Packages and piezoelectric vibration devices

Abstract

To enable welding joints while suppressing splash defects without using a sealing ring, thereby achieving a lower profile. [Solution] The package 2 comprises a bottomed cylindrical package body 10 having a bottom wall portion 10a and a peripheral wall portion 10b, and a lid 11 that is welded to the upper end opening edge of the peripheral wall portion to close the opening of the package body and form a sealing space C between itself and the package body, wherein a metal layer 30 is formed on the upper end opening edge of the peripheral wall portion, and the lid comprises a base material 40 which is a metal base material, and a plating layer 41 formed on the surface of the base material at least at the joint portion with the upper end opening edge of the peripheral wall portion, wherein the plating layer comprises a heat transfer plating layer 42 which has a lower melting point than the base material, and a molten plating layer 43 which has a lower melting point than the heat transfer plating layer and melts together with the metal layer.

Description

Technical Field

[0001] The present invention relates to a package and a piezoelectric vibration device.

Background Art

[0002] Conventionally, for example, in electronic devices such as mobile phones, a piezoelectric vibration device including a piezoelectric vibrating piece using quartz has been used. As this type of piezoelectric vibration device, for example, a configuration including a ceramic package having a recess with an open upper portion, a piezoelectric vibrating piece housed in the ceramic package, and a metal lid joined to the opening of the ceramic package is generally known.

[0003] The metal lid is overlapped on the frame-shaped upper end opening edge of the ceramic package and is welded and joined by resistance welding such as seam welding to seal the inside of the ceramic package. When welding and joining this type of metal lid, a method of welding and joining the ceramic package and the metal lid via a seal ring and a method of directly welding and joining the ceramic package and the metal lid without using a seal ring (so-called direct seam method) are known.

[0004] The seal ring is formed of a metal having a thermal expansion coefficient close to that of the ceramic material forming the ceramic package, and is joined to the upper end opening edge of the ceramic package by baking, welding, etc. with a brazing material, a solder material, etc. Then, the metal lid is welded and joined to the seal ring by seam welding or the like. Thus, when welding a ceramic package and a metal lid together via a sealing ring, the sealing ring acts like a washer, making it possible to absorb in-plane displacement (variation) between the ceramic package and the metal lid. Furthermore, because the sealing ring provides stress relief, it can absorb high voltage (high power) during welding. As a result, it is possible to seal the package while suppressing warping of the metal lid.

[0005] However, using a sealing ring increases the number of components and adds to the overall thickness of the device. Therefore, when aiming for miniaturization and a low profile, direct seam joining methods that do not use sealing rings are often employed.

[0006] For example, Patent Document 1 describes a surface-mount type quartz crystal oscillator comprising a ceramic package, a quartz crystal diaphragm (piezoelectric vibrator) housed within the ceramic package, and a metal cover joined to the opening of the ceramic package. The metal lid is superimposed on the frame-shaped upper opening edge of the ceramic package and sealed inside the ceramic package by being directly welded to it by resistance welding such as seam welding. This metal lid comprises a plate-shaped metal base material, a copper layer formed over the entire lower surface of the metal base material, and a silver solder layer formed over the entire lower surface of the copper layer. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2003-158211 [Overview of the project] [Problems that the invention aims to solve]

[0008] The conventional metal lids described above employ a clad material consisting of a copper layer and a silver solder layer, joined together by rolling. However, it is known that clad materials can develop residual stress due to the manufacturing process and the combination of materials. As a result, the metal lids are prone to warping due to the residual stress in the clad material. Therefore, when welding, it becomes necessary to use high voltage (high power) welding to suppress warping of the metal lid while ensuring a secure seal to the ceramic package.

[0009] However, when welding is performed with high power, a phenomenon known as splashing, where weld metal is scattered from the welding interface, is likely to occur. Therefore, in the case of the conventional metal cover described above, there was a concern that the molten AgCu alloy (the welding alloy described above), consisting of the copper layer and silver solder layer, would be scattered into the ceramic package by splashing and adhere to components such as the quartz diaphragm or electrodes inside the package as conductive foreign matter. Such splash defects can lead to problems such as vibration failure and short circuits in the quartz diaphragm, posing a significant challenge. In particular, the inclusion of conductive foreign matter due to splash defects is difficult to screen during product inspection and can lead to product discarding, so a solution is highly desired.

[0010] This invention has been made in consideration of these circumstances, and its objective is to provide a package and piezoelectric vibration device that enable welding joints while suppressing splash defects without using a sealing ring, and that can achieve a low profile. [Means for solving the problem]

[0011] (1) The present invention relates to a package having a sealed space inside for housing a piezoelectric vibrator, comprising: a bottomed cylindrical package body having a bottom wall and a peripheral wall and opening upward; and a lid that closes the opening of the package body by welding to the upper end opening edge of the peripheral wall and forms the sealed space between itself and the package body, wherein a metal layer is formed on the upper end opening edge of the peripheral wall, and the lid comprises a base material which is a metal base material and a plating layer formed on the surface of the base material at least at the joint portion with the upper end opening edge of the peripheral wall, wherein the plating layer comprises a heat transfer plating layer formed on the surface of the base material and having a lower melting point than the base material, and a molten plating layer formed on the surface of the heat transfer plating layer and having a lower melting point than the heat transfer plating layer and melting together with the metal layer.

[0012] According to the present invention, after setting the lid on the upper opening edge of the peripheral wall of the package body so as to close the opening of the package body, the peripheral wall and the lid can be directly welded together. Therefore, the package body and the lid can be welded together without using a conventional sealing ring, and the piezoelectric vibrator contained within the sealed space can be sealed. In particular, the lid is constructed with a base material and a plating layer formed on the surface of the base material. Unlike conventional clad materials, it has low residual stress due to the plating process, and the lid itself is less prone to warping. Therefore, when welding the lid, it is not necessary to suppress the warping of the lid during welding, and welding can be performed with low power (low voltage). Furthermore, since the plating layer includes a heat-transfer plating layer formed on the surface of the substrate and a molten plating layer formed on the surface of the heat-transfer plating layer, welding heat (resistance heat) can be efficiently transferred to the entire molten plating layer via the heat-transfer plating layer. Therefore, even when welding is performed with low power, the molten plating layer and the metal layer on the package body can be melted together, enabling reliable welded joints. As a result, a package can be made that can seal the sealing space with high sealing performance.

[0013] Furthermore, because welding can be performed with lower power, splashing, where weld metal derived from the plating layer is scattered from the welding interface during welding, is less likely to occur. Consequently, splash defects, such as weld metal being scattered into the sealed space and adhering to the piezoelectric vibrator as conductive foreign matter, can be suppressed. Furthermore, since it does not utilize conventional sealing rings and the lid is made thinner by forming a plating layer (heat transfer plating layer, hot-dip plating layer) on the base material, it is possible to reduce the overall height of the package.

[0014] (2) The lid has an outer peripheral edge that overlaps the upper end opening edge of the peripheral wall over its entire circumference, and in a plan view of the package body, the overlapping region of the outer peripheral edge of the lid with respect to the upper end opening edge of the peripheral wall is a region that occupies a certain distance radially inward from the outer end surface of the lid and may have a joined region that is welded to the peripheral wall via the metal layer, and a non-joined region that is located radially inward from the joined region and is located between the joined region and the inner surface of the peripheral wall.

[0015] In this case, the entire overlapping region of the lid that rests on the upper opening edge of the peripheral wall of the package body is not welded together. Instead, the welding is performed in a joining region that occupies a certain distance radially inward from the outer end surface of the lid, and the non-jointed region of the overlapping region that is radially inward from the joining region is not welded. Therefore, it is possible to arrange a joining region where the peripheral wall of the package body and the lid are welded together, and a non-jointed region where they are not welded together, between the peripheral wall of the package body and the lid.

[0016] In particular, the joining region is located on the outer peripheral edge side, including the outer end surface of the lid, while the non-joining region is located between the joining region and the inner surface of the peripheral wall. Therefore, during welding, by mainly applying heat to the outer peripheral edge side of the lid, the molten plating layer and the metal layer can be melted together in the joining region to perform welding. Furthermore, because the non-joining region is located between the joining region and the inner surface of the peripheral wall, even if weld metal originating from the plating layer is generated in the joining region during welding, a distance can be ensured for the weld metal to reach the sealed space. Therefore, the occurrence of splash defects can be further reduced.

[0017] (3) The cover may be welded together such that the ratio of the non-jointed width along the radial direction of the non-jointed area to the wall width along the radial direction of the peripheral wall is greater than 11%.

[0018] In this case, since the ratio of the non-jointed width to the wall width of the peripheral wall is greater than 11%, a gap can be secured between the jointed area and the inner surface of the peripheral wall. Therefore, even if weld metal originating from the plating layer is generated in the jointed area during welding, it is less likely for the weld metal to reach the sealed space. As a result, the occurrence of splash defects can be further reduced.

[0019] (4) The cover may be welded together such that the ratio of the unjoined width to the wall width is less than 29%.

[0020] In this case, the ratio of the non-jointed width to the wall width of the peripheral wall is less than 29%, making it easier to secure a sufficient joint width in the jointed area while reducing the occurrence of the splash defects mentioned above. This further enhances the airtightness within the sealed space and allows for the maintenance of a high vacuum within the sealed space. Therefore, the resistance when the piezoelectric vibrator vibrates can be suppressed, thus preventing an increase in the CI value (Crystal Impedance). Consequently, this makes it possible to create a package suitable for housing a piezoelectric vibrator vibrator.

[0021] (5) The lid may be welded and joined such that the non-joining width along the radial direction of the non-joining region is larger than the joining width along the radial direction of the joining region.

