JP2009152988A - Piezoelectric vibration chip, piezoelectric device and manufacturing methods for them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric vibration chip that can simplify wiring by decreasing connection electrodes formed of base electrodes and make the wiring itself thick. <P>SOLUTION: The piezoelectric vibration chip (20) includes a base (29) formed with first and second base electrodes (23a, 25a); a first vibration arm portion (21) and a second vibration arm portion (22) protruding from the base; first and second surface electrodes (23d, 25d) formed on surfaces of the first and second vibration arm portions; first and second side face electrodes (23e, 25e) formed on side faces of the first and second vibration arm portions; and a first connection electrode portion (25b) connecting the first base electrode and first surface electrode to each other and connecting with the first side face electrode between the first vibration arm portion and second vibration arm portion, and a second connection electrode portion (23b) formed only on a surface and connecting the second base electrode and second surface electrode to each other. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an improvement of a piezoelectric vibrating piece and a piezoelectric device in which a piezoelectric vibrating piece is accommodated in a package. Moreover, it is related with those manufacturing methods.

  Piezoelectric devices such as piezoelectric vibrating reeds and piezoelectric oscillators are widely used in small information devices such as HDDs (hard disk drives), mobile computers, IC cards, and clock sources for mobile phones.

  The piezoelectric vibrating piece disclosed in Patent Document 1 forms a tuning fork-shaped outer shape by wet etching a piezoelectric material such as a quartz wafer. The tuning fork type piezoelectric vibrating piece includes a rectangular base portion to be mounted on a package and a pair of vibrating arms extended from the base portion. A long groove is formed on the main surface (front and back surfaces) of these vibrating arms, and necessary driving electrodes are formed. In such a tuning-fork type piezoelectric vibrating piece, when a driving voltage is applied via a driving electrode, the tip of each vibrating arm is bent and vibrated so that a predetermined frequency is obtained. The signal is extracted. Two extraction electrodes are formed on the rectangular base of the tuning fork type piezoelectric vibrating piece. A conductive adhesive is applied to the extraction electrode, and the tuning fork type piezoelectric vibrating piece is mounted on a package such as ceramic.

FIG. 10 shows an example of such a tuning-fork type piezoelectric vibrating piece 120. The tuning-fork type crystal vibrating piece 120 includes, for example, a small vibrator having a resonance frequency of 32.768 kHz, and finally, for example, a watch or the like. It will be used by being incorporated into precision equipment.
The tuning fork type crystal vibrating piece 120 is configured such that the left and right arm portions 121 and 122 vibrate when a current is applied from the outside. Specifically, the groove electrode 123d and the groove electrode 125d are formed in the grooves 131 and 132 of the surfaces 121f and 122f of the arm portions 121 and 122 shown in FIG. On the other hand, the side electrode 123e and the side electrode 125e are formed on both side surfaces 121s and 122s where the grooves 131 and 132 are not provided. When a current is applied, an electric field is generated between the groove electrode 123d and the groove electrode 125d and the side electrode 123e and the side electrode 125e, so that the arm portions 121 and 122 vibrate.

Base electrodes 123a and 125a are formed on the base 129 of the tuning fork type piezoelectric vibrating piece 120, and current is supplied to the base electrodes 123a and 125a from the outside. In order to supply current from the base electrodes 123a and 125a to the groove electrode 123d, the groove electrode 125d, the side electrode 123e, and the side electrode 125e, connection electrodes 123b and 125b are formed.
The base electrode 125a supplies current to the groove electrode 125d and the side electrode 125e via the two connection electrodes 125b and 125b that are divided in two directions. A current is supplied from the side electrode 125e on one side to the side electrode 125e on the opposite surface 121s via the connection electrode 125c.
The base electrode 123a supplies current to the side electrode 123e via the connection electrode 123b, and current is supplied from the side electrode 123e on one side to the side electrode 123e on the opposite side 122s via the connection electrode 123c. The groove electrode 123d on the surface 121f and the side electrode 123e on the side surface 122s are connected by a connection electrode 123b.
JP 2002-261575 A

  The connection electrode 123b that connects the groove electrode 123d on the surface 121f and the side electrode 123e on the side surface 122s is greatly influenced by the pattern of the connection electrode 125b. Due to the miniaturization of the tuning fork type piezoelectric vibrating piece 120, the width of the connection electrode 123b or the connection electrode 125b has to be narrowed, which causes a problem of disconnection or short circuit.

  The present invention has been made in order to solve the above-described problems. The number of connection electrodes formed from the base electrode is reduced to simplify the wiring, and the wiring itself can be thickened to cause disconnection or short circuit. An object of the present invention is to provide a piezoelectric vibrating piece or a piezoelectric device that is not allowed to move. Moreover, the manufacturing method of these piezoelectric vibrating pieces or a piezoelectric device is provided.

A piezoelectric vibrating piece according to a first aspect includes a base portion on which first and second base electrodes are formed, a first vibrating arm portion and a second vibrating arm portion protruding from the base portion, and first and second vibrating arm portions. First and second surface electrodes formed on the surface of the first, second and second side electrodes formed on the side surfaces of the first and second vibrating arm portions, a first base electrode, and a first surface electrode, A first connection electrode part connected to the first side electrode between the first vibrating arm part and the second vibrating arm part, and a second base electrode and a second surface electrode formed only on the surface. A second connection electrode portion to be connected.
According to the configuration of the first aspect, the first connection electrode portion connects the first base electrode and the first surface electrode, and the first side electrode between the first vibrating arm portion and the second vibrating arm portion. Connect to. Further, the second connection electrode portion is formed only on the surface, and connects the second base electrode and the second surface electrode. Conventionally, as shown in FIG. 10A, the second connection electrode portion requires an electrode 123b that connects the second surface electrode and the second side electrode. However, according to the present invention, such an electrode 123b is not necessary, and the widths of the electrodes of the first connection electrode portion and the second connection electrode portion can be increased, and the first connection electrode portion, the second connection electrode portion, I was able to widen the interval. That is, the present invention can reduce the occurrence of disconnection or short circuit.

