Crystal vibration piece and crystal vibration device

Abstract

The crystal vibrating piece (2) is provided with an outer frame part (23) and a vibrating part (22) which is thinner than the outer frame part (23), a penetrating part (2a) is formed between the outer frame part (23) and the vibrating part (22), the outer frame part (23) and the vibrating part (22) are connected through a holding part (24) which is thinner than the outer frame part (23), and a connecting part (25) which is arranged on one main surface of the outer frame part (23) and is connected with the holding part (24) is connected with the holding part (24). A flat region (25b) formed on the same plane as the holding section (24) and an inclined region (25a) inclined with respect to the flat region (25b) are provided, and at least regions (24b, 24c) on the penetration section (2a) side of the end section (24a) on the connection section (25) side of the holding section (24) are connected to the flat region (25b).

Description

Technical Field

[0001] The invention relates to a crystal vibrating plate and a crystal vibrating device. Background Art

[0002] In recent years, the operating frequencies of various electronic devices have been increasing, and the packages have been becoming smaller (especially lower). Therefore, with the increase in frequencies and the miniaturization of packages, crystal vibration devices (such as crystal resonators, crystal oscillators, etc.) are also required to correspond to the increase in frequencies and the miniaturization of packages.

[0003] As a crystal resonator device suitable for miniaturization and low profile, a crystal resonator device called a sandwich structure is known. The shell of the crystal resonator device of the sandwich structure is composed of a package body that is approximately rectangular. The package body includes a first sealing member and a second sealing member, for example, made of glass or crystal, and a crystal resonator plate with excitation electrodes formed on two main surfaces, and the first sealing member and the second sealing member are stacked and bonded across the crystal resonator plate. In addition, the vibration part of the crystal resonator plate arranged inside the package body (internal space) is hermetically sealed by the first sealing member and the second sealing member (for example, refer to patent document 1).

[0004] The crystal vibrating plate used in the sandwich structure crystal vibrating device as described above is formed on the crystal plate by forming a vibrating portion with an excitation electrode, an outer frame portion arranged around the vibrating portion, and a holding portion connecting and holding the vibrating portion to the outer frame portion. As such a crystal vibrating plate, AT-cut crystal plates are widely used because they are easy to process and have excellent frequency-temperature characteristics.

[0005] In such a crystal vibrating plate, the vibrating portion and the holding portion are constructed to have a wall thickness smaller than the outer frame portion, and a through portion is formed between the thick outer frame portion and the thin vibrating portion. However, if the outer shape of such a crystal vibrating plate is processed by etching, due to the anisotropy of the crystal (crystal), a part of the outer frame portion will form an inclined region where the wall thickness gradually becomes thinner from the thick outer frame portion to the thin holding portion. Such an inclined region is also formed in the portion where the outer frame portion and the holding portion are connected. Therefore, there is a problem that the inclined region intersects with the side surface of the holding portion (the surface connected to the through portion), resulting in a groove that is recessed into the inside of the holding portion formed in the root area of ​​the outer frame side of the holding portion during etching. If such a groove is formed, the vibration characteristics of the vibrating portion may deteriorate due to the increase in resistance caused by the breaking of the holding portion, the disconnection of the lead wiring, or the thinning of the lead wiring.

[0006] [Patent Document 1]: Japanese Patent Application Publication No. 2010-252051 Summary of the invention

[0007] In view of the above circumstances, an object of the present invention is to provide a crystal resonator piece and a crystal resonator device capable of preventing a groove from being formed in a root region on the outer frame portion side of a holding portion.

[0008] As a technical solution to the above technical problems, the present invention adopts the following structure. That is, the present invention is a crystal vibrating piece, which has an outer frame portion and a vibrating portion with a thinner wall thickness than the outer frame portion, a through portion is formed between the outer frame portion and the vibrating portion, and the outer frame portion and the vibrating portion are connected by a holding portion with a thinner wall thickness than the outer frame portion, characterized in that: a connecting portion connected to the holding portion on one main surface of the outer frame portion is provided with a flat area formed in the same plane as the holding portion, and an inclined area inclined relative to the flat area, and at least the area on the through portion side of the end portion of the holding portion is provided to be connected to the flat area.

[0009] Based on the above structure, the connecting portion between the outer frame portion and the holding portion is provided with a flat area, and the inclined area does not directly intersect with the side of the holding portion, thereby preventing the formation of grooves in the root area of ​​the outer frame portion side of the holding portion during etching. Thus, it is possible to prevent the vibration characteristics of the vibration portion from being deteriorated due to the breaking of the holding portion, the disconnection of the lead wiring or the high resistance. In addition, when there is a thickness difference such as a step between the outer frame portion and the holding portion, the force (stress or impact force) will be concentrated on the thin part, but the inclined area provided at the connecting portion between the outer frame portion and the holding portion can gradually weaken the force. Thus, by providing the inclined area, the external stress acting from the outer frame portion to the vibration portion can be alleviated, so that the anti-breaking and other impact resistance of the holding portion can be improved.

[0010] In the above structure, preferably, the length in the direction in which the retaining portion extends is such that the flat area is larger than the inclined area. Thus, external stress from the outer frame (such as stress during welding installation) can be effectively suppressed, and the displacement of the oscillation frequency and the deterioration of the CI (Crystal Impedance) value can be prevented.

[0011] In the above structure, preferably, the length of the flat area in the direction in which the holding portion extends is smaller than that of the inclined area. Thus, the vibration area of ​​the vibration portion can be ensured, thereby improving the impact resistance.

