Piezoelectric resonator device

Abstract

To provide a piezoelectric vibration device excellent in electric characteristics and high in operational reliability by adopting a structure hard to be affected by the adverse effect of radiation noise in a laminated piezoelectric vibration device which is miniaturized and has high wiring density.SOLUTION: The first output connection path RT1 and the second output connection path RT2 are symmetrically arranged with respect to a line L connecting the centers of the short sides on the A1 side and the A2 side of the piezoelectric vibrator. The first output connection path RT1 and the second output connection path RT2 are arranged in a symmetrical positional relationship with respect to the line L, and the wiring length and the wiring area of the first and second output connection paths RT1 and RT2 are made substantially equal to each other to make the path length and the capacitance substantially equal to each other.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a piezoelectric vibration device. [Background technology]

[0002] Conventionally, there has been a stacked piezoelectric vibration device that has a piezoelectric vibration plate that is rectangular in plan view, an upper sealing plate, and a lower sealing plate, the upper and lower surfaces of the piezoelectric vibration plate being covered by the upper sealing plate and the lower sealing plate, respectively, and hermetically sealed to form a piezoelectric vibrator, and an integrated circuit element with a built-in oscillation amplifier is connected to the upper surface side of the upper sealing plate of the piezoelectric vibrator (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6547825 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, with the increasing speed of data transmission and the increasing volume of data being transmitted, there has been a demand for piezoelectric oscillators that support differential output in stacked piezoelectric resonator devices. However, stacked piezoelectric devices are smaller than those with ceramic package structures and the wiring is also more closely packed, so there is a risk that the operation of the piezoelectric oscillator may be adversely affected by unwanted radiation (hereinafter referred to as radiation noise) generated by alternating current and high-frequency signals that flow through the conduction paths of the output-related parts of integrated circuit elements (hereinafter referred to as ICs) that incorporate oscillation amplifiers.

[0005] Generally, in a piezoelectric oscillator, even if the frequency of the signal flowing through the conduction path of the output-related part of the IC and the frequency of the signal flowing through the conduction path of the input / output-related part of the piezoelectric resonator are the same, a potential difference occurs between the two signals due to a phase shift or a difference in signal waveform. As a result, these phase shifts and potential differences can cause operational malfunctions due to interactions between the output signal of the IC and the signal flowing through the connection part of the piezoelectric resonator.

[0006] In particular, while the input and output signals of a piezoelectric vibrator are sine waves, the output signal of an IC is a square wave, which means that the output signal contains high-frequency components that become radiated noise in addition to the main vibration. The higher the frequency of the piezoelectric oscillator, the more likely these high-frequency components are to be radiated as electromagnetic waves, so this radiated noise may have a negative impact on the vibration frequency of the piezoelectric vibrator, which is the source of the noise. In addition, in ICs that support differential output, these square-wave signals become two signals with a 180-degree phase inversion between positive and negative, making them even more susceptible to the effects of radiated noise. Therefore, a wiring structure that is less susceptible to the effects of radiated noise is required.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a piezoelectric vibration device that is compact, has a high wiring density, and is a stacked piezoelectric vibration device that has excellent electrical characteristics and high operational reliability by adopting a structure that is less susceptible to the adverse effects of radiated noise. [Means for solving the problem]

[0008] In order to achieve the above object, a piezoelectric vibration device according to the present invention has a piezoelectric vibration plate having a rectangular shape in a plan view, an upper sealing plate, and a lower sealing plate, and the upper and lower surfaces of the piezoelectric vibration plate are covered and hermetically sealed by the upper sealing plate and the lower sealing plate, respectively, to form a piezoelectric vibrator, and an integrated circuit element having a built-in oscillation amplifier is connected to the upper surface side of the upper sealing plate of the piezoelectric vibrator. In this piezoelectric vibration device, the piezoelectric vibration plate has a vibration part on which a pair of excitation electrodes are formed, and an outer frame part surrounding an outer peripheral wall of the vibration part, and there is no gap between the vibration part and the upper sealing plate and the lower sealing plate. the upper sealing plate has an integrated circuit element connecting wiring portion formed on its upper surface to which the integrated circuit element is electrically connected; the lower sealing plate has a power supply external terminal, an earth external terminal, a first output external terminal, and a second output external terminal formed at four corners of its lower surface; the piezoelectric vibrator has a first output connection path connecting the integrated circuit element to the first output external terminal, and a second output connection path connecting the integrated circuit element to the second output external terminal, and the first output connection path and the second output connection path are formed to have approximately the same wiring length and wiring area.

[0009] According to this configuration, by forming the first output connection path and the second output connection path to have approximately the same wiring length and wiring area, the path length and capacity of the first output connection path and the second output connection path become approximately the same, and the phase difference of the signal output from the vibration part of the piezoelectric diaphragm can be eliminated.As a result, there is no difference in the influence of the radiation noise from the first and second output external terminals on the first output connection path and the second output connection path, and as a result, the influence of the radiation noise generated from the first and second output external terminals on the input and output to the vibration part of the piezoelectric diaphragm can be suppressed.

[0010] In this case, the piezoelectric vibration plate may further include a holding portion that connects the outer peripheral wall of the vibration portion and the inner peripheral wall of the outer frame portion, and a cutout portion that is formed by cutting out the piezoelectric vibration plate in the plate thickness direction between the vibration portion and the outer frame portion.

[0011] Preferably, the first output connection path and the second output connection path are arranged symmetrically with respect to a line connecting the centers of opposing short sides of the rectangular shape of the piezoelectric diaphragm.

[0012] According to this configuration, it becomes easier to form the first output connection path and the second output connection path so that the wiring length and wiring area are substantially the same.

[0013] In addition, it is preferable that the width of the outer frame portion of the piezoelectric diaphragm at a portion corresponding to the short sides of the rectangle of the piezoelectric diaphragm is greater than that at a portion corresponding to the long sides.

[0014] With this configuration, a large effective area for wiring paths can be secured in the outer frame of the piezoelectric diaphragm, which is wider and stronger than the long sides, and high strength can be maintained even when through holes or notches are formed, thereby reducing the congestion of wiring that accompanies miniaturization. [Effects of the Invention]

[0015] According to the present invention, a stacked piezoelectric vibration device that is small and has a high wiring density can be provided, which has excellent electrical characteristics and high operational reliability by adopting a structure that is less susceptible to the adverse effects of radiated noise. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of a piezoelectric vibration device according to a first embodiment of the present invention. [Figure 2] 2 is a schematic plan view of a first main surface side of a first sealing member (upper sealing plate) of the piezoelectric vibration device of FIG. 1. FIG. [Figure 3] 2 is a schematic bottom view of the second main surface side of the first sealing member of the piezoelectric vibration device of FIG. 1. FIG. [Figure 4] 2 is a schematic plan view of a first main surface side of a piezoelectric vibration plate of the piezoelectric vibration device of FIG. 1. FIG. [Figure 5] 2 is a schematic bottom view of the second main surface side of the piezoelectric vibration plate of the piezoelectric vibration device of FIG. 1. FIG. [Figure 6]2 is a schematic plan view of a first main surface side of a second sealing member (lower sealing plate) of the piezoelectric vibration device of FIG. 1. FIG. [Figure 7] 2 is a schematic bottom view of the second main surface side of the second sealing member of the piezoelectric vibration device of FIG. 1. FIG. [Figure 8] 2 is a schematic bottom view of an integrated circuit element (IC chip) connected to the piezoelectric vibration device of FIG. 1. FIG. [Figure 9] FIG. 4 is a cross-sectional view showing a schematic configuration of a piezoelectric vibration device according to a second embodiment of the present invention. [Figure 10] 10 is a schematic plan view of the first main surface side of the first sealing member (upper sealing plate) of the piezoelectric vibration device of FIG. [Figure 11] 10 is a schematic bottom view of the second main surface side of the first sealing member of the piezoelectric vibration device of FIG. 9. FIG. [Figure 12] 10 is a schematic plan view of a first main surface side of a piezoelectric vibration plate of the piezoelectric vibration device of FIG. 9. FIG. [Figure 13] 10 is a schematic bottom view of the second main surface side of the piezoelectric vibration plate of the piezoelectric vibration device of FIG. 9. FIG. [Figure 14] 10 is a schematic plan view of the first main surface side of the second sealing member (lower sealing plate) of the piezoelectric vibration device of FIG. 9. FIG. [Figure 15] 10 is a schematic bottom view of the second main surface side of the second sealing member of the piezoelectric vibration device of FIG. 9. FIG. [Figure 16] 10 is a schematic bottom view of an integrated circuit element (IC chip) connected to the piezoelectric vibration device of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] First Embodiment A piezoelectric vibration device according to a first embodiment of the present invention will be described in detail with reference to Figures 1 to 8. In the following first embodiment, a case will be described in which quartz crystal is used for the piezoelectric vibration plate. However, in the piezoelectric vibration device of the present invention, the material used for the piezoelectric vibration plate is not limited to quartz crystal as long as it generates piezoelectric vibrations.

