JP2013070367A - Vibrator, electronic component and method of manufacturing vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress hindrance of a contour vibration by a connection part, in a vibrator for which two vibrating bodies configured to generate the contour vibration in phase with each other by expansion and contraction between a center and an outer circumference of a piezoelectric thin film over a circumferential direction are connected by the connection part.SOLUTION: A tuning fork type vibrating body 11 is interposed between disk resonators 31 and 13 that generate the contour vibration in phase with each other, and the disk resonators 31 and 31 are connected to vibration arm parts 14 and 14 of the tuning fork type vibrating body 11. Then, the tuning fork type vibrating body 11 is vibrated in reverse phase relative to the disk resonators 31 and 31 so as to absorb the expansion and contraction of the disk resonators 31 and 31.

Description

  The present invention relates to a vibrator in which excitation electrodes are respectively formed on upper and lower surfaces of a piezoelectric thin film, an electronic component including the vibrator, and a method of manufacturing the vibrator.

  For example, as a vibrator using the piezoelectric / inverse piezoelectric effect of a piezoelectric thin film such as aluminum nitride (AlN), the piezoelectric thin film is formed in a disk shape, for example, and molybdenum (Mo) or the like is excited on the upper and lower surfaces of the piezoelectric thin film. Disc resonators (vibrators) formed as electrodes are known. In this disc resonator, a contour vibration in which the piezoelectric thin film expands and contracts in the radial direction of the piezoelectric thin film occurs in the circumferential direction with the central portion of the piezoelectric thin film as a node. Therefore, in order to support (fix) the disk resonator with a simple structure on the silicon substrate in a state in which the disturbance of the contour vibration is suppressed, the two disk resonators are arranged in a horizontal direction, and the outer edges of these disk resonators are There is known a method of connecting by a substantially box-shaped connecting portion and fixing the lower surface side of the connecting portion to a silicon substrate.

  That is, the diameter and mass of the piezoelectric thin film are aligned between the disk resonators so that these disk resonators vibrate in phase, and the upper excitation electrodes and the lower excitation electrodes have the same potential. In addition, an electrical signal is input to and output from the excitation electrode via the connecting portion. Therefore, since the node of the contour vibration is formed in the connecting portion, each disc resonator is supported in a state where the inhibition of the contour vibration is suppressed. Then, when adjusting the resonance frequency after manufacturing such a disk resonator, for example, laser processing or the like is used to make a hole in the excitation electrode or piezoelectric thin film of each disk resonator, so that the rigidity and mass of the disk resonator are increased. Is changed (decreased).

Here, in the configuration in which the two disk resonators are connected by the connecting portion, the vibration of the disk resonator is actually hindered by the connecting portion, as shown in the simulation results described later, so that it is not an ideal vibration mode. End up. For this reason, the electrical characteristics of the disk resonator are deteriorated as compared with the case of vibrating in an ideal vibration mode.
In addition, if the processing position and processing amount vary between the two disk resonators when performing the laser processing described above, the vibration balance is lost in these disk resonators, and elastic energy leaks through the connecting portion, resulting in a Q value. Will deteriorate.
Patent Document 1 describes two disc resonators connected by a connecting portion, and Patent Documents 2 to 5 describe a contour vibration type resonator. However, the above-described problems have not been studied. Absent.

JP2008-124747 JP-A-2005-159620 Special table 2007-535275 JP-A-2005-348222 JP 2006-41911 A

  The present invention has been made in view of such circumstances, and its purpose is to provide two configurations each configured so that contour vibrations that expand and contract between the central portion and the outer edge portion of the piezoelectric thin film occur in phase with each other. An object of the present invention is to provide a vibrator, an electronic component, and a method for manufacturing a vibrator that can suppress the contour vibration from being obstructed by the connecting portion in the vibrator in which the vibrator is connected by the connecting portion. Another object of the present invention is to provide a technique capable of adjusting the resonance frequency in a state where the vibration balance of these vibrating bodies is uniform.

The vibrator of the present invention is
A base substrate;
A base portion supported by the base substrate, two vibrating arm portions each extending away from the base portion and configured by a piezoelectric body, and a pair of excitation electrodes formed so as to sandwich each of the vibrating arm portions A tuning fork type vibrator having
A piezoelectric thin film having an outer edge connected to one of the pair of vibrating arms, and a pair of excitation electrodes formed so as to sandwich the piezoelectric thin film from the plate thickness direction; A first vibrating body configured to generate contour vibration that expands and contracts between the portion and the outer edge portion;
A piezoelectric thin film having an outer edge connected to the other vibrating arm of the pair of vibrating arms, and a pair of excitation electrodes formed so as to sandwich the piezoelectric thin film from the plate thickness direction. A second vibrating body configured to cause the contour vibration to occur in phase with the body;
A first extraction electrode formed on the one vibrating arm and connected to the excitation electrode of the first vibrating body;
A second extraction electrode formed on the other vibrating arm and connected to the excitation electrode of the second vibrating body;
An input / output port for inputting / outputting electrical signals to / from each of the first extraction electrode, the second extraction electrode, and the excitation electrode of the vibrating arm portion, formed on the base portion,
The tuning fork type vibrating body is bent in a phase opposite to the vibration of the first vibrating body and the second vibrating body so as to absorb the contour vibration of the first vibrating body and the second vibrating body. It is configured to vibrate.

The vibrator may be configured as follows.
A configuration in which electrode patterns for adjusting the oscillation frequencies of the first vibrating body and the second vibrating body are formed on the one vibrating arm portion and the other vibrating arm portion, respectively. Each of the electrode patterns has a configuration in which a plurality of electrode films are formed with a gap region therebetween. The electrode pattern in the one vibrating arm portion and the electrode pattern in the other vibrating arm portion are formed symmetrically with respect to each other via a line between the one vibrating arm portion and the other vibrating arm portion. Configuration.

