Frequency adjustment method of vibration element

Abstract

To provide a frequency adjustment method of a vibration element, capable of achieving both of securing a large frequency adjustment amount for roughly adjusting a resonance frequency and combining with a target frequency with high accuracy by finely adjusting the resonance frequency, and adjusting the resonance frequency with efficiency and high accuracy a small number of discharge times.SOLUTION: A frequency adjustment method of a vibration element, comprises: a preparation step of preparing a vibration arm having a first surface and a second surface in a front and back relation, and a support part for supporting one end part of the vibration arm; a first adjustment pattern formation step of forming a first adjustment pattern by an inkjet method in a first region on the first surface side; and a second adjustment pattern formation step of forming a second adjustment pattern which is smaller in mass amount than the first adjustment pattern by the inject method in a second region positioned closer to a base end side than the first region on the first surface side.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a method for adjusting the frequency of a vibration element. [Background technology]

[0002] For example, Patent Document 1 describes a method for adjusting the frequency of a double-ended tuning fork quartz crystal unit having a pair of arms and a pair of supports supporting both ends of the pair of arms. In Patent Document 1, a frequency adjustment point is provided in the center of each arm, and the frequency of the double-ended tuning fork quartz crystal unit is adjusted by attaching a nano metal paste ejected by an inkjet method to the frequency adjustment point. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-064752 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, since the area for attaching the nano metal paste, which is the weight for frequency adjustment, is limited, it is difficult to simultaneously secure a large frequency adjustment amount for coarsely adjusting the frequency and finely adjust the frequency to match the target frequency with high accuracy. In other words, it is difficult to adjust the frequency efficiently and accurately with a small number of ejections. [Means for solving the problem]

[0005] The frequency adjustment method of the present invention for a vibration element includes a preparation step of preparing a vibration element having a vibration arm having a first surface and a second surface that are reversed, and a support portion that supports one end of the vibration arm; a first adjustment pattern forming step of forming a first adjustment pattern in a first region on the first surface side by an inkjet method; and a second adjustment pattern forming step of forming a second adjustment pattern having a smaller mass than the first adjustment pattern by an inkjet method in a second region located on the base end side of the first region on the first surface side.

[0006] The frequency adjustment method of the present invention for a vibration element includes a preparation step of preparing a vibration element having a vibration arm having a first surface and a second surface that are reversed, and a support part that supports one end of the vibration arm; a first frequency measurement step of measuring a resonance frequency of the vibration element; a first weight portion forming step of forming a first weight portion having an area determined based on the measurement result in the first frequency measurement step by an inkjet method in a first region on the first surface side; a second frequency measurement step of measuring a resonance frequency of the vibration element after the first weight portion forming step; and a second weight portion forming process for forming, by an inkjet method, a second weight portion having an area smaller than that of the first weight portion, the second weight portion being determined based on the measurement results in the second frequency measurement process, in a second region located on the base end side of the first region on the first surface side. [Brief description of the drawings]

[0007] [Figure 1] 1 is a plan view of a MEMS element according to a first embodiment. [Diagram 2] 2 is a cross-sectional view taken along line AA in FIG. 1. [Diagram 3] FIG. 2 is a cross-sectional view taken along line BB in FIG. [Figure 4] FIG. 2 is an enlarged cross-sectional view of a piezoelectric element. [Diagram 5] 4 is a cross-sectional view showing how ink ejected from an inkjet head is attached to a vibrating arm of a vibration element. FIG. [Figure 6] 10 is a flowchart showing a method for adjusting the frequency of a vibration element. [Figure 7] 4 is a cross-sectional view showing the MEMS element before a lid portion is bonded thereto. FIG. [Figure 8] FIG. 2 is a plan view showing a frequency adjustment area. [Figure 9]4 is a plan view of a vibration element on which a first adjustment pattern is formed. FIG. [Figure 10] FIG. 11 is a cross-sectional view showing a state in which the first adjustment patterns are laminated. [Figure 11] 13 is a plan view of a vibration element on which a second adjustment pattern is formed. FIG. [Figure 12] 13 is a plan view of a vibration element on which a third adjustment pattern is formed. FIG. [Figure 13] 10 is a flowchart showing a method for adjusting the frequency of a vibration element according to a second embodiment. [Figure 14] 13 is a flowchart showing a method for adjusting the frequency of a vibration element according to a third embodiment. [Figure 15] 4 is a plan view of a vibration element on which a first weight portion is formed. FIG. [Figure 16] 13 is a plan view of a vibration element on which a second weight portion is formed. FIG. [Figure 17] 13 is a plan view of a vibration element on which a third weight portion is formed. FIG. [Figure 18] 4 is a plan view of a vibration element on which a first weight portion is formed. FIG. [Figure 19] 13 is a plan view of a vibration element on which a second weight portion is formed. FIG. [Figure 20] 13 is a plan view of a vibration element on which a third weight portion is formed. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for adjusting the frequency of a vibration element according to the present invention will be described in detail with reference to the embodiments shown in the accompanying drawings.

[0009] First Embodiment FIG. 1 is a plan view of the MEMS element according to the first embodiment. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. FIG. 3 is a cross-sectional view taken along line BB in FIG. 1. FIG. 4 is an enlarged cross-sectional view of a piezoelectric element. FIG. 5 is a cross-sectional view showing how ink ejected from an inkjet head is applied to a vibrating arm of a vibration element. FIG. 6 is a flowchart showing a frequency adjustment method for a vibration element. FIG. 7 is a cross-sectional view showing a MEMS element before a lid portion is bonded. FIG. 8 is a plan view showing a frequency adjustment area. FIG. 9 is a plan view of a vibration element on which a first adjustment pattern is formed. FIG. 10 is a cross-sectional view showing a state in which the first adjustment pattern is laminated. FIG. 11 is a plan view of a vibration element on which a second adjustment pattern is formed. FIG. 12 is a plan view of a vibration element on which a third adjustment pattern is formed.

[0010] For ease of explanation, each figure except for Fig. 6 shows an X-axis, a Y-axis, and a Z-axis that are perpendicular to each other. The arrow side of each axis is also called the "plus side" and the opposite side is also called the "minus side." The plus side of the Z-axis is also called the "upper" and the minus side is also called the "lower."

[0011] 1, the MEMS element 1 includes an SOI (Silicon on Insulator) substrate 10 on which a vibration element 20 is formed, and a lid 5 for hermetically sealing the vibration element 20. The lid 5 is made of single crystal silicon or the like, and has a recess that opens to the bottom surface. The bottom surface of the lid 5 is bonded to the top surface of the SOI substrate 10.

[0012] As shown in FIG. 2 and FIG. 3, the SOI substrate 10 is a substrate in which a silicon layer 11, a BOX (Buried Oxide) layer 12, and a surface silicon layer 13 are laminated in this order. For example, the silicon layer 11 and the surface silicon layer 13 are made of single crystal silicon, and the BOX layer 12 is made of a silicon oxide layer (SiO2 or the like). In addition, the surface silicon layer 13 is formed with a vibration substrate 21 and a frame-shaped frame portion 131 surrounding the periphery of the vibration substrate 21. In addition, a pair of electrode pads PAD1 and PAD2 are arranged on the upper surface of the frame portion 131. In addition, at positions overlapping with the electrode pads PAD1 and PAD2, through electrodes 14 and 15 that penetrate the SOI substrate 10 in the thickness direction are formed. The through electrode 14 is electrically connected to the electrode pad PAD1, and the through electrode 15 is electrically connected to the electrode pad PAD2. As a result, the electrode pads PAD1 and PAD2 are drawn out to the outside of the MEMS element 1.

