JP2007097046A - Processing method of crystal base plate and crystal vibrating piece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machining method capable of relatively easily controlling a quartz base plate to have a cross-sectional tapered shape or a convex-convex shape and a crystal vibrating piece excellent in vibration characteristics.
Photoresist R1 to R5 having different sensitivities are overlaid and laminated on a crystal element piece 1a so as to increase the sensitivity from the surface of the crystal element piece 1a toward the upper layer. Next, after exposure is performed by irradiating exposure light through the photomask 8, the photoresists R1 to R5 are developed. Since the photoresists R1 to R5 have more unexposed portions as they go to the lower layer, the photoresist pattern after development has a cross-sectional taper shape that spreads outward toward the surface of the crystal element piece 1a. Then, when the crystal wafer 1 is dry-etched by the RIE (reactive ion etching) method, a substantially cross-sectional taper shape is formed on the end face of the crystal element piece 1a.
[Selection] Figure 2

Description

  The present invention relates to a method for processing a crystal base plate, and more particularly to a method for processing a crystal base plate for processing a crystal base plate into a tapered cross section or a convex convex shape.

  Conventionally, in various information / communication equipment, OA equipment, and electronic equipment such as consumer equipment, a piezoelectric device including a piezoelectric vibrator is widely used as a clock source of an electronic circuit. Especially in the field of information and communication equipment, the piezoelectric vibrators have become smaller and thinner as devices such as mobile phones become smaller and thinner. There is a demand for a surface-mount type piezoelectric device suitable for mounting.

  A typical surface-mount type piezoelectric device is one in which an excitation electrode is formed on a quartz crystal vibrating piece made of a rectangular thin plate of quartz material, and a conductive adhesive is applied to the connection terminal of the package at its base end. Many crystal resonators having a structure that is joined so as to be held and supported are used. In this way, in the rectangular thin plate crystal resonator element, for example, it is proposed that the crystal resonator element cross section is not rectangular but a convex shape in which the thickness is gradually reduced from the central portion to the end portion where the excitation electrode is formed. ing. This is because if the quartz crystal resonator element has a convex convex cross section, the amount of vibration displacement attenuation at the end of the quartz crystal resonator element can be increased to enhance the energy confinement effect and improve the vibration characteristics such as the Q value (Patent Literature). 1). Furthermore, according to the above-described convex shape, it is known that the vibration characteristics of the quartz crystal resonator element can be improved with a size smaller than that of the rectangular cross section.

  Conventionally, for example, a barrel grinder has been used to form such a quartz-crystal vibrating piece having a convex shape in cross section. A barrel polishing machine puts hundreds to thousands of crystal element pieces cut out from a quartz base plate (crystal wafer) into a rectangular shape with a polishing agent into a pot together with an abrasive and puts the pot at a predetermined speed. By rotating for a time, a convex convex cross section is formed.

  Further, Patent Document 1 further includes a method of manufacturing a crystal vibrating piece by a chemical processing method in which the convex shape is approximately replaced with a staircase shape, and the staircase shape is etched by changing the etching resist size stepwise. Are listed.

Japanese Patent Laid-Open No. 11-355094

  However, the above-described processing by the conventional barrel polishing machine has a problem that manufacturing efficiency and productivity are low because it takes a long time. For example, in the case of a crystal vibrating piece used in a low frequency band of about 4 MHz, a processing time of 40 hours or more is required.

  Further, the processing by the barrel polishing machine described above is difficult to control the convex shape, and the processing accuracy is relatively low. In addition, since the processing of individual quartz crystal vibrating pieces in the bulk cannot be controlled, the variation in cross-sectional shape becomes large. Furthermore, since the polishing agent acts on the entire surface of the quartz crystal vibrating piece, the center region is roughened, and therefore there is a risk of deteriorating the frequency characteristics such as the CI value. To avoid this, a chemical such as light etching is performed again. The process is complicated because it is necessary to use a general processing method together.

On the other hand, as described in Patent Document 1, the method of etching by changing the dimensions of the etching resist stepwise is complicated and takes a lot of man-hours, and therefore may cause a decrease in productivity and an increase in cost. is there.
Therefore, the present invention has been made to solve the above problems, and its purpose is to make a quartz base plate into a shape that is at least approximate to a cross-sectional taper shape or a cross-sectional convex shape by a relatively easy processing method. It is to provide a processing method for processing.

