JP2000317816A - Piezoelectric element and machining method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vibrator thinner than the thickness of manufacturing limit or a lens-shaped lamina upper curved surface by installing a material to be polished equal to or a little lower than the height of projection from the upper surface of a first machining assisting tool upper surface of a second machining assisting tool fitted in a ring-shaped or quadrangular groove or stepped part of the upper surface of the first machining assisting tool. SOLUTION: A second cylindrical machining assisting tool 19 a little higher than the depth of a ring-shaped or quadrangular groove or stepped part 12 formed on the upper surface of a first machining assisting tool 11 is fitted in the inside of the first machining assisting tool 11, a quartz plate 13 which is equal to or a little lower or higher than the height of projection from the first machining assisting tool 11 is installed, and the quartz plate 13, the second machining assisting tool 19 and the back face where the ring-shaped or stepped part 12 is formed are polished by lapping plates 17, 18. Cemented carbide or iron harder than the quartz plate 13 is used to manufacture the second machining assisting tool 19, and a polishing agent such as cerium oxide or the like is used, whereby a smooth line of a concave lens shape can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to barium titanate, quartz, lithium niobate or potassium niobate used for an acceleration sensor or an angular velocity sensor.
The present invention relates to a processing tool and a processing method for processing a piezoelectric element such as another single crystal, a piezoelectric ceramic, or another ceramic, an optical lens, or another substance.

[0002]

2. Description of the Related Art Quartz resonators, which are a type of piezoelectric element, are used for clock generation of microcomputers for general-purpose computers, OA information equipment, and home appliances, as well as oscillation sources of the reference frequency of communication equipment and measurement equipment. Although it is diverse,
In order to improve the performance of information processing and transmission, it is required to reduce the thickness of a vibrator and increase its natural vibration frequency. In order to obtain a high-quality vibrator, it has been proposed to finish it into a lens shape, and it has been used in a relatively low frequency range.

[0003] However, as a problem in reducing the thickness of the vibrator, there is currently a limit of production of 27.8 μm (= 60 MHz) in the production method using a double-sided lapping machine. Also, when the vibrator is finished in a lens shape, it is very difficult to create a curved surface on a thin section, and there has been no example manufactured so far.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a piezoelectric element and a method for processing the same, which are thinner than the manufacturing limit, which has been conventionally difficult.

[0005]

In order to solve the above-mentioned problems, a method of processing a piezoelectric element according to the present invention is directed to a method of manufacturing a piezoelectric element, comprising: In, to form a groove or a step of a ring shape or a square shape or other shape, and a little higher than the depth of the groove or the step, a cylindrical or other shape, glass or,
A second working aid made of super steel or iron or other material is fitted into the groove or the step, and the second working aid protrudes from the upper surface of the first working aid. The same as the height, or slightly lower than the protruding height, or high disk-shaped or other shape, the piezoelectric element polished object is installed, the piezoelectric element polished object, on the lower surface, the lower An extremely thin workpiece is polished by using two upper and lower wrapping plates of an upper wrapping plate on the lapping plate and the first processing aid.

[0006] As a method of fixing the first processing aid to the disk-shaped or other object to be polished, a circular shape formed on the upper surface of the first processing aid, or another method. A liquid of a viscous substance (for example, a substance such as a surfactant) is put into a groove or a step having a shape of the above, and the piezoelectric element to be polished so that the periphery of the lower surface of the piezoelectric element to be polished adheres to the liquid. By placing on the first processing aid and using the surface tension of the liquid or by freezing,
On the upper surface of the first processing aid, placed, on the hydrophilic thin plate impregnated with water, place the object to be polished piezoelectric element,
Using the surface tension of water included in the hydrophilic thin plate, or forming a plurality of holes in the first processing aid, syrup, honey, adhesive bond or grease, etc. in these holes Alternatively, a method of filling the lower surface of the object to be polished with the viscous substance by filling the viscous substance or another adhesive (for example, a rubber-based adhesive) with the viscous substance may be adopted. It is sufficient to place the object to be polished on the piezoelectric element on the processing aid. In addition, glass or
Fixing the first processing aid and the second processing aid made of super steel, iron, or other metal using rosin, starch glue, or other adhesives Although it can be used, there is a case where it is not necessary to use it fixedly.

In the piezoelectric element of the present invention, a pressure receiving surface made of a material having a piezoelectric effect, such as quartz, barium titanate, lithium niobate, or other ceramics, is formed at the center of the cylinder. A pair of electrodes is formed on the pressure receiving surface. The cylinder and the pressure receiving surface can be made of an integral material having a piezoelectric effect.

Further, the method for processing a piezoelectric element according to the present invention comprises:
Made of a material having a piezoelectric effect, from both ends of the round bar, respectively, using a grinding means, punch a cylindrical hole, at the center of the round bar, to form a pressure receiving surface of a predetermined thickness, the A pair of electrodes is provided on the pressure receiving surface to convert external air vibration into an amplified electric signal.
The grinding means forms a groove on the surface of the barrel-shaped grindstone, and by injecting compressed air or liquid into the groove, the grindstone is rotated, or using other mechanical means,
The barrel-shaped whetstone may be rotated. A barrel-shaped grindstone can also be formed using a steel ball close to a true sphere.

[0009]

Embodiments of the present invention will be described below. The present inventor has developed a new processing method classified as a grinding method, and has a 9 μm-thick uniconvex lens shape (Pl).
(ano-convex type) Quartz vibrator was successfully manufactured. Further, for the purpose of improving the performance of the crystal resonator, the relationship between the thickness and the electrical characteristics of the resonator having a thickness of 500 μm or less was investigated.

[0010] Since quartz is a hard and brittle material, it has been considered that applicable processing methods are limited to mechanical lapping or chemical etching. Therefore, the grinding method is hardly used for processing the high frequency crystal resonator.

As shown in FIG. 1, the grinding method developed by the present inventor is a method using a ball grinding stone 1 in which diamond abrasive grains are electrodeposited on steel balls. That is, a quartz plate 4 is attached on a cylindrical magnet 3 attached to a main shaft 2 of an ultra-precision lathe, and a tool holder 6 provided with a seat on which a ball rides is attached to a tip of a grinding spindle 5. When this is brought close to the cylindrical magnet 3, the steel ball is attracted and held by the tool holder 6 by magnetic induction. Since the tool holder 6 is smaller than the diameter of the cylindrical magnet 3, the magnetic flux density is smaller than that between the ball grinding wheel 1 and the cylindrical magnet 3.
The space between the ball grinding wheel 1 and the tool holder 6 is larger. For this reason, the ball grindstone 1 is strongly sucked into the tool holder 6, and does not come off even when rotated at a high speed, and is strongly integrated.

The steel balls are electrodeposited and fixed with diamond abrasive grains to form the ball grinding stone 1. Since the steel balls are held by the magnetic force in the cylindrical tool holder 6, they are easily formed. The whetstone can be replaced. Moreover, since the steel balls are held by using the cylindrical tool holder 6 and the high-precision steel balls, the work of centering the grindstone 1 which is necessary at the time of replacement is unnecessary. It has a feature that the ball grindstone 1 used for the rough processing and the finishing processing can be quickly replaced. Since the movement of the ball grinding wheel 1 is controlled by the NC device, a curved surface can be created. Ball whetstone 1 made of steel balls used for ball bearings, etc.
The diameter of the diamond abrasive grains 57 to be electrodeposited and fixed is, for example, 30 μm used for rough machining, 16 μm used for medium finishing, and 4 μm used for finishing. In the case of, the diameters of the ball grinding stones 1 are different from each other by the diameter of the diamond abrasive grains 57. If the diameters of the diamond abrasive grains 57 are different,
When the ball grinding stone 1 is attracted to and held by the cylindrical tool holder 6 using the magnetic induction of the cylindrical magnet 3 on the main shaft 2 side, the diameter of the diamond abrasive grains 57 differs by the amount corresponding to each other. The center point of the ball grindstone 1 held by the tool holder 6 by magnetic force moves in the vertical direction. As a solution to this problem, as shown in FIG. 1B, the ball whetstone 1 is held by the tool holder 6.
If only the area of the holding portion 56 of the ball grindstone 1 is not fixed to the diamond grindstone 57 by electrodeposition and the ball grindstone 1 is used, as shown in FIG. Regardless of the thickness, the center axes of the vertical and horizontal χ and γ axes, particularly the vertical χ axis of the ball grinding wheel 1 are always fixed, so that the ball grinding wheel 1 for rough finishing can be used.
Even if the ball grinding stone 1 for the intermediate finishing and the ball grinding stone 1 for the finishing are exchanged for the ball grinding stone 1 for the finishing, respectively, χ, γ
As shown in FIG. 1C, the axis does not always change, so that the replacement of the ball grindstone 1 is facilitated.

