JP6163379B2 - Method for manufacturing crystal resonator element - Google Patents

Description

  The present invention relates to a crystal resonator element used for a reference signal source, a clock signal source, and the like and a manufacturing method thereof, and more particularly to a tuning fork-type bent crystal resonator element (hereinafter abbreviated as “vibrator element”).

  The crystal piece of the vibration element includes a base, two vibration arm portions extending from the base in the same direction, and groove portions formed on the front and back surfaces of the vibration arm portions. This crystal piece is obtained by performing wet etching on a crystal wafer. The general wet etching process is divided into a process of forming the outer shape of the base part and the vibrating arm part and a process of forming the groove part. This is because if both the outer shape and the groove portion are formed by one wet etching, the groove portion penetrates on the front and back sides.

  Among such vibration elements, one having a through hole in a groove is known. For example, Patent Document 1 discloses a vibrating element in which a through hole is provided in a groove near the base of a vibrating arm (see FIG. 2). According to the technique of Patent Document 1, the crystal impedance is reduced by increasing the lines of electric force by the electrodes in the through holes (paragraph 0011 of the publication). Patent Document 1 does not describe a manufacturing method.

  Further, Patent Document 2 discloses a vibrating element in which a through hole is provided in a groove near the middle of a vibrating arm (see FIGS. 1 and 5). This through hole is provided at a position closer to the base than at a position intermediate in the length of the entire groove. According to the technique of Patent Document 2, by providing a through-hole in the node of the vibrating arm portion, double vibration based on the node can be stably obtained (paragraph 0033 of the same publication), and the electrode is connected through the through-hole. This means that the wiring can be simplified (paragraph 0037 of the publication). The wet etching process described in Patent Document 2 is divided into a process of forming the outer shape and through-holes of the base part and the vibrating arm part, and a process of forming a groove part (FIG. 6 of the publication).

JP 2006-217603 A JP 2010-010734 A

  However, the techniques of Patent Documents 1 and 2 have the following problems.

  (1) In the techniques of Patent Documents 1 and 2, the position of the through hole is closer to the base than the middle position of the entire groove. Therefore, if an attempt is made to provide a through-hole by applying the techniques of Patent Documents 1 and 2 to an existing vibration element that does not have a through-hole in the groove, the frequency characteristic greatly differs from the frequency characteristic of the existing vibration element. There is a risk. The reason is that the portion closer to the base portion of the vibrating arm portion has a greater influence on the frequency characteristics.

  The frequency characteristics here include the oscillation frequency, its temperature characteristics, changes with time, and the like. The main reason why the frequency adjusting metal film is provided on the distal end side of the vibrating arm portion is in the portion far from the base portion in the vibrating arm portion, so that the influence on the frequency characteristics is small and the oscillation frequency can be finely adjusted. Because.

  (2) In recent years, since the vibration element has been further miniaturized, it is difficult to accurately provide a finer through-hole in the fine groove. In particular, in the technique of Patent Document 2, since the photomask in the groove and the photomask in the through hole are different, the position of the through hole in the groove is likely to shift due to an error in mask alignment.

  Accordingly, an object of the present invention is to reduce the influence on the frequency characteristics of an existing vibration element when a through hole is provided in the groove of the existing vibration element, and to accurately insert the through hole in the groove of the vibration element. There is to provide.

The vibration element according to the present invention is
The base,
Two vibrating arms extending in the same direction from this base,
A front side groove part and a back side groove part respectively provided along the extending direction of the vibration arm part on the front and back surfaces of these vibration arm parts;
Excitation electrodes provided in these front side grooves and back side grooves,
A through-hole provided in the front-side groove and in the back-side groove, and penetrating the front-side groove and the back-side groove,
An electrode wiring that is provided in the through-hole and electrically connects the excitation electrode in the front-side groove and the excitation electrode in the back-side groove;
In a vibration element comprising
The through-hole is provided at a position closer to the tip of the vibrating arm portion than an intermediate position of the length in the extending direction of the front-side groove portion and the back-side groove portion,
It is characterized by that.

