JP5088686B2 - Vibrating piece and vibrating device - Google Patents

Description

The present invention relates to a resonator element and a mesa type vibration device .

  The mesa type resonator element includes a mesa part (thick part) and a thin part made thinner than the mesa part. The thin portion is provided integrally with the periphery of the mesa portion. Thereby, the mesa-type vibrating piece has convex portions on both main surfaces of the base plate. An excitation electrode is provided on the main surface of the mesa portion, and a mount electrode that is in one-to-one connection with the excitation electrode is provided on the thin portion.

  By the way, although the piezoelectric vibration element described in Patent Document 1 is a mesa type, the first convex portion is provided in a thin portion on the fixed end side that supports one end of the piezoelectric vibration element. That is, the 1st convex part is provided between the part (2nd convex part) used as the mesa thick wall, and a fixed end. A conductive adhesive is provided between the fixed end and the first convex portion, and the piezoelectric vibration element is mounted on the package base. Since the shrinkage occurs when the conductive adhesive is cured, the free end opposite to the fixed end rotates with the first convex portion as a fulcrum. That is, the end portion on the free end side of the piezoelectric vibration element is lifted. Thus, a piezoelectric vibration element having a one-end support structure is obtained.

In addition, the mesa-type crystal resonator described in Patent Literature 2 has a quartz substrate dimension, an excitation electrode dimension, a thick vibration part thickness, and a thin wall thickness in order to suppress bending vibration, which is unnecessary vibration. It defines the thickness of the surrounding area.
Japanese Patent Laying-Open No. 2005-268830 (page 6-7) JP 2006-340023 A

Vibrating pieces such as mesa type vibrating pieces are mounted on various electronic devices. However, as electronic devices are downsized, there is a demand for downsizing of the planar size of the vibrating pieces. . However, in the invention described in Patent Document 1 described above, since the first convex portion is provided in the thin portion of the piezoelectric vibration element, the planar size of the thin portion must be widened. The planar size of the piezoelectric vibration element is increased. Since the distance from the fixed end to the free end of the piezoelectric vibration element becomes longer, the free end rotates with the first convex portion as a fulcrum when the conductive adhesive bonded to the piezoelectric vibration element hardens or contracts. It becomes difficult to do.
Patent Document 2 only describes suppression of bending vibration.

The present invention, while miniaturizing the planar size, and to provide a was suppressed unwanted vibration resonator element. It is another object of the present invention to provide a vibrating device using the vibrating piece .

の関係を満たすことを特徴とする。
更に上記いずれかの形態において、前記厚肉部の厚さをｔとし、前記薄肉部の主面から前記厚肉部の主面までの前記突出している部分の高さをΔＴとしたとき、前記ΔＴは、前記ｔの１０％〜３０％の範囲内であることを特徴とする。
また、本発明に係る振動デバイスは、上記いずれかの形態に係る振動片と、前記振動片が搭載されている保持器と、を含み、前記保持器の一方の面に配置されている電極端子の上に前記導電性接着剤が設けられ、前記導電性接着剤の上に前記振動片の前記基端側の前記薄肉部が配設され、前記マウント電極および前記端部の最下段における前記マウント電極側の側面が、前記導電性接着剤と接合している、ことを特徴とする。
上記振動デバイスにおいて、前記電極端子および前記マウント電極を介して前記励振電極に導通し、前記励振電極に電気信号を印加して主振動を励起させる発振回路が、前記保持器に設けられていることを特徴とする。 SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.
The mesa type resonator element according to the present invention has a thick portion where an excitation electrode is provided on a main surface, a thickness smaller than the thick portion, and is integrated with the thick portion along an outer edge of the thick portion. One of the edges of the thin portion is a base end side, and the thin portion on the base end side is electrically connected to the excitation electrode. The mount electrode is provided, a stepped step portion is provided on a side surface of the thick portion protruding from the thin portion, and an end portion of the protruding portion has a plurality of steps. The side surface on the side of the mount electrode in the lowermost stage is a mount step portion joined with a conductive adhesive.
In the above embodiment, when the edge of the thick part and the edge of the excitation electrode are arranged at the antinodes of bending vibration and the wavelength of the bending vibration is λ, The antinode of bending vibration is shifted by an odd multiple of λ / 2.
In the above embodiment, the thick part and the thin part are made of quartz, and the length of the thick part along the X axis, which is the crystal axis of the crystal, is ML, and bending vibration is generated in the X axis direction. When the wavelength of λ is λ, ML and λ are