The present inventor has used this processing method to obtain FIG.
As shown in (a), the Plano-convex type processing in which the holding portion 51 and the groove 52 were integrally formed was successfully performed. The curve connecting the holding portion 51 and the groove 52 is called a smooth line 53. As shown in FIG. 2 (b), the shape of the quartz crystal disk was ground at 25 μm.
The lens shape has a radius of curvature of 3 mm and a shape error of 0.1 μm or less. Heretofore, it has been considered that a crystal resonator having this shape is likely to be accompanied by sub-vibration, and cannot exhibit sufficient performance. However, as is apparent from FIG. 2C, the reactance frequency characteristic draws a sharp resonance curve and does not involve any sub-vibration, so that it is understood that it is almost ideal as a crystal resonator.

An attempt was made to produce a thinner crystal resonator, and a crystal resonator having a thickness of 9 μm and a radius of curvature of 200 mm was successfully processed. The surface was further removed by about 0.5 μm by polishing with cerium oxide, and as a result, FIG.
An element as shown in (a) was obtained. As shown in FIG. 3B, the reactance frequency characteristics of the resonance curve lack a little sharpness, suggesting that Q is slightly smaller than that of the crystal resonator of FIG. Is not accompanied at all. As a cause of the lack of sharpness of the resonance curve, it is expected that damage due to processing is inherent below the surface of the crystal unit, and the thickness of the crystal unit is reduced,
This is probably because the ratio of the thickness of the damaged layer was relatively increased. However, the characteristics can be improved by removing the damaged layer by an etching method.

Next, under the condition that the radius of curvature of the Plano-convex type is 30 mm and the thickness of the lens portion is
Tried to increase. Until it reaches a thickness of 125 μm
A sharp resonance curve without secondary vibration similar to FIG. 2 was maintained. However, beyond that, a phenomenon appeared with accompanying or no vibration.

On the other hand, as shown in FIG. 4 (a), the thickness of the vibrating portion is 27 μm in a planar shape (Inverted m).
esa type) was also manufactured. P with similar resonance frequency
Compared to the lan-convex type, as shown in FIG. 4B, it can be seen that although the electrical characteristics are somewhat inferior, there is no accompanying secondary vibration. Further Inverted Mesa
When the thickness of the flat part of the mold is increased, the thickness becomes 30 μm
Beyond, a phenomenon that did not cause vibration appeared. Inv
In the erted mesa type, the radius of curvature of the lens portion is
It is considered to be an infinite Plano-convex type, and it can be said that this type of crystal resonator having a ring support has a region exhibiting good vibration characteristics and a region which cannot vibrate due to the thickness and curvature of the vibrating portion.

The following conclusions have been obtained by the method of the present invention. Until now, it has been considered that a favorable quartz-crystal vibrator without a sub-vibration cannot be obtained unless the shape is a Bi-convex type. However, even in the Plano-convex type, when a ring support is provided and the thickness is reduced to about 30 μm,
It has been found that a crystal resonator having ideal reactance frequency characteristics without secondary vibration can be obtained.

As described above, a result is obtained in which the performance of the quartz resonator can be expected to be improved in a thin region. But,
It was also found that when the thickness exceeds 125 μm, sub-vibration occurs or the vibration stops.

The present inventor has been studying a processing method for reducing the thickness of the crystal unit as much as possible. 5 and 6 show that the diameter and thickness of the polish point are 5 mm, 76.7 μm and 10 mm, respectively.
FIG. 9 shows a reactance frequency characteristic in the case of 0 μm. According to this, it is understood that the sub-vibration exists near the frequency of the main vibration. FIG. 7 shows the reactance frequency characteristics of a crystal resonator having a thickness of 33 μm.
No sub-vibration exists in the frequency range of 5 MHz.
As shown in FIG. 8, a complicated sub-vibration is observed in a frequency region separated by about 6 MHz. FIG. 9 shows that the thickness is 31 μm.
This shows the reactance frequency characteristics of the crystal resonator of the above. There is no sub-vibration in the ± 5 MHz region of the main vibration. However, as shown in FIG. , About 8 MHz apart. From this, it can be seen that the sub-vibration departs from the frequency of the main vibration as the thickness of the crystal resonator decreases.

FIGS. 11 to 19 show an apparatus for processing an ultra-thin quartz crystal unit. In this processing equipment,
As shown in FIG. 11, on the upper surface of the first processing aid 11,
A groove or step 12 having a ring shape or a square shape or another shape is formed, and as shown in FIG. 12, a cylindrical shape or a slightly higher depth than the depth of the ring or other shape groove or step 12 is formed. A second processing aid 19 having a shape is fitted therein, and as shown in FIG.
The second processing aid 19 is fitted into the inside of the disk-shaped member, and a disk-shaped or slightly higher or slightly higher than the projection height (for example, 40 μm) from the first processing auxiliary tool 11 or A piezoelectric element to be polished in another shape, in this example, a quartz plate 13 is provided. Further, as another processing order, the following is more preferable because the distortion generated at the stage of processing the quartz plate 13 is corrected. Before placing the quartz plate 13 on the first processing aid 11, as a pretreatment, a metal such as gold or silver or aluminum is vapor-deposited on one surface of the quartz plate 13, After forming a metal coating on one side of the plate 13 or using other means, the one side of the quartz plate 13 is subjected to a surface treatment so that the front and back surfaces of the quartz plate 13 can be distinguished. For example,
When an extremely thin metal coating is formed, the crystal plate 13 is placed on the first processing aid 11 with the surface on which the metal coating is formed facing downward, and The thickness of
For example, if both sides are polished and the thickness is 40 μm,
Even at the stage of polishing to a thickness of about 20 μm, considerable distortion occurs on the polished surface of the quartz plate 13.
In order to remove this distortion, at this stage, the processing aid formed by using the first processing aid 11 and the second processing aid 19, and the quartz plate being processed, 13 is taken out from the double-side polishing machine, washed well, and the surface of the metal film formed on the surface of the quartz plate 13 is turned up again. The quartz plate 13 having a thickness of 5 μm or less, which is a final target, is polished from the surface where the quartz plate 13 is placed on the surface of the processing aid 1 and is coated with a metal. Can be easily polished, and at the same time, the crystal plate 13 can be polished.
Is polished from both sides.
3, the generation of distortion generated by polishing from one side can be suppressed to a minimum,
Extremely thin, quartz plate 1 without changing the characteristics of quartz
3 can be polished. By the way, when the deposition is performed by using gold, the thickness of the deposition layer is 100 ° (angstrom) to 200 °, and the deposition layer can be formed uniformly on one surface of the quartz plate 13. Because you can
The thickness of the vapor deposition layer itself is a thickness that does not matter as compared with the thickness of the quartz plate 13 to be polished. By depositing a metal such as gold on one side of the crystal plate 13, even if the crystal plate 13 is processed halfway, the crystal mixed in the polishing agent such as cerium oxide. The plate 13 is easily separated from the crystal plate 13 by easily washing the abrasive and the crystal plate 13 with water.
Can be taken out.