[0013] The vibration element 20 has a vibration substrate 21 formed on the surface silicon layer 13, and three piezoelectric elements 29A, 29B, and 29C arranged on the vibration substrate 21. The vibration substrate 21 has a support portion 210 supported by the silicon layer 11 and the BOX layer 12, and three vibration arms 211, 212, and 213 separated from the BOX layer 12. The upper surface of the vibration substrate 21 is covered with an insulating layer (not shown) made of, for example, silicon oxide (SiO2). The vibration arms 211, 212, and 213 each extend from the support portion 210 toward the positive side in the Y-axis direction, and are arranged at equal intervals in the X-axis direction. The vibration arms 211, 212, and 213 are aligned to have the same shape. In the following, the free end side of the vibration arms 211, 212, and 213, that is, the side opposite to the support portion 210, is also referred to as the tip side, and the fixed end side, that is, the side of the support portion 210, is also referred to as the base side.

[0014] As shown in Fig. 4, the vibrating arms 211, 212, and 213 have an upper surface 21A as a first surface and a lower surface 21B as a second surface, which are in a front-back relationship with each other. A piezoelectric element 29A is arranged on the upper surface 21A of the vibrating arm 211, a piezoelectric element 29B is arranged on the upper surface 21A of the vibrating arm 212, and a piezoelectric element 29C is arranged on the upper surface 21A of the vibrating arm 213. Note that "piezoelectric elements 29A, 29B, and 29C are arranged on the upper surfaces 21A of the vibrating arms 211, 212, and 213" means that the piezoelectric element 29A is arranged directly on the upper surfaces 21A of the vibrating arms 211, 212, and 213, as well as the case where another layer (insulating layer in this embodiment) is interposed between them.

[0015] The piezoelectric elements 29A, 29B, and 29C have the same configuration, and each have a lower electrode 291 arranged on the upper surface 21A of the vibrating arms 211, 212, and 213, a piezoelectric layer 292 arranged on the upper surface of the lower electrode 291, and an upper electrode 293 arranged on the upper surface of the piezoelectric layer 292. In other words, the piezoelectric elements 29A, 29B, and 29C have a configuration in which the piezoelectric layer 292 is sandwiched between the lower electrode 291 and the upper electrode 293 from above and below.

[0016] In this embodiment, the piezoelectric elements 29A, 29B, and 29C are disposed at about half the base end side of the entire length of the vibrating arms 211, 212, and 213, respectively. In this way, by disposing the piezoelectric elements 29A, 29B, and 29C at about half the base end side of the vibrating arms 211, 212, and 213, the vibrating arms 211, 212, and 213 can be greatly bent, and a frequency adjustment area E for applying the ink I for frequency adjustment can be secured at the tip portion of the vibrating arms 211, 212, and 213 sufficiently wide. However, only the lower electrode 291 is disposed extending to the tip of the vibrating arms 211, 212, and 213. Such a lower electrode 291 functions as a base layer for applying the ink I to the vibrating arms 211, 212, and 213. However, it is not limited to this, and the lower electrode 291 may also have the same length as the piezoelectric layer 292 and the upper electrode 293.

[0017] The constituent materials of each part of the piezoelectric elements 29A, 29B, and 29C are not particularly limited, but for example, the piezoelectric layer 292 is made of aluminum nitride (AlN) or the like, and the lower electrode 291 and the upper electrode 293 are made of titanium nitride (TiN) or the like.

[0018] In addition, the piezoelectric elements 29A, 29B, and 29C are wired so that adjacent vibrating arms 211, 212, and 213 vibrate in opposite phases. That is, the piezoelectric elements 29A, 29B, and 29C are wired so that a state in which the vibrating arms 211 and 213 bend upward and the vibrating arm 212 bend downward and a state in which the vibrating arms 211 and 213 bend downward and the vibrating arm 212 bend upward are alternately repeated. Specifically, the lower electrodes 291 of the piezoelectric elements 29A and 29C and the upper electrode 293 of the piezoelectric element 29B are electrically connected to the electrode pad PAD1 via wiring (not shown), and the upper electrodes 293 of the piezoelectric elements 29A and 29C and the lower electrode 291 of the piezoelectric element 29B are electrically connected to the electrode pad PAD2 via wiring (not shown).

[0019] According to this configuration, by applying a drive voltage between the electrode pads PAD1 and PAD2, the piezoelectric elements 29A and 29C and the piezoelectric element 29B expand and contract in opposite phases, and the adjacent vibrating arms 211, 212, and 213 vibrate in opposite phases. This vibration is highly excited at the inherent resonant frequency fr, and the impedance becomes minimum. As a result, by connecting this MEMS element 1 to an oscillation circuit, it transmits at an oscillation frequency determined by the resonant frequency fr. The resonant frequency fr is mainly determined by the resonant frequency of the vibrating arms 211, 212, and 213.

[0020] Next, a method for adjusting the frequency of the vibration element 20 will be described. Briefly, this frequency adjustment method is performed by attaching (landing) ink I ejected from an inkjet head IJH to a frequency adjustment area E secured in approximately half of the tip side of the upper surface 21A of the vibrating arms 211, 212, and 213, as shown in Fig. 5, and increasing the mass of the vibrating arms 211, 212, and 213 to lower the resonance frequency fr and match it to a target frequency. The method for adjusting the resonance frequency fr will be described in detail below.

[0021] In addition, the ink I is not particularly limited, but preferably contains a metal. In this case, for example, the ink I can be configured to contain metal particles in a solvent. This makes it easier to increase the specific gravity of the ink I compared to when other materials are used, and the resonance frequency fr can be efficiently adjusted with a small amount of ink I used. The metal is not particularly limited, but for example, tungsten, molybdenum, or other metals with a large specific gravity are preferable. This further makes it possible to efficiently adjust the resonance frequency fr with a small amount of ink I used. In addition, for example, gold, aluminum, magnesium, stainless steel, or other metals that are difficult to oxidize are also preferable. This makes it possible to prevent the ink I from oxidizing, and effectively suppress the aging change of the resonance frequency fr.

[0022] In addition, it is preferable that the ink I contains an oxide. In this case, for example, the ink I may be configured to contain oxide particles in a solvent. This can prevent the ink I from being oxidized, and can effectively suppress the change over time in the resonance frequency fr. The oxide is not particularly limited, but examples thereof include silica (SiO2), and various ceramics such as alumina and titania.

[0023] 6, the frequency adjustment method of the vibration element 20 includes a preparation step S1 for preparing the vibration element 20, a first frequency measurement step S2 for measuring the resonance frequency fr of the vibration element 20, a first adjustment pattern formation step S3 for forming a first adjustment pattern P1 by the inkjet method in a first region E1 of the vibrating arms 211, 212, and 213, a second adjustment pattern formation step S5 for forming a second adjustment pattern P2 by the inkjet method in a second region E2 of the vibrating arms 211, 212, and 213, and a third adjustment pattern formation step S7 for forming a third adjustment pattern P3 by the inkjet method in a third region E3 of the vibrating arms 211, 212, and 213. Each of these steps will be described in order below.

[0024] ≪Preparation process S1≫ In the preparation step S1, as shown in FIG. 7, the MEMS element 1 before the lid portion 5 is bonded is prepared.

[0025] <First frequency measurement process S2> In the first frequency measurement process S2, first, the resonant frequency fr of the vibration element 20 is measured. The method of measuring the resonant frequency fr is not particularly limited, and for example, it can be measured using a laser Doppler measurement device. Next, from the difference Δf between the resonant frequency fr and the target frequency f0, it is calculated how much mass of ink I should be attached to which area of ​​the frequency adjustment area E in order to make the resonant frequency fr coincide with the target frequency f0. Here, the above-mentioned "making the resonant frequency fr coincide with the target frequency f0" includes the meaning of making the resonant frequency fr fall within a predetermined error range with respect to the target frequency f0. The ink I is arranged in the same manner in the frequency adjustment area E of the three vibration arms 211, 212, and 213. This point will be described in detail below.