[0018] As shown in FIG. 1, the piezoelectric vibration device 101 according to the first embodiment includes a piezoelectric diaphragm 2, a first sealing member 3, and a second sealing member 4, each of which has a substantially rectangular shape in plan view, and an IC chip 5 connected to the first sealing member 3. In this piezoelectric vibration device 101, the piezoelectric diaphragm 2 is bonded to the first sealing member 3, and the piezoelectric diaphragm 2 is bonded to the second sealing member 4 to form a package 12, which serves as a piezoelectric vibrator with a substantially rectangular sandwich structure. The IC chip 5 is mounted on the main surface (top surface) of the first sealing member 3, opposite the surface bonded to the piezoelectric diaphragm 2. The IC chip 5 is a one-chip integrated circuit element that incorporates an oscillation amplifier and forms an oscillation circuit together with the piezoelectric diaphragm 2. Here, the first sealing member 3 and the second sealing member 4 correspond to the "upper sealing plate" and "lower sealing plate," respectively, and the IC chip 5 corresponds to the "integrated circuit element" of the present invention.

[0019] In the piezoelectric diaphragm 2, a first excitation electrode 221 is formed on one of the main surfaces, that is, a first main surface 211, and a second excitation electrode 222 is formed on the other main surface, that is, a second main surface 212. In the piezoelectric vibrating device 101, a first sealing member 3 and a second sealing member 4 are bonded to both main surfaces (the first main surface 211, the second main surface 212) of the piezoelectric diaphragm 2, respectively, to form a cavity in the package 12, and a vibrating part 22 (see FIGS. 4 and 5) including the first excitation electrode 221 and the second excitation electrode 222 is hermetically sealed in the cavity.

[0020] The piezoelectric vibration device 101 according to the first embodiment has a package size of, for example, 1.0 × 0.8 mm, and is designed to be compact and low-profile. In addition, in order to achieve the miniaturization, the package 12 does not have castellations, but rather uses through-holes (described later) to achieve electrode conduction.

[0021] Next, the piezoelectric vibration plate 2, the first sealing member 3, and the second sealing member 4 of the piezoelectric vibration device 101 will be described with reference to Figures 1 to 7. Note that the following describes each of the components that are configured as individual components that are not joined together.

[0022] As shown in Figures 4 and 5, the piezoelectric diaphragm 2 is a piezoelectric substrate made of quartz crystal, and a first main surface 211 and a second main surface 212 are formed as flat, smooth surfaces (mirror-finished). In the first embodiment, an AT-cut quartz crystal plate that performs thickness-shear vibration is used as the piezoelectric diaphragm 2. In the piezoelectric diaphragm 2 shown in Figures 4 and 5, the first and second main surfaces 211, 212 of the piezoelectric diaphragm 2 are the XZ' plane.

[0023] In this XZ' plane, the direction parallel to the short side (short side) of the rectangular piezoelectric diaphragm 2 is the X-axis direction, and the direction parallel to the long side (long side) of the rectangular piezoelectric diaphragm 2 is the Z'-axis direction. Note that AT-cut is a processing technique in which artificial quartz is cut at an angle of 35°15' around the X-axis relative to the Z-axis, one of the three crystal axes of the artificial quartz: the electrical axis (X-axis), the mechanical axis (Y-axis), and the optical axis (Z-axis). In an AT-cut quartz plate, the X-axis coincides with the crystal axis of the quartz. The Y'-axis and Z'-axis coincide with the axes tilted 35°15' from the Y-axis and Z-axis, respectively, of the crystal axes of the quartz. The Y'-axis and Z'-axis directions correspond to the cutting direction when the AT-cut quartz plate is cut. Note that the piezoelectric diaphragm 2 is not limited to the AT-cut quartz plate described above; an SC-cut quartz plate can also be used, and a tuning fork-type vibrator can also be used.

[0024] The piezoelectric diaphragm 2 has a vibration portion 22 having a substantially rectangular shape in plan view, with a pair of excitation electrodes (first excitation electrode 221, second excitation electrode 222) formed on a first main surface 211 and a second main surface 212, respectively; an outer frame portion 23 having an inner peripheral wall that is rectangular in plan view and surrounds the outer peripheral wall of the vibration portion 22; a holding portion 24 that holds the vibration portion 22 by connecting the outer peripheral wall of the vibration portion 22 and the inner peripheral wall of the outer frame portion 23; and a cutout portion 25 formed by cutting out the piezoelectric diaphragm 2 in the plate thickness direction between the vibration portion 22 and the outer frame portion 23. In other words, the piezoelectric diaphragm 2 has a configuration in which the vibration portion 22, the outer frame portion 23, and the holding portion 24 are integrally provided. Here, the outer frame portion 23 is formed so that the width of the portion corresponding to the short sides of the rectangle of the piezoelectric diaphragm 2 is larger than the portion corresponding to the long sides.

[0025] The holding portion 24 is provided at only one location between the vibrating portion 22 and the outer frame portion 23. Furthermore, the vibrating portion 22 and the holding portion 24 are formed thinner than the outer frame portion 23. Due to this 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 differ, and propagation of the vibration excited in the vibrating portion 22 is suppressed. Furthermore, by joining the first sealing member 3 and the second sealing member 4 to the piezoelectric diaphragm 2, a gap is formed inside the inner circumferential wall of the outer frame portion 23 between the vibrating portion 22 and the first sealing member 3 and the second sealing member 4, and this gap is sealed. Alternatively, the outer frame 23 of the piezoelectric diaphragm 2 may be made thicker than the vibrating portion 22 and the holding portion 24, and the gap may be formed by joining the flat first and second sealing members 3 and 4, or the outer frame 23 may be made the same thickness as the vibrating portion 22 and the holding portion 24, and the gap may be formed by forming recesses in the first and second sealing members 3 and 4 and joining them. Also, the position where the holding portion 24 is formed is not limited to one, and it may be provided in two or more positions between the vibrating portion 22 and the outer frame 23.

[0026] The holding portion 24 extends (protrudes) in the +Z' direction from only one corner of the vibrating portion 22, which is located in the +X direction and the -Z' direction, to the outer frame portion 23. In this way, the holding portion 24 is provided at a corner of the outer periphery of the vibrating portion 22, where the displacement of the piezoelectric vibration is relatively small. Therefore, compared to when the holding portion 24 is provided at a portion other than the corner (the center of the side), it is possible to prevent the piezoelectric vibration from leaking to the outer frame portion 23 via the holding portion 24, and it is possible to more efficiently piezoelectrically vibrate the vibrating portion 22. Furthermore, compared to when the holding portion 24 is provided at two or more locations, it is possible to reduce the stress acting on the vibrating portion 22, thereby reducing the frequency shift of the piezoelectric vibration caused by such stress and improving the stability of the piezoelectric vibration.

[0027] The first excitation electrode 221 is provided on the first main surface 211 side of the vibrating section 22, and the second excitation electrode 222 is provided on the second main surface 212 side of the vibrating section 22. Lead-out wiring (first lead-out wiring 223, second lead-out wiring 224) for connecting these excitation electrodes to external electrode terminals is connected to the first excitation electrode 221 and the second excitation electrode 222. The first lead-out wiring 223 is led out from the first excitation electrode 221 and connected to a substantially circular connection bonding pattern 27 formed on the outer frame section 23 via the holding section 24. The second lead-out wiring 224 is led out from the second excitation electrode 222 and connected to an oval connection bonding pattern 28 in the X-axis direction formed on the outer frame section 23 via the holding section 24. In this manner, the first escape routing 223 is formed on the first main surface 211 side of the holding portion 24, and the second escape routing 224 is formed on the second main surface 212 side of the holding portion 24.

[0028] The first main surface 211 and the second main surface 212 of the piezoelectric diaphragm 2 are provided with vibration-side sealing portions for bonding the piezoelectric diaphragm 2 to the first sealing member 3 and the second sealing member 4, respectively. The vibration-side sealing portion of the first main surface 211 is provided with a vibration-side first bonding pattern 251 for bonding to the first sealing member 3. The vibration-side sealing portion of the second main surface 212 is provided with a vibration-side second bonding pattern 252 for bonding to the second sealing member 4. 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 formed in an annular shape in a plan view. 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.

