Piezoelectric oscillator

Abstract

The present invention provides a piezoelectric oscillator that achieves excellent thermal conductivity in a mounting substrate on which a piezoelectric vibrator and an IC chip are mounted. [Solution] The crystal oscillator comprises a piezoelectric vibrator 2 having a vibrator-side mounting pattern, a mounting substrate 3 having a substrate-side mounting pattern, and a bonding member that faces the substrate-side mounting pattern toward the vibrator-side mounting pattern and bonds the piezoelectric vibrator onto the mounting substrate. The vibrator-side mounting pattern consists of vibrator-side signal terminals 19a and 19b provided at two corners on the lower surface of the piezoelectric vibrator package, and a vibrator-side GND terminal 19c provided in a region surrounding the vibrator-side signal terminals, at a predetermined distance from the other two corners on the lower surface of the package. The substrate-side mounting pattern consists of substrate-side signal terminals 29a and 29b provided at a position opposite to the vibrator-side signal terminals, and a substrate-side GND terminal 29c provided at a predetermined distance from the substrate-side signal terminals, surrounding them and opposite to the vibrator-side GND terminal.

Description

Technical Field

[0001] The present disclosure relates to a piezoelectric oscillator having a structure in which a mounting substrate on which electronic components are mounted and a surface-mounted piezoelectric vibrator are laminated.

Background Art

[0002] In various electronic devices such as mobile phones and personal computers, a crystal oscillator that combines a crystal resonator and an integrated circuit (IC) chip is known in order to easily obtain a stable frequency required for information processing or communication processing. As such a crystal oscillator, there are a type in which a crystal resonator and an IC chip are mounted on the same mounting substrate (base), and a laminated type in which a piezoelectric vibrator including a crystal vibrating piece and a mounting substrate on which an IC chip is mounted are laminated.

[0003] As a type in which a crystal vibrating piece and an IC chip are mounted on the same mounting substrate, a structure in which the crystal vibrating piece and the IC chip are mounted in the same room, and a so-called H-type structure in which the crystal vibrating piece and the IC chip are mounted in separate rooms are widely known. On the other hand, in a laminated type crystal oscillator, a structure in which a terminal electrode provided on the piezoelectric vibrator and a terminal connection electrode provided on the mounting substrate are connected by a bonding member such as solder is adopted (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when a crystal oscillator is mounted on a circuit board along with other electronic components, it is affected by the heat generated from the IC chip, the heat generated from other surrounding electronic components, and the temperature of the surrounding environment in which the circuit board is installed. In particular, in multilayer crystal oscillators, heat conduction between the crystal oscillator and the mounting board occurs only between electrodes via solder, which is inefficient, and time is required for thermal equilibrium between the crystal oscillator and the mounting board.

[0006] This disclosure has been made in view of the above issues, and its purpose is to provide a stacked piezoelectric oscillator that can achieve excellent thermal conductivity in the mounting substrate on which the piezoelectric resonator and the IC chip are mounted. [Means for solving the problem]

[0007] According to one aspect of the present disclosure, a piezoelectric oscillator is provided comprising: a rectangular package in plan view, a piezoelectric vibrator mounted on the upper surface of the package, and a vibrator-side mounting pattern provided on the lower surface of the package; a mounting substrate comprising a rectangular base member in plan view, an IC chip mounted on the lower surface of the base member, and a substrate-side mounting pattern provided on the upper surface of the base member; and a bonding member that faces the substrate-side mounting pattern toward the vibrator-side mounting pattern and bonds the piezoelectric vibrator onto the mounting substrate, wherein the vibrator-side mounting pattern comprises vibrator-side signal terminals provided at two corners on the lower surface of the package, a vibrator-side GND terminal provided in a region surrounding the vibrator-side signal terminals at a predetermined distance from the vibrator-side signal terminals, including the other two corners on the lower surface of the package, and the substrate-side mounting pattern comprises a substrate-side signal terminal provided at a position opposite to the vibrator-side signal terminals, and a substrate-side GND terminal provided at a predetermined distance from the substrate-side signal terminals and facing the vibrator-side GND terminal. [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide a stacked piezoelectric oscillator that can achieve excellent thermal conductivity in the mounting substrate on which the piezoelectric oscillator and the IC chip are mounted.

