Crystal vibration device

Abstract

The present invention provides a crystal vibration device with which both miniaturization and impact resistance can be attained.　Provided is a crystal oscillator 1 comprising: a package 6 having a rectangular parallelepiped outer shape with an open upper surface, the package 6 including, on the inside thereof, a recess 61 formed to be biased to one side, a step 62 formed above an inner bottom surface 61a of the recess 61, and crystal oscillating-element mounting pads 63a, 63b provided to the step 62 and conductively bonded to two external terminals 32b, 32c, respectively; an IC 5 disposed on the inner bottom surface 61a of the recess 61; and a substrate 30 with one end side thereof being supported as a fixed end and the other end side thereof disposed above the IC 5 as a free end, with the two external terminals 32b, 32c being bonded respectively to the crystal oscillating-element mounting pads 63a, 63b via a conductive adhesive 65. The conductive adhesive 65 adheres the external terminals 32b, 32c to the crystal oscillating-element mounting pads 63a, 63b and adheres the substrate 30 to a base region 66.

Description

Crystal vibrating device

[0001] The present invention relates to a crystal vibrating device.

[0002] Conventionally, there is a crystal vibrating device disclosed in Patent Document 1, in which a crystal vibrating element is hermetically sealed inside a package. As shown in FIG. 8 of Patent Document 1, this type of crystal vibrating device comprises, for example, a ceramic package that has a rectangular parallelepiped outer shape, a recess formed inside, and an open top surface, a pedestal blank that forms a stepped portion joined to the inner bottom surface of the recess of the package with an adhesive, a crystal vibrating element having one end side joined and fixed in a cantilevered state to the top surface of the pedestal blank, and a lid member that closes the top opening of the package and hermetically seals the inside of the package. At this time, the other end of the crystal vibrating element opposite to the one end on the cantilever support side is a freely displaceable free end.

[0003] Japanese Unexamined Patent Application Publication No. 2016-15757

[0004] However, as disclosed in Patent Document 1, in the case of a crystal vibrating device having a configuration in which a crystal vibrating element is supported in a cantilevered state via a substrate in a package, when an external impact is applied to the device, the free end side of the substrate on which the element is mounted, which is opposite to the cantilever support side, is greatly displaced toward the inner bottom surface of the package by the external impact and comes into contact with the inner bottom surface, which may adversely affect the characteristics of the crystal vibrating device.

[0005] Further, in a configuration where a stepped portion is formed at a position higher and closer to the top opening than the inner bottom surface of the package, one end of the crystal vibrating element is cantilever-supported via the substrate on the stepped portion, and an integrated circuit element including an oscillation amplifier circuit is disposed on the inner bottom surface of the package, when the free end of the substrate on which the crystal vibrating element is mounted is greatly displaced by external impact, the free end of the substrate may come into contact with the integrated circuit element.

[0006] Possible solutions to these challenges include, for example, arranging the free end of the substrate so that it does not overlap with the integrated circuit elements in a plan view, or increasing the bonding strength by widening the bonding area between the cantilever support side of one end of the substrate and the package. However, given the strong demand for miniaturization of quartz oscillator devices in recent years, space constraints often prevent such measures from being taken. Therefore, there is a need for quartz oscillator devices that can achieve both miniaturization and shock resistance.

[0007] This invention has been made in view of the above problems, and aims to provide a quartz oscillator device that achieves both miniaturization and shock resistance.

[0008] The present invention relates to a quartz oscillator device comprising a substrate that is substantially rectangular in plan view and has at least two connection terminals on its outer bottom surface, a quartz oscillator mounted on the opposite side of the outer bottom surface of the substrate, an electronic component, and a package that hermetically seals the substrate, the quartz oscillator mounted on the substrate, and the electronic component, wherein the package has a rectangular parallelepiped outer shape with an open top surface, a recess formed off-center to one side, a stepped portion formed above the inner bottom surface of the recess, and a pair of mounting pads provided on the stepped portion that are electrically connected to each of the two connection terminals, The electronic component is arranged on the inner bottom surface of the recess, and the substrate is supported at one end as a fixed end and at the other end as a free end, with two connection terminals bonded to a pair of mounting pads via a conductive adhesive, and is positioned above the electronic component or the stepped portion. The substrate has a high-adhesion region with higher adhesive strength to the conductive adhesive compared to the connection terminals, and the conductive adhesive is a quartz oscillator device that bonds the connection terminals to the mounting pads and also bonds the connection terminals to the high-adhesion region.

[0009] In other words, the quartz oscillator device of the present invention has a substrate with a high-adhesion region that has higher adhesive strength with the conductive adhesive compared to the connection terminals, and the conductive adhesive adheres the connection terminals to the mounting pad and also adheres the connection terminals to the high-adhesion region. With this configuration, even if the internal space of the package is constrained due to the miniaturization of the quartz oscillator device, and one end of the substrate is supported as a fixed end and the other end is positioned above an electronic component or the stepped portion as a free end, sufficient bonding strength by the conductive adhesive can be ensured. That is, even if the package is subjected to an external impact, vertical displacement of the substrate and the quartz oscillator element mounted on the substrate can be suppressed. Furthermore, even if the package is subjected to an external impact, the substrate can be prevented from falling off, improving the shock resistance of the quartz oscillator device, thus enabling both miniaturization and shock resistance of the quartz oscillator device.