[0026] In this embodiment, as shown in FIG. 8, the frequency adjustment area E is provided in about half of the tip end of the upper surface 21A of the vibrating arms 211, 212, and 213. The frequency adjustment area E is located on the tip end side of the piezoelectric elements 29A, 29B, and 29C. As described above, the lower electrode 291 extends into the frequency adjustment area E, and the lower electrode 291 functions as a base layer for the ink I. Furthermore, three regions are set in the frequency adjustment area E. These three regions are a first region E1 located at the tip end of the frequency adjustment area E, a second region E2 located at the center of the frequency adjustment area E, and a third region E3 located at the base end of the frequency adjustment area E. That is, the second region E2 is located on the base end side of the first region E1, and the third region E3 is located on the base end side of the second region E2.

[0027] Here, the amount of change in the resonance frequency fr with respect to the mass is larger toward the tip of the vibrating arms 211, 212, and 213. Therefore, when the same mass of ink I is applied to the first, second, and third regions E1, E2, and E3, the amount of change in the resonance frequency fr is first region E1>second region E2>third region E3. Due to this property, in this embodiment, the resonance frequency fr is roughly adjusted using the first region E1, the resonance frequency fr is finely adjusted using the third region E3, and the resonance frequency fr is adjusted using the second region E2 so as to fill the gap between the rough adjustment and the fine adjustment.

[0028] Furthermore, in this embodiment, the ejection amount (mass) of each droplet of ink I ejected from the inkjet head IJH is made different between the first, second, and third regions E1, E2, and E3. Specifically, the ejection amount of ink I ejected to the first region E1 is the largest, the ejection amount of ink I ejected to the second region E2 is the next largest, and the ejection amount of ink I ejected to the third region E3 is the smallest. In other words, when the ejection amount of ink I ejected to the first region E1 is the first ejection amount M1, the ejection amount of ink I ejected to the second region E2 is the second ejection amount M2, and the ejection amount of ink I ejected to the third region E3 is the third ejection amount M3, the first ejection amount M1>second ejection amount M2>third ejection amount M3. With this configuration, in the first region E1, the amount of change in the resonance frequency fr when the ink I is deposited becomes larger, enhancing the coarse tuning effect, whereas in the third region E3, the amount of change in the resonance frequency fr when the ink I is deposited becomes smaller, enhancing the fine tuning effect. Therefore, with a smaller number of times of ejection of the ink I, the resonance frequency fr can be accurately matched to the target frequency f0.

[0029] Here, the inkjet head IJH includes an ink chamber that contains the ink I, a nozzle for ejecting the ink I from the ink chamber, a vibration plate that constitutes a part of the wall surface of the ink chamber, and a piezoelectric element that vibrates the vibration plate. A voltage is applied to the piezoelectric element to vibrate the piezoelectric element, thereby vibrating the vibration plate and ejecting the ink I in the ink chamber from the nozzle. The larger the voltage applied to the piezoelectric element, the larger the vibration plate vibrates and the more ink I is ejected. Taking advantage of such characteristics, in this embodiment, the amount of ink I ejected per droplet is controlled by changing the voltage applied to the piezoelectric element when the ink I is applied to the first region E1, when the ink I is applied to the second region E2, and when the ink I is applied to the third region E3. Specifically, the voltages are set so that the voltage V1 applied to the piezoelectric element to eject the first ejection amount M1 of ink I>the voltage V2 applied to the piezoelectric element to eject the second ejection amount M2 of ink I>the voltage V3 applied to the piezoelectric element to eject the third ejection amount M3 of ink I. According to this method, the ejection amount of ink I per drop can be accurately controlled with simple control.

[0030] However, there is no particular limitation on the method for controlling the ejection amount of the ink I. For example, an inkjet head IJH having a plurality of nozzles with different diameters may be used, and the ejection amount per droplet of the ink I may be controlled by changing the nozzle to be used when the ink I is applied to the first region E1, when the ink I is applied to the second region E2, and when the ink I is applied to the third region E3.

[0031] In addition, the method for ejecting the ink I from the inkjet head IJH is not limited to the piezoelectric inkjet method using the piezoelectric element described above, but may also be any of the following: a charge control method in which the ink I ejected continuously from the nozzle of the ink chamber is charged and the deposition position is controlled by an electric field; a thermal method that uses the film boiling phenomenon of the ink; a bubble ejection method in which bubbles are generated in the ink I by applying heat and the ink I is ejected; and an electrostatic actuator method in which a vibration plate that constitutes part of the ink chamber is displaced and vibrated by electrostatic force to eject the ink I.

[0032] In this embodiment, the change amount Δf1 of the resonance frequency fr when one drop of ink I of the first ejection amount M1 is deposited on the first region E1, the change amount Δf2 of the resonance frequency fr when one drop of ink I of the second ejection amount M2 is deposited on the second region E2, and the change amount Δf3 of the resonance frequency fr when one drop of ink I of the third ejection amount M3 is deposited on the third region E3 are measured and stored in advance. Note that the changes Δf1, Δf2, and Δf3 are naturally in the order of change amount Δf1>change amount Δf2>change amount Δf3, but for example, it is preferable that the change amount Δf2 is about 10 times the change amount Δf3, and the change amount Δf1 is about 100 times the change amount Δf3. This makes the difference between the changes Δf1, Δf2, and Δf3 appropriate, and the above-mentioned effect becomes more prominent. In other words, the resonance frequency fr can be accurately matched to the target frequency f0 with a smaller number of ejections of ink I.

[0033] In the first frequency measurement step S2, the amount of change Δf1, Δf2, and Δf3 is then referenced to calculate how many drops of ink I should be deposited in the first region E1, how many drops of ink I should be deposited in the second region E2, and how many drops of ink I should be deposited in the third region E3 in order to make the resonance frequency fr coincide with the target frequency f0 with a smaller number of times of ejection of ink I. That is, when the number of drops of ink I deposited in the first region E1 is a, the number of drops of ink I deposited in the second region E2 is b, and the number of drops of ink I deposited in the third region E3 is c, a, b, and c that satisfy a×Δf1+b×Δf2+c×Δf3=Δf and minimize a+b+c are calculated. However, it is not essential that a+b+c is the minimum, and for example, it may be calculated so that a+b+c falls within a predetermined number of times.

[0034] <First adjustment pattern forming process S3> 9, in the first adjustment pattern forming process S3, a first adjustment pattern P1 is formed in the first region E1 of the vibrating arms 211, 212, and 213 by the inkjet method based on the measurement result in the first frequency measurement process S2. For example, if the measurement result in the first frequency measurement process S2 is a=1, the ink I is ejected once with the first ejection amount M1 to form one first adjustment pattern P1 in the first region E1, and if the measurement result in the first frequency measurement process S2 is a=5, the ink I is ejected five times with the first ejection amount M1 to form five first adjustment patterns P1 in the first region E1. Also, if the measurement result in the first frequency measurement process S2 is a=0, this process S3 is skipped.

[0035] In this embodiment, when forming a plurality of first adjustment patterns P1, the plurality of first adjustment patterns P1 are stacked as shown in Fig. 10. By stacking a plurality of first adjustment patterns P1 in this manner, more first adjustment patterns P1 can be formed in the finite first region E1, and a large coarse adjustment range can be secured. However, this is not limited to this, and the plurality of first adjustment patterns P1 may be formed at intervals so as not to overlap with each other.

[0036] The first adjustment pattern P1 is formed symmetrically with respect to the central axis of the vibrating arms 211, 212, and 213. This makes it possible to effectively prevent the vibrating arms 211, 212, and 213 from experiencing unnecessary vibration modes, particularly torsional vibration modes.

[0037] <<Second adjustment pattern forming process S5>> 11, in the second adjustment pattern forming process S5, b second adjustment patterns P2 are formed in the second region E2 of the vibrating arms 211, 212, and 213 by the inkjet method based on the measurement result in the first frequency measurement process S2. For example, if the measurement result in the first frequency measurement process S2 is b=1, the ink I is discharged once with the second discharge amount M2 to form one second adjustment pattern P2 in the second region E2, and if the measurement result in the first frequency measurement process S2 is b=5, the ink I is discharged five times with the second discharge amount M2 to form five second adjustment patterns P2 in the second region E2. Also, if the measurement result in the first frequency measurement process S2 is b=0, this process S5 is skipped.

