JP2002290181A - Manufacturing method of vibration piece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a vibrating piece, by which a production cost is not increased, a uniform resist film is generated, photolithography precision is enhanced in an electrode pattern and which is provided with an excitation electrode with high precision by suppressing defective perforation. SOLUTION: The vibrating piece is provided with a base 110 and vibrating arm parts 121 and 122 formed, projecting from the base. In the vibrating piece, the electrode pattern is formed by a photolithographic work, through the use of the resist film 137 as an etching mask, which is formed by applying a high voltage to a photoresist 132a as ultrafine particles and performing electrostatics coating on the front surface of a crystal wafer, which is placed on a grounded electrode 135.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a resonator element made of, for example, quartz.

[0002]

2. Description of the Related Art A tuning-fork type quartz vibrating piece 10, which is a vibrating piece,
For example, it is configured as shown in FIG. That is, the tuning-fork type quartz vibrating reed 10 has a base 11 and two vibrating arms 12 and 13 protruding from the base 11. As shown in FIG. 6, grooves 12a and 13a are formed on the front and back surfaces of the two vibrating arms 12 and 13, respectively. For this reason, as shown in FIG. 7, which is a cross-sectional view taken along the line AA ′ of FIG. 6, the vibrating arms 12 and 13 have a substantially H-shaped cross-sectional shape.

[0003] Such grooves 12a, 13a are connected to the arms 12,
13, a film of Cr or Au is formed on the tuning-fork type quartz vibrating piece 10 by sputtering or the like, and is etched by a photolithography technique, and as shown in FIG.
Excitation electrodes 12c and 13c are formed inside a, and excitation electrodes 12d and 13d are formed outside the arms 12 and 13.

[0004]

In the manufacture of such a conventional resonator element, a photoresist is applied by using a general spray coating method for forming the electrode pattern. However, there has been a problem that the resist does not easily enter the groove portion and the side surface of the vibrating arm portion, and uneven coating of the resist occurs. FIG. 8 schematically shows the unevenness of application of the photoresist. The resist film 14 applied to the shoulder portion of the vibrating arm, the side surface of the vibrating arm, the side surface of the groove, and the bottom surface of the groove becomes thinner. I have. Therefore, when etching is performed using this resist film as an etching mask, the excitation electrodes 12c, 13c inside the groove and the excitation electrodes 12d, 12d
There was also a problem that a defect that a hole was formed in 13d occurred, and as a result, the manufacturing yield was reduced, and the production cost was increased.

In view of the above problems, the present invention provides a highly accurate method for manufacturing a vibrating reed that suppresses poor perforation of the excitation electrode by reducing unevenness in resist application without increasing production costs. The purpose is to do.

[0006]

A method of manufacturing a vibrating reed according to the present invention has a base and a vibrating arm formed so as to protrude from the base, and an electrode is formed on the base and the vibrating arm. A method of manufacturing a resonator element, comprising forming an electrode layer on a surface of a substrate constituting the base, applying a voltage to a photoresist made of fine particles, applying the photoresist particles to the surface of the substrate, An electrode is formed on the base portion and the vibrating arm portion by performing photolithography using the as an etching mask.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention,
Although various technically preferable limits are given, the scope of the present invention is not limited to these modes unless otherwise specified in the following description.

FIG. 1 is a view showing a tuning-fork type quartz vibrating piece 100 which is a vibrating piece according to an embodiment of the present invention. The tuning-fork type crystal vibrating piece 100 is formed by cutting a single crystal of quartz at a specific cutting angle (cut angle) so as to form a so-called crystal Z plate, for example. The tuning-fork type crystal vibrating piece 100 shown in FIG. 1 is a vibrating piece that oscillates at a frequency of, for example, 32.768 kHz, and thus is a very small vibrating piece. Such a tuning-fork type quartz vibrating piece 100 has a base 110 as shown in FIG. And this base 1
Two tuning fork arms 121 and 122, which are vibrating arms, are arranged to project upward from FIG.

On the front and back surfaces of the tuning fork arms 121 and 122, grooves 123 and 124 are formed as shown in FIG. The grooves 123 and 124 are similarly formed on the back surfaces of the tuning fork arms 121 and 122 not shown in FIG. 1, and as shown in FIG. Tuning fork arms 121, 12 having
2 has a substantially H-shaped cross section. By the way, FIG.
Grooves 12 formed in tuning fork arms 121 and 122 shown in FIG.
As shown in FIG. 1, excitation electrodes 123
a and 124a are respectively formed. The excitation electrodes 123a and 124a are also arranged on the side surfaces of the tuning fork arms 121 and 122, as shown in FIG. A power supply electrode 112 for supplying power or the like is also provided on the base 110 or the like of the tuning-fork type quartz vibrating piece 100.