It is characterized by satisfying the relationship.
Furthermore, in any one of the above embodiments, when the thickness of the thick portion is t, and the height of the protruding portion from the main surface of the thin portion to the main surface of the thick portion is ΔT, ΔT is in the range of 10% to 30% of the t.
An oscillating device according to the present invention includes an oscillating piece according to any one of the above aspects and a cage on which the oscillating piece is mounted, and an electrode terminal disposed on one surface of the cage. The conductive adhesive is provided on the conductive adhesive, and the thin-walled portion on the base end side of the vibrating piece is disposed on the conductive adhesive, and the mount electrode and the mount at the lowermost stage of the end are provided. A side surface on the electrode side is bonded to the conductive adhesive.
In the vibration device, an oscillation circuit that is electrically connected to the excitation electrode through the electrode terminal and the mount electrode and applies an electric signal to the excitation electrode to excite main vibration is provided in the cage. It is characterized by.

  [Application Example 1] A mesa portion including an excitation electrode on a main surface, and a thin portion that is thinner than the mesa portion and is provided on the side integrally with the mesa portion, and has an edge of the thin portion Any one side constituting the portion is a base end side, and a mount electrode connected to the excitation electrode is provided on the base end side, and a side surface of the mesa portion on the mount electrode side is formed of a conductive adhesive. A mesa type resonator element characterized in that it is a mount step portion to be joined.

  As a result, the side surface on the base end side in the mesa portion becomes the mount portion, so that the planar size of the thin portion can be reduced, and consequently the planar size of the mesa-type vibrating piece can be reduced. Also, when mounting a mesa-type vibrating piece on a cage, if a conductive adhesive is bonded to the side surface on the base end side of the mesa part or the mount electrode, the conductive adhesive shrinks when cured, and becomes like a lever. The tip side of the mesa-type vibrating piece can be lifted up.

  Application Example 2 When the edge of the mesa and the edge of the excitation electrode are located at the antinodes of bending vibration, which is unnecessary vibration, and the wavelength of the bending vibration is λ, The mesa-type vibrating piece according to Application Example 1, wherein the antinodes of the bending vibration are shifted by an odd multiple of λ / 2.

  Thereby, the bending vibration generated in the mesa-type vibrating piece can be suppressed, and the crystal impedance (CI) value can be reduced.

（ｎは正の整数）
の関係を満たすことを特徴とする適用例１に記載のメサ型振動片。
これによりメサ型振動片に生じる屈曲振動を抑圧でき、ＣＩ値を低減できる。 Application Example 3 The mesa portion and the thin portion are integrally formed using quartz, and the length of the mesa along the X axis of the crystal axis of the quartz is not required to be generated in the ML and X axis directions. Assuming that the wavelength of flexural vibration, which is vibration, is λ, ML and λ are

(N is a positive integer)
The mesa-type vibrating piece according to Application Example 1, which satisfies the relationship:
Thereby, the bending vibration generated in the mesa-type vibrating piece can be suppressed, and the CI value can be reduced.

  Application Example 4 When the thickness of the mesa portion is t and the height of the mesa portion step from the main surface of the thin portion to the main surface of the mesa portion is ΔT, the height ΔT of the mesa portion step is 4. The mesa resonator element according to any one of application examples 1 to 3, wherein the mesa type resonator element is in a range of 10% to 30% of a thickness t of the mesa portion.

  By setting the height of the mesa portion step as described above, it is possible to prevent the effective length of the length (long side) of the base plate in the X-axis direction from being shortened and to prevent the CI value from increasing.

  Application Example 5 A stepped step portion is provided on the side surface of the mesa portion so that the mesa portion is multi-staged, and the side surface on the mount electrode side at the lowest step of the multi-stage mesa portion is the conductive adhesive. The mesa type resonator element according to any one of Application Examples 1 to 4, wherein the mount step portion is bonded to each other.