  In order to solve the above-described problems, in the present invention, a quartz base plate is coated with a plurality of photosensitive resins having different sensitivities, an exposure step of exposing a pattern shape to the photosensitive resin, and a photosensitive resin. At least a developing step for developing the substrate and an etching step for etching the quartz base plate. In the coating step, a photosensitive resin having a higher sensitivity is applied as it goes upward from the surface of the quartz base plate. The main purpose is to etch the crystal base plate using a dry etching method, and to process the crystal base plate into a shape approximate to a cross-sectional taper shape or a cross-sectional convex shape.

  According to this configuration, the plurality of photosensitive resins applied in layers increase in the number of unexposed portions as they go down, so that the photosensitive resin pattern after development becomes more outward as it goes to the surface side of the quartz base plate. An expanding cross-sectional taper shape is formed. When the quartz base plate is dry-etched, a tapered cross section or a convex convex shape can be formed on the end face of the quartz base plate. Thereby, it is possible to manufacture a quartz element piece having a cross-sectional taper shape in a short time as compared with a cross-section taper shape processing by a conventional barrel polishing machine. In addition, since it is possible to avoid crystal cracking and chipping or surface roughness that are likely to occur due to mechanical cross-section taper processing by a barrel polishing machine, high-quality quartz vibration can be achieved without complicating the process such as etching again. You can get a piece. Also, dry etching is excellent in etching anisotropy. In particular, according to the RIE (reactive ion etching) method by the action of ions, a so-called undercut in which the crystal immediately below the development pattern of the photoresist is etched from the side surface direction. Since it does not occur easily, the action of the processing method of the tapered cross section of the present invention can be effectively utilized. Furthermore, the angle and smoothness of the cross-section taper shape can be arbitrarily controlled to some extent by selecting the sensitivity of each photoresist to be used and controlling the coating conditions and patterning conditions. Therefore, it is possible to relatively easily process the crystal vibrating piece controlled to have a desired cross-sectional taper shape or cross-sectional convex shape.

  In the present invention, the exposure step may be a step of exposing a plurality of the photosensitive resins at a time.

  According to this configuration, the exposure process can be shortened.

  In this invention, you may make it perform the process from an application | coating process to an etching process for every double side | surface or single side | surface.

  According to this configuration, since different etching processes can be performed from the front surface and the back surface of the quartz base plate, the cross-sectional shapes on the front surface side and the back surface side can be arbitrarily changed, and the desired frequency is obtained. Further, it is possible to provide a processing method capable of processing into an arbitrary cross-sectional taper shape.

  The quartz crystal vibrating piece of the present invention is processed using the above-described processing method.

The quartz crystal resonator element manufactured using the above-described processing method of the present invention has an arbitrary cross-sectional taper shape. For example, in a quartz crystal resonator element having a convex shape in cross section, a pair of excitation electrodes is formed at the thickest central portion, and the convex portions become thinner from the central portion toward both end portions. The vibration energy generated when an electric field is applied to the quartz vibrating piece through the excitation electrode is concentrated in the thick central portion and the mass is large, and the damping rate of the vibration energy is rectangular in cross section toward the thin end portions. It will be better than As a result, loss of vibration energy caused by a large amount of vibration energy transmitted to the mount portion can be suppressed without increasing the size of the vibration piece. Further, various sub-vibration (spurious vibration) modes caused by reflection from the outline of the quartz crystal vibrating piece can be attenuated to obtain a high Q value. Therefore, it is possible to provide a quartz crystal resonator element that is smaller and has excellent vibration characteristics.
Further, according to the processing method of the present invention described above, since the cross-section taper processing is performed by photolithography, it is possible to perform different cross-section taper processing on both the front and back surfaces or both end portions. Therefore, it is possible to form a crystal resonator element that can be formed into a cross-sectional shape having a relatively high degree of freedom, has a desired frequency characteristic, and can be easily bonded to a substrate or the like.

(First embodiment)
Hereinafter, a first embodiment of a method for processing a crystal blank according to the present invention will be described with reference to the drawings.

  Fig.1 (a) is a front view of the quartz crystal vibrating piece 10 manufactured by the processing method of the quartz base plate of this invention, Comprising: The figure (b) is A in the figure (a) which shows a longitudinal cross section. A cross-sectional view taken along the line -A, and FIG. 5C is a cross-sectional view taken along the line A′-A ′ of FIG.