The quartz plate 13 and the upper surface of the first processing aid 11 are usually fixed with an adhesive or polished without using an adhesive. Using an agent, on the upper surface of the first processing aid 11, on the entire surface,
When the adhesive is applied and attached, in the case of a thin plate (for example, a thickness of 10 μm) or a quartz plate, the quartz plate 13 receives a strong external stress due to a contraction force when the adhesive hardens. As a result, the characteristics of the crystal plate 13 are reduced due to the distortion, and the characteristics of the crystal plate 13 are lost. Therefore, it is not possible to apply an adhesive to the entire lower surface of the crystal plate 13 to perform bonding. Can not. Therefore, as shown in FIG. 14, a circular or other shape formed on the upper surface of the first processing aid 11 ', pure water is put in the groove 14, or rosin or other adhesive is applied. Put the crystal plate 1 in this pure water
3, the crystal plate 13 is placed so that the periphery of the lower surface is in close contact, and the surface tension of water is used, or water is frozen, or rosin or other adhesive is used. 1
The first processing aid 11 'and the crystal plate 13 are fixed using a part of only the outer peripheral portion of the groove 14, which has a circular or other shape formed on the upper surface of the processing aid 11'. can do.

As another example, a first processing aid 11 "having a first structure having a shape as shown in FIG.
Processing aid 1 formed using the processing aid 19 of FIG.
Using a processing aid 11 "having a 1" structure, the quartz plate 1
3 can also be polished.

Further, as another example, as shown in FIG. 17, a plurality of holes 16 are formed in the first processing aid 11, and two or three holes 16 are appropriate. This hole 16
By filling a viscous substance such as starch syrup, honey, an adhesive bond or grease or other adhesive, the lower surface of the quartz plate 13 is brought into close contact with the viscous substance, and the first processing aid 11 and The crystal plate 13 is spotted and fixed only by the area of the hole 16. Note that the arrangement of the holes 16 is as shown in FIG.
As shown in FIG.
As shown in (b), they may be arranged concentrically, but are not limited to these examples. Also, using the hole 16 formed in the first processing aid 11, the first processing aid 11 and the quartz plate 13 are separated by using the area of the area of the hole 16, In the case where the first processing aid 11 and the crystal plate 13 are spotted and fixed to only a part, the second processing aid 19 may not be used.

The first processing aid 11 described above is connected to the first processing aid 11 shown in FIG.
As shown in (a), the upper wrapping plate 18
The upper and lower two wrapping plates of the lower wrapping plate 17 are used.
Quartz and cylindrical or other shapes are processed, the upper lapping plate 18 is formed with a ring or square or other shape groove or step 12, the back surface is polished, and a double-side polishing machine is used. Polishing extremely thin workpieces. Further, the first processing aid 11 is manufactured by using a metal such as super steel or iron or a glass, which is difficult to be polished, and the second processing aid is made of glass or
When made using metal such as steel or iron, the upper wrapping plate 18 made of metal such as iron
Polished the first processing aid 11 made of iron or the like, and the lower lapping plate 17 is made of a second processing aid 19 made of metal such as glass or super steel or iron. The quartz plate 13 is processed, or FIG.
As shown in FIG. 16A, the second processing aid 19 and the quartz plate 13 are arranged in a state opposite to the means described with reference to FIG. The tool 19 and the quartz plate 13 may be polished, and the first processing aid 11 may be polished using the lower lapping plate 17.

FIGS. 18 and 19 show the state of FIG.
3, a quartz plate 13 formed by using the first processing aid 11 and the second processing aid 19 and formed by polishing using the processing aid, The figure shows a polished shape. The reason why the shape of the quartz plate 13 shown in FIG. 18 is different from the shape of the quartz plate 13 shown in FIG. 19 is as follows.
The processing aid is manufactured using a material different from the material used for manufacturing the processing aid 19 of FIG. 19 and the material forming the second processing aid 19 shown in FIG. That's why. Second processing aid 19 shown in FIG.
The second processing aid 19 is formed by using a hard glass made of quartz and having substantially the same hardness as the quartz plate 13.
19, the second processing aid 19 shown in FIG. 19 is made of plastics or hard metal which is harder to grind than the quartz plate 13. The second processing aid 19 is manufactured by using super steel, iron, or the like. However, it is a condition that cerium oxide, alumina, GC, diamond, or another abrasive is used as the abrasive. The reason is that when an abrasive such as cerium oxide is used, the quartz plate 13 and the hard glass are made of the same quartz, and therefore, when cerium oxide is used, both can be polished well. However, metals such as super steel or iron can hardly be polished using cerium oxide. However, when an abrasive such as cerium oxide is used, the quartz plate 13 can be polished well. This is because the processing can be performed, and the polishing of the processing aid made of a metal such as super steel or iron can be delayed more than the polishing of the crystal plate 13. This difference is the reason why the shape of the quartz plate 13 shown in FIG. 18 is different from the shape of the quartz plate 13 shown in FIG. The concave lens-shaped quartz plate 13 shown in FIG.
The finished dimensional diagram has the same shape as the quartz plate 13 shown in FIG. 26 and has the holding portion 51 and the smooth line 53. Therefore, the characteristics of the quartz oscillator are as shown in FIG. 3 and FIG. 4, as in the case described above, the crystal resonator has a shape that exhibits ideal characteristics. Another important point in performing the above-mentioned polishing process is that when performing the polishing process, usually, both sides are covered with a suede or a nonwoven fabric (hereinafter, referred to as a suede), and the wrapping plates 17 and 18 are attached. In the case of manufacturing a concave lens-shaped quartz plate 13 shown in FIG. 19, for example, a lapping plate made of a metal plate such as iron on one side is used. 17 using a suede wrapping plate 18
As shown in FIG. 16 (b), the upper lapping plate 18 is sueded by polishing, and the lower lapping plate 17 is made of a metal such as iron. By using a lapping plate 17 made of a plate and polishing it, the back surface of the first processing aid 11 made of a metal such as super steel or iron can be made of a metal plate. Polishing using the wrapping plate 17
Since the conditions are satisfied, the hardness of the metal plate forming the wrapping plate 17 and the hardness of the metal forming the first processing aid 11 are substantially equal to each other, so that the first processing is performed. The back surface of the auxiliary tool 11 is a condition that is as difficult as possible to be polished. Accuracy can be easily increased. Further, another important point is that the suede on the upper wrapping plate 18 is formed with undulations or undulations similar to the undulations.
Polishing using a suede is also an important condition in manufacturing the quartz plate 13 having a concave lens shape. In addition, by using a double-side polishing machine, the quartz plate 13 having the shape shown in FIG. 26 can be polished, so that the reproducibility or accuracy of the finished quartz plate 13 is extremely high. There is also an advantage that a large amount of precision quartz plates 13 can be produced at low cost.

Although not shown in the drawings, the above-described processing aid is formed by using the first processing aid and the second processing aid as the polishing means. As another method of use, even if a single-side polishing machine other than the double-side polishing machine is used, the concave lens-shaped quartz plate 13 having the shape shown in FIG. Can be polished.

Further, using the processing aids formed by using the first processing aid 11 and the second processing aid 19, the quartz plate is formed into a shape as shown in FIG. 13
Is polished using a double-side polishing machine or a single-side polishing machine, when previously polished into a concave lens shape using a processing means as shown in FIG. 25 or FIG. 26, by grinding the quartz plate 13 into a concave lens shape as shown in FIG.
A mask is applied to the central portion of the crystal plate 13, and laser irradiation such as an excimer laser is performed only on the central portion, and the initial thickness of the crystal plate 13 having, for example, 40 μm is
For example, only the central portion is subjected to 0.1 mm by one heat irradiation pulse.
A processing layer of about 1 μm is removed, and a heat irradiation pulse of about 200 pulses is performed in total, and a concave lens shape (inverted MESA type) having a depth of, for example, about 20 μm as shown in FIG. The shape of the crystal plate 13 is processed by using a laser or by using a chemical such as hydrofluoric acid or ammonium chloride to etch the quartz plate 13 so that only the central portion of the quartz plate 13 is formed. Into a concave lens shape,
Either processing, or using a fluorine-based gas, or the like, using a processing means such as ion milling or plasma etching, only the central portion of the quartz plate 13 is processed into a concave lens shape, or After processing the quartz plate 13 into a concave lens shape using other means,
As a subsequent processing step, the quartz plate 13 processed into a concave lens shape is polished using a processing aid as shown in FIG. 13, or as shown in FIG. Without using a processing aid, the carrier 37 shown in FIG.
Next, the carrier 37 is used to move the crystal plate 13 into a planetary motion. Using a double-side polishing machine, the crystal plate 13 is formed to remove the work-affected layer. When the processing is performed and the chemical etching is performed again, the quartz plate 13 having a concave lens shape with high accuracy as shown in FIG.
It can be manufactured in large quantities in a short time.

