JP2017085327A - Crystal diaphragm, and crystal vibration device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crystal diaphragm of which the reliability is more improved such that functional regions of the crystal diaphram are easily secured while being adaptable to downsizing, and a crystal vibration device.SOLUTION: An AT cut crystal diaphragm 2 comprises: a first excitation electrode which is formed in a rectangular shape in which there are long sides in a Z' axis direction and there are short sides in an X axis direction, and formed on one principal plane; and a second excitation electrode that is formed on the other principal plane. The AT cut crystal diaphragm comprises a substantially rectangular vibration part 21 which is formed in a rectangular shape in which there are short sides in the Z' axis direction and there are long sides in the X axis direction, and performs piezoelectric vibrations by applying voltages to the first excitation electrode and the second excitation electrode; a cutout part 24 which is formed in an outer periphery of the vibration part; an outer frame part 23 which is formed in an outer periphery of the cutout part; and a coupling part 22 which connects the vibration part and the outer frame part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an AT-cut type crystal diaphragm including a first excitation electrode formed on one main surface and a second excitation electrode formed on another main surface, and a crystal including the crystal vibration plate. The present invention relates to a vibration device.

  In recent years, the operating frequency of various electronic devices has been increased, and the size of packages has been reduced (especially low profile). For this reason, with the increase in the frequency and the size of the package, the crystal vibrating device is required to cope with the increase in the frequency and the size of the package.

  In particular, the quartz resonator device corresponding to the miniaturization includes a first sealing member and a second sealing member whose casing is configured by a rectangular parallelepiped package and made of a brittle material such as glass or quartz. A quartz crystal plate having an excitation electrode formed on a surface thereof, the first sealing member and the second sealing member being laminated and bonded via the quartz plate, and disposed inside the package Some of the plate excitation electrodes are hermetically sealed (see, for example, Patent Document 1 below). Such a laminated crystal vibration device is generally called a sandwich structure.

Japanese Patent Laying-Open No. 2015-122652

  By the way, in the quartz resonator device having the sandwich structure as described above, a vibration region for exciting as a crystal resonator, a crystal resonator plate, and a sealing member are bonded to the functional region of the crystal resonator plate to vibrate. A region as an outer frame part for hermetically sealing the part, and a region as a cutout part for isolating the outer frame part and the vibration part so that the excitation of the vibration part is not hindered by the outer frame part , A region as a connecting portion for connecting the vibrating portion and the outer frame portion, and a wiring portion for electrically connecting the wiring of the crystal diaphragm and the wiring of the sealing member (a wiring pattern or a through hole for wiring) Etc.). However, the present situation is that it is becoming difficult to secure the above-mentioned respective functional areas with the miniaturization of the crystal vibrating device (crystal vibrating plate).

  In addition, when etching each region as described above into a quartz diaphragm, it is a common method to use wet etching with high work efficiency. An etching rate difference occurs depending on the direction, and it is difficult to form a necessary area with respect to a necessary area.

  In particular, when the vibration part, the cutout part, the outer frame part, the connection part, and the like are formed by the wet etching technique, the X-axis is compared with the cutout part along the Z′-axis direction due to the influence of the etching rate difference. The cutout portion along the direction is necessary for the wider region to penetrate therethrough. For this reason, if a long and narrow cutout is formed along the periphery of the vibration part of the quartz diaphragm, the vibration along the X axis is greater than the end of the vibration part along the Z ′ axis and the end of the outer frame part. Since the area of the end portion of the portion and the end portion of the outer frame portion is narrowed by the cutout portion, it is difficult to secure an effective region. From the above, it is the present situation that securing the necessary area of each region of the quartz diaphragm by wet etching is becoming more difficult as the quartz diaphragm is downsized.

  Accordingly, in order to solve the above-described problems, an object of the present invention is to provide a more reliable crystal diaphragm and a crystal vibration device that can easily secure each functional area of the crystal diaphragm while reducing the size. And

  In order to achieve the above object, the present invention has a rectangular shape having a long side in the Z′-axis direction and a short side in the X-axis direction, an AT-cut crystal diaphragm, and the center of the crystal diaphragm The first excitation electrode formed on one main surface and the second excitation formed on the other main surface, formed in a rectangular shape with a short side in the Z′-axis direction and a long side in the X-axis direction. A vibrating portion provided with an electrode; a cutout portion formed on an outer periphery of the vibrating portion; an outer frame portion formed on an outer periphery of the cutout portion; and a connecting portion connecting the vibrating portion and the outer frame portion. Have

  With the above configuration, since the vibration part is arranged in the short side direction with respect to the long side direction of the crystal diaphragm, the end part in the long side direction of the crystal diaphragm functions as a crystal vibration plate in addition to the vibration part. The effective area can be secured. In other words, without reducing the effective area as a vibrating part for exciting as a quartz vibrator, the area as an outer frame part for sealing the vibrating part by bonding the quartz vibrating plate and the sealing member, An area as a cutout part for isolating the outer frame part and the vibration part so that excitation of the vibration part is not hindered by the frame part, an area as a connection part for connecting the vibration part and the outer frame part, Each functional area is expanded as necessary, such as areas as wiring parts (wiring patterns, wiring through-holes, etc.) for electrically connecting the quartz diaphragm wiring and the sealing member wiring. can do. As a result, it is possible to secure a necessary functional area while realizing miniaturization as a quartz-crystal vibrating device, and the vibration characteristics are not deteriorated.