  The quartz crystal resonator element 10 has a quartz element piece 1a having a convex cross-section formed by subjecting an AT-cut strip-shaped quartz base plate cut out from quartz to surface processing described later. The cross section in the width direction of the crystal element piece 1a has a so-called biconvex shape in which a flat portion is formed at the center of each of the front and back surfaces, and convex convex shapes are formed toward both ends (FIG. 1). (C)). The cross section in the longitudinal direction of the crystal element piece 1a also has a biconvex shape in which a convex portion is formed from the central portion toward both ends, having a flat portion at the substantially central portion of each of the front and back surfaces. (FIG. 1B).

Excitation electrodes 2a and 2b, which are a pair of counter electrodes, are formed on both the front and back surfaces of the crystal element piece 1a. Also, external connection electrodes 4a and 4b are formed at one end of the back surface of the crystal element piece 1a. An external lead electrode 3a is provided between the excitation electrode 2a formed on the surface side of the crystal element piece 1a and the external connection electrode 4a via the other end side surface, and the excitation electrode 2a and the external connection electrode 4a is electrically connected. Further, an external lead electrode 3b is provided between the excitation electrode 2b on the back side of the crystal element piece 1a and the external connection electrode 4b, and the excitation electrode 2b and the external connection electrode 4b are electrically connected. ing. These excitation electrodes 2a and 2b, external lead electrodes 3a and 3b, and external connection electrodes 4a and 4b generally form an electrode film on the surface of the crystal element piece 1a by sputtering or vapor deposition of an electrode material.
When the electric field is applied between the excitation electrodes 2a and 2b by an electric signal input from the outside to the external connection electrodes 4a and 4b, the crystal resonator element 10 having the above-described configuration has a predetermined frequency determined by its shape and size. It comes to vibrate.

Next, a processing method for forming a cross-sectional convex shape of the crystal element piece 1a in the method of manufacturing the crystal vibrating piece 10 will be described with reference to the drawings as a tapered surface forming method for convenience of description.
FIGS. 2A to 2I schematically show a process of forming a crystal element piece 1a by forming a tapered cross section on a crystal wafer 1 having a rectangular cross section, and a partial cross section of the crystal wafer 1 or crystal element piece 1a. FIG.

  First, as shown in FIG. 2 (a), coating and drying are repeated so that liquid photoresists R1 to R5, which are photosensitive resins, are sequentially laminated on the surface of a quartz wafer 1 whose both surfaces are mirror-polished. To do. The photoresists R1 to R5 have the lowest sensitivity of the photoresist R1 first applied to the surface of the crystal wafer 1, and go upward from the photoresist R1 to the photoresist R2, the photoresist R3, the photoresist R4, and the photoresist R5. In order, the ones with higher sensitivity are applied. The method of overcoating so that the liquid photoresists R1 to R5 are laminated is as follows. First, the photoresist R1 is uniformly applied to the surface of the crystal wafer 1 by, eg, spin coating, and then at least the coating film of the photoresist R1 is applied. Temporary drying is performed to such an extent that the surface solidifies. Photoresist R2, photoresist R3, photoresist R4, and photoresist R5 are applied in this order and the photoresists R1 to R5 are laminated in the same manner. At this time, in order to prevent the temporarily dried lower layer photoresist from being dissolved in the liquid photoresist applied as the upper layer and mixed together, the second and subsequent layers of photoresist R2 to R5 have a solvent content. It is desirable to reduce as much as possible. Alternatively, when applying the second and subsequent layers of photoresists R2 to R5, a method of applying a predetermined thickness while forcibly drying by applying warm air to the application portion may be used. As a coating method in this case, it is preferable to apply a liquid resist in the form of fine particles by using a spray method or the like because it can be solidified in a shorter time and the photoresist can be prevented from being mixed at the lamination interface.

