JP2002374135A - Method for manufacturing piezoelectric vibrating reed, the piezoelectric vibrating reed, and piezoelectric vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a piezoelectric vibrating reed, which prevents increase of resistance value and disconnection of wiring pattern formed on the step difference around an excitation part, improves flexibility of wiring pattern drawing, reduces the amount of frequency offset generated, when a piezoelectric vibrating reed is fixed, and can prevent main vibration of a piezoelectric vibrating reed from overlapping with mechanical vibration generated in the excitation part, and provide a piezoelectric vibrating reed and a piezoelectric vibrator. SOLUTION: In order to manufacture an inverted mesa type quartz vibrating reed 10, in which a frame body 12 and the excitation part 14 inside the frame 12 are formed, a vibrating reed turning to the original form of the frame 12 is subjected to half-etching, and the excitation part 14 is formed. Half-etching is performed plural number of times so that step differences are formed outside the excitation part 14, thereby forming a step-wise step difference 22 between the frame body 12 and the excitation part 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a piezoelectric vibrating piece, a piezoelectric vibrating piece, and a piezoelectric vibrator, and more particularly to a method for manufacturing a piezoelectric vibrating piece using an inverted mesa vibrating piece and a piezoelectric vibrating piece. And a piezoelectric vibrator.

[0002]

2. Description of the Related Art Conventionally, there has been known a piezoelectric vibrating reed that obtains a predetermined frequency by applying a drive voltage through an excitation electrode formed on a surface of a piezoelectric material made of a thin plate of quartz or the like. In addition, such a piezoelectric vibrating reed is required to have an improved fundamental frequency as electronic devices operate at higher speeds.

FIG. 8 is an explanatory view showing the shape of a conventional inverted-mesa type piezoelectric vibrating reed. FIG. 8 (1) is an external perspective view, and FIG. 8 (2) is the same as FIG. It is sectional drawing.
As shown in these figures, a conventional inverted-mesa type piezoelectric vibrating reed 1 is generally made of quartz, and has a frame 2 having an outer shape, and is formed like a depression in a central portion of the frame 2. And an excitation unit 3 made of a thin plate. Here, the thickness of the excitation section 3 is set to be very thin (10 MHz at 167 MHz) in order to obtain high-frequency vibration (80 MHz or more).
μm). Therefore, the excitation unit 3 alone does not have enough strength to maintain the posture of the excitation unit 3 itself, and the excitation unit 3 is held by the strong frame 2 formed around the excitation unit 3.

[0004] In such a piezoelectric vibrating reed 1, the excitation electrodes 4 are formed on the front and back surfaces of the excitation section 3, and the frame 2
A mount electrode 5 is formed at the corner of the step 6, and a wiring pattern 7 is formed on the surface of the step 6 so as to connect these electrodes.
Are formed. By applying a voltage from the mount electrode 5 to the excitation electrodes 4 provided on the front and back surfaces of the excitation section 3, a predetermined frequency is obtained.

[0005]

The above-described conventional piezoelectric vibrating reed 1 has the following problems. That is, in the conventional inverted-mesa type piezoelectric vibrating reed 1, when forming the excitation electrode 4 and the wiring pattern 6, first, an electrode film is formed on the surface of the piezoelectric vibrating reed 1 using sputtering or vapor deposition. After a resist is applied to the upper layer of the electrode film, a wiring pattern 7 is formed from the electrode film by photolithography (or a mask is placed on the surface of the piezoelectric vibrating reed and the wiring pattern 7 is formed by sputtering or vapor deposition. May be formed), the frame 2 and the excitation unit 3
Since the step 6 (including the corner portion) between them has a steeply inclined surface, the thickness of the electrode film or the resist cannot be sufficiently secured, so that the resistance value of the wiring pattern 6 increases, or There was a possibility that disconnection would occur at the step 6 (so-called step disconnection).

The piezoelectric piece used for the piezoelectric vibrating piece 1 is
It is cut out from an original piezoelectric single crystal at an arbitrary angle. For this reason, when the excitation section 3 is formed by etching, the degree of progress of the etching varies depending on the crystal axis (crystal orientation), so that an angle difference occurs on the slope of the step 6 formed around the excitation section 3. . Piezoelectric vibrating reed 1
Is usually formed on a wafer obtained by slicing a rough piezoelectric single crystal, but forming a wiring pattern 7 on a step 6 on a steep slope increases the risk of disconnection and the like, and forming a wiring pattern 7 to prevent this. The step 6 to be formed is limited, and the position of the mount electrode 5 is also limited.