[0012] In the above structure, it is preferred that a connecting portion connected to the retaining portion on the main surface of the other side of the outer frame portion is provided with a flat area formed in the same plane as the retaining portion and an end area of ​​the outer frame portion, and the end of the connecting portion side of the retaining portion is connected to the flat area. In this case, by disposing at least a portion of the end area on the main surface of the other side of the outer frame portion at a position overlapping with the inclined area on the main surface of the one side of the outer frame portion when viewed from above, the influence of external stress from the outer frame portion (such as stress during welding installation) can be reduced, and the impact resistance can be improved. In addition, by disposing at least a portion of the flat area on the main surface of the other side of the outer frame portion at a position overlapping with the flat area on the main surface of the one side of the outer frame portion when viewed from above, the influence of external stress from the outer frame portion can be reduced, and the stress balance on the outer frame portion can be improved.

[0013] In addition, the present invention is a crystal vibrator device, comprising a crystal vibrator plate having any of the above-mentioned structures, characterized in that it comprises a first sealing member covering one principal surface side of the vibrating portion of the crystal vibrator plate, and a second sealing member covering another principal surface side of the vibrating portion of the crystal vibrator plate, wherein the first sealing member is bonded to the crystal vibrator plate, and the second sealing member is bonded to the crystal vibrator plate, so that the vibrating portion of the crystal vibrator plate is sealed. Based on a crystal vibrator device having a crystal vibrator plate having the above-mentioned structure, the same effect as that of the above-mentioned crystal vibrator plate can be obtained. That is, in the case of using a crystal vibrator plate with a frame body in which the vibrating portion and the outer frame portion are connected by a retaining portion, miniaturization and low profile of the crystal vibrator device can be achieved, and in a crystal vibrator device that has achieved such miniaturization and thinness, it is possible to prevent the formation of grooves in the root area on the outer frame side of the retaining portion.

[0014] Effect of the invention:

[0015] According to the crystal resonator plate and the crystal resonator device of the present invention, since a flat area is provided at the connection portion where the outer frame portion and the holding portion are connected, and the inclined area does not directly intersect the side surface of the holding portion, it is possible to prevent a groove from being formed in the root area of ​​the outer frame portion side of the holding portion during etching. Thus, it is possible to prevent the vibration characteristics of the vibrating portion from being deteriorated due to the breaking of the holding portion, the disconnection of the lead wiring, or the high resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic configuration diagram schematically showing each component of a crystal oscillator according to an embodiment of the present invention.

[0017] Figure 2 This is a schematic plan view of the first principal surface side of the first sealing member of the crystal oscillator.

[0018] Figure 3 It is a schematic plan view of the second main surface side of the first sealing member of the crystal oscillator.

[0019] Figure 4 This is a schematic plan view of the first principal surface side of the crystal resonator piece of the crystal oscillator.

[0020] Figure 5 This is a schematic plan view of the second principal surface side of the crystal resonator piece of the crystal oscillator.

[0021] Figure 6 It is a schematic plan view of the first principal surface side of the second sealing member of the crystal oscillator.

[0022] Figure 7 It is a schematic plan view of the second main surface side of the second sealing member of the crystal oscillator.

[0023] Figure 8 It is a schematic plan view schematically showing the structure of the second principal surface side of the crystal resonator piece.

[0024] Fig. 9 yes Figure 8 D1-D1 line cross-sectional view.

[0025] Fig.10 It is a perspective view showing the structure of the second main surface side of the connection portion between the holding portion and the outer frame portion of the crystal resonator piece.

[0026] Fig.11 It is a schematic plan view schematically showing the structure of the second principal surface side of the crystal resonator piece according to the first modification.

[0027] Fig.12 It is a schematic plan view schematically showing the structure of the first principal surface side of the crystal resonator piece according to the second modification.

[0028] Fig.13 yes Fig.12 D2-D2 line cross-sectional view.

[0029] Fig.14 It is a schematic plan view of the second principal surface side of a tuning-fork type crystal vibrating piece of a crystal oscillator according to another embodiment.

[0030] Fig.15 1 is a schematic plan view schematically showing the structure of the first principal surface side of the crystal resonator piece according to the third modification.

[0031] <Description of Reference Numerals>

[0032] 101 Crystal Oscillator (Crystal Vibration Device)

[0033] 2 Crystal oscillator

[0034] 2a Through-hole

[0035] 22 Vibration

[0036] 23 Outer frame

[0037] 24. Maintaining part

[0038] 24a End portion on the connection side

[0039] 24b, 24c Area on the side of the penetration portion

[0040] 25 Connection part

[0041] 25a Sloped area

[0042] 25b Flat area

[0043] 212 Second main surface DETAILED DESCRIPTION

[0044] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following embodiments, the crystal vibrating device to which the present invention is applied is described as a crystal oscillator. However, the crystal vibrating device to which the present invention is applied is not limited to a crystal oscillator, and the present invention can also be applied to a crystal resonator.

[0045] The crystal oscillator 101 according to this embodiment is as follows: Figure 1 As shown in the figure, it is provided with a crystal vibrating plate 2, a first sealing member 3, a second sealing member 4, and an IC chip 5. In the crystal oscillator 101, the crystal vibrating plate 2 is bonded to the first sealing member 3, and the crystal vibrating plate 2 is bonded to the second sealing member 4, thereby forming a package 12 with a sandwich structure that is approximately rectangular. In addition, an IC chip 5 is mounted on the main surface of the first sealing member 3 on the opposite side of the bonding surface bonded to the crystal vibrating plate 2. The IC chip 5, which is an electronic component element, is a single-chip integrated circuit element that constitutes an oscillation circuit together with the crystal vibrating plate 2.

[0046] In the crystal resonator plate 2, a first excitation electrode 221 is formed on a first main surface 211 as one main surface, and a second excitation electrode 222 is formed on a second main surface 212 as the other main surface. In the crystal oscillator 101, the two main surfaces (the first main surface 211 and the second main surface 212) of the crystal resonator plate 2 are bonded to the first sealing member 3 and the second sealing member 4, respectively, so as to form an internal space of the package 12, and the vibration part 22 including the first excitation electrode 221 and the second excitation electrode 222 (see Figure 4 , Figure 5 ) is hermetically sealed in the internal space.