  As a result, since the conductive adhesive is bonded to the first mesa stage at the lowermost stage of the mesa portion of the mesa-type vibrating piece, the tip side can be separated from the retainer, and the first mesa stage allows the first mesa stage to move away from the first mesa stage. It is possible to prevent the conductive adhesive from flowing into the main surface of another mesa step or mesa portion on the step.

  [Application Example 6] A cage having the mesa-type vibrating piece according to any one of Application Examples 1 to 5 mounted thereon, a cage-side mount electrode provided on one surface of the cage, and the cage The conductive adhesive is provided on the side mount electrode, the mesa-type vibrating piece is provided on the conductive adhesive, and the side surface of the mount electrode and the mesa portion and the conductive adhesive are provided. A mesa type vibration device characterized by being joined.

  As a result, the mesa vibrating device can separate the tip of the mesa vibrating piece from the cage, so that various characteristics such as drop characteristics and power fluctuations can be improved, and a conductive adhesive is applied to the main surface of the mesa section. Inflow can be prevented.

  Application Example 7 The cage is provided with an oscillation circuit that conducts to the excitation electrode through the cage-side mount electrode and the mount electrode, and excites main vibration by applying an electric signal to the excitation electrode. The mesa type vibration device according to Application Example 6 characterized by the above.

  As a result, the mesa type vibration device can be an oscillator. This oscillator has improved characteristics such as drop characteristics.

  Application Example 8 A conductive adhesive is applied on the cage-side mount electrode formed on one surface of the cage to form a mesa portion and a thin portion that is thinner than the mesa portion. The mesa-type vibrating piece is placed on the conductive adhesive, the conductive adhesive is brought into contact with the mount electrode formed on the thin portion and the side surface of the mesa portion, and the conductive adhesive is cured. A method for manufacturing a mesa-type vibrating device, wherein the mesa-type vibrating piece is contracted, the tip side of the mesa-type vibrating piece is separated from one surface of the cage, and the mesa-type vibrating piece and the cage are joined.

  As a result, the tip side of the mesa-type vibrating piece can be separated from the cage, so the mesa-type vibrating device can improve various characteristics such as drop characteristics and power supply fluctuations, and conductive adhesive is applied to the main surface of the mesa section. Inflow can be prevented.

  Hereinafter, a best mode for providing a mesa vibrating piece, a mesa vibrating device, and a method for manufacturing a mesa vibrating device according to the present invention will be described. FIG. 1 is an explanatory diagram of a mesa-type vibrating piece. Here, FIG. 1A is a schematic cross-sectional view of a mesa-type vibrating piece, and FIG. 1B is a diagram for explaining the relationship between the mesa-type vibrating piece and bending vibration. A wavy line shown in FIG. 1B shows a vibration mode of bending vibration.

  The mesa-type vibrating piece 10 includes a base plate 16 in which a mesa portion 12 and a thin portion 14 provided integrally around the mesa portion 12 are formed. The thin portion 14 is thinner than the mesa portion 12, and is provided at the center portion of the mesa portion 12 in the height direction. Therefore, the base plate 16 has a bimesa structure in which convex portions that become the mesa portions 12 are provided on both main surfaces 12a. When the base plate 16 is formed of a piezoelectric material, the mesa type vibrating piece 10 may be called a mesa type piezoelectric vibrating piece. If the piezoelectric material is quartz, the mesa-type vibrating piece 10 may be called a mesa-type quartz vibrating piece.

  Excitation electrodes 20 are provided on the main surface 12 a of the mesa portion 12, and mount electrodes 22 are provided at both end portions of any one side constituting the edge portion of the thin portion 14. That is, the mount electrode 22 is provided at a corner portion on the supported base end 26 side in order to support the mesa-type vibrating piece 10 in a cantilevered manner, It is provided on the main surface 14a. Thereby, regardless of the front and back of the base plate 16, the mesa-type vibrating piece 10 can be mounted on a retainer described later. The excitation electrode 20 and the mount electrode 22 are electrically connected one-to-one by a connection electrode (not shown) drawn around the surface of the base plate 16.