After the piezoelectric vibrating reed 1 is formed, it is sealed in a package. At this time, it is necessary to connect the mount electrode 5 to an electrode in the package using a conductive adhesive. If the strength of the frame 2 is low when the adhesive is cured, the frame 2 is deformed by the shrinkage force at the time of curing of the adhesive and the annealing process for relaxing the shrinkage force. There was a risk that the frequency would fluctuate significantly.

Further, in the piezoelectric vibrating reed 1 as described above, the ratio of the thickness of the excitation section 3 to the length of each side of the excitation section 3 (so-called side ratio) increases, so that the parasitic vibration with respect to the main vibration (Spurious vibration) occurs frequently, and the main vibration frequency jumps.

The present invention focuses on the above-mentioned conventional problems, and prevents an increase in the resistance value of a wiring pattern formed on a step around an excitation section, disconnection of the wiring pattern, and a design of the wiring pattern layout. A piezoelectric vibrating piece that improves the degree of freedom and reduces the amount of frequency offset that occurs when the piezoelectric vibrating piece is attached, and that prevents the main vibration of the piezoelectric vibrating piece from overlapping with the mechanical auxiliary vibration that occurs in the excitation unit. And a piezoelectric vibrating reed, and a piezoelectric vibrator.

[0010]

SUMMARY OF THE INVENTION The present invention is to reduce the size of a step per step by forming a plurality of steps at the center of the frame body by etching. This is based on the finding that the thickness of a resist or a wiring pattern is prevented from being reduced.

That is, in the method of manufacturing a piezoelectric vibrating reed according to the present invention, a concave recess is formed by etching inside a vibrating reed made of a piezoelectric material, and the vibrating reed is positioned on a frame and on the inside of the frame. After forming the excitation section, an excitation electrode is provided on the excitation section, and a step of forming the wiring pattern extending from the excitation electrode to the frame is formed on a step around the excitation section formed by the etching. In the method, after etching the vibrating reed a plurality of times to form the step in a step shape, the wiring pattern is formed on the step formed in the step shape, and the excitation electrode is formed on the frame body. I pulled it out. It is desirable that the processing speed of the etching be changed every plural times, and that the processing speed of the final etching in which the excitation section is formed be minimized.

In the piezoelectric vibrating reed according to the present invention, a step having a plurality of steps is formed between a frame forming the outer shape of the vibrating reed and an exciting portion formed in a concave shape inside the frame. An excitation electrode is formed in the excitation section, a wiring pattern is provided on the step having a plurality of steps, and the excitation electrode is drawn out to the frame by the wiring pattern.

The piezoelectric vibrating reed according to the present invention is an inverted-mesa-type piezoelectric vibrating reed in which a recess having a concave cross section is formed on one surface of the vibrating reed, and the vibrating reed is constituted by a frame and an exciting portion located inside the frame. A piezoelectric vibrating reed, wherein a step having a plurality of steps is formed between the frame and the excitation section, and an excitation electrode is formed on the excitation section, and a wiring pattern is provided on the step having the plurality of steps. The excitation pattern is configured to be drawn out to the frame by the wiring pattern, or a recess is formed on both surfaces of the resonator element such that the resonator element has a cross-sectional H shape,
The vibrating reed is a frame, and an inverted-mesa type piezoelectric vibrating reed configured by an excitation unit located inside the frame, forming a step having a plurality of steps between the frame and the excitation unit, An excitation electrode may be formed on the excitation section, a wiring pattern may be provided on the step having a plurality of steps, and the excitation electrode may be drawn out to the frame by the wiring pattern.
In addition, it is preferable that the plurality of steps are formed on both surfaces of the vibrating reed.

In the piezoelectric vibrating reed according to the present invention, a step having a plurality of steps is formed between a frame forming an outer shape of the vibrating reed and an exciting portion formed in a recess inside the frame. The structure is such that the spuriousness of the excitation unit is reduced by reducing the area of the excitation unit. And it is desirable to set the area of the excitation section so that the ratio of the side length to the thickness of the excitation section is 50 or less, furthermore, the material of the piezoelectric vibrating piece,
Quartz is preferred.

