JP2002050807A - Manufacturing method of piezoelectric device and washing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a piezoelectric device that is strong against fluctuation of a drive voltage and can improve drive level characteristics, and a washing device utilized in this manufacturing method. SOLUTION: In the manufacturing method of the piezoelectric device for forming a specific piezoelectric chip by cutting a piezoelectric material, namely wafer (ST11), forming an electrode at the piezoelectric chip as a piezoelectric vibration piece (ST14), and accommodating the piezoelectric vibration piece in a specific package 12, an aligning tool used for forming the electrode is used for washing the piezoelectric chip before forming the electrode (ST13).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for manufacturing a piezoelectric device such as a piezoelectric vibrator or a piezoelectric oscillator, and a cleaning apparatus used in a specific step of such a manufacturing method.

[0002]

2. Description of the Related Art FIG. 12 is a flowchart simply showing the steps of manufacturing a conventional piezoelectric device.

In the figure, first, a rectangular crystal wafer is cut out of a crystal of, for example, artificial quartz as a piezoelectric material (ST1).

[0004] Next, the crystal wafers are stacked and fixed with an adhesive or the like, and the stacked wafers are cut along a predetermined cutting line to form a wafer block. After bonding the end faces of this wafer block together to make the whole flat,
Further, cutting is performed again along a predetermined cutting line to form a crystal chip block. The crystal chip block is used as a processing unit, and after the corner is polished, the adhesive is peeled off to obtain a crystal chip called a blank (ST2).

Next, this crystal chip is etched to a predetermined thickness (ST3). Further, in order to form necessary electrodes on the front and back surfaces of the crystal chip, an electrode pattern is provided by, for example, vapor deposition, and a predetermined drive electrode is formed. The crystal resonator element provided is obtained (ST4).

[0006] The piezoelectric vibrating reed is mounted on a predetermined base (ST5), and a driving voltage is applied to a driving electrode of the piezoelectric vibrating reed to monitor a vibration frequency, and for example, apply a laser beam or an electron beam to the surface thereof. By performing irradiation, plasma etching, or the like, the mass of the piezoelectric vibrating piece is reduced, the vibration frequency is increased, and the frequency is adjusted to match the desired frequency (ST6).

Finally, a lid is vacuum-sealed on the base,
Or sealed in an inert gas atmosphere such as nitrogen gas,
A piezoelectric vibrator is completed (ST7).

[0008]

By the way, in a piezoelectric vibrator formed by such a manufacturing method, when the piezoelectric vibrator is assembled in a predetermined electronic device after completion and a driving voltage is applied, the driving voltage is reduced. Owing to the fluctuation, oscillation was rarely stopped particularly when the voltage was significantly reduced.

That is, a recent piezoelectric device is driven at a lower voltage as compared with a conventional case driven by a relatively large driving voltage. For this reason, although very rarely, the phenomenon that the vibration stops is observed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is provided with a method of manufacturing a piezoelectric device which is resistant to fluctuations in drive voltage and can improve drive level characteristics, and a method for manufacturing the same. It is an object of the present invention to provide a cleaning device that is performed.

[0011]

SUMMARY OF THE INVENTION According to the first aspect of the present invention, a predetermined piezoelectric chip is formed by cutting a wafer of a piezoelectric material, and an electrode is formed on the piezoelectric chip to form a piezoelectric vibrating reed. In the method for manufacturing a piezoelectric device for accommodating the piezoelectric vibrating reed in a predetermined package, the method for manufacturing a piezoelectric device includes, before forming the electrodes, cleaning the piezoelectric chip using an alignment jig used for forming the electrodes. Is achieved.

According to the first aspect of the present invention, before the electrodes are formed on the piezoelectric chips, the piezoelectric chips are cleaned using the alignment jig used for forming the electrodes. This is for the following reasons.

According to the study of the present inventor, it has been found that the deterioration of the drive level characteristic due to the piezoelectric device, especially the stoppage of the oscillation caused by the piezoelectric device is caused by the handling in the conventional process. In particular, after forming a blank and adjusting the thickness by etching, when forming an electrode, a worker arranges a quartz chip, which is a piezoelectric chip, on a jig for forming an electrode. During this operation, extremely fine foreign matter may adhere to the piezoelectric chip, and an electrode is formed with the foreign matter attached. This affects the drive characteristics of the completed piezoelectric vibrating reed. Therefore, the present inventors pay attention to this electrode forming step, and perform cleaning using the jig in a state where the piezoelectric chips are arranged on the jig before forming the electrodes. This cleans the surface of the piezoelectric chip on which the electrodes are to be formed, so that extremely fine foreign substances attached when the piezoelectric chips are arranged on the jig are removed. In particular, since the cleaning is performed with the piezoelectric chips arranged in a jig, compared to when the piezoelectric chips are put together in a basket or the like, very thin piezoelectric chip pieces overlap and stick together, and the surface is hidden. The surface is cleanly cleaned. By forming the electrodes in this state, it is possible to prevent the electrodes from being formed in a state where extremely fine foreign matter is attached, and to appropriately perform the oscillation operation.