[0047] The crystal oscillator 101 according to the present embodiment has a package size of, for example, 1.0×0.8 mm, achieving miniaturization and low profile. In addition, with miniaturization, castellations are not formed in the package 12, and conduction of electrodes is achieved using through holes described later.

[0048] Below, refer to Figure 1 to Figure 7 , the crystal resonator plate 2, the first sealing member 3, and the second sealing member 4 in the crystal oscillator 101 will be described. In addition, here, each member having a single structure and not yet bonded will be described.

[0049] like Figure 4 , Figure 5 As shown, the crystal resonator plate 2 is a piezoelectric substrate made of crystal, and its two main surfaces (first main surface 211 and second main surface 212) are processed (mirror-finished) to be flat and smooth. In this embodiment, an AT-cut crystal plate that performs thickness shear vibration is used as the crystal resonator plate 2. Figure 4 , Figure 5 In the crystal vibrator plate 2 shown, the two main surfaces (211, 212) of the crystal vibrator plate 2 are located in the XZ' plane. In the XZ' plane, the direction parallel to the short side direction of the crystal vibrator plate 2 is the X-axis direction, and the direction parallel to the long side direction of the crystal vibrator plate 2 is the Z' axis direction. In addition, AT cutting refers to a processing technique of cutting the three crystal axes of artificial crystal, namely, the electrical axis (X axis), the mechanical axis (Y axis) and the optical axis (Z axis), in the circumferential direction of the X axis at an angle of 35°15' relative to the Z axis. In the AT-cut crystal plate, the X axis coincides with the crystal axis of the crystal. The Y' axis and the Z' axis coincide with axes that are inclined at 35°15' respectively to the Y axis and the Z axis of the crystal axis of the crystal. The Y' axis direction and the Z' axis direction are equivalent to the cutting direction when cutting the AT-cut crystal plate.

[0050] A pair of excitation electrodes (a first excitation electrode 221 and a second excitation electrode 222) are formed on the two main surfaces (211, 212) of the crystal vibrating plate 2. The crystal vibrating plate 2 includes a vibrating portion 22 formed in a substantially rectangular shape, an outer frame portion 23 surrounding the outer periphery of the vibrating portion 22, and a holding portion 24 that holds the vibrating portion 22 by connecting the vibrating portion 22 to the outer frame portion 23. That is, the crystal vibrating plate 2 has a structure in which the vibrating portion 22, the outer frame portion 23, and the holding portion 24 are integrated, and a through portion 2a (see Figure 8 ).

[0051] In the present embodiment, the holding portion 24 is provided at only one position between the vibration portion 22 and the outer frame portion 23. In addition, the vibration portion 22 and the holding portion 24 are configured to have a thinner wall thickness than the outer frame portion 23. By such a difference in thickness between the outer frame portion 23 and the holding portion 24, the natural frequencies of the piezoelectric vibrations of the outer frame portion 23 and the holding portion 24 can be made different, so that the outer frame portion 23 is not easy to resonate with the piezoelectric vibration of the holding portion 24. However, the formation position of the holding portion 24 is not limited to one position, and the holding portion 24 can also be provided at two positions between the vibration portion 22 and the outer frame portion 23 (for example, both sides in the Z′ axis direction).

[0052] The holding portion 24 extends (protrudes) from only one corner of the vibration portion 22 in the +X direction and the -Z' direction toward the outer frame portion 23. In this way, since the holding portion 24 is provided at the corner where the displacement of the piezoelectric vibration is small among the outer peripheral ends of the vibration portion 22, compared with the case where the holding portion 24 is provided at a portion other than the corner (the middle portion of the side), the holding portion 24 can prevent the piezoelectric vibration from leaking to the outer frame portion 23, so that the vibration portion 22 can perform piezoelectric vibration more efficiently. In addition, compared with the case where two or more holding portions 24 are provided, the stress acting on the vibration portion 22 can be reduced, and the frequency displacement of the piezoelectric vibration caused by such stress can be reduced, thereby improving the stability of the piezoelectric vibration.

[0053] The first excitation electrode 221 is provided on the first principal surface 211 side of the vibration part 22, and the second excitation electrode 222 is provided on the second principal surface 212 side of the vibration part 22. Leading wires (first leading wire 223 and second leading wire 224) for connecting these excitation electrodes to external electrode terminals are connected to the first excitation electrode 221 and the second excitation electrode 222. The first leading wire 223 is led out from the first excitation electrode 221, and connected to the connection bonding pattern 27 formed on the outer frame part 23 via the holding part 24. The second leading wire 224 is led out from the second excitation electrode 222, and connected to the connection bonding pattern 28 formed on the outer frame part 23 via the holding part 24. In this way, the first leading wire 223 is formed on the first principal surface 211 side of the holding part 24, and the second leading wire 224 is formed on the second principal surface 212 side of the holding part 24.

[0054] On the two main surfaces (the first main surface 211 and the second main surface 212) of the crystal vibrating plate 2, vibration side sealing portions for bonding the crystal vibrating plate 2 to the first sealing member 3 and the second sealing member 4 are respectively provided. As the vibration side sealing portion of the first main surface 211, a vibration side first bonding pattern 251 for bonding to the first sealing member 3 is formed. In addition, as the vibration side sealing portion of the second main surface 212, a vibration side second bonding pattern 252 for bonding to the second sealing member 4 is formed. The vibration side first bonding pattern 251 and the vibration side second bonding pattern 252 are provided on the outer frame portion 23 and are configured to be annular when viewed from above. The first excitation electrode 221 and the second excitation electrode 222 are not electrically connected to the vibration side first bonding pattern 251 and the vibration side second bonding pattern 252.

