JP6848589B2 - Frequency adjustment method of vibrating element, manufacturing method of vibrating element and vibrating element - Google Patents

Description

The present invention relates to a method for adjusting the frequency of a vibrating element, a method for manufacturing a vibrating element, and a method for vibrating the vibrating element.

Conventionally, a physical quantity detecting device that detects a physical quantity such as an angular velocity or an acceleration by using a vibrating element such as a piezoelectric vibrator or a MEMS (Micro Electro Mechanical Systems) vibrator has been known.

As an example of such a physical detection device, for example, Patent Document 1 describes a base, a connecting arm extending from the base, a plurality of drive arms extending from the tip of the connecting arm, and a base. A vibrating gyroscope is disclosed that includes a plurality of extended detection arms and a piezoelectric vibrating piece. In such a vibrating gyroscope, when the drive arm is flexed and vibrated and receives an angular velocity in a predetermined direction, a Coriolis force acts on the drive arm, and the detection arm flexes and vibrates accordingly. By detecting the bending vibration of such a detection arm, the angular velocity can be detected.

Further, in the vibrating gyroscope described in Patent Document 1, a weight layer made of metal is provided at the tip of each drive arm. Then, in order to reduce the vibration leakage from the drive arm to the base portion caused by the imbalance of the resonance frequency of the drive arm, the mass of the drive arm is adjusted by removing the weight layer at the tip of each drive arm.

Japanese Unexamined Patent Publication No. 2006-105614

In the mass adjustment of the drive arm described in Patent Document 1, the removal area of the weight layer in a plan view is adjusted according to the adjustment amount of the resonance frequency. Therefore, since the removal area in the plan view is different for each drive arm due to the difference in the adjustment amount of the resonance frequency, the amount of foreign matter such as water and organic substances adhering to the surface of the activated removal region is different for each drive arm. As a result, there is a problem that the vibration balance of the adjusted drive arm is deviated with time.

An object of the present invention is a method for adjusting the frequency of a vibrating element capable of reducing vibration leakage due to a deviation in the vibration balance of the vibrating arm over time, a method for manufacturing a vibrating element including a method for adjusting the frequency of the vibrating element, and a method for manufacturing the vibrating element. An object of the present invention is to provide a vibrating element in which vibration leakage due to a time-dependent shift in the vibrating balance of the vibrating arm is reduced.

The above object is to solve at least a part of the above-mentioned problems, and can be realized by the following.

The frequency adjusting method of the vibrating element of this application example is a method of adjusting the resonance frequency of a vibrating element having a base portion and a pair of vibrating arms extending from the base portion, and the resonance frequency of the pair of vibrating arms is adjusted. Based on the measurement results, a removal step of irradiating a part of the region on the tip side opposite to the base of each of the pair of vibrating arms with an energy beam to remove a part of the surface layer. In a plan view from the thickness direction of the base, the area of the region where the energy beam of one of the vibrating arms is irradiated is the area of the region of which the energy beam of the other vibrating arm is irradiated. It is the same, and the removal depth removed by irradiating the energy beam of one of the vibrating arms is different from the removal depth removed by irradiating the energy beam of the other vibrating arm.

According to such a frequency adjusting method of the vibrating element, since the resonance frequency is adjusted by adjusting the removal depth, the area of the region irradiated with the energy beam in the plan view is made equal to each other by the pair of vibrating arms. be able to. Therefore, since the amounts of water and organic substances adhering to the processed surface can be made substantially equal, it is possible to reduce the deterioration of the vibration balance of the adjusted vibrating arm. Therefore, it is possible to reduce the vibration leakage due to the vibration balance of the vibrating arm being deviated with time.

In the frequency adjusting method of the vibrating element of the present application example, the region on the tip side of each of the pair of vibrating arms has a length along the direction orthogonal to the extending direction of the vibrating arms in the plan view. It is preferable to include a wide portion having a certain width larger than the width on the base side.

As a result, the mass on the tip side of the vibrating arm can be increased while suppressing the total length of the vibrating arm. In addition, the resonance frequency of the vibrating arm can be adjusted with high accuracy.

In the frequency adjusting method of the vibrating element of the present application example, the region on the tip side of each of the pair of vibrating arms includes a weight film as the surface layer of the vibrating arm in the plan view, and the energy beam irradiates the region. The region to be formed is preferably a region including at least a part of the pyramidal membrane.
As a result, the resonance frequency of the vibrating arm can be adjusted efficiently and accurately.

In the frequency adjusting method of the vibrating element of the present application example, it is preferable that the pair of vibrating arms are parallel to each other and extend in the same direction from the base in the plan view.

As a result, it is possible to suppress the deformation of the base portion due to the bending vibration in which the pair of vibrating arms alternately approach and separate from each other in the plane, and further suppress the vibration leakage from the base portion to the outside.

In the frequency adjusting method of the vibrating element of the present application example, the pair of vibrating arms are parallel to each other in the plan view, and the region irradiated with the energy beam passes through the center of gravity of the base in the plan view. It is preferable that the pair of vibrating arms are at a position line-symmetrical with respect to the center line parallel to the extending direction.
As a result, the resonance frequency of the vibrating arm can be adjusted efficiently and accurately.

In the method for adjusting the frequency of the vibrating element of the present application example, after the removing step, the vibrating element is housed in a closed space in which a predetermined substance exists, so that the surface of the removed portion removed by irradiating the energy beam is provided. It is preferable to carry out the adhesion step of adhering the predetermined substance.

As a result, it is possible to further prevent a predetermined substance or other substance from adhering to the removed portion, so that it is possible to more effectively reduce the deterioration of the vibration balance of the adjusted vibrating arm.

The method for manufacturing the vibrating element of this application example includes a method of adjusting the frequency of the vibrating element of this application example.
According to such a method for manufacturing a vibrating element, it is possible to obtain a vibrating element in which vibration leakage due to a time-dependent shift in the vibration balance of the vibrating arm is reduced.

The vibrating element of this application example is a vibrating element having a base portion and a pair of vibrating arms extending from the base portion, and each of the pair of vibrating arms is on the tip side opposite to the base portion. The area of the recess of one of the vibrating arms is the same as the area of the recess of the other vibrating arm in a plan view from the thickness direction of the base. The depth of the recess of one of the vibrating arms is different from the depth of the recess of the other vibrating arm, on the surface of each of the recesses of the pair of vibrating arms and on the surface of the recess of the other vibrating arm. Each is provided with a film containing a material different from the material constituting the vibrating arm.

According to such a vibrating element, it is possible to prevent a predetermined substance or other substance from further adhering to the film provided in the recess. Therefore, it is possible to reduce the deterioration of the vibration balance of the vibrating arm. Therefore, it is possible to reduce the vibration leakage due to the vibration balance of the vibrating arm being deviated with time.