[0022] In this case, while ensuring a sufficient joining width in the joining region, a non-joining region where the non-joining width is larger than the joining width can be arranged between the joining region and the inner surface of the peripheral wall portion, so that the occurrence of splash defects can be reduced.

[0023] (6) The lid may be welded and joined such that the total area of the lid satisfies 65% or more and 85% or less with respect to the outer surface area of the package body.

[0024] In this case, since the total area of the lid with respect to the outer surface area of the package body is within the above range, it is possible to suppress the overall size of the lid from becoming too large while ensuring a sufficient overlapping region. Particularly, since it is 65% or more, an overlapping region sufficient to sufficiently suppress splash defects can be ensured. Further, since it is 85% or less, the overall size of the lid can be reduced, the increase in component cost can be suppressed, and the overall package can be made more compact.

[0025] (7) The heat transfer plating layer is a copper layer, the molten plating layer is a silver layer, and the plating layer may be formed such that the ratio (T2 / T1) of the thickness T2 of the heat transfer plating layer, which is the copper layer, to the thickness T1 of the molten plating layer, which is the silver layer, is greater than 1 and satisfies 2.5 or less.

[0026] In this case, since the heat transfer plating layer is a copper layer with excellent thermal conductivity, even if welding is performed at low power, the welding heat can be efficiently transmitted to the molten plating layer through the heat transfer plating layer. Further, since the molten plating layer is a silver layer containing a silver brazing layer, for example, it can be welded and joined by silver brazing or the like, and it is easy to improve the airtightness in the sealed space. In particular, since (T2 / T1) is set to be greater than 1 and 2.5 or less, it is possible to suppress the thickness of the heat transfer plating layer T2 from becoming excessively thick relative to the thickness of the molten plating layer T1. The thicker the thickness of the heat transfer plating layer T2 becomes, the easier it is for welding heat to diffuse radially, which can cause the molten plating layer to melt and spread. In contrast, by reducing the thickness T2 of the heat transfer plating layer, excessive heat diffusion can be suppressed. As a result, the molten plating layer and the metal layer can be melted within the limited area of ​​the joining region, and the transfer of welding heat to the non-joined region can be suppressed. Therefore, it is possible to properly melt the molten plating layer in the joining region and perform fusion joining while suppressing the melting of the molten plating layer in the non-joined region. This means that even if weld metal originating from the plating layer is generated during welding, it can be generated within the welding region rather than the non-joined region, preventing the weld metal from reaching the sealing space and reducing the occurrence of splash defects.

[0027] (8) The joining region may be welded to the peripheral wall by melting the metal layer and the silver layer.

[0028] In this case, the package body and the lid can be firmly welded together by melting the metal layer and silver solder in the joining region.

[0029] (9) The molten plating layer may be formed to wrap around to the outer end surface of the lid and cover at least the heat transfer plating layer from the outside.

[0030] In this case, since the molten plating layer covers the heat transfer plating layer from the outside, the molten plating layer can function as a barrier layer, preventing the heat transfer plating layer from reacting with moisture, for example. As a result, even if the heat transfer plating layer is a copper layer, corrosion of the copper layer can be prevented, preventing the occurrence of cracks caused by corrosion and suppressing a decrease in airtightness within the sealed space.

[0031] (10) On the upper surface of the lid in the joining region, an inclined surface is formed around the entire circumference such that the thickness of the lid gradually decreases toward the radially outward direction, and welding marks may be formed on the inclined surface.

[0032] In this case, during welding, for example, by applying current while pressing a roller electrode against an inclined surface, seam welding can be performed by heating under pressure. Therefore, the package body and the lid can be firmly welded together in the joining area.

[0033] (11) The piezoelectric vibration device according to the present invention is characterized by comprising the package and a piezoelectric vibration piece housed in the sealing space of the package and mounted on the bottom wall via a conductive adhesive.

[0034] According to the piezoelectric vibration device of the present invention, since the piezoelectric vibrator is mounted within the sealed space of the package described above, the piezoelectric vibrator can be operated within a sealed space with excellent airtightness. Therefore, the piezoelectric vibrator can be vibrated accurately within a predetermined resonant frequency band. Furthermore, since a low-profile package is used, a low-profile piezoelectric vibration device can also be achieved. In particular, since the package can suppress the occurrence of splash defects, conductive foreign matter caused by splash is less likely to adhere to the piezoelectric vibrator, etc. Therefore, the piezoelectric vibrator can be operated well, and a high-quality piezoelectric vibration device can be obtained.

[0035] (12) The plating layer may contain voids, and the number of voids may decrease from the outer end surface of the lid toward the radially inward direction.

[0036] In this case, for example, when mounting a piezoelectric vibration device, even if heat treatment is applied by reflow soldering, it is possible to suppress the release of gases contained in the void into the sealed space. Therefore, a high vacuum level can be maintained within the sealed space, and an increase in the CI value of the piezoelectric vibration piece can be suppressed. Consequently, a piezoelectric vibration device with improved operational reliability can be obtained.

[0037] (13) The piezoelectric vibrator may also include a piezoelectric plate having a pair of vibrating arms extending along a first direction and arranged parallel to a second direction, and a base that integrally fixes the base ends of the vibrating arms, and an excitation electrode formed on the outer surface of the piezoelectric plate which vibrates the pair of vibrating arms when a voltage is applied.

[0038] In this case, by supplying current to the excitation electrode, the pair of vibrating arms can be vibrated in a predetermined frequency band in directions that move them closer together or further apart from each other. In particular, a general tuning fork-type vibrating piece having a pair of vibrating arms can be used as the piezoelectric vibrating piece, which can reduce component costs.

[0039] (14) The piezoelectric vibrator is of the side-arm type and includes a pair of support arms that extend outward from the base in the second direction and then extend in the first direction, and the pair of support arms may be mounted on the bottom wall via the conductive adhesive.

[0040] In this case, since the piezoelectric vibrator can be mounted using a pair of support arms, vibration leakage can be suppressed without increasing the overall length of the piezoelectric vibrator (length along the first direction). Therefore, the increase in the CI value can be suppressed.

[0041] (15) The package body has an integrated circuit having a plurality of integrated circuit terminals, and the integrated circuit may be mounted on the opposite side of the piezoelectric vibrator with the bottom wall of the package body in between.

[0042] In this case, the piezoelectric vibrator can be vibrated within a predetermined resonant frequency band, and the piezoelectric properties can convert this vibration into an electrical signal. Then, an integrated circuit can be used to generate an output signal, such as a clock signal, based on the electrical signal. This allows it to function, for example, as an oscillator. [Effects of the Invention]

[0043] According to the present invention, the package body and the lid can be welded together while suppressing the occurrence of splash defects without using a sealing ring, and the package can be made lower in height. [Brief explanation of the drawing]

[0044] [Figure 1] This figure shows a first embodiment of a piezoelectric vibration device according to the present invention, and is a perspective view of the external appearance of a piezoelectric vibrator. [Figure 2] Figure 1 is an exploded perspective view of the piezoelectric vibrator shown. [Figure 3] Figure 1 is a longitudinal cross-sectional view of the piezoelectric vibrator shown. [Figure 4] Figure 3 is an enlarged cross-sectional view of the area near the welded joint between the peripheral wall of the package body and the lid. [Figure 5] Figure 2 is a top view of the piezoelectric vibrator (including each electrode). [Figure 6] This figure shows the heat accumulation range due to welding heat when seam welding a lid with high power. [Figure 7] This diagram shows the heat accumulation range due to welding heat when seam welding a lid with low power. [Figure 8] This figure shows a modified example of the first embodiment, and is an enlarged cross-sectional view of the vicinity of the welded joint between the peripheral wall portion of the package body and the lid. [Figure 9] This figure shows a modified example of the first embodiment, illustrating the relationship between the area of ​​the opening of the package body and the total area of ​​the lid. [Figure 10] This figure shows a modified example of the first embodiment, and is an enlarged cross-sectional view of the vicinity of the welded joint between the peripheral wall portion of the package body and the lid. [Figure 11] This figure shows a second embodiment of the piezoelectric vibration device according to the invention, and is an external perspective view of the oscillator. [Figure 12] Figure 11 is an exploded perspective view of the oscillator. [Figure 13] Figure 11 is a longitudinal cross-sectional view of the oscillator along the AA line. [Figure 14] Figure 12 is a top view of the piezoelectric vibrator (including each electrode). [Figure 15] This figure shows a modified example of a piezoelectric vibrator, and is a perspective view of an AT-cut vibrator. [Modes for carrying out the invention]

[0045] (First Embodiment) Hereinafter, a first embodiment of the package and piezoelectric vibration device according to the present invention will be described with reference to the drawings. In this embodiment, a piezoelectric vibrator is used as an example of a piezoelectric vibration device.

[0046] As shown in Figures 1 to 3, the piezoelectric vibrator (piezoelectric vibration device according to the present invention) 1 of this embodiment is a so-called ceramic package type surface mount vibrator. The piezoelectric vibrator 1 comprises a package 2 having an internally hermetically sealed cavity (sealed space according to the present invention) C, and a piezoelectric vibrating piece 3 housed within the cavity C.

[0047] The piezoelectric vibrator 1 is formed in the shape of a rectangular parallelepiped having a constant thickness in the thickness direction T. In this embodiment, two mutually orthogonal directions are defined as the first direction L1 and the second direction L2 when viewed from the thickness direction T in a plan view. Furthermore, in the thickness direction T, the direction from the package body 10 (described later) toward the lid 11 is defined as upward, and the opposite direction is defined as downward.