[0009] The effects described above are merely illustrative for the sake of explanation, and the effects relating to this disclosure are not limited to those described above. In addition to the effects described above, any other effects described herein may be achieved. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view of a crystal oscillator according to an embodiment. [Figure 2] Figure 2(a) is an end view along the dashed line AA in Figure 1, and Figure 2(b) is a rear view of the crystal oscillator according to the embodiment. [Figure 3] Figure 3(a) is a diagram of the crystal oscillator side mounting pattern of the crystal resonator constituting the crystal oscillator according to the embodiment, and Figure 3(b) is a diagram of the substrate side mounting pattern of the mounting substrate constituting the crystal oscillator according to the embodiment. [Figure 4] Figure 4(a) is a diagram of the oscillator-side mounting pattern of the crystal oscillator constituting the crystal oscillator according to the modified embodiment 1, and Figure 4(b) is a diagram of the substrate-side mounting pattern of the mounting substrate constituting the crystal oscillator according to the modified embodiment 1. [Figure 5] Figure 5(a) is a diagram of the oscillator-side mounting pattern of the crystal oscillator constituting the crystal oscillator according to the modified embodiment 2, and Figure 5(b) is a diagram of the substrate-side mounting pattern of the mounting substrate constituting the crystal oscillator according to the modified embodiment 2. [Modes for carrying out the invention]

[0011] The following description will detail a crystal oscillator, which is an example of a piezoelectric oscillator according to this disclosure, with reference to the drawings. Note that this disclosure is not limited to the content described below, and can be modified and implemented as long as the gist of the disclosure is not altered. Furthermore, the drawings used in the embodiments and their modifications are schematic representations of the crystal oscillator according to this disclosure, and have been partially emphasized, enlarged, reduced, or omitted to enhance understanding, and may not accurately represent the scale or shape of each component. Additionally, some numerical values ​​used in the embodiments and their modifications are examples only and can be changed as needed. Common components in the drawings are denoted by the same reference numerals.

[0012] (Embodiment) First, the basic structure of the crystal oscillator according to this disclosure will be described with reference to Figures 1 to 3. Figure 1 is a perspective view of the crystal oscillator according to the embodiment. Figure 2(a) is an end view along the dashed line AA in Figure 1, and Figure 2(b) is a rear view of the crystal oscillator according to the embodiment. Furthermore, Figure 3(a) is a diagram of the oscillator-side mounting pattern of the crystal resonator constituting the crystal oscillator according to this disclosure, and Figure 3(b) is a diagram of the substrate-side mounting pattern of the mounting substrate constituting the crystal oscillator according to this disclosure.

[0013] As shown in Figure 1, a crystal oscillator 1, an example of a piezoelectric device, has a structure in which a rectangular crystal resonator 2 and a mounting substrate 3 on which an IC chip (described later) is mounted are stacked via a bonding member 4 such as solder. The crystal oscillator 1 can generate a stable frequency and produce a regular reference signal. In the following, the stacking direction of the crystal resonator 2 and the mounting substrate 3 is defined as the vertical direction, and the direction perpendicular to the vertical direction is defined as the horizontal direction.

[0014] The crystal oscillator 1 may have, for example, a surface acoustic wave (SAW) resonator, other piezoelectric resonators, or micro-electro-mechanical systems (MEMS) resonators instead of the crystal resonator 2. In other words, the piezoelectric resonator is not limited to the crystal resonator 2 as in this embodiment, but may be a resonator equipped with other materials having resonant characteristics (such as ceramics or silicon piezoelectric vibrators), or a MEMS resonator, etc.

[0015] As can be seen from Figures 1, 2(a), and 2(b), the quartz crystal oscillator 2, which is an example of a piezoelectric oscillator, has a quartz crystal oscillator package 11 (hereinafter simply referred to as package 11), a quartz crystal diaphragm 12 mounted in the concave mounting space 11a of package 11, and a metal cover (lid) 13 for sealing the mounting space 11a. The quartz crystal oscillator 2 is an element that can generate a constant frequency due to the piezoelectric effect when a voltage is applied to the quartz crystal diaphragm 12, which is an example of a piezoelectric diaphragm. Regarding the quartz crystal diaphragm, the type of cut from the quartz crystal is not limited to AT cut, but may also be a Z cut or a two-turn cut such as SC cut.