[0010] Furthermore, the high-adhesion region may be the substrate material itself. With such a configuration, the strength between the substrate and the conductive adhesive can be further improved. For example, when the substrate is a quartz plate, the bonding strength with a silicone-based adhesive can be particularly improved.

[0011] Furthermore, the substrate may have multiple grooves on its side surface that are concave toward the interior of the substrate, and the conductive adhesive may be configured to bond the connection terminal and the mounting pad, as well as to bond across the multiple grooves.

[0012] In this configuration, even if the internal space of the package is constrained by the miniaturization of the quartz oscillator device, and one end of the substrate is supported as a fixed end while the other end is positioned above the electronic component as a free end, the conductive adhesive adheres across multiple grooves, thereby increasing the bonding area between the conductive adhesive and the substrate. Consequently, sufficient bonding strength can be ensured by the anchoring effect of the conductive adhesive. In other words, it is possible to suppress the substrate from falling off due to external impacts on the package, thereby improving the shock resistance of the quartz oscillator device, and thus achieving both miniaturization and shock resistance of the quartz oscillator device.

[0013] Furthermore, the groove may be formed extending in the thickness direction of the substrate and penetrating from the outer bottom surface to the opposite surface. With such a configuration, the conductive adhesive can easily crawl up along the groove, increasing the contact area between the conductive adhesive and the substrate and improving the bonding strength.

[0014] According to the present invention, it is possible to provide a quartz oscillator device that achieves both miniaturization and shock resistance.

[0015] A side cross-sectional view of a crystal oscillator, which is the first embodiment of the crystal oscillator device according to the present invention. A plan view of the crystal oscillator in Figure 1 with the lid member, crystal resonator, and IC removed. A schematic plan diagram showing the superposition relationship between the external terminals of the crystal resonator, the conductive adhesive, and the crystal resonator mounting pad in the crystal oscillator in Figure 1. A side view of the crystal resonator in Figure 1. A schematic plan view of the first main surface side of the sealing member of the crystal resonator in Figure 1. A schematic plan view of the second main surface side of the sealing member of the crystal resonator in Figure 1. A schematic plan view of the first main surface side of the crystal resonating element of the crystal resonator in Figure 1. A schematic plan view of the second main surface side of the crystal resonating element of the crystal resonator in Figure 1. A schematic plan view of the first main surface side of the substrate of the crystal resonator in Figure 1. A schematic plan view of the second main surface side of the substrate of the crystal resonator in Figure 1. A side cross-sectional view of a crystal oscillator, which is the second embodiment of the crystal oscillator device according to the present invention. An enlarged side view of the substrate in Figure 11. A plan view of the multiple grooves in Figure 11 viewed from the thickness direction of the substrate. A plan view of the crystal oscillator in Figure 11 with the cover member, crystal oscillator, and IC removed. A schematic plan view showing the superposition relationship between the external terminals of the crystal oscillator in the crystal oscillator in Figure 11, the conductive adhesive, and the crystal oscillator mounting pad. An enlarged side view showing the superposition relationship between the conductive adhesive and the substrate in Figure 11. A side view of the crystal oscillator in Figure 11. A modified example of the second embodiment, a plan view with the cover member, crystal oscillator, and IC removed.

[0016] Embodiments of the present invention will be described in detail below with reference to the drawings. In the following embodiments, the case in which the crystal oscillator device to which the present invention is applied will be described.

[0017] <First Embodiment> As shown in Figure 1, the crystal oscillator 1 in the first embodiment comprises a substrate 30 that is substantially rectangular in plan view and has at least two connection terminals on its outer bottom surface (bottom surface), a crystal oscillator 10, an integrated circuit element (hereinafter referred to as IC) 5 which is an electronic component, and a ceramic package 6 that hermetically seals the substrate 30, the crystal oscillator 10 mounted on the substrate 30, and the IC 5. In this embodiment, the substrate 30 and the crystal oscillator 10 are joined together, and the crystal oscillator 10 and the sealing member 20 are further joined together to form a crystal resonator 100. In this embodiment, a metal lid member 7 is seam-welded to the upper surface of the package 6 by a substantially rectangular metal member 8, thereby sealing the package 6. In this embodiment, the electronic component is an IC, but it may also be a temperature sensor.

[0018] As shown in Figure 1, the package 6 has a rectangular parallelepiped shape with an open top surface. Inside, a recess 61 is formed, offset to one side (the right side in Figure 1), and a stepped portion 62 is formed above the inner bottom surface 61a of the recess 61, protruding to approximately the center in a plan view. The stepped portion 62 is provided with a pair of mounting pads (crystal oscillator mounting pads 63a, 63b) which are electrically bonded to the two connection terminals (external terminals 32b, 32c) of the substrate 30 via a conductive adhesive 65. In addition, six IC mounting pads 64a to 64f (details to be described later) are provided on the inner bottom surface 61a of the recess 61, and the IC 5 is electrically connected to these six IC mounting pads 64a to 64f and mounted inside the package 6.

[0019] Figure 2 is a plan view showing the state before the lid member 7 of the package 6 is removed and the crystal oscillator 100 and IC 5 are housed inside the package 6, as in Figure 1. Figure 3 is a schematic plan view showing the superposition relationship between the external terminals 32a, 32b, and 32c of the crystal oscillator 100 in the crystal oscillator 1, the conductive adhesive 65, and the crystal oscillator mounting pads 63a and 63b. In Figure 2, the dotted rectangle R1 represents the outline of the crystal oscillator 100 in a plan view, and the double dotted rectangle R2 represents the outline of the IC 5 in a plan view. As shown in Figure 2, the stepped portion 62 inside the package 6 is provided with a pair of crystal oscillator mounting pads 63a and 63b that are conductively bonded to the two external terminals 32b and 32c of the crystal oscillator 100 (substrate 30) via the conductive adhesive 65. Furthermore, the recess 61 is provided with the first to sixth IC mounting pads 64a, 64b, 64c, 64d, 64e, and 64f.