[0038] Since the second discharge amount M2 is smaller than the first discharge amount M1, it is easy to form the second adjustment pattern P2 having a smaller mass than the first adjustment pattern P1. Since the second discharge amount M2 is smaller than the first discharge amount M1, the area of ​​the second adjustment pattern P2 is smaller than the area of ​​the first adjustment pattern P1 in a plan view from the Z-axis direction. Therefore, the second region E2 can be made smaller, and it is easy to ensure the second region E2 within the finite frequency adjustment area E. When forming a plurality of second adjustment patterns P2, the plurality of second adjustment patterns P2 are formed at a distance so as not to overlap each other. This makes it easy to check, for example, how many second adjustment patterns P2 have been formed later. However, this is not limited to this, and a plurality of second adjustment patterns P2 may be formed by stacking them in the same way as the first adjustment pattern P1.

[0039] The second adjustment pattern P2 is formed symmetrically with respect to the central axis of the vibrating arms 211, 212, and 213. This makes it possible to effectively prevent the vibrating arms 211, 212, and 213 from experiencing unnecessary vibration modes, particularly torsional vibration modes.

[0040] <Third adjustment pattern forming process S7> 12, in the third adjustment pattern forming process S7, c third adjustment patterns P3 are formed in the third region E3 of the vibrating arms 211, 212, and 213 by the inkjet method based on the measurement result in the first frequency measurement process S2. For example, if the measurement result in the first frequency measurement process S2 is c=1, the ink I is ejected once with the third ejection amount M3 to form one third adjustment pattern P3 in the third region E3, and if the measurement result in the first frequency measurement process S2 is c=5, the ink I is ejected five times with the third ejection amount M3 to form five third adjustment patterns P3 in the third region E3. Also, if the measurement result in the second frequency measurement process S4 is c=0, this process S7 is skipped.

[0041] Since the third discharge amount M3 is smaller than the second discharge amount M2, it is easy to form the third adjustment pattern P3 having a smaller mass than the second adjustment pattern P2. Since the third discharge amount M3 is smaller than the second discharge amount M2, the area of ​​the third adjustment pattern P3 is smaller than the area of ​​the second adjustment pattern P2 in a plan view from the Z-axis direction. Therefore, the third region E3 can be made smaller, and it is easy to secure the third region E3 within the finite frequency adjustment area E. When forming a plurality of third adjustment patterns P3, the plurality of third adjustment patterns P3 are formed at a distance so as not to overlap each other. This makes it easy to check, for example, how many third adjustment patterns P3 have been formed later. However, this is not limited to this, and a plurality of third adjustment patterns P3 may be formed by stacking them in the same manner as the first adjustment pattern P1.

[0042] The third adjustment pattern P3 is formed symmetrically with respect to the central axis of the vibrating arms 211, 212, and 213. This makes it possible to effectively prevent the vibrating arms 211, 212, and 213 from experiencing unnecessary vibration modes, particularly torsional vibration modes.

[0043] The method for adjusting the resonance frequency fr has been described above. According to such a method, it is possible to ensure a large frequency adjustment amount for coarsely adjusting the resonance frequency fr and to finely adjust the resonance frequency fr to match the target frequency f0 with high accuracy. Therefore, the resonance frequency fr can be adjusted efficiently and accurately with a small number of ejections of the ink I. In particular, in this embodiment, since there are three first, second, and third regions E1, E2, and E3 in which the amount of change in the resonance frequency fr per droplet of the ink I is different, the resonance frequency fr can be adjusted with higher accuracy.

[0044] However, the method of adjusting the resonance frequency fr is not particularly limited, and for example, the third adjustment pattern forming step S7 may be omitted. That is, only the first region E1 and the second region E2 are set in the frequency adjustment area E, and the resonance frequency fr may be adjusted using the first adjustment pattern P1 formed in the first region E1 and the second adjustment pattern P2 formed in the second region E2.

[0045] The frequency adjustment method of the vibration element 20 has been described above. As described above, the frequency adjustment method of the vibration element 20 includes a preparation step S1 for preparing the vibration element 20 having the vibration arms 211, 212, and 213 having the upper surface 21A as the first surface and the lower surface 21B as the second surface, which are in a front-back relationship, and a support part 210 for supporting one end of the vibration arms 211, 212, and 213, a first adjustment pattern forming step S3 for forming the first adjustment pattern P1 by the inkjet method in the first region E1 on the upper surface 21A side, and a second adjustment pattern forming step for forming the second adjustment pattern P2 having a smaller mass than the first adjustment pattern P1 by the inkjet method in the second region E2 located on the base end side of the first region E1 on the upper surface 21A side. According to this method, it is possible to simultaneously secure a large frequency adjustment amount for coarsely adjusting the resonance frequency fr and finely adjust the resonance frequency fr to match the target frequency f0 with high accuracy. Therefore, the resonance frequency fr can be adjusted efficiently and accurately with a small number of ejections of the ink I.

[0046] As described above, in a plan view of upper surface 21A, the area of ​​second adjustment pattern P2 is smaller than the area of ​​first adjustment pattern P1. Therefore, second region E2 can be made smaller, making it easier to ensure second region E2 within frequency adjustment area E, which is finite.

[0047] As described above, in the first adjustment pattern forming step S3, a plurality of first adjustment patterns P1 are laminated. According to this method, more first adjustment patterns P1 can be formed in the first region E1, and a large coarse adjustment range can be secured.

[0048] As described above, the frequency adjustment method for the vibration element 20 further includes a third adjustment pattern forming step S7 for forming a third adjustment pattern P3 having a smaller mass than the second adjustment pattern P2 by an inkjet method in a third region E3 located closer to the base end than the second region E2 on the upper surface 21A side. In this way, by including the third adjustment pattern forming step S7 in addition to the first adjustment pattern forming step S3 and the second adjustment pattern forming step S5, the resonance frequency fr can be adjusted with higher accuracy.

[0049] As described above, in a plan view of upper surface 21A, the area of ​​second adjustment pattern P2 is smaller than the area of ​​first adjustment pattern P1, and the area of ​​third adjustment pattern P3 is smaller than the area of ​​second adjustment pattern P2. Therefore, second region E2 can be made smaller, making it easier to secure second region E2 within finite frequency adjustment area E. Similarly, third region E3 can be made smaller, making it easier to secure third region E3 within finite frequency adjustment area E.

[0050] As described above, in the first adjustment pattern forming process S3, the first adjustment pattern P1 is formed by depositing the first ejection amount M1 of ink I on the first region E1, and in the second adjustment pattern forming process S5, the second adjustment pattern P2 is formed by depositing the second ejection amount M2 of ink I, which is smaller than the first ejection amount M1, on the second region E2. This makes it easy to form the first and second adjustment patterns P1 and P2.

[0051] As described above, it is preferable that the ink I contains a metal. This makes it easier to increase the specific gravity of the ink I compared to when other materials are used, and makes it possible to efficiently adjust the resonance frequency fr with a small amount of ink I used.

[0052] As described above, it is preferable that the ink I contains an oxide, which can prevent oxidation of the first, second, and third adjustment patterns P1, P2, and P3, and can effectively suppress the change over time in the resonance frequency fr.

[0053] <Second embodiment> FIG. 13 is a flowchart showing a method for adjusting the frequency of the vibration element according to the second embodiment.

[0054] The frequency adjustment method of the vibration element according to this embodiment is the same as the frequency adjustment method of the vibration element 20 of the first embodiment described above, except that it further includes a second frequency measurement step S4 and a third frequency measurement step S6. In the following description, the frequency adjustment method of the vibration element 20 of this embodiment will be described with a focus on the differences from the first embodiment described above, and the description of the same points will be omitted. In addition, in the drawings of this embodiment, the same reference numerals are used for the same configurations as those of the above-mentioned embodiment.