The manufacturing method according to the present invention includes:
A method for producing a resonator element according to the invention,
A corrosion-resistant film forming step of forming a corrosion-resistant film on the front and back surfaces of the crystal wafer;
A photosensitive resist film forming step of forming a photosensitive resist film on the corrosion-resistant film;
An exposure development process for forming the photosensitive resist film in a predetermined pattern;
A patterning step of creating a mask made of the corrosion resistant film by removing the corrosion resistant film not covered with the photosensitive resist film;
A wet etching step of wet etching the crystal wafer using the mask made of the corrosion-resistant film;
Including
In the exposure and development step, using a single photomask, the photosensitive resist film is left in the region to be the base and the vibrating arm, and the photosensitive resist is to be formed in the region to be the front groove and the back groove. Forming an etching suppression pattern made of a film, and removing the photosensitive resist film in a region to be the through hole;
It is characterized by that.

  According to the vibration element according to the present invention, since the position of the through hole in the groove portion is closer to the tip of the vibration arm portion than the middle position of the groove portion, the through hole is provided in the groove portion of the existing vibration element. In this case, the influence on the frequency characteristics of the existing vibration element can be reduced.

  According to the manufacturing method according to the present invention, when the vibration element according to the present invention is manufactured, the groove portion and the through hole are formed by using a single photomask, so that an error in mask alignment does not occur, so that the fineness is small. A finer through hole can be provided in the groove with high accuracy.

FIG. 3 is a plan view showing the resonator element according to the first embodiment. FIG. 3 is a bottom view showing the resonator element according to the first embodiment. It is the III-III sectional view taken on the line in FIG. It is the IV-IV sectional view taken on the line in FIG. FIG. 3 is a schematic cross-sectional view illustrating a state where the vibration element according to Embodiment 1 is mounted on an element mounting member. It is sectional drawing which shows the manufacturing method of Embodiment 2, and a process advances in order of [1]-> [2]-> [3]. It is sectional drawing which shows the manufacturing method of Embodiment 2, and a process progresses in order of [4]-> [5A] [5B]. It is a top view which expands and shows a part of pattern of the photosensitive resist film in a manufacturing method of Embodiment 2, and a corrosion-resistant film.

  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 the present specification and drawings, the same reference numerals are used for substantially the same components. The shapes depicted in the drawings are drawn so as to be easily understood by those skilled in the art, and thus do not necessarily match the actual dimensions and ratios.

  FIG. 1 is a plan view illustrating the vibration element according to the first embodiment. FIG. 2 is a bottom view showing the resonator element according to the first embodiment. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a schematic cross-sectional view illustrating a state where the vibration element according to the first embodiment is mounted on an element mounting member. Hereinafter, description will be given based on these drawings.

  As shown in FIGS. 1 and 2, the crystal of the crystal is a trigonal system, the crystal axis passing through the apex of the crystal is the Z axis (optical axis), and the three crystal axes connecting the ridge lines in the plane perpendicular to the Z axis. Is an X axis (electrical axis), and a coordinate axis orthogonal to the X axis and the Z axis is a Y axis (mechanical axis). Here, when the coordinate system consisting of these X, Y, and Z axes is rotated within a range of ± 5 degrees around the X axis, the rotated Y axis and Z axis are respectively represented as Y ′ axis and Z axis. 'As axis. In this case, in the first embodiment, the extending direction of the two vibrating arm portions 12a and 12b is the Y′-axis direction, and the direction in which the two vibrating arm portions 12a and 12b are arranged is the X-axis direction.