The excitation electrode in the one vibrating arm portion and the excitation electrode in the other vibrating arm portion also serve as the first extraction electrode and the second extraction electrode, respectively. The base portion is formed on one side and the other side of the vibrating arm portion, supported by the base substrate, and the input / output port is formed on each of the base portions.
The electronic component of the present invention is characterized by including the vibrator.

The method of manufacturing the vibrator of the present invention includes
On the base substrate, a base portion supported by the base substrate, extending from the base portion apart from each other, and being formed so as to sandwich each of the two vibrating arm portions each made of a piezoelectric body and these vibrating arm portions. Forming a tuning fork type vibrator having a pair of excitation electrodes,
The outer edge of the piezoelectric thin film is connected to one vibrating arm of the pair of vibrating arms, and a pair of excitation electrodes are formed so as to sandwich the piezoelectric thin film from the plate thickness direction. A step of configuring the first vibrating body so that contour vibration that expands and contracts between the outer edge portion and the outer portion occurs;
An outer edge portion of a piezoelectric thin film is connected to the other vibrating arm portion of the pair of vibrating arm portions, and a pair of excitation electrodes are formed so as to sandwich the piezoelectric thin film from the plate thickness direction. Configuring the first vibrator so that the contour vibration occurs in phase with the body;
Forming a first extraction electrode connected to the excitation electrode of the first vibrating body on the one vibrating arm portion;
Forming a second extraction electrode connected to the excitation electrode of the second vibrating body on the other vibrating arm portion;
Forming an input / output port for inputting / outputting an electric signal to / from each of the first extraction electrode, the second extraction electrode, and the excitation electrode of the vibrating arm at the base;
Forming electrode patterns for adjusting oscillation frequencies of the first vibrating body and the second vibrating body on the one vibrating arm section and the other vibrating arm section, respectively.
The tuning fork type vibrating body is bent in a phase opposite to the vibration of the first vibrating body and the second vibrating body so as to absorb the contour vibration of the first vibrating body and the second vibrating body. It is configured to vibrate.

  After the step of forming the electrode pattern, the electrode pattern in the one vibrating arm portion and the electrode pattern in the other vibrating arm portion are between the one vibrating arm portion and the other vibrating arm portion. Removing these electrode patterns so as to be symmetric with each other via a line, and adjusting each of the oscillation frequencies while aligning the oscillation frequencies of the first vibrator and the second vibrator. You can go.

  In the present invention, a base portion is supported on a base substrate between two vibrating bodies each configured so that contour vibrations that expand and contract between a central portion and an outer edge portion of a piezoelectric thin film occur in phase with each other, and a pair A tuning-fork type vibrating body having a vibrating arm portion is interposed as a connecting portion, and one vibrating arm portion and the other vibrating arm portion are connected to the outer edge portion of the piezoelectric thin film in each vibrating body. The tuning fork type vibrating body is configured to bend and vibrate in an opposite phase to the vibrations of the first vibrating body and the second vibrating body so as to absorb the contour vibration of these vibrating bodies. For this reason, it is possible to suppress the vibrations of the respective vibrating bodies from being inhibited, so that it is possible to suppress deterioration of electrical characteristics. Moreover, since the electrode pattern for adjusting the oscillation frequency of a vibrating body is formed in each vibrating arm part, each oscillation frequency can be adjusted in the state where the vibration balance of these vibrating bodies was equalized.

It is a perspective view which shows an example of the vibrator | oscillator of this invention. It is a top view which shows the said vibrator | oscillator. It is a longitudinal cross-sectional view showing the vibrator. It is a longitudinal cross-sectional view showing the vibrator. It is a longitudinal cross-sectional view which shows the process of manufacturing the said vibrator | oscillator. It is a longitudinal cross-sectional view which shows the process of manufacturing the said vibrator | oscillator. It is a longitudinal cross-sectional view which shows the process of manufacturing the said vibrator | oscillator. It is a longitudinal cross-sectional view which shows the process of manufacturing the said vibrator | oscillator. It is a longitudinal cross-sectional view which shows the process of manufacturing the said vibrator | oscillator. It is a longitudinal cross-sectional view which shows the process of manufacturing the said vibrator | oscillator. It is a longitudinal cross-sectional view which shows the process of manufacturing the said vibrator | oscillator. It is a longitudinal cross-sectional view which shows the process of manufacturing the said vibrator | oscillator. It is a longitudinal cross-sectional view which shows the process of manufacturing the said vibrator | oscillator. It is a longitudinal cross-sectional view which shows the process of manufacturing the said vibrator | oscillator. It is a longitudinal cross-sectional view which shows the process of manufacturing the said vibrator | oscillator. It is a longitudinal cross-sectional view which shows the process of manufacturing the said vibrator | oscillator. It is a top view which shows the process of manufacturing the said vibrator | oscillator. It is a top view which shows the process of manufacturing the said vibrator | oscillator. It is a top view which shows the process of manufacturing the said vibrator | oscillator. It is a top view which shows the process of manufacturing the said vibrator | oscillator. It is a schematic diagram which shows a mode that the said vibrator vibrates. It is a schematic diagram which shows a mode that the said vibrator vibrates. It is a characteristic view showing a simulation result obtained for the vibrator. It is a characteristic view showing a simulation result obtained for the vibrator. It is the schematic which shows the electric circuit where the said vibrator | oscillator is used. FIG. 6 is a partially enlarged plan view showing another example of the vibrator. FIG. 6 is a plan view showing another example of the vibrator. FIG. 6 is a plan view showing another example of the vibrator. FIG. 6 is a plan view showing another example of the vibrator. FIG. 6 is a plan view showing another example of the vibrator. It is a top view which shows the vibrator | oscillator in the said other example.

