JP2006339749A - Quartz vibrator and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a quartz vibrator consisting of a vibration section of a thin-piece vibration blank plate and a reinforcing section surrounding it, and to provide the vibrator. <P>SOLUTION: In order to achieve the above purpose, the method of manufacturing the quartz vibrator, in which the vibration section of the quartz thin and blank plate having many pieces of quartz vibrators formed on one wafer and reinforcing section surrounding it are integrally formed, has a process of forming an electrode on a vibration region of the quartz thin and blank plate; a process of masking a vibration portion including the electrode of the thin-piece blank plate; a process of vapor depositing a desired thickness oxide silicon on the vicinity of the masking portion of the thin-piece blank plate; and an a process of peeling the masking portion from the thin-piece blank plate. Photolithography is used to mask the resonating region of the thin-piece blank plate, and the oxide silicon vapor depositing layer for surrounding the vibrator for surrounding the vibrator is deposited and formed on the quartz thin and blank plate having a portion where an electrode to be formed and is used as a vibration portion. Thus, the above problem is solved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a quartz crystal device and relates to a method of manufacturing a quartz crystal resonator that performs thickness-shear vibration used in a crystal oscillator mainly used in a transmission system apparatus in the communication field, and the crystal resonator.

  Piezoelectric devices such as crystal resonators and filters used in recent mobile objects and information communication equipment have high basic specifications such as ultra-high frequency and high bandwidth, coupled with the development of miniaturization and digitalization of equipment. There is a tendency to become functional. In addition, along with the remarkable miniaturization of the above-described devices, there is a rapid demand for further miniaturization of electronic components mounted on crystal devices and the like used in these devices.

  As an example of conventional technology for oscillating high frequencies, a rectangular concave recess is formed by photolithography and etching on a part of the main surface of a quartz base plate mounted in a quartz resonator container. The thickness of the concave portion is etched so as to obtain a vibration having a desired frequency, thereby forming a vibration region portion in a thickness-shear vibration mode. Around the vibration region portion, a thicker reinforcing portion that supports and reinforces the vibration region portion is formed integrally with the concave portion described above.

  The vibration mode of the AT-cut quartz resonator is thickness-shear vibration, and its frequency is inversely proportional to the thickness of the vibration region described above. Therefore, to increase the frequency, it is necessary to reduce the thickness of the vibration region. . In the case of the quartz crystal resonator as shown in FIG. 5 integrally formed with the above-described reinforcing portion thicker than the thickness of the vibration region portion, the thickness of the piezoelectric vibration region portion of the concave portion is about 2 μm, and the thickness slip of the fundamental wave A quartz crystal having a vibration frequency of about 800 MHz is made.

JP 2000-031769 A JP 2001-168673 A JP 2004-040198 A JP 2003-309445 A

  The applicant has not found any prior art documents related to the present invention other than the prior art documents specified by the prior art document information described above by the time of filing of the present application.

  However, the thickness of the vibration part of the crystal unit described above is very thin, such as 1/10 or less of the thickness of the reinforcement part. The structure is easily affected by slight mechanical distortion, and the previous mechanical distortion changes the thickness of the vibration plate, resulting in the generation of many unnecessary spurious vibrations other than the main vibration. There was a risk of inviting.

  In view of the above, the vibration part of the crystal resonator having such an integrated shape is formed by etching from the thickness of the thick reinforcement part to the thickness of the vibration part at which a desired frequency can be obtained. In general, a large number of crystal resonators each having a shape including a vibrating portion of a base plate thin plate and a reinforcing portion of a quartz base plate thick plate surrounding the substrate are patterned on a single wafer.

  However, when the thickness of the vibration part becomes several μm or less (for example, about 3 μm), unevenness in etching occurs due to uneven etching, and the distribution of the frequency in the vibration part deteriorates, so that a stable frequency cannot be obtained. There was a problem of fear.

  When a large number of crystal resonators are formed on a single wafer, the vibration characteristics of each crystal resonator vary and stable quality cannot be obtained, resulting in a decrease in production yield. There was a problem that there was.

  The present invention has been made under the technical background as described above. Accordingly, the object of the present invention is to provide a quartz resonator including a vibrating portion of a thin-plate vibrating element plate and a reinforcing portion surrounding the periphery thereof. It is to provide a manufacturing method and a crystal resonator thereof.

  In order to achieve the above object, a method for manufacturing a quartz crystal resonator according to the present invention includes a vibrating portion of a quartz thin piece base plate in which a large number of quartz crystal resonators are formed on a single wafer, and a periphery of the vibrating portion. A step of forming an electrode portion in a portion to be a vibration region of the quartz thin plate element (S101), and a method of manufacturing the quartz thin plate element electrode, (S102) for masking the vibrating portion including the step of depositing silicon oxide with a desired thickness on the periphery of the masked portion of the quartz thin plate (S103); It has the process (S104) which peels from a base plate, It is characterized by the above-mentioned.

  Further, the present invention is characterized in that masking is performed on a portion to be a vibration region of the quartz thin plate element using photolithography.

  Further, the present invention is characterized in that a vapor deposition layer of silicon oxide is formed on a quartz thin plate having a portion where an electrode is formed to be a vibrating portion so as to surround the vibrating portion.

  According to the method for manufacturing a crystal resonator of the present invention, since a quartz thin plate element having a very small thickness variation is used, it is possible to obtain a stable quality crystal resonator having a remarkably good frequency distribution in the vibration part.

  Further, since the formation of the vibration surface of the crystal resonator is not based on etching, the production yield can be increased.