[0048] (package) Package 2 comprises a package body 10 and a lid (cover according to the present invention) 11, which is a sealing plate welded to the package body 10 so as to overlap it in the thickness direction T.

[0049] (Package itself) The package body 10 has a bottom wall portion 10a and a peripheral wall portion 10b, and is formed in a bottomed cylindrical shape that opens upward. Specifically, the package body 10 includes a mounting substrate 20 which is a laminated substrate in which a first mounting substrate 21 and a second mounting substrate 22 are joined vertically. The first mounting substrate 21 and the second mounting substrate 22 are made of an insulating material, such as ceramic. Examples of ceramic materials include HTCC (High Temperature Co-Fired Ceramic) made from alumina, and LTCC (Low Temperature Co-Fired Ceramic) made from glass ceramics.

[0050] The first mounting substrate 21 is a flat substrate having a predetermined thickness, and is formed in a rectangular shape in a plan view from the thickness direction T, where the length along the first direction L1 is longer than the length along the second direction L2.

[0051] The second mounting substrate 22 is positioned above the first mounting substrate 21 and is integrally bonded to the upper surface of the first mounting substrate 21 by sintering or the like. The second mounting substrate 22 is a flat substrate having a predetermined thickness and is formed so that its external shape is the same as that of the first mounting substrate 21. The second mounting substrate 22 has a through-hole 23 that penetrates the substrate 22 in the thickness direction T. The through-hole 23 is formed in a rectangular shape corresponding to the outer shape of the second mounting substrate 22, with a length along the first direction L1 being longer than the length along the second direction L2 in a plan view. The four corners of the through-hole 23 are formed in a rounded curved shape. Therefore, the second mounting substrate 22 is formed in a frame shape having the through-hole 23.

[0052] In the mounting substrate 20 configured as described above, the upper surface of the first mounting substrate 21 functions as a mounting surface 21a on which the piezoelectric vibrator 1 is mounted. The region (internal space) enclosed by the frame-shaped second mounting substrate 22 functions as a cavity C. Furthermore, the inside of the second mounting substrate 22 functions as an opening for the package body 10. In this embodiment, the mounting substrate 20 is constructed from a laminated substrate in which a first mounting substrate 21 and a second mounting substrate 22 are stacked. However, the embodiment is not limited to this case, and for example, a single-layer mounting substrate 20 may also be used. In this case, for example, a recess that is indented downwards can be formed on the upper surface of the mounting substrate 20.

[0053] The package body 10 has notches 24 formed at each of its four corners, which are cut out in the shape of a quarter-circle arc when viewed from above. The notches 24 are formed across the entire package body 10 (first mounting substrate 21, second mounting substrate 22) in the thickness direction T.

[0054] The notches 24 are formed, for example, due to the manufacturing process of the package body 10. Specifically, when manufacturing the package body 10, two wafer-shaped ceramic substrates for forming the first mounting substrate 21 and the second mounting substrate 22 are stacked and joined together, and then multiple through-holes are formed in a matrix so as to penetrate the laminate of joined ceramic substrates. Subsequently, by using each through-hole as a reference hole (pilot hole) and cutting the laminate of ceramic substrates in a grid pattern, it becomes possible to manufacture multiple package bodies 10. In this manufacturing process, the notches 24 are formed when the through-holes are divided into four sections.

[0055] In the package body 10 configured as described above, the first mounting substrate 21 functions as the bottom wall portion 10a of the package body 10, and the frame-shaped second mounting substrate 22 functions as the peripheral wall portion 10b of the package body 10. A metal layer 30 for welding the lid 11 is formed on the upper opening edge of the peripheral wall portion 10b (the upper opening edge of the second mounting substrate 22). The metal layer 30 is formed over the entire upper opening edge of the peripheral wall portion 10b. The metal layer 30 can be formed by electrolytic plating, electroless plating, vapor deposition, sputtering, etc. The metal layer 30 may be a single layer of a single metal, or a laminated metal layer made of different metals. Note that the thickness of the metal layer 30 is exaggerated in each drawing.

[0056] (Implemented electrodes) A pair of mounting electrodes 31 are formed on the mounting surface 21a, which is the upper surface of the first mounting substrate 21. The pair of mounted electrodes 31 are designed to conduct electricity with the pair of excitation electrodes 60 and 61, described later, when the piezoelectric vibrator 3 is mounted. Therefore, the pair of mounted electrodes 31 are electrically connected to the piezoelectric vibrator 3. The mounted electrodes 31 are patterned on the mounting surface 21a using a metallic material. The mounted electrodes 31 may be, for example, a single-layer metal film made of a single metal, or a multilayer metal film made of stacked different metals.

[0057] The mounted electrode 31 is electrically connected to the external connection electrode 32 formed on the surface of the notch 24. The external connection electrode 32 is formed to cover the surface of each of the notches 24 located at the four corners of the package body 10, and in this embodiment, it is formed across the lower surface of the first mounting substrate 21. However, the external connection electrode 32 does not need to be formed on both the outer surface of the notch 24 and the lower surface of the first mounting substrate 21; it is sufficient if it is formed on at least one of the outer surface of the notch 24 and the lower surface of the first mounting substrate 21. Furthermore, the external connection electrode 32 may be, for example, a single-layer metal film made of a single metal, or a multilayer metal film made of stacked different metals.

[0058] One mounted electrode 31 is electrically connected to, for example, two of the four external connection electrodes 32, while the other mounted electrode 31 is electrically connected to the remaining two external connection electrodes 32. Furthermore, the mounted electrode 31 and the external connection electrodes 32 are electrically connected via conductive electrodes (not shown) formed on or inside the surface of the first mounting substrate 21.

[0059] (Lid) The lid 11 is positioned above the package body 10 and is welded to the upper opening edge of the peripheral wall portion 10b (second mounting substrate 22), thereby closing the opening of the package body 10. This forms an airtight cavity C between the lid 11 and the package body 10. The lid 11 is formed so that its external shape is larger than the opening size of the package body 10 in order to close the opening of the package body 10. The lid 11 is formed so that its external shape is smaller than the external shape of the peripheral wall portion 10b (second mounting substrate 22).

[0060] The welding method between the package body 10 and the lid 11 is not particularly limited, but in this embodiment, they are welded together by seam welding (resistance welding) using a roller electrode E (see Figure 4). However, this is not limited to this case; other resistance welding methods such as laser welding and ultrasonic bonding may also be used, as may friction stir welding (FSW).

[0061] As shown in Figures 3 and 4, the lid 11 comprises a base material 40 which is a metal base material, and a plating layer 41 formed on the surface of the base material 40 at least at the joint portion with the upper end opening edge of the peripheral wall portion 10b (second implementation substrate).

[0062] The base material 40 is formed in the shape of a flat plate having a predetermined thickness and is made of, for example, Kovar alloy. However, the material of the base material 40 is not limited to Kovar alloy, and other metal materials may be used. Furthermore, a metal plating film, such as nickel plating (not shown), may be formed by applying a plating treatment to the entire surface of the base material 40.

[0063] The plating layer 41 is formed by plating the entire lower surface of the substrate 40. The plating layer 41 has a heat transfer plating layer 42 and a molten plating layer 43, and these are stacked in two layers to form a multilayer plating layer. Note that in each drawing, the thickness of the plating layer 41, including the heat transfer plating layer 42 and the molten plating layer 43, is exaggerated in the illustration.

[0064] The heat transfer plating layer 42 is formed on the entire lower surface of the substrate 40 and is a plating layer with a lower melting point than the substrate 40. In this embodiment, the heat transfer plating layer 42 is a copper layer having a melting point (approximately 1080°C) lower than the melting point (approximately 1450°C) of the substrate 40 made of Kovar alloy. The molten plating layer 43 is formed on the entire lower surface of the heat transfer plating layer 42 and has a lower melting point than the heat transfer plating layer 42. It is a plating layer that melts together with the metal layer 30 on the package body 10 side during seam welding. In this embodiment, the molten plating layer 43 is a silver solder layer (silver layer according to the present invention) having a lower melting point (around 600-800°C) than the heat transfer plating layer (copper layer) 42.

[0065] As shown in Figure 4, the plating layer 41 is formed with a film thickness adjusted such that the ratio of the thickness T2 of the heat transfer plating layer 42, which is the copper layer, to the thickness T1 of the molten plating layer 43, which is the silver solder layer (T2 / T1), is greater than 1 and less than or equal to 2.5. In other words, the thickness T2 of the heat transfer plating layer 42, which is the copper layer, is greater than the thickness T1 of the molten plating layer 43, which is the silver solder layer, and is less than or equal to 2.5 times the thickness T1.

[0066] The lid 11, configured as described above, is welded and joined by seam welding with its outer peripheral edge overlapping the upper opening edge of the peripheral wall portion 10b (second mounting substrate 22) over its entire circumference. Specifically, as shown in Figure 4, by applying current while pressing the roller electrode E against the upper surface of the outer edge of the lid 11, the entire circumference of the lid 11 is heated under pressure. This allows the molten plating layer 43, which is the silver brazing layer, and the metal layer 30 on the package body 10 side to melt each other due to welding heat (resistance heat). Therefore, a molten alloy layer 44 can be formed at the welding interface between the molten plating layer 43 and the metal layer 30, and the lid 11 can be welded together by so-called silver brazing.

[0067] Therefore, on the upper surface of the outer peripheral edge of the base material 40 in the lid 11, an inclined surface 45 is continuously formed around the entire circumference, inclined so that the thickness of the lid 11 decreases radially outward due to the pressure applied by the roller electrode E. The inclined surface 45 is a pressing surface formed by the pressure applied by the roller electrode E. On the surface of the inclined surface 45, a weld mark M (see Figures 1 and 2) is formed due to the effect of heating by the roller electrode E. Therefore, the presence or absence of a weld mark M on the inclined surface 45 makes it possible to determine whether or not heating was performed via the roller electrode E, and to identify the location where welding heat was applied.

