JP2984245B2 - Method for processing metal film on base material, method for manufacturing vibrator, and method for manufacturing vibration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing a metal film on a substrate, a method for manufacturing a vibrator, and a method for manufacturing a vibration device. This vibrator can be particularly suitably used in an angular velocity sensor used for detecting a rotational angular velocity in a rotary system.

[0002]

2. Description of the Related Art Conventionally, as an angular velocity sensor for detecting a rotational angular velocity in a rotating system, a vibrating gyroscope using a piezoelectric body has been used for confirming the position of an aircraft, a ship, a space satellite, or the like. Was. Recently, it has been used as a consumer field for car navigation, detection of camera shake of a VTR or a still camera, and the like.

[0003] Such a piezoelectric vibratory gyroscope utilizes the fact that when an angular velocity is applied to a vibrating object, a Coriolis force is generated in a direction perpendicular to the vibration. And the principle is analyzed with a mechanical model (for example,
"Acoustic Wave Technology Handbook", Ohmsha, 491
497). Various types of piezoelectric vibrating gyroscopes have been proposed so far. For example, Sperry tuning fork type gyroscope, Watson tuning fork type gyroscope, equilateral triangular prism type resonating gyroscope,
A cylindrical sound piece gyroscope and the like are known.

When manufacturing a vibrator for such a vibratory gyroscope, it is necessary to cut a quartz substrate, for example, by etching in a liquid and pattern the substrate.
For example, Japanese Patent Application Laid-Open No. Sho 60-73414 discloses that semiconductor manufacturing techniques such as formation of a conductive thin film and photoresist are diverted. Also, Japanese Patent Application Laid-Open No.
In Japanese Patent No. 5338, metal films are formed on both the front and back surfaces of a substrate (especially, a vibrator) in order to form circuits such as electrodes on the front and back surfaces of a vibrator made of quartz or the like. When irradiated so as to converge on the focal point, electromagnetic waves capable of melting and evaporating the metal film (especially YAG
(Laser light) Irradiation device is prepared, and Y
The AG laser is converged by a lens and irradiated to the vibrator. At this time, the relative position of the vibrator and the YAG laser irradiation device is adjusted so that the YAG laser light is focused on a focal point located at an intermediate position between the front and back surfaces of the vibrator. Adjust the position. As a result, YAG
On the front side where the laser is incident, the metal film in that part melts and evaporates only in the range where the laser is irradiated, and also on the back side of the vibrator, the metal film in that part only in the range where the laser is emitted Melts and evaporates.

[0005]

However, when the present inventor worked an electrode on a vibrator using this technique, it was found that distortion and microcracks actually occurred in the vibrator. did. Since the vibrator of the piezoelectric vibratory gyroscope requires extremely high dimensional accuracy, there is a possibility that the vibrator may malfunction due to distortion or micro cracks caused by such laser processing.

An object of the present invention is to process a workpiece having a base material made of a piezoelectric material and metal films provided on a plurality of surfaces of the base material, In removing each of the metal films on the surface of the substrate, the processing accuracy of the metal films on the plurality of surfaces on the base material is increased, and distortion, reduction in dimensional accuracy, and micro cracks in the base material are prevented. It is to be.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method for processing a workpiece comprising a base material made of a piezoelectric material and metal films provided on a plurality of surfaces of the base material. A method of removing each metal film on a plurality of surfaces of the material, respectively, passing laser light through a mask member having a predetermined pattern,
Diffusion light is obtained by converging laser light at a focal point at a position distant from the workpiece, allowing the diffusion light to pass through each metal film and base material on multiple surfaces, and the diffused light is substantially absorbed in the piezoelectric material. Characterized by removing a region of each metal film irradiated with diffused light by dissociating and evaporating metal atoms constituting each metal film without penetrating the base material without being absorbed. .

The present invention also relates to a method of manufacturing a vibrator made of a piezoelectric material, comprising preparing a substrate made of a piezoelectric material and having a pair of main surfaces and a pair of side surfaces, A metal film serving as a material for an etching mask is provided on a pair of main surfaces to obtain a work piece for a vibrator, and a laser beam is passed through a mask member having a predetermined pattern corresponding to the shape of the vibrator to be processed. Diffuse light is obtained by converging the laser light at a focal point located away from the body, allowing the diffused light to pass through the metal film and substrate on each main surface, and the diffused light is substantially absorbed in the piezoelectric material. By transmitting through the substrate without being absorbed and dissociating and evaporating the metal atoms constituting the metal film, a region of the metal film irradiated with the diffused light is removed and a mask is formed on each main surface of the substrate. And then The substrate was prepared vibrator by etching, and removing the mask from the vibrator.