As described above, the excitation electrodes 123a, 124a are arranged in the grooves 123, 124, and the tuning fork arms 121, 122
The excitation electrodes 123a and 124a are also arranged on the side surfaces of the fork arms 123a and 124a. When a voltage is applied to the excitation electrodes 123a and 124a, an electric field is efficiently generated in the tuning fork arms 123 and 124, and the vibration loss of the tuning fork arms 123 and 124 is reduced. Vibration will occur with a low CI value (crystal impedance or equivalent series resistance). In particular, as described above, the tuning-fork type quartz vibrating piece 100 shown in FIG. 1 has a frequency of 32.768 kHz.
However, such a vibrating piece is a high-performance vibrating piece with low vibration loss and low CI value.

As shown in FIG. 1, the entire base 110 of the tuning-fork type quartz vibrating piece 100 is formed in a substantially plate shape. As shown in FIG. 1, two cuts 125 are provided on both sides of the base 110. As shown in FIG. 1, the position of the notch 125 is located below the lower ends of the grooves 123 and 124 of the tuning fork arms 121 and 122.
Does not hinder the vibration of the tuning fork arms 121 and 122.

The area that is actually fixed when the tuning-fork type quartz vibrating piece 100 is fixed in the package is the fixed area 113 in FIG. As shown in FIG.
Since the lower end of 25 is arranged in the information of FIG. 1 rather than the fixed region 113, the cut portion 125 does not affect the fixed region 113, and adversely affects the fixed state of the tuning fork type quartz vibrating piece 100 to the package. It is configured so that there is nothing.

Since the notch 125 is disposed at such a position, the leakage vibration leaked from the grooves 123 and 124 due to the vibration of the tuning fork arms 121 and 122 is reduced.
25 makes it difficult to transmit to the fixed region 113 of the base 110. As described above, it is difficult for the leakage vibration to be transmitted to the fixed region 113, so that energy escape is unlikely to occur. Specifically, the conventional variation of the CI value between the resonator element elements has occurred with a standard deviation of 10 kΩ or more.
In the resonator element according to the present embodiment, the standard deviation is 1
It decreased sharply to kΩ.

By the way, such a tuning-fork type quartz vibrating piece 1
In order for 00 to operate at a stable frequency, the excitation electrode 121 for vibrating the tuning fork arms 123 and 124 shown in FIG.
a and 122a need to be highly accurate. Hereinafter, a method of forming a highly accurate electrode pattern will be described by using a tuning fork type quartz vibrating piece 100.
The method will be described together with the method of manufacturing.

FIGS. 3 and 4 are flowcharts showing a method of manufacturing a resonator element according to the present embodiment. First, in FIG. 3, a quartz wafer is anisotropically etched to form a base 110 and tuning fork arms 121, 1 as shown in FIG.
22 and the grooves 123 and 124 are formed.
T1). Next, Cr and Au are formed by sputtering or the like (step ST2). Then, a resist film is formed in a photolithography process for forming an electrode pattern (step ST3).

This resist film is formed as shown in the flowchart of FIG. That is, the fine particle generator 131 of the photoresist of the ultra fine particle generator 130 shown in FIG.
In the above, the photoresist 132 is replaced with submicron (0.1 μm to less than 1.0 μm) fine particles 132 containing a solvent.
a (hereinafter referred to as resist fine particles) (step S
T21).

Then, the resist fine particles 132a are carried to the nozzle 134 of the coating chamber 133 with a carrier gas of an inert gas such as air or nitrogen (step ST2).
2).

By disposing a negative high-voltage (30 kV to 100 kV) electrode 135 in the nozzle 134, the resist fine particles 132a are negatively charged (step ST23).

On the other hand, the substrate 1 is placed on the positive electrode 136 at the ground potential so as to face the nozzle 134, and the negatively charged resist fine particles 132b fly toward the substrate 1 at the ground potential. Then, it is efficiently and uniformly attached to the surface of the substrate 1 (step ST24). By doing so, the resist fine particles 132b can be applied to the surface of the substrate 1 with a uniform thickness to form the resist film 137.

In this embodiment, as the ultrafine particle generator 130, an aero coat system manufactured by Nordson Corporation is used. The resist fine particles 132a
Is not limited to a negative high voltage, but may be a positive high voltage.