In addition, since the dedicated jig is common to the electrode forming jig, there is no need to transfer the piezoelectric chip to another jig when forming the electrodes, and there is no possibility that extremely fine foreign matter adheres. .

According to a second aspect of the present invention, in the configuration of the first aspect, the dedicated jig used for the cleaning holds the plurality of piezoelectric chips side by side so as not to overlap each other.

According to the second aspect of the present invention, since the dedicated jig holds a plurality of piezoelectric chips so that they do not overlap each other, the surface of each piezoelectric chip on which electrodes are to be formed is hidden. And a plurality can be washed simultaneously.

According to a third aspect of the present invention, in the configuration of the second aspect, the exclusive jig is held such that a direction in which the piezoelectric chips are arranged in a cleaning tank is aligned in a vertical direction.

According to the third aspect of the present invention, the piezoelectric chips can be immersed in the cleaning tank with the direction in which the piezoelectric chips are lined up in the vertical direction, and all the piezoelectric chips can be cleaned in a state of being immersed in the cleaning liquid. You.

According to a fourth aspect of the present invention, in the configuration of the first to third aspects, the cleaning is performed in a cleaning solution having a high wettability to the piezoelectric chip in the cleaning tank, and while applying ultrasonic waves. This is performed by swinging the dedicated jig.

According to the structure of the fourth aspect, the cleaning effect is enhanced by using a cleaning liquid having a high wettability particularly to the piezoelectric chip. In addition, in the cleaning liquid, the piezoelectric chip is oscillated and ultrasonic waves are applied, so that the adhered extremely fine foreign matter is effectively cleaned.

According to a fifth aspect of the present invention, in the first to fourth aspects, the cleaning is performed while applying ultrasonic waves to the piezoelectric chip from at least two different directions in the cleaning tank. I do.

According to the fifth aspect, by applying ultrasonic waves to the piezoelectric chip from at least two different directions, extremely fine foreign matter is vibrated from two different directions. As a result, cleaning can be performed more effectively.

According to a sixth aspect of the present invention, in the configuration of the fifth aspect, the cleaning is performed by applying ultrasonic waves having different frequencies from at least two different directions to the piezoelectric chip in the cleaning tank. It is characterized by.

According to the sixth aspect of the present invention, since ultrasonic waves having different frequencies are applied to the piezoelectric chip from at least two different directions, a plurality of vibrations having different frequencies are provided, which further enhances the effect. Is washed.

According to a seventh aspect of the present invention, in the configuration of the first to sixth aspects, the cleaning and the replacement liquid are vaporized and applied to the cleaned piezoelectric chip in a cleaning apparatus. Features.

According to the configuration of claim 7, the piezoelectric chip after cleaning is moved to another facility or the like and dried with hot air, etc., so that there is no fear of contamination by other facilities and the piezoelectric chip is immediately moved to the next step. Therefore, there is no danger of recontamination depending on the standing time.

According to the present invention, a predetermined piezoelectric chip is formed by cutting a wafer made of a piezoelectric material.
An electrode is formed on the piezoelectric chip to form a piezoelectric vibrating reed, and in a method of manufacturing a piezoelectric device in which the piezoelectric vibrating reed is housed in a predetermined package, the piezoelectric vibrating reed is adjusted after adjusting the frequency of the piezoelectric vibrating reed. This is achieved by a method of manufacturing a piezoelectric device, in which a piezoelectric vibrating reed is cleaned using a jig used for sealing before sealing in a package.

According to the eighth aspect of the present invention, the frequency of the piezoelectric vibrating reed after the electrodes are formed on the piezoelectric chip is adjusted, and then the piezoelectric vibrating reed is cleaned using the sealing jig. . This is for the following reasons.

According to the study of the present inventors, it has been found that another cause of the deterioration of the drive level characteristic due to the piezoelectric device, especially the stop of the oscillation, which is observed in the past, is after the frequency adjustment step. In particular, conventionally, through several steps after the formation of the electrodes, the package is sealed in a state in which extremely fine foreign matter adheres to the piezoelectric vibrating reed, and a completed product is obtained. This affects the drive characteristics of the completed piezoelectric vibrating reed. Therefore, the present inventors pay attention to this sealing step, and before performing the sealing step, perform cleaning using the jig in a state where the base on which the piezoelectric vibrating reed is mounted is arranged on the jig. As a result, extremely fine foreign matters attached to the piezoelectric vibrating reed are removed, so that the piezoelectric vibrating reed is sealed in a clean state, and the oscillation operation can be appropriately performed.

According to a ninth aspect of the present invention, in the configuration of the eighth aspect, the exclusive jig used for the cleaning holds a plurality of bases on which the piezoelectric vibrating reeds are mounted so as not to overlap each other. And

According to a tenth aspect of the present invention, in the configuration of the ninth aspect, the exclusive jig is held such that a direction in which the bases are lined up in the cleaning tank is aligned in a vertical direction. Item 10. The method for manufacturing a piezoelectric device according to Item 9.

