WO2013027381A1 - Vibrating element, resonator, electronic device, and electronic apparatus - Google Patents

Vibrating element, resonator, electronic device, and electronic apparatus Download PDF

Info

Publication number
WO2013027381A1
WO2013027381A1 PCT/JP2012/005196 JP2012005196W WO2013027381A1 WO 2013027381 A1 WO2013027381 A1 WO 2013027381A1 JP 2012005196 W JP2012005196 W JP 2012005196W WO 2013027381 A1 WO2013027381 A1 WO 2013027381A1
Authority
WO
WIPO (PCT)
Prior art keywords
axis
vibration
piezoelectric
layer
electrode
Prior art date
Application number
PCT/JP2012/005196
Other languages
French (fr)
Japanese (ja)
Inventor
石井　修
孝夫 森田
Original Assignee
セイコーエプソン株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by セイコーエプソン株式会社 filed Critical セイコーエプソン株式会社
Priority to CN201290000764.5U priority Critical patent/CN203747763U/en
Publication of WO2013027381A1 publication Critical patent/WO2013027381A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/15—Constructional features of resonators consisting of piezoelectric or electrostrictive material
    • H03H9/17—Constructional features of resonators consisting of piezoelectric or electrostrictive material having a single resonator
    • H03H9/19—Constructional features of resonators consisting of piezoelectric or electrostrictive material having a single resonator consisting of quartz
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/05—Holders; Supports
    • H03H9/0538—Constructional combinations of supports or holders with electromechanical or other electronic elements
    • H03H9/0542—Constructional combinations of supports or holders with electromechanical or other electronic elements consisting of a lateral arrangement
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/05—Holders; Supports
    • H03H9/0538—Constructional combinations of supports or holders with electromechanical or other electronic elements
    • H03H9/0547—Constructional combinations of supports or holders with electromechanical or other electronic elements consisting of a vertical arrangement
    • H03H9/0552—Constructional combinations of supports or holders with electromechanical or other electronic elements consisting of a vertical arrangement the device and the other elements being mounted on opposite sides of a common substrate
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/05—Holders; Supports
    • H03H9/10—Mounting in enclosures
    • H03H9/1007—Mounting in enclosures for bulk acoustic wave [BAW] devices
    • H03H9/1014—Mounting in enclosures for bulk acoustic wave [BAW] devices the enclosure being defined by a frame built on a substrate and a cap, the frame having no mechanical contact with the BAW device
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/125—Driving means, e.g. electrodes, coils
    • H03H9/13—Driving means, e.g. electrodes, coils for networks consisting of piezoelectric or electrostrictive materials
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/125—Driving means, e.g. electrodes, coils
    • H03H9/13—Driving means, e.g. electrodes, coils for networks consisting of piezoelectric or electrostrictive materials
    • H03H9/131—Driving means, e.g. electrodes, coils for networks consisting of piezoelectric or electrostrictive materials consisting of a multilayered structure
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/15—Constructional features of resonators consisting of piezoelectric or electrostrictive material
    • H03H9/17—Constructional features of resonators consisting of piezoelectric or electrostrictive material having a single resonator
    • H03H9/177—Constructional features of resonators consisting of piezoelectric or electrostrictive material having a single resonator of the energy-trap type

