] The layered conductor 27a of wiring 27B may partially or entirely overlap with the frame portion 23b (it may be located between the substrate portion 23a and the frame portion 23b). The direction and shape of the layered conductor 27c of wiring 27D are arbitrary. In the example in Figure 9, the layered conductor 27c extends toward the +D1 side (the short side of the outer edge of the frame portion 23b). Unlike the illustrated example, the layered conductor 27c may extend toward, for example, the +D2 side (the long side of the outer edge of the frame portion 23b). Alternatively, the layered conductor 27c may extend toward the +D1 side while having the same length as the length of the connecting electrode 31 in the D2 direction. The material and / or thickness of the layered conductor 27c may be the same as or different from the material and / or thickness of the connecting electrode 31 and / or the first metal layer 35. The layered conductor 27c does not need to be clearly distinguishable from the connecting electrode 31 and / or the first metal layer 35 in terms of material, thickness, and planar shape. In addition to or instead of the via conductor 27d of the wiring 27D, a layered conductor arranged on the inner surface of the castellation may be used.

[0193] The terminal 3 connected to the connecting electrode 31B may, for example, be to which a reference potential is applied. When the recess R1 of the mounting substrate 11 in Figure 9 is covered by a conductive cover 13, the first metal layer 35 may contribute to applying a reference potential to the cover 13 via the second metal layer 37. Of course, as mentioned above, the cover 13 does not have to be conductive, nor does it have to be to which a reference potential is applied. Also, the connecting electrode 31B may be to which a potential other than the reference potential is applied.

[0194] Figure 10 is a perspective view showing another specific example of wiring 27. This figure is similar to Figure 9.

[0195] In the example in Figure 10, only the configuration of the wiring 27D differs from that of the example in Figure 9. The wiring 27D does not include the first metal layer 35. In other words, the connecting electrode 31B is not electrically connected to the first metal layer 35. Specifically, the wiring 27D consists of a layered conductor 27c extending from the connecting electrode 31B toward the -D1 side and a via conductor 27d overlapping the layered conductor 27c. One end of the via conductor 27b is connected to the layered conductor 27c, and the other end is connected to terminal 3 located on both the -D1 and +D2 sides.

[0196] According to the specific examples of wiring 27 in Figures 9 and 10, for example, it is easy to position wiring 27, whose potential changes in a plan view, inside the sealing material 33. As a result, for example, sealing the wiring 27 or electromagnetically shielding the wiring 27 becomes easier.

[0197] Figure 11 is a plan view showing yet another specific example of the wiring 27. This figure is a plan view of the mounting substrate 11A, and the crystal element 5 mounted on the mounting substrate 11A is also shown.

[0198] In this example, the two connecting electrodes 31 (or, in other words, the two external electrodes 7b) are located outside the first metal layer 35 (or, in other words, the sealing material 33), contrary to the embodiment. The possibility of such an configuration is evident, for example, from the configuration in Figure 5(a) in which the sealing material 33C is joined to the lid 13 via the temperature-sensitive film 7a. In the configuration in which the lower surface 13b of the lid and the sealing material 33 are insulating, only the external electrodes 7b (or the relay conductor connecting the external electrodes 7b to the functional part) may extend from the inside of the sealing material 33 to the outside of the sealing material 33. One connecting electrode 31 (the connecting electrode 31 on the +D1 side) may or may not be connected to the first metal layer 35, as in the embodiment (as shown in the example).

[0199] In the example in Figure 11, as in the example in Figure 9, the two terminals 3 connected to the two pads 25 are located at two diagonal corners of the second substrate surface 23d, and the two terminals 3 connected to the two connecting electrodes 31 are located at the other two diagonal corners. The positions of the two pads 25 are as described with reference to Figure 1, etc. In the example in Figure 11, the wiring 27A and 27B are the same as in the example in Figure 9.

