JP2006238257A - Manufacturing method of crystal vibrator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a crystal vibrator for thickness shear mode vibration integrating a vibrator of a crystal thin plate ensuring good working efficiency and the reinforcing part of a crystal thick plate surrounding the circumference of the vibrator. <P>SOLUTION: A crystal vibrator for thickness shear mode vibration integrates a vibrator of the crystal thin plate, and a reinforcing part of the crystal thick plate surrounding the circumference of the vibrator. The manufacturing method of the vibrator comprises steps of patterning the vibrating surface, conducting external processing etching, forming a vibrating surface and an etchant stopper groove on the rear surface of the surface having a recessed region of the vibrating surface, peeling a protection film, and adjusting a frequency by dropping the etchant to the rear surface of the rear including recessed region of the vibrating surface. Moreover, the etchant stopper groove of a width of 200 μm to 300 μm is formed on the rear surface of the surface having the recessed region of the vibrating surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

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

          Avoiding the occurrence of unnecessary spurious vibrations in a quartz crystal with thickness-slip vibration that is formed by integrating the vibration part of a conventional quartz base plate thin plate and the reinforcement part of the thick quartz base plate surrounding it. For this reason, it has been general to make the size of the vibration surface of the crystal resonator as large as possible with respect to the size of the electrode surface.

          On the other hand, the recent trend is centered on transmission systems in the communications field, and the mounted parts, including crystal resonators, are rapidly becoming smaller and lower in height from the market. In fact, there is a demand for pricing.

JP 2000-031769 A JP 2001-168673 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 above-described crystal resonator is a thin plate having a thickness of about 10 μm in the case of a main vibration frequency of 150 MHz, for example, in a crystal resonator that performs AT-cut fundamental wave thickness sliding vibration. Because of this, it is configured to be easily affected by slight mechanical distortion of the surrounding part of the vibration part of the crystal unit. The mechanical distortion changes the thickness of the thin plate of the vibration part. As a result, there is a possibility that a large number of unnecessary spurious vibrations other than the main vibration may be caused.

          In view of the above, the crystal resonator having such a shape is formed by etching, and as described above, from the vibrating portion of the quartz base plate thin plate and the reinforcing portion of the quartz base plate thick plate surrounding the surrounding portion. In general, a large number of crystal resonators having a shape are patterned on a single wafer.

          As described above, in order to adjust the frequency of the thin plate-like vibrating portion of each vibrator in which a large number of crystal vibrators are patterned on a single wafer, it is divided into a desired size by dicing or the like. Then, it is generally adjusted by immersing in an etching solution for each group classified by frequency classification.

          However, with the recent reduction in size and frequency of mounted components, the crystal resonators to be handled tend to be miniaturized and thinned. In the above-described method of adjusting by etching for each group, the crystal resonator In fact, there are concerns about the loss or breakage of small pieces, and the fact that the number of processes is increasing is becoming disadvantageous in terms of cost.

          As a countermeasure, a method of performing an etching operation without dividing a large number of crystal resonators formed on one wafer can be considered, but the frequency of each crystal resonator in the wafer is not necessarily uniform. For this reason, as described above, the work method in which a single wafer is etched by immersing it in an etchant at a time cannot be applied because the yield is poor.

          Therefore, in order to make the frequency of each quartz crystal resonator in the previous wafer uniform, a method of dropping the etchant sequentially onto the thin plate-like vibrating portion of the crystal resonator is taken. However, conventionally, when an etchant is dropped on a thin plate-like vibrating portion, the external shape of each crystal resonator itself has become fine as described above, and the area of the vibrating surface is reduced accordingly. Therefore, as shown in FIG. 5, when an etchant is dropped on a thin plate-like vibrating part, a space is left at the bottom of the vibrating surface where the liquid etchant is dropped, resulting in a void. Although not shown in the figure, the etchant is not yet dropped and etched, but the crystal plate having the vibrating portion of a certain thin plate is adjacent to the vibrating portion of the thin plate of another crystal resonator. However, there has been a problem that the liquid etchant flows in and the desired etching is not performed.

          The present invention has been made under the technical background as described above. Accordingly, the purpose of the present invention is to provide a quartz base plate thick plate that surrounds the vibrating portion of the quartz base plate thin plate with good working efficiency and the periphery thereof. It is an object to provide a method of manufacturing a quartz crystal resonator that performs thickness-shear vibration in which reinforcing portions of the material are integrally formed.