Definitions

  • the present invention relates to a vibrator that vibrates in a thickness shear vibration mode, and more particularly to a vibrator having a so-called reverse mesa structure, a vibrator, an electronic device, and an electronic device using the vibrator.
  • the AT-cut quartz oscillator has a thickness-shear vibration mode as the vibration mode of the main vibration to be excited, and it exhibits a cubic curve suitable for miniaturization and high frequency and has excellent frequency temperature characteristics. It is used in many ways.
  • Patent Document 1 discloses an AT-cut quartz oscillator having a so-called reverse mesa structure in which a high frequency is achieved by forming a recess in a part of the main surface.
  • a so-called Z 'long substrate in which the length in the Z' axis direction of the quartz substrate is longer than the length in the X axis direction is used.
  • an AT-cut quartz vibrator having an inverted mesa structure having a structure in which thick thick supporting portions are continuously provided on three sides of a rectangular thin vibrating portion, and one side of the thin vibrating portion is exposed.
  • the quartz crystal vibrating piece is an in-plane rotated AT-cut quartz substrate formed by rotating the X axis and Z ′ axis of the AT-cut quartz substrate in the range of ⁇ 120 ° to + 60 ° around the Y ′ axis, It is said that it is a structure that secures a vibration area and is excellent in mass productivity (multi-piece).
  • Patent Documents 3 and 4 an AT-cut quartz of an inverted mesa structure having a structure in which thick thick supporting portions are provided continuously on three sides of a rectangular thin vibrating portion and one side of the thin vibrating portion is exposed.
  • a vibrator is disclosed, and a so-called X-long substrate in which the length of the quartz substrate in the X-axis direction is longer than the length in the Z'-axis direction is used as the quartz crystal vibrating piece.
  • thick supporting portions are provided continuously on two adjacent sides of a rectangular thin vibrating portion, and an L-shaped thick portion is provided in plan view, and the thin vibrating portion
  • An inverted mesa AT-cut quartz oscillator having a structure in which two sides are exposed is disclosed.
  • Patent Document 5 discloses an AT-cut quartz vibrator having an inverted mesa structure having a structure in which a thick supporting portion is continuously provided only on one side of a thin vibrating portion and three sides of the thin vibrating portion are exposed. There is.
  • Patent Document 7 discloses an AT-cut vibrator having a reverse mesa structure in which high frequency is achieved by forming recessed portions on both main surfaces of a quartz substrate so as to face each other on the front and back.
  • An X long substrate is used as a quartz substrate, and a structure is proposed in which an excitation electrode is provided in a region where flatness of a vibration region formed in a recessed portion is secured.
  • the thickness slip vibration mode excited in the vibration area of the AT-cut quartz vibrator has an elliptical shape having a major axis in the X-axis direction due to the anisotropy of the elastic constant.
  • Patent Document 8 discloses a piezoelectric vibrator for exciting thickness shear vibration, which has a pair of ring-like electrodes arranged symmetrically on the front and back sides of the piezoelectric substrate. The difference between the diameter of the outer periphery and the diameter of the inner periphery of the ring-shaped electrode is set so that the ring-shaped electrode excites only the symmetric zero-order mode and hardly excites other anharmonic higher-order modes.
  • Patent Document 9 discloses a piezoelectric vibrator in which the shapes of the piezoelectric substrate and the excitation electrodes provided on the front and back of the piezoelectric substrate are both oblong.
  • Patent Document 10 the shapes of both ends in the longitudinal direction (X-axis direction) of the quartz substrate and both ends in the X-axis direction of the electrode are both semielliptical, and the ratio of the major axis to the minor axis of the ellipse (length There is disclosed a crystal unit in which the axis / short axis) is approximately 1.26.
  • Patent Document 11 discloses a quartz oscillator in which an elliptic excitation electrode is formed on an elliptic quartz substrate. The ratio of the major axis to the minor axis is preferably 1.26: 1, but it is said that the range of 1.14 to 1.39: 1 is practical in consideration of variations in manufacturing dimensions and the like.
  • Patent Document 12 discloses a piezoelectric vibrator having a structure in which a notch or a slit is provided between the vibrating portion and the support portion in order to further improve the energy confinement effect of the thickness-shear piezoelectric vibrator.
  • Patent Document 13 discloses a quartz crystal vibrator in which a notch or a slit is provided between a vibrating portion and a support portion of a rectangular flat AT-shaped quartz crystal vibrator.
  • Patent Document 14 discloses a vibrator in which a notch or a slit is provided between a vibrating portion and a support portion of a reverse mesa type piezoelectric vibrator in order to improve (reduce) mount distortion (stress).
  • Patent Document 15 discloses a piezoelectric vibrator in which the conduction of the electrodes on the front and back surfaces is ensured by providing slits (through holes) in the support portion of the reverse mesa type piezoelectric vibrator.
  • Patent Document 16 discloses a quartz oscillator in which unwanted modes of a high-order contour system are suppressed by providing a slit in a support portion of an AT-cut quartz oscillator in a thickness shear vibration mode. Further, in Patent Document 17, a spurious is provided by providing a slit in a connection portion between a thin vibrating portion of an inverted mesa AT-cut quartz crystal unit and a thick holding portion, that is, a residual portion having an inclined surface. There is disclosed an oscillator that suppresses
  • An object of the present invention is to provide a vibration element, a vibrator, an electronic device, and an electronic device using the vibrator of the present invention.
  • the present invention has been made to solve at least a part of the above-mentioned problems, and can be realized as the following modes or application examples.
  • the vibration element according to the present invention comprises: a substrate having a vibration part including a vibration area; a pair of excitation electrodes arranged to face the vibration area on the front and back sides; When the film thickness of the excitation electrode is t1 and the film thickness of the lead electrode is t2, t1 ⁇ t2.
  • the vibration element is characterized in that
  • the lead electrode is electrically connected to the excitation electrode, and the first lead electrode having a film thickness of t1 is provided on the support portion, and the film thickness is t2
  • the vibration element as described in the first application example, characterized in that the second lead electrode is electrically connected.
  • the excitation electrode of the film thickness t1 and the first lead electrode of the same thickness are set to an appropriate plate back amount, and the film thickness t2 of the lead electrode is set to a film thickness without ohmic loss As a result, the CI value of the vibrating element is reduced.
  • the vibrating element is characterized in that the lead electrode is configured such that the first lead electrode and the second lead electrode overlap in at least a partial region. It is a vibration element given in application example 1 or 2.
  • the first lead electrode and the second lead electrode are laminated in a part, there is no conduction failure between the excitation electrode and the lead electrode, and the CI value can be reduced. There is an effect that a vibration element with less spurious can be obtained.
  • the excitation electrode is formed by sequentially laminating the first layer and the second layer on the substrate, and the lead electrode is formed by sequentially forming the third layer on the substrate. It is a vibration element given in the example 1 or 2 of application characterized by laminating the 4th layer.
  • the first layer and the second layer of the excitation electrode are sequentially stacked, and then the third layer and the fourth layer of the lead electrode are sequentially stacked. Therefore, the conductivity of the laminated portion is sufficient. In addition, the adhesion between the lead electrode and the substrate is enhanced, so that the wire bonding can be sufficiently sustained.
  • the partial region is formed by sequentially laminating the third layer, the fourth layer, the first layer, and the second layer on the substrate in this order. According to a third aspect of the invention, there is provided a vibration element as described in the third aspect of the invention.
  • the third layer, the fourth layer, the first layer, and the second layer are sequentially stacked in a portion of the stacked portion of the lead electrode, and the strength and conductivity of the stacked portion are There is an effect that a sufficient vibration element with a small CI value can be obtained.
  • the vibration element according to Application Example 4 is characterized in that the material of the second layer and the fourth layer is gold.
  • gold is used as a material for the second layer and the fourth layer of a portion of the laminated portion of the lead electrode, which is an advantage in that it is extremely excellent in terms of conductivity and aging. There is.
  • the material of the first layer and the third layer is nickel or chromium. This is the vibration element according to the application example 5 or 6.
  • nickel or chromium is used as a material for the first layer and the third layer of a portion of the laminated portion of the lead electrode, and the adhesion to the substrate and the adhesion between the layers are obtained. It has the advantage of being superior to sex.
  • the thick portion is thicker than the vibrating portion, and the thick thick portion has the effect of easily supporting and fixing the vibrating element. Furthermore, when the film thickness of the excitation electrode and the lead electrode is set appropriately, the CI value of the main vibration is small, and the ratio of the adjacent spurious CI value to the main vibration CI value, ie, a large ratio of the CI value is obtained. It has the effect of Furthermore, there is an advantage that the high frequency vibration element using the fundamental wave is miniaturized.
  • the vibration device according to application 8 is characterized in that at least one side of the vibration region is opened.
  • the vibration element according to Application Example 9 is characterized in that the major surface of the thick portion protrudes from at least one of the main surfaces of the vibrating portion.
  • the support of the vibration portion is robust by supporting and fixing the second support portion, and high frequency There is an effect that a vibrating element can be obtained.
  • the second thick portion may be an inclined portion whose thickness increases as it is separated from one end of the vibration region adjacent to one side toward the other end.
  • a vibrating element according to Application Example 8 further comprising: a thick portion main body connected to the other end edge of the inclined portion.
  • one of the inclined portions is continuously provided in the vibration area, and the second thick portion main body is continuously provided on the other (thick one) of the inclined portion.
  • the stress due to the holding is absorbed by the second thick part main body and the inclined part, so that there is an effect that a vibration element having a frequency value characteristic of a smooth cubic curve with a small CI value can be obtained.
  • the vibration element is an orthogonal coordinate system in which the substrate is composed of an X axis as an electrical axis which is a crystal axis of quartz, a Y axis as a mechanical axis, and a Z axis as an optical axis.
  • An axis in which the Z axis is inclined by a predetermined angle in the -Y direction of the Y axis with the X axis as a center is a Z 'axis
  • the Y axis is inclined by the predetermined angle in the + Z direction of the Z axis
  • it is a quartz plate having an axis as a Y 'axis, a plane parallel to the X axis and the Z' axis, and a thickness in a direction parallel to the Y 'axis. It is a vibrating element as described.
  • the vibrating element is characterized in that the substrate includes a fourth thick portion, and the protruding portion of the fourth thick portion is on the negative side of the Z 'axis.
  • 24 is a vibrating element described in application example 8;
  • the vibration element according to Application Example 8 is characterized in that at least one slit is formed through the second thick portion.
  • the vibrator according to the present invention is a vibrator including the vibration element according to application 1 or 2 and a package for housing the vibration element.
  • the excitation electrode and the lead electrode use the vibration element configured as described above, the CI value of the main vibration is small, and the ratio of the CI value of the near spurious to the CI value of the main vibration That is, there is an effect that a vibrator having a large CI value ratio can be obtained. Furthermore, while the high-frequency vibrator is miniaturized, the position to support the vibration element is one point, and by providing a slit between the thick portion and the vibration area, the stress caused by the conductive adhesive is reduced. Thus, there is an effect that a vibrator excellent in frequency repeatability, frequency temperature characteristics, CI temperature characteristics, and frequency aging characteristics can be obtained.
  • An electronic device is an electronic device including the vibrating element according to the application example 1 or 2 and an electronic component in a package.
  • the electronic device according to Application 16 is characterized in that the electronic component is any one of a variable capacitance element, a thermistor, an inductor, and a capacitor.
  • the electronic device piezoelectric device
  • the variable capacitance element the variable capacitance element
  • the thermistor the inductor
  • the capacitor the electronic device
  • the electronic device is the electronic device according to Application 16 characterized in that the package is provided with an oscillation circuit for exciting the vibration element.
  • the electronic device is configured by using the vibration element in which the excitation electrode and the lead electrode are configured as described above and the oscillation circuit, a high frequency piezoelectric oscillator, a temperature compensation type Electronic devices such as a piezoelectric oscillator and a voltage controlled piezoelectric oscillator can be configured. Furthermore, when a voltage control type piezoelectric oscillator is configured, it is possible to obtain an electronic device having excellent frequency reproducibility and aging characteristics, a wide frequency variable range because of using a fundamental wave, and a good S / N ratio (signal-to-noise ratio). effective.
  • Application Example 19 An electronic apparatus comprising the vibrator according to Application Example 15.
  • FIG. 8 is a plan view showing the configuration of a modification of the piezoelectric vibrating element 1;
  • FIG. 10 is a plan view showing the configuration of another modification of the piezoelectric vibrating element 1;
  • FIG. 10 is a plan view showing the configuration of another modification of the piezoelectric vibrating element 1;
  • A) of the piezoelectric vibrating element 1 is a top view which shows the structure of another modification,
  • (b) is a top view which shows the structure of another modification.
  • FIG. 2 is a longitudinal sectional view of an electronic device (piezoelectric device) 6.
  • A) is a longitudinal cross-sectional view of the electronic device (piezoelectric device) 7,
  • (b) is a top view.
  • FIG. 2 is a longitudinal sectional view of an electronic device (piezoelectric device) 7.
  • FIG. (A), (b), (c) is structure explanatory drawing of the piezoelectric substrate which concerns on a modification.
  • (A), (b), (c) is structure explanatory drawing of the piezoelectric substrate which concerns on another modification. It is a modification of the piezoelectric vibration element 1 which concerns on this invention, (a) is a top view, (b) is an enlarged view of the principal part, (c) is the sectional drawing.
  • FIG. 1 is a schematic view showing the configuration of a piezoelectric vibrating element 1 according to an embodiment of the present invention.
  • FIG. 1 (a) is a plan view of the piezoelectric vibration element 1
  • FIG. 1 (b) is a cross-sectional view of the PP cross section viewed from the + X axis direction
  • FIG. 1 (c) is a QZ cross section It is a cross-sectional view seen from the axial direction.
  • the piezoelectric vibration element (vibration element) 1 includes a vibration portion including a thin vibration region 12 and a piezoelectric substrate (substrate) having thick support portions (thick portions) 14, 15 and 16 continuously connected to the vibration region 12. 10, and excitation electrodes 25a and 25b formed so as to face each of the main surfaces (front and back surfaces) of the vibration region 12, and pad electrodes 29a provided in thick portions from the excitation electrodes 25a and 25b, respectively. And lead electrodes 27a and 27b formed extending to 29b.
  • the vibration region means a region in which vibration energy is confined, ie, a region where vibration energy is substantially zero, and the dimensions of the vibration region in the X axis direction and the dimensions of the vibration region in the Z ′ axis direction
  • the ratio of is 1.26: 1 as is well known.
  • the vibrating portion refers to the entire piezoelectric substrate including the vibrating region and its peripheral portion.
  • the piezoelectric substrate 10 has a rectangular shape, and a thin and flat vibration region 12 and a thick support portion (thick portion) 13 integrated along three sides excluding one side of the vibration region 12 (thick portion) 13 14, 15, 16) and a structure in which one side of the vibration area 12 is exposed.
  • the thick support portion (also referred to as a thick portion support portion) 13 includes a first support portion (first thick portion) 14 and a second support portion (a first support portion), which are disposed opposite to each other with the vibration region 12 interposed therebetween. 2) thick-walled portion 15) and a third supporting portion (third thick-walled portion) 16 connecting the base ends of the first and second supporting portions 14 and 15 in a row It has a U-shaped (U-shaped) structure.
  • the thick support portion 13 and the first support portion 14 and the second support portion 15 which are disposed opposite to each other across the vibration area 12 so as to open one of the four sides of the vibration area 12
  • a third support portion 16 provided in series between the proximal end portions of the first and second support portions 14 and 15.
  • "open” includes the case where one side is exposed and the case where one portion is not exposed but completely exposed.
  • the first support portion 14 is continuous with one side 12 a of the thin flat plate-like vibration area 12, and is connected to the one side 12 a of the vibration area 12 from one end (inner side edge) to the other end
  • the first inclined portion 14b having a gradually increasing thickness as it moves away from the end edge, and the thick and square pillar-shaped first support portion body 14a connected to the other end edge of the first inclined portion 14b. And have.
  • the second support portion 15 is connected to one side 12 b of the thin flat plate-like vibration area 12 and is connected to one side 12 b of the vibration area 12 from one end (inner side edge) to the other
  • the second inclined portion 15b having a gradually increasing thickness as it moves away from the outer edge), and a thick, square-pillar-shaped second support portion main body connected to the other end of the second inclined portion 15b.
  • 15a is connected to one side 12 b of the thin flat plate-like vibration area 12 and is connected to one side 12 b of the vibration area 12 from one end (inner side edge) to the other
  • the second inclined portion 15b having a gradually increasing thickness as it moves away from the outer edge), and a thick, square-pillar-shaped second support portion main body connected to the other end of the second inclined portion 15b.
  • 15a is connected to one side 12 b of the thin flat plate-like vibration area 12 and is connected to one side 12 b of the vibration area 12 from one end (inner side edge) to the other
  • the third support portion 16 is connected to one side 12c of the thin flat plate-like vibration area 12 and is connected to the one side 12c of the vibration area 12 from the one end (inner side edge) to the other end (outside)
  • the third inclined portion 16b having a gradually increasing thickness as it moves away from the end edge, and a thick, square-pillar-shaped third support portion body 16a connected to the other end edge of the third inclined portion 16b.
  • the thin vibration region 12 constitutes a recessed portion 11 whose three sides are surrounded by the first, second, and third support portions 14, 15, 16 and the other side is opened.
  • At least one stress relief slit 20 is formed through the second support portion 15. In the embodiment shown in FIG.
  • a support part main body (14a, 15a, 16a) means the area
  • One main surface of the vibration area 12 and one surface of each of the first, second and third support portions 14, 15, 16 are on the same plane, ie, XZ 'of the coordinate axis shown in FIG. It is on a plane parallel to the plane, and this one main surface (the lower surface side in FIG. 1 (b)) is called a flat surface (flat surface), and the other surface which is the other main surface (FIG. 1 (b)
  • the upper surface side of) is called a recessed surface.
  • the concave portion 11 side is a front surface
  • the flat surface is a rear surface.
  • a piezoelectric material such as quartz belongs to a trigonal system and has crystal axes X, Y and Z orthogonal to each other as shown in FIG.
  • the X axis, Y axis, and Z axis are respectively referred to as an electric axis, a mechanical axis, and an optical axis.
  • As the quartz substrate a flat plate cut out from quartz is used as a piezoelectric substrate along a plane obtained by rotating the XZ plane about the X axis by a predetermined angle ⁇ . For example, in the case of an AT-cut quartz substrate, ⁇ is approximately 35 ° 15 ′.
  • the AT cut quartz substrate (piezoelectric substrate) 10 has crystal axes X, Y ', Z' orthogonal to each other.
  • the thickness direction is the Y 'axis
  • the XZ' plane (plane including the X axis and the Z 'axis) orthogonal to the Y' axis is the main surface
  • thickness shear vibration is the main vibration. It is excited.
  • the piezoelectric substrate 10 has a Z-axis that is Y-axis centered on the X-axis of an orthogonal coordinate system consisting of X-axis (electrical axis), Y-axis (mechanical axis), and Z-axis (optical axis).
  • the axis tilted in the -Y direction of is the Z 'axis
  • the Y axis is tilted in the + Z direction of the Z axis is the Y' axis, composed of planes parallel to the X axis and the Z 'axis
  • the Y' axis This is an AT-cut quartz substrate whose thickness is in the parallel direction.
  • the piezoelectric substrate 10 has a direction parallel to the Y ′ axis (hereinafter referred to as “Y ′ axis direction”) as a thickness direction, and a direction parallel to the X axis (hereinafter referred to as “X axis The direction is referred to as a long side, and the direction parallel to the Z 'axis (hereinafter referred to as the "Z' axis direction”) is a short side.
  • the piezoelectric substrate according to the present invention is not limited to the AT cut of which the angle ⁇ is about 35 ° 15 ', but it can be widely applied to a piezoelectric substrate such as a BT cut which excites thickness shear vibration. Yes.
  • the excitation electrodes 25a and 25b for driving the piezoelectric substrate 10 are rectangular in the embodiment shown in FIG. 1, and are formed to face both front and back surfaces (upper and lower surfaces) of the substantially central portion of the vibration region 12 There is. At this time, the size of the area of the excitation electrode 25b on the flat surface side (the back surface side in FIG. 1B) is smaller than the size of the excitation electrode 25a on the recessed surface side (the surface side in FIG. 1B). Set large enough. This is because the energy confinement coefficient due to the mass effect of the excitation electrode is not increased more than necessary.
  • the plate back amount ⁇ ( (fs ⁇ fe) / fs, where fs is the cutoff frequency of the piezoelectric substrate, and fe is the entire surface of the piezoelectric substrate by making the excitation electrode 25 b on the back surface side (lower surface side) sufficiently large.
  • the frequency when the excitation electrode is attached depends on only the mass effect of the excitation electrode 25a on the surface side (upper surface side).
  • the excitation electrodes 25a and 25b for example, nickel (Ni) is formed on a base using a vapor deposition apparatus or a sputtering apparatus, and gold (Au) is stacked on the base to form a film.
  • gold (Au) is stacked on the base to form a film.
  • S0 main vibration
  • S1 oblique symmetric inharmonic mode
  • S1, S3 symmetric inharmonic mode
  • the lead electrode 27a extended from the excitation electrode 25a formed on the front surface side passes through the third inclined portion 16b and the third support portion main body 16a from above the vibrating region 12 to form the second support portion main body 15a. It is conductively connected to the pad electrode 29a formed on the upper surface of the.
  • the lead electrode 27b extended from the excitation electrode 25b formed on the back surface side is a pad electrode 29b formed on the back surface of the second support portion main body 15a via the end edge portion of the back surface of the piezoelectric substrate 10. It is connected conductively.
  • the embodiment shown in FIG. 1A is an example of the lead-out structure of the lead electrodes 27a and 27b. Since the film thickness t2 of the lead electrodes 27a and 27b does not affect the vibration mode of the vibration region, there is no ohmic loss, and it is preferable to be thick so as to be suitable for wire bonding. That is, when the thickness of the excitation electrode 25a on the surface side (upper surface side) is t1, the lead electrodes 27a and 27b are configured to satisfy t1 ⁇ t2.
  • An enlarged cross-sectional view of a film configuration of a portion indicated by UU of the excitation electrodes 25a and 25b is shown on the lower right side of FIG. 1A.
  • a nickel film 25n is formed on a base, and a gold film 25g is laminated thereon. Further, an enlarged cross-sectional view of a film configuration of a portion indicated by SS of the lead electrode 27a is shown at the center in the lower part of FIG. 1A.
  • a chromium film 27c is formed in the first layer, a gold film 27g in the second layer, a nickel film 27n in the third layer, and a gold film 27g in the fourth layer.
  • the second lead electrode (lead electrodes 27a and 27b) of film thickness t2 is formed first, and the excitation electrode 25a of film thickness t1 is formed in the next step, so the tip of the lead electrodes 27a and 27b And a first lead electrode (leader) extending from the excitation electrodes 25a and 25b are formed to overlap each other to form a four-layer structure.
  • the second lead electrodes sequentially form the first layer (chromium film) 27c and the second layer (gold film) 27g on the piezoelectric substrate 10, and are excited thereon
  • a third layer (nickel film) 27n of a first lead electrode (leader) extending from the electrode 25a and a fourth layer (gold film) 27g are stacked and formed.
  • an enlarged cross-sectional view of a film configuration of a portion indicated by RR of the lead electrode 27a is shown on the left side under the FIG. 1A.
  • a chromium film 27c is formed on the base, and a gold film 25g is laminated on the chromium film 27c.
  • the lead electrode 27a may pass through another support.
  • the lengths of the lead electrodes 27a and 27b be the shortest, and it is desirable that the increase in capacitance be suppressed by considering that the lead electrodes 27a and 27b do not intersect with each other across the piezoelectric substrate 10.
  • the example in which the pad electrodes 29a and 29b are respectively formed to face the front and back surfaces of the piezoelectric substrate 10 is shown. Since the pad electrodes 29a and 29b are simultaneously formed in the same process as the lead electrodes 27a and 27b, the film thickness is t2.
  • the piezoelectric vibrating element 1 When the piezoelectric vibrating element 1 is accommodated in a package, as described later, the piezoelectric vibrating element 1 is turned over, and the pad electrode 29a and the element mounting pad of the package are mechanically fixed and electrically connected with a conductive adhesive. The pad electrode 29b and the electrode terminal of the package are electrically connected using a bonding wire. Thus, if the site
  • the reason why the slits 20 are provided between the vibration area 12 and the pad electrodes 29 a and 29 b which are the supporting portions of the piezoelectric vibration element 1 is to prevent the spread of the stress generated at the time of curing of the conductive adhesive. That is, when the piezoelectric vibration element is supported and fixed to the package by the conductive adhesive, first, the conductive adhesive is applied to the supported portion (pad electrode) 29a of the second support portion main body 15a, and this is packaged Place it on an element mounting pad such as, and press it a little. The conductive adhesive is held at a high temperature for a predetermined time to cure.
  • the second support portion main body 15a and the package are both expanded and the adhesive is also temporarily softened, so that no stress is generated in the second support portion main body 15a.
  • the conductive adhesive cures, when the second support body 15a and the package cool and the temperature returns to normal temperature (25 ° C.), the conductive adhesive, the package, and the second support body 15a
  • the stress generated from the hardened adhesive is spread from the second support body 15 a to the first and third supports 14 and 16 and the vibration area 12 due to the difference between the respective linear expansion coefficients.
  • a slit 20 for stress relaxation is provided.
  • the slit 20 is disposed close to the boundary (connecting portion) of the second support body 15a, the area of the supported portion (pad electrode) 29a of the second support body 15a is secured widely.
  • the diameter of the conductive adhesive to be applied can be increased.
  • the slit 20 is arranged closer to the supported portion (pad electrode) 29a of the second support main body 15a, the area of the supported portion (pad electrode) 29a becomes smaller, and the diameter of the conductive adhesive Must be made smaller.
  • the slit 20 be disposed close to the boundary (connecting portion) of the second support body 15a.
  • the piezoelectric vibration element In order to obtain stress (wedge strain) distribution occurring in the piezoelectric substrate 10, it is general to perform simulation using a finite element method. As the stress in the vibration region 12 is smaller, a piezoelectric vibration element having excellent frequency temperature characteristics, frequency reproducibility and frequency aging characteristics can be obtained.
  • the conductive adhesive there are silicone type, epoxy type, polyimide type, bismaleimide type, etc., taking into consideration the frequency secular change due to the degassing of the piezoelectric vibration element 1 and using the polyimide type conductive adhesive. . Since the polyimide conductive adhesive is hard, the magnitude of the stress generated by one support can be reduced rather than supporting two separate places.
  • a structure of one support is used for the piezoelectric vibration element 1 for a high frequency band of 100 to 500 MHz, for example, a voltage controlled crystal oscillator (VCXO) of 490 MHz. That is, the pad electrode 29a is mechanically fixed to the element mounting pad of the package using conductive adhesion and electrically connected, and the other pad electrode 29b is electrically connected using the electrode terminal of the package and the bonding wire. I decided to connect to
  • the outer shape of the piezoelectric substrate 10 shown in FIG. 1 is a so-called X-long in which the length in the X-axis direction is longer than the length in the Z'-axis direction.
  • the stress is generated when the piezoelectric substrate 10 is fixed and connected with a conductive adhesive or the like, but as is well known, the frequency when the force is applied to both ends along the X-axis direction of the AT cut quartz substrate.
  • the frequency change is smaller when the force is applied to both ends in the Z ′ axis direction. That is, it is preferable to provide the support point along the Z 'axis direction because the frequency change due to stress becomes smaller.
  • FIG. 3A is a plan view showing the configuration of the lead electrodes 27a and 27b and the pad electrodes 29a and 29b formed on the piezoelectric substrate 10.
  • the lead electrode 27 a extends from the edge of the excitation electrode 25 a on the surface, passes through the surface of the third support 16, and continues to the pad electrode 29 a provided on the surface of the center of the second support 15. It is formed to set up.
  • the lead electrode 27b extends from the edge of the excitation electrode 25b on the back surface, and is connected to the pad electrode 29b provided on the back surface of the central portion of the second support 15 via the end portion on the back surface. It is formed as.
  • Each of the lead electrodes 27a and 27b includes a first layer made of a thin film of chromium (Cr) and a second layer made of a thin film of gold (Au) stacked on the first layer.
  • a chromium thin film (chromium film) 27c is used as a base on the surface side (upper surface side) of the second support body 15a.
  • a thin film of gold (gold film) 27g is deposited on top to form a lead electrode 27a.
  • the pad electrodes 29a and 29b provided on the front and back surfaces of the central portion of the second support portion 15 are each formed of a first layer made of a chromium (Cr) thin film, and gold (laminated on this first layer). And a second layer made of a thin film of Au).
  • a chromium thin film 29c is used as a base on the surface side (upper surface side) of the second support body 15a.
  • a thin film 29g is deposited to form a pad electrode 29a.
  • FIG. 3 (b) is a plan view showing the configuration of the excitation electrodes 25a, 25b formed on the piezoelectric substrate 10 so as to be aligned with the lead electrodes 27a, 27b and the pad electrodes 29a, 29b formed in the previous step. It is.
  • the excitation electrode 25a is formed on the front surface
  • the excitation electrode 25b is formed on the back surface sufficiently larger than the excitation electrode 25a.
  • the excitation electrodes 25a, 25b are formed such that at least a part thereof overlaps with the lead electrodes 27a, 27b formed in the previous step. For example, as shown in FIG.
  • the excitation electrode 25a has a portion 27a 'of the lead electrode extended from the end.
  • a portion 27a 'of the lead electrode is configured to overlap the surface of the lead electrode 27a.
  • the excitation electrode 25a and the lead electrode 27a can be electrically connected reliably, and a conduction defect can be prevented.
  • the same configuration is applied to the excitation electrode 25b formed on the back surface side (flat surface side).
  • a part of the lead electrode 27b previously formed in the previous step may be formed so as to enter (overlap) the region of the excitation electrode 25b.
  • the amount of plateback which determines the resonance frequency depends only on the mass effect of the excitation electrode 25a formed on the main surface on the concave side which is the surface side, so the amount of plateback does not change from the design value
  • a part of the lead electrode 27 b is configured to be positioned outside the outer shape of the excitation electrode 25 a so that the excitation electrode 25 a and the piezoelectric substrate 10 do not overlap with each other.
  • One example of the configuration of the excitation electrodes 25a and 25b includes a first layer made of a thin film of nickel (Ni) and a second layer made of a thin film of gold (Au) stacked on the first layer. .
  • An example of the film thickness is 70 ⁇ for the thin film of nickel (Ni) in the first layer, and 600 ⁇ for the thin film of gold (Au). Note that another metal film may be sandwiched between the nickel (Ni) thin film and the gold (Au) thin film.
  • the fundamental wave frequency of the vibration area 12 of the piezoelectric substrate 10 is a high frequency band of extremely high frequency of 490 MHz, respective electrode materials of the lead electrodes 27a and 27b, the pad electrodes 29a and 29b, and the excitation electrodes 25a and 25b.
  • the reason for making the electrode film thickness different will be described below.
  • lead electrodes 27a and 27b, pad electrodes 29a and 29b, and excitation electrodes 25a and 25b are formed of, for example, a thin film of nickel (Ni) of 70 ⁇ in the first layer and a thin film of gold (Au) of 600 ⁇ in the second layer, although the main vibration is sufficiently confined and the crystal impedance (CI; equivalent resistance) is also reduced, the thin film of gold (Au) of the lead electrodes 27a and 27b may cause an ohmic loss of the thin film.
  • the pad electrodes 29a and 29b are formed of a thin film of nickel (Ni) of 70 ⁇ in the first layer and a thin film of gold (Au) of 600 ⁇ in the second layer, the bonding strength is insufficient when performing wire bonding. .
  • the lead electrodes 27a and 27b, the pad electrodes 29a and 29b, and the excitation electrodes 25a and 25b are formed of, for example, a thin film of chromium (Cr) of 70 ⁇ in the first layer and a thin film of gold (Au) of 600 ⁇ in the second layer. Then, since the thin film of gold (Au) is thin, chromium (Cr) is diffused into the thin film of gold (Au) by heat, which may cause a large CI of main vibration.
  • the pad electrodes 29a and 29b formed of a thin film of nickel (Ni) of 70 ⁇ in the first layer and a thin film of gold (Au) of 600 ⁇ in the second layer bonding strength is insufficient.
  • the steps of forming the lead electrodes 27a and 27b and the pad electrodes 29a and 29b and the excitation electrodes 25a and 25b are separated, and the material and thickness of each electrode thin film are functions of the respective thin films.
  • the lead electrodes 27a and 27b and the pad electrodes 29a and 29b were set thickly to a film thickness of 100 ⁇ of chromium (Cr) and a film thickness of 2000 ⁇ of gold (Au) in order to reduce the film resistance of the thin lead electrodes. That is, the excitation electrodes 25a, 25b are composed of 70 ⁇ of nickel (Ni) in the first layer and gold (Au) of 600 ⁇ in the second layer, and a portion 27a ′ of the lead electrode extended from the excitation electrode 25a.
  • a portion where the lead electrode 27a and a part 27d of the lead electrode extended from the excitation electrode 25b overlap the lead electrode 27b in a partial region is chromium (Cr) with a film thickness of 100 ⁇ , and a film thickness with a second layer It has a four-layer structure in which gold (Au) of 2000 ⁇ , nickel (Ni) of 70 ⁇ in thickness, and gold (Au) of 600 ⁇ in thickness are stacked in the third layer. Also in this case, a thin film of another metal may be sandwiched between chromium (Cr) and gold (Au) or nickel (Ni) and gold (Au).
  • the above-mentioned film thickness is an example, and it is not limited to this numerical value.
  • the excitation electrodes 25a and 25b a laminated film of nickel (Ni) and gold (Au) of an optimum film thickness was used in consideration of the energy confinement theory and the ohmic loss of the thin film. Further, the film thickness of the lead electrodes 27a and 27b and the pad electrodes 29a and 29b is a laminated film of chromium (Cr) and gold (Au) having a necessary thickness in consideration of the ohmic loss of the thin film and the bonding strength. Using. The manufacturing method of excitation electrode 25a, 25b, lead electrode 27a, 27b, and pad electrode 29a, 29b is mentioned later.
  • the excitation electrodes 25a and 25b have a quadrangular shape, that is, a square or a rectangular shape (with the long side in the X-axis direction), but it is not necessary to limit to this.
  • the excitation electrode 25a on the front side is circular
  • the excitation electrode 25b on the back side is a square that is sufficiently larger than the excitation electrode 25a.
  • the excitation electrode 25b on the back surface side may also be a sufficiently large circle.
  • the excitation electrode 25a on the front surface side is elliptical
  • the excitation electrode 25b on the back surface side is a square that is sufficiently larger than the excitation electrode 25a.
  • the excitation electrode 25a may be oval.
  • FIG. 6 is a schematic plan view showing the configuration of a modification of the piezoelectric vibrating element 1 shown in FIG.
  • the modified example of FIG. 6 differs from the piezoelectric vibration element 1 shown in FIG. 1 in the position where the stress relaxation slit 20 is provided.
  • the slit 20 is formed in the second inclined portion 15 b which is separated from the end edge of the side 12 b of the thin vibration area 12.
  • both end edges of the second inclined portion 15b are provided further apart. That is, in the second inclined portion 15b, an extremely thin inclined portion 15bb connected to the end edge of the side 12b of the vibration area 12 is left. In other words, the extremely thin inclined portion 15bb is formed between the side 12a and the slit 20.
  • 7A and 7B are schematic plan views showing the configuration of another modification of the piezoelectric vibrating element 1 shown in FIG. 1, respectively.
  • 7A differs from the piezoelectric vibration element 1 shown in FIG. 1 in that the first slit 20a is provided in the plane of the second support portion main body 15a, and the second inclined portion 15b is formed.
  • the second slits 20b are formed in the plane, and two stress relaxation slits are provided.
  • the first slits 20a and the second slits 20b are not arranged side by side in the X-axis direction as in the plan view shown in FIG. 7A, but are disposed stepwise apart from each other in the Z'-axis direction.
  • the configuration of the modification shown in FIG. 7B is a piezoelectric vibration element in which the effects of the slits 20 shown in FIG. 1 and FIG. 6 are respectively obtained, and the slits 20 have a second inclined portion 15b and It is configured to straddle the second support main body 15a.
  • FIG. 8 is a schematic view showing the configuration of the piezoelectric vibrating element 2 according to the second embodiment.
  • FIG. 8 (a) is a plan view of the piezoelectric vibrating element 2
  • FIG. 8 (b) is a cross-sectional view of the PP cross section viewed from the + X axis direction
  • FIG. 8 (c) is a PP cross section. It is a cross-sectional view seen from the axial direction
  • the same figure (d) is a cross-sectional view showing the QQ cross-section from the + Z ′ axis direction.
  • the piezoelectric vibration element 2 includes a thin vibration region 12 and a piezoelectric substrate 10 having a thick support portion 13 connected to the vibration region 12, and an excitation electrode formed to face both main surfaces of the vibration region 12. 25a, 25b, lead electrodes 27a, 27b extended from the excitation electrodes 25a, 25b to the thick support portion 13, and pad electrodes 29a, 29b connected to respective ends of the lead electrodes 27a, 27b, Is equipped.
  • the piezoelectric substrate 10 includes a rectangular thin-walled flat vibration region 12 and a square annular thick support portion 13 integrated along the four sides of the periphery of the vibration region 12.
  • the thick support portion 13 includes a first support portion 14 and a second support portion 15 which are provided on the two principal surfaces of the main surface of the vibration area 12 so as to project along the two opposing sides 12a and 12b.
  • a third supporting portion 16 provided in a protruding manner so as to connect between both end portions of the first and second supporting portions 14 and 15 on one main surface side (surface side) of the vibration area 12;
  • a fourth support portion 17 provided to project along the other principal surface side (rear surface side) of one side 12d of the vibration area 12 opposed to the support portion 16 of the fourth embodiment.
  • the first support portion 14 is connected to one side 12 a of the thin flat plate-like vibration region 12 and is provided to protrude on both main surfaces.
  • a first inclined portion 14b whose thickness gradually increases as it is separated from one side 12a of the vibration region 12, and a thick support portion 14b having a thick rectangular prism-like first supporting portion main body 14a connected to the other end edge of the first inclined portion 14b; Is equipped. That is, as shown in FIG. 8 (d), the first support portion 14 is formed to protrude on both principal surface sides of the vibration area 12.
  • the second support portion 15 is connected to one side 12 b of the thin flat plate-like vibration region 12 and is provided to protrude on both main surface sides.
  • a second inclined portion 15b whose thickness gradually increases as it is separated from one side 12b of the vibration area 12, and a thick square prism second supporting portion main body 15a connected to the other end edge of the second inclined portion 15b; Is equipped.
  • the third support portion 16 is connected to the side 12c on the surface side of the thin flat plate-like vibration region 12 and has a third inclined portion 16b whose thickness gradually increases with distance from the side 12c of the vibration region 12; And a third supporting portion main body 16a having a thick-walled square pillar shape connected to the other end edge of the inclined portion 16b. That is, the third support portion 16 is formed to protrude on one main surface side (surface side) of the vibration area 12.
  • the fourth support portion 17 is provided continuously with one side 12 d of the vibration area 12 so as to face the third support portion 16 on the back surface side of the thin vibration area 12, from the side 12 d of the vibration area 12 It has a fourth inclined portion 17b whose thickness gradually increases as it is separated, and a thick quadrangular prism-like fourth supporting portion main body 17a connected to the other end edge of the fourth inclined portion 17b.
  • the third support portion 16 and the fourth support portion 17 are in point-symmetrical relation with respect to the middle point of the vibration region 12, and the first, second, third and fourth support portions 14, 15, 16 And 17 are configured such that their respective ends are connected to form a square ring, and the vibration area 12 is held at the central part thereof.
  • the support main body (the first support main body 14a to the fourth support main body 17a) refers to a region having a constant thickness parallel to the Y ′ axis.
  • the thin vibration area 12 is surrounded by the first, second, third, and fourth supporting portions 14, 15, 16, 17 on the four sides of its peripheral edge. That is, etching is performed from both the front and back sides of the rectangular flat plate-like piezoelectric substrate to form two recessed portions facing both main surfaces, and unnecessary portions are eliminated to form a thin vibration region 12 for downsizing. ing. Furthermore, in the piezoelectric substrate 10, at least one stress relief slit 20 is formed through the second support portion 15. In the embodiment shown in FIG. 8, the slit 20 is formed in the plane of the second support portion body 15a along the boundary portion (connected portion) between the second inclined portion 15b and the second support portion body 15a. It is done.
  • FIG. 7 since the example which forms the slit for stress relaxation in the site
  • the surfaces of the first and second support bodies 14a and 15a and the surface of the third support body 16a are on the same plane, and the back surfaces of the first and second support bodies 14a and 15a And the back surface of the fourth support body 1a are on the same plane.
  • the configurations of the excitation electrodes 25a and 25b, the lead electrodes 27a and 27b, and the pad electrodes 29a and 29b of the piezoelectric vibrating element 2 shown in FIG. 8 are similar to those of the piezoelectric vibrating element 1 of FIG. That is, the steps of forming the lead electrodes 27a and 27b and the pad electrodes 29a and 29b and the excitation electrodes 25a and 25b are separated, and the material and thickness of each thin film become optimum for the function of each thin film. Is set as.
  • the lead electrodes 27a and 27b and the pad electrodes 29a and 29b are composed of 100 ⁇ of chromium (Cr) in the first layer and 2000 ⁇ of gold (Au) in the second layer.
  • the excitation electrodes 25a, 25b are composed of 70 ⁇ of nickel (Ni) in the first layer and gold (Au) of 600 ⁇ in the second layer, and a portion 27a ′ of the lead electrode extended from the excitation electrode 25a.
  • a portion where the lead electrode 27a and a part 27d of the lead electrode extended from the excitation electrode 25b overlap the lead electrode 27b in a partial region is chromium (Cr) with a film thickness of 100 ⁇ , and a film thickness with a second layer It has a four-layer structure in which gold (Au) of 2000 ⁇ , nickel (Ni) of 70 ⁇ in thickness, and gold (Au) of 600 ⁇ in thickness are stacked in the third layer.
  • a thin film of another metal may be sandwiched between chromium (Cr) and gold (Au) or nickel (Ni) and gold (Au). Also in this case, a thin film of another metal may be sandwiched between chromium (Cr) and gold (Au) or nickel (Ni) and gold (Au).
  • the shapes of the excitation electrodes 25a and 25b may be similar to those of the piezoelectric vibrating element 1 of FIGS. 4 and 5, and the slits for stress relaxation also have the same positions as those of FIGS. At least one may be formed in
  • the lead electrode can withstand wire bonding. It has the effect of
  • the first lead electrode having the same thickness as the excitation electrode 25a with the film thickness t1 is set to an appropriate plateback amount, and the film thickness t2 of the lead electrodes 27a and 27b is a film thickness without ohmic loss. By being set, there is an effect that the CI value of the piezoelectric vibrating element becomes small.
  • first lead electrode (leader) and the second lead electrode 27a are laminated in a part, there is no conduction failure between the excitation electrode 25a and the lead electrode 27a, and the CI value can be reduced. As a result, there is an effect that a piezoelectric vibration element with less spurious can be obtained.
  • the first layer and the second layer of the lead electrode 27a are sequentially stacked in a portion of the stacked portion of the lead electrode 27a, and then the third layer and the fourth layer are sequentially stacked of the excitation electrode 25a. Therefore, the conductivity of the laminated portion is sufficient.
  • the adhesive force between the lead electrode and the piezoelectric substrate is enhanced, so that the wire bonding can be sufficiently resisted.
  • first layer, the second layer, the third layer, and the fourth layer are sequentially stacked in a part of the stacked portion of the lead electrode 27a, and the strength and the conductivity of the stacked portion are sufficient.
  • a piezoelectric vibration element having a small CI value can be obtained.
  • Nickel or chromium is used as the material for the first layer and the third layer of a portion of the laminated portion of the lead electrode 27a, and the adhesion to the piezoelectric substrate and the adhesion between the layers are excellent.
  • gold is used as a material for the second layer and the fourth layer of a portion of the laminated portion of the lead electrode 27a, which has the advantage of being extremely excellent in terms of conductivity and aging.
  • the first to fourth support portions 14 to 17 which are thicker than the vibration portion have an effect of facilitating the support and fixation of the piezoelectric vibration element by the thick support portion. Furthermore, when excitation electrodes 25a and 25b and lead electrodes 27a and 27b are set to appropriate film thicknesses, the CI value of the main vibration is small, and the ratio of the CI value of the near spurious to the CI value of the main vibration, There is an effect that a large piezoelectric vibrating element can be obtained. Furthermore, there is an advantage that the high frequency piezoelectric vibrating element using the fundamental wave is miniaturized. Further, as shown in FIG.
  • the piezoelectric vibration element can be miniaturized and a piezoelectric vibration element having a small CI value can be obtained.
  • the thickness of the second support portion 15 is thicker than the thickness of the vibration area 12 as shown in FIG. 1, the support of the vibration area 12 is robust by supporting and fixing the second support portion 15. There is an effect that a high frequency piezoelectric vibration element can be obtained.
  • one side (thin side) of the second inclined portion 15b is continuously provided in the vibration area 12, and the second support main body 15a is continuously provided in the other side (thick side) of the second inclined portion 15b.
  • the piezoelectric vibrating element Because the stress due to the holding of the piezoelectric vibrating element is absorbed almost by the second support body 15a and the second inclined portion 15b, the piezoelectric vibrating element has a small CI value and a smooth temperature curve of a cubic curve. Has the effect of Further, as shown in FIG. 2, by forming the piezoelectric substrate, it is possible to configure the required specification with a more suitable cut angle, and has frequency temperature characteristics in accordance with the specification, and a small CI value, There is an effect that a high frequency piezoelectric vibrating element having a large CI value ratio can be obtained. Further, as shown in FIG.
  • the projecting portion (fourth support portion 17) is provided continuously to the vibration region 12 and provided on the minus side of the Z 'axis, piezoelectric vibration that is robust against external vibration and impact is provided. There is an effect that a device can be obtained. Further, by providing the slits 20 in the second support portion 15, the slits 20 have an effect of suppressing the spread of the stress generated when the second support portion 15 is fixed using a conductive adhesive or the like. .
  • FIG. 9 is a manufacturing process diagram according to the formation of the outer shape of the piezoelectric substrate 10 and the formation of slits (not shown) while forming the recessed portions 11 and 11 ′ on both surfaces of the piezoelectric substrate 10.
  • a quartz wafer is taken as an example of a piezoelectric wafer, and the drawing shows only a cross section.
  • step S1 a crystal wafer 10W having a predetermined thickness polished on both sides, for example, 80 ⁇ m, is sufficiently cleaned and dried, and then chromium (Cr) is used as a base on the front and back by sputtering or the like.
  • a metal film (corrosion resistant film) M in which gold (Au) is laminated is formed respectively.
  • a photoresist film (referred to as a resist film) R is coated on both surfaces of the metal film M on the front and back surfaces.
  • step S3 the resist film R at the portion corresponding to the recessed portion on the front and back surfaces is exposed using the exposure device and the mask pattern.
  • the metal films M at positions corresponding to the recessed portions on the front and back surfaces are exposed.
  • the gold layer films M exposed from the respective resist films R are dissolved and removed using a solution such as aqua regia, the quartz surface at the position corresponding to the recessed portions on the front and back surfaces is exposed.
  • step S4 the exposed quartz crystal surface is etched from the front and back surfaces to a desired thickness using a mixed solution of hydrofluoric acid (hydrofluoric acid) and ammonium fluoride.
  • step S5 the resist films R on both sides are peeled off using a predetermined solution, and the exposed metal films M on both sides are removed using aqua regia or the like.
  • the crystal wafer 10W is slightly deviated on both main surfaces to form the recessed portions 11 and 11 ', respectively, and they are arranged regularly in a lattice.
  • metal films M Cr + Au
  • step S7 a resist film R is applied to both surfaces of the metal film M (Cr + Au) formed in step S6.
  • step S8 each resist film R at a portion corresponding to the outer shape of the piezoelectric substrate 10 and a slit (not shown) is exposed from both sides and developed using an exposure apparatus and a predetermined mask pattern. Peel the membrane R. Furthermore, the exposed metal film M is dissolved and removed with a solution such as aqua regia.
  • step S9 the exposed quartz crystal face is etched using a mixture of hydrofluoric acid (hydrofluoric acid) and ammonium fluoride to form the outer shape of the piezoelectric substrate 10 and a slit.
  • step S10 the remaining resist film R is peeled off, and the exposed excess metal film M is dissolved and removed.
  • the piezoelectric substrates 10 are connected by the support strip and are regularly arranged in a lattice.
  • third and fourth members are formed on the both main surfaces of the piezoelectric substrate 10 with the recessed portions 11 and 11 'respectively forming the vibrating region 12 and connected to the vibrating region 12.
  • the support portions 16 and 17 are formed point-symmetrically with respect to the center of the piezoelectric substrate 10.
  • the thickness of the vibration area 12 of each piezoelectric substrate 10 regularly arranged in a lattice shape on the quartz wafer 10W is measured, for example, using an optical method.
  • the thickness of each measured vibration area 12 is thicker than a predetermined thickness, the thickness is finely adjusted to fall within the predetermined thickness range.
  • step S11 a chromium (Cr) thin film is formed on the entire front and back surfaces of the quartz wafer 10W by sputtering or the like, and a gold (Au) thin film is stacked thereon to form a metal film M.
  • step S12 a resist is applied on the metal film M, and a resist film R is formed.
  • step 13 the resist film R at a portion corresponding to the lead electrode and the pad electrode is exposed using the lead electrode and the mask pattern Mk for the pad electrode.
  • step 14 the resist film R is developed, and the unnecessary resist film R is peeled off.
  • the metal film M exposed by this peeling is dissolved and removed with a solution such as aqua regia.
  • the lead electrode and the pad electrode are left as they are.
  • a nickel (Ni) thin film is formed on the entire front and back surfaces of the quartz wafer 10W by sputtering or the like, a gold (Au) thin film is stacked thereon, and a metal film M is formed.
  • the metal film and the resist film (M + R) are represented using a symbol C in order to avoid complication.
  • a resist is applied on the metal film M, and a resist film R is formed.
  • the resist film R at the portion corresponding to the excitation electrodes 25a and 25b is exposed.
  • the exposed resist film R is developed and the unnecessary resist film R is stripped using a solution.
  • step S17 the metal film M exposed by peeling off the resist film R is dissolved and removed with a solution such as aqua regia.
  • step S18 the symbol C is represented back to (M + R).
  • excitation electrodes 25a and 25b of (Ni + Au) are formed on the respective piezoelectric substrates 10,
  • the lead electrodes 27a and 27b of Cr + Au) and the pad electrodes 29a and 29b are formed (step S19).
  • the split piezoelectric vibrating element 2 is obtained by breaking the half-etched support strip connected to the quartz wafer 10W.
  • the feature of the piezoelectric vibration element 2 according to the second embodiment of the present invention is that the etching proceeds from both main surfaces of the piezoelectric substrate 10 to form concave portions 11 and 11 ′ facing each other on both main surfaces. As a result, the processing time required for etching can be halved. Further, as shown in FIG. 11 (d), it is one of the features that the piezoelectric substrate can be miniaturized by removing both the outer sides in the two broken lines indicated by Zc1 and Zc2 by etching. Since the etching is advanced from both main surfaces of the piezoelectric substrate 10, the depth to be excavated from the respective main surfaces of the piezoelectric substrate 10 can be made shallow, so that the individual pieces in the wafer are laid out during manufacturing.
  • FIGS. 11 (c) and 11 (d) a manufacturing method was established on the premise that the both ends in the figure unnecessary as the vibration area were deleted. Compared to the structure provided with the thick part of the prior art mentioned as the prior art, the size of the piezoelectric vibration element 1 can be reduced while securing the area of the flat ultra-thin part to be the vibration area .
  • the change in the frequency circumference when the force is applied to both ends in the X-axis direction of the AT cut quartz substrate (the stress / strain caused by mounting is described as the force), and the Z 'axis Comparing the frequency change when the same force is applied to both ends of the direction
  • the X direction of the piezoelectric substrate 10 can be reduced because the frequency change can be reduced when the force is applied to both ends in the Z ′ axis direction. Since the length in the direction is a so-called X-long, which is longer than the length in the Z'-axis direction, the area of the vibrating portion can be widely secured in the X-axis direction.
  • a thick support portion is provided on at least one of the front and back with respect to the main surface of the vibrating portion over the entire circumference of the vibrating portion of the piezoelectric vibrating element 1 according to the present invention Since the end of the portion is not exposed to the outside, when the piezoelectric vibrating element 1 is manufactured, or the piezoelectric vibrating element 1 is mounted on a container to manufacture a piezoelectric vibrator, etc. Also from the viewpoint of the reliability such as impact resistance of the piezoelectric vibration element 1 due to impact or the like, since the strength is maintained high, the reliability can be maintained high.
  • FIG. 11 is a more detailed view of the piezoelectric vibrating element 2 shown in FIG. 8, wherein FIG. 11 (a) is a perspective view, and FIG. 11 (b) is a cutaway view of the QQ cross section in FIG. It is.
  • FIG. 11B in the outer shape of the piezoelectric vibrating element 2, an inclined surface appears on the end face intersecting the X axis. That is, the inclined surface A1 appears on the end surface on the ⁇ X axis side, and the inclined surface A2 appears on the end surface on the + X axis side.
  • the cross-sectional shapes parallel to the XY ′ plane of the inclined surface A1 and the inclined surface A2 are different.
  • the inclined surfaces a1 and a2 constituting the inclined surface A1 are substantially symmetrical with respect to the X axis, and in the inclined surfaces b1, b2, b3 and b4 constituting the inclined surface A2, b1 and b4, b2 and b3 are It was found that each was approximately symmetrical with respect to the X axis. Furthermore, the inclination angle ⁇ of the inclined surfaces a1 and a2 with respect to the X axis and the inclination angle ⁇ of the inclined surfaces b1 and b4 with respect to the X axis have a relationship of ⁇ ⁇ .
  • the excitation electrodes 25a, 25 and the lead electrodes 27a, 27b and the pad electrodes 29a, 29b respectively use different metal materials and have appropriate thickness. Since the configuration is made, there is an effect that a piezoelectric vibration element having a small CI value of the main vibration and a large ratio of the CI value of the near spurious to the CI value of the main vibration, that is, a large CI value ratio can be obtained.
  • the high frequency piezoelectric vibrating element using the fundamental wave is miniaturized, and by providing the slit between the support portion and the vibration region, the spread of stress due to adhesion and fixation can be suppressed, so that the frequency temperature characteristic There is an effect that a piezoelectric vibration element excellent in CI temperature characteristics and frequency aging characteristics can be obtained.
  • the excitation electrodes 25a and 25b are laminated films of nickel and gold, and the lead electrodes 27a and 27b and the pad electrodes 29a and 29b are chromium and gold.
  • the piezoelectric vibration element which has a small CI value of the main vibration and a large ratio of the adjacent spurious CI value to the CI value of the main vibration, that is, a large CI value ratio. It has the effect of Further, the high-frequency piezoelectric vibrating element using the fundamental wave is miniaturized, and the support of the vibrating region is strong, so that the piezoelectric vibrating element resistant to vibration, impact and the like can be obtained.
  • the piezoelectric substrate 10 is formed as shown in the cutting angle diagram of FIG. 2, it is possible to configure the required specification with a more suitable cut angle, and has frequency temperature characteristics conforming to the specification, and CI There is an effect that a high frequency piezoelectric vibrating element having a small value and a large CI value ratio can be obtained.
  • a quartz AT-cut quartz substrate as a piezoelectric substrate, it is possible to utilize the results and experiences of photolithography technology and etching technique, so that not only mass production of the piezoelectric substrate is possible but also a piezoelectric substrate with high accuracy is obtained.
  • the yield of the piezoelectric vibration element having a small CI value and a large CI value ratio is significantly improved.
  • FIG. 12 is a view showing the configuration of the piezoelectric vibrator 5 according to the embodiment of the present invention, and FIG. 12 (a) is a longitudinal sectional view, and FIG. 12 (b) is a plan view omitting a lid member.
  • the piezoelectric vibrator 5 includes, for example, the piezoelectric vibration element 2 (may be the piezoelectric vibration element 1) of FIG. 8 and a package for housing the piezoelectric vibration element 2.
  • the package comprises a package body 40 formed in a rectangular box shape and a lid member 49 made of metal, ceramic, glass or the like. As shown in FIG.
  • the package body 40 is formed by laminating a first substrate 41, a second substrate 42, and a third substrate 43, and is made of an aluminum oxide ceramic as an insulating material. -It forms by sintering, after shape
  • a plurality of mounting terminals 45 are formed on the outer bottom surface of the first substrate 41.
  • the third substrate 43 is an annular body from which the central portion is removed, and a metal seal ring 44 such as Kovar is formed on the upper peripheral edge of the third substrate 43.
  • the third substrate 43 and the second substrate 42 form a recess (cavity) for housing the piezoelectric vibrating element 2.
  • a plurality of element mounting pads 47 electrically connected to the mounting terminals 45 by the conductors 46 are provided at predetermined positions on the upper surface of the second substrate 42.
  • the position of the element mounting pad 47 is arranged to correspond to the pad electrode 29 a formed on the second support portion main body 14 a when the piezoelectric vibrating element 1 is mounted.
  • the conductive adhesive 30 is applied to the pad electrode 29 a of the piezoelectric vibrating element 2, and this is reversed (reversed) to be mounted on the element mounting pad 47 of the package main body 40.
  • the magnitude of the stress (strain of strain) caused by the adhesive 30 increases in the order of the silicone adhesive, the epoxy adhesive, and the polyimide adhesive.
  • degassing becomes large in order of a polyimide adhesive, an epoxy adhesive, and a silicone adhesive.
  • the conductive adhesive 30 it was decided to use a polyimide-based adhesive with little degassing in consideration of aging.
  • the conductive adhesive 30 of the piezoelectric vibrating element 2 mounted on the package main body 40 In order to cure the conductive adhesive 30 of the piezoelectric vibrating element 2 mounted on the package main body 40, it is placed in a high temperature furnace at a predetermined temperature for a predetermined time. After the conductive adhesive 30 is cured, the pad electrode 29b turned to the front surface side and the electrode terminal 48 of the package main body 40 are conductively connected by the bonding wire BW. As shown in FIG. 12B, the portion for supporting and fixing the piezoelectric vibrating element 2 to the package main body 40 is one point (one point), so the magnitude of the stress generated by the supporting and fixing can be reduced. It becomes. After annealing, mass is added to the excitation electrodes 25a and 25b or mass is reduced to perform frequency adjustment.
  • the lid member 49 is placed on the seal ring 44 formed on the upper surface of the package body 40, and the lid member 49 is seam welded and sealed in vacuum or in an atmosphere of nitrogen N 2 gas, and the piezoelectric vibrator 5 Complete.
  • the lid member 49 is also a method of placing the lid member 49 on the low melting point glass applied to the upper surface of the package body 40, melting and adhering.
  • the inside of the package cavity is evacuated or filled with an inert gas such as nitrogen N 2 gas to complete the piezoelectric vibrator 5.
  • pad electrodes 29a and 29b are formed to face the upper and lower surfaces of the piezoelectric substrate 10, respectively.
  • the piezoelectric vibrating element 2 is housed in the package, the piezoelectric vibrating element 2 is turned over, and the pad electrode 29a and the element mounting pad 47 of the package are fixed and connected with a conductive adhesive.
  • the pad electrode 29b on the front side and the electrode terminal 48 of the package are connected by the bonding wire BW.
  • the portion supporting the piezoelectric vibration element 1 becomes one point, the stress caused by the conductive adhesive decreases.
  • the piezoelectric vibrating element 2 is turned over and the larger excitation electrode 25 b is placed on the top surface when housed in a package, the frequency fine adjustment of the piezoelectric vibrating element 1 is facilitated.
  • the piezoelectric vibrating element may be configured such that the pad electrodes 29a and 29b are spaced apart from each other.
  • a piezoelectric vibrator can be configured as in the case of the piezoelectric vibrator 5 described with reference to FIG.
  • a piezoelectric vibration element may be formed in which the pad electrodes 29a and 29b are formed on the same surface at an interval.
  • the piezoelectric vibration element has a structure in which a conductive adhesive is applied to two places (two points) to achieve conduction, support, and fixation. Although the structure is suitable for reducing the height, the stress due to the conductive adhesive may be slightly increased.
  • the piezoelectric vibrator 5 In the embodiment of the piezoelectric vibrator 5 described above, an example in which a laminated plate is used for the package main body 40 has been described, but a single-layer ceramic plate is used for the package main body 40 and a cap subjected to drawing processing is used for the lid. Thus, the piezoelectric vibrator may be configured.
  • the electrode material of the excitation electrodes 25a, 25b and the electrode materials of the lead electrodes 27a, 27b and the pad electrodes 29a, 29b are made different or their film thicknesses.
  • the piezoelectric vibration elements 1 and 2 configured to be optimal for each function are used, the CI value of the main vibration is small, and the ratio of the adjacent spurious CI value to the main vibration CI value, ie, the CI value ratio There is an effect that a large piezoelectric vibration element 2 can be obtained.
  • the high-frequency piezoelectric vibrator is miniaturized, and as shown in the embodiment shown in FIG.
  • the portion supporting the piezoelectric vibration element is one point, and a slit is provided between the support portion and the vibration region. Since the stress generated due to the conductive adhesive can be reduced, it is possible to obtain a piezoelectric vibrator excellent in frequency reproducibility, frequency temperature characteristics, CI temperature characteristics, and frequency aging characteristics.
  • FIG. 13 is a longitudinal sectional view showing an embodiment of the piezoelectric device 6 according to the present invention.
  • the electronic device 6 includes the piezoelectric vibrating element 2 (which may be the piezoelectric vibrating element 1) of the present invention and one of the electronic components, the thermistor Th which is a temperature sensitive element, the piezoelectric vibrating element 2 and the thermistor Th. And a package to be accommodated.
  • the package includes a package body 40 a and a lid member 49.
  • the package body 40a has a cavity 31 for receiving the piezoelectric vibrating element 1 on the upper surface side, and a recess 32 for receiving the thermistor Th on the outer lower surface side.
  • a plurality of element mounting pads 47 are provided at the end of the inner bottom surface of the cavity 31, and each element mounting pad 47 is conductively connected to the plurality of mounting terminals 45 by an internal conductor 46.
  • the conductive adhesive 30 is applied to the pad electrode 29 a of the piezoelectric vibrating element 2, and this is inverted and placed on the element mounting pad 47.
  • a seal ring 44 made of Kovar or the like is fired on the upper portion of the package body 40a.
  • a lid member 49 is placed on the seal ring 44 and welded using a resistance welder or the like to hermetically seal the cavity 31. Do.
  • the inside of the cavity 31 may be evacuated or may be filled with an inert gas.
  • the terminal of the thermistor Th is connected to the recess 32 on the back surface using a solder ball or the like to complete the electronic device 6.
  • the recess 32 is formed on the outer lower surface side of the package body 40a and the electronic component is mounted. However, the recess 32 is formed on the inner bottom surface of the package body 40a to mount the electronic component.
  • the electronic component accommodated in the package body 40a includes at least one of a thermistor, a capacitor, a reactance element, and a semiconductor element It is desirable to house the electronic device to accommodate the
  • the thermistor Th of the temperature sensing element is very close to the piezoelectric vibrating element 2. Since they are arranged, there is an effect that the temperature change of the piezoelectric vibrating element 2 can be detected quickly. Further, by constituting an electronic device by the piezoelectric vibration element of the present invention and the above electronic component, a high frequency and small electronic device can be constituted, so that there is an effect that it can be used for various applications.
  • an electronic device piezoelectric device
  • any one of a variable capacitance element, a thermistor, an inductor, and a capacitor for an electronic component an electronic device suitable for the required specification can be realized in a small size and at low cost. It has the effect of
  • FIG. 14 is a view showing the configuration of a piezoelectric oscillator 7 which is a type of electronic device according to an embodiment of the present invention, wherein FIG. 14 (a) is a longitudinal sectional view and FIG. Is a plan view with no
  • the piezoelectric oscillator 7 includes the package body 40b, the lid member 49, the piezoelectric vibrating element 2, and an IC part 51 having an oscillating circuit for exciting the piezoelectric vibrating element 2, a variable capacitance element whose capacitance changes with voltage, temperature And at least one of an electronic component 52 such as a thermistor, an inductor or the like whose resistance changes.
  • the conductive adhesive (polyimide type) 30 is applied to the pad electrode 29a of the piezoelectric vibrating element 2, and this is inverted to be mounted on the element mounting pad 47 of the package main body 40b, and the pad electrode 29a and the element mounting pad 47 Conduct continuity.
  • the pad electrode 29b which is inverted to the upper surface side is connected to the other electrode terminal 48 of the package main body 40b by a bonding wire, so that conduction with one electrode terminal 55 of the IC component 51 is achieved.
  • the IC component 51 is fixed at a predetermined position of the package body 40b, and the terminal of the IC component 51 and the electrode terminal 55 of the package body 40b are connected by the bonding wire BW.
  • the electronic component 52 is placed at a predetermined position of the package body 40b, and connected using a metal bump or the like.
  • the package body 40 b is filled with vacuum or an inert gas such as nitrogen, and the package body 40 b is sealed with a lid 49 to complete the electronic device (piezoelectric oscillator) 7.
  • the portion supporting the piezoelectric vibrating element 2 becomes one point, and the stress generated due to the conductive adhesive is reduced.
  • the piezoelectric vibrating element 1 is inverted and the larger excitation electrode 25b is on the top when housed in the package, the frequency fine adjustment of the electronic device (piezoelectric oscillator) 7 is facilitated.
  • the electronic device (piezoelectric oscillator) 7 shown in the embodiment of FIG. 14 has the piezoelectric vibrating element 2, the IC component 51, and the electronic component arranged on the same piezoelectric substrate, but the electronic device (piezoelectric device of the embodiment shown in FIG.
  • the oscillator 7 uses the H-shaped package body 60, accommodates the piezoelectric vibrating element 1 in the cavity 31 formed in the upper part, fills the inside of the cavity with vacuum or nitrogen N 2 gas, and seals with the lid member 61.
  • an oscillator circuit for exciting the piezoelectric vibration element 2 an IC part 51 equipped with an amplifier circuit and the like, a variable capacitance element, and electronic parts 52 such as an inductor, a thermistor and a capacitor as needed are metal bumps ( Conduction and connection are made to the terminal 67 of the package body 60 through the Au bump 68.
  • the electronic device (piezoelectric oscillator) 7 of the present invention separates the piezoelectric vibrating element 2 from the IC component 51 and the electronic component 52, and hermetically seals the piezoelectric vibrating element 1 alone. The frequency aging characteristics are excellent.
  • a piezoelectric device for example, a voltage controlled piezoelectric oscillator
  • the frequency reproducibility, frequency temperature characteristics, and aging characteristics are excellent, and a small-sized voltage controlled piezoelectric of high frequency (for example, 490 MHz band)
  • a small-sized voltage controlled piezoelectric of high frequency for example, 490 MHz band
  • a piezoelectric oscillator it is possible to constitute a piezoelectric oscillator, a temperature compensation type piezoelectric oscillator, a voltage control type piezoelectric oscillator, etc. as a piezoelectric device, and a piezoelectric oscillator excellent in frequency reproducibility and aging characteristics, temperature compensation excellent in frequency temperature characteristics.
  • a piezoelectric oscillator a voltage controlled piezoelectric oscillator having a stable frequency, a wide variable range, and a good S / N ratio (signal-to-noise ratio).
  • FIG. 16 is a schematic configuration view showing the configuration of the electronic device according to the present invention.
  • the electronic device 8 includes the piezoelectric vibrator 5 described above. Examples of the electronic device 8 using the piezoelectric vibrator 5 include a transmission device and the like. In these electronic devices 8, the piezoelectric vibrator 5 is used as a reference signal source or a voltage variable piezoelectric oscillator (VCXO) or the like, and can provide a compact electronic device with excellent characteristics.
  • VCXO voltage variable piezoelectric oscillator
  • an electronic device having a high frequency stability at high frequency and a good reference frequency source of S / N ratio can be configured. It has the effect of
  • the piezoelectric substrate 10 in the embodiment of FIG. 17A is a piezoelectric substrate 10 provided with a thin portion having a vibration region 12 and a thick portion which is provided around the thin portion and thicker than the thin portion.
  • the mount portion F is connected side by side to the thick support portion 13 via the buffer portion S in the direction of the edge, and the buffer portion S is between the mount portion and the thick support portion.
  • the slit portion 20 is provided, and the mount portion F has chamfers 21 at both end portions in the direction orthogonal to the direction in which the mount portion F, the buffer portion S, and the thick support portion 13 are arranged.
  • the piezoelectric substrate 10 in FIG. 17B is a piezoelectric substrate 10 provided with a thin portion having a vibration region 12 and a thick support portion 13 provided on the periphery of the thin portion and thicker than the thin portion,
  • the mount portion F is connected side by side to the meat support portion 13 via the buffer portion S.
  • the buffer portion S has a slit 20 between the mount portion F and the thick support portion 13.
  • the mount portion is Notches 22 are provided at both ends orthogonal to the direction in which the mount portion F, the buffer portion S, and the thick support portion 13 are arranged, and the longitudinal direction of the slit 20 is parallel to the orthogonal direction.
  • the width in the orthogonal direction of the slit is narrower than the width in the longitudinal direction of the slit, and both end portions in the longitudinal direction of the slit are closer to the outer periphery in the orthogonal direction of the buffer portion S than the both ends of the mount portion F.
  • the piezoelectric substrate 10 shown in FIG. 17C is a piezoelectric substrate 10 having a thin portion having a vibration region 12 and a thick support portion 13 provided on the periphery of the thin portion.
  • the buffer portion S and the mount portion F are connected in order, the buffer portion S has a slit 20 between the mount portion F and the thick-walled support portion 13, and the mount portion F includes the mount portion F and the buffer portion S. It is characterized in that notches 22 are provided at both ends in the direction orthogonal to the direction in which the thick support portion 13 is arranged.
  • FIG. 18 is characterized in that it takes the form of a two-point support, ie, a mount portion F1 and a mount portion F2, with respect to the structure of FIG.
  • FIG. 17 and FIG. 18 while the inclined portions are illustrated on the inner walls of the support portions 14, 15 and 16 of the thick support portion 13, the side wall surface on the outer side of the thick support portion 13 is shown.
  • the inclined surfaces as shown in FIG. 12 are not shown, the inclined portions and the inclined surfaces are formed at corresponding portions as shown in FIG.
  • corresponds with the site
  • FIG. 19 (a) is a plan view of the piezoelectric vibrating element 2
  • FIG. 19 (b) shows an enlarged plan view of an embodiment of the pad electrode 29a (mount portion F) of the piezoelectric vibrating element 1
  • FIG. 6C shows a cross-sectional view of the mount portion F.
  • an area is obtained by making the surface uneven so as to improve the adhesive strength.
  • the present invention has been described by way of an inverted mesa type vibrator as an example, the present invention is not limited to this, and can be widely applied to a piezoelectric vibrator having an ultrathin flat piezoelectric substrate in a high frequency band of 100 to 500 MHz. Needless to say.
  • Vibration area, 12a, 12b, 12c, 12d one side of the vibration area, 13: support portion, 14: first support portion, 14a: first support portion main body, 14b: first inclined portion, 15: second Support portion 15a: second support portion main body, 15b: second inclined portion, 15b ′: extremely small piece, 16: third support portion, 16a: third support portion main body, 16b: third inclination Portion 17 17 fourth support portion 17a fourth support portion main body 17b fourth inclined portion 20 slit 20a first slit 20b second slit 21 chamfered portion 21 22 ... notched part, 25a, 25b ... excitation electrode, 27a, 27b, 27g ...