[0020] The outer bottom surface (underside) of IC5 is provided with six terminals (not shown). Each terminal has a function such as a power terminal, output terminal, crystal oscillator connection terminal, and ground connection terminal. These six terminals are electrically connected to the first to sixth IC mounting pads 64a to 64f on the package 6 side, for example, by metal bumps.

[0021] Furthermore, the crystal oscillator 100 is electrically bonded to the stepped portion 62 (crystal oscillator mounting pads 63a, 63b) of the package 6 via a conductive adhesive 65 at one of the short sides of the crystal oscillator 100 at the external terminals 32b, 32c. That is, one end of the crystal oscillator 100 is supported as a fixed end, and the other end is a free end. At this time, the free end and the IC 5 overlap in a plan view. The conductive adhesive 65 can be any known conductive adhesive, such as an epoxy adhesive or a silicone adhesive, but it is preferable to use a silicone adhesive.

[0022] Then, when the crystal oscillator 100 and IC 5 are placed in predetermined positions within the package 6 and conductively bonded, the external terminals 32b and 32c on the outer bottom surface of the crystal oscillator 100 (substrate 30), the crystal oscillator mounting pads 63a and 63b, and the conductive adhesive 65 overlap. At this time, as shown in Figure 3, the conductive adhesive 65 overlaps with the base material region 66 of the crystal oscillator 100 (substrate 30). That is, the conductive adhesive 65 adheres not only to the external terminals 32b and 32c and the crystal oscillator mounting pads 63a and 63b, but also to the base material region 66 of the crystal oscillator 100 (substrate 30). The base material region 66 is made of a material with higher bonding strength to the conductive adhesive 65 than the gold that forms the outermost layer of the external terminals 32b and 32c and the crystal oscillator mounting pads 63a and 63b. In other words, the base material region 66 in this embodiment corresponds to the high-adhesion region in the present invention. The highly adhesive region is preferably the base material portion of the quartz crystal oscillator 100 (substrate 30).

[0023] As shown in Figure 4, the quartz oscillator 100 is configured as a roughly rectangular sandwich-structured package by joining the quartz oscillator element 10 and the sealing member 20 at a sealing portion (seal path) 115, and joining the quartz oscillator element 10 and the substrate 30 at a sealing portion (seal path) 116. In other words, in the quartz oscillator 100, the sealing member 20 and the substrate 30 are joined to each of the two main surfaces of the quartz oscillator element 10 to form an internal space (cavity) of the package, and the vibrating part 11 (see Figures 7 and 8) is hermetically sealed in this internal space. In this embodiment, the quartz oscillator 100 is composed of a quartz oscillator element 10, a sealing member 20, and a substrate 30 (details will be described later).

[0024] Next, the quartz oscillator element 10, the sealing member 20, and the substrate 30 in the quartz oscillator 100 described above will be explained with reference to Figures 5 to 10. Here, we will explain each component as a separate unit that is not bonded together. Figures 5 to 10 merely show one example configuration of the quartz oscillator element 10, the sealing member 20, and the substrate 30, and these do not limit the present invention.

[0025] In the first embodiment, the quartz oscillator 10 is a quartz oscillator made using an AT-cut quartz plate (piezoelectric substrate) that performs thickness-sliding vibration. As shown in Figures 5 and 6, both main surfaces 101 and 102 of the quartz oscillator 10 are the XZ' plane. In this XZ' plane, the direction parallel to the short side of the quartz oscillator 10 is the X-axis direction, and the direction parallel to the long side of the quartz oscillator 10 is the Z' axis direction. AT cutting is a processing method in which a quartz crystal is cut at an angle of 35°15′ around the X-axis with respect to the Z-axis, one of the three crystal axes of 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' and Z' axes coincide with axes that are inclined approximately 35°15′ from the Y and Z axes of the quartz crystal axis, respectively (this cutting angle may be slightly changed within the range of adjusting the frequency-temperature characteristics of the AT-cut quartz oscillator). The Y' and Z' axis directions correspond to the cutting direction when cutting out the AT-cut quartz plate. Furthermore, both main surfaces (first main surface 101, second main surface 102) of the quartz oscillator 10 are formed as flat, smooth surfaces whose surfaces are finished to a mirror finish, for example, by polishing.

[0026] The quartz oscillator 10 has a vibrating portion 11 formed in a substantially rectangular shape, an outer frame portion 12 surrounding the outer circumference of the vibrating portion 11, and a holding portion 13 that holds the vibrating portion 11 by connecting the vibrating portion 11 and the outer frame portion 12. In other words, the quartz oscillator 10 has a configuration in which the vibrating portion 11, the outer frame portion 12, and the holding portion 13 are integrally provided. The holding portion 13 extends (projects) from only one corner of the vibrating portion 11 located in the +X direction and the -Z' direction to the outer frame portion 12 in the -Z' direction. A cutout portion 10a formed by cutting out the quartz oscillator 10 is provided between the vibrating portion 11 and the outer frame portion 12. In this embodiment, the quartz oscillator 10 is provided with only one holding portion 13 that connects the vibrating portion 11 and the outer frame portion 12, and the cutout portion 10a is formed continuously so as to surround the outer circumference of the vibrating portion 11.