In the piezoelectric vibrating piece according to the second aspect, a first base electrode is formed on one side surface, a second base electrode is formed on the other side surface, a first vibrating arm portion protruding from the base portion, and a second And a vibrating arm. In the piezoelectric vibrating piece, a first base electrode and a second side electrode are formed from one side surface of the base portion to a side surface of the second vibrating arm portion, and the first base electrode and the second side surface electrode are interposed between the first base electrode and the second side electrode. A non-electrode portion is formed.
According to the configuration of the second aspect, the non-electrode portion is formed between the first base electrode and the second side electrode. Conventionally, as shown in FIG. 10B, only one electrode can be formed on the side surface of the piezoelectric vibrating piece, but the first base electrode and the second side electrode are arranged by forming a non-electrode portion. I was able to do it. This leads to an increase in the width of the electrodes of the first connection electrode portion and the second connection electrode portion, and an increase in the distance between the first connection electrode portion and the second connection electrode portion.

In the piezoelectric vibrating piece according to the third aspect, grooves are formed on the surfaces of the first and second vibrating arms.
According to the configuration of the third aspect, since the groove is formed, the CI (crystal impedance) value can be lowered.

The non-electrode portion according to the fourth aspect is a region where the electrode disappears due to etching.
The piezoelectric vibrating piece according to the fourth aspect forms a non-electrode part by etching.

The non-electrode portion according to the fifth aspect is a region where a part of the base portion is cut and the electrode disappears.
The piezoelectric electrode piece of the fifth aspect forms a non-electrode part by cutting a part of the base part.

A piezoelectric device according to a sixth aspect includes the piezoelectric vibrating piece according to any one of the first to fifth aspects, a package that accommodates the piezoelectric vibrating piece, and a sealing portion that seals the package.
According to the configuration of the sixth aspect, a piezoelectric device can be configured using a piezoelectric vibrating piece that is less likely to cause disconnection or short circuit.

A manufacturing method for manufacturing a piezoelectric vibrating piece from a piezoelectric wafer according to a seventh aspect includes a base, a first vibrating arm portion and a second vibrating arm portion protruding from the base portion, and a protrusion having a thin tip protruding from the base portion. Forming a metal film, forming a metal film after the outer shape forming process, applying a resist on the metal film, exposing an electrode pattern, and removing the resist through the exposure process And a step of etching the portion where the resist is not applied at the protrusion having a thin tip.
According to the structure of the 7th viewpoint, the front-end | tip which protrudes from a base part forms a thin protrusion in the external shape formation process. Then, when applying the resist to form the electrode pattern, the resist is not applied to the protrusion with a thin tip. For this reason, a metal film having a thin tip is etched during etching. In this manner, this manufacturing method can form the non-electrode portion on the side surface of the piezoelectric vibrating piece. That is, the present invention can reduce the occurrence of disconnection or short circuit. Since this manufacturing method is almost the same manufacturing process as the conventional manufacturing method except that the tip protruding from the base is provided in the outer shape forming process, there is no need for a new capital investment.

In the method for manufacturing a piezoelectric vibrating piece according to the eighth aspect, the protrusion having a thin tip includes a protrusion having a sharp tip and a protrusion having a width of 0.03 mm or less at the tip.
According to the configuration of the eighth aspect, the resist is not applied when the protrusion with a thin tip is a protrusion with a sharp tip or the tip has a width of 0.03 mm or less.

In the method for manufacturing a piezoelectric vibrating piece according to the ninth aspect, three or more protrusions with thin tips are provided on the base.
According to the configuration of the ninth aspect, for example, in order to reliably form the non-electrode part, it is possible to provide three or more protrusions with thin tips at the base part.

A method of manufacturing a piezoelectric vibrating piece according to a tenth aspect includes a base, a first vibrating arm portion and a second vibrating arm portion protruding from the base, a connecting portion connecting the piezoelectric wafer and the piezoelectric vibrating piece, and a connecting portion. Forming a cutting rod provided between the first vibrating arm portion and the first vibrating arm portion base and the second vibrating arm portion base, a step of forming a metal film after the outer shape forming step, and an upper surface of the metal film A resist coating step, an exposure step of exposing the electrode pattern, a step of etching the metal film from which the resist has been removed by the exposure step, and a step of cutting the cutting bar.
According to the configuration of the tenth aspect, the cutting bar is formed between the connecting portion and the first vibrating arm portion and the second vibrating arm portion base. After forming the electrode pattern, the electrode pattern is cut by cutting the cutting bar. In this manner, this manufacturing method can form the non-electrode portion on the side surface of the piezoelectric vibrating piece. This manufacturing method is a manufacturing method that is easy to introduce because it is almost the same manufacturing step as the number of steps for cutting the cutting portion is increased as compared with the conventional manufacturing method.

In the method for manufacturing a piezoelectric vibrating piece according to the eleventh aspect, the dent is formed so that the cutting bar can be easily cut.
With this configuration, the cutting bar can be cut at the position of the recess.

In the piezoelectric vibrating piece manufacturing method according to the twelfth aspect, the cutting rod is connected to the piezoelectric vibrating piece and the piezoelectric wafer.
With this configuration, the cutting bar not only forms the non-electrode portion, but also the piezoelectric vibrating piece is less likely to be removed from the piezoelectric wafer by vibration or impact, and the handling of the piezoelectric wafer in the manufacturing method is facilitated.

