JP2012217111A - Piezoelectric device and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric device which prevents inadequate joining and airtightness due to outflow of an unnecessary sealing material, and to provide a manufacturing method of the piezoelectric device.SOLUTION: A piezoelectric device 100 includes: a piezoelectric vibration frame 10 having a piezoelectric vibration piece 101, a frame body 104 enclosing the piezoelectric vibration piece, a pair of extraction electrodes formed in the frame body 104 and spaced a first clearance SP1 away from each other, and first castellations 106a, 106b formed in positions of the frame body which correspond to the first clearances SP1 and recessed from an outer periphery of the frame body; a first plate 12 having a first end surface M1, a mounting surface M3, and second castellations 122a, 122b, mounting terminals 125a, 125b formed on the mounting surface and the second castellations, and a pair of connection electrodes 126a, 126b formed on the first end surface and spaced a second clearance SP2 away from each other. The extraction electrodes of the piezoelectric vibration frame are joined with the connection electrodes of the first plate, and a sealing material is disposed in the first castellations.

Description

  The present invention relates to a surface-mount type piezoelectric device including a piezoelectric vibration frame having a frame body and a manufacturing method thereof.

  As a piezoelectric device such as a piezoelectric vibrator, a surface mount type (SMD) type package is mainly used. The piezoelectric device is hermetically sealed in the package for vibration stabilization.

  For example, in the piezoelectric device disclosed in Patent Document 1, a ceramic base portion and a ceramic lid portion are sealed using sealing glass. Since sealing may not be achieved when the sealing glass is reduced, Patent Document 1 discloses a structure in which a little more sealing glass is applied and excess sealing glass flows out of the package.

JP 2001-024079 A

  However, the piezoelectric device disclosed in Patent Document 1 is low in mass productivity because one ceramic lid is sealed with sealing glass with respect to one ceramic base. In mass production in units of wafers, the lid wafer on which the sealing glass is printed is heated in a stacked state to melt the glass, but a large volume of the sealing glass is printed so as to be sufficiently airtight. However, when the sealing glass flows out, there arises a problem that the extraction electrode to the excitation electrode cannot be conducted.

  An object of the present invention is to provide a piezoelectric device and a method for manufacturing the same that can prevent insufficient airtightness due to unnecessary flow of sealing material.

  A piezoelectric device according to a first aspect includes a piezoelectric vibrating piece that vibrates by application of a voltage, a frame body that is formed so as to surround the piezoelectric vibrating piece, a pair of extraction electrodes that are separated from each other by a first gap, and the frame body. A piezoelectric vibration frame having a first castellation formed at a position corresponding to the first gap and recessed from the outer periphery, a first end surface joined to one main surface of the frame, and a mounting surface opposite to the first end surface A second castellation formed at a position corresponding to the first castellation of the piezoelectric vibration frame and recessed from the outer periphery, a mounting surface, a pair of mounting terminals formed on the second castellation, and a first end surface are formed on the second gap. A first plate having a pair of connection electrodes respectively conductive to the pair of remote mounting terminals. In addition, the extraction electrode of the piezoelectric vibration frame and the connection electrode of the first plate are joined, and the sealing material is disposed on the first castellation.

  In the piezoelectric device according to the second aspect, the volume of the first castellation is larger than the volume of the second castellation.

  In the piezoelectric device according to the third aspect, the sealing material is disposed so as to fill part or all of the first gap and the second gap.

  In the piezoelectric device according to the fourth aspect, the sealing material is disposed in the second castellation.

  In the piezoelectric device according to the fifth aspect, a conductive eutectic metal is disposed between the extraction electrode of the piezoelectric vibration frame and the connection electrode of the first plate.

  In the piezoelectric device according to the sixth aspect, the piezoelectric vibrating frame further includes a connecting portion that connects the piezoelectric vibrating piece and the frame, and a through opening between the piezoelectric vibrating piece and the frame. The extraction electrode extracted from the excitation electrode formed on the surface is formed to extend to one main surface of the frame body through the connecting portion and the through opening.

  In the piezoelectric device according to the seventh aspect, the first plate has a third castellation recessed from the outer periphery, and the mounting terminal is formed to extend from the mounting surface to the first end surface via the third castellation.

  A piezoelectric device according to an eighth aspect includes a second plate having a second end surface joined to the other main surface of the frame body of the piezoelectric vibration frame.

  In the piezoelectric device according to the ninth aspect, a pair of metal films that are separated from each other by a third gap are formed on the second end face of the second plate, and a sealing material is disposed in the third gap.

In the piezoelectric device according to the tenth aspect, an extraction electrode drawn from the excitation electrode formed on the other main surface of the piezoelectric vibrating piece is formed on the other main surface of the frame body, and the metal film of the second plate and the piezoelectric vibration frame A eutectic metal layer is disposed between the lead electrode formed on the main surface.
In the piezoelectric device according to the eleventh aspect, the sealing material is low-melting glass or polyimide resin.
In the piezoelectric device according to the twelfth aspect, the frame is formed thicker than the thickness of the piezoelectric vibrating piece.