[0068] In particular, in package 2 of this embodiment, as shown in Figure 4, in a plan view of the package body 10, the entire overlapping region R at the outer peripheral edge of the lid 11 with respect to the upper opening edge of the peripheral wall portion 10b (second mounting substrate 22) is not welded and joined by seam welding.

[0069] I will explain in detail. The overlapping region R has a joining region R1 that occupies a certain distance radially inward from the outer end surface 11a of the lid 11, and a non-joining region R2 that is located radially inward from the joining region R1. The bonded region R1 is located below the inclined surface 45 and is the region where the package body 10 and the lid 11 are substantially welded together by the melting of the molten plating layer 43 and the metal layer 30. In contrast, the non-bonded region R2 is located between the bonded region R1 and the inner surface of the peripheral wall portion 10b (second mounting substrate 22) and is the region where the package body 10 and the lid 11 are not welded together. Therefore, in the non-bonded region R2, the molten alloy layer 44 formed by the melting of the molten plating layer 43 and the metal layer 30 is not formed.

[0070] (Piezoelectric vibrator) As shown in Figures 2 and 3, the piezoelectric vibrator 3 is positioned above the first mounting substrate 21, housed within the cavity C, and mounted on the mounting surface 21a. Specifically, the piezoelectric vibrator 3 is electrically connected to the mounting electrode 31 via a conductive adhesive 35, and is also physically supported by the conductive adhesive 35, floating above the mounting surface 21a. The conductive adhesive 35 is provided so as to fit within the outer shape pattern of the mounting electrode 31.

[0071] As shown in Figures 2 and 5, the piezoelectric vibrator 3 comprises a piezoelectric plate 50 having a pair of vibrating arms 51 arranged parallel to each other and a base 52 that integrally fixes the base ends of the pair of vibrating arms 51, and various electrodes (excitation electrodes 60, 61, mounting electrodes 62, 63, weight electrodes 64, 65) formed on the outer surface of the piezoelectric plate 50. Therefore, the piezoelectric vibrator 3 in this embodiment is a so-called tuning fork type vibrator in which a pair of vibrating arms 51 vibrate when a voltage is applied.

[0072] The piezoelectric vibrator 3 is sized to fit inside the frame-shaped second mounting substrate 22, and is miniaturized in both the first direction L1 and the second direction L2. The piezoelectric plate 50 is formed from a piezoelectric material such as quartz, lithium tantalate, or lithium niobate. For example, when forming the piezoelectric plate 50 from quartz, a Lambert crystal ore is sliced ​​at predetermined angles with respect to the X, Y, and Z axes, which are mutually orthogonal to each other, to form a wafer, and then the piezoelectric plate 50 is produced by etching this wafer.

[0073] The pair of vibrating arms 51 are spaced apart in the second direction L2 and are formed to extend parallel to each other from the base 52 along the first direction L1. In this embodiment, the pair of vibrating arms 51 have the same width dimension from the fixed end (base 52 side) to the free end (tip 51a).

[0074] Of the pair of vibrating arms 51, the upper and lower surfaces facing each other in the thickness direction T have elongated grooves 51b of a certain width formed from the base end to the tip end 51a of the vibrating arm 51. As a result, the portion of the pair of vibrating arms 51 in which the grooves 51b are formed has an H-shaped cross-section. However, the grooves 51b are not essential, and the vibrating arms 51 do not need to have grooves 51b.

[0075] As shown in Figure 5, various electrodes (excitation electrodes 60, 61, mounting electrodes 62, 63, and weight electrodes 64, 65) are patterned on the outer surface of the piezoelectric vibrator 3 configured as described above. The excitation electrodes 60 and 61 are electrodes that vibrate a pair of vibrating arms 51 at a predetermined resonant frequency in a direction (second direction L2) that moves them closer together or further apart from each other when a voltage is applied, and are mainly patterned on the outer surfaces of the pair of vibrating arms 51 in an electrically isolated state. Specifically, one excitation electrode 60 is mainly formed over the side and upper and lower surfaces of one vibrating arm 51, and also formed inside the groove 51b and over the upper and lower surfaces of the other vibrating arm 51. The other excitation electrode 61 is mainly formed inside the groove 51b and over the upper and lower surfaces of one vibrating arm 51, and also formed over the side and upper and lower surfaces of the other vibrating arm 51.

[0076] The mounting electrodes 62 and 63 are formed on the outer surface of the base 52. Specifically, the pair of mounting electrodes 62 and 63 are formed across the upper and lower surfaces of the base 52, electrically isolated from each other. Furthermore, one mounting electrode 62 is electrically connected to one excitation electrode 60, and the other mounting electrode 63 is electrically connected to the other excitation electrode 61.

[0077] The weight electrodes 64 and 65 are formed on the outer surface of the tip portion 51a of the pair of vibrating arms 51 and are configured to be electrically connected to the excitation electrodes 60 and 61, respectively. The weight electrodes 64 and 65 primarily function as adjustment electrode films used to adjust the frequency of the piezoelectric vibrator 3. For example, during the assembly process of the piezoelectric vibrator 1, a voltage is applied to the piezoelectric vibrator 3 using a monitor electrode (not shown) or the like to vibrate the pair of vibrating arms 51 and check the vibration status. Then, depending on the difference between the measured actual frequency and a preset target frequency, the weight electrodes 64 and 65 can be partially removed by laser trimming or the like to adjust the frequency band of the piezoelectric vibrator 3 so that it falls within the target frequency band. However, the weight electrodes 64 and 65 are not essential and do not need to be provided.

[0078] As described above, the piezoelectric vibrator 3 is housed within the cavity C and supported in a state where it is floating above the mounting surface 21a, as shown in Figure 3. Furthermore, a pair of mounting electrodes 62 and 63 are electrically connected to the mounting electrode 31 via a conductive adhesive 35. Thus, the pair of excitation electrodes 60 and 61 and the mounting electrode 31 are electrically connected through the conductive adhesive 35 and the mounting electrodes 62 and 63.

[0079] (The action of a piezoelectric vibrator) Next, the operation of the piezoelectric vibrator 1 configured as described above will be explained. The piezoelectric vibrator 1 is used by being mounted on, for example, a control board of an electronic device (not shown). In this case, it is possible to mount the piezoelectric vibrator 1 (for example, by reflow soldering) with the external connection electrodes 32 electrically connected to the terminals of the control board using external electrodes such as metal bumps or solder (not shown).

[0080] By applying a predetermined drive voltage to the external connection electrode 32 of the piezoelectric vibrator 1 implemented in this manner, current can be passed through the pair of mounted electrodes 31 to the excitation electrodes 60, 61 of the pair of vibrating arms 51. This allows the interaction of the excitation electrodes 60, 61 to be used to vibrate the pair of vibrating arms 51 shown in Figure 2 in a direction (second direction L2) that moves them closer together and further apart from each other, within a predetermined resonant frequency band. Therefore, by utilizing the vibration of the pair of vibrating arms 51, the piezoelectric vibrator 1 can be used as, for example, a time source, a timing source for control signals, or a reference signal source.

[0081] (Manufacturing method for piezoelectric vibrators) Next, we will briefly explain the manufacturing method of the piezoelectric vibrator 1. In this case, the piezoelectric vibrator 3 is housed in the cavity C of the package body 10 shown in Figure 2, and the piezoelectric vibrator 3 is mounted on the mounting surface 21a via a conductive adhesive 35. Next, a lid 11 is set on the upper opening edge of the peripheral wall portion 10b (second mounting substrate 22) of the package body 10 so as to close the opening of the package body 10, and then the peripheral wall portion 10b and the lid 11 are directly welded together by seam welding. Therefore, with the package 2 constituting the piezoelectric vibrator 1, the package body 10 and the lid 11 can be directly welded together without using a conventional sealing ring, and the piezoelectric vibrator piece 3 housed in the cavity C can be hermetically sealed.

[0082] In particular, as shown in Figures 3 and 4, the lid 11 is constructed with a base material 40 and a plating layer 41 formed on the lower surface of the base material 40. Therefore, unlike conventional clad materials, the lid 11 has low residual stress due to the plating process, and the lid 11 itself is less prone to warping. Consequently, when welding the lid 11 by seam welding, it is not necessary to suppress the warping of the lid 11 while welding, so seam welding can be performed with low power (low voltage).

[0083] Furthermore, since the plating layer 41 includes a heat transfer plating layer 42 and a molten plating layer 43, welding heat can be efficiently transferred to the entire molten plating layer 43, which is a silver solder layer, via the heat transfer plating layer 42, which is a copper layer. Therefore, even when welding is performed at low power, the molten plating layer 43 and the metal layer 30 on the package body 10 can be melted together, enabling reliable welded joints by seam welding. As a result, a package 2 can be made that seals the cavity C with high airtightness.

[0084] Furthermore, since seam welding can be performed with even lower power, it is less likely to cause splash, where the weld metal originating from the plating layer 41 generated during welding scatters from the welding interface. Therefore, it is possible to suppress the occurrence of splash defects, such as weld metal scattering into the cavity C due to splashing and adhering to the piezoelectric vibrator 3 as conductive foreign matter. Furthermore, since it does not utilize conventional sealing rings and a thin lid 11 is formed by creating a plating layer 41 (heat transfer plating layer 42, molten plating layer 43) on the base material 40, the overall height of the package 2 can be reduced.