A manufacturing method for manufacturing a piezoelectric device according to a thirteenth aspect includes an adhesion step for bonding a piezoelectric vibrating piece manufactured by the manufacturing method according to the seventh aspect to the twelfth aspect in a package, and sealing for sealing the package A process.
With this configuration, it is possible to manufacture a piezoelectric vibrating piece that is less likely to cause a disconnection or a short circuit by a simple method, and to configure a piezoelectric device following the method.

<Configuration of crystal resonator element>
FIG. 1A is a perspective view showing an embodiment of a tuning-fork type crystal vibrating piece 20 of the present invention.
The tuning fork type crystal vibrating piece 20 is constituted by a crystal single crystal wafer cut out to be a crystal Z plate 10, for example. At this time, it is cut out from a single crystal of crystal so that the X axis shown in FIG. 1 is an electric axis, the Y axis is a mechanical axis, and the Z axis is an optical axis. In addition to quartz, piezoelectric materials such as lithium tantalate and lithium niobate can be used.

  Such a tuning fork type crystal vibrating piece 20 includes a vibrating arm 21, a vibrating arm 22, and a base 29. The vibrating arm 21 and the vibrating arm 22 that are vibrating arm portions extend from the base portion 29 so as to protrude in the Y direction. Further, since the tuning-fork type crystal vibrating piece 20 shown in FIG. 1 is a vibrating piece that oscillates a signal at, for example, 32.768 KHz, it is an extremely small vibrating piece.

  A first electrode pattern 23 and a second electrode pattern 25 are formed on the vibrating arm 21, the vibrating arm 22, and the base portion 29 of the tuning fork type crystal vibrating piece 20. Both the first electrode pattern 23 and the second electrode pattern 25 have a structure in which a gold (Au) layer of 200 angstroms to 3000 angstroms is formed on a chromium (Cr) layer of 50 angstroms to 700 angstroms. A tungsten (W) layer or a titanium (Ti) layer may be used instead of the chromium (Cr) layer, and a silver (Ag) layer may be used instead of the gold (Au) layer. Further, it may be composed of a single metal film. In this case, for example, an Al (aluminum) layer is used. The electrode pattern is also used as a corrosion resistant film for crystal etching.

  The first electrode pattern 23 has a base electrode 23 a formed on the right surface of the base 29, and has a surface electrode 23 d and side electrodes 23 e formed on the vibrating arm 21 and the vibrating arm 22. The second electrode pattern 25 has a base electrode 25 a formed on the left surface of the base 29, and has a surface electrode 25 d and side electrodes 25 e formed on the vibrating arm 21 and the vibrating arm 22.

  As shown in FIG. 1A, a base electrode 23a is formed on the right side surface of the base 29 so that the base electrode 23a wraps around the base electrode 23a on the surface of the opposite surface. Between the side electrode 25e of the vibrating arm 22 and the base electrode 23a of the base 29, a non-electrode region 24 in which no electrode pattern is formed is provided. Although not shown in the drawing, similarly, a base electrode 25a is formed on the left side surface of the base 29, and an electrode pattern is formed between the side electrode 23e of the vibrating arm 21 and the base electrode 25a of the base 29. A non-electrode region 24 that is not provided is provided.

FIG. 1B is a cross-sectional view taken along line bb in FIG.
A pair of second electrode surface electrodes 25 d is formed on the surface 21 f of the vibrating arm 21, and a pair of first electrode side electrodes 23 e is formed on the side surface 21 s of the vibrating arm 21. Also, a pair of first electrode surface electrodes 23 d is formed on the surface 22 f of the vibrating arm 22, and a pair of second electrode side electrodes 25 e is formed on the side surface 22 s of the vibrating arm 22. When a current is passed through the surface electrode 23d and the side electrode 23e of the first electrode and the surface electrode 25d and the side electrode 25e of the second electrode, an electric field is generated, and the vibrating arm 21 and the vibrating arm 22 vibrate.

2A is a plan view of the tuning-fork type crystal vibrating piece 20 provided with the groove portion 31, and FIG. 2B is a side view thereof.
On the surface of the vibrating arm 21 and the vibrating arm 22 of the tuning-fork type crystal vibrating piece 20, two groove portions 31 are formed on the vibrating arm 21 and two on the vibrating arm 22. Since the groove 31 is formed on the opposite side of the vibrating arm 21 and the vibrating arm 22 in the same manner, the sectional view of the groove 31 of the vibrating arm 21 is substantially H-shaped. The groove portion 31 is provided to suppress an increase in CI (crystal impedance) value. A surface electrode 23d and a surface electrode 25d are formed in the groove 31.

The size of the tuning fork type crystal vibrating piece 20 is as follows.
The longitudinal length L2 of the base portion 29 of the tuning fork type crystal vibrating piece 20 is, for example, 0.58 mm to 0.64 mm. On the other hand, the longitudinal length L1 of the vibrating arm 21 and the vibrating arm 22 disposed so as to protrude from the base portion 29 is formed to be about 1.45 mm to 1.65 mm. Accordingly, the length of the base 29 with respect to the vibrating arm 21 or the vibrating arm 22 is about 40 percent. The arm width W3 of the vibrating arm 21 or the vibrating arm 22 is about 0.08 to 0.12 mm. Further, the width of the groove 31 is about 0.07 mm to 0.1 mm, which is about 80% of the arm width W3 of the vibrating arm 21 or the vibrating arm 22. The thickness d1 of the tuning fork type crystal vibrating piece 20 is about 0.08 mm to 0.12 mm. This is equivalent to the thickness of a quartz single crystal wafer. The depth of the groove 31 is 30% to 45% of the thickness of the vibrating arm 21 or the vibrating arm 22, and is 0.03 mm to 0.45 mm.

