JP2003101349A - Quartz oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized quartz oscillator capable to output a plurality of oscillating frequencies. SOLUTION: The quartz oscillator 1 has a plurality of quartz vibrating elements 2 having respective different resonating frequencies from each other; a container 3 with a cavity having a plurality of formed mounting portions whereon the plurality of quartz vibrating elements are mounted respectively; and output terminals provided on the outer surface of the container for outputting via the inner wirings of the container the oscillating signals generated by the quartz vibrating elements. Further, in the quartz oscillator 1, the plurality of quartz vibration elements are so arranged that they overlap with each other in the direction of their thicknesses.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crystal oscillator used for a clock of various electronic devices. 2. Description of the Related Art As a conventional example of a crystal oscillator used for a clock of various electronic devices, for example, a crystal oscillator shown in FIG. 8 is known. In a conventional crystal oscillator 100, a crystal resonator element 103 is fixedly connected to a cavity 102 of a concave container 101 made of ceramic or the like by a conductive bonding material 104, and an IC chip which is a component of an oscillation circuit. 10
Electronic component elements 105 such as 5a and a capacitor 105b are housed. The quartz vibrating element 103 is fixed and connected to an electrode pad 107 formed on a stepped portion 106 in a cavity 102 of the container 101 with, for example, a silicon-based conductive bonding material 104. 101 occupies substantially the entire bottom surface area. Also, the IC chip 105a
The electronic component element 105 such as the capacitor and the capacitor 105b is housed in the bottom of the cavity 102 of the container 101,
01, the wiring pattern 111 formed inside
It is connected to the crystal oscillator 103 and the external electrode 108. The quartz vibrating element 103 has excitation electrodes (not shown) formed on both main surfaces thereof, and the electronic component elements 10 such as an IC chip 105a and a capacitor 105b.
5 and an oscillation circuit, and vibrates at a specific frequency by applying a predetermined drive voltage to the oscillation circuit. [0006] The container 101 is formed of a multilayer substrate formed by laminating a plurality of ceramic insulating layers.
After accommodating the electronic component elements 105 such as the crystal resonator element 103, the IC chip 105a, and the capacitor 105b in the device 2, they are hermetically sealed by a seam ring 109 and a metal lid 110 by a method such as seam welding. FIG. 9 shows a circuit configuration of a conventional crystal oscillator 100. The figure shows an example of a general oscillation circuit of the crystal oscillator 100. Both ends of the crystal resonator element XTAL are connected to load capacitors C1 and C1.
2 and CM in parallel with the crystal unit XTAL
It is composed of a Colpitts oscillation circuit to which an OS inverter IC and a feedback resistor Rf are connected. [0008] In recent years, the functions of electronic devices have been advanced, complicated, and diversified in accordance with market demands, and a large number of sophisticated and complicated controls have been provided inside the electronic devices. Is being performed. Accordingly, the clocks required for the control circuits are diversified, and a clock having a different appropriate frequency is required for each control circuit. However, in the above-described crystal oscillator 100, only one crystal oscillation element 103 is accommodated in the cavity 102 of the container 101, and as a result, only one kind of signal having a fixed oscillation frequency is output. Was. Therefore, in order to obtain a plurality of clock signals, it is necessary to use a plurality of crystal oscillators. This has led to increased costs. In addition, mounting a plurality of crystal oscillators 100 requires a plurality of mounting spaces on a mounting board,
This is a factor that hinders miniaturization of electronic devices. On the other hand, some of the crystal oscillators 100 have a built-in multiplication or frequency division circuit therein and can output a frequency different from the resonance frequency of the crystal resonator element. However, the output frequency of the oscillation signal is 2 times, 4 times, or 1/2 or 1/4 of the resonance frequency of the crystal resonator element
