JPH11308065A - Method and device for adjusting frequency of crystal resonator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily adjust frequency in atmospheric pressure. SOLUTION: In a crystal wafer 10, a 1st resonator chip is arranged at a working position by an XY stage 12. An image processor 42 inputs to a control unit 34 that the chip is set to the working position from an image-pickup image of a positioning camera 40. A processing unit 14 makes a jetting nozzle 18 spray reaction gas from a discharging unit 22 to the wafer 10, an absorption nozzle 20 absorbs jetted reaction gas and locally etches the crystal wafer. The unit 34 controls the position of the unit 14 via a drive mechanism 46, based on a detection signal of a position sensor 48, makes the unit 14 move and etch crystal, stops the etching of the wafer 10 when an oscillation frequency detected by a net analyzer 30 becomes a reference value, feeds the stage 12 by a prescribed pitch and sets the next chip to the working position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency adjusting method for adjusting the oscillation frequency of a crystal unit, and more particularly, to adjusting the oscillation frequency of a crystal unit in a state of a crystal wafer provided with a large number of crystal unit chips. The present invention relates to a method and an apparatus for adjusting the frequency of a crystal resonator suitable for the above.

[0002]

2. Description of the Related Art A crystal oscillator converts a natural mechanical vibration into an electric signal, converts an electric signal into a natural mechanical vibration, or the like, so that a clock circuit of an electronic timepiece or a computer, or an oscillator circuit or a receiver of a transmitter. Widely used for frequency selection circuits. In addition, since the natural mechanical vibration of the crystal unit, that is, the oscillation frequency is different depending on the thickness of the crystal unit, in recent years, when adjusting the oscillation frequency, the crystal is etched to change the thickness of the crystal unit. It has become.

Conventionally, when adjusting the frequency of a crystal unit, the crystal unit is cut out from a crystal wafer and cut into 20 mm × 2 mm.
After forming a chip having a size of about 0 mm and disposing the chip in a vacuum vessel, the inside of the vacuum vessel is decompressed and a fluorine-based gas is introduced to generate plasma of a fluorine-based gas in the vacuum vessel. Was used to etch the crystal.

[0004]

However, the above-mentioned conventional frequency adjustment method requires an expensive and large-sized vacuum apparatus such as a vacuum vessel and a vacuum pump since the quartz is etched by plasma in the vacuum vessel. And it is not easy to handle. Further, it is necessary to perform a mask process to etch only a necessary portion of the crystal, and it is not easy to monitor whether or not the vibrator can be adjusted to a predetermined oscillation frequency, which increases a defective rate.

The present invention has been made to solve the above-mentioned drawbacks of the prior art, and has as its object to make it possible to easily adjust the frequency at atmospheric pressure.

Another object of the present invention is to reduce the defective rate.

[0007]

In order to achieve the above object, a method for adjusting the frequency of a quartz oscillator according to the present invention comprises disposing a blowing nozzle close to a quartz wafer provided with a number of oscillator chips. Then, while controlling the relative position between the blow nozzle and the quartz wafer and monitoring the oscillation frequency of the vibrator chip, a reactive gas at atmospheric pressure or a pressure near the atmospheric pressure is blown from the blow nozzle to the quartz wafer. Then, the crystal wafer is locally etched to adjust the oscillation frequency of the vibrator chip to a predetermined frequency.

According to the present invention having the above-described structure, a fluorine-based reaction gas such as HF, F ₂ , or COF _{2 at} or near atmospheric pressure is blown onto a quartz wafer from a thin blowing nozzle to locally deposit the quartz wafer. Since the etching is performed, the frequency of the crystal resonator can be easily adjusted without using an expensive and large-sized vacuum apparatus. Moreover, since the crystal is etched while monitoring the oscillation frequency of the crystal resonator, the desired oscillation frequency can be easily, reliably and quickly adjusted to a desired value, and the defect rate can be reduced. Since the etching is performed by blowing out the reaction gas from the blowing nozzle, there is no need to perform a masking process on a non-etched portion unlike the etching by vacuum plasma, and the process can be simplified.

When the reaction gas blown out from the blow-out nozzle is sucked around the blow-out nozzle, the extent of spreading of the reaction gas blown out from the blow-out nozzle can be adjusted by the suction amount. Therefore, increasing the suction amount of the reaction gas can reduce the etching area of the crystal, and reducing the suction amount of the reaction gas allows the reaction gas to spread more and increase the etching area. The etching area can be controlled accordingly.

