JP2008113238A - Piezoelectric vibrator, and manufacturing method and electronic components of piezoelectric vibrator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric vibrator which can achieve improvement of breakdown voltage for electrostatic destruction. <P>SOLUTION: In a piezoelectric vibrating reed in which a plurality of vibrating arm units project from a base unit, and a piezoelectric vibrator in which exciting electrodes are formed ranging from main planes to side planes of the vibrating arm units, and lead out electrodes pulled out from the exciting electrodes are formed in the base unit, slot units are formed on a surface of the base unit, and the lead out electrodes are formed in the slot units. Moreover, a depth of the slot units is made to be more than thickness of the lead out electrodes formed in the slot units. Furthermore, an insulation film is formed on the front surface of the base unit so as to cover the lead out electrodes formed in the slot units. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a piezoelectric vibrator, a method for manufacturing a piezoelectric vibrator, and an electronic component, and more particularly, to a technique for preventing destruction of the piezoelectric vibrator and the electronic component due to electrostatic discharge.

  The tuning fork type crystal resonator is small, inexpensive, and has low power consumption, so that it has been conventionally employed as a signal source for engraving the rate of a wristwatch, and its application is going to expand. This crystal resonator is required to have a smaller CI (crystal impedance) value in order to suppress power loss. For this reason, a crystal resonator having a groove portion with improved vibration efficiency is used. Yes.

  As shown in FIG. 14, the crystal resonator includes a base 1 provided with a pair of vibrating arms 2a and 2b, and grooves 31 and 32 are provided on both main surfaces of the vibrating arms 2a and 2b, respectively. In addition, this crystal resonator includes a pair of one electrode and the other electrode. That is, one excitation electrode 41 and the other excitation electrode 51 are respectively formed on the groove portions 31 and 32 and both side surfaces of one vibration arm portion 2a, and the other is formed on the groove portions 31 and 32 and both side surfaces of the other vibration arm portion 2b. The excitation electrode 51 and the excitation electrode 41 are respectively formed on one side. In addition, an extraction electrode 42 is formed on the surface of the base 1 so that the one excitation electrode 41 is electrically connected to each other, and the other excitation electrode 51 is electrically connected to the other of the base 1. A lead electrode 52 is formed on the surface. In FIG. 14, the excitation electrodes 41 and 51 are indicated by using a hatched line and a black dotted area in order to make the drawing easy to see. Therefore, the oblique lines in FIG. 14 do not indicate the cross section of the crystal piece.

  The above-described crystal resonator is housed in a package made of ceramics having an SMD (Surface Mounted Device) structure, thereby constituting an electronic component. This electronic component is mounted on a wiring board on which circuit components of the oscillation circuit are mounted.

  By the way, the above-described crystal resonator is easily broken by electrostatic discharge (ESD), that is, has a problem that the ESD withstand voltage is low. There are the following three factors that cause electrostatic breakdown. First, electrostatic breakdown occurs due to discharge occurring when a charged operator touches the crystal unit. Second, when an electronic component is mounted on a wiring board, when the wiring board is not sufficiently grounded, electric charges flow from the wiring board side, and an electric discharge is caused by the discharge. Thirdly, the electronic component itself is charged, and when this electronic component touches a metal component or the like, a discharge occurs and electrostatic breakdown occurs.

  Such electrostatic breakdown is caused by discharge between the electrode films formed on the surface of the crystal resonator, and there are the following three paths as charge transfer paths. The first is a path through which charges move from the extraction electrode 42 to the extraction electrode 52 through the atmosphere above the base 1 as shown by a in FIG. 15, and the second is shown by b in FIG. In this way, the charge moves from the extraction electrode 42 through the surface of the base 1 to the extraction electrode 52, and the third is a path from the extraction electrode 42 through the inside of the base 1 as shown in FIG. This is a path through which charges move to 52. Further, even when impurities (attachments) adhere to the surface of the crystal unit between the extraction electrode 42 and the extraction electrode 52, the extraction electrode 42, the impurity, and the extraction electrode 52 are arranged side by side on the surface of the base 1. These intervals are shortened and become continuous, whereby charge transfer occurs through the impurities. FIG. 15 is a schematic enlarged view of a cross-sectional portion taken along line FF in FIG. Further, r in FIG. 15 is a creepage distance between the electrodes 42 and 52.