[0027] The thickness of the substrate of the quartz oscillator 10 can be, for example, about 40 μm or about 60 μm. Furthermore, the vibrating portion 11 of the quartz oscillator 10 can be formed to be thinner than the outer frame portion 12. For example, the thickness of the vibrating portion 11 can be about half the thickness of the outer frame portion 12. In this case, it is preferable that the positions of the first main surface 101 of the outer frame portion 12 and the first main surface 101 of the vibrating portion 11 are different in the thickness direction (Y' direction). The thickness of the vibrating portion 11 is related to the frequency of the quartz oscillator 100. Therefore, the thickness of the vibrating portion 11 may be adjusted as appropriate to obtain a quartz oscillator 100 having a desired frequency.

[0028] A pair of excitation electrodes (first excitation electrode 111, second excitation electrode 112) are formed on both main surfaces 101 and 102 of the quartz oscillator element 10. The first excitation electrode 111 is provided on the first main surface 101 side of the vibrating part 11, and the second excitation electrode 112 is provided on the second main surface 102 side of the vibrating part 11. Lead wires (first lead wire 113, second lead wire 114) for connecting these excitation electrodes to external terminals are connected to the first excitation electrode 111 and the second excitation electrode 112. The first lead-out wiring 113 is led out from the first excitation electrode 111 and connected via the holding portion 13 to a connecting joint pattern 12a formed on the first main surface 101 side of the outer frame portion 12. Furthermore, the connecting joint pattern 12a is connected via the second front-to-back routing wiring 18 formed on the inner wall surface of the outer frame portion 12 to a connecting joint pattern 12e formed on the second main surface 102 side of the outer frame portion 12. In addition, the second lead-out wiring 114 is led out from the second excitation electrode 112 and connected via the holding portion 13 to a connecting joint pattern 12d formed on the second main surface 102 side of the outer frame portion 12.

[0029] Furthermore, as shown in Figures 7 and 8, both main surfaces (first main surface 101 and second main surface 102) of the quartz oscillator 10 are provided with vibration element-side sealing portions for joining the quartz oscillator 10 to the sealing member 20 and the substrate 30. A vibration element-side first bonding pattern 121 is formed as the vibration element-side sealing portion of the first main surface 101, and a vibration element-side second bonding pattern 122 is formed as the vibration element-side sealing portion of the second main surface 102. The vibration element-side first bonding pattern 121 and the vibration element-side second bonding pattern 122 are provided on the outer frame portion 12 and are formed in an annular shape in plan view. The outer edge of the vibration element-side first bonding pattern 121 is provided close to the outer edge of the first main surface 101 of the quartz oscillator 10 (outer frame portion 12). The outer edge of the vibration element-side second bonding pattern 122 is provided close to the outer edge of the second main surface 102 of the quartz oscillator 10 (outer frame portion 12). In this embodiment, the first bonding pattern 121 on the vibration element side and the second bonding pattern 122 on the vibration element side are connected via a first front-to-back routing wiring 17 formed on the inner wall surface of the outer frame portion 12. The first front-to-back routing wiring 17 is provided on the inner wall surface of the outer frame portion 12 that is aligned with the Z' axis direction and is on the -X direction side.

[0030] As shown in Figures 5 and 6, the sealing member 20 in this embodiment is formed from a single rectangular parallelepiped AT-cut quartz plate. The first main surface 201 and the second main surface 202 (the surfaces that join to the quartz oscillator 10) of the sealing member 20 are formed as flat, smooth surfaces (mirror-finished). Although the sealing member 20 does not have a vibrating part, it is preferable to use an AT-cut quartz plate in the same way as the quartz oscillator 10. Furthermore, the orientation of the X, Y, and Z' axes of the sealing member 20 in this embodiment is the same as that of the quartz oscillator 10. In addition, it is preferable that the thickness of the sealing member 20 is the same as that of the quartz oscillator 10.

[0031] Furthermore, the sealing member 20 does not have any through holes that penetrate between the first main surface 201 and the second main surface 202. Therefore, the first main surface 201 of the sealing member 20 in this embodiment (the upper surface of the quartz oscillator 100) is a smooth surface in which the quartz forming the sealing member 20 is fully exposed.

[0032] As shown in Figure 6, a sealing member-side bonding pattern 24 for bonding to the quartz crystal oscillator 10 is formed on the second main surface 202 of the sealing member 20. The sealing member-side bonding pattern 24 is formed in an annular shape in plan view. The outer edge of the sealing member-side bonding pattern 24 is provided close to the outer edge of the second main surface 202 of the sealing member 20. In addition, the second main surface 202 of the sealing member 20 has a connecting bonding pattern 22a for bonding to the connecting bonding pattern 12a formed on the first main surface 101 of the outer frame portion 12 of the quartz crystal oscillator 10, a connecting bonding pattern 22b for bonding to the connecting bonding pattern 12b formed on the first main surface 101 of the outer frame portion 12 of the quartz crystal oscillator 10, and a connecting bonding pattern 22c for bonding to the connecting bonding pattern 12c formed on the first main surface 101 of the outer frame portion 12 of the quartz crystal oscillator 10.