[0200] The wiring 27C connecting one of the two connecting electrodes 31 (connecting electrode 31C located on the -D1 side in the example of Figure 11) to terminal 3 is composed of a via conductor 27d that penetrates the substrate portion 23a and the frame portion 23b in the thickness direction. One end of this via conductor 27d is connected to the connecting electrode 31C, and the other end is connected to terminal 3 located on both the -D1 and +D2 sides. The wiring 27C connecting the other of the two connecting electrodes 31 (connecting electrode 31D located on the +D1 side in the example of Figure 11) to terminal 3 is composed of a via conductor 27d that penetrates the substrate portion 23a and the frame portion 23b in the thickness direction. One end of this via conductor 27d is connected to the connecting electrode 31D, and the other end is connected to terminal 3 located on both the +D1 and -D2 sides. Through these two wirings 27, the two connecting electrodes 31 are connected to two diagonally opposite terminals 3.

[0201] In the example shown in Figure 11, the connecting electrode 31D and the first metal layer 35 are connected. Therefore, the upper end of the via conductor 27d of the wiring 27D may be connected to the first metal layer 35 together with the connecting electrode 31D (as in the illustrated example), or it may be connected only to the connecting electrode 31D, or it may be connected only to the first metal layer 35. In addition to, or instead of, the via conductor 27d of the wiring 27C and / or 27D, layered conductors arranged on the inner surface of the castellation may be used. The terminal 3 connected to the connecting electrode 31D may be given, for example, a reference potential. Of course, as mentioned above, the connecting electrode 31D may be given a potential other than the reference potential.

[0202] As shown in the specific example of wiring 27 in Figure 11, for example, it is easy to avoid crossing of wiring 27 with different potentials. As a result, electrical interference between the wiring 27 is reduced, which in turn improves the characteristics of the oscillator.

[0203] <Examples of uses for quartz crystal oscillators> Figure 12 is a schematic diagram showing an example of the use of the crystal oscillator 1. For convenience, the reference numerals of the first embodiment are used, but the description here may be applied to other embodiments and modifications.

[0204] As shown in the lower cross-sectional view of Figure 12, the oscillator 1 is used by being mounted on, for example, a circuit board 53. More specifically, as previously described, the opposing terminals 3 and a pad (not shown) on the upper surface of the circuit board 53 are joined together by a conductive bonding material (not shown). The oscillator 1 may be mounted on a substrate other than the circuit board 53. For example, the oscillator 1 may be mounted on a substrate having a shape that deviates from the concept of a circuit board (for example, a substrate that constitutes a package). In this explanation, the term "circuit board 53" may be replaced with the term "substrate" as a higher-level concept, as long as it does not cause any inconsistencies.

[0205] The resonator 1 mounted on the circuit board 53 may be sealed with an insulating sealant 55 (as shown in the illustrated example), or it may not be sealed. Examples of the material for the sealant 55 include resin. The resin may contain an insulating (or conductive) filler. The physical properties of the sealant 55 (e.g., thermal insulation and rigidity) may be set as appropriate. For example, the sealant 55 is bonded to the top surface of the circuit board 53 while covering the top and sides of the resonator 1. The sealant 55 may be interposed between the resonator 1 and the circuit board 53, or it may not be interposed. Unlike the illustrated example, the sealant 55 does not have to cover the top surface of the resonator 1. The sealant 55 may also seal other electronic components mounted on the circuit board 53 together with the resonator 1.

[0206] The circuit board 53 includes, for example, a wiring board (e.g., a printed circuit board) and one or more electronic elements mounted or embedded on the wiring board. Examples of electronic elements include integrated circuit elements (ICs), capacitors, inductors, and resistors. The circuit board 53 has various circuits (53a to 53d) composed of one or more electronic elements, as shown in the upper part of Figure 12. For convenience, these are referred to as "circuits," but some or all of these various circuits may be realized by a processor executing a program. The circuits that the circuit board 53 has are, for example, as follows.

