JP2020123906A - Piezoelectric vibration device - Google Patents

Abstract

To provide a piezoelectric vibration device capable of suppressing damage to an excitation electrode and the like during marking.SOLUTION: In a piezoelectric vibrating device 100, a first sealing member and a crystal vibrating plate are bonded. In the piezoelectric vibrating device 100, a second sealing member and the crystal vibrating plate are bonded to each other so that an internal space is provided that hermetically seals a vibrating portion 11 of the crystal diaphragm including a first excitation electrode 111 and a second excitation electrode. A first metal film 22 is formed on a first main surface 201 of the first sealing member. The first metal film 22 is provided with a marking area M1 capable of printing a character on a surface of the first metal film 22. In the marking area M1, the first excitation electrode 111 and the second excitation electrode are provided so as not to overlap with each other in a plan view.SELECTED DRAWING: Figure 8

Description

The present invention relates to a piezoelectric vibration device such as a piezoelectric vibrator.

2. Description of the Related Art In recent years, operating frequencies of various electronic devices have been increased, and packages have been downsized (especially height reduction). Therefore, along with the increase in the frequency and the miniaturization of the package, the piezoelectric vibration device (for example, crystal oscillator, crystal oscillator, etc.) is also required to cope with the high frequency and the miniaturization of the package.

In this type of piezoelectric vibrating device, its housing is formed of a substantially rectangular parallelepiped package. This package includes a first sealing member and a second sealing member made of, for example, glass or crystal, and a piezoelectric vibrating plate made of, for example, crystal and having excitation electrodes formed on both main surfaces thereof. The second sealing member and the second sealing member are laminated and bonded via the piezoelectric vibration plate. The vibrating portion (excitation electrode) of the piezoelectric vibrating plate disposed inside the package (internal space) is hermetically sealed (for example, Patent Document 1). Hereinafter, such a laminated form of the piezoelectric vibration device is referred to as a sandwich structure.

JP, 2010-252051, A

By the way, in the piezoelectric vibration device, for example, marking is performed by a laser to print the model name of the product, the manufacturing time, and the like. Here, of the piezoelectric vibration devices, for example, in a piezoelectric oscillator, it is possible to provide a marking area for marking on the back surface of the IC mounted on the first sealing member of the package described above. On the other hand, for example, in a piezoelectric vibrator, unlike a piezoelectric oscillator, since such an IC is not provided, it is necessary to perform marking directly on the package. However, if an excitation electrode or the like is provided below the marking area, the excitation electrode or the like may be irradiated with laser during marking, which may damage the excitation electrode or the like. I'm worried.

The present invention has been made in consideration of the above situation, and an object of the present invention is to provide a piezoelectric vibration device capable of suppressing damage to an excitation electrode or the like during marking.

The present invention has the following means for solving the above-mentioned problems. That is, the present invention relates to a piezoelectric vibrating plate having a first excitation electrode formed on one main surface of a substrate and a second excitation electrode paired with the first excitation electrode formed on the other main surface of the substrate; A first sealing member that covers the first excitation electrode of the piezoelectric diaphragm and a second sealing member that covers the second excitation electrode of the piezoelectric diaphragm are provided, and the first sealing member and the piezoelectric element are provided. The vibrating plate and the second sealing member and the piezoelectric vibrating plate are bonded to each other, so that the vibrating portion of the piezoelectric vibrating plate including the first excitation electrode and the second excitation electrode is separated. In a piezoelectric vibrating device provided with a tightly sealed internal space, a metal film is formed on one main surface of the first sealing member, and the metal film has a print area capable of being printed on the surface of the metal film. Is provided, and the print area is provided so as not to overlap the first excitation electrode and the second excitation electrode in a plan view.

According to the above configuration, it is possible to prevent the first excitation electrode and the second excitation electrode from being irradiated with the laser at the time of marking, and to prevent damage to the first excitation electrode and the second excitation electrode at the time of marking. Therefore, it is possible to prevent the frequency characteristics of the first excitation electrode and the second excitation electrode from changing.

In the above structure, the print region is provided so as not to overlap in plan view with electrodes and wirings formed on the piezoelectric vibration device other than the one main surface of the first sealing member. Is preferably provided. According to this configuration, at the time of marking, the laser is applied to the electrodes and wirings formed on the other main surface of the first sealing member, both main surfaces of the piezoelectric vibration plate, and both main surfaces of the second sealing member. Can be suppressed, and damage to these electrodes and wiring during marking can be suppressed.