[0029] 4 and 5, the piezoelectric diaphragm 2 has five through holes formed between the first main surface 211 and the second main surface 212. Specifically, the four first through holes 261 of the piezoelectric diaphragm 2 are provided in the four corner regions of the outer frame portion 23, respectively. The second through hole 262 is provided in the outer frame portion 23 on one side in the Z′-axis direction of the vibrating portion 22 (the +Z′-direction side in FIGS. 4 and 5). On the first main surface 211, connection bonding patterns 253 are formed around the first through holes 261, and the connection bonding patterns 253 in the +Z′-direction and +X-direction are connected to the vibration-side first bonding pattern 251. On the second main surface 212, connection bonding patterns 254 are formed around the second through holes 262, respectively. The connection bonding patterns 254 in the +Z′-direction and +X-direction are connected to the vibration-side second bonding pattern 252. Furthermore, on the first main surface 211, a substantially circular connection bonding pattern 29 is formed around the second through-hole 262.

[0030] In the first through hole 261 and the second through hole 262, a through electrode for achieving electrical continuity between the electrodes formed on the first main surface 211 and the second main surface 212 is formed along the inner wall surface of each through hole. In addition, the central portion of each of the first through hole 261 and the second through hole 262 is a hollow through portion that penetrates between the first main surface 211 and the second main surface 212.

[0031] In the piezoelectric diaphragm 2, the first excitation electrode 221, the second excitation electrode 222, the first lead wiring 223, the second lead wiring 224, the vibration-side first bonding pattern 251, the vibration-side second bonding pattern 252, and the connection bonding patterns 253, 254, 27, 28, and 29 can be formed in the same process. Specifically, these can be formed from base films formed by physical vapor deposition on both main surfaces 211 and 212 of the piezoelectric diaphragm 2, and bonding films formed by physical vapor deposition on the base films. In the first embodiment, Ti (or Cr) is used for the base films, and Au is used for the bonding films.

[0032] 2 and 3, the first sealing member 3 is, for example, a rectangular parallelepiped substrate formed from a single piezoelectric substrate made of quartz, and the second main surface 312 (the lower surface that bonds to the piezoelectric diaphragm 2) of this first sealing member 3 is formed as a flat, smooth surface (mirror-finished). Note that it is preferable to use AT-cut quartz similar to that used for the piezoelectric diaphragm 2 for the first sealing member 3 in order to ensure that the thermal expansion coefficients of both are the same, but other quartz cut plates, piezoelectric substrates, glass substrates, etc. may also be used.

[0033] 2, six electrode patterns 37 are formed on the first main surface 311 (top surface on which the IC chip 5 is mounted) of the first sealing member 3 that does not face the piezoelectric diaphragm 2, and these electrode patterns 37 are formed so that some or all of them are located on the periphery of a dashed rectangle R in FIG. 2 that corresponds to the outer shape of the gap on the piezoelectric diaphragm 2 side, i.e., the inner peripheral wall of the outer frame portion 23. Note that in FIG. 2, a rectangle Ra that corresponds to the outer peripheral wall of the vibration portion 22 of the piezoelectric diaphragm 2 is also shown by a dashed line, and the area sandwiched between the rectangle R and the rectangle Ra corresponds to the cutout portion 25.

[0034] The six electrode patterns 37 are formed in the arrangement shown in Fig. 2. That is, electrode pattern 37a is formed in a generally U-shape at a corner in the A2-B1 direction, electrode pattern 37b is formed in a generally L-shape at approximately the center of one short side on the A2 side of first sealing member 3, electrode pattern 37c is formed in a generally U-shape at a corner in the A2-B2 direction, electrode pattern 37d is formed in a generally U-shape at a corner in the A1-B2 direction, electrode pattern 37e is formed in a generally L-shape extending in the A2 direction from approximately the center of the other short side on the A1 side of first sealing member 3, and electrode pattern 37f is formed in a generally U-shape at a corner in the A1-B1 direction. Here, as shown by the dashed dotted line in Fig. 2, when a line connecting the centers of the short sides on the A1 side and the A2 side of the rectangle of the piezoelectric vibrator is taken as line L, wiring patterns 37d and 37f are formed in a shape symmetrical with respect to line L.

[0035] The six electrode patterns 37a to 37f are provided at locations located inside a rectangle R indicated by a dashed line in Fig. 2. As will be described in detail later, as shown in Fig. 8, a power supply pad 51a, a piezoelectric vibrator output pad 51b, a piezoelectric vibrator input pad 51c, a ground pad 51d, a second output pad 51e, and a first output pad 51f are provided on the connection surface (lower surface) of the IC chip 5 facing the first sealing member 3, and an integrated circuit element wiring section to which these pads 51a to 51f are connected is provided inside the rectangle R of each electrode pattern.

[0036] That is, the first sealing member 3 is provided with a power supply wiring portion 39a connected to the power supply pad 51a of the IC chip 5 at a position inside the rectangle R of the electrode pattern 37a, a second piezoelectric vibrator wiring portion 39b connected to the piezoelectric vibrator output pad 51b at a position inside the rectangle R of the electrode pattern 37b, a first piezoelectric vibrator wiring portion 39c connected to the piezoelectric vibrator input pad 51c at a position inside the rectangle R of the electrode pattern 37c, a ground wiring portion 39d connected to the ground pad 51d at a position inside the rectangle R of the electrode pattern 37d, a second output wiring portion 39e connected to the second output pad 51e at a position inside the rectangle R of the electrode pattern 37e, and a first output wiring portion 39f connected to the first output pad 51f at a position inside the rectangle R of the electrode pattern 37f. In this case, the four wiring portions 39a to 39d and the two wiring portions 39e and 39f are arranged along each of the two opposing long sides of the rectangle R.

[0037] These wiring portions 39a to 39f are then bonded to six pads 51a to 51f of the IC chip 5 by FCB (Flip Chip Bonding) using metal bumps (for example, Au bumps) B (see FIG. 1).

[0038] As shown in FIGS. 2 and 3, the first sealing member 3 has six through holes formed therein, each of which is connected to the electrode patterns 37a, 37c, 37d, and 37f and the electrode patterns 37b and 37e located at the four corners and penetrates between the first main surface 311 and the second main surface 312. Specifically, four third through holes 322 are provided in the electrode patterns 37a, 37b, 37d, and 37f at the four corners (corner portions) of the first sealing member 3. Fourth and fifth through holes 323 and 324 are provided in the electrode patterns 37b and 37e, respectively. The A1 and A2 directions in FIGS. 2, 3, 6, and 7 correspond to the -Z' and +Z' directions in FIGS. 4 and 5, respectively, and the B1 and B2 directions in FIGS. 2, 3, 6, and 7 correspond to the -X and +X directions in FIGS. 4 and 5, respectively.

[0039] In the third through hole 322 and the fourth and fifth through holes 323, 324, through electrodes for achieving electrical continuity between the electrodes formed on the first main surface 311 and the second main surface 312 are formed along the inner wall surfaces of the respective through holes. In addition, the central portions of the third through hole 322 and the fourth and fifth through holes 323, 324 form hollow through portions that penetrate between the first main surface 311 and the second main surface 312.

[0040] A sealing-side first bonding pattern 321 is formed on the second main surface 312 of the first sealing member 3 as a sealing-side first sealing portion for bonding to the upper surface side of the piezoelectric diaphragm 2. This sealing-side first bonding pattern 321 is formed in a ring shape in a plan view, similar to the vibration-side first bonding pattern 251 of the piezoelectric diaphragm 2.

[0041] Furthermore, connection bond patterns 34 are formed at the four corners (corner portions) of the second main surface 312 of the first sealing member 3, a substantially circular connection bond pattern 351 is formed around the fourth through hole 323 on the A2 side, and a substantially circular connection bond pattern 352 is formed around the fifth through hole 324 on the A1 side. Furthermore, a substantially circular connection bond pattern 353 is formed on the A2 side of the first sealing member 3 at a position closer to the B1 direction than the connection bond pattern 351, and the connection bond pattern 352 and the connection bond pattern 353 are connected by the wiring pattern 33. Note that the connection bond patterns 352 and 353 are not connected to the connection bond pattern 351.

[0042] The third, fourth, and fifth through holes 322, 323, and 324 have through electrodes formed along the inner wall surfaces thereof to ensure electrical connection between the electrodes formed on the first main surface 311 and the second main surface 312. The central portions of the third to fifth through holes 322 to 324 each form a hollow through portion that penetrates between the first main surface 311 and the second main surface 312.

[0043] In the first sealing member 3, the electrode patterns 37a to 37f, the sealing-side first bonding pattern 321, the wiring pattern 33, and the connection bonding patterns 34, 351 to 353 can be formed in the same process. Specifically, these can be formed from base films formed by physical vapor deposition on the first and second main surfaces 311, 312 of the first sealing member 3, and bonding films formed by physical vapor deposition on the base films. In this embodiment, Ti (or Cr) is used for the base films, and Au is used for the bonding films.