[0016] Package 11 is a ceramic package formed by stacking multiple ceramics on which a desired metal pattern is formed on the surface. Specifically, package 11 has a laminated structure in which a frame wall 14, which is a bank portion with an opening of a predetermined size, and a rectangular bottom plate 15 in plan view are stacked. In particular, the frame wall 14 is provided along the edge of the bottom plate 15. Due to this laminated structure, package 11 has a mounting space 11a with a concave shape for mounting the quartz crystal oscillator 12.

[0017] Here, the shape of the package 11 is a rectangular parallelepiped, and in a plan view, it is rectangular. In the following, the horizontal direction described above may be distinguished as the long side direction (the longitudinal direction) and the short side direction (the lateral direction) of the crystal oscillator 2 and the package 11. Further, in the crystal oscillator 2, the surface located on the upper side in the vertical direction may be referred to as the upper surface or the front surface, and the surface located on the lower side may be referred to as the lower surface or the back surface.

[0018] On the exposed surface (the surface located on the upper side in the vertical direction) of the frame wall 14 of the package 11, a conductor pattern 16 for sealing is formed. The planar shape of the conductor pattern 16 is a frame shape similar to the frame wall 14. And a cover 13 is joined on the conductor pattern 16 by a known metal joining. Thereby, the mounting space 11a of the package is sealed, and the mounting space 11a is sealed using a gas such as vacuum or nitrogen.

[0019] On the exposed surface (the upper surface 15a located on the upper side in the vertical direction) of the bottom plate 15 of the package 11, two crystal oscillator mounting terminals 17 which are adhesive pads are formed. In particular, the crystal oscillator mounting terminals 17 are provided at one end side in the long side direction in the inner region surrounded by the frame wall 14. Here, the crystal oscillator 12 is mounted on the crystal oscillator mounting terminals 17 via a conductive adhesive 18.

[0020] On the other hand, as can be seen from FIGS. 2(a) and 3(a), on the lower surface 15b of the bottom plate 15 of the package 11, a vibrator side mounting pattern 19 for supplying power to the crystal oscillator 12 is formed. The vibrator side mounting pattern 19 includes vibrator side signal terminals 19a and 19b provided at two corner portions on the lower surface 15b of the bottom plate 15 of the package 11. In particular, the vibrator side signal terminals 19a and 19b are provided at two corner portions located on the diagonal line on the lower surface 15b of the bottom plate 15 of the package 11. Also, the shapes of the vibrator side signal terminals 19a and 19b are rectangular in a plan view.

[0021] The oscillator-side mounting pattern 19 includes the other two corners of the lower surface 15b of the bottom plate 15 of the package 11, and includes an oscillator-side GND terminal 19c provided in a region surrounding the oscillator-side signal terminals 19a and 19b at a predetermined distance from the oscillator-side signal terminals 19a and 19b. In particular, the oscillator-side GND terminal 19c is provided on the lower surface 15b of the bottom plate 15 of the package 11, extending from one of the two corners to the other. Thereby, the shape of the oscillator-side GND terminal 19c is S-shaped in plan view.

[0022] In addition, it is preferable that the oscillator-side GND terminal 19c is provided in an area of 50% or more of the lower surface 15b of the bottom plate 15 of the package 11. More preferably, the oscillator-side GND terminal 19c is provided in an area of 60% or more and 85% or less of the lower surface 15b of the bottom plate 15 of the package 11. Thus, by making the dimensions of the oscillator-side GND terminal 19c larger, the heat conduction efficiency between the crystal oscillator 2 and the mounting substrate 3 can be improved, and the reason for this will be described later.

[0023] On the other hand, considering joining the crystal oscillator 2 and the mounting substrate 3 with solder, if the distance between the oscillator-side signal terminals 19a and 19b and the oscillator-side GND terminal 19c is too narrow, there is a risk of short circuit. For this reason, assuming that the long side dimension of the package 11 is 5.0 mm and the short side dimension is 3.2 mm, when the distance between the oscillator-side signal terminals 19a and 19b and the oscillator-side GND terminal 19c is made sufficiently wide, the oscillator-side GND terminal 19c will be provided in an area of approximately 65% (for example, 68%) of the lower surface 15b of the bottom plate 15 of the package 11. Also, when the distance between the oscillator-side signal terminals 19a and 19b and the oscillator-side GND terminal 19c is made as narrow as possible, the oscillator-side GND terminal 19c will be provided in an area of approximately 80% (for example, 77%) of the lower surface 15b of the bottom plate 15 of the package 11.

