JP6043588B2 - Quartz vibrating element and method for manufacturing the same - Google Patents

Description

  The present invention relates to a crystal resonator element used in an electronic device or the like and a manufacturing method thereof.

  In an electronic device such as a computer, a mobile phone, or a small information device, a crystal resonator or a crystal oscillator is mounted as one of electronic components. This crystal resonator or crystal oscillator is used as a reference signal source or a clock signal source. In addition, a crystal resonator element is included inside the crystal resonator and the crystal oscillator. As an example of the crystal resonator element, a tuning fork-type bent crystal resonator element (hereinafter abbreviated as “vibrator element”) is taken up.

  Patent Document 1 discloses a vibration element in which a protrusion having a slit is provided on the crotch of two vibrating arm portions. The slit plays a role of preventing a short circuit of the electrode film when the electrode film is formed on the vibrating arm portion by a lift-off method. This vibration element is referred to as the vibration element of Related Art 1. FIG. 9 is a plan view showing a resonator element according to Related Technique 1. FIG. Hereinafter, description will be given based on this drawing.

  The vibration element 80 of the related technology 1 is extended from a base 81, two vibration arm portions 82a and 82b extending in the same direction from the base portion 81, and a base portion 81 between the vibration arm portions 82a and 82b. And a slit 84 drilled from the inside of the projection 83 to the outer edge in the same direction as the extending direction 801 of the vibrating arm portions 82a and 82b. Groove portions 85a and 85b are formed in the vibrating arm portions 82a and 82b, respectively. The base portion 81, the vibrating arm portions 82 a and 82 b, and the protruding portion 83 constitute a crystal vibrating piece 86. The vibration element 80 includes pad electrodes 91a and 91b, excitation electrodes 92a and 92b, frequency adjusting metal films 93a and 93b, and wiring patterns 94a and 94b in addition to the crystal vibrating piece 86.

  A slit 84 is provided along the extending direction 801 on the distal end side of the protrusion 83. The slit 84 penetrates in the thickness direction of the protrusion 83. When the excitation electrodes 92a and 92b are formed on the side surfaces of the vibrating arm portions 82a and 82b by the lift-off method, the slit 84 is formed on the side surfaces of the vibrating arm portion 82a and the excitation electrode 92b on the side surface of the vibrating arm portion 82b. It works to cut off.

  Next, in order to explain the operation of the slit 84, a method for manufacturing the vibration element 80 will be briefly described.

  First, a corrosion resistant film (not shown) is formed on the front and back of a quartz wafer (not shown) by sputtering. Subsequently, a photosensitive resist (positive type) is formed on the corrosion-resistant film on the front and back surfaces of the quartz wafer, and the photosensitive resist is patterned (exposed, developed, and dried) so that a tuning-fork-shaped corrosion-resistant film remains on both surfaces. The anticorrosion film other than the tuning fork shape is removed by etching.

  Subsequently, a photosensitive resist (positive type) is patterned again on the front and back corrosion-resistant films in order to determine the shape of the electrodes. The crystal portion that becomes the slit 84 is directly covered with a photosensitive resist without passing through the corrosion-resistant film.

  Subsequently, the exposed crystal portion is removed by wet etching. At this time, the shape of the slit 84 and the outer shape of the quartz crystal vibrating piece 86 are simultaneously formed. That is, the base 81, the vibrating arm portions 82a and 82b, and the protrusion 83 are formed with the photosensitive resist remaining. Note that the photosensitive resist covering the projection 83 is left in a state of straddling the slit 84.

  Subsequently, the corrosion-resistant film exposed on the front and back surfaces of the crystal vibrating piece 86 is removed by etching. Thereby, a crystal surface is obtained.

  Subsequently, an electrode film (not shown) is formed on the entire surface of the quartz crystal vibrating piece 86 with the photosensitive resist left by sputtering. At this time, an electrode film is formed on the side surface of the protrusion 83 across the slit 84 by the photosensitive resist covering the protrusion 83. This is because the slit 84 is covered with a photosensitive resist and the side gap is narrow, and therefore no electrode film is formed in the slit 84.