The upper and lower wrapping plates 17,
18, the carrier 37 on which the first processing aid 11 is mounted is rotated by the rotation together with the supply of the slurry (free abrasive grains), as shown in FIGS.
And the internal gear 38, and the processing aid 1
1 is revolved around the sun gear 39 and revolves around the planetary gear to make planetary motion. When the other side of the auxiliary tool 11 is polished using the upper lapping plate 18, the extremely thin quartz plate 13 can be easily polished. When a single-side polishing machine is used, the quartz plate 13 can be polished by the same means as the above-mentioned polishing means.

Further, after processing the extremely thin quartz plate 13 by the above means (for example, when the thickness is 10 μm)
Then, since the crystal plate 13 is extremely thin, it is difficult to handle it, and it is difficult to form electrodes on the crystal plate 13. Therefore, as shown in FIG. At the center of the fixing frame 48 made of non-insulating material,
3 is set, and the crystal plate 13 is fixed to the fixing frame 48 using an extremely thin gold wire 49 (for example, about 18 μm) using a bonding machine. The crystal plate 13
After being fixed to the fixing frame 48, as shown in FIG.
As shown in the figure, when the entire surface of the crystal plate 13 is lifted from below or by other means, the slackness of the gold wire 49 is corrected, and the gold wire 49 is brought into a linear state. Good.
In addition, as shown in FIG. 22, when the crystal plate 13 is fixed from at least three directions to the fixing frame 48 using the gold wire 49 by means as shown in FIG. By using a very thin gold wire 49, the crystal plate 13 is fixed in the air, so that the vibration of the crystal plate 13 is absorbed by the gold wire 49. The properties are not reduced to the extreme.

Further, as shown in FIG. 23, the quartz plate 13 is fixed to a fixing frame 48 using a gold wire 49, and then, as shown in FIG. In order to provide the electrodes, only a very small portion of the central portion of the quartz plate 13 is deposited using gold or the like, and then the deposited machine is mounted on the central portion of the quartz plate 13 from both sides. Is used to connect between the crystal plate 13 and the fixing frame 48 using a gold wire 49, and the gold wire 49 is attached to the center of the crystal plate 13 and used as an electrode 50. In comparison with a conventionally used electrode (for example, an electrode formed by vapor deposition on the front and back of a quartz plate), an extremely thin gold wire 49 (18 ·
) Can be used to form the electrode 50, so that the characteristics of the crystal are not degraded.

FIG. 25 shows an apparatus for manufacturing a crystal plate 13 having a concave surface on one side. In FIG. 25, 11 is the first
, A reference numeral 19 denotes a second processing aid, and 41 denotes a low-speed rotation of the processing aids 11 and 19 (for example, 100 to 300 rpm).
m), a motor 43 for rotating the polishing tool 44 at a high speed (for example, 5000 rpm). As the polishing tool 44, a soft tool such as a felt, a cotton swab, a buff or the like is used, and a polishing agent such as cerium oxide, GC, or diamond is used to polish about 1 μm per minute. As shown in FIG. 26, a disk-shaped crystal plate having an initial thickness of about 40 μm is finished into a concave lens-shaped crystal plate 13 having a thickness of 10 to 2 μm at the center. Also, the quartz plate 13 can be processed into a concave lens shape by using an apparatus having a structure as shown in FIG. 25. The polishing tool 44 used in this case is a diamond abrasive. By using a polishing tool 44 made of electroplated foil, the quartz plate 13 can be easily processed into a concave lens shape. Then, the quartz plate 13 processed into a concave lens shape
Is polished using a double-sided polishing machine or a single-sided polishing machine, a concave lens-shaped quartz plate 13 as shown in FIG. 19 can be polished and finished.

As the processing aid, in addition to the structure shown in FIG. 25, as shown in FIG.
1 ′ ″ or a configuration in which a ring-shaped processing aid 11a and a disk-shaped processing aid 11b shown in FIG. 28 are combined, integrated with an adhesive or the like, and the crystal plate 13 is placed thereon. It can also be.

As shown in FIG. 29, an aluminum adhesive tape 45 having a hole formed on the upper surface of the crystal plate 13 and extending over the periphery is attached to the second processing aid 19, By polishing with a polishing apparatus shown in FIG. 25, it is possible to manufacture a crystal plate 13 having a concave portion only at the central portion as shown in FIG.

Next, as an application example of the piezoelectric element of the present invention,
The acoustic-electric converter will be described. Conventionally, seismic exploration and prediction include ocean observation, underground structure exploration, geomagnetic observation, observation by GPS, and measurement of the movement of the earth's core by laser measurement of the distance between two points. Observing the vibration of air due to an earthquake or tsunami is another predictive method.

As a means for converting the vibration of air into an electric signal which can be easily recorded and analyzed, there is a sound collecting microphone.

FIGS. 30 (a) to 30 (e) show embodiments of an acoustic-electric converter using the piezoelectric element of the present invention. The acoustic-electric converter includes quartz, lithium niobate, or another single crystal. A cylinder 21 made of a material having a piezoelectric effect, such as crystal or barium titanate or other ceramics
Alternatively, the pressure receiving surface 22 is formed in the center of the cylinder 54, and a pair of electrodes 23 and 24 are formed on the pressure receiving surface 22.
Amplifier 25 for measuring the induced voltage between 3, 24
Are connected. (Only the electrodes 23 and 24 and the amplifier 25 are shown in FIG. 30A). 30 (a) is a biconvex lens (bi-convex) type, (b) is a biconcave lens type, (c) is a planar type, (d) is a planar type with R formed around it, and (e) is a uniconvex ( (plano-convex) type. As shown in FIG.
Is sealed using two pieces, and the inside of the cylinder 21 is sealed.
A chamber is formed, the inside of the cylinder 54 is sealed, and a chamber B is formed,
The left and right cylinders 21 of the cylinders 21 and 54 both have a structure in which the inside of the cylinder 21 is sealed and the inside of the cylinder A is sealed, and the inside of the cylinder 54 and the inside of the chamber B are both decompressed (preferably in a vacuum state). And the cylinder 54 catches vibrations in the horizontal axis direction and the vertical axis direction, and forms the pressure receiving surface 22 formed in the center portion of the cylinder 21 and the cylinder 54, when the cylinder 21 and the cylinder 54 are not formed. In comparison, the pressure receiving surface 22 has a structure that catches vibration more strongly. In addition,
For the above reasons, the smaller the diameter and the longer the length of the cylinders 21 and 54 are, the more the vibration from the outside is generated by the pressure receiving surface 2.
2 is easy to receive, so that a highly accurate pressure sensor can be made. In addition, when not depressurizing the insides of the chambers A and B, it is preferable to inject an inert gas.

FIG. 31 is a top view shown in FIGS. 30 (a) and 30 (e). The vibrated vibration caused the cylinder 21 and the cylinder 54 to vibrate from the portion A to the portion B or from the portion B to the portion A shown in FIGS. 30 (a) and 30 (e). Vibration
By freely moving from both ends, the cylinder 21 and the cylinder 5
Vibration (vibration of part A,
Vibration caused by vibrating the portion B) is caused by the cylinder 21 and the cylinder 54
By freely moving from both ends, the vibration that vibrated the portion A and the vibration that vibrated the portion B resonated in the center portion, causing a resonance phenomenon, and When the space portion 47 is not formed, the pressure receiving surface 22 formed in the center portion is vibrated stronger than the space portion 47 by comparison.