[0024] Furthermore, assuming that the long side dimension of package 11 is 7.0 mm and the short side dimension is 5.0 mm, if the distance between the transducer-side signal terminals 19a, 19b and the transducer-side GND terminal 19c is sufficiently wide, the transducer-side GND terminal 19c will be located in an area of ​​approximately 60% (for example, 60%) of the lower surface 15b of the bottom plate 15 of package 11. Also, if the distance between the transducer-side signal terminals 19a, 19b and the transducer-side GND terminal 19c is narrowed as much as possible, the transducer-side GND terminal 19c will be located in an area of ​​approximately 85% (for example, 84%) of the lower surface 15b of the bottom plate 15 of package 11.

[0025] As can be seen from Figures 1, 2(a), and 2(b), the mounting substrate 3 has a base member 21 and an IC chip 22 mounted in the concave mounting space 21a of the base member 21. In other words, the mounting substrate 3 functions as a component that controls the crystal oscillator 2 by the IC chip 22.

[0026] The base member 21 is a ceramic member formed by laminating multiple ceramics on which a desired metal pattern is formed on both the front and back surfaces. Specifically, the base member 21 has a laminated structure in which a frame-shaped frame wall 23 having an opening of a predetermined size and a base 24 with a rectangular shape in plan view are laminated. Specifically, in the base member 21, the frame wall 23 is laminated on the lower surface 24a of the base 24.

[0027] Here, the shape of the base member 21 is a rectangular parallelepiped, and in plan view it is rectangular. In the following, the horizontal direction described above may be distinguished as the long side direction (long side direction) and the short side direction (short side direction) of the mounting substrate 3 and the base member 21. Furthermore, on the mounting substrate 3, the side on which the IC chip 22 is mounted may be referred to as the back surface or bottom surface, and the side on which it is joined to the crystal oscillator 2 may be referred to as the front surface or top surface.

[0028] Six IC chip electrode terminals 26 for mounting the IC chip 22 are formed on the lower surface 24a of the base member 21's base 24. In particular, the shape of the IC chip electrode terminals 26 is rectangular in plan view, and the six IC chip electrode terminals 26 are arranged side by side in the mounting space 21a. The IC chip 22 is mounted on the IC chip electrode terminals 26 via a conductive adhesive 27.

[0029] Furthermore, four external connection terminals 28 are formed on the exposed surface (the surface located on the lower side in the vertical direction) of the frame wall 23 of the base member 21. Each of the external connection terminals 28 is electrically connected to either the IC chip electrode terminal 26 or the substrate-side signal terminals described later, via connection wiring (not shown) provided inside the package 11.

[0030] On the other hand, as can be seen from Figures 2(a) and 3(b), a substrate-side mounting pattern 29 for supplying power to the IC chip 22 is formed on the upper surface 24b of the base 24 of the base member 21. The substrate-side mounting pattern 29 includes substrate-side signal terminals 29a and 29b provided at two corners on the upper surface 24b of the base 24 of the base member 21. In particular, the substrate-side signal terminals 29a and 29b are provided at two diagonally opposite corners on the upper surface 24b of the base 24 of the base member 21. Furthermore, the shape of the substrate-side signal terminals 29a and 29b is rectangular in plan view.

[0031] The substrate-side mounting pattern 29 includes the other two corners of the upper surface 24b of the base 24 of the base member 21, and is provided with a substrate-side GND terminal 29c located in the region surrounding the substrate-side signal terminals 29a and 29b, at a predetermined distance from them. In particular, the substrate-side GND terminal 29c is provided on the upper surface 24b of the base 24 of the base member 21, extending from one corner to the other. As a result, the shape of the substrate-side GND terminal 29c is S-shaped in plan view.

[0032] In addition, in this embodiment, it is preferable that the substrate-side GND terminal 29c be provided in an area of ​​50% or more of the upper surface 24b of the base 24 of the base member 21. More preferably, it is preferable that the substrate-side GND terminal 29c be provided in an area of ​​60% to 85% of the upper surface 24b of the base 24 of the base member 21. By increasing the size of the substrate-side GND terminal 29c in this way, the thermal conductivity efficiency between the crystal oscillator 2 and the mounting substrate 3 can be improved, the reason for which will be explained later.

