JP2010177984A - Piezoelectric vibrator and piezoelectric device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric vibrator with electrode pads such that a circuit element is mounted with high reliability. <P>SOLUTION: The piezoelectric vibrator 100 has: a case body 10 having a flat external bottom surface 10s; a lid body 20 for sealing the case body 10; a vibrating piece 30 installed in a cavity 18 formed of the case body 10 and lid body 20; a plurality of first electrode pads 40 having a first thickness and formed on the external bottom surface 10s; and a plurality of second electrode pads 50 having a second thickness and formed on the external bottom surface 10s, wherein the first thickness is less than the second thickness. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a piezoelectric vibrator and a piezoelectric device.

  A surface-mount type piezoelectric device is generally composed of a piezoelectric vibrator and a circuit element that drives and controls the piezoelectric vibrator, and an example thereof is a piezoelectric device that outputs a transmission signal. A device on which a piezoelectric device such as a piezoelectric device is mounted is required to be downsized, and further downsizing is also required for a piezoelectric device such as a crystal oscillator. In response to such a request, for example, the following proposals have been made.

  Japanese Patent Laying-Open No. 2003-046251 (Patent Document 1) proposes an electronic component (crystal oscillator) in which a vibrator and a circuit element are integrally mounted by a multilayer substrate. Japanese Laid-Open Patent Publication No. 2004-147221 (Patent Document 2) proposes a piezoelectric device in which circuit elements are directly mounted on the lower surface of a ceramic package of a vibrator.

  There is a description that each of these piezoelectric devices has a structure in which piezoelectric vibrators and circuit elements are laminated in the thickness direction, so that the surface mounting density can be increased. Moreover, since the piezoelectric device described in Patent Document 2 does not have a wiring board, there is a description that the height can be reduced.

  On the other hand, in general, a piezoelectric vibrator often takes the form of a package in which a cavity is formed. In the piezoelectric vibrator having such a configuration, a piezoelectric vibrating piece is accommodated in a cavity. As a package of a piezoelectric vibrator, for example, there is a package formed by joining a case body having an opening on an upper surface and a lid body called a lid for sealing the upper surface.

The manufacture of a piezoelectric device in which a circuit element is mounted on a package of a piezoelectric vibrator is generally performed by applying a so-called flip chip method, for example. Specifically, first, an electrode pad for connecting to a circuit element or the like was formed with the outer bottom surface of the case body facing up, and then the case body was turned over and the piezoelectric vibrating piece was placed inside the case body Thereafter, a method is adopted in which a lid is bonded onto the case body to form a package, the package is turned over again, and circuit elements are mounted on the back surface (the outer bottom surface of the case body).
JP 2003-046251 A JP 2004-147221 A

  Due to the demand for miniaturization of piezoelectric devices, the circuit elements mounted on the piezoelectric devices have also become extremely small. Even when the piezoelectric devices are manufactured by the flip chip method, the piezoelectric vibrator is used when the circuit elements are mounted on the package. There has been a problem that the bump function of the electrode pad for connecting the circuit element becomes insufficient.

  The inventor transports a case body or package in which electrode pads for connecting circuit elements are formed, with the surface on which the electrode pads are formed being placed on the lower side, that is, facing the transport tray. It has been found that the electrode pad is in contact with the transport tray and damaged when the process is performed or when other processes are performed.

  Further, the inventor of the present invention has made it easier for the inspection probe in the inspection of the piezoelectric vibrator to come into contact with the electrode pad for connecting the circuit element and to damage the electrode pad by downsizing the piezoelectric vibrator. However, it has been found that it contributes to other problems.

  One of the objects of some aspects according to the present invention is to provide a piezoelectric vibrator having an electrode pad on which a circuit element can be mounted with high reliability.

  One of the objects of some embodiments according to the present invention is to provide a piezoelectric device with high electrical connection between a piezoelectric vibrator and a circuit element.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
A case body having a flat outer bottom surface;
A lid for sealing the case body;
A vibrating piece provided in a cavity formed by the case body and the lid body;
A plurality of first electrode pads having a first thickness and formed on the outer bottom surface;
A plurality of second electrode pads having a second thickness and formed on the outer bottom surface;
Have
The piezoelectric vibrator, wherein the first thickness is smaller than the second thickness.