The invention of claim 11 is the invention of claims 8 to 10
Wherein the cleaning is performed in a cleaning bath, in a cleaning liquid having high wettability with respect to the piezoelectric vibrating reed, and is performed by oscillating the dedicated jig while applying ultrasonic waves. And

[0033] The invention of claim 12 is the invention of claims 8 to 11
Wherein the cleaning is performed in a cleaning tank while applying ultrasonic waves to the piezoelectric vibrating reed from at least two different directions.

According to a thirteenth aspect of the present invention, in the configuration of the twelfth aspect, the cleaning is performed by applying ultrasonic waves having different frequencies from at least two different directions to the piezoelectric vibrating reed in the cleaning tank. It is characterized by the following.

The invention of claim 14 is the invention of claims 8 to 13
Is characterized in that the cleaning liquid or the replacement liquid is vaporized and applied to the cleaned piezoelectric vibrating reed in the cleaning apparatus to dry it.

Further, according to the present invention, there is provided a cleaning tank for storing a cleaning liquid for cleaning a piezoelectric chip, in which a plurality of piezoelectric chips are overlapped with each other. Means for vertically holding and swinging a dedicated jig which is arranged and held so as not to be applied, means for applying ultrasonic waves to the piezoelectric chip in the cleaning tank, and holding the piezoelectric chip on the dedicated jig And a means for sending to the electrode forming step as it is.

According to the structure of the fifteenth aspect, it is possible to provide a cleaning apparatus suitable for executing the method of the first to fourth aspects.

According to a sixteenth aspect of the present invention, in the configuration of the fifteenth aspect, a means for applying ultrasonic waves to the piezoelectric chip from at least two different directions in the cleaning tank is provided.

A seventeenth aspect of the invention is characterized in that, in the configuration of the sixteenth aspect, there is provided means for applying ultrasonic waves with a plurality of different frequencies to the piezoelectric chip from at least two different directions.

The invention of claim 18 is the invention of claims 15 to 1
The structure of the seventh aspect is characterized in that cooling means for cooling the stored liquid is provided around the cleaning tank.

According to the configuration of the eighteenth aspect, it is possible to suitably prevent the temperature of the cleaning liquid from rising to an unnecessary limit by applying ultrasonic waves.

Further, according to the present invention, there is provided a cleaning tank for storing a cleaning liquid for cleaning a piezoelectric vibrating reed mounted on a base, wherein the cleaning tank is provided in the cleaning tank. Means for vertically holding and swinging a dedicated jig for holding a plurality of bases on which the vibrating reeds are mounted so as not to overlap each other, and a piezoelectric vibrating reed mounted on the base in the cleaning tank. This is achieved by a cleaning apparatus including: means for applying ultrasonic waves to the dedicated jig; and means for sending to a sealing step while holding the base on which the piezoelectric vibrating reed is mounted on the dedicated jig.

According to the configuration of claim 19, it is possible to provide a cleaning apparatus suitable for performing the method of claims 8 to 11.

According to a twentieth aspect of the present invention, in the configuration of the nineteenth aspect, there is provided means for applying ultrasonic waves to the piezoelectric vibrating reed mounted on the package from at least two different directions in the cleaning tank. And

According to a twenty-first aspect of the present invention, in the configuration of the twentieth aspect, there is provided means for applying ultrasonic waves having a plurality of different frequencies from at least two different directions to the piezoelectric vibrating reed mounted on the base. Features.

The invention of claim 22 is the invention of claims 19 to 2
In the first aspect, a cooling unit for cooling the stored liquid is provided around the cleaning tank.

[0047]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

The method of manufacturing a piezoelectric device according to this embodiment is characterized in that, unlike the conventional method, a predetermined cleaning step is introduced. Before describing the manufacturing process, a configuration of a crystal resonator, which is an example of the piezoelectric device of the present embodiment, will be described with reference to FIG. 11 for convenience of understanding.

In FIG. 11, a crystal resonator 10 is joined to a box-shaped base 12 having a space 12a for accommodating a plate-shaped crystal resonator element 11, and to the base 12 so as to seal the space 12a. A plate-shaped lid 13 is provided. The quartz vibrating reed 11 is connected and fixed via an adhesive (not shown) on an electrode 14 disposed at a step portion having one end 11a integrally provided in the space 12a, and the other end 11b is connected to a free end. Have been. The base 12 and the lid 13 are joined via a sealing material (a brazing material) 15.

In this embodiment, the piezoelectric vibrating reed is the crystal vibrating reed 11 made of quartz in the present embodiment, but is not limited to this. For example, a piezoelectric material such as quartz, LiTaO ₃ , LiNbO ₃ is used. Thus, a piezoelectric vibrating reed may be configured.

As a material of the base 12, a ceramic such as alumina is used, and as a material of the lid 13, a metal such as Kovar or a ceramic such as alumina is used. In addition, as a material of the sealing material 15, low melting point glass, silver brazing, solder, or the like is used.