Then, returning to the flowchart of FIG.
Using the resist film 137 as an etching mask, Au and Cr are wet-etched by photolithography to form an electrode pattern (step ST4). Specifically, the excitation electrodes 123a and 124a of FIG.
The power supply electrode 112 is disposed on the base 110 and the like. Further, frequency adjusting electrodes 114 are disposed at the tips of the tuning fork arms 121 and 122, as shown in FIG.

After each electrode is thus formed,
The frequency is adjusted by irradiating a laser or the like to the frequency adjusting electrodes 114 formed on the tuning fork arms 121 and 122 through other predetermined steps (step ST5).

As described above, the tuning-fork type quartz vibrating piece 100 as shown in FIG. 1 is manufactured. According to the method of manufacturing the vibrating piece according to the present invention, the vibrating arm has a groove or a through groove. By applying a photoresist 132 to the vibrating reed using an electrostatic coating method, resist fine particles 132a containing a solvent adhere almost uniformly to the quartz substrate, and the resist film 137 having a small thickness unevenness. Can be formed. In particular, by making the photoresist 7 ultrafine particles of submicron, the thickness of the resist film 137 can be made more uniform.

An etching mask formed by exposing and developing the resist film 137 has a small dimensional variation, and an electrode formed by etching using the etching mask has a small finished dimensional variation. In addition, since there is no unevenness in the application of the resist, the pattern of the electrode after etching has significantly reduced defects such as holes,
A vibrating reed having a highly accurate electrode can be manufactured while increasing the manufacturing yield.

In each of the above embodiments, 32.7 is used.
A 68 kHz tuning-fork type quartz vibrating piece was described as an example.
It is apparent that the present invention can be applied to a tuning fork type quartz vibrating piece of kHz to 155 kHz. Furthermore, the present invention is not limited to the above embodiment, and various changes can be made without departing from the scope of the claims. The configuration of the above embodiment can be partially omitted or changed to another arbitrary combination not described above.

[0026]

As described above, according to the present invention,
The resist coating method, which is particularly important for forming electrode patterns with high precision, is a submicron ultrafine resist electrostatic coating method, so that the resist can be applied almost uniformly to the base and the vibrating arm. Because it can be applied
Photolithography accuracy is increased, and excitation electrodes can be formed with high accuracy.
It is possible to provide a method of manufacturing a vibrating reed that can be manufactured at a high yield without significantly increasing the production cost by significantly reducing a hole defect of the excitation electrode.

[0027]

[Brief description of the drawings]

FIG. 1 is a schematic view of a tuning-fork type quartz vibrating piece manufactured by a method of manufacturing a vibrating piece according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view taken along line F-F 'of FIG.

FIG. 3 is a flowchart showing one embodiment of a method for manufacturing a resonator element according to the embodiment of the present invention.

FIG. 4 is a flowchart showing a resist film manufacturing process which is one process of the method for manufacturing a resonator element according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a simple structure of an ultrafine particle generator used for manufacturing a resist film as one step of the method for manufacturing a resonator element according to the embodiment of the present invention.

FIG. 6 is a schematic view showing a conventional tuning-fork type quartz vibrating piece.

FIG. 7 is a schematic sectional view taken along line A-A ′ of FIG. 10;

FIG. 8 is a schematic diagram of a resist film formed in a conventional manufacturing process of a resonator element.

[Explanation of symbols]

 100: tuning-fork type crystal vibrating piece 110: base 112: power supply electrode 113: fixed area 114: frequency adjusting electrode 121, 122: tuning fork arm 123, 124: groove 123a, 124a ... excitation electrode 125 ... cut part 131 ... ultrafine particle generator 132 ... photoresist 132a ... resist fine particles 132b ... negatively charged resist fine particles 133 ... coating chamber 134 ..Nozzle 135 ... negative electrode 136 ... positive electrode 137 ... resist film

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Fumitaka Kitamura 3-3-5 Yamato, Suwa-shi, Nagano F-term (reference) in Seiko Epson Corporation 5J108 MM15

Claims (2)

[Claims] 1. A method of manufacturing a vibrating reed having a base and a vibrating arm protruding from the base, wherein the base and the vibrating arm are provided with electrodes, wherein the base is formed. An electrode layer is formed on the surface of the substrate, a voltage is applied to a photoresist made of fine particles, the photoresist particles are applied to the surface of the substrate, and photolithography is performed using the photoresist as an etching mask, whereby A method for manufacturing a vibrating reed, comprising forming an electrode on the vibrating arm. 2. The method according to claim 1, wherein the vibrating arm has a groove or a through groove.