Landscapes

  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
  • Oscillators With Electromechanical Resonators (AREA)

Abstract

The present invention achieves a high-frequency miniature vibrating element for which the CI value is small and which suppresses frequency spurs in the vicinity with a fundamental wave. A piezoelectric vibrating element (1) is provided with a piezoelectric substrate (10) having a rectangular vibrating area (12) and a supporting portion (13), exciting electrodes (25a and 25b), and lead electrodes (27a and 27b). The supporting portion (13) is provided with a first supporting portion (14), a second supporting portion (15), and a third supporting portion (16). The second supporting portion (15) is provided with at least one slit (20). The exciting electrodes (25a and 25b) and the lead electrodes (27a and 27b) are configured so as to have differing electrode materials and film thicknesses.

Description

振動素子、振動子、電子デバイス、及び電子機器Vibrating element, vibrator, electronic device, and electronic device
　本発明は、厚みすべり振動モードで振動する振動子に関し、特に所謂逆メサ型構造を有する振動素子、振動子、電子デバイス、及び振動子を用いた電子機器に関する。 The present invention relates to a vibrator that vibrates in a thickness shear vibration mode, and more particularly to a vibrator having a so-called reverse mesa structure, a vibrator, an electronic device, and an electronic device using the vibrator.
　ＡＴカット水晶振動子は、励振する主振動の振動モードが厚みすべり振動であり、小型化、高周波数化に適し、且つ周波数温度特性が優れた三次曲線を呈するので、圧電発振器、電子機器等の多方面で使用されている。
　特許文献１には、主面の一部に凹陥部を形成して高周波化を図った所謂逆メサ構造のＡＴカット水晶振動子が開示されている。水晶基板のＺ’軸方向の長さが、Ｘ軸方向の長さより長い、所謂Ｚ’ロング基板を用いている。
　特許文献２には、矩形状の薄肉の振動部の三辺に各々厚肉の支持部が連設され、前記薄肉の振動部の一辺が露出した構造を有する逆メサ構造のＡＴカット水晶振動子が開示されている。更に、水晶振動片は、ＡＴカット水晶基板のＸ軸とＺ’軸を、夫々Ｙ’軸を中心に－１２０°～＋６０°の範囲で回転させてなる面内回転ＡＴカット水晶基板であり、振動領域を確保し、且つ量産性に優れた（多数個取り）構造であるという。 The AT-cut quartz oscillator has a thickness-shear vibration mode as the vibration mode of the main vibration to be excited, and it exhibits a cubic curve suitable for miniaturization and high frequency and has excellent frequency temperature characteristics. It is used in many ways.
Patent Document 1 discloses an AT-cut quartz oscillator having a so-called reverse mesa structure in which a high frequency is achieved by forming a recess in a part of the main surface. A so-called Z 'long substrate in which the length in the Z' axis direction of the quartz substrate is longer than the length in the X axis direction is used.
In Patent Document 2, an AT-cut quartz vibrator having an inverted mesa structure having a structure in which thick thick supporting portions are continuously provided on three sides of a rectangular thin vibrating portion, and one side of the thin vibrating portion is exposed. Is disclosed. Furthermore, the quartz crystal vibrating piece is an in-plane rotated AT-cut quartz substrate formed by rotating the X axis and Z ′ axis of the AT-cut quartz substrate in the range of −120 ° to + 60 ° around the Y ′ axis, It is said that it is a structure that secures a vibration area and is excellent in mass productivity (multi-piece).
　特許文献３、４には、矩形状の薄肉の振動部の三辺に各々厚肉の支持部が連設され、前記薄肉の振動部の一辺が露出した構造を有する逆メサ構造のＡＴカット水晶振動子が開示されており、水晶振動片は水晶基板のＸ軸方向の長さがＺ’軸方向の長さより長い、所謂Ｘロング基板が用いられている。
　特許文献５には、矩形状の薄肉の振動部の隣接する二辺に各々厚肉の支持部が連設され、平面視でＬ字状に厚肉部が設けられ、前記薄肉の振動部の二辺が露出した構造を有する逆メサ構造のＡＴカット水晶振動子が開示されている。水晶基板にはＺ’ロング基板が用いられている。
　しかしながら、特許文献５においては、Ｌ字状の厚肉部を得るために、特許文献５の図１（ｃ）、（ｄ）に記載されているように線分αと、線分βに沿って厚肉部を削除しているが、当該削除はダイシング等の機械加工で削除することを前提としているため、切断面にチッピングやクラック等のダメージを負い、超薄部が破損してしまう問題がある。また、振動領域にスプリアスの原因となる不要振動の発生やＣＩ値の増加等の問題が発生する。
　特許文献６には、薄肉の振動部の一辺のみに厚肉の支持部が連設され前記薄肉の振動部の三辺が露出した構造を有する逆メサ構造のＡＴカット水晶振動子が開示されている。 In Patent Documents 3 and 4, an AT-cut quartz of an inverted mesa structure having a structure in which thick thick supporting portions are provided continuously on three sides of a rectangular thin vibrating portion and one side of the thin vibrating portion is exposed. A vibrator is disclosed, and a so-called X-long substrate in which the length of the quartz substrate in the X-axis direction is longer than the length in the Z'-axis direction is used as the quartz crystal vibrating piece.
According to Patent Document 5, thick supporting portions are provided continuously on two adjacent sides of a rectangular thin vibrating portion, and an L-shaped thick portion is provided in plan view, and the thin vibrating portion An inverted mesa AT-cut quartz oscillator having a structure in which two sides are exposed is disclosed. A Z 'long substrate is used as a quartz substrate.
However, in Patent Document 5, in order to obtain an L-shaped thick-walled portion, as described in FIGS. 1 (c) and (d) of Patent Document 5, the line segment α and the line segment β are used. The thick part is deleted, but since the deletion is premised to be deleted by machining such as dicing, there is a problem that the ultra thin part is damaged by the damage such as chipping or crack on the cut surface There is. In addition, problems such as generation of unnecessary vibration and increase in CI value which cause spurious in the vibration region occur.
Patent Document 6 discloses an AT-cut quartz vibrator having an inverted mesa structure having a structure in which a thick supporting portion is continuously provided only on one side of a thin vibrating portion and three sides of the thin vibrating portion are exposed. There is.
　特許文献７には、水晶基板の両主面であって表裏面で対向するように凹陥部を形成することにより、高周波化を図った逆メサ構造のＡＴカット振動子が開示されている。水晶基板にはＸロング基板が用いられ、凹陥部に形成された振動領域の平坦性が確保された領域に励振電極が設けられ構造が提案されている。
　ところで、ＡＴカット水晶振動子の振動領域に励振される厚み滑り振動モードは、弾性定数の異方性により振動変位分布がＸ軸方向に長径を有する楕円状になることが知られている。特許文献８には、圧電基板の表裏両面に表裏対称に配置された一対のリング状電極を有する厚みすべり振動を励振する圧電振動子が開示されている。リング状電極が対称零次モードのみを励起し、それ以外の非調和高次モードをほとんど励起しないように、リング状電極の外周の径と内周の径との差を設定したものである。 Patent Document 7 discloses an AT-cut vibrator having a reverse mesa structure in which high frequency is achieved by forming recessed portions on both main surfaces of a quartz substrate so as to face each other on the front and back. An X long substrate is used as a quartz substrate, and a structure is proposed in which an excitation electrode is provided in a region where flatness of a vibration region formed in a recessed portion is secured.
By the way, it is known that the thickness slip vibration mode excited in the vibration area of the AT-cut quartz vibrator has an elliptical shape having a major axis in the X-axis direction due to the anisotropy of the elastic constant. Patent Document 8 discloses a piezoelectric vibrator for exciting thickness shear vibration, which has a pair of ring-like electrodes arranged symmetrically on the front and back sides of the piezoelectric substrate. The difference between the diameter of the outer periphery and the diameter of the inner periphery of the ring-shaped electrode is set so that the ring-shaped electrode excites only the symmetric zero-order mode and hardly excites other anharmonic higher-order modes.
　特許文献９には、圧電基板、及び圧電基板の表裏に設ける励振電極の形状を、共に長円形状にした圧電振動子が開示されている。
　特許文献１０には、水晶基板の長手方向（Ｘ軸方向）の両端部、及び電極のＸ軸方向の両端部の形状を共に半楕円状とし、且つ楕円の長軸対短軸の比（長軸／短軸）を、ほぼ１．２６とした水晶振動子が開示されている。
　特許文献１１には、楕円の水晶基板上に楕円の励振電極を形成した水晶振動子が開示されている。長軸対短軸の比は、１．２６：１が望ましいが、製造寸法のバラツキ等を考慮すると、１．１４～１．３９：１の範囲程度が実用的であるという。 Patent Document 9 discloses a piezoelectric vibrator in which the shapes of the piezoelectric substrate and the excitation electrodes provided on the front and back of the piezoelectric substrate are both oblong.
In Patent Document 10, the shapes of both ends in the longitudinal direction (X-axis direction) of the quartz substrate and both ends in the X-axis direction of the electrode are both semielliptical, and the ratio of the major axis to the minor axis of the ellipse (length There is disclosed a crystal unit in which the axis / short axis) is approximately 1.26.
Patent Document 11 discloses a quartz oscillator in which an elliptic excitation electrode is formed on an elliptic quartz substrate. The ratio of the major axis to the minor axis is preferably 1.26: 1, but it is said that the range of 1.14 to 1.39: 1 is practical in consideration of variations in manufacturing dimensions and the like.
　特許文献１２には、厚みすべり圧電振動子のエネルギー閉じ込め効果をより改善するために、振動部と支持部との間に切り欠きやスリットを設けた構造の圧電振動子が開示されている。
　ところで、圧電振動子の小型化を図る際に、接着剤に起因する残留応力により、電気的特性の劣化や周波数エージング特性に不良が生じることがある。特許文献１３には、矩形平板状のＡＴカット水晶振動子の振動部と支持部との間に、切り欠きやスリットを設けた水晶振動子が開示されている。このような構造を用いることにより、残留応力が振動領域へ広がるのを抑制できるという。
　特許文献１４には、マウント歪（応力）を改善（緩和）するために、逆メサ型圧電振動子の振動部と支持部との間に切り欠きやスリットを設けた振動子が開示されている。特許文献１５には、逆メサ型圧電振動子の支持部にスリット（貫通孔）を設けることにより、表裏面の電極の導通を確保した圧電振動子が開示されている。 Patent Document 12 discloses a piezoelectric vibrator having a structure in which a notch or a slit is provided between the vibrating portion and the support portion in order to further improve the energy confinement effect of the thickness-shear piezoelectric vibrator.
By the way, when the size of the piezoelectric vibrator is to be reduced, the residual stress caused by the adhesive may cause deterioration of the electrical characteristics or a defect in the frequency aging characteristics. Patent Document 13 discloses a quartz crystal vibrator in which a notch or a slit is provided between a vibrating portion and a support portion of a rectangular flat AT-shaped quartz crystal vibrator. By using such a structure, it is possible to suppress the spread of residual stress into the vibration region.
Patent Document 14 discloses a vibrator in which a notch or a slit is provided between a vibrating portion and a support portion of a reverse mesa type piezoelectric vibrator in order to improve (reduce) mount distortion (stress). . Patent Document 15 discloses a piezoelectric vibrator in which the conduction of the electrodes on the front and back surfaces is ensured by providing slits (through holes) in the support portion of the reverse mesa type piezoelectric vibrator.
　特許文献１６には、厚みすべり振動モードのＡＴカット水晶振動子の支持部に、スリットを設けることにより、高次輪郭系の不要モードを抑圧した水晶振動子が開示されている。
　また、特許文献１７には、逆メサ型ＡＴカット水晶振動子の薄肉の振動部と、厚肉の保持部との連設部、即ち傾斜面を有する残渣部に、スリットを設けることにより、スプリアスを抑圧する振動子が開示されている。 Patent Document 16 discloses a quartz oscillator in which unwanted modes of a high-order contour system are suppressed by providing a slit in a support portion of an AT-cut quartz oscillator in a thickness shear vibration mode.
Further, in Patent Document 17, a spurious is provided by providing a slit in a connection portion between a thin vibrating portion of an inverted mesa AT-cut quartz crystal unit and a thick holding portion, that is, a residual portion having an inclined surface. There is disclosed an oscillator that suppresses
特開２００４－１６５７４３公報JP, 2004-165743, A 特開２００９－１６４８２４公報JP, 2009-164824, A 特開２００６－２０３７００公報JP, 2006-203700, A 特開２００２－１９８７７２公報JP 2002-198772 gazette 特開２００２－０３３６４０公報Japanese Patent Application Publication No. 2002-033640 特開２００１－１４４５７８公報Japanese Patent Application Publication No. 2001-144578 特開２００３－２６４４４６公報Japanese Patent Application Publication No. 2003-264446 特開平２－０７９５０８号公報Unexamined-Japanese-Patent No. 2-079508 特開平９－２４６９０３号公報JP-A-9-246903 特開２００７－１５８４８６公報Japanese Patent Application Publication No. 2007-158486 特開２００７－２１４９４１公報JP 2007-214941 gazette 実開昭６１－１８７１１６号公報Japanese Utility Model Publication No. 61-187116 特開平９－３２６６６７号公報Unexamined-Japanese-Patent No. 9-326667 gazette 特開２００９－１５８９９９公報JP, 2009-158999, A 特開２００４－２６０６９５公報JP 2004-260695 A 特開２００９－１８８４８３公報JP, 2009-188483, A 特開２００３－０８７０８７公報Japanese Patent Application Publication No. 2003-087087
　近年、圧電デバイスの小型化、高周波化、並びに高性能化に対する要求は強い。しかしながら、前述のごとき構造の圧電振動子は、主振動のＣＩ値、近接するスプリアスＣＩ値比（＝ＣＩｓ／ＣＩｍ、ここでＣＩｍは主振動のＣＩ値、ＣＩｓはスプリアスのＣＩ値で、規格の１例は１．８以上）等が要求を満たせないという問題があることが判明した。特に、周波数が数百ＭＨｚという高周波になると、圧電振動素子に形成する励振電極、及びリード電極の電極膜厚が問題になる。圧電振動素子の主振動のみを閉じ込めモードにしようとすると、電極膜が薄くなり、オーミックロスが生じ、圧電振動素子のＣＩ値が大きくなるという問題があった。
　また、電極膜のオーミックロスを防ぐために膜厚を厚くすると、主振動の他に多くのインハーモニック・モードが閉じ込めモードとなり、近接するスプリアスＣＩ値比を満たせないという問題があった。
　そこで、本発明は上記問題を解決するためになされたもので、高周波化（１００～５００ＭＨｚ帯）を図ると共に、主振動のＣＩ値を低減し、スプリアスＣＩ値比等の電気的要求を満たした振動素子、振動子、電子デバイス、及び本発明の振動子を用いた電子機器を提供することにある。 In recent years, demands for miniaturization, high frequency, and high performance of piezoelectric devices are strong. However, the piezoelectric vibrator with the above-mentioned structure has the CI value of the main vibration, the ratio of the spurious CI values close to each other (= CIs / CIm, where CIm is the CI value of the main vibration and CIs is the CI value of the spurious It has been found that there is a problem that one case can not meet the requirement). In particular, when the frequency is as high as several hundred MHz, the film thickness of the excitation electrode and the lead electrode formed on the piezoelectric vibration element becomes a problem. When only the main vibration of the piezoelectric vibrating element is made into the confinement mode, the electrode film becomes thin, causing an ohmic loss, and there is a problem that the CI value of the piezoelectric vibrating element becomes large.
In addition, when the film thickness is increased to prevent ohmic loss of the electrode film, many inharmonic modes other than the main vibration become confinement modes, and there is a problem that the ratio of adjacent spurious CI values can not be satisfied.
Therefore, the present invention has been made to solve the above-mentioned problems, and aims to increase the frequency (100 to 500 MHz band), reduce the CI value of the main vibration, and satisfy the electrical requirements such as spurious CI value ratio. An object of the present invention is to provide a vibration element, a vibrator, an electronic device, and an electronic device using the vibrator of the present invention.
　本発明は、上記の課題の少なくとも一部を解決するためになされたものであり、以下の形態又は適用例として実現することが可能である。 The present invention has been made to solve at least a part of the above-mentioned problems, and can be realized as the following modes or application examples.
　［適用例１］本発明に係る振動素子は、振動領域を含む振動部を有する基板と、前記振動領域に表裏で対向するように配置された一対の励振電極と、当該一対の励振電極に電気的に接続され、前記支持部上に夫々延在して設けられたリード電極と、を含み、前記励振電極の膜厚をｔ１とし、前記リード電極の膜厚をｔ２としたとき、ｔ１＜ｔ２を満足することを特徴とする振動素子である。 [Example 1 of application] The vibration element according to the present invention comprises: a substrate having a vibration part including a vibration area; a pair of excitation electrodes arranged to face the vibration area on the front and back sides; When the film thickness of the excitation electrode is t1 and the film thickness of the lead electrode is t2, t1 <t2. The vibration element is characterized in that
　この構成によると、励振電極のプレートバック（周波数低下量）適切に設定するとともに、リード電極のオーミックロスを低減し、ワイヤーボンディングに耐えられるリード電極とすることができるという効果がある。 According to this configuration, it is possible to appropriately set the plate back (frequency reduction amount) of the excitation electrode, reduce the ohmic loss of the lead electrode, and provide a lead electrode that can withstand wire bonding.
　［適用例２］また振動素子は、前記リード電極が、前記励振電極と電気的に接続され、膜厚がｔ１となる第１のリード電極と、前記支持部上に設けられ、膜厚がｔ２の第２のリード電極と、を電気的に接続して構成されていることを特徴とする適用例１に記載の振動素子である。 Application Example 2 In the vibration element, the lead electrode is electrically connected to the excitation electrode, and the first lead electrode having a film thickness of t1 is provided on the support portion, and the film thickness is t2 According to the first aspect of the invention, there is provided the vibration element as described in the first application example, characterized in that the second lead electrode is electrically connected.
　この構成によると、膜厚ｔ１の励振電極と同じ厚さの第１のリード電極とが、適切なプレートバック量に設定されると共に、リード電極の膜厚ｔ２がオーミックロスのない膜厚に設定されることにより、振動素子のＣＩ値が小さくなるという効果がある。 According to this configuration, the excitation electrode of the film thickness t1 and the first lead electrode of the same thickness are set to an appropriate plate back amount, and the film thickness t2 of the lead electrode is set to a film thickness without ohmic loss As a result, the CI value of the vibrating element is reduced.
　［適用例３］また振動素子は、前記リード電極が、前記第１のリード電極と前記第２のリード電極とが、少なくとも一部の領域で重畳するように構成されていることを特徴とする適用例１又は２に記載の振動素子である。 [Application Example 3] The vibrating element is characterized in that the lead electrode is configured such that the first lead electrode and the second lead electrode overlap in at least a partial region. It is a vibration element given in application example 1 or 2.
　この構成によると、第１のリード電極と第２のリード電極とが一部の部分で積層されており、励振電極とリード電極との導通不良がなく、ＣＩ値を小さくすることができると共に、スプリアスの少ない振動素子が得られるという効果がある。 According to this configuration, the first lead electrode and the second lead electrode are laminated in a part, there is no conduction failure between the excitation electrode and the lead electrode, and the CI value can be reduced. There is an effect that a vibration element with less spurious can be obtained.
　［適用例４］また振動素子は、前記励振電極が、前記基板上に順に第１の層と第２の層を積層してなり、前記リード電極は、前記基板上に順に第３の層と第４の層を積層してなる、ことを特徴とする適用例１又は２に記載の振動素子である。 Application Example 4 In the vibration element, the excitation electrode is formed by sequentially laminating the first layer and the second layer on the substrate, and the lead electrode is formed by sequentially forming the third layer on the substrate. It is a vibration element given in the example 1 or 2 of application characterized by laminating the 4th layer.
　この構成によると、励振電極の一部の積層部分は、励振電極による第１の層と第２の層が順に積層され、次にリード電極による第３の層と第４の層が順に積層されているので、積層部の導通性は十分である。その上、リード電極と基板との接着力は強くなり、ワイヤーボンディングに十分に耐えられるという効果がある。 According to this configuration, the first layer and the second layer of the excitation electrode are sequentially stacked, and then the third layer and the fourth layer of the lead electrode are sequentially stacked. Therefore, the conductivity of the laminated portion is sufficient. In addition, the adhesion between the lead electrode and the substrate is enhanced, so that the wire bonding can be sufficiently sustained.
　［適用例５］また振動素子は、前記一部の領域は、前記基板上に順に前記第３の層、前記第４の層、前記第１の層、前記第２の層を積層してなることを特徴とする適用例３に記載の振動素子である。 Application Example 5 In the vibration element, the partial region is formed by sequentially laminating the third layer, the fourth layer, the first layer, and the second layer on the substrate in this order. According to a third aspect of the invention, there is provided a vibration element as described in the third aspect of the invention.
　この構成によれば、リード電極の一部の積層部分は、第３の層、第４の層、第１の層、第２の層が順に積層されており、積層部分の強度、導電性は十分であり、ＣＩ値の小さな振動素子がえられるという効果がある。 According to this configuration, the third layer, the fourth layer, the first layer, and the second layer are sequentially stacked in a portion of the stacked portion of the lead electrode, and the strength and conductivity of the stacked portion are There is an effect that a sufficient vibration element with a small CI value can be obtained.
　［適用例６］また振動素子は、前記第２の層と前記第４の層の材料は金であることを特徴とする適用例４に記載の振動素子である。 [Application Example 6] The vibration element according to Application Example 4 is characterized in that the material of the second layer and the fourth layer is gold.
　この構成によれば、リード電極の一部の積層部分の第２の層と第４の層には、材料として金が使われており、導電性、経年変化の点で極めて優れているという利点がある。 According to this configuration, gold is used as a material for the second layer and the fourth layer of a portion of the laminated portion of the lead electrode, which is an advantage in that it is extremely excellent in terms of conductivity and aging. There is.
　［適用例７］また振動素子は、前記第１の層と前記第３の層の材料は、ニッケル又はクロムであることを特徴とする適用例５又は６に記載の振動素子である。 Application Example 7 In the vibration element, the material of the first layer and the third layer is nickel or chromium. This is the vibration element according to the application example 5 or 6.
　この構成によれば、リード電極の一部の積層部分の第１の層と第３の層には、材料としてニッケル又はクロムが使われており、基板との接着性と、各層間の付着力性とに優れているという利点がある。 According to this configuration, nickel or chromium is used as a material for the first layer and the third layer of a portion of the laminated portion of the lead electrode, and the adhesion to the substrate and the adhesion between the layers are obtained. It has the advantage of being superior to sex.
　［適用例８］また振動素子は、前記基板が、前記振動部と一体化され、前記振動部よりも厚みが厚い第１の厚肉部、第２の厚肉部、及び前記第１の厚肉部と前記第２の厚肉部の基端部間を連接している第３の厚肉部を有することを特徴とする請求項１又は２に記載の振動素子である。 [Application Example 8] In the vibration element, a first thick portion, a second thick portion, and the first thickness, in which the substrate is integrated with the vibrating portion, and the thickness is larger than that of the vibrating portion. The vibration element according to claim 1 or 2, further comprising a third thick portion connecting between a thick portion and a base end of the second thick portion.
　この構成によれば、振動部より厚い厚肉部を有しており、厚い厚肉部により振動素子の支持・固定が容易になるという効果がある。更に、励振電極及びリード電極を適切な膜厚に設定すると、主振動のＣＩ値が小さく、主振動のＣＩ値に対する近接したスプリアスのＣＩ値の比、即ちＣＩ値比の大きな振動素子が得られるという効果がある。更に、基本波を用いた高周波振動素子が小型化されるという利点がある。 According to this configuration, the thick portion is thicker than the vibrating portion, and the thick thick portion has the effect of easily supporting and fixing the vibrating element. Furthermore, when the film thickness of the excitation electrode and the lead electrode is set appropriately, the CI value of the main vibration is small, and the ratio of the adjacent spurious CI value to the main vibration CI value, ie, a large ratio of the CI value is obtained. It has the effect of Furthermore, there is an advantage that the high frequency vibration element using the fundamental wave is miniaturized.
　［適用例９］また振動素子は、前記振動領域の少なくとも１辺が開放されていることを特徴とする適用例８に記載の振動素子である。 [Application 9] The vibration device according to application 8 is characterized in that at least one side of the vibration region is opened.
　この構成によれば、１辺が開放されているため、振動素子が小型化されると共に、ＣＩ値の小さな振動素子が得られるという効果がある。 According to this configuration, since one side is opened, there is an effect that the vibration element can be miniaturized and a vibration element with a small CI value can be obtained.
　［適用例１０］また振動素子は、前記厚肉部主面は前記振動部の少なくとも何れかの主面よりも突設されていることを特徴とする適用例９に記載の振動素子である。 [Application Example 10] The vibration element according to Application Example 9 is characterized in that the major surface of the thick portion protrudes from at least one of the main surfaces of the vibrating portion.
　この構成によれば、振動部の厚さより第２の支持部の厚さの方が厚いため、第２の支持部を支持・固定することにより、振動部の支持は堅牢であり、且つ高周波の振動素子が得られるという効果がある。 According to this configuration, since the thickness of the second support portion is thicker than the thickness of the vibration portion, the support of the vibration portion is robust by supporting and fixing the second support portion, and high frequency There is an effect that a vibrating element can be obtained.
　［適用例１１］また振動素子は、前記第２の厚肉部は、前記振動領域の一辺に連設した一方の端縁から他方の端縁に向かって離間するにつれて厚みが増加する傾斜部と、当該傾斜部の前記他方の端縁に連設する厚肉部本体と、を有することを特徴とする適用例８に記載の振動素子である。 In the vibration element, the second thick portion may be an inclined portion whose thickness increases as it is separated from one end of the vibration region adjacent to one side toward the other end. A vibrating element according to Application Example 8, further comprising: a thick portion main body connected to the other end edge of the inclined portion.
　この構成によれば、振動領域に傾斜部の一方（薄い方）が連設し、傾斜部の他方（厚い方）には第２の厚肉部本体が連設された構成であり、振動素子の保持による応力は、ほぼ第２の厚肉部本体と傾斜部で吸収されるため、ＣＩ値が小さく、滑らかな３次曲線の周波数温度特性を有する振動素子が得られるという効果がある。 According to this configuration, one of the inclined portions (thin one) is continuously provided in the vibration area, and the second thick portion main body is continuously provided on the other (thick one) of the inclined portion. The stress due to the holding is absorbed by the second thick part main body and the inclined part, so that there is an effect that a vibration element having a frequency value characteristic of a smooth cubic curve with a small CI value can be obtained.
　［適用例１２］また振動素子は、前記基板は、水晶の結晶軸である電気軸としてのＸ軸と、機械軸としてのＹ軸と、光学軸としてのＺ軸と、からなる直交座標系の前記Ｘ軸を中心として、前記Ｚ軸を前記Ｙ軸の－Ｙ方向へ所定の角度だけ傾けた軸をＺ’軸とし、前記Ｙ軸を前記Ｚ軸の＋Ｚ方向へ前記所定の角度だけ傾けた軸をＹ’軸とし、前記Ｘ軸と前記Ｚ’軸に平行な面で構成され、前記Ｙ’軸に平行な方向を厚みとする水晶板であることを特徴とする適用例１又は２に記載の振動素子である。 [Example 12 of application] The vibration element is an orthogonal coordinate system in which the substrate is composed of an X axis as an electrical axis which is a crystal axis of quartz, a Y axis as a mechanical axis, and a Z axis as an optical axis. An axis in which the Z axis is inclined by a predetermined angle in the -Y direction of the Y axis with the X axis as a center is a Z 'axis, and the Y axis is inclined by the predetermined angle in the + Z direction of the Z axis In the application example 1 or 2, it is a quartz plate having an axis as a Y 'axis, a plane parallel to the X axis and the Z' axis, and a thickness in a direction parallel to the Y 'axis. It is a vibrating element as described.
　この構成によれば、基板が上述のように形成されることにより、要求仕様をより適したカットアングルで構成することが可能となり、且つ仕様に沿った周波数温度特性を有し、ＣＩ値が小さく、ＣＩ値比の大きな高周波振動素子が得られるという効果がある。 According to this configuration, by forming the substrate as described above, it is possible to configure the required specification with a more suitable cut angle, and it has frequency temperature characteristics in accordance with the specification, and the CI value is small. There is an effect that a high frequency vibration element having a large CI value ratio can be obtained.
　［適用例１３］また振動素子は、前記基板が、第４の厚肉部を備え、前記第４の厚肉部の突設部が、前記Ｚ’軸のマイナス側にあることを特徴とする適用例８に記載の振動素子である。 [Application Example 13] The vibrating element is characterized in that the substrate includes a fourth thick portion, and the protruding portion of the fourth thick portion is on the negative side of the Z 'axis. 24 is a vibrating element described in application example 8;
　この構成によれば、振動部と連設してＺ’軸のマイナス側に突設部を設けたので、外部からの振動、衝撃に堅牢な振動素子が得られるという効果がある。 According to this configuration, since the projecting portion is provided on the negative side of the Z 'axis in series with the vibrating portion, there is an effect that a vibrating element that is robust against external vibration and impact is obtained.
　［適用例１４］また振動素子は、前記第２の厚肉部には、少なくとも一つのスリットが貫通形成されていることを特徴とする適用例８に記載の振動素子である。 [Application Example 14] The vibration element according to Application Example 8 is characterized in that at least one slit is formed through the second thick portion.
　この構成によれば、第２の厚肉部にスリットを設けることにより、導電性接着剤等を用いて第２の厚肉部を固定する際に生じる応力の広がりを、スリットにより抑圧するという効果がある。 According to this configuration, by providing the slit in the second thick portion, the effect of suppressing the spread of the stress generated when fixing the second thick portion using a conductive adhesive or the like by the slit There is.
　［適用例１５］本発明の振動子は、適用例１又は２に記載の振動素子と、該振動素子を収容するパッケージと、を備えたことを特徴とする振動子である。 Application 15 The vibrator according to the present invention is a vibrator including the vibration element according to application 1 or 2 and a package for housing the vibration element.
　この構成によれば、励振電極及びリード電極が上記のように構成された振動素子を用いているため、主振動のＣＩ値が小さく、主振動のＣＩ値に対する近接したスプリアスのＣＩ値の比、即ちＣＩ値比の大きな振動子が得られるという効果がある。更に、高周波振動子が小型化されると共に、振動素子を支持する部位が一点であり、且つ厚肉部と振動領域の間にスリットを設けることにより導電性接着剤に起因して生じる応力を小さくすることができるため、周波数再現性、周波数温度特性、ＣＩ温度特性、及び周波数エージング特性に優れた振動子が得られるという効果がる。 According to this configuration, since the excitation electrode and the lead electrode use the vibration element configured as described above, the CI value of the main vibration is small, and the ratio of the CI value of the near spurious to the CI value of the main vibration That is, there is an effect that a vibrator having a large CI value ratio can be obtained. Furthermore, while the high-frequency vibrator is miniaturized, the position to support the vibration element is one point, and by providing a slit between the thick portion and the vibration area, the stress caused by the conductive adhesive is reduced. Thus, there is an effect that a vibrator excellent in frequency repeatability, frequency temperature characteristics, CI temperature characteristics, and frequency aging characteristics can be obtained.
　［適用例１６］本発明の電子デバイスは、適用例１又は２に記載の振動素子と、電子部品と、をパッケージに備えたことを特徴とする電子デバイスである。 Application Example 16 An electronic device according to the present invention is an electronic device including the vibrating element according to the application example 1 or 2 and an electronic component in a package.
　この構成によれば、振動素子と、電子部品とを用いて電子デバイス（圧電デバイス）を構成することにより、周波数再現性、周波数温度特性、エージング特性が優れ、小型で且つ高周波の電子デバイスが得られるという効果がある。 According to this configuration, by configuring the electronic device (piezoelectric device) using the vibration element and the electronic component, it is possible to obtain a small-sized and high-frequency electronic device which is excellent in frequency reproducibility, frequency temperature characteristics and aging characteristics. Have the effect of
　［適用例１７］また電子デバイスは、前記電子部品は、可変容量素子、サーミスター、インダクター、コンデンサーのうちの何れかであることを特徴とする適用例１６に記載の電子デバイスである。 [Application 17] The electronic device according to Application 16 is characterized in that the electronic component is any one of a variable capacitance element, a thermistor, an inductor, and a capacitor.
　この構成によれば、本発明の振動素子と、可変容量素子、サーミスター、インダクター、コンデンサーのうちの何れかを用いて電子デバイス（圧電デバイス）を構成することにより、要求仕様により適した電子デバイスが、小型で且つ低コストで実現できるという効果がある。 According to this configuration, the electronic device (piezoelectric device) is configured using any one of the vibration element of the present invention, the variable capacitance element, the thermistor, the inductor, and the capacitor, thereby making the electronic device more suitable for the required specification. However, there is an effect that it can be realized at a small size and at low cost.
　［適用例１８］また電子デバイスは、前記振動素子を励振する発振回路をパッケージに備えたことを特徴とする適用例１６に記載の電子デバイスである。 [Application 18] The electronic device is the electronic device according to Application 16 characterized in that the package is provided with an oscillation circuit for exciting the vibration element.
　この構成によれば、励振電極及びリード電極が上記のように構成された振動素子と、発振回路とを用いて、電子デバイス（圧電デバイス）を構成することにより、高周波の圧電発振器、温度補償型圧電発振器、及び電圧制御型圧電発振器等の電子デバイスが、構成できる。更に、電圧制御型圧電発振器を構成すると、周波数再現性、エージング特性が優れ、基本波を用いるため周波数可変範囲も広く、且つＳ／Ｎ比（信号雑音比）の良好な電子デバイスが得られるという効果がある。 According to this configuration, the electronic device (piezoelectric device) is configured by using the vibration element in which the excitation electrode and the lead electrode are configured as described above and the oscillation circuit, a high frequency piezoelectric oscillator, a temperature compensation type Electronic devices such as a piezoelectric oscillator and a voltage controlled piezoelectric oscillator can be configured. Furthermore, when a voltage control type piezoelectric oscillator is configured, it is possible to obtain an electronic device having excellent frequency reproducibility and aging characteristics, a wide frequency variable range because of using a fundamental wave, and a good S / N ratio (signal-to-noise ratio). effective.
　［適用例１９］適用例１５に記載の振動子を備えたことを特徴とする電子機器である。 Application Example 19 An electronic apparatus comprising the vibrator according to Application Example 15.
　この構成によれば、本発明の振動子を電子機器の用いることにより、高周波で周波数安定度に優れ、Ｓ／Ｎ比の良好な基準周波数源を備えた電子機器が構成できるという効果がある。 According to this configuration, by using the vibrator of the present invention in an electronic device, there is an effect that an electronic device provided with a reference frequency source excellent in frequency stability at high frequency and having a good S / N ratio can be configured.
本発明に係る圧電振動素子１の構造を示した概略図であり、（ａ）は平面図であり、（ｂ）はＰ－Ｐ断面を＋Ｘ軸方向からみた図、（ｃ）はＱ－Ｑ断面を＋Ｚ’軸方向からみた図。It is the schematic which showed the structure of the piezoelectric vibration element 1 which concerns on this invention, (a) is a top view, (b) is the figure which saw the PP cross section from + X-axis direction, (c) is QQ. The figure which looked at the cross section from + Z 'axial direction. ＡＴカット水晶基板と結晶軸との関係を説明する図。The figure explaining the relationship between AT cut crystal substrate and a crystal axis. （ａ）はリード電極とパッド電極の構成を示す平面図であり、（ｂ）は励振電極の構成を示す平面図。(A) is a top view which shows the structure of a lead electrode and a pad electrode, (b) is a top view which shows the structure of an excitation electrode. 圧電振動素子１の変形例の構成を示す平面図。FIG. 8 is a plan view showing the configuration of a modification of the piezoelectric vibrating element 1; 圧電振動素子１の他の変形例の構成を示す平面図。FIG. 10 is a plan view showing the configuration of another modification of the piezoelectric vibrating element 1; 圧電振動素子１の他の変形例の構成を示す平面図。FIG. 10 is a plan view showing the configuration of another modification of the piezoelectric vibrating element 1; 圧電振動素子１の、（ａ）は他の変形例の構成を示す平面図であり、（ｂ）は他の変形例の構成を示す平面図。(A) of the piezoelectric vibrating element 1 is a top view which shows the structure of another modification, (b) is a top view which shows the structure of another modification. 第２の実施形態例の圧電振動素子２の構造を示した概略図であり、（ａ）は平面図であり、（ｂ）はＰ－Ｐ断面を＋Ｘ軸方向からみた断面図であり、（ｃ）はＰ－Ｐ断面を－Ｘ軸方向からみた断面図であり、（ｄ）はＱ－Ｑ断面を＋Ｚ’方向からみた断面図。It is the schematic which showed the structure of the piezoelectric vibration element 2 of the 2nd example of embodiment, (a) is a top view, (b) is a sectional view which saw PP section from + X axial direction, c) is a cross-sectional view of the PP cross section viewed from the -X-axis direction, and (d) is a cross-sectional view of the QQ cross section viewed from the + Z 'direction. 本発明の圧電基板の製造工程図。The manufacturing-process figure of the piezoelectric substrate of this invention. 本発明の圧電振動素子の励振電極及びリード電極の製造工程図。The manufacturing process figure of the excitation electrode of the piezoelectric vibration element of this invention, and a lead electrode. （ａ）は第２の実施形態に係る圧電振動素子２の斜視図であり、（ｂ）はＱ－Ｑ縦断面図。(A) is a perspective view of the piezoelectric vibrating element 2 which concerns on 2nd Embodiment, (b) is a QQ longitudinal cross-sectional view. （ａ）は本発明に係る圧電振動子５の縦断面図であり、（ｂ）は平面図。(A) is a longitudinal cross-sectional view of the piezoelectric vibrator 5 which concerns on this invention, (b) is a top view. 電子デバイス（圧電デバイス）６の縦断面図。FIG. 2 is a longitudinal sectional view of an electronic device (piezoelectric device) 6. （ａ）は電子デバイス（圧電デバイス）７の縦断面図であり、（ｂ）は平面図。(A) is a longitudinal cross-sectional view of the electronic device (piezoelectric device) 7, (b) is a top view. 電子デバイス（圧電デバイス）７の縦断面図。FIG. 2 is a longitudinal sectional view of an electronic device (piezoelectric device) 7. 電子機器の模式図。FIG. （ａ）、（ｂ）、（ｃ）は変形例に係る圧電基板の構成説明図。(A), (b), (c) is structure explanatory drawing of the piezoelectric substrate which concerns on a modification. （ａ）、（ｂ）、（ｃ）は他の変形例に係る圧電基板の構成説明図。(A), (b), (c) is structure explanatory drawing of the piezoelectric substrate which concerns on another modification. 本発明に係る圧電振動素子１の変形例であり、（ａ）は平面図であり、（ｂ）は要部の拡大図であり、（ｃ）はその断面図。It is a modification of the piezoelectric vibration element 1 which concerns on this invention, (a) is a top view, (b) is an enlarged view of the principal part, (c) is the sectional drawing.
　以下、本発明の実施の形態を図面に基づいて詳細に説明する。図１は、本発明の一実施形態に係る圧電振動素子１の構成を示す概略図である。図１（ａ）は圧電振動素子１の平面図であり、同図（ｂ）はＰ－Ｐ断面を＋Ｘ軸方向からみた断面図であり、同図（ｃ）はＱ－Ｑ断面を－Ｚ’軸方向からみた断面図である。
　圧電振動素子（振動素子）１は、薄肉の振動領域１２を含む振動部、及び振動領域１２に連設された厚肉の支持部（厚肉部）１４、１５、１６を有する圧電基板（基板）１０と、振動領域１２の両主面（表裏面）に夫々対向するようにして形成された励振電極２５ａ、２５ｂと、励振電極２５ａ、２５ｂから夫々厚肉部に設けられたパッド電極２９ａ、２９ｂに向けて延出されて形成されたリード電極２７ａ、２７ｂと、を備えている。ここで、振動領域とは振動エネルギーが閉じ込められている領域、即ち振動エネルギーがほぼ零となる領域の内側を言い、Ｘ軸方向の振動領域の寸法と、Ｚ’軸方向の振動領域の寸法との比は周知のように、１．２６：１である。また、振動部とは振動領域とその周縁部とを含んだ圧電基板全体をいう。 Hereinafter, embodiments of the present invention will be described in detail based on the drawings. FIG. 1 is a schematic view showing the configuration of a piezoelectric vibrating element 1 according to an embodiment of the present invention. FIG. 1 (a) is a plan view of the piezoelectric vibration element 1, FIG. 1 (b) is a cross-sectional view of the PP cross section viewed from the + X axis direction, and FIG. 1 (c) is a QZ cross section It is a cross-sectional view seen from the axial direction.