  Further, even when the cutout part is formed by the wet etching technique along the periphery of the vibration part, the long side of the crystal vibration plate and the short side of the vibration part are set as the Z ′ axis, and the short side of the crystal vibration plate By setting the long side of the vibration part as the X axis, the area of the cutout part along the X axis can be reduced, so the area of the end of the vibration part and the end of the outer frame part by the cutout part Can be suppressed from being narrowed.

  Moreover, the said connection part may protrude toward the said outer frame part only from one corner | angular part in the said vibration part.

  According to such a configuration, when the vibration part is not held at the center position of the side along the X-axis direction, and the crystal vibration plate is piezoelectrically vibrated, it is a vibration attenuation region 1 in the outer peripheral end of the vibration part. Since it is held by only one corner, vibration leakage from the connecting portion toward the outer frame portion is reduced, and piezoelectric vibration can be performed more efficiently. In addition, since the degree of stress applied to the vibration part can be reduced as compared with the case where two coupling parts are provided, the frequency shift due to the stress can be reduced, and the crystal diaphragm can be stably piezoelectrically vibrated.

  Moreover, the 1st sealing member which covers the said one main surface of the said quartz-crystal diaphragm and the 2nd sealing member which covers the said other main surface of the said quartz-crystal diaphragm may be provided.

  According to such a configuration, since the crystal diaphragm is sandwiched between the first sealing member and the second sealing member, a relatively small crystal vibration device can be obtained. In addition, since the above-described crystal diaphragm is provided, the wiring part in the outer frame part (a wiring pattern, a through hole for connection with each sealing member arranged above and below) in addition to the vibration part of the crystal diaphragm A necessary area for forming the connection portion can be secured, and a region for forming the connecting portion and a necessary area can be secured. As a result, since the effective area of the vibration portion and the joint portion with each sealing member in the hydroelectric diaphragm is not reduced, vibration characteristics and airtightness are not hindered, and a miniaturization as a hydroelectric vibration device is realized. The performance is not degraded.

  As described above, according to the present invention, it is possible to provide a more reliable quartz crystal plate and quartz crystal device that can easily secure each functional area of the quartz plate while reducing the size.

FIG. 1 is a schematic configuration diagram showing each configuration of an embodiment of a crystal resonator according to the present invention. FIG. 2 is a schematic plan view of the first sealing member of the crystal resonator according to the present embodiment. FIG. 3 is a schematic bottom view of the first sealing member of the crystal resonator according to the present embodiment. FIG. 4A is a schematic plan view of the first embodiment of the crystal diaphragm according to the present invention. FIG. 4B is a schematic plan view of another example of the first embodiment of the crystal diaphragm according to the present invention. FIG. 5 is a schematic bottom view of the first embodiment of the crystal diaphragm according to the present invention. 6A is a cross-sectional view taken along line AA shown in FIG. 4A. 6B is a cross-sectional view taken along line BB shown in FIG. 4B. FIG. 6C is a cross-sectional view of another example of the quartz crystal diaphragm according to the present invention. FIG. 7 is a schematic plan view of the second sealing member of the crystal resonator according to the present embodiment. FIG. 8 is a schematic bottom view of the second sealing member of the crystal resonator according to the present embodiment. FIG. 9 is a schematic plan view of the second embodiment of the crystal diaphragm according to the present invention. FIG. 10 is a schematic plan view of another example of the second embodiment of the crystal diaphragm according to the present invention.

  Hereinafter, a crystal vibration device according to the present invention will be described with reference to the drawings.

-Configuration of the crystal oscillating device of the first embodiment-
The configuration of the crystal vibrating device 1 according to the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram illustrating each configuration of an embodiment of a crystal resonator.

  The crystal resonator device 1 according to the present invention is, for example, a crystal resonator, and includes a crystal resonator plate 2, a first sealing member 3 that hermetically seals the main surface 2a of the crystal resonator plate 2, and a crystal And a second sealing member 4 that covers the other main surface 2b of the diaphragm 2 and hermetically seals. In the crystal vibrating device 1, the crystal vibrating plate 2 and the first sealing member 3 are joined, and the crystal vibrating plate 2 and the second sealing member 4 are joined.

  That is, in the crystal vibrating device 1, the internal space 13 between the first sealing member 3 and the crystal vibrating plate 2 and the internal space 13 between the crystal vibrating plate 2 and the second sealing member 4 are hermetically sealed. The sandwiched package 12 is formed (see FIG. 1).