  Such a piezoelectric vibrator has an electrode pad on which a circuit element can be mounted with high reliability.

[Application Example 2]
In application example 1,
The second electrode pad is a piezoelectric vibrator provided on the outer peripheral side of the first electrode pad when the outer bottom surface is viewed in plan.

  In such a piezoelectric vibrator, when the piezoelectric vibrator is placed on the placement surface so that the outer bottom surface of the case body faces down, the first electrode pad is less likely to come into contact with the placement surface. The protective effect of the pad can be enhanced.

[Application Example 3]
In application example 1 or application example 2,
The outline of the outer bottom surface of the case body is rectangular in plan view,
The second electrode pad is a piezoelectric vibrator provided at four corners of the outline in a plan view of the outer bottom surface of the case body.

  In such a piezoelectric vibrator, when the piezoelectric vibrator is placed on the placement surface so that the outer bottom surface of the case body faces down, the first electrode pad is less likely to come into contact with the placement surface. The protective effect of the pad can be enhanced.

[Application Example 4]
In any one of the application examples 1 to 3,
When the piezoelectric vibrator is placed on the placement surface such that the outer bottom surface of the case body faces the flat placement surface, the second electrode pad is in contact with the placement surface, and the first A piezoelectric vibrator in which a gap is formed between the electrode pad and the mounting surface.

  In such a piezoelectric vibrator, since a gap is formed between the first electrode pad and the mounting surface, the protective effect of the first electrode pad can be enhanced.

[Application Example 5]
In any one of the application examples 1 to 4,
The first electrode pad is a piezoelectric vibrator, which is a circuit element connection pad.

  Such a piezoelectric vibrator can increase the reliability of electrical connection when the circuit element is connected to the first electrode pad.

[Application Example 6]
In any one of the application examples 1 to 5,
The second electrode pad is a piezoelectric vibrator including at least one of a test pad, an external connection pad, and a dummy pad.

  Such a piezoelectric vibrator can enhance the protection effect of the first electrode pad by using, as the second electrode pad, a pad to which no circuit element is connected among the pads formed on the outer bottom surface of the case body.

[Application Example 7]
The piezoelectric vibrator according to any one of Application Examples 1 to 6, and
A circuit element connected to the first electrode pad;
A piezoelectric device.

  Such a piezoelectric device has high reliability of electrical connection between the piezoelectric vibrator and the circuit element.

  Preferred embodiments of the present invention will be described below with reference to the drawings. In addition, the following embodiment demonstrates an example of this invention.

1. Piezoelectric Vibrator FIG. 1 is a cross-sectional view schematically showing a piezoelectric vibrator 100 according to the present embodiment. FIG. 2 is a bottom view schematically showing the piezoelectric vibrator 100. 1 corresponds to a cross-sectional view taken along line AA in FIG. 3 and 4 are bottom views schematically showing modifications of the piezoelectric vibrator 100. FIG. In the bottom views of FIGS. 2 to 4, the surface layer of each electrode pad is omitted.

  The piezoelectric vibrator 100 includes at least a case body 10, a lid body 20, a vibrating piece 30, a first electrode pad 40, and a second electrode pad 50.

1.1. Case Body The case body 10 has a container shape that can accommodate the resonator element 30. The outer bottom surface 10s of the case body 10 has a flat shape. The planar shape of the case body 10 has a rectangular shape in the present embodiment, but is not limited thereto, and may be a circle or the like. Moreover, in this embodiment, as illustrated in FIG. 1, the case body 10 has a configuration in which a bottom member 12 that forms the bottom of the container and a wall member 14 that forms the side wall of the container are joined. The case body 10 may be a member in which the bottom member 12 and the wall member 14 are integrated. The upper portion of the case body 10 has an opening that allows the vibrator 30 to be placed inside the case body 10. The opening of the case body 10 can be hermetically sealed by the lid body 20. The bottom member 12 can have a through hole 16a. The through hole 16a is filled with a conductive material, and can be a via hole 16 that electrically connects the conductive member inside the case body 10 and the external conductive member. Examples of the conductive material used for the via hole 16 include tungsten and molybdenum. The via hole 16 can have airtightness. The material of the case body 10 can be an inorganic material such as ceramic or glass.

