OSCILLATOR

An oscillator includes: a resonator element; a circuit element electrically coupled to the resonator element and configured to output a clock signal; and a container accommodating the resonator element and the circuit element and including a substrate having a first surface on which the circuit element is mounted. The substrate includes a first electrode provided on the first surface and electrically coupled to the resonator element, a second electrode electrically coupled to the resonator element, and an output electrode configured to output the clock signal. The first electrode and the second electrode are disposed side by side in a first direction. The output electrode is disposed adjacent to the first electrode in a second direction orthogonal to the first direction. When a virtual line that passes through an end portion of the output electrode on the first electrode side and extends along the first direction is defined as a virtual line A, an interval between an end portion of the first electrode on the output electrode side and the virtual line A is larger than an interval between an end portion of the second electrode on the output electrode side and the virtual line A in the second direction.

The present application is based on, and claims priority from JP Application Serial Number 2021-194026, filed Nov. 30, 2021, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to an oscillator.

2. Related Art

In the related art, an oscillator includes a substrate on which an element is mounted, and an integrated circuit element and a piezoelectric element mounted on the substrate. For example, WO2008/136340 discloses a crystal oscillator for surface mounting. The crystal oscillator includes a container having a so-called H-type structure in which first and second recessed portions are respectively provided on two main surfaces, a crystal element is hermetically sealed in the first recessed portion, and an IC chip is accommodated in the second recessed portion. Mounting electrodes corresponding to a pair of crystal terminals of the IC chip provided for coupling with the crystal element are provided on a bottom surface of the second recessed portion. The mounting electrodes have a larger area than other mounting electrodes and are formed as a pair of monitor electrodes used for characteristic inspection of the crystal element.

However, in the crystal oscillator described in WO2008/136340, a contact property is improved by increasing sizes of the mounting electrodes corresponding to the crystal terminals as in the related art, and meanwhile, the following problem occurs. For example, when one of a first crystal electrode and a second crystal electrode, which are two crystal electrodes, and an output electrode are disposed to be adjacent to each other, a first parasitic capacitance between the first crystal electrode and the output electrode is larger than a second parasitic capacitance between the second crystal electrode and the output electrode, and a difference between the first parasitic capacitance and the second parasitic capacitance increases. When the difference between the parasitic capacitances increases, frequency accuracy of an oscillation output signal deteriorates.

SUMMARY

An oscillator includes: a resonator element; a circuit element electrically coupled to the resonator element and configured to output a clock signal; and a container accommodating the resonator element and the circuit element and including a substrate having a first surface on which the circuit element is mounted. The substrate includes a first electrode provided on the first surface and electrically coupled to the resonator element, a second electrode provided on the first surface and electrically coupled to the resonator element, and an output electrode provided on the first surface and configured to output the clock signal. The first electrode and the second electrode are disposed side by side in a first direction. The output electrode is disposed adjacent to the first electrode in a second direction orthogonal to the first direction. When a virtual line that passes through an end portion of the output electrode on the first electrode side and extends along the first direction is defined as a virtual line A, an interval between an end portion of the first electrode on the output electrode side and the virtual line A is larger than an interval between an end portion of the second electrode on the output electrode side and the virtual line A in the second direction.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

1. First Embodiment

First, an oscillator1according to a first embodiment will be described with reference toFIGS.1to5by taking an oscillator including a tuning fork type resonator element50as an example.

InFIG.1, for convenience of description of an internal configuration of the oscillator1, a state in which a lid18is removed is shown. InFIG.2, a wire, which electrically couples mounting terminals14provided in a container10to electrodes31c,31d,31e, and31fprovided on a first surface11aof a substrate11, and a wire, which electrically couples an excitation electrode55to a coupling terminal56, are not shown.

For convenience of description, in the following drawings, an X axis, a Y axis, and a Z axis are shown as three axes orthogonal to one another. A direction along the X axis is referred to as an “X direction”, a direction along the Y axis is referred to as a “Y direction”, and a direction along the Z axis is referred to as a “Z direction”. Further, an arrow tip side in each axial direction is also referred to as a “plus side”, a proximal end side is also referred to as a “minus side”, a plus side in the Z direction is referred to as “upper”, and a minus side in the Z direction is referred to as “lower”.

