JPH112527A - Vibrating gyro with pzt thin-film bimorph structure and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibrating gyro having a PZT thin-film bimorph structure which can readily provide a number of bimorph structures, can be formed into a small bimorph structure, and resists twisting. SOLUTION: A vibrating gyro 1 comprises a pair of parallel flat-plate structures 2, 3 connected in series along the vertical direction. The parallel flat plate structure 2 comprises flat plate-shaped piezoelectric elements 4 constructed of a pair of bimorph structures opposed and secured to each other with an adhesive, with prism-shaped insulating spacers 5 sandwiched between the upper and lower ends thereof. Each of the piezoelectric elements 4 has a PZT thin film 7 formed on each side of a base 6 made from titanium into a flat plate shape of uniform thickness, with an electrode film 8 formed bn the PZT thin film 7 on each side. The parallel flat plate structures 2, 3 are placed in such a way that the sides on which the electrode films 8 are formed are perpendicular to each other, and are bonded together with an adhesive at their upper and lower end faces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrating gyroscope having a PZT thin film bimorph structure and a method for manufacturing the same.

[0002]

2. Description of the Related Art As a conventional vibration gyro, a tuning fork type shown in FIG. 12 and a sound piece type shown in FIG. 13 are known.

In a tuning fork type vibrating gyroscope 21, as shown in FIG. 12, a pair of driving piezoelectric ceramic plates 23 are provided at both ends of a connecting portion 22 so as to stand in parallel with each other, and the plane faces in the X direction in the drawing. Are located in A piezoelectric ceramic plate 24 for detection is integrally erected on the center of the upper end of the piezoelectric ceramic plate 23 for driving, and is arranged so that its plane faces the Y direction in the figure. Note that the X direction and the Y direction are orthogonal to each other. And
By applying an alternating voltage to the lower piezoelectric ceramic plate 23 for driving, the piezoelectric ceramic plate 23
Vibrates in the direction. In this vibration state, the vibration gyro 21
When the rotation around the Z-axis is applied to the detection piezoelectric ceramic 24, the detection piezoelectric ceramic 24 is distorted, and the voltage generated at that time is detected, whereby the force applied to the detection piezoelectric ceramic 24 can be detected. This force is the Coriolis force Fc
And is generally represented by the following equation.

Fc = 2mV × Ω (1) where m is the mass of the vibrating gyroscope 21, V is the vibration speed of the vibrating gyroscope 21, and Ω is the angular velocity of the vibrating gyroscope 25 around the Z axis.

[0005] A vibrating gyroscope 25 of the sound piece type is shown in FIG.
As shown in FIG. 7, a square-pole vibrator 26 made of a constant elastic metal is provided, and a pair of piezoelectric ceramic plates 27 for driving are attached to the side surfaces of the vibrator 26 opposite to each other by 180 degrees. (Only one is shown in the drawing).
A pair of piezoelectric ceramic plates for detection 28 are adhered to the other side surfaces (only one of them is shown in the drawing).
The vibrating gyroscope 25 vibrates the resonator element vibrator 26 in the X and anti-X directions by applying an alternating voltage to the driving piezoelectric ceramic plate 27. In this state, when rotation about the Z-axis is applied to the vibrating gyroscope 26, the detecting piezoelectric ceramics 2
8 is distorted, and by detecting the voltage generated at that time, it becomes possible to detect the Coriolis force acting on the detecting piezoelectric ceramics 28. If the mass m and the vibration velocity V are known, the angular velocity Ω can be derived.

By the way, bulk PZT (ceramic made of a solid solution of lead zircon / titanate: lead titanate, lead zirconate) is provided on the driving piezoelectric ceramic plates 23 and 27 and the detecting piezoelectric ceramic plates 24 and 28. Is used.

[0007]

However, the bulk PZT as described above has a problem that it is difficult to reduce the thickness of the bulk itself and to reduce the size of the entire vibrating gyroscope.

Further, when a vibrating gyroscope is formed by sticking a piezoelectric ceramic plate like a vibrating gyroscope of a sound piece type, there is a problem that the sticking process is increased and the bonding accuracy, that is, the positional accuracy is poor. Therefore, there is a problem that it affects the detection sensitivity and the like, and it is difficult to accurately manufacture a homogeneous product.