The piezoelectric vibration element (vibration element) 1 includes a vibration portion including a thin vibration region 12 and a piezoelectric substrate (substrate) having thick support portions (thick portions) 14, 15 and 16 continuously connected to the vibration region 12. 10, and excitation electrodes 25a and 25b formed so as to face each of the main surfaces (front and back surfaces) of the vibration region 12, and pad electrodes 29a provided in thick portions from the excitation electrodes 25a and 25b, respectively. And lead electrodes 27a and 27b formed extending to 29b. Here, the vibration region means a region in which vibration energy is confined, ie, a region where vibration energy is substantially zero, and the dimensions of the vibration region in the X axis direction and the dimensions of the vibration region in the Z ′ axis direction The ratio of is 1.26: 1 as is well known. Also, the vibrating portion refers to the entire piezoelectric substrate including the vibrating region and its peripheral portion.
　圧電基板１０は、矩形状をなし、且つ薄肉で平板状の振動領域１２と、振動領域１２の一辺を除いた三辺に沿って一体化された厚肉の支持部（厚肉部）１３（１４、１５、１６）と、前記振動領域１２の一辺が露出した構造を備えている。厚肉の支持部（厚肉部支持部とも称する）１３は、振動領域１２を挟んで対向配置された第１の支持部（第１の厚肉部）１４、及び第２の支持部（第２の厚肉部）１５と、第１及び第２の支持部１４、１５の基端部間を連設する第３の支持部（第３の厚肉部）１６と、を備え、平面視でコ字状（Ｕ字状）の構造を有している。
　つまり、厚肉の支持部１３は、振動領域１２の四辺のうち１辺を開放するように、振動領域１２を挟んで対向配置された第１の支持部１４、及び第２の支持部１５と、第１及び第２の支持部１４、１５の基端部間を連設する第３の支持部１６と、を備える。ここで、「開放する」とは、一辺が露出している場合と、一部が露出しているのではなく完全に露出している場合と、を含む。 The piezoelectric substrate 10 has a rectangular shape, and a thin and flat vibration region 12 and a thick support portion (thick portion) 13 integrated along three sides excluding one side of the vibration region 12 (thick portion) 13 14, 15, 16) and a structure in which one side of the vibration area 12 is exposed. The thick support portion (also referred to as a thick portion support portion) 13 includes a first support portion (first thick portion) 14 and a second support portion (a first support portion), which are disposed opposite to each other with the vibration region 12 interposed therebetween. 2) thick-walled portion 15) and a third supporting portion (third thick-walled portion) 16 connecting the base ends of the first and second supporting portions 14 and 15 in a row It has a U-shaped (U-shaped) structure.
That is, the thick support portion 13 and the first support portion 14 and the second support portion 15 which are disposed opposite to each other across the vibration area 12 so as to open one of the four sides of the vibration area 12 And a third support portion 16 provided in series between the proximal end portions of the first and second support portions 14 and 15. Here, "open" includes the case where one side is exposed and the case where one portion is not exposed but completely exposed.
　更に、第１の支持部１４は、薄肉平板状の振動領域１２の一辺１２ａに連設し、振動領域１２の一辺１２ａに連接する一方の端縁（内側端縁）から他方の端縁（外側端縁）に向かって離間するにつれて厚みが漸増する第１の傾斜部１４ｂと、第１の傾斜部１４ｂの前記他方の端縁に連設する厚肉で四角柱状の第１の支持部本体１４ａと、を備えている。同様に、第２の支持部１５は、薄肉平板状の振動領域１２の一辺１２ｂに連設し、振動領域１２の一辺１２ｂに連接する一方の端縁（内側端縁）から他方の端縁（外側端縁）に向かって離間するにつれて厚みが漸増する第２の傾斜部１５ｂと、第２の傾斜部１５ｂの前記他方の端縁に連設する厚肉で四角柱状の第２の支持部本体１５ａと、を備えている。 Furthermore, the first support portion 14 is continuous with one side 12 a of the thin flat plate-like vibration area 12, and is connected to the one side 12 a of the vibration area 12 from one end (inner side edge) to the other end The first inclined portion 14b having a gradually increasing thickness as it moves away from the end edge, and the thick and square pillar-shaped first support portion body 14a connected to the other end edge of the first inclined portion 14b. And have. Similarly, the second support portion 15 is connected to one side 12 b of the thin flat plate-like vibration area 12 and is connected to one side 12 b of the vibration area 12 from one end (inner side edge) to the other The second inclined portion 15b having a gradually increasing thickness as it moves away from the outer edge), and a thick, square-pillar-shaped second support portion main body connected to the other end of the second inclined portion 15b. And 15a.
　更に、第３の支持部１６は、薄肉平板状の振動領域１２の一辺１２ｃに連設し、振動領域１２の一辺１２ｃに連接する一方の端縁（内側端縁）から他方の端縁（外側端縁）に向かって離間するにつれて厚みが漸増する第３の傾斜部１６ｂと、第３の傾斜部１６ｂの前記他方の端縁に連設する厚肉で四角柱状の第３の支持部本体１６ａと、を備えている。
　つまり、薄肉の振動領域１２は、三辺を第１、第２、及び第３の支持部１４、１５、１６に囲まれ、且つ他の一辺が開放された凹陥部１１を構成している。
　第２の支持部１５には、少なくとも一つの応力緩和用のスリット２０が貫通形成されている。図１に示した実施形態例では、スリット２０は第２の傾斜部１５ｂと第２の支持部本体１５ａとの境界部に沿って第２の支持部本体１５ａの面内に形成されている。
　なお、支持部本体（１４ａ、１５ａ、１６ａ）とは、Ｙ’軸に平行な厚みが一定である領域をいう。振動領域１２の一方の主面と、第１、第２及び第３の支持部１４、１５、１６の夫々の一方の面とは、同一平面上、即ち図１に示す座標軸のＸ－Ｚ’平面と平行な平面上にあり、この一方の主面（図１（ｂ）の下面側）をフラット面（平坦面）といい、他方の主面である反対側の面（図１（ｂ）の上面側）を凹陥面という。凹陥部１１側を表面とし、フラット面を裏面とする。 Furthermore, the third support portion 16 is connected to one side 12c of the thin flat plate-like vibration area 12 and is connected to the one side 12c of the vibration area 12 from the one end (inner side edge) to the other end (outside) The third inclined portion 16b having a gradually increasing thickness as it moves away from the end edge, and a thick, square-pillar-shaped third support portion body 16a connected to the other end edge of the third inclined portion 16b. And have.
That is, the thin vibration region 12 constitutes a recessed portion 11 whose three sides are surrounded by the first, second, and third support portions 14, 15, 16 and the other side is opened.
At least one stress relief slit 20 is formed through the second support portion 15. In the embodiment shown in FIG. 1, the slit 20 is formed in the plane of the second support portion body 15a along the boundary between the second inclined portion 15b and the second support portion body 15a.
In addition, a support part main body (14a, 15a, 16a) means the area | region where thickness parallel to a Y 'axis | shaft is constant. One main surface of the vibration area 12 and one surface of each of the first, second and third support portions 14, 15, 16 are on the same plane, ie, XZ 'of the coordinate axis shown in FIG. It is on a plane parallel to the plane, and this one main surface (the lower surface side in FIG. 1 (b)) is called a flat surface (flat surface), and the other surface which is the other main surface (FIG. 1 (b) The upper surface side of) is called a recessed surface. The concave portion 11 side is a front surface, and the flat surface is a rear surface.
　水晶等の圧電材料は三方晶系に属し、図２に示すように互いに直交する結晶軸Ｘ、Ｙ、Ｚを有する。Ｘ軸、Ｙ軸、Ｚ軸は、夫々電気軸、機械軸、光学軸と呼称される。そして水晶基板は、ＸＺ面をＸ軸の回りに所定の角度θだけ回転させた平面に沿って、水晶から切り出された平板が圧電基板として用いられる。例えば、ＡＴカット水晶基板の場合は、θは略３５°１５′である。なお、Ｙ軸及びＺ軸もＸ軸の周りにθ回転させて、夫々Ｙ’軸、及びＺ’軸とする。従って、ＡＴカット水晶基板（圧電基板）１０は、直交する結晶軸Ｘ、Ｙ’、Ｚ’を有する。ＡＴカット水晶基板１０は、厚み方向がＹ’軸であって、Ｙ’軸に直交するＸＺ’面（Ｘ軸及びＺ’軸を含む面）が主面であり、厚みすべり振動が主振動として励振される。 A piezoelectric material such as quartz belongs to a trigonal system and has crystal axes X, Y and Z orthogonal to each other as shown in FIG. The X axis, Y axis, and Z axis are respectively referred to as an electric axis, a mechanical axis, and an optical axis. As the quartz substrate, a flat plate cut out from quartz is used as a piezoelectric substrate along a plane obtained by rotating the XZ plane about the X axis by a predetermined angle θ. For example, in the case of an AT-cut quartz substrate, θ is approximately 35 ° 15 ′. The Y-axis and the Z-axis are also rotated around the X-axis by θ, to form Y'-axis and Z'-axis, respectively. Therefore, the AT cut quartz substrate (piezoelectric substrate) 10 has crystal axes X, Y ', Z' orthogonal to each other. In the AT-cut quartz substrate 10, the thickness direction is the Y 'axis, and the XZ' plane (plane including the X axis and the Z 'axis) orthogonal to the Y' axis is the main surface, and thickness shear vibration is the main vibration. It is excited.
　即ち、圧電基板１０は、図２に示すようにＸ軸（電気軸）、Ｙ軸（機械軸）、Ｚ軸（光学軸）からなる直交座標系のＸ軸を中心として、Ｚ軸をＹ軸の－Ｙ方向へ傾けた軸をＺ’軸とし、Ｙ軸をＺ軸の＋Ｚ方向へ傾けた軸をＹ’軸とし、Ｘ軸とＺ’軸に平行な面で構成され、Ｙ’軸に平行な方向を厚みとするＡＴカット水晶基板である。
　圧電基板１０は、図１（ａ）に示すように、Ｙ’軸に平行な方向（以下、「Ｙ’軸方向」という）を厚み方向として、Ｘ軸に平行な方向（以下、「Ｘ軸方向」という）を長辺とし、Ｚ’軸に平行な方向（以下、「Ｚ’軸方向」という）を短辺とする矩形の形状を有する。
　なお、本発明に係る圧電基板は、前記角度θが略３５°１５′のＡＴカットに限定されるものではなく、厚みすべり振動を励振するＢＴカット等の圧電基板にも広く適用できるのは言うまでもない。 That is, as shown in FIG. 2, the piezoelectric substrate 10 has a Z-axis that is Y-axis centered on the X-axis of an orthogonal coordinate system consisting of X-axis (electrical axis), Y-axis (mechanical axis), and Z-axis (optical axis). The axis tilted in the -Y direction of is the Z 'axis, the Y axis is tilted in the + Z direction of the Z axis is the Y' axis, composed of planes parallel to the X axis and the Z 'axis, the Y' axis This is an AT-cut quartz substrate whose thickness is in the parallel direction.
As shown in FIG. 1A, the piezoelectric substrate 10 has a direction parallel to the Y ′ axis (hereinafter referred to as “Y ′ axis direction”) as a thickness direction, and a direction parallel to the X axis (hereinafter referred to as “X axis The direction is referred to as a long side, and the direction parallel to the Z 'axis (hereinafter referred to as the "Z' axis direction") is a short side.
The piezoelectric substrate according to the present invention is not limited to the AT cut of which the angle θ is about 35 ° 15 ', but it can be widely applied to a piezoelectric substrate such as a BT cut which excites thickness shear vibration. Yes.
　圧電基板１０を駆動する励振電極２５ａ、２５ｂは、図１に示す実施形態例では四角形状であり、振動領域１２のほぼ中央部の表裏両面（上面、及び下面両面）に対向して形成されている。この際、フラット面側（図１（ｂ）の裏面側）の励振電極２５ｂの面積の大きさは、凹陥面側（図１（ｂ）の表面側）の励振電極２５ａの大きさに対し、十分に大きく設定する。これは、励振電極の質量効果によるエネルギー閉じ込め係数を、必要以上に大きくしないためである。つまり、裏面側（下面側）の励振電極２５ｂを十分に大きくすることにより、プレートバック量Δ（＝（ｆｓ－ｆｅ）／ｆｓ、ここでｆｓは圧電基板のカットオフ周波数、ｆｅは圧電基板全面に励振電極を付着した場合の周波数）は、表面側（上面側）の励振電極２５ａの質量効果のみに依存する。 The excitation electrodes 25a and 25b for driving the piezoelectric substrate 10 are rectangular in the embodiment shown in FIG. 1, and are formed to face both front and back surfaces (upper and lower surfaces) of the substantially central portion of the vibration region 12 There is. At this time, the size of the area of the excitation electrode 25b on the flat surface side (the back surface side in FIG. 1B) is smaller than the size of the excitation electrode 25a on the recessed surface side (the surface side in FIG. 1B). Set large enough. This is because the energy confinement coefficient due to the mass effect of the excitation electrode is not increased more than necessary. That is, the plate back amount Δ (= (fs−fe) / fs, where fs is the cutoff frequency of the piezoelectric substrate, and fe is the entire surface of the piezoelectric substrate by making the excitation electrode 25 b on the back surface side (lower surface side) sufficiently large. The frequency when the excitation electrode is attached depends on only the mass effect of the excitation electrode 25a on the surface side (upper surface side).
　励振電極２５ａ、２５ｂは、蒸着装置、あるいはスパッター装置等を用いて、例えば、下地にニッケル（Ｎｉ）を成膜し、その上に金（Ａｕ）を重ねて成膜する。金（Ａｕ）の厚さは、オーミックロスが大きくならない範囲で、主振動（Ｓ０）のみを閉じ込めモードとし、斜対称インハーモニックモード（Ａ０、Ａ１・・）、及び対称インハーモニックモード（Ｓ１、Ｓ３・・）を、閉じ込めモードとしないことが望ましい。しかし、例えば、４９０ＭＨｚ帯という極めて高い高周波帯の圧電振動素子を構成しようとすると、電極膜厚のオーミックロスを避けるように成膜すると、低次のインハーモニックモードが閉じ込めモードになることは避けられない。
　表面側に形成した励振電極２５ａから延出したリード電極２７ａは、振動領域１２上から第３の傾斜部１６ｂと、第３の支持部本体１６ａとを経由して、第２の支持部本体１５ａの上面に形成されたパッド電極２９ａに導通接続されている。また、裏面側に形成された励振電極２５ｂから延出したリード電極２７ｂは、圧電基板１０の裏面の端縁部を経由して、第２の支持部本体１５ａの裏面に形成されたパッド電極２９ｂと導通接続されている。 For the excitation electrodes 25a and 25b, for example, nickel (Ni) is formed on a base using a vapor deposition apparatus or a sputtering apparatus, and gold (Au) is stacked on the base to form a film. In the thickness of gold (Au), only the main vibration (S0) is used as a confinement mode within the range in which the ohmic loss does not increase, and the oblique symmetric inharmonic mode (A0, A1 ···), and the symmetric inharmonic mode (S1, S3) · · · It is desirable not to set the confinement mode. However, for example, when forming a piezoelectric vibration element of a very high frequency band of 490 MHz band, when the film formation is performed so as to avoid the ohmic loss of the electrode film thickness, the low-order inharmonic mode is avoided to be a confinement mode. Absent.
The lead electrode 27a extended from the excitation electrode 25a formed on the front surface side passes through the third inclined portion 16b and the third support portion main body 16a from above the vibrating region 12 to form the second support portion main body 15a. It is conductively connected to the pad electrode 29a formed on the upper surface of the. Further, the lead electrode 27b extended from the excitation electrode 25b formed on the back surface side is a pad electrode 29b formed on the back surface of the second support portion main body 15a via the end edge portion of the back surface of the piezoelectric substrate 10. It is connected conductively.
　図１（ａ）に示した実施形態例は、リード電極２７ａ、２７ｂの引出し構造の一例である。リード電極２７ａ、２７ｂの膜厚ｔ２は、振動領域の振動モードに影響を及ぼさないので、オーミックロスが無く、且つワイヤーボンディングに適するように厚くする方がよい。つまり、表面側（上面側）の励振電極２５ａの厚さをｔ１とするとき、ｔ１＜ｔ２を満たすようにリード電極２７ａ、２７ｂを構成する。図１（ａ）の下の右側には励振電極２５ａ、２５ｂのＵ－Ｕで示す部分の膜構成の拡大断面図を示す。下地にニッケル膜２５ｎ、その上に金の膜２５ｇを積層して形成されている。また、図１（ａ）の下の中央にはリード電極２７ａのＳ－Ｓで示す部分の膜構成の拡大断面図を示す。一層目にクロム膜２７ｃ、二層目に金の膜２７ｇ、三層目にニッケル膜２７ｎ、四層目に金の膜２７ｇが積層されて形成されている。これは、膜厚ｔ２の第２のリード電極（リード電極２７ａ、２７ｂ）を先に形成し、次の工程で、膜厚ｔ１の励振電極２５ａを形成するので、リード電極２７ａ、２７ｂの先端部と、励振電極２５ａ、２５ｂから延びる第１のリード電極（引出部）と、が重なるために形成されて、四層構成になる。つまり、第２のリード電極（リード電極２７ａ、２７ｂ）は、圧電基板１０上に順に第１の層（クロム膜）２７ｃと第２の層（金の膜）２７ｇを形成し、その上に励振電極２５ａから延びる第１のリード電極（引出部）の第３の層（ニッケル膜）２７ｎと、第４の層（金の膜）２７ｇが積層されて形成される。また、図１（ａ）の下の左側にリード電極２７ａのＲ－Ｒで示す部分の膜構成の拡大断面図を示す。下地にクロム膜２７ｃ、その上に金の膜２５ｇを積層して形成されている。リード電極２７ａは他の支持部を経由してもよい。ただ、リード電極２７ａ、２７ｂの長さは最短であることが望ましく、リード電極２７ａ、２７ｂ同志が圧電基板１０を挟んで交差しないように配慮することにより静電容量の増加を抑えることが望ましい。
　また、図１の実施形態例では、圧電基板１０の表裏面に対向して夫々パッド電極２９ａ、２９ｂを形成する例を示した。パッド電極２９ａ、２９ｂは、リード電極２７ａ、２７ｂと同じ工程で同時に形成されるので、その膜厚はｔ２となる。圧電振動素子１をパッケージに収容する際に、後述するように、圧電振動素子１を裏返し、パッド電極２９ａとパッケージの素子搭載パッドとを導電性接着剤で機械的に固定・電気的に接続し、パッド電極２９ｂとパッケージの電極端子とをボンディングワイヤーを用いて電気的に接続する。このように圧電振動素子１を支持する部位が一点になると、導電性接着剤に起因して生じる応力を小さくすることが可能である。 The embodiment shown in FIG. 1A is an example of the lead-out structure of the lead electrodes 27a and 27b. Since the film thickness t2 of the lead electrodes 27a and 27b does not affect the vibration mode of the vibration region, there is no ohmic loss, and it is preferable to be thick so as to be suitable for wire bonding. That is, when the thickness of the excitation electrode 25a on the surface side (upper surface side) is t1, the lead electrodes 27a and 27b are configured to satisfy t1 <t2. An enlarged cross-sectional view of a film configuration of a portion indicated by UU of the excitation electrodes 25a and 25b is shown on the lower right side of FIG. 1A. A nickel film 25n is formed on a base, and a gold film 25g is laminated thereon. Further, an enlarged cross-sectional view of a film configuration of a portion indicated by SS of the lead electrode 27a is shown at the center in the lower part of FIG. 1A. A chromium film 27c is formed in the first layer, a gold film 27g in the second layer, a nickel film 27n in the third layer, and a gold film 27g in the fourth layer. This is because the second lead electrode (lead electrodes 27a and 27b) of film thickness t2 is formed first, and the excitation electrode 25a of film thickness t1 is formed in the next step, so the tip of the lead electrodes 27a and 27b And a first lead electrode (leader) extending from the excitation electrodes 25a and 25b are formed to overlap each other to form a four-layer structure. That is, the second lead electrodes (lead electrodes 27a and 27b) sequentially form the first layer (chromium film) 27c and the second layer (gold film) 27g on the piezoelectric substrate 10, and are excited thereon A third layer (nickel film) 27n of a first lead electrode (leader) extending from the electrode 25a and a fourth layer (gold film) 27g are stacked and formed. Further, an enlarged cross-sectional view of a film configuration of a portion indicated by RR of the lead electrode 27a is shown on the left side under the FIG. 1A. A chromium film 27c is formed on the base, and a gold film 25g is laminated on the chromium film 27c. The lead electrode 27a may pass through another support. However, it is desirable that the lengths of the lead electrodes 27a and 27b be the shortest, and it is desirable that the increase in capacitance be suppressed by considering that the lead electrodes 27a and 27b do not intersect with each other across the piezoelectric substrate 10.
Further, in the embodiment shown in FIG. 1, the example in which the pad electrodes 29a and 29b are respectively formed to face the front and back surfaces of the piezoelectric substrate 10 is shown. Since the pad electrodes 29a and 29b are simultaneously formed in the same process as the lead electrodes 27a and 27b, the film thickness is t2. When the piezoelectric vibrating element 1 is accommodated in a package, as described later, the piezoelectric vibrating element 1 is turned over, and the pad electrode 29a and the element mounting pad of the package are mechanically fixed and electrically connected with a conductive adhesive. The pad electrode 29b and the electrode terminal of the package are electrically connected using a bonding wire. Thus, if the site | part which supports the piezoelectric vibration element 1 becomes one point, it is possible to make the stress which originates in a conductive adhesive small.
　振動領域１２と、圧電振動素子１の支持部であるパッド電極２９ａ、２９ｂとの間にスリット２０を設ける理由は、導電性接着剤の硬化時に発生する応力の広がりを防止することにある。即ち、圧電振動素子をパッケージに導電性接着剤により支持・固定する場合には、まず第２の支持部本体１５ａの被支持部（パッド電極）２９ａに導電性接着剤を塗布し、これをパッケージ等の素子搭載パッドに載置し少し押さえる。導電性接着剤を硬化させるために高温で所定の時間保持する。高温状態では第２の支持部本体１５ａ、及びパッケージも共に膨張し、接着剤も一時的に軟化するので、第２の支持部本体１５ａには応力は生じない。導電性接着剤が硬化した後、第２の支持部本体１５ａ、及びパッケージが冷却してその温度が常温（２５℃）に戻ると、導電性接着剤、パッケージ、及び第２の支持部本体１５ａの各線膨張係数との差により、硬化した道電性接着剤から生じる応力が、第２の支持部本体１５ａから第１及び第３の支持部１４、１６、振動領域１２へと広がる。この応力の広がりを防止するために、応力緩和用のスリット２０を設けている。
　このように、スリット２０を第２の支持本体１５ａの前記境界部（連接部）へ寄せて配置したので、第２の支持部本体１５ａの被支持部（パッド電極）２９ａの面積を広く確保することができ、塗布する導電性接着剤の径を大きくすることができる。これに対して、スリット２０が第２の支持本体１５ａの被支持部（パッド電極）２９ａ寄りに配置されると、被支持部（パッド電極）２９ａの面積が狭くなり、導電性接着剤の径を小さくしなければならない。その結果、導電性接着剤内に含まれる導電フィラーの絶対量も減り、導電性が悪化し、圧電振動素子１の共振周波数が安定しなくなり周波数変動（通称、Ｆ飛び）が発生しやすくなる虞がある。
　従って、スリット２０は第２の支持本体１５ａの前記境界部（連接部）へ寄せて配置することが好ましい。 The reason why the slits 20 are provided between the vibration area 12 and the pad electrodes 29 a and 29 b which are the supporting portions of the piezoelectric vibration element 1 is to prevent the spread of the stress generated at the time of curing of the conductive adhesive. That is, when the piezoelectric vibration element is supported and fixed to the package by the conductive adhesive, first, the conductive adhesive is applied to the supported portion (pad electrode) 29a of the second support portion main body 15a, and this is packaged Place it on an element mounting pad such as, and press it a little. The conductive adhesive is held at a high temperature for a predetermined time to cure. In the high temperature state, the second support portion main body 15a and the package are both expanded and the adhesive is also temporarily softened, so that no stress is generated in the second support portion main body 15a. After the conductive adhesive cures, when the second support body 15a and the package cool and the temperature returns to normal temperature (25 ° C.), the conductive adhesive, the package, and the second support body 15a The stress generated from the hardened adhesive is spread from the second support body 15 a to the first and third supports 14 and 16 and the vibration area 12 due to the difference between the respective linear expansion coefficients. In order to prevent the spread of the stress, a slit 20 for stress relaxation is provided.
As described above, since the slit 20 is disposed close to the boundary (connecting portion) of the second support body 15a, the area of the supported portion (pad electrode) 29a of the second support body 15a is secured widely. The diameter of the conductive adhesive to be applied can be increased. On the other hand, when the slit 20 is arranged closer to the supported portion (pad electrode) 29a of the second support main body 15a, the area of the supported portion (pad electrode) 29a becomes smaller, and the diameter of the conductive adhesive Must be made smaller. As a result, the absolute amount of the conductive filler contained in the conductive adhesive is also reduced, and the conductivity is deteriorated, and the resonance frequency of the piezoelectric vibration element 1 may not be stabilized and frequency fluctuation (commonly called F jump) may easily occur. There is.
Therefore, it is preferable that the slit 20 be disposed close to the boundary (connecting portion) of the second support body 15a.
　圧電基板１０に生じる応力（∝歪）分布を求めるために、有限要素法を用いてシミュレーションを行うのが一般的である。振動領域１２における応力が少ない程、周波数温度特性、周波数再現性、周波数エージング特性の優れた圧電振動素子が得られる。
　導電性接着剤としては、シリコン系、エポキシ系、ポリイミド系、ビスマレイミド系等があるが、圧電振動素子１の脱ガスによる周波数経年変化を考慮に入れて、ポリイミド系の導電性接着剤を用いる。ポリイミド系の導電性接着剤は硬いので、離れた二カ所を支持するよりも一カ所支持の方が発生する応力の大きさを低減できる。このため、１００～５００ＭＨｚの高周波数帯、例えば４９０ＭＨｚの電圧制御型圧電発振器（Voltage Controlled Crystal Oscillator：ＶＣＸＯ）用の圧電振動素子１には、一カ所支持の構造を用いた。つまり、パッド電極２９ａは導電性接着を用いてパッケージの素子搭載パッドに機械的に固定すると共に、電気的にも接続し、他方のパッド電極２９ｂはパッケージの電極端子とボンディングワイヤーを用いて電気的に接続することにした。 In order to obtain stress (wedge strain) distribution occurring in the piezoelectric substrate 10, it is general to perform simulation using a finite element method. As the stress in the vibration region 12 is smaller, a piezoelectric vibration element having excellent frequency temperature characteristics, frequency reproducibility and frequency aging characteristics can be obtained.
As the conductive adhesive, there are silicone type, epoxy type, polyimide type, bismaleimide type, etc., taking into consideration the frequency secular change due to the degassing of the piezoelectric vibration element 1 and using the polyimide type conductive adhesive. . Since the polyimide conductive adhesive is hard, the magnitude of the stress generated by one support can be reduced rather than supporting two separate places. For this reason, a structure of one support is used for the piezoelectric vibration element 1 for a high frequency band of 100 to 500 MHz, for example, a voltage controlled crystal oscillator (VCXO) of 490 MHz. That is, the pad electrode 29a is mechanically fixed to the element mounting pad of the package using conductive adhesion and electrically connected, and the other pad electrode 29b is electrically connected using the electrode terminal of the package and the bonding wire. I decided to connect to
　また、図１に示した圧電基板１０の外形は、Ｘ軸方向の長さがＺ’軸方向の長さより長い、所謂Ｘロングとした。これは、圧電基板１０が導電性接着剤等で固定・接続される際に応力が生じるが、周知のように、ＡＴカット水晶基板のＸ軸方向に沿った両端に力を加えたときの周波周変化と、Ｚ’軸方向に沿った両端に同じ力を加えたときの周波周変化と、を比べると、Ｚ’軸方向の両端に力を加えたときの方が、周波数変化が小さい。つまり、支持点はＺ’軸方向に沿って設ける方が応力による周波数変化は小さくなり、好ましい。 The outer shape of the piezoelectric substrate 10 shown in FIG. 1 is a so-called X-long in which the length in the X-axis direction is longer than the length in the Z'-axis direction. The stress is generated when the piezoelectric substrate 10 is fixed and connected with a conductive adhesive or the like, but as is well known, the frequency when the force is applied to both ends along the X-axis direction of the AT cut quartz substrate When the circumferential change is compared with the frequency circumferential change when the same force is applied to both ends along the Z ′ axis direction, the frequency change is smaller when the force is applied to both ends in the Z ′ axis direction. That is, it is preferable to provide the support point along the Z 'axis direction because the frequency change due to stress becomes smaller.
　本発明の特徴は、励振電極２５ａ、２５ｂ、リード電極２７ａ、２７ｂ、及びパッド電極２９ａ、２９ｂの構成にある。図３（ａ）は、圧電基板１０上に形成されたリード電極２７ａ、２７ｂ、及びパッド電極２９ａ、２９ｂの構成を示す平面図である。リード電極２７ａは、表面の励振電極２５ａの端縁から延在され、第３の支持部１６の表面を経由し、第２の支持部１５の中央部の表面に設けられたパッド電極２９ａに連設するように形成されている。また、リード電極２７ｂは、裏面の励振電極２５ｂの端縁から延在され、裏面の端部を経由し、第２の支持部１５の中央部の裏面に設けられたパッド電極２９ｂに連設するように形成されている。リード電極２７ａ、２７ｂは、夫々クロム（Ｃｒ）の薄膜から成る第１層と、この第１層上に積層された金（Ａｕ）の薄膜から成る第２層と、を備えている。リード電極２７ａの一部２７ａＡのＲ－Ｒ断面を拡大した図を左側に示すように、第２の支持本体１５ａの表面側（上面側）にクロムの薄膜（クロム膜）２７ｃを下地とし、この上に金の薄膜（金の膜）２７ｇを積層成膜してリード電極２７ａを構成する。リード電極２７ｂについても同様である。
　また、第２の支持部１５の中央部の表裏面に設けられたパッド電極２９ａ、２９ｂは、夫々クロム（Ｃｒ）の薄膜から成る第１層と、この第１層上に積層された金（Ａｕ）の薄膜から成る第２層と、を備えている。パッド電極２９ａの一部２９ａＡのＴ－Ｔ断面を拡大した図を下部に示すように、第２の支持本体１５ａの表面側（上面側）にクロムの薄膜２９ｃを下地とし、この上に金の薄膜２９ｇを積層成膜してパッド電極２９ａを構成する。パッド電極２９ｂについても同様である。
　リード電極２７ａ、２７ｂ、及びパッド電極２９ａ、２９ｂは、同一工程で形成されるため、膜厚の一例は、第１層のクロム（Ｃｒ）の薄膜が１００Å（１Å＝０．１ｎｍ（ナノメートル））、金（Ａｕ）の薄膜が２０００Åと厚く形成されている。このため、リード電極２７ａ、２７ｂ、及びパッド電極２９ａ、２９ｂのオーミックロスは生ぜず、ボンディング強度も十分である。
　なお、クロム（Ｃｒ）薄膜と金（Ａｕ）薄膜との間に、他の金属膜を挟んだ構成でもよい。 The feature of the present invention resides in the configuration of the excitation electrodes 25a, 25b, the lead electrodes 27a, 27b, and the pad electrodes 29a, 29b. FIG. 3A is a plan view showing the configuration of the lead electrodes 27a and 27b and the pad electrodes 29a and 29b formed on the piezoelectric substrate 10. As shown in FIG. The lead electrode 27 a extends from the edge of the excitation electrode 25 a on the surface, passes through the surface of the third support 16, and continues to the pad electrode 29 a provided on the surface of the center of the second support 15. It is formed to set up. Further, the lead electrode 27b extends from the edge of the excitation electrode 25b on the back surface, and is connected to the pad electrode 29b provided on the back surface of the central portion of the second support 15 via the end portion on the back surface. It is formed as. Each of the lead electrodes 27a and 27b includes a first layer made of a thin film of chromium (Cr) and a second layer made of a thin film of gold (Au) stacked on the first layer. As shown on the left side of the enlarged view of the RR cross section of a part 27aA of the lead electrode 27a, a chromium thin film (chromium film) 27c is used as a base on the surface side (upper surface side) of the second support body 15a. A thin film of gold (gold film) 27g is deposited on top to form a lead electrode 27a. The same applies to the lead electrode 27b.
The pad electrodes 29a and 29b provided on the front and back surfaces of the central portion of the second support portion 15 are each formed of a first layer made of a chromium (Cr) thin film, and gold (laminated on this first layer). And a second layer made of a thin film of Au). As shown in the lower part of the enlarged view of the T-T cross section of a portion 29aA of the pad electrode 29a, a chromium thin film 29c is used as a base on the surface side (upper surface side) of the second support body 15a. A thin film 29g is deposited to form a pad electrode 29a. The same applies to the pad electrode 29b.
Since the lead electrodes 27a and 27b and the pad electrodes 29a and 29b are formed in the same step, an example of the film thickness is 100 Å (1 Å = 0.1 nm (nanometers) for the thin film of chromium (Cr) in the first layer. And gold (Au) thin film is formed as thick as 2000 Å. Therefore, ohmic loss does not occur in the lead electrodes 27a and 27b and the pad electrodes 29a and 29b, and bonding strength is also sufficient.
Note that another metal film may be sandwiched between the chromium (Cr) thin film and the gold (Au) thin film.
　図３（ｂ）は、前工程で形成されたリード電極２７ａ、２７ｂ、及びパッド電極２９ａ、２９ｂと整合するように、圧電基板１０上に形成された励振電極２５ａ、２５ｂの構成を示す平面図である。表面に励振電極２５ａが形成され、裏面に励振電極２５ａより十分に大きな励振電極２５ｂが形成される。
　ここで、励振電極２５ａ、２５ｂの形成においては、前工程で先に形成したリード電極２７ａ、２７ｂと少なくとも一部が重なり合うように励振電極２５ａ、２５ｂを形成する。例えば、図３（ｂ）に示すように、励振電極２５ａは、端部から延在されたリード電極の一部分２７ａ’を有している。当該リード電極の一部分２７ａ’が、リード電極２７ａの表面に重なり合うように構成されている。このように構成することにより、励振電極２５ａとリード電極２７ａとを電気的に確実に接続することができ、導通不良をきたすことを防止することができる。裏面側（フラット面側）に形成する励振電極２５ｂについても同様な構成としている。
　又は、前工程で先に形成するリード電極２７ｂの一部分が、励振電極２５ｂの領域に入り込む（重なり合う）ように形成してもよい。その際、共振周波数を決定するプレートバック量は、前記表面側である凹陥側の主面に形成される励振電極２５ａの質量効果のみに依存しているので、プレートバック量が設計値から変化しないように、リード電極２７ｂの一部分が、励振電極２５ａと圧電基板１０を挟んで重ならないように、励振電極２５ａの外形よりも外側に位置するように構成する。
　励振電極２５ａ、２５ｂの構成の一例は、ニッケル（Ｎｉ）の薄膜から成る第１層と、この第１層上に積層された金（Ａｕ）の薄膜から成る第２層と、を備えている。膜厚の一例は、第１層のニッケル（Ｎｉ）の薄膜が７０Åであり、金（Ａｕ）の薄膜が６００Åである。
　なお、ニッケル（Ｎｉ）薄膜と金（Ａｕ）薄膜の間に他の金属膜を挟んだ構成でもよい。 FIG. 3 (b) is a plan view showing the configuration of the excitation electrodes 25a, 25b formed on the piezoelectric substrate 10 so as to be aligned with the lead electrodes 27a, 27b and the pad electrodes 29a, 29b formed in the previous step. It is. The excitation electrode 25a is formed on the front surface, and the excitation electrode 25b is formed on the back surface sufficiently larger than the excitation electrode 25a.
Here, in the formation of the excitation electrodes 25a, 25b, the excitation electrodes 25a, 25b are formed such that at least a part thereof overlaps with the lead electrodes 27a, 27b formed in the previous step. For example, as shown in FIG. 3 (b), the excitation electrode 25a has a portion 27a 'of the lead electrode extended from the end. A portion 27a 'of the lead electrode is configured to overlap the surface of the lead electrode 27a. With such a configuration, the excitation electrode 25a and the lead electrode 27a can be electrically connected reliably, and a conduction defect can be prevented. The same configuration is applied to the excitation electrode 25b formed on the back surface side (flat surface side).
Alternatively, a part of the lead electrode 27b previously formed in the previous step may be formed so as to enter (overlap) the region of the excitation electrode 25b. At this time, the amount of plateback which determines the resonance frequency depends only on the mass effect of the excitation electrode 25a formed on the main surface on the concave side which is the surface side, so the amount of plateback does not change from the design value As described above, a part of the lead electrode 27 b is configured to be positioned outside the outer shape of the excitation electrode 25 a so that the excitation electrode 25 a and the piezoelectric substrate 10 do not overlap with each other.
One example of the configuration of the excitation electrodes 25a and 25b includes a first layer made of a thin film of nickel (Ni) and a second layer made of a thin film of gold (Au) stacked on the first layer. . An example of the film thickness is 70 Å for the thin film of nickel (Ni) in the first layer, and 600 Å for the thin film of gold (Au).
Note that another metal film may be sandwiched between the nickel (Ni) thin film and the gold (Au) thin film.
　圧電基板１０の振動領域１２の基本波周波数を４９０ＭＨｚという極めて周波数の高い高周波数帯とした場合、リード電極２７ａ、２７ｂ、及びパッド電極２９ａ、２９ｂと、励振電極２５ａ、２５ｂとの夫々の電極材料、及び電極膜厚を異ならせる理由を以下に説明する。リード電極２７ａ、２７ｂ、パッド電極２９ａ、２９ｂ、及び励振電極２５ａ、２５ｂを、例えば第１層に７０Åのニッケル（Ｎｉ）の薄膜、第２層に６００Åの金（Ａｕ）の薄膜で構成すると、主振動は十分に閉じ込めモードとなり、そのクリスタルインピーダンス（ＣＩ；等価抵抗）も小さくなるが、リード電極２７ａ、２７ｂの金（Ａｕ）の膜厚が薄いために薄膜のオーミックロスが生じる虞がある。更に、パッド電極２９ａ、２９ｂを、第１層に７０Åのニッケル（Ｎｉ）の薄膜、第２層に６００Åの金（Ａｕ）の薄膜で形成すると、ワイヤーボンディングを行う際にボンディングの強度不足となる。 When the fundamental wave frequency of the vibration area 12 of the piezoelectric substrate 10 is a high frequency band of extremely high frequency of 490 MHz, respective electrode materials of the lead electrodes 27a and 27b, the pad electrodes 29a and 29b, and the excitation electrodes 25a and 25b. The reason for making the electrode film thickness different will be described below. If lead electrodes 27a and 27b, pad electrodes 29a and 29b, and excitation electrodes 25a and 25b are formed of, for example, a thin film of nickel (Ni) of 70 Å in the first layer and a thin film of gold (Au) of 600 Å in the second layer, Although the main vibration is sufficiently confined and the crystal impedance (CI; equivalent resistance) is also reduced, the thin film of gold (Au) of the lead electrodes 27a and 27b may cause an ohmic loss of the thin film. Furthermore, when the pad electrodes 29a and 29b are formed of a thin film of nickel (Ni) of 70 Å in the first layer and a thin film of gold (Au) of 600 Å in the second layer, the bonding strength is insufficient when performing wire bonding. .
　また、リード電極２７ａ、２７ｂ、パッド電極２９ａ、２９ｂ、及び励振電極２５ａ、２５ｂを、例えば第１層に７０Åのクロム（Ｃｒ）の薄膜、第２層に６００Åの金（Ａｕ）の薄膜で構成すると、金（Ａｕ）の薄膜が薄いため、熱によりクロム（Ｃｒ）が金（Ａｕ）の薄膜に拡散し、主振動のＣＩが大きくなるという虞が生じる。また、第１層に７０Åのニッケル（Ｎｉ）の薄膜、第２層に６００Åの金（Ａｕ）の薄膜で形成されたパッド電極２９ａ、２９ｂでは、ボンディングの強度が不足する。 The lead electrodes 27a and 27b, the pad electrodes 29a and 29b, and the excitation electrodes 25a and 25b are formed of, for example, a thin film of chromium (Cr) of 70 Å in the first layer and a thin film of gold (Au) of 600 Å in the second layer. Then, since the thin film of gold (Au) is thin, chromium (Cr) is diffused into the thin film of gold (Au) by heat, which may cause a large CI of main vibration. In the pad electrodes 29a and 29b formed of a thin film of nickel (Ni) of 70 Å in the first layer and a thin film of gold (Au) of 600 Å in the second layer, bonding strength is insufficient.
　そこで本発明では、リード電極２７ａ、２７ｂ、及びパッド電極２９ａ、２９ｂと、励振電極２５ａ、２５ｂとの形成工程を分離し、且つ夫々の電極薄膜の材料、及び膜厚を、夫々の薄膜の機能に最適になるように設定することにした。つまり、励振電極２５ａ、２５ｂは、主振動を閉じ込めモードとし、近接したインハーモニックモードはできるだけ伝搬モード（非閉じ込めモード）となるように、例えば電極膜厚をニッケル７０Å、金６００Åと薄く設定した。一方、リード電極２７ａ、２７ｂ、及びパッド電極２９ａ、２９ｂは、細いリード電極の膜抵抗を低減すべく、クロム（Ｃｒ）の膜厚１００Å、金（Ａｕ）の膜厚２０００Åと厚く設定した。
　即ち、励振電極２５ａ、２５ｂは、一層目に７０Åのニッケル（Ｎｉ）と、二層目に６００Åの金（Ａｕ）とで構成され、励振電極２５ａから延在されたリード電極の一部分２７ａ’とリード電極２７ａ、励振電極２５ｂから延在されたリード電極の一部分２７ｄとリード電極２７ｂとが一部の領域で重なる部分は一層目に膜厚１００Åのクロム（Ｃｒ）と、二層目に膜厚２０００Åの金（Ａｕ）と、三層目に膜厚７０Åのニッケル（Ｎｉ）と、四層目に膜厚６００Åの金（Ａｕ）と、が積層された４層構造とした構成となる。この場合も、クロム（Ｃｒ）と金（Ａｕ）との間、又はニッケル（Ｎｉ）と金（Ａｕ）との間に他の金属の薄膜を挟んだ構成でもよい。
　上記の膜厚は一例でありこの数値に限定するものではない。励振電極２５ａ、２５ｂに、エネルギー閉じ込め理論と、薄膜のオーミックロスとを考慮して、最適の膜厚のニッケル（Ｎｉ）及び金（Ａｕ）の積層膜を用いた。また、リード電極２７ａ、２７ｂ、及びパッド電極２９ａ、２９ｂの膜厚は、薄膜のオーミックロスとボンディング強度とを考慮して、必要な厚さのクロム（Ｃｒ）と金（Ａｕ）の積層膜を用いた。
　励振電極２５ａ、２５ｂ、リード電極２７ａ、２７ｂ、及びパッド電極２９ａ、２９ｂの製造方法については後述する。 Therefore, in the present invention, the steps of forming the lead electrodes 27a and 27b and the pad electrodes 29a and 29b and the excitation electrodes 25a and 25b are separated, and the material and thickness of each electrode thin film are functions of the respective thin films. I decided to set it to be the best. That is, the excitation electrodes 25a and 25b have the main vibration as a confinement mode, and the electrode film thickness is set thin as, for example, 70 Å for nickel and 600 Å for gold so that a close inharmonic mode becomes a propagation mode (non-confined mode) as much as possible. On the other hand, the lead electrodes 27a and 27b and the pad electrodes 29a and 29b were set thickly to a film thickness of 100 Å of chromium (Cr) and a film thickness of 2000 Å of gold (Au) in order to reduce the film resistance of the thin lead electrodes.
That is, the excitation electrodes 25a, 25b are composed of 70 Å of nickel (Ni) in the first layer and gold (Au) of 600 Å in the second layer, and a portion 27a ′ of the lead electrode extended from the excitation electrode 25a. A portion where the lead electrode 27a and a part 27d of the lead electrode extended from the excitation electrode 25b overlap the lead electrode 27b in a partial region is chromium (Cr) with a film thickness of 100 Å, and a film thickness with a second layer It has a four-layer structure in which gold (Au) of 2000 Å, nickel (Ni) of 70 Å in thickness, and gold (Au) of 600 Å in thickness are stacked in the third layer. Also in this case, a thin film of another metal may be sandwiched between chromium (Cr) and gold (Au) or nickel (Ni) and gold (Au).