  Subsequently, the photosensitive resist formed on the front and back surfaces of the quartz crystal vibrating piece 86 and the electrode film formed thereon are peeled off. This is realized by immersing these in a solution for dissolving the photosensitive resist. At this time, since the photosensitive resist straddling the slit 84 is also removed, the excitation electrode 92a on the side surface of the vibrating arm portion 82a and the side surface of the vibrating arm portion 82b connected via the electrode film on the photosensitive resist are removed. The excitation electrode 92b is cut off.

  Finally, the corrosion-resistant film remaining under the photosensitive resist is removed by etching.

  In this way, since the electrodes are formed on the crystal vibrating piece 86, the slits 84 connect the excitation electrode 92a on the side surface of the vibrating arm portion 82a and the excitation electrode 92b on the side surface of the vibrating arm portion 82b even if the lift-off method is used. It can be in a disconnected state.

JP 2011-151567 A JP 2004-236008 A

  However, the vibration element 80 of Related Art 1 has the following problems.

  As the protrusion 83 is longer or larger with respect to the extending direction 801 of the vibrating arms 82a and 82b, spurious is more likely to occur. This is presumably because parasitic vibration occurs because the shape of the projection 83 with the slit 84 is similar to the vibration arm portions 82a and 82b.

  In the step of forming the crystal vibrating piece 86 by wet etching, an etching residue due to the crystal axis anisotropy of the etching rate is likely to be generated around the protrusion 83. As a result, the etching residue generated in the left and right vibrating arm portions 82a and 82b in different sizes and shapes is added to the etching residue of the projection 83 in the middle thereof, so that the rigidity of the left and right vibrating arm portions 82a and 82b is increased. As a result of being unbalanced, adverse effects such as an increase in CI (Crystal Impedance) occur. This is presumably because the protrusion 83 promotes the generation of etching residues by preventing the flow of the etching solution.

  On the other hand, Patent Document 2 discloses a vibrating element in which a slit along the extending direction of the vibrating arm portion is provided in the crotch (base) of the two vibrating arm portions. Hereinafter, this vibrating element is referred to as a vibrating element according to Related Technique 2. The slits in the vibration element of Related Art 2 are not used for the lift-off method, but are for suppressing this effect when a difference in rigidity occurs between the left and right vibrating arms due to etching anisotropy.

  In order to apply such a structure in which a slit is formed in the base portion to the related technique 1 and use it in the lift-off method, the slit must be elongated to some extent. This is because the electrode cannot be cut with a short slit. Then, the following problems occur.

  (1) Since the slit reaches the vicinity of the center of the base, the impact resistance of the base is lowered by the slit becoming the starting point of breakage. (2) The left and right vibrating arms exchange their vibration energies with each other at the base, but the CI increases because the slits block this exchange. (3) Since the wiring pattern is routed around the base while avoiding the slit, the area occupied by the wiring pattern increases.

  To solve these problems, the base must be enlarged to some extent. This is contrary to the recent demand for downsizing of the vibration element, and it is technically meaningless to combine the related technology 1 with the related technology 1.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a vibrating element having a slit suitable for the lift-off method, which is less prone to spurious and less susceptible to etching residue, and a method for manufacturing the vibrating element.

The vibration element according to the present invention is
A base having a pad electrode for voltage application ;
Two vibrating arms extending in the same direction from this base,
A protrusion extending from the base between these two vibrating arms,
A slit drilled from the inside of this protrusion to the outer edge;
An electrode film formed on the two vibrating arms and separated by the slit;
A quartz crystal resonator element comprising :
The slit is
Drilled in a direction different from the extending direction of the vibrating arm part,
The two vibrating arm portions are equidistant from each other and provided one by one symmetrically with respect to the center line along the extending direction.
It is characterized by that .