In the above configuration, the piezoelectric vibrating plate includes the vibrating portion, an outer frame portion that surrounds an outer periphery of the vibrating portion, and a holding portion that connects the vibrating portion and the outer frame portion, and the vibrating portion and the A cutout portion formed by cutting out the piezoelectric vibrating plate is provided between the cutout portion and the outer frame portion, and the print region is preferably provided so as to overlap the cutout portion in a plan view. According to this configuration, since the laser passes through the cutout portion provided apart from the first excitation electrode and the second excitation electrode during marking, damage to the first excitation electrode and the second excitation electrode during marking Can be suppressed more reliably.

In the above-mentioned configuration, it is preferable that the print region is electrically connected to the first excitation electrode or the second excitation electrode and serves as an inspection terminal of the vibrating portion of the piezoelectric vibrating plate. According to this configuration, the printed area provided on the one main surface of the first sealing member is used as an inspection terminal of the vibrating portion of the piezoelectric vibrating plate, so that the piezoelectric vibrating plate is joined before the second sealing member is joined. It is possible to easily inspect the vibrating part. As described above, the printing area is provided in the inspection terminal which is used in the manufacturing process of the piezoelectric vibration device but is not used after the piezoelectric vibration device is commercialized. Therefore, it has a more desirable form because it does not affect the electrical characteristics after the product is commercialized.

In the above configuration, it is preferable that the print region is provided on a shield electrode that is not electrically connected to the first excitation electrode and the second excitation electrode. Here, since the shield electrode is provided in a relatively wide area, even if a part of the shield electrode is cut off by laser irradiation, the deterioration of the shield performance is suppressed to a relatively small level, and compared with other electrodes and wiring. Therefore, the degree of influence on electrical characteristics is considered to be small. For this reason, it is possible to provide the print area on a part of the shield electrode.

According to the piezoelectric vibrating device of the present invention, it is possible to suppress laser irradiation to the first excitation electrode and the second excitation electrode during marking, and the first excitation electrode and the second excitation electrode during marking. Of the first excitation electrode and the second excitation electrode can be prevented from changing.

It is a schematic block diagram which showed typically each structure of the crystal oscillator concerning this Embodiment. FIG. 2 is a schematic plan view of the first main surface side of the first sealing member of the crystal unit. FIG. 3 is a schematic plan view of the second main surface side of the first sealing member of the crystal unit. FIG. 4 is a schematic plan view of the crystal plate of the crystal unit on the first main surface side. FIG. 5 is a schematic plan view of the crystal plate of the crystal unit on the second main surface side. FIG. 6 is a schematic plan view of the second main surface of the second sealing member of the crystal unit. FIG. 7 is a schematic plan view of the second main surface side of the second sealing member of the crystal unit. FIG. 8 is a schematic plan view showing the positional relationship between the marking area on the first main surface of the first sealing member of the crystal unit and the electrodes, wirings and the like provided on the crystal unit. FIG. 9 is a schematic plan view showing the positional relationship between the marking area on the first main surface of the first sealing member of the crystal resonator and the cutout portion provided on the crystal diaphragm. FIG. 10 is a diagram showing an example of markings printed in the marking area.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, a case where the piezoelectric vibrating device to which the present invention is applied is a crystal resonator will be described.

First, the basic structure of the crystal unit 100 according to the present embodiment will be described. As shown in FIG. 1, the crystal unit 100 includes a crystal diaphragm (piezoelectric diaphragm) 10, a first sealing member 20, and a second sealing member 30. In this crystal unit 100, the crystal vibration plate 10 and the first sealing member 20 are bonded together, and the crystal vibration plate 10 and the second sealing member 30 are bonded together to form a package having a substantially rectangular parallelepiped sandwich structure. Composed. That is, in the crystal unit 100, the internal space (cavity) of the package is formed by joining the first sealing member 20 and the second sealing member 30 to both main surfaces of the crystal diaphragm 10. The vibrating portion 11 (see FIGS. 4 and 5) is hermetically sealed in this internal space.