The Coriolis force Fc increases as the mass m of the vibrating gyroscope increases, as shown in the above equation (1). As a result, the amount of distortion of the detecting piezoelectric ceramic increases. As a result, the detection voltage also increases. That is, the detection sensitivity is increased. For this reason, it is preferable that the mass of the vibrating gyroscope is large in order to obtain detection sensitivity. However, in the case of a vibrating gyroscope using bulk PZT, there is a problem that the mass cannot be increased unless the base material constituting the bulk PZT is enlarged, and there is a limit in increasing the detection sensitivity.

The Coriolis force Fc, as shown by the above equation (1), increases the Coriolis force when the vibration velocity V is increased. As a result, the amount of distortion of the detecting piezoelectric ceramic increases. Also, the detection voltage increases and the detection sensitivity increases. However, in the case of a tuning fork type vibrating gyroscope, for example, in the case of a tuning fork type vibrating gyroscope, if the bulk PZT base material is thinned, the rigidity is reduced, so that it becomes easy to be twisted and does not vibrate accurately, The distortion for detecting the element is also in a state in which the element is twisted, which causes a problem that accurate detection cannot be performed.

In addition, in the case of bulk PZT, it is difficult to easily produce a bimorph structure,
There was a problem that many bimorph structures could not be obtained each time.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a first object of the present invention is to easily obtain a large number of bimorph structures and to make a small bimorph structure. Another object of the present invention is to provide a vibrating gyroscope having a PZT thin film bimorph structure resistant to twisting.

A second object is to provide a tuning fork type vibration gyro having a PZT thin film bimorph structure which can easily obtain a large number of bimorph structures, can be made into a small bimorph structure, and is resistant to twisting. To provide.

A third object is to provide a manufacturing method capable of obtaining a vibrating gyroscope having a large number of PZT thin film bimorph structures at one time.

[0015]

In order to solve the above-mentioned problems, the present invention according to claim 1 is directed to a method in which a first side surface of a titanium base material and a first side surface are located at 180 degrees opposite to each other. Second
A first parallel plate structure in which a pair of PZT thin film bimorph structures each having a PZT thin film formed thereon and electrodes provided on the PZT thin film are connected to each other in parallel via a spacer; A first parallel plate structure having the same configuration as the first parallel plate structure;
And the second parallel plate structure are integrally connected in series, the first side surface of the titanium base material in one parallel plate structure, and the titanium side in the other parallel plate structure. A gyroscope having a PZT thin-film bimorph structure, which is arranged so as to be orthogonal to the first side surface of the base material, has a gist thereof.

According to a second aspect of the present invention, there is provided a tuning fork type vibrating gyroscope in which the vibrating gyroscope according to the first aspect is provided on both ends of a connecting portion. The invention of claim 3 is
A step of forming a PZT thin film on a first side surface of the titanium base material and a second side surface located 180 degrees opposite to the first side surface by a hydrothermal method; A step of forming electrodes, a step of cutting between adjacent electrodes to obtain a plurality of PZT thin film bimorph structures, and a pair of PZT thin film bimorph structures arranged in a parallel plate shape via spacers and connected and fixed. Obtaining a parallel plate structure, connecting the pair of parallel plate structures in series, and forming a first side surface of a titanium base material in one parallel plate structure and a titanium substrate in the other parallel plate structure. The gist of the present invention is a method of manufacturing a vibrating gyroscope including the steps of arranging and integrating the material so as to be orthogonal to the first side surface of the material.