[0055] In addition, if Figure 4 , Figure 5 As shown, five through holes are formed on the crystal vibrating plate 2, penetrating between the first main surface 211 and the second main surface 212. Specifically, the four first through holes 261 are respectively provided in the four corners (corner portions) of the outer frame portion 23. The second through hole 262 is provided on one side of the vibrating portion 22 in the Z′ axis direction on the outer frame portion 23 ( Figure 4 , Figure 5 The +Z′ direction side is formed in the center of the first through hole 261. The connection bonding pattern 253 is formed around the first through hole 261. In addition, the connection bonding pattern 254 is formed around the second through hole 262 on the first main surface 211 side, and the connection bonding pattern 28 is formed on the second main surface 212 side.

[0056] In the first through hole 261 and the second through hole 262, a through electrode is formed along the inner wall surface of each through hole for conducting the electrodes formed on the first main surface 211 and the second main surface 212. In addition, the middle portion of each of the first through hole 261 and the second through hole 262 becomes a through portion in a hollow state that penetrates between the first main surface 211 and the second main surface 212.

[0057] In the crystal vibrating piece 2, the first excitation electrode 221, the second excitation electrode 222, the first lead wiring 223, the second lead wiring 224, the first bonding pattern 251, the vibration side second bonding pattern 252, and the connection bonding pattern (253, 254, 27, 28) can be formed by the same process. Specifically, they can be composed of a base film formed by physical vapor deposition on the two main surfaces (211, 212) of the crystal vibrating piece 2, and a bonding film stacked by physical vapor deposition on the base film. In addition, in this embodiment, Ti (or Cr) can be used for the base film, and Au can be used for the bonding film.

[0058] like Figure 2 , Figure 3As shown, the first sealing member 3 is a rectangular parallelepiped substrate composed of a crystal wafer, and the second main surface 312 (the surface bonded to the crystal vibrating plate 2) of the first sealing member 3 is processed (mirror-finished) to be a flat and smooth surface. On the first main surface 311 (the surface on which the IC chip 5 is mounted) of the first sealing member 3, as shown in FIG. Figure 2 As shown in FIG. 1 , six electrode patterns 37 including mounting pads for mounting an IC chip 5 as an oscillation circuit element are formed. The IC chip 5 is provided with metal bumps (eg, Au bumps) 38 (see FIG. 1 ). Figure 1 ) and bonded to the electrode pattern 37 by FCB (Flip Chip Bonding) method.

[0059] like Figure 2 , Figure 3 As shown in FIG. 1 , six through holes are formed on the first sealing member 3, which are connected to the six electrode patterns 37 and penetrate between the first main surface 311 and the second main surface 312. Specifically, the four third through holes 322 are arranged in the four corners (corners) of the first sealing member 3. The fourth through hole 323 and the fifth through hole 324 are respectively arranged in Figure 2 and Figure 3 A2 direction, A1 direction. Here, Figure 2 , Figure 3 , Figure 6 , Figure 7 The A1 and A2 directions are Figure 4 , Figure 5 The -Z' direction and +Z' direction are consistent, Figure 2 , Figure 3 , Figure 6 , Figure 7 The B1 and B2 directions are Figure 4 , Figure 5 The -X direction and +X direction are consistent.

[0060] In the third through hole 322, the fourth through hole 323, and the fifth through hole 324, a through electrode for conducting the electrodes formed on the first main surface 311 and the second main surface 312 is formed along the inner wall surface of each through hole. In addition, the middle portion of each of the third through hole 322, the fourth through hole 323, and the fifth through hole 324 becomes a through portion in a hollow state that penetrates between the first main surface 311 and the second main surface 312.

[0061] A sealing side first bonding pattern 321 as a sealing side first sealing portion for bonding to the crystal vibrating piece 2 is formed on the second main surface 312 of the first sealing member 3. The sealing side first bonding pattern 321 is configured in an annular shape in a plan view.

[0062] In addition, in the second main surface 312 of the first sealing member 3, the connection bonding pattern 34 is formed around the third through hole 322. The connection bonding pattern 351 is formed around the fourth through hole 323, and the connection bonding pattern 352 is formed around the fifth through hole 324. Further, the connection bonding pattern 353 is formed on the opposite side (A1 direction side) of the long axis direction of the first sealing member 3 with respect to the connection bonding pattern 351, and the connection bonding pattern 351 and the connection bonding pattern 353 are connected through the wiring pattern 33. In addition, the connection bonding pattern 353 is not connected to the connection bonding pattern 352.

[0063] In the first sealing member 3, the sealing side first bonding pattern 321, the connection bonding pattern (34, 351 to 353), and the wiring pattern 33 can be formed by the same process. Specifically, they can be composed of a base film formed by physical vapor deposition on the second main surface 312 of the first sealing member 3, and a bonding film stacked by physical vapor deposition on the base film. In addition, in this embodiment, Ti (or Cr) can be used for the base film, and Au can be used for the bonding film.

[0064] like Figure 6 , Figure 7 As shown, the second sealing member 4 is a rectangular parallelepiped substrate composed of a crystal wafer, and the first main surface 411 (the surface bonded to the crystal vibrating plate 2) of the second sealing member 4 is processed (mirror-finished) into a flat and smooth surface. On the first main surface 411 of the second sealing member 4, a sealing side second bonding pattern 421 is formed as a sealing side second sealing portion for bonding to the crystal vibrating plate 2. The sealing side second bonding pattern 421 is configured to be annular when viewed from above.

[0065] Four external electrode terminals 43 electrically connected to the outside are provided on the second main surface 412 (outer main surface not facing the crystal vibrating plate 2 ) of the second sealing member 4 . The external electrode terminals 43 are located at four corners (corners) of the second sealing member 4 .