  On the other hand, in Patent Document 1, in the inverted mesa type piezoelectric vibrating piece, in order to prevent disconnection of the wiring pattern formed in the step portion between the frame body and the excitation portion, the step is formed in a step shape. Although it is described that the step size per step is reduced, this does not solve the above-described problem.

JP 2002-374135 (paragraph 0010, FIG. 1)

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a piezoelectric vibrator capable of improving the breakdown voltage against electrostatic breakdown, a method for manufacturing the piezoelectric vibrator, and an electronic component having the piezoelectric vibrator. The purpose is to provide.

In the present invention, a piezoelectric vibrating piece in which a plurality of vibrating arms extend from a base, and an excitation electrode are formed from the main surface to the side of the vibrating arm, and the base is drawn from the excitation electrode. In the piezoelectric vibrator in which the extraction electrode is formed,
A groove portion is formed on the surface of the base portion, and the extraction electrode is formed in the groove portion.

  In the piezoelectric vibrator described above, the depth of the groove is preferably equal to or greater than the thickness of the extraction electrode formed in the groove. Further, an insulating film may be formed on the surface of the base so as to cover the extraction electrode formed in the groove.

Further, the present invention is a method for manufacturing the above-described piezoelectric vibrator by obtaining an outer shape portion corresponding to a plurality of piezoelectric vibrating pieces by etching from a piezoelectric substrate,
After forming the outer shape of the piezoelectric vibrating piece, the metal film is formed using a resist mask having an opening in a portion corresponding to the groove portion of the vibrating arm portion with respect to a substrate having a metal film formed on the entire surface. Removing, and
Thereafter, the substrate is brought into contact with an etching solution, a portion where the surface of the substrate is exposed is etched, and a groove portion is formed in the vibrating arm portion; and
Patterning the resist formed on the surface corresponding to the base of the piezoelectric vibrating piece so as to have an opening in a portion corresponding to the groove of the base; and
Thereafter, using the resist mask, the step of bringing the substrate into contact with an etching solution to remove the metal film;
Using the metal film as a mask, the substrate is brought into contact with an etching solution, and a groove is formed on the exposed surface of the base, and a new groove is formed in the exposed groove of the vibrating arm. Process,
Peeling all the metal film remaining on the surface of the substrate;
Next, a step of forming a metal film to be an electrode on the entire surface of the portion where the outer shape is formed,
Next, a resist film having a region covering the metal film from the main surface to the side surface of the vibrating arm portion is formed, and a resist film is formed in a portion corresponding to the groove portion of the base portion, and these resist films are used. And etching the metal film to form an excitation electrode from the main surface to the side surface of the vibrating arm portion, and forming a lead electrode in the groove portion of the base portion.

In the piezoelectric vibrator manufacturing method described above, after the step of forming the excitation electrode on the vibrating arm portion and forming the extraction electrode in the groove portion of the base portion, the extraction electrode is provided to secure a connection portion with the conductive member. And a step of forming an insulating film having an opening in at least a part of the formed portion.
The piezoelectric vibrator of the present invention is manufactured by the method described above.

  Furthermore, an electronic component of the present invention includes the above-described piezoelectric vibrator, a container for housing the piezoelectric vibrator, and an external electrode formed on the container and electrically connected to the lead electrode of the base. It is characterized by having.

According to the present invention, since the groove portion is formed on the surface of the base portion and the extraction electrode is formed in the groove portion, the creeping distance between the adjacent electrodes becomes long. For this reason, the electric discharge which generate | occur | produces between the electrodes of the base part surface can be suppressed, and the proof pressure (ESD proof pressure) with respect to electrostatic breakdown improves.
According to the present invention, the ESD breakdown voltage of the piezoelectric vibrator can be further improved by forming the insulating film so as to cover the extraction electrode formed in the groove portion of the base portion.

