Classifications

• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
  • H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
  • H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
  • H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
  • H03H3/04—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks for obtaining desired frequency or temperature coefficient
• • 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
  • H03H9/0504—Holders; Supports for bulk acoustic wave devices
  • H03H9/0514—Holders; Supports for bulk acoustic wave devices consisting of mounting pads or bumps
• • 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
  • H03H9/02007—Details of bulk acoustic wave devices
  • H03H9/02086—Means for compensation or elimination of undesirable effects
• • 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
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
  • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
  • H03H9/46—Filters
  • H03H9/54—Filters comprising resonators of piezoelectric or electrostrictive material
  • H03H9/58—Multiple crystal filters

Definitions

• the present invention relates to a method for adjusting the frequency of a piezoelectric resonance component and a piezoelectric resonance component, and more specifically, to adjust the frequency by irradiating an energy beam such as an ion beam to reduce the thickness of the electrode.
• the present invention relates to a method of adjusting the frequency of a piezoelectric resonance component including a step to be performed, and a piezoelectric resonance component used in the frequency adjustment method.
• Patent Document 1 discloses an example of a frequency adjustment method for a piezoelectric resonance component.
• FIG. 8 is a schematic configuration diagram for describing the frequency adjustment method of the piezoelectric element described in Patent Document 1.
• the piezoelectric element 101 is arranged in the evacuated chamber.
• the piezoelectric element 101 has a piezoelectric body and an electrode provided on the piezoelectric body and having an aluminum force.
• a mask 102 is arranged on the surface of the piezoelectric element 101 on which the electrode is provided.
• the mask 102 has an opening 102a.
• the opening 102a is configured to expose the electrode of the piezoelectric element 101.
• a discharge electrode 103 is disposed in front of the mask 102.
• plasma 104 is generated in front of the mask 102.
• the electrode of the piezoelectric element 101 is etched by the plasma 104, and the frequency is adjusted.
• Patent Document 1 Patent No. 3252542
• the electrode on the upper surface of the piezoelectric element 101 to be etched is provided so as to reach the edges of the pair of side surfaces, a gap is generated between the side surface of the piezoelectric element 101 and the mask 102. Therefore, when the electrode of the piezoelectric element 101 is etched by the plasma, the scattered metal powder tends to scatter from a gap to a portion other than the electrode forming surface of the piezoelectric element 101 and tend to adhere. That is, the metal powder may adhere to the side surface of the piezoelectric element 101 that is continuous with the electrode forming surface.
• the insulation resistance value of the piezoelectric element 101 may be reduced or, in extreme cases, a short circuit failure may occur. Furthermore, when a bias voltage is applied to the piezoelectric element 101, migration may occur between an electrode on the upper surface of the piezoelectric element 101 and another electrode.
• a piezoelectric resonator component with a built-in load capacitance in which a capacitor element and a piezoelectric element are laminated on a case substrate in this order is known.
• this type of piezoelectric resonance component with a built-in load capacitance when the capacitor element and the piezoelectric resonance element are laminated on the case substrate, etching is performed from above the piezoelectric resonance element to adjust the frequency. Migration tends to occur between the upper electrode and other electrodes. Power! In addition, the metal powder may fall down and adhere to the electrodes of the capacitor element. Therefore, there has been a demand for a structure capable of adjusting the frequency with high accuracy without causing insulation resistance failure or short-circuit failure in this type of piezoelectric resonator component with a built-in load capacitance.
• An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and to provide a method of adjusting the frequency of a piezoelectric resonance component, which includes a step of adjusting the frequency by irradiation of an energy beam such as an ion beam, plasma, or laser light.
• a method of adjusting the frequency of a piezoelectric resonance component which makes it possible to adjust the frequency with a high degree of accuracy in which there is little risk of migration between the electrodes, which is unlikely to cause insulation resistance failure or short-circuit failure due to frequency adjustment, and the frequency adjustment.
• An object of the present invention is to provide a piezoelectric resonance component suitable for the method.
• Another object of the present invention is to adjust the frequency with a high degree of accuracy in which the frequency is adjusted by irradiating an energy ray, thereby causing a defect in insulation resistance or a short circuit, and the likelihood of migration between electrodes is reduced. It is an object of the present invention to provide a piezoelectric resonance component with a built-in load capacitance that enables the above.
