JP2010192960A - Piezoelectric device and method of manufacturing piezoelectric device - Google Patents

Abstract

Provided is a piezoelectric device that can be thinned and has improved manufacturing yield and quality.
A crystal oscillator as a piezoelectric device includes a crystal vibrating piece 30, an IC chip 20, and a package 10 that mounts the crystal vibrating piece 30 and the IC chip 20 on a base portion 11 and accommodates them inside. The vibrating piece 30 has a through hole 31 that penetrates in the thickness direction, and the IC chip 20 is mounted on the base portion 11 in the through hole 31 in a plan view.
[Selection] Figure 1

Description

  The present invention relates to a piezoelectric device represented by a piezoelectric oscillator and the like, and a method for manufacturing the piezoelectric device.

In recent years, piezoelectric devices such as piezoelectric oscillators used in various electronic devices such as information devices and mobile communication devices are required to be further reduced in size and thickness as electronic devices become smaller.
In order to meet this demand, the following configuration of a piezoelectric device is known for the purpose of reducing the size and thickness of the piezoelectric device (see, for example, Patent Document 1).
In this piezoelectric device, a semiconductor integrated circuit (hereinafter referred to as an IC chip) and a piezoelectric vibrator (hereinafter referred to as a piezoelectric vibrating piece) are incorporated in a package. The piezoelectric device is mounted on the base portion of the package in a state where the piezoelectric vibrating piece overlaps with the IC chip in a plan view and straddles the IC chip.

JP 2001-274653 A

Since the piezoelectric vibration piece is disposed so as to overlap with the IC chip in plan view, the size of the piezoelectric device can be reduced accordingly.
However, the piezoelectric device has a problem in that the thickness of the piezoelectric vibrating piece is directly added to the thickness of the IC chip as it is.

In the piezoelectric device, since the IC chip is disposed on the base part side of the piezoelectric vibrating piece, the IC chip is necessarily mounted on the base part before the piezoelectric vibrating piece.
As a result, the above-mentioned piezoelectric device is discarded as it is even if the IC chip is a non-defective product because it is extremely difficult to replace the piezoelectric vibrating piece when a failure occurs in the piezoelectric vibrating piece mounted later. Will be.
Therefore, the above-mentioned piezoelectric device has a problem in that the yield of manufacturing is reduced because a non-defective IC chip can be discarded due to structural restrictions.

  In the above piezoelectric device, since the IC chip is mounted first, the characteristics of the IC chip are deteriorated and the reliability of the connection part between the IC chip and the base part due to thermal stress applied when the piezoelectric vibrating piece is mounted thereafter. There is a risk of deterioration of the property.

  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 piezoelectric device according to this application example includes a piezoelectric vibration piece, an IC chip, and a package that mounts the piezoelectric vibration piece and the IC chip on a base portion and accommodates the piezoelectric vibration piece and the IC chip inside the piezoelectric vibration piece. The piece has a through-hole penetrating in the thickness direction, and the IC chip is mounted on the base portion in the through-hole in a plan view.

According to this, the piezoelectric device has the through-hole through which the piezoelectric vibrating piece penetrates in the thickness direction, and the IC chip is mounted on the base portion of the package in the through-hole in a plan view.
From this, in the piezoelectric device, the thickness of the IC chip or the thickness of the piezoelectric vibrating piece is reflected in the total thickness of the piezoelectric device only in the conventional plan view. As compared with the case where the piezoelectric vibrating piece and the IC chip are arranged to overlap each other, the thickness can be further reduced.

  Application Example 2 In the piezoelectric device according to the application example described above, it is preferable that the IC chip is mounted on the base portion by flip chip mounting.

According to this, since the IC chip is mounted on the base part by flip chip mounting, the electrical connection and mechanical connection between the IC chip and the base part are collectively performed on the base part side of the IC chip. Done.
Therefore, in the piezoelectric device, it is unnecessary to secure the loop height of the wire as compared with the case where the electrical connection between the IC chip and the base portion is performed using a wire such as wire bonding. The gap between the IC chip and the lid of the package can be reduced.
Therefore, the piezoelectric device can be further reduced in thickness as compared with the case where the electrical connection between the IC chip and the base portion is performed using a wire such as wire bonding.