[0085] Based on the above, the package 2 of this embodiment allows for welding the package body 10 and the lid 11 together while suppressing the occurrence of splash defects without using a sealing ring, and also enables a lower profile package 2. Furthermore, according to the piezoelectric vibrator 1 of this embodiment, since the piezoelectric vibrator 3 is mounted within the cavity C of the package 2, the piezoelectric vibrator 3 can be operated within the airtight cavity C. Therefore, the piezoelectric vibrator 3 can be vibrated accurately within a predetermined resonant frequency band. In addition, since a low-profile package 2 is used, a low-profile piezoelectric vibrator 1 can also be achieved. In particular, since package 2 can suppress the occurrence of splash defects, conductive foreign matter caused by splash is less likely to adhere to the piezoelectric vibrator 3, etc. Therefore, the piezoelectric vibrator 3 can operate smoothly, resulting in a high-quality piezoelectric vibrator 1.

[0086] Furthermore, in package 2 of this embodiment, as shown in Figure 4, the entire overlapping region R of the lid 11 that overlaps the upper opening edge of the peripheral wall portion 10b (second mounting substrate 22) of the package body 10 is not welded together; rather, it is welded in the joining region R1, but not in the non-joining region R2. Therefore, a jointed region R1, where the peripheral wall portion 10b (second mounting substrate 22) and the lid 11 are welded together, and a non-jointed region R2, where they are not welded together, can be placed between the peripheral wall portion 10b (second mounting substrate 22) of the package body 10 and the lid 11.

[0087] In particular, the joining region R1 is located on the outer peripheral edge side including the outer end surface 11a of the lid 11, and the non-joining region R2 is located between the joining region R1 and the inner surface of the peripheral wall 10b. Therefore, when welding by seam welding, by mainly applying heat to the outer peripheral edge side of the lid 11, the molten plating layer 43 and the metal layer 30 can be melted together in the joining region R1 to perform welding. At this time, since the non-joining region R2 is located between the joining region R1 and the inner surface of the peripheral wall 10b, even if weld metal originating from the plating layer 41 is generated in the joining region R1 during welding, a distance can be secured for it to reach the cavity C. Therefore, the occurrence of splash defects can be further reduced.

[0088] On the other hand, during seam welding, the roller electrode E can be pressed against the inclined surface 45 of the lid 11 while current is applied, allowing for appropriate pressure and heating. Therefore, the package body 10 and the lid 11 can be firmly welded together in the joining region R1. In particular, since the heat transfer plating layer 42 is a copper layer with excellent thermal conductivity, heat can be efficiently transferred to the molten plating layer 43 through the heat transfer plating layer 42 even when welding is performed at low power. Furthermore, since the molten plating layer 43 is a silver brazing layer, the package body 10 and the lid 11 can be firmly welded together by silver brazing or the like. Therefore, it is easy to improve the airtightness inside the cavity C.

[0089] Furthermore, the plating layer 41 is formed such that (thickness T2 / thickness T1) is greater than 1 and 2.5 or less. Therefore, it is possible to prevent the thickness T2 of the heat transfer plating layer 42, which is the copper layer, from becoming excessively thick relative to the thickness T1 of the molten plating layer 43, which is the silver solder layer. The thicker the heat transfer plating layer 42 (T2), the easier it becomes for the welding heat applied during welding to diffuse radially, causing, for example, the molten plating layer 43 to melt and spread. In contrast, according to this embodiment, by reducing the thickness T2 of the heat transfer plating layer 42, excessive diffusion of welding heat can be suppressed. As a result, in addition to being able to melt the molten plating layer 43 and the metal layer 30 in the limited area of ​​the joining region R1, it is possible to suppress the transfer of welding heat to the non-joining region R2. Consequently, it is possible to properly melt and join the molten plating layer 43 in the joining region R1 while suppressing the melting of the molten plating layer 43 in the non-joining region R2. As a result, even if weld metal originating from the plating layer 41 is generated during welding, it can be generated in the joining region R1 rather than the non-joining region R2, thus preventing the weld metal from reaching the cavity C and reducing the occurrence of splash defects.

[0090] Furthermore, it is known that when welding joints are made by seam welding, as shown in Figure 4, a molten alloy layer 44 is formed by the melting of the molten plating layer 43 and the metal layer 30, and that voids (air spaces) B containing gases, etc., are trapped within the plating layer 41, including the molten alloy layer 44. This type of void B is sometimes referred to as a blowhole or pit. Void B is particularly likely to occur when seam welding is performed at high power, causing rapid melting.

[0091] In this regard, in package 2 of this embodiment, seam welding is performed at low power, so the occurrence of void B itself can be suppressed. In addition, in the overlapping region R, the molten plating layer 43 and the metal layer 30 are melted in the joining region R1 to form a molten alloy layer 44, while welding is not performed in the non-joining region R2. Therefore, as shown in Figure 4, even if voids B are present in the plating layer 41, they can be distributed in the plating layer 41 such that the number of voids B decreases radially inward from the outer end surface 11a of the lid 11.

[0092] Therefore, even if the piezoelectric vibrator 1 is subjected to heat treatment during reflow mounting, for example, it is possible to suppress the release of gas contained in void B into cavity C. Consequently, a high vacuum can be maintained inside cavity C, and an increase in the CI value (Crystal Impedance) of the piezoelectric vibrator 3 can be suppressed. Consequently, the piezoelectric vibrator 1 can be made more reliable in operation.

[0093] Here, we will briefly explain the relationship between splash defects and welding heat (resistance heat) in the case of conventional high-power (high-voltage) seam welding and the case of low-power (low-voltage) seam welding as described in this embodiment.

[0094] As shown in Figure 6, when heating is performed by pressing the roller electrode E (see Figure 4) against the inclined surface 45 of the lid 11 and continuously performing seam welding along the arrow F, if a high-power voltage is applied, the temperature of the welding heat transmitted from the roller electrode E itself becomes high. Therefore, the localized heat accumulation area H transmitted to the lid 11 tends to gradually increase as the seam welding progresses. This makes it easier for weld metal originating from the plating layer 41 generated during welding to fly off the welding interface, leading to splash defects and also making it easier for voids B to form.

[0095] In contrast, when a low-power voltage is applied, as in this embodiment, the temperature of the welding heat transmitted from the roller electrode E can be lowered, as shown in Figure 7. Therefore, the localized heat storage area H transmitted to the lid 11 does not change easily even as seam welding progresses along arrow F. This allows for stable seam welding while suppressing splash defects and noise generation.

[0096] (Modification of the first embodiment) In the first embodiment, as shown in Figure 4, when the wall width along the radial direction of the peripheral wall portion 10b (second mounting substrate 22) is defined as W0, the joint width along the radial direction of the joint region R1 is defined as W1, and the non-join width along the radial direction of the non-join region R2 is defined as W2, it is preferable that the lid 11 is welded to satisfy the following conditions.

[0097] First, it is preferable that the lid 11 is welded together such that the ratio of the unjoined width W2 to the wall width W0 is greater than 11%. In this case, since the ratio of the non-joined width W2 to the wall width W0 is greater than 11%, a gap can be secured between the joined region R1 and the inner surface of the peripheral wall portion 10b. Therefore, even if weld metal originating from the plating layer 41 is generated in the joined region R1 during welding, it becomes difficult for the weld metal to reach into the cavity C. As a result, the occurrence of splash defects can be further reduced.

[0098] Furthermore, it is preferable that the lid 11 is welded together such that the ratio of the unjoined width W2 to the wall width W0 is less than 29%. In this case, the ratio of the non-jointed width W2 to the wall width W0 is less than 29%, making it easier to secure a sufficient joint width W1 in the joint region R1 while reducing the occurrence of splash defects. This further improves the airtightness inside the cavity C and allows for the maintenance of a high vacuum inside the cavity C. Therefore, the resistance when the piezoelectric vibrator 3 vibrates can be suppressed, thus preventing an increase in the CI value. Consequently, a suitable package 2 can be made for housing the piezoelectric vibrator 3.

[0099] Therefore, it is preferable that the lid 11 is welded together such that the ratio of the non-joined width W2 to the wall width W0 is in the range of 11% to 29%. In particular, in this case, it is even more preferable that the lid 11 is welded together such that the ratio of the joined width W1 to the wall width W0 is in the range of 42% to 59%. By keeping both the ratio of the non-jointed width W2 to the wall width W0 and the ratio of the jointed width W1 to the wall width W0 within the above range, package 2 can be created that effectively reduces the occurrence of splash defects and improves the airtightness within the cavity C.

[0100] The ratio of the non-jointed width W2 to the wall width W0, and the ratio of the jointed width W1 to the wall width W0, can be calculated, for example, using a digital microscope. In this embodiment, the calculations were specifically performed using a KEYENCE VHX-8000 digital microscope. The method for calculating the ratio involves preparing multiple package bodies 10 having a wall width W0. Next, the wall width W0 is measured by plane measurement of the package body 10 using the digital microscope. Then, multiple piezoelectric vibrators 1 are manufactured by welding lids 11 while varying the joint width W1 and non-join width W2. After conducting performance verification tests to confirm the characteristics of each of these piezoelectric vibrators 1, the lids 11 are removed, and the joint width W1 and non-join width W2 of each piezoelectric vibrator 1 are measured in plane using the digital microscope. At this time, it is possible to determine the joint width W1 and non-join width W2 from the state of the weld interface using the digital microscope. Furthermore, the part where the joint width W1 and non-join width W2 are widest around the entire circumference of the package body 10 was adopted as the valid measurement value.

[0101] Then, the results of the performance verification test of the piezoelectric vibrator 1, the relationship between the ratio of the non-jointed width W2 to the wall width W0 and the ratio of the joined width W1 to the wall width W0 are calculated, and the ratio of the present invention that can exhibit the effects described above is calculated.