          In order to achieve the above object, the method for manufacturing a crystal resonator according to the present invention provides a thickness shear vibration in which a vibrating portion of a quartz plate thin plate and a reinforcing portion of a quartz plate thick plate surrounding the quartz plate are integrally formed. In the manufacturing method of the quartz crystal resonator, the outer shape processing etching, the vibration surface formation, the step of forming a groove on the back surface of the vibration surface depression, the step of removing the protective film, and the surface of the vibration surface depression It is characterized by having a step of forming an etchant stop groove on the back surface and a step of adjusting the frequency by dropping the etchant on the back surface of the surface where the vibration surface is depressed.

          In addition, an etchant stop groove portion having a width of 200 μm to 300 μm is formed on the back surface of the surface having the depression of the vibration surface.

          According to the method for manufacturing a crystal resonator of the present invention, the bottom of the vibration surface on which the etchant is dropped in order to perform etching by dropping the etchant to adjust the frequency from the back surface of the concave surface of the vibration surface forming the recess. No voids are left on the surface, and no voids are formed, and the groove formed on the back surface of the surface having the vibration surface is not etched by dropping the etchant. Vibration of the thin plate to be etched As a result, the problem that the etchant flows into the back surface of the vibrating part of the thin plate of another crystal unit adjacent to the crystal unit having a part and unwanted etching is prevented is reliably prevented. Yield can be significantly improved.

          Further, according to the present invention, the groove formed on the back surface of the surface having the recess of the vibration surface is formed at the same time as the outer shape processing etching and the vibration surface formation process. Productivity can be significantly increased.

          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 flowchart showing a method for manufacturing a crystal resonator according to the present invention. That is, in the method of manufacturing a crystal resonator that performs thickness-shear vibration in which the vibrating portion 1 of the quartz base plate thin plate and the reinforcing portion 2 of the surrounding quartz base plate are integrally formed, the wafer 10 is first cleaned. Performing the step (S101), then depositing the protective film (S102), and further performing the patterning step (S103) of the vibration surface 4, followed by outer shape etching, formation of the vibration surface 4, and vibration surface A step (S104) of forming a groove on the back surface of the surface having the depression is performed, and then a step of peeling the protective film (protective film) is performed (S105). Further, the etchant 9 is dropped from the back surface 6 of the surface 5 having the depression of the vibration surface 4, that is, the surface where the etchant stop groove portion 7 is formed in the previous step, and the frequency adjusting etching step (S 108) is performed. A step (S109) of vapor deposition (electrode formation) is performed. In this embodiment, two frequency inspection steps (S106) and (S109) are provided between the above-described steps. Further, dicing (S110) for dividing each crystal resonator 3 formed in large numbers on one wafer 10 (S110), and the dicing and batch etchant stop groove 7 removal step (S110) are performed. The process of assembling / mounting the individual crystal units 3 (S111) is performed.

          FIG. 2 is a schematic front view of a wafer 10 showing a state in which a large number of crystal resonators 3 and a groove portion 7 are formed on the back surface 6 of the surface 5 with the depression of the vibration surface 4 on a single wafer 10 of the present invention. FIG. Grooves 7 are formed on the back surface 6 of the surface 5 having depressions in the vibration surface corresponding to the top and bottom of the vibration surface and the left and right positions so as to surround the vibration surface of the vibration portion 1 of the thin plate of one crystal resonator 3 (S104). ). When the width 8 of the groove portion 7 of the back surface 6 of the surface 5 with the recess of the vibration surface is 200 μm to 300 μm, the rear surface of the surface with the recess of the vibration surface of the crystal resonator 3 adjacent to the etchant 9 is partitioned. It was most effective with no inflow to the surface.

          FIG. 3 shows a partitioned vibration surface 4 in which an etchant stop groove portion 7 is formed on the back surface 6 of the recessed surface 5 of the vibration surface 4 of a single wafer 10 on which a large number of crystal resonators 3 of the present invention are formed. It is the partial schematic diagram seen from the side surface direction which showed a mode that the etchant 9 was dripped on the back surface 6 of the surface 5 with a hollow of this for frequency adjustment. In order to perform etching by dropping a liquid etchant 9 to adjust the frequency from the back surface 6 of the concave surface 5 of the vibration surface 4 forming a recess, a space portion remains at the bottom of the vibration surface 4 where the etchant 9 is dropped. As a result, no etching is performed by dropping the etchant 9 by the etchant groove 7 formed on the back surface 6 of the surface 5 with the depression of the vibration surface 4. The etchant 9 flows into the back surface of the vibrating portion 1 of the thin plate of another crystal resonator 3 adjacent to the quartz resonator 3 having the thin vibrating portion 1, and undesired etching is surely performed. Is prevented.