[0055] 13, the frequency adjustment method of the vibration element 20 of this embodiment includes a preparation step S1 of preparing the vibration element 20, a first frequency measurement step S2 of measuring the resonance frequency fr of the vibration element 20, a first adjustment pattern formation step S3 of forming a first adjustment pattern P1 by the inkjet method in the first region E1 of the vibrating arms 211, 212, and 213, a second frequency measurement step S4 of measuring the resonance frequency fr of the vibration element 20, a second adjustment pattern formation step S5 of forming a second adjustment pattern P2 by the inkjet method in the second region E2 of the vibrating arms 211, 212, and 213, a third frequency measurement step S6 of measuring the resonance frequency fr of the vibration element 20, and a third adjustment pattern formation step S7 of forming a third adjustment pattern P3 by the inkjet method in the third region E3 of the vibrating arms 211, 212, and 213. Each of these steps will be described in order below.

[0056] ≪Preparation process S1≫ In the preparation step S1, the MEMS element 1 before the lid portion 5 is bonded is prepared.

[0057] <First frequency measurement process S2> In the first frequency measurement step S2, first, the resonance frequency fr of the vibration element 20 is measured. Then, the number of droplets (=a) of the ink I to be deposited on the first region E1 is calculated by referring to the amount of change Δf1. Specifically, a is calculated so that a×Δf1<Δf is satisfied and is maximum.

[0058] <First adjustment pattern forming process S3> In the first adjustment pattern forming process S3, a number of first adjustment patterns P1 are formed in the first region E1 of each of the vibrating arms 211, 212, and 213 by an inkjet method based on the measurement results in the first frequency measuring process S2.

[0059] <<Second frequency measurement process S4>> In the second frequency measurement process S4, first, the vibration element 20 in the state where the first adjustment pattern formation process S3 is completed is annealed to harden the first adjustment pattern P1. Next, the resonance frequency fr of this vibration element 20 is measured. Then, the number of droplets (=b) of ink I to be deposited on the second region E2 is calculated with reference to the amount of change Δf2. Specifically, b is calculated so that b×Δf2<Δf-(a×Δf1) is satisfied and is maximum.

[0060] <<Second adjustment pattern forming process S5>> In the second adjustment pattern forming process S5, b second adjustment patterns P2 are formed in the second regions E2 of the vibrating arms 211, 212, and 213 by an inkjet method, based on the measurement results in the second frequency measuring process S4.

[0061] <Third frequency measurement process S6> In the third frequency measurement process S6, first, the vibration element 20 in the state where the second adjustment pattern formation process S5 is completed is annealed to harden the second adjustment pattern P2. Next, the resonance frequency fr of this vibration element 20 is measured. Then, the number of droplets (=c) of ink I to be deposited on the third region E3 is calculated with reference to the amount of change Δf3. Specifically, c is calculated so as to satisfy c×Δf3=Δf-(a×Δf1)-(b×Δf2).

[0062] <Third adjustment pattern forming process S7> In the third adjustment pattern forming process S7, c third adjustment patterns P3 are formed in the third region E3 of each of the vibrating arms 211, 212, and 213 by the inkjet method based on the measurement results in the third frequency measuring process S6.

[0063] The above describes the frequency adjustment method for the vibration element 20. In this method, before the second adjustment pattern forming process S5, a second frequency measurement process S4 is performed to measure the resonance frequency fr of the vibration element 20 after the first adjustment pattern forming process S3, and before the third adjustment pattern forming process S7, a third frequency measurement process S6 is performed to measure the resonance frequency fr of the vibration element 20 after the second adjustment pattern forming process S5. In this way, by measuring and checking the resonance frequency fr of the vibration element 20 every time the first and second adjustment patterns P1 and P2 are formed, b and c can be appropriately determined, and the resonance frequency fr can be adjusted with higher accuracy.

[0064] As described above, the frequency adjustment method of the vibration element 20 further includes a first frequency measurement process S2 for measuring the resonance frequency fr of the vibration element 20 prior to the first adjustment pattern formation process S3, and a second frequency measurement process S4 for measuring the resonance frequency fr of the vibration element 20 after the first adjustment pattern formation process S3 and prior to the second adjustment pattern formation process S5, in which the first adjustment pattern formation process S3 forms the first adjustment patterns P1 in a number determined based on the measurement results in the first frequency measurement process S2, and the second adjustment pattern formation process S5 forms the second adjustment patterns P2 in a number determined based on the measurement results in the second frequency measurement process S4. According to this method, the number (=b) of the second adjustment patterns P2 to be formed can be appropriately determined, and the resonance frequency fr can be adjusted with higher accuracy.

[0065] As described above, the frequency adjustment method for the vibration element 20 further includes a first frequency measurement process S2 for measuring the resonant frequency fr of the vibration element 20 prior to the first adjustment pattern formation process S3, a second frequency measurement process S4 for measuring the resonant frequency fr of the vibration element 20 prior to the second adjustment pattern formation process S5 after the first adjustment pattern formation process S3, and a third frequency measurement process S6 for measuring the resonant frequency fr of the vibration element 20 prior to the third adjustment pattern formation process S7, in which in the first adjustment pattern formation process S3, a number of first adjustment patterns P1 determined based on the measurement results in the first frequency measurement process S2 are formed, in the second adjustment pattern formation process S5, a number of second adjustment patterns P2 determined based on the measurement results in the second frequency measurement process S4 are formed, and in the third adjustment pattern formation process S7, a number of third adjustment patterns P3 determined based on the measurement results in the third frequency measurement process S6 are formed. According to such a method, the number of second adjustment patterns P2 (=b) and the number of third adjustment patterns P3 (=c) can be appropriately determined, and the resonance frequency fr can be adjusted with higher accuracy.

[0066] The second embodiment as described above can also achieve the same effects as the first embodiment described above.

[0067] <Third embodiment> Fig. 14 is a flowchart showing a method for adjusting the frequency of a vibration element according to a third embodiment. Fig. 15 is a plan view of a vibration element on which a first weight portion is formed. Fig. 16 is a plan view of a vibration element on which a second weight portion is formed. Fig. 17 is a plan view of a vibration element on which a third weight portion is formed.

[0068] The frequency adjustment method of the vibration element according to this embodiment is the same as the frequency adjustment method of the vibration element 20 of the first embodiment described above, except that a weight part is formed instead of an adjustment pattern. In the following description, the frequency adjustment method of the vibration element 20 of this embodiment will be described mainly with respect to the differences from the first embodiment described above, and the description of the similar points will be omitted. In addition, in the drawings of this embodiment, the same reference numerals are used for the same configurations as those of the above-mentioned embodiment.

[0069] As shown in FIG. 14 , the frequency adjustment method of the vibration element 20 of the present embodiment includes a preparation step S11 of preparing the vibration element 20, a first frequency measurement step S12 of measuring the resonance frequency fr of the vibration element 20, a first weight portion formation step S13 of forming a first weight portion P11 having an area determined based on the measurement result in the first frequency measurement step S12 by an inkjet method in the first region E1 of the vibrating arms 211, 212, and 213, a second frequency measurement step S14 of measuring the resonance frequency fr of the vibration element 20, and a second frequency measurement step S15 of forming a first weight portion P11 having an area determined based on the measurement result in the first frequency measurement step S12 in the first region E1 of the vibrating arms 211, 212, and 213 by an inkjet method. The method includes a second weight forming process S15 for forming a second weight P12 having an area smaller than that of the first weight P11 in the region E2 by an inkjet method based on the measurement results in the second frequency measurement process S14, a third frequency measurement process S16 for measuring the resonance frequency fr of the vibration element 20, and a third weight forming process S17 for forming a third weight P13 having an area smaller than that of the second weight P12 in the third region E3 of the vibrating arms 211, 212, and 213 by an inkjet method based on the measurement results in the third frequency measurement process S16. Each of these processes will be described in order below.

[0070] ≪Preparation process S11≫ In the preparation step S11, the MEMS element 1 before the lid portion 5 is bonded is prepared.