Next, a method of forming the pressure receiving surface 22 will be described. Basically, as shown in FIG. 32, quartz or barium titanate, lithium niobate or other ceramics, and other materials having a piezoelectric effect,
A round bar 30 made of a material is attached to a chuck 31 of a processing machine such as a lathe.
A processing tool 33 having a grindstone 32 with a diamond stone attached to the surface of a metal ball and a rotatably provided grinding wheel 32 at the tip is gripped by a tool holder 34. Whetstone 32
As shown in FIG. 33, is a sphere whose opposing surface is cut,
It is rotatably mounted. On the peripheral surface of the whetstone 32,
FIG. 34A is an enlarged cross-sectional view of FIG.
As shown in (b), a V-shaped groove 32a is formed, and one of the inner walls of the groove 32a has a directionality included in a plane passing through the center of the grindstone 32. This whetstone 32
Is rotated at high speed (preferably 8.000 to 50.000 rpm) by a jet stream of air, which is tangentially jetted from the air nozzle 40 to the peripheral surface of the grindstone 32,
Take the surface to be ground slowly (for example, 1μ
m) Sharpening. During this grinding, from the fountain nozzle 41
Water is injected to cool the grindstone 32 and discharge shavings. When the grindstone 32 is driven to rotate, the round bar 30
As shown in FIG. 2, a circular or cylindrical hole is formed by the grindstone 32 driven to rotate around the axis. As another method of using the grinding or polishing means described above, the use of a grindstone 32 ″ as shown in FIG. The shape shown in FIG. 4 or another shape can be applied to grinding or polishing.

When the polished surface of the pressure receiving surface 22 is convex, a drum-shaped whetstone 32 'is used as shown in FIG. 36 ((a) is a front view, and (b) is a plan view). When the polished surface of the pressure receiving surface 22 is flat, as shown in FIG.
A flat grindstone 32 "is used. Alternatively, as shown in FIG. 37, a grindstone 32 'having a diameter much smaller than the hole diameter is used, and the same rotational drive as the machining tool 33 shown in FIG. 33 is applied to the grindstone 32'. The grindstone 32 'is rotated while moving the processing tool 33' along a curved surface of the pressure receiving surface by an NC device or the like, and at the same time, the pressure receiving surface is processed while rotating the chuck 31 and the round bar 30. When the grindstone 32 ″ having a shape as shown in FIG. 36D is used as a means for forming the hole or space portion 47, the hole or space portion 47 can be easily processed while leaving the holding portion 47. Can be done. Further, as means for forming the hole or the space portion 47,
Even if you use a drill electrodeposited with ordinary diamond,
It is possible to form a hole or space part 47.

For machining a circular hole, a tool rotating around a normal axis can also be used. A spherical grinding wheel as shown in FIG. 38 and a disk grinding wheel as shown in FIG. 39 can also be used. Can be used. When the grinding process is completed using the grindstone 32, a polishing grindstone 32 ″ for polishing having the same structure as the grindstone 32 is manufactured using a material such as a felt or a buff and polished. When the grinding wheel 32 ″ is replaced with the grinding wheel 32 ″ and the polishing is performed using the grinding wheel 32 ″, the finishing process can be performed. Also, like the means for rotating and driving the grindstone 32, the groove 32
If (a) is formed and the air nozzle 40 is used to perform a rotational drive, the polishing can be easily performed.

It should be noted that FIGS.
Is a grinding and polishing apparatus having the structure shown in FIG.
FIG. The diameter of the whetstone 32 actually manufactured is 2
0 mm, the depth of the groove 32 (a) is 1 mm, the number of grooves
The air is supplied to the grinding and polishing device with the structure of 16 pieces.
A tangential direction from the nozzle 40 to the peripheral surface of the grindstone 32
In addition, the injected air pressure and the rotation speed of the grindstone 32 were actually measured.
The actual number of revolutions is the following number. When the air pressure is 0.5 atm, the rotation speed of the grindstone 32
Is the number of revolutions of about 12.200 revolutions. When the air pressure is 1.0 atm, the rotation speed of the grindstone 32
Is the number of revolutions of about 22,000 revolutions. When the air pressure is 2.0 atm, the rotation speed of the grindstone 32
Is the number of revolutions of about 37.500 revolutions. The rotation speed of the grindstone 32 when the air pressure is 3.0 atm.
Is the number of revolutions of about 47.800 revolutions.  When the air pressure is 4.0 atm, the rotation speed of the grindstone 32
Is about the limit that a bearing can withstand, about 5
This is the number of revolutions of 0.000 revolutions.

In the grinding and polishing apparatus having the structure shown in FIGS. 40 and 41, a metal such as iron, aluminum, or copper, or a buff or
36. A polishing grindstone 32 ″ ″ (e) shown in FIG. 36 is made of felt, glass, plastic, ceramics, or another polishing material, and the polishing grindstone 32 ″ ″ (e) is formed. , As an abrasive, diamond paste or cerium oxide or alumina or GC or
Using other abrasives, a crystal is formed into a shape as shown in FIGS. 2A, 3A and 4A by using the processing method shown in FIG. Such as a piezoelectric material,
Grinding and polishing are performed simultaneously. Grinding and polishing can be performed simultaneously because the rotation speed of the grinding wheel 32 "" (e) is limited to the rotation speed up to 50.000 rotations, which is the limit that the bearing can withstand. Since the grinding wheel 32 "" (e) can be easily driven, the polishing process can be performed efficiently and in a very short time only by the polishing process. With a piezoelectric material such as this, two processes of grinding and polishing can be performed simultaneously using a polishing grindstone 32 ″ ″ (e) made of felt, buff, iron, or the like.

FIG. 42A shows an angular velocity sensor or a piezoelectric plate 57 made of a piezoelectric material such as lithium niobate or potassium niobate for manufacturing the angular velocity sensor. A thick plate of the piezoelectric plate 57, for example, a thick plate of about 350 μm, and a thin piezoelectric plate 57, for example, a plate of about 25 μm, are formed by using an adhesive layer 59 made of an insulator. 2 shows a piezoelectric plate 57 which is bonded and plywood.

FIG. 42 (b) shows a circular plate having a diameter of about 3 mm on the center of the thick plate of the piezoelectric plate 57 by using the processing means shown in FIG. , Processed into a concave lens shape (Inverted mesa type), the thickness was set to 25 μm, and the adhesive layer 59 was sandwiched.
This example shows a case where the processing was successful, which was used for an electrostatic capacity type angular velocity sensor and had a total of 50 μm. Although this lithium niobate or potassium niobate is a material that is very difficult to process, if the processing means shown in FIG. 1 is used, the material is not affected by heat and can be processed with high accuracy. It can be easily processed. In the case of lithium niobate, processing is difficult because the allowable temperature difference is a temperature difference within 20 ° C. or the allowable temperature difference is not allowed.

[0045] What is shown in FIG. 43 (a) is hydrofluoric acid, by using a fluorine-based gas, or other chemicals such as CHF _3, the quartz plate 13, over the mask, the central portion FIG. 2 shows the shape of a quartz plate 13 formed by etching a concave lens shape (inverted MESA shape) having a diameter of 1.5 mm, for example. When the quartz plate 13 or other piezoelectric material is etched using a chemical such as hydrofluoric acid, it is indicated by oblique lines.
The shape of the outer peripheral part becomes a U-shape (floor digging shape), and when forming an electrode using vapor deposition, the hatched part becomes a shadow and it is difficult to form an electrode. This is a disadvantage of the etching process.