It is sectional drawing which shows an example of the physical quantity sensor which includes the vibrating element which concerns on 1st Embodiment. It is a top view of the vibrating element. FIG. 2 is a cross-sectional view taken along the line A1-A1 in FIG. It is a flow figure for demonstrating an example of the manufacturing method of a vibrating element. It is a top view of the vibrating element obtained through the vibrating element forming process. It is a top view of the vibrating element in a frequency adjustment process. It is a top view of the vibrating element after frequency adjustment. It is a top view of the vibrating element in a sealing process. It is a graph which shows the vibration leakage amount in each process of the frequency adjustment method of the conventional vibrating element. It is a graph which shows the vibration leakage amount in each step of the frequency adjustment method of the vibrating element which concerns on 1st Embodiment. It is a figure which shows the vibrating element which concerns on 2nd Embodiment. It is a graph which shows the vibration leakage amount in each step of the frequency adjustment method of the vibrating element which concerns on 2nd Embodiment.

Hereinafter, a method for adjusting the frequency of the vibrating element, a method for manufacturing the vibrating element, and a preferred embodiment of the vibrating element will be described in detail with reference to the accompanying drawings. In each figure, there are some parts that are enlarged or reduced as appropriate so that the parts to be explained can be recognized, and some parts that are schematically shown.

Further, in the present specification, "same" and "equal" mean that they are substantially the same or equal, and include errors in mechanical design and installation. Therefore, "same" and "equal" mean that the difference between the objects is within ± 5%.

<First Embodiment>
1. 1. Physical quantity sensor First, prior to the description of the manufacturing method of the vibrating element of this application example, the physical quantity sensor including the vibrating element of this application example will be briefly described.

FIG. 1 is a cross-sectional view showing an example of a physical quantity sensor including a vibrating element according to the first embodiment.

The physical quantity sensor 10 shown in FIG. 1 includes a vibrating element 1, a package 11 accommodating the vibrating element 1, a support substrate 12 supporting the vibrating element 1 with respect to the package 11, a wiring pattern 13, and the inside of the package 11. It has a circuit element 14 arranged in.

The package 11 includes a box-shaped base 111 having a recess for accommodating the vibrating element 1 and a plate-shaped lid 112 joined to the base 111 via a joining member 113 so as to close the opening of the recess of the base 111. Have. The space S (closed space) in the package 11 may be in a reduced pressure (vacuum) state, or may be filled with an inert gas such as nitrogen, helium, or argon. Further, a through hole 115 as a sealing hole is provided at the bottom of the base 111, and the through hole 115 is sealed with a sealing material 116 formed of, for example, various glass materials or metal materials. ing.

The recess of the base 111 has an upper surface located on the opening side, a lower surface located on the bottom side, and a middle surface located between these surfaces. The constituent material of the base 111 is not particularly limited, but various ceramics such as aluminum oxide and various glass materials can be used. Further, the constituent material of the lid 112 is not particularly limited, but a member having a linear expansion coefficient similar to that of the constituent material of the base 111 is preferable. For example, when the constituent material of the base 111 is the above-mentioned ceramics, it is preferable to use an alloy such as Kovar. Further, in the present embodiment, the seam ring is used as the joining member 113, but the joining member 113 may be constructed by using, for example, low melting point glass, an adhesive or the like.

A plurality of connection terminals (not shown) are provided on the upper surface and the middle surface of the recess of the base 111, respectively. Of the plurality of connection terminals provided on the middle surface, some of them are connected to terminals (not shown) provided on the bottom surface of the base 111 via a wiring layer (not shown) provided on the base 111. It is electrically connected, and the rest is electrically connected to a plurality of connection terminals provided in the upper stage via wiring (not shown). These connection terminals are not particularly limited as long as they have conductivity, but for example, Ni (nickel), Au (gold), and Ag are formed on a metallized layer (underlayer) such as Cr (chromium) and W (tungsten). It is composed of a metal coating in which each coating such as (silver) and Cu (copper) is laminated.

The circuit element 14 is fixed to the lower surface of the recess of the base 111 with an adhesive 16 or the like. As the adhesive 16, for example, an epoxy-based, silicone-based, or polyimide-based adhesive can be used. The circuit element 14 has a plurality of terminals (not shown), and each terminal is electrically connected to each connection terminal provided on the middle surface described above by a conductive wire 15. The circuit element 14 includes a drive circuit for driving and vibrating the vibrating element 1 and a detection circuit for detecting the detected vibration generated in the vibrating element 1 when an angular velocity is applied.

Further, the wiring pattern 13 is connected to the plurality of connection terminals provided on the upper surface of the recess of the base 111 via the conductive adhesive 17. The wiring pattern 13 is joined to the support substrate 12. Further, as the conductive adhesive 17, for example, an epoxy-based, silicone-based, or polyimide-based conductive adhesive in which a conductive substance such as a metal filler is mixed can be used.

The support substrate 12 has an opening in the central portion, and a plurality of elongated leads included in the wiring pattern 13 extend in the opening. A vibrating element 1 is connected to the tips of these leads via conductive bumps (not shown).

In the present embodiment, the circuit element 14 is provided inside the package 11, but the circuit element 14 may be provided outside the package 11.

2. Vibrating element FIG. 2 is a plan view of the vibrating element. FIG. 3 is a cross-sectional view taken along the line A1-A1 in FIG. In FIG. 2, for convenience of explanation, the X-axis, the Y-axis, and the Z-axis are shown as three axes orthogonal to each other. -". Further, the direction parallel to the X-axis is referred to as "X-axis direction", the direction parallel to the Y-axis is referred to as "Y-axis direction", and the direction parallel to the Z-axis is referred to as "Z-axis direction". Further, the + Z axis direction side is also referred to as "upper", and the −Z axis direction side is also referred to as “lower”. Further, in the present embodiment, the X-axis, the Y-axis, and the Z-axis correspond to the electric axis, the mechanical axis, and the optical axis, which are crystal axes of quartz, respectively.

The vibrating element 1 shown in FIG. 2 is a sensor element that detects the angular velocity ω around the Z axis. The vibrating element 1 has a vibrating body 4 (vibrating piece), and an electrode film pattern (not shown) and a pyramid film pattern 5 formed on the surface of the vibrating body 4. Note that the electrode film pattern is not shown in FIGS. 2 and 3.

-Vibrator-
The vibrating body 4 is a plate having a spread in the XY plane defined by the Y-axis (mechanical axis) and the X-axis (electrical axis), which are the crystal axes of the quartz substrate, and having a thickness in the Z-axis (optical axis) direction. It is in shape. That is, the vibrating body 4 is composed of a Z-cut crystal plate. The Z-axis does not necessarily have to coincide with the thickness direction of the vibrating body 4, and may be slightly tilted with respect to the thickness direction from the viewpoint of reducing the change in frequency due to temperature in the vicinity of room temperature. Specifically, the Z-cut quartz plate is such that the surface orthogonal to the Z-axis is rotated around at least one of the X-axis and the Y-axis in the range of 0 to 10 degrees to be the main surface. Includes a crystal plate with a cut angle. The vibrating body 4 may not have piezoelectricity such as silicon. In this case, a piezoelectric element may be appropriately provided on the vibrating body 4.