In the present embodiment, a first direction is the X direction, and a second direction orthogonal to the first direction is the Y direction.

As shown inFIGS.1and2, the oscillator1according to the present embodiment includes a circuit element40, the resonator element50, the container10that accommodates the circuit element40and the resonator element50, and the lid18that hermetically seals an accommodation space S1in which the resonator element50is accommodated.

The circuit element40includes an oscillation circuit that oscillates the resonator element50, is electrically coupled to the resonator element50, and outputs a clock signal based on an oscillation frequency of the resonator element50.

As shown inFIG.3, the circuit element40includes a first terminal41acoupled to the resonator element50, a second terminal41bcoupled to the resonator element50and disposed side by side with the first terminal41ain the X direction, an output terminal41cdisposed adjacent to the first terminal41ain the Y direction and configured to output a clock signal, a ground terminal41ddisposed adjacent to the second terminal41bin the Y direction, a power supply terminal41edisposed adjacent to the first terminal41aat an opposite side from the output terminal41cside, and a control terminal41fdisposed adjacent to the second terminal41bat an opposite side from the ground terminal41dside.

The resonator element50is a tuning fork type resonator element having two support arms54aand54b, and oscillates at a resonance frequency caused by an outer shape or an outer dimension and outputs a desired oscillation frequency.

The resonator element50uses a piezoelectric material such as quartz crystal as a base material, and includes, as shown inFIG.1, a base portion51, two vibrating arms52extending from the base portion51in a minus Y direction, weight portions53coupled to tip end portions of the vibrating arms52in the minus Y direction, a first support arm54aand a second support arm54bextending from the base portion51in the minus Y direction and provided so as to sandwich the vibrating arms52, excitation electrodes55formed on the vibrating arms52and made of gold or the like, and coupling terminals56formed on the support arms54aand54band made of gold or the like. In addition, the resonator element50also includes a wire (not shown) that is made of gold or the like and is formed on the vibration arms52and the support arms54aand54bso as to electrically couple the excitation electrodes55to the coupling terminals56.

The container10is made of ceramics or the like, and is formed by stacking the substrate11on which the circuit element40and the resonator element50having a flat plate shape are mounted, an annular first frame substrate12from which a central portion forming the accommodation space S1for accommodating the resonator element50is removed, and an annular second frame substrate13which is disposed at an opposite side from the first frame substrate12to sandwich the substrate11with the first frame substrate12and from which a central portion forming an accommodation space S2for accommodating the circuit element40is removed.

The substrate11includes the first surface11aon which the circuit element40is mounted, and a second surface11bwhich is in a front-back relationship with the first surface11aand on which the resonator element50is mounted.

As shown inFIG.4, a first electrode31aelectrically coupled to the first terminal41a, a second electrode31belectrically coupled to the second terminal41b, and an output electrode31celectrically coupled to the output terminal41cand configured to output the clock signal are provided on the first surface11aof the substrate11. In addition, a coupling electrode31delectrically coupled to the ground terminal41d, a power supply electrode31eelectrically coupled to the power supply terminal41e, and a control electrode31felectrically coupled to the control terminal41fare provided. The output electrode31c, the coupling electrode31d, the power supply electrode31e, and the control electrode31fare electrically coupled to the mounting terminals14provided on a bottom surface of the container10by a wire (not shown), respectively.

The first electrode31aand the second electrode31bare disposed side by side in the X direction, which is the first direction, and the output electrode31cis disposed adjacent to the first electrode31ain the Y direction, which is the second direction. When a virtual line that passes through an end portion of the output electrode31con the first electrode31aside and extends along the X direction is defined as a virtual line A, an interval L1between an end portion of the first electrode31aon the output electrode31cside and the virtual line A is larger than an interval L2between an end portion of the second electrode31bon the output electrode31cside and the virtual line A in the Y direction. A length W1of the first electrode31ain the Y direction is smaller than a length W2of the second electrode31bin the Y direction.