[0033] On the other hand, considering that the crystal oscillator 2 and the mounting board 3 are joined by soldering, there is a risk of short circuit if the distance between the board-side signal terminals 29a, 29b and the board-side GND terminal 29c is too narrow. For this reason, assuming that the long side dimension of the base member 21 is 5.0 mm and the short side dimension is 3.2 mm, if the distance between the board-side signal terminals 29a, 29b and the board-side GND terminal 29c is sufficiently wide, the board-side GND terminal 29c will be located in an area of ​​approximately 65% ​​(for example, 68%) of the upper surface 24b of the base 24 of the base member 21. Also, if the distance between the board-side signal terminals 29a, 29b and the board-side GND terminal 29c is narrowed as much as possible, the board-side GND terminal 29c will be located in an area of ​​approximately 80% (for example, 77%) of the upper surface 24b of the base 24 of the base member 21.

[0034] Furthermore, assuming that the long side dimension of the base member 21 is 7.0 mm and the short side dimension is 5.0 mm, if the distance between the board-side signal terminals 29a, 29b and the board-side GND terminal 29c is sufficiently wide, the board-side GND terminal 29c will be located in an area of ​​approximately 60% (for example, 60%) of the upper surface 24b of the base 24 of the base member 21. Also, if the distance between the board-side signal terminals 29a, 29b and the board-side GND terminal 29c is narrowed as much as possible, the board-side GND terminal 29c will be located in an area of ​​approximately 85% (for example, 84%) of the upper surface 24b of the base 24 of the base member 21.

[0035] In this embodiment, the oscillator-side mounting pattern 19 and the substrate-side mounting pattern 29 have substantially the same shape and dimensions. In the joined state, the oscillator-side signal terminals 19a and 19b face each other, and the substrate-side signal terminals 29a and 29b face each other, and the oscillator-side GND terminal 19c faces each other, with each being positioned to overlap in the vertical direction. In this overlapping position, they are joined via the joining member 4 to form a single crystal oscillator 1.

[0036] As described above, in this embodiment, in the bonding region between the crystal oscillator 2 and the mounting substrate 3, the dimensions of the oscillator-side GND terminal 19c and the substrate-side GND terminal 29c are made as large as possible, and the region where the ceramic materials of the package 11 and the base member 21 face each other at a predetermined distance (the region where the bonding member 4 does not exist) is reduced. In other words, the hollow portion between the crystal oscillator 2 and the mounting substrate 3 caused by the presence of the bonding member 4 is reduced. With this structure, thermal equilibrium between the crystal oscillator 2 and the mounting substrate 3 can be easily achieved via the bonding member 4, and the thermal conductivity of the crystal oscillator 1 can be improved.

[0037] In addition, in this embodiment, the oscillator-side signal terminals 19a, 19b and the substrate-side signal terminals 29a, 29b have significantly smaller dimensions compared to the oscillator-side GND terminal 19c and the substrate-side GND terminal 29c. For example, the oscillator-side GND terminal 19c is located in an area of ​​approximately 25% or less of the lower surface 15b of the bottom plate 15 of the package 11, and the substrate-side GND terminal 29c is located in an area of ​​approximately 25% or less of the upper surface 24b of the base 24 of the base member 21. As a result, the stray capacitance in the crystal oscillator 1 is reduced, and its influence on oscillator characteristics is suppressed. In other words, in this embodiment, excellent heat conduction efficiency is achieved while reducing stray capacitance and suppressing its influence on oscillator characteristics.

[0038] (Modified examples of the embodiment) <Example 1> In the above embodiment, only the IC chip 22 was mounted on the mounting substrate 3, but the connection with the crystal oscillator 2 may be made with other electronic components further mounted. This case will be described as Modification 1 of the embodiment with reference to Figure 4. Here, Figure 4(a) is a diagram of the crystal oscillator side mounting pattern of the crystal oscillator constituting Modification 1 of this embodiment, and Figure 4(b) is a diagram of the substrate side mounting pattern of the mounting substrate constituting the crystal oscillator constituting Modification 1 of this embodiment. Components identical to those in the above embodiment are denoted by the same reference numerals, and their descriptions are simplified or omitted.