According to a fourth aspect of the present invention, in the third aspect, in the hydrothermal method, a lead nitrate solution and zirconium oxychloride are stirred together with a mineralizer, pressurized and heated to form a first and a second titanium substrate. A step of obtaining seed crystals on the second side surface, and stirring a lead nitrate solution, a zirconium oxychloride, and a titanium tetrachloride solution with a mineralizer, heating and pressurizing the base material from which the seed crystals are obtained. Performing a PZT crystal growth on each of the first and second side surfaces of the titanium base material to form a PZT thin film on the first and second side surfaces of the titanium base material. And (Operation) According to the first aspect of the present invention, since the vibrating gyroscope includes the first and second parallel plate structures,
Rigidity is increased and resistance to twisting is increased. Further, since the first and second parallel plate structures have a pair of PZT thin film bimorph structures via the spacer, the mass of the vibrating gyroscope can be increased by the spacer, and the detection sensitivity can be improved. It becomes possible. In addition, since the PZT thin film bimorph structure can be obtained by a hydrothermal method, a large number of bimorph structures can be easily obtained, and a small bimorph structure can be obtained. Be transformed into

According to the second aspect of the present invention, since the tuning fork type vibrating gyroscope includes the first and second parallel plate structures, the rigidity is increased and the torsion resistance is improved. Also, the first
The second parallel plate structure has a pair of PZT thin film bimorph structures with a spacer interposed therebetween. As a result, the weight of the vibrating gyroscope can be increased by the spacer, and the detection sensitivity can be improved. Further, since the PZT thin film bimorph structure can be obtained by a hydrothermal method, a large number of bimorph structures can be easily obtained and a small bimorph structure can be obtained. As a result, a tuning fork type vibration gyro can be obtained. Is reduced in size.

According to the third aspect of the present invention, a PZT thin film is formed on the first and second side surfaces of the titanium substrate by a hydrothermal method, and thereafter, electrodes are formed on the PZT thin film, respectively. This results in a PZT thin film bimorph structure. Here, the hydrothermal method refers to a method of depositing and growing crystals from an aqueous solution under heating and pressure. The term “pressurization” is intended to include not only a case where pressure is positively applied but also an increase in vapor pressure due to heating in a pressure vessel. The hydrothermal method is generally referred to as a hydrothermal synthesis method, but in this specification, is referred to as a hydrothermal method.

When the adjacent electrodes are cut off, a plurality of PZT thin film bimorph structures are obtained.
Next, when a pair of PZT thin film bimorph structures are arranged in a parallel plate shape and connected and fixed via a spacer, a parallel plate structure is obtained. Further, when the pair of parallel plate structures are connected in series and integrated, a vibrating gyroscope is obtained.

According to the invention of claim 4, the lead nitrate solution and the zirconium oxychloride are stirred together with the mineralizer,
Pressurizing and heating to obtain seed crystals on the first and second sides of the titanium substrate. Thereafter, a lead nitrate solution, a zirconium oxychloride, and a titanium tetrachloride solution were stirred with a mineralizer, heated and pressed against the base material from which the seed crystal was obtained, and heated and pressed to obtain the first and second titanium base materials. When PZT crystal growth is performed on each of the side surfaces, a PZT thin film is obtained on the first and second side surfaces of the titanium base material.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
0 will be described. FIG. 1 is a perspective view of the vibrating gyroscope, and FIG. 2 is a sectional view of a main part of the vibrating gyroscope. In addition, the thickness of each member illustrated in each drawing including the above-described drawing is appropriately enlarged and illustrated from the actual one for convenience of explanation.

As shown in FIG. 1, the vibrating gyroscope 1 has a pair of parallel flat plate structures 2, 3 connected in series vertically. Since the parallel plate structures 2 and 3 have the same configuration, the parallel plate structure 2 located at the lower portion will be described with reference to FIG. 2, and the members constituting the parallel plate structure 3 located at the upper portion will be parallel. The same reference numerals as those of the members of the flat plate structure 2 are assigned the same reference numerals, and description thereof will be omitted. The parallel plate structures 2 and 3 correspond to the first and second parallel plate structures of the present invention.

As shown in FIG. 1, the parallel plate structure 2 is
The plate-shaped piezoelectric elements 4 composed of a pair of bimorph structures are made to face each other, and are fixed to each other with an adhesive with a prismatic insulating spacer 5 interposed between upper and lower ends thereof. The insulating spacers 5 are used to prevent a short circuit between the piezoelectric elements 4.