Basically, it is possible to generate the signal of. Therefore, some control circuits cannot satisfy the requirements with a fixed frequency, and the present invention has not been able to output the frequency of a free oscillation signal individually in view of the above problem. An object of the present invention is to provide a crystal oscillator that can be reduced in size without using a plurality of crystal oscillators and can output a free oscillation signal as appropriate when generating a plurality of oscillation signals. is there. [0013] In order to solve the above-mentioned problems, the present invention provides a plurality of quartz vibrating elements having different resonance frequencies and a plurality of quartz vibrating elements respectively mounting the plurality of quartz vibrating elements. In a crystal oscillator having a container having a cavity in which a mounting portion is formed, and an output terminal on an outer surface of the container for outputting an oscillation signal from the crystal vibrating element via an internal wiring of the container, A crystal oscillator is provided, wherein the elements are arranged so as to overlap each other in the thickness direction of the crystal vibrating elements. According to the present invention, a plurality of crystal vibrating elements are arranged so as to overlap each other in the thickness direction of the elements, and oscillation signals of different frequencies can be output by the respective crystal vibrating elements. Therefore, a plurality of crystal vibrating elements can be accommodated in one crystal oscillator without increasing the bottom area of the container, whereby when mounted on an electronic device,
A single crystal oscillator can support a plurality of oscillation signals, which can contribute to miniaturization and cost reduction of electronic devices. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A surface mount type crystal oscillator of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an external perspective view of a crystal oscillator 1 according to the present invention, and FIG. 2 is a cross-sectional view taken along a center line of the crystal oscillator 1 according to the present invention. The crystal oscillator 1 includes a crystal vibrating element 2a, a crystal vibrating element 2b, a concave container 3 made of ceramic or the like, a conductive bonding material 4, electronic components 5 such as an IC chip 5a and a capacitor 5b, a seam ring 6, and It is constituted by a metal lid 7. As shown in FIG. 3, the crystal vibrating elements 2a and 2b have excitation electrodes 21 formed on both main surfaces of a strip-shaped crystal piece 20, and each of them overlaps in the thickness direction of the element. Are arranged as follows. Further, an oscillation circuit is constituted by the electronic component elements 5 such as the IC chip 5a, the capacitor 5b, and the feedback resistor 5c in FIG. The container 3 is formed of a multilayer substrate formed by laminating a plurality of insulating layers, and has a cavity 8 formed therein. On the bottom surface of the cavity 8 of the container 3, electronic component elements 5 such as an IC chip 5a, a capacitor 5b, and a feedback resistor 5c are accommodated. A step is formed in the side wall of the container 3 in a step-like manner.
a, a first mounting portion 9a and a second mounting portion 9b on which the quartz-crystal vibrating element 2b is mounted, respectively, and the first mounting portion 9a and the second mounting portion 9b have a height from the bottom surface of the cavity 8. Are formed at different heights, and the first mounting portion 9
The electrode pad 10a is formed on the flat portion of the line a, and the electrode pad 10b is formed on the second mounting portion 9b. The crystal vibrating element 2a is mounted on the electrode pad 10a, and the crystal vibrating element 2b is mounted on the electrode pad 10b. That is, the quartz vibrating element 2a and the quartz vibrating element 2b are arranged in the cavity 8 of the container 3 at different heights in the thickness direction. Since the quartz crystal vibrating elements 2a and 2b and the electronic component element 5 are formed in the thickness direction as described above, they are designed for miniaturization. In addition, since the first mounting portion 9a and the second mounting portion 9b are at different heights, interference between the conductive bonding materials 4 connected to each other can be avoided, and the quartz vibrating elements 2a, 2b Are joined, so that a stable joining force can be obtained. The crystal vibrating element 2a, the crystal vibrating element 2b, the electronic component elements 5 such as the IC chip 5a and the capacitor 5b, and the terminal electrodes 11 formed on the outer surface of the container 3 are housed in the container 3. Are connected by internal wirings 12 formed between the insulating layers. The container 3 houses the crystal vibrating element 2a, the crystal vibrating element 2b, and the electronic component elements 5 such as the IC chip 5a and the capacitor 5b.
The hermetic sealing is performed by the seam ring 6 and the metal lid 7 by a method such as seam welding. By applying a predetermined drive voltage to the oscillation circuit constituted by the electronic component element 5,
Since the crystal vibrating element 2a and the crystal vibrating element 2b each have a unique resonance frequency depending on the thickness of the crystal piece 20, the crystal vibrating element 2a and the crystal vibrating element 2b output an oscillation signal to the terminal electrode 11 via the oscillation circuit constituted by the electronic component element 5. Is done. That is,
By preparing the crystal blanks 20 having different thicknesses from each other, the crystal vibrating elements 2a and 2b having different resonance frequencies are used, whereby desired different oscillation signals can be obtained. The oscillation frequency output from the crystal oscillator 1 in FIG. 2 is, for example, a changeover switch SW for externally switching the crystal vibrating element in the circuit diagram shown in FIG.