In the base 29, the base 29 on the vibrating arm 21 and the vibrating arm 22 side has a length (width) in the X direction W <b> 1, and the base on the opposite side of the vibrating arm 21 and the vibrating arm 22 has a length in the X direction ( Width) is a width W2 wider than the width W1. The width W1 is about 75 to 90 percent of the width W2. For example, the width W1 is 0.42 mm and the width W2 is 0.50 mm. For this reason, the leakage vibration leaking from the groove portion 31 due to the vibration of the vibrating arm 21 and the vibrating arm 22 is difficult to be transmitted to the connecting portion 28 side of the base portion 29.
The base portion 29 is formed with two connecting portions 28. The two connecting portions 28 are members that remain when the tuning fork type crystal vibrating piece 20 is cut from the crystal single crystal wafer. After the exposure process and the crystal etching process, several thousands of connection parts 28 are formed on one crystal single crystal wafer. A tuning fork type crystal vibrating piece 20 is connected.

  The current supplied from the external electrode of the package (see FIG. 9) is supplied to the base electrode 23a of the first electrode and the base electrode 25a of the second electrode of the tuning fork type crystal vibrating piece 20. The connection electrode 23b of the first electrode is formed so that the current that has reached the base electrode 23a of the first electrode flows through the surface electrode 23d and the side electrode 23e of the first electrode. Further, the connection electrode 25b of the first electrode is formed so that the current that has reached the base electrode 25a of the second electrode flows to the surface electrode 25d and the side electrode 25e of the second electrode. On the surface shown in FIG. 2 (a), the first electrode connection electrode 23b is connected to the surface electrode 23d, and the second electrode connection electrode 25b is connected to the surface electrode 25d and the side electrode 25e. Connected. On the opposite side not shown in the figure, conversely, the second electrode connection electrode 25b is connected to the surface electrode 25d and the first electrode connection electrode 23b is connected to the surface electrode 23d and the side electrode 23e. Connected.

  As shown in FIG. 10, in the conventional electrode pattern, a connection electrode for connecting the surface electrode 23d of the first electrode and the side electrode 23e is necessary on the surface of the base 29, or the surface electrode 25d of the second electrode A connection electrode for connecting the side electrode 25e may be necessary on the surface of the base 29. However, in the present embodiment, such a connection electrode is not necessary, and a space between the connection electrode 23b of the first electrode and the connection electrode 25b of the second electrode is increased, or the connection electrode 23b of the second electrode itself or the first electrode The width of the two-electrode connection electrode 25b itself can be increased.

  The reason why such a configuration is possible is that the non-electrode region 24 is provided on the side surface of the tuning-fork type crystal vibrating piece 20 as shown in FIG. That is, the side electrode 25e of the second electrode formed on the side surface 22s of the vibrating arm 22 and the base electrode 23a of the first electrode formed on the side surface of the base 29 are insulated. Until now, the non-electrode region 24 has not been formed on the side surface of the tuning-fork type crystal vibrating piece 20. The electrode pattern is generally formed by an exposure (photolithography) process. In this exposure step, the exposure light is applied to the surface of the tuning fork type crystal vibrating piece 20 from the Z direction. That is, since the exposure light is not irradiated on the side surface of the tuning fork type crystal vibrating piece 20, the non-electrode region 24 cannot be formed.

<Method for forming non-electrode region>
A manufacturing method for forming the non-electrode region 24 will be briefly described with reference to FIG. When forming the outer shape of the tuning fork type crystal vibrating piece 20, for example, the protrusion 41-1 is formed. The non-electrode region 24 is formed by forming the protrusion 41-1 in a shape not coated with the photoresist RES, or folding the cutting bar 45 after the first electrode pattern 23 and the second electrode pattern 25 are formed. Hereinafter, the formation of the non-electrode region 24 will be described in detail with reference to FIGS.

<First Non-Electrode Region Manufacturing Method>
As a first manufacturing method, a method for forming the protrusion 41 to which the photoresist RES is not applied will be described. 3 to 4 show a process for manufacturing the tuning fork vibrator 50 from a quartz single crystal wafer.

<< Process for Forming External Shape of Quartz Vibrating Piece >>
FIG. 3A is a flowchart of a process for forming the outer shape of the tuning-fork type crystal vibrating piece, and FIG. 3B is a diagram of a first outer shape photomask 91 used for forming the outer shape of the tuning-fork type crystal vibrating piece 20. It is the figure which showed the part.
In step S112, a corrosion resistant film is formed on the entire surface of the quartz single crystal wafer by a technique such as sputtering or vapor deposition. That is, when a crystal single crystal wafer as a piezoelectric material is used, it is difficult to directly form a film of gold (Au), silver (Ag), etc., so that chromium (Cr), titanium (Ti), etc. used. That is, in this embodiment, a metal film in which a gold layer is stacked on a chromium layer is used as the corrosion resistant film.

  In step S114, the photoresist layer RES is uniformly applied to the entire surface of the quartz single crystal wafer on which the chromium layer and the gold layer are formed by a technique such as spin coating. For the photoresist layer RES, for example, a positive photoresist made of a novolac resin can be used.

  Next, in step S116, an exposure apparatus (not shown) exposes the pattern 91-2 of the first external photomask 91 shown in FIG. 3B on the quartz single crystal wafer coated with the photoresist layer RES. The exposure apparatus exposes both surfaces of the crystal single crystal wafer so that wet etching can be performed from both surfaces of the crystal single crystal wafer. A projection pattern 93 corresponding to the projection 41-1 is formed on the pattern 91-2. The protrusion pattern 93 has a thin tip and an acute angle.