The present invention is also a method of manufacturing a vibrating device comprising a vibrator made of a piezoelectric material and electrodes having a predetermined pattern provided on the vibrator.
A substrate made of a piezoelectric material and having a pair of main surfaces and a pair of side surfaces is prepared, and a mask metal film serving as a material for an etching mask is provided on at least the pair of main surfaces of the substrate to form a vibrator cover. A work piece is obtained, laser light is passed through a first mask member having a predetermined pattern corresponding to the shape of the vibrator, and the laser light is diffused by converging the laser light at a focus located at a position away from the work piece for the vibrator. Light, allowing the diffused light to pass through each mask metal film and substrate on each major surface, allowing the diffused light to pass through the substrate without being substantially absorbed in the piezoelectric material; By dissociating and evaporating the metal atoms that make up the metal film, the regions of each metal film for the mask that were exposed to the diffused light were removed, and a mask was formed on each main surface of the substrate, and then the substrate was etched. Process And a mask is removed from the vibrator, a metal film for an electrode is provided on each of a plurality of surfaces selected from a main surface and side surfaces of the vibrator, and a shape corresponding to the shape of the electrode is formed. Laser light is passed through a second mask member having the laser light, and the laser light is converged at a focal point at a position away from the vibrator to obtain diffused light so that the diffused light passes through the vibrator and the metal film for each electrode. At this time, the diffused light passes through the vibrator without being substantially absorbed in the piezoelectric material, and dissociates and evaporates the metal atoms constituting the metal film for each electrode, thereby forming the metal film for each electrode. Of these, the region irradiated with the diffused light is removed to form electrodes on a plurality of surfaces, respectively.

The principle of the present invention will be described with reference to the schematic diagram of FIG. A laser beam 2A having a predetermined wavelength is oscillated from the laser light source 1, and at this time, the laser beam 2A
The wavelength is set so as to transmit through the base material without being substantially absorbed in the piezoelectric material, and to dissociate and evaporate the metal atoms constituting the metal film. That is, the wavelength is set within a range where the metal film can be ablated.

Next, the laser beam 2A is passed through a mask member 3 having a predetermined pattern, and the contour of the laser beam is shaped to obtain a laser beam 2B having a predetermined pattern. This pattern corresponds to the plane form of the vibrator and the form of the electrodes on the vibrator as described later.
Next, the lens 4 at a position away from the workpieces 6 and 7
Through the laser beam 2B to obtain a convergent beam 2C. The convergent light 2C focuses on the focal point 5 before the workpieces 6 and 7 to become diffused light 2D, and the diffused light 2D is applied to the workpieces 6 and 7. In the workpieces 6 and 7, each metal film and the base material on the plurality of surfaces are irradiated with the diffused light 2D, but the diffused light 2D is substantially absorbed in the piezoelectric material. By dissociating and evaporating the metal atoms that are transmitted and constitute the metal film, the region of the metal film irradiated with the diffused light is removed.

As described above, in the present invention, a laser beam having a wavelength that allows the metal film to be ablated by passing through the substrate is used, and the laser beam is focused on a focal point at a position distant from the substrate. The light was once collected to obtain diffused light, and this diffused light was irradiated to the workpiece. by this,
Distortion, deterioration of dimensional accuracy,
It has been discovered that each metal film on a plurality of surfaces on a substrate can be simultaneously patterned without generating myrocracks.

The present inventor has further studied the reason why the above-mentioned effects are obtained. That is, in the ablation process, the material of the metal film is instantaneously decomposed and vaporized in the light-irradiated portion, so that the portion of the metal film to which the laser light is not directly applied and the piezoelectric material forming the base material It is considered that there was almost no influence of heat, stress, and the like, and no affected layer was formed at all.