[0039] As shown in Figure 4(a), the crystal oscillator 2 according to Modification 1 is identical to the crystal oscillator 2 according to the above embodiment, so its description is omitted. On the other hand, the mounting substrate 103 has a base 124 that is different from the base 124 according to the above embodiment. Specifically, in addition to the substrate-side signal terminals 129a, 129b and the substrate-side GND terminal 129c, six electronic component mounting terminals 131 are formed on the upper surface 124b of the base 124. Other electronic components 141 (for example, capacitors, resistors, etc.) different from the IC chip 22 are mounted on the electronic component mounting terminals 131 via solder.

[0040] In the modified example 1, the oscillator-side mounting pattern 19 and the substrate-side mounting pattern 129 have substantially the same shape and dimensions. In the joined state, the oscillator-side signal terminals 19a and 19b face each other, and the substrate-side signal terminals 129a and 129b face each other, and the oscillator-side GND terminal 19c faces each other, with each being positioned to overlap vertically. In this overlapping position, they are joined via a joining member to form a single crystal oscillator. Therefore, the electronic component 141 mounted on the electronic component mounting terminal 131 is positioned alongside the crystal oscillator 2.

[0041] In this modified example 1, the dimensions of the oscillator-side GND terminal 19c and the substrate-side GND terminal 129c in the junction region between the crystal oscillator 2 and the mounting substrate 103 are made as large as possible, and the region where the ceramic materials of the package 11 and the base member 121 face each other at a predetermined distance (the region where the bonding member 4 does not exist) is reduced. In other words, the hollow portion between the crystal oscillator 2 and the mounting substrate 3 caused by the presence of the bonding member 4 is reduced. With this structure, thermal equilibrium between the crystal oscillator 2 and the mounting substrate 3 can be easily achieved via the bonding member 4, and the thermal conductivity of the crystal oscillator 1 can be improved.

[0042] Furthermore, in the modified example 1, it is preferable that the substrate-side GND terminal 129c is provided in an area of ​​50% or more of the upper surface 124b of the base 124 of the base member 121. More preferably, it is preferable that the substrate-side GND terminal 129c is provided in an area of ​​60% to 85% of the upper surface 124b of the base 124 of the base member 121.

[0043] <Modification 2> In the above embodiment, the oscillator-side GND terminal 19c and the substrate-side GND terminal 29c had an S-shape in plan view, but are not limited to this shape. For example, the oscillator-side GND terminal 19c and the substrate-side GND terminal 29c may have a T-shape in plan view. Such a case will be described as Modification 2 of the embodiment with reference to Figure 5. Here, Figure 5(a) is a diagram of the oscillator-side mounting pattern of the crystal oscillator constituting Modification 2 of this embodiment, and Figure 5(b) is a diagram of the substrate-side mounting pattern of the mounting substrate constituting the crystal oscillator constituting Modification 2 of this embodiment. Components identical to those in the above embodiment are denoted by the same reference numerals, and their descriptions are simplified or omitted.

[0044] As shown in Figure 5(a), a resonator-side mounting pattern 219 for supplying power to the crystal oscillator 12 is formed on the lower surface 15b of the bottom plate 15 of the package 11. The resonator-side mounting pattern 219 includes resonator-side signal terminals 219a and 219b provided at two corners on the lower surface 15b of the bottom plate 15 of the package 11. In particular, the resonator-side signal terminals 219a and 219b are provided at two corners located at both ends of the same long side on the lower surface 15b of the bottom plate 15 of the package 11. Furthermore, the shape of the resonator-side signal terminals 219a and 219b is rectangular in plan view.

[0045] The transducer-side mounting pattern 219 includes the other two corners of the lower surface 15b of the bottom plate 15 of the package 11, and is provided with a transducer-side GND terminal 219c located in the region surrounding the transducer-side signal terminals 219a and 219b, at a predetermined distance from them. In particular, the transducer-side GND terminal 219c is formed in a T-shape in plan view on the lower surface 15b of the bottom plate 15 of the package 11.

[0046] On the other hand, as shown in Figure 5(b), a substrate-side mounting pattern 229 for supplying power to the IC chip 22 is formed on the upper surface 24b of the base 24 of the base member 21. The substrate-side mounting pattern 229 includes substrate-side signal terminals 229a and 229b provided at two corners on the upper surface 24b of the base 24 of the base member 21. In particular, the substrate-side signal terminals 229a and 229b are provided at two corners located at both ends of the same long side on the upper surface 24b of the base 24 of the base member 21. Furthermore, the shape of the substrate-side signal terminals 229a and 229b is rectangular in plan view.