The vibrating body 4 of the present embodiment has a so-called double T shape. The vibrating body 4 extends from the base 41, a pair of connecting arms 42 and 43 extending from the base 41, two driving vibrating arms 44 and 45 extending from the connecting arm 42, and the connecting arm 43. It has two driving vibrating arms 46 and 47 and two (pair) detection vibrating arms 48 and 49 extending from the base 41. The vibrating body 4 is formed symmetrically on the left and right sides in FIG. In the present embodiment, the pair of drive vibrating arms 44, 46 that are parallel to each other and extend in the same direction (+ Y-axis direction) with respect to the base 41 and the pair of drive vibrating arms 44, 46 that are parallel to each other and extend in the same direction with respect to the base 41 (-Y). It has a pair of drive vibrating arms 45, 47 extending in the axial direction). That is, in this embodiment, it has two sets of "pair of vibrating arms".

The base 41 is fixed to the base 111 of the package 11 via the support substrate 12 and the wiring pattern 13 described above.

The connecting arms 42 and 43 extend from the base 41 in opposite directions along the X-axis direction. In addition, each of the upper surface and the lower surface of the connecting arms 42 and 43 may be provided with grooves or holes extending in the length direction (X-axis direction) thereof.

The drive vibrating arms 44 and 45 extend from the tip of the connecting arm 42 in opposite directions along the Y-axis direction. Similarly, the drive vibrating arms 46 and 47 extend in opposite directions along the Y-axis direction from the tip end portion of the connecting arm 43. In the present embodiment, the region on the distal end side of the drive vibrating arms 44, 45, 46, 47 has a width W1 wider than the width W2 of the region on the proximal end side of the drive vibrating arms 44, 45, 46, 47, respectively. Includes wide portions 441, 451, 461, 471. The upper surface and the lower surface of the drive vibrating arms 44 to 47 may be provided with grooves or holes extending in the extending direction, respectively.

The detection vibrating arms 48 and 49 extend from the base 41 in the opposite directions along the Y-axis direction. In the present embodiment, the region on the distal end side of the detected vibrating arms 48 and 49 has wide portions 481 and 491 having a width wider than the width of the region on the proximal end side of the detected vibrating arms 48 and 49, respectively. The upper surface and the lower surface of the detection vibrating arms 48 and 49 may be provided with grooves or holes extending in the extending direction, respectively.

-Electrode film pattern-
Although not shown, the electrode film pattern provided on the surface of the vibrating body 4 described above is provided on the drive signal electrodes and the drive ground electrodes provided on the drive vibrating arms 44 to 47, and the detection vibrating arms 48 and 49. It has a detection signal electrode and a detection ground electrode, and a plurality of terminals provided on the base 41 corresponding to these electrodes.

− Pile membrane pattern −
Although not shown, the pyramidal membrane pattern 5 is provided on the electrode membrane pattern described above. As shown in FIG. 2, the plurality of weight membrane patterns 5 are formed on the weight membranes 51, 52, provided at the tips (wide portions 441, 451, 461, 471) of the driving vibrating arms 44, 45, 46, 47. It has 53, 54 (surface layer) and weight films 55, 56 provided at the tip portions (wide portions 481, 491) of the detection vibrating arms 48, 49.

The weight films 51 to 54 have a function of adjusting the resonance frequency (hereinafter, also referred to as “driving frequency”) of the driving vibrating arms 44 to 47. The weight films 55 and 56 have a function of adjusting the resonance frequency (hereinafter, also referred to as “detection frequency”) of the detection vibrating arms 48 and 49.

As shown in FIG. 2, a part of the pyramidal membranes 51 to 54 has been removed. Therefore, the wide portion 441 has a recess 511 formed by removing a part of the weight film 51. The wide portion 451 has a recess 521 formed by removing a part of the weight film 52. The wide portion 461 has a recess 531 formed by removing a part of the weight film 53. The wide portion 471 has a recess 541 formed by removing a part of the weight film 54. As will be described later, the leakage vibration can be removed by removing a part of the weight membranes 51 to 54 in this way.

The recess 511 and the recess 531 pass through the center of the base 41 and are provided at symmetrical positions about the line segment A parallel to the Y axis. Similarly, the recess 521 and the recess 541 are provided at symmetrical positions about the line segment A. Further, in the present embodiment, the recesses 511, 521, 513, and 541 are located on the tip side of the wide portions 441, 451, 461, and 471.

The recesses 511 to 541 have the same shape and the same area as each other in a plan view from the thickness direction of the base 41. In the present embodiment, the shape of the recesses 511 to 541 in a plan view is rectangular, but the shape is not limited to this and may be any shape. The area in plan view of the recess 511 to 541 is, for example, 1μm ² ~20000μm ² about.

In this embodiment, the depth of at least one of the recesses 511 to 541 is different from the depth of the other recesses. For example, in the present embodiment, as shown in FIG. 3, the depth d1 of the recess 511 is deeper than the depth d3 of the recess 531. Although not shown, the depth d2 of the recess 521 is deeper than the depth d4 of the recess 541. The depths d1 to d4 of the recesses 511 to 541 are, for example, about 1 nm to 2000 nm, respectively.

A film 50 is provided on the surface of the recesses 511 to 541. In this embodiment, the membrane 50 is composed of, for example, a monolayer containing silicone. The film thickness d5 of each film 50 provided on the surface of the recesses 511 to 541 is equal. The film thickness d5 of the film 50 is, for example, about 0.1 nm to 5 nm. As will be described later, by providing this film 50, it is possible to suppress a change in frequency with time and reduce leakage vibration with time.

The constituent materials of such weight films 51 to 56 are not particularly limited, and for example, a metal (metal material), an inorganic compound, a resin, or the like can be used, but it is preferable to use a metal or an inorganic compound. The metal or inorganic compound can be easily and highly accurately formed by the vapor phase film forming method. Further, the weight films 51 to 56 made of a metal or an inorganic compound can be removed efficiently and with high accuracy by irradiating with an energy beam. Therefore, by forming the weight film pattern 5 by forming a film of a metal or an inorganic compound, the frequency adjustment described later becomes more efficient and highly accurate.

Examples of such metal materials include nickel (Ni), gold (Au), gold alloys, platinum (Pt), aluminum (Al), aluminum alloys, silver (Ag), silver alloys, chromium (Cr), and chromium alloys. Examples thereof include copper (Cu), molybdenum (Mo), niobium (Nb), tungsten (W), iron (Fe), titanium (Ti), cobalt (Co), zinc (Zn), zirconium (Zr), and the like. Of these, one or a combination of two or more can be used. Above all, from the viewpoint that it can be collectively formed with the driving electrode and the detection electrode, Al, Cr, Fe, Ni, Cu, Ag, Au, Pt or an alloy containing at least one of these is used as the metal material. Is preferable.

Examples of such inorganic compounds include oxide ceramics such as alumina (aluminum oxide), silica (silicon oxide), titania (titanium oxide), zirconia, ittoria, and calcium phosphate, silicon nitride, aluminum nitride, titanium nitride, and boron nitride. Carbide-based ceramics such as nitride ceramics, graphite, and tungsten carbide, and other strong dielectric materials such as barium titanate, strontium titanate, PZT, PLZT, and PLLZT can be mentioned. Among them, silicon oxide (SiO ₂ ). , Titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ) and other insulating materials are preferably used.