  Embodiments of the present invention will be described. With respect to the structure of the crystal resonator which is a piezoelectric resonator according to this embodiment, a groove is formed on the surface of the base, and a lead electrode is formed in the groove. Since the crystal unit is the same as that described above, description of the same part is omitted.

  1 and 2 are a schematic front view and a schematic perspective view of a crystal resonator according to an embodiment of the present invention, and FIG. 3 is an enlarged view of a cross-sectional portion taken along the line AA in FIGS. FIG. 4 is a schematic enlarged view of a cross-sectional portion taken along the line CC in FIGS. 1 and 2. As shown in FIGS. 2 and 3, groove portions 5 are formed on both the front and back surfaces of the base portion 1, and the depth d of the groove portions 5 is set to 0.2 μm to 10 μm, for example. In the groove 5, lead electrodes 42 and 52 described later are formed. The thickness e of the extraction electrodes 42 and 52 is set to be the same as the depth d of the groove or smaller than the depth d of the groove. In FIG. 2, the electrodes 42 and 52 formed in the groove portion 5 of the base portion 1 are indicated by hatching. Further, as shown in FIG. 2, the groove portions 32 and 32 of the vibrating arm portions 2 a and 2 b and the groove portion 5 of the base portion 1 are connected. The lead electrodes 42 and 52 formed in the groove portion 5 of the base portion 1 are connected to the excitation electrodes 41 and 51 formed in the groove portions 32 and 32 of the vibrating arm portions 2a and 2b. In this way, the groove portion 5 is formed on the surface of the base portion 1, and the lead electrodes 42 and 52 are formed in the groove portion 5, so that the creeping distance r between the adjacent electrodes 42 and 52 as shown in FIG. This is longer than the creepage distance r (see FIG. 15) between the electrodes 42 and 52 when the extraction electrodes 42 and 52 are formed on the surface of the electrode. As the creeping distance r increases, the breakdown voltage (Break Down Voltage) increases. Further, if the extraction electrodes 42 and 52 are lower than the surface of the base 1, the discharge generated from the extraction electrode 42 through the atmosphere above the base 1 can be suppressed.

  Returning to FIG. 1 and FIG. 2, this crystal resonator includes a pair of one electrode and the other electrode. First, paying attention to the vibrating arm portion 2 a, one excitation electrode 41 is formed between the entire inner surfaces of the two groove portions 31 and 32 of the vibrating arm portion 2 a and the groove portions 31 and 32. That is, the excitation electrodes 41 in the groove portions 31 and 32 of the vibrating arm portion 2a are connected to each other by the excitation electrode 41 formed in the bridge portion corresponding to the groove portions 31 and 32. The other excitation electrode 51 is formed on both side surfaces of the vibrating arm portion 2a. An adjustment weight 50, which is a metal film for adjusting the oscillation frequency by adjusting the weight of the vibration arm 2a, is provided at the tip of the vibration arm 2a.

  When attention is paid to the vibrating arm portion 2b, the entire inner surfaces of the two groove portions 31 and 32 of the vibrating arm portion 2b and the other excitation electrode 51 are formed between the groove portions 31 and 32, respectively. One excitation electrode 41 is formed on both side surfaces of the vibrating arm portion 2b. Note that an adjustment weight 40 for adjusting the oscillation frequency by adjusting the weight is also provided at the tip of the vibrating arm 2a. The arrangement of the electrodes provided on the vibrating arm portions 2a and 2b is the same except that the excitation electrodes 41 and 51 are opposite to each other. The lead electrode 42 is formed in the groove portion 5 formed on the surface of the base 1 so that the one excitation electrode 41 is electrically connected, and the other excitation electrode 51 is connected. An extraction electrode 52 is formed in the groove 5 formed on the surface of the base 1. In FIG. 1 and FIG. 2, the excitation electrodes 41 and 51 and the extraction electrodes 42 and 52 are shown separately using diagonal lines and black interspersed regions in order to make the drawings easy to see. Accordingly, the hatched lines in FIGS. 1 and 2 do not indicate the cross section of the crystal piece.