Japanese Patent Application Laid-Open No. Hei 7-115338 discloses a technique in which a metal film on the front surface and the back surface of a substrate is melted and processed by heat. For this purpose, a YAG laser beam having a wavelength of 1000 nm or more is used. Each metal film on the front surface and the back surface is melted and evaporated. To carry out such a thermal process, a focal point is located in the substrate,
It is necessary to generate heat intensively in each metal film on the front surface and the back surface of the substrate. However, in this process, when the metal film was melted, heat and stress were concentrated on the interface between the metal film and the substrate, and it is considered that large internal stress was generated in the substrate.

In the method of utilizing laser light for thermal melting as disclosed in Japanese Patent Application Laid-Open No. Hei 7-115338, the light intensity distribution becomes sharpest at the convergence position of the laser light. Therefore, the highest processing accuracy can be obtained by adjusting the light convergence position to the position of the substrate. As the substrate moves away from the light condensing position, the light intensity distribution becomes unclear, and the processing accuracy is significantly reduced.

On the other hand, in the method of the present invention,
The collimated light 2A is once passed through the mask member 3 to obtain light 2B having a pattern of the mask member 3. The light 2 </ b> B is condensed by the lens 4, and the pattern of the mask member 3 can be imaged at a predetermined imaging position 30.
The pattern of the mask member 3 borne by the laser light becomes unclear as the distance from the mask member 3 increases. However, at the image forming position 30, a clear image accurately corresponding to the pattern of the mask member 3 is formed. Therefore, by setting the workpieces 6 and 7 at the image forming position without adjusting the light convergence position to the position of the substrate, high processing accuracy can be obtained.

The image forming position 30 is [1 / f = 1 / a
(A is the distance between the mask member 3 and the lens 4, b is the distance between the lens 4 and the imaging position 30, and f is the focal length of the lens 4 Is.). Further, the enlargement and reduction magnification of the pattern of the mask member 3 at the image forming position are also determined by these positional relationships.

Hereinafter, more specific embodiments of the present invention will be described. The vibrator obtained by the present invention can be suitably used, for example, for a vibration gyroscope for a rotation speed sensor used in a vehicle control method of a vehicle body rotation speed feedback type. In such a system, the direction of the steered wheels is detected by the rotation angle of the steering wheel. At the same time, the rotational speed at which the vehicle body is actually rotating is detected by the vibration gyroscope. Then, the direction of the steered wheels is compared with the actual rotational speed of the vehicle body to obtain a difference, and the wheel torque and the steering angle are corrected based on the difference, thereby realizing stable vehicle body control.

Although the material of the vibrator or the substrate is not particularly limited, quartz, LiNbO ₃ , LiTaO ₃ , lithium niobate-lithium tantalate solid solution (Li (Nb, Ta)
A piezoelectric single crystal composed of O ₃ ) single crystal, lithium borate single crystal, langasite single crystal and the like is particularly preferable. Also, PZ
Piezoelectric ceramics such as T can also be used.

The wavelength of the laser is 150 to 300.
Excimer laser light in the ultraviolet region of nm is preferred.
Excimer lasers are characterized in that the wavelength can be selected according to the type of gas to be sealed. Ablation processing is a processing method in which high-energy light such as excimer laser light is applied to a material to be processed, thereby instantaneously decomposing and vaporizing a portion irradiated with light, thereby obtaining a target shape.

The wavelength of the light source for ablation needs to be a wavelength at which the metal film can be ablated. Since the wavelength region suitable for such ablation processing varies depending on the position of the light absorption edge of the crystal to be processed, it cannot be uniformly defined. However, generally, it is necessary to use light having a shorter wavelength than the absorption edge of the metal film. In this respect, light having a wavelength of 400 nm or less is usually preferable, light having a wavelength of 350 nm or less is particularly preferable, and 300 nm or less is more preferable.

On the other hand, the wavelength of the laser light must be longer than the absorption edge of the piezoelectric material constituting the base material or the substrate, and is more preferably 100 nm or more longer than the absorption edge. . For this reason, the wavelength of the laser light is preferably 150 nm or more, and 200 nm
It is more preferable to make the above.

As actual light sources, in addition to excimer laser light sources, the fourth harmonic of YAG (laser light of 266 nm) and excimer lamps are currently practical.