In the crystal resonator 10, first, a base 12 is formed of a ceramic material such as alumina, and an electrode portion is formed by, for example, plating so as to correspond to the crystal resonator element 11.

The quartz vibrating reed 11 on which electrodes necessary for driving the excitation electrodes and the connection electrodes are formed as described later is mounted on the electrode portion of the base 12 via conductive adhesives 14a. . Next, by irradiating the surface of the crystal vibrating piece 11 with an electron beam or plasma to adjust the weight, the frequency is adjusted as described later.

Next, the lid 13 is placed on the base 12 and, for example, an electron beam is irradiated from above the lid 13 to complete the sealing.

FIG. 1 is a flowchart simply showing a manufacturing process including a process of forming the quartz-crystal vibrating piece 11 in the above-described process of manufacturing the quartz-crystal resonator 10.

In this manufacturing process, ST10 to ST10
Steps up to 12 are the same as those in the conventional manufacturing process described with reference to FIG. 12. First, a rectangular crystal wafer is cut out from a crystal of, for example, artificial quartz as a piezoelectric material (ST10).

After the cut quartz wafer is processed to a predetermined thickness by polishing or the like, these quartz wafers are stacked and fixed with an adhesive or the like, and the laminated wafer is cut along a predetermined cutting line to form a wafer block. . After bonding the end faces of the wafer block to each other to form a flat shape as a whole, the wafer block is cut again along a predetermined cutting line to form a crystal chip block. The crystal chip block is used as a processing unit, and after the corner portion is polished, the adhesive is peeled off to obtain a crystal chip called a blank (ST11).

Next, this crystal chip is etched and adjusted to a predetermined thickness (frequency) (ST12). here,
Conventionally, electrodes are formed on the front and back surfaces of the crystal chip. In the present embodiment, alignment cleaning is performed here (ST13). In this embodiment, the cleaning of ST13 is as follows.
For example, since the cleaning is performed using the cleaning apparatus of FIG. 2, a detailed description thereof will be given later.

Next, in order to form necessary electrodes on the front surface and the back surface of the crystal chip, an electrode pattern is provided by vapor deposition or sputtering to obtain the crystal vibrating piece 11 provided with a predetermined drive electrode (ST14). That is, the one in which the electrodes are formed on the crystal chip in this step is the crystal vibrating piece 11 described in FIG.

As described above, this crystal vibrating piece 11 is
It is mounted on the base 12 which is a predetermined package (ST
15) Applying a drive voltage to the drive electrode of the crystal vibrating piece,
While monitoring the vibration frequency, for example, the surface of the crystal resonator element 11 is irradiated with a laser beam or an electron beam, or plasma etching is performed to reduce the mass of the crystal vibrating piece 11 and increase the vibration frequency to a desired frequency. The frequency is adjusted so as to match (step ST16). After the frequency adjustment, in the present embodiment, the alignment cleaning is performed (ST17). Since the alignment cleaning is performed using, for example, the cleaning apparatus shown in FIG. 9, a detailed description will be given later.

Lastly, the lid 13 is vacuum-sealed in the package or sealed in an inert gas atmosphere such as nitrogen gas to complete the crystal unit 10 (ST18).

FIG. 2 shows an example of the cleaning device. In this case, it is a schematic configuration diagram of the cleaning device used in ST13 of FIG.

In the figure, a cleaning apparatus 20 includes a cleaning processing chamber 21 for cleaning a quartz chip, and a sputtering chamber 22 for forming electrodes on the washed quartz chip to form a crystal vibrating piece 11. ing. The cleaning processing chamber 21 and the vapor deposition (sputtering) chamber 22 are airtightly partitioned by partition walls.

A plurality of cleaning tanks 23,
24 and 25 are disposed, and each cleaning tank may be used as a plurality of cleaning tanks for storing a cleaning liquid as described later, or a part of the cleaning tank may be used as a cleaning tank and a storage tank for a replacement agent for drying. You may use them properly. Multiple washing tanks 23,2
A guide means 26a extending along the process order is provided above the fourth and 25th steps.
A swing arm 26b is provided. This swing arm 2
6b, the jig holding arm 26 is attached to the tip,
A dedicated jig 30 described later is attached to and detached from the jig holding arm 26, and a crystal chip is set on the dedicated jig 30 as described later. In this state, the swing arm 26b can swing the dedicated jig 30 vertically in the figure, or rotate or rotate around a central axis passing in the vertical direction. Arbitrary swinging can be performed in accordance with the movement of the guide means 26a.