The crystal unit 100 according to the present embodiment has a package size of, for example, 1.0×0.8 mm, and is intended to be downsized and have a low profile. Further, with the miniaturization, in the package, the conduction of the electrodes is achieved without forming the castellation by using the through holes described later. Further, the crystal unit 100 is electrically connected to an external circuit board (not shown) provided outside via solder.

Next, each member of the crystal diaphragm 10, the first sealing member 20, and the second sealing member 30 in the above-described crystal resonator 100 will be described with reference to FIGS. In addition, here, each member that is not joined and is configured as a single unit will be described. 2 to 7 merely show one configuration example of each of the crystal diaphragm 10, the first sealing member 20, and the second sealing member 30, and these do not limit the present invention.

As shown in FIGS. 4 and 5, the crystal diaphragm 10 is a piezoelectric substrate made of crystal, and both main surfaces (first main surface 101, second main surface 102) thereof are flat smooth surfaces (mirror surface processing). Has been formed. In the present embodiment, an AT-cut crystal plate that performs thickness shear vibration is used as the crystal vibration plate 10. In the crystal diaphragm 10 shown in FIGS. 4 and 5, both principal surfaces 101 and 102 of the crystal diaphragm 10 are XZ′ planes. In this XZ′ plane, the direction parallel to the lateral direction (short side direction) of the crystal diaphragm 10 is the X-axis direction, and the direction parallel to the longitudinal direction (long side direction) of the crystal diaphragm 10 is the Z′ axis. It is considered as a direction. The AT cut is 35° around the X-axis with respect to the Z-axis among the three crystal axes of the artificial crystal, the electric axis (X-axis), the mechanical axis (Y-axis), and the optical axis (Z-axis). This is a processing method of cutting out at an angle inclined by 15'. In the AT-cut quartz plate, the X axis coincides with the crystal axis of quartz. The Y′ axis and the Z′ axis are respectively inclined by approximately 35°15′ from the Y axis and the Z axis of the crystal axis of the crystal (the cutting angle may be slightly changed within the range of adjusting the frequency temperature characteristic of the AT cut crystal diaphragm). May match) axis. The Y′-axis direction and the Z′-axis direction correspond to the cutting directions when cutting the AT-cut crystal plate.

A pair of excitation electrodes (first excitation electrode 111, second excitation electrode 112) are formed on both main surfaces 101, 102 of the crystal diaphragm 10. The crystal diaphragm 10 holds the vibrating section 11 by connecting the vibrating section 11 formed in a substantially rectangular shape, the outer frame section 12 surrounding the outer periphery of the vibrating section 11, and the vibrating section 11 and the outer frame section 12. And a holding portion 13 that operates. That is, the crystal diaphragm 10 has a configuration in which the vibrating portion 11, the outer frame portion 12, and the holding portion 13 are integrally provided. The holding portion 13 extends (projects) from the one corner portion of the vibrating portion 11 located in the +X direction and the −Z′ direction to the outer frame portion 12 in the −Z′ direction. Then, a cutout portion 10 a formed by cutting out the crystal diaphragm 10 is provided between the vibrating portion 11 and the outer frame portion 12. In the present embodiment, the quartz crystal diaphragm 10 is provided with only one holding portion 13 that connects the vibrating portion 11 and the outer frame portion 12, and the cutout portion 10 a surrounds the outer periphery of the vibrating portion 11. Are formed continuously.

The first excitation electrode 111 is provided on the first main surface 101 side of the vibrating section 11, and the second excitation electrode 112 is provided on the second main surface 102 side of the vibrating section 11. Lead wires (first lead wires 113, second lead wires 114) for connecting these exciting electrodes to external electrode terminals are connected to the first exciting electrodes 111 and the second exciting electrodes 112. The first extraction wiring 113 is extracted from the first excitation electrode 111 and is connected to the connection bonding pattern 14 formed on the outer frame portion 12 via the holding portion 13. The second extraction wiring 114 is extracted from the second excitation electrode 112 and is connected to the connection bonding pattern 15 formed on the outer frame portion 12 via the holding portion 13.

A vibration side seal for joining the crystal diaphragm 10 to the first sealing member 20 and the second sealing member 30 is provided on both main surfaces (first main surface 101, second main surface 102) of the crystal diaphragm 10. Each stop is provided. The vibration-side first bonding pattern 121 is formed as the vibration-side sealing portion of the first main surface 101, and the vibration-side second bonding pattern 122 is formed as the vibration-side sealing portion of the second main surface 102. There is. The vibration-side first bonding pattern 121 and the vibration-side second bonding pattern 122 are provided on the outer frame portion 12 and are formed in an annular shape in a plan view.