As a light irradiation apparatus for ablation processing, a so-called batch exposure type apparatus and a multiple reflection type apparatus are known. The multiple reflection method has a feature that the light utilization rate is high even when the aperture ratio of the mask is small. In the present invention, it is more preferable to use an ablation processing apparatus using a multiple reflection system,
Thereby, it is possible to process the entire vibrator having a dimension of 1 inch or more in a short time.

Here, the excimer laser will be further described. An excimer laser is a pulse repetition oscillation laser of ultraviolet light, and has ArF (wavelength 193 nm), Kr
Ultraviolet light oscillated by a gaseous compound such as F (wavelength: 248 nm) and XeCl (wavelength: 308 nm) is extracted by using an optical resonator with uniform directionality. Since an excimer laser is a short-wavelength laser of ultraviolet light, bonds of atoms and molecules constituting a substance can be decomposed by the energy of photons.

It is reported that ablation using an excimer laser is used to form holes for fine processing of, for example, polyimide and the like, and that fine holes having a good shape can be formed. As a literature on applied technology of excimer laser, "O plus E" 1
A special feature, “Excimer Laser Entering the Practical Use Period”, Nov. 995, pp. 64-108, can be mentioned. In the present invention, when processing by excimer laser, spot scan processing, batch transfer processing, and slit scan processing can be used.

The energy density of the laser beam is 0.5-
It is preferably 5.0 J / cm ² . By setting the energy density to 0.5 J / cm ² or more, it is easy to completely remove the metal film as designed. By setting the energy density to 5.0 J / cm ² or less, thermal effects on the substrate side can be further suppressed.

A method of forming a vibrator mask from a substrate made of a piezoelectric material and further obtaining a vibrator with electrodes will be described with reference to FIGS.

As shown in FIG. 2A, mask metal films 9A and 9B are formed on both main surfaces 8a and 8b of a substrate 8 made of a piezoelectric material, respectively, to obtain a workpiece 6A. Next, as shown in FIG. 2B, according to the present invention, the surface 8a is irradiated with diffused light 2D carrying information corresponding to the mask pattern. The diffused light 2D ablates and removes the mask metal films on the front and back sides of the substrate. As a result, the masks 10A and 10B having the same shape and dimensions are formed on the front surface 8a and the back surface 8b of the substrate 8, respectively.
10C and 10D are formed. Dimension a of mask on front side
Is typically 1 μm.
It is possible to:

Next, the substrate with the mask is subjected to etching, and the substrate shown in FIGS. 2 (c), 2 (d) and 4 (a),
The vibrator 11 as shown in FIG. This etching process is described in, for example, Japanese Patent No. 1048133.
This is described in detail in the official gazette.

The form of the vibrator 11 is not particularly limited. For example, the vibrator 11 includes a pair of tuning fork-type vibrating pieces 12A and 12B, and a gap 13 is provided between the vibrating pieces. In addition,
12a and 12b are the front and back surfaces of each resonator element,
c and 12d are side surfaces of each resonator element.

Next, for example, as shown in FIG.
An electrode metal film 14 is formed on the surface of the vibrator 11. The method for forming such a metal film is not particularly limited, and a sputtering method, a chemical vapor deposition method, a physical vapor deposition method, or the like can be used. In the case of using the sputtering method, the metal film covers almost the entire surface of the vibrator. It is formed.

Then, according to the present invention, the diffused light 2D having information on the electrode pattern is applied to each of the vibrating bars 12A, 1A.
2B is irradiated to remove the metal film 14 for each electrode. In this example, for example, each surface 12a of each vibrating piece 12A, 12B
By removing a certain area of each metal film 14 on the back surface 12b, the metal film on the front surface or the back surface and the side surface 1 are removed.
Each metal film on 2c and 12d is insulated from each other, thereby obtaining bending vibration pieces 16A and 16B (FIG. 3 (c)).
And FIGS. 4 (a) and 4 (b)). In the vibrator of this embodiment, the surface 12 is irradiated with diffused light as shown in FIG.
4A and 4B, at the time of patterning the metal films on the upper surface a and the back surface 12b, as shown in FIGS.
The metal film is also removed on the tip 21 side of each of 6A and 16B, and a removal region 22 is provided.