In the piezoelectric oscillator according to the present invention, a step having a plurality of steps is formed between a frame forming the outer shape of the resonator element and an exciting portion formed in a recess inside the frame. A piezoelectric vibrating reed in which an excitation electrode is formed in the excitation section, a wiring pattern is provided on the step having a plurality of steps, and the excitation electrode is drawn out to the frame by the wiring pattern,
A base substrate having a terminal electrode connected to the wiring pattern drawn out to the frame of the piezoelectric vibrating reed via a conductive adhesive, and a cover covering the base substrate and sealing the piezoelectric vibrating reed. It was comprised so that it might have.

Conventionally, the frame and the excitation section are formed with one step, but in the present invention, the frame and the excitation section are formed with a plurality of steps. If the space between the frame and the excitation unit is configured in a step-like manner as described above, when a metal film for forming a wiring pattern is formed on the surface of the step by sputtering or vapor deposition, the thickness of the metal film and the height of each step are different. The ratio with the height is reduced (the height on which the metal film rides is reduced), and the thickness of the metal film is prevented from fluctuating (thinning). The resist film used for photolithography can also have a sufficient thickness for the same reason, and when a piezoelectric vibrating reed is put into a sputtering apparatus, the resist film ensures protection of a metal film disposed below. Can be performed.

Due to these factors, it is possible to ensure a sufficient thickness of the wiring pattern formed by photo-etching or the like from the metal film, thereby preventing the resistance value of the wiring pattern from being reduced, Disconnection (step disconnection) in the wiring pattern can be prevented. Also, the step-like step can be applied to a piezoelectric vibrating piece having a dent formed on one side or both sides, and in a piezoelectric vibrating piece having a dent formed on both sides, it can be applied to either one side. A step-like step may be formed.

Further, even when the step slope is steep, if the steps are formed in a plurality of steps, the angle of the slope connecting the leading end of the step can be made gentle. For this reason, the wiring pattern can be drawn out from any slope adjacent to the excitation unit without being influenced by the crystal axis (crystal orientation) from which the piezoelectric vibrating piece is cut out, and the degree of design freedom such as pattern routing can be improved. .

If the step formed between the frame and the excitation section is stepped, the area of the excitation section can be reduced. If the area of the excitation section, that is, the side dimensions forming the excitation section, is reduced, the ratio of the side length to the thickness of the excitation section can be reduced, and spurious vibration of the excitation section occurs on the side where the side ratio is small. Can be extended. For this reason, it is easy to set the dimensions of the excitation unit so that the main vibration and the spurious vibration generated in the excitation unit do not overlap, and the degree of freedom in design can be increased.

When such a piezoelectric vibrating reed is connected to the base substrate using a conductive adhesive, a contraction force and a stress relaxation due to an annealing treatment are applied to the frame when the conductive adhesive is cured. However, since the step between the frame and the excitation unit is stepped, the range where the step is located is wide, and the torsional rigidity of the frame is high. For this reason, even if the contraction force is applied to the frame, the amount of deformation of the frame can be reduced, so that the frequency fluctuation of the excitation plate arranged inside the frame can be minimized. .

In the present invention, the step between the frame and the exciting portion is formed by a step-like step. However, as long as the above-mentioned function is satisfied, the height of each step is uniform. And different dimensions. In addition, the etching time can be shortened by individually changing the etching speed of a plurality of etchings performed to form a step, and if the processing speed of the final etching in which the excitation unit is formed is minimized, the etching speed can be reduced. Even if there is a slight error in time,
Since the processing speed is low, the progress of the etching does not proceed, and the thickness error of the excitation unit can be reduced.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a method for manufacturing a piezoelectric vibrating piece, a piezoelectric vibrating piece, and a piezoelectric vibrator according to the present invention will be described below in detail with reference to the drawings.
FIG. 1 is an explanatory view showing the shape of a quartz-crystal vibrating piece according to the present embodiment. FIG. 1A is an external perspective view, and FIG. 1B is a sectional view in FIG. FIG. 3 (3) is an enlarged view of a main part in FIG. 2 (2). As shown in these drawings, a quartz-crystal vibrating reed 10 serving as a piezoelectric vibrating reed according to the present embodiment includes a frame 12 having an outer shape, and a thin plate-shaped excitation portion 14 formed inside the frame 12. It is composed of Here, the thickness of the excitation section 14 is set to be very thin (about 10 μm in the present embodiment) in order to obtain high-frequency vibration (80 MHz or more). For this reason, the excitation unit 14 alone does not have sufficient strength to maintain the posture of the excitation unit 14 itself, and the excitation unit 14 is held by the strong frame 12 formed around the excitation unit 14.