[0207] The oscillation circuit 53a generates an oscillation signal by applying an alternating current to the crystal element 5. The temperature compensation circuit 53b (abbreviated as "compensation circuit" in Figure 12) compensates for changes in the frequency characteristics of the crystal element 5 caused by temperature by inputting a signal corresponding to the detected temperature detected by the temperature sensing element 7 to the oscillation circuit 53a. More specifically, the temperature sensing element 7 outputs an analog signal having a signal level (e.g., voltage or current) corresponding to the temperature. The A / D circuit 53d converts the analog signal from the temperature sensing element 7 into a digital signal and outputs it. The conversion circuit 53c converts the value of the digital signal from the A / D circuit 53d into a temperature and outputs it to the compensation circuit 53b. The combination of the resonator 1 and the circuit board 53 (or, from another perspective, at least the oscillation circuit 53a among the circuits on the circuit board 53) may be considered as an oscillator 53.

[0208] In the embodiments and modifications described above, the crystal oscillators 1, 1C, 1D, 1E, 201, and 301 are examples of piezoelectric devices, respectively. The crystal element 5 is an example of a piezoelectric element.

[0209] The technology relating to this disclosure is not limited to the embodiments described above and may be implemented in various forms.

[0210] Piezoelectric materials are not limited to quartz. For example, a piezoelectric material may be any other single crystal or a polycrystalline material (e.g., ceramic). Note that quartz with appropriate dopants added is considered a type of quartz.

[0211] A piezoelectric device is not limited to a quartz crystal oscillator (piezoelectric oscillator). For example, a piezoelectric device may be an oscillator that, in addition to a piezoelectric element (e.g., a quartz crystal), has an integrated circuit (IC) that generates an oscillation signal by applying a voltage to the piezoelectric element. Furthermore, the piezoelectric device does not have to contribute to the generation of an oscillation signal. For example, the piezoelectric device may be a gyro sensor. Also, a piezoelectric device may include electronic elements other than the piezoelectric element, temperature-sensing element, and IC.

[0212] As can be understood from the above, the number of pads (e.g., pad 25 and connecting electrode 31) and external terminals (e.g., terminal 3) of a piezoelectric device are arbitrary, and the connection relationships between multiple pads and multiple external terminals are also arbitrary. For example, in an oscillator, the piezoelectric element and the temperature sensing element may be electrically connected to the IC rather than to the external terminals of the piezoelectric device.

[0213] In piezoelectric devices, the structure of the package that packages the piezoelectric element may be configured as appropriate. For example, the package may have an H-shaped cross-section with recesses on the top and bottom surfaces. In this case, for example, the IC mentioned above may be mounted in the recess on the bottom surface. The package may also have a constant temperature chamber. Furthermore, the piezoelectric device does not have to be surface-mounted; for example, it may be through-hole mounted. Regardless of whether the piezoelectric device is surface-mounted or not, the external terminals of the package (terminal 3 in this embodiment) do not have to be layered; for example, they may be pin-shaped.

[0214] Various mounting configurations are possible for the piezoelectric element on the mounting substrate. For example, the piezoelectric element may be supported at both ends by two conductive bonding materials joined to two lead electrodes. Alternatively, for example, the piezoelectric element may have a conductive bonding material joined to one lead electrode, and a bonding wire joined to the other lead electrode. Furthermore, an insulating (or conductive) bonding material may be used as a bonding material to support one or both ends of the piezoelectric element, and it may be joined to a region different from the region of the lead electrodes.

[0215] As shown in the third embodiment (Figure 8), the temperature-sensing element located on the wall of the recess may be a temperature-sensing element having a temperature-sensing film, as in the first embodiment. Even in this case, the temperature-sensing film has a portion located on the lid side of the piezoelectric element, which reduces the influence of the temperature on the bottom surface of the recess on the measured temperature. Such a temperature-sensing film may overlap the inner circumferential surface of the wall of the recess, or, similar to the connecting electrode 31 in the third embodiment, it may overlap the upper surface of the first frame portion 23ba (however, it may be located above the crystal element 5).