1, SW2 may be provided to select either the crystal resonator element XTAL1 or the crystal resonator element XTAL2. As a result, the oscillation frequency can be selected. That is,
Although the power supply voltage is omitted in FIG. 4, the power supply voltage is applied, and the CMOS inverter IC, which is the electronic component element 5 via one of the crystal vibrating elements XTAL1 and XTAL2 selected by the changeover switches SW1 and SW2, By the Colpitts oscillation circuit of the feedback resistor Rf and the load capacitors C1 and C2, different frequencies can be freely output to the output terminal, and the electronic components can be used in common, and the number of components can be reduced to achieve downsizing. Further, as shown in FIG.
Oscillation circuits may be individually formed in the TAL1 and the crystal resonator XTAL2, and a plurality of oscillation frequencies may be output simultaneously. At that time, as shown in FIG. 6, the power supply voltage Vcc (not shown in FIG. 6) and the output terminals 1 (OUT1) and 2 (OUT2) of FIG. 5 are formed at different positions on the bottom surface of the container 3, respectively. . In the figure,
IC1 and IC2 may be formed into one IC. In the above-described embodiment, the receivers 9a and 9b formed on the side wall of the container 3 and the receivers 9a and 9b
Although the electrode pads 10a and 10b formed on the substrate and the quartz crystal vibrating elements 2a2b are joined, the number is not limited to two as long as the number is plural. Further, it is not necessary to accommodate a plurality of quartz-crystal vibrating elements in the same direction in which the quartz-crystal vibrating element is accommodated. For example, as shown in FIG. A plurality of quartz-crystal vibrating elements may be accommodated in different directions, such as accommodating the element 2b in the long side direction of the container 3. That is, the resonance frequency of the crystal resonator element is basically determined by the thickness of the crystal piece. However, when the crystal resonator element is optimally designed in different frequency bands, the element size of the crystal resonator element in each frequency band becomes larger. Each will be different. Therefore, by utilizing these different dimensions, the inner dimension in the long side direction of the container 3 is set for a quartz resonator having a long dimension in a certain frequency band, and the quartz resonator element having a short dimension in another frequency band is used. If the inner dimensions in the short side direction of the container 3 correspond to each other, the container can be efficiently stored, and a single type of container can support different frequency bands. Furthermore, not only the crystal oscillator 1 for outputting a plurality of frequency signals but also a crystal oscillator 1 for outputting a single frequency signal, which may be applicable to different frequency bands. According to the present invention, the bottom area can be increased by accommodating a plurality of quartz-crystal vibrating elements in a thickness direction in a crystal oscillator having a cavity by using different steps formed in the container. And a crystal oscillator capable of outputting a plurality of frequency signals can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an external perspective view of a crystal oscillator according to the present invention. FIG. 2 is a central longitudinal sectional view of the crystal oscillator of the present invention. FIG. 3 is an external perspective view of the crystal resonator element of the present invention. FIG. 4 is a diagram illustrating an equivalent circuit of the crystal oscillator according to the present invention. FIG. 5 is a diagram illustrating another equivalent circuit of the crystal oscillator according to the present invention. FIG. 6 is a diagram showing a bottom view of the crystal oscillator of the present invention. FIG. 7 is an internal explanatory view showing another embodiment of the crystal oscillator of the present invention. FIG. 8 is a central longitudinal sectional view of a conventional crystal oscillator. FIG. 9 is a diagram illustrating an equivalent circuit of a conventional crystal oscillator. [Description of Signs] 1 ... Crystal oscillators 2a, 2b ... Crystal vibrating element 3 ... Container 4 ... Conductive bonding material 5 ... Electronic component element 9 ... ..Step portion 10 ... Electrode pad

Claims (1)

Claims: 1. A container having a plurality of crystal vibrating elements having different resonance frequencies, and a cavity having a plurality of mounting sections for mounting the plurality of crystal vibrating elements, respectively. A crystal oscillator having, on an outer surface of the container, an output terminal for outputting an oscillation signal from the crystal vibrating element via an internal wiring of the container, wherein the plurality of crystal vibrating elements overlap each other in a thickness direction of the crystal vibrating elements A crystal oscillator characterized by being arranged as follows.