  In the first outer shape photomask 91, when the photoresist layer RES is a positive photoresist, the mask frame 91-1 and the tuning fork type vibrating piece pattern 91-2 are drawn with chromium on quartz glass. The hatched portion 91-3 remains transparent quartz glass in the transmission region. Conversely, when the photoresist layer RES is a positive photoresist, the shaded portion 91-3 is shielded from light by chromium. In the present embodiment, the following description is based on a positive photoresist. The tuning fork type vibrating piece pattern 91-2 matches the outer shape of the vibrating arm 21, the vibrating arm 22 and the base 29 of the tuning fork type crystal vibrating piece 20 shown in FIG. In addition, a protrusion 41-1 is formed on the base 29. However, unlike FIG. 2, the positions in the Y direction of the left and right protrusions 41-1 formed on the base 29 are different. This is to prevent the photoresist RES from adhering between the tip of the adjacent projection 41-1 and the tip of the projection 41-1 in step S124 if the adjacent projection 41-1 is too close. is there. When there is a certain distance between the tip of the adjacent projection 41-1 and the tip of the projection 41-1, the projection 41-1 may be provided at the same position as shown in FIG. good.

  In step S118, the photoresist layer RES of the crystal single crystal wafer is developed, and the exposed photoresist layer RES is removed. Further, the gold layer exposed from the photoresist layer RES is etched using, for example, an aqueous solution of iodine and potassium iodide. Next, the chromium layer exposed by removing the gold layer is etched with, for example, an aqueous solution of ceric ammonium nitrate and acetic acid. The concentration of the aqueous solution, the temperature, and the time of immersion in the aqueous solution are adjusted so that excess portions are not eroded. Thus, the metal film (corrosion resistant film) can be removed. Next, using a hydrofluoric acid solution as an etchant, wet etching is performed on the quartz material exposed from the photoresist layer RES and the metal film (corrosion resistant film) so that the outer shape of the tuning fork type crystal vibrating piece 20 is obtained. This wet etching takes about 6 hours to about 15 hours, although the time varies depending on the concentration, type and temperature of the hydrofluoric acid solution.

  In step S120, the tuning-fork type crystal vibrating piece 20 shown in FIG. 2 is formed by removing the photoresist layer RES and the corrosion-resistant film that are no longer needed. However, the crystal single crystal wafer and the tuning fork type crystal vibrating piece 20 are connected by the connecting portion 28, and the tuning fork type crystal vibrating piece 20 is not cut out individually. This is because a large number of tuning-fork type crystal vibrating pieces 20 are collectively processed at a time in the following steps.

<< Electrode Formation Process >>
4A is a flowchart of the electrode pattern and packaging process, and FIG. 4B is an enlarged view of the tuning-fork type crystal vibrating piece 20 to which the photoresist RES is applied.
In step S122, the tuning fork type crystal vibrating piece 20 is washed with pure water, and a metal film for forming an excitation electrode or the like as a drive electrode is formed on the entire surface of the tuning fork type crystal vibrating piece 20 by a technique such as vapor deposition or sputtering. .

In step S124, a photoresist RES is applied to the entire surface by spraying. In the application of the photoresist RES by spin coating, since the photoresist RES is not applied to a fine area, the application is performed by spraying. However, even when the photoresist RES is applied by spraying, it is difficult to form the photoresist layer RES on the 90-degree corners of the vibrating arm 21, the vibrating arm 22, and the base 29. As shown in FIG. 4B, the photoresist RES, which is a liquid, is hardly applied to the sharp protrusions narrower than 90 degrees or the thin protrusions of 0.03 mm or less. Therefore, even when the photoresist RES is applied by spraying, the photoresist RES is not applied to the tip portions of the left and right protrusions 41-1 formed on the base 29.
In step S126, an electrode photomask (not shown) corresponding to the electrode pattern is prepared, and the crystal single crystal wafer coated with the photoresist layer RES is exposed to the electrode pattern. Since this electrode pattern needs to be formed on both sides of the tuning fork type quartz vibrating piece 20, both sides of the tuning fork type quartz vibrating piece 20 are exposed.

In step S128, after developing the photoresist layer RES, the exposed photoresist RES is removed. The remaining photoresist RES becomes a photoresist layer RES corresponding to the electrode pattern. That is, a metal film appears in a region other than the photoresist layer RES corresponding to the electrode pattern. Further, as described in step S124, since the photoresist layer RES is not formed at the tip portion of the protrusion 41-1, the metal film at the tip portion of the protrusion 41-1 also appears.
Next, the metal film to be an electrode is etched. The exposed gold layer is etched, for example, with an aqueous solution of iodine and potassium iodide, and then the chromium layer is etched, for example, with an aqueous solution of ceric ammonium nitrate and acetic acid. The metal film at the tip of the protrusion 41-1 is also etched, and the non-electrode region 24 is formed.
Subsequently, in step S130, all the photoresist RES is removed. Through these steps, the electrode pattern 23 and the electrode pattern 25 are formed at an accurate position and width on the tuning-fork type crystal vibrating piece 20.
In step S132, the connecting portion 28 of the tuning fork type crystal vibrating piece 20 is folded, and the tuning fork type crystal vibrating piece 20 is cut out from the quartz single crystal wafer.

<< Frequency adjustment and packaging process >>
Since the tuning fork type crystal vibrating piece 20 having electrodes formed thereon is obtained through the above steps, in step S134, the tuning fork type crystal vibrating piece 20 is attached to the ceramic package (see FIG. 9A) with a conductive adhesive. Glue. Specifically, the electrode parts 23a and 25a of the base 29 of the tuning fork type crystal vibrating piece 20 are placed on a conductive adhesive applied to a ceramic package, and the conductive adhesive is temporarily cured. Next, the conductive adhesive is fully cured in a curing furnace. Further, the vibrating arm 21 and the vibrating arm 22 of the tuning-fork type crystal vibrating piece 20 are irradiated with laser light, and the weight metal of the vibrating arm 21 and the vibrating arm 22 is evaporated and sublimated to adjust the frequency by the mass reduction method.