[0216] In the description of the embodiments, particular attention was paid to the effect that by positioning the temperature-sensing element closer to the lid than the piezoelectric element, the influence of the temperature on the bottom surface of the recess on the measured temperature is reduced, and the measured temperature is more likely to follow the temperature of the piezoelectric element. However, such an effect is not necessarily required. Even if such an effect is not achieved, various effects can be obtained by positioning the temperature-sensing element closer to the lid than the piezoelectric element. For example, the degree of design freedom is improved (technology is enriched). Also, for example, in embodiments in which the temperature-sensing element is fixed to the lid (first and second embodiments), as described in the description of the first embodiment, the influence of inspection or processing after mounting the piezoelectric element on the mounting substrate and before fixing the lid to the mounting substrate on the temperature-sensing element is reduced.

[0217] The following concepts can be extracted from this disclosure. (Concept 1) Piezoelectric element and A mounting substrate having a recess, on which the piezoelectric element is mounted on the bottom surface of the recess, The cover that seals the recess, A temperature-sensing element having a portion located closer to the cover than the piezoelectric element, A piezoelectric device having [a certain characteristic]. (Concept 2) The temperature-sensing element has a temperature-sensing film that overlaps the first surface of the cover on the side of the mounting substrate. A piezoelectric device as described in Concept 1. (Concept 3) The temperature-sensitive film has a portion that overlaps with the recess in planar view. A piezoelectric device as described in Concept 2. (Concept 4) The temperature-sensitive film has a portion located outside the recess in planar view. A piezoelectric device as described in Concept 2 or 3. (Concept 5) The temperature sensing element is a chip-type element mounted on the side of the cover that faces the mounting substrate. A piezoelectric device as described in Concept 1. (Concept 6) The temperature sensing element is a chip-type element mounted on the wall of the recess. A piezoelectric device as described in Concept 1. [Explanation of symbols]

[0218] 1...Crystal oscillator (piezoelectric device), 5...Crystal element (piezoelectric element), 7...Temperature sensing element, 11...Mounting substrate, 13...Lid, R1...Recess.

Claims

1. Piezoelectric element and A mounting substrate having a recess and a frame surrounding the recess, with the piezoelectric element mounted on the bottom surface of the recess, The cover that seals the recess, A temperature-sensing element having a portion located closer to the cover than the piezoelectric element, A frame-shaped, conductive sealing material is used to join the upper surface of the frame and the lid, It has, The temperature-sensing element has a temperature-sensing film that overlaps the first surface of the cover on the side of the mounting substrate. The aforementioned thermosensitive film has a portion located outside the recess in planar view, The mounting substrate has at least one connecting electrode located on the upper surface of the frame portion, away from the sealing material toward the inner circumference, and connected to the temperature sensing element. Piezoelectric devices.

2. Piezoelectric element and A mounting substrate having a recess and a frame surrounding the recess, with the piezoelectric element mounted on the bottom surface of the recess, The cover that seals the recess, A temperature-sensing element having a portion located closer to the cover than the piezoelectric element, A frame-shaped, conductive sealing material is used to join the upper surface of the frame and the lid, It has, The temperature-sensing element has a temperature-sensing film that overlaps the first surface of the cover on the side of the mounting substrate. The aforementioned thermosensitive film has a portion located outside the recess in planar view, The mounting substrate has at least one connecting electrode located on the upper surface of the frame portion, away from the outer periphery of the sealing material, and connected to the temperature sensing element. Piezoelectric devices.

3. The temperature-sensitive film has a portion that overlaps with the recess in planar view. The piezoelectric device according to claim 1 or 2.

4. The at least one connecting electrode is A first connecting electrode that is not electrically connected to the aforementioned sealing material, The encapsulating material has a second connecting electrode that is electrically connected to it. The piezoelectric device according to claim 1 or 2.

5. The at least one connecting electrode has a first connecting electrode that is not electrically connected to the sealing material, The aforementioned temperature sensing element is The first external electrode is joined to the first connecting electrode, It has a second external electrode bonded to the aforementioned sealing material. The piezoelectric device according to claim 1 or 2.

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