  A piezoelectric device manufacturing method according to a thirteenth aspect includes a piezoelectric vibrating piece that vibrates by application of a voltage, a frame body that is formed so as to surround the piezoelectric vibrating piece, and a pair of extraction electrodes that are formed on the frame body and are separated from each other by a first gap. A step of preparing a piezoelectric wafer including a plurality of piezoelectric vibration frames having a first through hole formed at a position corresponding to the first gap in the frame, a first end surface, and a mounting surface opposite to the first end surface; The second through-hole formed at a position corresponding to the first through-hole of the piezoelectric vibration frame, the mounting surface, the mounting terminal formed on the second through-hole, and the first end surface are formed on the first clearance and away from each other to the mounting terminal. Second wafer including a plurality of second plates having a step of preparing a first wafer including a plurality of first plates having connecting terminals to be connected, and a second end surface and a sealing material disposed on the second end surface Preparing the piezoelectric wafer extraction electrode and the first electrode Comprising a bonding step of the wafer connection electrode to bond the piezoelectric wafer and the first wafer and the second wafer to bonding, the. In the step of preparing the second wafer, the sealing material is disposed at a position corresponding to the first through hole of the piezoelectric wafer, and in the bonding step, the sealing material disposed on the second end surface of the second wafer is formed in the first through hole. Be placed.

  In the piezoelectric device manufacturing method according to the fourteenth aspect, in the bonding step, the extraction electrode and the connection electrode are bonded by activating the eutectic metal bonding method using a conductive eutectic metal or the extraction electrode and the connection electrode. Joined by direct joining method.

  The present invention provides a piezoelectric device and a method for manufacturing the same that can prevent bonding and airtightness due to unnecessary flow of sealing material.

2 is an exploded perspective view of a first crystal resonator 100. FIG. FIG. 4A is a plan view of the crystal frame 10 viewed from the + Y′-axis side. (B) is a transparent view of the crystal frame 10 as viewed from the + Y′-axis side. (A) is a top view of the base part 12 seen from the + Y'-axis side. (B) is a transparent view of the base portion 12 as viewed from the + Y′-axis side. FIG. 6 is a transparent view of the lid portion 11 as viewed from the + Y′-axis side. (A) is AA sectional drawing of FIG. (B) is BB sectional drawing of FIG. 3 is a flowchart showing a method for manufacturing the first crystal unit 100. It is a transparent view of the lid wafer 11W viewed from the + Y′-axis side. FIG. 6 is a plan view of a crystal wafer 10W viewed from the + Y′-axis side. It is a transparent view of the quartz crystal wafer 10W viewed from the + Y′-axis side. It is a plan view of the base wafer 12W viewed from the + Y′-axis side. (A) is CC sectional drawing in FIGS. 7-10, and is the figure which showed the state in which eutectic metal EC was mounted in the groove part for eutectic metals. (B) is CC sectional drawing in FIGS. 7-10, and is the figure which showed the state in which the lid wafer 11W, the quartz wafer 10W, and the base wafer 12W were joined by the eutectic metal EC. (A) is DD sectional drawing in FIGS. 7-10, and is the figure which showed the state of the low melting glass LG before joining. (B) is DD sectional drawing in FIGS. 7-10, and is the figure which showed the state of the low melting glass LG after joining. 4 is an exploded perspective view of a second crystal resonator 200. FIG. (A) is a top view of the base part 22 seen from the + Y'-axis side. FIG. 6B is a transparent view of the base portion 22 as viewed from the + Y′-axis side. 4 is an exploded perspective view of a third crystal resonator 300. FIG. FIG. 4A is a plan view of the crystal frame 30 viewed from the + Y′-axis side. (B) is a transparent view of the crystal frame 30 as viewed from the + Y′-axis side. FIG. 6 is a transparent view of the lid portion 31 as viewed from the + Y′-axis side. It is AA sectional drawing of FIG. It is a transparent view of the lid wafer 31W viewed from the + Y′-axis side. (A) is DD sectional drawing in FIG. 19, and is the figure which showed the state of the low melting glass LG before joining. (B) is DD sectional drawing in FIG. 19, and is the figure which showed the state of the low melting glass LG after joining.

  In this specification, a crystal resonator is used as the piezoelectric device, and an AT-cut crystal frame is used as the piezoelectric vibration frame. In other words, the AT-cut crystal frame has a main surface (YZ plane) inclined with respect to the Y axis of the crystal axis (XYZ) from the Z axis to the Y axis direction by 35 degrees 15 minutes with respect to the X axis. Therefore, the new tilted axes are used as the Y ′ axis and the Z ′ axis with reference to the X axis direction of the AT-cut crystal frame. That is, in this embodiment, the longitudinal direction of the crystal resonator is described as the X-axis direction, the height direction of the crystal resonator is defined as the Y′-axis direction, and the direction perpendicular to the X-axis direction and the Y′-axis direction is described as the Z′-axis direction. .

(First embodiment)
<Overall Configuration of First Crystal Resonator 100>
The first crystal unit 100 is a surface mount type and is used by being mounted on a printed circuit board or the like. The overall configuration of the first crystal unit 100 will be described with reference to FIGS. FIG. 1 is an exploded perspective view of the first crystal unit 100.

  As shown in FIG. 1, the first crystal unit 100 includes a lid portion 11 having a lid recess 111, a base portion 12 having a base recess 121, and a crystal frame 10 sandwiched between the lid portion 11 and the base portion 12. With.