The method for manufacturing a vibration element according to the present invention includes:
A method for producing a resonator element according to the invention,
A first step of forming and patterning a corrosion-resistant film on a quartz substrate;
A second step of forming a resist pattern on the corrosion-resistant film and on the exposed portion of the quartz crystal substrate serving as the slit;
A third step of forming a quartz crystal vibrating piece composed of the base, the vibrating arm, the protrusion, and the slit by removing an exposed portion of the quartz substrate not covered with the corrosion-resistant film by wet etching;
A fourth step of removing the corrosion-resistant film not covered with the resist pattern;
A fifth step of forming an electrode film on the exposed portion of the crystal vibrating piece excluding the inside of the slit and on the resist pattern;
A sixth step of removing the electrode film formed on the resist pattern together with the resist pattern;
A seventh step of removing the corrosion-resistant film exposed by removing the resist pattern;
It is characterized by including.

  According to the present invention, by providing the slit drilled from the inner side of the protrusion to the outer edge in a direction different from the extending direction of the vibrating arm part, the protruding part is shortened with respect to the extending direction of the vibrating arm part Can be small. As a result, parasitic vibrations at the protrusions are reduced, and spurious generation can be suppressed. In addition, since the flow of the etching solution is improved by the amount of the projection portion being shorter or smaller, the influence of the etching residue can be reduced.

FIG. 3 is a plan view showing the resonator element according to the first embodiment. It is the elements on larger scale which show the protrusion part periphery in FIG. It is the III-III line longitudinal cross-sectional view in FIG. FIG. 4 is a cross-sectional view showing a manufacturing process of a vertical cross section taken along line IV-IV in FIG. 1, and the processes proceed in the order of FIGS. It is sectional drawing which shows the manufacturing process of the IV-IV line longitudinal cross section in FIG. 1, and a process progresses in order of FIG. 5 [5], FIG. 5 [6], and FIG. 6 is a plan view showing a vibration element according to Embodiment 2. FIG. It is the elements on larger scale which show the protrusion part periphery in FIG. FIG. 6 is a plan view illustrating a vibration element according to a third embodiment. FIG. 12 is a plan view showing a vibration element of Related Art 1.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “embodiments”) will be described with reference to the accompanying drawings. In addition, since the shape drawn in drawing is drawn so that those skilled in the art can understand easily, it does not necessarily correspond with an actual dimension and ratio.

  FIG. 1 is a plan view illustrating the vibration element according to the first embodiment. FIG. 2 is a partially enlarged view showing the periphery of the protrusion in FIG. 3 is a vertical sectional view taken along line III-III in FIG. Hereinafter, description will be given based on these drawings.

  The vibration element 10 of the first embodiment is extended from the base 11, the two vibrating arms 12a and 12b extending from the base 11 in the same direction, and the base 11 between the vibrating arms 12a and 12b. And the slits 14a and 14b drilled from the inner side to the outer edge of the projecting part 13 in a direction different from the extending direction 101 of the vibrating arm parts 12a and 12b.

  The slits 14 a and 14 b are provided one by one symmetrically with respect to the center line 102 that is equidistant from the vibrating arm portions 12 a and 12 b and extends in the extending direction 101. The slitting directions 10a and 10b of the slits 14a and 14b are perpendicular to the extending direction 101, respectively.

  The slits 14 a and 14 b are provided at the boundary between the protrusion 13 and the base 11 in the protrusion 13. The shape of the slits 14a and 14b is not limited to a linear shape as shown in the figure, but may be a curved shape or a broken line shape. The shape of the protrusion 13 including the slits 14a and 14b is a rectangular shape in which the extending direction 101 is a short side and the direction perpendicular to the extending direction 101 is a long side.

  Groove portions 15a and 15b are formed in the vibrating arm portions 12a and 12b, respectively. The base portion 11, the vibrating arm portions 12 a and 12 b, and the protruding portion 13 constitute a crystal vibrating piece 16. In addition to the crystal vibrating piece 16, the vibration element 10 includes pad electrodes 21a and 21b, excitation electrodes 22a and 22b, frequency adjusting metal films 23a and 23b, wiring patterns 24a and 24b, and the like.

  Next, the configuration of the vibration element 10 will be described in more detail.