Next, as shown in FIG. 3C, the vibrator 11 is inclined by a predetermined angle, and the diffused light 2D is irradiated on the side surface 12c.
Irradiation. This diffused light removes the metal film on the side surface 12c, passes through the vibrator 11, and exits from the back surface 12b. As a result, as shown in FIGS. 4A and 4B, the metal film on the side surface 12c on the tip 21 side of each bending vibration piece is deleted, and a removal region 23 is provided. Next, the vibrator 11
Is tilted by a predetermined angle in the direction opposite to the direction shown in FIG. 3C, the diffused light 2D is irradiated on the side surface 12d, and the metal film on the side surface 12d is deleted at the tip 21 side of each bending vibration piece. And
A removal region 23 is provided.

Each bending vibration piece 1 shown in FIGS. 4 (a) and 4 (b)
In 6A and 16B, the c-axis extends between the surfaces 12a and 12b, and the a-axis extends between the side surfaces 12c and 12d. This is the case, for example, when using quartz.
Then, each electrode 15A on the front and back surfaces and the side surface 12
By applying an alternating electric field between each electrode 15B on c and 12d, each bending vibration piece can be caused to vibrate in the direction of the a-axis.

In the present invention, the metal film 14 on the surface of the substrate or the vibrator and the metal film on the side surface, or the metal film on the back surface and the metal film on the side surface are simultaneously irradiated by the same diffused light. It can be removed and patterned.
Hereinafter, an embodiment applied to a vibrator will be described with reference to FIGS. 5 and 6.

As shown in FIG. 3A, an electrode metal film 14 is provided on the entire surface of the vibrator. Next, as shown in FIG. 5, the vibrator 11A is tilted by a predetermined angle,
D is irradiated toward the side surface 12c. The diffused light ablates the metal film in the irradiation area on the side surface 12c, and further ablates the metal film in the irradiation area on the back surface 12b.

As shown in FIG. 6A, the vibrator 1
The diffused light 2D is irradiated toward the surface 12a while 1A is tilted by a predetermined angle. This diffused light is
The metal film in the irradiation area on a is ablated, and the metal film in the irradiation area on the side surface 12d is ablated.

Next, as shown in FIG. 6B, the vibrator 11A is tilted by a predetermined angle to the opposite side to that of FIG. Ablation processing is performed on each metal film in each irradiation area on the side surface 12c. Further, ablation processing is performed on each metal film in each irradiation region on the side surface 12d and the back surface 12b,
An electrode 15C is provided.

Further, a hole can be provided in each bending vibration piece so as to extend in the longitudinal direction of each bending vibration piece of the vibrator. This hole may be a through hole that penetrates the bending vibration piece, or may be a blind hole that does not penetrate the bending vibration piece, that is, a concave portion. Thereby, the natural resonance frequency of the vibration of the bending vibration piece can be reduced, and the Q value of the drive vibration or the detection can be further improved. Also in this case, the electrode can be formed at a predetermined position of the vibrator by applying the processing method of the present invention.

FIG. 7 and FIG. 8 respectively show a processing process of each bending vibration piece according to this embodiment.

In FIG. 7A, an electrode metal film 14 is formed on, for example, the entire surface of the resonator element 17A. Here, the vibrating piece 17A has a through hole 1 extending in the length direction thereof.
8 are provided. However, 17a and 17e are the front surfaces of the resonator element 17A, 17c and 17g are the back surfaces, and 1
7b and 17h are outer surfaces of the resonator element, and 17d and 17h.
f is an inner surface facing the through hole of the resonator element. Also in the present embodiment, a piezoelectric single crystal plate having an a-axis of a three-fold symmetry axis in a predetermined plane, such as quartz, is used. For this reason, c is applied between the front surface and the back surface of each resonator element. The axis is extended,
The a-axis extends between the inner surface and the outer surface of each resonator element.

In this state, diffused light 2D is irradiated as shown in FIG.
7 g of each metal film 14 is removed. At this time, the inner surface 17
The metal films on d and 17f and the respective metal films on the outer surfaces 17b and 17h are left. These remaining metal films can be used as drive electrodes or detection electrodes.

For example, in the driving bending vibrating piece 24A shown in FIG. 7C, drive electrodes 15D and 15G are provided on the outer surfaces 17b and 17h, respectively, and on the inner surfaces 17d and 17f, respectively. Drive electrodes 15E, 15F
Is provided. For example, the drive electrode 15D on the outer surface,
15G to the AC power supply 20 and drive electrode 1 on the inner surface.
Ground 5E and 15F. As a result, the drive electrode 15D
Since the voltage application direction is reversed between the combination of −15E and the combination of the drive electrodes 15F to 15G, the bending vibration piece 24A bends in the direction of the a-axis.