Therefore, an interval between the first electrode31aand the output electrode31ccan be increased, and a parasitic capacitance between the first electrode31aand the output electrode31ccan be reduced as compared with a case in which the interval L1between the first electrode31aand the virtual line A is equal to the interval L2between the second electrode31band the virtual line A. Therefore, a difference between the parasitic capacitance between the first electrode31aand the output electrode31cand a parasitic capacitance between the second electrode31band the output electrode31ccan be reduced.

The substrate11is provided with through electrodes32a,32b,32c,32d,32e, and32fpenetrating the first surface11aand the second surface11b. The through electrodes32a,32b,32c,32d,32e, and32fare electrically coupled to the electrodes31a,31b,31c,31d,31e, and31fon the first surface11a, respectively.

The circuit element40is mounted on the first surface11aof the substrate11. As shown inFIG.2, the electrodes31a,31b,31c,31d,31e, and31fon the first surface11aand the terminals41a,41b,41c,41d,41e, and41fprovided on the circuit element40are electrically and mechanically coupled to each other through a conductive adhesive or bonding members19such as a gold bump.

As shown inFIG.5, the second surface11bof the substrate11is provided with a first wire33aelectrically coupled to the first electrode31athrough the through electrode32a, a second wire33belectrically coupled to the second electrode31bthrough the through electrode32b, and an output wire33celectrically coupled to the output electrode31cthrough the through electrode32c. In addition, a ground wire33delectrically coupled to the coupling electrode31dthrough the through electrode32d, a power supply wire33eelectrically coupled to the power supply electrode31ethrough the through electrode32e, and a control wire33felectrically coupled to the control electrode31fthrough the through electrode32fare provided.

The second surface11bof the substrate11is provided with a first mount electrode16aelectrically coupled to the through electrode32aat a first position71overlapping the first electrode31aprovided on the first surface11ain a plan view, and a second mount electrode16belectrically coupled to the through electrode32bat a second position72overlapping the second electrode31bprovided on the first surface11ain a plan view.

The resonator element50is mounted on the second surface11bof the substrate11, the first support arm54aof the resonator element50is bonded to the first mount electrode16aat the first position71, and the second support arm54bof the resonator element50is bonded to the second mount electrode16bat the second position72. More specifically, as shown inFIG.2, the mount electrodes16aand16bon the second surface11band the coupling terminals56provided on the support arms54aand54bof the resonator element50are electrically and mechanically coupled to each other through bonding members60such as a gold bump. Therefore, the first electrode31aand the second electrode31bare electrically coupled to the resonator element50.

The lid18is made of metal, ceramics, glass, or the like, and is bonded to the container10through bonding members17such as a seal ring or low melting point glass, so that the accommodation space S1in which the resonator element50is accommodated and hermetically sealed can be formed. The accommodation space S1is an airtight space, and is in a depressurized state, preferably in a state closer to a vacuum.

In the present embodiment, the tuning fork type resonator element including the support arms54aand54bis described as an example of the resonator element50. The present disclosure is not limited thereto, and a tuning fork type resonator element or a thickness-shear resonator element without the support arms54aand54bmay be used.

In the oscillator1according to the present embodiment, since the interval L1between the first electrode31aand the virtual line A is larger than the interval L2between the second electrode31band the virtual line A, the interval between the first electrode31aand the output electrode31ccan be increased, and the parasitic capacitance between the first electrode31aand the output electrode31ccan be reduced as compared with the case in which the interval L1between the first electrode31aand the virtual line A is equal to the interval L2between the second electrode31band the virtual line A. Therefore, the difference between the parasitic capacitance between the first electrode31aand the output electrode31cand the parasitic capacitance between the second electrode31band the output electrode31ccan be reduced, and a highly accurate oscillation output signal can be output.

2. Second Embodiment

Next, an oscillator1aaccording to a second embodiment will be described with reference toFIG.6.