• a first invention of the present application is a method for adjusting the frequency of a piezoelectric resonance component having a piezoelectric body and at least one vibrating electrode formed on an upper surface of the piezoelectric body, wherein the upper surface, the lower surface, and the A piezoelectric body having a number of side surfaces, and at least one electrode formed on an upper surface of the piezoelectric body, wherein the electrodes are formed so as to reach edges of at least a pair of the side surfaces and the upper surface.
• the inclined surface of the piezoelectric resonance component may be a flat surface or a curved surface.
• the piezoelectric resonance component further includes an electrode formed on a lower surface of the piezoelectric body, The electrodes formed on the lower surface are arranged so as to face each other via the piezoelectric body.
• the opposite parts of the electrodes formed on the upper surface and the lower surface of the piezoelectric body are energy. It constitutes a confinement type vibrating part.
• the method further includes a step of mounting the piezoelectric resonance component on a case substrate before irradiating the energy ray.
• a second invention is directed to a piezoelectric body including an upper surface, a lower surface, and a plurality of side surfaces connecting the upper surface and the lower surface; and an edge formed between the upper surface of the piezoelectric material and at least one pair of the side surface and the upper surface.
• At least one electrode formed so as to reach the upper surface of the piezoelectric body, and the pair of side surfaces is an inclined surface whose lower part is located closer to the center of the piezoelectric body than the upper end of the side surface.
• a piezoelectric resonance component characterized by the following.
• the inclined surface may be a flat surface or a curved surface.
• the electrodes formed on the upper surface and the lower surface of the piezoelectric body are opposed to each other via the piezoelectric body, and the portions forming an energy trapping type vibrating portion.
• a case substrate, a plate-shaped capacitor element mounted on the case substrate, and a piezoelectric element stacked on the capacitor element are provided.
• the piezoelectric element is constituted by the piezoelectric resonance component according to the second aspect of the present invention.
• the pair of side surfaces where the electrode edges of the piezoelectric resonance component are connected are such that a lower portion is located closer to the center of the piezoelectric body than an upper end.
• a mask with an exposed part of the electrode as an opening is placed on the upper surface of the piezoelectric resonance component, and the upper part of the mask is also irradiated with energy rays to etch the electrode. In this case, even if the metal powder constituting the electrode scatters, the metal powder simply falls down from the upper end of the inclined surface, and adheres to the inclined surface. hard.
• the first invention it is possible to adjust the frequency of the piezoelectric resonance component with high accuracy without causing insulation resistance failure, short circuit failure, and the like.
• the inclined surface of the piezoelectric resonance component When the inclined surface of the piezoelectric resonance component is flat, it can be easily formed by polishing the piezoelectric body with polishing ganite or cutting it with a dicing blade.
• the inclined surface may be a curved surface.
• a curved inclined surface can be formed by using a dicing blade or the like having the curved inclined surface.
• an electrode formed on the lower surface of the piezoelectric body is further provided, and the electrodes formed on the upper surface and the lower surface of the piezoelectric body are interposed through the piezoelectric body.
• the energy confinement type vibrating portion is constituted by the electrode opposing portion, the energy confinement type
• the frequency adjustment of the piezoelectric resonance component can be performed with high accuracy without causing a short circuit failure or a decrease in insulation resistance. Therefore, it is possible to easily provide an energy-trap type piezoelectric resonance component with less frequency variation.
• the method further includes a step of mounting the piezoelectric resonance component on the case substrate prior to the irradiation with the energy ray, the frequency adjustment is performed in a state closer to the finished product. Frequency variation of the resonance component can be effectively reduced.
• the electrode edge of the piezoelectric body is reached! / A pair of side surfaces 1S
• the lower part is located closer to the center of the piezoelectric body than the upper end, and the inclined surface is Therefore, in the method for adjusting the frequency of the piezoelectric resonance component according to the first invention, it is not only possible to adjust the frequency with high accuracy by irradiating the energy beam, but also by irradiating the energy beam with the metal powder which is a constituent material of the electrode. Even if the metal powder is scattered, the metal powder simply falls below the inclined surface, and hardly adheres to the inclined surface. Therefore, it is possible to adjust the frequency of the piezoelectric resonance component with high accuracy while reducing the risk of lowering the insulation resistance, short-circuit failure and migration between the electrodes.
• the inclined surface may be a flat surface or a curved surface.
• the inclined surface can be easily formed using abrasive gantry or a dicing blade.