  Application Example 3 In the piezoelectric device according to the application example described above, it is preferable that the piezoelectric vibrating piece is electrically connected to the IC chip by wire bonding and mounted on the base portion by an adhesive. .

According to this, in the piezoelectric device, the piezoelectric vibrating piece is electrically connected to the IC chip by wire bonding, and is mounted on the base portion by the adhesive.
For this reason, the piezoelectric device does not have to be electrically conductive, thereby increasing the choice of adhesive.
Accordingly, for the piezoelectric device, for example, a non-conductive adhesive that generates less outgas such as siloxane that adversely affects the aging characteristics of the piezoelectric vibrating piece can be selected.

  Application Example 4 In the piezoelectric device according to the application example described above, it is preferable that the piezoelectric vibrating piece is mounted on the base portion at one location by the adhesive.

According to this, in the piezoelectric device, the piezoelectric vibrating piece is mounted on the base portion at one location by the adhesive.
For this reason, the piezoelectric device is caused by a difference in thermal expansion coefficient between the piezoelectric vibrating piece and the base portion when the ambient temperature changes, for example, as compared with a case where the piezoelectric device is mounted at two general locations. Generation of stress can be suppressed.
Thereby, the piezoelectric device can reduce the frequency fluctuation of the piezoelectric vibrating piece.

  Application Example 5 In the piezoelectric device according to the application example, it is preferable that the base portion is formed in a flat plate shape.

According to this, since the base part is formed in a flat plate shape, the piezoelectric device is compared with the base part having a step between the mounting surface of the IC chip and the mounting surface of the piezoelectric vibrating piece as in the past. Thus, the package can be easily manufactured.
In addition, the piezoelectric device has a difference in heat conduction state from the mounting surface to the piezoelectric vibrating piece and the IC chip compared to the base portion having a step between the mounting surface of the IC chip and the mounting surface of the piezoelectric vibrating piece. As a result, the difference in timing of the temperature change between the piezoelectric vibrating piece and the IC chip due to an external temperature change is reduced.
As a result, the piezoelectric device can more accurately perform temperature characteristic compensation by the IC chip with respect to the oscillation frequency of the piezoelectric vibrating piece, for example.

  Application Example 6 A method for manufacturing a piezoelectric device according to this application example includes a piezoelectric vibrating piece, an IC chip, and a package that mounts the piezoelectric vibrating piece and the IC chip on a base portion and accommodates them inside. A method for manufacturing a piezoelectric device, comprising: a through hole forming step for forming a through hole penetrating in a thickness direction in the piezoelectric vibrating piece; and mounting the piezoelectric vibrating piece with the through hole formed on the base portion. A piezoelectric vibrating piece mounting step; and an IC chip mounting step of mounting the IC chip on the base portion in the through hole in plan view after the piezoelectric vibrating piece mounting step.

  According to this, the piezoelectric device manufacturing method includes a through-hole forming step for forming a through-hole penetrating in the thickness direction in the piezoelectric vibrating piece, and a piezoelectric device for mounting the piezoelectric vibrating piece having the through-hole formed on a base portion. A vibration piece mounting step; and an IC chip mounting step of mounting the IC chip on the base portion in the through hole after the piezoelectric vibration piece mounting step.

Therefore, in the piezoelectric device manufacturing method, the piezoelectric vibrating piece mounting process can be performed by performing the piezoelectric vibrating piece mounting process before the IC chip mounting process, and the piezoelectric vibrating piece is a non-defective product. Only in this case, it is possible to flow to the IC chip mounting process.
Therefore, compared with the conventional manufacturing method in which the IC chip is mounted before the piezoelectric vibrating piece, the manufacturing method of the piezoelectric device improves the manufacturing yield by eliminating the need to discard the non-defective IC chip. Can be made.