In such a crystal vibrating piece 10, the excitation unit 1
Excitation electrodes 16 are respectively formed on the front and back surfaces of No. 4 and a mount electrode 18 corresponding to the excitation electrodes 16 is formed at a corner of the frame 2. Then, the excitation electrode 16 and the mount electrode 18 are connected so as to connect these electrodes.
A wiring pattern 20 is routed between them, and by applying a voltage to the mount electrode 18, a frequency preset by the thickness of the excitation unit 14 is obtained.

As shown in FIG. 2B, a step 22 is provided between the frame 12 and the excitation section 14 so that the height between the frame 12 and the excitation section 14 is high. I try to absorb the difference. Here, the wiring pattern 2 described above
0 is formed in the upper layer of the step-like step 22, and as shown in FIG.
Since the ratio of the thickness of the wiring pattern 20 to the thickness of the wiring body 20 is smaller than that in the case where the gap between the frame body 12 and the excitation section 14 is formed by one step (the conventional step shape), the wiring pattern 20 rides over each step. At this time, it is possible to prevent the thickness of the wiring pattern 20 from being reduced.

Even when the wiring pattern 20 is formed by photolithography, if a step-like step is formed between the frame 12 and the excitation section 14 and the height of each step is set low, the individual The ratio between the height of the step and the thickness when the resist is applied is reduced, and when the resist film rides over each step, the thickness of the resist film can be prevented from being reduced. For this reason, protection of the metal film for forming the wiring pattern 20 can be reliably performed, and it is possible to prevent the thickness of the metal film from becoming thin. Further, since the height and the number of steps of each individual step can be arbitrarily selected, the wiring pattern 20 can be formed without being influenced by the angle of the slope formed by etching around the excitation section 14, and the design in pattern routing can be realized. Degree of freedom can be improved.

The inventor conducted various experiments and studies on the above-mentioned invention, and demonstrated the effects thereof. Table 1 below shows detailed data of the test sample, and Table 2 shows a comparison of experimental results with the sample.

[Table 1]

[Table 2]

An AT-cut quartz-crystal vibrating piece used in the experiment was used. As shown in Table 1, the external shape of the conventional example and that of the embodiment need to be equalized due to the restrictions of the package. Therefore, the shape of the excitation unit 12 is slightly reduced in the embodiment (stepped step shape). I have.

The quartz-crystal vibrating piece 10 according to the present embodiment
When the average value of the crystal impedance of the resonator element is compared with that of the conventional crystal impedance, as shown in Table 2, it is found that the value of the crystal impedance in the resonator element is low and the degree of variation is further reduced.

Further, the quartz vibrating reed 10 was attached to the base substrate using a conductive adhesive, and the difference between the frequency immediately after mounting and the frequency after passing through an annealing process for stress relaxation was verified. As shown in Table 2, it is better to make the steps stepwise.
It has been found that the frequency shift after the completion of the annealing step is reduced, which is advantageous from the viewpoint of frequency yield.

FIG. 2 shows a form of a crystal resonator in which the crystal resonator element according to the present embodiment is mounted on a base substrate. FIG. 2A is a cross-sectional view of the crystal resonator, and FIG. )
FIG. 3 is a top view of the vibrator, and FIG. 3C is an explanatory diagram of an external force applied to a crystal resonator element.

As shown in FIGS. 1A and 1B, in the quartz-crystal vibrating piece 10 according to the present embodiment, the frame 12
The mounting electrode 18 formed on the base substrate 24 is attached to a connection electrode 26 provided on the surface of the base substrate 24 by a conductive adhesive 28. After electrical connection between the terminal electrode 30 formed on the back side of the base substrate 24 and the crystal vibrating piece 10 is achieved, a cover 32 is placed on the front side of the base substrate 24 to seal the crystal vibrating piece 10. And this is the crystal oscillator 3
4 is assumed.