1.2. Lid Body The lid body 20 has a flat plate shape that seals the upper opening of the case body 10. The planar shape of the lid body 10 is arbitrary as long as the opening of the case body 10 can be sealed. Examples of the material of the lid body 10 include ceramic, glass, and metal. Adhesion between the case body 10 and the lid body 10 can be performed using, for example, plasma welding, seam welding, ultrasonic bonding, or an adhesive. The cavity 18 formed by the case body 10 and the lid body 20 becomes a space for the vibration piece 30 to operate. Moreover, since the cavity 18 can be sealed, the resonator element 30 can be placed in a decompressed space or an inert gas atmosphere.

1.3. The vibrating piece 30 is provided in a cavity 18 formed by the case body 10 and the lid body 20. The vibration piece 30 may be any form of vibration piece. Examples of the vibration piece 30 include an AT vibration piece, a tuning fork type vibration piece, a SAW vibration piece, and a walk type vibration piece. Further, the resonator element 30 itself may be formed of a piezoelectric material such as quartz, lithium tantalate, or lithium niobate, or may be formed of a material that does not have piezoelectricity. When the vibration piece 30 is formed of a material that does not have piezoelectricity, for example, a piezoelectric element may be further included in the configuration of the vibration piece 30.

  In this embodiment, the case where the vibrating piece 30 is a tuning fork type vibrating piece formed of quartz is illustrated. The resonator element 30 can be fixed to a wall surface in the cavity 18 (in the illustrated example, the upper surface of the bottom member 12) with, for example, an adhesive, a paste, a brazing material, or the like. In the illustrated example, the resonator element 30 is fixed to the upper surface of the bottom member 12 by an adhesive layer 38. The vibrating piece 30 of the present embodiment has two vibrating rods 32 and is supported by the base 34 in a cantilever shape. The vibrating rod 32 extending from the base portion 34 can bend and vibrate in the cavity 18. A plurality of electrodes 36 for bending and vibrating at least the vibrating rod 32 can be provided on the vibrating rod 32 and the base 34.

1.4. Electrode Pad A plurality of first electrode pads 40 are formed on the outer bottom surface 10 s of the case body 10. The first electrode pad 40 has a first thickness. The first electrode pad 40 can have a function as a terminal when a circuit element is mounted on the piezoelectric vibrator 100 (see FIG. 5). Further, all of the plurality of first electrode pads 40 may be circuit element connection terminals. As shown in FIG. 2, the first electrode pads 40 may be arranged in a plurality of rows and a plurality of columns. The first electrode pad 40 may be connected to the via hole 16. As shown in FIG. 1, the first electrode pad 40 can be composed of, for example, a base layer 42 and a surface layer 44. The thickness of the foundation layer 42 is, for example, 5 to 15 μm. The thickness of the surface layer 44 is, for example, 1 to 5 μm. One of the functions of the surface layer 44 is to prevent the material of the base layer 42 from being oxidized. Examples of the material of the base layer 42 include tungsten or molybdenum. Examples of the material of the surface layer 44 include gold, nickel, and the like. The surface layer 44 can have a single layer or a multilayer structure of nickel and gold.

  A plurality of second electrode pads 50 are formed on the outer bottom surface 10 s of the case body 10. The second electrode pad 50 has a second thickness. The second electrode pad 50 may be a test pad, an external connection pad, or a dummy pad. As in the example shown in FIG. 2, the second electrode pad 50 can have a terminal function when the piezoelectric vibrator 100 is mounted on an external substrate or the like (see FIG. 18). Further, as in the modification of FIG. 3, the second electrode pad 50 can be an inspection pad that is not used for external connection. Furthermore, as in the modification of FIG. 4, the second electrode pad 50 may be a dummy pad that is not electrically connected to another conductive member. Although not shown, when the second electrode pad 50 is a dummy pad, it may be electrically connected to another conductive member. The second electrode pad 50 is preferably provided so as not to interfere with a circuit element or the like mounted on the first electrode pad 40.

