Package for crystal oscillator, and crystal oscillator including the same

Abstract

To provide a crystal oscillator capable of integrating all components including passive elements into a package while improving a degree of freedom in design by allowing the use of general-purpose passive elements.SOLUTION: A package for a crystal oscillator includes a first cavity 1A that is a recess formed from one face side toward the other face side, and a second cavity 1B that is a recess formed from the other face side toward the one face side. A crystal oscillator body 3 and an IC chip 4 with a built-in electronic circuit to drive the crystal oscillator body 3 are mounted in the cavity 1A, and passive elements such as a capacitor 6, a thermistor 7, and capacitors 8A, 8B which work with the electronic circuit to drive the crystal oscillator body 3 are mounted in the second cavity 1B.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a package for a crystal oscillator and a crystal oscillator having the same, and is particularly useful when applied to a case where passive elements are integrated into the package body together with a crystal resonator body and an IC chip. [Background technology]

[0002] FIG. 3 shows a ceramic package for a quartz crystal unit according to a conventional technology, with (a) being a plan view, (b) being a longitudinal cross-sectional view, and (c) being a rear view. As shown in these figures, the package body 01, formed from a rectangular ceramic member, has a cavity 01A, which is a recess formed from one side to the other, and a quartz crystal unit body (not shown) is mounted in the cavity 01A. A predetermined wiring pattern is also formed inside the package body 01. Note that the "quartz crystal unit body" referred to here refers to a quartz crystal as an electronic component with electrodes formed on both sides of the quartz crystal blank. In contrast, a "quartz crystal unit" refers to a product in which a quartz crystal unit body (a quartz crystal for electronic components with electrodes formed on both sides of the quartz crystal blank) is connected to a package and sealed with a cap.

[0003] The package with the crystal unit body mounted in the cavity 01A in this way is further connected to a predetermined wiring pattern formed on a motherboard (not shown) via electrodes 02 on the backside. The motherboard is mounted with an IC chip that incorporates an electronic circuit for driving the crystal unit, as well as passive elements such as coils and capacitors that work in conjunction with the IC chip to drive the crystal unit and make it function as a crystal oscillator, and these are electrically connected via the wiring pattern.

[0004] Conventional technology has realized crystal oscillators in which a general-purpose IC chip for crystal oscillation, which integrates the crystal unit itself, an IC chip, and passive elements, is housed in a single package. Furthermore, crystal oscillators have also been proposed that aim to improve functionality by independently adding passive elements such as capacitors and thermistors to the general-purpose IC chip for crystal oscillation.

[0005] However, as mentioned above, crystal oscillators that aim to improve performance encounter the following new problem. While it is possible to mount the crystal unit itself and the crystal oscillator IC chip together in the same space, the crystal unit itself and the passive elements used to improve performance must essentially be mounted in separate, isolated spaces. This is because crystal oscillator IC chips are mounted using wire bonding or gold bumps, so mounting does not generate harmful gases that would deteriorate the crystal unit itself. However, when passive elements are mounted using standard soldering, the crystal unit itself comes into contact with gases generated when the solder melts, which adversely affects and deteriorates the crystal unit itself.

[0006] To avoid such deterioration, passive elements must be bonded with a conductive adhesive such as conductive silver paste, which requires that the electrodes of the capacitor, for example, be made of a special alloy compatible with the conductive adhesive, creating the problem that general-purpose ceramic capacitors cannot be used.

[0007] Patent Document 1 discloses a ceramic package with an H-shaped structure. However, the package in Patent Document 1 mounts a crystal unit body in a first chamber and an IC chip in a second chamber stacked back-to-back on the first chamber. In other words, the passive elements are not integrated into a crystal oscillator as a single package. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent Publication No. 2021-175002 Summary of the Invention [Problem to be solved by the invention]

[0009] In view of the above circumstances, an object of the present invention is to provide a crystal oscillator package that allows the use of general-purpose passive elements, improving design freedom, and that can integrate all components, including passive elements, into a package, and a crystal oscillator having the same. [Means for solving the problem]

[0010] The first aspect of the present invention that achieves the above object is: a first cavity that is a recess formed from one surface of the package body toward the other surface; a second cavity that is a recess formed from the other surface side of the package body toward the one surface side, the first cavity has a first mounting area for mounting a crystal unit body and a second mounting area for mounting an IC chip having a built-in electronic circuit for driving the crystal unit body; The second cavity has a third mounting area for mounting a passive element that cooperates with the electronic circuit to drive the crystal resonator body.

[0011] A second aspect of the present invention is In the crystal oscillator package according to the first aspect, The first mounting area in the first cavity is located closer to the opening of the first cavity than the second mounting area.

[0012] A third aspect of the present invention is In the crystal oscillator package according to the first aspect, The first mounting area and the second mounting area are located adjacent to each other on the bottom surface of the first cavity.