As in the present embodiment, in each through hole of each bending vibration piece, driving electrodes are provided on the inner and outer surfaces on both sides of the hole 18 so that one bending vibration piece is indicated by an arrow A. Can be bent as follows. This makes it possible to drive the bending vibration piece by applying a voltage in the a-axis direction having the highest excitation efficiency.

The electrodes 15D, 15E, 15F, 15
When G is used as a detection electrode, a gap for detection is provided at the position of the AC power supply.

In each of the above embodiments, each arm is driven by applying a voltage in the direction of the a-axis of the piezoelectric single crystal. On the other hand, in the case of, for example, lithium niobate, lithium tantalate, or a lithium niobate-lithium tantalate solid solution single crystal, for example, FIG.
As shown in the figure, a 130 ° Y plate is used. In this case, the c-axis forms an angle of 50 ° with the main surface of the vibrator, and at this angle, the temperature characteristics of the vibrator become the best.

The vibrating piece 17B has a through hole 18 extending in the longitudinal direction. In this state, FIG.
As shown in (2), the diffused light 2D is irradiated to simultaneously remove the metal films 14 on the outer surface 17b, the inner surface 17d, the inner surface 17f, and the outer surface 17h. At this time, the surfaces 17a, 17e
The upper metal film and the metal films on the back surfaces 17c and 17g are left. These remaining metal films can be used as drive electrodes or detection electrodes.

For example, in the driving bending vibration piece 17B shown in FIG. 8C, elongated driving electrodes 15H, 15J, 15K and 15L are provided at positions on both sides of each through hole 18. Drive electrode 15H-15J and drive electrode 15K-1
Since the application direction of the voltage becomes opposite to that between 5 L and 5 L, the bending vibration piece bends as shown by arrow B.

The electrodes 15H, 15J, 15K, 15
When L is used as a detection electrode, a gap for detection is provided at the position of the AC power supply.

In each of the above-described examples of FIGS. 7, 7 and 8, instead of the through hole 18, a concave portion having the same planar shape as the through hole 18 may be provided. That is, in each bending vibration piece, a thin wall can be provided without penetrating the through hole 18 between the front surfaces 17a and 17e and the back surfaces 17c and 17g.

Next, according to the present invention, a tuning fork vibrator for a piezoelectric vibratory gyroscope was manufactured as described with reference to FIGS. Specifically, a quartz Z-plate 8 having a length of 2 inches, a width of 2 inches and a thickness of 0.3 mm is prepared, and a thickness of 20 nm is formed on both the front and back surfaces of the Z-plate by a normal sputter deposition method. And a 200 nm-thick gold layer were formed to obtain a workpiece 6A. The workpiece 6A was placed on a processing stage of a KrF excimer laser processing device (laser light wavelength: 248 nm), and the metal film on the front and back surfaces of the Z plate was removed and patterned by this device. At this time, the laser energy density on the surface of the substrate was set to 2.0 J / cm ²
And the scanning speed of the laser beam is 1.2 mm / sec,
The pulse repetition frequency was set to 195 Hz, and the pulse width was set to 120 nsec.

Next, the processing stage was moved up and down so that the size of each of the metal films on the front and back surfaces of the substrate after removal was within a predetermined accuracy range, and the focal point of the laser beam was moved away from the substrate by about 10 mm. It was set at the position, and a laser beam was made incident from the surface side of the substrate to form a mask pattern for etching.

Next, the substrate was wet-etched in an ammonium fluoride solution, and the outer shape was cut out to obtain a vibrator 11 having a desired shape. The vibrator 11 was immersed in a mixed solution of ceric ammonium nitrate + nitric acid + perchloric acid to dissolve and remove the mask.

Next, the vibrator 11 was washed with an organic solvent, and a titanium layer having a thickness of 20 nm and a gold layer having a thickness of 200 nm were formed again by the sputter deposition method. The vibrator was set in the same apparatus as that used for forming the etching mask described above, and only the metal film 14 was removed by laser ablation processing and patterned to form the electrodes 15A and 15B.