  In addition, the piezoelectric device manufacturing method performs the IC chip mounting process after the piezoelectric vibrating piece mounting process, thereby degrading the characteristics of the IC chip due to thermal stress applied during mounting of the piezoelectric vibrating piece as in the prior art. In addition, it is possible to avoid a decrease in reliability of the connection portion between the IC chip and the base portion.

  Application Example 7 In the piezoelectric device manufacturing method according to the application example, it is preferable that the IC chip is mounted on the base portion by flip chip mounting in the IC chip mounting step.

According to this, in the method of manufacturing a piezoelectric device, in the IC chip mounting process, the IC chip is mounted on the base portion by flip chip mounting.
From this, the manufacturing method of the piezoelectric device can obtain the effects described in Application Example 2 above.

  Application Example 8 In the piezoelectric device manufacturing method according to the application example described above, in the piezoelectric vibrating piece mounting step, the piezoelectric vibrating piece is mounted on the base portion with an adhesive, and in the IC chip mounting step, the IC is mounted. After mounting the chip, the piezoelectric vibrating piece is preferably electrically connected to the IC chip by wire bonding.

According to this, in the piezoelectric device manufacturing method, the piezoelectric vibrating piece is mounted on the base portion with an adhesive in the piezoelectric vibrating piece mounting step, and after mounting the IC chip in the IC chip mounting step, the piezoelectric vibrating piece is It is electrically connected to the IC chip by wire bonding.
From this, the manufacturing method of the piezoelectric device can obtain the effects described in Application Example 3 above.

  Application Example 9 In the piezoelectric device manufacturing method according to the application example, it is preferable that the piezoelectric vibrating piece is mounted on the base portion at one location by the adhesive in the piezoelectric vibrating piece mounting step.

According to this, in the piezoelectric device manufacturing method, in the piezoelectric vibrating piece mounting step, the piezoelectric vibrating piece is mounted on the base portion at one place by the adhesive.
From this, the manufacturing method of the piezoelectric device can obtain the effects described in Application Example 4 above.

  Application Example 10 In the piezoelectric device manufacturing method according to the application example described above, it is preferable that the through hole forming step is performed together with the outer shape formation of the piezoelectric vibrating piece.

  According to this, since the manufacturing method of a piezoelectric device performs a through-hole formation process collectively with the external shape formation of a piezoelectric vibrating piece, a through-hole can be formed without increasing the manufacturing man-hour of a piezoelectric vibrating piece.

The schematic diagram which shows schematic structure of the crystal oscillator of 1st Embodiment. FIG. 3 is a schematic cross-sectional view illustrating the method for manufacturing the crystal oscillator according to the first embodiment in the order of steps. The schematic diagram which shows schematic structure of the crystal oscillator of 2nd Embodiment. FIG. 6 is a schematic cross-sectional view illustrating a method for manufacturing a crystal oscillator according to a second embodiment in the order of steps. The schematic diagram which shows schematic structure of the crystal oscillator of the modification of 2nd Embodiment. The schematic diagram which shows schematic structure of the crystal oscillator of 3rd Embodiment.

Hereinafter, embodiments of a piezoelectric device and a method for manufacturing the piezoelectric device will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic diagram illustrating a schematic configuration of a crystal oscillator as an example of the piezoelectric device according to the first embodiment. FIG. 1A is a plan view, and FIG. 1B is a cross-sectional view taken along line AA in FIG. In the plan view of FIG. 1 and the following plan views, the lid portion is omitted for easy understanding, and the outer shape of the lid portion is represented by a two-dot chain line.

  As shown in FIG. 1, a crystal oscillator 1 according to the first embodiment includes a package 10, an IC (Integrated Circuit) chip 20, a crystal vibrating piece 30 as a piezoelectric vibrating piece, and the like.

The package 10 includes a base part 11, a lid part 12, and a joint part 13. In the package 10, the IC chip 20 and the crystal vibrating piece 30 are accommodated while being mounted on the base portion 11.
For the base portion 11, an aluminum oxide sintered body obtained by laminating ceramic green sheets, forming a substantially rectangular flat plate shape, and firing it is used.