  Similar to the first electrode pad 40, the second electrode pad 50 can have a laminated structure of a base layer and a surface layer. When the base layer is a single layer, the base layer is formed thicker than the base layer 42 of the first electrode pad 40. Further, as shown in FIG. 1, the second electrode pad 50 can be configured by, for example, laminating a first base layer 52, a second base layer 54, and a surface layer 56. In this case, since the second electrode pad 50 includes the first base layer 52 and the second base layer 54, when the first base layer 52 is shared with the base layer 42 of the first electrode pad 40, the first electrode The second underlayer 54 is formed thicker than the pad 40. The thickness of the 1st foundation layer 52 and the 2nd foundation layer 54 is 5-10 micrometers, respectively, for example. The surface layer 56 is the same as the surface layer 44 of the first electrode pad 40. Examples of the material of the first underlayer 52 and the second underlayer 54 include tungsten and molybdenum, respectively.

  The thickness (first thickness) of the first electrode pad 40 is smaller than the thickness (second thickness) of the second electrode pad 50. Therefore, when the piezoelectric vibrator 100 is placed on a flat placement surface with the outer bottom surface 10 s of the case body 10 facing down, only the second electrode pad 50 comes into contact with the placement surface. In other words, when the piezoelectric vibrator 100 is placed on a flat placement surface with the outer bottom surface 10s of the case body 10 facing down, the first electrode pad 40 does not contact the placement surface, and the first A gap is formed between the electrode pad 40 and the mounting surface. This can prevent the first electrode pad 40 from being damaged when the piezoelectric vibrator 100 is placed on a tray or the like so that the outer bottom surface 10s of the case body 10 faces down. Therefore, reliability when mounting a circuit element or the like on the first electrode pad 40 can be improved. In addition, the piezoelectric device in which the circuit element is mounted on the first electrode pad 40 of the piezoelectric vibrator 100 according to the present embodiment has high reliability in mounting the circuit element.

  In the present embodiment, the thickness of the second electrode pad 50 is larger than the thickness of the first electrode pad 40 by providing the second underlayer 54. Although the method of increasing the thickness of the second electrode pad 50 is arbitrary, according to the present embodiment, the thickness of the second electrode pad 50 can be increased only by laminating the second underlayer 54. . In the case of the present embodiment, the thickness of the second electrode pad 50 can be arbitrarily increased by increasing the number of times of forming the underlayer.

  The difference between the thickness of the second electrode pad 50 and the thickness of the first electrode pad 40 (the difference between the second thickness and the first thickness) is preferably 5 μm or more, and more preferably 10 μm or more. If the difference between the second thickness and the first thickness is smaller than 5 μm, the effect of protecting the first electrode pad 40 may not be obtained.

  The plurality of second electrode pads 50 prevent the piezoelectric vibrator 100 from rattling when the piezoelectric vibrator 100 is placed on a flat placement surface with the outer bottom surface 10 s of the case body 10 facing down. Placed in. That is, when the piezoelectric vibrator 100 is placed on the placement surface with the outer bottom surface 10s of the case body 10 facing down, the second bottom surface 10s and the placement surface of the second electrode pad 50 are maintained in parallel. Arranged so that. The number and shape of the plurality of second electrode pads 50 are, for example, as shown in FIG. 3, when there are two second electrode pads 50, the piezoelectric vibrator 100 has a rectangular shape by having a rectangular shape. It can be arranged so that it does not rattle. Further, if the number of the second electrode pads 50 is increased, the above effect is further enhanced.

  As the arrangement of the plurality of second electrode pads 50, for example, when the outer bottom surface 10s of the case body 10 is viewed in plan, it can be arranged so as to be symmetric with respect to the center of the outer bottom surface 10s. By arranging the second electrode pad 50 in this way, when the piezoelectric vibrator 100 is placed on a flat placement surface with the outer bottom surface 10s of the case body 10 facing down, the outer bottom surface 10s and the placement surface are placed. Are easily maintained in parallel. For example, the second electrode pad 50 can be provided on the outer peripheral side of the first electrode pad 40 when the outer bottom surface 10 s of the case body 10 is viewed in a plan view. By arranging the second electrode pad 50 in this way, when the piezoelectric vibrator 100 is placed on a flat placement surface with the outer bottom surface 10s of the case body 10 facing down, the first electrode pad 40 is placed in a horizontal plane. In addition, it is more difficult to contact, and the protective effect of the first electrode pad 40 can be further enhanced. Further, for example, the second electrode pad 50 can be provided at a position sandwiching the first electrode pad 40 when the outer bottom surface 10 s of the case body 10 is viewed in plan. When the second electrode pads 50 are arranged in this way, at least a pair of second electrode pads 50 arranged so as to sandwich the first electrode pad 40 are in contact with the placement surface. Therefore, the first electrode pad 40 is less likely to come into contact with the mounting surface, and the protective effect of the first electrode pad 40 can be further enhanced.

  Further, in the example of FIGS. 2 and 4, the outline of the outer bottom surface 10 s of the case body 10 is rectangular in plan view, and the second electrode pad 50 is the outline of the outer bottom surface 10 s of the case body 10 in plan view. Are provided at the four corners. By arranging the second electrode pad 50 in this way, when the piezoelectric vibrator 100 is placed on a flat placement surface with the outer bottom surface 10s of the case body 10 facing down, the outer bottom surface 10s and the horizontal surface The effect of maintaining parallelism and the effect of preventing the first electrode pad 40 from contacting the horizontal plane can be further enhanced.

1.5. Other Configurations Some of the configurations that can be included in the piezoelectric vibrator 100 will be described below. The piezoelectric vibrator 100 can further include other configurations.

  A wiring 60 for electrically connecting to the electrode 36 of the vibrating piece 30 can be provided on the inner surface of the case body 10. A plurality of wirings 60 can be provided as necessary. The wiring 60 can have an arbitrary shape. The wiring 60 may function as a connection inside the case body 10, or may function as an electrical connection to the outside of the case body 10 by being connected to the via hole 16. The material of the wiring 60 is arbitrary as long as it has conductivity. The wiring 60 can have the same configuration as the first electrode pad 40 in order to simplify the manufacturing process of the piezoelectric vibrator 100. As shown in FIG. 1, the wiring 60 can be composed of, for example, a base layer 62 and a surface layer 64. The surface layer 64 and the base layer 62 can be the same as described for the first electrode pad 40.

  Moreover, wiring 70 for electrically connecting each electrode pad can be provided on the outer bottom surface 10 s of the case body 10. A plurality of wirings 70 can be provided as necessary. The wiring 70 can have the same configuration as the first electrode pad 40 in order to simplify the manufacturing process of the piezoelectric vibrator 100. As shown in FIG. 1, the wiring 70 can be composed of, for example, a base layer 72 and a surface layer 74. The surface layer 74 and the base layer 72 can be the same as described in the first electrode pad 40. If the thickness of the wiring 70 is set to the first thickness, the wiring 70 becomes thinner than the second electrode pad 50, so that it can be hardly damaged. Further, the wiring 70 can have the same thickness as the second electrode pad 50 as long as it does not interfere with the circuit element mounted on the first electrode pad 40. In this case, the wiring 70 can have the same function as the second electrode pad 50.

  The piezoelectric vibrator 100 according to this embodiment includes a first electrode pad 40 that is thinner than the second electrode pad 50. Therefore, damage to the first electrode pad 40 can be reduced in a manufacturing process or the like. Thereby, a circuit element can be mounted on the first electrode pad 40 with high reliability.

2. Piezoelectric Device The piezoelectric device 300 according to the present embodiment includes the piezoelectric vibrator 100 and the circuit element 200 described in the section “1. Piezoelectric vibrator”. FIG. 5 is a cross-sectional view schematically showing the piezoelectric device 300 of the present embodiment.

  As shown in FIG. 5, the circuit element 200 is connected to the first electrode pad 40 of the piezoelectric vibrator 100. The circuit element 200 can include, for example, a control circuit for the resonator element 30. The size of the circuit element 200 is arbitrary, but has a shape that does not overlap the second electrode pad 50 of the piezoelectric vibrator 100 in a plan view. The circuit element 200 can be connected to the first electrode pad 40 by, for example, a face-down flip chip method. In the illustrated example, the first electrode pad 40 and the circuit element 200 are joined by a solder ball 202.