[0013] A fourth aspect of the present invention is A crystal oscillator package having a first cavity which is a recess formed from one surface of a package body toward the other surface thereof, and a second cavity which is a recess formed from the other surface of the package body toward one surface thereof, wherein the first cavity has a first mounting area and a second mounting area, while the second cavity has a third mounting area, a crystal unit body is mounted in the first mounting area of ​​the first cavity, and an IC chip having a built-in electronic circuit for driving the crystal unit body is mounted in the second mounting area; Furthermore, a passive element that drives the crystal resonator body in cooperation with the electronic circuit is mounted in the third mounting region of the second cavity.

[0014] A fifth aspect of the present invention is In the crystal oscillator according to the fourth aspect, the crystal unit body is mounted in the first mounting area located closer to an opening of the first cavity than the second mounting area within the first cavity; The IC chip is mounted in the second mounting area below the crystal unit body.

[0015] A sixth aspect of the present invention is In the crystal oscillator according to the fourth aspect, The crystal unit body and the IC chip are mounted adjacent to each other in the first mounting area and the second mounting area, which are positioned adjacent to each other on the bottom surface of the first cavity. [Effects of the Invention]

[0016] According to the present invention, the crystal unit body and IC chip can be mounted in the first cavity, and passive elements can be mounted in the second cavity, so all components related to the crystal oscillator can be integrated into a single package. In this case, since the second cavity is an independent and isolated space from the first cavity, generic passive elements can be mounted in the second cavity using ordinary methods, which increases the degree of freedom in design. [Brief explanation of the drawings]

[0017] [Figure 1] 1A to 1C are diagrams showing a crystal oscillator package according to a first embodiment of the present invention and a crystal oscillator having the same, in which (a) is a plan view, (b) is a vertical cross-sectional view, and (c) is a rear view. [Figure 2] 10A, 10B, and 10C are diagrams showing a crystal oscillator package according to a second embodiment of the present invention and a crystal oscillator having the same, in which FIG. 10A is a plan view, FIG. 10B is a longitudinal sectional view, and FIG. [Figure 3] 1A, 1B, and 1C are diagrams showing a ceramic package for a quartz crystal unit according to a conventional technique, in which (a) is a plan view, (b) is a longitudinal cross-sectional view, and (c) is a rear view. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described. Note that the first and second embodiments are merely examples, and the present invention is not limited to the following descriptions.

[0019] First Embodiment 1A and 1B show a crystal oscillator package according to a first embodiment of the present invention and a crystal oscillator including the package, with (a) being a plan view, (b) being a longitudinal cross-sectional view, and (c) being a rear view. As shown in these figures, package body 1, a rectangular ceramic member, has a first cavity 1A, which is a recess formed from one surface (top surface; the same applies hereinafter) toward the other surface (bottom surface; the same applies hereinafter), and a second cavity 1B, which is a recess formed from the other surface toward the one surface. In other words, package body 1 has first and second cavities 1A and 1B, which are two independent spaces isolated from each other, formed back to back.

[0020] Furthermore, a stepped space is formed in the center of the first cavity 1A, with a volume slightly smaller than the opening side of the first cavity 1A (see FIG. 1(b)). These two spaces, one large and one small, are integrated together to form the first cavity 1A, which is formed on the upper side of the package body 1 in FIG.

[0021] In a crystal oscillator having such a package, the space above the first cavity 1A serves as a first mounting area, with the crystal unit body 3 mounted with both longitudinal ends in contact with the bottom surface of the cavity 1A. At the same time, an IC chip 4 incorporating an electronic circuit for driving the crystal unit body 3 is mounted in a second mounting area, which is the space below the first cavity 1A. That is, in this embodiment, the crystal unit body 3 is mounted in the first mounting area within the first cavity 1A above the IC chip 4 mounted in the second mounting area within the first cavity 1A. The first cavity 1A, with the crystal unit body 3 and IC chip 4 mounted in this manner, is finally filled with an inert gas and sealed with a metal or ceramic cover called a lid 5. In this way, the crystal unit body 3 and IC chip 4 can be mounted within the first cavity 1A and the third cavity 1C in as small an area as possible in a plan view.

[0022] Meanwhile, the second cavity 1B, which is the space formed on the lower side of the package body 1 in Figure 1, contains passive elements: capacitor 6, thermistor 7, and two capacitors 8A and 8B, which work in cooperation with the electronic circuit to drive the crystal unit body 3. The combination of these passive elements, along with their number, can be freely selected as needed. Since this is a temperature-compensated crystal oscillator (TCXO), the thermistor 7, which detects the ambient temperature of the crystal unit body 3, is essential. If this were a crystal oscillator without temperature control or temperature compensation (SPXO: Simple Packaged Crystal Oscillator) or a voltage-controlled crystal oscillator (VCXO: Voltage Controlled Crystal Oscillator) whose output frequency can be varied or modulated by an external control voltage, the thermistor 7 would not be necessary.