Specifically, it is preferable that the weight films 51 to 56 have a structure in which, for example, an upper layer made of Au (gold) is laminated on a base layer made of Cr (chromium). As a result, the adhesion to the vibrating body 4 formed by using the crystal is excellent, and the resonance frequency can be adjusted with high accuracy and efficiency.

The thickness (average thickness) of each of the weight membranes 51 to 56 is not particularly limited, but is, for example, about 10 nm or more and 10,000 nm or less.

In the vibrating element 1 described above, when an electric field is generated between the driving signal electrode and the driving ground electrode by inputting a driving signal to the driving signal terminal in a state where the angular velocity is not applied to the vibrating element 1, each driving vibrating arm 44 to 47 perform bending vibration (driving vibration) in the direction indicated by the arrow α in FIG. At this time, since the drive vibrating arms 44 and 45 and the drive vibrating arms 46 and 47 vibrate symmetrically in FIG. 2, the base 41 and the detected vibrating arms 48 and 49 hardly vibrate.

When the angular velocity ω around the axis a (center of gravity) along the Z axis is applied to the vibrating element 1 in the state of performing this drive vibration, the detected vibration (vibration in the detection mode) is excited. Specifically, the Coriolis force in the direction indicated by the arrow γ in FIG. 2 acts on the driving vibrating arms 44 to 47 and the connecting arms 42 and 43 to excite new vibrations. Along with this, the detected vibrations 48 and 49 in the direction indicated by the arrow β in FIG. 2 are excited so as to cancel the vibrations of the connecting arms 42 and 43. Then, the electric charges generated in the detection vibrating arms 48 and 49 by the detection vibration are taken out as a detection signal from the detection signal electrode, and the angular velocity is obtained based on the detection signal.

The vibrating element 1 as described above has a base 41 and a pair of vibrating arms extending from the base 41. In the present embodiment, the vibrating element 1 has a pair of driving vibrating arms 44 and 46 (a pair of vibrating arms) and a pair of driving vibrating arms 45 and 47 (a pair of vibrating arms). Further, the drive vibrating arm 44 has a recess 511 in a part of a region (wide portion 441) on the tip side opposite to the base 41, and the drive vibrating arm 46 has a tip opposite to the base 41. It has a recess 531 in a part of the side region (wide portion 461). Similarly, the drive vibrating arm 45 has a recess 521 in a part of a region (wide portion 451) on the tip side opposite to the base 41, and the drive vibrating arm 47 is on the opposite side to the base 41. A recess 541 is provided in a part of the region on the tip side (wide portion 471). Further, in a plan view from the thickness direction of the base 41, the area of the recess 511 of the drive vibrating arm 44 (one vibrating arm) is the same as the area of the recess 531 of the drive vibrating arm 46 (the other vibrating arm). .. The depth d1 of the recess 511 of the drive vibrating arm 44 (one vibrating arm) is different from the depth d3 of the recess 531 of the drive vibrating arm 46 (the other vibrating arm). Similarly, in a plan view from the thickness direction of the base 41, the area of the recess 521 of the drive vibrating arm 45 (one vibrating arm) is the same as the area of the recess 541 of the drive vibrating arm 47 (the other vibrating arm). is there. The depth d2 of the recess 521 of the drive vibrating arm 45 (one vibrating arm) is different from the depth d4 of the recess 541 of the drive vibrating arm 47 (the other vibrating arm). The materials constituting the drive vibrating arms 44 and 46 are formed on the surface of the recess 511 of the drive vibrating arm 44 (one vibrating arm) and the surface of the recess 531 of the drive vibrating arm 46 (the other vibrating arm), respectively. A film 50 containing different materials is provided. Similarly, the surface of the recess 521 of the drive vibrating arm 45 (one vibrating arm) and the surface of the recess 541 of the drive vibrating arm 47 (the other vibrating arm) are made of materials constituting the drive vibrating arms 45 and 47, respectively. Is provided with a film 50 containing different materials. According to such a vibrating element 1, it is possible to prevent a predetermined substance (for example, water, an organic substance, etc.) from further adhering to the film 50 provided in the recesses 511 to 541. Therefore, it is possible to reduce the deterioration of the vibration balance of the drive vibration arms 44 to 47 over time. Therefore, it is possible to reduce the vibration leakage due to the vibration balance of the drive vibration arms 44 to 47 being deviated with time.

As described above, the physical quantity sensor 10 as described above includes a vibration element 1 that reduces vibration leakage due to the vibration balance of the drive vibration arms 44 to 47 being deviated with time. Therefore, the physical quantity sensor 10 has high accuracy and excellent stability.

3. 3. Method for Manufacturing Physical Quantity Sensor Next, a method for manufacturing the physical quantity sensor will be described by taking the case of manufacturing the physical quantity sensor 10 described above as an example.

FIG. 4 is a flow chart for explaining an example of a method for manufacturing a vibrating element.
As shown in FIG. 4, the physical quantity sensor 10 is manufactured by [1] vibrating element forming step (step S1), [2] mounting step (step S2), and [3] frequency adjusting step (step S3). , [4] Sealing step (step S4). Here, the method for manufacturing the physical quantity sensor 10 includes a method for adjusting the frequency of the vibrating element 1 and a method for manufacturing the vibrating element 1. The frequency adjusting method of the vibrating element 1 includes at least [3] steps among the above steps [1] to [4]. The method for manufacturing the vibrating element 1 includes at least [1] step and [3] step among the above steps [1] to [4]. Hereinafter, each step will be described in sequence.

[1] Vibration element forming step (step S1)
FIG. 5 is a plan view of the vibrating element obtained through the vibrating element forming step.

First, the vibrating element 1a shown in FIG. 5 (vibrating element 1a before frequency adjustment) is formed. That is, in this step, as shown in FIG. 5, a weight membrane pattern having weight membranes 51a, 52a, 53a, 54a and weight membranes 55, 56 before the recesses 511, 521, 531, 541 are formed. A vibrating element 1a including 5a is formed.

Specifically, for example, first, a crystal substrate which is a base material of the vibrating body 4 is prepared, a photoresist is applied on one surface of the crystal substrate, and exposure / development is performed in a shape corresponding to the vibrating body 4. By doing so, a resist mask (not shown) is obtained. Next, with the resist mask formed, a Cr layer and an Au layer are formed on both sides of the quartz substrate in this order by, for example, a vapor deposition method or a sputtering method, and a Ni layer is formed on the Au layer by, for example, a plating method. Is formed. Then, the resist mask is removed by, for example, etching or the like to obtain a mask.