The oscillator1aaccording to the present embodiment is the same as the oscillator1according to the first embodiment except that a shape of an output electrode31caprovided on a first surface11aof a substrate110ais different from that of the oscillator1according to the first embodiment. Differences from the first embodiment described above will be mainly described, and a description of the same matters will be omitted.

In the oscillator1a, as shown inFIG.6, in the output electrode31caprovided on the first surface11aof the substrate110a, when an end portion of the first electrode31aon a side close to the second electrode31bis defined as a first end portion34, the output electrode31caincludes a first region35indicated by diagonal lines and disposed closer to the second electrode31bside than the first end portion34in the X direction. That is, a length of the output electrode31cain the X direction is longer than that of the output electrode31cof the first embodiment.

Therefore, an interval between the second electrode31band the output electrode31cacan be reduced, and a parasitic capacitance between the second electrode31band the output electrode31cacan be increased as compared with a case in which the first region35is not provided. Therefore, a difference between a parasitic capacitance between the first electrode31aand the output electrode31caand the parasitic capacitance between the second electrode31band the output electrode31cacan be reduced.

With such a configuration, it is possible to obtain the same effect as that of the oscillator1according to the first embodiment.

Next, an oscillator1baccording to a third embodiment will be described with reference toFIG.7.

The oscillator1baccording to the present embodiment is the same as the oscillator1according to the first embodiment except that a shape of an output electrode31cbprovided on a first surface11aof a substrate110bis different from that of the oscillator1according to the first embodiment. Differences from the first embodiment described above will be mainly described, and a description of the same matters will be omitted.

In the oscillator1b, as shown inFIG.7, the output electrode31cbprovided on the first surface11aof the substrate110bis electrically coupled to the through electrode32cthrough a lead wire34cextending from the through electrode32c. When an end portion of the output electrode31cbat an opposite side from the first region35is referred to as a second end portion36and an end portion of the first electrode31aat an opposite side from the first end portion34is referred to as a third end portion37, the second end portion36is located closer to the first region35than the third end portion37in the X direction. That is, a length of the output electrode31cbin the X direction is shorter than that of the output electrode31cof the first embodiment. An area of the output electrode31cbis smaller than areas of the first electrode31aand the second electrode31b.

Therefore, a region of the output electrode31cbclose to the first electrode31acan be reduced, and a parasitic capacitance between the first electrode31aand the output electrode31cbcan be reduced. Therefore, a difference between the parasitic capacitance between the first electrode31aand the output electrode31cband a parasitic capacitance between the second electrode31band the output electrode31cbcan be reduced.

With such a configuration, it is possible to obtain the same effect as that of the oscillator1according to the first embodiment.

Next, an oscillator1caccording to a fourth embodiment will be described with reference toFIG.8.

The oscillator1caccording to the present embodiment is the same as the oscillator1according to the first embodiment except that a shape of a second electrode31bcprovided on a first surface11aof a substrate110cis different from that of the oscillator1according to the first embodiment. Differences from the first embodiment described above will be mainly described, and a description of the same matters will be omitted.

In the oscillator1c, as shown inFIG.8, in the second electrode31bcprovided on the first surface11aof the substrate110c, when a virtual line that passes through an end portion on the output electrode31cside of the coupling electrode31ddisposed adjacent to the second electrode31bcin the Y direction and extends along the Y direction is defined as a virtual line B, the second electrode31bcincludes a second region38formed closer to the first electrode31aside than the virtual line B. That is, a length of the second electrode31bcin the X direction is longer than that of the second electrode31bof the first embodiment.

Therefore, an interval between the second electrode31bcand the output electrode31ccan be reduced, and a parasitic capacitance between the second electrode31bcand the output electrode31ccan be increased as compared with a case in which the second region38is not provided. Therefore, a difference between a parasitic capacitance between the first electrode31aand the output electrode31cand the parasitic capacitance between the second electrode31bcand the output electrode31ccan be reduced.

With such a configuration, it is possible to obtain the same effect as that of the oscillator1according to the first embodiment.