<< Configuration of Crystal Frame 10 >>
First, the configuration of the crystal frame 10 will be described with reference to FIGS. 1 and 2. 2A is a plan view of the crystal frame 10 viewed from the + Y ′ axis side, and FIG. 2B is a transparent view of the crystal frame 10 viewed from the + Y ′ axis side. Note that the perspective view of the present specification refers to a diagram in which only one electrode on the other side is drawn without drawing an electrode on one side. As shown in FIG. 1, the crystal frame 10 is formed of an AT-cut quartz material, and has a surface Me on the + Y ′ side and a back surface Mi on the −Y ′ side. The crystal frame 10 includes a crystal vibrating unit 101 and a frame body 104 surrounding the crystal vibrating unit 101. A through opening 108 that penetrates from the front surface Me to the back surface Mi is formed between the crystal vibrating portion 101 and the frame body 104. Portions where the through opening 108 is not formed are connecting portions 105 a and 105 b that connect the crystal vibrating portion 101 and the frame body 104. Here, the connecting portion 105 a is connected to the −Z′-axis side of the crystal vibrating portion 101, and the connecting portion 105 b is connected to the + Z′-axis side of the crystal vibrating portion 101.

  Further, castellations 106a and 106b when the through holes CH (see FIGS. 8 and 9) are formed are formed on both sides in the X-axis direction of the crystal frame 10, respectively. Specifically, a castellation 106 a is formed on the −X axis side of the crystal frame 10, and a castellation 106 b is formed on the + X axis side of the crystal frame 10. The castellations 106 a and 106 b are provided with a low melting point glass LG as a sealing material, and seal the first crystal unit 100.

  The low melting point glass LG includes lead-free vanadium-based glass that melts at 350 ° C. to 410 ° C. Vanadium-based glass is in the form of a paste with a binder and a solvent added, and is melted and then solidified to adhere to other members. In addition, this vanadium-based glass has high reliability such as airtightness at the time of bonding, water resistance and moisture resistance. Furthermore, the thermal expansion coefficient of vanadium glass can be flexibly controlled by controlling the glass structure.

  As shown in FIG. 2A, the crystal frame 10 has a first excitation electrode 102 a formed on the surface Me of the crystal vibrating part 101. In addition, a first extraction electrode 103 a that is extracted from the first excitation electrode 102 a is formed on the surface Me of the crystal frame 10. Note that the first extraction electrode 103a is formed on substantially half of the frame body 104 on the −Z′-axis side from the crystal vibrating portion 101 via the connecting portion 105a. Further, the first extraction electrode 103a formed on the surface Me of the crystal frame 10 is extracted to the back surface Mi of the crystal frame 10 through the through opening 108 (see FIG. 2B).

  As shown in FIG. 2B, the crystal frame 10 has the second excitation electrode 102 b formed on the back surface Mi of the crystal vibrating portion 101. Further, a second extraction electrode 103b extracted from the second excitation electrode 102b is formed on the back surface Mi of the crystal frame 10. Note that the second extraction electrode 103b is formed on the half of the + Z′-axis side of the frame body 104 from the crystal vibrating part 101 through the connecting part 105b. Further, the second extraction electrode 103b formed on the back surface Mi of the crystal frame 10 is extracted to the surface Me of the crystal frame 10 through the through opening 108 (see FIG. 2A).

  As shown in FIG. 2, the first extraction electrode 103a and the second extraction electrode 103b form a first gap SP1 having a predetermined width in the Z′-axis direction on the front surface Me and the rear surface Mi of the crystal frame 10. Has been placed. Thereby, it can be ensured that the first extraction electrode 103a and the second extraction electrode 103b do not short-circuit. Further, a low melting point glass LG is disposed as a sealing material in the first gap SP1. Thereby, the cavity CT (see FIG. 5) of the first crystal unit 100 can be hermetically sealed.

  Here, for the first excitation electrode 102a, the second excitation electrode 102b, the first extraction electrode 103a, and the second extraction electrode 103b, for example, a chromium (Cr) layer is used as a base, and a gold (Au) layer is formed on the upper surface of the chromium layer. Is used. The chromium layer has a thickness of, for example, 0.05 μm to 0.1 μm, and the gold layer has a thickness of, for example, 0.2 μm to 2 μm.

<< Configuration of Base Unit 12 >>
Next, the structure of the base part 12 is demonstrated, referring FIG.1 and FIG.3. 3A is a plan view of the base portion 12 viewed from the + Y′-axis side, and FIG. 3B is a transparent view of the base portion 12 viewed from the + Y′-axis side. As shown in FIG. 1, the base portion 12 is made of glass or quartz material, and has a first end face M1 on the outer periphery of the + Y ′ side face. On both sides of the base portion 12 in the X-axis direction, castellations 122a and 122b when the through holes BH (see FIG. 10) are formed are formed. Specifically, a castellation 122 a is formed on the −X axis side of the base portion 12, and a castellation 122 b is formed on the + X axis side of the base portion 12.

  As shown in FIG. 3, the mounting terminal 125a is formed on the −X axis side of the mounting surface M3 and the castellation 122a, and the mounting terminal 125b is formed on the + X axis side of the mounting surface M3 and the castellation 122b. Yes. In addition, a connection electrode 126a conductive to the mounting terminal 125a is formed on the first end face M1, and a connection electrode 126b conductive to the mounting terminal 125b is formed on the first end face M1. Here, the connection electrode 126a is formed on approximately half of the first end face M1 on the −Z axis side, and the connection electrode 126b is formed on approximately half of the first end face M1 on the + Z axis side.

  In the first end face M1, the connection electrode 126a and the connection electrode 126b are arranged so as to form a second gap SP2 having a predetermined width in the Z′-axis direction. Thereby, it is possible to ensure that the mounting terminal 125a and the mounting terminal 125b are not short-circuited. Further, a low melting point glass LG is disposed as a sealing material in the second gap SP2. Thereby, the cavity CT (see FIG. 5) of the first crystal unit 100 can be hermetically sealed.