[0066] like Figure 6 , Figure 7As shown, four through holes are formed on the second sealing member 4 to penetrate between the first main surface 411 and the second main surface 412. Specifically, four sixth through holes 44 are arranged in the areas of the four corners (corners) of the second sealing member 4. In the sixth through holes 44, a through electrode for conducting the electrodes formed on the first main surface 411 and the second main surface 412 is formed along the inner wall surface of each through hole. In addition, the middle part of each of the sixth through holes 44 becomes a through part in a hollow state that penetrates between the first main surface 411 and the second main surface 412. In addition, in the first main surface 411 of the second sealing member 4, a connection bonding pattern 45 is formed around the sixth through holes 44.

[0067] In the second sealing member 4, the sealing side second bonding pattern 421 and the connection bonding pattern 45 can be formed by the same process. Specifically, they can be composed of a base film formed by physical vapor deposition on the first main surface 411 of the second sealing member 4, and a bonding film stacked by physical vapor deposition on the base film. In addition, in this embodiment, Ti (or Cr) can be used for the base film, and Au can be used for the bonding film.

[0068] In the crystal oscillator 101 including the crystal vibrating plate 2, the first sealing member 3, and the second sealing member 4 having the above-mentioned structure, the crystal vibrating plate 2 and the first sealing member 3 are diffusion-bonded in a state where the vibration-side first bonding pattern 251 and the sealing-side first bonding pattern 321 are overlapped, and the crystal vibrating plate 2 and the second sealing member 4 are diffusion-bonded in a state where the vibration-side second bonding pattern 252 and the sealing-side second bonding pattern 421 are overlapped, thereby forming Figure 1 The sandwich structure of the package 12 is shown. As a result, the internal space of the package 12, that is, the storage space of the vibration part 22 is hermetically sealed.

[0069] At this time, the connection bonding patterns are also diffusion-bonded in an overlapping state. Thus, in the crystal oscillator 101, the first excitation electrode 221, the second excitation electrode 222, the IC chip 5 and the external electrode terminal 43 can be electrically connected by bonding the connection bonding patterns.

[0070] Specifically, the first excitation electrode 221 is connected to the IC chip 5 in sequence via the first lead wiring 223, the joint portion between the connection bonding pattern 27 and the connection bonding pattern 353, the wiring pattern 33, the connection bonding pattern 351, the through electrode in the fourth through hole 323, and the electrode pattern 37. The second excitation electrode 222 is connected to the IC chip 5 in sequence via the second lead wiring 224, the connection bonding pattern 28, the through electrode in the second through hole 262, the joint portion between the connection bonding pattern 254 and the connection bonding pattern 352, the through electrode in the fifth through hole 324, and the electrode pattern 37. In addition, the IC chip 5 is connected to the external electrode terminal 43 in sequence via the electrode pattern 37, the through electrode in the third through hole 322, the joint portion between the connection bonding pattern 34 and the connection bonding pattern 253, the through electrode in the first through hole 261, the joint portion between the connection bonding pattern 253 and the connection bonding pattern 45, and the through electrode in the sixth through hole 44.

[0071] Thus, in the sandwich structure package 12 manufactured as described above, there is a gap of less than 1.00 μm between the first sealing member 3 and the crystal vibrating plate 2, and there is a gap of less than 1.00 μm between the second sealing member 4 and the crystal vibrating plate 2. That is, the thickness of the bonding member between the first sealing member 3 and the crystal vibrating plate 2 is less than 1.00 μm, and the thickness of the bonding member between the second sealing member 4 and the crystal vibrating plate 2 is less than 1.00 μm (specifically, the Au-Au bonding of this embodiment is 0.15 μm to 1.00 μm). In addition, as a comparison, the conventional metal paste sealing member using Sn is 5 μm to 20 μm.

[0072] In the present embodiment, in the crystal vibrator plate 2 of the above-described structure, the vibrating portion 22 and the holding portion 24 are constructed to have a wall thickness thinner than that of the outer frame portion 23, and the holding portion 24 extends in the Z′ axis direction. In the connecting portion 25 connected to the holding portion 24 on the main surface of one side of the outer frame portion 23 (here, the second main surface 212), there are provided a flat area 25b formed in the same plane as the holding portion 24, and an inclined area 25a inclined relative to the flat area 25b. In the end portion 24a on the connecting portion 25 side of the holding portion 24, at least the area (24b, 24c) on the side of the through portion 2a is provided to be connected to the flat area 25b. Hereinafter, referring to Figure 4 , Figure 5 , Figure 8 to Figure 10 , this point is explained. In addition, Figure 8 to Figure 10 In the figure, electrodes, through holes, and the like formed on the crystal resonator plate 2 are omitted from illustration.

[0073] Here, the crystal vibrating piece 2 is formed by performing two etching processes, namely, frequency adjustment etching and outer shape forming etching, on a rectangular crystal piece. Figure 4 , Figure 5 , Figure 8 In the frequency adjustment etching, the thickness of the vibration part 22 and the holding part 24 are adjusted so that the oscillation frequency of the crystal oscillator 101 becomes a predetermined value. In the shape forming etching, a through part 2a (see Figure 8 ), and the outer shapes of the vibration part 22, the outer frame part 23 and the holding part 24 are formed. In addition, the through hole on the crystal vibration plate 2 is also formed in the outer shape forming etching.

[0074] After the outer shape of the crystal vibrating plate 2 is formed by etching as described above, due to the anisotropy of the crystal, an inclined region is formed in which the thickness of a part of the outer frame 23 gradually becomes thinner (thin wall) from the thick outer frame 23 to the thin retaining portion 24. In such an inclined region, since the protective coating cannot be made straight or the coating amount is easily uneven compared to the flat region, the pattern cannot be formed correctly, and loose parts will be generated after etching. Therefore, there is a problem that a groove recessed into the retaining portion 24 is formed in the root region of the outer frame 23 side of the retaining portion 24 when the outer shape is formed by etching because the inclined region intersects with the side surface of the retaining portion 24 (the surface connected to the through portion 2a).