[0071] <<First frequency measurement process S12>> In the first frequency measurement step S12, first, the resonance frequency fr of the vibration element 20 is measured. Then, based on the difference Δf between the resonance frequency fr and the target frequency f0, the area, i.e., the mass, of the first weight portion P11 formed in the first region E1 is calculated, and the number of ejections (=a) of the ink I that will result in the calculated area is calculated. At this time, the area of ​​the first weight portion P11 is calculated so that the resonance frequency fr is not less than the target frequency f0.

[0072] ≪First weight part forming step S13≫ As shown in FIG. 15, in the first weight portion forming process S13, based on the measurement results of the first frequency measurement process S12, ink I is ejected a times from the inkjet head IJH into the first region E1 of each of the vibrating arms 211, 212, and 213 with a first ejection amount M1, to form a first weight portion P11 with the area determined in the first frequency measurement process S12.

[0073] In this embodiment, the length L11 of the first weight P11 in the Y-axis direction, i.e., the length in the extension direction of the vibrating arms 211, 212, and 213, is determined in advance, and the area of ​​the first weight P11 is adjusted by adjusting the length W11 of the first weight P11 in the X-axis direction, i.e., the length in the width direction perpendicular to the extension direction of the vibrating arms 211, 212, and 213, based on the measurement results in the first frequency measurement process S12. In this way, by keeping the length L11 constant, the amount of change in the resonant frequency fr with respect to the area of ​​the first weight P11 is kept constant, so that the resonant frequency fr can be easily adjusted.

[0074] <<Second frequency measurement process S14>> In the second frequency measurement process S14, first, the resonance frequency fr of the vibration element 20 is measured. Then, based on the difference Δf between the resonance frequency fr and the target frequency f0, the area, i.e., the mass, of the second weight portion P12 formed in the second region E2 is calculated, and further, the number of ejections (=b) of the ink I that will result in the calculated area is calculated. At this time, the area of ​​the second weight portion P12 is calculated so that the resonance frequency fr is not less than the target frequency f0.

[0075] ≪Second weight forming step S15≫ 16, in the second weight portion forming process S15, based on the measurement result in the second frequency measurement process S14, ink I is discharged b times from the inkjet head IJH in the second discharge amount M2 onto the second region E2 of each of the vibrating arms 211, 212, and 213 to form the second weight portion P12 having the area determined in the second frequency measurement process S14. Note that since the second discharge amount M2 is smaller than the first discharge amount M1, the second weight portion P12 can be formed with high precision.

[0076] In this embodiment, the length L12 of the second weight P12 in the Y-axis direction, i.e., the length in the extension direction of the vibrating arms 211, 212, and 213, is determined in advance, and the area of ​​the second weight P12 is adjusted by adjusting the length W12 of the second weight P12 in the X-axis direction, i.e., the length in the width direction perpendicular to the extension direction of the vibrating arms 211, 212, and 213, based on the measurement results in the second frequency measurement process S14. In this way, by keeping the length L12 constant, the amount of change in the resonant frequency fr with respect to the area of ​​the second weight P12 is kept constant, so that the resonant frequency fr can be easily adjusted.

[0077] <Third frequency measurement process S16> In the third frequency measurement process S16, first, the resonance frequency fr of the vibration element 20 is measured. Then, based on the difference Δf between the resonance frequency fr and the target frequency f0, the area, i.e., the mass, of the third weight portion P13 to be formed in the third region E3 is calculated, and further, the number of ejections (=c) of the ink I that will result in the calculated area is calculated. At this time, the area of ​​the third weight portion P13 is calculated so that the resonance frequency fr coincides with the target frequency f0.

[0078] ≪Third weight forming step S17≫ 17, in the third weight portion forming process S17, based on the measurement result in the third frequency measurement process S16, the ink I is discharged c times from the inkjet head IJH into the third region E3 of each of the vibrating arms 211, 212, and 213 at the third discharge amount M3 to form the third weight portion P13 having the area determined in the third frequency measurement process S16. Note that since the third discharge amount M3 is smaller than the second discharge amount M2, the third weight portion P13 can be formed with high precision.

[0079] In this embodiment, the length L13 of the third weight P13 in the Y-axis direction, i.e., the length in the extension direction of the vibrating arms 211, 212, and 213, is determined in advance, and the area of ​​the third weight P13 is adjusted by adjusting the length W13 of the third weight P13 in the X-axis direction, i.e., the length in the width direction perpendicular to the extension direction of the vibrating arms 211, 212, and 213, based on the measurement results in the third frequency measurement process S16. In this way, by keeping the length L13 constant, the amount of change in the resonant frequency fr with respect to the area of ​​the third weight P13 is kept constant, so that the resonant frequency fr can be easily adjusted.

[0080] The frequency adjustment method of the vibration element 20 has been described above. According to such a method, it is possible to secure a large frequency adjustment amount for coarsely adjusting the resonance frequency fr and to finely adjust the resonance frequency fr to match the target frequency f0 with high accuracy. Therefore, the resonance frequency fr can be adjusted efficiently and accurately with a small number of ejections of the ink I. In particular, in this embodiment, since there are three first, second, and third regions E1, E2, and E3 having different amounts of change in the resonance frequency fr per area of ​​the weight, the resonance frequency fr can be adjusted with higher accuracy.

[0081] However, the method of adjusting the resonance frequency fr is not particularly limited, and for example, the third weight portion forming step S17 may be omitted. That is, only the first region E1 and the second region E2 are set in the frequency adjustment area E, and the resonance frequency fr may be adjusted using the first adjustment pattern P1 formed in the first region E1 and the second adjustment pattern P2 formed in the second region E2.

[0082] The above-described frequency adjustment method for the vibration element 20 includes, as described above, a preparation step S11 for preparing the vibration element 20 having the vibration arms 211, 212, and 213 with the upper surface 21A as a first surface and the lower surface 21B as a second surface, which are in a front-back relationship, and the support portion 210 for supporting one end of the vibration arms 211, 212, and 213; a first frequency measurement step S12 for measuring the resonance frequency fr of the vibration element 20; and a first frequency measurement step S13 for measuring the resonance frequency fr of the vibration element 20 by ink-jet printing on the first region E1 on the upper surface 21A side. The method includes a first weight forming step S13 for forming a first weight P11 having an area determined based on the measurement results in step S12, a second frequency measurement step S14 for measuring the resonance frequency fr of the vibration element 20, and a second weight forming step S15 for forming a second weight P12 having an area smaller than that of the first weight P11, determined based on the measurement results in the second frequency measurement step S14, in a second region E2 located on the base end side of the first region E1 on the upper surface 21A side, by an inkjet method. According to this method, it is possible to both ensure a large frequency adjustment amount for roughly adjusting the resonance frequency fr and finely adjust the resonance frequency fr to match the target frequency f0 with high accuracy. Therefore, the resonance frequency fr can be adjusted efficiently and accurately with a small number of ejections of the ink I.

[0083] As described above, in the first weight forming process S13, the length L11 of the first weight P11 in the extension direction of the vibrating arms 211, 212, 213 is determined, and the area of ​​the first weight P11 is adjusted by adjusting the length W11 of the width direction of the first weight P11 perpendicular to the extension direction of the vibrating arms 211, 212, 213 based on the measurement results in the first frequency measuring process S12. In this way, by keeping the length L11 constant, the amount of change in the resonant frequency fr with respect to the area of ​​the first weight P11 is kept constant, so that the resonant frequency fr can be easily adjusted.

[0084] As described above, in the second weight forming process S15, the length L12 of the second weight P12 in the extension direction of the vibrating arms 211, 212, 213 is determined, and the area of ​​the second weight P12 is adjusted by adjusting the length W12 of the width direction perpendicular to the extension direction of the vibrating arms 211, 212, 213 of the second weight P12 based on the measurement results in the second frequency measuring process S14. In this way, by keeping the length L12 constant, the amount of change in the resonant frequency fr with respect to the area of ​​the second weight P12 is kept constant, so that the resonant frequency fr can be easily adjusted.