[0033] In this embodiment, the substrate 30 is formed from a single AT-cut quartz plate, as shown in Figures 9 and 10. The first main surface 301 (the surface that bonds to the quartz oscillator 10) and the second main surface 302 (the bottom surface of the quartz oscillator 100) of the substrate 30 are formed as flat, smooth surfaces (mirror-finished). It is preferable that the substrate 30 is made from an AT-cut quartz plate, similar to the quartz oscillator 10, and that the orientation of the X, Y, and Z' axes is the same as that of the quartz oscillator 10. Furthermore, it is preferable that the thickness of the substrate 30 is the same as that of the quartz oscillator 10 and the sealing member 20.

[0034] As shown in Figure 10, three external terminals 32a, 32b, and 32c are provided on the second main surface 302 of the substrate 30 (the outer main surface not facing the quartz oscillator 10). In this embodiment, each of the external terminals 32a, 32b, and 32c is rectangular in plan view and has a different size. External terminal 32b has the largest area in this embodiment and is formed from near one end to near the other end in the long side direction of the rectangular substrate 30. External terminal 32c has the second largest area in this embodiment and is formed from near one end to near the center in the long side direction of the rectangular substrate 30. External terminal 32a has the smallest area in this embodiment and is formed adjacent to external terminal 32c in the long side direction of the substrate 30.

[0035] A substrate-side bonding pattern 31 for bonding to the quartz crystal oscillator 10 is formed on the first main surface 301 of the substrate 30. The substrate-side bonding pattern 31 is formed in an annular shape in plan view. The outer edge of the substrate-side bonding pattern 31 is provided close to the outer edge of the first main surface 301 of the substrate 30. In addition, the first main surface 301 of the substrate 30 has a connecting bonding pattern 33a for bonding to a connecting bonding pattern 12e formed on the second main surface 102 of the quartz crystal oscillator 10, a connecting bonding pattern 33b for bonding to a connecting bonding pattern 12f formed on the second main surface 102 of the quartz crystal oscillator 10, and a connecting bonding pattern 33c for bonding to a connecting bonding pattern 12d formed on the second main surface 102 of the quartz crystal oscillator 10. Furthermore, the connecting bonding pattern 33b and the connecting bonding pattern 33c are connected by a wiring pattern 34.

[0036] The substrate 30 has three through-holes that penetrate between the first main surface 301 and the second main surface 302. Specifically, the substrate 30 has a first through-hole 161, a second through-hole 162, and a third through-hole 163. The first, second, and third through-holes 161, 162, and 163 are formed so that, in a plan view from the second main surface 302 side, each falls within one region selected from the three external terminals 32a, 32b, and 32c. Conductive electrodes are formed on the inner walls of these through-holes. Therefore, the corresponding bonding patterns on the front and back sides and the external terminals are electrically connected by the conductive electrodes formed on the inner walls of the first, second, and third through-holes 161, 162, and 163.

[0037] In the quartz oscillator 100, each internal electrode, including the various bonding patterns and wiring patterns described above, and each excitation electrode may be formed by stacking multiple layers on the main surface of each quartz substrate, with a Ti (titanium) metal layer and an Au (gold) metal layer formed from the bottom layer side by vapor deposition or sputtering. Furthermore, the external terminals 32a, 32b, and 32c may be formed from a Ti (titanium) metal layer, a Ni (nickel) metal layer, and an Au (gold) metal layer formed from the bottom layer side by vapor deposition or sputtering. The various bonding patterns, wiring patterns, and electrodes described above may also be formed by photolithography.

[0038] In the quartz oscillator 100, which includes the quartz oscillator 10, sealing member 20, and substrate 30 as described above, the quartz oscillator 10 and the sealing member 20 are diffusion-bonded with the first bonding pattern 121 on the oscillator side and the bonding pattern 24 on the sealing member side superimposed, and the quartz oscillator 10 and the substrate 30 are diffusion-bonded with the second bonding pattern 122 on the oscillator side and the bonding pattern 31 on the substrate side superimposed, thereby manufacturing a sandwich-structured package. As a result, the internal space of the package, that is, the space housing the vibrating part 11, is hermetically sealed.

[0039] Furthermore, at this time, the aforementioned connection patterns are also diffusely bonded while superimposed. Through the bonding of the connection patterns, electrical conductivity is obtained between the first excitation electrode 111 and the external terminal 32c, and between the second excitation electrode 112 and the external terminal 32b in the crystal oscillator 100. Specifically, the first excitation electrode 111 is connected to the external terminal 32c via the first lead wiring 113, connection pattern 12a, second front-to-back routing wiring 18, connection pattern 12e, connection pattern 33a, and the conductive electrode of the third through hole 163 in that order. The second excitation electrode 112 is connected to the external terminal 32b via the second lead wiring 114, connection pattern 12d, connection pattern 33c, wiring pattern 34, connection pattern 33b, and the conductive electrode of the second through hole 162 in that order.

[0040] Furthermore, in the crystal oscillator 100 of this embodiment, a sealing portion (seal path) is formed to hermetically seal the vibrating portion 11 of the crystal oscillator element 10. The seal path consists of a first seal path 115 formed by diffusion bonding (Au-Au bonding) of the first bonding pattern 121 on the vibrating element side and the bonding pattern 24 on the sealing member side, and a second seal path 116 formed by diffusion bonding (Au-Au bonding) of the second bonding pattern 122 on the vibrating element side and the bonding pattern 31 on the substrate side. The first and second seal paths 115 and 116 are not electrically connected to the electrical conduction path between the first and second excitation electrodes 111 and 112 and the external terminals 32b and 32c. Specifically, the first seal path 115 is connected to the second seal path 116 via the first front-to-back wiring 17, and furthermore, the second seal path 116 is connected to the external terminal 32a via the conductive electrode of the first through hole 161.