[0075] In this regard, in this embodiment, if Figure 8 to Figure 10 As shown in the figure, a flat region 25b is formed at the connection portion 25 between the outer frame portion 23 and the holding portion 24, and the flat region 25b is formed in the same plane as the second main surface 212 of the holding portion 24. During the frequency adjustment etching, the flat region 25b is formed in the same plane as the second main surface 212 of the holding portion 24. By providing such a flat region 25b, when the outer shape is formed by etching, an inclined region 25a can be formed at the connection portion 25 between the outer frame portion 23 and the holding portion 24 together with the penetration portion 2a, and the inclined region 25a does not directly intersect the side surface (the side surface on the ±X direction side) of the holding portion 24.

[0076] More specifically, if Figure 8As shown, the end 24a on the -Z' direction side of the holding portion 24 is connected to the flat area 25b which is approximately rectangular when viewed from above, and the flat area 25b is connected to the inclined area 25a. There is a flat area 25b between the holding portion 24 and the inclined area 25a. In the end (end on the -Z' direction side) 24a on the connecting portion 25 side of the holding portion 24, the entire area from the area 24b on the -X direction side to the area 24c on the +X direction side is connected to the flat area 25b. The width of the flat area 25b in the X-axis direction is larger than the width of the end 24a on the connecting portion 25 side of the holding portion 24 in the X-axis direction. The flat area 25b is formed in a part of the inner end of the outer frame portion 23 on the side connected to the penetration portion 2a, and a recess corresponding to the shape of the flat area 25b and the inclined area 25a is provided in the outer frame portion 23. The ends on the ±X direction sides of the flat area 25b are connected to the inclined areas (26a, 26b).

[0077] The flat region 25b is formed by retreating the rectangular opening formed during the frequency adjustment etching only to the outer frame 23 side by an area equivalent to the flat region 25b. At this time, the retreat amount to the outer frame 23 side is preferably 20 μm or more. Then, by etching to form the outer shape, it is possible to form an inclined region (25a, 26a, 26b) in the area on the side of the through-portion 2a of the outer frame 23 (the area on the +Z′ direction side) together with the through-portion 2a, but in the area where the retaining portion 24 is formed, the retaining portion 24 is not directly connected to the inclined region 25a, but is connected via the flat region 25b. In addition, in the structure of the present embodiment in which the retaining portion 24 is connected in the -Z′ direction, the inclined region (25a, 26a, 26b) is formed on the second principal surface 212 side of the crystal vibrating plate 2, but is not formed on the first principal surface 211 side of the crystal vibrating plate 2.

[0078] According to the present embodiment, the flat region 25b is provided at the connection portion 25 between the outer frame portion 23 and the holding portion 24, and the inclined region 25a does not directly intersect the side surface (the side surface on the ±X direction side) of the holding portion 24, thereby preventing the formation of a groove in the root region of the outer frame portion 23 side of the holding portion 24 during etching. Thus, the second lead wiring 224 (see FIG. 24 ) can be prevented from being broken due to the breaking of the holding portion 24. Figure 5 ) disconnection or high resistance, resulting in the deterioration of the vibration characteristics of the vibration part 22. In addition, when there is a thickness difference such as a step between the outer frame part 23 and the holding part 24, the force (stress or impact) will be concentrated on the thin part, but the inclined area 25a provided at the connection part 25 between the outer frame part 23 and the holding part 24 can gradually weaken the force. Therefore, by providing the inclined area 25a, the external stress acting from the outer frame part 23 to the vibration part 22 can be alleviated, so that the impact resistance performance such as anti-breakage of the holding part 24 can be improved.

[0079] Here, the length Lb of the flat region 25b in the extension direction (Z′ axis direction) of the holding portion 24 may be at least 1 μm, but in order to achieve miniaturization of the crystal vibrating plate 2 while ensuring the area of ​​the vibrating portion 22, it is preferably 1 μm to 30 μm. In this case, by making the length Lb of the flat region 25b in the Z′ axis direction greater than the length La of the inclined region 25a in the Z′ axis direction, it is possible to effectively suppress external stress from the outer frame portion 23 (for example, stress during soldering and mounting), thereby preventing displacement of the oscillation frequency and deterioration of the CI value. Such a dimensional relationship (Lb>La) is effective for a relatively low-frequency crystal oscillator 101, such as an oscillation frequency of 48 MHz.

[0080] On the contrary, by making the length Lb of the flat region 25b in the Z'-axis direction smaller than the length La of the inclined region 25a in the Z'-axis direction, the vibration region of the vibration portion 22 can be ensured and the shock resistance can be improved. Such a dimensional relationship (Lb<La) is effective for a relatively high-frequency crystal oscillator 101 having an oscillation frequency of 60 MHz or more, for example.

[0081] The inclination angle α1 of the inclined region 25 a with respect to the flat region 25 b may be, for example, 28°, but in the case of an AT-cut crystal vibrating piece, it is preferably 25° to 35°.

[0082] In this embodiment, the crystal vibrating piece 2 includes a vibrating portion 22, an outer frame portion 23 surrounding the outer periphery of the vibrating portion 22, and a holding portion 24 connecting the vibrating portion 22 and the outer frame portion 23, and a penetration portion 2a penetrating in the thickness direction is provided between the vibrating portion 22 and the outer frame portion 23. When the crystal vibrating piece 2 with a frame in which the vibrating portion 22 and the outer frame portion 23 are connected by the holding portion 24 is used, the crystal oscillator 101 can be miniaturized and low-profiled, and the crystal oscillator 101 that has achieved such miniaturization and thinness can also obtain the same effect as the above-mentioned crystal vibrating piece 2.