[0085] As described above, the frequency adjustment method of the vibration element 20 further includes, after the second weight forming step S15, a third frequency measurement step S16 for measuring the resonance frequency fr of the vibration element 20, and a third weight forming step S17 for forming a third weight P13, which is determined based on the measurement result in the third frequency measurement step S16 and has an area smaller than that of the second weight P12, by an inkjet method in the third region E3 located on the base end side of the second region E2 on the upper surface 21A side. In this way, by including the third weight forming step S17 in addition to the first weight forming step S13 and the second weight forming step S15, the resonance frequency fr can be adjusted with higher accuracy.

[0086] As described above, in the first plummet forming process S13, the first plummet P11 is formed by depositing the first ejection amount M1 of ink I on the first region E1, and in the second plummet forming process S15, the second plummet P12 is formed by depositing the second ejection amount M2 of ink I, which is smaller than the first ejection amount M1, on the second region E2. In this way, by making the second ejection amount M2<the first ejection amount M1, the second plummet P12 can be formed with high accuracy.

[0087] As in the first embodiment, the ink I preferably contains a metal. This makes it easier to increase the specific gravity of the ink I compared to when other materials are used, and allows the resonance frequency fr to be adjusted efficiently with a small amount of ink I used.

[0088] As in the first embodiment, the ink I preferably contains an oxide, which can prevent oxidation of the first, second, and third adjustment patterns P1, P2, and P3, and can effectively suppress the change over time in the resonance frequency fr.

[0089] The fourth embodiment as described above can also achieve the same effects as the first embodiment described above.

[0090] <Fifth embodiment> Fig. 18 is a plan view of a vibration element on which a first weight portion is formed, Fig. 19 is a plan view of a vibration element on which a second weight portion is formed, and Fig. 20 is a plan view of a vibration element on which a third weight portion is formed.

[0091] The frequency adjustment method of the vibration element according to this embodiment is the same as the frequency adjustment method of the vibration element 20 of the third embodiment described above, except that the methods of forming the first, second, and third weight portions P11, P12, and P13 are different. In the following description, the frequency adjustment method of the vibration element 20 of this embodiment will be described with a focus on the differences from the third embodiment described above, and the description of the similar points will be omitted. In addition, in the drawings of this embodiment, the same reference numerals are used for the same configurations as those of the above-mentioned embodiment.

[0092] 18, in the first weight forming step S13 of this embodiment, the length W11 of the first weight P11 is determined, and the area of ​​the first weight P11 is adjusted by adjusting the length L11 of the first weight P11 based on the measurement result in the first frequency measurement step S12. According to this method, the length L11 can be made shorter than in the third embodiment described above, making it easier to ensure the first region E1 within the finite frequency adjustment area E. Also, the frequency adjustment area E can be made smaller.

[0093] Moreover, the position T11 of the tip of the first weight P11 is fixed, and the area of ​​the first weight P11 is adjusted by changing the position B11 of the base end. According to this method, the first weight P11 can be arranged closer to the tip side of the vibrating arms 211, 212, and 213, so that the amount of change in the resonance frequency fr per unit area of ​​the first weight P11 can be increased. Therefore, the area of ​​the first weight P11 can be reduced. However, this is not limited to the above, and the position B11 of the base end may be fixed, and the area of ​​the first weight P11 may be adjusted by changing the position T11 of the tip.

[0094] 19, in the second weight forming process S15, the length W12 of the second weight P12 is determined, and the area of ​​the second weight P12 is adjusted by adjusting the length L12 of the second weight P12 based on the measurement results in the second frequency measurement process S14. According to this method, the length L12 can be made shorter than in the third embodiment described above, making it easier to secure the second region E2 within the finite frequency adjustment area E. Also, the frequency adjustment area E can be made smaller.

[0095] Moreover, the position T12 of the tip of the second weight P12 is fixed, and the area of ​​the second weight P12 is adjusted by changing the position B12 of the base end. According to this method, the second weight P12 can be arranged closer to the tip side of the vibrating arms 211, 212, and 213, so that the amount of change in the resonance frequency fr per unit area of ​​the second weight P12 can be increased. Therefore, the area of ​​the second weight P12 can be reduced. However, this is not limited to the above, and the position B12 of the base end may be fixed, and the area of ​​the second weight P12 may be adjusted by changing the position T12 of the tip.

[0096] 20, in the third weight forming process S17, the length W13 of the third weight P13 is determined, and the area of ​​the third weight P13 is adjusted by adjusting the length L13 of the third weight P13 based on the measurement results in the third frequency measurement process S16. According to this method, the length L13 can be made shorter than in the third embodiment described above, making it easier to secure the third region E3 within the finite frequency adjustment area E. Also, the frequency adjustment area E can be made smaller.

[0097] Moreover, the position B13 of the base end of the third weight P13 is fixed, and the area of ​​the third weight P13 is adjusted by changing the position T13 of the tip end. According to this method, the third weight P13 can be arranged closer to the base ends of the vibrating arms 211, 212, and 213, so that the amount of change in the resonance frequency fr per unit area of ​​the third weight P13 can be reduced. Therefore, the resonance frequency fr can be adjusted with high precision. However, this is not limited to the above, and the area of ​​the third weight P13 may be adjusted by changing the position T13 of the base end.

[0098] In the above-described frequency adjustment method for the vibration element 20, as described above, in the first weight forming step S13, the length W11 of the first weight P11, i.e., the length in the width direction perpendicular to the extension direction of the vibrating arms 211, 212, and 213, is determined, and the area of ​​the first weight P11 is adjusted by adjusting the length L11 of the first weight P11, i.e., the length in the extension direction of the vibrating arms 211, 212, and 213, based on the measurement results in the first frequency measurement step S12. According to this method, the length L11 can be made shorter than in the third embodiment described above, and it becomes easier to secure the first region E1 within the finite frequency adjustment area E. Also, the frequency adjustment area E can be made smaller.

[0099] As described above, the position T11 of the tip of the first weight P11 is fixed, and the area of ​​the first weight P11 is adjusted by changing the position B11 of the base end. According to this method, the first weight P11 can be disposed closer to the tips of the vibrating arms 211, 212, and 213, so that the amount of change in the resonant frequency fr caused by the first weight P11 can be increased. Therefore, the area of ​​the first weight P11 can be reduced.

[0100] As described above, in the third weight forming process S17, the length W13 of the third weight P13, i.e., the length in the width direction perpendicular to the extension direction of the vibrating arms 211, 212, and 213, is determined, and the area of ​​the third weight P13 is adjusted by adjusting the length L13 of the third weight P13, i.e., the length in the extension direction of the vibrating arms 211, 212, and 213, based on the measurement results in the third frequency measurement process S16. According to this method, the length L13 can be made shorter than in the third embodiment described above, making it easier to secure the third region E3 within the finite frequency adjustment area E. Also, the frequency adjustment area E can be made smaller.

[0101] As described above, the position B13 of the base end of the third weight P13 is fixed, and the area of ​​the third weight P13 is adjusted by changing the position T13 of the tip end. According to this method, the third weight P13 can be disposed closer to the base ends of the vibrating arms 211, 212, and 213, so that the amount of change in the resonance frequency fr per unit area of ​​the third weight P13 can be reduced. Therefore, the resonance frequency fr can be adjusted with high precision.

[0102] The fifth embodiment can also achieve the same effects as the first embodiment described above.

[0103] Although the frequency adjustment method of the vibration element of the present invention has been described based on the illustrated embodiment, the present invention is not limited thereto. The configuration of each part can be replaced with any configuration or process having a similar function. In addition, any other configuration or process may be added to the present invention. In addition, the present invention may be a combination of any two or more configurations of the above-mentioned embodiments.