The above-mentioned film thickness is an example, and it is not limited to this numerical value. For the excitation electrodes 25a and 25b, a laminated film of nickel (Ni) and gold (Au) of an optimum film thickness was used in consideration of the energy confinement theory and the ohmic loss of the thin film. Further, the film thickness of the lead electrodes 27a and 27b and the pad electrodes 29a and 29b is a laminated film of chromium (Cr) and gold (Au) having a necessary thickness in consideration of the ohmic loss of the thin film and the bonding strength. Using.
The manufacturing method of excitation electrode 25a, 25b, lead electrode 27a, 27b, and pad electrode 29a, 29b is mentioned later.
　図１の実施形態例では、励振電極２５ａ、２５ｂの形状として四角形、つまり正方形、または矩形（Ｘ軸方向を長辺とする）とした例を示したが、これに限定する必要はない。図４に示す実施形態例は、表面側の励振電極２５ａが円形であり、裏面側の励振電極２５ｂは、励振電極２５ａより十分に大きな四角形である。なお、裏面側の励振電極２５ｂも十分に大きな円形であってもよい。
　図５に示す実施形態例は、表面側の励振電極２５ａが楕円形であり、裏面側の励振電極２５ｂは、励振電極２５ａより十分に大きな四角形である。弾性定数の異方性によりＸ軸方向の変位分布と、Ｚ’軸方向の変位分が異なり、変位分布をＸ－Ｚ’平面に平行な面で切った切断面は、楕円形になる。そのため、楕円形状の励振電極２５ａを用いた場合が最も効率よく、圧電振動素子１を駆動できる。即ち、圧電振動素子１の容量比γ（＝Ｃ０／Ｃ１、ここで、Ｃ０は静電容量、Ｃ１は直列共振容量）を最小にできる。また、励振電極２５ａは長円形であってもよい。 In the embodiment shown in FIG. 1, the excitation electrodes 25a and 25b have a quadrangular shape, that is, a square or a rectangular shape (with the long side in the X-axis direction), but it is not necessary to limit to this. In the embodiment shown in FIG. 4, the excitation electrode 25a on the front side is circular, and the excitation electrode 25b on the back side is a square that is sufficiently larger than the excitation electrode 25a. The excitation electrode 25b on the back surface side may also be a sufficiently large circle.
In the embodiment shown in FIG. 5, the excitation electrode 25a on the front surface side is elliptical, and the excitation electrode 25b on the back surface side is a square that is sufficiently larger than the excitation electrode 25a. The displacement distribution in the X-axis direction and the displacement in the Z'-axis direction differ due to the anisotropy of the elastic constant, and the cut surface obtained by cutting the displacement distribution at a plane parallel to the XZ 'plane is elliptical. Therefore, the piezoelectric vibration element 1 can be driven most efficiently when the elliptical excitation electrode 25a is used. That is, the capacitance ratio γ (= C 0 / C 1, where C 0 is a capacitance and C 1 is a series resonance capacitance) of the piezoelectric vibration element 1 can be minimized. The excitation electrode 25a may be oval.
　図６は、図１に示す圧電振動素子１の変形例の構成を示す概略平面図である。図６の変形例が、図１に示す圧電振動素子１と異なる点は、応力緩和用のスリット２０を設ける位置である。本例では、スリット２０は、薄肉の振動領域１２の一辺１２ｂの端縁より離間した第２の傾斜部１５ｂ内に形成されている。振動領域１２の一辺１２ｂに沿って、スリット２０の一方の端縁が一辺１２ｂに接するように第２の傾斜部１５ｂ内にスリット２０を形成するのではなく、第２の傾斜部１５ｂの両端縁より離間してスリット２０を設けている。つまり第２の傾斜部１５ｂには、振動領域１２の一辺１２ｂの端縁と連接する極細の傾斜部１５ｂｂが残されている。換言すれば、一辺１２ａとスリット２０との間に極細の傾斜部１５ｂｂが形成されている。 FIG. 6 is a schematic plan view showing the configuration of a modification of the piezoelectric vibrating element 1 shown in FIG. The modified example of FIG. 6 differs from the piezoelectric vibration element 1 shown in FIG. 1 in the position where the stress relaxation slit 20 is provided. In the present example, the slit 20 is formed in the second inclined portion 15 b which is separated from the end edge of the side 12 b of the thin vibration area 12. Instead of forming the slit 20 in the second inclined portion 15b so that one edge of the slit 20 is in contact with the side 12b along the side 12b of the vibration area 12, both end edges of the second inclined portion 15b The slits 20 are provided further apart. That is, in the second inclined portion 15b, an extremely thin inclined portion 15bb connected to the end edge of the side 12b of the vibration area 12 is left. In other words, the extremely thin inclined portion 15bb is formed between the side 12a and the slit 20.
　図７（ａ）、（ｂ）は、夫々図１に示す圧電振動素子１の他の変形例の構成を示す概略平面図である。図７（ａ）の変形例が、図１に示す圧電振動素子１と異なる点は、第２の支持部本体１５ａの面内に第１のスリット２０ａを設けると共に、第２の傾斜部１５ｂの面内に第２のスリット２０ｂを形成して、２個の応力緩和用のスリットを設けた点である。第１のスリット２０ａ、及び第２のスリット２０ｂを、図７（ａ）に示す平面図のようにＸ軸方向に並置するのではなく、Ｚ’軸方向に互いに離れるように段差状に配置してもよい。２個のスリット２０ａ、２０ｂを設けた方が、導電性接着剤に起因して生じる応力を、振動領域１２まで広げないようにすることが可能である。
　また、図７（ｂ）に示す変形例の構成は、図１、図６に夫々示すスリット２０の効果を合わせ持つようにした圧電振動素子であり、スリット２０は、第２の傾斜部１５ｂと第２の支持本体１５ａとに跨って構成されている。 7A and 7B are schematic plan views showing the configuration of another modification of the piezoelectric vibrating element 1 shown in FIG. 1, respectively. 7A differs from the piezoelectric vibration element 1 shown in FIG. 1 in that the first slit 20a is provided in the plane of the second support portion main body 15a, and the second inclined portion 15b is formed. The second slits 20b are formed in the plane, and two stress relaxation slits are provided. The first slits 20a and the second slits 20b are not arranged side by side in the X-axis direction as in the plan view shown in FIG. 7A, but are disposed stepwise apart from each other in the Z'-axis direction. May be Providing the two slits 20 a and 20 b can prevent the stress caused by the conductive adhesive from spreading to the vibration area 12.
Further, the configuration of the modification shown in FIG. 7B is a piezoelectric vibration element in which the effects of the slits 20 shown in FIG. 1 and FIG. 6 are respectively obtained, and the slits 20 have a second inclined portion 15b and It is configured to straddle the second support main body 15a.
　図８は、第２の実施形態に係る圧電振動素子２の構成を示す概略図である。図８（ａ）は圧電振動素子２の平面図であり、同図（ｂ）はＰ－Ｐ断面を＋Ｘ軸方向からみた断面図であり、同図（ｃ）はＰ－Ｐ断面を－Ｘ軸方向から見た断面図であり、同図（ｄ）はＱ－Ｑ断面を＋Ｚ’軸方向からみた断面図である。図１を参照し、同図と同じ機能の部分には同一符号を付して説明する。
　圧電振動素子２は、薄肉の振動領域１２、及び振動領域１２に連設された厚肉支持部１３を有する圧電基板１０と、振動領域１２の両主面に夫々対向して形成された励振電極２５ａ、２５ｂと、励振電極２５ａ、２５ｂから夫々厚肉の支持部１３に延長形成されたリード電極２７ａ、２７ｂと、リード電極２７ａ、２７ｂの夫々の終端に接続されたパッド電極２９ａ、２９ｂと、を備えている。 FIG. 8 is a schematic view showing the configuration of the piezoelectric vibrating element 2 according to the second embodiment. FIG. 8 (a) is a plan view of the piezoelectric vibrating element 2, FIG. 8 (b) is a cross-sectional view of the PP cross section viewed from the + X axis direction, and FIG. 8 (c) is a PP cross section. It is a cross-sectional view seen from the axial direction, and the same figure (d) is a cross-sectional view showing the QQ cross-section from the + Z ′ axis direction. The parts having the same functions as those in FIG.
The piezoelectric vibration element 2 includes a thin vibration region 12 and a piezoelectric substrate 10 having a thick support portion 13 connected to the vibration region 12, and an excitation electrode formed to face both main surfaces of the vibration region 12. 25a, 25b, lead electrodes 27a, 27b extended from the excitation electrodes 25a, 25b to the thick support portion 13, and pad electrodes 29a, 29b connected to respective ends of the lead electrodes 27a, 27b, Is equipped.
　圧電基板１０は、矩形で且つ薄肉平板状の振動領域１２と、振動領域１２周縁の四辺に沿って一体化された四角い環状の厚肉支持部１３と、を備えている。
　厚肉支持部１３は、振動領域１２の主面の対向する２つの辺１２ａ、１２ｂに沿って両主面に夫々突設された第１の支持部１４、及び第２の支持部１５と、振動領域１２の一方の主面側（表面側）において第１及び第２の支持部１４、１５の夫々の両端部間を連設する突設された第３の支持部１６と、前記第３の支持部１６と対向する振動領域１２の一辺１２ｄの他方の主面側（裏面側）に沿って突設された第４の支持部１７と、を備えている。 The piezoelectric substrate 10 includes a rectangular thin-walled flat vibration region 12 and a square annular thick support portion 13 integrated along the four sides of the periphery of the vibration region 12.
The thick support portion 13 includes a first support portion 14 and a second support portion 15 which are provided on the two principal surfaces of the main surface of the vibration area 12 so as to project along the two opposing sides 12a and 12b. And a third supporting portion 16 provided in a protruding manner so as to connect between both end portions of the first and second supporting portions 14 and 15 on one main surface side (surface side) of the vibration area 12; And a fourth support portion 17 provided to project along the other principal surface side (rear surface side) of one side 12d of the vibration area 12 opposed to the support portion 16 of the fourth embodiment.
　第１の支持部１４は、薄肉平板状の振動領域１２の一辺１２ａに連設し、両主面に夫々突設されている。振動領域１２の一辺１２ａから離間するにつれて厚みが漸増する第１の傾斜部１４ｂと、第１の傾斜部１４ｂの他端縁に連設する厚肉四角柱状の第１の支持部本体１４ａと、を備えている。つまり、図８（ｄ）に示すように、第１の支持部１４は、振動領域１２の両主面側に突設して形成されている。
　同様に、第２の支持部１５は、薄肉平板状の振動領域１２の一辺１２ｂに連設し、両主面側に夫々突設されている。振動領域１２の一辺１２ｂから離間するにつれて厚みが漸増する第２の傾斜部１５ｂと、第２の傾斜部１５ｂの他端縁に連設する厚肉四角柱状の第２の支持部本体１５ａと、を備えている。 The first support portion 14 is connected to one side 12 a of the thin flat plate-like vibration region 12 and is provided to protrude on both main surfaces. A first inclined portion 14b whose thickness gradually increases as it is separated from one side 12a of the vibration region 12, and a thick support portion 14b having a thick rectangular prism-like first supporting portion main body 14a connected to the other end edge of the first inclined portion 14b; Is equipped. That is, as shown in FIG. 8 (d), the first support portion 14 is formed to protrude on both principal surface sides of the vibration area 12.
Similarly, the second support portion 15 is connected to one side 12 b of the thin flat plate-like vibration region 12 and is provided to protrude on both main surface sides. A second inclined portion 15b whose thickness gradually increases as it is separated from one side 12b of the vibration area 12, and a thick square prism second supporting portion main body 15a connected to the other end edge of the second inclined portion 15b; Is equipped.
　第３の支持部１６は、薄肉平板状の振動領域１２の表面側に、一辺１２ｃに連設し、振動領域１２の一辺１２ｃから離間するにつれて厚みが漸増する第３の傾斜部１６ｂと、第３の傾斜部１６ｂの他端縁に連設する厚肉四角柱状の第３の支持部本体１６ａと、を備えている。つまり、第３の支持部１６は、振動領域１２の一方の主面側（表面側）に突設して形成されている。
　また、第４の支持部１７は、薄肉の振動領域１２の裏面側に、第３の支持部１６と対向するように、振動領域１２の一辺１２ｄに連設し、振動領域１２の一辺１２ｄから離間するにつれて厚みが漸増する第４の傾斜部１７ｂと、第４の傾斜部１７ｂの他端縁に連設する厚肉四角柱状の第４の支持部本体１７ａと、を備えている。
　第３の支持部１６と第４の支持部１７とは、振動領域１２の中点に関し、点対称の関係にあり、第１、第２、第３及び第４の支持部１４、１５、１６及び１７は、夫々の端部が連結されて、四角い環状を形成し、その中央部に振動領域１２を保持するように構成されている。
　なお、支持部本体（第１の支持部本体１４ａ～第４の支持部本体１７ａ）とは、Ｙ’軸に平行な厚みが一定の領域をいう。 The third support portion 16 is connected to the side 12c on the surface side of the thin flat plate-like vibration region 12 and has a third inclined portion 16b whose thickness gradually increases with distance from the side 12c of the vibration region 12; And a third supporting portion main body 16a having a thick-walled square pillar shape connected to the other end edge of the inclined portion 16b. That is, the third support portion 16 is formed to protrude on one main surface side (surface side) of the vibration area 12.
Further, the fourth support portion 17 is provided continuously with one side 12 d of the vibration area 12 so as to face the third support portion 16 on the back surface side of the thin vibration area 12, from the side 12 d of the vibration area 12 It has a fourth inclined portion 17b whose thickness gradually increases as it is separated, and a thick quadrangular prism-like fourth supporting portion main body 17a connected to the other end edge of the fourth inclined portion 17b.
The third support portion 16 and the fourth support portion 17 are in point-symmetrical relation with respect to the middle point of the vibration region 12, and the first, second, third and fourth support portions 14, 15, 16 And 17 are configured such that their respective ends are connected to form a square ring, and the vibration area 12 is held at the central part thereof.
The support main body (the first support main body 14a to the fourth support main body 17a) refers to a region having a constant thickness parallel to the Y ′ axis.
　薄肉の振動領域１２は、その周縁の四辺を第１、第２、第３、及び第４の支持部１４、１５、１６、１７に包囲されている。つまり、矩形平板状の圧電基板の表裏両面からエッチングを進め、両主面に対向する２つの凹陥部を形成し、小型化を図るため不要な部位を削除して薄肉の振動領域１２を形成している。
　更に、圧電基板１０は、第２の支持部１５に少なくとも一つの応力緩和用のスリット２０が貫通形成されている。図８に示した実施形態例では、スリット２０は第２の傾斜部１５ｂと第２の支持部本体１５ａとの境界部（連接部）に沿って第２の支持部本体１５ａの面内に形成されている。また、図６、図７の実施形態と同様な部位に応力緩和用のスリットを形成する例は、同様であるので説明を省略する。
　なお、第１、及び第２の支持本体１４ａ、１５ａ夫々の表面と、第３の支持本体１６ａの表面と、は同一平面上にあり、第１、第２の支持本体１４ａ、１５ａ夫々の裏面と、第４の支持本体１ａの裏面とは同一平面上にある。 The thin vibration area 12 is surrounded by the first, second, third, and fourth supporting portions 14, 15, 16, 17 on the four sides of its peripheral edge. That is, etching is performed from both the front and back sides of the rectangular flat plate-like piezoelectric substrate to form two recessed portions facing both main surfaces, and unnecessary portions are eliminated to form a thin vibration region 12 for downsizing. ing.
Furthermore, in the piezoelectric substrate 10, at least one stress relief slit 20 is formed through the second support portion 15. In the embodiment shown in FIG. 8, the slit 20 is formed in the plane of the second support portion body 15a along the boundary portion (connected portion) between the second inclined portion 15b and the second support portion body 15a. It is done. Moreover, since the example which forms the slit for stress relaxation in the site | part similar to embodiment of FIG. 6, FIG. 7 is the same, it abbreviate | omits description.
The surfaces of the first and second support bodies 14a and 15a and the surface of the third support body 16a are on the same plane, and the back surfaces of the first and second support bodies 14a and 15a And the back surface of the fourth support body 1a are on the same plane.
　図８に示す圧電振動素子２の励振電極２５ａ、２５ｂ、リード電極２７ａ、２７ｂ、及びパッド電極２９ａ、２９ｂの構成も、図１の圧電振動素子１のそれと同様な構成になっている。即ち、リード電極２７ａ、２７ｂ、及びパッド電極２９ａ、２９ｂと、励振電極２５ａ、２５ｂとの形成工程を分離し、且つ夫々の薄膜の材料、及び膜厚が、夫々の薄膜の機能に最適になるように設定されている。リード電極２７ａ、２７ｂ、及びパッド電極２９ａ、２９ｂは、一層目に１００Åのクロム（Ｃｒ）と、二層目に２０００Åの金（Ａｕ）とで構成されている。
　即ち、励振電極２５ａ、２５ｂは、一層目に７０Åのニッケル（Ｎｉ）と、二層目に６００Åの金（Ａｕ）とで構成され、励振電極２５ａから延在されたリード電極の一部分２７ａ’とリード電極２７ａ、励振電極２５ｂから延在されたリード電極の一部分２７ｄとリード電極２７ｂとが一部の領域で重なる部分は一層目に膜厚１００Åのクロム（Ｃｒ）と、二層目に膜厚２０００Åの金（Ａｕ）と、三層目に膜厚７０Åのニッケル（Ｎｉ）と、四層目に膜厚６００Åの金（Ａｕ）と、が積層された４層構造とした構成となる。この場合も、クロム（Ｃｒ）と金（Ａｕ）との間、又はニッケル（Ｎｉ）と金（Ａｕ）との間に他の金属の薄膜を挟んだ構成でもよい。
　この場合も、クロム（Ｃｒ）と金（Ａｕ）との間、又はニッケル（Ｎｉ）と金（Ａｕ）との間に他の金属の薄膜を挟んだ構成でもよい。
　また、励振電極２５ａ、２５ｂの形状については、図４、及び図５の圧電振動素子１のそれと同様な形状でもよく、また応力緩和用のスリットについても、図６、及び図７と同様な位置に少なくとも１つ形成されていてもよい。 The configurations of the excitation electrodes 25a and 25b, the lead electrodes 27a and 27b, and the pad electrodes 29a and 29b of the piezoelectric vibrating element 2 shown in FIG. 8 are similar to those of the piezoelectric vibrating element 1 of FIG. That is, the steps of forming the lead electrodes 27a and 27b and the pad electrodes 29a and 29b and the excitation electrodes 25a and 25b are separated, and the material and thickness of each thin film become optimum for the function of each thin film. Is set as. The lead electrodes 27a and 27b and the pad electrodes 29a and 29b are composed of 100 Å of chromium (Cr) in the first layer and 2000 Å of gold (Au) in the second layer.
That is, the excitation electrodes 25a, 25b are composed of 70 Å of nickel (Ni) in the first layer and gold (Au) of 600 Å in the second layer, and a portion 27a ′ of the lead electrode extended from the excitation electrode 25a. A portion where the lead electrode 27a and a part 27d of the lead electrode extended from the excitation electrode 25b overlap the lead electrode 27b in a partial region is chromium (Cr) with a film thickness of 100 Å, and a film thickness with a second layer It has a four-layer structure in which gold (Au) of 2000 Å, nickel (Ni) of 70 Å in thickness, and gold (Au) of 600 Å in thickness are stacked in the third layer. Also in this case, a thin film of another metal may be sandwiched between chromium (Cr) and gold (Au) or nickel (Ni) and gold (Au).
Also in this case, a thin film of another metal may be sandwiched between chromium (Cr) and gold (Au) or nickel (Ni) and gold (Au).
Further, the shapes of the excitation electrodes 25a and 25b may be similar to those of the piezoelectric vibrating element 1 of FIGS. 4 and 5, and the slits for stress relaxation also have the same positions as those of FIGS. At least one may be formed in
　励振電極２５ａのプレートバック（周波数低下量）適切に設定すると共に、リード電極２７ａ、２７ｂの膜厚をオーミックロスを低減するように設定することにより、ワイヤーボンディングに耐えられるリード電極とすることができるという効果がある。
　また、膜厚ｔ１の励振電極２５ａと同じ厚さの第１のリード電極とが、適切なプレートバック量に設定されると共に、リード電極２７ａ、２７ｂの膜厚ｔ２がオーミックロスのない膜厚に設定されることにより、圧電振動素子のＣＩ値が小さくなるという効果がある。
　また、第１のリード電極（引出）と第２のリード電極２７ａとが一部の部分で積層されており、励振電極２５ａとリード電極２７ａとの導通不良がなく、ＣＩ値を小さくすることができると共に、スプリアスの少ない圧電振動素子が得られるという効果がある。
　また、リード電極２７ａの一部の積層部分は、リード電極２７ａによる第１の層と第２の層が順に積層され、次に励振電極２５ａによる第３の層と第４の層が順に積層されているので、積層部の導通性は十分である。その上、リード電極と圧電基板との接着力は強くなり、ワイヤーボンディングに十分に耐えられるという効果がある。
　また、リード電極２７ａの一部の積層部分は、第１の層、第２の層、第３の層、第４の層が順に積層されており、積層部分の強度、導電性は十分であり、ＣＩ値の小さな圧電振動素子がえられるという効果がある。リード電極２７ａの一部の積層部分の第１の層と第３の層には、材料としてニッケル又はクロムが使われており、圧電基板との接着性と、各層間の付着力性とに優れているという利点がある。
　また、リード電極２７ａの一部の積層部分の第２の層と第４の層には、材料として金が使われており、導電性、経年変化の点で極めて優れているという利点がある。 By appropriately setting the plate back (frequency reduction amount) of the excitation electrode 25a and setting the film thickness of the lead electrodes 27a and 27b so as to reduce the ohmic loss, the lead electrode can withstand wire bonding. It has the effect of
In addition, the first lead electrode having the same thickness as the excitation electrode 25a with the film thickness t1 is set to an appropriate plateback amount, and the film thickness t2 of the lead electrodes 27a and 27b is a film thickness without ohmic loss. By being set, there is an effect that the CI value of the piezoelectric vibrating element becomes small.
In addition, the first lead electrode (leader) and the second lead electrode 27a are laminated in a part, there is no conduction failure between the excitation electrode 25a and the lead electrode 27a, and the CI value can be reduced. As a result, there is an effect that a piezoelectric vibration element with less spurious can be obtained.
The first layer and the second layer of the lead electrode 27a are sequentially stacked in a portion of the stacked portion of the lead electrode 27a, and then the third layer and the fourth layer are sequentially stacked of the excitation electrode 25a. Therefore, the conductivity of the laminated portion is sufficient. In addition, the adhesive force between the lead electrode and the piezoelectric substrate is enhanced, so that the wire bonding can be sufficiently resisted.
Further, the first layer, the second layer, the third layer, and the fourth layer are sequentially stacked in a part of the stacked portion of the lead electrode 27a, and the strength and the conductivity of the stacked portion are sufficient. There is an effect that a piezoelectric vibration element having a small CI value can be obtained. Nickel or chromium is used as the material for the first layer and the third layer of a portion of the laminated portion of the lead electrode 27a, and the adhesion to the piezoelectric substrate and the adhesion between the layers are excellent. Has the advantage of
In addition, gold is used as a material for the second layer and the fourth layer of a portion of the laminated portion of the lead electrode 27a, which has the advantage of being extremely excellent in terms of conductivity and aging.
　振動部より厚い第１～第４支持部１４～１７（図８）を有しており、厚い支持部により圧電振動素子の支持・固定が容易になるという効果がある。更に、励振電極２５ａ、２５ｂ及びリード電極２７ａ、２７ｂを適切な膜厚に設定すると、主振動のＣＩ値が小さく、主振動のＣＩ値に対する近接したスプリアスのＣＩ値の比、即ちＣＩ値比の大きな圧電振動素子が得られるという効果がある。更に、基本波を用いた高周波圧電振動素子が小型化されるという利点がある。また、図１のように、１辺が開放されているため、圧電振動素子が小型化されると共に、ＣＩ値の小さな圧電振動素子が得られるという効果がある。
　また、図１のように振動領域１２の厚さより第２の支持部１５の厚さの方が厚いため、第２の支持部１５を支持・固定することにより、振動領域１２の支持は堅牢であり、且つ高周波の圧電振動素子が得られるという効果がある。また、振動領域１２に第２の傾斜部１５ｂの一方（薄い方）が連設し、第２の傾斜部１５ｂの他方（厚い方）には第２の支持本体１５ａが連設された構成であり、圧電振動素子の保持による応力は、ほぼ第２の支持本体１５ａと第２の傾斜部１５ｂで吸収されるため、ＣＩ値が小さく、滑らかな３次曲線の周波数温度特性を有する圧電振動素子が得られるという効果がある。
　また、図２のように、圧電基板が形成されることにより、要求仕様をより適したカットアングルで構成することが可能となり、且つ仕様に沿った周波数温度特性を有し、ＣＩ値が小さく、ＣＩ値比の大きな高周波圧電振動素子が得られるという効果がある。
　また、図８のように、振動領域１２と連設してＺ’軸のマイナス側に突設部（第４の支持部１７）を設けたので、外部からの振動、衝撃に堅牢な圧電振動素子が得られるという効果がある。
　また、第２の支持部１５にスリット２０を設けることにより、導電性接着剤等を用いて第２の支持部１５を固定する際に生じる応力の広がりを、スリット２０により抑圧するという効果がある。 The first to fourth support portions 14 to 17 (FIG. 8) which are thicker than the vibration portion have an effect of facilitating the support and fixation of the piezoelectric vibration element by the thick support portion. Furthermore, when excitation electrodes 25a and 25b and lead electrodes 27a and 27b are set to appropriate film thicknesses, the CI value of the main vibration is small, and the ratio of the CI value of the near spurious to the CI value of the main vibration, There is an effect that a large piezoelectric vibrating element can be obtained. Furthermore, there is an advantage that the high frequency piezoelectric vibrating element using the fundamental wave is miniaturized. Further, as shown in FIG. 1, since one side is open, there is an effect that the piezoelectric vibration element can be miniaturized and a piezoelectric vibration element having a small CI value can be obtained.
Further, since the thickness of the second support portion 15 is thicker than the thickness of the vibration area 12 as shown in FIG. 1, the support of the vibration area 12 is robust by supporting and fixing the second support portion 15. There is an effect that a high frequency piezoelectric vibration element can be obtained. Further, one side (thin side) of the second inclined portion 15b is continuously provided in the vibration area 12, and the second support main body 15a is continuously provided in the other side (thick side) of the second inclined portion 15b. Because the stress due to the holding of the piezoelectric vibrating element is absorbed almost by the second support body 15a and the second inclined portion 15b, the piezoelectric vibrating element has a small CI value and a smooth temperature curve of a cubic curve. Has the effect of
Further, as shown in FIG. 2, by forming the piezoelectric substrate, it is possible to configure the required specification with a more suitable cut angle, and has frequency temperature characteristics in accordance with the specification, and a small CI value, There is an effect that a high frequency piezoelectric vibrating element having a large CI value ratio can be obtained.
Further, as shown in FIG. 8, since the projecting portion (fourth support portion 17) is provided continuously to the vibration region 12 and provided on the minus side of the Z 'axis, piezoelectric vibration that is robust against external vibration and impact is provided. There is an effect that a device can be obtained.
Further, by providing the slits 20 in the second support portion 15, the slits 20 have an effect of suppressing the spread of the stress generated when the second support portion 15 is fixed using a conductive adhesive or the like. .
　図８に示す第２の実施形態に係る圧電振動素子２を構成する圧電基板１０の製造方法を、図９に示す製造工程図を用いて説明する。図９は、圧電基板１０の両面に凹陥部１１、１１’を形成すると共に、圧電基板１０の外形及びスリット（図示されず）の形成に係る製造工程図である。ここでは、圧電ウェハーとして水晶ウェハーを例にし、図は断面のみを示す。工程Ｓ１では、両面がポリッシュ加工された所定の厚さ、例えば８０μｍの水晶ウェハー１０Ｗを、十分に洗浄し、乾燥した後、表裏面にスパッタリング等により、クロム（Ｃｒ）を下地にし、その上に金（Ａｕ）を積層した金属膜（耐蝕膜）Ｍを夫々成膜する。
　工程Ｓ２では、表裏面の金属膜Ｍの上に夫々フォトレジスト膜（レジスト膜と称す）Ｒを両面に塗布する。工程Ｓ３では、露光装置とマスクパターンを用いて、表裏面の凹陥部に相当する部位のレジスト膜Ｒを露光する。感光したレジスト膜Ｒを現像して、感光したレジスト膜を剥離すると、表裏面の凹陥部に相当する位置の金属膜Ｍが夫々露出する。夫々のレジスト膜Ｒから露出した各金層膜Ｍを王水等の溶液を用いて溶かして除去すると、表裏面の凹陥部に相当する位置の水晶面が露出する。 A method of manufacturing the piezoelectric substrate 10 constituting the piezoelectric vibrating element 2 according to the second embodiment shown in FIG. 8 will be described with reference to a manufacturing process diagram shown in FIG. FIG. 9 is a manufacturing process diagram according to the formation of the outer shape of the piezoelectric substrate 10 and the formation of slits (not shown) while forming the recessed portions 11 and 11 ′ on both surfaces of the piezoelectric substrate 10. Here, a quartz wafer is taken as an example of a piezoelectric wafer, and the drawing shows only a cross section. In step S1, a crystal wafer 10W having a predetermined thickness polished on both sides, for example, 80 μm, is sufficiently cleaned and dried, and then chromium (Cr) is used as a base on the front and back by sputtering or the like. A metal film (corrosion resistant film) M in which gold (Au) is laminated is formed respectively.
In step S2, a photoresist film (referred to as a resist film) R is coated on both surfaces of the metal film M on the front and back surfaces. In step S3, the resist film R at the portion corresponding to the recessed portion on the front and back surfaces is exposed using the exposure device and the mask pattern. When the exposed resist film R is developed and the exposed resist film is peeled off, the metal films M at positions corresponding to the recessed portions on the front and back surfaces are exposed. When the gold layer films M exposed from the respective resist films R are dissolved and removed using a solution such as aqua regia, the quartz surface at the position corresponding to the recessed portions on the front and back surfaces is exposed.
　工程Ｓ４では、露出した水晶面をフッ化水素酸（フッ酸）とフッ化アンモニウムとの混合液を用いて、所望の厚さになるまで表裏面からエッチングする。工程Ｓ５では、所定の溶液を用いて両面のレジスト膜Ｒを剥離し、更に露出した両面の金属膜Ｍを、王水等を用いて除去する。この段階で水晶ウェハー１０Ｗは、両主面に夫々少しずれて凹陥部１１、１１’が形成され、夫々が格子状に規則的に並んだ状態となる。工程Ｓ６では、工程Ｓ５で得られた水晶ウェハー１０Ｗの両面に金属膜Ｍ（Ｃｒ＋Ａｕ）を成膜する。工程Ｓ７では、工程Ｓ６で形成された金属膜Ｍ（Ｃｒ＋Ａｕ）の両面に夫々レジスト膜Ｒを塗布する。
　工程Ｓ８では、露光装置と所定のマスクパターンを用いて、圧電基板１０の外形とスリット（図示されず）とに相当する部位の各レジスト膜Ｒを表裏両面から感光し、現像して、各レジスト膜Ｒを剥離する。更に、露出した金属膜Ｍを王水等の溶液で溶かして除去する。 In step S4, the exposed quartz crystal surface is etched from the front and back surfaces to a desired thickness using a mixed solution of hydrofluoric acid (hydrofluoric acid) and ammonium fluoride. In step S5, the resist films R on both sides are peeled off using a predetermined solution, and the exposed metal films M on both sides are removed using aqua regia or the like. At this stage, the crystal wafer 10W is slightly deviated on both main surfaces to form the recessed portions 11 and 11 ', respectively, and they are arranged regularly in a lattice. In step S6, metal films M (Cr + Au) are formed on both sides of the quartz wafer 10W obtained in step S5. In step S7, a resist film R is applied to both surfaces of the metal film M (Cr + Au) formed in step S6.
In step S8, each resist film R at a portion corresponding to the outer shape of the piezoelectric substrate 10 and a slit (not shown) is exposed from both sides and developed using an exposure apparatus and a predetermined mask pattern. Peel the membrane R. Furthermore, the exposed metal film M is dissolved and removed with a solution such as aqua regia.
　工程Ｓ９では露出した水晶面をフッ化水素酸（フッ酸）とフッ化アンモニウムとの混合液を用いてエッチングし、圧電基板１０の外形とスリットを形成する。工程Ｓ１０では、残ったレジスト膜Ｒを剥離し、露出した余分の金属膜Ｍを溶かして除去する。この段階では水晶ウェハー１０Ｗは、圧電基板１０が支持細片で連接し、格子状に規則的に並んだ状態となる。本発明の特徴は、工程Ｓ１０に示すように、圧電基板１０の両主面に夫々凹陥部１１、１１’が形成されて振動領域１２となり、振動領域１２に連設された第３及び第４の支持部１６、１７が、圧電基板１０の中心に対して点対称に形成されていることである。
　工程Ｓ１０が終了した後、水晶ウェハー１０Ｗに格子状に規則的に並んだ各圧電基板１０の振動領域１２の厚さを、例えば光学的手法を用いて計測する。計測した各振動領域１２の厚さが所定の厚さより厚い場合には、夫々厚さの微調整を行って所定の厚さの範囲に入るようにする。 In step S9, the exposed quartz crystal face is etched using a mixture of hydrofluoric acid (hydrofluoric acid) and ammonium fluoride to form the outer shape of the piezoelectric substrate 10 and a slit. In step S10, the remaining resist film R is peeled off, and the exposed excess metal film M is dissolved and removed. At this stage, in the quartz wafer 10W, the piezoelectric substrates 10 are connected by the support strip and are regularly arranged in a lattice. The feature of the present invention is that, as shown in step S10, third and fourth members are formed on the both main surfaces of the piezoelectric substrate 10 with the recessed portions 11 and 11 'respectively forming the vibrating region 12 and connected to the vibrating region 12. The support portions 16 and 17 are formed point-symmetrically with respect to the center of the piezoelectric substrate 10.
After the step S10 is completed, the thickness of the vibration area 12 of each piezoelectric substrate 10 regularly arranged in a lattice shape on the quartz wafer 10W is measured, for example, using an optical method. When the thickness of each measured vibration area 12 is thicker than a predetermined thickness, the thickness is finely adjusted to fall within the predetermined thickness range.
　次に、水晶ウェハー１０Ｗに形成された各圧電基板１０の振動領域１２の厚さを、所定の厚さの範囲内に調整した後、各圧電基板１０に励振電極２５ａ、２５ｂ、及びリード電極２７ａ、２７ｂを形成する手順を、図１０に示す製造工程図を用いて説明する。工程Ｓ１１では、水晶ウェハー１０Ｗの表裏全面にスパッタリング等でクロム（Ｃｒ）薄膜を成膜し、その上に金（Ａｕ）薄膜を積層して、金属膜Ｍを成膜する。次に工程Ｓ１２では、金属膜Ｍの上に夫々レジストを塗布し、レジスト膜Ｒを成膜する。工程１３では、リード電極、及びパッド電極用のマスクパターンＭｋを用いて、リード電極、及びパッド電極に相当する部位のレジスト膜Ｒを露光する。次の工程Ｓ１４では、レジスト膜Ｒを現像し、不要のレジスト膜Ｒを剥離する。この剥離により露出した金属膜Ｍを王水等の溶液で溶かして除去する。リード電極、及びパッド電極の部分はそのまま残しておく。 Next, after the thickness of the vibration area 12 of each piezoelectric substrate 10 formed on the quartz wafer 10W is adjusted within a predetermined thickness range, the excitation electrodes 25a and 25b and the lead electrode 27a are provided on each piezoelectric substrate 10 , 27b will be described with reference to the manufacturing process chart shown in FIG. In step S11, a chromium (Cr) thin film is formed on the entire front and back surfaces of the quartz wafer 10W by sputtering or the like, and a gold (Au) thin film is stacked thereon to form a metal film M. Next, in step S12, a resist is applied on the metal film M, and a resist film R is formed. In step 13, the resist film R at a portion corresponding to the lead electrode and the pad electrode is exposed using the lead electrode and the mask pattern Mk for the pad electrode. In the next step S14, the resist film R is developed, and the unnecessary resist film R is peeled off. The metal film M exposed by this peeling is dissolved and removed with a solution such as aqua regia. The lead electrode and the pad electrode are left as they are.
　次の工程Ｓ１５では、水晶ウェハー１０Ｗの表裏全面にスパッタリング等でニッケル（Ｎｉ）薄膜を成膜し、その上に金（Ａｕ）薄膜を積層して、金属膜Ｍを成膜する。工程Ｓ１５の図では、煩雑さを避けるため、金属膜とレジスト膜（Ｍ＋Ｒ）を、記号Ｃを用いて表わしている。更に、金属膜Ｍの上に夫々レジストを塗布しレジスト膜Ｒを成膜する。そして、励振電極用のマスクパターンＭｋを用いて励振電極２５ａ、２５ｂに相当する部位のレジスト膜Ｒを露光する。工程Ｓ１６では、感光したレジスト膜Ｒを現像して不要のレジスト膜Ｒを、溶液を用いて剥離する。次の工程Ｓ１７では、レジスト膜Ｒが剥離して露出した金属膜Ｍを王水等の溶液で溶かして除去する。工程Ｓ１８では、符号Ｃを（Ｍ＋Ｒ）に戻して表わし、金属膜Ｍ上に残った不要のレジスト膜Ｒを剥離すると、各圧電基板１０上には（Ｎｉ＋Ａｕ）の励振電極２５ａ、２５ｂと、（Ｃｒ＋Ａｕ）のリード電極２７ａ、２７ｂ、及びパッド電極２９ａ、２９ｂが形成されている（工程Ｓ１９）。水晶ウェハー１０Ｗに連接するハーフエッチングされた支持細片を折り取りすることにより、分割された圧電振動素子２が得られる。
　本発明の第２の実施形態に係る圧電振動素子２の特徴は、圧電基板１０の両主面よりエッチングを進め、両主面に夫々対向する凹陥部１１、１１’を形成して振動領域１２とした点にあり、エッチングに要する加工時間を半減することが可能となった。また、図１１（ｄ）に示すように、Ｚｃ１、Ｚｃ２で示す２つの破線の図中外側を共にエッチングにより取り去ることにより、圧電基板の小型化が図れたことも特徴の一つである。圧電基板１０の両主面よりエッチングを進めるので、圧電基板１０の夫々の主面からエッチングにより掘られる深さを浅くすることができるので、製造時に、ウェハー内の各個片がレイアウトされている領域間で、或いはウェハー間において、薄肉となる振動部の厚みのバラツキを低減することができた。この理由として、圧電基板１０をエッチング溶液の中に長時間、浸していると、エッチング溶液内での溶液の濃度に差が生じる虞があり、当該濃度差に起因して、圧電基板１０に対するエッチングの均一性が保てなくなる虞があり、ウェハー内の各個片がレイアウトされている領域間で、或いはウェハー間で前記振動部の厚みのバラツキが発生してしまい、厚みの制御が困難となる問題があるからである。 In the next step S15, a nickel (Ni) thin film is formed on the entire front and back surfaces of the quartz wafer 10W by sputtering or the like, a gold (Au) thin film is stacked thereon, and a metal film M is formed. In the diagram of step S15, the metal film and the resist film (M + R) are represented using a symbol C in order to avoid complication. Further, a resist is applied on the metal film M, and a resist film R is formed. Then, using the mask pattern Mk for the excitation electrode, the resist film R at the portion corresponding to the excitation electrodes 25a and 25b is exposed. In step S16, the exposed resist film R is developed and the unnecessary resist film R is stripped using a solution. In the next step S17, the metal film M exposed by peeling off the resist film R is dissolved and removed with a solution such as aqua regia. In step S18, the symbol C is represented back to (M + R). When the unnecessary resist film R remaining on the metal film M is peeled off, excitation electrodes 25a and 25b of (Ni + Au) are formed on the respective piezoelectric substrates 10, The lead electrodes 27a and 27b of Cr + Au) and the pad electrodes 29a and 29b are formed (step S19). The split piezoelectric vibrating element 2 is obtained by breaking the half-etched support strip connected to the quartz wafer 10W.
The feature of the piezoelectric vibration element 2 according to the second embodiment of the present invention is that the etching proceeds from both main surfaces of the piezoelectric substrate 10 to form concave portions 11 and 11 ′ facing each other on both main surfaces. As a result, the processing time required for etching can be halved. Further, as shown in FIG. 11 (d), it is one of the features that the piezoelectric substrate can be miniaturized by removing both the outer sides in the two broken lines indicated by Zc1 and Zc2 by etching. Since the etching is advanced from both main surfaces of the piezoelectric substrate 10, the depth to be excavated from the respective main surfaces of the piezoelectric substrate 10 can be made shallow, so that the individual pieces in the wafer are laid out during manufacturing. It was possible to reduce the variation in the thickness of the vibrating portion which becomes thin between wafers or between wafers. The reason for this is that if the piezoelectric substrate 10 is immersed in the etching solution for a long time, there is a possibility that a difference may occur in the concentration of the solution in the etching solution, and the etching of the piezoelectric substrate 10 may occur due to the difference in concentration. Problem that the uniformity of the vibration part may not be maintained, and the thickness of the vibrating portion may vary between the areas where the individual pieces are laid out in the wafer or between the wafers, making it difficult to control the thickness. Because there is
　更に、図１１（ｃ）、（ｄ）に示すように、振動領域として不要な図中両端部を削除することを前提として製造方法を確立した。先行技術として掲げた従来の厚肉部を備えた構造に比べて、振動領域となる平坦な超薄部の面積を確保しながらも、圧電振動素子１のサイズを小型化することを実現できた。
　また、更に前述したように、ＡＴカット水晶基板のＸ軸方向の両端に力を加えた（実装に起因した応力・歪みを前記力として説明している）ときの周波周変化と、Ｚ’軸方向の両端に同じ力を加えたときの周波周変化と、を比べると、Ｚ’軸方向の両端に力を加えたときの方の周波周変化量を小さくできるため、圧電基板１０のＸ軸方向の長さをＺ’軸方向の長さより長い、所謂Ｘロングとしたので、Ｘ軸方向に振動部の面積を広く確保することができた。
　また、本発明に係る圧電振動素子１の振動部の全周に亘って、振動部の主面に対して表裏のうちの少なくともどちらか一方には厚肉の支持部を設けているので、振動部の端部が外部に露出することがないので、圧電振動素子１の製造時や、圧電振動素子１を容器に実装し、圧電振動子を製造する過程、等で圧電振動素子１を何かにぶつけてしまう等による圧電振動素子１の耐衝撃性等の信頼性の観点でも、強度を高く維持しているので、信頼性を高く維持することができている。 Furthermore, as shown in FIGS. 11 (c) and 11 (d), a manufacturing method was established on the premise that the both ends in the figure unnecessary as the vibration area were deleted. Compared to the structure provided with the thick part of the prior art mentioned as the prior art, the size of the piezoelectric vibration element 1 can be reduced while securing the area of the flat ultra-thin part to be the vibration area .