[0083] The present invention may be implemented in various other ways without exceeding its concept, purpose or main features. Therefore, the above-mentioned embodiments are only examples of various aspects and cannot be interpreted in a restrictive manner. The scope of the present invention is the scope shown in the claims and is not subject to any limitation in the specification. Moreover, all modifications and changes that fall within the scope equivalent to the claims are within the scope of the present invention.

[0084] In the above embodiment, as the crystal vibrating plate, an AT-cut crystal vibrating plate that performs thickness shear vibration is used, but other crystal vibrating plates (such as SC-cut crystal vibrating plates, Z-cut crystal vibrating plates (crystal Z plates), etc.) may also be used. For example, the present invention is also applicable to Fig.14 A tuning fork type crystal vibrator piece using a Z-cut crystal vibrator piece as shown.

[0085] Fig.14 The tuning fork type crystal vibrating piece 6 shown has a structure including a vibrating portion 62 formed in the shape of a tuning fork, an outer frame portion 63 surrounding the outer periphery of the vibrating portion 62, and a holding portion 64 holding the vibrating portion 62 by connecting the vibrating portion 62 and the outer frame portion 63. The tuning fork type crystal vibrating piece 6 has a structure in which the vibrating portion 62, the outer frame portion 63, and the holding portion 64 are provided as an integral body, and a through portion 6a is formed between the outer frame portion 63 and the vibrating portion 62. In addition, Fig.14 2 shows the second main surface 612 side of the tuning fork type crystal vibrating piece 6. In addition, the first excitation electrode and the second excitation electrode formed on the vibrating portion 62 and the lead wiring connected to the first excitation electrode and the second excitation electrode are omitted from illustration.

[0086] The vibration part 62 has a structure including two legs (62a, 62b) extending in the Y′-axis direction and a base 62c connected to the ends of the legs (62a, 62b). The legs (62a, 62b) extend from the ends of the base 62c on the -Y′-direction side toward the -Y′-direction. Concave portions (62d, 62e) are formed on the first principal surface and the second principal surface 612 of the legs (62a, 62b), respectively, and the cross-sectional shape of the legs (62a, 62b) is approximately H-shaped. The holding portion 64 is provided only at one location between the vibration part 62 and the outer frame 63. At the end of the base 62c on the +Y′-direction side of the vibration part 62, the holding portion 64 extends from the middle portion of the base 62c in the X-axis direction to the outer frame 63 toward the +Y′-direction.

[0087] Furthermore, the vibrating portion 62 and the holding portion 64 are configured to have a thinner wall thickness than the outer frame portion 63, and the holding portion 64 extends in the Y′-axis direction. In the connecting portion 65 connected to the holding portion 64 on one main surface of the outer frame portion 63 (here, the second main surface 612), there are provided a flat area 65b formed in the same plane as the holding portion 64, and an inclined area 65a inclined relative to the flat area 65b. In the end portion 64a on the connecting portion 65 side of the holding portion 64, at least the area (64b, 64c) on the side of the penetrating portion 6a is provided to be connected to the flat area 65b. Specifically, as Fig.14 As shown in the figure, the end 64a on the -Y' direction side of the holding portion 64 is connected to the flat area 65b which is approximately rectangular when viewed from above, and the flat area 65b is connected to the inclined area 65a. There is a flat area 65b between the holding portion 64 and the inclined area 65a. In addition, a flat area and an inclined area may be provided in the connecting portion 65 connected to the holding portion 64 on the other main surface (first main surface) side of the outer frame portion 63.

[0088] In the above embodiment, the flat region 25b is formed only on a portion of the inner end of the outer frame portion 23 on the side in contact with the through portion 2a. However, for example, Fig.11 As shown in the first modification example of FIG. 2 , a flat region 25 b is formed over the entire inner end portion of the outer frame portion 23 on the side in contact with the penetration portion 2 a .

[0089] In the above embodiment, for example, Fig.12 , Fig.13 As shown in the second modification example, a connecting portion 25 connected to the retaining portion 24 on the other main surface of the outer frame portion 23 (here, the first main surface 211) is provided with a flat area 25c formed in the same plane as the retaining portion 24, and an end area 23a of the outer frame portion 23, and the end 24a on the connecting portion 25 side of the retaining portion 24 is connected to the flat area 25c.

[0090] Fig.12 , Fig.13 In the second variation shown, a flat region 25c is formed in the connection portion 25 where the outer frame portion 23 and the holding portion 24 are connected, and the flat region 25c is formed in the same plane as the first main surface 211 of the holding portion 24. In the frequency adjustment etching, the flat region 25c is formed in the same plane as the first main surface 211 of the holding portion 24. The end 24a on the -Z′ direction side of the holding portion 24 is connected to the flat region 25c which is approximately triangular in plan view. A portion of the end 24a on the connection portion 25 side of the holding portion 24 (the end on the -Z′ direction side) is connected to the flat region 25c. The width of the flat region 25c in the X-axis direction is smaller than the width of the end 24a on the connection portion 25 side of the holding portion 24 in the X-axis direction.

[0091] A flat region 25c is formed at a portion of the inner end of the outer frame portion 23 on the side in contact with the through portion 2a, and a substantially triangular recess corresponding to the flat region 25c is formed on the outer frame portion 23. Figure 8 Unlike the example, no inclined region connected to the flat region 25c is provided on the first main surface 211 side of the outer frame portion 23, and the flat region 25c is connected to a wall surface (step surface) extending in the vertical direction. The flat region 25c is connected to the end region 23a of the outer frame portion 23 via the wall surface.

[0092] Here, you can also Fig.13 As shown in the figure, at least a portion of the end region 23a of the outer frame portion 23 is arranged at a position overlapping with the inclined region 25a of the second main surface 212 of the outer frame portion 23 when viewed from above. Based on this structure, the influence of external stress (such as stress during welding installation) from the outer frame portion 23 can be reduced, so that the impact resistance is improved.