The piezoelectric element 4 composed of a bimorph structure is
A P having a thickness of several tens of μm with respect to both side surfaces of a base material (titanium base material) 6 made of titanium in a flat plate shape having a uniform thickness.
A ZT thin film 7 is formed, and an electrode film 8 made of aluminum and having a thickness of several μm is formed on the PZT thin film 7 on both side surfaces thereof. The thickness of the substrate 6 is set to 20 μm. Both sides of the substrate 6 are the first side in the present invention and the first side.
Corresponds to the second side face located 180 degrees opposite to the side face. Further, the electrode film 8 corresponds to the electrode of the present invention.

The parallel plate structures 2 and 3 are arranged so that the surfaces on which the electrode films 8 are formed are orthogonal to each other, and the upper end surface and the lower end surface are bonded and fixed with an adhesive. That is, the side surface of the base material 6 of the parallel plate structure 2 and the side surface of the base material 6 of the parallel plate structure 3 are arranged to be orthogonal to each other.

FIG. 2 shows a PZT constructed as described above.
1 shows an electric circuit when a thin-film bimorph parallel plate structure 2 is used as a vibrator. Note that the polarization direction of the PZT thin film 7 at this time is A. AC power supplies B1, B2 and B3, B4 for applying the same voltage are connected in series, respectively. Then, one of the terminals of the AC power supplies B1 and B3 is connected to the electrode film 8 on the left side surface of each piezoelectric element 4 in FIG. Connect the terminal to the right side electrode film 8
Then, the other terminal is connected to the base material 6. This is to apply an electric field uniformly to each of the PZT thin films 7 formed on both side surfaces of the base material 6. If the PZT thin film 7 has a uniform thickness, the AC power supplies B1, B2, and B3 It is not necessary to connect the intermediate connection point of B4 to the substrate 6, and only one AC power supply is required. However, double voltage is required to obtain the same displacement.

When the AC power supplies B1 and B3 both apply a positive potential to the electrode film 8 on the left side, the AC power supplies B2 and B4 apply the positive potential to the electrode face 8 on the right side. And a negative potential having the same absolute value is applied, and the alternating voltage is applied in synchronization.

Then, the vibrating gyroscope 1 having the above-mentioned structure is arranged with the lower end of the parallel plate structure 2 fixed to a stand (not shown) or the like, as shown in FIG.
, An alternating voltage is applied to side surfaces of the pair of piezoelectric elements 4 located in the same direction by the AC power supplies B1 to B4 via the electrode film 8. Then, the PZT thin film 7 applied to the positive potential side is compressed, and the PZT thin film 7 applied to the negative potential side is stretched. The PZT thin film 7 of the piezoelectric element 4 is changed by the change in polarity due to the alternating voltage.
Is alternately compressed and stretched,
The parallel plate structure 2 is driven in the X and anti-X directions, and the upper parallel plate structure 3 vibrates in the same direction.

Then, in this vibration state, the vibration gyro 1
When a rotation about the Z axis is applied to the
In the PZT thin film 7 on one side, compression (strain)
Then, the other side surface (a side surface 180 degrees opposite to the one side surface) is stretched (distorted). As a result, it is possible to detect the Coriolis force acting on the vibrating gyroscope 1 by detecting the voltage generated at that time.

The piezoelectric element 4 of the parallel plate structure 3
Has a bimorph structure, so that a voltage twice as high as that of a unimorph can be obtained in this embodiment.

Next, a method of manufacturing the vibrating gyroscope 1 will be described with reference to FIGS. FIG. 3 shows the base material 6A. The base material 6A made of titanium has a flat plate shape with a uniform thickness, and has an area corresponding to a plurality of the base materials 6. First, the base material 6A is cleaned with an acid or the like, and one end side (the base end side in FIG. 1) is made of a synthetic resin or a material other than titanium by a physical film forming method such as sputtering or vacuum deposition. To form a mask M, and then a PZT thin film 7 is formed on both sides by a hydrothermal method.