[0041] With the above configuration, a crystal oscillator device that achieves both miniaturization and shock resistance can be provided. In the first embodiment, the crystal oscillator 1 has a substrate 30 with a high-adhesion region where the adhesive strength with the conductive adhesive 65 is higher than that with respect to the external terminals 32b and 32c. The conductive adhesive 65 adheres the external terminals 32b and 32c to the crystal oscillator mounting pads 63a and 63b, and also adheres the external terminals 32b and 32c to the high-adhesion region (base region 66). With this configuration, even if the internal space of the package 6 is constrained when miniaturizing the crystal oscillator 1, and one end of the substrate 30 (crystal oscillator 100) is supported as a fixed end and the other end is positioned above the IC 5 as a free end, sufficient bonding strength by the conductive adhesive 65 can be ensured. In other words, even if the package 6 is subjected to an external shock, vertical displacement of the substrate 30 and the crystal oscillator element 10 mounted on the substrate 30 can be suppressed. Furthermore, even if the package 6 is subjected to an external impact, the substrate 30 (crystal oscillator 100) is prevented from falling off, improving the shock resistance of the crystal oscillator 1. Thus, both miniaturization and shock resistance of the crystal oscillator 1 can be achieved.

[0042] Furthermore, the high-adhesion region is a base region 66 formed of the base material of the substrate 30. With this configuration, the bonding strength between the substrate 30 and the conductive adhesive 65 can be further improved. For example, when the substrate 30 is formed of a quartz crystal plate, the bonding strength can be improved particularly when a silicone-based adhesive is used as the conductive adhesive 65.

[0043] <Second Embodiment> The configuration of a crystal oscillator 1A according to a second embodiment will be described with reference to Figs. 11 to 17. Hereinafter, differences from the crystal oscillator 1 of the first embodiment will be mainly described.

[0044] As shown in Figs. 11 to 13, the crystal oscillator 1A of the second embodiment differs from the crystal oscillator 1 of the first embodiment in that a plurality of grooves 4 recessed toward the inner direction are formed on at least the side surface of the substrate 30 constituting the crystal resonator 100. That is, the above-described grooves 4 have an arc shape in plan view, and are vertical grooves (vertical streaks) extending in the thickness direction of the substrate 30 and penetrating from the outer bottom surface to the upper surface. Further, the plurality of grooves 4 in the second embodiment are provided side by side on the side surface of the substrate 30 so as to be adjacent to each other in a direction orthogonal to the thickness direction. In the second embodiment, the grooves 4 are formed in the substrate 30, but similar grooves may be formed not only in the substrate 30 but also in the crystal vibrating element 10 and / or the sealing member 20. Further, although it is preferable that the grooves 4 have an arc shape in plan view as in the present embodiment, the cross-sectional shape is not particularly limited and may be various shapes. Furthermore, although the plurality of grooves 4 in the present embodiment are configured such that adjacent grooves 4 are adjacent to each other, adjacent grooves 4 may be spaced apart from each other.

[0045] Furthermore, as shown in Figures 14 and 15, the conductive adhesive 65 overlaps not only the external terminals 32b, 32c, the crystal oscillator mounting pads 63a, 63b, and the substrate region 66b (corresponding to the substrate region 66 in the first embodiment), but also the substrate region 66a of the package 6, which is another difference from the crystal oscillator 1 in the first embodiment. In this case, the substrate region of the package 6 has a rougher surface compared to the metal film surface, which is advantageous in that it increases the contact area with the adhesive and enhances bonding strength. Here, if the adhesive extends to the side wall of the package 6, there is a risk of short circuits due to it crawling up the side wall or coming into contact with interlayer wiring (not shown), so it is preferable that it does not come into contact with the side wall.

[0046] Furthermore, as shown in Figure 16, the conductive adhesive 65 adheres to the side surface of the substrate 30 of the quartz oscillator 100 by creeping up. At this time, the conductive adhesive 65 adheres across multiple grooves 4 provided on the side surface of the substrate 30. On the other hand, the conductive adhesive 65 does not adhere to the area of ​​the quartz oscillator 100 above the substrate 30. That is, the conductive adhesive 65 does not adhere to the quartz oscillator element 10 and the sealing member 20. In this embodiment, the entire surface of the side surface of the substrate 30 is formed of quartz, which is the base material of the substrate 30.

[0047] Furthermore, as shown in Figure 17, the quartz oscillator 10 and the sealing member 20 are joined at a sealing portion (seal path) 115, and the quartz oscillator 10 and the substrate 30 are joined at a sealing portion (seal path) 116, thereby forming a package with a substantially rectangular parallelepiped sandwich structure. That is, in the quartz oscillator 100 of this embodiment, similar to the first embodiment, the sealing member 20 and the substrate 30 are joined to each of the two main surfaces of the quartz oscillator 10 to form an internal space (cavity) of the package, and the vibrating part 11 is hermetically sealed in this internal space.