  The vibrating element 10 according to the first embodiment includes a base 11, two vibrating arms 12a and 12b extending from the base 11 in the Y′-axis direction, and a surface 131 of the vibrating arm 12a in the Y′-axis direction. The front side groove portions 141a and 142a provided along the front surface 131, the front surface groove portions 141b and 142b provided along the Y ′ axis direction on the surface 131 of the vibrating arm portion 12b, and the Y ′ axis on the rear surface 132 of the vibrating arm portion 12a. Back side grooves 143a, 144a provided along the direction, back side grooves 143b, 144b provided along the Y′-axis direction on the back surface 132 of the vibrating arm 12b, and provided in the front side groove 141a and the back side groove 143a. A through hole 151a penetrating the front side groove portion 141a and the back side groove portion 143a, and a through hole 1 provided in the front side groove portion 142a and the back side groove portion 144a and penetrating the front side groove portion 142a and the back side groove portion 144a. 2a, a through-hole 151b provided in the front-side groove 141b and the back-side groove 143b and passing through the front-side groove 141b and the back-side groove 143b, and a front-side groove 142b and the back-side groove 144b provided in the front-side groove 142b and the back-side groove 144b. And a through hole 152b that penetrates the groove 144b. These consist of a crystal piece 13 obtained by processing a crystal wafer.

  Further, the vibration element 10 includes excitation electrodes 21b provided in the front side groove portions 141a and 142a, the back side groove portions 143a and 144a, and the side surfaces 133 and 134 of the vibration arm portion 12b, and the front side groove portions 141b and 142b. 143b, 144b and the excitation electrode 21a provided on the side surfaces 133, 134 of the vibrating arm portion 12a, the excitation electrode 21b provided in the through-hole 151a and in the front side groove portion 141a, and the excitation electrode 21b in the back side groove portion 143a. The electrode wiring 221b that is electrically connected, the electrode wiring 222b that is provided in the through-hole 152a and electrically connects the excitation electrode 21b in the front-side groove 142a and the excitation electrode 21b in the back-side groove 144a, and the through-hole 151b An electrode that is provided inside and electrically connects the excitation electrode 21a in the front-side groove 141b and the excitation electrode 21a in the back-side groove 143b. And it includes a line 221a, and an electrode wiring 222a electrically connects the excitation electrode 21a in the excitation electrodes 21a and the back groove 144b of the through hole 152b provided in the table side groove 142b. These are made of a metal film formed on the crystal piece 13.

  The through hole 151a is provided at a position closer to the tip 121 of the vibrating arm portion 12a than the middle position 145 of the length in the Y′-axis direction of the front-side groove portion 141a and the back-side groove portion 143a. Similarly, the through hole 152a is provided at a position closer to the tip 121 of the vibrating arm portion 12a than the position 145 in the middle of the length in the Y′-axis direction of the front-side groove portion 142a and the back-side groove portion 144a. The through hole 151b is provided at a position closer to the tip 121 of the vibrating arm portion 12b than a position 145 in the middle of the length in the Y′-axis direction of the front groove portion 141b and the back groove portion 143b. Similarly, the through hole 152b is provided at a position closer to the tip 121 of the vibrating arm portion 12b than the middle position 145 of the length in the Y′-axis direction of the front groove portion 142b and the back groove portion 144b.

  Specifically, the through holes 151a and 152a are provided at positions closest to the tip 121 of the vibrating arm portion 12a in the front side groove portions 141a and 142a and the back side groove portions 143a and 144a. The through holes 151b and 152b are provided at positions closest to the tip 121 of the vibrating arm portion 12b in the front side groove portions 141b and 142b and the back side groove portions 143b and 144b.

  The front side groove portions 141a and 142a are provided in parallel in the Y ′ axis direction, the back side groove portions 143a and 144a are provided in parallel in the Y ′ axis direction, and the front side groove portions 141b and 142b are provided in parallel in the Y ′ axis direction, The back side grooves 143b and 144b are provided in parallel in the Y′-axis direction. Any of the through holes 151a, 152a, 151b, and 152b is provided in any one of the front-side groove portions 141a, 142a, 141b, and 142b and the back-side groove portions 143a, 144a, 143b, and 144b.