• a die-sin blade having a curved cross section is used, a curved inclined surface can be easily formed.
• the piezoelectric resonance component according to the present invention further includes an electrode formed on the lower surface of the piezoelectric body and arranged so as to face the electrode formed on the upper surface.
• the resonance frequency can be adjusted with high accuracy in accordance with the present invention, and the insulation resistance at the time of frequency adjustment decreases, short-circuit failure occurs, and the like. It is possible to provide an energy trapping type piezoelectric resonance component which is less likely to cause migration between electrodes and has excellent reliability.
• the piezoelectric element according to the present invention has a configuration in which a plate-shaped capacitor element and a piezoelectric element are stacked on a case substrate. It is composed of a piezoelectric resonance component. Therefore, when the frequency is adjusted by irradiating an upward force energy beam, the frequency can be adjusted with high accuracy, and the frequency adjustment does not easily cause a decrease in insulation resistance, short-circuit failure, or migration between electrodes. . In addition, even if the metal powder falls downward, it is difficult for the plate-like capacitor element to adhere to the electrodes and the like. Accordingly, it is possible to provide a piezoelectric resonator component with a built-in load capacitance having excellent reliability.
• FIG. 1 is a schematic partially cutaway cross-sectional view for explaining a method of adjusting the frequency of a piezoelectric resonance component according to a first embodiment of the present invention.
• FIG. 2 is a side view for explaining a piezoelectric resonance component prepared in the first embodiment.
• FIG. 3 is a schematic cross-sectional view for explaining an example of a processing method in which the side surfaces of the piezoelectric body are inclined surfaces in the first embodiment.
• FIG. 4 is a cross-sectional view for explaining another example of the processing method in the first embodiment in which the side surfaces of the piezoelectric body are flat inclined surfaces.
• FIG. 5 shows an embodiment in which the side surface of the piezoelectric body has an inclined surface of +1 degree, the cross section is an inverted trapezoid, the structure when the side surface is not inclined, and the cross section in which the side surface is inclined at 1 degree.
• FIG. 4 is a diagram showing insulation resistance after frequency adjustment when a piezoelectric resonance element having a trapezoidal structure is used.
• FIG. 6 is a cross-sectional view for explaining a modification of the piezoelectric resonance component of the present invention.
• FIG. 7 is a cross-sectional view for explaining a processing method for forming an inclined surface of the piezoelectric resonance component shown in FIG. 6.
• FIG. 8 is a schematic configuration diagram for explaining an example of a conventional frequency adjustment method for a piezoelectric resonance component.
• the piezoelectric resonance component shown in FIG. 2 is prepared. That is, the piezoelectric resonance component 1 has a rectangular plate-shaped case substrate 2.
• the case substrate 2 is made of an insulating ceramic such as alumina or glass ceramic.
• Electrodes 3-5 are formed on the case substrate 2 so as to reach a pair of side surfaces and a lower surface of the upper surface force.
• the capacitor element 7 is joined to the electrodes 3-5 using conductive adhesives 6a-6c.
• the capacitor element 7 faces the dielectric substrate 8, the first and second capacitance electrodes 9 and 10 formed on the upper surface of the dielectric substrate 8, and the first and second capacitance electrodes 9 and 10. And a third capacitor electrode 11 formed on the lower surface of the dielectric substrate 8.
• the dielectric substrate 8 can be made of an appropriate dielectric ceramic such as a barium titanate-based ceramic.
• the capacitance electrodes 911 can be made of an appropriate conductive material such as Al, Ag, Cu or an alloy thereof.
• the piezoelectric resonance element 13 is fixed on the capacitor element 7 using conductive adhesives 12a and 12b.
• the piezoelectric resonance element 13 is an energy trapping type piezoelectric resonance element using a thickness slip mode.
• the piezoelectric resonance element 13 has an elongated rectangular plate-shaped piezoelectric substrate 14.
• the piezoelectric substrate 14 is made of piezoelectric ceramics such as lead titanate zirconate-based ceramics and lead titanate-based ceramics, and is polarized in its length direction.
• a first vibration electrode 15 is formed on the upper surface of the piezoelectric substrate 14, and a second vibration electrode 16 is formed on the lower surface.
• the vibrating electrodes 15, 16 are made of an appropriate conductive material such as Ag, Cu, A1, or an alloy thereof.