  An example of a vibrator according to an embodiment of the present invention will be described with reference to FIGS. This vibrator is provided on a base substrate 1 made of, for example, silicon (Si), and is supported by the base substrate 1 (more specifically, a nitride film 4 described later) as shown in FIGS. A tuning fork-type vibrating body 11 and disc resonators 31 and 31 that are substantially disc-shaped vibrating bodies connected to the left and right sides (X direction in FIG. 1) of the tuning-fork type vibrating body 11 are provided. As shown in FIG. 3, the disc resonators 31 and 31 are supported by the tuning fork type vibrating body 11 so as to float from the base substrate 1. Each of the disk resonators 31 and 31 does not inhibit the contour vibration by the tuning fork vibrator 11 when contour vibration that expands and contracts in the circumferential direction occurs between the center portion and the outer edge portion, as will be described later. In other words, it is configured such that the inhibition of contour vibration is suppressed. Hereinafter, the tuning fork type vibrator 11 and the disk resonators 31 and 31 will be described in detail. 3 and 4 show longitudinal sections in which the vibrator is cut along lines AA and BB in FIGS. 1 and 2, respectively. 1-4, the base substrate 1 is notched and drawn.

  On the base substrate 1, an oxide film 2 made of silicon oxide or the like and a nitride film 4 made of silicon nitride or the like are laminated in this order from the lower side, and the tuning fork vibrator 11 described above is The central portion in the length direction (Y direction in FIG. 2) is supported (fixed) on the nitride film 4 so as to float from the oxide film 2 and the nitride film 4. In other words, the oxide film 2 and the nitride film 4 are formed with a recess 3 that is approximately one size larger than the vibrator, and the tuning fork vibrator 11 has the recess 3 on one end side and the other end side in the length direction. Further, it extends to the far side and the near side, respectively, and this extended portion is fixed on the nitride film 4. In the tuning fork type vibrator 11, a rear side region and a front side region (specifically, a region slightly closer to the center in addition to these regions) fixed on the nitride film 4 respectively extend in the left-right direction to extend to the base 12, Twelve. The electrode structure in the bases 12 and 12 will be described later. In FIG. 2, the tuning fork type vibrator 11 and the disk resonators 31 and 31 are hatched in areas where a metal film 16 and excitation electrodes 32 to be described later are formed. It is drawn separately.

  An opening 13 extending to the length of the tuning fork type vibrator 11 is provided at a portion held between the base portions 12 and 12 in a state of floating from the nitride film 4 so that the tuning fork type vibrator 11 is vertically moved at the central portion of the portion. It is formed to penetrate. Therefore, the regions extending in the front-rear direction so as to connect the base portions 12, 12 on the left and right sides of the opening portion 13 form the vibrating arm portions 14, 14 in the tuning fork type vibrator 11, respectively. That is, as shown in FIG. 4, the vibrating arms 14 and 14 are made of a piezoelectric thin film 15 made of aluminum nitride (AlN) or the like, and molybdenum (Mo) formed so as to sandwich the piezoelectric thin film 15 from above and below. As described later, when a voltage is applied between the metal films 16, 16, the vibrating arm portions 14, 14 are configured to bend and vibrate in the left-right direction. ing. Specifically, the oscillation frequency f1 (for example, 30 to 200 MHz) in this bending vibration is f1 ≦ ± f2 × 1.2 so as to be the same (reverse phase) frequency as the resonance frequency f2 in the disk resonators 31 and 31. The length dimension and the width dimension of each vibration arm part 14 and 14 are adjusted so that it may become. The metal films 16 and 16 serve as excitation electrodes for the vibrating arms 14 and 14 and also serve as lead electrodes for inputting and outputting electric signals to and from the disk resonator 31 as will be described later.

  Around the opening 13 described above on the upper surface of the tuning fork vibrator 11, the metal films 16 and 16 are cut out into a substantially rectangular shape, and the piezoelectric thin film 15 is exposed. Electrode patterns 17 and 17 for adjusting the oscillation frequency (resonance frequency) of the disk resonators 31 and 31 are formed on the vibrating arm portions 14 and 14 at the portions where the piezoelectric thin film 15 is exposed, respectively. Each of the electrode patterns 17, 17 is formed in an island shape so that dotted electrode films 18 made of, for example, molybdenum are arranged in a row through a gap region at a plurality of locations. 14 are arranged so as to be symmetrical to each other with a line extending in the front-rear direction as a boundary. In this example, the electrode films 18 are formed to have the same dimensions (diameter dimension and height). Specifically, the diameter dimension of the electrode film 18 is, for example, 2 to 10 μm, and 5 μm in this example, and the distance dimension between the electrode films 18 and 18 adjacent to each other is, for example, 5 to 30 μm, and 10 μm in this example.

  Similarly to the vibrating arm portion 14, the base portions 12 and 12 include a piezoelectric thin film 15 and metal films 16 and 16 formed on the upper and lower surfaces of the piezoelectric thin film 15, respectively. The metal film 16 on the upper surface of the base portion 12 on the near side is integrally formed with the metal film 16 on the upper surfaces of the vibrating arm portions 14 and 14 and connected to each other. On the other hand, the metal film 16 on the upper surface of the base 12 on the back side is electrically insulated from the metal film 16 on the upper surfaces of the vibrating arm portions 14 and 14 by a gap region 19 formed on the front side of the base 12. ing. The metal film 16 on the lower surface side of the base portion 12 is formed at a position closer to the center than the portion where the base portion 12 and the nitride film 4 are in contact with each other in the length direction of the base portion 12 in order to lead out the lower electrode. ing.