FIG. 43B shows the state of FIG.
In order to correct the disadvantages of the etching process described in (a), using a double-side polishing machine shown in FIG. 20, for example, the upper lapping plate 18 is a lapping plate on which a suede 15 is stuck. And the lower wrapping plate 17 is made of a metal wrapping plate such as iron or the like.
Using the wrapping plate 17 and the wrapping plate 18 on which the concave lens 5 is attached, the etched lens-shaped concave lens-shaped portion of the quartz plate 13 shown in FIG.
The first advantage is that a smooth line 53 as shown in FIG. 43B can be formed by polishing using a suede 15 and an abrasive such as cerium oxide. is there. Further, the second advantage is that since the abrasive is accumulated inside the concave lens shape, the inside of the concave lens shape can be polished more and more gradually using the upper lapping plate 18. And that the lower lapping plate 17 can be polished from both sides, so that the extremely thin quartz plate 13 having a thickness as small as possible, for example, about 0.5 μm (natural vibration frequency of about 3 GHz) can be formed. Even if it is polished, the thickness of the holding portion 51 can be maintained in the range of 40 μm to 30 μm, so that the strength of the concave lens portion can be maintained even if it is extremely thin. And there is no difficulty in handling. Furthermore, the third advantage is that
The concave lens shape can be polished using a plane polishing machine. The above three advantages are obtained from the etching and polishing combined use, or the etching and polishing combined use combined use of the etching and the double-side polishing machine or the single-side polishing machine or other polishing means.

FIGS. 44 (a), (b), (c) and (d)
In FIG. 13, the processing surface formed by forming a concave lens shape on the quartz plate 13 by using plasma etching or other means is held by using the processing aid 11 shown in FIG. One side is a back side processed into a concave lens shape, and the other side is one side of a processing aid 11.
21 shows a state in which polishing is simultaneously performed from both the upper and lower sides using a double-side polishing machine or other processing means shown in FIG. Note that FIG.
(D) shows a completed dimensional diagram.

FIG. 45 or FIG. 46 shows that a concave lens shape is formed on the quartz plate 13 and rosin, paraffin or other resin is formed inside the concave lens shape of the quartz plate 13. 44, the strength inside the concave lens shape is reinforced, and the quartz plate 13 reinforced inside the concave lens shape is made into a concave lens shape using a double-side polishing machine as shown in FIG. The processed back surface and the other surface show a state where one surface of the processing aid 11 is being polished.

FIG. 45 (e) and FIG. 46 (e) show that a concave lens shape is formed on the quartz plate 13 and pine resin is formed inside the concave lens shape of the quartz plate 13. After injecting a resin such as paraffin or glue to reinforce the strength inside the concave lens shape, the quartz plate 13 is polished on both sides using the processing aid 11, and then immersed in alcohol or another solvent. This shows a state in which resin such as rosin is dissolved. Incidentally, as shown in FIG.
The processing aid 11 and the processing aid 1 shown in FIG.
The structure of 1 "has a different structure.

As shown in FIGS. 44, 45 and 46,
The processing aid 11 is used to hold the concave lens-shaped surface of the quartz plate 13 formed with the concave lens shape, and the back surface of the quartz plate 13 formed with the concave lens shape and one surface of the processing aid 11 are formed. By using a double-side polishing machine, polishing is performed simultaneously from the upper and lower sides, and the concave surface is formed. One surface of the quartz plate 13 is not polished, and the concave surface is formed. Since only polishing can be performed, there are the following advantages. By using a double-side polishing machine, it is possible to polish the crystal plate 13 having an extremely thin and concave lens shape. Even if the processing is performed using a double-side polishing machine, the one surface on which the concave lens shape is formed on the crystal plate 13 by using the processing aid 11 is not polished at all, and the rear surface on which the concave lens shape is formed. Can be polished, so that the processing dimensional accuracy of the concave lens shape portion does not change. By using the processing aid 11, a single-side polishing can be performed using a double-side polishing machine. Therefore, even if the polishing is performed from the lapping, which is a rough processing, to the polishing, the concave lens-shaped portion is formed. However, the precision of the processing dimensions does not change. By using the processing aid 11, it is possible to achieve the parallel accuracy and the planar accuracy, which are the advantages of the double-side polishing machine, while performing the single-side polishing. By using the processing aid 11, both the advantages of the chemical etching process, the advantages of the single-side polishing machine, and the advantages of the double-side polishing machine can be utilized. By performing the one-side polishing using the processing aid 11, the disadvantage of the one-side polishing machine is eliminated.

FIG. 47 shows a quartz plate 1 in the form of a concave lens formed from both sides of the quartz plate 13 by plasma or other chemical etching.
3 is made to perform planetary motion directly using the carrier 37 shown in FIG. 20 using the double-side polishing machine without using the processing aid 11 shown in FIG. Then, after the process-affected layer due to the etching process is removed by mechanical processing, etching is performed again, and then,
The machining state of the quartz plate 13 obtained by performing machining from both sides by using both machining and etching again is shown. FIG. 45 (c) shows an example of a completed dimensional diagram.

FIG. 48 shows that when the quartz plate 13 is actually manufactured, several hundreds of the 2.5-inch wafers are etched on the surface of the quartz plate 13 by etching.
Thousands, a concave lens shape on one side, or a concave lens shape on both sides to form a quartz plate 13, then cut the quartz plate 13, use the quartz plate 13 in a square shape, Or, a state in which the quartz plate 13 is reworked and used in a round shape is shown.

Although the processing means described with reference to FIGS. 44, 45 and 46 describes a processing method one by one, actually, as shown in FIG. Using a 5-inch wafer, a large amount of etching can be performed at once, and the processing aid 11 or the processing aid 11 ″ or other shapes capable of holding the crystal plate 13 that has been subjected to the large etching. In FIG. 20, processing is performed by using a processing aid, or directly without using the processing aid 11 or the processing aid 11 ″.
When the carrier 37 is used to perform a planetary motion, perform polishing from both sides, perform etching again, and then cut and manufacture the quartz plate 13 one by one. Highly accurate quartz plate 13 at low cost
Can be manufactured in a large amount in a short time.

When the quartz plates 13 shown in FIGS. 48C and 48D are polished one by one, FIG.
A processing aid 61 as shown in FIGS.
Using a plastic, metal, or other material, a processing aid 61 is manufactured, and the quartz plate 13 is placed in the space 62 of the processing aid 61, as shown in FIGS.
As shown in FIG. 20, after the quartz plate 13 is inserted into the space portion 62, the carrier 37 shown in FIG. A processing step of performing processing and performing etching again may be used.

The crystal plate 13 shown in FIG. 49 (c) has a rectangular shape, and the processing aid 61 into which the rectangular crystal plate 13 is inserted is also a rectangular space. When polishing is performed using the processing aid 61 forming the processing assisting tool 61, compared to the processing assisting tool 61 forming the round space portion 62 shown in FIG. 49 (e). If the carrier 37 is used directly and the planetary motion is performed by using the square-shaped processing aid 61, the polishing can be more effectively performed.

FIG. 50 shows that a polishing agent, such as cerium oxide, is difficult to be polished, and is a material. For example, a plastic such as Lumirror, whose product name is Toray, is used. When the manufactured processing aid 61 is used, the portion of the processing aid 61, which is indicated by oblique lines, is difficult to be polished, so that the outer peripheral portion of the crystal plate 13 is hardly polished. Only the portion of 0.05 mm or 0.1 mm or other shape being etched and the lower surface, that is, the back surface, will be polished. Although FIGS. 49 and 50 show processing examples using one quartz plate 13 each, the diameter shown in FIG. 48 is 2.5 inches. A processing aid 6 made of plastics, such as polyester, for polishing using a quartz plate 13 having a rectangular shape or other shapes.
1 can also be used for polishing.