Next, as shown in FIG. 2B, the photoresist R1 to R5 laminated and applied on the quartz wafer 1 are exposed by irradiating exposure light from a mercury lamp or the like through a photomask 8. On the photomask 8, an exposure pattern 9 is formed of chromium (Cr) or the like at a position that becomes a taper-shaped base point that is finally formed on the crystal element piece 1a, and exposure is performed on the photoresists R1 to R5. The light is blocked.
After the exposure, the photoresists R1 to R5 are developed with an alkaline developer. In the present embodiment, the photoresists R1 to R5 are so-called positive photoresists in which the portions irradiated with the exposure light are soluble in the developer by a photoreaction. The most sensitive photoresist R5 with the highest sensitivity is exposed reflecting the exposure pattern 9 of the photomask 8 most. On the other hand, a photoresist with low sensitivity tends to generate an unexposed portion, and an end portion of a developed pattern to be obtained is formed outside the exposed pattern 9 of the photomask 8, and this tendency becomes more prominent as the sensitivity of the photoresist is lower. . Further, in the photoresists R1 to R5 applied in a laminated manner, the reach of the light energy of the exposure light decreases as it goes downward in the thickness direction, so that the spread of the development pattern to the outside increases. Further, due to the development rate when the photoresist is developed, the tendency of the bottom of the development pattern end section to become wider becomes more noticeable as the photoresist has a lower sensitivity. As described above, the photoresist R1 to R5 have more unexposed portions as they go down, so that the end portion of the developed photoresist pattern spreads outward as it goes to the surface side of the crystal wafer 1. A tapered cross section or a stepped cross section is formed (FIG. 2C).

Next, a process of etching the crystal wafer 1 on which the photoresist pattern is formed as described above to form a cross-sectional taper shape of the crystal element piece 1a will be described (FIGS. 2D to 2H).
In this embodiment, the crystal wafer 1 is dry-etched by RIE (reactive ion etching) using a reactive gas such as CHF ₃ . FIG. 2D shows a state immediately after the start of etching of the crystal wafer 1. Dry etching by the RIE method is excellent in anisotropy, and so-called undercut is not easily caused by etching the crystal immediately below the edge of the development pattern of the photoresists R1 to R5, so that the photoresists R1 to R5 have a tapered shape. Etching proceeds along the side surface of the end portion. Furthermore, as the etching of the quartz wafer 1 proceeds, so-called film reduction, in which the surface of the photoresist R5 and the side surfaces and ends of the photoresists R1 to R5 are slightly scraped, also proceeds. FIGS. 2D to 2H schematically show a process in which the etching of the crystal wafer 1 and the film reduction of the photoresists R1 to R5 proceed. FIG. 2 (h) shows a state in which the photoresists R5 and R4 are finally removed due to film reduction and a part of R3 remains in the upper layer.
As described above, as shown in FIG. 2 (h), the crystal element piece 1a having a tapered cross section on the end side surface is formed. Finally, the photoresists R1 to R5 are peeled off to obtain a crystal element piece 1a having a tapered cross section (FIG. 2 (i)). In the method of the present embodiment, the cross-section is selected by selecting the sensitivity of each photoresist to be used, adjusting the density, or controlling the thickness of each coating, the exposure amount in the processing step, the development conditions, the etching conditions, and the like. A taper-shaped angle, smoothness, etc. can be arbitrarily formed to some extent. Thereby, it is possible to form a sectional convex shape or a sectional bevel shape.
In the present embodiment, the example in which the photoresist has five layers has been described. However, if the resist has a plurality of layers, the same effect can be obtained. In an actual manufacturing process, a plurality of photomasks 8 capable of simultaneously patterning a large number of crystal element pieces 1a on a crystal wafer 1 are subjected to cross-section taper processing and then subjected to individual processing by mechanical processing such as dicing. A method of dividing the quartz crystal piece 10 into pieces is used.

  Next, the effect of the said embodiment is described below.

  (1) In the first embodiment, the quartz crystal vibrating piece is formed by applying a plurality of photoresists R1 to R5 having different sensitivities to the quartz wafer 1 so as to form a substantially cross-sectional tapered shape by photolithography. 10 was obtained.

  According to this configuration, it is possible to manufacture the crystal element piece 1a having a cross-sectional taper shape in a short time compared to a cross-sectional taper shape processing by a conventional barrel polishing machine. In addition, since it is possible to avoid crystal cracking and chipping or surface roughness that are likely to occur due to mechanical cross-section taper processing by a barrel polishing machine, high-quality quartz vibration can be achieved without complicating the process such as etching again. Piece 10 can be obtained. Furthermore, by controlling the sensitivity, concentration or coating thickness of each photoresist, exposure amount in the processing step, development conditions, etching conditions, etc., the angle and smoothness of the cross-section taper shape are controlled, so that any cross section It is possible to form a taper shape or a convex convex shape. Therefore, since any cross-section taper shape or cross-section convex shape can be formed so as to have a desired vibration characteristic by a relatively easy processing method, it is possible to manufacture the quartz crystal vibrating piece 10 having excellent vibration characteristics. it can.