  The base 11 is a flat plate having a substantially rectangular shape in plan view. The quartz crystal resonator element 16 has a tuning fork shape in which the base 11 and the vibrating arms 12a and 12b are integrated, and is manufactured by a film forming technique, a photolithography technique, and a chemical etching technique.

  Groove portions 15a and 15b may be provided in the length direction of the vibrating arm portions 12a and 12b, respectively. The groove portions 15a and 15b are, for example, two on the front and back surfaces of the vibrating arm portion 12a and two on the front and back surfaces of the vibrating arm portion 12b, from the boundary portion with the base 11 to the tip of the vibrating arm portions 12a and 12b. Thus, the vibrating arms 12a and 12b are provided with a predetermined length in parallel with the length direction. In the first embodiment, two grooves 15a and 15b are provided on the front and back surfaces of the vibrating arm 12a and two grooves on the front and back surfaces of the vibrating arm 12b. However, the number of the grooves 15a and 15b is not limited. For example, one may be provided on the front and back surfaces of the vibrating arm portion 12a and one on each of the front and back surfaces of the vibrating arm portion 12b, or may be provided on only one side of the front and back surfaces.

  Excitation electrodes 22a are provided on both side surfaces of the vibrating arm 12a so that the planes facing each other across the crystal have the same polarity, and excitation is provided inside the groove 15a on the front and back surfaces and between the two grooves 15a. An electrode 22b is provided. Similarly, the vibrating arm portion 12b is provided with excitation electrodes 22b on both side surfaces so that the planes facing each other across the crystal have the same polarity, and inside the groove portion 15b on the front and back surfaces and on the two groove portions 15b. An excitation electrode 22a is provided between them. Therefore, in the vibrating arm portion 12a, the excitation electrode 22a provided on both sides and the excitation electrode 22b provided in the groove 15a have different polarities, and in the vibrating arm portion 12b, the excitation electrode 22b provided on both sides. And the excitation electrode 22a provided in the groove 15b have different polarities.

  The base 11 is provided with pad electrodes 21a and 21b and wiring patterns 24a and 24b that electrically connect the pad electrodes 21a and 21b and the excitation electrodes 22a and 22b. The pad electrode 21a, the excitation electrode 22a, the frequency adjusting metal film 23a, and the wiring pattern 24a are electrically connected to each other. The pad electrode 21b, the excitation electrode 22b, the frequency adjusting metal film 23b, and the wiring pattern 24b are also electrically connected to each other. However, the metal film 22c on the side surface of the protrusion 13 is not connected anywhere.

  The pad electrodes 21a and 21b, the excitation electrodes 22a and 22b, the frequency adjusting metal films 23a and 23b, the wiring patterns 24a and 24b, and the metal film 22c are formed from the same metal film by a lift-off method, for example, Pd on the Ti layer. Or it has a laminated structure in which an Au layer is provided.

  When the tuning fork type vibration element 10 is vibrated, an alternating voltage is applied to the pad electrodes 21a and 21b. When an electrical state after application is instantaneously captured, the excitation electrodes 22b provided in the groove portions 15a on the front and back of the vibrating arm portion 12a have a positive potential, and the excitation electrodes 22a provided on both side surfaces of the vibrating arm portion 12a are A negative electric potential is generated, and an electric field is generated from positive to negative. At this time, the excitation electrodes 22a provided in the groove portions 15b on the front and back of the vibrating arm portion 12b have a negative potential, and the excitation electrodes 22b provided on both side surfaces of the vibrating arm portion 12b have a positive potential, and are generated in the vibrating arm portion 12a. The polarity is opposite to the polarity, and an electric field is generated from plus to minus. The electric field generated by the alternating voltage causes a stretching phenomenon in the vibrating arm portions 12a and 12b, and a flexural vibration mode having a predetermined resonance frequency is obtained.

  The slits 14a and 14b penetrate in the thickness direction of the protrusion 13, and when the excitation electrodes 22a and 22b are formed on the side surfaces of the vibrating arm portions 12a and 12b by the lift-off method, the side surfaces of the vibrating arm portion 12a are excited. It plays a role of separating the electrode 22a from the excitation electrode 22b on the side surface of the vibrating arm portion 12b.