This hydrothermal method consists of two stages. (Stage 1) a base 6A, zirconium oxychloride as a raw material (ZrOC ₂ · 8H ₂ O) and nitrate (Pb (N
An aqueous solution of O ₃ ) ₂ ) and a KOH (8N) solution are charged into a Teflon bottle (not shown) and stirred. In addition, PZT
The piezoelectricity of the thin film 7 depends on the lead titanate in the PZT thin film 7,
Since it is determined by the composition ratio of lead zirconate, the molar ratio of zirconium oxychloride to nitrate may be determined according to the piezoelectricity of the PZT thin film 7 to be formed later.

Next, in a pressure vessel (not shown), the base material 6A is disposed above, and zirconium oxychloride (Zr
OC ₂ · 8H ₂ O), an aqueous solution of nitrate _{(Pb (NO 3) 2)} , and while stirring KOH (8N) solution, heating and
Apply pressure. The pressurization here is pressurization by the vapor pressure of the heated solution. Temperature condition is 150 ° C
This state is continued for 48 hours. In addition, stirring was performed for 30 minutes.
Perform at 0 rpm.

As a result, in the supersaturated state, seed crystals (nuclei) of PZT are formed on both flat sides of the base material 6A. After the elapse of the above time, the base material 6A is taken out of the pressure vessel, washed with water and dried.

[0036] (second step) Next, the seed crystal is nucleation substrate 6A, zirconium oxychloride as a raw material (ZrOC ₂ · 8H _two O) and nitrate (Pb (N
An aqueous solution of O ₃ ) ₂ ), a titanium tetrachloride (TiCl ₄ ) and KOH (4N) solution are charged into a Teflon bottle (not shown) and stirred. The PZT thin film 7 has a piezoelectricity of PZT
The molar ratio between zirconium oxychloride and nitrate may be determined according to the piezoelectricity of PZT to be formed later, since it is determined by the composition ratio of lead titanate and lead zirconate.

Next, in a pressure vessel (not shown), the base material 6A is disposed above and zirconium oxychloride (Zr
OC ₂ · 8H ₂ O), an aqueous solution of nitrate _{(Pb (NO 3) 2)} , titanium tetrachloride (TiCl ₄₎ and KOH (4N)
Heat and pressurize while stirring the solution. The pressurization here is pressurization by the vapor pressure of the heated solution. The temperature condition is 120 ° C., and this state is maintained for 48 hours. The stirring is performed at 300 rpm.

As a result, in the supersaturated state, the PZT thin film 7 is formed with a predetermined thickness (several tens of μm in this embodiment) on both flat side surfaces of the base material 6A (see FIG. 4). After the elapse of the above time, the base material 6A is taken out of the pressure vessel, washed with water and dried. After that, the mask M is removed.

Next, as shown in FIG. 5, electrode films 8 are formed on both sides of the base material 6A including the PZT thin film 7 by a physical film forming method such as sputtering or vacuum evaporation. Then, both front and back surfaces of the substrate 6A are patterned so that a plurality of (three in this embodiment) piezoelectric elements 4 can be removed, and unnecessary portions of the electrode film 8 are removed (FIG. 6).
And FIG. 7). The electrode film 8 after patterning
Has the same area as the electrode film 8 on the opposite side surface.

Subsequently, as shown in FIG.
A pair of substrates 6A provided with the electrode films 8 are opposed to each other, and are fixed to each other via a prismatic insulating spacer 5 made of a synthetic resin between both ends thereof to form a parallel plate structure 2A (3
A). The parallel plate structure 2A (3A) has a configuration in which a single parallel plate structure is connected to each other. The insulating spacer 5 fixes the base material 6A with a highly rigid adhesive at the time of curing (see FIG. 9).

Next, the parallel plate structure 2A (3A) shown in FIG.
Is cut at a dotted line portion L provided between the electrode thin films 8 and separated into a single parallel plate structure 2 (3) (see FIG. 10). This cutting is performed by electric discharge machining or laser cutting.

Then, the parallel plate structures 2 (3) separated as described above are arranged so that the surfaces on which the electrode films 8 are formed are orthogonal to each other, and the upper end surface and the lower end surface are bonded to an adhesive. (See FIG. 1).