When the thus-obtained transducer with electrodes was inspected visually and by ultrasonic testing, no microcracks were observed. The dimensional accuracy of each electrode was within ± 5 μm.

[Brief description of the drawings]

FIG. 1 shows a laser beam 2A according to the present invention;
FIG. 7 is a schematic diagram for explaining a process up to irradiation with No. 7;

FIG. 2A is a cross-sectional view showing a workpiece 6A;
(B) is a cross-sectional view schematically showing a state where the workpiece 6A is irradiated with diffused light, (c) is a cross-sectional view showing the vibrator 11, (d) is a vibrating piece 12A, It is a fracture | rupture perspective view which shows 12B.

3A is a cross-sectional view schematically illustrating a state in which a metal film 14 is provided on a vibrator 11, and FIG. 3B is a state in which diffused light is irradiated on the vibrator in FIG. FIG.
(C) is a cross-sectional view showing a state in which the vibrator of (b) is further inclined to perform ablation processing.

FIG. 4A is a side view of bending vibration pieces 16A and 16B.
FIG. 2B is a front view when viewed from the side 2c, and FIG. 2B is a front view when the bending vibration pieces 16A and 16B are viewed from the front surface 12a side.

FIG. 5 is a cross-sectional view for explaining a process of processing the oscillator 11A by inclining it.

FIGS. 6 (a) and 6 (b) are cross-sectional views for explaining a process in which the bending vibrating pieces 12C and 12D of the vibrator 11A are machined by being inclined.

FIGS. 7A, 7B, and 7C are cross-sectional views schematically showing one suitable process for processing a bending vibrating piece of a vibrator made of quartz or the like having a through hole 18. FIGS. .

FIGS. 8A, 8B and 8C are cross-sectional views schematically showing one suitable process for processing a bending vibrating piece of a vibrator made of lithium niobate or the like having a through hole 18; It is.

[Explanation of symbols]

1 Laser light source 2A Laser light of predetermined wavelength
2B Laser light carrying a predetermined pattern 2C
Convergent light 2D Diffuse light 3 Mask member 4
Lens 5 Focus 6, 6A, 7 Workpiece
8 Substrate made of piezoelectric material 8a, 8b Main surface (front and back) of substrate 9A, 9B Metal film for mask 10A, 10B, 10C, 10D Mask 11, 11A Transducer 12A, 12B,
17A Vibrating bar 12a, 17a, 17e Surface of vibrating bar 12b, 17c, 17g Back surface of vibrating bar
12c, 12d Side surface of resonator element 14 Metal film for electrode 15A, 15B Drive electrode 16A,
16B Flexural vibrating piece 17b, 17h Outer side face of vibrating piece 17d, 17f Inner side face facing through hole of vibrating piece 18 Through hole

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C23F 4/02 B23K 26/00 G01C 19/56 H03H 3/02 G01P 9/04

Claims (11)