(2) In the first embodiment, the crystal wafer 1 is etched using the RIE method which is a kind of dry etching method.
According to this configuration, the RIE method based on the action of ions is excellent in etching anisotropy, and the so-called undercut in which the crystal immediately below the development pattern of the photoresist is etched from the side surface direction hardly occurs. The effect of the method can be effectively utilized. Thereby, it becomes possible to manufacture the quartz crystal vibrating piece 10 having a desired cross-sectional taper shape or cross-sectional convex shape.

(Second Embodiment)
In the said 1st Embodiment, the processing method for forming the cross-sectional taper shape of the crystal element piece 1a, and the crystal vibrating piece 10 obtained by it were demonstrated. Not only this but according to the processing method of the quartz base plate explained in the first embodiment, it is possible to provide the quartz crystal vibrating piece 20 having the cross-sectional bevel shape shown in FIG.

FIG. 3 is an explanatory diagram illustrating an example of a quartz crystal resonator element having a cross-sectional bevel shape. 3A is a front view of the quartz crystal vibrating piece 20 having a cross-sectional bevel shape according to the present embodiment, and FIG. 3B is a cross-sectional view taken along the line BB of FIG. is there.
The crystal resonator element 20 is a rectangular strip-shaped crystal thin plate, and has constricted portions T1 to T4 in which both longitudinal ends of both front and back surfaces are beveled. And it is comprised from the vibration part 21a which makes the constricted shape parts T1-T4 both ends, and the support parts 25a and 25b formed thicker than the vibration part 21a integrated with this vibration part 21a. Excitation electrodes 22a and 22b, which are counter electrodes, are respectively formed at substantially central portions of the front and back surfaces of the vibration part 21a, and external connection electrodes 24a provided on the support parts 25a and 25b via the external lead electrodes 23a and 23b, respectively. , 24b. According to this configuration, the vibration energy of the vibration part 21a is confined immediately below the excitation electrodes 22a and 22b provided at the substantially central part, and the vibration displacement becomes maximum at the central part of the vibration part 21a and approaches the end part. Attenuates. In addition, since the cross-sections at both ends of the vibration part 21a are processed into a bevel shape, the amount of vibration displacement attenuation increases. Further, one end portion in the longitudinal direction is not mounted on the mounting substrate with a conductive adhesive or the like as in a normal crystal vibrating piece, but is externally supported from both sides by support portions 25a and 25b provided integrally. A joining structure can be taken. At this time, due to the action of the constricted shape portions T1 to T4, the vibration of the vibration portion 21a is difficult to leak to the support portions 25a and 25b, and the influence of the joint portion when the support portions 25a and 25b are joined to the outside is affected. It is difficult to reach the vibration part 21a. Therefore, it is possible to provide the crystal resonator 20 that can be easily mounted on a substrate or the like, has excellent bonding strength, and excellent vibration characteristics.

(Third embodiment)
In the said 1st and 2nd embodiment, the processing method for forming the cross-sectional taper shape of the crystal | crystallization element piece 1a or the vibration part 21a, and the crystal vibration piece 10 and cross-sectional bevel shape which have the cross-sectional convex shape obtained by it are used. The quartz crystal resonator element 20 having the above has been described. Not only this but according to the processing method of the quartz base plate explained in the first embodiment, it is possible to provide the quartz crystal vibrating piece 30 having the plano-convex shape shown in FIG.

FIG. 4 is an explanatory diagram showing an example of a schematic structure of the quartz crystal vibrating piece 30 having a so-called plano-convex cross section. FIG. 4A is a front view of the crystal vibrating piece 30 having a plano-convex section according to this embodiment, and FIG. 4B is a cross-sectional view taken along the line CC in FIG.
The crystal vibrating piece 30 includes a crystal element piece 31a having a so-called plano-convex cross section in which a convex convex shape is formed on one surface (surface) of a crystal base plate processed into a cylindrical shape. Excitation electrodes 32a and 32b, which are circular counter electrodes, are formed at substantially central portions of the front and back surfaces of the crystal element piece 31a, respectively, and external connections provided on the side surfaces of the crystal element piece 31a via external lead electrodes 33a and 33b. The electrodes 34a and 34b are electrically connected to each other. According to this configuration, vibration energy generated when an electric field is applied to the quartz crystal vibrating piece 30 through the excitation electrodes 32a and 32b is concentrated in a portion where the central portion has a large thickness and a large mass, and there are no excitation electrodes 32a and 32b. The vibration energy attenuation rate is improved as compared with the rectangular cross section. Thereby, the loss of vibration energy can be suppressed without increasing the size of the resonator element. In addition, various sub-vibration (spurious vibration) modes caused by reflection from the outline of the quartz crystal vibrating piece 30 are attenuated, and the temperature characteristic is improved, and at the same time, a high Q value can be obtained. Therefore, it is possible to provide a quartz resonator element that is smaller, excellent in frequency characteristics, and highly reliable.