Next, in step S136, the package containing the tuning fork type crystal vibrating piece 20 is transferred into a vacuum chamber or the like, and the lid is sealed with a sealing material.
In step S138, the tuning fork vibrator 50 is finally inspected to check the driving characteristics of the tuning fork vibrator 50.

<Shape of the protrusion 41>
FIGS. 5A to 5C are enlarged views of the tuning-fork type crystal vibrating piece 20 having various protrusion 41 shapes. The protrusion 41-1 shown in FIG. 2A or FIG. 4B had an acute angle extending linearly.
On the other hand, the protrusion 41-2 shown in FIG. Since the tip of the protrusion 41-2 has an acute angle, the photoresist layer RES is not formed. However, assuming that the photoresist RES is also formed at the tip due to a change in temperature or material, the shape of the protrusion 41-2 can be easily cut. If the protrusion 41-2 does not break from the notch 43 after the electrode pattern 23 and the electrode pattern 25 are formed, the non-electrode region 24 is formed at the broken portion.

  The protrusion 41-3 shown in FIG. 5B is formed with a plurality of protrusions on one side of the base. That is, since at least a pair is required on the left and right sides of the base portion 29, the base portion 29 is formed with a plurality of three or more protrusions. Since the tip of the protrusion 41-3 has an acute angle, the photoresist layer RES is not formed. However, even if the photoresist RES is formed at the tip of one protrusion 41-3 due to a change in temperature or material, the remaining protrusion 41-3 has a photoresist layer RES. If is not formed, the non-electrode region 24 is surely formed.

The protrusion 41-4 shown in FIG. 5C is formed with a protrusion having a rectangular tip. The width ΔL of the tip of the protrusion 41-4 is 0.03 mm or less. The tip of the thin protrusion 41-4 is not formed with the photoresist layer RES, like the tip of the acute protrusion. For this reason, the non-electrode region 24 is formed.
In addition, you may provide notch part 43 in protrusion 41-4, and may combine them suitably, such as providing several protrusion 41-4.

<Second Non-electrode Area Manufacturing Method>
In the first manufacturing method, the non-electrode region 24 was formed by forming the protrusion 41 on which the photoresist layer RES was not formed on the base 29. In the second manufacturing method, a cutting bar 45 (see FIG. 7B) is formed on the base 29, and the cutting bar 45 is cut to form the non-electrode region 24.

FIG. 6A is a part of the second outer shape photomask 95, and FIG. 6B is an enlarged view of the pattern 95-2.
In step S116 of FIG. 3, instead of using the first external photomask 91, the second non-electrode region manufacturing method uses the second external photomask 95. That is, an exposure apparatus (not shown) exposes the pattern 95-2 of the second outer shape photomask 95 shown in FIG. 6B onto the quartz single crystal wafer coated with the photoresist layer RES. The exposure apparatus exposes both surfaces of the crystal single crystal wafer so that wet etching can be performed from both surfaces of the crystal single crystal wafer. In the pattern 95-2, a connection pattern 99 corresponding to the cutting bar 45 is formed.

  After the pattern 95-2 of the second outer shape photomask 95 is exposed on the crystal single crystal wafer, the processing from step S118 in FIG. 3 to step S130 in FIG. 4 is performed. By these processes, the electrode pattern 23 and the electrode pattern 25 are formed on the tuning fork type crystal vibrating piece 20 with accurate positions and widths. In this state, the electrode pattern 23 and the electrode pattern 25 are also formed on the side surface of the cutting bar 45 of the tuning fork type crystal vibrating piece 20.

In step S132 of FIG. 3, the connecting portion 28 of the tuning fork type crystal vibrating piece 20 is folded, and the tuning fork type crystal vibrating piece 20 is cut out from the crystal single crystal wafer. At this time, the cutting rod 45 is also cut off. A non-electrode region 24 is formed in the cross section of the base 29 from which the cutting bar 45 is cut.
As shown in FIG. 6B, when the concave portion 99-1 is formed in the connection pattern 99 of the second outer shape photomask 95, after the quartz material is wet etched, the tuning fork type crystal vibrating piece 20 is cut. The bar 45 is also formed with a recess. For this reason, the cutting bar 45 can be easily cut off from the base portion 29.

FIG. 7A is a part of the third outer shape photomask 96, and FIG. 7B is an enlarged view of the base 29 of the tuning-fork type crystal vibrating piece 20.
An exposure apparatus (not shown) exposes the pattern 96-2 of the third outer shape photomask 96 shown in FIG. 7A to the quartz single crystal wafer coated with the photoresist layer RES. The exposure apparatus exposes both surfaces of the crystal single crystal wafer so that wet etching can be performed from both surfaces of the crystal single crystal wafer. A connection pattern 99 corresponding to the cutting bar 45 is formed in the pattern 96-2. FIG. 6 is a difference in whether the number of connecting portions is one or two. Since the cutting bar 45 is formed, the single connecting portion 28-1 has a sufficiently strong strength.

  After the pattern 95-2 of the second outer shape photomask 95 is exposed on the crystal single crystal wafer, the processing from step S118 in FIG. 3 to step S130 in FIG. 4 is performed. By these processes, the electrode pattern 23 and the electrode pattern 25 are formed on the tuning fork type crystal vibrating piece 20 with accurate positions and widths. In this state, the electrode pattern 23 and the electrode pattern 25 are also formed on the side surface of the cutting bar 45 of the tuning fork type crystal vibrating piece 20.

  In step S132 of FIG. 3, the connecting portion 28-1 of the tuning fork type crystal vibrating piece 20 is folded, and the tuning fork type crystal vibrating piece 20 is cut out from the single crystal crystal wafer. At this time, the cutting rod 45 is also cut off. A non-electrode region 24 is formed in the cross section of the base 29 from which the cutting bar 45 is cut.

  The crystal single crystal wafer using the second outer shape photomask 95 or the third outer shape photomask 96 shown in FIGS. 6 and 7 is resistant to vibration or impact in the steps S122 to S130 of FIG. There is a merit that The thickness of the crystal single crystal wafer is about 0.1 mm, and if the tuning fork type crystal vibrating piece 20 is connected to the crystal single crystal wafer only by the connecting portion 28, the tuning fork type crystal vibration is performed during steps S122 to S130. The piece 20 may be broken by vibration. Since the cutting bar 45 is formed on the base 29 in a direction orthogonal to the longitudinal direction of the connecting portion 28, the quartz single crystal wafer is extremely resistant to vibration or impact.

8A is a part of the fourth outer shape photomask 97, and FIG. 8B is an enlarged view of the base portion 29 of the tuning-fork type crystal vibrating piece 20. FIG.
An exposure device (not shown) exposes the pattern 97-2 of the fourth outer shape photomask 97 shown in FIG. 8A onto the quartz single crystal wafer coated with the photoresist layer RES. The exposure apparatus exposes both surfaces of the crystal single crystal wafer so that wet etching can be performed from both surfaces of the crystal single crystal wafer. In the pattern 97-2, a connection pattern 99 corresponding to the cutting bar 45 is formed on the base 29.

  As shown in FIG. 8B, before the cutting bar 45 is cut off, the state is on the left side of the base 29, and after the cutting bar 45 is cut off, the state is on the right side of the base 29, and the non-electrode part 24 is It is formed. As can be understood from the peripheral shape of the non-electrode portion 24, the leakage vibration leaking from the groove portion 31 due to the vibration of the vibrating arm 21 and the vibrating arm 22 is blocked by the cut shape in which the non-electrode portion 24 is formed. Thereby, there is an effect that leakage vibration is hardly transmitted to the connection portion 28 side of the base portion 29.

<Packaging>
<< Configuration of tuning fork crystal unit >>
FIG. 9A is a cross-sectional view showing a ceramic package tuning fork type crystal resonator 50 according to the present embodiment. This package tuning fork type resonator 50 made of ceramic uses the tuning fork type crystal vibrating piece 20 of the plurality of embodiments described above. The tuning fork type crystal vibrating piece 20 is mounted on a package 51 by a conductive adhesive 31. Thereafter, the lid 56 and the sealing material 58 are fixed by seam welding or the like, so that the tuning fork type crystal vibrating piece 20 is sealed in the package 51.

<< Configuration of tuning fork crystal oscillator >>
FIG. 9B shows the tuning fork crystal oscillator 60. The tuning fork crystal oscillator 60 has the same configuration in many parts as the above-described ceramic package tuning fork resonator 50. Therefore, the configurations, operations, and the like of the ceramic package tuning fork vibrator 50 and the tuning fork crystal vibrating piece 20 are denoted by the same reference numerals, and the description thereof is omitted.

  The tuning fork type crystal oscillator 60 shown in FIG. 9B includes an integrated circuit 61 on the base portion 51a below the tuning fork type crystal vibrating piece 20 of the ceramic package tuning fork vibrator 50 shown in FIG. 9A. It is arranged. That is, in the tuning fork crystal oscillator 60, when the tuning fork type crystal vibrating piece 20 disposed therein vibrates, the vibration is input to the integrated circuit 61, and then functions as an oscillator by extracting a predetermined frequency signal. Will do. Such an integrated circuit 61 is mounted on the package 51, and then the tuning fork type crystal vibrating piece 20 is mounted on the package 51 with the conductive adhesive 31.

<< Configuration of Cylinder Type Tuning Fork Crystal Oscillator >>
FIG. 9C is a schematic view showing a cylinder type tuning fork vibrator 70. The cylinder type tuning fork vibrator 70 uses the tuning fork type crystal vibrating piece 20 described above. The cylinder type tuning fork vibrator 70 has a metal cap 75 for accommodating the tuning fork type crystal vibrating piece 20 therein. The cap 75 is press-fitted into the stem 73 so that the inside thereof is maintained in a vacuum state. Two leads 71 for holding the tuning fork type crystal vibrating piece 20 accommodated in the cap 75 are arranged. The lead 71 and the tuning-fork type crystal vibrating piece 20 are conductively joined with a conductive adhesive 31. The tuning fork type crystal vibrating piece 20 vibrates when a constant current is applied from the electrode portion.

In each embodiment, the tuning-fork type crystal vibrating piece 20 forms the vibrating arm 21 and the vibrating arm 22. However, the present invention is not limited to this, and the number of vibrating arms may be three or four or more.
In addition, the rods left by folding the protrusions 41 or the cutting rods 45 remain in the base portion 29 in the non-electrode region 24, but they do not affect the vibration frequencies of the vibrating arms 21 and 22. Accordingly, the protrusion 41 or the cutting bar 45 may be folded to leave the remaining bar. If there is a problem such as contact with the package, or a problem such as poor appearance, it may be deleted manually or by a cutting device (not shown).
Furthermore, this embodiment showed the method of forming the non-electrode area | region 24 by folding the protrusion 41 or the cutting bar 45. FIG. However, the exposure light strikes the side surface of the tuning-fork type crystal vibrating piece 20, and the non-electrode region 24 may be formed by the exposure process and etching of the metal film without providing the protrusion 41 or the cutting bar 45. Good.