Further, as described above, the change in the frequency circumference when the force is applied to both ends in the X-axis direction of the AT cut quartz substrate (the stress / strain caused by mounting is described as the force), and the Z 'axis Comparing the frequency change when the same force is applied to both ends of the direction, the X direction of the piezoelectric substrate 10 can be reduced because the frequency change can be reduced when the force is applied to both ends in the Z ′ axis direction. Since the length in the direction is a so-called X-long, which is longer than the length in the Z'-axis direction, the area of the vibrating portion can be widely secured in the X-axis direction.
In addition, since a thick support portion is provided on at least one of the front and back with respect to the main surface of the vibrating portion over the entire circumference of the vibrating portion of the piezoelectric vibrating element 1 according to the present invention Since the end of the portion is not exposed to the outside, when the piezoelectric vibrating element 1 is manufactured, or the piezoelectric vibrating element 1 is mounted on a container to manufacture a piezoelectric vibrator, etc. Also from the viewpoint of the reliability such as impact resistance of the piezoelectric vibration element 1 due to impact or the like, since the strength is maintained high, the reliability can be maintained high.
　図１１は、図８に示した圧電振動素子２のより詳細な図であり、同図（ａ）は斜視図であり、同図（ｂ）は図１（ａ）におけるＱ－Ｑ断面の切り口である。図１１（ｂ）に示すように、圧電振動素子２の外形では、Ｘ軸に交わる端面に傾斜面が現出する。つまり、－Ｘ軸側の端面には傾斜面Ａ１が現出し、＋Ｘ軸側の端面には傾斜面Ａ２が現出している。傾斜面Ａ１と傾斜面Ａ２のＸＹ’平面に平行な断面形状が、異なっている。
　傾斜面Ａ１を構成する傾斜面ａ１、ａ２は、Ｘ軸に対してほぼ対称関係にあり、傾斜面Ａ２を構成する傾斜面ｂ１、ｂ２、ｂ３、ｂ４では、ｂ１とｂ４、ｂ２とｂ３とが、各々Ｘ軸に対してほぼ対称関係にあることが判明した。更に、傾斜面ａ１、ａ２のＸ軸に対する傾斜角度αと、傾斜面ｂ１、ｂ４のＸ軸に対する傾斜角度βとは、β＜αの関係にある。 FIG. 11 is a more detailed view of the piezoelectric vibrating element 2 shown in FIG. 8, wherein FIG. 11 (a) is a perspective view, and FIG. 11 (b) is a cutaway view of the QQ cross section in FIG. It is. As shown in FIG. 11B, in the outer shape of the piezoelectric vibrating element 2, an inclined surface appears on the end face intersecting the X axis. That is, the inclined surface A1 appears on the end surface on the −X axis side, and the inclined surface A2 appears on the end surface on the + X axis side. The cross-sectional shapes parallel to the XY ′ plane of the inclined surface A1 and the inclined surface A2 are different.
The inclined surfaces a1 and a2 constituting the inclined surface A1 are substantially symmetrical with respect to the X axis, and in the inclined surfaces b1, b2, b3 and b4 constituting the inclined surface A2, b1 and b4, b2 and b3 are It was found that each was approximately symmetrical with respect to the X axis. Furthermore, the inclination angle α of the inclined surfaces a1 and a2 with respect to the X axis and the inclination angle β of the inclined surfaces b1 and b4 with respect to the X axis have a relationship of β <α.
　図１、図３の実施形態例に示すように、励振電極２５ａ、２５と、リード電極２７ａ、２７ｂ及びパッド電極２９ａ、２９ｂとは、夫々異種の金属材料が用いられ、且つ適切な膜厚で構成されているため、主振動のＣＩ値が小さく、主振動のＣＩ値に対する近接したスプリアスのＣＩ値の比、即ちＣＩ値比の大きな圧電振動素子が得られるという効果がある。更に、基本波を用いた高周波圧電振動素子が小型化されると共に、支持部と振動領域の間にスリットを設けることにより、接着・固定に起因する応力の広がりを抑圧できるので、周波数温度特性、ＣＩ温度特性、及び周波数エージング特性に優れた圧電振動素子が得られるという効果がある。
　また、図１、図３、図８の実施形態例に示すように、励振電極２５ａ、２５ｂはニッケルと金の積層膜で、リード電極２７ａ、２７ｂ、及びパッド電極２９ａ、２９ｂはクロムと金の積層膜で形成されているため、主振動のＣＩ値が小さく、主振動のＣＩ値に対する近接したスプリアスのＣＩ値の比、即ちＣＩ値比の大きな、ボンディングに十分耐えられる圧電振動素子が得られるという効果がある。更に、基本波を用いた高周波圧電振動素子が小型化されると共に、振動領域の支持が強固であり、振動、衝撃等に強い圧電振動素子が得られるという効果がある。 As shown in the embodiment of FIG. 1 and FIG. 3, the excitation electrodes 25a, 25 and the lead electrodes 27a, 27b and the pad electrodes 29a, 29b respectively use different metal materials and have appropriate thickness. Since the configuration is made, there is an effect that a piezoelectric vibration element having a small CI value of the main vibration and a large ratio of the CI value of the near spurious to the CI value of the main vibration, that is, a large CI value ratio can be obtained. Furthermore, the high frequency piezoelectric vibrating element using the fundamental wave is miniaturized, and by providing the slit between the support portion and the vibration region, the spread of stress due to adhesion and fixation can be suppressed, so that the frequency temperature characteristic There is an effect that a piezoelectric vibration element excellent in CI temperature characteristics and frequency aging characteristics can be obtained.
As shown in the embodiment of FIGS. 1, 3 and 8, the excitation electrodes 25a and 25b are laminated films of nickel and gold, and the lead electrodes 27a and 27b and the pad electrodes 29a and 29b are chromium and gold. Since it is formed of a laminated film, it is possible to obtain a piezoelectric vibration element which has a small CI value of the main vibration and a large ratio of the adjacent spurious CI value to the CI value of the main vibration, that is, a large CI value ratio. It has the effect of Further, the high-frequency piezoelectric vibrating element using the fundamental wave is miniaturized, and the support of the vibrating region is strong, so that the piezoelectric vibrating element resistant to vibration, impact and the like can be obtained.
　圧電基板１０が、図２の切断角度図に示すように形成されるため、要求仕様をより適したカットアングルで構成することが可能であり、且つ仕様にそった周波数温度特性を有し、ＣＩ値が小さく、ＣＩ値比の大きな高周波圧電振動素子が得られるという効果がある。
　また、圧電基板に水晶ＡＴカット水晶基板を用いることにより、フォトリソグラフィー技術及びエッチング技法に関する実績・経験が活用できるので、圧電基板の量産が可能であるのみならず、高精度の圧電基板が得られ、ＣＩ値が小さく、ＣＩ値比の大きな圧電振動素子の歩留まりが大幅に改善されるという効果がある。 Since the piezoelectric substrate 10 is formed as shown in the cutting angle diagram of FIG. 2, it is possible to configure the required specification with a more suitable cut angle, and has frequency temperature characteristics conforming to the specification, and CI There is an effect that a high frequency piezoelectric vibrating element having a small value and a large CI value ratio can be obtained.
In addition, by using a quartz AT-cut quartz substrate as a piezoelectric substrate, it is possible to utilize the results and experiences of photolithography technology and etching technique, so that not only mass production of the piezoelectric substrate is possible but also a piezoelectric substrate with high accuracy is obtained. There is an effect that the yield of the piezoelectric vibration element having a small CI value and a large CI value ratio is significantly improved.
　図１２は、本発明に係る実施形態の圧電振動子５の構成を示す図であり、同図（ａ）は縦断面図であり、同図（ｂ）は蓋部材を省略した平面図である。圧電振動子５は、例えば図８の圧電振動素子２（圧電振動素子１でもよい）と、圧電振動素子２を収容するパッケージとを備えている。パッケージは、矩形の箱状に形成されているパッケージ本体４０と、金属、セラミック、ガラス等から成る蓋部材４９とから成る。
　パッケージ本体４０は、図１２に示すように、第１の基板４１と、第２の基板４２と、第３の基板４３とを積層して形成されており、絶縁材料として、酸化アルミニウム質のセラミック・グリーンシートを成形し、箱状とした後で、焼結して形成される。実装端子４５は、第１の基板４１の外部底面に複数形成されている。第３の基板４３は中央部が除去された環状体であり、第３の基板４３の上部周縁に例えばコバール等の金属シールリング４４が形成されている。
　第３の基板４３と第２の基板４２とにより、圧電振動素子２を収容する凹部（キャビティ）が形成される。第２の基板４２の上面の所定の位置には、導体４６により実装端子４５と電気的に導通する複数の素子搭載パッド４７が設けられている。素子搭載パッド４７の位置は、圧電振動素子１を載置した際に第２の支持部本体１４ａに形成したパッド電極２９ａに対応するように配置されている。 FIG. 12 is a view showing the configuration of the piezoelectric vibrator 5 according to the embodiment of the present invention, and FIG. 12 (a) is a longitudinal sectional view, and FIG. 12 (b) is a plan view omitting a lid member. . The piezoelectric vibrator 5 includes, for example, the piezoelectric vibration element 2 (may be the piezoelectric vibration element 1) of FIG. 8 and a package for housing the piezoelectric vibration element 2. The package comprises a package body 40 formed in a rectangular box shape and a lid member 49 made of metal, ceramic, glass or the like.
As shown in FIG. 12, the package body 40 is formed by laminating a first substrate 41, a second substrate 42, and a third substrate 43, and is made of an aluminum oxide ceramic as an insulating material. -It forms by sintering, after shape | molding a green sheet, making it into a box shape. A plurality of mounting terminals 45 are formed on the outer bottom surface of the first substrate 41. The third substrate 43 is an annular body from which the central portion is removed, and a metal seal ring 44 such as Kovar is formed on the upper peripheral edge of the third substrate 43.
The third substrate 43 and the second substrate 42 form a recess (cavity) for housing the piezoelectric vibrating element 2. A plurality of element mounting pads 47 electrically connected to the mounting terminals 45 by the conductors 46 are provided at predetermined positions on the upper surface of the second substrate 42. The position of the element mounting pad 47 is arranged to correspond to the pad electrode 29 a formed on the second support portion main body 14 a when the piezoelectric vibrating element 1 is mounted.
　圧電振動子５を固定する際にはまず、圧電振動素子２のパッド電極２９ａに導電性接着剤３０を塗布し、これを反転（裏返し）してパッケージ本体４０の素子搭載パッド４７に載置して荷重をかける。導電性接着剤３０の特性として、接着剤３０に起因する応力（∝歪）の大きさは、シリコン系接着剤、エポキシ系接着剤、ポリイミド系接着剤の順で大きくなる。また、脱ガスは、ポリイミド系接着剤、エポキシ系接着剤、シリコン系接着剤の順で大きくなる。導電性接着剤３０としては経年変化を考慮して脱ガスの少ないポリイミド系接着剤を用いることにした。 When fixing the piezoelectric vibrator 5, first, the conductive adhesive 30 is applied to the pad electrode 29 a of the piezoelectric vibrating element 2, and this is reversed (reversed) to be mounted on the element mounting pad 47 of the package main body 40. Load. As a characteristic of the conductive adhesive 30, the magnitude of the stress (strain of strain) caused by the adhesive 30 increases in the order of the silicone adhesive, the epoxy adhesive, and the polyimide adhesive. Moreover, degassing becomes large in order of a polyimide adhesive, an epoxy adhesive, and a silicone adhesive. As the conductive adhesive 30, it was decided to use a polyimide-based adhesive with little degassing in consideration of aging.
　パッケージ本体４０に搭載された圧電振動素子２の導電性接着剤３０を硬化させるために、所定の温度の高温炉に所定の時間入れる。導電性接着剤３０を硬化させた後、反転して表面側になったパッド電極２９ｂと、パッケージ本体４０の電極端子４８とをボンディングワイヤーＢＷで導通接続する。図１２（ｂ）に示すように、圧電振動素子２をパッケージ本体４０に支持・固定する部分は、一カ所（１点）であるため、支持固定により生じる応力の大きさを小さくすることが可能となる。
　アニール処理を施した後、励振電極２５ａ、２５ｂに質量を付加するか、又は質量を減じて周波数調整を行う。パッケージ本体４０の上面に形成したシールリング４４上に、蓋部材４９を載置し、真空中、又は窒素Ｎ２ガスの雰囲気中で蓋部材４９をシーム溶接して密封し、圧電振動子５が完成する。又は、パッケージ本体４０の上面に塗布した低融点ガラスに蓋部材４９を載置し、溶融して密着する方法もある。この場合もパッケージのキャビティ内は真空にするか、又は窒素Ｎ２ガス等の不活性ガスで充填して、圧電振動子５が完成する。 In order to cure the conductive adhesive 30 of the piezoelectric vibrating element 2 mounted on the package main body 40, it is placed in a high temperature furnace at a predetermined temperature for a predetermined time. After the conductive adhesive 30 is cured, the pad electrode 29b turned to the front surface side and the electrode terminal 48 of the package main body 40 are conductively connected by the bonding wire BW. As shown in FIG. 12B, the portion for supporting and fixing the piezoelectric vibrating element 2 to the package main body 40 is one point (one point), so the magnitude of the stress generated by the supporting and fixing can be reduced. It becomes.
After annealing, mass is added to the excitation electrodes 25a and 25b or mass is reduced to perform frequency adjustment. The lid member 49 is placed on the seal ring 44 formed on the upper surface of the package body 40, and the lid member 49 is seam welded and sealed in vacuum or in an atmosphere of nitrogen N 2 gas, and the piezoelectric vibrator 5 Complete. Alternatively, there is also a method of placing the lid member 49 on the low melting point glass applied to the upper surface of the package body 40, melting and adhering. Also in this case, the inside of the package cavity is evacuated or filled with an inert gas such as nitrogen N 2 gas to complete the piezoelectric vibrator 5.
　図１、図８に示す夫々の圧電振動素子１、２は、圧電基板１０の上下面に対向して夫々パッド電極２９ａ、２９ｂが形成されている。図１２に示すように、圧電振動素子２をパッケージに収容する際に、圧電振動素子２を裏返し、パッド電極２９ａとパッケージの素子搭載パッド４７とを導電性接着剤で固定・接続する。表面側になったパッド電極２９ｂと、パッケージの電極端子４８とをボンディングワイヤーＢＷで接続する。このように圧電振動素子１を支持する部位が一点になると、導電性接着剤に起因して生じる応力が小さくなる。また、パッケージに収容するに当たり、圧電振動素子２を裏返して、より大きな励振電極２５ｂを上面にすると、圧電振動素子１の周波数微調が容易となる。 In each of the piezoelectric vibrating elements 1 and 2 shown in FIGS. 1 and 8, pad electrodes 29a and 29b are formed to face the upper and lower surfaces of the piezoelectric substrate 10, respectively. As shown in FIG. 12, when the piezoelectric vibrating element 2 is housed in the package, the piezoelectric vibrating element 2 is turned over, and the pad electrode 29a and the element mounting pad 47 of the package are fixed and connected with a conductive adhesive. The pad electrode 29b on the front side and the electrode terminal 48 of the package are connected by the bonding wire BW. As described above, when the portion supporting the piezoelectric vibration element 1 becomes one point, the stress caused by the conductive adhesive decreases. Further, when the piezoelectric vibrating element 2 is turned over and the larger excitation electrode 25 b is placed on the top surface when housed in a package, the frequency fine adjustment of the piezoelectric vibrating element 1 is facilitated.
　パッド電極２９ａ、２９ｂの間隔を離して形成した圧電振動素子を構成してもよい。この場合も図１２で説明した圧電振動子５と同様に圧電振動子を構成することができる。また、パッド電極２９ａ、２９ｂを同一面上に間隔を離して形成した圧電振動素子を構成してもよい。この場合、圧電振動素子は、２カ所（２点）に導電性接着剤を塗布して、導通と支持・固定を図るようにした構造である。低背化に適した構造であるが、導電性接着剤に起因する応力が少し大きくなる虞がある。
　以上の圧電振動子５の実施の形態例では、パッケージ本体４０に積層板を用いた例を説明したが、パッケージ本体４０に単層セラミック板を用い、蓋体に絞り加工を施したキャップを用いて圧電振動子を構成してもよい。 The piezoelectric vibrating element may be configured such that the pad electrodes 29a and 29b are spaced apart from each other. Also in this case, a piezoelectric vibrator can be configured as in the case of the piezoelectric vibrator 5 described with reference to FIG. Alternatively, a piezoelectric vibration element may be formed in which the pad electrodes 29a and 29b are formed on the same surface at an interval. In this case, the piezoelectric vibration element has a structure in which a conductive adhesive is applied to two places (two points) to achieve conduction, support, and fixation. Although the structure is suitable for reducing the height, the stress due to the conductive adhesive may be slightly increased.
In the embodiment of the piezoelectric vibrator 5 described above, an example in which a laminated plate is used for the package main body 40 has been described, but a single-layer ceramic plate is used for the package main body 40 and a cap subjected to drawing processing is used for the lid. Thus, the piezoelectric vibrator may be configured.
　図２、図８の実施形態例に示すように、励振電極２５ａ、２５ｂの電極材料と、リード電極２７ａ、２７ｂ、及びパッド電極２９ａ、２９ｂの電極材料と、を異ならせ、又それらの膜厚も夫々の機能に最適なように構成した圧電振動素子１、２を用いているため、主振動のＣＩ値が小さく、主振動のＣＩ値に対する近接したスプリアスのＣＩ値の比、即ちＣＩ値比の大きな圧電振動素子２が得られるという効果がある。更に、高周波圧電振動子が小型化されると共に、図１２の実施形態例に示すように、圧電振動素子を支持する部位が一点であり、且つ支持部と振動領域の間にスリットを設けることにより、導電性接着剤に起因して生じる応力を小さくすることができるため、周波数再現性、周波数温度特性、ＣＩ温度特性、及び周波数エージング特性に優れた圧電振動子が得られるという効果がる。 As shown in the embodiment of FIGS. 2 and 8, the electrode material of the excitation electrodes 25a, 25b and the electrode materials of the lead electrodes 27a, 27b and the pad electrodes 29a, 29b are made different or their film thicknesses Also, since the piezoelectric vibration elements 1 and 2 configured to be optimal for each function are used, the CI value of the main vibration is small, and the ratio of the adjacent spurious CI value to the main vibration CI value, ie, the CI value ratio There is an effect that a large piezoelectric vibration element 2 can be obtained. Furthermore, the high-frequency piezoelectric vibrator is miniaturized, and as shown in the embodiment shown in FIG. 12, the portion supporting the piezoelectric vibration element is one point, and a slit is provided between the support portion and the vibration region. Since the stress generated due to the conductive adhesive can be reduced, it is possible to obtain a piezoelectric vibrator excellent in frequency reproducibility, frequency temperature characteristics, CI temperature characteristics, and frequency aging characteristics.
　図１３は、本発明に係る圧電デバイス６の実施形態を示す縦断面図である。電子デバイス６は、本発明の圧電振動素子２（圧電振動素子１でもよい）と、電子部品の１つであり、感温素子であるサーミスターＴｈと、圧電振動素子２、及びサーミスターＴｈを収容するパッケージと、を概略備えている。パッケージは、パッケージ本体４０ａと、蓋部材４９とを備えている。パッケージ本体４０ａは、上面側に圧電振動素子１を収容するキャビティ３１が形成され、外部下面側にサーミスターＴｈを収容する凹部３２が形成されている。キャビティ３１の内底面の端部に複数の素子搭載パッド４７が設けられ、各素子搭載パッド４７は内部導体４６で複数の実装端子４５と導通接続されている。圧電振動素子２のパッド電極２９ａに導電性接着剤３０を塗布し、これを反転し、素子搭載パッド４７に載置する。パッケージ本体４０ａの上部には、コバール等からなるシールリング４４が焼成されており、このシールリング４４に蓋部材４９を載置し、抵抗溶接機等を用いて溶接し、キャビティ３１を気密封止する。キャビティ３１内は真空にしてもよいし、不活性ガスを封入してもよい。裏面の凹部３２に半田ボール等を用いてサーミスターＴｈの端子を接続して、電子デバイス６を完成する。 FIG. 13 is a longitudinal sectional view showing an embodiment of the piezoelectric device 6 according to the present invention. The electronic device 6 includes the piezoelectric vibrating element 2 (which may be the piezoelectric vibrating element 1) of the present invention and one of the electronic components, the thermistor Th which is a temperature sensitive element, the piezoelectric vibrating element 2 and the thermistor Th. And a package to be accommodated. The package includes a package body 40 a and a lid member 49. The package body 40a has a cavity 31 for receiving the piezoelectric vibrating element 1 on the upper surface side, and a recess 32 for receiving the thermistor Th on the outer lower surface side. A plurality of element mounting pads 47 are provided at the end of the inner bottom surface of the cavity 31, and each element mounting pad 47 is conductively connected to the plurality of mounting terminals 45 by an internal conductor 46. The conductive adhesive 30 is applied to the pad electrode 29 a of the piezoelectric vibrating element 2, and this is inverted and placed on the element mounting pad 47. A seal ring 44 made of Kovar or the like is fired on the upper portion of the package body 40a. A lid member 49 is placed on the seal ring 44 and welded using a resistance welder or the like to hermetically seal the cavity 31. Do. The inside of the cavity 31 may be evacuated or may be filled with an inert gas. The terminal of the thermistor Th is connected to the recess 32 on the back surface using a solder ball or the like to complete the electronic device 6.
　以上の実施形態例では、パッケージ本体４０ａの外部下面側に凹部３２を形成し、電子部品を搭載した例を説明したが、パッケージ本体４０ａの内部底面に凹部３２を形成し、電子部品を搭載してもよい。
　また、圧電振動素子２とサーミスターＴｈとをパッケージ本体４０ａに収容した例を説明したが、パッケージ本体４０ａに収容する電子部品としては、サーミスター、コンデンサー、リアクタンス素子、半導体素子のうち少なくとも一つを収容して電子デバイスを構成することが望ましい。 In the above embodiment, the recess 32 is formed on the outer lower surface side of the package body 40a and the electronic component is mounted. However, the recess 32 is formed on the inner bottom surface of the package body 40a to mount the electronic component. May be
Further, although the example in which the piezoelectric vibrating element 2 and the thermistor Th are accommodated in the package body 40a has been described, the electronic component accommodated in the package body 40a includes at least one of a thermistor, a capacitor, a reactance element, and a semiconductor element It is desirable to house the electronic device to accommodate the
　図１３に示す実施形態例のように、圧電振動素子２とサーミスターＴｈとをパッケージ本体４０ａに収容した電子デバイス６を構成すると、感温素子のサーミスターＴｈが圧電振動素子２の極めて近くに配置されているので、圧電振動素子２の温度変化を素早く感知することができるという効果がある。また、本発明の圧電振動素子と上記の電子部品とで電子デバイスを構成することにより、高周波、且つ小型の電子デバイスが構成できるので、多方面の用途に利用できるという効果がある。
　また、電子部品に可変容量素子、サーミスター、インダクター、コンデンサーのうちの何れかを用いて電子デバイス（圧電デバイス）を構成すると、要求仕様により適した電子デバイスが、小型で且つ低コストで実現できるという効果がある。 As in the embodiment shown in FIG. 13, when the electronic device 6 in which the piezoelectric vibrating element 2 and the thermistor Th are accommodated in the package body 40 a is configured, the thermistor Th of the temperature sensing element is very close to the piezoelectric vibrating element 2. Since they are arranged, there is an effect that the temperature change of the piezoelectric vibrating element 2 can be detected quickly. Further, by constituting an electronic device by the piezoelectric vibration element of the present invention and the above electronic component, a high frequency and small electronic device can be constituted, so that there is an effect that it can be used for various applications.
In addition, when an electronic device (piezoelectric device) is configured using any one of a variable capacitance element, a thermistor, an inductor, and a capacitor for an electronic component, an electronic device suitable for the required specification can be realized in a small size and at low cost. It has the effect of
　図１４は、本発明の実施形態例に係る電子デバイスの一種である圧電発振器７の構成を示す図であって、同図（ａ）は縦断面図であり、同図（ｂ）は蓋部材を省略した平面図ある。圧電発振器７は、パッケージ本体４０ｂ、及び蓋部材４９と、圧電振動素子２と、圧電振動素子２を励振する発振回路を搭載したＩＣ部品５１と、電圧により容量が変化する可変容量素子、温度より抵抗が変化するサーミスター、インダクター等の電子部品５２の少なくとも１つと、を備えている。
　圧電振動素子２のパッド電極２９ａに導電性接着剤（ポリイミド系）３０を塗布し、これを反転してパッケージ本体４０ｂの素子搭載パッド４７に載置し、パッド電極２９ａと素子搭載パッド４７との導通を図る。反転して上面側になったパッド電極２９ｂと、パッケージ本体４０ｂの他の電極端子４８とをボンディングワイヤーにて接続し、ＩＣ部品５１の１つの電極端子５５との導通を図る。ＩＣ部品５１をパッケージ本体４０ｂの所定の位置に固定し、ＩＣ部品５１の端子と、パッケージ本体４０ｂの電極端子５５とをボンディングワイヤーＢＷにて接続する。また、電子部品５２は、パッケージ本体４０ｂの所定の位置に載置し、金属バンプ等を用いて接続する。パッケージ本体４０ｂを真空、あるいは窒素等の不活性気体で満たし、パッケージ本体４０ｂを蓋部材４９で密封して電子デバイス（圧電発振器）７を完成する。
　パッド電極２９ａとパッケージの電極端子４８とをボンディングワイヤーＢＷで接続する工法は、圧電振動素子２を支持する部位が一点になり、導電性接着剤に起因して生じる応力を小さくする。また、パッケージに収容するに当たり、圧電振動素子１を反転して、より大きな励振電極２５ｂを上面にしたので、電子デバイス（圧電発振器）７の周波数微調が容易となる。 FIG. 14 is a view showing the configuration of a piezoelectric oscillator 7 which is a type of electronic device according to an embodiment of the present invention, wherein FIG. 14 (a) is a longitudinal sectional view and FIG. Is a plan view with no The piezoelectric oscillator 7 includes the package body 40b, the lid member 49, the piezoelectric vibrating element 2, and an IC part 51 having an oscillating circuit for exciting the piezoelectric vibrating element 2, a variable capacitance element whose capacitance changes with voltage, temperature And at least one of an electronic component 52 such as a thermistor, an inductor or the like whose resistance changes.
The conductive adhesive (polyimide type) 30 is applied to the pad electrode 29a of the piezoelectric vibrating element 2, and this is inverted to be mounted on the element mounting pad 47 of the package main body 40b, and the pad electrode 29a and the element mounting pad 47 Conduct continuity. The pad electrode 29b which is inverted to the upper surface side is connected to the other electrode terminal 48 of the package main body 40b by a bonding wire, so that conduction with one electrode terminal 55 of the IC component 51 is achieved. The IC component 51 is fixed at a predetermined position of the package body 40b, and the terminal of the IC component 51 and the electrode terminal 55 of the package body 40b are connected by the bonding wire BW. In addition, the electronic component 52 is placed at a predetermined position of the package body 40b, and connected using a metal bump or the like. The package body 40 b is filled with vacuum or an inert gas such as nitrogen, and the package body 40 b is sealed with a lid 49 to complete the electronic device (piezoelectric oscillator) 7.
In the method of connecting the pad electrode 29a and the electrode terminal 48 of the package with the bonding wire BW, the portion supporting the piezoelectric vibrating element 2 becomes one point, and the stress generated due to the conductive adhesive is reduced. In addition, since the piezoelectric vibrating element 1 is inverted and the larger excitation electrode 25b is on the top when housed in the package, the frequency fine adjustment of the electronic device (piezoelectric oscillator) 7 is facilitated.
　図１４の実施形態に示した電子デバイス（圧電発振器）７は、同一圧電基板上に圧電振動素子２、ＩＣ部品５１及び電子部品を配置したが、図１５に示した実施形態の電子デバイス（圧電発振器）７は、Ｈ型のパッケージ本体６０を用い、上部に形成したキャビティ３１に圧電振動素子１を収容し、キャビティ内部を真空、又は窒素Ｎ２ガスで満たし、蓋部材６１で密封する。下部には圧電振動素子２を励振する発振回路、増幅回路等を搭載したＩＣ部品５１と、可変容量素子、及び必要に応じてインダクター、サーミスター、コンデンサー等の電子部品５２と、を金属バンプ（Ａｕバンプ）６８を介して、パッケージ本体６０の端子６７に導通・接続する。
　本発明の電子デバイス（圧電発振器）７は、圧電振動素子２と、ＩＣ部品５１及び電子部品５２とを分離し、圧電振動素子１を単独で気密封止しているために、圧電発振器７の周波数エージング特性が優れている。 The electronic device (piezoelectric oscillator) 7 shown in the embodiment of FIG. 14 has the piezoelectric vibrating element 2, the IC component 51, and the electronic component arranged on the same piezoelectric substrate, but the electronic device (piezoelectric device of the embodiment shown in FIG. The oscillator 7 uses the H-shaped package body 60, accommodates the piezoelectric vibrating element 1 in the cavity 31 formed in the upper part, fills the inside of the cavity with vacuum or nitrogen N 2 gas, and seals with the lid member 61. In the lower part, an oscillator circuit for exciting the piezoelectric vibration element 2, an IC part 51 equipped with an amplifier circuit and the like, a variable capacitance element, and electronic parts 52 such as an inductor, a thermistor and a capacitor as needed are metal bumps ( Conduction and connection are made to the terminal 67 of the package body 60 through the Au bump 68.
The electronic device (piezoelectric oscillator) 7 of the present invention separates the piezoelectric vibrating element 2 from the IC component 51 and the electronic component 52, and hermetically seals the piezoelectric vibrating element 1 alone. The frequency aging characteristics are excellent.
　図１４に示すように、圧電デバイス（例えば電圧制御型圧電発振器）を構成することにより、周波数再現性、周波数温度特性、エージング特性が優れ、小型で且つ高周波（例えば４９０ＭＨｚ帯）の電圧制御型圧電発振器が得られるという効果がある。また、圧電デバイスは基本波の圧電振動素子２を用いているので、容量比が小さく、周波数可変幅が広がる。更に、Ｓ／Ｎ比の良好な電圧制御型圧電発振器が得られるという効果がある。
　また、圧電デバイスとして圧電発振器、温度補償型圧電発振器、及び電圧制御型圧電発振器等を構成することが可能であり、周波数再現性、エージング特性が優れた圧電発振器、周波数温度特性に優れた温度補償圧電発振器、周波数が安定で可変範囲が広く、且つＳ／Ｎ比（信号雑音比）の良好な電圧制御型圧電発振器を構成することが得られるという効果がある。 As shown in FIG. 14, by configuring a piezoelectric device (for example, a voltage controlled piezoelectric oscillator), the frequency reproducibility, frequency temperature characteristics, and aging characteristics are excellent, and a small-sized voltage controlled piezoelectric of high frequency (for example, 490 MHz band) There is an effect that an oscillator can be obtained. Further, since the piezoelectric device uses the piezoelectric vibration element 2 of the fundamental wave, the capacity ratio is small, and the frequency variable width is expanded. Furthermore, there is an effect that a voltage control type piezoelectric oscillator having a good S / N ratio can be obtained.
In addition, it is possible to constitute a piezoelectric oscillator, a temperature compensation type piezoelectric oscillator, a voltage control type piezoelectric oscillator, etc. as a piezoelectric device, and a piezoelectric oscillator excellent in frequency reproducibility and aging characteristics, temperature compensation excellent in frequency temperature characteristics. There is an effect that it is possible to configure a piezoelectric oscillator, a voltage controlled piezoelectric oscillator having a stable frequency, a wide variable range, and a good S / N ratio (signal-to-noise ratio).
　図１６は本発明に係る電子機器の構成を示す概略構成図である。電子機器８は上記の圧電振動子５を備えている。圧電振動子５を用いた電子機器８としては、伝送機器等が挙げられる。これらの電子機器８において圧電振動子５は、基準信号源、あるいは電圧可変型圧電発振器（ＶＣＸＯ）等として用いられ、小型で、特性の良好な電子機器を提供できる。 FIG. 16 is a schematic configuration view showing the configuration of the electronic device according to the present invention. The electronic device 8 includes the piezoelectric vibrator 5 described above. Examples of the electronic device 8 using the piezoelectric vibrator 5 include a transmission device and the like. In these electronic devices 8, the piezoelectric vibrator 5 is used as a reference signal source or a voltage variable piezoelectric oscillator (VCXO) or the like, and can provide a compact electronic device with excellent characteristics.
　図１６の模式図に示すように、本発明の圧電振動子を電子機器の用いることにより、高周波で周波数安定度に優れ、Ｓ／Ｎ比の良好な基準周波数源を備えた電子機器が構成できるという効果がある。 As shown in the schematic view of FIG. 16, by using the piezoelectric vibrator of the present invention in an electronic device, an electronic device having a high frequency stability at high frequency and a good reference frequency source of S / N ratio can be configured. It has the effect of
　［変形実施形態］
　圧電振動素子の実装に起因した応力を更に軽減、抑圧する手法として、以下に示すごとき構造を採用することができる。
　図１７（ａ）の実施形態における圧電基板１０は、振動領域１２を有する薄肉部と、前記薄肉部の周縁に設けられ、当該薄肉部よりも厚い厚肉部とを備えた圧電基板１０であって、圧電基板においては、厚肉支持部１３には、縁辺の方向に緩衝部Ｓを介してマウント部Ｆが横並びで接続され、緩衝部Ｓは、マウント部と厚肉支持部との間にスリット２０を有し、マウント部Ｆは、マウント部Ｆと緩衝部Ｓと厚肉支持部１３との並ぶ方向に対して直交方向の両端部に、面取り部２１を有していることを特徴とする。
　図１７（ｂ）の圧電基板１０は、振動領域１２を有する薄肉部と、薄肉部の周縁に設けられ、薄肉部よりも厚い厚肉支持部１３とを備えた圧電基板１０であって、厚肉支持部１３には、緩衝部Ｓを介してマウント部Ｆが横並びで接続され、緩衝部Ｓは、マウント部Ｆと厚肉支持部１３との間にスリット２０を有し、マウント部は、マウント部Ｆと緩衝部Ｓと厚肉支持部１３との並ぶ方向に対して直交方向の両端部に切欠き部２２を有し、スリット２０の長手方向は直交方向と平行であり、マウント部Ｆの直交方向の幅を、スリットの長手方向の幅より狭く、スリットの長手方向の両端部は、マウント部Ｆの両端部よりも緩衝部Ｓの直交方向の外周寄りにあることを特徴とする。
　図１７（ｃ）の圧電基板１０は、振動領域１２を有する薄肉部と、薄肉部の周縁に設けられた厚肉支持部１３とを備えた圧電基板１０であって、厚肉支持部１３には、緩衝部Ｓとマウント部Ｆが順に連結され、緩衝部Ｓは、マウント部Ｆと厚肉支持部１３との間にスリット２０を有し、マウント部Ｆは、マウント部Ｆと緩衝部Ｓと厚肉支持部１３との並ぶ方向に対して直交方向の両端部に、切欠き部２２を有していることを特徴とする。 [Modified embodiment]
The structure shown below can be adopted as a method of further reducing and suppressing the stress caused by the mounting of the piezoelectric vibration element.
The piezoelectric substrate 10 in the embodiment of FIG. 17A is a piezoelectric substrate 10 provided with a thin portion having a vibration region 12 and a thick portion which is provided around the thin portion and thicker than the thin portion. In the piezoelectric substrate, the mount portion F is connected side by side to the thick support portion 13 via the buffer portion S in the direction of the edge, and the buffer portion S is between the mount portion and the thick support portion. The slit portion 20 is provided, and the mount portion F has chamfers 21 at both end portions in the direction orthogonal to the direction in which the mount portion F, the buffer portion S, and the thick support portion 13 are arranged. Do.
The piezoelectric substrate 10 in FIG. 17B is a piezoelectric substrate 10 provided with a thin portion having a vibration region 12 and a thick support portion 13 provided on the periphery of the thin portion and thicker than the thin portion, The mount portion F is connected side by side to the meat support portion 13 via the buffer portion S. The buffer portion S has a slit 20 between the mount portion F and the thick support portion 13. The mount portion is Notches 22 are provided at both ends orthogonal to the direction in which the mount portion F, the buffer portion S, and the thick support portion 13 are arranged, and the longitudinal direction of the slit 20 is parallel to the orthogonal direction. The width in the orthogonal direction of the slit is narrower than the width in the longitudinal direction of the slit, and both end portions in the longitudinal direction of the slit are closer to the outer periphery in the orthogonal direction of the buffer portion S than the both ends of the mount portion F.
The piezoelectric substrate 10 shown in FIG. 17C is a piezoelectric substrate 10 having a thin portion having a vibration region 12 and a thick support portion 13 provided on the periphery of the thin portion. The buffer portion S and the mount portion F are connected in order, the buffer portion S has a slit 20 between the mount portion F and the thick-walled support portion 13, and the mount portion F includes the mount portion F and the buffer portion S. It is characterized in that notches 22 are provided at both ends in the direction orthogonal to the direction in which the thick support portion 13 is arranged.
　図１８は、図１７の構造に対し、２点支持、即ちマウント部Ｆ１、及びマウント部Ｆ２の形態をとることを特徴としている。
　なお、図１７、図１８においては、厚肉支持部１３の各支持部１４、１５、１６の内壁に傾斜部が図示されている一方で、また厚肉支持部１３の外側の側壁面には図１２に示した如き傾斜面が図示されていないが、これらの傾斜部、傾斜面は図１１に示しているように対応する部位に形成されることになる。
　なお、図１７、図１８中の各符号は、上記各実施形態の同じ符号が示す部位と対応している。 FIG. 18 is characterized in that it takes the form of a two-point support, ie, a mount portion F1 and a mount portion F2, with respect to the structure of FIG.
In FIG. 17 and FIG. 18, while the inclined portions are illustrated on the inner walls of the support portions 14, 15 and 16 of the thick support portion 13, the side wall surface on the outer side of the thick support portion 13 is shown. Although the inclined surfaces as shown in FIG. 12 are not shown, the inclined portions and the inclined surfaces are formed at corresponding portions as shown in FIG.
In addition, each code | symbol in FIG. 17, FIG. 18 respond | corresponds with the site | part which the same code | symbol of said each embodiment shows.
［変形実施例その２］
　更に、図１９（ａ）は圧電振動素子２の平面図であり、同図（ｂ）は圧電振動素子１のパッド電極２９ａ（マウント部Ｆ）の実施形態例の拡大図平面図を示し、同図（ｃ）はマウント部Ｆの断面図を示している。このマウント部Ｆにおいては、接着強度を向上させるために凹凸状とすることによって面積を稼いでいる。 [Modified embodiment 2]
Further, FIG. 19 (a) is a plan view of the piezoelectric vibrating element 2, and FIG. 19 (b) shows an enlarged plan view of an embodiment of the pad electrode 29a (mount portion F) of the piezoelectric vibrating element 1, FIG. 6C shows a cross-sectional view of the mount portion F. In the mount portion F, an area is obtained by making the surface uneven so as to improve the adhesive strength.
　本発明は、逆メサ型振動子を例にして説明したが、これに限らず、１００～５００ＭＨｚの高周波数帯の超薄状のフラットな圧電基板を備えた圧電振動子にも広く適用できることは言うまでもない。 Although the present invention has been described by way of an inverted mesa type vibrator as an example, the present invention is not limited to this, and can be widely applied to a piezoelectric vibrator having an ultrathin flat piezoelectric substrate in a high frequency band of 100 to 500 MHz. Needless to say.
　１、２、３、４…圧電振動素子、５、圧電振動子、６、７…圧電デバイス、８…電子機器、１０…圧電基板、１０Ｗ…水晶ウェハー、１１、１１’…凹陥部、１２…振動領域、１２ａ、１２ｂ、１２ｃ、１２ｄ…振動領域の一辺、１３…支持部、１４…第１の支持部、１４ａ…第１の支持部本体、１４ｂ…第１の傾斜部、１５…第２の支持部、１５ａ…第２の支持部本体、１５ｂ…第２の傾斜部、１５ｂ’…極細片、１６…第３の支持部、１６ａ…第３の支持部本体、１６ｂ…第３の傾斜部、１７…第４の支持部、１７ａ…第４の支持部本体、１７ｂ…第４の傾斜部、２０…スリット、２０ａ…第１のスリット、２０ｂ…第２のスリット、２１…面取り部、２２…切欠き部、２５ａ、２５ｂ…励振電極、２７ａ、２７ｂ、２７ｇ…リード電極、２９ａ、２９ｂ、２９ｃ、２９ｇ…パッド電極、３０…導電性接着剤、３１…キャビティ、３２…凹部、３３…電子部品搭載用パッド、４０、４０ａ、４０ｂ…パッケージ本体、４１…第１の基板、４２…第２の基板、４３…第３の基板、４４…シールリング、４５…実装端子、４６…導体、４７…素子搭載パッド、４８…電極端子、４９…蓋部材、５１…ＩＣ部品、５２電子部品、５５…電極端子、６０…パッケージ本体、６１…蓋部材、６５…実装端子、６６…導体、６７…部品端子、６８…金属バンプ（Ａｕバンプ）、Ｔｈ…サーミスター、Ｆ、Ｆ１、Ｆ２…マウント部、Ｓ…緩衝部。 1, 2, 3, 4 ... piezoelectric vibration element, 5, piezoelectric vibrator, 6, 7 ... piezoelectric device, 8 ... electronic device, 10 ... piezoelectric substrate, 10 W ... crystal wafer, 11, 11 '... recessed portion, 12 ... Vibration area, 12a, 12b, 12c, 12d: one side of the vibration area, 13: support portion, 14: first support portion, 14a: first support portion main body, 14b: first inclined portion, 15: second Support portion 15a: second support portion main body, 15b: second inclined portion, 15b ′: extremely small piece, 16: third support portion, 16a: third support portion main body, 16b: third inclination Portion 17 17 fourth support portion 17a fourth support portion main body 17b fourth inclined portion 20 slit 20a first slit 20b second slit 21 chamfered portion 21 22 ... notched part, 25a, 25b ... excitation electrode, 27a, 27b, 27g ... lead electrode , 29a, 29b, 29c, 29g: pad electrode, 30: conductive adhesive, 31: cavity, 32: recess, 33: electronic component mounting pad, 40, 40a, 40b: package body, 41: first substrate , 42: second substrate, 43: third substrate, 44: seal ring, 45: mounting terminal, 46: conductor, 47: element mounting pad, 48: electrode terminal, 49: lid member, 51: IC part, DESCRIPTION OF SYMBOLS 52 electronic components, 55 ... electrode terminal, 60 ... package main body, 61 ... lid member, 65 ... mounting terminal, 66 ... conductor, 67 ... component terminal, 68 ... metal bump (Au bump), Th ... thermistor, F, F1 , F2 ... mount portion, S ... buffer portion.