  The piezoelectric device 300 according to the present embodiment includes the piezoelectric vibrator 100 having the first electrode pad 40 that is thinner than the second electrode pad 50. Therefore, damage to the first electrode pad 40 is reduced in the manufacturing process and the like. Therefore, the piezoelectric device 300 according to the present embodiment has high reliability of electrical connection between the piezoelectric vibrator 100 and the circuit element 200.

2. Method for Manufacturing Piezoelectric Vibrator and Piezoelectric Device An example of a method for manufacturing the piezoelectric vibrator 100 according to the present embodiment will be described. 6 to 15 are schematic views showing manufacturing steps of the piezoelectric vibrator 100 according to the present embodiment.

  The following description describes a case where the case body 10 and the lid body 20 of the piezoelectric vibrator 100 are ceramic.

  First, a bottom material substrate 12a in the state of a ceramic green sheet is prepared. Next, as shown in FIG. 6, a through hole 16 a is formed at a predetermined position of the bottom substrate 12 a, a conductive material is embedded in the through hole 16 a, and a via hole 16 is formed. The through hole 16a can be formed by, for example, mechanical cutting or etching using a mask. The conductive material can be embedded, for example, by depositing tungsten by a CVD method.

  Next, as shown in FIG. 7, each base layer is formed on both surfaces of the bottom substrate 12a. In the present embodiment, the base layer 62 of the wiring 60 formed inside the package, the base layer 42 of the first electrode pad 40 formed on the outer bottom surface 10 s, and the first base layer 52 of the second electrode pad 50 by this step. And a base layer 72 of the wiring 70 are formed. This step can be performed, for example, by applying a conductive paste in which a metal powder of tungsten or molybdenum is dispersed in a vehicle as an ink, using a printing method such as screen printing or an ink jet method, and baking it ( Metallization). Moreover, you may perform this process by general film-forming and patterning. By using a refractory metal such as tungsten or molybdenum for the underlayer, it is possible to suppress melting of the underlayer in a subsequent process such as firing the ceramic green sheet.

  Next, as shown in FIG. 8, a second underlayer 54 is formed at a predetermined site where the second electrode pad 50 is to be formed. This step can be performed in the same manner as the step of forming the base layer described above. Since the second underlayer 54 is formed by being laminated on the first underlayer 52, the thickness of the entire underlayer is increased at the site where the second underlayer 54 is formed by this step. This process can be repeated until an underlayer having a desired thickness is formed.

  Next, as shown in FIG. 9, a wall material substrate 14a in which holes to be cavities 18 are formed is laminated on the bottom material substrate 12a. As the wall material substrate 14a, a ceramic green sheet is used. By laminating the bottom material substrate 12a and the wall material substrate 14a and then firing, an integrated ceramic case body substrate 10a can be formed as shown in FIG.

  Next, as shown in FIG. 11, surface layers (64, 44, 56, 74) are formed on the exposed surfaces of the base layers (62, 42, 52, 54, 72). The surface layer can be formed by, for example, electrolytic plating of gold. When the surface layer has a multi-layer structure, the surface layer is formed by, for example, forming a nickel layer on the surface of the underlayer by electrolytic plating of nickel, and then layering the gold on the surface of the nickel layer by electrolytic plating of gold. Can be performed. Then, as shown in FIG. 12, the seam ring 22 for joining the cover body 20 is formed as needed. In the illustrated example, the seam ring 22 is provided, but a metal brazing material layer may be provided. Further, when the lid 20 is joined by plasma welding or ultrasonic joining, the formation of the seam ring 22 can be omitted.

  Then, the case body substrate 10a is cut into pieces by dicing or the like. The separated case body 10 is placed in the recess 82 of the tray 80 as shown in FIG. The tray 80 has a function of facilitating the handling of the individual case body 10. As illustrated, the individual pieces of the case body 10 can be accommodated one by one in the recess 82 of the tray 80. The bottom surface of the recess 82 is a flat surface, and the outer periphery of the recess 82 is slightly larger than the outer periphery of the case body 10.