Further, as shown in FIGS. 4 and 5, the quartz diaphragm 10 is provided with five through holes penetrating between the first main surface 101 and the second main surface 102. Specifically, the four first through holes 161 are provided in the four corners (corners) of the outer frame portion 12, respectively. The second through hole 162 is the outer frame portion 12 and is provided on one side of the vibrating portion 11 in the Z′-axis direction (−Z′ direction side in FIGS. 4 and 5 ). Connection joint patterns 123 are formed around the first through holes 161. Further, around the second through hole 162, the connecting joint pattern 124 is formed on the first main surface 101 side and the connecting joint pattern 15 is formed on the second main surface 102 side.

In the first through hole 161 and the second through hole 162, through electrodes for achieving electrical continuity of the electrodes formed on the first main surface 101 and the second main surface 102 are provided along the inner wall surface of each through hole. Has been formed. Further, the central portion of each of the first through hole 161 and the second through hole 162 is a hollow penetrating portion that penetrates between the first main surface 101 and the second main surface 102.

As shown in FIGS. 2 and 3, the first sealing member 20 is a rectangular parallelepiped substrate formed from one AT-cut crystal plate, and the second main surface 202 (crystal vibration) of the first sealing member 20. The surface to be joined to the plate 10 is formed as a flat smooth surface (mirror surface processing). Although the first sealing member 20 does not have a vibrating portion, the thermal expansion coefficient of the quartz diaphragm 10 and the first sealing member 20 can be increased by using an AT-cut quartz plate like the quartz diaphragm 10. The same can be applied, and thermal deformation of the crystal unit 100 can be suppressed. Further, the directions of the X axis, the Y axis, and the Z′ axis in the first sealing member 20 are also the same as those of the crystal diaphragm 10.

As shown in FIG. 2, first and second metal films 22 and 23 for wiring are formed on the first main surface 201 of the first sealing member 20 (the outer main surface that does not face the crystal diaphragm 10 ). , And a third metal film 28 for shielding is formed. The first and second metal films 22 and 23 for wiring electrically connect the first and second excitation electrodes 111 and 112 of the crystal diaphragm 10 and the external electrode terminals 32 of the second sealing member 30. It is provided as a wiring for. The first and second metal films 22 and 23 are provided at both ends in the Z′-axis direction, the first metal film 22 is provided on the +Z′ direction side, and the second metal film 23 is −Z′. It is provided on the direction side. The first and second metal films 22 and 23 are formed so as to extend in the X-axis direction. The first metal film 22 is formed in a substantially rectangular shape, but the +X direction side portion of the first metal film 22 is provided with a protrusion 22a that protrudes in the −Z′ direction side. The second metal film 23 is formed in a substantially rectangular shape, but the second metal film 23 has a protrusion portion 23a that protrudes toward the +Z′ direction side in the −X direction side portion.

The third metal film 28 is provided between the first and second metal films 22 and 23, and is arranged at a predetermined distance from the first and second metal films 22 and 23. The third metal film 28 is provided on almost all the regions of the first main surface 201 of the first sealing member 20 where the first and second metal films 22 and 23 are not formed.

As shown in FIGS. 2 and 3, the first sealing member 20 has six through holes penetrating between the first main surface 201 and the second main surface 202. Specifically, four third through holes 211 are provided in the four corner (corner) regions of the first sealing member 20. The fourth and fifth through holes 212 and 213 are provided in the +Z′ direction and the −Z′ direction of FIGS.

In the third through hole 211 and the fourth and fifth through holes 212, 213, through electrodes for establishing electrical continuity between the electrodes formed on the first main surface 201 and the second main surface 202 are provided in each of the through holes. It is formed along the inner wall surface. The central portions of the third through-hole 211 and the fourth and fifth through-holes 212, 213 are hollow portions that penetrate between the first main surface 201 and the second main surface 202. Then, the two third through holes 211 and 211 located diagonally to the first principal surface 201 of the first sealing member 20 (the third through holes located at the corners in the +X direction and the +Z′ direction in FIGS. 2 and 3). The hole 211 and the through electrodes of the third through hole 211) located at the corners in the −X direction and the −Z′ direction are electrically connected by the third metal film 28. Further, the through electrode of the third through hole 211 and the through electrode of the fourth through hole 212 located at the corners in the −X direction and the +Z′ direction are electrically connected by the first metal film 22. The through electrode of the third through hole 211 and the through electrode of the fifth through hole 213 located at the corners in the +X direction and the −Z′ direction are electrically connected by the second metal film 23.