Claims (19)

  1. 　振動領域を含む振動部を有する基板と、
    　前記振動領域に表裏で対向するように配置された一対の励振電極と、
    　当該一対の励振電極に電気的に接続され、前記支持部上に夫々延在して設けられたリード電極と、
    を含み、
    　前記励振電極の膜厚をｔ１とし、
    　前記リード電極の膜厚をｔ２としたとき、
    　　ｔ１＜ｔ２を満足することを特徴とする振動素子。     A substrate having a vibrating portion including a vibrating region;
    A pair of excitation electrodes arranged to face the vibration region on the front and back;
    Lead electrodes electrically connected to the pair of excitation electrodes and extended respectively on the support;
    Including
    Let the film thickness of the excitation electrode be t1,
    When the film thickness of the lead electrode is t2,
    A vibration element characterized by satisfying t1 <t2.
  2. 　前記リード電極は、
    　前記励振電極と電気的に接続され、膜厚がｔ１となる第１のリード電極と、
    　前記支持部上に設けられ、膜厚がｔ２の第２のリード電極と、を電気的に接続して構成されていることを特徴とする請求項１に記載の振動素子。     The lead electrode is
    A first lead electrode electrically connected to the excitation electrode and having a film thickness of t1;
    The vibrating element according to claim 1, characterized in that it is configured by electrically connecting a second lead electrode provided on the support portion and having a thickness of t2.
  3. 　前記リード電極は、
    　前記第１のリード電極と前記第２のリード電極とが、少なくとも一部の領域で重畳するように構成されていることを特徴とする請求項１又は２に記載の振動素子。     The lead electrode is
    The vibrating element according to claim 1, wherein the first lead electrode and the second lead electrode are configured to overlap in at least a partial region.
  4. 　前記励振電極は、前記基板上に順に第１の層と第２の層を積層してなり、
    　前記リード電極は、前記基板上に順に第３の層と第４の層を積層してなることを特徴とする請求項１又は２に記載の振動素子。     The excitation electrode is formed by sequentially laminating a first layer and a second layer on the substrate,
    The vibration element according to claim 1, wherein the lead electrode is formed by sequentially laminating a third layer and a fourth layer on the substrate.
  5. 　前記一部の領域は、
    　前記基板上に順に前記第３の層、前記第４の層、前記第１の層、前記第２の層を積層してなることを特徴とする請求項３に記載の振動素子。     The partial area is
    4. The vibration element according to claim 3, wherein the third layer, the fourth layer, the first layer, and the second layer are sequentially stacked on the substrate.
  6. 　前記第２の層と前記第４の層の材料は金であることを特徴とする請求項４に記載の振動素子。 5. The vibrating element according to claim 4, wherein a material of the second layer and the fourth layer is gold.
  7. 　前記第１の層と前記第３の層の材料は、ニッケル又はクロムであることを特徴とする請求項５又は６に記載の振動素子。 7. The vibrating element according to claim 5, wherein a material of the first layer and the third layer is nickel or chromium.
  8. 　前記基板は、
    　前記振動部と一体化され、前記振動部よりも厚みが厚い第１の厚肉部、第２の厚肉部、及び前記第１の厚肉部と前記第２の厚肉部の基端部間を連接している第３の厚肉部を有することを特徴とする請求項１又は２に記載の振動素子。     The substrate is
    A first thick portion, a second thick portion, and a proximal end portion of the first thick portion and the second thick portion which are integrated with the vibrating portion and thicker than the vibrating portion The vibration element according to claim 1 or 2, further comprising a third thick portion connecting the two.
  9. 　前記振動領域の少なくとも１辺が開放されていることを特徴とする請求項８に記載の振動素子。 The vibrating element according to claim 8, wherein at least one side of the vibrating area is open.
  10. 　前記厚肉部の主面は前記振動部の少なくとも何れかの主面よりも突設されていることを特徴とする請求項９に記載の振動素子。 The vibration element according to claim 9, wherein the main surface of the thick portion protrudes from at least one main surface of the vibration portion.
  11. 　前記第２の厚肉部は、
    　前記振動領域の一辺に連設した一方の端縁から他方の端縁に向かって離間するにつれて厚みが増加する傾斜部と、
    　当該傾斜部の前記他方の端縁に連設する厚肉部本体と、を有することを特徴とする請求項８に記載の振動素子。     The second thick portion is
    An inclined portion which increases in thickness as it moves away from one end edge of the vibration region one side to the other end edge,
    9. The vibration element according to claim 8, further comprising: a thick portion main body connected to the other end of the inclined portion.
  12. 　前記基板は、
    　水晶の結晶軸である電気軸としてのＸ軸と、機械軸としてのＹ軸と、光学軸としてのＺ軸と、からなる直交座標系の前記Ｘ軸を中心として、
    　前記Ｚ軸を前記Ｙ軸の－Ｙ方向へ所定の角度だけ傾けた軸をＺ’軸とし、
    　前記Ｙ軸を前記Ｚ軸の＋Ｚ方向へ前記所定の角度だけ傾けた軸をＹ’軸とし、
    　前記Ｘ軸と前記Ｚ’軸に平行な面で構成され、
    　前記Ｙ’軸に平行な方向を厚みとする水晶板であることを特徴とする請求項１又は２に記載の振動素子。     The substrate is
    Centering on the X-axis of an orthogonal coordinate system consisting of an X-axis as an electrical axis which is a crystal axis of quartz crystal, a Y-axis as a mechanical axis, and a Z-axis as an optical axis
    An axis obtained by inclining the Z axis by a predetermined angle in the -Y direction of the Y axis is taken as a Z 'axis,
    An axis in which the Y axis is inclined by the predetermined angle in the + Z direction of the Z axis is taken as a Y ′ axis,
    It is composed of a plane parallel to the X axis and the Z 'axis,
    The vibrating element according to claim 1 or 2, wherein the vibrating element is a quartz plate having a thickness in a direction parallel to the Y 'axis.
  13. 　前記基板は、
    　第４の厚肉部を備え、
    　前記第４の厚肉部の突設部が、前記Ｚ’軸のマイナス側にあることを特徴とする請求項８に記載の振動素子。     The substrate is
    Equipped with a fourth thick part,
    The vibration element according to claim 8, wherein the protruding portion of the fourth thick portion is on the negative side of the Z 'axis.
  14. 　前記第２の厚肉部には、
    　少なくとも一つのスリットが貫通形成されていることを特徴とする請求項８に記載の振動素子。     In the second thick portion,
    9. The vibrator element according to claim 8, wherein at least one slit is formed through.
  15. 　請求項１又は２に記載の振動素子と、
    　該振動素子を収容するパッケージと、を備えたことを特徴とする振動子。     A vibrating element according to claim 1 or 2;
    And a package for containing the vibration element.
  16. 　請求項１又は２に記載の振動素子と、
    　電子部品と、をパッケージに備えたことを特徴とする電子デバイス。     A vibrating element according to claim 1 or 2;
    An electronic device comprising: an electronic component in a package.
  17. 　前記電子部品は、可変容量素子、サーミスター、インダクター、コンデンサーのうちの何れかであることを特徴とする請求項１６に記載の電子デバイス。 The electronic device according to claim 16, wherein the electronic component is any one of a variable capacitance element, a thermistor, an inductor, and a capacitor.
  18. 　前記振動素子を励振する発振回路をパッケージに備えたことを特徴とする請求項１６に記載の電子デバイス。 The electronic device according to claim 16, wherein the package includes an oscillation circuit that excites the vibration element.
  19. 　請求項１５に記載の振動子を備えたことを特徴とする電子機器。 An electronic device comprising the vibrator according to claim 15.
PCT/JP2012/005196 2011-08-22 2012-08-20 Vibrating element, resonator, electronic device, and electronic apparatus WO2013027381A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201290000764.5U CN203747763U (en) 2011-08-22 2012-08-20 Vibrating element, vibrator, electronic element, and electronic equipment