  Pad electrodes 231 a and 231 b are provided on the front surface 131 of the base 11, and pad electrodes 232 a and 232 b are provided on the back surface 132 of the base 11. As shown in FIG. 5, the pad electrodes 232 a and 232 b are electrically connected to the pad electrode 31 of the element mounting member 30 via a conductive adhesive 32. As shown in FIG. 1, on the surface 131 of the base 11, an electrode wiring 24b that electrically connects the pad electrode 231b and the excitation electrode 21b in the front side grooves 141a and 142a, and the pad electrode 231a and the front side groove An electrode wiring 24a that electrically connects the excitation electrode 21a in 141b and 142b is provided.

  However, as shown in FIG. 2, the electrode wiring for electrically connecting the pad electrode 232 b and the excitation electrode 21 b in the back-side groove portions 143 a and 144 a is also formed on the back surface 132 of the base 11, and the pad electrode 232 a and the back-side groove portion 143 b, There is also no electrode wiring that electrically connects the excitation electrode 21a in 144b.

  In addition to these, the vibration element 10 includes metal films 25a and 25b for frequency adjustment on the tip 121 side of the vibrating arm portions 12a and 12b.

  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 crystal piece 13 has a tuning fork shape in which the base portion 11 and the vibrating arm portions 12a and 12b are integrated, and is manufactured by a film forming technique, a photolithography technique, a wet etching technique, or the like.

  The number of front side groove portions 141a,... And the back side groove portions 143a,... Is not limited. Also, it may be provided only on one side of the front and back.

  In the vibrating arm portion 12a, excitation electrodes 21a are provided on the side surfaces 133 and 134, and excitation electrodes 21b are provided inside the front side groove portions 141a and 142a and the back side groove portions 143a and 144a. Similarly, in the vibrating arm portion 12b, excitation electrodes 21b are provided on the side surfaces 133 and 134, and excitation electrodes 21a are provided inside the front side groove portions 141b and 142b and the back side groove portions 143b and 144b.

  Therefore, in the vibrating arm portion 12a, the excitation electrode 21a provided on the side surfaces 133 and 134 and the excitation electrode 21b provided in the front side groove portions 141a and 142a and the back side groove portions 143a and 144a have different polarities, and the vibrating arm In the portion 12b, the excitation electrodes 21b provided on the side surfaces 133 and 34 and the excitation electrodes 21a provided in the front-side grooves 141b and 142b and the back-side grooves 143b and 144b have different polarities.

  On the surface 131 of the base 11, the pad electrodes 231a and 231b, the electrode wiring 24a that electrically connects the pad electrode 231a and the excitation electrode 21a, and the pad electrode 231b and the excitation electrode 21b are electrically connected. And an electrode wiring 24b to be connected. The pad electrodes 231a and 232a, the excitation electrode 21a, the frequency adjusting metal film 25a, the electrode wiring 24a, and the electrode wirings 221a and 222a are electrically connected to each other. The pad electrodes 231b and 232b, the excitation electrode 21b, the frequency adjusting metal film 25b, the electrode wiring 24b, and the electrode wirings 221b and 222b are electrically connected to each other.

  As shown in FIG. 5, the vibration element 10 is fixed and electrically connected to the pad electrode 31 on the element mounting member 30 side via the pad electrodes 232 a and 232 b and the conductive adhesive 32.

  In the drawing, for easy understanding, the front surface 131 and the rear surface 132 are parallel to the bottom surfaces of the front side groove portions 141a,... And the back side groove portions 143a, and etching residues are omitted. However, the actual shape is slightly different from the illustrated shape due to the anisotropy of quartz wet etching.

  Next, the operation of the vibration element 10 will be described.