Next, dry etching by reactive ion etching (RIE) using a quartz substrate from one surface side of the quartz substrate through a mask such as C ₄ F ₈ as an etching gas. As a result, the vibrating body 4 is formed. At this stage, the vibrating body 4 is in a state of being connected to another part of the crystal substrate (hereinafter, also referred to as a “wafer state”). In this wafer state, the vibrating body 4 is connected to the other part of the quartz substrate, for example, via a fragile cut-out portion in which at least one of the width and the thickness is small and fragile. Further, in the wafer state, a plurality of vibrating elements 1 can be collectively formed on the crystal substrate.

After that, for example, a metal film is uniformly formed on the surface of the vibrating body 4 by a film forming apparatus such as sputtering. Then, a photoresist is applied, exposed and developed to obtain a resist mask, and then an etching solution is used to remove the metal film on the exposed portion from the resist mask. As a result, an electrode film pattern is formed.
Next, a weight film pattern 5a is formed on the electrode film pattern by, for example, mask deposition.

The vibrating element 1a is formed as described above.
After forming the vibrating element 1a, a detuning frequency adjusting step of adjusting the detuning frequency, which is the difference between the resonance frequencies of the detected vibrating arms 48 and 49 and the resonance frequencies of the driving vibrating arms 44 to 47, as necessary. It can be performed. In the detuning frequency adjusting step, for example, the resonance frequencies of the detected vibrating arms 48 and 49 and the driving vibrating arms 44 to 47 are measured, and at least a part of the weight films 55 and 56 is removed based on the measurement results. .. Thereby, the resonance frequencies of the detected vibrating arms 48 and 49 can be adjusted, and the detuning frequency can be adjusted.

[2] Mounting step (step S2)
Next, although not shown, the vibrating element 1a in the wafer state is separated from the crystal substrate (for example, the folded portion is cut off), and the vibrating element 1a is mounted on the base 111 of the package 11 described above (see FIG. 1). In this step, the lid 112 is not joined to the base 111. Further, in this step, the circuit element 14 is fixed to the lower surface of the recess of the base 111 by the adhesive 16, and the wiring pattern 13 is provided on the upper surface of the recess of the base 111 by the conductive adhesive 17. It is connected to a plurality of connection terminals (see FIG. 1).

[3] Frequency adjustment step (step S3)
FIG. 6 is a plan view of the vibrating element in the frequency adjustment process. FIG. 7 is a plan view of the vibrating element after frequency adjustment.

Next, a part of the weight films 51a to 54a is removed so that the resonance frequencies of the drive vibration arms 44 to 47 are equal to each other, and the vibration leakage amount is adjusted. Here, the "vibration leakage amount" is a signal (offset or zero point signal) output from the detected vibrating arms 48 and 49 when the driving vibrating arms 44 to 47 are driven and vibrated and no rotation is applied. It refers to the size of.

In this step, first, the resonance frequencies of the drive vibrating arms 44 to 47 are measured. Further, at least one part of the weight films 51a to 54a is removed by a specified amount, and the amount of change in the drive frequency due to the removal is measured to obtain the amount of change in the drive frequency with respect to the amount of processing. It should be noted that the measurement of the resonance frequencies of the drive vibrating arms 44 to 47 and the determination of the amount of change in the drive frequency are performed for each of the plurality of vibrating bodies 4.

Next, as shown in FIG. 6, the resonance frequencies of the drive vibrating arms 44 to 47 are equal to each other based on the measurement results of the resonance frequencies of the drive vibrating arms 44 to 47 and the amount of change in the drive frequency with respect to the machining amount. The energy beam E is applied to a part of the weight films 51a to 54a to remove a part of the weight films 51a to 54a as shown in FIG. 7s. As a result, as shown in FIG. 7, recesses 511 to 541 are formed.

As the energy beam E (energy ray), for example, it is preferable to use a laser having a pulse width of 1 ps (picosecond) or less (for example, an excimer laser), an ion beam, or the like. In particular, it is preferable to use an ion beam such as FIB (Focused Ion Beam) or IBF (Ion Beam Figuring). Further, by using FIB, fine processing can be performed with higher accuracy. By using IBF, fine processing can be performed quickly, so that productivity can be improved.

As shown in FIG. 6, the regions S51, S52, S53, and S54 (irradiation regions) to irradiate the energy beam E are the tip sides of the wide portions 441, 451, 461, and 471. Further, the area S51 and the area S53 are in line-symmetrical positions with respect to the line segment A. Similarly, the region S51 and the region S53 are in line-symmetrical positions with respect to the line segment A. Further, the regions S51 to S54 have the same shape and the same area as each other in a plan view. Area in plan view of the region S51~S54 is, for example, 1μm ² ~20000μm ² about.

Further, the irradiation time, irradiation amount or output of the energy beam E is set for each of the regions S51 to S54 based on the measurement result of the resonance frequency of the driving vibration arms 44 to 47 and the amount of change in the driving frequency with respect to the processing amount. Is preferable. As a result, the resonance frequencies of the drive vibrating arms 44 to 47 can be adjusted with high accuracy. In the present embodiment, for example, the irradiation time, irradiation amount, or output of the energy beam E for the regions S51 and S52 is larger than that for the regions S53 and S54.

As described above, the vibrating element 1b shown in FIG. 7 is formed. In the present embodiment, as described above, since the irradiation time, irradiation amount, or output of the energy beam E is adjusted, in the vibrating element 1b, the depth d1 of the recess 511 of the driving vibrating arm 44 is the driving vibrating arm 46. It is formed deeper than the depth d3 of the recess 531 of the above (see FIG. 3). Although not shown, the depth d2 of the recess 521 of the drive vibrating arm 45 is formed deeper than the depth d4 of the recess 541 of the drive vibrating arm 47. The magnitude relation of the depths d1 and d3 and the magnitude relation of the depths d2 and d4 may be reversed, respectively.

Further, the surfaces of the recesses 511 to 541 of the vibrating element 1b are in a state where the dangling bond is exposed by irradiation with the energy beam E, and is in a chemically active state. The surface of the recesses 511 to 541 may be chemically activated by, for example, cleaning after irradiating the energy beam E.

[4] Sealing step (step S4)
Next, the lid 112 is joined to the base 111 by the joining member 113, and the concave portion of the base 111 is sealed. As a result, the vibrating element 1b is housed in the package 11 (see FIG. 1). The sealing step includes a sealing step 1 for joining the lid 112 and a sealing step 2 for sealing the inside of the package 11 in a predetermined environment, for example, in a vacuum state.

<Sealing step 1>
To join the lid 112 to the base 111, a joining member 113 (seam ring) is provided on the base 111, the lid 112 is placed on the joining member 113, and the joining member 113 is attached to the base 111 by using, for example, a resistance welder. Is done by seam welding.