  The package size of the quartz crystal vibrating device 1 is 1.0 × 0.8 mm, which is intended to reduce size and height. In addition, with the downsizing, the package 12 does not form a castellation and uses the through-holes (first through-hole h1, second through-hole h2, and third through-hole h3) described later to conduct the electrodes. I am trying.

  As shown in FIG. 1, the internal space 13 is biased to one end side (left side in plan view) of the package 12 in plan view.

  Hereinafter, each configuration will be described in detail.

-1st sealing member The 1st sealing member 3 of the quartz-crystal vibrating device 1 which concerns on this invention is demonstrated referring FIG. FIG. 2 is a schematic plan view of the first sealing member, and FIG. 3 is a schematic bottom view of the first sealing member.

The first sealing member 3 is made of a material having a bending rigidity (secondary moment of section × Young's modulus) of 1000 [N · mm ² ] or less. Specifically, as shown in FIGS. 2 and 3, the first sealing member 3 is a rectangular parallelepiped substrate formed from one glass wafer or quartz wafer, with one main surface 3 a side as the upper surface, and the other The main surface 3b (surface joined to the crystal diaphragm 2) is formed as a flat smooth surface (mirror finish).

  On the other main surface 3 b of the first sealing member 3, a sealing-side first bonding pattern 31 for bonding to the quartz crystal plate 2 is provided so as to surround the internal space 13. In the present embodiment, for example, the sealing-side first bonding pattern 31 is located on the left side in plan view of the other main surface 3b of the first sealing member 3 as shown in FIG. The line width of the sealing-side first bonding pattern 31 is the same at all positions.

  The sealing-side first bonding pattern 31 was formed by stacking a base PVD film formed by physical vapor deposition on the first sealing member 3 and a physical vapor deposition on the base PVD film. It consists of an electrode PVD film. In this embodiment, Ti (or Cr) is used for the base PVD film, and Au is used for the electrode PVD film. Moreover, the sealing side 1st joining pattern 31 is a non-Sn pattern.

-Quartz diaphragm The embodiment of the quartz diaphragm 2 according to the present invention will be described with reference to FIGS. 4A is a schematic plan view of the first embodiment of the crystal diaphragm, FIG. 4B is a schematic plan view of another example of the first embodiment of the crystal diaphragm, and FIG. 5 is a first embodiment of the crystal diaphragm. 6A is a cross-sectional view taken along the line AA shown in FIG. 4A, FIG. 6B is a cross-sectional view taken along the line BB shown in FIG. 4B, and FIG. 6C is another example of the crystal diaphragm. FIG.

  The crystal diaphragm 2 according to the present embodiment is an AT-cut type crystal that is processed by rotating a rectangular crystal plate by 35 ° 15 ′ around the X axis that is the crystal axis of the crystal. The connecting portion 22, the outer frame portion 23, and the cutout portion 24 are provided (see FIGS. 4A and 5). In this specification, the crystal axes of the artificial quartz are the X axis, the Y axis, and the Z axis, and the Y axis and the Z axis of the AT cut type crystal rotated by 35 ° 15 ′ around the X axis, The Y ′ axis and the Z ′ axis are assumed.

  Further, the quartz crystal plate 2 according to the present embodiment is formed in a substantially rectangular shape having long sides L1 and L2 in the Z′-axis direction and short sides W1 and W2 in the X-axis direction.

  In the example of illustration, it has the cut-out part (penetration part which the crystal plate penetrates) 24 formed by cutting out a rectangular-shaped quartz plate, and the said cut-out part 24 has planar view reverse concave shape body k1, and plane. It is composed of a rectangular view body k2. The plan view reverse concave body k1 and the plan view rectangular body k2 configured as the cutout portions 24 are formed along the outer periphery of the vibration unit 21 described later. Further, as shown in FIGS. 4 and 5, the cutout portion 24 of the plan view inverted concave body k1 has portions k12 and k13 along the X axis, and a portion k11 along the Z ′ axis. The cutout portion 24 of the reverse viewing concave body k2 has only a portion k21 along the Z ′ axis. The quartz diaphragm 2 is made of quartz which is a piezoelectric material, and both principal surfaces (one principal surface 2a and the other principal surface 2b) are flat and smooth surfaces (mirror finish).

  The vibration part 21 has a substantially rectangular shape that piezoelectrically vibrates when a voltage is applied. Further, the vibration unit 21 according to the present embodiment is formed in a substantially rectangular shape having the short sides W3 and W4 in the Z′-axis direction and the long sides L3 and L4 in the X-axis direction. In addition, the shape of the vibration part 21 may not be a right angle by chamfering a corner | angular part, when formed by wet etching. A first excitation electrode 211 and a second excitation electrode 212 for applying a voltage to the vibration part 21 are formed on one main surface 2a and the other main surface 2b of the vibration part 21, respectively. At the position where the first excitation electrode 211 and the second excitation electrode 212 are formed in the vibration part 21, a mesa structure 213 is formed in which the thickness of the central area of the vibration part 21 is thicker than the surrounding area. (See FIG. 6A). In this case, in the mesa structure 213, since the thickness of the crystal diaphragm 2 at the center is thick, the confinement effect of piezoelectric vibration can be improved.

  The first excitation electrode 211 and the second excitation electrode 212 are formed at positions away from a region on an extension line obtained by extending a connecting portion 22 described later in the Z′-axis direction toward the center direction of the vibration portion 21. As a result, the first excitation electrode 211 and the second excitation electrode 212 are not formed on the line extending the connecting portion 22 in the Z′-axis direction. The distance between them can be relatively long. Thereby, it is possible to prevent the piezoelectric vibration of the crystal vibrating plate 2 from leaking to the outer frame portion 23 through the connecting portion 22, and to confine the piezoelectric vibration of the crystal vibrating plate 2 in the vibrating portion 21.

  The first excitation electrode 211 and the second excitation electrode 212 are formed by physical vapor deposition on the underlying PVD film (Ti or Cr) formed by physical vapor deposition on the vibrating portion 21 and the underlying PVD film. The electrode PVD film (Au) is formed by lamination.

  The first excitation electrode 211 and the second excitation electrode 212 are drawn out of the vibrating portion 21 by the connecting portions 22 and 22 in which the first extraction electrode 214 or the second extraction electrode 215 from which the electrodes are extracted are formed. . In the illustrated example, the first lead electrode 214 is drawn from the corner portion of the first excitation electrode 211 on the one main surface 2a side, and the first lead electrode on the one main surface 2a side is on the other main surface 2b side. The second extraction electrode 215 is extracted from the corner portion of the second excitation electrode 212 so as to be opposite to the direction in which 214 is extracted (see FIG. 6A).

  The connecting portions 22, 22 protrude from the corner portion of the rectangular vibrating portion 21 in the Z-cut direction of the AT cut. In the present embodiment, the connecting portions 22 and 22 protrude from the two corner portions 21a on the Z ′ axis in the vibrating portion 21 toward the outer frame portion 23 (see FIGS. 4A and 5), and the vibrating portion. 21 and an outer frame portion 23 to be described later are connected. In the illustrated example, the first excitation electrode 211 is drawn out by the connecting portion 22 on the left side (−Z ′ axis direction side) in plan view, and the second excitation electrode 212 is connected by the connecting portion 22 on the right side (+ Z ′ axis direction side) in plan view. Has been pulled out.

  The outer frame part 23 surrounds the outer periphery of the vibration part 21 and the cutout part 24 (planar inverted concave body k1 and planar view rectangular body k2) and holds the connecting part 22. A vibration-side first bonding pattern 216 for bonding to the first sealing member 3 is formed on the one main surface 2a, and a vibration-side second bonding for bonding to the second sealing member 4 is bonded to the other main surface 2b. A pattern 217 is formed. In the present embodiment, for example, the vibration-side first bonding pattern 216 and the vibration-side second bonding pattern 217 are arranged so as to be biased to the left in plan view of both the main surfaces 2a and 2b, as shown in FIG.

  The vibration side first bonding pattern 216 and the vibration side second bonding pattern 217 are physically formed on the base PVD film (Ti or Cr) formed by physical vapor deposition on the outer frame portion 23 and on the base PVD film. It consists of an electrode PVD film (Au) formed by vapor deposition and has a non-Sn pattern. That is, the same material as the first excitation electrode 211 and the second excitation electrode 212 is used. The vibration side first bonding pattern 216 and the vibration side second bonding pattern 217 may be made of an electrode material different from the first excitation electrode 211 and the second excitation electrode 212.

  The outer frame portion 23 is formed with a first through hole h1 for drawing out the vibration side first joining pattern 216 connected to the first excitation electrode 211 to the other main surface 2b side. In the present embodiment, for example, the first through-hole h1 is arranged outside the internal space 13, and is located on the other end side in plan view (right side in plan view) of both the main surfaces 2a and 2b as shown in FIG. However, the first through hole h <b> 1 is not formed inside the internal space 13. Here, the inside of the internal space 13 means strictly the inside of the inner peripheral surface of the bonding material 11 without including the bonding material 11 (vibration side first bonding pattern 216).

  In addition, it is preferable that the thickness of the outer frame part 23 is thicker than the thickness of the connection part 22 (refer FIG. 6A). In this case, since the natural frequency of the piezoelectric vibration of the outer frame portion 23 and the connecting portion 22 is different due to the difference in the thickness of the outer frame portion 23 and the thickness of the connecting portion 22, the outer frame portion 23 is affected by the piezoelectric vibration of the connecting portion 22. Is less likely to resonate. Further, the space between the piezoelectric diaphragm 2 and the first sealing member 3 and the space between the piezoelectric diaphragm 2 and the second sealing member 4 can be widened, and the vibration portion 21 of the piezoelectric diaphragm 2 can be widened. And the contact between the first sealing member 3 and the second sealing member 4 can be prevented.

  In general, piezoelectric vibration hardly propagates from a thick part to a thin part, and has an effect of blocking the piezoelectric vibration.

  Therefore, as another example of the crystal diaphragm 2 of the present embodiment, the thickness of the connecting portion 22 may be greater than the thickness of the vibrating portion 21 as shown in FIGS. 4B and 6B. In this case, since the boundary is formed at a position where the thicknesses of the connecting portion 22 and the vibrating portion 21 are different, it is not necessary to consider unnecessary vibration including the connecting portion 22 in the piezoelectric vibration of the vibrating portion 21.

  As another example of the crystal diaphragm 2 of the present embodiment, the thickness of the connecting portion 22 may be made larger than the thickness of the mesa structure 213 of the vibrating portion 21 as shown in FIG. 6C. In this case, since the thickness of the connecting portion 22 is thicker than the thickness of the mesa structure 213, the vibration of the connecting portion 22 and the vibration of the vibrating portion 21 do not easily resonate, and the vibration energy of the vibrating portion 21 is transmitted to the connecting portion. Loss can be effectively prevented.

-2nd sealing member The 2nd sealing member of the crystal vibration device which concerns on this invention is demonstrated referring FIG. FIG. 7 is a schematic plan view of the second sealing member of the crystal resonator, and FIG. 8 is a schematic bottom view of the second sealing member of the crystal resonator.

The second sealing member 4 is made of a material having a bending rigidity (secondary moment of section × Young's modulus) of 1000 [N · mm ² ] or less. Specifically, as shown in FIG. 7, the second sealing member 4 is a rectangular parallelepiped substrate formed from one glass wafer or quartz wafer, and one main surface 4 a of the second sealing member 4. (Surface bonded to the quartz diaphragm 2) is formed as a flat smooth surface (mirror finish).

  On one main surface 4 a of the second sealing member 4, a sealing-side second bonding pattern 41 for bonding to the crystal diaphragm 2 is provided so as to surround the internal space 13. In the present embodiment, for example, the sealing-side second bonding pattern 41 is located on the left side of the main surface 4a of the second sealing member 4 in a plan view as shown in FIGS. The line width of the sealing-side second bonding pattern 41 is the same at all positions.

  The sealing-side second bonding pattern 41 includes a base PVD film formed by physical vapor deposition on the second sealing member 4 and an electrode formed by stacking by physical vapor deposition on the base PVD film. It consists of a PVD film.

  In this embodiment, Ti (or Cr) is used for the base PVD film, and Au is used for the electrode PVD film. Further, the sealing-side second bonding pattern 41 is a non-Sn pattern.

  The other main surface 4b of the second sealing member 4 is provided with a pair of external electrode terminals (one external electrode terminal 42a and another external electrode terminal 42b) that are electrically connected to the outside (see FIG. 8). Note that the number of external electrode terminals is not limited to two, and may be three or more.

  One external electrode terminal 42 a is electrically connected directly to the first excitation electrode 211 via the vibration side first bonding pattern 216, and the other external electrode terminal 42 b is connected to the second excitation via the vibration side second bonding pattern 217. It is electrically connected directly to the electrode 222.

  As shown in FIG. 8, the one external electrode terminal 42 a and the other external electrode terminal 42 b are positioned at both ends in the longitudinal direction of the second main surface 4 b of the second sealing member 4, respectively. The pair of external electrode terminals (one external electrode terminal 42a and the other external electrode terminal 42b) are a base PVD film formed by physical vapor deposition on the other main surface 4b and a physical gas on the base PVD film. It consists of an electrode PVD film formed by phase growth.

  The thickness of the underlying PVD film of the external electrode terminals (one external electrode terminal 42a and the other external electrode terminal 42b) is the vibration side first bonding pattern 216, vibration side second bonding pattern 217, and sealing side first bonding. It is thick with respect to the thickness of each base PVD film of the pattern 31 and the sealing side second bonding pattern 41. Further, the one external electrode terminal 42 a and the other external electrode terminal 42 b occupy a region of 1/3 or more of the other main surface 4 b of the second sealing member 4.

  Further, as shown in FIGS. 1, 7, and 8, the second sealing member 4 is formed with two through holes (second through hole h2 and third through hole h3). In the present embodiment, for example, the second through hole h2 and the third through hole h3 are arranged outside the internal space 13, and as shown in FIG. 7, the second through hole h2 has both main surfaces (one main surface). 4a, the other main surface 4b) is located on the right side in plan view, and the third through hole h3 is located on the upper left side in plan view. That is, the second through hole h <b> 2 and the third through hole h <b> 3 are not formed inside the internal space 13.

  Here, the inside of the internal space 13 means strictly the inside of the inner peripheral surface of the bonding material 11 without including the bonding material 11 (sealing side second bonding pattern 41).

-Manufacturing Method of Crystal Vibration Device of First Embodiment-
Next, a method for manufacturing the crystal vibrating device 1 using the above-described crystal vibrating plate 2, the first sealing member 3, and the second sealing member 4 will be described.

  The first sealing member 3 and the crystal diaphragm 2 are joined in a state where the vibration-side first joint pattern 216 of the crystal diaphragm 2 and the seal-side first joint pattern 31 of the first sealing member 3 are overlapped. To do.

  Similarly, the bonding of the second sealing member 4 and the crystal diaphragm 2 is performed by overlapping the vibration-side second bonding pattern 217 of the crystal diaphragm 2 and the sealing-side second bonding pattern 41 of the second sealing member 4. In the state.

  The bonding between the first sealing member 3 and the crystal diaphragm 2 and the bonding between the first sealing member 3 and the crystal diaphragm 2 are performed by diffusion bonding by overlapping the respective bonding patterns. By using diffusion bonding as a bonding method, generation of gas generated when bonding using an adhesive or the like can be prevented, but a known bonding-only material such as an adhesive may be used.

  In the manufactured package 12 manufactured as described above, the first sealing member 3 and the crystal diaphragm 2 have a gap of 1.00 μm or less, and the second sealing member 4 and the crystal diaphragm 2 Has a gap of 1.00 μm or less. That is, the thickness of the bonding material 11 between the first sealing member 3 and the crystal vibrating plate 2 is 1.00 μm or less, and the bonding material 11 between the second sealing member 4 and the crystal vibrating plate 2 The thickness is 1.00 μm or less (specifically, 0.15 μm to 1.00 μm in the Au—Au bonding of this embodiment). For comparison, a conventional metal paste sealing material using Sn has a thickness of 5 μm to 20 μm.

-Functional effects of the crystal resonator device of the first embodiment-
As described above, in the crystal diaphragm 2 according to the present embodiment, the connecting portion 22 protrudes from the corner portion 21a of the vibrating portion 21 in the Z-axis direction of the AT cut and is held by the outer frame portion 23. Unlike the conventional quartz diaphragm, the vibration part 21 is not held at the center position of the vibration part 21 along the X-axis direction where the displacement of the piezoelectric vibration is large. Therefore, when the crystal diaphragm 2 is vibrated piezoelectrically, the vibration efficiency is high and the piezoelectric vibration can be efficiently performed.

  Further, since the vibration part 21 of the crystal diaphragm 2 is held by the outer frame part 23 via the connection part 22 from the two corner parts 21a on the Z ′ axis that is the vibration attenuation region, the connection part 22 The vibration leakage toward the outer frame portion 23 is reduced. Since the connecting portion 22 extends in the Z′-axis direction orthogonal to the X-axis direction, which is the vibration displacement direction of the vibrating portion 21, the influence of vibration leakage in the vibrating portion 21 hardly occurs. Thus, the piezoelectric vibration can be more efficiently performed.

  In addition, by forming the connecting portion 22 along the Z′-axis direction by a wet etching method, the etching rate is increased in the width (X-axis direction) direction of the connecting portion 22 as compared with that along the X-axis direction. Since the influence of the difference hardly occurs, it is easy to form by controlling the width of the connecting portion 22. On the other hand, in the length direction (Z ′ direction) of the connecting part 22, since the influence of the etching rate difference is strong, the cutout part 24 is formed wider than the width (X-axis direction) direction of the connecting part 22. Therefore, the length of the connecting portion 22 can be formed long and the influence of vibration leakage can be easily reduced.

  Further, by forming the connecting portion 22 along the Z′-axis direction by a wet etching method, the cross-sectional shape of the connecting portion 22 can be made symmetrical with respect to the center line in the thickness direction of the crystal diaphragm 2. It is possible to make a configuration in which unnecessary stress is not easily applied to the vibration part 21.

  In the present embodiment, the connecting portion 22 is formed at the corner on the + X-axis side of the two corners of the vibration portion 21, so that the corner portion of the vibration portion 21 caused by the etching rate difference is suppressed. be able to.

  Furthermore, the wiring patterns of the first excitation electrode 211 and the second excitation electrode 212 formed on each main surface of the crystal diaphragm 2 can be independently arranged by the connecting portions 22 protruding from the two corner portions 21a. Therefore, the parasitic capacitance between the wiring patterns can be suppressed, and the frequency variable amount can be prevented from being reduced.

  In addition, the vibration part 21 is arranged with the short sides W3 and W4 (Z′-axis direction) with respect to the long sides L1 and L2 (Z′-axis direction) of the crystal vibration plate 2, so In addition to the vibration part 21, effective areas such as the connection part 22 and the outer frame part 23 can be secured at both ends of L <b> 1 and L <b> 2. For this reason, the wiring part (the wiring region for connecting with the 1st through-hole h1, the 2nd through-hole h2 of the 2nd sealing member, and the 3rd through-hole h3) in the outer frame part 23 of the crystal diaphragm 2 is used. A necessary area for formation can be secured, and a region for forming the connecting portion 22 and a necessary area can be secured. As a result, since the effective area of the vibration part 21 in the crystal diaphragm 2 is not reduced, the vibration characteristics and airtightness are not hindered, and the performance can be deteriorated while realizing the miniaturization of the crystal vibration device 1. Absent.

Further, when the vibration part 21, the cutout part 24, the outer frame part 23, the connection part 22 and the like are formed on the crystal diaphragm 2 by a method such as wet etching, the Z is compared with the X-axis direction due to the influence of the etching rate difference. A wider region is required to form the cutout 24 in the 'axis direction.
That is, an elongated cutout 24 along the periphery of the vibration part 21 of the crystal diaphragm (in FIGS. 4 and 5, the parts k12 and k13 along the X axis in the plan view reverse concave body k1 and the plan view reverse concave shape. When forming the part k11 along the Z′-axis of the body k1 and the part k21 along the Z′-axis of the rectangular body k2 in plan view, a cut-out portion along the X-axis (FIGS. 4 and 5). Then, since the etching rate difference occurs in the Z′-axis direction, which is the width direction orthogonal to the k12 and k13), the cutout portion 24 along the Z′-axis (in FIGS. 4 and 5, k11 and k11). The cutout portion 24 is wider than k21), and it is difficult to secure an effective area in the crystal diaphragm 2.

  In the present invention, an area of an effective region for functioning as a crystal diaphragm is secured in addition to the vibration part 21 at both ends of the long sides L1, L2 (Z′-axis direction) of the crystal diaphragm, and the crystal vibration The long sides L1, L2 of the plate 2 and the short sides W3, W4 of the vibrating part 21 are set as the Z ′ axis, and the short sides W1, W2 of the quartz vibrating plate 2 and the long sides L3, L4 of the vibrating part 21 are set as the X axis. ing. For this reason, the cut portions 24 (k12 and k13 in FIG. 4 and FIG. 5) along the X-axis that are formed to have a wide width due to the difference in etching rate are used as the short sides W1 and W2 of the crystal diaphragm 2, and etching is performed. Cutout portions 24 (k11 and k21 in FIGS. 4 and 5) along the Z ′ axis that are unlikely to cause a rate difference and do not easily increase in width can be the long sides L1 and L2 of the quartz crystal plate 2. As a result, the effective area such as the vibrating portion 21 of the crystal diaphragm is reduced by the cutout portion 24 (k11 and k21 in FIGS. 4 and 5) along the Z ′ axis, in which the difference in etching rate does not easily occur and the width does not easily increase. Can be suppressed.

  In addition, according to the configuration of the present embodiment, the quartz crystal vibrating plate 2 is sandwiched between the first sealing member 3 and the second sealing member 4, so that the relatively small quartz crystal vibrating device 1 can be obtained. it can. Since the above-described quartz diaphragm 2 is provided, in addition to the vibrating portion 21 of the quartz diaphragm 2, a wiring portion in the outer frame portion (a wiring pattern, a through hole for connection with each sealing member arranged above and below, etc.) ) Can be ensured, and the area for forming the connecting portion 22 and the necessary area can be ensured. As a result, since the effective area of the joint portion between the vibration portion 21 and each of the sealing members 3 and 4 in the hydroelectric diaphragm 2 is not reduced, vibration characteristics and airtightness are not hindered, and the hydroelectric vibration device 1 is provided. Performance is not degraded while miniaturization is realized.

-Configuration of the crystal oscillating device of the second embodiment-
Next, the configuration of the crystal resonator device of the second embodiment will be described with reference to FIG. In the present embodiment, only the position and the number of the connecting portions 22 in the crystal diaphragm 2 are different. Therefore, only the differences will be described below, and the same components are denoted by the same reference numerals and the same components are denoted by the same reference numerals. A part of the description is omitted.

-Quartz diaphragm In the second embodiment, as in the above embodiment, the quartz diaphragm 2 is formed in a substantially rectangular shape having long sides L1, L2 in the Z'-axis direction and short sides W1, W2 in the X-axis direction. And is formed in a substantially rectangular shape having short sides W3 and W4 in the Z′-axis direction of the vibration part 21 and long sides L3 and L4 in the X-axis direction.

  The connecting portion 22 of the quartz crystal plate 2 of the second embodiment protrudes from only one corner portion 21 a of the vibrating portion 21 in the AT cut Z′-axis direction and protrudes toward the outer frame portion 23. In this case, the vibration part 21 of the crystal diaphragm is held by the outer frame part 23 via the connection part 22 protruding toward the outer frame part 23 from only one corner part 21a. The vibration part 21 can be efficiently held by reducing the number.

  Moreover, the cutout part 24 of 2nd Embodiment is comprised from the planar view substantially square-shaped body k3 to which only one corner | angular part is not connected. As shown in FIG. 9, the substantially rectangular body k <b> 3 in plan view is formed along the outer periphery of the vibration portion 21, and includes portions k <b> 32 and k <b> 33 along the X axis, and a portion k <b> 31 along the Z ′ axis. k34.

  In this embodiment, the vibration part 21 is arranged with short sides W3 and W4 with respect to the long sides L1 and L2 of the crystal diaphragm 2, so that vibration is generated at both ends of the long sides L1 and L2 of the crystal diaphragm 2. In addition to the portion 21, an effective area for functioning as the crystal diaphragm 2 can be secured. Therefore, as another example of the crystal diaphragm 2 of the second embodiment, FIG. 10 shows an example in which the area of the outer frame portion 23 is enlarged as an example of an effective region, and a necessary wiring portion in the outer frame portion 21 is secured. Is shown. More specifically, in the effective area inside and outside the bonding pattern (only the vibration side first bonding pattern 216 is disclosed in FIG. 10) to be bonded to each sealing member formed in the outer frame portion 23, a necessary wiring portion ( In FIG. 10, a first wiring pattern p1, a second wiring pattern p2, a fourth through hole h4 for connection, and a fifth through hole h5) are formed, and the first excitation electrode 211 passes through these wiring portions. To one external electrode terminal 42a and from the second excitation electrode 212 to the other external electrode terminal 42b.

-Functional effects of the crystal resonator device of the second embodiment-
In addition to the function and effect of the above-described embodiment, according to the above configuration, when the vibration unit 21 is not held at the center position of the side along the X-axis direction and the crystal diaphragm 2 is piezoelectrically vibrated, the piezoelectric portion is efficiently vibrated. be able to. Moreover, since the vibration part 21 of the crystal diaphragm 2 is held by the outer frame part 23 via the connection part 22 protruding toward the outer frame part 23 from only one corner 21a, By reducing the number, vibration leakage to the outer frame portion 23 can be further prevented. In addition, since the degree of stress can be reduced as compared with the case where the two connecting portions 22 are provided, the frequency shift due to the stress can be reduced, and the crystal diaphragm 2 can be stably piezoelectrically vibrated.

  In addition, since the connecting portion 22 along the Z′-axis direction can be configured to have a higher (constant) elastic constant than those along the X-axis direction, it is difficult to bend even when an impact is applied from the outside. Thus, the vibrating portion 21 can be reliably held so that the vibrating portion 21 does not contact the first sealing member 3 and the second sealing member 4.

  The above-described embodiments and examples of the present invention are all examples of the present invention, and are not of a nature that limits the technical scope of the present invention. In each of the above embodiments, the crystal resonator device is a crystal resonator, but the present invention can also be applied to a crystal resonator device (for example, a crystal oscillator) other than the crystal resonator.

DESCRIPTION OF SYMBOLS 1 Quartz vibration device 11 Bonding material 12 Package 13 Internal space 2 Quartz diaphragm 2a One main surface 2b Other main surface 21 Vibrating part 21a Corner part 22 Connection part 23 Outer frame part 24 Cutout part 211 First excitation electrode 212 Second excitation electrode 213 Mesa structure 214 First extraction electrode 215 Second extraction electrode 216 Vibration-side first bonding pattern 217 Vibration-side second bonding pattern k1 Reverse-recessed shape body k2 Planar view rectangular shape k3 Plane view substantially rectangular shape 3 First Sealing member 3a One main surface 3b of the first sealing member Other main surface 31 of the first sealing member Sealing side first joining pattern 4 Second sealing member 41 Sealing side second joining pattern 42a One external electrode terminal 42b Other external electrode terminal h1 First through hole h2 Second through hole h3 Third through hole h4 Fourth through hole h5 Fifth through hole p1 First wiring pattern p2 Second wiring pattern

Claims (3)

Formed in a rectangular shape with a long side in the Z′-axis direction and a short side in the X-axis direction, there is an AT-cut crystal diaphragm,
Formed in the central part of the quartz crystal plate, formed in a rectangular shape having a short side in the Z′-axis direction and a long side in the X-axis direction, the first excitation electrode formed on one main surface and the other main surface A vibrating portion provided with the formed second excitation electrode;
A cutout portion formed on the outer periphery of the vibrating portion;
An outer frame portion formed on the outer periphery of the cutout portion;
A connecting portion connecting the vibrating portion and the outer frame portion;
A quartz crystal diaphragm characterized by comprising: A crystal diaphragm according to claim 1, wherein
The crystal oscillating plate according to claim 1, wherein the connecting portion protrudes from only one corner portion of the vibrating portion toward the outer frame portion. A crystal diaphragm according to claim 1 or claim 2,
A first sealing member that covers the one main surface of the crystal diaphragm;
A second sealing member that covers the other main surface of the crystal diaphragm;
Quartz vibration device equipped with.

Images