  The mount electrode 22 and the side surface 12b of the mesa portion 12 on the side of the mount electrode 22 are places where a conductive adhesive used when the mesa-type vibrating piece 10 is cantilevered and mounted on the cage is joined. It has become. Therefore, the side surface 12b of the mesa portion 12 adjacent to the mount electrode 22 becomes the mount step portion 18 to separate the tip 28 side of the mesa-type vibrating piece 10 from the cage, and the conductive adhesive is the main portion of the mesa portion 12. It has a role to prevent the flow into the surface 12a.

  For example, when an AT cut quartz base plate is used for the mesa-type vibrating piece 10, thickness shear vibration is excited as main vibration, but unnecessary vibration (flexural vibration) coupled to the thickness shear vibration is also excited. For this reason, in the mesa-type vibrating piece 10 according to the present embodiment, the dimensions of the mesa portion 12, the thin portion 14, and the excitation electrode 20 are defined in order to suppress bending vibration.

  Here, in the mesa-type vibrating piece 10 shown in FIG. 1B, when an AT-cut quartz base plate is used, the direction connecting the base end 26 and the tip 28 of the base plate 16 becomes the X axis of the crystal axis of the crystal. The thickness direction of the base plate 16 is the Y axis of the crystal axis of the crystal. In order to suppress the bending vibration, the mesa-type vibrating piece 10 is sequentially along the X axis, the edge A of the mesa portion 12 on the proximal end 26 side, the edge B of the excitation electrode 20 on the proximal end 26 side, and the distal end 28. When the edge C of the excitation electrode 20 on the side and the edge D of the mesa 12 on the tip 28 side are arranged, the positions of the edges AD match the positions of the antinodes of bending vibration.

  That is, the amplitude of the bending vibration antinode located at the edge A of the mesa portion 12 on the proximal end 26 side is opposite to the amplitude of the bending vibration antinode located at the edge B of the excitation electrode 20 on the proximal end 26 side. It is in the direction. Also, the antinodes of the bending vibration at the position of the edge B of the excitation electrode 20 on the base end 26 side and the amplitudes of the antinodes of the bending vibration at the position of the edge C of the excitation electrode 20 on the tip 28 side are opposite directions. It has become. Furthermore, the amplitude of the bending vibration antinode located at the edge C of the excitation electrode 20 on the tip 28 side and the amplitude of the bending vibration antinode located at the edge D of the mesa portion 12 on the tip 28 side are in opposite directions. It has become. In other words, if the wavelength of the bending vibration is λ, the antinodes of the bending vibration are shifted by an odd multiple of λ / 2 at the adjacent edge portion.

ここでｎは正の整数である。 When the length (width) of the mesa portion 12 in the direction along the X axis is ML, ML and λ satisfy the relationship shown in Equation 4 .

Here, n is a positive integer.

If the length (width) of the excitation electrode 20 in the direction along the X axis is Ex, ML, Ex, and λ satisfy the relationship shown in Equation 5 .

  If the thickness of the mesa portion 12 is t and the height from the main surface 14a of the thin portion 14 to the main surface 12a of the mesa portion 12 (heap height of the mesa portion) is ΔT, the height ΔT of the mesa portion step difference Is 30% or less of the thickness t of the mesa portion 12 and 10% or more. With such a mesa portion step height, the effective length of the length (long side) of the base plate 16 in the X-axis direction can be prevented from being shortened, and the crystal impedance (CI) value can be prevented from increasing. . Further, when the height of the mesa portion step is set, the effect of confining the main vibration in the mesa portion 12 can be maintained. Further, the mesa portion step can prevent the conductive adhesive from flowing into the main surface 12 a of the mesa portion 12.

  According to such a mesa type resonator element 10, the planar size can be reduced. In addition, since the dimensions of the mesa-type vibrating piece 10 are defined, bending vibration that is unnecessary vibration can be suppressed, and the CI value can be reduced. Note that the dimension L (see FIG. 1B) of the mount portion of the mesa-type vibrating piece 10 depends on the dimension of the mesa-type vibrating piece 10 in the X-axis direction, for example, 0.2 to 0.4 [mm]. Can be about.

  The mesa vibrating piece 10 described above can be mounted on the cage to constitute a mesa vibrating device. FIG. 2 is an enlarged explanatory view of a part of the mesa type vibration device. The mesa vibrating device 30 includes the cage 32 on which the mesa vibrating piece 10 is mounted. For example, the cage 32 may be a package base having a recessed portion formed of an insulating material. A cage-side mount electrode 34 is provided on the bottom surface 32a (one surface) of the recess, and is electrically connected to an external terminal (not shown) provided on the outer surface of the package base.