The quartz resonator 34 is manufactured through the above steps. The mount electrode 18 of the quartz resonator blank 10 and the connection electrode 26 formed on the base substrate 24 are connected by the conductive adhesive 28. In doing so, the volume of the conductive adhesive 28 is reduced by curing. And a pair of mounting electrodes 1
When an external force from the conductive adhesive 28 is applied to the frame 8, the frame 12 is deformed as shown in FIG. 3C (see the arrow 36 in the figure for the direction of the deformation), and the frame 12 is deformed. With the deformation of 12, the excitation unit 14 is also deformed, and the main frequency of the excitation unit 14 may greatly deviate from the set value. Usually, the quartz vibrating reed 10 is put into a constant temperature bath or the like together with the base substrate 24 and subjected to an annealing process by heating, so that the external force from the conductive adhesive 28 is reduced, and the excitation unit 1
The main frequency of No. 4 is returned to the vicinity of the set value. However, if the strength of the frame 12 described above is low, the amount of deformation increases, and even after annealing, the main frequency of the excitation unit 14 moves to the vicinity of the set value. It may be gone. However, in the quartz-crystal vibrating reed 10 according to the present embodiment, since the step-like step 22 is formed between the frame 12 and the excitation section 14, the range in which the step 22 is located becomes wide, and the frame 12 Has increased torsional rigidity. For this reason, as shown in Table 2, even if the contracting force of the conductive adhesive 28 is applied to the frame 12, the amount of deformation of the frame 12 can be reduced, and the excitation disposed inside the frame 12 can be reduced. Frequency fluctuations of the plate can be minimized.

FIG. 3 is a perspective view of an excitation unit in the crystal resonator element according to the present embodiment. As shown in FIG.
2 is the same as that of the conventional quartz-crystal vibrating piece and the step-like step 22 is formed, the side dimension (area) of the excitation section 14 serving as the reverse mesa section is reduced, but the side ratio (size / thickness) is reduced. A smaller value is advantageous in spurious suppression. FIG.
Is a graph showing a main vibration set in the excitation unit, and a mode chart of spurious vibration generated in the excitation unit,
FIG. 1A shows a case where the dimensional ratio is in a low range, and FIG.
Indicates a case where the dimensional ratio is in a high range.

As shown in these figures, the higher the side ratio, the larger the number of spurious components (see black circles 38 in the figure). Note that the spurious described in the present embodiment indicates mechanical vibration generated in the excitation unit 14, and indicates a frequency generated at a wavelength obtained by dividing the dimension of the excitation unit 14 by an integer, and each side of the excitation unit 14. The frequency that occurs at the least common multiple when divided by an arbitrary integer corresponds. If the frequency of the spurious vibration and the frequency of the excitation unit 14 match, an obstacle occurs that the amplitude of the main vibration cannot be detected normally.

The main vibration of the excitation section 14 is called a thickness shear vibration.

[Formula 1] Is set by

When the value of the frequency f of the main vibration is set here, it is necessary to set the dimensions of the excitation section 14 so that the spurious vibration does not coincide with the value of the main vibration, as described above. As shown in 2), usually, the side ratio of the inverted-mesa AT type quartz-crystal vibrating piece is around 100, and it is very difficult to avoid spurious.

However, by forming a step-like step 22 between the frame 12 and the excitation section 14, the length of each side forming the excitation section 14 can be reduced. As shown in the figure, the side ratio is about half of the conventional one (side ratio 50)
This makes it possible to easily avoid spurious emissions and increase the degree of freedom in design.

The procedure for manufacturing such a crystal resonator element 10 will be described below. 5 to 7 are process explanatory diagrams showing a manufacturing process of a step-like step in the crystal resonator element according to the present embodiment.

After both surfaces of the crystal wafer 40 are mirror-finished as shown in FIG. 5A, as shown in FIG.
Is formed to a thickness of 50 to 300 nm by vapor deposition or sputtering to form a corrosion-resistant film 42 of hydrofluoric acid.

Then, as shown in FIG.
A photoresist is applied to the upper layer of the corrosion-resistant film 42 made of and dried to form a resist film 44. Next, as shown in FIG.
A stainless steel mask 48 from which the etching pattern portion of the corrosion-resistant film 42 of No. 6 is removed is brought into close contact with the quartz wafer 40.

After the mask 48 is brought into close contact with the resist film 44 in this manner, as shown in FIG. 5 (5), oxygen plasma is applied to the entire surface of the quartz wafer 40, and the resist in the etching pattern portion exposed from the mask 48 is exposed. Removing the membrane 44,
The corrosion-resistant film 42 made of Au / Cr is exposed.

Then, as shown in FIG. 6A, Au / C
After the corrosion-resistant film 42 made of r is removed by etching to expose the surface of the quartz wafer 40, as shown in FIG. 2B, the exposed surface of the quartz wafer 40 is etched with an etchant such as hydrofluoric acid. Half-etch to a predetermined thickness. After the half-etching is performed in this manner, a stainless steel mask 52 having a recess 50 slightly larger than the recess 46 is brought into close contact with the resist film 44 as shown in FIG. As shown in (2), oxygen plasma is applied to the entire surface of the quartz wafer 40 to remove the resist film 44 in the etching pattern portion exposed from the mask 52, thereby exposing the corrosion-resistant film 42 made of Au / Cr.

Next, as shown in FIG.
The corrosion resistant film 42 made of Cr is removed by etching to expose the surface of the quartz wafer 40, and as shown in FIG.
The crystal wafer 40 may be half-etched to a predetermined thickness with an etchant such as hydrofluoric acid so that the step 22 is formed.

After the step 22 is formed, the resist film 4 remaining on the surface as shown in FIG.
4 and then the corrosion-resistant film 42 of Au / Cr remaining on the surface of the crystal wafer 40 as shown in FIG. By performing such a procedure, a step-like step 22 can be formed between the frame body 12 and the excitation unit 14.

[0045]

As described above, according to the present invention, a method for manufacturing a piezoelectric vibrating reed is provided by forming a concave recess by etching inside a vibrating reed made of a piezoelectric material, After the excitation portion is located inside the frame, an excitation electrode is provided on the excitation portion, and a wiring pattern led out from the excitation electrode to the frame on a step formed around the excitation portion formed by the etching. A method of manufacturing a piezoelectric vibrating reed, wherein the step of etching the vibrating reed a plurality of times to form the step in a step shape, and then forming the wiring pattern on the step formed in the step shape, A step of pulling out the excitation electrode to the frame,

In the piezoelectric vibrating reed according to the present invention, a step having a plurality of steps is formed between a frame forming the outer shape of the vibrating reed and an exciting portion formed in a recess inside the frame. Forming an excitation electrode in the excitation section, providing a wiring pattern on the step having a plurality of steps, pulling out the excitation electrode to the frame by the wiring pattern, and a frame that forms the outer shape of the resonator element, A step formed of a plurality of steps is formed between the exciting portion formed in a concave shape inside the frame body, and by reducing the area of the exciting portion, the spurious of the exciting portion is reduced.

Further, the piezoelectric oscillator according to the present invention is characterized in that a step having a plurality of steps is formed between a frame forming the outer shape of the vibrating reed and an exciting portion formed in a recess inside the frame. A piezoelectric vibrating reed in which an excitation electrode is formed in the excitation section, a wiring pattern is provided on the step having a plurality of steps, and the excitation electrode is drawn out to the frame by the wiring pattern,
A base substrate having a terminal electrode connected to the wiring pattern drawn out to the frame of the piezoelectric vibrating reed via a conductive adhesive, and a cover covering the base substrate and sealing the piezoelectric vibrating reed. From having

It is possible to prevent an increase in the resistance value of the wiring pattern formed on the step around the excitation portion and the disconnection of the wiring pattern, to improve the degree of freedom in designing the wiring pattern, and to attach the piezoelectric vibrating piece. The frequency offset amount can be reduced, and the main vibration of the piezoelectric vibrating piece can be prevented from overlapping the mechanical auxiliary vibration generated in the excitation unit.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a shape of a quartz-crystal vibrating piece according to the present embodiment.

FIG. 2 is an explanatory view showing a form of a crystal resonator in which a crystal resonator element according to the present embodiment is mounted on a base substrate.

FIG. 3 is a perspective view of an excitation unit in the crystal resonator element according to the present embodiment.

FIG. 4 is a graph showing a mode chart of a main vibration set in an excitation unit and a spurious vibration generated in the excitation unit.

FIG. 5 is a process explanatory view showing a manufacturing process of a step-like step in the quartz-crystal vibrating piece according to the present embodiment.

FIG. 6 is a process explanatory view showing a manufacturing process of a step-like step in the quartz-crystal vibrating piece according to the present embodiment.

FIG. 7 is a process explanatory view showing a manufacturing process of a step-like step in the quartz-crystal vibrating piece according to the present embodiment.

FIG. 8 is an explanatory view showing the shape of a conventional inverted-mesa type piezoelectric vibrating reed.