  When the tuning fork type vibration element 10 is vibrated, an alternating voltage is applied to the pad electrodes 232a and 232b. When an electrical state after application is instantaneously captured, the excitation electrodes 21b provided in the front side groove portions 141a and 142a and the back side groove portions 143a and 144a of the vibrating arm portion 12a have a positive potential, and the side surface 133 of the vibrating arm portion 12a. , 134 has a negative potential, and an electric field is generated from positive to negative. At this time, the excitation electrode 21a provided in the front side groove portions 141b and 142b and the back side groove portions 143b and 144b of the vibrating arm portion 12b has a negative potential, and the excitation electrode 21b provided on the side surfaces 133 and 134 of the vibrating arm portion 12b is positive. It becomes an electric potential, and has a polarity opposite to that generated in the vibrating arm 12a, 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.

  Next, the operation and effect of the vibration element 10 will be described.

  (1) According to the vibration element 10, the positions of the front side groove portions 141 a,... And the back side groove portions 143 a,... Are in the middle of the lengths of the front side groove portions 141 a,. Since the through-holes 151a,... Are provided at positions that have less influence on the frequency characteristics by being closer to the tips 121 of the vibrating arm portions 12a, 12b than the position 145, the through-holes 151a,. Variations in frequency characteristics can be reduced. Therefore, according to the vibration element 10, when the through hole is provided in the groove portion of the existing vibration element, the influence on the frequency characteristics of the existing vibration element can be reduced.

  (2) By providing the through holes 151a, ... in the positions closest to the tips 121 of the vibrating arms 12a, 12b in the front side grooves 141a, ... and in the back side grooves 143a, ..., the through holes 151a, ... are provided. Therefore, the fluctuation of the frequency characteristic due to this can be minimized.

  (3) The front side groove portions 141a,... And the back side groove portions 143a,... Are provided in parallel along the Y'-axis direction, and the through-holes 151a,... Are all the front side groove portions 141a,. .., Even if poor conduction occurs in one through-hole 151a,..., Conduction can be obtained in the other through-hole 152a,.

  (4) As described above, all the electrode wirings can be made unnecessary on the back surface 132 of the base 11. The reason why the electrode wiring is not required is that the excitation electrode 21b in the back side grooves 143a and 144a is electrically connected to the excitation electrode 21b in the front side grooves 141a and 142a via the electrode wirings 221b and 222b in the through holes 151a and 152a. And the excitation electrodes 21a in the back-side grooves 143b and 144b are electrically connected to the excitation electrodes 21a in the front-side grooves 141b and 142b via the electrode wirings 221a and 222a in the through holes 151b and 152b. This is because they are connected.

  On the other hand, in the vibration element having no through hole in the groove, electrode wiring is also required on the back surface of the base. For this reason, when the vibration element is mounted on the element mounting member, the conductive adhesive protrudes from the pad electrode on the back surface of the base, which may cause insulation failure between the pad electrode and the electrode wiring or between the electrode wiring. It was. In particular, with the recent downsizing of vibration elements, the area of the base has become smaller and this tendency has become a major problem.

  On the other hand, according to the vibration element 10, all the electrode wirings can be made unnecessary on the back surface 132 of the base 11, so that even if the conductive adhesive 32 protrudes from the pad electrodes 232 a and 232 b, there is an insulation failure in the electrode wiring. Since it does not occur, the yield can be improved.

  Next, a method for manufacturing the resonator element according to the first embodiment will be described as a manufacturing method according to the second embodiment. 6 and 7 are cross-sectional views illustrating the manufacturing method of the second embodiment. FIG. 8 is an enlarged plan view showing a part of the pattern of the photosensitive resist film and the corrosion-resistant film in the manufacturing method of the second embodiment. Hereinafter, the manufacturing method according to the second embodiment will be described with reference to FIGS. 6 to 8 and also FIGS. 1 to 4.

  First, as shown in FIG. 6 [1], a corrosion resistant film 42 is formed on the front and back of the quartz wafer 41 (corrosion resistant film forming step). For example, the corrosion-resistant film 42 made of chromium or two layers of chromium and gold is formed by sputtering.

  Subsequently, as shown in FIG. 6 [2], a photosensitive resist film 43 is formed on the corrosion-resistant film 42 (photosensitive resist film forming step). As the photosensitive resist film 43, for example, a positive type is used.