[0047] The substrate-side mounting pattern 229 includes the other two corners of the upper surface 24b of the base 24 of the base member 21, and is provided with a substrate-side GND terminal 229c located in the region surrounding the substrate-side signal terminals 229a and 229b, at a predetermined distance from them. In particular, the substrate-side GND terminal 229c is formed in a T-shape in plan view on the upper surface 24b of the base 24 of the base member 21.

[0048] Furthermore, in the modified example 2, it is preferable that the transducer-side GND terminal 219c be provided in an area of ​​50% or more of the lower surface 15b of the bottom plate 15 of the package 11. More preferably, it is preferable that the transducer-side GND terminal 219c be provided in an area of ​​60% to 85% of the lower surface 15b of the bottom plate 15 of the package 11. Similarly, it is preferable that the substrate-side GND terminal 229c be provided in an area of ​​50% or more of the upper surface 24b of the base 24 of the base member 21. More preferably, it is preferable that the substrate-side GND terminal 229c be provided in an area of ​​60% to 85% of the upper surface 24b of the base 24 of the base member 21.

[0049] In addition, in the above embodiment, modified example 1, and modified example 2, if the formation of the transducer-side GND terminal and the substrate-side GND terminal satisfies the above-mentioned preferred numerical range, holes (non-formed areas) may exist in part of the transducer-side GND terminal and the substrate-side GND terminal. That is, even if there is at least one island-shaped non-formed area in the formation area of ​​the transducer-side GND terminal and the substrate-side GND terminal, it is possible to achieve the same effects as the above embodiment, modified example 1, and modified example 2.

[0050] (Embodiments of this disclosure) A first embodiment of the present disclosure is a piezoelectric oscillator comprising: a package that is rectangular in plan view, a piezoelectric vibrator mounted on the upper surface of the package, and a vibrator-side mounting pattern provided on the lower surface of the package; a mounting substrate comprising a base member that is rectangular in plan view, an IC chip mounted on the lower surface of the base member, and a substrate-side mounting pattern provided on the upper surface of the base member; and a bonding member that faces the substrate-side mounting pattern toward the vibrator-side mounting pattern and bonds the piezoelectric vibrator onto the mounting substrate, wherein the vibrator-side mounting pattern comprises vibrator-side signal terminals provided at two corners on the lower surface of the package, a vibrator-side GND terminal provided in a region surrounding the vibrator-side signal terminals at a predetermined distance from the vibrator-side signal terminals, including the other two corners on the lower surface of the package, and the substrate-side mounting pattern comprises a substrate-side signal terminal provided at a position opposite to the vibrator-side signal terminals, and a substrate-side GND terminal provided at a predetermined distance from the substrate-side signal terminals and surrounding them, and facing the vibrator-side GND terminal.

[0051] In this way, by maximizing the dimensions of the oscillator-side GND terminal and the substrate-side GND terminal in the bonding region between the piezoelectric vibrator and the mounting substrate, the region where the package and base material face each other at a predetermined distance can be reduced. In other words, the hollow space between the piezoelectric vibrator and the mounting substrate caused by the presence of the bonding member is reduced. With this structure, thermal equilibrium between the piezoelectric vibrator and the mounting substrate can be easily achieved through the bonding member, and the thermal conductivity of the piezoelectric oscillator can be improved.

[0052] A second embodiment of the present disclosure is that, in the first embodiment, the oscillator-side GND terminal is provided extending from one of the other two corners to the other. This makes it easier to achieve thermal equilibrium between the piezoelectric oscillator and the mounting substrate via the bonding member, and further improves the thermal conductivity of the piezoelectric oscillator.

[0053] A third embodiment of the present disclosure is that, in the first or second embodiment, the oscillator-side GND terminal is provided in an area of ​​50% or more of the lower surface of the package, and the substrate-side GND terminal is provided in an area of ​​50% or more of the upper surface of the base member. This makes it easier to achieve thermal equilibrium between the piezoelectric oscillator and the mounting substrate via the bonding member, and further improves the thermal conductivity of the piezoelectric oscillator.

[0054] A fourth embodiment of the present disclosure is that, in any of the first to third embodiments, the oscillator-side GND terminal is provided in an area of ​​60% to 85% of the lower surface of the package, and the substrate-side GND terminal is provided in an area of ​​60% to 85% of the upper surface of the base member. This makes it easier to achieve thermal equilibrium between the piezoelectric oscillator and the mounting substrate via the bonding member, and further improves the thermal conductivity of the piezoelectric oscillator.