(57) [Claims] An object to be processed comprising a base material made of a piezoelectric material and metal films provided on a plurality of surfaces of the base material is processed, and a workpiece is formed on the plurality of surfaces of the base material. A method of removing each of the metal films, wherein the laser light is passed through a mask member having a predetermined pattern, and the laser light is converged at a focal point at a position distant from the workpiece. To transmit the diffused light to the respective metal film and the substrate on the plurality of surfaces, the diffused light is transmitted through the substrate without being substantially absorbed in the piezoelectric material, A method for processing a metal film on a base material, wherein a region of the metal film irradiated with the diffused light is removed by dissociating and evaporating metal atoms constituting the metal films. . 2. The method according to claim 1, wherein the pattern of the mask member is imaged in the workpiece with the diffused light.
The method for processing a metal film on a substrate according to claim 1. 3. The method for processing a metal film on a substrate according to claim 1, wherein the piezoelectric material is an oxide single crystal. 4. The oxide single crystal is selected from the group consisting of quartz, lithium niobate, lithium tantalate, lithium niobate-lithium tantalate solid solution single crystal, lithium borate single crystal and langasite single crystal. The method for processing a metal film on a substrate according to claim 3, wherein the metal film is at least one oxide single crystal. 5. The method according to claim 1, wherein the laser light is 150 to 350 n.
The method for processing a metal film on a base material according to any one of claims 1 to 4, wherein a laser beam having a wavelength of m is used. 6. The base material is a substrate having a pair of main surfaces and a pair of side surfaces, wherein the metal films are provided on the pair of main surfaces, respectively. Characterized in that at least part of the metal film is removed at the same time,
A method for processing a metal film on a base material according to any one of claims 1 to 5. 7. The base material is a substrate having a pair of main surfaces and a pair of side surfaces, and the metal film is provided on at least one of the pair of main surfaces and at least one of the pair of side surfaces. The method according to claim 1, wherein at least a part of the metal film on the main surface and the metal film on the side surface is removed by irradiation with the diffused light. 5. The method for processing a metal film on a substrate according to the above. 8. A substrate, wherein a hole is provided in the base material, the metal film is provided on an inner wall surface of the base material facing the hole, and at least the metal film on the inner wall surface is provided. The method for processing a metal film on a base material according to claim 1, wherein a part of the metal film is removed by irradiation with the diffused light. 9. A method for manufacturing a vibrator made of a piezoelectric material, comprising: preparing a substrate made of the piezoelectric material, the substrate having a pair of main surfaces and a pair of side surfaces; A workpiece for the vibrator is obtained by providing a metal film serving as a material for an etching mask on the main surface, and a laser beam is passed through a mask member having a predetermined pattern corresponding to the shape of the vibrator, thereby forming the workpiece. Diffuse light is obtained by converging the laser light at a focus located at a position distant from the workpiece, so that the diffused light passes through the metal film and the substrate on each of the main surfaces, and the diffused light is By transmitting through the substrate without being substantially absorbed in the piezoelectric material, and by dissociating and evaporating the metal atoms constituting the metal film, the region of the metal film irradiated with the diffused light, Removal Then, a mask is produced on each main surface of the substrate, and then the substrate is etched to produce the vibrator, and the mask is removed from the vibrator. Production method. 10. A method of manufacturing a vibrating device comprising a vibrator made of a piezoelectric material and electrodes of a predetermined pattern provided on the vibrator, the method comprising: A workpiece provided on each of a plurality of surfaces and including an electrode metal film to be a material of the electrode is prepared, and laser light is passed through a mask member having a shape corresponding to the shape of the electrode. Converging the laser light at a focal point at a position distant from the workpiece to obtain diffused light, and allowing the diffused light to pass through the vibrator and the metal film for each electrode, The light passes through the vibrator without being substantially absorbed in the piezoelectric material, and dissociates and evaporates the metal atoms constituting the metal film for each electrode, thereby forming the metal film for each electrode. Before A method for manufacturing a vibrating device, comprising: removing an area irradiated with the diffused light to form the electrodes on each of the plurality of surfaces. 11. A method of manufacturing a vibrating device comprising a vibrator made of a piezoelectric material and electrodes of a predetermined pattern provided on the vibrator, comprising: a pair of piezoelectric materials; A substrate having a main surface and a pair of side surfaces is prepared, and a metal film for a mask serving as a material for an etching mask is provided on at least the pair of main surfaces of the substrate to obtain a workpiece for the vibrator. Laser light is passed through a first mask member having a predetermined pattern corresponding to the shape of the vibrator, and diffused light is obtained by converging the laser light at a focus located at a position distant from the workpiece for vibrator. The diffused light is transmitted through each of the mask metal films and the substrate on each of the main surfaces, and the diffused light is transmitted through the substrate without being substantially absorbed in the piezoelectric material. And each of the above By dissociating and evaporating the metal atoms constituting the mask metal film, regions of the mask metal film irradiated with the diffused light were removed to form masks on the respective main surfaces of the substrate. Then, the vibrator is manufactured by etching the substrate, the mask is removed from the vibrator, and the electrode metal is formed on a plurality of surfaces selected from the main surface and the side surfaces of the vibrator. A film is provided, laser light is passed through a second mask member having a shape corresponding to the shape of the electrode, and diffused light is obtained by converging the laser light at a focus located at a position distant from the vibrator, The diffused light is transmitted through the vibrator and the metal film for each electrode. At this time, the diffused light passes through the vibrator without being substantially absorbed in the piezoelectric material, and By dissociating and evaporating metal atoms constituting each metal film for an electrode, a region of the metal film for each electrode irradiated with the diffused light is removed to form each of the electrodes on the plurality of surfaces. A method of manufacturing a vibration device, comprising: