JP2012015824A - Piezoelectric vibration device and manufacturing method for piezoelectric vibration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a piezoelectric vibration device which reduces cost by having the same structure for its upper and lower plates.SOLUTION: A manufacturing method for a piezoelectric vibration device comprises: a process for preparing a piezoelectric wafer containing multiple piezoelectric frames having a piezoelectric vibration piece and an outer frame to support the piezoelectric vibration piece, and having at least a pair of first through-holes (S101); a frist electrode formation process for forming an excitation electrode and forming a drawer electrode and a first side face electrode (S103); a process for preparing two plate wafers having multiple plates with first and second sides, and having at least a pair of second through-holes (S111); a second electrode formation process for forming an external electrode and a second side face electrode (S113); an encapsulation member positioning process for positioning a non-conductive encapsulation member in an annular form (S12); a joint process for jointing the piezoelectric wafer and the two plate wafers with the encapsulation member (S13); and a third electrode formation process for forming connection electrodes in the first side and the first and second through-holes after the joint process (S14).

Description

  The present invention relates to a piezoelectric vibrating device having a tuning fork type piezoelectric vibrating piece or an AT vibrating piece having a pair of vibrating arms, and a manufacturing method thereof.

  Patent Document 1 discloses a piezoelectric vibration device in which plate-shaped flat plates having one concave portion and one through hole are bonded to both main surfaces of the vibration plate by interatomic bonds. The diaphragm has a tongue-like vibrating portion held at one end and an outer frame surrounding the periphery. A pair of external electrodes is formed on each of the two flat plates, and the through holes are connected to the pair of external electrodes. The pair of external electrodes are formed on the upper flat plate and the lower flat plate, and can be mounted either vertically.

  An extraction electrode is formed from the excitation electrode formed on the tongue-shaped vibrating portion, and the extraction electrode is connected to a pair of external electrodes via a through hole. Also, an electrode pattern covered with a glass layer is formed on one of the two flat plates so that the pair of external electrodes are not short-circuited.

JP-A-7-106905

  Although the piezoelectric vibration device of Patent Document 1 can be mounted either up or down, the two flat plates are not the same structure. For this reason, each flat plate must be prepared, resulting in high manufacturing costs. Moreover, since it is necessary to form the electrode pattern covered with the glass layer which is an insulating layer in one flat plate, there existed a problem that manufacturing cost would be expensive.

  The present invention provides a method of manufacturing a piezoelectric vibration device that can reduce the cost by making the upper and lower flat plates have the same structure and can be mass-produced in wafer units. It is another object of the present invention to provide a piezoelectric vibration device having two flat plates having the same structure.

  A method of manufacturing a piezoelectric vibrating device according to a first aspect includes a plurality of piezoelectric frames having a piezoelectric vibrating piece having one main surface and another main surface and an outer frame surrounding the piezoelectric vibrating piece and supporting the piezoelectric vibrating piece. A step of preparing a piezoelectric wafer in which at least a pair of first through holes penetrating from one main surface to another main surface is formed between adjacent outer frames, and a pair of excitation electrodes on one main surface and the other main surface. A first electrode forming step of forming a pair of extraction electrodes formed from the pair of excitation electrodes to the pair of first through holes and a first side electrode formed in the first through hole and connected to the extraction electrode; A plurality of flat plates having a first surface and a second surface opposite to the first surface, and at least a pair of second through holes penetrating from the first surface to the second surface are formed between adjacent flat plates. A process of preparing two flat wafers and a pair of external electrodes on the first surface Forming a second side surface electrode in the second through-hole, between one main surface of the outer frame and one second surface of the flat wafer, and the other main surface of the outer frame and the flat plate A sealing material disposing step of annularly disposing a non-conductive sealing material between the other second surface of the wafer, and two flat wafers on the first main surface and the second main surface of the piezoelectric wafer A connecting step for joining the first side surface electrode, the second side surface electrode, and the external electrode to the first surface, the first through hole, and the second through hole, respectively. A third electrode forming step to be formed.

  A method of manufacturing a piezoelectric vibrating device according to a second aspect includes a plurality of piezoelectric frames having a piezoelectric vibrating piece having one main surface and another main surface and an outer frame surrounding the piezoelectric vibrating piece and supporting the piezoelectric vibrating piece. A step of preparing a piezoelectric wafer in which at least a pair of first through holes penetrating from one main surface to another main surface is formed between adjacent outer frames, and a pair of excitation electrodes on one main surface and the other main surface. A first electrode forming step of forming a pair of extraction electrodes formed from the pair of excitation electrodes to the pair of first through holes and a first side electrode formed in the first through hole and connected to the extraction electrode; A plurality of flat plates having a first surface and a second surface opposite to the first surface, and at least a pair of second through holes penetrating from the first surface to the second surface are formed between adjacent flat plates. The process of preparing two flat wafers, one main surface of the outer frame and the flat wafer A sealing material disposing step of annularly disposing a non-conductive sealing material between one of the second surfaces and between the other main surface of the outer frame and the other second surface of the flat wafer. A bonding step of bonding two flat wafers to the first main surface and the second main surface of the piezoelectric wafer with a sealing material, and after the bonding step, external electrodes are formed on the first surface, and the second through holes Forming a second side electrode, and forming a connection electrode for connecting the second side electrodes to the first through hole.

  In the method for manufacturing a piezoelectric vibration device according to the third aspect, the sealing material includes a glass film or a polyimide resin adhesive.

  According to the fourth aspect of the piezoelectric vibrating device manufacturing method, when viewed from the direction from one main surface to the other main surface, the outer periphery of the outer frame and the outer periphery of the flat plate are rectangular, and the first through hole and the second through hole are rectangular. It is formed at the corners.

  According to the fifth aspect of the piezoelectric vibrating device manufacturing method, when viewed from the direction from one main surface to the other main surface, the outer periphery of the outer frame and the outer periphery of the flat plate are rectangular, and the first through hole and the second through hole are rectangular. The method of manufacturing a piezoelectric vibration device according to claim 1, wherein the piezoelectric vibration device is formed on a side of the piezoelectric vibration device.

  In the method of manufacturing a piezoelectric vibrating device according to the sixth aspect, the step of preparing the piezoelectric wafer includes the step of preparing a predetermined gap between the piezoelectric vibrating piece and the two flat plates when the piezoelectric vibrating piece and the two flat plates are joined. Is formed on one main surface and the other main surface of the outer frame.

  A piezoelectric vibrating device according to a seventh aspect is drawn out from a piezoelectric vibrating piece having a pair of excitation electrodes formed on one main surface and another main surface, an outer frame surrounding the periphery of the piezoelectric vibrating piece, and the pair of excitation electrodes. A piezoelectric frame having a pair of lead electrodes extending to the side surface of the outer frame, a first side electrode formed on the first side surface connecting one main surface and the other main surface, and the first surface and opposite to the first surface Two flat plates having the same structure and having an external electrode formed on the first surface and a second side electrode formed on the second side surface connecting the first surface and the second surface And a non-conductive sealing material arranged in an annular shape so as to go around one main surface and the other main surface of the outer frame. Also, one second surface of the flat plate is bonded to one main surface of the frame body by the sealing material, and the other second surface of the flat plate is bonded to the other main surface of the frame body, and the first surface of the two flat plates Are formed with a pair of external electrodes, and the pair of excitation electrodes are electrically connected to the first side electrode, the second side electrode, and the external electrode, respectively.

In the piezoelectric vibrating device according to the eighth aspect, the sealing material includes a glass film or a polyimide resin adhesive.
When viewed from the direction from one main surface to the other main surface, the piezoelectric vibration device according to the ninth aspect has a rectangular outer periphery and a flat plate outer periphery, and a castellation that is depressed at the corners of the rectangle is formed. The electrode is formed in a castellation.

  When viewed from the direction from one main surface to the other main surface, the piezoelectric vibrating device according to the tenth aspect has a rectangular outer periphery and a flat plate outer periphery, and a castellation that is depressed on the sides of the rectangular shape is formed. Are formed into castellations.

  According to the eleventh aspect of the piezoelectric vibrating device, when the piezoelectric vibrating piece and the two flat plates are joined, a predetermined gap is formed between the piezoelectric vibrating piece and the two flat plates. And protrusions are formed on the other main surface.

In the piezoelectric vibrating device according to the twelfth aspect, the thickness of the sealing material is larger than the thickness of the excitation electrode or the extraction electrode.
In the piezoelectric vibrating device according to the thirteenth aspect, the height of the protrusion is larger than the thickness of the excitation electrode or the extraction electrode.

  In the piezoelectric vibrating device according to the fourteenth aspect, the extraction electrode is extracted from the piezoelectric vibrating piece from different directions.

  The present invention provides a method of manufacturing a piezoelectric vibration device that can reduce the cost by making the upper and lower flat plates have the same structure and can be mass-produced in wafer units. Also, a piezoelectric vibration device having two flat plates having the same structure can be obtained.

It is a disassembled perspective view of the first crystal unit 100A. FIG. 2 is a cross-sectional view taken along the line A-A in FIG. 1 and shows a state after the crystal frame 10 and the pair of crystal flat plates 11 are joined. 10 is a flowchart showing the manufacture of the first crystal unit 100A. It is a top view of quartz wafer 10W. It is a top view of the flat wafer 11W. It is a disassembled perspective view of the 2nd crystal oscillator 100B. It is a disassembled perspective view of the third crystal resonator 100C. It is a top view of quartz wafer 30W. It is a top view of the flat wafer 31W. It is a disassembled perspective view of 4th crystal oscillator 100D. It is a side view of 4th crystal oscillator 100D. It is sectional drawing corresponding to the AA cross section of FIG. 1 in the 5th crystal oscillator 100E. It is the flowchart which showed manufacture of the 5th crystal oscillator 100E. It is sectional drawing corresponding to the AA cross section of FIG. 1 in the 6th crystal oscillator 100F.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In each of the following embodiments, an AT-cut crystal vibrating piece is used as the piezoelectric vibrating piece. Here, in the AT-cut quartz crystal vibrating piece, the main surface (YZ plane) is inclined 35 degrees 15 minutes from the Z axis to the Y axis centering on the X axis with respect to the Y axis of the crystal axis (XYZ). . For this reason, in the following embodiments, the new axes that are inclined with respect to the axial direction of the AT-cut quartz crystal vibrating piece are used as the X ′ axis, the Y ′ axis, and the Z ′ axis. In the description of the present specification, the height in the Y′-axis direction is expressed as the + direction being high and the − direction being low.

(First embodiment)
<Overall Configuration of First Crystal Resonator 100A>
The overall configuration of the first crystal unit 100A will be described with reference to FIGS.
FIG. 1 is an exploded perspective view of the first crystal unit 100A, and the connection electrodes 118a and 118b (see FIG. 2) are omitted. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1 and shows a state after the crystal frame 10 and the pair of crystal plates 11 are joined.

  As shown in FIGS. 1 and 2, the first crystal unit 100 </ b> A includes a pair of crystal plates 11 having the same shape and a crystal frame 10 sandwiched between the pair of crystal plates 11. When the pair of crystal plates 11 are bonded to both surfaces of the crystal frame 10 in nitrogen gas or in vacuum, the cavity CT (FIG. 2) sealed with nitrogen gas or vacuum by the pair of crystal plates 11 and crystal frame 10. Are formed).

  The pair of crystal flat plates 11 have a mounting surface M1 and a flat plate bonding surface M2. Further, a pair of external electrodes 115a and 115b are formed on the mounting surface M1 of the quartz plate 11, respectively, and two pairs of plates when a circular through hole BH1 (see FIG. 5) is formed at the corner of the quartz plate 11. Castellations 116a and 116b are formed. The pair of plate castellations 116a is formed with a plate side electrode 117a connected to the external electrode 115a, and the pair of plate castellations 116b is formed with a plate side electrode 117b connected to the external electrode 115b. Yes.

  The quartz frame 10 is formed of an AT-cut quartz material, and has a + Y′-side quartz bonding surface M3 and a −Y′-side quartz bonding surface M4. The crystal frame 10 includes a crystal vibrating part 101 and an outer frame 102 surrounding the crystal vibrating part 101. Further, a U-shaped gap portion 103 penetrating vertically is formed between the crystal vibrating portion 101 and the outer frame 102, and a portion where the gap portion 103 is not formed is formed between the crystal vibrating portion 101 and the outer frame 102. It becomes the connection part 109 of this. Excitation electrodes 104a and 104b are formed on the crystal bonding surface M3 and the crystal bonding surface M4 of the crystal vibrating part 101, respectively, and excitation electrodes 104a and 104b and conductive extraction electrodes 105a and 105b are respectively formed on both surfaces of the outer frame 102. Is formed. Furthermore, crystal castellations 106a and 106b when the circular through hole CH1 (see FIG. 4) is formed are formed at the corners of the crystal frame 10. Further, a crystal side electrode 107a is formed on each of the pair of crystal castellations 106a, and the crystal side electrode 107a is connected to the extraction electrode 105a and the flat plate side electrode 117a. Similarly, a crystal side electrode 107b is formed on each of the pair of crystal castellations 106b, and the crystal side electrode 107b is connected to the extraction electrode 105b and the flat plate side electrode 117b, respectively.

  Further, as shown in FIG. 2, the crystal bonding surfaces M3 and M4 in the outer frame 102 of the crystal frame 10 and the plate bonding surfaces M2 of the pair of crystal plates 11 are bonded by the non-conductive sealing material SL. The crystal frame 10 and the pair of crystal flat plates 11 are joined. Here, low-melting glass or polyimide resin is used as the sealing material SL. Note that the low-melting glass or polyimide resin used as the sealing material SL is excellent in water resistance and moisture resistance, so that moisture in the air can be prevented from entering the cavity or deteriorating the degree of vacuum in the cavity. . The low melting point glass is a lead-free vanadium-based glass that melts at 350 to 400 ° C. Vanadium-based glass is in the form of a paste with a binder and a solvent added, and is bonded to other members by firing. The melting point of the vanadium glass is lower than the melting point of the quartz plate 11 made of a piezoelectric material or glass, and the vanadium glass has high reliability such as airtightness at the time of bonding, water resistance and moisture resistance. Furthermore, since the thermal expansion coefficient of vanadium glass can be controlled flexibly by controlling the glass structure, it is easy to adhere to various materials having different thermal expansion coefficients such as ceramics, glass, semiconductor, and metal.

  Note that it is desirable that the thickness W of the sealing material SL be larger than the thickness D of each electrode (for example, the excitation electrode) so as not to affect the vibration of the quartz crystal vibrating portion 101.

  Furthermore, the first crystal unit 100A has a connection electrode 118a and a connection electrode 118b on the outermost side. The connection electrode 118a covers all or a part of the external electrode 115a, the flat plate side electrode 117a, and the crystal side electrode 107a. The connection electrode 118b covers all or a part of the external electrode 115b, the flat plate side surface electrode 117b, and the crystal side surface electrode 107b. Thereby, the external electrodes 115a and 115b, the flat plate side surface electrodes 117a and 117b, and the crystal side surface electrodes 107a and 107b are reliably electrically connected.

  For example, as shown by the dotted line B, even if a situation in which the external electrode 115b and the flat plate side surface electrode 117b are not connected due to a manufacturing defect occurs, the connection electrode 118b is formed outside the external electrode 115b, The flat plate side electrode 117b can be reliably connected. Further, for example, as indicated by a dotted line C, when the crystal frame 10 and the crystal plate 11 on the −Y ′ side are joined, the sealing material SL leaks outside and covers a part of the crystal side surface electrode 107b. Even in this case, the flat plate side surface electrode 117b and the crystal side surface electrode 107b can be reliably connected by forming the connection electrode 118b outside them.

  Further, an alternating voltage (a potential alternating between positive and negative) is applied to the pair of external electrodes 115a and 115b and the connection electrodes 118a and 118b formed on the mounting surface M1 of the crystal plate 11 of the first crystal unit 100A. The external electrode 115a, the plate side electrode 117a, the connection electrode 118a, the crystal side electrode 107a, the extraction electrode 105a, and the excitation electrode 104a have the same polarity, and the external electrode 115b, the plate side electrode 117b, the connection electrode 118b, the crystal side electrode 107b, the extraction electrode 105b and the excitation electrode 104b have the same polarity.

<Method for Manufacturing First Crystal Resonator 100A>
FIG. 3 is a flowchart showing the manufacture of the first crystal unit 100A. In FIG. 3, the manufacturing step S10 of the crystal frame 10 and the manufacturing step S11 of the pair of crystal flat plates 11 can be performed separately and in parallel. 4 is a plan view of the quartz wafer 10W, and FIG. 5 is a plan view of the flat wafer 11W.

In step S10, the crystal frame 10 is manufactured. Step S10 includes steps S101 to S103.
In step S101, the outer shape of the plurality of crystal frames 10 is formed by etching on a uniform crystal wafer 10W (see FIG. 4). That is, the crystal vibrating portion 101, the outer frame 102, and the gap portion 103 are formed, and the circular through holes CH1 are formed at the four corners of each crystal frame 10 so as to penetrate the crystal wafer 10W as shown in FIG. Is done. When the circular through hole CH1 is divided into four, one castellation 106a or 106b (see FIG. 1) is obtained.

  In step S102, a chromium layer and a gold layer are sequentially formed on both surfaces of the quartz wafer 10W and the circular through hole CH1 by sputtering or vacuum deposition. Here, the thickness of the chromium layer as the base is, for example, 0.05 μm to 0.1 μm, and the thickness of the gold layer is, for example, 0.2 μm to 2 μm.

  In step S103, a photoresist is uniformly applied to the entire surface of the metal layer. Then, using an exposure apparatus (not shown), the patterns of the excitation electrodes 104a and 104b, the extraction electrodes 105a and 105b, and the crystal side electrodes 107a and 107b drawn on the photomask are exposed to the crystal wafer 10W. Next, the metal layer exposed from the photoresist is etched. As a result, as shown in FIGS. 1 and 2, excitation electrodes 104a and 104b and extraction electrodes 105a and 105b are formed on both surfaces of the quartz wafer 10W, and quartz side electrodes 107a and 107b are formed in the circular through hole CH1. .

In step S11, the crystal flat plate 11 is manufactured. Step S11 includes steps S111 to S113.
In step S111, first, two flat wafers 11W made of quartz and having the same shape are prepared. Then, circular through holes BH1 (see FIG. 5) are formed by etching so as to penetrate the flat plate wafer 11W at locations corresponding to the four corners of the crystal flat plate 11 of each flat plate wafer 11W. When the circular through hole BH1 is divided into four, one castellation 116a or 116b (see FIG. 1) is obtained.

  In step S112, a chromium layer and a gold layer are sequentially formed on the mounting surface M1 and the circular through hole BH1 of the flat wafer 11W by sputtering or vacuum deposition. Here, the thickness of the chromium layer as the base is, for example, 0.05 μm to 0.1 μm, and the thickness of the gold layer is, for example, 0.2 μm to 2 μm.

  In step S113, a photoresist is uniformly applied to the metal layer. Then, using an exposure apparatus (not shown), the patterns of the external electrodes 115a and 115b and the flat plate side surface electrodes 117a and 117b drawn on the photomask are exposed on the flat plate wafer 11W. Next, the metal layer exposed from the photoresist is etched. As a result, as shown in FIGS. 1 and 2, the external electrodes 115a and 115b are formed on the mounting surface M1 of the flat wafer 11W, and the flat plate side electrodes 117a and 117b are formed in the circular through hole BH1.

  In step S12, the sealing material SL made of low-melting glass or polyimide resin is uniformly formed on both surfaces of the outer frame 102 of the crystal wafer 10W. For example, when the sealing material SL is a low melting point glass, the low melting point glass is formed on both surfaces of the outer frame 102 of the crystal wafer 10W by screen printing. Here, a woven fabric such as nylon, tetron or stainless steel is used as the screen. When the sealing material SL is a polyimide resin, the polyimide resin is formed on both surfaces of the outer frame 102 by applying the polyimide resin to both surfaces of the outer frame 102 and then pre-baking. At this time, the temporary firing temperature may be about 250 ° C. (about 75% of the complete firing temperature).

  In step S13, the quartz wafer 10W and the two flat wafers 11W are overlaid. As shown in FIG. 4, an orientation flat OF is formed on a part of the peripheral part of the quartz wafer 10W, and an orientation flat is formed on a part of the peripheral part of the two flat wafers 11W as shown in FIG. OF is formed. Therefore, the crystal wafer 10W and the two flat wafers 11W are precisely overlapped with the orientation flat OF as a reference. Then, the sealing material SL is heated to about 350 ° C. to 400 ° C., and the quartz wafer 10W and the two flat wafers 11W are pressed. By this step, the quartz wafer 10W and the two flat wafers 11W are bonded.

  In step S14, the connection electrode 118a and the connection electrode 118b are formed on the outermost side.

  In step S15, a process of cutting the bonded quartz wafer 10W and the two flat wafers 11W in units of the first quartz oscillator 100A is performed. In the cutting process, the first crystal unit 100A is unitized along the dashed line cut line CL shown in FIGS. 4 and 5 using a dicing apparatus using a laser or a dicing apparatus using a cutting blade. As a piece. As a result, the first crystal unit 100A adjusted to hundreds to thousands of accurate frequencies is manufactured.

(Second Embodiment)
<Second crystal unit 100B>
The second crystal unit 100B will be described with reference to FIG. FIG. 6 is an exploded perspective view of the second crystal unit 100B. In FIG. 6, connection electrodes (see FIG. 2) are omitted.
The second crystal unit 100B and the first crystal unit 100A have different connecting portions. The same components as those in the first embodiment will be described with the same reference numerals.

  As shown in FIG. 6, the second crystal unit 100 </ b> B includes a pair of crystal plates 11 having the same shape and a crystal frame 20 sandwiched between the pair of crystal plates 11.

  The crystal frame 20 is formed of an AT-cut crystal material and has a + Y′-side crystal bonding surface M3 and a −Y′-side crystal bonding surface M4. The crystal frame 20 includes a crystal vibrating part 101 and an outer frame 202 surrounding the crystal vibrating part 101. Further, a pair of connecting portions 209 a and 209 b connected to the outer frame 202 so as to extend from the crystal vibrating portion 101 along both sides in the Z′-axis direction are provided between the crystal vibrating portion 101 and the outer frame 202. ing. For this reason, two “L” -shaped gap portions 203 are formed between the crystal vibrating portion 101 and the outer frame 202. Further, an extraction electrode 205a is formed on the crystal bonding surface M3 of the coupling portion 209a, and an extraction electrode 205a connected to the crystal side surface electrode 107a of the crystal castellation 106a is formed from the excitation electrode 104a, and the excitation electrode 104b is formed on the crystal bonding surface M4 of the coupling portion 209b. A lead electrode 205b connected to the crystal side electrode 107b of the lead crystal castellation 106b is formed.

  Further, in the second crystal unit 100B, the extraction electrode 205a connected to the excitation electrode 104a and the extraction electrode 205b connected to the excitation electrode 104b respectively extend from the crystal oscillation unit 101 along both sides in the Z′-axis direction and are separately provided. The crystal side electrodes 107a and 107b in the vicinity thereof are connected. Therefore, the extraction electrodes 205a and 205b are formed shorter, and the excitation electrode, the crystal side surface electrode, and the flat plate side surface electrode can be more reliably connected.

<Method for Manufacturing Second Crystal Resonator 100B>
The manufacturing method of the second crystal unit 100B shown in FIG. 6 is the same as the flowchart of FIG. 3 described in the first embodiment. However, in step S101 in which the outer shape of the crystal frame 20 is formed by etching, two “L” -shaped gaps 203 are formed in each crystal frame 20, and in step S103, the extraction electrodes 205a and 205b are formed by photolithography and etching. Then, the extraction electrodes 205a and 205b having the shape shown in FIG. 6 are formed.

(Third embodiment)
<Overall Configuration of Third Crystal Resonator 100C>
The overall configuration of the third crystal unit 100C will be described with reference to FIG.
FIG. 7 is an exploded perspective view of the third crystal resonator 100C. In FIG. 7, connection electrodes (see FIG. 2) are omitted.
The third crystal resonator 100C and the second crystal resonator 100B have different castellation shapes. Moreover, the same code | symbol is attached | subjected and demonstrated to the same component as 2nd Embodiment.

  As shown in FIG. 7, the third crystal unit 100 </ b> C includes a pair of crystal plates 31 having the same shape and a crystal frame 30 sandwiched between the pair of crystal plates 31. Further, by bonding a pair of crystal plates 31 to both surfaces of the crystal frame 30 in nitrogen gas or in vacuum, a cavity CT sealed with nitrogen gas or vacuum by the pair of crystal plates 31 and crystal frame 30 (FIG. 2). Are formed).

  In the pair of quartz plates 31, a pair of external electrodes 315a and 315b are respectively formed on the mounting surface M1 of the quartz plate 31, and rounded rectangular through holes BH2 (see FIG. 9) are formed on both sides in the Z′-axis direction of the quartz plate 31. A pair of flat plate castellations 316a and 316b are formed. Further, a flat plate side electrode 317a connected to the external electrode 315a is formed on the flat plate castellation 316a, and a flat plate side electrode 317b connected to the external electrode 315b is formed on the flat plate castellation 316b.

  The crystal frame 30 includes an outer frame 302 that surrounds the crystal vibration unit 101. In addition, extraction electrodes 305a and 305b that are electrically connected to the excitation electrodes 104a and 104b are formed on both surfaces of the outer frame 302, respectively. Further, crystal castellations 306a and 306b when rounded rectangular through holes CH2 (see FIG. 8) are formed are formed on both sides of the crystal frame 30 in the Z′-axis direction. In addition, the pair of crystal castellations 306a and 306b are respectively connected to the extraction electrodes 305a and 305b, and at the same time, the crystal side electrodes 307a connected to the plate side electrodes 317a and 317b formed on the upper and lower crystal plates 11, respectively. , 307b are formed.

<Method for Manufacturing Third Crystal Resonator 100C>
The manufacturing method of the third crystal unit 100C shown in FIG. 7 is the same as the flowchart of FIG. 3 described in the first embodiment. However, only the shapes of the rounded rectangular through hole CH2 and the rounded rectangular through hole BH2 according to the manufacturing step S10 of the crystal frame 30 and the manufacturing step S11 of the crystal flat plate 31 are different. FIG. 8 is a plan view of the quartz wafer 30W, and FIG. 9 is a plan view of the flat wafer 31W.

  In step S10, the crystal frame 30 is manufactured. In addition, when the outer shape of the plurality of crystal frames 30 is formed by etching, a rounded rectangle or a rectangular shape so as to penetrate the crystal wafer 30W as shown in FIG. 8 on both sides in the Z′-axis direction of each crystal frame 30 An elliptical rounded rectangular through hole CH2 is formed. Here, half of the rounded rectangular through hole CH2 becomes one castellation 306a or 306b (see FIG. 7).

  In step S11, the crystal flat plate 31 is manufactured. Note that, as shown in FIG. 9, rounded rectangular or elliptical rounded rectangular through holes BH <b> 2 are formed on both sides of each crystal flat plate 31 in the Z′-axis direction so as to penetrate the flat plate wafer 31 </ b> W. Here, half of the rounded rectangular through hole BH2 becomes the respective castellation 316a or 316b (see FIG. 7).

(Fourth embodiment)
<Overall Configuration of Fourth Crystal Resonator 100D>
The overall configuration of the fourth crystal unit 100D will be described with reference to FIG.
FIG. 10 is an exploded perspective view of the fourth crystal unit 100D, and the connection electrodes 118a and 118b (see FIG. 11) are omitted. FIG. 11 is a side view of the fourth crystal resonator 100D. Moreover, the same code | symbol is attached | subjected and demonstrated to the same component as 2nd Embodiment.

  As shown in FIG. 10, the fourth crystal unit 100D is formed with eight protrusions 108 in the vicinity of, for example, the four corners of both sides of the crystal frame 40, as compared with the second piezoelectric unit 100B described in the second embodiment. Has been. In the first to third embodiments, the thickness W of the sealing material SL is made larger than the thickness D of the excitation electrode so as not to affect the vibration of the crystal vibrating portion 101. However, eight protrusions 108 are formed in order to ensure that the thickness W of the sealing material SL is larger than the thickness D of the excitation electrode. In the fourth embodiment, the truncated cone-shaped protrusion 108 is used, but it may be in the shape of a cylinder, a polyhedral column, or a truncated pyramid.

  Use of the sealing material SL so that when the crystal frame 40 and the two crystal flat plates 11 are bonded, the crystal flat plate 11 hits the protrusion 108 formed on the crystal frame 40 and can be sufficiently bonded by the sealing material SL. It is preferable to make the amount larger. For example, the thickness of the sealing material SL before joining is made larger than the height H of the protrusions 108. At this time, even if the sealing material SL covers a part of the crystal side electrodes 107a and 107b formed on the crystal castellations 106a and 106b, the connection electrodes 118a and 118b are formed outside the crystal side electrodes 107a and 107b. Therefore, the crystal side surface electrodes 107a and 107b can be reliably connected to the flat plate side surface electrodes 117a and 117b (see the portion indicated by the dotted line C in FIG. 2).

  In the fourth embodiment, four protrusions 108 are formed on the crystal bonding surfaces M3 and M4 of the crystal frame 40, but three protrusions 108 may be formed on the crystal bonding surfaces M3 and M4, or five or more. It may be formed. The protrusions 108 are also formed at the same position on the crystal bonding surface M4 corresponding to the protrusions 108 formed on the crystal bonding surface M3, but the number of protrusions formed on the crystal bonding surface M3 and the crystal bonding surface M4 Or a position does not need to correspond. For example, three protrusions may be formed on the crystal bonding surface M3, and five protrusions may be formed on the crystal bonding surface M4 at positions different from the protrusions of the crystal bonding surface M3.

<Method for Manufacturing Fourth Crystal Resonator 100D>
The manufacturing method of the fourth crystal unit 100D shown in FIGS. 10 and 11 is almost the same as the manufacturing method of the second crystal unit 100B described in the second embodiment. However, in step S101 of the flowchart of FIG. 3 for forming the outer shape of the crystal frame 40, the crystal vibrating portion 101, the connecting portions 209a and 209b, and the crystal castellations 106a and 106b at the four corners are simultaneously formed by etching, and at the same time, the eight protrusions 108 are formed. An outer frame 402 is formed.

(Fifth embodiment)
<Overall Configuration of Fifth Crystal Resonator 100E>
The overall configuration of the fifth crystal unit 100E will be described with reference to FIG.
FIG. 12 is a cross-sectional view of the fifth crystal unit 100E.

  As shown in FIG. 12, the fifth crystal unit 100 </ b> E includes a pair of crystal plates 51 having the same shape, and a crystal frame 10 sandwiched between the pair of crystal plates 51. The fifth crystal unit 100E is not provided with connection electrodes 118a and 118b (see FIG. 2) as compared to the first crystal unit 100A described in the first embodiment.

  In the fifth embodiment, the external electrodes 515a and 515b are arranged from the mounting surface M1 of the crystal flat plate 51 on the + Y ′ side to the flat plate castellations 116a and 116b of the crystal flat plate 51, the crystal castellations 106a and 106b of the crystal frame 10, and −. The flat plate castellations 116 a and 116 b of the crystal plate 51 on the Y ′ side are crossed to the mounting surface M 1 of the crystal plate 51.

  According to such a configuration, for example, when the crystal frame 10 and the crystal plate 51 on the −Y ′ side are joined as shown by the dotted line C, the sealing material SL leaks to the outside and the crystal side surface electrode 107b becomes one. Even when the parts are covered, the external electrode 515b and the crystal side surface electrode 107b can be reliably connected by forming the external electrode 515b on the outside thereof. That is, the external electrodes 515a and 515b can be reliably connected to the excitation electrodes 104a and 104b connected to the crystal side electrodes 107a and 107b.

<Manufacturing Method of Fifth Crystal Resonator 100E>
FIG. 13 is a flowchart showing the manufacture of the fifth crystal unit 100E. In FIG. 13, the same steps as those in the manufacturing method of the first crystal unit 100 </ b> A described in FIG. 3 of the first embodiment will be described with the same reference numerals. Further, in the flowchart of FIG. 13, the manufacturing step S10 of the crystal frame 10 and the manufacturing step T11 of the pair of crystal flat plates 51 can be performed separately in parallel.

  As in the first embodiment, the crystal frame 10 is manufactured in step S10, and includes steps S101 to S103.

  In step T11, the crystal flat plate 51 is manufactured. Step T11 includes the same steps S111 and S112 as in the first embodiment.

In step S12, the sealing material SL made of low-melting glass or polyimide resin is uniformly formed on both surfaces of the outer frame 102 of the crystal wafer 10W (see FIG. 4).
In step S13, the quartz wafer 10W and the two flat wafers 11W are bonded by the sealing material SL.

  In step T14, a portion of the mounting surface M1 (see FIG. 12) of the crystal flat plate 51 and the circular through hole BH1 (see FIG. 5) of the flat plate wafer 11W and the crystal wafer 10W are etched by using a photoresist. External electrodes 515a and 515b are formed so as to cover the crystal side electrodes 107a and 107b formed in the circular through hole CH1 (see FIG. 4).

  In step S15, a step of cutting the fifth crystal unit 100E as a unit is performed. As a result, the fifth crystal unit 100E adjusted to an accurate frequency of hundreds to thousands is manufactured.

(Sixth embodiment)
<Overall Configuration of Sixth Crystal Resonator 100F>
The overall configuration of the sixth crystal unit 100F will be described with reference to FIG.
FIG. 14 is a cross-sectional view corresponding to the AA cross section of FIG. 1 in the sixth crystal unit 100F.

  As shown in FIG. 14, the sixth crystal unit 100 </ b> F includes a pair of crystal plates 11 having the same shape, and a crystal frame 60 sandwiched between the pair of crystal plates 11. Here, in the sixth crystal unit 100F, the same constituent elements as those in the first embodiment will be described with the same reference numerals.

  In the crystal resonators described in the first to fifth embodiments, since the pair of crystal flat plates and the crystal frame are flat plates, the sealing material SL is used so as not to affect the vibration of the crystal vibrating portion 101. Alternatively, the protrusion 108 needs to have a certain thickness or height. Correspondingly, the crystal frame 60 of the sixth crystal unit 100F of the sixth embodiment is an inverted mesa type in which the crystal vibrating part 601 is configured to be thinner than the outer frame 102.

  Even if the pair of crystal flat plates 11 and the outer frame 102 of the crystal frame 60 are in close contact with each other, the crystal frame 60 has an inverted mesa shape, and therefore, it is necessary to make the thickness of the sealing material SL larger than the thickness of the excitation electrode. Absent. Even if the sealing material SL is thin, the flat plate bonding surface M2 does not contact the crystal vibrating part 101, and therefore the sixth crystal unit 100F vibrates at an accurate frequency.

<Manufacturing Method of Sixth Crystal Resonator 100F>
The manufacturing method of the sixth crystal unit 100F shown in FIG. 14 is the same as the flowchart of FIG. 3 described in the first embodiment. However, in step S101 for forming the outer shape of the crystal frame described with reference to the flowchart of FIG. 3, the inverted mesa crystal frame 60 is formed by etching the crystal vibrating portion 601 more than in the first embodiment.

  As described above, the optimal embodiment of the present invention has been described in detail. 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. For example, the present invention can be applied to a piezoelectric oscillator in which an IC or the like incorporating an oscillation circuit is disposed on the base portion in addition to the piezoelectric vibrator. In this specification, the AT-cut type piezoelectric vibrating piece is described as an example, but the present invention can also be applied to a tuning-fork type piezoelectric vibrating piece having a pair of vibrating arms. Further, the pair of quartz plates 11 may be formed of a piezoelectric body or glass other than quartz.

10 to 40, 60 ... crystal frame 10W, 30W ... crystal wafer 11, 31, 51 ... crystal plate 11W, 31W ... plate wafer,
100A to 100F: Crystal resonators 101, 601: Crystal vibrating portions 102, 202, 302, 402 ... Outer frame 103, 203 ... Gap portions 104a, 104b ... Excitation electrodes 105a, 105b, 205a, 205b, 305a, 305b, 605a, 605b ... Extraction electrode 106a, 106b, 306a, 306b, 116a, 116b, 316a, 316b ... Castellation 107a, 107b, 307a, 307b, 117a, 117b, 317a, 317b ... Side electrode 108 ... Projection 118a, 118b ... Connection electrode BH , CH ... Through hole CL ... Cut line CT ... Cavity D ... Electrode thickness H ... Protrusion height M1 ... Mounting surface, M2 ... Flat plate bonding surface, M3, M4 ... Quartz bonding surface SL ... Sealing material W ... Sealing Stopping material thickness

Claims (14)

A plurality of piezoelectric frames each including a piezoelectric vibrating piece having one main surface and another main surface and an outer frame surrounding the piezoelectric vibrating piece and supporting the piezoelectric vibrating piece; Preparing a piezoelectric wafer having at least a pair of first through holes penetrating from a main surface to the other main surface;
A pair of excitation electrodes are formed on the one main surface and the other main surface, and formed on a pair of extraction electrodes and the first through holes respectively drawn from the pair of excitation electrodes to the pair of first through holes. A first electrode forming step of forming a first side electrode connected to the extraction electrode;
A plurality of flat plates having a first surface and a second surface opposite to the first surface are included, and at least a pair of second through holes penetrating from the first surface to the second surface is formed between the adjacent flat plates. Preparing two flat plate wafers,
A second electrode forming step of forming a pair of external electrodes on the first surface and forming a second side electrode in the second through hole;
Between the one main surface of the outer frame and one of the second surfaces of the flat wafer, and between the other main surface of the outer frame and the other second surface of the flat wafer, A sealing material arranging step of arranging a conductive sealing material in an annular shape;
A bonding step of bonding the two flat wafers to the first main surface and the second main surface of the piezoelectric wafer, respectively, with the sealing material;
After the joining step, a third connection electrode is formed on the first surface, the first through hole, and the second through hole so as to connect the first side electrode, the second side electrode, and the external electrode. An electrode forming step;
A method of manufacturing a piezoelectric vibration device comprising: A plurality of piezoelectric frames each having a piezoelectric vibrating piece having one main surface and another main surface and an outer frame surrounding the piezoelectric vibrating piece and supporting the piezoelectric vibrating piece; Preparing a piezoelectric wafer in which at least a pair of first through holes penetrating from a surface to the other main surface is formed;
A pair of excitation electrodes are formed on the one main surface and the other main surface, and formed on a pair of extraction electrodes and the first through holes respectively drawn from the pair of excitation electrodes to the pair of first through holes. A first electrode forming step of forming a first side electrode connected to the extraction electrode;
A plurality of flat plates having a first surface and a second surface opposite to the first surface are included, and at least a pair of second through holes penetrating from the first surface to the second surface is formed between the adjacent flat plates. Preparing two flat plate wafers,
Between the one main surface of the outer frame and one of the second surfaces of the flat wafer, and between the other main surface of the outer frame and the other second surface of the flat wafer, A sealing material arranging step of arranging a conductive sealing material in an annular shape;
A bonding step of bonding the two flat wafers to the first main surface and the second main surface of the piezoelectric wafer, respectively, with the sealing material;
After the joining step, a pair of external electrodes are formed on the first surface, a second side electrode is formed on the second through hole, and a connection electrode that connects the second side electrodes to the first through hole is formed. A fourth electrode forming step to be formed;
A method of manufacturing a piezoelectric vibration device comprising:   The method of manufacturing a piezoelectric vibration device according to claim 1, wherein the sealing material includes a glass film or a polyimide resin adhesive.   When viewed from the direction from the one main surface to the other main surface, the outer periphery of the outer frame and the outer periphery of the flat plate are quadrangular, and the first through hole and the second through hole are formed at corners of the quadrangle. The manufacturing method of the piezoelectric vibration device as described in any one of Claim 1 to 3 performed.   When viewed from the direction from the one main surface to the other main surface, the outer periphery of the outer frame and the outer periphery of the flat plate are square, and the first through hole and the second through hole are formed on the sides of the square. The manufacturing method of the piezoelectric vibration device as described in any one of Claims 1-3.   The step of preparing the piezoelectric wafer forms a predetermined gap between the piezoelectric vibrating piece and the two flat plates when the piezoelectric vibrating piece and the two flat plates are joined. 6. The method for manufacturing a piezoelectric vibration device according to claim 1, wherein protrusions are formed on the one main surface and the other main surface of a frame. 7. A piezoelectric vibrating piece having a pair of excitation electrodes formed on one main surface and the other main surface, an outer frame surrounding the piezoelectric vibrating piece, and a side surface of the outer frame drawn from the pair of excitation electrodes A piezoelectric frame having a pair of extending extraction electrodes, and a first side electrode formed on a first side surface connecting the one main surface and the other main surface;
A first surface and a second surface opposite to the first surface; the external electrode formed on the first surface; and the second surface formed on the second side surface connecting the first surface and the second surface. Two flat plates of the same structure having two side electrodes;
A non-conductive sealing material disposed in an annular shape so as to go around the one main surface and the other main surface of the outer frame,
With the sealing material, one of the second surfaces of the flat plate is bonded to the one main surface of the frame, and the other second surface of the flat plate is bonded to the other main surface of the frame,
A pair of external electrodes is formed on the first surface of the two flat plates,
The pair of excitation electrodes are piezoelectric vibration devices that are electrically connected to the first side electrode, the second side electrode, and the external electrode, respectively.   The piezoelectric vibration device according to claim 7, wherein the sealing material includes a glass film or a polyimide resin adhesive. When viewed from the direction from the one main surface to the other main surface, the outer periphery of the outer frame and the outer periphery of the flat plate are quadrangular, and a castellation that is depressed at the corner of the quadrangle is formed,
The piezoelectric vibration device according to claim 7 or 8, wherein the first and second side electrodes are formed on the castellation. When viewed from the direction from the one main surface to the other main surface, the outer periphery of the outer frame and the outer periphery of the flat plate are quadrangular, and a castellation that is depressed on the side of the quadrangle is formed,
The piezoelectric vibration device according to claim 7 or 8, wherein the first and second side electrodes are formed on the castellation.   In order to form a predetermined gap between the piezoelectric vibrating piece and the two flat plates when the piezoelectric vibrating piece and the two flat plates are joined, the one main surface of the outer frame and the other The piezoelectric vibration device according to any one of claims 7 to 10, wherein a protrusion is formed on the main surface.   The piezoelectric vibrating device according to any one of claims 7 to 11, wherein a thickness of the sealing material is larger than a thickness of the excitation electrode or the extraction electrode.   The piezoelectric vibration device according to claim 11, wherein the height of the protrusion is thicker than the thickness of the excitation electrode or the extraction electrode.   14. The piezoelectric vibration device according to claim 7, wherein the extraction electrode is extracted from the piezoelectric vibration piece in different directions.