[0010] A frequency adjusting device for a quartz oscillator for implementing the above-described frequency adjusting method includes a stage on which a quartz wafer provided with a large number of oscillator chips is arranged, and a quartz crystal arranged in close proximity to the quartz wafer. A blow nozzle that blows a reaction gas at atmospheric pressure or a pressure close to the atmospheric pressure for etching the wafer, and a suction nozzle that opens around the blow nozzle and sucks the reaction gas blown from the blow nozzle are provided. A processing unit for locally etching the quartz wafer by the reaction gas blown out by the blowing nozzle, suction means connected to the suction nozzle of the processing unit, and Driving means for changing a relative position of the processing unit, and detecting a position of the processing unit with respect to the quartz wafer Position detecting means, a frequency detecting means for detecting an oscillation frequency of the vibrator chip via an electrode formed on the vibrator chip, and an oscillation frequency of the vibrator chip based on a detection signal of the frequency detecting means. Control means for determining whether or not a predetermined frequency has been reached, and for changing a relative position between the crystal wafer and the processing unit via the drive means based on a detection signal of the position detection means. It is. The control means
The suction amount of the exhaust unit can be controlled based on a detection signal of at least one of the frequency detection unit and the position detection unit.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method and an apparatus for adjusting the frequency of a crystal unit according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an explanatory view of a frequency adjusting device for a crystal unit according to an embodiment of the present invention. 1, an XY stage 1 on which a crystal wafer 10 provided with a number of oscillator chips (not shown) is arranged.
The XY stage 12 allows the quartz wafer 10 to be moved two-dimensionally in a plane. A processing unit 14 is provided above the XY stage 12.

The processing unit 14 has a blow nozzle 18 at the center of the holder 16 and a holder 16.
The suction nozzle 20 is attached to the lower part of the. The tip (lower end) of the blowing nozzle 18 is arranged close to the quartz wafer 10 on the XY stage 12 during the etching treatment of the quartz wafer 10. Also, the blowing nozzle 18
Is connected via a pipe 24 to a discharge unit 22 having a rear end serving as a supply source of a reaction gas, so that a reaction gas, which will be described in detail later, can be blown onto the quartz wafer. On the other hand, the suction nozzle 20 is
At the lower end, a suction opening formed concentrically with the blowing nozzle 18 is provided around the periphery of the nozzle 8. Furthermore, the suction nozzle 20
It is connected to a suction device (suction means) 28 such as a blower or a pump through an exhaust pipe 26 so that the reaction gas blown out by the blowing nozzle 18 can be sucked through a suction opening.

The discharge unit 22 includes CF ₄ and water vapor (H ₂
O) is supplied, and CF ₄ and water vapor are reacted by discharge to generate reactive fluorine-based gas such as HF and COF ₂ , and these reactive fluorine-based gas are generated. The reaction gas containing the gas is supplied to the blowing nozzle 18 via the pipe 24. A steam pipe is connected to the pipe 24 so that steam can be added to the reaction gas flowing from the discharge unit 22 into the pipe 24. This water vapor reacts with the fluorine-based gas in the reaction gas to generate fluorine ions, hydrogen fluoride ions, and the like that can etch the quartz wafer 10.

An electrode pattern is formed on the vibrator chip provided on the crystal wafer 10, and a probe 32 having a net analyzer 30 connected to the electrode pattern.
And the oscillation frequency of the vibrator chip can be detected by the net analyzer 30. The output side of the net analyzer 30 is connected to a control unit 34 as control means, and the detected frequency is input to the control unit 34. The control unit 34 is connected to a stage driving device 38 for moving the XY stage 12.
Receives the control signal from the control unit 34, moves the XY stage 12, and moves each vibrator chip of the crystal wafer 10 to a processing position.

A positioning camera 40 is provided above the XY stage 12. The positioning camera 40 captures an image of the vibrator chip below the processing unit 14 at the processing position, and inputs a video signal to the image processing device 42. Then, the image processing device 42 compares the pattern given in advance with the pattern imaged by the positioning camera 40, and inputs to the control unit 34 whether or not the transducer chip has been arranged at a predetermined processing position. Control device 34
Is connected to a display device 44 so that the positioning state of the vibrator chip, the oscillation frequency of the vibrator, and the like can be displayed.

The processing unit 14 is mounted on a drive mechanism 46 provided with a servo motor and the like, and is capable of three-dimensional movement. The drive mechanism 46 includes a position sensor 4 including a plurality of rotary encoders and the like.
8 is provided so that the position of the processing unit 14 can be detected and input to the control unit 34. The control unit 34 outputs a signal to the position sensor 48 based on the output signal.
The relative position between the oscillator chip and the processing unit 14 is obtained,
A control signal is output to the drive mechanism 46 to move the processing unit 14 to a processing position (etching position) of the vibrator chip.