          FIG. 4 is a schematic partial schematic view of a single wafer 10 of the present invention as viewed from the side. Since the etchant stop groove 7 is formed in a lattice shape on the back surface 6 of the hollow surface 5 of the vibration surface 4 corresponding to the thin plate vibration portion 1 of each crystal resonator, the liquid etchant 9 is formed. When the frequency is adjusted by dropping the liquid crystal, the inflow of the etchant 9 into the vibrating portion 1 of the thin plate of the crystal resonator 3 adjacent to the target crystal resonator 3 is surely prevented by the etchant stop groove portion 7. It is shown.

          In FIG. 5, a large number of crystal resonators 3 are formed on a conventional wafer 10, and a liquid etchant 9 is dropped on the vibration surface of the vibrating portion 1 of the thin plate of the one crystal resonator 3 to obtain a frequency. It is the general | schematic partial schematic diagram seen from the side surface direction which showed a mode that adjustment was performed. Etchant 9 is sequentially dropped onto the vibration surface 4 of the vibration part of the concave thin plate to perform frequency adjustment etching, but a space is left at the bottom of the vibration surface where the liquid etchant 9 is dropped, resulting in a void. In addition, the etchant 9 is moved from the concave portion forming the vibration surface 4 of the vibration part 1 of the thin plate to be etched to the vibration surface 4 of the vibration part 1 of the thin plate of the adjacent crystal resonator 3 where etching is not performed. There was a problem of inflow.

          FIG. 6 is a process diagram showing a conventional method for manufacturing the crystal unit 3. In the case of dropping an etchant on a conventional vibration surface, there has been a problem that a void is generated by leaving a space at the bottom of the vibration surface where the liquid etchant is dropped.

It is process drawing of the manufacturing method of the crystal oscillator of this invention. FIG. 4 is a schematic diagram viewed from a surface with a hollow of a vibration part showing a state in which a large number of crystal resonators and etchant stopper grooves are formed on a single wafer of the present invention, and a schematic diagram of the back surface thereof. . 1 shows a state in which a large number of crystal resonators and an etchant stop groove portion are formed on the back surface thereof on a single wafer of the present invention, and the etchant is dropped on the partitioned back surface of the vibration portion of the thin plate of the single crystal resonator. It is the general | schematic partial schematic diagram seen from the side direction. 1 shows a state in which a large number of crystal resonators and an etchant stop groove portion are formed on the back surface thereof on a single wafer of the present invention, and the etchant is dropped on the partitioned back surface of the vibration portion of the thin plate of the single crystal resonator. It is the general | schematic partial schematic diagram seen from the side direction. Viewed from a schematic side view showing how a large number of quartz resonators are formed on a single conventional wafer and the frequency is adjusted by dropping an etchant on the vibrating part of the thin plate of the quartz resonator. It is a partial schematic diagram. It is a manufacturing process figure of the manufacturing method of the conventional crystal oscillator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vibrating part of quartz base plate thin plate 2 Reinforcing part of quartz base plate thick board 3 Quartz crystal oscillator 4 Vibrating surface 5 Surface with dent of vibrating surface 6 Back surface of surface with dent of vibrating surface 7 Etchant retaining groove 8 Etchant retaining groove Width 9 Etchant 10 Wafer

Claims (2)

In the manufacturing method of the crystal resonator that performs the thickness shear vibration in which the vibrating portion of the quartz base plate thin plate and the reinforcing portion of the quartz base plate thick plate surrounding the quartz plate are integrally formed,
The process of patterning the vibration surface;
Forming a groove on the back surface of the surface having a recess in the vibration surface, and outer shape processing etching, vibration surface formation,
A protective film peeling process;
Forming an etchant stop groove on the back surface of the surface having the depression of the vibration surface so as to surround the vibration surface;
And a step of adjusting the frequency by dropping an etchant on the back surface of the vibration surface having the depression.           2. The method for manufacturing a crystal resonator according to claim 1, wherein the etchant stop groove portion having a width of 200 μm to 300 μm is formed on the back surface of the surface having the depression of the vibration surface.

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