[0044] 6 and 7, the second sealing member 4 is, for example, a rectangular parallelepiped substrate formed from a single piezoelectric substrate made of quartz, and the first main surface 411 (the upper surface that bonds to the piezoelectric diaphragm 2) of this second sealing member 4 is formed as a flat, smooth surface (mirror-finished). Note that it is preferable to use an AT-cut quartz similar to that used for the piezoelectric diaphragm 2 for the first sealing member 3 in order to make the thermal expansion coefficients of both the materials the same, but other quartz cut plates, piezoelectric substrates, glass substrates, etc. may also be used.

[0045] A sealing-side second bonding pattern 421 is formed on the first main surface 411 of this second sealing member 4 as a sealing-side second sealing portion for bonding to the piezoelectric diaphragm 2. The sealing-side second bonding pattern 421 is formed in a ring shape in a plan view, similar to the vibration-side first and second bonding patterns 251 and 252 of the piezoelectric diaphragm 2 and the sealing-side first bonding pattern 321 of the first sealing member 3.

[0046] Four external electrode terminals 43 are provided on the second main surface 412 of the second sealing member 4 (the outer lower surface that does not face the piezoelectric diaphragm 2). Specifically, four external electrode terminals 43a, 43b, 43c, and 43d that are electrically connected to the outside are provided on the second main surface 412 of the second sealing member 4 in a clockwise direction on the plane of the paper in Fig. 7, and these external electrode terminals 43a, 43b, 43c, and 43d are located at the four corners (corner portions) of the second sealing member 4. The four external electrode terminals 43a to 43d correspond to the "power supply external terminal," "earth external terminal," "second output external terminal," and "first output external terminal" in the present invention, respectively.

[0047] As shown in FIGS. 6 and 7 , the second sealing member 4 has sixth through holes 44 formed therein. The sixth through holes 44 are formed at positions on the first main surface 411 that overlap the connection bonding patterns 45, and at positions on the second main surface 412 that overlap the four external electrode terminals 43a to 43d, respectively. A through electrode for establishing electrical connection between the electrodes formed on the first main surface 411 and the second main surface 412 is formed along the inner wall surface of each sixth through hole 44. The central portion of each sixth through hole 44 forms a hollow through portion that penetrates between the first main surface 411 and the second main surface 412. On the first main surface 411 of the second sealing member 4, connection bonding patterns 45 are formed around each sixth through hole 44. The connection bonding patterns 45 in the A2-B2 direction are connected to the sealing-side second bonding pattern 421.

[0048] In the second sealing member 4, the external electrode terminal 43, the sealing-side second bonding pattern 421, and the connection bonding pattern 45 can be formed by the same process. Specifically, these can be formed from an underlayer formed by physical vapor deposition on the first and second main surfaces 411, 412 of the second sealing member 4, and a bonding film formed by physical vapor deposition on the underlayer. In this embodiment, Ti (or Cr) is used for the underlayer, and Au is used for the bonding film.

[0049] The IC chip 5 has a built-in oscillation amplifier with two phase-inverted outputs, and as shown in Figure 1, is bonded to the upper surface of the first sealing member 3 by, for example, the FCB method using metal bumps B, to form a differential output type piezoelectric vibrator.

[0050] Six pads are formed on the lower surface of the IC chip 5 at positions facing the six wiring portions 39a to 39f, respectively. Specifically, as shown in FIG. 8, six pads are formed on the peripheral portion of the lower surface of the IC chip 5 at positions facing the power supply wiring portion 39a, and the six pads are connected to the power supply (V DD ), a piezoelectric vibrator output pad 51b facing the second piezoelectric vibrator wiring portion 39b and connected to the output of the piezoelectric vibrator, a piezoelectric vibrator input pad 51c facing the first piezoelectric vibrator wiring portion 39c and connected to the input of the piezoelectric vibrator, an earth pad 51d facing the earth wiring portion 39d and connected to the earth (ground), a second output pad 51e facing the second output wiring portion 39e and connected to the second output of the piezoelectric vibrator, and a first output pad 51f facing the first output wiring portion 39f and connected to the first output of the piezoelectric vibrator.

[0051] The pads 51a to 51f of the IC chip 5 are bonded and electrically connected to the wiring portions 39a to 39f of the first sealing member 3 by, for example, the FCB method using metal bumps B (see FIG. 1).

[0052] In the piezoelectric vibration device 101 including the piezoelectric diaphragm 2, first sealing member 3, and second sealing member 4, the piezoelectric diaphragm 2 and the first sealing member 3 are diffusion-bonded with the vibrating-side first bonding pattern 251 and the sealing-side first bonding pattern 321 overlapping each other, and the piezoelectric diaphragm 2 and the second sealing member 4 are diffusion-bonded with the vibrating-side second bonding pattern 252 and the sealing-side second bonding pattern 421 overlapping each other, thereby producing the sandwich-structured package 12 shown in FIG. 1 . This hermetically seals the accommodating space for the vibrating part 22, which is the gap in the package 12. At this time, the connecting bonding patterns are also diffusion-bonded with each other overlapping each other.

[0053] By joining the connection bonding patterns together, in the piezoelectric vibration device 101, electrical conduction is obtained between the first excitation electrode 221, the second excitation electrode 222, the IC chip 5, and the external electrode terminals 43a to 43d.

[0054] Specifically, the first excitation electrode 221 is connected to the IC chip 5 via the first escape wiring 223, the junction between the connection bond pattern 27 and the connection bond pattern 351, the through electrode in the fourth through hole 323, and the electrode pattern 37b in this order. The second excitation electrode 222 is connected to the IC chip 5 via the second escape wiring 224, the connection bond pattern 28, the through electrode in the second through hole 262, the connection bond pattern 29, the connection bond pattern 353, the wiring pattern 33, the connection bond pattern 352, the through electrode in the fourth through hole 323, and the electrode pattern 37e in this order.

[0055] In addition, the IC chip 5 is connected to external electrode terminals 43a to 43d via electrode patterns 37a, 37d, 37e, and 37f, the through electrodes in the third through hole 322, the junction between the connection junction pattern 34 and the connection junction pattern 253, the through electrodes in the first through hole 261, the junction between the connection junction pattern 254 and the connection junction pattern 45, and the through electrodes in the sixth through hole 44, in that order.

[0056] In this way, a first output connection path RT1 (path of electrode pattern 37f, through electrode in third through hole 322, joint between connection joint pattern 34 and connection joint pattern 253, through electrode in first through hole 261, joint between connection joint pattern 254 and connection joint pattern 45, through electrode in sixth through hole 44, and external electrode terminal 43d) that connects IC chip 5 and external electrode terminal 43d, which is the "first output external terminal" of second sealing member 4, is formed. In addition, a second output connection path (electrode pattern 37d, the through electrode in the third through hole 322, the joint between the connection joint pattern 34 and the connection joint pattern 253, the through electrode in the first through hole 261, the joint between the connection joint pattern 254 and the connection joint pattern 45, and the through electrode in the sixth through hole 44, and the path of the external electrode terminal 43c) RT2 is formed, connecting the IC chip 5 and the external electrode terminal 43c, which is the "second output external terminal" of the second sealing member 4.

[0057] At this time, the first output connection path RT1 and the second output connection path RT2 are disposed symmetrically with respect to a line L (shown by a dashed line in FIG. 2) connecting the centers of the short sides on the A1 and A2 sides of the rectangle of the piezoelectric vibrator. The first output connection path RT1 and the second output connection path RT2 are disposed in a symmetrical positional relationship with respect to the line L, and furthermore, the wiring patterns 37d and 37f of the first sealing member 3 are formed in line-symmetric shapes, so that the first output connection path RT1 and the second output connection path RT2 can be formed to have approximately the same wiring length and wiring area.

[0058] According to the first embodiment, the first output connection path RT1 and the second output connection path RT2 are arranged symmetrically with respect to a line L (see Figure 2) connecting the centers of the short sides on the A1 and A2 sides of the rectangle of the first sealing member 3, and are formed to have approximately the same wiring length and wiring area.This makes it possible to make the path lengths and capacitances of the first output connection path RT1 and the second output connection path RT2 approximately the same, and to eliminate the phase difference of the signals output from the vibration portion of the piezoelectric diaphragm.