The guide means 26a is provided with a dedicated jig 30 held by the jig holding arm 26 via a swing arm 26b.
Is moved in the direction of arrow A while performing the cleaning process by the plurality of cleaning tanks 23, 24, 25, and the conveyor 2
7 The conveyer 27 conveys the dedicated jig 30 in the direction of arrow D, and carries the jig 30 from the door 29 a of the pre-vacuum chamber 29 into the pre-vacuum chamber 29. The pre-vacuum chamber 29 acts as an air lock,
By closing 9a, it is airtightly shut off from the cleaning processing chamber 21. A vacuum evacuation unit such as a vacuum pump (not shown) is provided in the vacuum preliminary chamber 29.
The dedicated jig 30 is carried in and the door 29a is closed, and the door 29a is evacuated. A door 22a communicating with the vapor deposition (sputter) chamber 22 is provided on the back side of the vacuum preliminary chamber 29, and when the vacuum preliminary chamber 29 is in a vacuum state,
When the door 22a is opened, the exclusive jig 30 is moved to the vacuum preliminary chamber 29.
An electrode forming step (ST in FIG. 1) is carried into the sputtering chamber 22 by the transfer conveyor 28 in the
14).

FIG. 3 is an exploded perspective view simply showing the structure of the dedicated jig 30. As shown in FIG.

In the figure, the special jig 30 is the same as the ST shown in FIG.
This is a jig commonly used for cleaning 13 and forming electrodes in ST14.

The exclusive jig 30 has a large number of crystal chips 16 positioned by the outer plate 33 sandwiched between the upper plate 31 and the lower plate 34.

FIG. 5 shows a state in which the quartz chip 16 is held by a dedicated jig 30. External plate 33 of FIG.
Has holes 33a of the same shape in the vertical and horizontal directions having an inner diameter slightly larger than the outer shape of the crystal chip 16, and in this hole 33a, the crystal chips 16 are horizontally placed one by one so that they do not overlap each other. Are positioned side by side.

The upper plate 31 and the lower plate 34 are masks for forming electrodes, and as shown in FIG.
Is formed with a through-hole (a portion excluding a hatched portion) 31a (see FIG. 5) corresponding to the shape of the electrode 11c to be formed on the surface of the crystal chip 16. Similarly, the lower plate 34 is also a mask for forming electrodes, and has a through hole 34a (see FIG. 5) for forming an electrode similar to that of FIG.

The cover plate 36 shown in FIG. 5 and the base plate 35 shown in FIG. 3 are members having holes larger than the through holes 31a and the through holes 34a. It has a function to suppress these from the outside.

As a result, a plurality of or a large number of crystal chips 16 are arranged as shown in FIG. 3, and are held by the exclusive jig 30 with the surfaces of the individual crystal chips 16 on which the electrodes are to be formed being exposed to the outside. It has become so.

FIG. 6 shows how the dedicated jig 30 holding a large number of crystal chips 16 is set on the jig holding arm 26 as described above.

A holding means 41 is formed at the tip (the lower end in FIG. 2) of the jig holding arm 26. A pair of grooves 42 having a U-shaped cross section are formed in the holding means 41 with their openings facing each other.

Thus, as shown by the arrow in FIG. 6, by inserting the dedicated jig 30 into the pair of grooves 42, the jig is held and held in the holding means 41 of the jig holding arm 26. Thus, the jig holding arm 26 is held in parallel and in a vertical direction so that a plurality or a large number of crystal chips 16 do not overlap each other. Is held in a state where the surface on which the electrode is to be formed (corresponding to the shape of the electrode 11c in FIG. 4) is exposed to the outside.

Next, FIG. 7 is a perspective view schematically showing the structure of the cleaning tank 23. The cleaning tank 23 contains a cleaning liquid, which will be described later, and the quartz chip 16 stored in the dedicated jig 30 is immersed therein.

When the cleaning tank 23 is formed, for example, in a rectangular parallelepiped shape, at least the first side wall 23a and the second side wall 23b are provided with ultrasonic generating means 37 and 38 having a built-in horn or the like. Each is provided. Preferably, the frequency of the ultrasonic waves generated by the ultrasonic wave generating means 37 and 38 is variable, so that the ultrasonic wave generating means 37 and 38 generate ultrasonic waves having different frequencies, respectively. You can do it.

Further, a cooling pipe 45 for circulating cooling water is disposed so as to be in contact with and surround the outer wall of the washing tank 23. These facilities may also be provided in the cleaning tanks 24 and 25.

Thus, as shown in the plan view of FIG. 8 (a view from above), the ultrasonic wave is applied to the dedicated jig 30 immersed in the cleaning tank 23 from two different directions. Ultrasonic waves S1 and S2 by the generating means 37 and 38 are applied. In this case, the function of each of the ultrasonic wave generating means 37 and 38 is adjusted so that not only the ultrasonic waves with the same frequency but the same power are applied, but also from two different directions.
Cleaning can be performed while applying ultrasonic waves S1 and S2 of different frequencies to the dedicated jig 30. Then, the temperature of the cleaning liquid is adjusted by the function of the cooling pipe 45 so that the temperature of the cleaning liquid does not rise more than necessary by the application of the ultrasonic wave.

The cleaning apparatus 20 of FIG. 2 is configured as described above. Next, an example of the cleaning method will be described.

In FIG. 2, at least the first cleaning tank 23 contains, as a cleaning liquid, an organic solvent, for example, isopropyl alcohol (IPA) as a liquid having good wettability with respect to the quartz chip 16. It is kept above 20 degrees.