  In order to mount the mesa-type vibrating piece 10 on such a holder 32, the conductive adhesive 36 is applied to the holder-side mount electrode 34, and then the mesa-type vibrating piece 10 is placed on the conductive adhesive 36. May be provided. At this time, the conductive adhesive 36 is bonded to the mount portion of the mesa-type vibrating piece 10, that is, the mount electrode 22 and the mount step portion 18. The conductive adhesive 36 may be any adhesive that shrinks when cured, and may be, for example, a resin adhesive containing a conductive filler. More specifically, any silicone adhesive containing a conductive filler may be used. When the conductive adhesive 36 is heated and cured, the conductive adhesive 36 contracts, so that the tip 28 side of the mesa-type vibrating piece 10 is lifted up. When the curing of the conductive adhesive 36 is completed, as shown in FIG. 2, the mesa-type vibrating piece 10 is fixed to the cage 32 in a state where the tip 28 side is lifted from the base end 26 side.

  Thus, the mesa-type vibrating piece 10 disposed in the cage 32 is hermetically sealed by joining a lid (not shown) to the upper surface of the cage 32. The mesa vibrating piece 10 is fixed in an inclined state, but the tip 28 side does not come into contact with the lid.

  The mesa vibrating device 30 can constitute an oscillator of the mesa vibrating piece 10 by mounting an oscillation circuit together with the mesa vibrating piece 10 on the holder 32. Further, the mesa type vibration device 30 constitutes a voltage control type oscillator if a voltage control circuit that varies the frequency of an output signal according to the magnitude of the control voltage supplied from the outside is also mounted on the holder 32. be able to. Further, the mesa resonator element 10 can be configured as a temperature-compensated oscillator if a temperature compensation circuit that reduces the amount of change in the frequency of the output signal regardless of the ambient temperature is mounted on the holder 32. .

  According to such a mesa vibration device 30, the tip 28 side of the mesa vibration piece 10 can be separated from the cage 32 by using the mesa vibration piece 10 described above. As a result, various characteristics such as drop characteristics and power supply fluctuations of the mesa-type vibrating device 30 can be improved, and the conductive adhesive 36 can be prevented from flowing into the main surface 12a of the mesa portion 12.

  Further, since the mesa portion stepped portion of the mesa-type vibrating piece 10 is used as a portion to be directly mounted, the planar size of the mesa-type vibrating piece 10 can be minimized, and the shape is more suitable for downsizing. That is, when the mount step portion 18 is provided separately from the mesa portion 12 as in the prior art, the planar size of the base plate 16 is increased correspondingly, but the mesa-type vibrating piece 10 according to the present embodiment has a planar size. Can be downsized. For this reason, since the mesa vibration device 30 uses such a mesa vibration piece 10, the planar size of the mesa vibration device 30 can be reduced.

  That is, in other words, if the size of the package base (cavity type package) provided with the concave portion is the same, the planar size of the mesa portion 12 of the mesa vibrating piece 10 can be increased, and therefore the CI value can be reduced. Further, when reducing the planar size of the package, the thin portion 14 approaches the mesa portion 12 while the planar size of the mesa portion 12 of the mesa-type vibrating piece 10 is kept small as in the prior art (the planar size of the thin portion 14 is Therefore, the planar size of the mesa vibrating piece 10 can be reduced, and consequently the planar size of the mesa vibrating device 30 can also be reduced.

  In the mesa-type vibrating piece 10 described above, the mesa portion 12 has a single-stage structure, but the mesa portion of the mesa-type vibrating piece according to the present invention may have a multi-stage structure. FIG. 3 is an enlarged view of a part of a mesa-type vibrating device provided with a mesa-type vibrating piece having a multi-stage mesa portion. In FIG. 3, a mesa-type vibrating piece having a two-stage mesa portion is shown as an example of a configuration in which the mesa portion is multi-staged.