• the first and second vibrating electrodes 15 and 16 are opposed to each other via the piezoelectric substrate 14 at the center in the length direction of the piezoelectric substrate 14.
• the part where the vibrating electrodes 15 and 16 face constitutes an energy trap type piezoelectric vibrating part.
• the vibration electrode 15 on the upper surface reaches an edge formed by the upper surface of the piezoelectric substrate 14 and the pair of side surfaces 14a and 14b.
• the vibrating electrode 15 is formed so as to reach the lower surface via the end surface of the piezoelectric substrate 14.o
• the conductive adhesives 12a and 12b extend to the vibrating electrode 16 and the lower surface of the piezoelectric substrate 14 of the vibrating electrode 15.
• the electrode extension portions are joined to the first and second capacitance electrodes 9 and 10 of the capacitor element, respectively.
• a cap (not shown) is finally fixed on the upper surface of the case substrate 2. That is, it is mounted on the case substrate 2 so as to seal the laminated body composed of the capacitor element 3 and the piezoelectric resonance element 7 having a capping force having an opening opened downward.
• the processing step and the frequency adjustment step described below are performed before the cap is fixed.
• the prepared piezoelectric resonance element 13 is processed so that a pair of side surfaces of the piezoelectric body 14 become inclined surfaces. That is, a lower portion of the pair of side surfaces extending in the length direction of the piezoelectric body 14 is located closer to the center of the piezoelectric body 14 than the upper end. It is inclined to place. For example, as shown in a schematic sectional view of FIG. 3, after preparing a large number of piezoelectric resonance elements 13, the upper surface of the piezoelectric resonance elements 13 is polished with respect to the polishing surface 21 a of the gantry 21.
• the piezoelectric body 14 can be formed by polishing the side surface 14a of the piezoelectric body 14 with the polishing surface 21a of the polishing gantry 21 by inclining from a direction perpendicular to the direction.
• the side surface 14a is an inclined surface.
• the side surface 14b opposite to the side surface 14a is also inclined by the same polishing process.
• the side surfaces 14a and 14b are flat inclined surfaces as described above, and the piezoelectric resonance element 13 configured to have the inclined surfaces is prepared. Then, as shown in FIG. 2, after mounting the capacitor element 7 on the case substrate 2, the piezoelectric resonance element 13 having the inclined surface is fixed on the capacitor element 7.
• FIG. 1 is a schematic partial cutaway cross-sectional view for explaining a frequency adjustment step. It should be pointed out that the case substrate 2 is not shown in FIG. Further, the cross section shown in FIG. 1 is a cross section corresponding to a portion obtained by cutting the capacitor element and the piezoelectric resonance element 13 at the center of the energy trapping type vibration part of the piezoelectric resonance element 13.
• the mask 22 is arranged on the upper surface of the piezoelectric resonance element 13 after obtaining the above-mentioned laminated structure.
• the mask 22 has an opening 22a.
• the opening 22a has a shape corresponding to the planar shape of the vibrating portion of the piezoelectric resonance element 13. That is, the opening 22a is formed so as to have a planar shape corresponding to a portion where the vibrating electrodes 15 and 16 face each other.
• an ion beam is irradiated from above the mask 22 as shown by an arrow A in FIG. 1, and the frequency is adjusted so that the thickness of the vibration electrode 15 decreases.
• the frequency is adjusted so that the thickness of the vibration electrode 15 decreases.
• the metal powder only falls down. Since the side surfaces 14a and 14b are the inclined surfaces, the metal powder hardly adheres to the side surfaces 14a and 14b.
• the lower portion is positioned such that the lower portion is located closer to the center of the piezoelectric body 14 than the upper ends of the side surfaces 14a and 14b. Since the surfaces 14a and 14b are inclined, the metal powder hardly adheres to the side surfaces 14a and 14b. Therefore, in the piezoelectric resonance element 13, a decrease in insulation resistance or short-circuit failure due to adhesion of metal powder to the side surface is unlikely to occur, and migration between the electrodes between the vibrating electrodes 15 and 16 is unlikely to occur. Therefore, the frequency can be adjusted with high accuracy by ion beam irradiation, and the insulation resistance failure of the piezoelectric resonance element can be suppressed, so that a highly reliable piezoelectric resonance component can be provided.