A jig holding arm 26 is attached to the tip of the swing arm 26b as shown in the figure, and the dedicated jig 30 is held at the tip as described above. By the function of the guide means 26a, the exclusive jig 30 is immersed in the cleaning tank 23 through the swing arm 26b and the jig holding arm 26 while the crystal jig is accommodated therein.

In this state, the swing arm 26b is moved to the dedicated jig 3
0 is rocked in the liquid. This swing, as described above,
Up and down movement and rotation or rotation are appropriately combined.
Further, at the same time, ultrasonic waves having different frequencies, for example, with an output of about 100 W or more are applied to the dedicated jig 30 from the ultrasonic wave generating means 37 and 38 from two different directions. The time during this period is about 10 seconds.

Thus, the cleaning is completed, and the swing arm 26
b is raised, stopped just above the cleaning liquid, and dried by exposing to the vapor of the cleaning liquid. This drying time is about 10
Seconds.

As a result, the cleaned quartz chip 16
Is moved in the direction of arrow A by the guide means 26a and sent to the conveyor 27. Conveyor 27
Transports the dedicated jig 30 in the direction of arrow D and carries it into the vacuum preliminary chamber 29 through the door 29 a of the vacuum preliminary chamber 29. When the dedicated jig 30 is carried into the vacuum preparatory chamber 29, the door 29a
Is evacuated in a closed state, the door 22 communicating with the vapor deposition (sputter) chamber 22 is opened, and the special jig 30 is opened.
Is carried into the vapor deposition (sputter) chamber 22 by the conveyor 28 in the vacuum preparatory chamber 29, and the process proceeds to an electrode forming step by vacuum vapor deposition (ST14 in FIG. 1).

When the cleaning tanks 23, 24, and 25 are used with different functions, the cleaning tank 23 contains a cleaning liquid such as IPA in the same manner as described above, and the next cleaning tank 24 is used.
For example, a fluorine-based cleaning agent is accommodated as a draining agent. As the draining agent, for example, hydrofluoroether (HFE) manufactured by 3M is suitable. And
The HFE is stored in the washing tank 24 up to a predetermined water level, and the space above the HFE can be used as a vapor layer.

In this case, the exclusive jig 30 that has been cleaned in the cleaning tank 23 is exposed to the vapor layer of the cleaning tank 24 containing the above-mentioned HFE for about 10 seconds, and then left for 10 seconds without being exposed to steam. Thereby, the cleaning liquid can be dried.

As described above, in the manufacturing method according to the present embodiment, before the electrodes are formed on the crystal chip, the special jig 3
Wash using 0. As a result, extremely fine foreign substances adhered when the crystal chips 16 are arranged on the dedicated jig 30 are cleaned, and the surface of the crystal chip 10 on which the electrodes are to be formed becomes clean.

Further, since the quartz chips 16 are washed in the exclusive jig 30 without overlapping each other, for example,
Compared with the case where the crystal chips 16 are put together in a basket or the like, since the very thin crystal chips overlap, the surface is not hidden and the surface is cleaned cleanly. By forming the electrodes in this state, it is possible to prevent the electrodes from being formed in a state in which extremely fine foreign matter is attached, and to appropriately perform the oscillation operation.

Further, the special jig 30 is formed by vapor deposition (sputtering).
Since the electrodes can be formed as they are carried into the chamber 22, there is no need to transfer the crystal chip 16 to another jig when forming the electrodes, and there is no possibility that extremely fine foreign matter will adhere.

Further, according to the above-described cleaning method, the cleaning effect is enhanced by using a cleaning liquid having a high wettability particularly to the crystal chip. In the cleaning liquid, the crystal chip is swung and an ultrasonic wave is applied, so that the attached extremely fine foreign matter is effectively cleaned. In addition, ultrasonic waves are applied to the quartz chip 16 from at least two different directions in the cleaning tank 23, and the frequency of the ultrasonic waves generated by the ultrasonic wave generating means 37 and 38 can be varied. Therefore, preferably, ultrasonic waves with a plurality of different frequencies are applied. For this reason, a plurality of vibrations with different frequencies are given to the crystal chip 16, and the crystal chip 16 is more effectively cleaned.

Further, with respect to the crystal chip 16 after cleaning,
Since the cleaning liquid or the replacement liquid is vaporized and dried in the cleaning device 20, the crystal chip 16 after the cleaning is transferred to another facility or the like and dried with hot air. There is no risk of contamination due to contamination, and it can be immediately moved to the next step, so there is no risk of re-contamination depending on the standing time.

FIG. 9 is a schematic configuration diagram showing an example of a cleaning apparatus 50 used for the alignment cleaning in ST17 in the manufacturing process described with reference to FIG. 1, ie, the alignment cleaning after frequency adjustment.

In FIG. 9, the portions denoted by the same reference numerals as those of the cleaning device 20 of FIG. 2 have the same configuration, and thus the duplicate description will be omitted, and the description will focus on the differences.

The interior of the cleaning device 50 is also divided into two. The cleaning device 50 is provided with the cleaning processing chamber 21 in common with the cleaning device 20, but an adjacent section is a sealing chamber 52 due to a difference in steps.