[0093] In addition, at least a portion of the flat region 25c may be formed at a position overlapping with the flat region 25b in a plan view. With such a structure, the influence of external stress from the outer frame portion 23 can be reduced, and the stress balance of the outer frame portion 23 can be improved.

[0094] in addition, Fig.12 , Fig.13 In the second modification shown in FIG. 1 , a flat region 25c formed on the same plane as the first main surface 211 of the holding portion 24 is provided only on a portion of the inner end of the outer frame portion 23 on the side in contact with the through portion 2a. Fig.15 As shown in the third modification example, a flat area 25d is formed in more than half of the inner end of the outer frame portion 23 on the side connected to the through portion 2a. In this modification example 3, a substantially trapezoidal recess corresponding to the flat area 25d is formed on the outer frame portion 23, and the flat area 25d is larger than Fig.12 , Fig.13 Thus, the intersection 25e between the first main surface 211 of the holding portion 24 and the outer frame portion 23 is included in the flat region 25d, so that a complex crystal surface is not easily formed at the intersection 25e, and cracking of the holding portion 24 can be prevented.

[0095] In the above embodiment, only one holding portion 24 connecting the vibration portion 22 and the outer frame portion 23 is provided on the crystal vibration plate 2, but more than two holding portions 24 may be provided. In this case, the connection portion 25 connecting each holding portion 24 and the outer frame portion 23 may adopt the structure of the above embodiment.

[0096] In addition, in the above embodiment, the holding portion 24 is provided at the corner of the vibration portion 22. Specifically, the holding portion 24 extends from the corners on the +X direction side and the -Z' direction side of the vibration portion 22 toward the -Z' direction side. However, the present invention is not limited thereto, and the holding portion 24 may extend from the corners on the +X direction side and the +Z' direction side of the vibration portion 22 toward the +Z' direction side. In addition, the holding portion 24 may be provided not at the corner of the vibration portion 22, but at a middle position in the X-axis direction or the Z'-axis direction of the vibration portion 22.

[0097] In the above embodiment, the entire region from the region 24b on the -X direction side to the region 24c on the +X direction side of the end portion 24a on the connection portion 25 side (the end portion on the -Z' direction side) of the holding portion 24 is connected to the flat region 25b. However, the present invention is not limited thereto, and at least the root region (24b, 24c) of the end portion 24a on the connection portion 25 side of the holding portion 24 may be connected to the flat region 25b, and the entire region from the region 24b on the -X direction side to the region 24c on the +X direction side may not be connected to the flat region 25b.

[0098] In the above embodiment, the first sealing member 3 and the second sealing member 4 are formed of a crystal plate, but the present invention is not limited to this. For example, the first sealing member 3 and the second sealing member 4 may be formed of glass. In addition, in the above embodiment, the bonding of the first sealing member 3 and the crystal vibrating plate 2 and the bonding of the second sealing member 4 and the crystal vibrating plate 2 are achieved by Au-Au bonding, but the bonding of the first sealing member 3 and the crystal vibrating plate 2 and the bonding of the second sealing member 4 and the crystal vibrating plate 2 may also be achieved by a brazing material. In addition, in the above embodiment, the present invention is applied to a crystal resonator having a sandwich structure in which the crystal vibrating plate 2 is sandwiched between the first sealing member 3 and the second sealing member 4, but the present invention is not limited to this. For example, the present invention may also be applied to a crystal resonator having a structure in which a crystal vibrating plate is mounted on a concave base substrate made of an insulating material such as ceramics and airtightly sealed with a cover member.

[0099] This application claims priority based on Japanese Patent Application No. 2022-120859 filed in Japan on July 28, 2022. It goes without saying that all the contents are incorporated into this application.

Claims

1. A crystal vibrating piece, comprising an outer frame portion, and a vibrating portion having a wall thickness thinner than that of the outer frame portion, a through portion being formed between the outer frame portion and the vibrating portion, and the outer frame portion and the vibrating portion being connected by a holding portion having a wall thickness thinner than that of the outer frame portion, characterized in that: A connection portion connected to the holding portion on one main surface of the outer frame portion includes a flat region formed in the same plane as the holding portion and an inclined region inclined relative to the flat region. In the end portion of the holding portion on the connection portion side, at least a region on the penetration portion side is provided so as to be continuous with the flat region.

2. The crystal vibrating plate according to claim 1, wherein: The length in the direction in which the holding portion extends is such that the flat region is larger than the inclined region.

3. The crystal vibrating plate according to claim 1, wherein: The length of the holding portion in the direction in which it extends is such that the flat region is smaller than the inclined region.

4. The crystal vibrating plate according to claim 1, wherein: A connection portion connected to the holding portion on the other main surface of the outer frame portion includes a flat region formed in the same plane as the holding portion and an end region of the outer frame portion. An end portion of the holding portion on the connection portion side is connected to the flat region.

5. The crystal vibrating plate according to claim 4, wherein: At least a portion of the end region on the other main surface of the outer frame portion is provided at a position overlapping with the inclined region on the one main surface of the outer frame portion in a plan view.

6. The crystal vibrating plate according to claim 4, wherein: At least a portion of the flat region on the other main surface of the outer frame portion is provided at a position overlapping with the flat region on the one main surface of the outer frame portion in a plan view.

7. A crystal vibrator device, comprising the crystal vibrator piece according to any one of claims 1 to 6, characterized in that: include a first sealing member covering one principal surface side of the vibration portion of the crystal vibrating piece, and a second sealing member covering the other principal surface side of the vibration portion of the crystal vibrating piece, The first sealing member is bonded to the crystal vibrating piece, and the second sealing member is bonded to the crystal vibrating piece, so that the vibrating portion of the crystal vibrating piece is sealed.

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