  An input / output port 20 made of, for example, aluminum (Al) is provided on the metal films 16 and 16 on the upper surface side of the respective base portions 12 and 12 in order to input / output electric signals from / to an external electronic device to the vibrator. , 20 are formed. As shown in FIG. 4, a contact hole 21 reaching the lower metal film 16 is formed in the piezoelectric thin film 15 of the base 12 on the back side, and the input / output port 20 on the back side is a contact hole. It is electrically connected to the metal film 16 on the lower surface side through the inside of 21. Further, the input / output port 20 on the near side is connected to the metal films 16 and 16 on the upper surface side of the vibrating arm portions 14 and 14 via the metal film 16 on the upper surface side of the piezoelectric thin film 15. Note that insulating films 34 made of, for example, silicon oxide are formed on the back and front sides of the input / output ports 20 and 20, respectively.

  Each of the disk resonators 31 and 31 includes a piezoelectric thin film 15 having a diameter of 50 μm, for example, and excitation electrodes 32 and 32 formed so as to sandwich the piezoelectric thin film 15 from the vertical direction (plate thickness direction). In these disk resonators 31, 31, the piezoelectric thin films 15, 15 in the disk resonators 31, 31 are formed integrally with the piezoelectric thin film 15 in the tuning fork type vibrating body 11 (vibrating arm portions 14, 14). That is, when the right side of the two vibrating arm portions 14 and 14 is referred to as one vibrating arm portion 14 and the left side is referred to as the other vibrating arm portion 14, the central portion in the longitudinal direction on the right side surface of the one vibrating arm portion 14 is provided. Is connected to one end side of a support portion 33 extending horizontally toward the right disc resonator 31, and the other end side of the support portion 33 is connected to an outer edge portion of the disc resonator 31.

  The metal films 16 and 16 of the one vibrating arm portion 14 are connected to the excitation electrodes 32 and 32 of the right disk resonator 31 via the support portion 33, respectively. Similarly, the other vibrating arm portion 14 is connected to the left disc resonator 31 via a support portion 33 provided at the center in the length direction of the other vibrating arm portion 14. At this time, the vibrator composed of the two disc resonators 31 and 31 and the tuning fork type vibrator 11 is symmetric when viewed in a plan view, and is also a region floating from the nitride film 4 when viewed in the thickness direction. Is symmetrical in the vertical direction. The metal film 16 and the excitation electrode 32 are integrally formed as will be described later. However, for convenience of explanation, reference numerals are used properly.

  And since the above-mentioned recessed part 3 is formed so that it may be slightly larger than these disk resonators 31, 31, each disk resonator 31, 31 has a base substrate 1, as shown in FIG. The tuning fork type vibrating body 11 is supported in a state where it floats from the oxide film 2 and the nitride film 4. In this way, the disk resonators 31 and 31 are configured such that contour vibration in which the piezoelectric thin film 15 expands and contracts in the radial direction occurs in the circumferential direction with the central portion of the disk resonators 31 and 31 as a node. At this time, the disk resonators 31 and 31 vibrate in phase with each other, that is, when one disk resonator 31 expands, the other disk resonator 31 expands in the same manner, and when one disk resonator 31 contracts. The other disk resonator 31 is also formed to have the same diameter and the like so as to contract.

  Next, a method for manufacturing this vibrator will be described with reference to FIGS. First, an oxide film 2, a nitride film 4, and a photoresist mask 41 made of an organic material are stacked in this order on the base substrate 1 from the lower layer side, and then correspond to the recesses 3 by photolithography as shown in FIG. A pattern is formed on the photoresist mask 41. Subsequently, the oxide film 2 and the nitride film 4 are etched by wet etching using, for example, a hydrofluoric acid aqueous solution through the photoresist mask 41 to form the recess 3. Then, after the photoresist mask 41 is peeled off, a sacrificial film 42 made of, for example, silicon oxide is formed on the base substrate 1 so that the recess 3 is embedded, and then, as shown in FIGS. 6 and 17, CMP (Chemical) The nitride film 4 and the sacrificial film 42 are planarized by mechanical policing.

  Next, on the base substrate 1 (nitride film 4 and sacrificial film 42), a thin film 43 made of, for example, molybdenum and a photoresist mask 44 are laminated in this order from the lower side, and photolithography is similarly performed as shown in FIG. The shape corresponding to the metal film 16 and the excitation electrode 32 is patterned on the thin film 43 by the method. Subsequently, as shown in FIG. 8, after removing the photoresist mask 44, the piezoelectric layer 45 made of, for example, aluminum nitride, the thin film 46 made of molybdenum, and the insulating film 34 made of silicon oxide are formed in this order from the lower side. A layer corresponding to the metal film 16 and the excitation electrode 32 is formed on the insulating film 34 by photolithography using a photoresist mask 47 as shown in FIG.

  Then, after removing the photoresist mask 47, as shown in FIG. 10, the thin film 46, the piezoelectric layer 45, and the thin film 43 are dry-etched using, for example, plasma through the insulating film 34, as shown in FIG. In addition, structures corresponding to the disk resonators 31 and 31 and the tuning fork type vibrating body 11 are formed. In this way, the disk resonators 31 and 31 composed of the piezoelectric thin film 15 sandwiched from above and below by the excitation electrodes 32 and 32 and the tuning fork type vibrator 11 composed of the piezoelectric thin film 15 sandwiched from above and below by the metal films 16 and 16 are formed. Further, an opening 13 is formed in the tuning fork type vibrating body 11. At this time, the insulating film 34 is also reduced by the etching.