According to the present embodiment, the following operation and effect can be obtained. (1) In this embodiment, since the PZT thin film 7 formed on both side surfaces of the base material 6 is formed as thin as several tens of μm, the piezoelectric element 4 as a PZT thin film bimorph structure is formed.
Can be reduced in size. As a result, the size of the vibrating gyroscope 1 can be reduced.

(2) In the present embodiment, the piezoelectric elements 4 composed of a pair of bimorph structures are made to face each other to form a parallel plate structure, so that the piezoelectric elements 4 can be resistant to torsion. Accordingly, the vibration driving parallel plate structure 2 can accurately vibrate, and the detection parallel plate structure 3
Can be accurately displaced, so that it is strong against noise.

FIG. 14 (a) shows a case where a single bimorph structure 10 vibrates, and FIG. 14 (b) shows a case where a single bimorph structure 10 vibrates. Structure 10 as viewed from the side
Shows the displacement position of the upper end of the. In FIG. 14B, the center position P1 is a position before the displacement, P2 is a position when the center position P1 is displaced to one side, and P3 is a position from the center position P1 and P2.
The figure shows a position when it is displaced to the other position on the opposite side. In this case, since the single bimorph structure 10 is formed in a flat plate shape, when a force other than the vibration direction is applied,
There is a problem of being twisted as shown by P2 and P3 in FIG. In FIG. 14B, the two-dot chain line indicates the bimorph structure 1 when no twist is applied.
This is a displacement position of 0.

FIG. 15A shows a case where the parallel plate structure 2 (3) of the present embodiment vibrates, and FIG.
Similarly, when the parallel plate structure 2 (3) is vibrating and viewed from above, the parallel plate structure 2
The displacement position of the upper end of (3) is shown. FIG. 15 (b)
Is the center position P1 before displacement, and P2 is the center position P1.
, P3 indicates a position when displaced from the center position P1 to the other position opposite to P2. In this case, the parallel plate structure 2 (3)
Even if a force other than the vibration direction is applied, since it has rigidity, it is resistant to torsion and will not be twisted as shown by P2 and P3 in FIG.

In FIGS. 14 and 15, the electrode film and the PZT thin film are omitted for convenience of explanation. (3) In the present embodiment, PZT thin films 7 are formed on both sides of a base material 6A having an area of a plurality of base materials 6 by a hydrothermal method. Electrode film 8
Was formed. As a result, since the PZT thin film 7 and the electrode film 8 can be formed on a plurality of base materials 6 at one time, a large number of bimorph structures can be formed at once, unlike the related art. As a result, a vibrating gyroscope having a PZT thin film bimorph structure can be easily manufactured.

(4) In the present embodiment, the hydrothermal method
PZT thin film 7 is formed on both sides of base material 6A, and then, on both sides of base material 6A on which PZT thin film 7 is formed,
A plurality of PZT thin film bimorph structures can be obtained by forming a plurality of electrode films 8 and cutting between adjacent electrode 8 films. As a result, the vibration driving parallel plate structure 2 obtained in the same step (step by the hydrothermal method)
The vibrating gyroscope 1 configured in combination with the parallel plate structure 3 for detection has a constant quality such as detection sensitivity, that is,
It can be homogeneous.

(5) Since the vibrating gyroscope 1 of the present embodiment has the bimorph structure, if the displacement is the same as that of the monomorph, twice the voltage can be obtained, and the detection sensitivity can be increased. it can.

(6) Parallel plate structure 2 for vibration drive
Sets the insulating spacer 5 to the Coriolis force Fc of the above equation (1).
Can be used as the mass m. Therefore, irrespective of the mass of the base material 6, it is possible to adjust m of the vibrating gyroscope 1 by appropriately changing the mass of the insulating spacer 5. Thereby, the detection sensitivity of the vibrating gyroscope 1 can be increased.

The embodiment of the present invention can be modified as follows in addition to the above embodiment. (1) In the above embodiment, the insulating spacer 5 is used.
When formed between the piezoelectric elements 4 so as not to cause a short circuit, a non-insulating spacer such as a metal spacer may be used. In this case, the attachment to the piezoelectric element 4 is performed by welding or the like.