[0059] Therefore, it is possible to prevent any difference in the influence of radiation noise from the first and second output external terminals (external electrode terminals 43d, 43c) on the first output connection path RT1 and the second output connection path RT2, and as a result, it is possible to suppress the influence of radiation noise generated from the first and second output external terminals on the input and output to the vibration part 22 of the piezoelectric vibration plate 2, and it is possible to provide a stacked piezoelectric vibration device that is excellent in electrical characteristics and operational reliability, is small, and has a high wiring density.

[0060] Furthermore, because the width of the outer frame portion 23, which corresponds to the short sides of the rectangle of the piezoelectric diaphragm 2, is formed larger than the portions corresponding to the long sides, a wide effective area for wiring paths can be secured in the outer frame portion 23 of the piezoelectric diaphragm 2, which is wider and stronger than the long sides, and high strength can be maintained even when through holes, notches, etc. are formed, thereby mitigating the congestion of wiring that accompanies miniaturization of the piezoelectric vibration device 101. Furthermore, because the pads 51a-51f of the IC chip 5 and the wiring portions 39a-39f of the first sealing member 3 can be bonded to each other in proximity to the short side portions of the outer frame portion 23 of the piezoelectric diaphragm 2, which are wider and stronger than the long sides, cracking of the first sealing member 3 due to pressure stress during bonding can be reliably prevented.

[0061] Furthermore, since the six pads 51a to 51f of the IC chip 5 are formed on the peripheral edge, the stress caused by the pressure when bonding the IC chip 5 to the first sealing member 3, for example, by the FCB method using metal bumps B, can be effectively dispersed.

[0062] Furthermore, on each of the two short sides of the rectangle R shown by the dashed line in FIG. 2, wiring portions 39a and 39f and wiring portions 39d and 39e of the first sealing member 3 are formed parallel to the short side direction (A1-A2 direction), and pads 51a and 51f and pads 51d and 51e of the IC chip 5 are formed. As a result, the stress caused by the pressing force during bonding can be distributed evenly at multiple linear positions in the short side direction of the rectangle R.

[0063] Second Embodiment A piezoelectric vibration device according to a second embodiment of the present invention will be described in detail with reference to Figures 9 to 16. In the second embodiment, the main difference is the configuration of the piezoelectric vibration plate 2A from the piezoelectric vibration plate 2 of the first embodiment. As shown in Figure 9, the schematic configuration of the piezoelectric vibration device 101A is substantially the same as that shown in Figure 1, which shows the cross section of the piezoelectric vibration device 101 of the first embodiment, and includes a piezoelectric vibration plate 2A, a first sealing member 3A, and a second sealing member 4A, each of which has a substantially rectangular shape in plan view, and an IC chip 5A connected to the first sealing member 3A.

[0064] The piezoelectric diaphragm 2A is formed using an AT-cut quartz crystal plate, as in the first embodiment. As shown in FIGS. 12 and 13, a first excitation electrode 221A is formed on one of the principal surfaces, a first principal surface 211A, and a second excitation electrode 222A is formed on the other principal surface, a second principal surface 212A. In the piezoelectric vibration device of the second embodiment, a first sealing member 3A and a second sealing member 4A are bonded to the first principal surface 211A and the second principal surface 212A of the piezoelectric diaphragm 2A, respectively, to form a cavity, as in the package 12A shown in FIG. 9, and a vibration part 22A including the first excitation electrode 221A and the second excitation electrode 222A is hermetically sealed in the cavity. Note that, as in the first embodiment, the piezoelectric diaphragm 2A is not limited to an AT-cut quartz crystal plate; an SC-cut quartz crystal plate may also be used, and a tuning fork-type vibrator may also be used.

[0065] As shown in Figures 12 and 13, the piezoelectric diaphragm 2A is configured to include a vibration portion 22A that is rectangular in plan view and has a first excitation electrode 221A and a second excitation electrode 222A formed on a first main surface 211A and a second main surface 212A, respectively, an outer frame portion 23A that has an inner peripheral wall that is rectangular in plan view and surrounds the outer peripheral wall of the vibration portion 22A, a holding portion 24A that connects the outer peripheral wall of the vibration portion 22A and the inner peripheral wall of the outer frame portion 23A, and cutout portions 25Aa and 25Ab that are formed by cutting out the piezoelectric diaphragm 2A in the plate thickness direction between the vibration portion 22A and the outer frame portion 23A. Here, the vibrating portion 22A and the holding portion 24A are formed thinner than the outer frame portion 23A, and by bonding the first sealing member 3A and the second sealing member 4A to the piezoelectric diaphragm 2A, a gap is formed inside the inner peripheral wall of the outer frame portion 23A between the vibrating portion 22A and the first sealing member 3A and the second sealing member 4A. Here, the cutout portions 25Aa and 25Ab are disposed in the gap. Note that recesses may be formed in the opposing surfaces of the first and second sealing members 3A and 4A facing the flat piezoelectric diaphragm 2A, and the gap may be formed by bonding the first and second sealing members 3A and 4A. Furthermore, as in the first embodiment, the width of the outer frame portion 23A in the portion corresponding to the short sides of the rectangular piezoelectric diaphragm 2A is formed larger than the portion corresponding to the long sides.

[0066] The inner peripheral wall of the outer frame portion 23A and the outer peripheral wall of the vibration portion 22A are both formed in a rectangular shape in a plan view. The long side direction of the piezoelectric vibration plate 2A in a plan view and the long side direction of the inner peripheral wall of the outer frame portion 23A in a plan view are arranged in a direction perpendicular to each other. One holding portion 24A is provided on each of the +X direction side and the -X direction side of the vibration portion 22A, and is composed of a vibration holding portion 24Aa on the vibration portion 22A side and an outer frame holding portion 24Ab on the outer frame portion 23A side. Details of the holding portions 24A will be described later.

[0067] The first excitation electrode 221A is provided on the first main surface 211A side of the vibrating part 22A, and the second excitation electrode 222A is provided on the second main surface 212A side of the vibrating part 22A. Lead-out wiring (first lead-out wiring 223A, second lead-out wiring 224A) is connected to the first excitation electrode 221A and the second excitation electrode 222A to connect them to external electrode terminals, respectively.

[0068] 12, the first escape wiring 223A is extracted in an L-shape from the first excitation electrode 221A in the +X direction, and is connected to a circular connection junction pattern 27A formed on the +Z'-direction side of the first main surface 211A of the outer frame portion 23A via a holding portion 24A provided on the +X direction of the vibrating portion 22A. As shown in Fig. 13, the second escape wiring 224A is extracted in an L-shape from the second excitation electrode 222A in the -X direction, and is connected to a circular connection junction pattern 28A formed on the +Z'-direction side of the second main surface 212A of the outer frame portion 23A via a holding portion 24A provided on the -X side of the vibrating portion 22A.

[0069] Furthermore, because the first escape wiring 223A and the second escape wiring 224A are escaped in different directions, the escape wirings are not arranged opposite each other across the vibrating part 22A in the vibrating part 22A, which eliminates unnecessary excitation by the escape wiring in the vibrating part 22A and improves the stability of the characteristics.

[0070] The retaining portion 24A has a pair of vibration retaining portions 24Aa along a first imaginary straight line L1 in a first direction (X-axis direction) passing through the center point C of the vibrating portion 22A in a planar view, and a pair of outer frame retaining portions 24Ab extending in a second direction (Z'-axis direction) different from the first direction and connecting each vibration retaining portion 24Aa to two points on the inner wall of the outer frame portion 23A, each vibration retaining portion 24Aa connecting the outer peripheral wall of the vibrating portion 22A to the outer frame retaining portion 24Ab, and the outer frame retaining portion 24Ab connecting the vibration retaining portion 24Aa to the inner wall of the outer frame portion 23A, and the outer frame retaining portions 24Ab are formed line-symmetrically with respect to the first imaginary straight line L1 and line-symmetrically with respect to a second imaginary straight line L2 along a second direction that is perpendicular to the first imaginary straight line L1 and passes through the center point C of the vibrating portion 22A in a planar view.

[0071] More specifically, holding portions 24A formed in a substantially T-shape in plan view are provided on the +X side and the -X side of vibrating portion 22A, which is rectangular in plan view, and holding portions 24A are arranged line-symmetrically with respect to first imaginary line L1 and second imaginary line L2. That is, holding portion 24A is integrally formed with vibration holding portion 24Aa extending linearly from the outer peripheral wall of vibrating portion 22A along first imaginary line L1, and outer frame holding portion 24Ab extending linearly parallel to second imaginary line L2.