[0048] With the above configuration, according to the crystal oscillator 1A of the second embodiment, the same advantageous effects as those of the first embodiment can be obtained, and the following advantageous effects can also be achieved. A plurality of groove portions 4 recessed toward the inside of the substrate 30 are provided on the side surface, and the conductive adhesive 65 bonds the external terminals 32b, 32c to the crystal resonator mounting pads 63a, 63b, and is bonded across the plurality of groove portions 4. With such a configuration, when the crystal oscillator 1 is miniaturized, the internal space of the package 6 is restricted. Even in a configuration in which one end side of the substrate 30 (crystal resonator 100) is supported as a fixed end and the other end side is disposed as a free end above the IC 5, the bonding area between the conductive adhesive 65 and the substrate 30 can be increased, so that sufficient bonding strength can be ensured by the anchor effect of the conductive adhesive 65. That is, falling off of the substrate 30 (crystal resonator 100) due to external impact applied to the package can be suppressed, and the impact resistance of the crystal oscillator 1 can be improved, so that both miniaturization and impact resistance of the crystal oscillator 1 can be achieved.

[0049] Further, since the groove portions 4 are formed extending in the thickness direction of the substrate 30 and penetrate from the outer bottom surface side to the opposite surface side, the conductive adhesive 65 can easily creep up along the groove portions 4, whereby the bonding area between the conductive adhesive 65 and the substrate 30 can be further increased, and the bonding strength can be improved.

[0050] Further, since the groove portions 4 have an arc shape in plan view, when the cross-sectional shape of the groove portions 4 has corners, it is particularly difficult for the conductive adhesive 65 to bond to the corner portions. If the groove portion 4 has an arc shape in plan view as in the present invention, the conductive adhesive 65 can easily bond to the entire inner circumference of the groove portion 4. That is, as a result, the bonding area between the conductive adhesive 65 and the substrate 30 can be further increased, and the bonding strength can be improved.

[0051] Furthermore, since the crystal oscillator 100 (substrate 30) has a high-adhesion area, and the conductive adhesive 65 is superimposed not only on the external terminals 32b, 32c, the crystal oscillator mounting pads 63a, 63b, and the base area 66b (corresponding to the base area 66 in the first embodiment), but also on the base area 66a of the package 6, it is possible to improve not only the bonding strength between the package 6 and the conductive adhesive 65, but also the bonding strength between the crystal oscillator 100 (substrate 30) and the conductive adhesive 65. In other words, the shock resistance of the crystal oscillator 1A can be further improved. In addition, the base area of ​​the package 6 has a rougher surface compared to the metal film surface, which is advantageous in that it increases the contact area with the adhesive and thus increases the bonding strength.

[0052] In the second embodiment described above, as shown in Figure 15, the conductive adhesive 65 protrudes from the crystal oscillator mounting pads 63a and 63b and adheres to the substrate area 66a of the package 6. However, as a modified example, as shown in Figure 18, the conductive adhesive 65 may not protrude from the crystal oscillator mounting pads 63a and 63b. With such a configuration, for example, even if the distance between the mounting pads 63a and 63b and the side wall of the package 6 has to be reduced in accordance with the enlargement of the mounted crystal oscillator element 100 or the miniaturization of the package 6, the conductive adhesive 65 can be prevented from coming into contact with the package 6, preventing it from creeping up the side wall or coming into contact with interlayer wiring (not shown) and causing a short circuit.

[0053] Furthermore, this invention is not limited to the configuration of the above-described embodiment, and many other embodiments can be obtained. For example, in the above-described embodiment, the base material regions 66 and 66b of the crystal oscillator 100 were used as the high-adhesion region, but the invention is not limited to this configuration. As the high-adhesion region, for example, the external terminals 32b and 32c may be formed by laminating Ti (titanium), Ni (nickel), and Au (gold) in that order from the bottom layer, and some of the Au, Au and Ni, or all of the metal layers including Ti may be removed. That is, in some parts of the external terminals 32b and 32c, the Ti or Ni constituting the layer can be exposed, and that region can be made into a high-adhesion region. Furthermore, a high-adhesion region may be formed by combining these regions with the base material region as in the above-described embodiment. With such a configuration, the range of the high-adhesion region can be made sufficiently large. That is, the adhesive strength can be increased, and the shock resistance of the crystal oscillator 1 can be improved.

[0054] Furthermore, in the above-described embodiment, the substrate areas 66 and 66b of the high-adhesion region were located on the outer circumference of the longer side of the crystal oscillator 100 as viewed from the external terminals 32b and 32c, but the configuration is not limited to this. For example, the high-adhesion region may be set on the inner circumference, the outer circumference of the shorter side, or both the outer circumference of the longer and shorter sides (corners) of the crystal oscillator 100 as viewed from the external terminals 32b and 32c. In this case, instead of the external terminals 32b and 32c being rectangular, a part of the inner circumference of the crystal oscillator 100 may be cut out so that the external terminals 32b and 32c are not formed, and the cut-out portion may be designated as the high-adhesion region. If the substrate areas 66 and 66b of the high-adhesion region are located on the outer circumference of the longer side of the crystal oscillator 100 as viewed from the external terminals 32b and 32c, as in the above-described embodiment, the risk of the free end of the crystal oscillator 100 coming into contact with the IC 5 due to external impact on the package 6 can be reduced. Furthermore, if the substrate regions 66 and 66b of the high-adhesion area are positioned on the outer periphery of the long side, the outer periphery of the short side, or both the outer periphery of the long side and the outer periphery of the short side (corner) of the crystal oscillator 100 as viewed from the external terminals 32b and 32c, it is possible to prevent the conductive adhesives 65 from coming into contact with each other and short-circuiting.