(2) In the above embodiment, the electrode film 8 is formed of aluminum. However, the electrode film 8 may be formed of Au (gold), or may be formed of another metal. (3) In the above embodiment, the electrode film 8, the PZT thin film 7,
The thickness of the substrate 6 is set to a predetermined value, but is not limited to the above value, and may be a value other than the above as needed.

(4) In the above embodiment, 3
Although it has been described that two bimorph structures are obtained at one time, the number is not limited, and two, four or more bimorph structures may be formed at one time.
Of course, it is also possible to manufacture one bimorph structure.

(5) In the above-described embodiment, the present invention is embodied in the vibrating gyroscope 1 of the reed type, but may be embodied in the vibrating gyroscope 11 of the tuning fork type as shown in FIG. in this case,
The tuning fork-type vibrating gyroscope 11 can be formed only by standing and fixing the pair of vibrating gyroscopes 1 in the above embodiment at both ends of a connecting plate 12 as a connecting portion. In this case, as shown in FIG. 11, the pair of vibrating gyroscopes 1 are arranged so as to face each other in the same direction.

In the tuning fork-type vibrating gyroscope 11, when acceleration is applied around the Z-axis, when the detected voltage values from both vibrating gyroscopes 1 disposed at both ends of the connecting plate 12 are added, the components related to the acceleration are mutually different. The offset can be eliminated, and the acceleration can be removed. The Z axis is an axis that passes through the center of the connecting plate 12 so as to be orthogonal.

Here, in addition to the technical ideas described in the claims, the technical ideas grasped by the above-described embodiments are listed below together with their effects. (1) In claim 3 or claim 4, before the step of forming the PZT thin film, a predetermined portion of the titanium base material is
A method for manufacturing a masked PZT thin film bimorph structure. By doing so, the masked portion has PZ
T film can not be formed.

[0057]

As described in detail above, according to the first aspect of the present invention, a large number of bimorph structures can be easily obtained, and a small bimorph structure can be obtained.
PZT with uniform detection sensitivity and strong torsion
A vibrating gyroscope having a thin film bimorph structure can be provided.

According to the second aspect of the present invention, a large number of bimorph structures can be easily obtained, and a small bimorph structure can be obtained. Further, it is possible to provide a tuning fork type vibration gyro having a uniform detection sensitivity and a PZT thin film bimorph structure resistant to twisting.

According to the third and fourth aspects of the present invention, it is possible to obtain a vibrating gyroscope having a PZT thin film bimorph structure having a large number of homogeneous detection sensitivities at once.

[Brief description of the drawings]

FIG. 1 is a perspective view of a vibrating gyroscope.

FIG. 2 is a sectional view of a parallel plate structure which is a main part of the vibrating gyroscope.

FIG. 3 is a sectional view of a substrate.

FIG. 4 is a cross-sectional view of a substrate covered with a PZT thin film.

FIG. 5 is a sectional view of a substrate on which an electrode film is formed.

FIG. 6 is a sectional view of a piezoelectric element formed by patterning an electrode film.

FIG. 7 is a perspective view of the same piezoelectric element.

FIG. 8 is an exploded perspective view showing a method of assembling the parallel plate structure.

FIG. 9 is a perspective view of a state where the parallel plate structure is assembled.

FIG. 10 is a perspective view of a PZT thin film bimorph-shaped parallel plate structure.

FIG. 11 is a perspective view of a tuning fork type vibration gyro.

FIG. 12 is a perspective view of a conventional vibrating gyroscope.

FIG. 13 is a perspective view of a conventional vibrating gyroscope.

14A is a perspective view showing the operation of a single PZT thin film bimorph structure, and FIG.

15A is a perspective view showing the operation of a parallel plate structure, and FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vibration gyroscope, 2, 3 ... Parallel plate structure (constituting 1st and 2nd parallel plate structure), 4 ... Piezoelectric element, 5
... insulating spacer, 6, 6A ... base material, 7 ... PZT thin film, 8
... electrode film.