  Next, a photoresist mask 48 is formed on the base substrate 1 so as to cover the structure. As shown in FIG. 11, the piezoelectric thin film 15 around the contact hole 21, the gap region 19 and the opening 13 described above is formed. The photoresist mask 48 is patterned so that the exposed surface is opened and the electrode pattern 17 is formed on the exposed surface. When the insulating film 34 and the thin film 46 are etched through the photoresist mask 48, as shown in FIGS. 11 and 19, the piezoelectric thin film 15 in the region where the contact hole 21 is formed and the gap region 19 is formed. As a result, the electrode pattern 17 is formed. In FIG. 19, in the disk resonators 31 and 31 and the tuning fork type vibrating body 11, the remaining areas of the insulating film 34 and the thin film 46 are hatched.

  Subsequently, after removing the photoresist mask 48, as shown in FIG. 12, a photoresist mask 49 is formed on the base substrate 1 so that only the formation region of the contact hole 21 is opened. The piezoelectric thin film 15 is etched using as a mask. Next, the photoresist mask 49 is peeled off to form a photoresist mask 50 so that only regions where the input / output ports 20 and 20 are formed are opened as shown in FIG. The insulating film 34 is etched through 50. Then, when a conductive film 51 made of, for example, aluminum is formed on the base substrate 1 by sputtering or the like, the conductive film 51 covers the inside of the contact hole 21 and the upper surface of the photoresist mask 50 as shown in FIG. A film is formed.

  Thereafter, when the base substrate 1 is immersed in, for example, an organic solvent, the photoresist mask 50 is dissolved in the organic solvent and formed on the photoresist mask 50 together with the photoresist mask 50 as shown in FIG. Excess conductive film 51 is removed. Through this process, the input / output ports 20 and 20 are formed. Thereafter, a photoresist mask (not shown) is formed on the base substrate 1 so as to cover, for example, the input / output ports 20 and 20 and the nitride film 4 and to expose the inner region of the opening 13, for example. For example, the base substrate 1 is immersed in a hydrofluoric acid aqueous solution. This hydrofluoric acid aqueous solution, for example, enters the sacrificial film 42 on the lower layer side of the vibrator through the inner region of the opening 13 and etches the sacrificial film 42. Therefore, as shown in FIG. 16, the center portion (other than the base portions 12 and 12) of the tuning fork type vibrator 11 is separated from the base substrate 1, and as shown in FIG. 3, the disk resonators 31 and 31 are provided. It floats from the base substrate 1 over the entire surface. By this etching, the insulating film 34 remaining on the upper surface of the electrode pattern 17 and the upper surfaces of the disk resonators 31 and 31 is removed.

  Subsequently, for example, when adjusting the oscillation frequency of the vibrator, a part of the electrode pattern 17 is removed (trimmed) by laser processing, for example. Specifically, the base substrate 1 is placed on a table (not shown), and the electrode film 18 of the electrode pattern 17 is irradiated with laser light from a laser light irradiation unit (not shown) to dissolve the electrode film 18. And evaporate. Next, when removing another electrode film 18 as well, the laser light irradiation unit is moved relative to the table, and the laser light is irradiated in the same manner. At this time, the electrode film 18 is removed so that one vibrating arm portion 14 and the other vibrating arm portion 14 are symmetrical to each other. FIG. 20 shows an example in which the second electrode films 18 and 18 from the back side and the sixth electrode films 18 and 18 from the back side are removed from the electrode patterns 17 of the vibrating arm portions 14 and 14. Is shown. Thus, by removing the electrode films 18 and 18 while maintaining the state in which the electrode patterns 17 and 17 in the vibrating arm portions 14 and 14 are symmetric, the vibration balance (oscillation frequency) of the disc resonators 31 and 31 is reduced. The oscillation frequency changes in the same manner (becomes higher) while being maintained.

  Here, when the part that connects the disk resonators 31 and 31 is not the tuning fork type vibrator 11, that is, when the connecting portion 90 of FIG. Even if the electrode film 18 on the portion 90 is trimmed, the oscillation frequencies of the disk resonators 31 and 31 do not change. On the other hand, when the tuning fork type vibrator 11 that oscillates similarly to the disk resonators 31 and 31 is provided between the disk resonators 31 and 31, the tuning fork type vibrator is obtained by trimming the electrode film 18 of the tuning fork type vibrator 11. 11 and the oscillation frequency of the disk resonators 31 and 31 change. As described above, the change in the oscillation frequency of the disc resonators 31 and 31 with the change in the oscillation frequency of the tuning fork type vibrator 11 is omitted in detail, but the lengths of the vibrating arm portions 14 and 14 are variously changed. This is confirmed by a separate simulation.

  When, for example, an external electric signal is input to the vibrator formed in this way via the input / output ports 20, 20, the disk resonators 31, 31 and the tuning fork type vibrating body 11 oscillate (vibrate) at respective resonance frequencies. Thus, an electrical signal based on this oscillation is taken out via the input / output ports 20 and 20. Specifically, for example, in the disk resonators 31, 31, contour vibration that expands and contracts in the radial direction occurs in the circumferential direction. Further, in the tuning fork type vibrating body 11, bending vibration occurs so that the vibrating arm portions 14, 14 are close to or away from each other.

  At this time, since the disk resonators 31 and 31 have the same diameter and the like of the piezoelectric thin film 15, the contour vibrations occur in phase with each other. Further, in the tuning fork type vibrating body 11, each dimension is adjusted so that bending vibration occurs at the same frequency as the disk resonators 31, 31, and the tuning fork type vibration is applied to the excitation electrode 32 on the upper surface side of the disk resonators 31, 31. The metal film 16 on the upper surface of the body 11 is connected, and the metal film 16 on the lower surface of the tuning fork type vibrator 11 is connected to the excitation electrode 32 on the lower surface of the disk resonators 31 and 31. Therefore, in the tuning fork type vibrator 11, bending vibration occurs in a phase opposite to those of the disc resonators 31 and 31. Therefore, as shown in FIG. 21, the vibrating arms 14 and 14 bend and vibrate so as to be separated from each other when the disk resonators 31 and 31 contract, while when the disk resonators 31 and 31 expand, as shown in FIG. As shown in FIG. In this way, the tuning fork vibrator 11 generates bending vibrations so that the expansion and contraction vibrations of the disk resonators 31 and 31 are absorbed, that is, the center positions of the disk resonators 31 and 31 are not displaced due to the contour vibration. . 21 and 22, the state of vibration of the tuning fork type vibrator 11 and the disk resonators 31 and 31 is exaggeratedly drawn.