On the second main surface 202 of the first sealing member 20, a sealing-side first bonding pattern 24 as a sealing-side first sealing portion for bonding to the crystal diaphragm 10 is formed. The sealing-side first bonding pattern 24 is formed in an annular shape in plan view. Further, on the second main surface 202 of the first sealing member 20, the connection bonding patterns 25 are formed around the third through holes 211, respectively. A connecting joint pattern 261 is formed around the fourth through hole 212, and a connecting joint pattern 262 is formed around the fifth through hole 213. Further, a connecting joint pattern 263 is formed on the opposite side (−Z′ direction side) in the major axis direction of the first sealing member 20 with respect to the connecting joint pattern 261, and is connected to the connecting joint pattern 261. The connection pattern 263 is connected by the wiring pattern 27.

As shown in FIGS. 6 and 7, the second sealing member 30 is a rectangular parallelepiped substrate formed from a single AT-cut crystal plate, and the second main surface 301 (crystal vibration) of the second sealing member 30. The surface to be joined to the plate 10 is formed as a flat smooth surface (mirror surface processing). It is desirable that the second sealing member 30 also uses an AT-cut quartz plate as in the quartz diaphragm 10 and that the X-axis, Y-axis, and Z′-axis directions are the same as those of the quartz diaphragm 10.

On the first main surface 301 of the second sealing member 30, a sealing-side second bonding pattern 31 as a sealing-side second sealing portion for bonding to the crystal diaphragm 10 is formed. The sealing-side second bonding pattern 31 is formed in an annular shape in plan view.

The second main surface 302 of the second sealing member 30 (the outer main surface that does not face the crystal diaphragm 10) has four outsides that are electrically connected to an external circuit board provided outside the crystal resonator 100. Electrode terminals 32 are provided. The external electrode terminals 32 are respectively located at the four corners (corners) of the second main surface 302 of the second sealing member 30.

As shown in FIGS. 6 and 7, the second sealing member 30 has four through holes penetrating between the first main surface 301 and the second main surface 302. Specifically, the four sixth through holes 33 are provided in the regions of the four corners (corners) of the second sealing member 30. Through electrodes are formed in the sixth through holes 33 along the inner wall surface of each of the sixth through holes 33 for achieving conduction between the electrodes formed on the first main surface 301 and the second main surface 302. There is. Thus, the electrode formed on the first main surface 301 and the external electrode terminal 32 formed on the second main surface 302 are electrically connected by the through electrode formed on the inner wall surface of the sixth through hole 33. .. Further, the central portion of each of the sixth through holes 33 is a hollow penetrating portion that penetrates between the first main surface 301 and the second main surface 302. Further, on the first main surface 301 of the second sealing member 30, the connection bonding patterns 34 are formed around the sixth through holes 33, respectively.

In the crystal resonator 100 including the crystal diaphragm 10, the first sealing member 20, and the second sealing member 30, the crystal diaphragm 10 and the first sealing member 20 are the vibration-side first bonding patterns 121 and Diffusion bonding is performed in a state where the sealing-side first bonding patterns 24 are overlapped, and the crystal diaphragm 10 and the second sealing member 30 are overlapped with the vibration-side second bonding pattern 122 and the sealing-side second bonding pattern 31. Then, the package having the sandwich structure shown in FIG. 1 is manufactured by diffusion bonding. As a result, the internal space of the package, that is, the accommodation space of the vibrating section 11 is hermetically sealed.

At this time, the above-described connecting joint patterns are also diffusion-joined in a state of being overlapped. In the crystal unit 100, the first excitation electrode 111, the second excitation electrode 112, and the external electrode terminal 32 are electrically connected to each other by the connection of the connection connection patterns. Specifically, the first excitation electrode 111 includes the first lead wire 113, the wiring pattern 27, the fourth through hole 212, the first metal film 22, the third through hole 211, the first through hole 161, and the sixth through hole. It is connected to the external electrode terminal 32 through the hole 33 in order. The second excitation electrode 112 includes the second lead wire 114, the second through hole 162, the fifth through hole 213, the second metal film 23, the third through hole 211, the first through hole 161, and the sixth through hole 33. Via the order, they are connected to the external electrode terminal 32. Further, the third metal film 28 is grounded (ground connection, part of the external electrode terminal 32 is used) through the third through hole 211, the first through hole 161, and the sixth through hole 33 in this order. ing.