[0023] In the crystal oscillator according to this embodiment, the crystal unit body 3, IC chip 4, capacitor 6, thermistor 7, and capacitors 8A and 8B are electrically connected to one another by a wiring pattern formed inside the package body 1. Furthermore, this crystal oscillator functions by being electrically connected to a predetermined wiring pattern formed on the motherboard via the electrodes 2. In this embodiment, the crystal unit body 3 and IC chip 4 are disposed in the height direction of the first cavity 1A, so although the occupied area of ​​the crystal unit body 3 and IC chip 4 is relatively large, this is particularly useful when there is room in the height direction of the first cavity 1A.

[0024] According to this embodiment, the crystal unit body 3 and IC chip 4 can be mounted in the first cavity 1A, and passive elements such as the capacitor 6, thermistor 7, and capacitors 8A and 8B can be mounted in the second cavity 1B, thereby integrating all components related to the crystal oscillator into a single package. In this case, the second cavity 1B is an independent and isolated space from the first cavity 1A, so there is no need to consider adverse effects such as solder vapor during mounting of passive elements mounted in the second cavity 1B. In other words, the mounting conditions for components in the same cavity 1A and 1B do not adversely affect each other, and if there is a possibility of adverse effects, the components are mounted separately in the independently formed first and second cavities. Therefore, general-purpose components can be used and conventional mounting processes can be applied.

[0025] <Second embodiment> 2A, 2B, and 2C are diagrams showing a crystal oscillator package according to a second embodiment of the present invention and a crystal oscillator including the same, with (a) being a plan view, (b) being a longitudinal cross-sectional view, and (c) being a rear view. As shown in these figures, the crystal oscillator package according to this embodiment differs in the manner in which the crystal resonator body 13 and IC chip 14 are mounted in the first cavity 1A. That is, the first cavity 1A is formed as a single space, which defines two mounting areas: a first mounting area in which the crystal resonator body 3 is mounted, and a second mounting area in which the IC chip 14 is mounted.

[0026] Therefore, in the crystal oscillator according to this embodiment, the crystal resonator body 13 and the IC chip 14 are disposed adjacent to each other in a direction along the bottom surface of the first cavity 1A.

[0027] One end of the quartz crystal resonator body 13 is cantilevered on the bottom surface of the first cavity 1A via a support member (not shown).

[0028] In this embodiment, the horizontal occupation area is large, so it is particularly useful when the crystal unit body 13 and IC chip 14 are small. [Explanation of symbols]

[0029] 1 Package 1A First cavity 1B Second cavity 3,13 Crystal unit body 4,14 IC chip 5 Lid 6 Capacitors (passive elements) 7 Thermistor (passive element) 8A, 8B Capacitor (passive element)

Claims

1. a first cavity that is a recess formed from one surface of the package body toward the other surface; a second cavity that is a recess formed from the other surface side of the package body toward the one surface side, the first cavity has a first mounting area for mounting a crystal unit body and a second mounting area for mounting an IC chip having a built-in electronic circuit for driving the crystal unit body, The crystal oscillator package according to claim 1, wherein the second cavity has a third mounting area for mounting a passive element that cooperates with the electronic circuit to drive the crystal resonator body.

2. 2. The crystal oscillator package according to claim 1, 10. A crystal oscillator package, comprising: a first mounting area within the first cavity, the first mounting area being located closer to an opening of the first cavity than the second mounting area;

3. 2. The crystal oscillator package according to claim 1, A crystal oscillator package, characterized in that within the first cavity, the first mounting area and the second mounting area are positioned adjacent to each other on the bottom surface of the first cavity.

4. A crystal oscillator package having a first cavity which is a recess formed from one surface of a package body toward the other surface thereof, and a second cavity which is a recess formed from the other surface of the package body toward one surface thereof, wherein the first cavity has a first mounting area and a second mounting area, while the second cavity has a third mounting area, a crystal unit body is mounted in the first mounting area of ​​the first cavity, and an IC chip having a built-in electronic circuit for driving the crystal unit body is mounted in the second mounting area; Furthermore, a passive element that drives the crystal resonator body in cooperation with the electronic circuit is mounted in the third mounting region of the second cavity.

5. 5. The crystal oscillator according to claim 4, the crystal unit body is mounted in the first mounting area located closer to an opening of the first cavity than the second mounting area within the first cavity; The crystal oscillator is characterized in that the IC chip is mounted in the second mounting area below the crystal resonator body.

6. 5. The crystal oscillator according to claim 4, The crystal oscillator is characterized in that the crystal resonator body and the IC chip are mounted adjacent to the first mounting area and the second mounting area located adjacent to each other on the bottom surface of the first cavity.

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