[0055] Furthermore, in the second embodiment, the groove 4 is formed only on the substrate 30 of the quartz oscillator 100, but the groove 4 may also be formed on one or both of the quartz oscillator element 10 and the sealing member 20. That is, the groove 4 only needs to be formed in the region to which the conductive adhesive 65 adheres on the quartz oscillator 100. For example, the groove 4 may or may not be formed on the quartz oscillator element 10 and the sealing member 20. Moreover, the groove 4 may not be formed on all sides of the substrate 30, but only on a portion including the region to which the conductive adhesive 65 adheres.

[0056] Furthermore, in the second embodiment, the groove 4 is shaped to extend in the thickness direction of the substrate 30 and penetrate through it, but the configuration is not limited to this. For example, it may be shaped to extend in the thickness direction but not penetrate through. Also, the shape of the groove 4 may be, for example, shaped to extend in a direction perpendicular to the thickness direction of the substrate 30 on the side surface of the substrate 30, or it may be circular, semicircular, or fan-shaped when viewed from the side surface of the substrate 30. Moreover, the shapes of multiple grooves 4 may each be different, only some of them may be different, or they may be a combination of multiple shapes.

[0057] Furthermore, in the second embodiment, each groove 4 has a uniform width, but for example, it may have a shape that gradually narrows from the outer bottom surface to the top surface, or a shape that gradually widens. If the groove 4 has a shape that gradually narrows from the outer bottom surface to the top surface, the risk of the conductive adhesive 65 crawling up to the seal path 116 and making contact (short circuit) can be suppressed. On the other hand, if the groove 4 has a shape that gradually widens from the outer bottom surface to the top surface, the conductive adhesive 65 can more easily crawl up the side surface of the substrate 30, thereby reliably increasing the bonding area between the conductive adhesive 65 and the substrate 30 and improving the bonding strength.

[0058] Furthermore, in the crystal oscillator 1 of each embodiment described above, a concave space is formed inside the package 6 for arranging the crystal resonator 100, etc., and the top surface of the package 6 is closed with a flat plate-shaped cover 7. However, the package may be designed without a concave space, with the piezoelectric resonator etc. arranged inside, and a cup-shaped cover having a U-shaped cross-section placed over the top surface of the package to close it.

[0059] Furthermore, although the crystal oscillator 1 in each of the embodiments described above was described as having a configuration in which the free end of the crystal resonator 100 is positioned above the IC 5, the free end of the crystal resonator 100 may also be positioned above the stepped portion 62 of the package 6, similar to the fixed end.

[0060] Furthermore, in the above-described embodiment, the quartz oscillator 100 has a three-layer structure in which the substrate 30, the quartz oscillator element 10, and the sealing member 20 are each diffusely bonded, but the embodiment is not limited to this configuration. For example, the quartz oscillator 100 does not need to have a sealing member 20. Also, each component may be brazed instead of diffusely bonded. Alternatively, the quartz oscillator element 10 may be a flat piezoelectric diaphragm and bonded to the substrate 30 via a conductive adhesive. Moreover, the substrate 30 may be made of ceramic or glass instead of quartz. In this case, the high-adhesion regions (substrate regions 66, 66b) in this embodiment will be ceramic.

[0061] The embodiments disclosed herein are illustrative in all respects and are not intended to be restrictive. Therefore, the technical scope of the present invention is not construed solely by the embodiments described above, but is defined by the claims. This includes all modifications within the meaning and scope of the equivalents of the claims.

[0062] The quartz oscillator device of the present invention can be used, for example, in the manufacturing and sales industry of quartz oscillator devices that house a quartz oscillator element and electronic components in the same space within a package.

[0063] 10...Quartz oscillator element 100...Quartz resonator 20...Sealing material 30...Substrate 32a, 32b, 32c...External terminals 4...Groove 5...IC 6...Package 61...Recess 61a...Inner bottom surface 62...Step 63a, 63b...Quartz resonator mounting pad 65...Conductive adhesive 66, 66b...Substrate area 7...Lid material

Claims

1. A quartz oscillator device comprising a substrate that is substantially rectangular in plan view and has at least two connection terminals on its outer bottom surface, a quartz oscillator mounted on the opposite side of the outer bottom surface of the substrate, an electronic component, and a package that hermetically seals the substrate, the quartz oscillator mounted on the substrate, and the electronic component, wherein the package has a rectangular parallelepiped outer shape with an open top surface, and has a recess formed off-center to one side, a stepped portion formed above the inner bottom surface of the recess, and a pair of mounting pads provided on the stepped portion that are conductively bonded to each of the two connection terminals, the electronic component is arranged on the inner bottom surface of the recess, the substrate is supported at one end as a fixed end and positioned above the electronic component or the stepped portion as a free end, with the two connection terminals being bonded to the pair of mounting pads via a conductive adhesive, and has a high-adhesion region with higher adhesive strength to the conductive adhesive compared to the two connection terminals. The conductive adhesive bonded the connection terminal and the mounting pad, as well as the high-adhesion region, to the quartz oscillator device.

2. The quartz oscillator device according to claim 1, wherein the high-adhesion region is the substrate material.

3. The quartz oscillator device according to claim 2, wherein the substrate has a plurality of grooves on its side surface that are concave toward the interior of the substrate, and the conductive adhesive adheres the connection terminal and the mounting pad, and also adheres across the plurality of grooves.

4. The quartz oscillator device according to claim 3, wherein the groove is formed extending in the thickness direction of the substrate and penetrates from the outer bottom surface side to the opposite surface side.

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