[0072] The vibration retaining portion 24Aa and the outer frame retaining portion 24Ab are connected in directions perpendicular to each other, with the vibration retaining portion 24Aa extending toward the outer frame retaining portion 24Ab parallel to the long side direction of the rectangular inner peripheral wall of the outer frame portion 23A, and the outer frame retaining portion 24Ab extending toward each of the two opposing inner peripheral walls of the outer frame portion 23A parallel to both short sides of the rectangular inner peripheral wall of the outer frame portion 23A. One end of the vibration retaining portion 24Aa on the side of the center point C is connected to the center of the long side of the vibrating portion 22A in the Z'-axis direction, and the other end of the vibration retaining portion 24Aa is connected to the center of the outer frame retaining portion 24Ab. The outer frame retaining portion 24Ab is connected to the four corners of the rectangular inner peripheral wall of the outer frame portion 23A. One end of outer frame holding part 24Ab in the +Z' direction is connected to one of the inner peripheral walls of outer frame part 23A facing the +Z' direction, and the other end of outer frame holding part 24Ab in the -Z' direction is connected to one of the inner peripheral walls of outer frame part 23A facing the -Z' direction. The length of vibration holding part 24Aa along the X-axis is shorter than the length of outer frame holding part 24Ab along the Z' axis, and the width of vibration holding part 24Aa along the Z' axis is wider than the width of outer frame holding part 24Ab along the X-axis.

[0073] By the holding portion 24A having such a configuration, the cutout portion formed between the outer peripheral wall of the vibrating portion 22A and the inner peripheral wall of the outer frame portion 23A is divided into four portions in a plan view. Specifically, the cutout portion 25Aa is divided into two portions surrounded by the outer peripheral wall of the vibrating portion 22A, the inner peripheral wall of the outer frame portion 23A, and the vibration holding portion 24Aa and outer frame holding portion 24Ab of the holding portion 24, and each portion is formed in a substantially U-shape in a plan view. The cutout portion 25Ab is divided into two portions surrounded by the inner peripheral wall of the outer frame portion 23A and the outer frame holding portion 24Ab of the holding portion 24, and each portion is formed in a straight line extending along the Z'-axis direction in a plan view. Furthermore, one end of a pair of vibration holding portions 24Aa is connected to each end of the vibration portion 22A in the X-axis direction, and both ends of two outer frame holding portions 24Ab extending in the Z'-axis direction are connected to four points on the inner wall of the outer frame portion 23A, so that the effects of external stress, etc. can be suppressed and deflection in the thickness direction can be suppressed.

[0074] The first and second main surfaces 211A and 212A of the piezoelectric diaphragm 2A are provided with vibration-side sealing portions for bonding the piezoelectric diaphragm 2A to the first and second sealing members 3A and 4A, respectively. The first main surface 211A includes a vibration-side first bonding pattern 251A for bonding to the first sealing member 3A. The second main surface 212A includes a vibration-side second bonding pattern 252A for bonding to the second sealing member 4A. The first and second bonding patterns 251A and 252A are provided on the outer frame 23A. These two bonding patterns 251A and 252A are formed in a shape surrounded by a rectangular outer frame that is slightly smaller than the rectangular shape of the piezoelectric diaphragm 2A in plan view and an approximately annular inner frame in plan view. Here, the first excitation electrode 221A and the second excitation electrode 222A are not electrically connected to the vibration-side first bonding pattern 251A and the vibration-side second bonding pattern 252A.

[0075] 12 and 13, five through holes are formed in the piezoelectric diaphragm 2A, penetrating between the first main surface 211A and the second main surface 212A. Specifically, the four first through holes 261A of the piezoelectric diaphragm 2A are provided in the four corner regions of the outer frame portion 23A. The second through holes 262A are provided in a circular connection bonding pattern 29A formed on the first main surface 211A side of the outer frame portion 23A.

[0076] A connecting bond pattern 254A is formed around each of the three first through holes 261A, excluding the first through hole 261A in the +Z' and +X directions, separated from the vibration-side first and second bonding patterns 251A and 252A by a rectangular slit 253A. A connecting bond pattern 256A is formed around the first through hole 261A in the +Z' and +X directions, separated from the vibration-side first and second bonding patterns 251A and 252A by a substantially C-shaped slit 255A, except for a portion thereof. This connecting bond pattern 256A is connected to the vibration-side first bonding pattern 251A and the vibration-side second bonding pattern 252A. A connecting bond pattern 29A is arranged on the first main surface 211A side around the second through hole 262A, and a circular connecting bond pattern 28A is arranged on the second main surface 212A side.

[0077] In first through hole 261A and second through hole 262A, a through electrode for achieving electrical connection between electrodes formed on first main surface 211A and second main surface 212A is formed along the inner wall surface of each through hole. In addition, the central portion of each of first through hole 261A and second through hole 262A forms a hollow through portion that penetrates between first main surface 211A and second main surface 212A.

[0078] In the piezoelectric vibration plate 2A, the first excitation electrode 221A, the second excitation electrode 222A, the first extraction wiring 223A, the second extraction wiring 224A, the vibration side first bonding pattern 251A, the vibration side second bonding pattern 252A, and the connection bonding patterns 254A, 256A, 27A, 28A, and 29A can be formed in the same process, as in the first embodiment.

[0079] 10 and 11, the first sealing member 3A has eight electrode patterns formed on the first main surface 311A ​​of the first sealing member 3A. Parts of six of these eight electrode patterns and two floating island electrode patterns have eight wiring sections used as integrated circuit element connecting wiring sections to which eight pads of the IC chip 5A (described later) are connected, formed so as to be located on the periphery of a rectangle R (a rectangular region elongated in the B1-B2 direction indicated by a dashed line in FIG. 10) on the inner peripheral wall of the outer frame portion 23A. Note that in FIG. 9, a rectangle Ra corresponding to the outer peripheral wall of the vibrating portion 22A of the piezoelectric diaphragm 2A is also indicated by a dashed line, and the area sandwiched between the rectangle R and the rectangle Ra corresponds to the cutout portion 25A.

[0080] Six electrode patterns 37Aa to 37Af as the electrode pattern 37A and electrode patterns 38Aa and 38Ab as the floating island electrode pattern 38A are formed in the arrangement shown in Fig. 10. That is, electrode pattern 37Aa is formed in a substantially U-shape at a corner in the A2-B1 direction, electrode pattern 37Ab is formed in a substantially L-shape at a substantially central portion of one short side on the A2 side of the first sealing member 3A, electrode pattern 37Ac is formed extending in the A1 direction from a corner in the A2-B2 direction along a long side on the B2 side of the first sealing member 3A, electrode pattern 37Ad is formed in a substantially L-shape at a corner in the A1-B2 direction, electrode pattern 37Ae is formed extending in the A2 direction from a substantially central portion of the other short side on the A1 side of the first sealing member 3A, and electrode pattern 37Af is formed in a substantially U-shape at a corner in the A1-B1 direction. In addition, a rectangular electrode pattern 38Aa is formed in the shape of a floating island at the corner inside the rectangle R in the A2-B2 direction, and another rectangular electrode pattern 38Ab is formed in the shape of a floating island separated by a slit 38Ac at a position inside the rectangle R of the electrode pattern 37Ae along the long side on the A1 side.

[0081] Some of the eight electrode patterns 37Aa to 37Af, i.e., floating island-like electrode patterns 38Aa and 38Ab, are arranged inside a rectangle R indicated by a dashed line in Fig. 10. As shown in Fig. 16, the connection surface (lower surface) of the IC chip 5A facing the first sealing member 3A is provided with power supply pads 51Aa, piezoelectric vibrator output pads 51Ab, piezoelectric vibrator input pads 51Ac, control function pads 51Ad, earth pads 51Ae, second output pads 51Af, data write pads 51Ag, and first output pads 51Ah, as will be described later.

[0082] The first sealing member 3A also includes a power supply wiring section 39Aa connected to the power supply pads 51Aa of the IC chip 5A at a position inside the rectangle R of the electrode pattern 37Aa, a second piezoelectric vibrator wiring section 39Ab connected to the piezoelectric vibrator output pads 51Ab at a position inside the rectangle R of the electrode pattern 37Ae, a first piezoelectric vibrator wiring section 39Ac connected to the piezoelectric vibrator input pads 51Ac at a position inside the rectangle R of the electrode pattern 37Ab, and a control function wiring section 39Ab connected to the control function pads 51Ad at a position inside the rectangle R of the electrode pattern 38Aa. 39Ad, an earth wiring section 39Ae connected to an earth pad 51Ae at a position inside the rectangle R of the electrode pattern 37Ac, a second output wiring section 39Af connected to a second output pad 51Af at a position inside the rectangle R of the electrode pattern 37Ad, a data write wiring section 39Ag connected to a data write pad 51Ag at a position of the electrode pattern 38Ab inside the rectangle R, and a first output wiring section 39Ah connected to a first output pad 51Ah at a position inside the rectangle R of the electrode pattern 37Af closer to the A2 direction.