  Here, FIG. 23 shows a result obtained by analyzing the vibration mode of the vibrator of the present invention by simulation. In addition to the disk resonators 31 and 31, the tuning fork type vibrator 11 vibrates (deforms), whereby each of the disk resonators. In 31 and 31, a node (a region where the amount of deformation is small) is formed at the center of each disk resonator 31, 31 and the amount of deformation increases toward the outer peripheral side, and the deformation is further uniform in the circumferential direction. It was an ideal vibration mode. Therefore, in this configuration, it can be seen that the elastic energy of the disk resonators 31 and 31 is not leaked through the tuning fork type vibrator 11, or the leak is suppressed.

  On the other hand, in the case where, for example, a rectangular connecting portion 90 is provided between the disk resonators 31 and 31 in place of the tuning fork-type vibrating body 11, the disk resonators 31 and 31 have a node at a substantially central portion as shown in FIG. Although formed, the amount of deformation was non-uniform across the radial and circumferential directions. Therefore, in FIG. 24, it can be seen that the energy of the disk resonators 31 and 31 leaks through the connecting portion 90, and the Q value is deteriorated as compared with the case of FIG.

  An example of an electric circuit of an electronic component (oscillator) in which the vibrator of the present invention described above is incorporated in an oscillation circuit will be briefly described with reference to FIG. FIG. 25 shows an example in which a Colpitts circuit including two capacitors C and C connected in series with each other and a transistor 101 is provided, and the base terminal of the transistor 101 is connected to the vibrator 100 and the variable capacitor of the present invention. A series circuit consisting of C1 is connected. A power supply unit 102 is connected to a connection point between the base terminal and the vibrator 100, and an output port 103 for extracting an electric signal is connected to a collector terminal of the transistor 101. In FIG. 25, 104 is a resistor, and 105 is an inductance.

  According to the above-described embodiment, the tuning fork type vibrating body 11 is interposed between the disk resonators 31 and 13 that generate contour vibrations in the same phase, and the vibrating arm portions 14 and 14 of the tuning fork type vibrating body 11 have a disk. Resonators 31 and 31 are connected. The tuning fork type vibrator 11 is vibrated in the opposite phase with respect to the disc resonators 31 and 31 so as to absorb the expansion and contraction of the disc resonators 31 and 31. Therefore, it is possible to suppress the vibrations of the respective disk resonators 31 and 31 from being inhibited, that is, it is possible to suppress the leakage of the elastic energy of the disk resonators 31 and 31 via the tuning fork type vibrator 11. Deterioration of the mechanical characteristics can be suppressed.

  As described above, in the present invention, the connecting portion having the role of connecting the two disc resonators 31 and 31 and being supported by the base substrate 1 vibrates in a phase opposite to that of the disc resonators 31 and 31 in addition to this role. It has a role as a vibrating body. On the other hand, conventionally, attention has not been paid to the function as a vibrating body for the connecting portion, and thus the shape and dimensions of the connecting portion have not been studied. That is, in the configuration as in Patent Document 1 described in the background section above, since the connecting portion is extremely smaller in size than the disc resonator, even if the connecting portion vibrates, the oscillation of the disc resonator. This is an extremely higher frequency than the frequency, and therefore it can be said that it is not oscillating when viewed from the disk resonator.

  On the other hand, in the present invention, as described above, the connecting portion between the disk resonators 31 and 31 is configured as the tuning fork type vibrating body 11 so as to vibrate in the reverse phase of the disk resonators 31 and 31. At this time, the bending vibration has a lower oscillation frequency than the above-described contour vibration even if the vibrating body (tuning fork type vibrating body 11 or disc resonator 31) has the same dimensions. In other words, when the tuning fork type vibrating body 11 is oscillated at the same frequency as that of the disk resonator 31, the tuning fork type vibrating body 11 may be smaller in size than the disk resonator 31. Therefore, when the tuning fork type vibrator 11 is oscillated at the same frequency and in the opposite phase as the disk resonators 31 and 31, it is not necessary to increase the size to the same level as the disk resonator 31. Deterioration of electrical characteristics can be suppressed.

Further, since the electrode pattern 17 is formed on each of the vibrating arm portions 14 and 14, the oscillation frequency of the vibrator can be adjusted via the electrode pattern 17 without processing the disk resonators 31 and 31. . At this time, since the electrode pattern 17 is formed symmetrically between the vibrating arm portions 14 and 14 and is trimmed symmetrically, the oscillation frequency is adjusted in a state where the vibration balance between the disk resonators 31 and 31 is uniform. Can be adjusted. Further, since the electrode films 18 adjacent to each other are separated from each other, the processing position and processing amount when performing laser processing (for example, the relative moving distance of the laser beam irradiation unit with respect to the above-described table and laser beam) Even when the irradiation time is varied, it is possible to prevent the other electrode film 18 from being irradiated with a laser beam when irradiating a certain electrode film 18 with a laser beam. Accordingly, when the electrode film 18 is trimmed, variation in the oscillation frequency between the disk resonators 31 and 31 can be suppressed, so that deterioration of the Q value can be prevented. Further, since the electrode pattern 17 is provided separately (electrically insulated) from the metal film 16, even if the electrode pattern 17 is removed, for example, the electric resistance of the disc resonator 31 or the tuning fork type vibrating body 11 There is no adverse effect such as increase.
Further, since the base portions 12 and 12 are provided on both sides of the vibrating arm portions 14 and 14, the vibrating arm portions 14 and 14 can be firmly held with respect to the base substrate 1 when the vibrating arm portions 14 and 14 vibrate.