In the crystal unit 100, various bonding patterns are formed by stacking a plurality of layers on a crystal plate, and forming a Ti (titanium) layer and an Au (gold) layer by vapor deposition from the lowermost layer side. It is preferable. Further, it is preferable that the other wirings and electrodes formed on the crystal unit 100 have the same structure as the bonding pattern because the bonding pattern, the wirings, and the electrodes can be simultaneously patterned.

In the crystal unit 100 configured as described above, the sealing units (seal paths) 115 and 116 that hermetically seal the vibrating unit 11 of the crystal vibrating plate 10 are annularly formed in a plan view. The seal path 115 is formed by diffusion bonding of the vibration-side first bonding pattern 121 and the sealing-side first bonding pattern 24 described above, and the outer edge shape and the inner edge shape of the seal path 115 are formed into a substantially octagonal shape. Similarly, the seal path 116 is formed by the diffusion bonding of the vibration-side second bonding pattern 122 and the sealing-side second bonding pattern 31 described above, and the outer edge shape and the inner edge shape of the seal path 116 are formed into a substantially octagonal shape.

In the crystal unit 100 in which the seal paths 115 and 116 are formed by diffusion bonding as described above, the first sealing member 20 and the crystal diaphragm 10 have a gap of 1.00 μm or less, and the second sealing member 30. The crystal diaphragm 10 has a gap of 1.00 μm or less. That is, the thickness of the seal path 115 between the first sealing member 20 and the crystal diaphragm 10 is 1.00 μm or less, and the thickness of the seal path 116 between the second sealing member 30 and the crystal diaphragm 10 is , 1.00 μm or less (specifically, 0.15 μm to 1.00 μm in the Au—Au junction of the present embodiment). As a comparative example, the conventional metal paste sealing material using Sn has a thickness of 5 μm to 20 μm.

In the present embodiment, in the crystal unit 100 having the above structure, the first metal film 22 formed on the first main surface 201 of the first sealing member 20 can be printed on the surface of the first metal film 22. A printing area (marking area) M1 is provided. The marking area M1 will be described with reference to FIGS. 2 and 8 to 10.

As described above, the first and second metal films 22 and 23 are formed on the first main surface 201 of the first sealing member 20, and one of the first and second metal films 22 and 23 is marked. A region M1 is provided. In the present embodiment, the marking region M1 is provided on the protruding portion 22a of the first metal film 22. The marking region M1 is a substantially rectangular region, and the vertical dimension (dimension in the X-axis direction) is, for example, 100 μm to 150 μm, and the lateral dimension (dimension in the Z′-axis direction) is, for example, 50 μm to 100 μm. ing.

It is possible to perform marking on the marking area M1 by printing (burning) the surface of the marking area M1 by irradiating the marking area M1 with, for example, a laser, and printing the model name of the product, the manufacturing time, etc. Is. As the laser, for example, a carbon dioxide gas laser, a semiconductor laser, a YAG laser or the like can be used. As a marking method, for example, there is a dot code, and FIG. 10 shows an example of marking by the dot code. FIG. 10 shows the case where the product manufacturing time is printed by the dot code of 4 bits×3 rows formed in the marking area M1. The dot code in FIG. 10 means [829]. Specifically, [1000] in the first column means [8] and corresponds to the manufacturing year (here, 2010 is the start year). The second row, [0010], means [2] and corresponds to the tens digit of the manufacturing week. [1001] in the third column means [9] and corresponds to the ones digit of the manufacturing week. It can be seen from the dot code in FIG. 10 that the manufacturing time of the product is the 29th week of 2018.

Next, the positional relationship between the marking area M1 and the first and second excitation electrodes 111 and 112 will be described.