<< Configuration of Lid Part 11 >>
Next, the structure of the lid part 11 is demonstrated, referring FIG.1 and FIG.4. FIG. 4 is a transparent view of the lid portion 11 as viewed from the + Y′-axis side. As shown in FIG. 1, the lid portion 11 is made of glass or quartz material, and has a second end face M <b> 2 on the outer periphery of the −Y ′ side face.

  As shown in FIG. 4, a lid recess 111 that is recessed from the second end face M2 in the Y′-axis direction is formed inside the entire circumference of the second end face M2. In addition, metal films 112a and 112b are formed on almost the entire surface of the second end face M2. Specifically, the metal film 112a is formed on approximately half of the −Z axis side of the second end face M2, and the metal film 112b is formed on approximately half of the + Z axis side of the second end face M2.

  In the second end face M2, the metal film 112a and the metal film 112b are arranged so as to form a third gap SP3 having a predetermined width in the Z′-axis direction. Thereby, it can be ensured that the metal film 112a and the metal film 112b are not short-circuited. Further, a low melting point glass LG is disposed as a sealing material in the third gap SP3. Thereby, the cavity CT (see FIG. 5) of the first crystal unit 100 can be hermetically sealed.

<< Assembly of First Crystal Resonator 100 >>
Finally, assembly of the first crystal unit 100 will be described with reference to FIGS. 1 and 5. 5A is a cross-sectional view taken along line AA in FIG. 1, and FIG. 5B is a cross-sectional view taken along line BB in FIG. As shown in FIGS. 1 and 5, the lid portion 11 is bonded to the + Y′-axis side of the crystal frame 10, and the base portion 12 is bonded to the −Y′-axis side of the crystal frame 10.

  That is, the metal film 112a on the second mating surface M2 of the lid portion 11 and the first extraction electrode 103a on the surface Me of the crystal frame 10 are joined, and the metal film 112b on the second mating surface M2 of the lid portion 11 and the crystal frame 10 are joined. The second extraction electrode 103b on the surface Me is joined. Similarly, the connection electrode 126a on the first end face M1 of the base portion 12 and the first extraction electrode 103a on the back surface Mi of the crystal frame 10 are joined, and the connection electrode 126b on the first end face M1 of the base portion 12 and the crystal frame 10 are connected. The second extraction electrode 103b on the back surface Mi is joined. The metal films 112a and 112b, the first extraction electrode 103a and the second extraction electrode 103b, and the connection electrodes 126a and 126b are joined by a eutectic metal. As the eutectic metal, a gold silicon (Au 3.15Si) alloy, a gold germanium (Au12Ge) alloy, or a gold tin (Au20Sn) alloy is used. In FIGS. 5A and 5B, the eutectic metal layer is not drawn. The eutectic metal bonding will be described in detail with reference to FIG.

  Here, the connection electrode 126a formed on the first end face M1 of the base portion 12 and the first extraction electrode 103a formed on the back surface Mi of the frame body 104 of the crystal frame 10 are conducted. Similarly, the connection electrode 126b formed on the first end surface M1 of the base portion 12 and the second extraction electrode 103b formed on the back surface Mi of the frame body 104 of the crystal frame 10 are electrically conducted. That is, the mounting terminal 125a formed on the mounting surface M3 of the base portion 12 and the first excitation electrode 102a of the crystal frame 10 are electrically conductive, and the mounting terminal 125b and the second excitation electrode 102b of the crystal frame 10 are electrically conductive. As a result, when an alternating voltage (potential alternating between positive and negative) is applied to the mounting terminals 125a and 125b, the quartz crystal vibrating portion 101 can vibrate in thickness.

  As shown in FIG. 5 (b), a low melting point glass LG is formed on the castellation 106 a of the crystal frame 10. That is, the first gap SP1 and the second gap SP are filled with the low melting point glass LG. Thereby, the metal film 112a and the metal film 112b of the lid part 11 are insulated, the first extraction electrode 103a and the second extraction electrode 103b of the crystal frame 10 are insulated, and the connection electrode 126a and the connection electrode 126b of the base part 12 are insulated. And are insulated. In addition, as shown in FIG. 5A, a cavity CT is formed in which the crystal vibrating portion 101 of the crystal frame 10 is sealed. The cavity CT is filled with nitrogen gas or is evacuated.

  Further, as described in a manufacturing method of the first crystal unit 100 described later, the low melting point glass LG is castellated 106a by pressing the lid portion 11 on which the low melting point glass LG is formed against the crystal frame 10. , 106b. For this reason, the excessive low melting point glass LG does not flow into the cavity CT but flows into the castellations 122a and 122b of the base portion 12. Although the extra low melting point glass LG may completely fill the castellations 122a and 122b, FIG. 5A shows a state in which the low melting point glass LG partially fills the castellations 122a and 122b. Further, as understood from FIGS. 5A and 5B, the volume of each castellation 106a, 106b is larger than the volume of the castellations 122a, 122b.

  In the first embodiment, the lid portion 11 and the crystal frame 10 are bonded with a eutectic metal, but in addition, a direct bonding method may be used. In the direct bonding method, the surfaces of the first extraction electrode 103a and the second extraction electrode 103b are activated by plasma treatment or the like, and the surfaces of the connection electrodes 126a and 126b are activated by plasma treatment or the like, and each is activated. It is the method of joining in the state.