FIGS. 51, 52, 53 and 54 show that the quartz plate 13 is formed into a concave lens shape by using a chemical etching means such as plasma etching. After processing into the shape, again, mechanical polishing, using a double-sided polishing machine or other polishing means, into a concave lens shape, chemical,
The affected layer of the processed surface formed using the etching means is removed by mechanical polishing to obtain the parallel accuracy and surface accuracy of both surfaces, and again, such as plasma etching,
When etching using chemical etching means, the disadvantage of etching is extremely small, several μm.
Unevenness is generated. By removing the unevenness by mechanical polishing, the crystal plate 13 can be easily and extremely reduced.
Shows a state in which it can be processed extremely and thinly. To summarize the above, the quartz plate 13 was processed into a concave lens shape by using a chemical etching means, and then mechanically polished to obtain a crystal plate. Remove small irregularities,
Parallel accuracy and surface accuracy can be improved. After that, the chemical etching process, the mechanical polishing process, and the etching process are repeated and repeated.
Even if the crystal plate 13 is made extremely thin, the surface accuracy is not reduced, and even if the crystal plate 13 is made extremely thin,
The crystal plate 13 is not perforated or damaged due to impurities due to excessive etching. FIG.
1 and 52, only one surface of the quartz plate 13 is processed into a concave lens shape, but FIGS. 52 and 54 show concave lens shapes on both surfaces of the quartz plate 13. 2 shows the crystal plate 13 in the case of forming. However, in order to reinforce the concave lens shape formed on the quartz plate 13 shown in FIGS. 45, 46, 53 and 54, the rosin 60 injected into the concave lens shape is used. It may or may not be used.

[0058]

According to the present invention, the object to be polished is etched, and then the surface is polished by using a double-side polishing machine, a single-side polishing machine, or other polishing means. I ca n’t make it,
Since a smooth line can be formed, an electrode can be easily formed by vapor deposition. In addition, this reduces auxiliary vibrations.

Since piezoelectric materials, particularly quartz, are hard and brittle materials, the processing method is limited to the lapping method and the etching method, and there is a limit to thinning. By developing a piezoelectric element processing technology of a new processing method using both etching and polishing or a processing method using both etching, polishing and etching, the thickness becomes 0.125 μm (natural vibration frequency of about 12.0 μm).
(GHz) high-frequency vibrator. Further, by using a processing technique in which etching / polishing or etching / polishing / etching is used in combination, it is possible to develop an oscillation element of the order of 0.06 μm (natural oscillation frequency of about 24,0 GHz) in the future. When the quartz plate is thinned to the limit and the natural vibration frequency is increased, the diameter of the vibrating portion of the quartz plate vibrates if it is 100 times or more the thickness of the vibrating portion. The higher the value, the smaller the diameter of the vibrating part, so the area of the quartz plate decreases in proportion to the natural vibration frequency. In other words, the higher the frequency, the higher the cost per area of the quartz plate,
It can be manufactured at low cost. Furthermore, there is an advantage that the higher the frequency, the higher the value of the product.

As described above, according to the present invention, it is possible to provide a piezoelectric element and a method for processing the same, which are thinner than conventionally difficult thicknesses. can do.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an outline of a processing method of the present invention.

FIGS. 2A and 2B show a first example of manufacturing a quartz oscillator, and FIG.
7A shows a cross-sectional shape of the vibrator, FIG. 6B shows a Nomarski micrograph of the vibrator, and FIG. 6C shows a reactance frequency characteristic. The surface material is AT cut, the thickness of the material is 103μ
m, the diameter is 5 mm, the processing size is 25 μm in thickness, and the radius of curvature is 30 mm.

FIGS. 3A and 3B show a second example of manufacturing a crystal unit, and FIG.
Shows the cross-sectional shape of the vibrator, and (b) shows the reactance frequency characteristics. The surface material is AT cut, the thickness of the material is 103 μm, the diameter is 5 mm, the processing size is 9 μm in thickness, and the radius of curvature is 200 mm.

FIG. 4 shows a third example of manufacturing a quartz oscillator, in which (a)
Shows the cross-sectional shape of the vibrator, and (b) shows the reactance frequency characteristics. The surface material is AT cut, the thickness of the material is 77 μm, the diameter is 5 mm, and the processing size is 27 μm.

FIG. 5 is a diagram showing a reactance frequency characteristic of a crystal resonator having an AT cut and a thick quartz resonator.

FIG. 6 is a diagram showing a reactance frequency characteristic of a quartz crystal unit having a thick AT-cut surface material.

FIG. 7 is a diagram showing the reactance frequency characteristics of a quartz crystal unit having a thin AT-cut surface material.

FIG. 8 is a diagram showing a reactance frequency characteristic of a thin quartz crystal unit in which a surface material is AT-cut and has a small thickness.

FIG. 9 is a diagram showing the reactance frequency characteristics of a quartz oscillator having a thinner AT material and a thinner thickness.

FIG. 10 is a diagram showing the reactance frequency characteristics of a quartz oscillator having a thinner AT material and a thinner thickness.

FIG. 11 is a sectional view of a first processing aid in the processing method of the present invention.

FIG. 12 is a sectional view of a second processing aid in the processing method of the present invention.

FIG. 13 is a cross-sectional view of a state in which a second processing aid and a quartz plate are set on the first processing aid.

FIG. 14 is a sectional view showing another example of the processing apparatus of the present invention.

FIG. 15 is a sectional view showing another example of the processing apparatus of the present invention.

FIG. 16 is a cross-sectional view showing a state where the processing apparatus of the present invention is sandwiched between lapping plates.

FIG. 17 is a plan view of another processing aid in the processing apparatus of the present invention.

FIG. 18 is a cross-sectional view of a quartz plate manufactured using the processing aid of FIG.

19 is a cross-sectional view of a quartz plate manufactured using the processing aid of FIG.

FIG. 20 is a plan view showing the movement of the wrapping plate.

FIG. 21 is a plan view showing the movement of the wrapping plate.

FIG. 22 is a top view showing an embodiment of the present invention.

FIG. 23 is a sectional view showing an embodiment of the present invention.

FIG. 24 is a sectional view showing an embodiment of the present invention.

FIG. 25 is a cross-sectional view showing an example of the processing apparatus of the present invention.

FIG. 26 is a cross-sectional view of a quartz plate manufactured by using FIG. 25 or another apparatus.

FIG. 27 is a cross-sectional view showing another example of the processing aid.

FIG. 28 is a cross-sectional view showing another example of the processing aid.

FIG. 29 is a cross-sectional view showing another example of the processing aid.

FIG. 30 is a sectional view showing an embodiment of the present invention.

FIG. 31 is a top view showing an embodiment of the present invention.

FIG. 32 is a cross-sectional view showing a processing method according to the present embodiment.

FIG. 33 is a side view showing a working tool in the present embodiment.

34A and 34B are a side view and an AA cross-sectional view illustrating an example of a grindstone according to the present example.

FIG. 35 is a cross-sectional view showing a processed example in the present example.

FIG. 36 is a side view and a plan view showing another example of the grindstone in the present embodiment.

FIG. 37 is a sectional view showing another example of the working tool according to the present embodiment.

FIG. 38 is a cross-sectional view showing another example of the working tool in the present embodiment.

FIG. 39 is a cross-sectional view showing another example of the working tool in the present embodiment.

FIG. 40 is a side view and a top view showing an actual production drawing of the working tool in the present embodiment.

FIG. 41 is a longitudinal sectional view and a side view of an enlarged view showing an actual production drawing of the working tool in this embodiment.

FIG. 42 is a cross-sectional view showing a processed example in the present example.

FIG. 43 is a cross-sectional view showing a processed example in the present example.

FIG. 44 is a cross-sectional view of a quartz plate manufactured using the processing aid of FIG.

FIG. 45 is a cross-sectional view of a quartz plate manufactured using the processing aid of FIG. 13;

FIG. 46 is a cross-sectional view of a quartz plate manufactured using the processing aid of FIG.

FIG. 47 is a sectional view showing an embodiment of the present invention.

FIG. 48 is a top view showing the embodiment of the present invention.

FIG. 49 is a top view showing the embodiment of the present invention.

FIG. 50 is a sectional view showing an embodiment of the present invention.

FIG. 51 is a sectional view showing an embodiment of the present invention.

FIG. 52 is a sectional view showing an embodiment of the present invention.

FIG. 53 is a sectional view showing an embodiment of the present invention.