  Here, in the case body 10 housed in the tray 80, only the second electrode pad 50 formed on the outer bottom surface 10s contacts the bottom surface of the tray 80. Therefore, even if the case body 10 moves in the lateral direction in the recess 82 of the tray 80, the first electrode pad 40 is suppressed from contacting the bottom surface of the tray 80. In addition, in the process of placing the resonator element 30 and the process of providing the lid 20, the first electrode pad 40 contacts the bottom surface of the tray 80 even if an external force is applied to press the case body 10 against the tray 80. Hard to do. Therefore, since at least the first electrode pad 40 is hardly damaged such as scratches, it is possible to improve reliability when the circuit element 200 is mounted in a later process.

  Next, as shown in FIG. 14, the resonator element 30 is placed in the cavity 18 of the case body 10. This step can be performed by a manipulator or the like, for example. As a method of fixing the vibrating piece 30, for example, an adhesive can be used. Then, the electrode 32 of the resonator element 30 is electrically connected to the wiring 60 formed in the case body 10 (not shown). This step can be performed, for example, by wire bonding.

  Next, as shown in FIG. 15, the lid 20 is joined to the case body 10. In this embodiment, this process is performed by seam joining (welding). Although not shown, in order to increase the degree of vacuum in the cavity 18 formed in the package, an exhaust hole is provided in the case body 10 or the lid body 20, and after the gas is exhausted by reducing the pressure in the cavity 18, the exhaust hole It is also possible to employ a method of sealing

  The piezoelectric vibrator 100 of this embodiment can be manufactured by the manufacturing method described above. Thereafter, the piezoelectric device 300 can be manufactured by mounting the circuit element 200 on the piezoelectric vibrator 100. Hereinafter, a process for manufacturing the piezoelectric device 300 and a process for mounting the piezoelectric device 300 on another circuit board 400 will be described.

  As shown in FIG. 16, the piezoelectric vibrator 100 is housed in the recess 82 of the tray 80 with the lid 20 facing down. In this state, the circuit element 200 is mounted on the first electrode pad 40. The circuit element 200 can be performed by, for example, a solder bump method. After the circuit element 200 is mounted, the piezoelectric device 300 may be inspected as necessary. The inspection of the piezoelectric device 300 can be performed by designing the second electrode pad 50 in advance for inspection and bringing the inspection probe into contact with the second electrode pad 50. Also in the inspection process of the piezoelectric device 300, the second electrode pad 50 is thicker than the first electrode pad 40 and the wiring 70. Therefore, when the inspection probe comes into contact with the second electrode pad 50, Hard to touch. Therefore, the piezoelectric device 300 is less likely to be damaged such as scratches, and the piezoelectric device 300 can be inspected while maintaining high reliability.

  The piezoelectric device 300 may have a solder ball 302 that contacts the second electrode pad 50 as shown in FIG. Here, the height of the solder ball 302 can be made larger than the height of the circuit element 200. Then, as shown in FIG. 18, it can be taken out from the tray 80 and mounted on a circuit board 400 having connection electrodes 402 formed in advance on the surface. When the second electrode pad 50 is subjected to the above-described process, the surface may be more damaged than the first electrode pad 40. However, as shown in the figure, the mounting of the solder ball 302 on the circuit board 400 has a size and scale of each member larger than the mounting of the circuit element 200 on the first electrode pad 40, and therefore the degree of reduction in reliability is low. Small enough.

  As described above, the piezoelectric vibrator 100 and the piezoelectric device 300 of this embodiment can be manufactured. According to the method for manufacturing a piezoelectric vibrator of this embodiment, it is possible to form an electrode pad on which a circuit element can be mounted with high reliability. According to the method for manufacturing a piezoelectric device of the present embodiment, the reliability of electrical connection between the piezoelectric vibrator and the circuit element can be improved.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same purposes and effects). In addition, the present invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