FIG. 8 is a plan view of the vibrating element in the sealing process.
In this step, gas generated from the adhesive 16 and the conductive adhesive 17 is generated inside the package 11 by seam welding. For example, when a silicone-based adhesive is used for the adhesive 16 or the conductive adhesive 17, the inside of the package 11 is filled with a gas containing silicone. Here, as described above, the surfaces of the recesses 511 to 541 are in a state where the dangling bonds are exposed and are in a chemically active state. Therefore, the dangling bond on the surface of the recesses 511 to 541 is in a state of being easily chemically bonded to the substance M (for example, a silicone molecule) contained in the gas generated from the adhesive 16 or the conductive adhesive 17 (for example, silicone molecule). (See FIG. 8). Therefore, at the time of seam welding, the dangling bond on the surface of the recesses 511 to 541 and the substance M are bonded in a short time of, for example, about several seconds. As a result, the film 50 is formed on the entire surface of the recesses 511 to 541, and the surface of the recesses 511 to 541 is in a stabilized state (see FIG. 2). For example, when the adhesive 16 or the conductive adhesive 17 uses a silicone-based adhesive, a film 50 composed of a monomolecular film containing silicone is formed.

Since the substance (for example, silicone molecule) constituting the film 50 does not have a dangling bond and is in a stable state, the surface of the film 50 is separated from other substances (for example, water, organic substances, etc.). It is in a state where it is difficult to chemically bond. Therefore, it is possible to suppress or prevent the change in the resonance frequency of the driving vibrating arms 44 to 47 due to the adhesion of other substances to the surface of the membrane 50 over time. Therefore, it is possible to reduce the loss of the vibration balance of the drive vibration arms 44 to 47 due to the change of frequency with time.

When the film 50 is a monolayer, the thickness of the film 50 is defined by the molecular weight, the degree of polymerization, and the like of the molecules forming the film 50. Therefore, the thickness of the film 50 can be grasped in advance depending on the types of the adhesive 16 and the conductive adhesive 17. Therefore, the frequency adjustment can be performed with higher accuracy by setting the removal amount to be removed in the frequency adjustment step (step S3) described above to be the amount obtained by subtracting the weight of the film 50.

In the present embodiment, the film 50 is formed by using the substance M contained in the gas generated from the adhesive 16 and the conductive adhesive 17, but the film 50 is formed by using another substance. It may have been done. For example, a desired substance (substance M or other substance) may be chemically bonded to the recesses 511 to 541 in advance after irradiating the energy beam E and before seam welding.
Further, a heating step (annealing step) may be added so that the film 50 is surely formed.

<Sealing step 2>
Next, the gas generated inside the package 11 during seam welding is discharged from the through hole 115 in the vacuum chamber (not shown), and the through hole 115 is sealed by the sealing material 116 (see FIG. 1).
The physical quantity sensor 10 can be formed as described above.

As described above, the frequency adjusting method of the vibrating element 1a includes [3] frequency adjusting step (step S3). That is, the frequency adjusting method of the vibrating element 1a is a method of adjusting the resonance frequency of the vibrating element 1a having the base 41 and a pair of vibrating arms extending from the base 41. In the present embodiment, the vibrating element 1a has a pair of driving vibrating arms 44 and 46 (a pair of vibrating arms) and a pair of driving vibrating arms 45 and 47 (a pair of vibrating arms). Further, based on the result of measuring the resonance frequency of the drive vibrating arms 44 to 47, the weight films 51a to 54a provided on the wide portions 441 to 471 of the drive vibrating arms 44 to 47 (on the side opposite to the base 41). A removal step (frequency adjustment step) in which a part of the surface layer (in this embodiment, the weight films 51, 52, 53, 54) is removed by irradiating a part of the tip side region) with the energy beam E. including. Then, in a plan view from the thickness direction of the base 41, the area of the region S51 irradiated with the energy beam E of the drive vibrating arm 44 (one vibrating arm) is the energy of the drive vibrating arm 46 (the other vibrating arm). It is the same as the area of the region S53 to which the beam E is irradiated. The removal depth (depth d1) removed by irradiating the energy beam E of the drive vibrating arm 44 (one vibrating arm) is the energy beam E of the drive vibrating arm 46 (the other vibrating arm). It is different from the removal depth (depth d3) that is removed by the above (in this embodiment, depth d1> depth d3). Similarly, in a plan view, the area of the region S52 where the energy beam E of the drive vibrating arm 45 (one vibrating arm) is irradiated is the region where the energy beam E of the drive vibrating arm 47 (the other vibrating arm) is irradiated. It is the same as the area of S54. The depth d2 of the drive vibrating arm 45 (one vibrating arm) is different from the depth d4 of the drive vibrating arm 47 (the other vibrating arm) (in this embodiment, depth d2> depth d4).

According to such a frequency adjusting method of the vibrating element 1, in order to adjust the resonance frequency of the driving vibrating arms 44 to 47 by adjusting the depths d1 to d4, the area of the regions S51 to S54 in a plan view is adjusted. The drive vibrating arms 44-47 can be equal to each other. Therefore, since the amount of the substance M adhering to the recesses 511 to 541 can be made equal, it is possible to reduce the deterioration of the vibration balance of the adjusted drive vibration arms 44 to 47. Therefore, it is possible to reduce vibration leakage due to a change in frequency with time. Further, since the resonance frequency of the drive vibrating arms 44 to 47 is adjusted based on the result of measuring the resonance frequencies of the drive vibrating arms 44 to 47, the accuracy of the vibration balance can be further improved for each vibrating element 1.

Further, as the frequency adjustment method, for example, there are a method of adjusting the removal area in a plan view and a method of adjusting the removal depth as in the present embodiment. The former uses the energy beam E as compared with the latter. The amount of movement to scan (scanning amount) is large. On the other hand, in the latter case, for example, the irradiation time may be adjusted, and the amount of movement (scanning amount) for scanning the energy beam E can be made smaller than that of the former. Therefore, according to the frequency adjusting method of the present embodiment, the frequency can be adjusted more easily and efficiently than the method of adjusting the removed area in a plan view.

FIG. 9 is a graph showing the amount of vibration leakage in each step of the conventional frequency adjusting method of the vibrating element. That is, it is a graph which shows the vibration leakage amount when the removal area in a plan view of the weight film 51-54 is adjusted according to the adjustment amount of a resonance frequency. In addition, one line segment shown in FIG. 9 shows the result of one vibrating element to which the conventional frequency adjustment method was applied.

As shown in FIG. 9, when the resonance frequency of the drive vibrating arm is adjusted by adjusting the area of the laser irradiation region in a plan view, the vibration leakage amount can be brought close to zero after the adjustment. However, the amount of vibration leakage is increased by the treatments of the sealing step 1 and the sealing step 2 after the adjustment. As described above, in the conventional frequency adjustment method, the vibration leakage amount increases with time after the adjustment regardless of the magnitude of the vibration leakage amount before the adjustment.

FIG. 10 is a graph showing the amount of vibration leakage in each step of the frequency adjusting method for the vibrating element according to the first embodiment. That is, FIG. 10 is a graph showing the amount of vibration leakage when the areas S51 to S54 are equal and the depths d1 to d4 vary. In addition, one line segment shown in FIG. 10 shows the result of one vibrating element 1 (vibrating element 1a, 1b) to which the frequency adjustment method of this embodiment was applied.