<Method for Manufacturing First Crystal Resonator 100>
FIG. 6 is a flowchart showing a method for manufacturing the first crystal unit 100. In FIG. 6, the manufacturing step S11 of the lid portion 11, the manufacturing step S12 of the crystal frame 10, and the manufacturing step S13 of the base portion 12 can be performed separately and in parallel. FIG. 7 is a transparent view of the lid wafer 11W viewed from the + Y′-axis side. FIG. 8 is a plan view of the crystal wafer 10W viewed from the + Y′-axis side, and FIG. 9 is a transparent view of the crystal wafer 10W viewed from the + Y′-axis side. FIG. 10 is a plan view of the base wafer 12W viewed from the + Y′-axis side. 8 to 10, the low-melting glass LG is drawn. However, after the lid wafer 11W, the crystal wafer 10W, and the base wafer 12W are bonded, the low-melting glass LG disposed on the lid wafer 11W in FIG. It shows that it is formed in the hole CH.

In step S11, the lid part 11 is manufactured. Step S11 includes steps S111 to S113.
In step S111, as shown in FIG. 7, hundreds to thousands of lid recesses 111 are formed in the crystal wafer lid wafer 11W having a uniform thickness. A lid recess 111 is formed on the lid wafer 11W by etching or machining, and a second end face M2 is formed on the outer periphery of the lid recess 111. At the same time, eutectic metal grooves 115 for positioning the spherical eutectic metal EC are formed at the four corners of the lid portion 11 in step S14 described later. That is, the eutectic metal groove 115 is formed in the middle of the four lid portions 11 adjacent to each other.

  In step S112, as shown in FIG. 7, metal films 112a and 112b are formed on the second end face M2 of the lid wafer 11W by sputtering or vacuum deposition. Here, the metal films 112a and 112b are formed on both sides of the lid portion 11 in the Z′-axis direction so as to correspond to the shapes of the first extraction electrode 103a and the second extraction electrode 103b formed in step S122 described later. . Further, the metal film 112a and the metal film 112b are formed apart so as to form the third gap SP3.

  In step S113, as shown in FIG. 7, the low melting point glass LG is formed in the third gap SP3 of the lid wafer 11W by screen printing. Thereafter, the low-melting glass LG is temporarily cured, so that the low-melting glass LG is arranged in the third gap SP3 of the lid wafer 11W.

In step S12, the crystal frame 10 is manufactured. Step S12 includes steps S121 and S122.
In step S121, as shown in FIGS. 8 and 9, the outer shape of the plurality of crystal frames 10 is formed on the uniform crystal wafer 10W by etching. That is, the crystal vibrating portion 101, the frame body 104, and the through opening 108 are formed. At the same time, rectangular through holes CH are formed on both sides of each crystal frame 10 in the X-axis direction so as to penetrate the crystal wafer 10W. When the through hole CH is divided in half, one castellation 106a, 106b (see FIG. 2) is obtained. At the same time, eutectic metal grooves 109 for positioning the spherical eutectic metal EC are formed at the four corners of the crystal frame 10 in step S14 described later. That is, the eutectic metal groove 109 is formed in the middle of the four crystal frames 10 adjacent to each other.

  In step S122, first, metal layers are formed on both surfaces of the quartz wafer 10W by sputtering or vacuum deposition. Then, a photoresist is uniformly applied on the entire surface of the metal layer. Thereafter, the pattern of the first excitation electrode 102a, the second excitation electrode 102b, the first extraction electrode 103a, and the second extraction electrode 103b drawn on the photomask is exposed to the crystal wafer 10W using an exposure apparatus (not shown). The Next, the metal layer exposed from the photoresist is etched. As a result, as shown in FIGS. 8 and 9, the first excitation electrode 102a, the second excitation electrode 102b, the first extraction electrode 103a, and the second extraction electrode 103b are formed on both surfaces of the quartz wafer 10W. The first extraction electrode 103a and the second extraction electrode 103b are formed so as to form the first gap SP1 on the front surface Me and the rear surface Mi of the quartz wafer 10W. Thereby, it can be ensured that the first extraction electrode 103a and the second extraction electrode 103b do not short-circuit.

In step S13, the base portion 12 is manufactured. Step S13 includes steps S131 and S132.
In step S131, as shown in FIG. 10, hundreds to thousands of base recesses 121 are formed on the base wafer 12W of a quartz plate having a uniform thickness. A base recess 121 is formed on the base wafer 12W by etching or machining, and a first end face M1 is formed on the outer periphery of the base recess 121. At the same time, rectangular through holes BH are formed on both sides of each base portion 12 in the X-axis direction so as to penetrate the base wafer 12W. When the through hole BH is divided in half, one castellation 122a, 122b (see FIG. 1) is obtained. At the same time, eutectic metal grooves 128 for positioning the spherical eutectic metal EC are formed at the four corners of the base portion 12 in step S14 described later. That is, the eutectic metal groove 128 is formed in the middle of the four base portions 12 adjacent to each other. The through hole BH is formed smaller than the through hole CH formed in step S121.

  In step S132, a pair of mounting terminals 125a and 125b and a pair of connection electrodes 126a and 126b are formed on the first end surface M1 and the mounting surface M3 of the base portion 12 by a sputtering and etching method (see FIG. 1). Here, the connection electrodes 126a and 126b are formed so as to correspond to the first extraction electrode 103a and the second extraction electrode 103b on the back surface Mi of the crystal wafer 10W formed in step S122. Further, the connection electrode 126a and the connection electrode 126b are formed so as to form a second gap SP2 on the first end face M1 of the base wafer 12W. Thereby, it is possible to ensure that the mounting terminal 125a and the mounting terminal 125b are not short-circuited.