FIG. 3 is a cross-sectional view schematically showing the piezoelectric vibrator 100 according to the embodiment. FIG. 3 is a bottom view schematically showing the piezoelectric vibrator 100 according to the embodiment. FIG. 6 is a bottom view schematically showing a modification of the piezoelectric vibrator 100 according to the embodiment. FIG. 6 is a bottom view schematically showing a modification of the piezoelectric vibrator 100 according to the embodiment. Sectional drawing which shows typically the piezoelectric device 300 concerning embodiment. Sectional drawing which shows typically the manufacturing process of the piezoelectric vibrator 100 concerning embodiment. Sectional drawing which shows typically the manufacturing process of the piezoelectric vibrator 100 concerning embodiment. Sectional drawing which shows typically the manufacturing process of the piezoelectric vibrator 100 concerning embodiment. Sectional drawing which shows typically the manufacturing process of the piezoelectric vibrator 100 concerning embodiment. Sectional drawing which shows typically the manufacturing process of the piezoelectric vibrator 100 concerning embodiment. Sectional drawing which shows typically the manufacturing process of the piezoelectric vibrator 100 concerning embodiment. Sectional drawing which shows typically the manufacturing process of the piezoelectric vibrator 100 concerning embodiment. Sectional drawing which shows typically the manufacturing process of the piezoelectric vibrator 100 concerning embodiment. Sectional drawing which shows typically the manufacturing process of the piezoelectric vibrator 100 concerning embodiment. Sectional drawing which shows typically the manufacturing process of the piezoelectric vibrator 100 concerning embodiment. Sectional drawing which shows typically the manufacturing process of the piezoelectric device 300 concerning embodiment. Sectional drawing which shows typically the mounting process of the piezoelectric device 300 concerning embodiment. Sectional drawing which shows typically the mounting process of the piezoelectric device 300 concerning embodiment.

DESCRIPTION OF SYMBOLS 10 ... Case body, 10a ... Case body board | substrate, 10s ... Outer bottom face, 12 ... Bottom material,
12a ... bottom material substrate, 14 ... wall material, 14a ... wall material substrate, 16 ... via hole,
16a ... through hole, 18 ... cavity, 20 ... lid, 22 ... seam ring,
30 ... Vibrating piece, 32 ... Vibrating rod, 34 ... Base, 36 ... Electrode, 38 ... Adhesive layer,
40 ... 1st electrode pad, 42 ... Underlayer, 44 ... Surface layer, 50 ... 2nd electrode pad,
52 ... 1st ground layer, 54 ... 2nd ground layer, 56 ... Surface layer, 60 ... Wiring, 62 ... Ground layer,
64 ... surface layer, 70 ... wiring, 72 ... underlayer, 74 ... surface layer, 80 ... tray, 82 ... concave,
100 ... piezoelectric vibrator, 200 ... circuit element, 202 ... solder ball,
300 ... piezoelectric device 302 ... solder ball 400 ... circuit board 402 ... connecting electrode

Claims (7)

A case body having a flat outer bottom surface;
A lid for sealing the case body;
A vibrating piece provided in a cavity formed by the case body and the lid body;
A plurality of first electrode pads having a first thickness and formed on the outer bottom surface;
A plurality of second electrode pads having a second thickness and formed on the outer bottom surface;
Have
The piezoelectric vibrator, wherein the first thickness is smaller than the second thickness. In claim 1,
The second electrode pad is a piezoelectric vibrator provided on the outer peripheral side of the first electrode pad when the outer bottom surface is viewed in plan. In claim 1 or claim 2,
The outline of the outer bottom surface of the case body is rectangular in plan view,
The second electrode pad is a piezoelectric vibrator provided at four corners of the outline in a plan view of the outer bottom surface of the case body. In any one of Claims 1 to 3,
When the piezoelectric vibrator is placed on the placement surface such that the outer bottom surface of the case body faces the flat placement surface, the second electrode pad is in contact with the placement surface, and the first A piezoelectric vibrator in which a gap is formed between the electrode pad and the mounting surface. In any one of Claims 1 thru | or 4,
The first electrode pad is a piezoelectric vibrator, which is a circuit element connection pad. In any one of Claims 1 thru | or 5,
The second electrode pad is a piezoelectric vibrator including at least one of a test pad, an external connection pad, and a dummy pad. The piezoelectric vibrator according to any one of claims 1 to 6,
A circuit element connected to the first electrode pad;
A piezoelectric device.

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