The operation of the embodiment configured as described above is as follows.

When the quartz wafer 10 is placed on the XY stage 12 and a frequency adjustment execution command is given to the control unit 34, the control unit 34
A drive control signal is output to 8 to drive the XY stage 12 to move the first vibrator chip to a predetermined processing position. At this time, the image processing device 42 compares the pattern captured by the positioning camera 40 with a reference pattern given in advance, and outputs to the control unit 34 whether or not the vibrator chip has been arranged at the processing position. The control unit 34
The stage driving device 38 is controlled so that the reference pattern matches the imaging pattern.

When the vibrator chip is located at the processing position, the control unit 34 drives a probe set device (not shown) to bring the probe 32 into contact with the electrodes of the vibrator chip, and the processing unit via the driving mechanism 46. 14 is moved to the etching start position, and the suction device 28 is driven to start suction by the suction nozzle 20. On the other hand, the net analyzer 30 detects the oscillation frequency of the vibrator via the probe 32 and inputs the value to the control unit 34. Further, the control unit 34 controls the discharge unit 22 to generate a reaction gas. That is, the discharge unit 22 causes the CF ₄ and the water vapor supplied under the atmospheric pressure to react with each other by electric discharge to generate a reactive gas containing a reactive fluorine-based gas such as HF or COF ₂ .

The reaction gas generated by the discharge unit 22 is
The water vapor flowing into the pipe 24 is supplied to the blowing nozzle 18 of the processing unit 14 at atmospheric pressure together with the water vapor, and is blown from the tip of the blowing nozzle 18 onto the crystal wafer 10 to locally etch the crystal wafer 10. Then, when the etching of the crystal unit 10 is started, the control unit 34 monitors the oscillation frequency detected by the net analyzer 30 and takes in the output signal of the position sensor 48 to control the relative position between the vibrator chip and the processing unit 14. The position is determined, a control signal is output to the drive mechanism 46, and the processing unit 1
While controlling the position of 4, the processing unit 14 is moved and the vibrator chip is etched. Further, the control unit 34 reads the oscillation frequency of the oscillator chip detected by the net analyzer 30, compares the read oscillation frequency with a predetermined reference frequency, and etches the crystal until the oscillation frequency matches the reference frequency. Thinner.

When the oscillation frequency of the vibrator chip reaches the reference frequency, the control unit 34
2 is stopped and the probe 32 is separated from the vibrator chip, and the processing unit 14 is returned to the initial etching start position. Further, the control unit 34 supplies a control signal to the stage driving device 38 to feed the XY stage 12 at a predetermined pitch, and arranges the next vibrator chip at the processing position. Hereinafter, the frequency adjustment of the second chip is similarly performed. This frequency adjustment is repeated until the last vibrator chip ends. When the frequency adjustment is completed for all the vibrator chips, the crystal wafer 10 is transferred to the next step and cut for each chip.

As described above, in the embodiment, the quartz wafer 10 provided with a large number of vibrator chips is arranged on the XY stage 12 and the blowing nozzle 1 of the processing unit 14 is provided.
Since the crystal is etched by the reaction gas blown out from the position 8 under the atmospheric pressure, the frequency of the crystal resonator can be easily adjusted without using an expensive and large-sized vacuum apparatus. Moreover, the oscillation frequency of the oscillator chip is detected by the net analyzer 30 and the control unit 34
However, since the frequency is adjusted while monitoring this, the frequency can be adjusted easily, accurately and quickly, and the defect rate can be reduced. Further, the position of the processing unit 14 is detected by the position sensor 48, the relative position between the processing unit 14 and the vibrator chip is obtained based on the detection signal, and the position of the processing unit 14 is controlled via the drive mechanism 46. Therefore, a desired position of the vibrator chip can be easily and accurately etched.

By the way, the present inventors can control the range of etching by sucking the reaction gas blown out from the blow nozzle around the blow nozzle, and also control the size and positional relationship between the blow nozzle and the suction nozzle. It has been found that the etching range changes. That is, as shown in FIG.
A, the inner diameter of the suction nozzle 20 is b, the distance (projection amount) between the tip of the blowing nozzle 18 and the tip of the suction nozzle 20 is c, and the flow rate of the reaction gas blown from the blowing nozzle 18 is q, the etching area (processing area), where Q is the suction amount (discharge amount) of the suction nozzle 20
Varies with these values. FIG. 3 shows an experimental result when quartz is etched by the processing unit.

In FIG. 3, each of the nozzles 18, 20
The unit of the inner diameter and the protrusion amount is mm, the unit of the blowout amount and the suction amount is SLM (a flow rate per minute in a standard state of gas in liter), and the unit of the etching area is mm ² . The distance between the blowing nozzle 18 and the crystal is 0.5 mm, and the concentration of the reactive fluorine-based gas in the reaction gas blown to the crystal is about 800,000 ppm in terms of HF.