  Subsequently, as shown in FIG. 6 [3], the photosensitive resist film 43 in the region 52 to be the base portion and the vibrating arm portion is left, and the photosensitive resist film 43 in the region 54 to be the groove portion is removed (exposure development). Process). Here, the photosensitive resist film 43 left on the quartz wafer 41 has a planar shape shown in FIG. The “groove” here is a general term for “front-side groove” and “back-side groove”.

  Subsequently, as shown in FIG. 7 [4], the anti-corrosion film 42 not covered with the photosensitive resist film 43 is removed to create a mask made of the anti-corrosion film 42 (patterning step). For removing the corrosion-resistant film 42, a strong acid that etches only the corrosion-resistant film 42 and does not etch the crystal wafer 41 is used. The mask made of the corrosion resistant film 42 also has a planar shape shown in FIG.

  Subsequently, as shown in FIGS. 7 [5A] and [5B], the quartz wafer 41 is wet-etched using a mask made of the corrosion-resistant film 42 (wet etching process). As this etching solution, hydrofluoric acid is used. 7 [5A] is a cross-sectional view of the region 56 having an etching suppression pattern in FIG. 8, and FIG. 7 [5B] is a region 55 to be a through hole in FIG. In FIG. 7 [5A] [5B], the photosensitive resist film 43 is removed. However, the photosensitive resist film 43 is left or newly formed, and an electrode or the like is formed using a lift-off method in the next step. May be.

  Thereafter, as shown in FIGS. 1 to 4, metal films such as excitation electrodes 21a and 21b are formed on the vibrating arms 12a and 12b. These metal films are formed by, for example, film formation, photolithography, and etching, and have a laminated structure in which, for example, palladium or gold is provided on titanium.

  As described above, the photosensitive resist film 43 left on the crystal wafer 41 in the exposure and development step (FIG. 6 [3]) has a planar shape shown in FIG. That is, as shown in FIG. 8, in the exposure and development process, using a single photomask, the photosensitive resist film 43 in the region 52 to be the base and the vibrating arm is left, and the photosensitive resist is left in the region 54 to be the groove. A protrusion 57 as an etching suppression pattern made of the film 43 is formed, and the photosensitive resist film 43 in the region 55 to be a through hole is removed. Therefore, the region 54 to be a groove portion is composed of a region 56 having an etching suppression pattern and a region 55 to be a through hole.

  The protrusions 57 are arranged at regular intervals 61 along the Y′-axis direction in the region 54 to be a groove. In the region 55 to be a through hole, one projection (imaginary line) is not formed.

  As described above, the mask made of the corrosion-resistant film 42 formed in the patterning step (FIG. 7 [4]) also has a planar shape shown in FIG. Then, as shown in FIG. 8, by using a mask made of such a corrosion-resistant film 42 having a planar shape, in the wet etching process, the crystal wafer 41 in the region not covered with the corrosion-resistant film 42 is removed and the corrosion-resistant film is used. The crystal wafer 41 in the region 58 covered with the projection 57 made of the film 42 is removed by side etching. At this time, since the projection 57 made of the corrosion resistant film 42 acts as an etching suppression pattern, the outer shape of the base portion 11 and the vibrating arm portions 12a, 12b, the through holes 151a,..., And the groove portions 141a,. Simultaneously formed by wet etching. That is, in one wet etching, the outer shape of the base 11 and the vibrating arms 12a, 12b and the through holes 151a,... Are completely removed, and the etching rate of the grooves 141a,. Thus, half-etching is performed halfway.

  Note that the constant interval 61, the slope 62, and the width 63 of the protrusions 57 shown in FIG. 8 are set to values that act as an etching suppression pattern and that the crystal in the region 58 disappears by side etching. Further, when the inclination 62 of the protrusion 57 is 60 °, the protruding direction of the crystal covered with the protrusion 57 is the −Y′-axis direction, and the normal direction of both side surfaces of the crystal is the ± X-axis direction. The quartz etching rate is greater in the ± X-axis direction than in the ± Y′-axis direction. Therefore, by setting the inclination 62 of the protrusion 57 to 60 °, the crystal covered with the protrusion 57 is easily side-etched. However, since there are three X-axes and three Y'-axes, the X-axis and Y'-axis here are different from the X-axis and Y'-axis shown in FIGS.

  According to the manufacturing method of the second embodiment, since the vibration element of the first embodiment can be manufactured, the following actions and effects can be obtained in addition to the same actions and effects as the vibration element of the first embodiment.

  (1) According to the manufacturing method of the second embodiment, when the vibration element 10 is manufactured, the groove portions 141a,... And the through holes 151a,. Since no error occurs, finer through holes 151a,... Can be accurately provided in the fine grooves 141a,.

  (2) The etching suppression pattern is a projection 57 made of the photosensitive resist film 43 arranged in the region 54 that becomes the groove portion at a constant interval 61 along the Y′-axis direction, and the projection 57 is formed in the region 55 that becomes the through hole. If not, the region 55 to be a through hole can be easily designed by (number of deleted protrusions 57) × (constant interval 61). Therefore, when a through hole is provided in a groove portion of an existing vibration element, a design change is easy.

  Next, a dimension example of the second embodiment will be described.

  In FIG. 1, the length of the vibrating arm portions 12a and 12b is 1200 μm, the width of the vibrating arm portions 12a and 12b is 58 μm, and the thickness of the vibrating arm portion 12a (that is, the quartz wafer 41) is 100 μm. In FIG. 8, the constant interval 61 of the protrusions 57 is 50 μm, the inclination 62 of the protrusions 57 from the Y′-axis direction is 60 °, and the width 63 of the protrusions 57 is 4.5 μm. The width 65 of the region 54 to be the groove is 13 μm, and the length 66 of the region to be the through hole is 50 μm. These dimensions are merely examples, and values appropriate for design may be selected.

  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. Furthermore, the present invention can be expressed as the following supplementary notes.

[Appendix 1] a base;
Two vibrating arms extending in the same direction from this base,
A front side groove part and a back side groove part respectively provided along the extending direction of the vibration arm part on the front and back surfaces of these vibration arm parts;
A through-hole provided in the front-side groove and in the back-side groove, and penetrating the front-side groove and the back-side groove,
A method of manufacturing a crystal resonator element comprising:
A corrosion-resistant film forming step of forming a corrosion-resistant film on the front and back surfaces of the crystal wafer;
A photosensitive resist film forming step of forming a photosensitive resist film on the corrosion-resistant film;
An exposure development process for forming the photosensitive resist film in a predetermined pattern;
A patterning step of creating a mask made of the corrosion resistant film by removing the corrosion resistant film not covered with the photosensitive resist film;
A wet etching step of wet etching the crystal wafer using the mask made of the corrosion-resistant film;
Including
In the exposure and development step, using a single photomask, the photosensitive resist film is left in the region to be the base and the vibrating arm, and the photosensitive resist is to be formed in the region to be the front groove and the back groove. Forming an etching suppression pattern made of a film, and removing the photosensitive resist film in a region to be the through hole;
A method for manufacturing a quartz crystal resonator element.

[Supplementary Note 2] The etching suppression pattern is a protrusion made of the photosensitive resist film arranged at regular intervals along the extending direction in the region to be the front groove portion and the back groove portion,
The projection is not formed in the region to be the through hole,
A method for manufacturing a crystal resonator element according to appendix 1.

[Appendix 3] Excitation electrodes provided in the front side groove and in the back side groove,
An electrode wiring that is provided in the through-hole and electrically connects the excitation electrode in the front-side groove and the excitation electrode in the back-side groove;
A method of manufacturing the crystal resonator element further comprising:
An electrode film forming step of forming an electrode film on the exposed portion of the crystal wafer and on the photosensitive resist film after the wet etching step;
After this electrode film formation step, a lift-off step of forming the excitation electrode and the electrode wiring by removing the electrode film formed on the photosensitive resist film together with the photosensitive resist film;
The method for manufacturing a crystal resonator element according to appendix 1 or 2, further comprising:

DESCRIPTION OF SYMBOLS 10 Vibration element 11 Base part 12a, 12b Vibration arm part 121 Tip 13 Crystal piece 131 Front surface 132 Back surface 133, 134 Side surface 141a, 142a, 141b, 142b Front side groove part 143a, 144a, 143b, 144b Back side groove part 145 Middle position 151a, 152a , 151b, 152b Through hole 21a, 21b Excitation electrode 221a, 222a, 221b, 222b Electrode wiring 231a, 232a, 231b, 232b Pad electrode 24a, 24b Electrode wiring 25a, 25b Frequency adjustment metal film 30 Element mounting member 31 Pad electrode 32 Conductive adhesive

41 Quartz wafer 42 Corrosion resistant film 43 Photosensitive resist film 52 Region to be a vibrating arm portion 54 Region to be a groove portion 55 Region to be a through hole 56 Region having an etching suppression pattern 57 Protrusion 58 Region covered by a protrusion

61 Fixed interval 62 Tilt 63, 65 Width 66 Length

Claims (5)

The base,
Two vibrating arms extending in the same direction from this base,
A front side groove part and a back side groove part respectively provided along the extending direction of the vibration arm part on the front and back surfaces of these vibration arm parts;
A through-hole provided in the front-side groove and the back-side groove, and penetrating the front-side groove and the back-side groove,
Excitation electrodes provided on both sides of the front side groove, the back side groove, and the vibrating arm part;
An electrode wiring that is provided in the through-hole and electrically connects the excitation electrode in the front-side groove and the excitation electrode in the back-side groove;
Equipped with a,
The through-hole is provided at a position closer to the tip of the vibrating arm portion than an intermediate position of the length in the extending direction of the front-side groove portion and the back-side groove portion,
A method of manufacturing a quartz resonator element, comprising:
A corrosion-resistant film forming step of forming a corrosion-resistant film on the front and back surfaces of the crystal wafer;
A photosensitive resist film forming step of forming a photosensitive resist film on the corrosion-resistant film;
An exposure development process for forming the photosensitive resist film in a predetermined pattern;
A patterning step of creating a mask made of the corrosion resistant film by removing the corrosion resistant film not covered with the photosensitive resist film;
A wet etching step of wet etching the crystal wafer using the mask made of the corrosion-resistant film;
Including
In the exposure and development step, using a single photomask, the photosensitive resist film is left in the region to be the base and the vibrating arm, and the photosensitive resist is to be formed in the region to be the front groove and the back groove. Forming an etching suppression pattern made of a film, and removing the photosensitive resist film in a region to be the through hole;
A method for manufacturing a quartz crystal resonator element. The through hole is provided at a position closest to the tip of the vibrating arm part,
A method for manufacturing a crystal resonator element according to claim 1. The front-side groove portion and the back-side groove portion are provided in parallel along the extending direction of the vibrating arm portion, two by two,
The through holes were provided in all the front side groove portions and the back side groove portions,
A method for manufacturing a crystal resonator element according to claim 1 or 2. Pad electrodes are respectively provided on the front and back surfaces of the base,
The pad electrode on the back surface is electrically connected to the pad electrode of the element mounting member via a conductive adhesive,
On the surface of the base portion, an electrode wiring that electrically connects the pad electrode and the excitation electrode in the front side groove portion is provided,
No electrode wiring is provided on the back surface of the base portion to electrically connect the pad electrode and the excitation electrode in the backside groove.
The manufacturing method of the crystal oscillation element as described in any one of Claims 1 thru | or 3. The etching suppression pattern is a protrusion made of the photosensitive resist film arranged at regular intervals along the extending direction in the region to be the front side groove and the back side groove.
The projection is not formed in the region to be the through hole,
A method for manufacturing a crystal resonator element according to claim 1 .

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