[0055] A fifth embodiment of the present disclosure is that, in any of the first to fourth embodiments, the oscillator-side signal terminals are provided at two diagonally opposite corners on the lower surface of the package. This makes it easier to achieve thermal equilibrium between the piezoelectric oscillator and the mounting substrate via the bonding member, and further improves the thermal conductivity of the piezoelectric oscillator.

[0056] A sixth embodiment of the present disclosure is that, in any of the first to fifth embodiments, the substrate-side signal terminals are provided at two diagonally opposite corners on the upper surface of the base member. This makes it easier to achieve thermal equilibrium between the piezoelectric oscillator and the mounting substrate via the bonding member, and further improves the thermal conductivity of the piezoelectric oscillator.

[0057] A seventh embodiment of the present disclosure is that, in any of the first to sixth embodiments, the oscillator-side GND terminal and the substrate-side GND terminal have an S-shape or T-shape in plan view. This makes it easier to achieve thermal equilibrium between the piezoelectric oscillator and the mounting substrate via the bonding member, and further improves the thermal conductivity of the piezoelectric oscillator. [Explanation of Symbols]

[0058] 1. Crystal oscillator (piezoelectric oscillator) 2. Crystal oscillator (piezoelectric oscillator) 3. Implemented circuit board 4. Joining members 11. Packages for crystal oscillators (packages) 11a Implementation space 12. Crystal vibrating element (piezoelectric vibrating element) 13 Cover (Lid) 14 Frame wall 15 Bottom plate 15a Top side 15b Bottom 16 Conductor Patterns 17 Terminals for mounting crystal oscillators 18 Conductive adhesive 19. Oscillator-side mounting pattern 19a, 19b Transducer-side signal terminals 19c Transducer side GND terminal 21 Base member 22 IC chips 23 Frame wall 24 base 24a Bottom side 24b Top surface 26 IC chip electrode terminals 27 Conductive adhesive 28 External connection terminals 29 PCB-side mounting pattern 29a, 29b Board side signal terminal 29c PCB-side GND terminal

Claims

1. A piezoelectric vibrator comprising a rectangular package in plan view, a piezoelectric vibrator mounted on the upper surface of the package, and a vibrator-side mounting pattern provided on the lower surface of the package, A mounting board comprising a rectangular base member in plan view, an IC chip mounted on the lower surface of the base member, and a substrate-side mounting pattern provided on the upper surface of the base member, The device has a bonding member that faces the substrate-side mounting pattern toward the vibrator-side mounting pattern and bonds the piezoelectric vibrator to the mounting substrate, The transducer-side mounting pattern consists of transducer-side signal terminals provided at two corners on the lower surface of the package, and a transducer-side GND terminal provided in a region surrounding the transducer-side signal terminals, including the other two corners on the lower surface of the package, at a predetermined distance from the transducer-side signal terminals. The piezoelectric oscillator is characterized in that the substrate-side mounting pattern comprises a substrate-side signal terminal provided at a position opposite to the oscillator-side signal terminal, and a substrate-side GND terminal provided at a predetermined distance from the substrate-side signal terminal and surrounding it, and opposite to the oscillator-side GND terminal.

2. The piezoelectric oscillator according to claim 1, characterized in that the oscillator-side GND terminal is provided extending from one of the other two corners to the other.

3. The oscillator-side GND terminal is provided in an area of ​​50% or more of the lower surface of the package. The piezoelectric oscillator according to claim 1, characterized in that the substrate-side GND terminal is provided in an area of ​​50% or more of the upper surface of the base member.

4. The oscillator-side GND terminal is provided in an area of ​​60% to 85% of the lower surface of the package. The piezoelectric oscillator according to claim 1, characterized in that the substrate-side GND terminal is provided in an area of ​​60% to 85% of the upper surface of the base member.

5. The piezoelectric oscillator according to claim 1, characterized in that the oscillator-side signal terminals are provided at two corners located diagonally opposite each other on the lower surface of the package.

6. The piezoelectric oscillator according to claim 1, characterized in that the board-side signal terminals are provided at two diagonally opposite corners on the upper surface of the base member.

7. The piezoelectric oscillator according to claim 1, characterized in that the oscillator-side GND terminal and the substrate-side GND terminal have an S-shape or T-shape in plan view.

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