As shown in FIG. 3, the etching area depends on the inner diameters a and b of the nozzles 18 and 20, and the smaller the inner diameter, the smaller the etching area. Further, the etching area depends on the protrusion amount c of the blowing nozzle 18 from the suction nozzle 20, and the larger the protrusion amount c, the larger the etching area. Furthermore, the etching area is
The etching area depends on the suction amount Q with respect to the blowing amount q, and the etching area decreases as the suction amount Q increases. Therefore, when etching a fine part, the diameter of the nozzle is small,
Further, the protrusion amount c is reduced, and the suction amount Q is increased.

For this reason, the control unit 34 according to the above-described embodiment outputs a control signal to the suction device 28 based on the detection signal of the position sensor 48 to etch a relatively large area of the vibrator chip. In the case where the amount of suction Q by the suction nozzle 20 is reduced to increase the etching area and to etch between minute patterns, the amount of suction Q is increased to reduce the etching area. Further, the control unit 34 controls the suction amount by the suction nozzle 20 to increase and the etching amount to decrease when the frequency adjustment amount decreases.

In the above embodiment, the case where the reaction gas is generated in the discharge unit 22 has been described. However, a stable gas containing fluorine may be generated by thermal decomposition, photolysis, or the like. Fluorine gas may be directly supplied from a cylinder as a reaction gas.

[0029]

As described above, according to the present invention, according to the present invention, HF and F ₂ of the pressure or near atmospheric, COF ₂
Fluorine-based reaction gas such as is blown onto the quartz wafer from a thin blowing nozzle to locally etch the quartz wafer, so that the frequency of the quartz oscillator can be easily adjusted without using an expensive and large-sized vacuum device. Can do it. In addition, since the crystal is etched while monitoring the oscillation frequency of the crystal resonator, the desired oscillation frequency can be easily, reliably, and quickly adjusted, and the defect rate can be reduced. Since the etching is performed by blowing out the reaction gas from the blowing nozzle, it is not necessary to perform a masking process on a portion not to be etched, and the process can be simplified.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a crystal oscillator frequency adjusting device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of parameters with respect to an etching area of a processing unit according to the embodiment.

FIG. 3 is an explanatory diagram of an etching result by a processing unit according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Quartz wafer 12 Stage (XY stage) 14 Processing unit 18 Blow-out nozzle 20 Suction nozzle 22 Discharge unit 28 Suction means (suction device) 30 Frequency detection means (net analyzer) 34 Control means (control unit) 38 Stage drive device 40 Positioning camera 46 drive means (drive mechanism) 48 position detection means (position sensor)

Claims (4)

[Claims] 1. A blow nozzle is arranged in close proximity to a quartz wafer provided with a number of vibrator chips, and a relative position between the blow nozzle and the quartz wafer is controlled.
While monitoring the oscillation frequency of the vibrator chip, a reaction gas at or near atmospheric pressure is blown from the blow nozzle onto the quartz wafer, and the quartz wafer is locally etched to reduce the oscillation frequency of the oscillator chip. A method for adjusting the frequency of a crystal resonator, wherein the frequency is adjusted to a predetermined frequency. 2. The frequency adjustment of the quartz oscillator according to claim 1, wherein the reactive gas blown from the blow nozzle is sucked around the blow nozzle to control an etching area of the quartz wafer. Method. 3. A stage on which a quartz wafer provided with a number of vibrator chips is arranged, and a blowout which is arranged close to the quartz wafer and blows a reaction gas at or near atmospheric pressure for etching the quartz wafer. A nozzle and a suction nozzle which is opened around the blowing nozzle and suctions the reaction gas blown from the blowing nozzle are provided, and the quartz gas wafer is locally etched by the reaction gas blown by the blowing nozzle. A processing unit; suction means connected to the suction nozzle of the processing unit; driving means for moving the processing unit in a plane to change a relative position with respect to the crystal wafer; and a position of the processing unit with respect to the crystal wafer. And a vibrator chip via electrodes formed on the vibrator chip Frequency detecting means for detecting an oscillation frequency; and, based on a detection signal from the frequency detecting means, determining whether or not the oscillation frequency of the vibrator chip has reached a predetermined frequency. Control means for changing a relative position between the crystal wafer and the processing unit via the driving means based on the driving means. 4. The apparatus according to claim 3, wherein said control means controls a suction amount of said suction means based on a detection signal of at least one of said frequency detection means and said position detection means. Crystal oscillator frequency adjustment device.