[0102] (Another variation of the first embodiment) Furthermore, in the first embodiment, as shown in Figure 8, the lid 11 may be welded together such that the non-jointed width W2 is larger than the joined width W1. In this case, while ensuring a sufficient joined width W1 in the joined region R1, a non-jointed region R2 with a non-jointed width W2 larger than the joined width W1 can be placed between the inner surface of the peripheral wall portion 10b of the joined region R1 and the non-jointed region R2, thereby reducing the occurrence of splash defects.

[0103] Furthermore, as shown in Figure 9, the lid 11 may be welded in place such that the total area S2 of the lid 11 is between 65% and 85% of the outer area S1 of the package body 10. In this case, it is possible to ensure a sufficient overlap area R between the package body 10 and the lid 11 while preventing the overall size of the lid 11 from becoming too large. In particular, since it is 65% or more, it is possible to ensure an overlap area R sufficient to adequately suppress splash defects. Furthermore, since it is 85% or less, the overall size of the lid 11 can be reduced, which helps to suppress an increase in component costs and makes the entire package 2 more compact.

[0104] Furthermore, the external area S1 of the package body 10 and the total area S2 of the lid 11 can also be calculated using, for example, a digital microscope. In this embodiment, the calculations were specifically performed using a KEYENCE VHX-8000 digital microscope. For calculating the area, the lid 11 was welded to the package body 10, and then the surface was measured using a digital microscope. Although notches 24 were formed at the four corners of the package body 10, the outer area S1 was calculated by treating the package body 10 as a virtual rectangle based on the length along the first direction L1 and the length along the second direction L2. Similarly, the total area S2 of the lid 11 was calculated based on the length along the first direction L1 and the length along the second direction L2. Next, the relationship between the performance verification test results of the piezoelectric vibrator 1, the external area S1 of the package body 10, and the total area S2 of the lid 11 is calculated, and the proportion of the area of ​​the present invention that can exhibit the above-mentioned effects is calculated.

[0105] For example, if planar measurement using a digital microscope reveals that the length of the package body 10 along the first direction L1 is 3.16 mm and the length along the second direction L2 is 1.47 mm, then the external area S1 is 4.6452 mm². 2 This is the result. Also, if the length of the lid 11 along the first direction L1 is 2.94 mm and the length along the second direction L2 is 1.26 mm, then the total area S2 is 3.7044 mm². 2 This is the result. In this case, the total area S2 of the lid 11 is approximately 80% of the outer area S1 of the package body 10, thus satisfying the scope of the present invention.

[0106] Furthermore, as shown in Figure 10, the molten plating layer 43 may be formed to have a wrap-around portion 43a that wraps around to the outer end surface 11a side of the lid 11. The wrap-around portion 43a covers at least the heat transfer plating layer 42 from the radial outside. In this case, since the wrap-around portion 43a of the molten plating layer 43 covers the heat transfer plating layer 42 from the outside, the molten plating layer 43 can function as a barrier layer, preventing the heat transfer plating layer 42 from reacting with moisture, etc. As a result, even if the heat transfer plating layer 42 is a copper layer, corrosion of the copper layer can be prevented, and the occurrence of cracks caused by corrosion can be prevented. Therefore, a decrease in the airtightness inside the cavity C can be suppressed.

[0107] (Second Embodiment) Next, a second embodiment of the package 2 and piezoelectric vibration device according to the present invention will be described with reference to the drawings. In the second embodiment, the same reference numerals are used for parts that are the same as those in the first embodiment, and their descriptions are omitted. In this embodiment, an oscillator will be given as an example of a piezoelectric vibration device.

[0108] As shown in Figures 11 to 13, the oscillator (piezoelectric vibration device according to the present invention) 100 of this embodiment comprises a package 101, a piezoelectric vibrator 102 mounted on the package 101, and an integrated circuit chip (integrated circuit according to the present invention) 103 mounted on the package 101. In this embodiment, the piezoelectric vibrator 102 functions as a so-called oscillator. The integrated circuit chip 103 is electrically connected to the piezoelectric vibrator 102 and has an oscillation circuit (not shown). The oscillation circuit has the function of generating output signals such as a clock signal (reference signal) based on the electrical signal from the piezoelectric vibrator 102.

[0109] Package 101 comprises a package body 110 and a lid 11. The package body 110 includes a mounting substrate 20 having a first mounting substrate 21 and a second mounting substrate 22, as well as a frame-shaped first frame 111 and a frame-shaped second frame 112 bonded to the mounting substrate 20. The first frame 111 and the second frame 112 are formed from an insulating material, similar to the mounting substrate 20, and are made of, for example, ceramic.

[0110] In this embodiment, the second mounting substrate 22 has a through hole 23 and a pair of mounting portions 120. The pair of mounting portions 120 are formed on the inner surface of the second mounting substrate 22 in the portion facing the second direction L2 and are formed to protrude inward from the through hole 23. The pair of mounting portions 120 are formed in a rectangular shape in plan view, with a length along the first direction L1 being longer than the length along the second direction L2, and the corners are formed in a curved shape with rounded edges.

[0111] In the mounting substrate 20 configured as described above, the upper surfaces of the pair of mounting sections 120 function as a first mounting surface 120a on which the piezoelectric vibrator 102 is mounted. Therefore, mounting electrodes 31 are formed on the upper surfaces of the pair of mounting sections 120. The lower surface of the first mounting substrate 21 functions as a second mounting surface 21b on which the integrated circuit chip 103 is mounted.

[0112] The first frame 111 is formed such that, in a plan view, its outer shape is the same as that of the second mounting substrate 22. Therefore, the first frame 111 is formed in a frame shape that is longer in the first direction L1 than in the second direction L2. In the illustrated example, the first frame 111 has the same thickness as the second mounting substrate 22. However, it is not limited to this case, and the thickness of the first frame 111 may be changed as appropriate. The first frame 111 is positioned above the second mounting board 22 and is superimposed on the upper surface of the second mounting board 22, and is integrally joined by sintering or the like.

[0113] The area (internal space) enclosed by the second mounting substrate 22 and the first frame 111, configured as described above, functions as a cavity C. Furthermore, the inner opening of the first frame 111 functions as an opening in the package body 110.

[0114] The second frame 112 is formed such that, in a plan view, its outer shape is the same as that of the first frame 111. Therefore, the second frame 112 is formed in a frame shape that is longer in the first direction L1 than in the second direction L2. In the illustrated example, the second frame 112 is thicker than the first mounting substrate 21. However, this is not limited to this case, and the thickness of the second frame 112 may be changed as appropriate. The second frame 112 is positioned below the first mounting substrate 21 and is superimposed on the lower surface of the first mounting substrate 21, and is integrally joined by sintering or the like. The area (internal space) enclosed by the second frame 112 functions as a mounting area K on which the integrated circuit chip 103 is mounted.

[0115] In the package body 110 configured as described above, the first mounting substrate 21 functions as the bottom wall portion 110a of the package body 110, and the frame-shaped second mounting substrate 22 and the first frame 111 function as the peripheral wall portion 110b of the package body 110. Therefore, the metal layer 30 is formed at the upper opening edge of the peripheral wall portion 110b (the upper opening edge of the first frame 111). In this embodiment, the notches 24 are formed across the entire package body 110 (first mounting substrate 21, second mounting substrate 22, first frame 111, and second frame 112) in the thickness direction T. Furthermore, the external connection electrodes 32 are formed to cover each surface of the notches 24 and also extend across the lower surface of the second frame 112.

[0116] (Lid) The lid 11 is positioned above the package body 110 and is welded to the upper opening edge of the peripheral wall portion 110b (first frame 111), thereby closing the opening of the package body 110. This forms an airtight cavity C between the lid 11 and the package body 110. In this embodiment as well, the lid 11 is welded to the package body 110 by seam welding, similar to the first embodiment.

[0117] (Piezoelectric vibrator) In this embodiment, the piezoelectric vibrator 102 is housed within the cavity C and mounted on the first mounting surface 120a, which is the upper surface of the pair of mounting parts 120. In other words, the piezoelectric vibrator 102 is electrically connected to the mounting electrode 31 via the conductive adhesive 35, and is also physically supported in a state where it is floating above the first mounting surface 120a via the conductive adhesive 35.

[0118] The piezoelectric vibrating piece 102 has a pair of so-called hammerhead-type vibrating arms 51. In this case, the width dimension of the vibrating arms 51 is wider at the tip end 51a, which is the free end, than at the base end (base 52 side), which is the fixed end.

[0119] Furthermore, the piezoelectric vibrating piece 102 of this embodiment is a so-called side-arm type, comprising a pair of support arms (side arms) 130 integrally formed with the base 52. However, even in this embodiment, as with the first embodiment, it may be a tuning fork type without a pair of support arms 130. The pair of support arms 130 are formed to extend outward from the base 52 along a second direction L2, and then extend along a first direction L1. As a result, the pair of support arms 130 are formed in an L-shape in plan view and are positioned outward in the second direction L2 than the pair of vibrating arms 51. Therefore, the pair of support arms 130 extend parallel to the pair of vibrating arms 51 along the first direction L1, with a gap between them.

[0120] The pair of support arms 130 are formed to overlap the pair of mounting sections 120 from above in a plan view (see Figure 11). This makes it possible to mount the piezoelectric vibrator 102 using the pair of support arms 130. As shown in Figure 14, of the mount electrodes 62 and 63, one mount electrode 62 is formed on the outer surface of one support arm 130, and the other mount electrode 63 is formed on the outer surface of the other support arm 130.