As shown in FIG. 8, the marking area M1 is provided so as not to overlap the first and second excitation electrodes 111 and 112 in a plan view. According to such a positional relationship, it is possible to prevent the first and second excitation electrodes 111 and 112 from being irradiated with the laser during marking, and the first and second excitation electrodes 111 and 112 during marking can be suppressed. It is possible to suppress damage to 112, and thus to suppress changes in frequency characteristics of the first and second excitation electrodes 111 and 112. Moreover, since the marking region M1 is provided on the first metal film 22 electrically connected to the first excitation electrode 111, the marking layer is formed on the first main surface 201 of the first sealing member 20. There is no need to provide a separate film or membrane.

Further, the marking region M1 is provided so as not to overlap in plan view with the electrodes and wirings formed on the crystal unit 100 other than the first main surface 201 of the first sealing member 20. Has been. That is, the marking area M1 is formed on the second main surface 202 of the first sealing member 20, both main surfaces 101 and 102 of the crystal diaphragm 10, and both main surfaces 301 and 302 of the second sealing member 30. The electrodes and the wiring are provided so as not to overlap with each other in a plan view.

In the present embodiment, as shown in FIG. 8, the marking area M1 is viewed in plan from the wiring electrically connected to the first excitation electrode 111 and the wiring electrically connected to the second excitation electrode 112. It is provided so as not to overlap. As the wiring electrically connected to the first excitation electrode 111, the first extraction wiring 113, the wiring pattern 27, the fourth through hole 212, the third through hole 211, the first through hole 161, and the sixth through hole 33, There is also an external electrode terminal 32. The wiring electrically connected to the second excitation electrode 112 includes the second lead wiring 114, the second through hole 162, the fifth through hole 213, the third through hole 211, the first through hole 161, and the sixth through hole. 33, and the external electrode terminal 32. Further, as shown in FIG. 8, the marking area M1 is provided so as not to overlap the seal paths 115 and 116 in a plan view.

According to such a positional relationship, at the time of marking, the second main surface 202 of the first sealing member 20, the both main surfaces 101 and 102 of the crystal diaphragm 10, and the both main surfaces 301 of the second sealing member 30. , 302 can be prevented from being irradiated with laser, and damage to these electrodes and wirings at the time of marking can be suppressed.

Further, as shown in FIG. 9, the marking area M1 is provided so as to overlap with the cutout portion 10a that surrounds the outer periphery of the vibrating portion 11 in a plan view. According to such a positional relationship, since the laser passes through the cutout portion 10a provided away from the first and second excitation electrodes 111 and 112 at the time of marking, the first and second excitations at the time of marking are performed. Damage to the electrodes 111 and 112 can be suppressed more reliably. Here, the crystal diaphragm 10 is an AT-cut crystal plate, and since the cutout portion 10a is formed by etching, inclined surfaces are formed on the end surfaces of the vibration portion 11 and the outer frame portion 12. When the laser hits these inclined surfaces, it is feared that the laser will be reflected in an unintended direction. Therefore, it is preferable that the marking area M1 is provided so as not to overlap with such an inclined surface in a plan view. That is, it is preferable that the marking area M1 is provided so as to overlap the penetrating portion of the cutout portion 10a in a plan view.

In the present embodiment, it is preferable that the marking area M1 provided on the protruding portion 22a of the first metal film 22 be an inspection terminal of the vibrating portion 11 of the crystal diaphragm 10. In this case, it is preferable that the protruding portion 23 a of the second metal film 23 also serves as an inspection terminal of the vibrating portion 11 of the crystal diaphragm 10. According to this, by using the marking area M1 provided on the first main surface 201 of the first sealing member 20 as an inspection terminal of the vibrating portion 11 of the crystal diaphragm 10, the second sealing member 30 of the second sealing member 30 can be obtained. It is possible to easily inspect the vibrating portion 11 of the crystal diaphragm 10 before joining. As described above, the marking region M1 is provided in the protruding portion 22a that is used in the manufacturing process of the crystal unit 100 but is not used after the crystal unit 100 is commercialized. Therefore, it has a more desirable form because it does not affect the electrical characteristics after the product is commercialized.

The embodiment disclosed this time is an example in all respects, and is not a basis for a limited interpretation. Therefore, the technical scope of the present invention should not be construed only by the embodiments described above, but should be defined based on the description of the claims. Also, the meaning equivalent to the scope of claims and all modifications within the scope are included.