FIG. 54 is a sectional view showing an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Ball whetstone, 2 spindles, 3 cylindrical magnets, 4 quartz plates, 5 grinding spindles, 6 tool holders, 11 first processing aids, 12 ring or square or other shaped grooves or steps, 13 Quartz plate, 14 circular or other shaped grooves, 15 suede, 16
Hole, 17 lower wrapping plate, 18 upper wrapping plate, 19 second processing aid, 21 and 54
Cylinder, 22 pressure receiving surface, 23, 24 electrodes, 25 amplifier,
30 round bar, 31 chuck, 32, 32 ', 32 ",
32 "', 32""grinding or polishing whetstone, 32 (a)
Groove, 33, 33 ', 33 "processing tool, 34 tool holder, 35 support arm, 36 bearing, 37 carrier, 38 internal gear, 39 sun gear, 40 air nozzle, 41 fountain nozzle, 42, 43 motor, 44
Polishing tool, 45 adhesive tape, 46 holes or space,
47 holding part, 48 fixing frame, 49 gold wire, 50
Electrode, 51 holding portion, 52 groove, 53 smooth line, 55 stopper, 56 holding portion, 57 diamond abrasive, 58 piezoelectric plate, 59 adhesive layer, 60 rosin, 61 is a third processing aid, 62 is a space portion ,

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 41/22 H01L 41/08 C H03H 3/02 41/22 Z

Claims (21)

[Claims] 1. A ring-shaped or square-shaped or other-shaped groove or step is formed on an upper surface of a first processing aid,
The depth of the groove or the step, a little higher than the depth, a cylindrical or other shape, a second processing aid is fitted into the groove or the step, the first of the second processing aid, A processing aid, a disk-shaped or other shaped piezoelectric element to be polished, which is the same as, or slightly lower or higher than, the protruding height from the upper surface, is installed; Using an upper lapping plate on the upper surface of the polished object and an upper and lower wrapping plate of a lower lapping plate below the first processing aid, an extremely thin workpiece is polished. A method for processing a piezoelectric element. 2. A liquid is poured into a circular or other shaped groove or step formed on the upper surface of the first processing aid, and the periphery of the lower surface of the object to be polished of the piezoelectric element is in close contact with the liquid. So that the object to be polished is placed on the first processing aid, and the liquid is used for surface tension or by freezing, so that the first processing aid is 2. The method for processing a piezoelectric element according to claim 1, wherein the object to be polished is fixed to the object to be polished. 3. The object to be polished is placed on a hydrophilic thin plate containing water placed on the upper surface of the first processing aid, and the polishing object is included in the hydrophilic thin plate. 2. The method for processing a piezoelectric element according to claim 1, wherein the first processing aid is fixed to the object to be polished by using surface tension of water. 4. A plurality of holes are formed in the first processing aid, and the holes are filled with a viscous substance such as starch syrup, honey, an adhesive bond or grease or other adhesive. The lower surface of the object to be polished is brought into close contact with the viscous substance, and the first processing aid and the object to be polished are spotted and fixed only by the area of the hole. The method for processing a piezoelectric element according to claim 1. 5. The method according to claim 5, wherein the first processing aid and the second processing aid are formed by using rosin, starch paste or other adhesive.
5. The method according to claim 1, wherein the piezoelectric element is fixed. 6. The first processing aid is manufactured using a metal such as iron, and the second processing aid is formed of a super steel or
Using iron or glass or a material similar to glass,
The method for processing a piezoelectric element according to claim 1, wherein the piezoelectric element is manufactured. 7. A mask is applied to the object to be polished by a mask using a mask, and only the central portion is subjected to ion milling or plasma etching using, for example, CHF ₃ or the like to form a concave lens shape (inverted MESA shape). , After processing,
As a subsequent processing means, using a double-sided polishing machine, or a single-sided polishing processing machine or other polishing processing means, performed the etching process, after polishing the processed surface, again, chemical etching and A method for processing a piezoelectric element, wherein the processing is performed by repeatedly using polishing. 8. The processing holder is configured to hold a crystal plate, one side of which is polished on one side of a quartz plate, and the other side is formed on one side of the processing holder by using a double-side polishing machine. A method for polishing a piezoelectric element, wherein a double-side polishing machine is used as a single-side polishing machine by simultaneously polishing from above and below. 9. A quartz plate processed into a concave lens shape is held by using a processing holder, one surface of which is one surface of the quartz plate, the other surface is one surface of the processing holder, and a double-side polishing machine is used. A method of polishing a piezoelectric element, wherein the polishing is performed simultaneously from above and below. 10. A quartz plate is processed into a concave lens shape, the surface processed into the concave lens shape is held using a processing holder, one surface is processed into a concave lens shape, and the other surface is processed and held. A polishing method for a piezoelectric element, in which an extremely thin, piezoelectric element is processed by simultaneously polishing one side of the tool from above and below using a double-side polishing machine. 11. Polishing a quartz plate having a concave lens shape on one or both sides by using a double-side polishing machine from the top and bottom simultaneously to process an extremely thin piezoelectric element. Processing method. 12. A mortar, paraffin or other resin is injected into the concave lens shape of the quartz plate processed into the concave lens shape to reinforce the strength inside the concave lens shape.
From the top and bottom, using a double-side polishing machine,
A polishing method for a piezoelectric element that performs polishing simultaneously. 13. The processing holder is made of a material such as plastics or iron, which is difficult to be polished with an abrasive such as cerium oxide, and is difficult to process on one side of the processing holder. The method for polishing a piezoelectric element according to claim 1, wherein the polishing is performed. 14. A piezo resin, paraffin, glue, or other resin is injected into a concave lens shape portion of a quartz plate obtained by processing a piezoelectric material such as a quartz plate into a concave lens shape by plasma etching or the like using a concave lens shape. Then, after reinforcing the strength inside the concave lens shape, the back surface forming the concave lens shape is polished or chemically etched. 15. A material having a piezoelectric effect such as quartz, lithium niobate, potassium niobate, or another single crystal, barium titanate, piezoelectric ceramics, or other ceramics is provided at the center of the cylinder. A method for processing a piezoelectric element, comprising: forming a pressure receiving surface; and forming a pair of electrodes on the pressure receiving surface. 16. The method for processing a piezoelectric element according to claim 15, wherein the cylinder and the pressure receiving surface are made of an integral material having a piezoelectric effect. 17. A round bar made of a material having a piezoelectric effect is formed by drilling holes from both ends using a grinding means, and a pressure-receiving surface having a predetermined thickness is formed at a central portion of the round bar. Furthermore, the air vibrations, which have entered the outer peripheral portion of the pressure receiving surface from the left and right, come and go, so that the air vibration of the cylinder, which has entered the pressure receiving surface from the left and right, can resonate at the central portion. In order to be able to form a hole or space part, the air vibration entered from the left and right of the cylinder,
A method for processing a piezoelectric element, characterized by causing resonance at a central portion of a cylinder to cause a resonance phenomenon and causing a pressure-receiving surface located at the central portion to vibrate more strongly. 18. A round hole made of a material having a piezoelectric effect and having a cylindrical shape is formed from both ends by using a grinding means, and a pressure-receiving surface having a predetermined thickness is formed in the center of the round bar. Is formed, and a pair of electrodes is provided on the pressure-receiving surface to reduce external air vibration, 19. The grinding means forms a groove in the surface of the barrel-shaped grindstone, and rotates the grindstone by injecting air or liquid into the groove, or uses other mechanical means. 19. The method according to claim 18, wherein the barrel-shaped grindstone is rotated. 20. The method for processing a piezoelectric element according to claim 18, wherein a barrel-shaped grindstone is formed using a steel ball close to a true sphere. 21. A central portion of a quartz plate, in which a metal such as gold is used for vapor deposition or plating on a central portion of the quartz plate, and a metal portion is formed using means such as vapor deposition. A method for processing a piezoelectric element, wherein a thin gold wire is connected and used as an electrode of a quartz plate, and a voltage is applied to the quartz plate using the gold wire.