  In step S14, a plurality of spherical eutectic metals EC are placed in the eutectic metal grooves as shown in FIG. FIG. 11A is a cross-sectional view taken along the line BB in FIGS. 7 to 10 and shows a state in which the eutectic metal EC is placed in the eutectic metal groove. As shown in FIG. 11A, the base wafer 12W is placed on a table (not shown), and the eutectic metal groove 128 of the base wafer 12W and the eutectic metal groove 109 on the surface Me of the crystal wafer 10W are spherical. The eutectic metal EC is placed.

  In step S15, the lid wafer 11W, the crystal wafer 10W, and the base wafer 12W are bonded by the eutectic metal EC and sealed by the low melting point glass LG. FIG. 11B is a cross-sectional view taken along the line B-B in FIGS. 7 to 10 and shows a state in which the lid wafer 11W, the crystal wafer 10W, and the base wafer 12W are bonded by the eutectic metal EC. Here, the eutectic metal EC is dissolved in a vacuum or in an inert atmosphere. The melted eutectic metal EC is subjected to capillarity by the metal films 112a and 112b of the lid wafer 11W, the first extraction electrode 103a and the second extraction electrode 103b on the front surface Me and the rear surface Mi of the quartz wafer 10W, and the connection electrode of the base wafer 12W It flows between 126a and 126b. Thereby, the surfaces of the metal films 112a and 112b, the first extraction electrode 103a and the second extraction electrode 103b, and the connection electrodes 126a and 126b are wetted. In addition, since the distances between adjacent eutectic metal grooves are substantially equal, the surfaces of the metal films 112a and 112b, the first extraction electrode 103a and the second extraction electrode 103b, and the connection electrodes 126a and 126b are sufficiently provided. Can be wet. When the eutectic metal EC is cooled below the melting point, the first extraction electrode 103a and the second extraction electrode 103b and the connection electrodes 126a and 126b become conductive and bonded.

  Further, as shown in FIG. 12, the lid wafer 11W, the crystal wafer 10W, and the base wafer 12W are further sealed with the low melting point glass LG. 12A is a cross-sectional view taken along the line DD in FIGS. 7 to 10, and shows a state of the low-melting glass LG before bonding. FIG. 12B is a cross-sectional view taken along the line DD in FIGS. In the figure, it is the figure which showed the state of the low melting glass LG after joining.

  As shown in FIG. 12A, the low melting point glass LG is disposed in a large amount with a predetermined thickness on the second end face M2 of the lid wafer 11W before the lid wafer 11W, the quartz wafer 10W, and the base wafer 12W are bonded. The

  Then, as shown in FIG. 12B, when the lid wafer 11W, the quartz wafer 10W, and the base wafer 12W are bonded while being pressed, the low melting point glass LG disposed on the second end face M2 of the lid wafer 11W is the quartz wafer. It flows into the through hole CH of 10W and the through hole BH of the base wafer 12W. Although not shown, the low melting point glass LG and the lid wafer 11W and the crystal so as to fill the first gap SP1 (see FIGS. 8 and 9) of the quartz wafer 10W and the second gap SP2 (see FIG. 10) of the base wafer 12W at the same time. It flows between the wafer 10W and the base wafer 12W. Thereby, the excess low melting glass LG does not flow into the cavity CT, and the cavity CT is sealed.

  In step S16, the bonded lid wafer 11W, crystal wafer 10W, and base wafer 12W are individually cut. In the cutting process, the first crystal unit 100 is unitized along the one-dot chain line scribe line SL shown in FIGS. 7 to 10 using a dicing apparatus using a laser or a dicing apparatus using a cutting blade. As a piece. Thereby, hundreds to thousands of first crystal units 100 are manufactured.

(Second Embodiment)
<Overall Configuration of Second Crystal Resonator 200>
The overall configuration of the second crystal unit 200 will be described with reference to FIGS. 13 and 14. FIG. 13 is an exploded perspective view of the second crystal unit 200. In the second embodiment, the same components as those in the first embodiment will be described with the same reference numerals.

  As shown in FIG. 13, the second crystal resonator 200 includes a lid portion 11, a base portion 22, and a crystal frame 10 sandwiched between the lid portion 11 and the base portion 22.

<< Configuration of Base Unit 22 >>
As shown in FIG. 13, the base portion 22 is made of glass or a quartz material and has a first end face M <b> 1 formed on the outer periphery of the base recess 121. On both sides of the base portion 22 in the X-axis direction, castellations 122a and 122b when the through holes BH (see FIG. 10) are formed are formed. In addition, castellations 223 a and 223 b that are recessed from the outer periphery are formed at the four corners of the base portion 22. Specifically, a pair of castellations 223a are formed at both corners on the −Z ′ axis side, and a pair of castellations 223b are formed at both corners on the + Z ′ axis side.

  As shown in FIG. 14B, mounting terminals 225a and 225b are formed on both sides of the Z′-axis of the mounting surface M3 of the base portion 22 and on the castellations 223a and 223b. As shown in FIG. 14A, the connection electrode 226a that is conductive to the mounting terminal 225a is formed so as to cover almost half of the first end face M1 on the −Z′-axis side, and is conductive to the mounting terminal 225b. The connection electrode 226b is formed so as to cover almost half of the first end face M1 on the + Z′-axis side.

  In addition, in the 1st end surface M1 of the base part 22, the connection electrode 226a and the connection electrode 226b are formed away so that the 2nd clearance gap SP2 may be formed. Thereby, it is possible to ensure that the mounting terminal 225a and the mounting terminal 225b are not short-circuited. Further, a low-melting glass LG as a sealing material is disposed in the second gap SP2 of the first end face M1 in the base portion 22.