The arrangement location, shape, and size of the marking area M1 described above are examples, and the arrangement location and size other than the above may be used. For example, the marking area M1 may be provided on the protruding portion 23a of the second metal film 23. In the case of the crystal unit 100 having the shield electrode inside, the marking region M1 may be provided so as not to overlap the shield electrode in a plan view.

However, since the shield electrode is provided in a relatively wide area, even if a part of the shield electrode is scraped off by laser irradiation, the deterioration of the shield performance is suppressed to a relatively small level, and compared with other electrodes and wiring. It is considered that the degree of influence on the electrical characteristics is small. For this reason, it is possible to provide the marking area M1 on a part of the shield electrode that is not electrically connected to the first excitation electrode 111 and the second excitation electrode 112. As such a shield electrode, there is the third metal film 28 formed on the first main surface 201 of the first sealing member 20, and the marking region M1 may be provided in a part of the third metal film 28. .. Alternatively, in the case of the crystal unit 100 having the shield electrode inside, the marking region M1 may be provided in the shield electrode.

The marking method described above is an example, and marking may be performed using a barcode, a QR code (registered trademark), or the like. Also, characters, numbers, symbols, etc. may be printed in the marking area M1. By using the above-described dot code, it is possible to reliably and easily perform marking even on an extremely small marking area M1 such as several hundreds μm×several hundreds μm.

Although the number of the external electrode terminals 32 on the second main surface 302 of the second sealing member 30 is four in the above-described embodiment, the number is not limited to this, and the number of the external electrode terminals 32 may be, for example, The number may be two, six, eight, or the like. Further, the case where the present invention is applied to the crystal resonator 100 has been described, but the present invention is not limited to this, and the present invention may be applied to, for example, a crystal oscillator.

In the above embodiment, the first sealing member 20 and the second sealing member 30 are formed by the crystal plate, but the present invention is not limited to this, and the first sealing member 20 and the second sealing member 30 are For example, it may be formed of glass.

10 Crystal diaphragm (piezoelectric diaphragm)
11 Vibrating Section 20 First Sealing Member 22 First Metal Film 30 Second Sealing Member 100 Crystal Resonator (Piezoelectric Vibration Device)
111 1st excitation electrode 112 2nd excitation electrode 201 1st main surface (1 main surface)
202 Second main surface (other main surface)
M1 marking area (printing area)

Claims (5)

A piezoelectric vibration plate having a first excitation electrode formed on one main surface of a substrate and a second excitation electrode paired with the first excitation electrode formed on the other main surface of the substrate;
A first sealing member that covers the first excitation electrode of the piezoelectric vibrating plate;
A second sealing member that covers the second excitation electrode of the piezoelectric vibrating plate,
The first excitation electrode and the second excitation electrode are included by joining the first sealing member and the piezoelectric vibrating plate and joining the second sealing member and the piezoelectric vibrating plate. In a piezoelectric vibrating device provided with an internal space that hermetically seals the vibrating portion of the piezoelectric vibrating plate,
A metal film is formed on one main surface of the first sealing member,
The metal film is provided with a printable area on the surface of the metal film,
The piezoelectric vibrating device, wherein the printed region is provided so as not to overlap the first excitation electrode and the second excitation electrode in a plan view. The piezoelectric vibration device according to claim 1,
The printed area is provided so as not to overlap with the electrodes and wirings provided on the piezoelectric vibration device other than the electrodes and wirings formed on the one main surface of the first sealing member in a plan view. Piezoelectric vibration device characterized by. The piezoelectric vibration device according to claim 1 or 2,
The piezoelectric vibrating plate includes the vibrating portion, an outer frame portion that surrounds the outer periphery of the vibrating portion, and a holding portion that connects the vibrating portion and the outer frame portion, and the vibrating portion and the outer frame portion. In between, a cutout portion formed by cutting out the piezoelectric diaphragm is provided,
The piezoelectric vibrating device, wherein the print area is provided so as to overlap the cutout portion in a plan view. The piezoelectric vibration device according to any one of claims 1 to 3,
The piezoelectric vibrating device, wherein the printed region is electrically connected to the first excitation electrode or the second excitation electrode and serves as an inspection terminal of the vibrating portion of the piezoelectric vibrating plate. The piezoelectric vibration device according to any one of claims 1 to 3,
The piezoelectric vibrating device, wherein the printed region is provided on a shield electrode that is not electrically connected to the first excitation electrode and the second excitation electrode.

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