  4 and 5 are cross-sectional views at each step corresponding to the vertical cross section taken along line IV-IV in FIG. Hereinafter, a method for manufacturing the vibration element 10 will be described with reference to FIGS. 1 to 5.

  The manufacturing method of Embodiment 1 includes the following first to seventh steps.

  In the first step shown in FIG. 4 [1], a corrosion-resistant film 32 is formed on the quartz substrate 31 and patterned. For example, a corrosion-resistant film 32 such as Cr or Cr + Au is formed on the front and back of the quartz substrate 31 by sputtering. Then, a photosensitive resist (positive type) is formed on the corrosion-resistant film 32, and the photosensitive resist is patterned (exposed, developed, and dried) so that the tuning-fork-shaped corrosion-resistant film 32 remains on the front and back of the quartz substrate 31. The anticorrosion film 32 other than the tuning fork shape is removed by etching.

  In the second step shown in FIG. 4 [2], a resist pattern 33 is formed on the corrosion-resistant film 32 and on the exposed portion 311 of the quartz substrate 31 that becomes the slits 14a and 14b. For example, a photosensitive resist (positive type) is patterned in order to determine the shape of the electrodes on the corrosion-resistant films 32 on the front and back surfaces of the quartz substrate 31.

  In the third step shown in FIG. 4 [3], the quartz vibrating piece 16 is formed by removing the exposed portion of the quartz substrate 31 that is not covered with the corrosion-resistant film 32 by wet etching. At this time, the slits 14 a and 14 b are formed at the same time as the crystal vibrating piece 16, and are formed by under-etching from below the resist pattern 33. Therefore, the resist pattern 33 is left at least on the protrusion 13 in a state of straddling the slits 14a and 14b. That is, the base 11, the vibrating arms 12a and 12b, and the protrusion 13 are formed with the resist pattern 33 remaining.

  In addition, when providing the groove parts 15a and 15b in the vibrating arm parts 12a and 12b, the groove parts 15a and 15b may be formed simultaneously with the shape of the crystal vibrating piece 16 in this third step. However, when the groove portions 15a and 15b are provided on the front and back surfaces of the vibrating arm portions 12a and 12b, it is desirable to form an etching suppression pattern in the groove portions 15a and 15b in order to avoid penetration of the groove portions 15a and 15b.

  In the fourth step shown in FIG. 4 [4], the corrosion resistant film 32 not covered with the resist pattern 33 is removed. That is, the crystal surface is obtained by removing the corrosion-resistant film 32 exposed on the front and back surfaces of the crystal vibrating piece 16 by etching.

  In the fifth step shown in FIG. 5 [5], the electrode film 34 is formed on the exposed portion of the crystal vibrating piece 16 and the resist pattern 33 except for the inside of the slits 14a and 14b. For example, the electrode film 34 is formed on the entire surface of the crystal vibrating piece 16 by sputtering. At this time, the electrode film 34 is formed on the side surface of the protrusion 13 across the slits 14a and 14b by the resist pattern 33 covering the protrusion 13 across the slits 14a and 14b. However, the slits 14a and 14b have a planar gap covered with the resist pattern 33 and a side gap that is narrow, so that the electrode film 34 is not formed in the slits 14a and 14b. Note that a film forming method such as vapor deposition may be used instead of sputtering.

  In the sixth step shown in FIG. 5 [6], the electrode film 34 formed on the resist pattern 33 is removed together with the resist pattern 33. That is, the resist pattern 33 formed on the front and back sides of the crystal vibrating piece 16 and the electrode film 34 formed thereon are peeled off. This can be easily removed by immersing them in a solution (for example, acetone) for dissolving the photosensitive resist. However, the corrosion resistant film 32 under the resist pattern 33 remains. Since the resist pattern 33 straddling the slits 14a and 14b is also removed, the excitation electrode 22a on the side surface of the vibrating arm portion 12a and the excitation electrode 22b on the side surface of the vibrating arm portion 12b are cut by the slits 14a and 14b. . This electrode film forming method in the sixth step is called a lift-off method.