  In the example described above, the electrode films 18 are formed so as to have the same dimensions. For example, as shown in FIG. 26, electrode films 18 having different dimensions are arranged in the electrode patterns 17 and 17, respectively. May be. FIG. 26 shows an example in which the diameter dimension of each electrode film 18 is gradually decreased from 2 μm to 10 μm, for example, from the back side toward the front side. By providing the electrode films 18 having different dimensions as described above, for example, the adjustment range of the oscillation frequency of the disc resonator 31 can be changed for each electrode film 18 to be removed, so that the frequency can be adjusted more easily. Can do. Also in this example, the left and right electrode patterns 17, 17 are formed so as to be bilaterally symmetric.

  The electrode patterns 17 and 17 are arranged so as to be bilaterally symmetric between the vibrating arm portions 14 and 14, but may be formed asymmetrical. Even in this case, when the electrode film 18 is removed, adjustment is made so that the oscillation frequency is uniform between the left and right disc resonators 31 and 31.

  Further, the tuning fork type vibrating body 11 may be configured to oscillate in a phase opposite to that of the disk resonators 31 and 31. For example, as shown in FIG. 14 and 14 may be gradually narrowed from the base 12, 12 side toward the central side (supporting portion 33). Further, as shown in FIG. 28, the opening 13 may be formed in a substantially circular shape, and the vibrating arm portions 14 and 14 may be formed in a substantially arc shape along the periphery of the opening 13. Furthermore, as shown in FIG. 29, for example, a configuration may be employed in which the vibrating arm portions 14 and 14 are each supported in a cantilever manner by the back-side base portion 12 without providing the front-side base portion 12. In this case, a contact hole 21 is formed, for example, on the left side of the base 12 on the back side, and the input / output port 20 provided in the contact hole 21 is adjacent to the right side through a gap region. An input / output port 20 connected to the metal film 16 extending from the upper surface of the tuning fork type vibrator 11 is disposed. 27 and 28 depict the vibrator in a simplified manner.

  Further, a disk resonator 110 may be provided in place of the tuning fork type vibrator 11 that connects the disk resonators 31 and 31. FIG. 30 and FIG. 31 show such an example, and the center disk resonator 110 is oscillated in the opposite phase and at the same frequency with respect to the disk resonators 31 and 31 on both sides. Specifically, these three disk resonators 31, 31, 110 are formed so that their diameters and the like are aligned. In addition, a substantially circular excitation electrode (metal film 16) for oscillating the disk resonator 110 is formed at the center of the upper and lower surfaces of the disk resonator 110, respectively. Further, arc-shaped routing electrodes 111 respectively connected to the excitation electrodes 32 and 32 on the upper surfaces of the left and right disk resonators 31 and 31 are formed on the outer edge portion on the upper surface of the disk resonator 110 so as to be separated from the metal film 16. Has been. The metal film 16 and the lead-out electrode 111 are connected to electrode lead-out portions 113 and 113 formed on the front side and the back side of the disc resonator 110, respectively.

  Further, at the peripheral edge portion of the lower surface of the disk resonator 110, an arc shape is connected to the excitation electrodes 32, 32 on the lower surface side of the left and right disk resonators 31, 31 and spaced apart from the metal film 16 on the lower surface. The lead-out electrode 112 is formed. The metal film 16 and the lead-out electrode 112 are connected to the electrode lead-out portions 113 and 113, respectively. In this way, the metal film 16 and the routing electrode 111 on the upper surface side of the disk resonator 110 and the metal film 16 and the routing electrode 112 on the back surface side of the disk resonator 110 are wired in the same manner as in FIG. The disk resonator 110 is configured to vibrate in reverse phase with respect to 31 expansion / degeneration vibrations. The metal films 16 and 16 in the disk resonator 110 form input / output ports 20 and 20, respectively.

Further, the disk resonator 110 is supported by the base substrate 1 at a position that is a node of the contour vibration at the center of the lower surface of the disk resonator 110, and inputs / outputs electric signals through the lead-out portion 113 described above. Is called.
In this example, the disc resonator 110 may be a triangle or a quadrangle instead of being circular. Similarly, the left and right disc resonators 31, 31 may be triangular or quadrangular.

  In the above example, in forming the electrode pattern 17, the process of forming the metal film 16 and the excitation electrode 32 on the upper surface side of the disk resonators 31 and 31 and the tuning fork type vibrator 11 (formation process of the thin film 46) is used. Then, in the step of forming the input / output ports 20 and 20 (the step of forming the conductive film 51), the photoresist mask 50 is patterned so that the periphery of the formation region of the electrode pattern 17 is opened. You may comprise with aluminum. In addition, after the series of steps is completed, the electrode patterns 17 may be individually formed using a photoresist mask for the electrode patterns 17.

Further, in the tuning fork type vibrating body 11, an excitation electrode for vibrating the tuning fork type vibrating body 11 and a lead electrode connecting the excitation electrode 32 of the disk resonators 31 and 31 and the input / output port 20 are used as the metal film 16. Although shared, these excitation electrodes and extraction electrodes may be arranged separately. In this case, excitation electrodes may be formed on the upper and lower surfaces of the vibrating arm portions 14 and 14, and lead electrodes may be formed on the side surfaces, for example.
In the above example, an example in which the vibrator of the present invention is incorporated in an oscillation circuit has been described. However, this vibrator may be used as a filter (electronic component). In this case, the electrical signal input to the input / output port 20 is taken out from the input / output port 20 after unnecessary electrical signals are removed from the vibrator.