  Next, a method for manufacturing the crystal unit shown in FIGS. 1 and 2 will be described with reference to FIGS. 5 to 8 illustrate one crystal resonator formed on a part of one piezoelectric substrate. 5 to 6 are views showing a manufacturing process for a cross-sectional portion along the line BB in FIGS. 1 and 2, and FIGS. 7 to 8 are lines AA and B in FIGS. It is a figure which shows the manufacturing process about the cross-sectional part along the -B line. First, after the quartz wafer 60, which is the cut out piezoelectric substrate, is polished and cleaned, a metal film 61 is formed by sputtering (FIG. 5A). As the metal film 61, for example, a film in which gold (Au) is laminated on a chromium (Cr) base film is used.

Subsequently, after applying a photoresist on such a metal film 61 by, for example, a spin coating method (FIG. 5B), this photoresist is exposed to a crystal piece shape, that is, a tuning fork shape pattern. Development is performed to form a tuning fork-shaped resist film 62 (FIG. 5C). Thereafter, the quartz wafer 60 is immersed in a potassium iodide (KI) solution using the resist film 62 as a mask, and wet etching is performed to remove a portion of the metal film 61 not covered with the resist film 62. (FIG. 5D).
Thereafter, while the resist film 62 is placed on the metal film 61, the crystal wafer 65 is wet etched by immersing the crystal wafer 60 in hydrofluoric acid as an etching solution using the metal film 61 as a mask. It forms (FIG.5 (e)). Thus, a plurality of crystal pieces 65 are formed on the crystal wafer 60 which is a piezoelectric substrate.
Subsequently, the resist film 63 remaining on the quartz wafer 60 is completely removed (FIG. 6F). Thereafter, a photoresist is applied to the entire surface of the quartz wafer 60 by, for example, a spray method to form a resist film 63 (FIG. 6G).
Next, the resist film 63 corresponding to the groove portions 31 and 32 shown in FIG. 1 is peeled off (FIG. 6H). Subsequently, using the resist film 63 as a mask, the quartz wafer 60 is immersed in a KI solution and wet etching is performed to remove the metal film 61 where the resist film 63 is peeled off (FIG. 6 (i)).
Thereafter, while the resist film 63 is placed on the metal film 61, the quartz wafer 60 is immersed in hydrofluoric acid as an etching solution using the metal film 61 as a mask to perform wet etching. Grooves 31 and 32 are formed on the surface (FIG. 6 (j)).

  Next, a process of forming the groove 5 in the surface corresponding to the base 1 shown in FIGS. 1 and 2 in the crystal piece 65 will be described. First, the resist film 63 formed on the surface corresponding to the base 1 of the crystal piece 65 is exposed and developed so as to form a pattern of a predetermined shape (FIG. 7 (k)). In this example, the resist film 63 other than the resist film 63 formed on the surface of the base 1 is not exposed and developed. Then, using the resist film 63 patterned in a predetermined shape as a mask, the quartz wafer 60 is immersed in a potassium iodide (KI) solution and wet etching is performed, so that the metal not covered with the resist film 63 is obtained. The part of the film 61 is removed (FIG. 7L). Then, after all the resist film 63 remaining on the quartz wafer 60 is peeled off, the quartz wafer 60 is wet etched by immersing the quartz wafer 60 in hydrofluoric acid as an etching solution using the metal film 61 as a mask. Grooves 5 are formed on the surface corresponding to the base 1 (FIG. 7 (m)). In this example, when the groove portion 5 is formed on the surface of the base portion 1, the base portion 1 is formed in the groove portions 31 and 32 formed on both main surfaces of the crystal wafer 60 as shown in FIG. A groove having the same depth as the formed groove 5 is formed. Thus, by making the groove portions 31 and 32 formed in the vibrating arm portions 2a and 2b into multistage grooves, the electrodes formed in the groove portions 31 and 32 are made to be more than the surfaces of the vibrating arm portions 2a and 2b as described later. Can be embedded below. By doing so, the creeping distance between the excitation electrodes 41 and 51 formed in the grooves 31 and 32 and the excitation electrodes 41 and 51 formed on the side surfaces of the vibrating arms 2a and 2b is increased, and the breakdown voltage (Break Down Voltage) is increased. Can be increased. Therefore, the ESD withstand voltage is improved. Thereafter, all the metal film 61 remaining on the quartz wafer 60 is peeled off (FIG. 7 (n)). Through the above steps, the prototype 6 having the groove portion 5 formed on the surface of the base portion 1 as shown in FIG. 9 is manufactured. In FIG. 9, a portion where the groove portion 5 is formed on the surface of the base portion 1 is indicated by hatching.