<Method for Manufacturing Second Crystal Resonator 200>
The manufacturing method of the second crystal unit 200 is the same as the flowchart shown in FIG. However, when the outer shape of the base portion 22 is formed in step S121, circular through holes are formed at the four corners of the base portion 22 (see FIG. 10).

  Corresponding to the above-described configuration, the eutectic metal groove portions of the lid wafer, the crystal wafer, and the base wafer are desirably formed on both sides in the Z′-axis direction where no through hole is formed.

(Third embodiment)
<Overall Configuration of Third Crystal Resonator 300>
The overall configuration of the third crystal unit 300 will be described with reference to FIGS. FIG. 15 is an exploded perspective view of the third crystal unit 300. As shown in FIG. 15, the third crystal resonator 300 includes a lid portion 31, a base portion 12, and a crystal frame 30 sandwiched between the lid portion 31 and the base portion 12.

<< Configuration of Crystal Frame 30 >>
16A is a plan view of the crystal frame 30 viewed from the + Y′-axis side, and FIG. 16B is a transparent view of the crystal frame 30 viewed from the + Y′-axis side. As shown in FIG. 16, a low-melting glass LG is disposed as a sealing material on the castellations 106a and 106b to seal the third crystal unit 300. Accordingly, the cavity CT (see FIG. 18) of the third crystal resonator 300 can be hermetically sealed. Here, the low melting point glass LG is disposed only in the castellations 106a and 106b, and a first gap SP1 is formed between the first extraction electrode 103a and the second extraction electrode 103b.

<< Configuration of lid portion 31 >>
FIG. 17 is a transparent view of the lid portion 31 as viewed from the + Y′-axis side. As shown in FIG. 17, the low melting point glass LG is disposed in the lid portion 31 only at positions corresponding to the castellations 106a and 106b of the crystal frame 30 on the second end face M2. Thereby, when the lid part 31 and the crystal frame 30 join, the cavity CT (refer FIG. 18) of the 3rd crystal oscillator 300 can be airtight. A third gap SP3 is formed between the metal film 112a and the metal film 112b.

<< Assembly of Third Crystal Resonator 300 >>
18 is a cross-sectional view taken along line AA in FIG. As shown in FIG. 18, a low melting point glass LG is formed on the castellation 106 a of the crystal frame 30. Further, the low-melting glass LG is not formed in the first gap SP1 and the second gap SP. Thereby, the cavity CT is sealed, the metal film 112a and the metal film 112b of the lid portion 31 are insulated, the first extraction electrode 103a and the second extraction electrode 103b of the crystal frame 10 are insulated, and the connection of the base portion 12 is performed. The electrode 126a and the connection electrode 126b are insulated.

<Method for Manufacturing Third Crystal Resonator 300>
A method for manufacturing the third crystal unit 300 will be described with reference to FIGS. 19 and 20. FIG. 19 is a transparent view of the lid wafer 31W viewed from the + Y′-axis side. 20A is a cross-sectional view taken along the line DD in FIG. 19 and shows the state of the low-melting glass LG before bonding. FIG. 20B is a cross-sectional view taken along the line DD in FIG. It is the figure which showed the state of melting | fusing point glass LG.

  In step S11, the lid part 31 is manufactured. Step S11 includes steps S111 to S113. In step S111, the outer shape of the lid portion 31 is formed by etching. In step S112, metal films 112a and 112b are formed on the second end face M2 of the lid wafer 31W by sputtering or vacuum deposition as shown in FIG.

  In step S113, as shown in FIG. 19, the low-melting glass LG is formed on the lid wafer 31W by screen printing. Here, the low-melting-point glass LG is formed only in a portion corresponding to the through hole CH formed in step S121 (see FIG. 20A), and a third gap is formed between the metal film 112a and the metal film 112b. SP3 is formed.

  In step S12, the crystal frame 30 is manufactured, and in step S13, the base portion 12 is manufactured.

  In step S14, a plurality of spherical eutectic metals EC are placed in the eutectic metal grooves (see FIG. 11A).

  In step S15, the lid wafer 31W, the quartz wafer 10W, and the base wafer 12W are bonded by the eutectic metal EC and sealed by the low melting point glass LG. As shown in FIG. 20A, before the lid wafer 31W, the quartz wafer 10W, and the base wafer 12W are bonded, the low melting point glass LG corresponds to the through hole CH of the quartz wafer 10W in the second end face M2 of the lid wafer 31W. A large amount is arranged at a predetermined thickness at the place to be.

  20B, when the lid wafer 31W, the crystal wafer 10W, and the base wafer 12W are bonded while being pressed, the low melting point glass LG disposed on the second end face M2 of the lid wafer 31W is the crystal wafer. It flows into the 10 W through hole CH. Thereby, the excess low melting glass LG does not flow into the cavity CT, and the cavity CT is sealed.

  In step S16, the bonded lid wafer 31W, crystal wafer 10W, and base wafer 12W are individually cut. Thereby, hundreds to thousands of third crystal resonators 300 are manufactured.

  As described above, the optimal embodiment has been described in detail in the present specification. However, as will be apparent to those skilled in the art, the present invention can be implemented with various modifications and variations within the technical scope thereof. .

  In this specification, the base wafer, the crystal wafer, the lid wafer, and the like are bonded to each other by the low melting point glass, but a polyimide resin may be used instead of the low melting point glass. When a polyimide resin is used, screen printing may be used, or exposure may be performed after a photosensitive polyimide resin is applied to the entire surface.

  For example, in this specification, an AT-cut crystal frame has been described as an example, but the present invention is also applicable to a tuning-fork type crystal frame having a pair of vibrating arms.

  The present invention is also applied to an inverted mesa type crystal frame in which the crystal vibration part is formed thinner than the frame.

  Furthermore, the present invention can be applied to a piezoelectric oscillator in which an IC incorporating an oscillation circuit is accommodated in a cavity in addition to a crystal resonator.

DESCRIPTION OF SYMBOLS 10, 30 ... Crystal frame, 10W ... Crystal wafer 11, 31 ... Lid part, 11W, 31W ... Lid wafer 12, 22 ... Base part, 12W ... Base wafer 100, 200, 300 ... Crystal oscillator 101 ... Crystal vibration part 102a ... First excitation electrode, 102b ... Second excitation electrode 103a, 203a ... First extraction electrode, 103b, 203b ... Second extraction electrode 104, 204 ... Frame body 105a, 105b ... Connection portion 106a, 106b, 122a, 122b, 223a, 223b ... Castration 108 ... Through-opening 109, 128 ... Eutectic metal groove 111 ... Lid recess, 121 ... Base recess 112a, 112b ... Metal film 125a, 125b, 225a, 225b ... Mounting terminal 126a, 126b, 226a, 226b ... Connection electrode CT ... Cavity EC ... Eutectic metal LG ... Low melting glass M1 ... First end face, M2 ... Second end face Me ... Front face, Mi ... Back face SL ... Scribe line SP ... Gaps

Claims (14)

A piezoelectric vibrating piece that vibrates when a voltage is applied; a frame formed to surround the piezoelectric vibrating piece; a pair of extraction electrodes formed on the frame and separated from each other by a first gap; and the first electrode in the frame. A piezoelectric vibration frame having a first castellation formed at a position corresponding to one gap and recessed from the outer periphery;
A first end surface joined to one main surface of the frame body, a mounting surface opposite to the first end surface, and a first recess formed from a position corresponding to the first castellation of the piezoelectric vibration frame. Two castellations, a pair of mounting terminals formed on the mounting surface and the second castellation, and a pair of connection electrodes formed on the first end surface and separated from each other by a second gap and respectively conducted to the pair of mounting terminals. A first plate having
The extraction electrode of the piezoelectric vibration frame and the connection electrode of the first plate are joined,
A piezoelectric device in which a sealing material is disposed on the first castellation.   The piezoelectric device according to claim 1, wherein a volume of the first castellation is larger than a volume of the second castellation.   The piezoelectric device according to claim 1, wherein the sealing material is disposed so as to fill a part or all of the first gap and the second gap.   The piezoelectric device according to any one of claims 1 to 3, wherein the sealing material is disposed in the second castellation.   5. The piezoelectric device according to claim 1, wherein a conductive eutectic metal is disposed between the extraction electrode of the piezoelectric vibration frame and the connection electrode of the first plate. 6. . The piezoelectric vibrating frame further includes a connecting portion that connects the piezoelectric vibrating piece and the frame, and a through opening between the piezoelectric vibrating piece and the frame.
The extraction electrode formed on the other main surface of the piezoelectric vibrating piece extends to the one main surface of the frame body through the connecting portion and the through-opening portion. The piezoelectric device according to claim 1. The first plate has a third castellation recessed from the outer periphery,
The piezoelectric device according to claim 1, wherein the connection electrode is formed to extend to the first end face through the third castellation.   The piezoelectric device according to any one of claims 1 to 7, further comprising a second plate having a second end face joined to the other main surface of the frame body of the piezoelectric vibration frame. A pair of metal films separated from each other by a third gap is formed on the second end surface of the second plate,
The piezoelectric device according to claim 8, wherein the sealing material is disposed in the third gap.   The piezoelectric device according to claim 8 or 9, wherein a layer of eutectic metal is disposed between the metal film of the second plate and the extraction electrode formed on the other main surface of the piezoelectric vibration frame. .   The piezoelectric device according to any one of claims 1 to 10, wherein the sealing material is low-melting glass or polyimide resin.   The piezoelectric device according to any one of claims 1 to 11, wherein the frame is formed thicker than a thickness of the piezoelectric vibrating piece. A piezoelectric vibrating piece that vibrates when a voltage is applied; a frame formed to surround the piezoelectric vibrating piece; a pair of extraction electrodes formed on the frame and separated from each other by a first gap; and the first electrode in the frame. Providing a piezoelectric wafer including a plurality of piezoelectric vibration frames having a first through hole formed at a position corresponding to one gap;
A first end surface, a mounting surface opposite to the first end surface, a second through hole formed at a position corresponding to the first through hole of the piezoelectric vibration frame, the mounting surface and the second through hole Providing a first wafer including a plurality of first plates each having a mounting terminal formed on the first end surface and a connection terminal formed on the first end face and separated from each other by a second gap;
Preparing a second wafer including a plurality of second plates having a second end face and a sealing material disposed on the second end face;
A bonding step of bonding the piezoelectric wafer, the first wafer, and the second wafer so that the extraction electrode of the piezoelectric wafer and the connection electrode of the first wafer are bonded;
In the step of preparing the second wafer, the sealing material is disposed at a position corresponding to the first through hole of the piezoelectric wafer,
In the bonding step, the piezoelectric device manufacturing method in which the sealing material disposed on the second end surface of the second wafer is disposed in the first through hole.   In the bonding step, the extraction electrode and the connection electrode are bonded by a eutectic metal bonding method using a conductive eutectic metal or a direct bonding method in which the extraction electrode and the connection electrode are activated and bonded. A method for manufacturing a piezoelectric device according to claim 11.