  The present invention is not limited to the above-described embodiments, and the following modifications can also be implemented.

  (Modification 1) In the first embodiment, a method of applying a plurality of liquid photoresists R1 to R5 having different sensitivities on the surface of the crystal wafer 1 and patterning is shown, but the present invention is not limited to this. It is also possible to use a plurality of dry film type photoresists having different sensitivities, and laminate and pattern them on the surface of the crystal wafer 1 in order from the one having the lowest sensitivity. According to this method, a photoresist drying step is not required, and the upper and lower photoresists are not mixed at the photoresist lamination interface, so that the photosensitive characteristics of each photoresist can be maintained and used for patterning. Become.

  (Modification 2) In the first to third embodiments, the crystal vibrating piece 10 having the biconvex cross section and the crystal vibrating piece 20 having the cross bevel shape or the crystal vibrating piece 30 having the plano convex shape have been described. . Not limited to this, by controlling the sensitivity, concentration or coating condition of the photoresist, or the exposure pattern, development condition or etching condition of the photomask on each of the front and back surfaces of the crystal base plate, any cross section can be formed on the crystal base plate. It is possible to form a shape. Moreover, it is possible to arbitrarily change the cross-sectional shape of the front surface side and the back surface side. For example, since it is possible to form a cross-sectional shape in which one surface of the quartz crystal vibrating piece is convex and the other surface is flat, it is possible to easily and more firmly join the package using the flat surface. it can. Therefore, the degree of freedom in designing the quartz crystal resonator element is relatively high, and the quartz crystal resonator element having excellent vibration characteristics and assemblability can be used for manufacturing.

(A) is a front view of the quartz crystal vibrating piece manufactured by the processing method of the present invention, (b) is a cross-sectional view taken along line AA in FIG. 1 (a), and (c) is a diagram of FIG. A'-A 'line sectional drawing. (A)-(i) is a fragmentary sectional view which shows typically the process in which the cross-section taper shape of the quartz crystal vibrating piece of this embodiment is formed. (A) is a front view of the quartz crystal vibrating piece having the cross-sectional bevel shape of the present invention, and (b) is a cross-sectional view taken along the line BB in FIG. (A) is a front view of the quartz crystal vibrating piece in which the plano-convex section of the present invention is formed, and (b) is a sectional view taken along the line CC in FIG. 4 (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Crystal wafer as a quartz base plate, 1a, 31a ... Crystal element piece which is the main body of a crystal vibrating piece, 21a ... Vibrating part which is the main body of a crystal vibrating piece 10, 20, 30 ... Crystal vibrating piece, R1-R5 ... Photoresist as photosensitive resin.

Claims (4)

A coating process for applying a plurality of photosensitive resins having different sensitivities to the quartz base plate in layers, an exposure process for exposing a pattern shape to the photosensitive resin, a developing process for developing the photosensitive resin, and the quartz element And at least an etching step for etching the plate,
In the coating process, the photosensitive resin is coated with higher sensitivity as it goes upward from the surface of the crystal blank, and in the etching process, the crystal blank is etched using a dry etching method,
A method for processing a crystal base plate, comprising processing the crystal base plate into a shape approximate to a cross-sectional taper shape or a cross-sectional convex shape. In the processing method of the quartz base plate of Claim 1,
The method for processing a quartz base plate, wherein the exposing step is a step of exposing a plurality of the photosensitive resins at a time. In the processing method of the quartz base plate of Claim 1 or 2,
A method of processing a quartz base plate, wherein the steps from the coating step to the etching step are performed on both sides or one side. A quartz crystal vibrating piece processed using the processing method according to claim 1.

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