Subsequently, a process of forming an electrode film on portions corresponding to the vibrating arm portion 2 and the base portion 1 of the crystal piece 65 will be described. After the step shown in FIG. 7 (n), metal films 66 to be electrodes are formed on both surfaces of the prototype 6 by sputtering (FIG. 8 (o)). As the metal film 66, for example, a film in which gold (Au) is laminated on a chromium (Cr) base film is used.
Subsequently, a photoresist is applied on the metal film 66 by a spray method (FIG. 8 (p)). Then, by photolithography, the resist film 67 other than the resist film 67 serving as the electrode pattern is peeled off at the portion corresponding to the vibrating arm portion 2 of the crystal piece 65 and the groove portion 5 of the base portion 1 at the portion corresponding to the base portion 1 of the crystal piece 65. The resist film 67 other than the resist film 67 formed at the site corresponding to is peeled off (FIG. 8 (q)). Next, the metal film 66 where the resist film 67 is peeled is etched to form the metal film 66 (excitation electrodes 41 and 51) from the main surface to the side surface of the vibrating arm portion 2, and in the base 1. A metal film 66 (lead electrodes 42 and 52) is formed (FIG. 8 (r)). The electrodes in the grooves 31 and 32 are embedded below the surfaces of the vibrating arm portions 2a and 2b. Thereafter, all the resist film 67 remaining on the master 6 is peeled off (FIG. 8 (s)).
Thereafter, the oscillation frequency is adjusted by shaving the surface of the metal film 66 formed on the tip of the vibrating arm 2 with a laser or the like and adjusting its weight. Then, the crystal resonator shown in FIGS. 1 and 2 is cut out from the master 6 on which the electrode pattern is formed.

  For example, as shown in FIG. 10, the above-described crystal resonator is stored in a package 7 made of ceramic having an SMD (Surface Mounted Device) structure. The package 7 includes a case body 7a made of, for example, ceramic whose upper surface is open, and a lid body 7b made of, for example, metal. The case body 7a and the lid body 7b are seam welded via a sealing material 7c made of, for example, a welding material, and the inside is in a vacuum state. In the tuning fork type crystal resonator 70 described above, lead electrodes 42 and 52 formed in the groove portion 5 of the base 1 are fixed to the conductive adhesive 7d on the base 71 portion in the package 7, and the vibrating arm portion 2a, 2b is fixed to the pedestal 71 in a lateral posture extending into the space inside the package 7. Conductive paths 72 and 73 (73 is a conductive path on the back side of the drawing) are wired on the surface of the pedestal 71, and lead electrodes 42 and 52 formed in the groove 5 of the base 1 are conductive. The conductive paths 72 and 73 are connected via an adhesive 7d. The conductive paths 72 and 73 are respectively connected to electrodes 74 and 75 provided so as to face the longitudinal direction of the outer bottom surface of the case body 7a. As a result, the electrodes 74 and 75 and the conductive paths 72 and 73 are connected. The crystal vibrator 70 is vibrated by applying a voltage to the lead electrodes 42 and 52 formed in the groove portion 5 of the base portion 1 through the conductive adhesive 7d. Thus, an electronic component is configured, and this electronic component is mounted on a wiring board (not shown) on which circuit components of the oscillation circuit are mounted.

According to the above-described embodiment, since the groove portion 5 is formed on the surface of the base portion 1 and the extraction electrodes 42 and 52 are formed in the groove portion 5, as shown in FIG. The creepage distance r of 52 becomes longer. As the creeping distance r increases, the breakdown voltage (Break Down Voltage) increases. Further, if the extraction electrodes 42 and 52 are lower than the surface of the base 1, the discharge generated from the extraction electrode 42 through the atmosphere above the base 1 can be suppressed. Even if impurities (attachments) are attached to the surface of the base 1, the lead electrodes 42 and 52 are embedded in the surface of the base 1, so that the distance between the lead electrodes 42 and 52 and the impurities is increased. There is no fear that the electric charge moves through. As a result, the withstand voltage against electrostatic breakdown (ESD withstand voltage) is improved. The inventor has confirmed through experiments that the ESD withstand voltage of a conventional crystal resonator is 1.5 times or more.
Further, according to the above-described embodiment, since the groove portions 5 are formed in the base portion 1 after the groove portions 31 and 32 are formed in the vibrating arm portions 2a and 2b, the mechanical strength of the crystal resonator can be maintained. it can.

  Next, another embodiment of the present invention will be described. In this embodiment, in the quartz crystal resonator shown in FIG. 1, an insulating film 9 is formed from the main surface to the side surface of the vibrating arm portion 2 and formed in the groove portion 5 of the base portion 1 as shown in FIG. Except for having an opening 91 at the portion of the extracted electrodes 42 and 52 and forming the insulating film 9 on the entire surface of the base 1 other than the opening 91, it has the same configuration as the above-described crystal resonator. . The opening 91 formed in the insulating film 9 is formed in the electronic component shown in FIG. 10 to electrically connect the extraction electrodes 42 and 52 and the conductive member, for example, the conductive adhesive 7d. The size of the opening 91 may be such that the extraction electrodes 42 and 52 and the conductive adhesive 7d can be sufficiently electrically connected. That is, the lead electrodes 42 and 52 other than the lead electrodes 42 and 52 connected to the conductive adhesive 7 d are covered with the insulating film 9. As the insulating film 9, for example, a silicon nitride film (SiN4) is used. 12 shows a cross-sectional portion along the line DD in FIG. 11, and FIG. 13 shows a cross-sectional portion along the line EE in FIG.

  The insulating film 9 is formed on the surface of the quartz wafer 60 after the step shown in FIG. That is, the excitation electrodes 41 and 51 are formed on the vibrating arm portion 2 and the extraction electrodes 42 and 52 are formed in the groove portion 5 of the base portion 1, and then the distal end portion of the vibration arm portion 2 and the predetermined electrodes of the extraction electrodes 42 and 52 are formed. A mask covering the portion is positioned on the upper side of the quartz wafer 60, and the insulating film 9 is formed on the surface of the quartz wafer 60 through this mask by, for example, a sputtering method or a CVD method. The insulating film 9 needs to have a thickness of 0.5 μm or more.

  Thus, by covering the excitation electrodes 41 and 51 formed on the vibrating arm portion 2 and the extraction electrodes 42 and 52 formed in the groove portion 5 of the base portion 1 with the insulating film 9, the ESD withstand voltage of the crystal resonator can be reduced. This can be further improved. In particular, by covering the extraction electrodes 42 and 52 formed in the groove portion 5 of the base 1 with the insulating film 9, it is possible to suppress discharge generated from the extraction electrode 42 to the extraction electrode 52 through the atmosphere above the base 1. it can.

  Further, in the above-described crystal resonator, grooves may be formed on both side surfaces of the vibrating arms 2a and 2b, and the excitation electrodes 41 and 51 may be formed in the grooves. In this way, the extraction electrodes 42 and 52 are embedded in the surface of the base 1 and the excitation electrodes 41 and 51 are embedded in the surfaces of the vibrating arms 2a and 2b, thereby further improving the ESD withstand voltage of the crystal resonator.

1 is a schematic front view showing a tuning fork type crystal resonator according to an embodiment of the present invention. 1 is a schematic perspective view showing a tuning fork type crystal resonator according to an embodiment of the present invention. It is sectional drawing of the groove part location currently formed in the base of the said tuning fork type crystal resonator. It is a general | schematic expanded sectional view which shows the creeping distance between the electrodes formed in the base of the said tuning fork type crystal resonator. It is a schematic sectional drawing which shows the manufacturing method of the tuning fork type crystal resonator which concerns on embodiment of this invention. It is a schematic sectional drawing which shows the manufacturing method of the tuning fork type crystal resonator which concerns on embodiment of this invention. It is a schematic sectional drawing which shows the manufacturing method of the tuning fork type crystal resonator which concerns on embodiment of this invention. It is a schematic sectional drawing which shows the manufacturing method of the tuning fork type crystal resonator which concerns on embodiment of this invention. It is a top view which shows an example of the prototype of the crystal oscillator manufactured in the manufacturing process of the tuning fork type crystal oscillator concerning an embodiment of the invention. FIG. 2 is a schematic longitudinal sectional view and a back view showing an example of an electronic component storing a tuning fork type crystal resonator according to an embodiment of the present invention. It is a schematic front view which shows the other example of the tuning fork type crystal resonator based on embodiment of this invention. It is sectional drawing of the groove part location currently formed in the vibration arm part of the said tuning fork type crystal resonator. It is sectional drawing of the groove part location currently formed in the base of the said tuning fork type crystal resonator. It is a schematic sectional drawing which shows the conventional tuning fork type crystal resonator. It is sectional drawing of the base location of the said tuning fork type crystal resonator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 2a, 2b Vibration arm part 5 Groove part 7 Package 9 Insulating film 31, 32 Groove part 40, 50 Adjustment weight 41, 51 Excitation electrode 42, 52 Extraction electrode 60 Crystal wafer 61, 66 Metal film 62, 63, 67 Resist film

Claims (7)

A piezoelectric vibrating piece having a plurality of vibrating arms extending from the base, and an excitation electrode formed from the main surface to the side of the vibrating arm, and an extraction electrode drawn from the excitation electrode formed on the base In the piezoelectric vibrator that is
A groove is formed on the surface of the base, and the lead electrode is formed in the groove.   2. The piezoelectric vibrator according to claim 1, wherein the depth of the groove is equal to or greater than the thickness of the extraction electrode formed in the groove.   3. The piezoelectric vibrator according to claim 1, wherein an insulating film is formed on a surface of the base portion so as to cover the extraction electrode formed in the groove portion. A method for producing a piezoelectric vibrator according to claim 1, wherein outer portions corresponding to a plurality of piezoelectric vibrating pieces are obtained by etching from a piezoelectric substrate,
After forming the outer shape of the piezoelectric vibrating piece, the metal film is formed using a resist mask having an opening in a portion corresponding to the groove portion of the vibrating arm portion with respect to a substrate having a metal film formed on the entire surface. Removing, and
Thereafter, the substrate is brought into contact with an etching solution, a portion where the surface of the substrate is exposed is etched, and a groove portion is formed in the vibrating arm portion; and
Patterning the resist formed on the surface corresponding to the base of the piezoelectric vibrating piece so as to have an opening in a portion corresponding to the groove of the base; and
Thereafter, using the resist mask, the step of bringing the substrate into contact with an etching solution to remove the metal film;
Using the metal film as a mask, the substrate is brought into contact with an etching solution, and a groove is formed on the exposed surface of the base, and a new groove is formed in the exposed groove of the vibrating arm. Process,
Peeling all the metal film remaining on the surface of the substrate;
Next, a step of forming a metal film to be an electrode on the entire surface of the portion where the outer shape is formed,
Next, a resist film having a region covering the metal film from the main surface to the side surface of the vibrating arm portion is formed, and a resist film is formed in a portion corresponding to the groove portion of the base portion, and these resist films are used. And a step of etching the metal film to form an excitation electrode from the main surface to the side surface of the vibrating arm portion and forming an extraction electrode in the groove portion of the base portion. A method for manufacturing a vibrator.   After forming the excitation electrode on the vibrating arm and forming the extraction electrode in the groove of the base, at least a part of the region where the extraction electrode is formed in order to secure a connection site with the conductive member The method of manufacturing a piezoelectric vibrator according to claim 4, further comprising a step of forming an insulating film having an opening in the substrate.   A piezoelectric vibrator manufactured by the method according to claim 4 or 5.   The piezoelectric vibrator according to any one of claims 1, 2, 3, and 6, a container for housing the piezoelectric vibrator, and formed in the container and electrically connected to the extraction electrode of the base And an external electrode.

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