[0083] These wiring portions 39Aa to 39Ah are arranged along the long side R1 on the A2 side and the long side R2 on the A1 side (see FIG. 10) of the rectangle R. Here, the wiring portions 39Ae and 39Ah are arranged closer to the A2 direction than the wiring portions 39Af and 39Ag. Note that the data write pad 51Ag of the IC chip 5A and the data write wiring portion 39Ag of the first sealing member 3A are not limited to data write and may be replaced with something other than data write.

[0084] Then, as in the first embodiment, these eight wiring portions 39Aa to 39Ah are bonded to eight pads 51Aa to 51Ah of the IC chip 5 by FCB (Flip Chip Bonding) using metal bumps (for example, Au bumps) B (see FIG. 9).

[0085] 10 and 11, six through holes are formed in the first sealing member 3A, which are connected to the six electrode patterns 37Aa to 37Af, respectively, and which penetrate between the first main surface 311A ​​and the second main surface 312A. Specifically, third through holes 322A at the four corners are formed in the electrode patterns 37Aa, 37Ac, 37Ad, and 37Af at the four corners of the first sealing member 3A, respectively. Fourth through holes 323A and fifth through holes 324A are provided in the two electrode patterns 37Ab and 37Ae other than the four corners, respectively, as shown in FIGS.

[0086] In third through hole 322A and fourth and fifth through holes 323A, 324A, through electrodes for achieving electrical connection between electrodes formed on first main surface 311A ​​and second main surface 312A are formed along the inner wall surfaces of the respective through holes. In addition, the central portions of third through hole 322A and fourth and fifth through holes 323A, 324A each form a hollow through portion that penetrates between first main surface 311A ​​and second main surface 312A.

[0087] A sealing-side first bonding pattern 321A for bonding to the upper surface of the piezoelectric diaphragm 2A is formed on the second main surface 312A of the first sealing member 3A. Similar to the vibration-side first bonding pattern 251A of the piezoelectric diaphragm 2A, this sealing-side first bonding pattern 321A is formed in a shape surrounded by a rectangular outer frame that is slightly smaller than the rectangular shape of the first sealing member 3A in plan view, and an approximately annular inner frame in plan view.

[0088] Third through holes 322A are formed at the four corners of the second main surface 312A of the first sealing member 3A that overlap the sealing-side first bonding pattern 321A, and connecting bonding patterns 326A are formed around each of the four third through holes 322A except for the corners in the A2-B2 direction, separated from the sealing-side first bonding pattern 321A by rectangular slits 325A. Furthermore, the third through holes 322A at the corners in the A2-B2 direction are surrounded by approximately C-shaped slits 327A and have connecting bonding patterns 328A connected to the sealing-side first bonding pattern 321A.

[0089] A substantially circular connection junction pattern 351A is formed around the fourth through hole 323A, and a substantially circular connection junction pattern 352A is formed around the fifth through hole 324A. Furthermore, the connection junction pattern 352A is disposed on the A1 side of the first sealing member 3A, and a substantially circular connection junction pattern 353A is formed on the A2 side of the first sealing member 3A, and the connection junction pattern 352A and the connection junction pattern 353A are connected by the wiring pattern 33A. Note that the connection junction pattern 353A is not connected to the connection junction pattern 351A.

[0090] In the third, fourth and fifth through holes 322A, 323A and 324A, through electrodes for achieving electrical continuity between the electrodes formed on the first main surface 311A ​​and the second main surface 312A are formed along the inner wall surfaces of the respective through holes. In addition, the central portions of the third to fifth through holes 322A to 324A are hollow through portions that penetrate between the first main surface 311A ​​and the second main surface 312A.

[0091] In the first sealing member 3A, the electrode patterns 37Aa to 37Af, 38Aa, and 38Ab, the sealing-side first bonding pattern 321A, the connection bonding patterns 326A, 328A, and 351A to 353A, and the wiring pattern 33A can be formed in the same process, as in the first embodiment.

[0092] As shown in Figures 14 and 15, the second sealing member 4A has a sealing-side second bonding pattern 421A formed on a first main surface 411A of the second sealing member 4A for bonding to the underside of the piezoelectric vibration plate 2A, and the sealing-side second bonding pattern 421A is formed in a shape surrounded by a rectangular outer frame that is slightly smaller than the rectangle of the second sealing member 4A in a planar view, and an approximately annular inner frame in a planar view, similar to the vibration-side first bonding pattern 251A of the piezoelectric vibration plate 2 and the sealing-side first bonding pattern 321A of the first sealing member 3.

[0093] As shown in Fig. 15, four external electrode terminals 43Aa to 43d are provided on the second main surface 412A of the second sealing member 4A. Specifically, four external electrode terminals 43Aa, 43Ab, 43Ac, and 43Ad for electrical connection to the outside are provided on the second main surface 412A of the second sealing member 4A in a clockwise direction on the plane of Fig. 14, and these external electrode terminals 43Aa to 43Ad are located at the four corners (corner portions) of the second sealing member 4A. The four external electrode terminals 43Aa to 43Ad correspond to the "power supply external terminal," "earth external terminal," "second output external terminal," and "first output external terminal" in the present invention, respectively.

[0094] As shown in Figures 14 and 15, sixth through holes 44A are formed in the second sealing member 4A, and these sixth through holes 44A are formed in positions on the first main surface 411A that overlap connection bonding patterns 46A and 48A described later, and are formed in positions on the second main surface 412A that overlap four external electrode terminals 43Aa to 43Ad, respectively.

[0095] 14, on the first main surface 411A, a connection bonding pattern 46A is formed around each of the four sixth through holes 44A except for the corners in the A2-B2 direction, the connection bonding pattern 46A being separated from the sealing-side second bonding pattern 421A by a rectangular slit 45A. Also, the sixth through hole 44A at the corner in the A2-B2 direction is surrounded by a substantially C-shaped slit 47A and is formed with a connection bonding pattern 48A connected to the sealing-side second bonding pattern 421A.

[0096] In the sixth through holes 44A, through electrodes for achieving electrical continuity between the electrodes formed on the first main surface 411A and the second main surface 412A are formed along the inner wall surfaces of the respective through holes. In addition, the central portions of the respective sixth through holes 44A form hollow through portions that penetrate between the first main surface 411A and the second main surface 412A.

[0097] In the second sealing member 4A, the external electrode terminal 43A, the sealing-side second bonding pattern 421A, and the connection bonding patterns 46A and 48A can be formed in the same process, as in the first embodiment.

[0098] As in the first embodiment, the IC chip 5A has a built-in oscillation amplifier with two phase-inverted outputs, and as shown in Figure 16, it is bonded to the upper surface of the first sealing member 3A by, for example, the FCB method using metal bumps to form a differential output type piezoelectric vibrator.

[0099] At the peripheral portion of the lower surface of the IC chip 5A, there are provided eight wiring portions 39Aa to 39Ah, each of which is opposite to the power supply wiring portion 39Aa. DD), a piezoelectric vibrator output pad 51Ab facing the second piezoelectric vibrator wiring section 39Ab and connected to the output of the piezoelectric vibrator, a piezoelectric vibrator input pad 51Ac facing the first piezoelectric vibrator wiring section 39Ac and connected to the input of the piezoelectric vibrator, a control function pad 51Ad facing the control function wiring section 39Ad and connected to the enable output, an earth pad 51Ae facing the earth wiring section 39Ae and connected to the earth (ground), a second output pad 51Af facing the second output wiring section 39Af and connected to the second output of the piezoelectric vibrator, a data write pad 51Ag facing the data write wiring section 39Ag and used for data writing, and a first output pad 51Ah facing the first output wiring section 39Ah and connected to the first output of the piezoelectric vibrator. As in the first embodiment, the pads 51Aa to 51Ah of the IC chip 5 are bonded and electrically connected to the wiring portions 39Aa to 39Ah of the first sealing member 3 by, for example, the FCB method using metal bumps B.

[0100] Then, the first and second sealing members 3A and 4A are bonded to the piezoelectric diaphragm 2A, and the IC chip 5A is bonded to form a piezoelectric vibration device. At this time, the first and second lead wirings 223A and 224A and the connection bonding patterns 27A, 28A, and 29A form a pair of piezoelectric vibrator connection paths RT3' on the first main surface 211A side and the second main surface 212A side, and a first output connection path (electrode pattern 37Af, through electrode in the third through hole 322A, the bond between the connection bonding pattern 326A and the connection bonding pattern 254A, the through electrode in the first through hole 261A, the bond between the connection bonding pattern 254A and the connection bonding pattern 46A) including the external electrode terminal 43Ad (first output external terminal) is formed. A second output connection path (electrode pattern 37Ad, the through electrode in the third through hole 322A, the junction between connection junction pattern 326A and connection junction pattern 254A, the through electrode in the first through hole 261A, the junction between connection junction pattern 254A and connection junction pattern 46A, the through electrode in the sixth through hole 44A, and the path of external electrode terminal 43Ac) RT2' is formed, which includes external electrode terminal 43Ac (second output external terminal).