The quartz vibrating reed, which is the piezoelectric vibrating reed after the frequency adjustment, is carried to the cleaning device 50 to be processed.
What is different from the cleaning apparatus 20 in the cleaning processing chamber 21 is that
The point is that the exclusive jig 55 and the cleaning jig cover removing unit 54 are provided.

To explain the cleaning jig 55,
Please refer to FIG.

As shown in the figure, the special jig 55
It has two members 57 and 58. Through holes are formed in the two plate-shaped members 57 and 58, respectively, and in a state where the plate-shaped members 57 and 58 are overlapped, each through hole has an inner surface facing the inner peripheral side. Direction step portions 57a and 58a are formed. As a result, the base on which the quartz vibrating piece 11 is mounted is accommodated in the recess 59 formed as shown in the figure. That is, ST15 in FIG.
2, the piezoelectric vibrating reed 11 mounted on the base 12, which is a package, is sandwiched between the plate-like members 57 and 58 together with the base 12, and the step portions 57a and 58a are respectively provided on the base 12. The quartz-crystal vibrating reed 11 mounted on the base 12 is held in contact with the end face and the lower face. In this state, the quartz-crystal vibrating piece 11 is exposed by the through hole 56.

Since the cleaning process in the apparatus is the same as that in the apparatus shown in FIG. 2, a duplicate description will be omitted.

The cleaned quartz vibrating piece 11 is carried into the sealing chamber 52 by opening the sealing chamber entrance door 52a, and
As shown in the figure, the lid 13 is placed and sealed (ST1).
8).

FIG. 2 shows various conditions involved in the cleaning process.
Since the cleaning device is the same as that of the cleaning device of FIG. 2, the same operation and effect as in the case of FIG.

The present invention is not limited to the above embodiment.

The present invention can be applied not only to the piezoelectric vibrator but also to various piezoelectric devices such as a piezoelectric oscillator using a piezoelectric chip.

For example, various conditions such as a cleaning liquid and a cleaning time can be appropriately adopted, and each constitution of the above-mentioned cleaning apparatus can be appropriately changed.

Furthermore, it is possible to appropriately omit some of the conditions and components of the above-described embodiment.

[0106]

As described above, according to the present invention, a method of manufacturing a piezoelectric device that is resistant to fluctuations in drive voltage and can improve drive level characteristics, and a cleaning apparatus used in this method Can be provided.

[Brief description of the drawings]

FIG. 1 is a flowchart schematically illustrating an example of a method for manufacturing a piezoelectric device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram illustrating an example of a cleaning apparatus that performs cleaning in ST13 according to the flowchart of FIG. 1;

FIG. 3 is an exploded perspective view showing a dedicated jig used for the cleaning device of FIG. 2;

FIG. 4 is an explanatory diagram for explaining the operation of the dedicated jig of FIG. 3;

FIG. 5 is a schematic cross-sectional view showing a state where a crystal chip is held by the exclusive jig of FIG. 3;

FIG. 6 is a schematic perspective view showing a configuration of a jig holding arm of the cleaning device of FIG. 2;

FIG. 7 is a schematic perspective view showing a configuration of a cleaning tank of the cleaning device of FIG. 2;

8 is a schematic plan view illustrating the function of a cleaning tank of the cleaning device of FIG.

FIG. 9 is a schematic configuration diagram illustrating an example of a cleaning apparatus that performs cleaning in ST17 according to the flowchart of FIG. 1;

FIG. 10 is a schematic partial cross-sectional view showing a dedicated jig used for the cleaning device of FIG. 9;

FIG. 11 is a partially cutaway perspective view showing a crystal resonator which is an example of the piezoelectric device of the present invention.

FIG. 12 is a flowchart simply showing an example of a conventional method for manufacturing a piezoelectric device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Quartz vibrator 11 Quartz vibrating piece 12 Base 13 Lid 20 Cleaning device 21 Cleaning processing chamber 22 Sputtering chamber 23 Cleaning tank 24 Cleaning tank 25 Cleaning tank 26a Guide means 26b Swing arm 26 Jig holding arm 30 Special jig 50 Cleaning Equipment 55 Exclusive jig

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[Procedure amendment]

[Submission date] June 14, 2001 (2001.6.1)
4)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

Next, the crystal chip is etched to a predetermined thickness (ST3). Further, in order to form necessary electrodes on the front and back surfaces of the crystal chip, an electrode pattern is provided by, for example, vapor deposition, and a predetermined drive electrode is formed. Is obtained (ST4).