  In the seventh step shown in FIG. 5 [7], the corrosion-resistant film 32 exposed by removing the resist pattern 33 is removed. That is, the corrosion-resistant film 32 remaining until the end is removed by etching.

  Thus, since the excitation electrodes 22a and 22b are formed on the crystal vibrating piece 16, the excitation electrode 22a on the side surface of the vibrating arm portion 12a and the excitation electrode 22b on the side surface of the vibrating arm portion 12b can be connected even if the lift-off method is used. It can be formed in a state cut by the slits 14a and 14b.

  Next, the action and effect when the vibration element 10 of the first embodiment is compared with the related technique 1 will be described.

  According to the resonator element 10 of the first embodiment, the slits 14a formed from the inner side of the protrusion 13 to the outer edge in a direction different from the extending direction 101 of the vibrating arm portions 12a and 12b (the drilling directions 10a and 10b). By providing 14b, the protrusion 13 can be made shorter or smaller with respect to the extending direction 101 of the vibrating arms 12a, 12b. Therefore, since the parasitic vibration at the protrusion 13 is reduced, the occurrence of spurious can be suppressed. Moreover, since the protrusion 13 is shorter or smaller, the flow of the etching solution is improved in the above-described third step, so that the influence of etching residues can be reduced.

  When the slits 14a and 14b are provided one by one symmetrically with respect to the center line 102, the following effects are obtained. Since the vibrating element 10 is symmetric with respect to the center line 102, the balance between the vibrating arm portions 12a and 12b is improved, so that the CI decreases. Further, even if one of the slits 14a and 14b is short-circuited, if the other is opened, the product is electrically good, so that the manufacturing yield can be improved.

  When the slits 14a and 14b are formed in directions 10a and 10b that are perpendicular to the extending direction 101, the protrusion 13 can be made the shortest in the extending direction 101, so that spurious generation can be further suppressed. Further, the influence of etching residue can be further reduced.

  FIG. 6 is a plan view showing the resonator element according to the second embodiment. FIG. 7 is a partially enlarged view showing the periphery of the protrusion in FIG. Hereinafter, description will be given based on these drawings.

  The vibration element 40 according to the second embodiment is extended from the base 11, the two vibrating arms 12a and 12b extending from the base 11 in the same direction, and the base 11 between the vibrating arms 12a and 12b. And the slits 44a and 44b drilled from the inner side of the projection 43 to the outer edge in a direction different from the extending direction 101 of the vibrating arm portions 12a and 12b.

  The slits 44 a and 44 b are provided one by one symmetrically with respect to the center line 102 that is equidistant from the vibrating arm portions 12 a and 12 b and extends in the extending direction 101. The drilling directions 40a and 40b of the slits 44a and 44b are acute angles with respect to the extending direction 101, respectively.

  The slits 44 a and 44 b are provided at the boundary between the protrusion 43 and the base 11 in the protrusion 43. The shape of the slits 44a and 44b is not limited to the linear shape as illustrated, but may be a curved shape or a polygonal shape. The shape of the protrusion 43 including the slits 44 a and 44 b is an inverted isosceles triangle shape in which the direction perpendicular to the extending direction 101 is the base and the oblique direction to the extending direction 101 is two sides.

  According to the resonator element 40 of the second embodiment, the slits 44a and 44b are formed in the drilling directions 40a and 40b at an acute angle with respect to the extending direction 101, so that the inner side surfaces of the vibrating arms 12a and 12b and the slits 44a and 44b Since the angle formed with 44b can be made obtuse (see FIG. 6), the etching solution can easily enter the slits 44a and 44b and the vicinity thereof, thereby further reducing the etching residue. Further, since the slits 44a and 44b can be formed longer than when the slits are formed at a right angle, the electrode material entering the slits 44a and 44b can be reduced, so that the electrodes can be cut more reliably. Other configurations, operations, and effects of the second embodiment are the same as those of the first embodiment.