[0101] In addition, a pair of piezoelectric vibrator connection paths RT3' on both main surfaces 211A, 212A are arranged near the short side on the A2 (+Z') side of the piezoelectric vibrator rectangle, and as shown in Figure 10, the wiring patterns 37Ad, 37Af have different shapes and are not line-symmetrical with respect to the line L' (which corresponds to line L2 in Figure 12) connecting the centers of the two opposing short sides on the A1 (-Z') side and A2 (+Z') side of the piezoelectric vibrator rectangle, but the path length and area of ​​the wiring from wiring pattern 39Ad to the third through hole 322A are formed to be approximately the same as the path length and area of ​​the wiring from wiring pattern 39Af to the third through hole 322A, and each output connection path other than wiring patterns 37Ad, 37Af is line-symmetrical with respect to line L' (path length and area are approximately the same), and as a result, the wiring length and wiring area of ​​the first output connection path RT1' and the second output connection path RT2' are formed to be approximately the same, and the path length and capacity are also approximately the same.

[0102] According to the second embodiment, the path length and area of ​​the wiring from the wiring pattern 39Ad of the first sealing member 3A to the third through hole 322A are formed to be approximately the same as the path length and area of ​​the wiring from the wiring pattern 39Af to the third through hole 322A, and each output connection path other than the wiring patterns 37Ad, 37Af are formed to be symmetrical about the line L' (see Figure 10) (path length and area are approximately the same).As a result, the wiring length and wiring area of ​​the first output connection path RT1' and the second output connection path RT2' are formed to be approximately the same, and the path length and capacity of the first output connection path RT1' and the second output connection path RT2' can be made approximately the same.Even in a piezoelectric vibration device having a piezoelectric vibration plate 2A configured to hold the vibration part 22A to the outer frame part 23A at four points by the holding part 24A, an effect equivalent to that of the first embodiment can be obtained.

[0103] Furthermore, because the structure holds the vibrating portion 22A at four corners of the inner peripheral wall of the outer frame portion 23A, miniaturization is not hindered while satisfying the acceleration sensitivity evaluation of the piezoelectric diaphragm 2A. Moreover, it is possible to provide a piezoelectric vibration device using the piezoelectric diaphragm 2A with a holding structure that ensures an effective planar view area for the vibrating portion 22A and has an excellent overall balance that is resistant to the effects of external stress and vibration leakage.

[0104] Moreover, because both ends of outer frame holding portions 24Ab of the two holding portions 24A are connected to the wider sides of outer frame portion 23A, it is advantageous for ensuring strength against external shock. Furthermore, because outer frame holding portions 24Ab are connected to the four corners of the inner peripheral wall of outer frame portion 23A, bending and stress of outer frame portion 23A due to external shock are easily alleviated, which is advantageous for stress alleviation.

[0105] Moreover, because one end of vibration holding portion 24Aa of holding portion 24A is connected to the center of the opposing short side of vibrating portion 22A, it is possible to effectively suppress deflection of vibrating portion 22A with few connecting points. Furthermore, because the other end of vibration holding portion 24Aa of holding portion 24A is connected to the center of outer frame holding portion 24Ab, it is possible to easily maintain the balance of holding portion 24A and effectively suppress deflection of vibrating portion 22A.

[0106] As in the first embodiment, the gap between the vibration portion 22A of the piezoelectric vibration plate 2A and the first and second sealing members 3A and 4A may be formed by forming the vibration portion 22A and the holding portion 24A of the piezoelectric vibration plate 2A thinner than the outer frame portion 23A and joining the flat first and second sealing members 3A and 4A together, or the outer frame portion 23A may be made the same thickness as the vibration portion 2A2 and the holding portion 2A4, and forming recesses in the first and second sealing members 3A and 4A and joining them together to form the gap.

[0107] The present invention is not limited to the above-described configuration, and various design modifications are possible within the scope of the claims. For example, in the above-described embodiment, the piezoelectric diaphragm 2, 2A includes the vibrating portion 22, 22A, the outer frame portion 23, 23A, the holding portion 24, 24Aa, 24Ab, and the cutout portion 25, 25Aa, 25Ab. However, the present invention can be applied to a configuration that does not include the holding portion and the cutout portion.

[0108] Furthermore, in the second embodiment described above, if the wiring length and wiring area of ​​the first output connection path RT1' and the second output connection path RT2' are approximately the same and the path length and capacity are approximately the same, the first output connection path RT1' and the second output connection path RT2' do not necessarily need to be arranged in a symmetrical positional relationship with respect to the line L' in Figure 10.

[0109] Furthermore, the piezoelectric diaphragms 2 and 2A in the above-described embodiments are not limited to AT-cut quartz crystal plates, but may also be SC-cut quartz crystal plates or tuning fork-type vibrators.

[0110] In the above-described embodiment, the electronic component element is an IC chip 5, 5A, which is an oscillator circuit element. The IC chip can be a CMOS output oscillation IC, a differential output oscillation IC, a VCXO IC, a TCXO IC, or the like.

[0111] The present invention can be widely applied to piezoelectric vibration devices that have a piezoelectric vibration plate that is rectangular in plan view, an upper sealing plate, and a lower sealing plate, the upper and lower surfaces of the piezoelectric vibration plate are covered and hermetically sealed by the upper sealing plate and the lower sealing plate, respectively, to form a piezoelectric vibrator, and an integrated circuit element with a built-in oscillation amplifier is connected to the upper surface side of the upper sealing plate of the piezoelectric vibrator. [Explanation of symbols]

[0112] 2,2A...Piezoelectric diaphragm 3,3A...First sealing member (upper sealing plate) 4, 4A ... Second sealing member (lower sealing plate) 5.5A...IC chip (integrated circuit element) 22,22A…Vibrating part 23, 23A ... outer frame 24,24Aa,24Ab…Holding part 25, 25Aa, 25Ab ...Cutout section 37a~37f, 37Aa~37Af, 38Aa, 38Ab...electrode patterns 39a~39f,39Aa~39Ah...Wiring section 51a~51fh, 51Aa~51Ah ... Pads RT1, RT1' ... Connection path for first output RT2,RT2' ...Second output connection path

Claims

1. A piezoelectric vibration device has a piezoelectric vibration plate having a rectangular shape in a plan view, an upper sealing plate, and a lower sealing plate, the upper and lower surfaces of the piezoelectric vibration plate are covered and hermetically sealed by the upper sealing plate and the lower sealing plate, respectively, to form a piezoelectric vibrator, and an integrated circuit element having a built-in oscillation amplifier is connected to the upper surface side of the upper sealing plate of the piezoelectric vibrator, The piezoelectric diaphragm is a vibration section on which a pair of excitation electrodes are formed; an outer frame portion surrounding an outer peripheral wall of the vibration portion; Equipped with a gap portion is provided between the vibration portion and the upper sealing plate and between the vibration portion and the upper sealing plate and the lower sealing plate; The upper sealing plate is an integrated circuit element connecting wiring portion formed on an upper surface thereof to which the integrated circuit element is electrically connected; The lower sealing plate is a power supply external terminal, a ground external terminal, a first output external terminal, and a second output external terminal formed at four corners of the lower surface; The piezoelectric vibrator is a first output connection path that connects the integrated circuit element and the first external output terminal; a second output connection path that connects the integrated circuit element and the second external output terminal; The first output connection path and the second output connection path are formed to have substantially the same wiring length and wiring area. A piezoelectric vibration device characterized by:

2. The piezoelectric diaphragm is a holding portion that connects the outer peripheral wall of the vibration portion and the inner peripheral wall of the outer frame portion; A cutout portion is formed by cutting out the piezoelectric vibration plate in the plate thickness direction between the vibration portion and the outer frame portion.

2. The piezoelectric vibration device according to claim 1, further comprising:

3. A piezoelectric vibration device as described in claim 1 or 2, characterized in that the first output connection path and the second output connection path are arranged symmetrically with respect to a line connecting the centers of the opposing short sides of the rectangular piezoelectric vibration plate.

4. 3. The piezoelectric vibration device according to claim 1, wherein the width of the outer frame of the piezoelectric vibration plate at a portion corresponding to a short side of the rectangle of the piezoelectric vibration plate is greater than that of a portion corresponding to a long side of the rectangle.

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