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2011180187A JP2013046085A (en) 2011-08-22 2011-08-22 Piezoelectric vibration element, piezoelectric vibrator, electronic device, and electronic device
JP2011-180187 2011-08-22

Publications (1)

Publication Number Publication Date
WO2013027381A1 true WO2013027381A1 (en) 2013-02-28

Family

ID=47746148

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2012/005196 WO2013027381A1 (en) 2011-08-22 2012-08-20 Vibrating element, resonator, electronic device, and electronic apparatus

Country Status (3)

Country Link
JP (1) JP2013046085A (en)
CN (1) CN203747763U (en)
WO (1) WO2013027381A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105281700A (en) * 2014-07-17 2016-01-27 精工爱普生株式会社 Vibration element, vibrator, oscillator, electronic apparatus, and moving object
CN113691227A (en) * 2020-05-19 2021-11-23 精工爱普生株式会社 Vibrating element and oscillator

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6179131B2 (en) * 2013-03-05 2017-08-16 セイコーエプソン株式会社 Vibration element, vibrator, oscillator, electronic device, and moving object
JP6303372B2 (en) 2013-10-01 2018-04-04 セイコーエプソン株式会社 Vibration element, vibrator, electronic device, electronic device, and moving object
JP2016174328A (en) * 2015-03-18 2016-09-29 セイコーエプソン株式会社 Wafer manufacturing method and wafer
JP2017208798A (en) * 2016-05-13 2017-11-24 日本電波工業株式会社 Crystal oscillator and method of manufacturing crystal oscillator
JP7240250B2 (en) 2019-05-23 2023-03-15 京セラ株式会社 Piezoelectric piece for vibration element, piezoelectric vibration element and piezoelectric device

Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01144713A (en) * 1987-11-30 1989-06-07 Nippon Dempa Kogyo Co Ltd Piezoelectric vibrator
JP2000332573A (en) * 1999-05-25 2000-11-30 Toyo Commun Equip Co Ltd Piezoelectric device
JP2002009580A (en) * 2000-06-21 2002-01-11 Nippon Dempa Kogyo Co Ltd Crystal vibrator
JP2002198772A (en) * 2000-12-27 2002-07-12 Toyo Commun Equip Co Ltd High frequency piezoelectric device
JP2002271142A (en) * 2001-03-13 2002-09-20 Nippon Dempa Kogyo Co Ltd Surface-mounted quartz oscillator and its manufacturing method
JP2003198300A (en) * 2001-12-27 2003-07-11 Seiko Epson Corp Manufacturing method of piezoelectric vibrating piece, mask for forming electrode of the piezoelectric vibrating piece, the piezoelectric vibrating piece, piezoelectric vibrator and piezoelectric oscillator
JP2004048582A (en) * 2002-07-15 2004-02-12 Nippon Dempa Kogyo Co Ltd High frequency quartz oscillator
JP2004260695A (en) * 2003-02-27 2004-09-16 Kyocera Kinseki Corp Quartz resonator and its manufacturing method
JP2005203858A (en) * 2004-01-13 2005-07-28 Nippon Dempa Kogyo Co Ltd Crystal oscillator
JP2007013569A (en) * 2005-06-30 2007-01-18 Kyocera Kinseki Corp Piezoelectric oscillator
JP2007189490A (en) * 2006-01-13 2007-07-26 Epson Toyocom Corp Piezoelectric device and temperature compensating circuit chip for piezoelectric device
JP2009158999A (en) * 2007-12-25 2009-07-16 Epson Toyocom Corp Piezoelectric device
JP2009164824A (en) * 2007-12-28 2009-07-23 Epson Toyocom Corp Quartz crystal resonator element, quartz crystal device, and method for producing quartz the crystal resonator element
JP2010103963A (en) * 2008-09-29 2010-05-06 Nippon Dempa Kogyo Co Ltd Crystal vibrator and crystal vibrator

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01144713A (en) * 1987-11-30 1989-06-07 Nippon Dempa Kogyo Co Ltd Piezoelectric vibrator
JP2000332573A (en) * 1999-05-25 2000-11-30 Toyo Commun Equip Co Ltd Piezoelectric device
JP2002009580A (en) * 2000-06-21 2002-01-11 Nippon Dempa Kogyo Co Ltd Crystal vibrator
JP2002198772A (en) * 2000-12-27 2002-07-12 Toyo Commun Equip Co Ltd High frequency piezoelectric device
JP2002271142A (en) * 2001-03-13 2002-09-20 Nippon Dempa Kogyo Co Ltd Surface-mounted quartz oscillator and its manufacturing method
JP2003198300A (en) * 2001-12-27 2003-07-11 Seiko Epson Corp Manufacturing method of piezoelectric vibrating piece, mask for forming electrode of the piezoelectric vibrating piece, the piezoelectric vibrating piece, piezoelectric vibrator and piezoelectric oscillator
JP2004048582A (en) * 2002-07-15 2004-02-12 Nippon Dempa Kogyo Co Ltd High frequency quartz oscillator
JP2004260695A (en) * 2003-02-27 2004-09-16 Kyocera Kinseki Corp Quartz resonator and its manufacturing method
JP2005203858A (en) * 2004-01-13 2005-07-28 Nippon Dempa Kogyo Co Ltd Crystal oscillator
JP2007013569A (en) * 2005-06-30 2007-01-18 Kyocera Kinseki Corp Piezoelectric oscillator
JP2007189490A (en) * 2006-01-13 2007-07-26 Epson Toyocom Corp Piezoelectric device and temperature compensating circuit chip for piezoelectric device
JP2009158999A (en) * 2007-12-25 2009-07-16 Epson Toyocom Corp Piezoelectric device
JP2009164824A (en) * 2007-12-28 2009-07-23 Epson Toyocom Corp Quartz crystal resonator element, quartz crystal device, and method for producing quartz the crystal resonator element
JP2010103963A (en) * 2008-09-29 2010-05-06 Nippon Dempa Kogyo Co Ltd Crystal vibrator and crystal vibrator

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105281700A (en) * 2014-07-17 2016-01-27 精工爱普生株式会社 Vibration element, vibrator, oscillator, electronic apparatus, and moving object
US9793875B2 (en) 2014-07-17 2017-10-17 Seiko Epson Corporation Vibration element, vibrator, oscillator, electronic apparatus, and moving object
CN105281700B (en) * 2014-07-17 2020-10-20 精工爱普生株式会社 Resonator element, resonator, oscillator, electronic apparatus, and moving object
CN113691227A (en) * 2020-05-19 2021-11-23 精工爱普生株式会社 Vibrating element and oscillator
CN113691227B (en) * 2020-05-19 2023-07-04 精工爱普生株式会社 Vibrating element and oscillator

Also Published As

Publication number Publication date
JP2013046085A (en) 2013-03-04
CN203747763U (en) 2014-07-30

Similar Documents

Publication Publication Date Title
US9923544B2 (en) Piezoelectric vibration element, manufacturing method for piezoelectric vibration element, piezoelectric resonator, electronic device, and electronic apparatus
JP5796355B2 (en) Piezoelectric vibration element, piezoelectric vibrator, electronic device, and electronic apparatus
US9948275B2 (en) Piezoelectric vibration element, piezoelectric vibrator, piezoelectric oscillator, and electronic device
US9225314B2 (en) Resonating element, resonator, electronic device, electronic apparatus, and mobile object
US8791766B2 (en) Resonating element, resonator, electronic device, electronic apparatus, moving vehicle, and method of manufacturing resonating element
WO2013027381A1 (en) Vibrating element, resonator, electronic device, and electronic apparatus
JP5824967B2 (en) Vibration element, vibrator, electronic device, and electronic apparatus
US20160028369A1 (en) Resonator element, resonator, oscillator, electronic apparatus, and mobile object
JP2013042440A (en) Piezoelectric vibrating element, piezoelectric vibrator, electronic device and electronic apparatus
JP2014007693A (en) Vibration element, vibrator, electronic device, electronic apparatus, and mobile body
JP5772082B2 (en) Piezoelectric vibration element, piezoelectric vibrator, piezoelectric oscillator, and electronic device
JP5910092B2 (en) Piezoelectric vibration element, piezoelectric vibrator, electronic device, and electronic apparatus
JP5824958B2 (en) Vibration element, vibrator, electronic device, and electronic apparatus
JP5668392B2 (en) Piezoelectric vibration element, piezoelectric vibrator and piezoelectric oscillator
JP2013162265A (en) Vibration element, vibrator, electronic device, oscillator and electronic apparatus
JP5155352B2 (en) Piezoelectric device
JP6137274B2 (en) Vibration element, vibrator, electronic device, and electronic apparatus
JP2013258452A (en) Vibration element, vibrator, electronic device, electronic apparatus, mobile body, and manufacturing method of vibration element
US9172347B2 (en) Wafer, method of manufacturing package, and piezoelectric oscillator
JP2013066061A (en) Crystal oscillator and manufacturing method therefor
JP2012175405A (en) Piezoelectric vibrating element, piezoelectric vibrator, piezoelectric oscillator, and electronic equipment
JPH066167A (en) Quartz oscillator and manufacture thereof
JPH08162893A (en) Piezoelectric component and manufacture of piezoelectric component

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 201290000764.5

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12826322

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12826322

Country of ref document: EP

Kind code of ref document: A1