  Here, the difference between the present invention described above and Japanese Patent Application Laid-Open No. 2008-124747, which is a known example described in the above background, will be described again. In this publicly known example, it is described that this vibration becomes a “radial extension mode with a node at the center (Radial Extension mode)”. However, when the present inventors are connected and supported by the “schematic box-shaped connecting portion”, as can be seen from FIG. 24 described above, “the higher-order non-ideal in which a plurality of nodes are generated on the outer peripheral portion. It was found by numerical analysis that the vibration mode was achieved. In this vibration mode, electrical characteristics are deteriorated due to vibration leakage or the like. On the other hand, in this embodiment, as shown in FIG. 23, by forming a vibrating arm portion on the support portion, the “influence by the support portion” is eliminated, and the “center of the diaphragm” that could not be realized with the conventional configuration. It is possible to form an “ideal vibration” in which the diaphragm expands and contracts in the radial direction with the node as a node over the circumferential direction.

DESCRIPTION OF SYMBOLS 1 Base substrate 11 Tuning fork type vibrating body 14 Vibrating arm part 15 Piezoelectric thin film 16 Metal film 17 Electrode pattern 18 Electrode film 20 Input / output port 31 Disc resonator 32 Excitation electrode

Claims (9)

A base substrate;
A base portion supported by the base substrate, two vibrating arm portions each extending away from the base portion and configured by a piezoelectric body, and a pair of excitation electrodes formed so as to sandwich each of the vibrating arm portions A tuning fork type vibrator having
A piezoelectric thin film having an outer edge connected to one of the pair of vibrating arms, and a pair of excitation electrodes formed so as to sandwich the piezoelectric thin film from the plate thickness direction; A first vibrating body configured to generate contour vibration that expands and contracts between the portion and the outer edge portion;
A piezoelectric thin film having an outer edge connected to the other vibrating arm of the pair of vibrating arms, and a pair of excitation electrodes formed so as to sandwich the piezoelectric thin film from the plate thickness direction. A second vibrating body configured to cause the contour vibration to occur in phase with the body;
A first extraction electrode formed on the one vibrating arm and connected to the excitation electrode of the first vibrating body;
A second extraction electrode formed on the other vibrating arm and connected to the excitation electrode of the second vibrating body;
An input / output port for inputting / outputting electrical signals to / from each of the first extraction electrode, the second extraction electrode, and the excitation electrode of the vibrating arm portion, formed on the base portion,
The tuning fork type vibrating body is bent in a phase opposite to the vibration of the first vibrating body and the second vibrating body so as to absorb the contour vibration of the first vibrating body and the second vibrating body. A vibrator characterized by being configured to vibrate.   Electrode patterns for adjusting the oscillation frequencies of the first vibrating body and the second vibrating body are formed on the one vibrating arm portion and the other vibrating arm portion, respectively. The vibrator according to claim 1.   3. The vibrator according to claim 2, wherein each of the electrode patterns includes a plurality of electrode films formed with a gap region therebetween.   The electrode pattern in the one vibrating arm portion and the electrode pattern in the other vibrating arm portion are formed symmetrically with respect to each other via a line between the one vibrating arm portion and the other vibrating arm portion. The vibrator according to claim 2, wherein the vibrator is provided.   2. The excitation electrode in the one vibrating arm portion and the excitation electrode in the other vibrating arm portion also serve as the first extraction electrode and the second extraction electrode, respectively. 5. The vibrator according to any one of 4 to 4. The base portions are respectively formed on one side and the other side of the vibrating arm portion, and are each supported by the base substrate,
The vibrator according to claim 1, wherein the input / output port is formed in each of the base portions.   An electronic component comprising the vibrator according to claim 1. On the base substrate, a base portion supported by the base substrate, extending from the base portion apart from each other, and being formed so as to sandwich each of the two vibrating arm portions each made of a piezoelectric body and these vibrating arm portions. Forming a tuning fork type vibrator having a pair of excitation electrodes,
The outer edge of the piezoelectric thin film is connected to one vibrating arm of the pair of vibrating arms, and a pair of excitation electrodes are formed so as to sandwich the piezoelectric thin film from the plate thickness direction. A step of configuring the first vibrating body so that contour vibration that expands and contracts between the outer edge portion and the outer portion occurs;
An outer edge portion of a piezoelectric thin film is connected to the other vibrating arm portion of the pair of vibrating arm portions, and a pair of excitation electrodes are formed so as to sandwich the piezoelectric thin film from the plate thickness direction. Configuring the first vibrator so that the contour vibration occurs in phase with the body;
Forming a first extraction electrode connected to the excitation electrode of the first vibrating body on the one vibrating arm portion;
Forming a second extraction electrode connected to the excitation electrode of the second vibrating body on the other vibrating arm portion;
Forming an input / output port for inputting / outputting an electric signal to / from each of the first extraction electrode, the second extraction electrode, and the excitation electrode of the vibrating arm at the base;
Forming electrode patterns for adjusting oscillation frequencies of the first vibrating body and the second vibrating body on the one vibrating arm section and the other vibrating arm section, respectively.
The tuning fork type vibrating body is bent in a phase opposite to the vibration of the first vibrating body and the second vibrating body so as to absorb the contour vibration of the first vibrating body and the second vibrating body. A method of manufacturing a vibrator, wherein the vibrator is configured to vibrate.   After the step of forming the electrode pattern, the electrode pattern in the one vibrating arm portion and the electrode pattern in the other vibrating arm portion are between the one vibrating arm portion and the other vibrating arm portion. Removing these electrode patterns so as to be symmetric with each other via a line, and adjusting each of the oscillation frequencies while aligning the oscillation frequencies of the first vibrator and the second vibrator. The method for manufacturing a vibrator according to claim 8, wherein the method is performed.