  In this mesa-type vibrating piece 50, the side surface 52 c on the mount electrode 22 side in the first (lowermost) mesa step (first mesa step 52 a) adjacent to the thin-walled portion 54 of the mesa portion 52 is a mount stepped portion 56. . The mesa stage formed on the upper side of the first mesa stage 52a is a second mesa stage 52b. The height ΔT of each mesa step difference between the first mesa step 52a and the second mesa step 52b is not less than 10% and not more than 30% of the thickness t of the mesa portion 52. Further, the length ML of the mesa portion 52 in the longitudinal direction and the length L of the mount portion may be the same as those in the case where the mesa portion 52 has only one stage.

  The mesa-type vibrating piece 50 having such a multi-stage mesa unit 52 is formed by holding the tip 58 side of the mesa-type vibrating piece 50 by holding the conductive adhesive 36 to the first mesa stage 52a. The conductive adhesive 36 can be prevented from flowing into the second mesa step 52b and the main surface 52d of the mesa portion 52. In addition, the mesa-type vibrating piece 50 can achieve the same effect as the mesa-type vibrating piece 10 including the mesa portion 12 having only one stage.

  Although the above-described mesa type vibrating pieces 10 and 50 have a bimesa structure, the mesa type vibrating piece according to the present invention may have a plano mesa structure. The mesa portion step in the plano mesa structure only needs to have twice the height of the mesa portion step in the bimesa structure. Further, when the mesa-type vibrating piece having the plano mesa structure is mounted on the holder 32, the mesa portion may be mounted facing the holder 32.

It is explanatory drawing of a mesa type vibration piece. It is explanatory drawing which expanded a part of mesa type vibration device. It is explanatory drawing which expanded a part of mesa type vibration device provided with the mesa type vibration piece which made the mesa part multistage.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Mesa type vibration piece, 12 ... Mesa part, 12a ... Main surface, 12b ... Side face, 14 ... Thin part, 16 ... Base plate, 18 ... Mount step part, 20 ... Excitation electrode, 22 ... Mount electrode, 26 ... Base End, 28 ... tip, 30 ... mesa type vibration device, 32 ... retainer, 36 ... conductive adhesive, 50 ... mesa type vibration piece, 52 ... mesa part, 52a ... first mesa stage, 52b ... second mesa stage 56 ... Mount stepped portion.

Claims (6)

A thick portion provided with an excitation electrode on the main surface ;
The thin part is thinner than the thick part, and is provided integrally with the thick part along the outer edge of the thick part,
Including
Any one side of the edge of the thin portion is the base end side,
The thin part on the base end side is provided with a mount electrode electrically connected to the excitation electrode,
The side surface of the portion protruding from the thin portion of the thick portion is provided with a stepped stepped portion, and the end portion of the protruding portion has a plurality of steps,
Resonator element, wherein the mounting electrode side surface of the lowermost of the end portion is a mounting step portion bonded to the conductive adhesive. In claim 1,
And the edge of the edge and the excitation electrode of the thick portion is disposed at the position of the antinodes of the bending vibration,
Wherein when the bending wavelength of vibration was lambda, the edges adjacent, resonator element, characterized in that belly of the bending vibration are shifted an odd multiple of lambda / 2. In claim 1,
The thick part and the thin part are made of quartz ,
When the length of the thick portion along the X-axis is the crystal axis of the crystal ML, the wavelength of bending vibration generated in the X-axis direction is lambda,
ML and λ are

A vibrating piece characterized by satisfying the relationship In any one of Claims 1 thru | or 3,
When the thickness of the thick portion is t, and the height of the protruding portion from the main surface of the thin portion to the main surface of the thick portion is ΔT ,
Wherein ΔT is vibrating piece, which is a range of 10% to 30% of the t. The resonator element according to any one of claims 1 to 4 ,
A cage on which the resonator element is mounted;
Including
The conductive adhesive is provided on the electrode terminal disposed on one surface of the cage ,
The thin portion on the base end side of the vibrating piece is disposed on the conductive adhesive ,
The side surface on the mount electrode side in the lowermost stage of the mount electrode and the end is joined to the conductive adhesive,
A vibrating device characterized by that. In claim 5,
Vibrating said electrode terminals and through the mount electrodes electrically connected to the excitation electrode, an oscillation circuit for exciting the primary vibration by applying an electrical signal to the excitation electrode, characterized in that provided on said retainer Device .

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