As shown in FIG. 10, when the resonance frequencies of the drive vibration arms 44 to 47 are adjusted by adjusting the removal depths (depths d1 to d4), the vibration leakage amount can be brought close to zero after the adjustment. .. Further, also in the sealing step 1 and the sealing step 2 after the adjustment, the vibration leakage amount does not become excessively large due to the treatment. As described above, according to the frequency adjustment method of the present embodiment, it is possible to suppress an increase in the amount of vibration leakage over time even after the adjustment. This is because adjusting the removal depth rather than adjusting the removal area of the weight films 51 to 54 in a plan view reduces the difference (variation) in the removal amount of the weight films 51 to 54 according to the adjustment amount of the resonance frequency. This is because the difference (variation) in the surface areas of the recesses 511 to 541 can be reduced. By reducing the difference (variation) in the surface area of the recesses 511 to 541, the difference (variation) in the size (amount of substance M adhering to the surface) of the film 50 formed on the surface of each recess 511 to 541 can be reduced. can do. Therefore, according to the present embodiment, it is possible to reduce the deterioration of the vibration balance of the adjusted drive vibration arms 44 to 47 over time.

Further, as described above, the pair of driving vibrating arms 44 and 46 (vibrating arms) are parallel to each other in a plan view. Similarly, the pair of drive vibrating arms 45, 47 (vibrating arms) are parallel to each other in a plan view. Further, the region S51 and the region S53 to which the energy beam E is irradiated pass through the center of gravity of the base 41 in a plan view and are in the extending direction of the pair of drive vibrating arms 44 and 46 (pair of drive vibrating arms 45 and 47). It is at a position line-symmetrical with respect to the line segment A along the extending direction of the drive vibrating arms 44 and 46 passing through the parallel center line, that is, the axis a. Similarly, the regions S52 and S54 are in line-symmetrical positions with respect to the center line of the base 41, that is, the line segment A passing through the axis a and along the extending direction of the drive vibrating arms 45 and 47. As a result, the resonance frequencies of the drive vibrating arms 44 to 47, which require fine adjustment, can be adjusted efficiently and accurately.

Further, as described above, in the frequency adjusting method of the present embodiment, in the [4] sealing step (step S4) after the [3] frequency adjusting step (step S3), a substance is formed on the surface of the recesses 511 to 541. M is attached to form the film 50. That is, after the removal step [3] frequency adjustment step (step S3), in the [4] sealing step (step S4), the vibrating element 1b is accommodated in the closed space (space S) in which the predetermined substance M exists. By doing so, a bonding step of adhering a predetermined substance M to the surface of the recesses 511 to 541, which are the removal points removed by irradiating the energy beam E, is performed. As a result, it is possible to more effectively reduce the deterioration of the vibration balance of the adjusted drive vibration arms 44 to 47. In particular, it is preferable that the surface of each film 50 is in a chemically stable state. As a result, it is possible to prevent the predetermined substance M and other substances from further adhering to the surface of the film 50.

Further, as described above, in the region on the tip end side of the drive vibrating arm 44, the width W1 along the direction intersecting the extending direction of the drive vibrating arm 44 is the width W2 on the base 41 side in a plan view. The region on the tip end side of the drive vibrating arm 46 includes the large wide portion 441, and the width W1 which is the length along the direction orthogonal to the extending direction of the drive vibrating arm 46 is on the base 41 side in a plan view. Includes a wide portion 461 that is larger than the width W2. Similarly, the region on the tip end side of the drive vibrating arm 45 includes the wide portion 451 and the region on the tip end side of the drive vibrating arm 47 includes the wide portion 471. As a result, the mass on the tip side of the drive vibrating arms 44 to 47 can be increased while suppressing the total length of the drive vibrating arms 44 to 47. Further, by having the wide portions 441 to 471, the resonance frequency of the drive vibrating arms 44 to 47 can be adjusted efficiently and accurately.

Further, as described above, in the vibrating element 1a, the region (wide portion 441) on the tip end side of the driving vibrating arm 44 includes the weight film 51a as the surface layer of the driving vibrating arm 44 in a plan view, and the driving vibrating arm 46 The region on the tip end side (wide portion 461) includes the weight film 53a as the surface layer of the driving vibrating arm 46 in a plan view. Similarly, in the vibrating element 1a, the region (wide portion 451) on the tip end side of the drive vibrating arm 45 includes the weight film 52a as the surface layer of the drive vibrating arm 45 in a plan view, and is on the tip end side of the drive vibrating arm 47. The region (wide portion 471) includes a weight film 54a as a surface layer of the driving vibrating arm 47 in a plan view. The regions S51, S52, S53, and S54 to which the energy beam E is irradiated are regions including at least a part of the weight membranes 51a, 52a, 53a, and 54a. In the present embodiment, the regions S51, S52, S53, and S54 are contained within the pyramidal membranes 51a, 52a, 53a, and 54a. As a result, the resonance frequencies of the drive vibrating arms 44 to 47 can be adjusted efficiently and with high accuracy. In particular, when the weight films 51a, 52a, 53a, 54a contain Au (gold), the processing is easy, so that the removal processing can be performed efficiently.

Further, as described above, the drive vibrating arms 44 and 46 (a pair of vibrating arms) are parallel to each other in a plan view and extend to the same side with respect to the base 41. Similarly, the drive vibrating arms 45 and 47 (a pair of vibrating arms) are parallel to each other in a plan view and extend to the same side with respect to the base 41. According to such a vibrating element 1 (vibrating element 1a), a pair of driving vibrating arms 44 and 46 alternately repeat approaching and separating from each other in the plane (in the XY plane), and a pair of driving vibrations. It is possible to suppress deformation of the base 41 due to bending vibration in which the arms 44 and 46 alternately approach and separate from each other, and further suppress vibration leakage from the base 41 to the outside. Further, by using the adjustment method in the present embodiment for such a vibrating element 1 (vibrating element 1a), vibration leakage due to the vibration balance of the driving vibrating arms 44 to 47 being deviated with time is reduced, and thus vibration leakage is reduced. It is possible to realize the vibrating element 1 with high accuracy and high stability.

As described above, the method for manufacturing the vibrating element 1 includes a method for adjusting the frequency of the vibrating element 1a. As a result, it is possible to obtain the vibrating element 1 in which the vibration leakage due to the vibration balance of the driving vibrating arms 44 to 47 being deviated with time is reduced. Then, by applying such a vibrating element 1 to the physical quantity sensor 10, it is possible to realize the physical quantity sensor 10 with high accuracy and high stability.

<Second Embodiment>
Next, the second embodiment of the present invention will be described.
FIG. 11 is a diagram showing a vibrating element according to the second embodiment.

The present embodiment is the same as the above-described embodiment except that the weight layer is not provided. In the following description, the second embodiment will be described mainly on the differences from the above-described embodiment, and the description of the same items will be omitted.

The vibrating element 1A shown in FIG. 11 does not include the weight films 51 to 56 of the vibrating element 1. Further, the wide portions 441 to 471 are not provided with an electrode pattern (not shown), and the wide portions 441 to 471 are in a state where the crystal is exposed. In this vibrating element 1A, recesses 511A, 521A, 513A, and 541A are formed on the tip side of the wide portions 441, 451, 461, and 471. The recesses 511A, 521A, 513A, and 541A have substantially the same configuration (for example, shape and arrangement) as the recesses 511, 521, 513, and 541 of the vibrating element 1. A film 50 is provided on the surfaces of the recesses 511A, 521A, 513A, and 541A.

In the present embodiment, the "surface layer" refers to a portion on the surface side of the wide portions 441, 451, 461, and 471.

Even for such a vibrating element 1A (more accurately, a vibrating element that becomes a vibrating element 1A by adjusting the frequency), the vibration of the adjusted drive vibrating arms 44 to 47 can be obtained by using the frequency adjusting method described above. It is possible to reduce the deterioration of the balance over time.

FIG. 12 is a graph showing the amount of vibration leakage in each step of the frequency adjusting method of the vibrating element according to the second embodiment. Note that FIG. 12 corresponds to FIG.

As shown in FIG. 12, in the vibrating element 1A as well, the vibration leakage amount can be brought close to zero after the adjustment, as in the vibrating element 1. Further, also in the sealing step 1 and the sealing step 2 after the adjustment, the vibration leakage amount does not become excessively large due to the treatment. As described above, according to the frequency adjusting method of the present embodiment, it is possible to suppress an increase in the amount of vibration leakage over time even after the adjustment, as in the frequency adjusting method of the vibrating element 1a in the first embodiment. it can.

The method for adjusting the frequency of the vibrating element, the method for manufacturing the vibrating element, and the vibrating element of the present invention have been described above based on the illustrated embodiments, but the present invention is not limited to this, and the configurations of each part are the same. It can be replaced with any configuration having the function of. Further, any other constituents may be added to the present invention.

In the above-described embodiment, the vibrating element has a wide portion, but the vibrating element may not have a wide portion. That is, the width of the region on the tip end side of the drive vibrating arm may be the same as the width of the region on the proximal end side. Further, the vibrating element had two pairs of driving vibrating arms parallel to each other and extending to the same side with respect to the base in a plan view, but the pair of driving vibrating arms was one set. May be good.

Further, in the above-described embodiment, the vibrating element has a so-called double T-shaped shape, but is not limited to this, and for example, various types such as H-shaped, bipod tuning fork, tripod tuning fork, orthogonal type, and prismatic type are used. It may be in the form of.

Further, as the constituent material of the vibrating body (vibrating piece) described above, for example, a piezoelectric single crystal such as lithium tantalate or lithium niobate or a piezoelectric material such as piezoelectric ceramic may be used other than quartz.

1 ... Vibrating element, 1A ... Vibrating element, 1a ... Vibrating element, 1b ... Vibrating element, 4 ... Vibrating body, 5 ... Weight film pattern, 5a ... Weight film pattern, 10 ... Physical quantity sensor, 11 ... Package, 12 ... Support substrate , 13 ... Wiring pattern, 14 ... Circuit element, 15 ... Conductive wire, 16 ... Adhesive, 17 ... Conductive adhesive, 41 ... Base, 42 ... Connecting arm, 43 ... Connecting arm, 44 ... Driving vibrating arm, 45 ... Drive vibration arm, 46 ... Drive vibration arm, 47 ... Drive vibration arm, 48 ... Detection vibration arm, 49 ... Detection vibration arm, 50 ... Membrane, 51 ... Weight membrane, 51a ... Weight membrane, 52 ... Weight membrane, 52a ... Weight membrane, 53 ... weight membrane, 53a ... weight membrane, 54 ... weight membrane, 54a ... weight membrane, 55 ... weight membrane, 56 ... weight membrane, 111 ... base, 112 ... lid, 113 ... joining member, 115 ... through hole , 116 ... Encapsulant, 441 ... Wide part, 451 ... Wide part, 461 ... Wide part, 471 ... Wide part, 481 ... Wide part, 491 ... Wide part, 511 ... Recessed part, 511A ... Recessed part, 521 ... Recessed part, 521A … Recessed part 533… Recessed part 533A… Recessed part, 541… Recessed part, 541A… Recessed part, A… Line segment, E… Energy beam, M… Material, S… Space, S1… Step, S2… Step, S3… Step, S4 ... Step, S51 ... region, S52 ... region, S53 ... region, S54 ... region, a ... axis, d5 ... film thickness, α ... arrow, β ... arrow, γ ... arrow, ω ... angular velocity, d1 ... depth, d3 ... depth, W1 ... width, W2 ... width

Claims (8)

A method of adjusting the resonance frequency of a vibrating element having a base portion and a pair of vibrating arms extending from the base portion.
Based on the result of measuring the resonance frequency of the pair of vibrating arms, an energy beam is applied to a part of the region on the tip side opposite to the base of each of the pair of vibrating arms to irradiate the surface layer. Includes a removal process that removes part of the
In a plan view from the thickness direction of the base, the area of the region irradiated with the energy beam of one of the vibrating arms is the same as the area of the region irradiated with the energy beam of the other vibrating arm. ,
The removal depth removed by irradiating the energy beam of one of the vibrating arms is different from the removal depth removed by irradiating the energy beam of the other vibrating arm. How to adjust the frequency of the vibrating element. The width of each of the pair of vibrating arms on the tip side is larger than the width on the base side in the plan view along the direction orthogonal to the extending direction of the vibrating arms. The method for adjusting the frequency of a vibrating element according to claim 1, which includes a wide portion. The distal region of each of the pair of vibrating arms includes a weight film as the surface layer of the vibrating arm in the plan view.
The frequency adjusting method for a vibrating element according to claim 1 or 2, wherein the region to which the energy beam is irradiated is a region including at least a part of the pyramidal membrane. The method for adjusting the frequency of a vibrating element according to any one of claims 1 to 3, wherein the pair of vibrating arms are parallel to each other in the plan view and extend in the same direction from the base. The pair of vibrating arms are parallel to each other in the plan view.
The region to be irradiated with the energy beam is located at a position line-symmetrical with respect to a center line that passes through the center of gravity of the base portion and is parallel to the extending direction of the pair of vibrating arms in the plan view. The method for adjusting the frequency of a vibrating element according to any one item. After the removal step, the vibration element is housed in a closed space in which a predetermined substance exists, so that the predetermined substance is attached to the surface of the removed portion removed by irradiating the energy beam. Item 5. The method for adjusting the frequency of a vibrating element according to any one of Items 1 to 5. A method for manufacturing a vibrating element, which comprises the method for adjusting the frequency of the vibrating element according to any one of claims 1 to 6. A vibrating element having a base and a pair of vibrating arms extending from the base.
Each of the pair of vibrating arms has a recess in a part of the region on the tip side opposite to the base.
In a plan view from the thickness direction of the base, the area of the recess of one of the vibrating arms is the same as the area of the recess of the other vibrating arm.
The depth of the recess of one of the vibrating arms is different from the depth of the recess of the other vibrating arm.
The surface of the concave portion of one of the vibrating arms and the surface of the concave portion of the other vibrating arm are each provided with a film containing a material different from the material constituting the vibrating arm. Vibration element.

Images