• the frequency is adjusted while the capacitor element 7 and the piezoelectric resonance element 13 are mounted on the case substrate 2 as described above. Since the frequency adjustment is performed in a close state, the frequency variation of the piezoelectric resonance component can be more effectively reduced.
• the width dimension of the capacitor element 7 is equal to the width dimension of the lower surface of the piezoelectric body 14. Therefore, even if the metal powder falls downward as indicated by arrow B during frequency adjustment, the metal powder hardly adheres to the side surface of capacitor element 8. Therefore, the insulation resistance of the capacitor element 8 and short-circuit failure hardly occur.
• the joints made by the conductive adhesives 12a and 12b that is, the joints made by the conductive adhesive for mounting the piezoelectric resonance element 13, are not covered by the energy It is located outside the region where the confined piezoelectric vibrating section is provided. Therefore, since the metal powder hardly adheres to the joints by the conductive adhesives 12a and 12b, a short circuit or the like at the joints by the conductive adhesives 12a and 12b is reliably prevented.
• the processing step of forming the side surfaces 14a and 14b into a linear inclined surface can be performed by various methods other than the method using the grinding wheel shown in FIG.
• the piezoelectric resonance element 13 in a state where the piezoelectric resonance element 13 is disposed on the holding member 23, the piezoelectric resonance element is mounted on the piezoelectric resonance element from above by using dicing blades 24 and 25 having cut surfaces having inclined surfaces.
• the element 13 may be cut, so that the side surfaces 14a and 14b may be inclined surfaces.
• the side surfaces 14a and 14b may be inclined so that the lower side is located at the center of the piezoelectric body 14 as compared with the upper end, but from the inclination angle of the inclined surface, that is, from the direction orthogonal to the upper surface. Is preferably 1 degree or more. That is, the tilt angle is 1 degree If the value is less than the above, it may be difficult to obtain the effect due to the inclined side surface of the piezoelectric body.
• FIG. 5 is a diagram showing the results of measuring the insulation resistance after frequency adjustment for three types of structures in which the inclination angles of the side surfaces 14a and 14b were -1 degree, 0 degree, and +1 degree.
• the prepared piezoelectric resonance element is composed of a piezoelectric material having a width of 0.5mm, a length of 2.2mm, and a thickness of 0.3mm, and has a target resonance frequency of 25MHz. It is a piezoelectric resonance element.
• the lower part of the side surfaces 14a and 14b was inclined so as to be positioned inside the piezoelectric body, and the piezoelectric resonance elements having inclination angles of -1 degree and +1 degree were manufactured. Further, a non-tilted piezoelectric resonance element was separately prepared.
• Figure 5 shows the results of measuring the insulation resistance of each of the three types of piezoelectric resonance elements.
• the inclined surface is flat, but as shown in Fig. 6, the side surfaces 14a, 14b of the piezoelectric body 14 may be curved inclined surfaces. Also in the curved inclined surfaces 14a and 14b shown in FIG. 6, the lower part is located closer to the center of the piezoelectric body 14 than the upper ends of the side surfaces 14a and 14b. Therefore, as in the case of the first embodiment, when the frequency is adjusted by irradiating the ion beam from above and etching the vibrating electrode 15, the metal powder is hardly adhered to the side surfaces 14a and 14b.
• the curved side surfaces 14a and 14b can be formed by cutting the piezoelectric resonance element 13 using dicing blades 26 and 27 having cut surfaces as shown in Fig. 7, for example.
• the frequency adjustment is performed with the capacitor element 7 and the piezoelectric resonance element 13 mounted on the case substrate 2, but the frequency adjustment of the piezoelectric resonance component according to the present invention is performed.
• the method may be performed by preparing only a piezoelectric resonance element, arranging a mask on the upper surface side of the piezoelectric resonance element, and irradiating an energy beam such as an ion beam.
• an energy ray used for frequency adjustment in the present invention various energy rays such as a laser beam can be used other than the ion beam.

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• Crystallography & Structural Chemistry (AREA)
• Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)

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• 2004
  • 2004-10-28 JP JP2005517191A patent/JP4062335B2/ja not_active Expired - Fee Related
  • 2004-10-28 WO PCT/JP2004/016043 patent/WO2005071832A1/ja active Application Filing
  • 2004-10-28 KR KR20057020920A patent/KR100744623B1/ko active IP Right Grant
  • 2004-10-28 CN CN2004800143368A patent/CN1795609B/zh active Active

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