[0104] Furthermore, the vibration element 20 is not particularly limited, and may be, for example, a quartz vibration element. [Explanation of symbols]

[0105] 1...MEMS element, 10...SOI substrate, 11...silicon layer, 12...BOX layer, 13...surface silicon layer, 131...frame portion, 14...through electrode, 15...through electrode, 20...vibration element, 21...vibration substrate, 21A...upper surface, 21B...lower surface, 210...support portion, 211...vibration arm, 212...vibration arm, 213...vibration arm, 29A...piezoelectric element, 29B...piezoelectric element, 29C...piezoelectric element, 291...lower electrode, 292...piezoelectric layer, 293...upper electrode, 5...lid portion, B11...position, B12...position, B13...position, E...frequency adjustment area, E1...first region, E2...second region, E3...third region, I...ink, IJH...inkjet head, P1...first adjustment pattern, P11...first weight portion, P12...second weight portion, P1 3...third weight, P2...second adjustment pattern, P3...third adjustment pattern, PAD1...electrode pad, PAD2...electrode pad, S1...preparation step, S11...preparation step, S12...first frequency measurement step, S13...first weight formation step, S14...second frequency measurement step, S15...second weight formation step, S16...third frequency measurement step, S17...third weight formation step, S2...first frequency measurement step, S3...first adjustment pattern formation step, S4...second frequency measurement step, S5...second adjustment pattern formation step, S6...third frequency measurement step, S7...third adjustment pattern formation step, T11...position, T12...position, T13...position, W11...length, W12...length, W13...length, L11...length, L12...length, L13...length

Claims

1. A preparation step of preparing a vibration element having a vibration arm having a first surface and a second surface which are in a front-back relationship, and a support part which supports one end of the vibration arm; a first adjustment pattern forming step of forming a first adjustment pattern in a first region on the first surface side by an inkjet method; A method for adjusting the frequency of a vibration element, comprising: a second adjustment pattern forming process for forming a second adjustment pattern having a smaller mass than the first adjustment pattern by an inkjet method in a second region located on the base end side of the first region on the first surface side.

2. In a plan view of the first surface, The method for adjusting a frequency of a vibration element according to claim 1 , wherein an area of ​​the second adjustment pattern is smaller than an area of ​​the first adjustment pattern.

3. The method for adjusting a frequency of a vibration element according to claim 1 , wherein in the first adjustment pattern forming step, a plurality of the first adjustment patterns are laminated.

4. The frequency adjustment method for a vibration element as described in claim 1, further comprising a third adjustment pattern forming step of forming a third adjustment pattern having a smaller mass than the second adjustment pattern by an inkjet method in a third region located on the base end side of the second region on the first surface side.

5. In a plan view of the first surface, an area of ​​the second adjustment pattern is smaller than an area of ​​the first adjustment pattern; The method for adjusting a frequency of a vibration element according to claim 4 , wherein an area of ​​the third adjustment pattern is smaller than an area of ​​the second adjustment pattern.

6. a first frequency measurement step of measuring a resonance frequency of the vibration element prior to the first adjustment pattern formation step; a second frequency measurement step of measuring a resonance frequency of the vibration element after the first adjustment pattern formation step and before the second adjustment pattern formation step, In the first adjustment pattern forming step, a number of the first adjustment patterns is formed that is determined based on a measurement result in the first frequency measuring step, 2 . The method for adjusting a frequency of a vibration element according to claim 1 , wherein in the second adjustment pattern forming step, a number of the second adjustment patterns is formed that is determined based on a measurement result in the second frequency measuring step.

7. a first frequency measurement step of measuring a resonance frequency of the vibration element prior to the first adjustment pattern formation step; a second frequency measurement step of measuring a resonance frequency of the vibration element after the first adjustment pattern formation step and prior to the second adjustment pattern formation step; a third frequency measurement step of measuring a resonance frequency of the vibration element after the second adjustment pattern formation step and before the third adjustment pattern formation step, In the first adjustment pattern forming step, a number of the first adjustment patterns is formed that is determined based on a measurement result in the first frequency measuring step, In the second adjustment pattern forming step, a number of the second adjustment patterns is formed that is determined based on a measurement result in the second frequency measurement step, 6. The method for adjusting a frequency of a vibration element according to claim 4, wherein in the third adjustment pattern forming step, a number of the third adjustment patterns is formed that is determined based on a measurement result in the third frequency measuring step.

8. In the first adjustment pattern forming step, the first adjustment pattern is formed by depositing a first amount of ink onto the first region; The method for adjusting a frequency of a vibration element according to claim 2 , wherein in the second adjustment pattern forming step, the second adjustment pattern is formed by depositing a second amount of the ink, which is smaller than the first amount, onto the second region.

9. The method for adjusting a frequency of a vibration element according to claim 8 , wherein the ink contains a metal.

10. The method for adjusting a frequency of a vibration element according to claim 8 , wherein the ink contains an oxide.

11. A preparation step of preparing a vibration element having a vibration arm having a first surface and a second surface which are in a front-back relationship and a support part which supports one end of the vibration arm; a first frequency measurement step of measuring a resonance frequency of the vibration element; a first weight portion forming step of forming a first weight portion having an area determined based on a measurement result in the first frequency measurement step by an inkjet method in a first region on the first surface side; a second frequency measurement step of measuring a resonance frequency of the vibration element after the first weight portion forming step; a second weight portion forming process for forming a second weight portion having an area smaller than that of the first weight portion, the second weight portion being determined based on a measurement result in the second frequency measurement process, in a second region located on the base end side of the first region on the first surface side by an inkjet method.

12. 12. The frequency adjustment method for a vibration element as described in claim 11, wherein in the first weight formation process, the length of the first weight in the extension direction of the vibrating arm is determined, and the area of ​​the first weight is adjusted by adjusting the length of the first weight in a width direction perpendicular to the extension direction of the vibrating arm based on the measurement results in the first frequency measurement process.

13. The frequency adjustment method for a vibration element as described in claim 11, wherein in the second weight forming process, the length of the second weight in the extension direction of the vibrating arm is determined, and the area of ​​the second weight is adjusted by adjusting the length of the second weight in a width direction perpendicular to the extension direction of the vibrating arm based on the measurement results in the second frequency measurement process.

14. 12. The frequency adjustment method for a vibration element as described in claim 11, wherein in the first weight formation process, a width direction length of the first weight perpendicular to the extension direction of the vibrating arm is determined, and an area of ​​the first weight is adjusted by adjusting the length of the first weight in the extension direction of the vibrating arm based on the measurement results in the first frequency measurement process.

15. The method for adjusting a frequency of a vibration element according to claim 14 , wherein a position of a tip end of the first weight portion is fixed, and an area of ​​the first weight portion is adjusted by changing a position of a base end of the first weight portion.

16. After the second weight portion forming step, a third frequency measurement step of measuring a resonance frequency of the vibration element; 16. The method for adjusting the frequency of a vibration element according to claim 11, further comprising: a third weight portion forming process for forming, by an inkjet method, a third weight portion having an area smaller than that of the second weight portion, the third weight portion being determined based on a measurement result in the third frequency measurement process, in a third region located on the base end side of the second region on the first surface side.

17. 17. The frequency adjustment method for a vibration element as described in claim 16, wherein in the third weight formation process, a width direction length of the third weight perpendicular to the extension direction of the vibrating arm is determined, and an area of ​​the third weight is adjusted by adjusting the length of the third weight in the extension direction of the vibrating arm based on the measurement results in the third frequency measurement process.

18. The method for adjusting a frequency of a vibration element according to claim 17 , wherein the position of a base end of the third weight portion is fixed, and the area of ​​the third weight portion is adjusted by changing the position of a tip end of the third weight portion.

19. In the first weight portion forming step, a first amount of ink is applied to the first region to form the first weight portion; The method for adjusting a frequency of a vibration element according to claim 11 , wherein in the second weight portion forming step, the second weight portion is formed by depositing a second ejection amount of the ink, which is smaller than the first ejection amount, onto the second region.

20. The method for adjusting a frequency of a vibration element according to claim 19 , wherein the ink contains a metal.

21. The method for adjusting a frequency of a vibration element according to claim 19 , wherein the ink contains an oxide.

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