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[Procedure amendment]

[Submission date] July 17, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction contents]

Next, in a pressure vessel (not shown), the base material 6A is disposed above, and zirconium oxychloride (Zr
_{OC l 2 · 8H 2 O)} , an aqueous solution of nitrate _{(Pb (NO 3) 2)} , and while stirring KOH (8N) solution, heated and pressurized. Note that the pressure here means a pressure by the vapor pressure of the heated solution. Temperature condition is 150
This condition is maintained at 48 ° C. for 48 hours. In addition, stirring is 3
Perform at 00 rpm.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0036

[Correction method] Change

[Correction contents]

[0036] (second step) Next, the seed crystal is nucleation substrate 6A, zirconium oxychloride as a raw material (ZrOC l ₂ · 8H ₂ O) and nitrate (Pb (NO _3)
2 ) aqueous solution of titanium tetrachloride (TiCl ₄ ) and KOH
(4N) The solution is put into a Teflon bottle (not shown) and stirred. Since the piezoelectricity of the PZT thin film 7 is determined by the composition ratio of lead titanate and lead zirconate in PZT, the molar ratio between zirconium oxychloride and nitrate may be determined according to the piezoelectricity of PZT to be formed later.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0037

[Correction method] Change

[Correction contents]

Next, in a pressure vessel (not shown), the base material 6A is disposed above and zirconium oxychloride (Zr
_{OC l 2 · 8H 2 O)} , an aqueous solution of nitrate _{(Pb (NO 3) 2)} , titanium tetrachloride (TiCl ₄₎ and KOH (4
N) Heat and pressurize while stirring the solution. Note that the pressure here means a pressure by the vapor pressure of the heated solution. The temperature condition is 120 ° C., and this state is maintained for 48 hours. The stirring is performed at 300 rpm.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Fumito Arai 501, 6-5-5 Aoyagi-cho, Chigusa-ku, Nagoya 501 (72) Inventor Koichi Itoigawa Noda 1 Toyoda-ji, Oji-machi, Oguchi-machi, Niwa-gun, Aichi Prefecture Address: Tokai Rika Electric Machinery Co., Ltd. (72) Inventor Hitoshi Iwata 1 Toyota Noda, Toyoda, Oguchi-machi, Oguchi-machi, Niwa-gun, Aichi Prefecture

Claims (4)

[Claims] 1. A PZT on a first side surface of a titanium base material and a second side surface located 180 degrees opposite to the first side surface.
A first parallel plate structure in which a thin film is formed and a pair of PZT thin film bimorph structures each provided with an electrode on the PZT thin film are connected in parallel via a spacer to each other; A second parallel plate structure having the same configuration as the structure, wherein the first parallel plate structure and the second parallel plate structure are integrally connected in series, and A first side surface of the titanium substrate in the flat plate structure and a first side surface of the titanium substrate in the other parallel plate structure are arranged so as to be orthogonal to each other; Vibrating gyro. 2. A tuning fork type vibration gyro according to claim 1, wherein the vibration gyro according to claim 1 is erected at both ends of a connecting portion. 3. a step of forming a PZT thin film on a first side surface of the titanium base material and a second side surface located 180 ° opposite to the first side surface by a hydrothermal method; Forming a plurality of PZT thin film bimorph structures by cutting electrodes adjacent to each other to obtain a plurality of PZT thin film bimorph structures; forming a pair of PZT thin film bimorph structures into a parallel plate through spacers; Arranging and connecting and fixing to obtain a parallel plate structure; connecting a pair of the parallel plate structures in series, a first side surface of a titanium base material in one parallel plate structure, and another parallel plate Arranging and integrating the first side surface of the titanium base material in the structure so as to be orthogonal to the first side surface thereof. 4. The method according to claim 1, wherein the lead nitrate solution and the zirconium oxychloride are stirred together with a mineralizer, pressurized and heated to form a first and second titanium substrate.
And a step of obtaining seed crystals on the side surface of the substrate, a lead nitrate solution, zirconium oxychloride, a solution of titanium tetrachloride with a mineralizer, agitating with a mineralizer, heating and pressurizing, Performing PZT crystal growth on each of the first and second side surfaces of the titanium substrate,
Forming a PZT thin film on the first and second side surfaces of the titanium base material.