Method for manufacturing a vibrating element

Abstract

Method for manufacturing a vibration element. The shape and the groove can be formed at the same time. In the method for manufacturing a vibration element having a first vibration arm and a second vibration arm each having a first surface and a second surface in a front-back relationship and a bottomed groove opening in the first surface, the method includes: a first protective film forming step of forming a first protective film; a first dry etching step of performing dry etching through the first protective film to form the groove and the shape of the first vibration arm and the second vibration arm; and a second protective film forming step of forming a second protective film in the groove; and a second dry etching step of performing dry etching through the second protective film to form the first surface and the shape of the first vibration arm and the second vibration arm.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a vibrating element. Background Technology

[0002] Patent Document 1 describes a method for forming a tuning fork-type oscillator by wet etching and dry etching, wherein the tuning fork-type oscillator has a bottomed groove on the vibrating arm. In this manufacturing method, the shape of the tuning fork-type oscillator is formed by wet etching of a quartz substrate, and then the groove is formed by dry etching.

[0003] Patent Document 2 describes a method for forming a tuning fork-type oscillator by dry etching, wherein the tuning fork-type oscillator has a bottomed groove on the vibrating arm. In this manufacturing method, when dry etching a substrate made of piezoelectric material, the width of the groove is narrowed relative to the width between a pair of vibrating arms, thereby utilizing the micro-load effect to make the etching depth of the groove shallower relative to the etching depth between a pair of vibrating arms, thus forming the groove and the outer shape of the oscillator.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2013-175933

[0005] Patent Document 2: Japanese Patent Application Publication No. 2007-013382

[0006] In the manufacturing method of Patent Document 1, the wet etching for forming the shape and the dry etching for forming the groove are different processes. Therefore, the manufacturing process is complex and prone to problems such as misalignment of the groove relative to the shape. Consequently, the vibration element based on this manufacturing method is prone to generating unwanted vibrations.

[0007] On the other hand, in the manufacturing method of Patent Document 2, the shape and groove are formed in the same process, so the above-mentioned problems do not occur. However, in this manufacturing method, the shape and groove are formed in the same process using the micro-load effect in dry etching, so the setting of dimensions such as the width of the vibrating arm and the width and depth of the groove is restricted, resulting in a low degree of design freedom.

[0008] Therefore, a manufacturing method is required that can form the shape and groove of the vibrating element simultaneously and has a high degree of design freedom. Summary of the Invention

[0009] In the manufacturing method of the vibration element of the present invention, the vibration element has a first vibration arm and a second vibration arm extending along a first direction and arranged along a second direction intersecting the first direction. The first vibration arm and the second vibration arm each have a first surface and a second surface, and a bottomed groove opening in the first surface. The first surface and the second surface are arranged in a positive-negative relationship in a third direction intersecting the first direction and the second direction. The manufacturing method includes: a preparation step of preparing a quartz substrate having a first substrate surface and a second substrate surface in a positive-negative relationship; and a first protective film formation step of forming the first protective film on the first substrate surface. A first protective film is formed in the first vibration arm forming region of the vibration arm and in the second vibration arm forming region of the second vibration arm, excluding the groove forming region. A first dry etching process is performed, in which the quartz substrate is dry etched from the first substrate surface side through the first protective film to form the groove and the outlines of the first and second vibration arms. A second protective film forming process is performed, in which the second protective film is formed in the groove. A second dry etching process is performed, in which the quartz substrate is dry etched from the first substrate surface side through the second protective film to form the first surface and the outlines of the first and second vibration arms. Attached Figure Description

[0010] Figure 1 This is a top view showing the vibrating element of Embodiment 1.

[0011] Figure 2 yes Figure 1 Sectional view along line A1-A1 in the diagram.

[0012] Figure 3 This is a diagram showing the manufacturing process of the vibration element according to Embodiment 1.

[0013] Figure 4 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating element.

[0014] Figure 5 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating element.

[0015] Figure 6 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating element.

[0016] Figure 7 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating element.

[0017] Figure 8 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating element.

[0018] Figure 9 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating element.

[0019] Figure 10 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating element.

[0020] Figure 11 This is a cross-sectional view used to illustrate the manufacturing method of the vibration element in Embodiment 2.

[0021] Figure 12 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating element.

[0022] Figure 13 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating element.

[0023] Figure 14 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating element.

[0024] Figure 15 It is a cross-sectional view used to illustrate the manufacturing method of a vibrating element.

[0025] Figure 16 This is a top view showing a modified example of the vibrating element.

[0026] Figure 17 yes Figure 16 Sectional view along line A3-A3 in the diagram.

[0027] Figure 18 This is a top view showing a modified example of the vibrating element.

[0028] Figure 19 yes Figure 18 Sectional view along line A4-A4 in the diagram.

[0029] Figure 20 yes Figure 18 Sectional view along line A5-A5.

[0030] Figure 21 This is a top view showing a modified example of the vibrating element.

[0031] Figure 22 yes Figure 21 Sectional view along line A6-A6 in the diagram.

[0032] Figure 23 yes Figure 21 Sectional view along line A7-A7 in the diagram.

[0033] Label Explanation

[0034] 1. Vibrating element; 2. Vibrating substrate; 2A. First surface; 2B. Second surface; 3. Electrode; 20. Quartz substrate; 20A. First substrate surface; 20B. Second substrate surface; 21. Base; 22. First vibrating arm; 23. Second vibrating arm; 221, 231. Grooves; 225, 235. Embankments; 51, 51a. First protective film; 52. Second protective film; Q1. Groove forming area; Q2. First vibrating arm forming area; Q3. Second vibrating arm forming area; Q4. Inter-arm area; Q5. Inter-element area; Qd1. Embankment forming area; S1. Preparation process; S2. First protective film forming process; S3. First dry etching process; S4. Second protective film forming process; S5. Second dry etching process; S6. First protective film removal process; S7. Second protective film removal process; S8. Electrode forming process. Detailed Implementation

[0035] 1. Implementation Method 1

[0036] The manufacturing method of the vibration element 1 in Embodiment 1 will be described.

[0037] First, refer to Figure 1 and Figure 2 The structure of vibrating element 1 will be explained, and then, referring to... Figures 3 to 10 The manufacturing method of vibration element 1 is explained.

[0038] For ease of explanation, except Figure 3 In the figures other than those shown, the X-axis, Y-axis, and Z-axis are shown as three mutually orthogonal axes. Furthermore, the direction along the X-axis, which is considered the second direction, is also called the X-direction; the direction along the Y-axis, which is considered the first direction, is also called the Y-direction; and the direction along the Z-axis, which is considered the third direction, is also called the Z-direction. Additionally, the arrow side of each axis is also called the positive side, and the opposite side is also called the negative side. Furthermore, the positive side of the Z-direction is also called "up," and the negative side is also called "down." Additionally, the view from the Z-direction is simply referred to as "top view." Furthermore, as described later, the X-axis, Y-axis, and Z-axis correspond to the crystal axes of quartz.

[0039] like Figure 1 and Figure 2 As shown, the vibrating element 1 is a tuning fork type vibrating element, having a vibrating substrate 2 and electrodes 3 formed on the surface of the vibrating substrate 2.

[0040] The vibrating substrate 2 is formed by patterning a Z-cut quartz substrate, which is a Z-cut quartz plate, into a desired shape. It extends along the XY plane, defined by the X-axis and Y-axis, which are the axes of the quartz crystal, and has a thickness along the Z-direction. The X-axis is also called the electrical axis, the Y-axis is also called the mechanical axis, and the Z-axis is also called the optical axis. In addition, the thickness along the Z-direction is also simply referred to as "thickness".

[0041] The vibrating substrate 2 is plate-shaped and has a first surface 2A and a second surface 2B arranged opposite each other along the Z direction. Furthermore, the vibrating substrate 2 has a base 21 and a first vibrating arm 22 and a second vibrating arm 23 extending from the base 21 along the Y direction and arranged along the X direction.

[0042] The first vibrating arm 22 has: a bottomed groove 221 with an opening on the first surface 2A; a dam 225 defining the groove 221; and a side surface 101 connecting the first surface 2A and the second surface 2B. The dam 225 is the portion on the first surface 2A that aligns the groove 221 along the X direction when viewed from above.

[0043] Similarly, the second vibrating arm 23 has: a bottomed groove 231 opening on the first surface 2A; a dam 235 defining the groove 231; and a side surface 103 connecting the first surface 2A and the second surface 2B. The dam 235 is the portion on the first surface 2A that sandwiches the groove 231 along the X direction when viewed from above.

[0044] Grooves 221 and 231 extend along the Y direction. Furthermore, embankments 225 and 235 are formed on both sides of grooves 221 and 231 in the X direction, extending along the Y direction. Therefore, the first vibrating arm 22 and the second vibrating arm 23 each have a generally U-shaped cross-sectional shape. This results in a vibrating element 1 that reduces thermoelastic losses and possesses excellent vibration characteristics.

[0045] Electrode 3 has a signal electrode 31 and a ground electrode 32. The signal electrode 31 is disposed on the first surface 2A and the second surface 2B of the first vibrating arm 22 and on the side surface 103 of the second vibrating arm 23. Conversely, the ground electrode 32 is disposed on the side surface 101 of the first vibrating arm 22 and on the first surface 2A and the second surface 2B of the second vibrating arm 23. When a drive signal is applied to the signal electrode 31 with the ground electrode 32 grounded, as... Figure 1 As indicated by the arrows, the first vibrating arm 22 and the second vibrating arm 23 undergo bending vibration in the X direction by repeatedly approaching and separating.

[0046] The above provides a brief description of the vibrating element 1.

[0047] Next, the manufacturing method of the vibrating element 1 will be described. For example... Figure 3As shown, the manufacturing method of the vibrating element 1 includes: a preparation step S1, preparing a quartz substrate 20 as the parent material for the vibrating substrate 2; a first protective film forming step S2, forming a first protective film 51 on the first substrate surface 20A of the quartz substrate 20; a first dry etching step S3, dry etching the quartz substrate 20 through the first protective film 51 to form grooves 221 and 231; a second protective film forming step S4, forming a second protective film 52 in the grooves 221 and 231; a second dry etching step S5, dry etching the quartz substrate 20 through the second protective film 52; a first protective film removal step S6, removing the first protective film 51 remaining on the first substrate surface 20A; a second protective film removal step S7, removing the second protective film 52 remaining on the grooves 221 and 231; and an electrode forming step S8, forming an electrode 3 on the surface of the vibrating substrate 2 obtained by the above steps.

[0048] Furthermore, the first protective film removal step S6 is equivalent to the "protective film removal step" in this invention.

[0049] The following sections will explain each of these processes in turn.

[0050] <<Preparation Process S1>>

[0051] like Figure 4 As shown, a quartz substrate 20 is prepared as the base material for the vibrating substrate 2. Multiple vibrating elements 1 are formed together from the quartz substrate 20. The quartz substrate 20 is plate-shaped and has a first substrate surface 20A and a second substrate surface 20B arranged opposite each other in the Z direction. Through grinding or polishing processes, the quartz substrate 20 is adjusted to a desired thickness, and the first substrate surface 20A and the second substrate surface 20B are sufficiently smoothed. Alternatively, a wet etching-based surface treatment can be performed on the quartz substrate 20 as needed.

[0052] Furthermore, the region where the first vibrating arm 22 is formed will be referred to as the first vibrating arm forming region Q2. Similarly, the region where the second vibrating arm 23 is formed will be referred to as the second vibrating arm forming region Q3. In addition, the region located between the first vibrating arm forming region Q2 and the second vibrating arm forming region Q3 will be referred to as the inter-arm region Q4. Furthermore, the region located between adjacent vibrating substrates 2 will be referred to as the inter-element region Q5.

[0053] The first vibrating arm forming region Q2 and the second vibrating arm forming region Q3 have a groove forming region Q1 for forming grooves 221 and 231 and a dam forming region Qd1 for forming dams 225 and 235. In other words, the dam forming region Qd1 corresponds to the region in the first vibrating arm forming region Q2 and the second vibrating arm forming region Q3 other than the groove forming region Q1. The grooves 221 and 231 and the dams 225 and 235 are formed by the first dry etching process S3 described later.

[0054] <<First Protective Film Forming Process S2>>

[0055] like Figure 5 As shown, a first protective film 51 is formed on the first substrate surface 20A of the quartz substrate 20. The first protective film 51 is formed in the embankment forming region Qd1 of the first substrate surface 20A.

[0056] In this embodiment, the first protective film 51 is a resin film formed from resin. For example, the first protective film 51 can be formed by coating a photoresist material, which is a photosensitive resin, onto the first substrate surface 20A and patterning it using photolithography. Alternatively, the first protective film 51 can also be formed by selectively coating resin using a printing method such as screen printing or embossing. In this way, a resin film can be easily formed, and therefore, by making the first protective film 51 a resin film, the first protective film formation process S2 can be simplified.

[0057] In this embodiment, the first protective film 51 is formed to be thick enough that it remains in the embankment formation region Qd1 at the end of the first dry etching process S3 and the second dry etching process S5, which will be described later. However, the first protective film 51 may also be formed to be thinner so that it can be removed from the embankment formation region Qd1 at the end of the first dry etching process S3 or the second dry etching process S5.

[0058] In this embodiment, the first protective film 51 is formed of resin, but it may also be formed of a material other than resin. For example, the first protective film 51 may also be a metal film formed of metal.

[0059] <<First Dry Etching Process S3>>

[0060] like Figure 6 As shown, the quartz substrate 20 is dry etched from the first substrate surface 20A side through the first protective film 51, simultaneously forming the grooves 221 and 231 and the outline of the vibrating substrate 2. Furthermore, "simultaneous formation" means forming both in a single process. More specifically, this process is reactive ion etching, performed using a reactive ion etching apparatus (RIE apparatus). Additionally, the reactive gas introduced into the RIE apparatus is not particularly limited; for example, SF6, CF4, C2F4, C2F6, C3F6, C4F8, etc., can be used.

[0061] In this process, the first protective film 51 formed in the dam formation region Qd1 is used as a mask to etch the area outside the dam formation region Qd1. The area outside the dam formation region Qd1 is the groove formation region Q1, the inter-arm region Q4, and the inter-element region Q5. Grooves 221 and 231 are formed by etching the groove formation region Q1 of the quartz substrate 20 from the first substrate surface 20A side. The etching depth in the groove formation region Q1 is equivalent to the depth of the grooves 221 and 231. The shape of the vibrating substrate 2 is formed by etching the inter-arm region Q4 and the inter-element region Q5 of the quartz substrate 20 from the first substrate surface 20A side. The etching depth in the inter-arm region Q4 and the inter-element region Q5 is equivalent to the depth of the shape of the vibrating substrate 2. In addition, the "shape of the vibrating substrate 2" is also referred to as the "shape of the first vibrating arm 22 and the second vibrating arm 23".

[0062] The first dry etching process S3 ends when the depth of the grooves 221 and 231 reaches the desired depth Wa. In this embodiment, the depth of the outer shape of the vibrating substrate 2 at the end of this process is approximately equal to the depth Wa of the grooves 221 and 231. Furthermore, "approximately equal" is a concept that includes cases where they are not strictly equal due to deviations in etching conditions, etc.

[0063] Furthermore, in this embodiment, as described above, the first protective film 51 is formed in the embankment formation region Qd1 of the first substrate surface 20A, and not in the trench formation region Q1, the inter-arm region Q4, and the inter-component region Q5. That is, the trench formation region Q1, the inter-arm region Q4, and the inter-component region Q5 of the first substrate surface 20A are exposed. Therefore, in the first dry etching process S3, etching of the trench formation region Q1, the inter-arm region Q4, and the inter-component region Q5 begins simultaneously with the start of dry etching. Therefore, the first dry etching process S3 can be performed in a short time.

[0064] <<Second Protective Film Forming Process S4>>

[0065] like Figure 7 As shown, a second protective film 52 is formed in grooves 221 and 231.

[0066] In this embodiment, the second protective film 52 is a resin film formed from resin. The second protective film 52 is formed by filling the grooves 221 and 231 with resin. For example, the second protective film 52 can be formed by coating a photoresist material as a photosensitive resin onto the quartz substrate 20 from the first substrate surface 20A side and patterning it using photolithography. Alternatively, for example, the second protective film 52 can also be formed by selectively coating resin using a printing method such as screen printing or embossing. In this way, a resin film can be easily formed, so by making the second protective film 52 a resin film, the second protective film formation process S4 can be simplified.

[0067] In this embodiment, the thickness of the second protective film 52 is formed to be greater than or equal to the depth Wa of the trenches 221 and 231 at the end of the second dry etching process S5 described later. However, the thickness of the second protective film 52 is formed to be sufficient so that the second protective film 52 remains on the bottom surface of the trenches 221 and 231 at the end of the second dry etching process S5.

[0068] In addition, in this embodiment, the second protective film 52 is a thick film formed by filling resin into the grooves 221 and 231, but it can also be a thin film covering the sidewalls and bottom of the grooves 221 and 231 respectively.

[0069] In this embodiment, the second protective film 52 is formed of resin, but it can also be formed of materials other than resin. For example, the second protective film 52 can also be a metal film formed of metal.

[0070] <<Second Dry Etching Process S5>>

[0071] like Figure 8 As shown, the quartz substrate 20 is dry-etched from the first substrate surface 20A side through the second protective film 52, simultaneously forming the first surface 2A of the first vibrating arm 22 and the second vibrating arm 23, as well as the outline of the vibrating substrate 2. This process is reactive ion etching and is performed using a RIE device.

[0072] In this process, the second protective film 52 formed in the trench forming region Q1 is used as a mask to etch the area outside the trench forming region Q1. However, in this embodiment, as described above, the first protective film 51 remains in the embankment forming region Qd1. Therefore, in this process, the first protective film 51 and the second protective film 52 are used as masks to etch the area of ​​the quartz substrate 20 other than the trench forming region Q1 and the embankment forming region Qd1. The areas outside the trench forming region Q1 and the embankment forming region Qd1 are the inter-arm region Q4 and the inter-element region Q5.

[0073] Thus, the shape of the vibrating substrate 2 is formed by etching the inter-arm region Q4 and inter-element region Q5 of the quartz substrate 20 from the first substrate surface 20A side.

[0074] The second dry etching process S5 ends when the depth of the outer shape of the vibrating substrate 2 reaches the desired depths Aa and Ba. That is, at the end of this process, the etching depth of the inter-arm region Q4 is depth Aa, and the etching depth of the inter-component region Q5 is depth Ba. In this embodiment, depths Aa and Ba are approximately equal.

[0075] In this embodiment, the depths Aa and Ba of the outer shape of the vibrating substrate 2 are both greater than or equal to the thickness Ta of the quartz substrate 20. That is, Aa ≥ Ta, Ba ≥ Ta. By making the depths Aa and Ba greater than or equal to the thickness Ta of the quartz substrate 20, the inter-arm region Q4 and the inter-element region Q5 are respectively connected in the second dry etching process S5. By connecting the inter-arm region Q4 and the inter-element region Q5, the first vibrating arm 22 and the second vibrating arm 23 are formed.

[0076] Furthermore, in this embodiment, the dry etching process S5 ends with the first protective film 51 remaining on the first substrate surface 20A of the quartz substrate 20. That is, the embankment formation region Qd1 of the first substrate surface 20A is protected by the first protective film 51 and is not etched in the first dry etching process S3 and the second dry etching process S5. In the first protective film removal process S6, which will be described later, the embankment formation region Qd1 of the first substrate surface 20A becomes the first surface 2A of the first vibrating arm 22 and the second vibrating arm 23.

[0077] Alternatively, in the second dry etching process S5, the dry etching can be completed before the first protective film 51 remains on the first substrate surface 20A. That is, the embankment formation region Qd1 can also be etched. In this case, the surface etched in the second dry etching process S5 becomes the first surface 2A of the first vibrating arm 22 and the second vibrating arm 23.

[0078] Thus, the first surface 2A of the first vibrating arm 22 and the second vibrating arm 23 is formed by etching or not etching the embankment forming region Qd1 of the first substrate surface 20A.

[0079] Here, the first protective film formation process S2, the first dry etching process S3, the second protective film formation process S4, and the second dry etching process S5 are summarized as follows.

[0080] According to dry etching, the process can be carried out without being affected by the quartz crystal surface, so the shapes of grooves 221, 231 and the first vibrating arm 22 and the second vibrating arm 23 can be formed with excellent dimensional accuracy.

[0081] Furthermore, by forming the grooves 221 and 231 and the outer shape of the vibrating substrate 2 together, it is possible to reduce the manufacturing process of the vibrating element 1 and lower its cost. In addition, by preventing the grooves 221 and 231 from shifting relative to the outer shape, the forming accuracy of the vibrating substrate 2 can be improved.

[0082] Furthermore, the shapes of grooves 221 and 231, as well as the first and second vibrating arms 22 and 23, can be formed without utilizing micro-load effects. Therefore, there are no restrictions on setting dimensions such as the width of the inter-arm region Q4, the width of the inter-element region Q5, and the widths of grooves 221 and 231, which increases the design freedom of the vibrating element 1. For example, in the first protective film forming process S2, the external dimensions of grooves 221 and 231, as well as the first and second vibrating arms 22 and 23, can be controlled by adjusting the thickness or width of the first protective film 51.

[0083] Furthermore, since the micro-load effect is not utilized, the constraints of dry etching conditions, such as the selection of reactive gases used in dry etching, can be mitigated. Therefore, compared with the case of utilizing the micro-load effect, it is easier to manufacture the vibrating element 1.

[0084] <<First Protective Film Removal Process S6>>

[0085] like Figure 9 As shown, the first protective film 51 remaining on the first substrate surface 20A of the quartz substrate 20 is removed. Thus, the first substrate surface 20A becomes the first surface 2A of the first vibrating arm 22 and the second vibrating arm 23. The first surface 2A of the first vibrating arm 22 and the second vibrating arm 23 is not etched in the first dry etching process S3 and the second dry etching process S5. Therefore, the thickness of the first vibrating arm 22 and the second vibrating arm 23 and the surface roughness of the first surface 2A maintain the thickness of the quartz substrate 20 and the surface roughness of the first substrate surface 20A. Therefore, the thickness accuracy of the first vibrating arm 22 and the second vibrating arm 23 is improved, suppressing the generation of unwanted vibrations such as torsional vibration.

[0086] If the first protective film 51 is removed from the first substrate surface 20A without any residue at the end of the second dry etching process S5, the first protective film removal process S6 may not be performed.

[0087] <<Second Protective Film Removal Process S7>>

[0088] like Figure 10 As shown, the second protective film 52 remaining in the grooves 221 and 231 is removed.

[0089] The order in which the first protective film removal step S6 and the second protective film removal step S7 are performed is not limited to this order, and the execution order can be changed. Alternatively, the first protective film removal step S6 and the second protective film removal step S7 can be performed as a single step to remove the first protective film 51 and the second protective film 52 together.

[0090] Through the above processes S1 to S7, such as Figure 10 As shown, multiple vibrating substrates 2 are formed together from the quartz substrate 20.

[0091] <<Electrode Formation Process S8>>

[0092] A metal film is formed on the surface of the vibrating substrate 2, and an electrode 3 is formed by patterning the metal film.

[0093] Thus, vibration element 1 is obtained.

[0094] As described above, the following effects can be obtained according to this embodiment.

[0095] In the manufacturing method of the vibrating element 1, the vibrating element 1 has a first vibrating arm 22 and a second vibrating arm 23 extending along the Y direction (a first direction) and arranged along the X direction (a second direction) intersecting the Y direction. The first vibrating arm 22 and the second vibrating arm 23 each have a first surface 2A and a second surface 2B, and bottomed grooves 221 and 231 opening in the first surface 2A. The first surface 2A and the second surface 2B are arranged in opposite directions along the Z direction (a third direction) intersecting the Y and X directions. The manufacturing method includes: a preparation step S1, preparing a quartz substrate 20 having a first substrate surface 20A and a second substrate surface 20B in opposite directions; and a first protective film forming step S2, forming the first vibrating arm 22 on the first substrate surface 20A. A first protective film 51 is formed in the area of ​​the first vibrating arm forming area Q2 and the second vibrating arm forming area Q3 forming the second vibrating arm 23, excluding the groove forming area Q1 forming grooves 221 and 231, i.e., the embankment forming area Qd1. In the first dry etching process S3, the quartz substrate 20 is dry etched from the first substrate surface 20A side through the first protective film 51 to form grooves 221 and 231 and the outlines of the first vibrating arm 22 and the second vibrating arm 23. In the second protective film forming process S4, a second protective film 52 is formed in grooves 221 and 231. In the second dry etching process S5, the quartz substrate 20 is dry etched from the first substrate surface 20A side through the second protective film 52 to form the first surface 2A and the outlines of the first vibrating arm 22 and the second vibrating arm 23.

[0096] Therefore, the shapes and grooves 221 and 231 of the first vibrating arm 22 and the second vibrating arm 23 can be formed at the same time. Furthermore, there are no restrictions on the setting of dimensions such as the width of the inter-arm region Q4, the width of the inter-element region Q5, and the width of the grooves 221 and 231, which can provide a manufacturing method for a vibrating element 1 with a high degree of design freedom.

[0097] Furthermore, as described above, by making the first protective film 51 formed in the embankment forming region Qd1 and the second protective film 52 formed in the trench forming region Q1 into resin films, the first protective film forming process S2 and the second protective film forming process S4 can be simplified.

[0098] 2. Implementation Method 2

[0099] Reference Figures 11-15 The manufacturing method of the vibration element 1 in Embodiment 2 is described below. Furthermore, structures identical to those in Embodiment 1 are labeled with the same reference numerals, and repeated descriptions are omitted.

[0100] In Embodiment 2, the first protective film 51a formed in the dike formation region Qd1 in the first protective film forming step S2 is a metal film. The first protective film 51a has a first metal film 511 and a second metal film 512. The first metal film 511 is formed in the region other than the dike formation region Qd1 in the first protective film forming step S2. Otherwise, it is the same as in Embodiment 1.

[0101] The first metal film 511 formed in the groove forming region Q1 in the region other than the dike forming region Qd1 is equivalent to the third protective film 55 in this application. The first metal film 511 formed in the inter-arm region Q4 and inter-element region Q5 in the region other than the dike forming region Qd1 is equivalent to the fourth protective film 57 in this application.

[0102] The preparation process S1 is the same as in Embodiment 1, so the description is omitted and the description will proceed from the first protective film formation process S2.

[0103] <<First Protective Film Forming Process S2>>

[0104] like Figure 11 As shown, firstly, a first metal film 511 is formed on the first substrate surface 20A of the quartz substrate 20. The first metal film 511 is a base film used to promote the formation of the second metal film 512, which will be described later. The first metal film 511 can be formed, for example, from copper (Cu), chromium (Cr), etc. The first metal film 511 can be formed, for example, using a vapor phase deposition method such as sputtering or evaporation.

[0105] Next, a photoresist film R1 is formed on the side of the first metal film 511 opposite to the quartz substrate 20 using photolithography. The side of the first metal film 511 opposite to the quartz substrate 20 is the positive side of the first metal film 511 in the Z direction. The photoresist film R1 has an opening in the embankment formation region Qd1. That is, the photoresist film R1 is patterned in such a way that the second metal film 512 can be formed in the embankment formation region Qd1.

[0106] Next, a second metal film 512 is formed on the surface of the first metal film 511 opposite to the quartz substrate 20 through the opening of the resist film R1. That is, the second metal film 512 is laminated on the first metal film 511 using the resist film R1 as a mask. In this way, a first protective film 51a having the first metal film 511 and the second metal film 512 is formed in the embankment forming region Qd1 on the first substrate surface 20A. The second metal film 512 can be formed, for example, by nickel (Ni). The second metal film 512 can be formed, for example, by an electroless plating method.

[0107] After the first protective film 51a is formed, the resist film R1 is removed. Thus, it becomes... Figure 12 That way.

[0108] like Figure 12 As shown, a first protective film 51a having a first metal film 511 and a second metal film 512 is formed in the embankment forming region Qd1 on the first substrate surface 20A. That is, in this embodiment, the first protective film 51a is a metal film formed of metal. Generally, the etching rate of metal is lower than the etching rate of the photosensitive resin used as the resist material. Therefore, by making the first protective film 51a a metal film, the thickness of the first protective film 51a can be reduced compared to a resin film. As a result, the dimensional accuracy of the first vibrating arm 22 and the second vibrating arm 23, the grooves 221, 231, etc. formed in the first dry etching process S3 can be improved.

[0109] Additionally, a first metal film 511, serving as a third protective film 55, is formed in the groove forming region Q1 of the first substrate surface 20A. A first metal film 511, serving as a fourth protective film 57, is formed in the inter-arm region Q4 and inter-element region Q5 of the first substrate surface 20A. The thickness of the first metal film 511, serving as the third protective film 55 and the fourth protective film 57, is thinner than that of the first protective film 51a.

[0110] <<First Dry Etching Process S3>>

[0111] like Figure 13 As shown, the quartz substrate 20 is dry-etched from the first substrate surface 20A side through the first protective film 51a.

[0112] In this embodiment, dry etching begins with a first metal film 511 formed in the trench forming region Q1, the inter-arm region Q4, and the inter-element region Q5 on the first substrate surface 20A. The first metal film 511 formed in the trench forming region Q1 as a third protective film 55 and the first metal film 511 formed in the inter-arm region Q4 and the inter-element region Q5 as a fourth protective film 57 are thinner than the first protective film 51a formed in the embankment forming region Qd1. Therefore, the third protective film 55 and the fourth protective film 57 are easier to remove in the first dry etching step S3 compared to the first protective film 51a.

[0113] Therefore, even when the first metal film 511, which serves as the third protective film 55, is formed in the groove forming region Q1, the shapes of the grooves 221 and 231 and the vibrating substrate 2 can be formed simultaneously. Therefore, the process of removing the first metal film 511, which serves as the third protective film 55, is not required, and the manufacturing process of the vibrating substrate 2 can be reduced.

[0114] Furthermore, even when the first metal film 511, which serves as the fourth protective film 57, is formed in the inter-arm region Q4 and the inter-element region Q5, the grooves 221 and 231 and the shape of the vibrating substrate 2 can be formed simultaneously. Therefore, the process of removing the first metal film 511, which serves as the fourth protective film 57, is not required, and the manufacturing process of the vibrating substrate 2 can be reduced.

[0115] <<Second Protective Film Forming Process S4>>

[0116] like Figure 14 As shown, a second protective film 52 is formed in grooves 221 and 231.

[0117] In this embodiment, the second protective film 52 is a resin film formed from resin. The second protective film 52 is formed by filling resin into grooves 221 and 231.

[0118] <<Second Dry Etching Process S5>>

[0119] like Figure 15 As shown, the quartz substrate 20 is dry-etched from the first substrate surface 20A side through the second protective film 52, thereby forming the first surface 2A of the first vibrating arm 22 and the second vibrating arm 23 and the outline of the vibrating substrate 2.

[0120] In this embodiment, the second dry etching process S5 ends with the first protective film 51a remaining on the first substrate surface 20A of the quartz substrate 20. That is, the embankment formation region Qd1 of the first substrate surface 20A is protected by the first protective film 51a and is not etched in the first dry etching process S3 and the second dry etching process S5. In the first protective film removal process S6 described later, the embankment formation region Qd1 of the first substrate surface 20A becomes the first surface 2A of the first vibrating arm 22 and the second vibrating arm 23. In addition, "the state in which the first protective film 51a remains" means "the state in which at least a portion of the first protective film 51a remains". For example, in this embodiment, at the end of the second dry etching process S5, the first metal film 511 and the second metal film 512 constituting the first protective film 51a remain on the first substrate surface 20A, but the second metal film 512 may also be removed.

[0121] When the second dry etching process S5 ends, the process moves to the first protective film removal process S6.

[0122] The first protective film removal process S6, the second protective film removal process S7, and the electrode formation process S8 are the same as in Embodiment 1, so the description is omitted.

[0123] Thus, vibration element 1 is obtained.

[0124] According to this embodiment, in addition to the effects of embodiment 1, the following effects can also be obtained.

[0125] By making the first protective film 51a formed in the dike forming region Qd1 a metal film, the dimensional accuracy of the first vibrating arm and the second vibrating arms 22, 23 and the grooves 221, 231, etc. can be improved.

[0126] The manufacturing method of the vibration element 1 has been described above according to Embodiments 1 and 2. However, the present invention is not limited thereto, and the structure of each part can be replaced with any structure having the same function. In addition, other arbitrary components can be added to the present invention. Furthermore, the embodiments can be appropriately combined.

[0127] For example, at least one of the first protective film 51 and the second protective film 52 may be a resin film.

[0128] Alternatively, for example, at least one of the first protective film 51 and the second protective film 52 may be a metal film.

[0129] Furthermore, for example, the fourth protective film 57 may not be formed in the interarm region Q4 of the first substrate surface 20A. That is, the interarm region Q4 of the first substrate surface 20A may also be exposed. In other words, the protective film may not be formed in the interarm region Q4 of the first substrate surface 20A.

[0130] Furthermore, for example, the fourth protective film 57 may not be formed in the inter-component region Q5 on the first substrate surface 20A. That is, the inter-component region Q5 on the first substrate surface 20A may also be exposed. In other words, the protective film may not be formed in the inter-component region Q5 on the first substrate surface 20A.

[0131] Furthermore, for example, in addition to the bottomed grooves 221 and 231 that open on the first surface 2A of the first vibrating arm 22 and the second vibrating arm 23, the vibrating element 1 may also have a bottomed groove that opens on the second surface 2B. That is, the manufacturing method of the vibrating element 1 can also be applied to vibrating elements that have bottomed grooves on the first surface 2A and the second surface 2B of the first vibrating arm 22 and the second vibrating arm 23, respectively.

[0132] Furthermore, the vibration element manufactured by the manufacturing method of the vibration element of the present invention is not particularly limited.

[0133] The vibration element manufactured using the manufacturing method of the vibration element of the present invention may be, for example, a... Figure 16 and Figure 17 The double tuning fork type vibrating element 7 is shown. In... Figure 16 and Figure 17The electrodes are omitted from the diagram. The double tuning fork type vibrating element 7 has a pair of bases 711 and 712 and a first vibrating arm 72 and a second vibrating arm 73 connecting the bases 711 and 712. The first vibrating arm 72 and the second vibrating arm 73 have a first surface 7A and a second surface 7B in a positive-negative relationship. Furthermore, the first vibrating arm 72 and the second vibrating arm 73 each have bottomed grooves 721 and 731 that open on the first surface 7A, and embankments 725 and 735 that define the grooves 721 and 731, respectively.

[0134] Alternatively, for example, the vibrating element can also be Figure 18 , Figure 19 and Figure 20 The gyroscope oscillating element 8 is shown. Additionally, in... Figure 18 , Figure 19 and Figure 20 The electrodes are omitted from the diagram. The gyroscope vibration element 8 has a base 81, a pair of detection vibration arms 82 and 83 extending from the base 81 in the Y direction, a pair of connecting arms 84 and 85 extending from the base 81 in the X direction, drive vibration arms 86 and 87 extending from the front end of the connecting arm 84 in the Y direction, and drive vibration arms 88 and 89 extending from the front end of the connecting arm 85 in the Y direction. In this gyroscope vibration element 8, when the drive vibration arms 86, 87, 88, and 89 are directed towards... Figure 18 When the angular velocity ωz around the Z-axis is applied under the bending vibration state in the direction of arrow SD, the Coriolis force re-excites the detection vibration arms 82 and 83 to bend in the direction of arrow SS, and the angular velocity ωz is detected based on the charge output from the detection vibration arms 82 and 83 through this bending vibration.

[0135] The detection vibrating arms 82 and 83 and the driving vibrating arms 86, 87, 88, and 89 have a first surface 8A and a second surface 8B in a positive-negative relationship. Furthermore, the detection vibrating arms 82 and 83 have bottomed grooves 821 and 831 opening on the first surface 8A, and embankments 825 and 835 defining the grooves 821 and 831. Similarly, the driving vibrating arms 86, 87, 88, and 89 have bottomed grooves 861, 871, 881, and 891 opening on the first surface 8A, and embankments 865, 875, 885, and 895 defining the grooves 861, 871, 881, and 891. In this gyroscope vibration element 8, for example, the driving vibrating arms 86 and 88 or the driving vibrating arms 87 and 89 become the first vibrating arm and the second vibrating arm, respectively.

[0136] Alternatively, for example, the vibrating element can also be Figure 21 , Figure 22 as well as Figure 23 The gyroscope oscillating element 9 is shown. Additionally, in... Figure 21 , Figure 22 as well as Figure 23The electrodes are omitted from the diagram. The gyroscope vibration element 9 has a base 91, a pair of driving vibration arms 92 and 93 extending from the base 91 in the positive Y direction and arranged in the X direction, and a pair of detection vibration arms 94 and 95 extending from the base 91 in the negative Y direction and arranged in the X direction. In this gyroscope vibration element 9, when the driving vibration arms 92 and 93 are directed towards... Figure 21 When the angular velocity ωy around the Y-axis is applied under the bending vibration state in the direction of arrow SD, the bending vibration in the direction of arrow SS is re-excited on the detection vibration arms 94 and 95 by the Coriolis force, and the angular velocity ωy is detected based on the charge output from the detection vibration arms 94 and 95 through this bending vibration.

[0137] The driving vibration arms 92 and 93 and the detecting vibration arms 94 and 95 have a first surface 9A and a second surface 9B in a positive-negative relationship. Furthermore, the driving vibration arms 92 and 93 have bottomed grooves 921 and 931 and delineating grooves 921 and 931 that open on the first surface 9A. Similarly, the detecting vibration arms 94 and 95 have bottomed grooves 941 and 951 and delineating grooves 941 and 951 that open on the first surface 9A. In this gyroscope vibration element 9, the driving vibration arms 92 and 93 or the detecting vibration arms 94 and 95 become the first vibration arm and the second vibration arm, respectively.

Claims

1. A method for manufacturing a vibrating element, the vibrating element having a first vibrating arm and a second vibrating arm extending along a first direction and arranged along a second direction intersecting the first direction, the first vibrating arm and the second vibrating arm each having a first surface and a second surface, and a bottomed groove opening in the first surface, the first surface and the second surface being arranged in a positive-negative relationship in a third direction intersecting the first direction and the second direction. The manufacturing method includes: Preparation process: Prepare a quartz substrate with a first substrate surface and a second substrate surface that are in a positive and negative relationship. In the first protective film forming process, a first protective film is formed in the areas other than the groove forming area that forms the groove in the first vibration arm forming area and the second vibration arm forming area that forms the second vibration arm on the first substrate surface. The first dry etching process involves dry etching the quartz substrate from the first substrate side through the first protective film to form the groove and the shapes of the first and second vibrating arms, ending when the groove reaches the desired depth. The second protective film forming process involves forming a second protective film in the groove formed by the first dry etching process; as well as In the second dry etching process, the quartz substrate is dry etched from the first substrate side through the first protective film and the second protective film to form the first surface, and the shape is formed until the depth of the shape of the first vibrating arm and the second vibrating arm formed by the first dry etching process is deeper than the depth of the groove formed by the first dry etching process.

2. The method for manufacturing a vibrating element according to claim 1, wherein, At least one of the first protective film and the second protective film is a resin film.

3. The method for manufacturing a vibrating element according to claim 1, wherein, At least one of the first protective film and the second protective film is a metal film.

4. The method for manufacturing a vibrating element according to any one of claims 1 to 3, wherein, In the first protective film forming process, a third protective film with a thickness thinner than the first protective film is formed in the groove forming area.

5. A method for manufacturing a vibrating element according to any one of claims 1 to 3, wherein, In the first protective film forming process, a fourth protective film with a thickness thinner than the first protective film is formed in the inter-arm region on the first substrate surface located between the first vibration arm forming region and the second vibration arm forming region.

6. A method for manufacturing a vibrating element according to any one of claims 1 to 3, wherein, No protective film is formed in the inter-arm region on the first substrate surface located between the first vibration arm forming region and the second vibration arm forming region.

7. A method for manufacturing a vibrating element according to any one of claims 1 to 3, wherein, In the second dry etching process, the dry etching is completed while the first protective film remains on the surface of the first substrate. The manufacturing method further includes a protective film removal step to remove any residue of the first protective film.

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