(A) is the perspective view which showed embodiment of the tuning fork type crystal vibrating piece 20 of this invention, (b) is the bb cross section of (a). (A) is a top view of the tuning fork type crystal vibrating piece 20 provided with the groove part 31, (b) is the side view. (A) is a flowchart of the process of forming the outer shape of the tuning-fork type crystal vibrating piece, and (b) shows a part of the first outer shape photomask 91 used for forming the outer shape of the tuning-fork type crystal vibrating piece 20. FIG. (A) is a flowchart of the electrode pattern and packaging process, and (b) is an enlarged view of the tuning-fork type crystal vibrating piece 20 coated with the photoresist RES. (A) to (c) are enlarged views of the tuning-fork type crystal vibrating piece 20 having various protrusion 41 shapes. (A) is a part of 2nd external shape photomask 95, (b) is an enlarged view of the pattern 95-2. (A) is a part of the third outer shape photomask 96, and (b) is an enlarged view of the base portion 29 of the tuning fork type crystal vibrating piece 20. (A) is a part of the fourth outer shape photomask 97, and (b) is an enlarged view of the base portion 29 of the tuning fork type crystal vibrating piece 20. It is a figure which shows the aspect of the packaged piezoelectric device. It is the front view and side view which show the conventional tuning fork type crystal vibrating piece 120.

Explanation of symbols

20 ... tuning fork type crystal vibrating pieces 21, 22 ... vibrating arms 23, 25 ... electrodes, 23a, 25a ... base electrodes, 23b, 25b ... connection electrodes, 23c, 25c ... connection electrodes, 23d, 25d ... surface electrodes, 23e, 25e ... side electrode 24 ... non-electrode region 28 ... connecting part 29 ... base 41 ... projection 45 ... cutting bar 50 ... package tuning fork type vibrator 51 ... package 60 ... tuning fork type crystal vibrator 70 ... cylinder type tuning fork vibrators 91, 95, 96 ... Outline photomask 120 ... Conventional tuning-fork type crystal vibrating piece

Claims (13)

A base on which first and second base electrodes are formed;
A first vibrating arm portion and a second vibrating arm portion protruding from the base portion;
First and second surface electrodes formed on the surfaces of the first and second vibrating arm portions;
First and second side electrodes formed on side surfaces of the first and second vibrating arm portions;
A first connection electrode portion connecting the first base electrode and the first surface electrode, and connecting to the first side electrode between the first vibrating arm portion and the second vibrating arm portion;
A second connection electrode portion formed only on the surface and connecting the second base electrode and the second surface electrode;
A piezoelectric vibrating piece comprising: A base having a first base electrode formed on one side and a second base electrode formed on the other side;
A first vibrating arm portion and a second vibrating arm portion protruding from the base portion;
First and second side electrodes formed on side surfaces of the first and second vibrating arm portions,
The first base electrode and the second side electrode are formed from one side surface of the base portion to the side surface of the second vibrating arm portion, and a non-contact is formed between the first base electrode and the second side electrode. A piezoelectric vibrating piece in which an electrode portion is formed. 3. The piezoelectric vibrating piece according to claim 1, wherein a groove portion is formed on a surface of each of the first and second vibrating arm portions. The piezoelectric vibrating piece according to claim 2, wherein the non-electrode portion is a region where an electrode is removed by etching. 3. The piezoelectric vibrating piece according to claim 2, wherein the non-electrode portion is a region in which a part of the base portion is cut and the electrode is removed. The piezoelectric vibrating piece according to any one of claims 1 to 5,
A package containing the piezoelectric vibrating piece;
A piezoelectric device comprising: a sealing portion that seals the package. In a manufacturing method for manufacturing a piezoelectric vibrating piece from a piezoelectric wafer,
An outer shape forming step of forming a base, a first vibrating arm portion and a second vibrating arm portion protruding from the base portion, and a protrusion having a thin tip protruding from the base portion;
After this outer shape forming step, a step of forming a metal film,
Applying a resist on the metal film;
An exposure process for exposing the electrode pattern;
A manufacturing method of manufacturing a piezoelectric vibrating piece, comprising: etching a portion where the resist has been removed by the exposure step and a portion where the resist is not applied at a protrusion having a thin tip. 8. The piezoelectric vibrating piece according to claim 7, wherein the protrusion having a thin tip includes a protrusion having an acute tip and a protrusion having a width of 0.03 mm or less at the tip. The manufacturing method for manufacturing a piezoelectric vibrating piece according to claim 7 or 8, wherein three or more protrusions having a thin tip are provided on the base. In a manufacturing method for manufacturing a piezoelectric vibrating piece from a piezoelectric wafer,
A base, a first vibrating arm portion and a second vibrating arm portion protruding from the base portion, a connecting portion connecting the piezoelectric wafer and the piezoelectric vibrating piece, the connecting portion, the first vibrating arm portion, and a second An outer shape forming step of forming a cutting rod provided between the vibrating arm base and
After this outer shape forming step, a step of forming a metal film,
Applying a resist on the metal film;
An exposure process for exposing the electrode pattern;
Etching the metal film from which the resist has been removed by this exposure step;
A method of manufacturing a piezoelectric vibrating piece, comprising: cutting the cutting bar. The manufacturing method for manufacturing a piezoelectric vibrating piece according to claim 10, wherein the cutting bar is formed with a recess so as to be easily cut. The manufacturing method for manufacturing the piezoelectric vibrating piece according to claim 10 or 11, wherein the cutting bar connects the piezoelectric vibrating piece and the piezoelectric wafer. In a manufacturing method for manufacturing a piezoelectric device,
A bonding step of bonding the piezoelectric vibrating piece manufactured by the manufacturing method according to any one of claims 7 to 11 in a package;
A sealing step for sealing the package;
A method for manufacturing a piezoelectric device comprising: