JP2010041550A - Piezoelectric device and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for preventing gas generated from a sealing material during melting from being left in a package of a piezoelectric device.
A method of manufacturing a piezoelectric device includes a first bonding step (S11) for bonding a wafer for a piezoelectric frame having a vibrating piece and an outer frame portion surrounding the vibrating piece and a base wafer having a through hole in the atmosphere. ), A sealing step (S12) for sealing the through-hole with a filler in the atmosphere, and a second bonding step (S13) for bonding the lid wafer to the piezoelectric frame in a vacuum or in an inert atmosphere, A dicing step (S14) for dicing the bonded piezoelectric frame wafer, base wafer, and lid wafer.
[Selection] Figure 5

Description

  The present invention relates to a piezoelectric device in which a piezoelectric vibrating piece is arranged in a package, and a method for manufacturing the piezoelectric device.

  Conventionally, as mobile communication devices, OA devices, and the like become smaller and lighter and have higher frequencies, piezoelectric vibrators used for them have been required to respond to further miniaturization and higher frequencies.

Conventionally, a piezoelectric vibrator is formed by applying a brazing material on a joint surface between a lid made of metal, glass or ceramic and a package member and superimposing them, and then melting the brazing material by heating in a vacuum or an inert gas. Sealing is performed. As such a piezoelectric vibrator, for example, one described in Patent Document 1 is known.
JP 2006-042096 A

  The piezoelectric vibrator disclosed in Patent Document 1 closes a sealing through hole (through hole) with a sealing material (solder material) or the like when bonding package members. Gas generated in the process of melting the sealing material or the like may be adsorbed by the piezoelectric vibrating piece. For this reason, variation has occurred in the vibration frequency. Further, when sealing the through hole, there is a concern that the gas generated from the sealing material at the time of melting is left in the package, thereby impairing the long-term stability of the piezoelectric vibrator.

  Furthermore, in Patent Document 1, since the crystal resonator is mounted on a package member made of a ceramic base material, the work efficiency of efficiently producing each piezoelectric resonator is poor. In other words, in the work of sealing the through holes of the package, the work time required to input the sealing material that fills a large number of through holes provided in each package is a bottleneck for improving work efficiency.

  Accordingly, an object of the present invention is to provide a piezoelectric device that can obtain long-term stability without causing variation in the vibration frequency of the resonator element by preventing the gas generated from the sealing material during melting from being left in the package. Is to provide.

A piezoelectric device according to a first aspect includes a piezoelectric frame having a vibrating piece on which an excitation electrode is formed, an outer frame portion that surrounds the vibrating piece and is connected to the excitation electrode, and an outer frame portion of the piezoelectric frame. An outer frame frame joined to one surface of the outer frame portion in a shape corresponding to the above, a lid joined to the surface of the outer frame frame, and a connection terminal joined to the other surface of the outer frame portion and connected to the connection electrode And a base having an external terminal formed on the opposite surface of the connection terminal, and a through-hole wiring connecting the connection terminal and the external terminal.
Since the outer frame is provided, the lid can be finally joined to the surface of the outer frame.

According to a second aspect of the present invention, there is provided a piezoelectric device comprising: a resonator element having an excitation electrode; a piezoelectric frame having a connection electrode surrounding the resonator element and connected to the excitation electrode; A lid joined to one surface of the outer frame portion of the frame; a connection terminal joined to the other surface of the outer frame portion and connected to the connection electrode; an external terminal formed on the opposite surface of the connection terminal; and a connection terminal And a base having through-hole wiring connecting the external terminal and the external terminal.
Since the piezoelectric frame has a thick outer frame portion, the lid can be finally bonded to one surface of the outer frame portion of the piezoelectric frame.

The through-hole wiring of the piezoelectric device according to the third aspect is formed by sealing a through-hole formed with a gold (Au) layer with a filler of gold (Au) and another metal.
The connection electrode and the excitation electrode of the piezoelectric device according to the fourth aspect are composed of a base layer made of chromium or nickel and a gold (Au) layer formed on the surface of the base layer.

According to a fifth aspect of the present invention, there is provided a piezoelectric device manufacturing method comprising: a first bonding step of bonding a wafer for a piezoelectric frame having a vibrating piece and an outer frame portion surrounding the vibrating piece, and a base wafer having a through hole in the atmosphere; A sealing step of sealing the through hole with a filler in the atmosphere, a second bonding step of bonding the lid wafer to the piezoelectric frame in a vacuum or in an inert atmosphere, a bonded piezoelectric frame wafer, A dicing step of dicing the base wafer and the lid wafer.
The gas generated in the process of melting the sealing material is released to the atmosphere, and the final packaging process is performed in a vacuum or in an inert atmosphere, so the gas generated from the sealing material is adsorbed to the vibrating piece. There is nothing.

A method for manufacturing a piezoelectric device according to a sixth aspect, wherein a base wafer and an outer frame having a through hole so as to sandwich a piezoelectric frame wafer having a vibrating piece and an outer frame portion surrounding the vibrating piece in the atmosphere A first joining step for joining with the outer frame frame corresponding to the part, a sealing step for sealing the through hole with a filler in the atmosphere, and a flat lid on the outer frame frame in a vacuum or in an inert atmosphere A second bonding step of bonding a wafer for use.
The gas generated in the process of melting the sealing material or the like is released into the atmosphere, and the final packaging process is performed in a vacuum or in an inert atmosphere. Further, since the lid wafer is flat, it can be easily handled in a vacuum or in an inert atmosphere.

In the piezoelectric device manufacturing method according to the seventh aspect, the base wafer and the piezoelectric frame wafer are made of quartz material, and the first bonding step is siloxane bonding.
In the piezoelectric device manufacturing method according to the eighth aspect, the lid wafer is a quartz material or a glass material, and the second bonding is a siloxane bond or anodic bonding.

  The method for manufacturing a piezoelectric device of the present invention can manufacture a piezoelectric device that can obtain long-term stability without causing variations in vibration frequency, and has good work efficiency.

<First Embodiment: Configuration of First Crystal Resonator 100>
Hereinafter, the 1st crystal oscillator 100 concerning each embodiment of the present invention is explained with reference to drawings. FIG. 1 shows a schematic diagram of a first crystal unit 100 according to the first embodiment of the present invention.
FIG. 1A is a perspective view of the divided first crystal unit 100 as viewed from the lid part side of the lid 10. FIG. 1B is a cross-sectional configuration diagram of the first crystal unit 100 taken along the line AA in FIG.

  As shown in FIGS. 1 (a) and 1 (b), the first crystal unit 100 includes an uppermost first lid 10, a first outer frame 20, a first piezoelectric frame 50, and a lowermost first lid. 1 base 40 is comprised. The first lid 10, the first outer frame 20, the first piezoelectric frame 50, and the first base 40 are made of a quartz material. The first piezoelectric frame 50 has a tuning-fork type crystal vibrating piece 30 formed by etching.

  In the first crystal unit 100, a first piezoelectric frame 50 having a tuning fork type crystal vibrating piece 30 is sandwiched around the first piezoelectric frame 50, and the first outer frame 20 is joined to the first piezoelectric frame 50. The first base 40 is joined under the piezoelectric frame 50. Further, the first lid 10 is joined on the first outer frame frame 20 to form a package 90. That is, the first lid 10 is bonded to the first outer frame 20, the first piezoelectric frame 50 is bonded to the first outer frame 20, and the first base 40 is bonded to the first piezoelectric frame 50 by siloxane bonding (Si—O—Si). It is the structure which seals.

  The first lid 10 has a flat plate shape. The first outer frame frame 20 has an outer frame portion 21, and a space portion 22 is formed. The space 22 that defines the inner shape is formed by crystal etching.

  The first piezoelectric frame 50 has a so-called tuning-fork type crystal vibrating piece 30 at the center and an outer frame portion 51 on the outside, and between the tuning-fork type crystal vibrating piece 30 and the outer frame portion 51. A space 52 is formed. The space 52 that defines the outer shape of the tuning-fork type crystal vibrating piece 30 is formed by crystal etching. The tuning-fork type crystal vibrating piece 30 has the same thickness as the outer frame portion 51. The tuning fork type crystal vibrating piece 30 includes a base portion 32 and a pair of vibrating arms 31 extending from the base portion 32. The base portion 32 and the outer frame portion 51 are integrally formed. The first base electrode 33 and the second base electrode 34 are formed on the first main surface of the base 32 and the outer frame portion 51, and the first base electrode 33 and the second base electrode 34 are similarly formed on the second main surface. Is formed.

  The first base 40 includes a base recess 47 on the first piezoelectric frame 50 side. The first base 40 forms a first through hole 41, a second through hole 43, and a stepped portion 49. A first connection electrode 42 and a second connection electrode 44 connected to the first through hole 41 and the second through hole 43 are formed in the stepped portion 49. The first base 40 includes a first external electrode 45 and a second external electrode 46 on the bottom surface.

  A metal film is formed on the inner surface of the first through hole 41 and the second through hole 43. The metal film on the inner surface is formed by a photolithography process simultaneously with the first connection electrode 42 and the second connection electrode 44, and the first external electrode 45 and the second external electrode 46. The metal film is composed of two layers, and a gold (Au) layer of 400 angstroms to 2000 angstroms is formed on a nickel (Ni) layer of 150 angstroms to 700 angstroms. Instead of a nickel (Ni) layer, a chromium (Cr) layer or a titanium (Ti) layer may be used.

  The first connection electrode 42 is electrically connected to the first external electrode 45 provided on the first base 40 through the first through hole 41. The second connection electrode 44 is electrically connected to the second external electrode 46 provided on the first base 40 through the second through hole 43.

  In the first crystal unit 100, the package 90 is formed by bonding the first lid 10, the first outer frame frame 20, the first piezoelectric frame 50, and the first base 40. That is, the first base electrode 33 is electrically joined to the first external electrode 45 of the first base 40, and the second base electrode 34 is electrically joined to the second external electrode 46 of the first base 40.

  FIG. 2 shows a schematic diagram of the first crystal unit 100. 2A is a top view of the first lid 10, FIG. 2B is a top view of the first outer frame frame 20, and FIG. 2C is a top view of the first piezoelectric frame 50. () Is a top view of the first base 40, and (e) is a schematic cross-sectional view showing the first crystal unit 100 in the AA cross section from (a) to (d). In FIG. 2, the description overlapping with FIG. 1 is omitted.

  As shown in FIG. 2A, the first lid 10 has a flat plate shape. As shown in FIG. 2B, the first outer frame frame 20 has an outer frame portion 21, and a space portion 22 that defines an inner shape is formed.

  As shown in FIG. 2C, the first piezoelectric frame 50 includes a tuning fork type crystal vibrating piece 30 and an outer frame portion 51. The tuning fork type crystal vibrating piece 30 includes a first excitation electrode 35 and a second excitation electrode 36 formed on a first main surface and a second main surface. The first excitation electrode 35 includes a base portion 32 and an outer frame portion 51. The second excitation electrode 36 is connected to the second base electrode 34 formed on the base 32 and the outer frame portion 51. Further, a weight portion 37 and a weight portion 38 are formed at the tip of the vibrating arm 31 of the crystal vibrating piece 30. The first base electrode 33 and the second base electrode 34, the first excitation electrode 35 and the second excitation electrode 36, the weight portion 37 and the weight portion 38 are simultaneously formed by a photolithography process. When a voltage is applied to these, the crystal vibrating piece 30 vibrates at a predetermined frequency. The weight part 37 and the weight part 38 are weights for the vibration arm 31 of the crystal vibrating piece 30 to easily vibrate and are provided for frequency adjustment.

  As shown in FIG. 2D, the first base 40 is formed with a first through hole 41 and a second through hole 43, a base concave portion 47 and a stepped portion 49 by etching. The first base 40 includes a first connection electrode 42 and a second connection electrode 44 at a stepped portion 49, and a first external electrode 45 and a second external electrode 46 on the back surface. The first connection electrode 42, the second connection electrode 44, the first external electrode 45, and the second external electrode 46 are created by a photolithography process.

  The first outer frame frame 20, the first piezoelectric frame 50, and the first base 40 are bonded by siloxane bonding in the first bonding step. Siloxane bonds are obtained by irradiating the contact surfaces of the first base 40 and the first outer frame frame 20 with ultraviolet rays having a short wavelength in an oxygen-containing atmosphere around the first piezoelectric frame 50 including the tuning-fork type crystal vibrating piece 30. Make it clean. Then, they are overlapped and bonded by pressing in a high-temperature tank (not shown) maintained at 350 ° C. to 450 ° C.

  The first outer frame frame 20, the first piezoelectric frame 50, and the first base 40, which have completed the siloxane bond in the first bonding step, are placed with the bottom surface of the first base 40 facing upward, and the first through holes are placed. 41 and the second through hole 43 are filled with a sealing material 48 formed in a spherical shape, and the sealing material 48 is melted by heating or the like to seal the first through hole 41 and the second through hole 43.

  The eutectic alloy of the sealing material 48 includes any one of a gold tin (Au20Sn) alloy having a melting point of 280 ° C, a gold germanium (Au12Ge) alloy having a melting point of 356 ° C, or a gold silicon (Au3.15Si) alloy having a melting point of 363 ° C. Used.

  In the second bonding step, the contact surface of the first outer frame frame 20 and the contact surface of the first lid 10 that have finished siloxane bonding in the first bonding step are irradiated with a short wavelength ultraviolet ray in an oxygen-containing atmosphere to be cleaned. Overlay in the state. The first base frame 20 with the siloxane-bonded first outer frame 20, the first piezoelectric frame 50, and the through-hole sealed is fixed by a vacuum reflow furnace (not shown) in a state where the first base 10 is overlapped with the first lid 10. The siloxane bonding is performed by heating for a period of time in a vacuum or in an inert atmosphere. Due to the siloxane bond, the first crystal unit 100 in which the inside of the package 90 is evacuated or filled with an inert gas is completed. Since packaging is performed by siloxane bonding, it is not necessary to use a bonding material for packaging. Further, since the first through hole 41 and the second through hole 43 are already sealed with the sealing material 48, no gas is generated from the bonding material and the sealing material 48.

  Furthermore, if the first lid 10 is siloxane bonded to the first outer frame frame 20, the first piezoelectric frame 50, and the first base 40 bonded with siloxane, there is an influence of the generation of gas generated from the bonding material and the sealing material 48. As a result, variation in the vibration frequency of the tuning-fork type crystal vibrating piece 30 is reduced, and the first crystal unit 100 with high accuracy can be produced.

  As shown in the schematic cross-sectional view of FIG. 2 (e), the first crystal unit 100 includes the first lid 10, the first outer frame 20, the first piezoelectric frame 50, and the first base 40, The figure which bonded the siloxane bond to the 1st 1st crystal oscillator 100 is shown.

  Siloxane bonds cause poor bonding even at electrode thicknesses (3000 to 4000 mm). For this reason, the surface facing the first base electrode 33 and the second base electrode 34 formed on the back surface of the outer frame portion 51 needs to form a stepped portion having a thickness greater than that of the wiring electrode. Further, the first connection electrode 42 and the second connection electrode 44 formed on the surface of the first base 40 need to form the stepped portion 49 with a depth corresponding to the thickness of the connection electrode. That is, the bonding surface is formed with a stepped portion of each electrode and its opposing surface so as not to inhibit the siloxane bond.

  The height of the stepped portion 49 provided on the first base 40 is 2500 mm to 3000 mm by wet etching or the like. The thicknesses of the first base electrode 33 and the second base electrode 34 formed on the outer frame portion 51 are also 1500 mm to 2000 mm. The thickness of the first connection electrode 42 and the second connection electrode 44 formed on the first base 40 is also 1500 mm to 2000 mm. That is, the sum of the thickness of the base electrode formed on the outer frame portion 51 and the thickness of the connection electrode formed on the first base 40 is 3000 mm to 4000 mm.

  When trying to contact the first base 40 and the outer frame portion 51, the first base electrode 33 and the second base electrode 34, and the first connection electrode 42 and the second connection electrode 44 first come into contact with each other. At this time, the gap between the bottom surface of the outer frame portion 51 and the top surface of the first base 40 is about 500 mm to 1000 mm. When quartz siloxane bonding is performed in this state, the gold layers of the first base electrode 33 and the second base electrode 34 and the first connection electrode 42 and the second connection electrode 44 are bonded to each other. In addition, the bottom surface of the outer frame portion 51 and the top surface of the first base 40 are firmly bonded by a siloxane bond.

  When an attempt is made to join the bottom surface of the outer frame portion 51 and the upper surface of the first base 40 without the stepped portion 49 being provided, a base electrode formed on the outer frame portion 51 and a connection electrode formed on the first base 40 The bottom thickness of the outer frame portion 51 and the upper surface of the first base 40 are often not coupled. On the other hand, if the stepped portion 49 having a total thickness (3000 mm to 4000 mm) of the base electrode and the connection electrode is provided, the outer frame portion 51 and the first base 40 can be bonded with siloxane, but the first base electrode In many cases, 33 and the second base electrode 34 are not coupled to the first connection electrode 42 and the second connection electrode 44, and the two are not conductive. Therefore, the stepped portion 49 has a crystal thickness that is about 10 to about 30 percent thinner than the total thickness of the first base electrode 33 and the second base electrode 34 and the first connection electrode 42 and the second connection electrode 44. Is forming a height.

<Manufacturing Process of First Crystal Resonator 100>
FIG. 3 shows a lid wafer 1, an outer frame frame wafer 60, a piezoelectric frame wafer 70 on which a tuning fork type crystal vibrating piece 30 is formed, and a base wafer 80 having a base recess 47. It is a figure before matching. For convenience of explanation, the first lid 10 is shown on the lid wafer 1, the first outer frame frame 20 is shown on the outer frame frame wafer 60, and the first piezoelectric is shown on the piezoelectric frame wafer 70. The frame 50 is shown, and the base 40 is shown on the base wafer 80. For convenience of explanation, 42 first lids 10 are drawn on the lid wafer 1. However, in actual manufacturing, hundreds to thousands of first lids 10 and first lids 10 are formed on one wafer. A piezoelectric frame 50 and the like are formed.

  Prior to superposition, a space portion 22 that defines the inner shape with a hatched portion is formed in the outer frame frame wafer 60 by crystal etching.

  In the piezoelectric frame wafer 70, an opening 52 that defines the outer shape of the tuning-fork type crystal vibrating piece 30 is shown by a hatched portion. The opening 52 is formed by crystal etching. In addition, the outer frame portion 51 of the first piezoelectric frame 50 and the tuning-fork type crystal vibrating piece 30 are provided on the crystal wafer unit by a first base electrode 33 and a second base electrode 34, and a first excitation electrode 35 and a second excitation electrode 36. In addition, a weight portion 37 and a weight portion 38 are formed.

  In the base wafer 80, a lid recess 47 of the first base 40 is formed by crystal etching. Further, a first connection electrode 42 and a second connection electrode 44, a first external electrode 45 and a second external electrode 46 are formed.

  The diameter of four crystal wafers comprising the lid wafer 1, the outer frame frame wafer 60, the piezoelectric frame wafer 70, and the base wafer 80 is, for example, 4 inches, and the four crystal wafers so that the axial direction can be specified. Orientation flats 1c, 60c, 70c and 80c for specifying the crystal direction of the crystal are formed in a part of the peripheral part 1e, peripheral part 60e, peripheral part 70e and peripheral part 80e. The orientation flats of the four quartz wafers are accurately aligned and overlapped.

<Second Embodiment: Configuration of Second Crystal Resonator 110>
FIG. 4 shows a schematic diagram of the second crystal unit 110. 4A is a top view of the second lid 10 ′, FIG. 4B is a top view of the second outer frame frame 20 ′, and FIG. 4C is a top view of the first piezoelectric frame 50, (D) is a top view of the 1st base 40, (e) is a schematic sectional drawing which carries out anodic bonding of the 2nd crystal oscillator 110 in the AA section of (a) to (d).

  The difference between the second crystal unit 110 and the first crystal unit 100 is that the second lid 10 'uses a lid wafer 1' made of a glass material. For this reason, in the second joining step, the second lid 10 'and the second outer frame frame 20' are joined by anodic joining. In the following description, main differences from the first crystal unit 100 will be described. In addition, the same code | symbol is used for the same structure part.

As shown in FIG. 4A, the second lid 10 ′ is made of glass containing metal ions such as sodium ions such as Pyrex (registered trademark) glass, borosilicate glass, or soda glass.
As shown in FIG. 4B, the second outer frame frame 20 ′ has an outer frame portion 21 ′, and a space portion 22 is formed. A metal film 25 is provided on the surface of the outer frame portion 21 ′. The metal film 25 is formed by a technique such as sputtering or vacuum deposition. The metal film 25 is made of, for example, an aluminum (Al) layer, and the thickness of the aluminum layer is about 1000 to 1500 mm. In addition to the aluminum layer, the metal film 25 may be a metal film in which a gold layer is stacked on an underlying chromium layer.

  In the second crystal unit 110, the second outer frame frame 20 ', the first piezoelectric frame 50, and the first base 40 are overlapped, and siloxane bonding is performed in the first bonding step. Next, the first base 40 is placed with the bottom face up, and the first through hole 41 and the second through hole 43 are filled with a spherical sealing material 48 and sealed by heating or the like. The material 48 is melted to seal the through hole.

  FIG. 4E is a schematic cross-sectional view for performing anodic bonding in the second bonding step. As described above, the second outer frame frame 20 ′ includes the metal film 25 on the surface, and the second lid 10 ′ is overlaid on the metal film 25.

  The second outer frame 20 'on which the second lid 10' is stacked is pressurized while being heated from 200 ° C to 400 ° C in vacuum or in an inert gas. At that time, the upper surface of the second lid 10 ′ is set to a negative potential, the metal film 25 on the surface of the second outer frame 20 ′ is set to a positive potential, and a DC voltage of 500 V to 1 kV is applied for 10 minutes using the DC power source 95. Applied. The second lid 10 'and the second outer frame 20' are joined by an anodic bonding technique to form a package 90 '. For convenience of explanation, the upper surface of the second lid 10 'is described as having a negative potential, and the metal film 25 on the surface of the second outer frame frame 20' is described as having a positive potential. The anodic bonding is performed with the upper surface of the wafer 1 ′ having a negative potential and the metal film 25 of the second outer frame frame 20 ′ of the outer frame frame wafer 60 ′ having a positive potential.

By the way, anodic bonding is established by a chemical reaction in which a metal at the bonding interface is oxidized. When anodic bonding is performed, a metal film is used as an anode, a cathode is disposed on a surface facing the bonding surface of the glass member, and an electric field is applied therebetween. As a result, metal ions such as sodium contained in the glass move to the cathode side, and as a result, the metal film in contact with the glass member at the bonding interface is oxidized, and a state where both are connected is obtained.
The first base may be a glass material, and in this case, the first base is anodically bonded.

<Packaging process>
FIG. 5 is a flowchart of packaging in units of wafers.
In step S11, the contact surface of the outer frame frame wafer 60 and the base wafer 80 is irradiated with short wavelength ultraviolet rays in an oxygen-containing atmosphere, with the piezoelectric frame wafer 70 having the tuning fork type crystal vibrating piece 30 as a center. Make it clean. Then, the siloxane bonds are performed by superimposing them and press-bonding them in a high-temperature tank (not shown) maintained at 350 ° C. to 450 ° C. This first joining step is performed in the atmosphere.

  In step S12, the first base 40, in which the siloxane bond has been completed in the first bonding step, is placed with the bottom surface facing upward, and the first through hole 41 and the second through hole 43 are formed into a spherical shape. The material 48 is filled, and the sealing material 48 is melted by heating or the like to seal these through holes. This process is also performed in the atmosphere. For example, a gold germanium (Au12Ge) alloy having a melting point of 356 ° C. is used for the eutectic alloy of the sealing material 48.

  In step S13, in the second bonding process, the contact surfaces of the outer frame frame wafer 60 and the lid wafer 1 that have completed siloxane bonding in the first bonding process are irradiated with a short wavelength ultraviolet ray in an oxygen-containing atmosphere to be cleaned. Overlay in the state. The siloxane-bonded outer frame wafer 60, the piezoelectric frame wafer 70, and the base wafer 80 in which the through holes are sealed are fixed by a vacuum reflow furnace (not shown) in a state where the wafer is overlapped with the lid wafer 1. Heating is maintained for a time in a vacuum or in an inert atmosphere. Due to the siloxane bond, the first crystal unit 100 in which the inside of the package 90 is evacuated or filled with an inert gas is completed.

On the lid wafer 1 ′ made of a glass material, the outer frame portion 21 ′ of the outer frame frame wafer 60 ′ has a metal film 25 on the surface. In the second bonding step, the outer frame frame wafer 60 ′ in which the siloxane bonding has been completed in the first bonding step is anodic bonded with the lid wafer 1 ′ overlapped. This anodic bonding is performed in a vacuum or in an inert gas, and the package 90 '.
The second crystal unit 110 in which the inside is evacuated or filled with an inert gas is completed.

  In step S <b> 14, the wafer on which the package 90 and the package 90 ′ are completed is cut by a dicing saw or a laser saw to be separated into the first crystal resonator 100 and the second crystal resonator 110. So-called packaging and electrode bonding can be performed at the same time, and since it can be manufactured in units of quartz wafers, productivity can be improved.

<Third Embodiment: Configuration of Third Crystal Resonator 120>
FIG. 6 shows a schematic diagram of the third crystal unit 120. 6A is a top view of the first lid 10, FIG. 6B is a top view of the second piezoelectric frame 50 ′, FIG. 6C is a top view of the second base 40 ′, and FIG. These are cross-sectional block diagrams which showed the 3rd crystal oscillator 120 in the BB cross section of (a) to (c). 1st lid 10 and 2nd piezoelectric frame 50 '
And the second base 40 'is made of quartz material. The third crystal unit 120 does not use the outer frame 20 used for the first crystal unit 100. The second base 40 ′ is a flat plate that does not include the base recess 47. In the third embodiment, a description overlapping that of the first embodiment is omitted.

As shown in FIG. 6A, the first lid 10 is a flat plate.
As shown in FIG. 6B, the second piezoelectric frame 50 ′ includes a tuning-fork type crystal vibrating piece 30 and an outer frame portion 51 ′. The tuning fork type crystal vibrating piece 30 is formed by crystal etching from both sides so as to be thinner than the thickness of the outer frame portion 51 ′, and at the same time, a step portion 39 is formed in the base portion 32. The configuration of the tuning fork type crystal vibrating piece 30 is the same as that of the first embodiment.

  As shown in FIG. 6C, the second base 40 ′ is a flat plate that does not include the base recess 47. In the second base 40 ′, the first through hole 41 and the second through hole 43 are formed by etching. Other configurations are the same as those of the first embodiment.

  As shown in FIG. 6D, the third crystal unit 120 cleans and superimposes the contact surface between the second piezoelectric frame 50 ′ and the second base 40 ′, and forms a siloxane bond in the first bonding step. Do. Next, the second base 40 ′ is placed with the bottom face up, and the first through hole 41 and the second through hole 43 are filled with a spherical sealing material 48 and sealed by heating or the like. The stop material 48 is melted to seal the through hole.

In the second bonding step, the contact surface between the second piezoelectric frame 50 ′ and the first lid 10 is cleaned, and a siloxane bond is performed to form a package 90 ″.
The anodic bonding may be performed using a wafer of the lid 10 ′ made of a glass material and a wafer having a metal film on the outer frame portion 51 ′ of the second piezoelectric frame 50 ′. Since the first through hole 41 and the second through hole 43 are sealed with the sealing material 48 and then joined in the second joining step, there is no influence of the generation of gas generated from the sealing material 48, and the tuning fork type The variation in the vibration frequency of the crystal vibrating piece 30 is reduced, and a highly accurate crystal resonator can be produced.

FIG. 2A is a perspective view showing the configuration of the first crystal unit 100. FIG. FIG. 4B is a cross-sectional configuration diagram of the first crystal unit 100. FIG. 4A is a top view of the first lid 10. FIG. 4B is a top view of the first outer frame frame 20. FIG. 4C is a top view of the first piezoelectric frame 50. FIG. FIG. 4D is a top view of the first base 40. FIG. 4E is a cross-sectional view of the first crystal unit 100. FIG. FIG. 3 is a perspective view before a lid wafer 1, an outer frame frame wafer 60, a piezoelectric frame wafer 70 on which a tuning fork type crystal vibrating piece 30 is formed, and a base wafer 80 are overlaid. (A) is a top view of the second lid 10 ′. (B) is a top view of the second outer frame 20 '. (C) is a top view of the first piezoelectric frame 50. (D) is a top view of the first base 40. (E) is a schematic cross-sectional view of anodic bonding of the second crystal unit 110. It is a flowchart of the packaging in a wafer unit. FIG. 4A is a top view of the first lid 10. (B) is a top view of the second piezoelectric frame 50 ′. (C) is a top view of the second base 40 ′. FIG. 4D is a cross-sectional configuration diagram of the third crystal unit 120.

Explanation of symbols

1 ... Lid wafers 1c, 60c, 70c, 80c ... Orientation flat
1e, 60e, 70e, 80e ... Wafer peripheral portion 10, 10 '... Lid
17 ...... Lid recesses 20, 20 ′ 外 Outer frame frames 21, 21 ′ 外 Outer frame portion 22 ...... Opening portion 25 ...... Metal film 30 …… Quartz vibrating piece 31 …… Vibrating arm 32 …… Base 33 , 34 ...... Base electrodes 35, 36 ...... Excitation electrodes 37, 38 ...... Weight parts 39, 49 ...... Stepped parts 40, 40 ′ ...... Bases 41, 43, …… Through holes 42, 42 ′, 44, 44 '... Connection electrodes 45, 45', 46, 46 '... External electrode 47 ... Base recess 48 ... Sealing material 50, 50' ... Piezoelectric frame 51, 51 '... Outer frame part 52 ... Opening 60 ... Outer frame wafer 70 ... Piezoelectric frame wafer 80 ... Base wafers 90, 90 ', 90 "... Package 95 ... DC power supply

Claims (8)

A piezoelectric frame having a vibrating piece on which an excitation electrode is formed, and an outer frame portion that surrounds the vibrating piece and is connected to the excitation electrode;
An outer frame frame joined to one surface of the outer frame portion in a shape corresponding to the outer frame portion of the piezoelectric frame;
A lid joined to a surface of the outer frame frame;
A connection terminal joined to the other surface of the outer frame and connected to the connection electrode, an external terminal formed on the opposite surface of the connection terminal, and a through-hole wiring connecting the connection terminal and the external terminal A base having
A piezoelectric device comprising: A piezoelectric frame having a vibrating piece on which an excitation electrode is formed, and an outer frame portion which is formed with a connection electrode surrounding the vibrating piece and connected to the excitation electrode and is thicker than the vibrating piece;
A lid joined to one surface of the outer frame portion of the piezoelectric frame;
A connection terminal joined to the other surface of the outer frame and connected to the connection electrode, an external terminal formed on the opposite surface of the connection terminal, and a through-hole wiring connecting the connection terminal and the external terminal A base having
A piezoelectric device comprising: 2. The through-hole wiring is formed by sealing a through-hole in which a gold (Au) layer is formed with a filler of gold (Au) and another metal. 2. The piezoelectric device according to 2. The said connection electrode and excitation electrode consist of a base layer which consists of chromium or nickel, and the gold | metal | money (Au) layer formed in the surface of a base layer, The claim 1 characterized by the above-mentioned. The piezoelectric device described. A method for manufacturing a piezoelectric device, comprising:
A first bonding step of bonding a wafer for a piezoelectric frame having a vibrating piece and an outer frame portion surrounding the vibrating piece and a base wafer having a through hole in the atmosphere;
A sealing step of sealing the through hole with a filler in the atmosphere;
A second bonding step of bonding a lid wafer to the piezoelectric frame in a vacuum or in an inert atmosphere;
A dicing step of dicing the bonded wafer for the piezoelectric frame, the wafer for the base and the wafer for the lid;
A method for manufacturing a piezoelectric device comprising: A method for manufacturing a piezoelectric device, comprising:
In air, a base wafer having a through hole and an outer frame frame corresponding to the outer frame portion are joined to sandwich a piezoelectric frame wafer having a vibrating piece and an outer frame portion surrounding the vibrating piece. 1 joining process,
A sealing step of sealing the through hole with a filler in the atmosphere;
A second bonding step of bonding a flat lid wafer to the outer frame frame in a vacuum or in an inert atmosphere;
A method for manufacturing a piezoelectric device comprising: 7. The method of manufacturing a piezoelectric device according to claim 5, wherein the base wafer and the piezoelectric frame wafer are made of a quartz material, and the first bonding step is a siloxane bond. 8. The piezoelectric device according to claim 5, wherein the lid wafer is the quartz material or the glass material, and the second bonding is a siloxane bond or an anodic bonding. 9. Production method.