[Explanation of symbols]

1 ... Piezoelectric vibrating reed, 2 ... Frame, 3 ... Exciting part,
4 ... Excitation electrode, 5 ... Mount electrode, 6 ... Step, 7 ... Wiring pattern, 10 ... Crystal vibrating piece, 1
2 ... frame, 14 ... excitation part, 16 ... excitation electrode, 18 ... mount electrode, 20 ... wiring pattern, 22 ... step, 24 ... base substrate, 26 ... …
... Connection electrodes, 28... Conductive adhesive, 30... Terminal electrodes 32... Cover 34.
6, arrows, 38, black circles, 40, quartz wafers, 42, corrosion-resistant films, 44, resist films, 46
... Recesses, 48 masks, 50 recesses, 5
2 ... mask

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J108 BB02 CC04 CC11 DD02 EE03 FF07 FF11 GG03 KK01 KK02 MM11 MM14

Claims (11)

[Claims] 1. A concave recess is formed inside a vibrating reed made of a piezoelectric material by etching, and the vibrating reed is formed as a frame,
After the excitation portion is located inside the frame, an excitation electrode is provided on the excitation portion, and a wiring pattern led out from the excitation electrode to the frame on a step formed around the excitation portion formed by the etching. A method of manufacturing a piezoelectric vibrating reed, wherein the step of etching the vibrating reed a plurality of times to form the step in a step shape, and then forming the wiring pattern on the step formed in the step shape, A method for manufacturing a piezoelectric vibrating reed, wherein the excitation electrode is drawn out to the frame. 2. The method for manufacturing a piezoelectric vibrating reed according to claim 1, wherein the processing speed of the etching is changed every plural times. 3. The method of manufacturing a piezoelectric vibrating reed according to claim 2, wherein the processing speed of the final etching for forming the excitation section is minimized. 4. A step having a plurality of steps is formed between a frame forming the outer shape of the resonator element and an excitation section formed in a recess inside the frame, and an excitation electrode is formed on the excitation section. And providing a wiring pattern on the step having a plurality of steps,
A piezoelectric vibrating reed, wherein the excitation electrode is drawn out to the frame by the wiring pattern. 5. An inverted-mesa type piezoelectric vibrating reed, wherein a recess having a concave cross section is formed on one surface of the vibrating reed, and the vibrating reed comprises a frame and an excitation unit located inside the frame. Forming a step comprising a plurality of steps between the frame and the excitation unit,
A piezoelectric vibrating reed, wherein an excitation electrode is formed in the excitation section, a wiring pattern is provided on the step having a plurality of steps, and the excitation electrode is drawn out to the frame by the wiring pattern. 6. An inverted-mesa type piezoelectric vibrator in which a recess is formed on both surfaces of a vibrating bar so that the vibrating bar has an H-shaped cross section, and the vibrating bar includes a frame and an excitation unit located inside the frame. Forming a plurality of steps between the frame and the excitation section, forming an excitation electrode on the excitation section, and providing a wiring pattern on the plurality of steps, A piezoelectric vibrating reed, wherein the excitation electrodes are drawn out to the frame by a pattern. 7. The piezoelectric vibrating reed according to claim 6, wherein the plurality of steps are formed on both surfaces of the vibrating reed. 8. A step formed of a plurality of steps is formed between a frame forming an outer shape of a resonator element and an excitation section formed in a concave shape inside the frame, and by reducing the area of the excitation section, A piezoelectric vibrating reed, wherein spurious reduction of the excitation section is reduced. 9. The piezoelectric vibrating reed according to claim 8, wherein the area of the excitation section is set such that a ratio of a side length to a thickness of the excitation section is 50 or less. 10. The piezoelectric vibrating reed according to claim 4, wherein the piezoelectric vibrating reed is made of quartz. 11. A step having a plurality of steps is formed between a frame forming an outer shape of a resonator element and an excitation section formed in a recess inside the frame, and an excitation electrode is formed on the excitation section. In addition, a wiring pattern is provided on the step formed of a plurality of steps, and the excitation electrode is drawn out to the frame by the wiring pattern, and the wiring pattern drawn out to the frame of the piezoelectric vibration piece is electrically connected to the wiring pattern. A piezoelectric vibrator, comprising: a base substrate having a terminal electrode connected through a conductive adhesive; and a cover covering the base substrate and sealing the piezoelectric vibrating reed.