  In addition, since the silicon oxide reinforcing portion surrounding the vibrating portion is formed by vapor deposition without using etching, the thickness of the quartz thin plate element can be set to a thickness at which a target frequency can be obtained from the beginning.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol in each figure shall show the same object.

FIG. 1 is a process diagram of a method for manufacturing a crystal resonator 2 according to the present invention. That is, the vibrating portion 4 of the quartz thin piece base plate 3 in which a large number of crystal resonators 2 are formed on a single wafer 1 and the vapor deposition layer 5 of silicon oxide (SiO ₂ ) surrounding the vibrating portion are integrated. In this method of manufacturing the quartz crystal resonator 2 that undergoes thickness shear vibration, an electrode 7 is first formed in a portion to be a vibration region of the crystal thin plate 3 (S101), and then the electrode 7 of the crystal thin plate 3 is formed. Is masked (S102), and silicon oxide having a desired thickness of 8 is deposited around the masked portion of the quartz thin plate 3 (S103). Finally, the masked portion is crystallized. It has the process (S104) which peels from the thin piece base plate 3. FIG. According to the method for manufacturing the quartz crystal resonator 2 of the present invention, since the thickness variation is very small, the quartz thin plate 3 having a thickness capable of obtaining a desired frequency from the beginning is used. It is possible to obtain a crystal unit 2 having a remarkably good and stable quality. It should be noted that the step (S101) of forming the electrode portion in the portion to be the vibration region of the quartz thin plate element plate is not necessarily performed before the step (S102) of masking the vibrating portion including the electrode of the quartz thin plate element plate. Needless to say, it may be performed after the step (S104) of peeling the masked portion from the quartz thin plate, and it goes without saying that this case is also included in the technical scope of the present invention. In order to peel the masked portion from the quartz thin plate, a chemical method using a liquid agent can be used without fear of damaging the vibration region having a delicate structure.

  FIG. 2 is a schematic side view of the crystal resonator 2 of the present invention as viewed from the side. Although FIG. 2 is a schematic side view and is not shown, the center portion of the crystal unit 2 has a concave shape as shown in FIG. According to the method for manufacturing the quartz crystal resonator 2 of the present invention, the formation of the concave shape is not performed by etching, but the silicon oxide reinforcing portion surrounding the vibrating portion 4 is formed by vapor deposition. The thickness of the plate 3 can be made from the beginning to obtain a desired frequency, and the production efficiency can be remarkably increased.

FIG. 3 is a schematic top perspective view of the crystal unit 2 of the present invention as seen from the oblique top direction. In addition, the quartz thin piece base plate 3 can use what was formed by the conventional grinding process, and what was formed by film-forming methods, such as CVD. The material forming the reinforcing portion is not limited to silicon oxide (SiO ₂ ) unless it has a reinforcing effect, forms a thick layer, and does not suppress the vibration characteristics of the vibrating portion 4. In addition, the formation method is not limited to the vapor deposition method, and any method such as EB (electron beam), sputtering, or CVD may be used. It goes without saying that these cases are also included in the technical scope of the present invention.

  FIG. 4 is a schematic top view as seen from the upper surface direction of the wafer 1, showing a state in which a large number of crystal resonators 2 of the present invention are formed on a single wafer 1. Thus, in the crystal resonator 2 of the present invention, by forming a large number of crystal resonators 2 on a single wafer 1, the manufacturing process of each crystal resonator 2 can be performed collectively. The crystal resonator 2 can be manufactured with extremely high production efficiency.

  FIG. 5 is a schematic top perspective view of the conventional crystal resonator 2 as seen from an oblique top surface. In the conventional crystal unit 2, since an etching process is required, if the thickness of the thin vibrating part 4 becomes several μm or less, the unevenness in the thickness of the concave vibrating part 4 occurs due to uneven etching, and the vibration of the frequency There is a problem that the internal distribution is deteriorated and a stable frequency may not be obtained.

It is process drawing of the manufacturing method of the crystal oscillator of this invention. It is the schematic side surface figure which looked at the crystal oscillator of this invention from the side surface direction. 1 is a schematic top perspective view of a crystal resonator according to an embodiment of the present invention when viewed from an oblique top surface direction. FIG. 3 is a schematic top plan view seen from the top surface of the wafer, showing a state in which a large number of crystal resonators of the present invention are formed on a single wafer. It is the outline top perspective view which looked at the conventional crystal oscillator from the slanting upper surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wafer 2 Crystal oscillator 3 Crystal thin piece base plate 4 Vibrating part 5 Silicon oxide vapor deposition layer 6 Vibrating area part 7 Electrode part 8 (silicon oxide) thickness

Claims (3)

A method of manufacturing a quartz crystal resonator having a thickness sliding vibration in which a plurality of crystal resonators are formed on a single wafer, and a vibrating portion of a quartz thin plate and a reinforcing portion surrounding the vibrating portion are integrated. In
A step of forming an electrode in a portion to be a vibration region of the quartz thin plate, a step of masking a vibrating portion including the electrode of the quartz thin plate,
Depositing a desired thickness of silicon oxide around the masked portion of the quartz flake plate;
Peeling the masking from the quartz flake base plate;
A method of manufacturing a crystal resonator having The method for manufacturing a crystal resonator according to claim 1, wherein masking is applied to a portion to be a vibration region of the quartz thin plate element using photolithography. A quartz crystal that vibrates in a thickness-shear manner, characterized in that an evaporated layer of silicon oxide is deposited on a quartz thin plate having a portion that becomes an oscillating portion and that serves as a oscillating portion, surrounding the oscillating portion. Vibrator.

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