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H01L 21/304 642 H03H 3/02 A 41/09 B H03H 3/02 H01L 41/22 Z 41/08 C

Claims (22)

[Claims] 1. A piezoelectric device in which a predetermined piezoelectric chip is formed by cutting a wafer made of a piezoelectric material, electrodes are formed on the piezoelectric chip to form a piezoelectric vibrating reed, and the piezoelectric vibrating reed is housed in a predetermined package. In the manufacturing method, before the electrode formation, the piezoelectric chip is cleaned by using an alignment jig used for electrode formation. 2. The method for manufacturing a piezoelectric device according to claim 1, wherein the exclusive jig used for the cleaning holds a plurality of the piezoelectric chips side by side so as not to overlap each other. 3. The method for manufacturing a piezoelectric device according to claim 2, wherein the dedicated jig is held in a cleaning tank with a direction in which the piezoelectric chips are lined up in a vertical direction. 4. The cleaning is performed in a cleaning bath in a cleaning liquid having a high wettability to the piezoelectric chip, and is performed by oscillating the dedicated jig while applying ultrasonic waves. The method for manufacturing a piezoelectric device according to claim 1, wherein 5. The piezoelectric device according to claim 1, wherein the cleaning is performed in a cleaning tank while applying ultrasonic waves to the piezoelectric chip from at least two different directions. Device manufacturing method. 6. The piezoelectric device according to claim 5, wherein the cleaning is performed by applying ultrasonic waves having different frequencies from at least two different directions to the piezoelectric chip in the cleaning tank. Device manufacturing method. 7. The cleaning method according to claim 1, wherein the cleaning and replacement liquid is vaporized and applied to the cleaned piezoelectric chip in a cleaning apparatus. Of manufacturing a piezoelectric device. 8. A piezoelectric device in which a predetermined piezoelectric chip is formed by cutting a wafer of a piezoelectric material, electrodes are formed on the piezoelectric chip to form a piezoelectric vibrating piece, and the piezoelectric vibrating piece is housed in a predetermined package. In the manufacturing method, after adjusting the frequency of the piezoelectric vibrating reed and before sealing the piezoelectric vibrating reed in the package, the piezoelectric vibrating reed is cleaned using a jig used for sealing. , A method of manufacturing a piezoelectric device. 9. The piezoelectric device according to claim 8, wherein the exclusive jig used for cleaning holds a plurality of bases on which the piezoelectric vibrating reeds are mounted so as not to overlap each other. Production method. 10. The method for manufacturing a piezoelectric device according to claim 9, wherein the dedicated jig is held in a cleaning tank with a direction in which the bases are lined up in a vertical direction. 11. The cleaning is performed in a cleaning bath in a cleaning liquid having a high wettability with respect to the piezoelectric vibrating reed, and is performed by rocking the dedicated jig while applying ultrasonic waves. The method for manufacturing a piezoelectric device according to any one of claims 8 to 10, wherein: 12. The cleaning method according to claim 8, wherein the cleaning is performed in a cleaning tank while applying ultrasonic waves to the piezoelectric vibrating reed from at least two different directions. A method for manufacturing a piezoelectric device. 13. The cleaning is performed by applying ultrasonic waves at a plurality of different frequencies from at least two different directions to the piezoelectric vibrating reed in a cleaning tank.
A method for manufacturing the piezoelectric device according to claim 12. 14. The cleaning method according to claim 8, wherein the cleaning liquid or the replacement liquid is vaporized and applied to the cleaned piezoelectric vibrating reed in a cleaning apparatus. A manufacturing method of the piezoelectric device according to the above. 15. A cleaning tank for storing a cleaning liquid for cleaning a piezoelectric chip, wherein a dedicated jig for vertically holding a plurality of piezoelectric chips in a vertical direction so as not to overlap each other is provided in the cleaning tank. Means for holding and oscillating; means for applying ultrasonic waves to the piezoelectric chip in the cleaning tank; means for sending to the electrode forming step while holding the piezoelectric chip in the dedicated jig A cleaning device, characterized in that: 16. In the cleaning tank, at least two different
The cleaning device according to claim 15, further comprising a unit configured to apply an ultrasonic wave to the piezoelectric chip from a direction. 17. The cleaning apparatus according to claim 16, further comprising: means for applying ultrasonic waves with a plurality of different frequencies to the piezoelectric chip from at least two different directions. 18. The cleaning apparatus according to claim 15, further comprising a cooling unit for cooling the stored liquid around the cleaning tank. 19. A cleaning tank for containing a cleaning liquid for cleaning a piezoelectric vibrating reed mounted on a base, wherein a plurality of bases on which the piezoelectric vibrating reeds are mounted overlap each other in the cleaning tank. Means for vertically holding and swinging a dedicated jig which is arranged and held so as not to be arranged; means for applying ultrasonic waves to the piezoelectric vibrating reed mounted on the base in the cleaning tank; Means for sending to a sealing step while holding the base on which the piezoelectric vibrating reed is mounted on a tool. 20. In the cleaning tank, at least two different
20. The cleaning apparatus according to claim 19, further comprising: means for applying ultrasonic waves to a piezoelectric vibrating reed mounted on the base from a direction. 21. The cleaning apparatus according to claim 20, further comprising: means for applying ultrasonic waves having a plurality of different frequencies from at least two different directions to the piezoelectric vibrating reed mounted on the base. . 22. The cleaning apparatus according to claim 19, further comprising a cooling unit for cooling the stored liquid around the cleaning tank.