Next, an oscillator1daccording to a fifth embodiment will be described with reference toFIG.9.

The oscillator1daccording to the present embodiment is the same as the oscillator1according to the first embodiment except that a shape of an output electrode31cdprovided on a first surface11aof a substrate110dis different from that of the oscillator1according to the first embodiment. Differences from the first embodiment described above will be mainly described, and a description of the same matters will be omitted.

In the oscillator1d, as shown inFIG.9, in the output electrode31cdprovided on the first surface11aof the substrate110d, when a virtual line that passes through an end portion of the coupling electrode31don the second electrode31bside and extends along the X direction is defined as a virtual line C, at least a part of an end portion of the output electrode31cdon the first electrode31aside is separated from the virtual line C to a side opposite from the first electrode31aside in the Y direction. That is, a length of a portion of the output electrode31cdon the first electrode31aside in the X direction is shorter than that of the output electrode31cof the first embodiment.

Therefore, a region of the output electrode31cdclose to the first electrode31acan be reduced, and a parasitic capacitance between the first electrode31aand the output electrode31cdcan be reduced. Therefore, a difference between the parasitic capacitance between the first electrode31aand the output electrode31cdand a parasitic capacitance between the second electrode31band the output electrode31cdcan be reduced.

With such a configuration, it is possible to obtain the same effect as that of the oscillator1according to the first embodiment.

Next, an oscillator1eaccording to a sixth embodiment will be described with reference toFIG.10.

The oscillator1eaccording to the present embodiment is the same as the oscillator1according to the first embodiment except that a shape of an output electrode31ceprovided on a first surface11aof a substrate110eis different from that of the oscillator1according to the first embodiment. Differences from the first embodiment described above will be mainly described, and a description of the same matters will be omitted.

As shown inFIG.10, in the oscillator1e, the output electrode31ceprovided on the first surface11aof the substrate110eis electrically coupled to the through electrode32cthrough the lead wire34cextending from the through electrode32c. The output electrode31cehas a circular shape in a plan view, and an area of the output electrode31ceis smaller than areas of the first electrode31aand the second electrode31b.

Therefore, a region of the output electrode31ceclose to the first electrode31acan be further reduced, and a parasitic capacitance between the first electrode31aand the output electrode31cecan be further reduced. Therefore, a difference between the parasitic capacitance between the first electrode31aand the output electrode31ceand a parasitic capacitance between the second electrode31band the output electrode31cecan be reduced.

In the present embodiment, the output electrode31cehas a circular shape in a plan view, but the present disclosure is not limited thereto, and the output electrode31cemay have an elliptical shape or an oval shape in the plan view.

With such a configuration, it is possible to obtain the same effect as that of the oscillator1according to the first embodiment.

Next, an oscillator1faccording to a seventh embodiment will be described with reference toFIG.11.

The oscillator1faccording to the present embodiment is similar to the oscillator1according to the first embodiment except that a shield electrode34gis provided on a first surface11aof a substrate110fas compared with the oscillator1according to the first embodiment. Differences from the first embodiment described above will be mainly described, and a description of the same matters will be omitted.

As shown inFIG.11, in the oscillator1f, the shield electrode34gis provided on the first surface11aof the substrate110f. The shield electrode34gis provided between the first electrode31aand the output electrode31cand between the second electrode31band the output electrode31c, and is electrically coupled to the coupling electrode31d. Since the coupling electrode31dis electrically coupled to the ground terminal41d, the shield electrode34gserves as a ground electrode.

Therefore, since the ground electrode is disposed between the first electrode31aand the output electrode31cand between the second electrode31band the output electrode31c, it is possible to further reduce generation of a parasitic capacitance between the first electrode31aand the output electrode31cor generation of a parasitic capacitance between the second electrode31band the output electrode31c. Therefore, a difference between the parasitic capacitance between the first electrode31aand the output electrode31cand the parasitic capacitance between the second electrode31band the output electrode31ccan be further reduced.

With such a configuration, it is possible to obtain the same effect as that of the oscillator1according to the first embodiment.