[0121] As described above, the piezoelectric vibrator 102 is mounted on a pair of mounting parts 120 via a conductive adhesive 35, as shown in Figure 13. This allows the piezoelectric vibrator 102 to be supported while suspended above the upper surfaces of the pair of mounting parts 120, while being housed within the cavity C. Furthermore, a pair of mounting electrodes 62 and 63 are electrically connected to the mounting electrode 31 via a conductive adhesive 35. Thus, the pair of excitation electrodes 60 and 61 and the mounting electrode 31 are electrically connected through the conductive adhesive 35 and the mounting electrodes 62 and 63.

[0122] (Integrated circuit chip) As shown in Figures 12 and 13, the integrated circuit chip 103 is positioned below the first mounting substrate 21 and is mounted on the second mounting surface 21b, which is the lower surface of the first mounting substrate 21, within the mounting area K surrounded by the second frame 112. Therefore, the integrated circuit chip 103 is mounted on the opposite side from the piezoelectric vibrator 102, with the package body 110 in between. Specifically, the integrated circuit chip 103 is mounted on the second mounting surface 21b via a conductive adhesive (not shown).

[0123] The integrated circuit chip 103 is formed in a rectangular parallelepiped shape in plan view, with a length along the first direction L1 being longer along the second direction L2, corresponding to the shape of the package 101. Note that the illustration of the integrated circuit chip 103 is simplified in each drawing.

[0124] The integrated circuit chip 103 includes at least an oscillator circuit (not shown) that generates an output signal based on an electrical signal from the piezoelectric vibrator 102. Furthermore, a plurality of integrated circuit terminals 140 are provided on the upper surface of the integrated circuit chip 103 so as to be exposed. The integrated circuit terminals 140 include at least a ground terminal. In addition to the ground terminal, the integrated circuit terminals 140 also include, for example, a power input terminal, a signal output terminal, a signal terminal that is conductive with the piezoelectric vibrator 102, a switch signal input terminal, etc. However, the integrated circuit terminals 140 are not limited to these terminals.

[0125] In this embodiment, the case in which six integrated circuit terminals 140 are provided on the integrated circuit chip 103 is used as an example, but the invention is not limited to this case, and the number and position of the integrated circuit terminals 140 may be changed as appropriate.

[0126] (Integrated circuit electrodes) As shown in Figure 13, multiple integrated circuit electrodes 141 are formed on the portion of the second mounting surface 21b, which is the lower surface of the first mounting substrate 21, that is located inside the second frame 112. The integrated circuit electrodes 141 are formed in a position that overlaps the integrated circuit terminals 140 formed on the integrated circuit chip 103 from above. Therefore, six integrated circuit electrodes 141 are provided, corresponding to the number of integrated circuit terminals 140, and each is electrically connected to each integrated circuit terminal 140. However, the number of integrated circuit electrodes 141 is not limited to six. The integrated circuit electrode 141 includes a ground electrode that is conductive to the ground terminal of the integrated circuit chip 103, and also includes a pair of monitor electrodes that are conductive to a pair of mounting electrodes 31 formed on the second mounting substrate 22. The pair of monitor electrodes and the pair of mounting electrodes 31 are electrically connected via, for example, a conductive electrode (not shown) formed inside the mounting substrate 20.

[0127] Furthermore, the integrated circuit electrode 141 includes, in addition to the ground electrode and a pair of monitor electrodes, a power electrode that conducts to the power input terminal, a signal output electrode that conducts to the signal output terminal, a signal electrode that conducts to the signal terminal, a switch electrode that conducts to the switch signal input terminal, and so on. However, the integrated circuit electrode 141 is not limited to these electrodes. The integrated circuit electrode 141 is electrically connected to the mounted electrode 31 and the external connection electrode 32 via conductive electrodes (not shown) formed on the surface or inside the mounted substrate 20 and the second frame 112.

[0128] (The function of an oscillator) Next, the operation of the oscillator 100 configured as described above will be explained. The oscillator 100 is used by being mounted on, for example, a control board of an electronic device (not shown). In this case, it is possible to mount the oscillator 100 (for example, by reflow soldering) with the external connection electrodes 32 electrically connected to the terminals of the control board using external electrodes such as metal bumps or solder (not shown).

[0129] By applying a predetermined drive voltage to the external connection electrode 32 of the oscillator 100 implemented in this manner, current can be passed through the pair of mounted electrodes 31 to the excitation electrodes 60, 61 of the pair of vibrating arms 51. This allows the pair of vibrating arms 51 shown in Figure 11 to be vibrated in a predetermined resonant frequency band in a direction (second direction L2) that moves them closer to and further apart from each other, utilizing the interaction of the excitation electrodes 60, 61, and the resulting vibration can be converted into an electrical signal due to the piezoelectric properties.

[0130] Therefore, the oscillator circuit of the integrated circuit chip 103 can be used to generate output signals such as clock signals based on the above electrical signals. This allows the output signals to be used as, for example, a time source, a timing source for control signals, a reference signal source, etc., and can function as an oscillator 100.

[0131] Furthermore, since the piezoelectric vibrating piece 102 is equipped with a hammerhead-type vibrating arm 51, the weight of the tip 51a of the vibrating arm 51 and the moment of inertia during vibration can be increased. As a result, the vibrating arm 51 can be made to vibrate more easily, and even if the length of the vibrating arm 51 is shortened, it is possible to prevent the vibration frequency from becoming too high. Therefore, it is possible to vibrate the piezoelectric vibrating piece 102 within a predetermined frequency band while miniaturizing it. Furthermore, since a side-arm type piezoelectric vibrator 102 is employed, the piezoelectric vibrator 102 can be mounted using a pair of support arms 130, and vibration leakage can be suppressed without increasing the overall length of the piezoelectric vibrator 102 (length along the first direction L1). Therefore, an increase in the CI value can be suppressed.

[0132] Furthermore, even in the case of the oscillator 100 of this embodiment, since it is equipped with a package 101 having a lid 11 similar to that of the first embodiment, the same effects and advantages as of the first embodiment can be achieved.

[0133] Although embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. Embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Embodiments and their modifications include, for example, those that can be easily imagined by those skilled in the art, those that are substantially the same, and those that are equivalent.

[0134] For example, in the first embodiment described above, a tuning fork-type piezoelectric vibrator 3 having a pair of vibrating arms 51 was given as an example of the piezoelectric vibrator, and in the second embodiment, a side-arm type piezoelectric vibrator 102 having a pair of support arms 130 was given as an example, but the invention is not limited to these cases. For example, a piezoelectric vibrator formed by AT cutting a quartz crystal and whose main vibration is thickness-sliding vibration (a so-called AT-cut vibrator) may be used. For example, as shown in Figure 15, a piezoelectric vibrator 150 can be employed that includes a piezoelectric plate 160 formed from an AT-cut quartz substrate and an electrode film 170 formed on the outer surface of the piezoelectric plate 160, which causes the piezoelectric plate 160 to vibrate with thickness sliding motion.

[0135] The piezoelectric plate 160 comprises a piezoelectric plate body 161 having a first main surface 161a and a second main surface 161b facing each other in the thickness direction T of the piezoelectric plate 160, and a first mesa portion 162 and a second mesa portion 163 formed to bulge out in the thickness direction T from the first main surface 161a and the second main surface 161b, respectively.

[0136] The electrode film 170 comprises a first electrode film 171 mainly formed on the first mesa portion 162, and a second electrode film 172 mainly formed on the second mesa portion 163. The first electrode film 171 includes an excitation electrode 173 formed on the top surface of the first mesa portion 162, a mounting electrode 174 formed across the first main surface 161a and the second main surface 161b of the piezoelectric plate body 161, and a connecting electrode 175 that electrically connects the excitation electrode 173 and the mounting electrode 174.

[0137] The second electrode film 172 has the same configuration as the first electrode film 171. Accordingly, the second electrode film 172 includes an excitation electrode 173 formed on the top surface of the second mesa portion 163, a mounting electrode 174 formed across the second main surface 161b and the first main surface 161a of the piezoelectric plate body 161, and a connecting electrode 175 that electrically connects the excitation electrode 173 and the mounting electrode 174.

[0138] In the case of the piezoelectric vibrating piece 150, by applying a drive voltage between the excitation electrode 173 on the first mesa portion 162 side and the excitation electrode 173 on the second mesa portion 163 side via the mounting electrode 174 and the connecting electrode 175, the piezoelectric plate 160 can be made to vibrate in the main vibration mode, which is thickness sliding vibration, and this can be used as the oscillation frequency, etc.

[0139] Furthermore, in each of the above embodiments, a plating layer 41 (heat transfer plating layer 42, molten plating layer 43) was formed over the entire lower surface of the base material 40 constituting the lid 11, but the invention is not limited to this case. For example, it is sufficient if at least a plating layer 41 is formed on the lower surface of the base material 40, at least at the joint portion with the upper end opening edge of the peripheral wall portions 10b, 110b.

[0140] Furthermore, in each of the above embodiments, the base material 40 is formed from a Kovar alloy, the heat transfer plating layer 42 is a copper layer, and the molten plating layer 43 is a silver solder layer (silver layer). However, the invention is not limited to these cases and can be modified as appropriate. In this case, the heat transfer plating layer 42 can be formed from a metal material with a lower melting point than the base material 40, and the molten plating layer 43 can be formed from a metal material with a lower melting point than the heat transfer plating layer 42. For example, the molten plating layer 43 may be a single silver layer, or it may be an alloy layer containing silver in an AgCu layer. Similarly, the heat transfer plating layer 42 may be an alloy layer containing copper.