  FIG. 8 is a plan view illustrating the resonator element according to the third embodiment. Hereinafter, description will be given based on this drawing.

  In the vibration element 50 of the third embodiment, cut portions 51 a and 51 b are provided on the vibration arm portions 12 a and 12 b side of the base portion 11, respectively. The cut portions 51a and 51b have an effect of preventing vibration from leaking from the vibrating arm portions 12a and 12b to the pad electrodes 21a and 21b.

  In the structure in which the slit is formed toward the center of the base in the related art 1, if the cut portions are formed on the left and right sides of the base, cracks are easily formed from three directions, so that the impact resistance is significantly reduced. On the other hand, according to the third embodiment, since the slits 44a and 44b are not formed toward the center of the base portion 11, the slits 44a and 44b are formed even if the cut portions 51a and 51b are inserted on the left and right sides of the base portion 11. The resulting impact resistance does not decrease. Other configurations, operations, and effects of the third embodiment are the same as those of the first and second embodiments.

  Although the present invention has been described with reference to the above embodiments, the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention. Further, the present invention includes a combination of some or all of the configurations of the above-described embodiments as appropriate.

DESCRIPTION OF SYMBOLS 10 Vibration element 101 Extension direction 102 Center line 10a, 10b Drilling direction 11 Base part 12a, 12b Vibration arm part 13 Projection part 14a, 14b Slit 15a, 15b Groove part 16 Quartz crystal vibration piece 21a, 21b Pad electrode 22a, 22b Excitation electrode 22c Metal film 23a, 23b Frequency adjusting metal film 24a, 24b Wiring pattern 31 Quartz substrate 311 Exposed portion 32 Corrosion resistant film 33 Resist pattern 34 Electrode film

40 Vibrating elements 40a, 40b Drilling direction 43 Protruding parts 44a, 44b Slit 50 Vibrating elements 51a, 51b Notches

DESCRIPTION OF SYMBOLS 80 Vibrating element 801 Extension direction 81 Base part 82a, 82b Vibrating arm part 83 Protrusion part 84 Slit 85a, 85b Groove part 86 Crystal vibrating piece 91a, 91b Pad electrode 92a, 92b Excitation electrode 93a, 93b Frequency adjustment metal film 94a, 94b Wiring pattern

Claims (4)

A base having a pad electrode for voltage application ;
Two vibrating arms extending in the same direction from this base,
A protrusion extending from the base between these two vibrating arms,
A slit drilled from the inside of this protrusion to the outer edge;
An electrode film formed on the two vibrating arms and separated by the slit;
A quartz crystal resonator element comprising :
The slit is
Drilled in a direction different from the extending direction of the vibrating arm part,
The two vibrating arm portions are equidistant from each other and provided one by one symmetrically with respect to the center line along the extending direction.
A crystal resonator element characterized by the above . The drilling directions of the two slits are perpendicular to the extending direction, respectively.
The crystal resonator element according to claim 1 . The drilling directions of the two slits are acute angles with respect to the extending direction, respectively.
The crystal resonator element according to claim 1 . A method for manufacturing the crystal resonator element according to any one of claims 1 to 3 ,
A first step of forming and patterning a corrosion-resistant film on a quartz substrate;
A second step of forming a resist pattern on the corrosion-resistant film and on the exposed portion of the quartz crystal substrate serving as the slit;
A third step of forming a quartz crystal vibrating piece composed of the base, the vibrating arm, the protrusion, and the slit by removing an exposed portion of the quartz substrate not covered with the corrosion-resistant film by wet etching;
A fourth step of removing the corrosion-resistant film not covered with the resist pattern;
A fifth step of forming an electrode film on the exposed portion of the crystal vibrating piece excluding the inside of the slit and on the resist pattern;
A sixth step of removing the electrode film formed on the resist pattern together with the resist pattern;
A seventh step of removing the corrosion-resistant film exposed by removing the resist pattern;
A method for manufacturing a crystal resonator element, comprising:

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