[0141] Furthermore, the present invention includes the following embodiments. <1> A package having an internal sealed space for housing a piezoelectric vibrator, A bottomed cylindrical package body having a bottom wall and a peripheral wall, and opening upwards, The package comprises a lid that is welded to the upper end opening edge of the peripheral wall portion to close the opening of the package body and to form the sealing space between itself and the package body, A metal layer is formed at the upper end opening edge of the peripheral wall portion. The aforementioned cover is The base material is a metal matrix, The substrate comprises a plating layer formed on the surface of the substrate, at least at the portion where it is joined to the upper end opening edge of the peripheral wall, The aforementioned plating layer is A heat transfer plating layer formed on the surface of the substrate, having a lower melting point than the substrate, A package characterized by having a molten plating layer formed on the surface of the heat transfer plating layer, having a lower melting point than the heat transfer plating layer, and melting together with the metal layer. <2> <1> In the package described above, The lid's outer edge is superimposed on the upper end opening edge of the peripheral wall over its entire circumference. In a plan view of the package body, the overlapping region of the outer peripheral edge of the lid with respect to the upper end opening edge of the peripheral wall is, A region occupying a certain distance radially inward from the outer end surface of the cover, which is a joint region welded to the peripheral wall via the metal layer, A package having a non-jointed region located radially inward from the jointed region and between the jointed region and the inner surface of the peripheral wall. <3> <2> In the package described above, The package is such that the lid is welded together such that the ratio of the non-jointed width along the radial direction of the non-jointed area to the wall width along the radial direction of the peripheral wall portion is greater than 11%. <4> <3> In the package described above, The package is such that the lid is welded together such that the ratio of the unjointed width to the wall width is less than 29%. <5> <2> In the package described above, The package is characterized in that the cover is welded together such that the non-jointed width along the radial direction of the non-jointed region is greater than the jointed width along the radial direction of the jointed region. <6> <1> from <5> In any one of the packages described, The package is characterized in that the lid is welded to the package body such that the total area of ​​the lid is 65% or more and 85% or less of the outer surface area of ​​the package body. <7> <1> from <6> In any one of the packages described, The heat transfer plating layer is a copper layer. The aforementioned molten plating layer is a silver layer. The package is formed such that the plating layer is such that the ratio (T2 / T1) of the thickness of the heat transfer plating layer, which is the copper layer, to the thickness T1 of the molten plating layer, which is the silver layer, is greater than 1 and less than or equal to 2.5. <8> <2> from <6> In any one of the packages described, The aforementioned joining region is welded to the peripheral wall by melting the metal layer and the silver layer, in a package. <9> <1> from <8> In any one of the packages described, A package in which the molten plating layer is formed to wrap around to the outer end surface of the lid and covers at least the heat transfer plating layer from the outside. <10> <2> from <6> In any one of the packages described, On the upper surface of the lid in the joining region, an inclined surface is formed around its entire circumference, such that the thickness of the lid gradually decreases toward the radially outward direction. A package in which welding marks are formed on the aforementioned inclined surface. <11> <1> from <10> The package described in any one of the following, A piezoelectric vibration device characterized by comprising: a piezoelectric vibrating piece housed within the sealing space of the package and mounted on the bottom wall via a conductive adhesive. <12> <11> In the piezoelectric vibration device described above, The aforementioned plating layer contains voids, A piezoelectric vibration device in which the voids are distributed in the plating layer such that their number decreases radially inward from the outer end surface of the lid. <13> <11> or <12> In the piezoelectric vibration device described above, The piezoelectric vibrating piece is A piezoelectric plate having a pair of vibrating arms extending along a first direction and arranged parallel to a second direction, and a base that integrally fixes the base ends of the vibrating arms, A piezoelectric vibration device comprising: an excitation electrode formed on the outer surface of the piezoelectric plate, which vibrates a pair of vibrating arms when a voltage is applied. <14> <13> In the piezoelectric vibration device described above, The piezoelectric vibrating piece is of the side-arm type, comprising a pair of support arms formed to extend outward from the base in the second direction and then in the first direction. A piezoelectric vibration device in which a pair of support arms are mounted on the bottom wall via the conductive adhesive. <15> <11> from <14> In a piezoelectric vibration device described in any one of the following, The package body has an integrated circuit having multiple integrated circuit terminals, The aforementioned integrated circuit is mounted on the opposite side of the piezoelectric vibrator from the bottom wall portion of the package body, with the bottom wall portion in between, in a piezoelectric vibrator device. [Explanation of Symbols]

[0142] B...Void C... Cavity (sealed space) M...Weld marks L1…first direction L2…Second direction R... Superposition region R1...Joining area R2…non-bonded area T1...Thickness of the hot-dip galvanized layer T2...Thickness of the heat transfer plating layer W0...Wall width of the surrounding wall W1…Join width W2…Unjoined width 1…Piezoelectric vibrator (piezoelectric vibration device) 2, 101... Package 3, 102... Piezoelectric vibrator 10, 110... Package body 11... Lid 11a... Outer surface of the lid (outer surface of the cover) 10a, 110a...Bottom wall part 10b, 110b...peripheral wall part 30...Metal layer 35... Conductive adhesive 40...Base material 41…Plating layer 42…Heat transfer plating layer (copper layer) 43…Molten plated layer (silver solder layer) 51...Vibrating arm part 52...Base 60, 61...excitation electrode 100... Oscillator (piezoelectric vibration device) 103… Integrated circuit chip (integrated circuit) 130...Support arm 140… Integrated Circuit Terminal

Claims

1. A package having an internal sealed space for housing a piezoelectric vibrator, A bottomed cylindrical package body having a bottom wall and a peripheral wall, and opening upwards, The package comprises a lid that is welded to the upper end opening edge of the peripheral wall portion to close the opening of the package body and to form the sealing space between itself and the package body, A metal layer is formed at the upper end opening edge of the peripheral wall portion. The aforementioned cover is The base material is a metal matrix, The substrate comprises a plating layer formed on the surface of the substrate, at least at the portion where it is joined to the upper end opening edge of the peripheral wall, The aforementioned plating layer is A heat transfer plating layer formed on the surface of the substrate, having a lower melting point than the substrate, A package characterized by having a molten plating layer formed on the surface of the heat transfer plating layer, having a lower melting point than the heat transfer plating layer, and melting together with the metal layer.

2. In the package according to claim 1, The outer peripheral edge of the cover overlaps the upper end opening edge of the peripheral wall over its entire circumference. In a plan view of the package body, the overlapping region of the outer peripheral edge of the lid with respect to the upper opening edge of the peripheral wall is, A region occupying a certain distance radially inward from the outer end surface of the cover, which is a joint region welded to the peripheral wall via the metal layer, A package having a non-jointed region located radially inward from the jointed region and between the jointed region and the inner surface of the peripheral wall.

3. In the package according to claim 2, The package is such that the cover is welded together such that the ratio of the non-jointed width along the radial direction of the non-jointed region to the wall width along the radial direction of the peripheral wall portion is greater than 11%.

4. In the package described in claim 3, The package is such that the lid is welded together such that the ratio of the unjointed width to the wall width is less than 29%.

5. In the package according to claim 2, The package is characterized in that the cover is welded together such that the non-jointed width along the radial direction of the non-jointed region is greater than the jointed width along the radial direction of the jointed region.

6. In the package according to claim 3 or 4, The lid is welded to the package such that the total area of ​​the lid is 65% or more and 85% or less of the outer surface area of ​​the package body.

7. In the package according to claim 2, The heat transfer plating layer is a copper layer. The aforementioned molten plating layer is a silver layer. The package is formed such that the plating layer is such that the ratio (T2 / T1) of the thickness of the heat transfer plating layer, which is the copper layer, to the thickness T1 of the molten plating layer, which is the silver layer, is greater than 1 and less than or equal to 2.

5.

8. In the package according to claim 7, The aforementioned joining region is welded to the peripheral wall by melting the metal layer and the silver layer, in a package.

9. In the package according to claim 1, A package in which the molten plating layer is formed to wrap around to the outer end surface of the lid and covers at least the heat transfer plating layer from the outside.

10. In the package according to claim 2, On the upper surface of the lid in the joining region, an inclined surface is formed around its entire circumference, such that the thickness of the lid gradually decreases toward the radially outward direction. A package in which welding marks are formed on the aforementioned inclined surface.

11. The package described in claim 1, A piezoelectric vibration device characterized by comprising: a piezoelectric vibrating piece housed within the sealing space of the package and mounted on the bottom wall via a conductive adhesive.

12. In the piezoelectric vibration device according to claim 11, The aforementioned plating layer contains voids, A piezoelectric vibration device in which the voids are distributed in the plating layer such that their number decreases radially inward from the outer end surface of the lid.

13. In the piezoelectric vibration device according to claim 11 or 12, The piezoelectric vibrating piece is A piezoelectric plate having a pair of vibrating arms extending along a first direction and arranged parallel to a second direction, and a base that integrally fixes the base ends of the vibrating arms, A piezoelectric vibration device comprising: an excitation electrode formed on the outer surface of the piezoelectric plate, which vibrates a pair of vibrating arms when a voltage is applied.

14. In the piezoelectric vibration device according to claim 13, The piezoelectric vibrating piece is of the side-arm type, comprising a pair of support arms formed to extend outward from the base in the second direction and then in the first direction. A piezoelectric vibration device in which a pair of support arms are mounted on the bottom wall via the conductive adhesive.

15. In the piezoelectric vibration device according to claim 11 or 12, The package body has an integrated circuit having multiple integrated circuit terminals, The aforementioned integrated circuit is mounted on the opposite side of the piezoelectric vibrator from the bottom wall portion of the package body, with the bottom wall portion in between, in a piezoelectric vibrator device.

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