On the inner surface (mount surface) 11 a of the base portion 11, mount electrodes 14 a and 14 b on which the crystal vibrating piece 30 is mounted, a plurality of joint terminals 15 to be joined to the IC chip 20, and the like are formed.
The mount electrodes 14a and 14b and the junction terminal 15 are made of a metal film in which films of nickel, gold, etc. are laminated on a metallized layer of tungsten or the like by plating.

The mount electrodes 14a and 14b are connected to 15a and 15b, respectively, of the junction terminals 15 by internal wiring. In addition, the mount electrodes 14a and 14b are connected to an inspection terminal (not shown) used when inspecting the mounted quartz crystal vibrating piece 30 alone.
A plurality of mounting terminals 16 made of the metal film are formed on the outer surface 11 b of the base portion 11. The mounting terminal 16 is connected to the junction terminal 15 by an internal wiring (not shown). The crystal oscillator 1 is mounted on an external electronic device or the like via the mounting terminal 16.

The lid portion 12 is formed in a substantially rectangular flat plate shape using a metal such as Kovar, and in a state where the IC chip 20 and the crystal vibrating piece 30 are accommodated in the package 10, a frame-shaped joint made of a metal such as Kovar. Seam welded to the portion 13. The joint portion 13 is joined to the base portion 11 in advance by brazing or the like. Thereby, the inside of the package 10 of the crystal oscillator 1 is hermetically sealed.
Note that the inside of the package 10 is sealed with a vacuum or an inert gas such as nitrogen, helium, or argon.

A crystal vibrating piece 30 is mounted on the base portion 11 of the package 10.
The crystal vibrating piece 30 is formed from a crystal wafer polished to a predetermined thickness in accordance with the oscillation frequency. In the present embodiment, the quartz crystal vibrating piece 30 is an AT-cut quartz crystal vibrating piece.
The quartz crystal vibrating piece 30 is formed in a substantially rectangular flat plate shape, and has a substantially rectangular through hole 31 penetrating in the thickness direction between the base portion 32 and the vibrating portion 33.

  An excitation electrode 35 is formed on one main surface 34 of the vibrating portion 33 of the crystal vibrating piece 30, and an excitation electrode 37 is formed on the other main surface 36. Lead electrodes 38 a and 38 b extend from the excitation electrodes 35 and 37 toward the base portion 32, respectively, and go around the main surfaces 34 and 36 at the base portion 32 of the crystal vibrating piece 30 via the side of the through hole 31. It is formed as follows. The excitation electrodes 35 and 37 and the extraction electrodes 38a and 38b are made of a metal film in which films such as chromium, nickel, and gold are laminated.

  The crystal vibrating piece 30 is mounted on the base portion 11 of the package 10 by bonding the lead electrodes 38a and 38b to the mount electrodes 14a and 14b via the conductive adhesive 40 as an adhesive. Thereby, the excitation electrodes 35 and 37 of the crystal vibrating piece 30 and the mount electrodes 14a and 14b are electrically connected.

The IC chip 20 is mounted on the base portion 11 of the package 10 in the through hole 31 of the crystal vibrating piece 30 in a plan view after the crystal vibrating piece 30 is mounted.
The IC chip 20 is made of a silicon substrate or the like, and has an oscillation circuit that excites the crystal vibrating piece 30 and amplifies and outputs an oscillation signal by an inverter or the like. In addition to the oscillation circuit, the IC chip 20 may include a temperature characteristic compensation circuit that compensates for the temperature characteristic of the oscillation frequency of the crystal vibrating piece 30.

The IC chip 20 has a plurality of circuit terminals 22 connected to the circuit on one main surface 21.
Among the plurality of circuit terminals 22, the circuit terminals 22 a and 22 b are terminals for connection to the crystal vibrating piece 30, and the others are an output terminal, a power supply terminal, a ground terminal, an inspection terminal, and the like. The circuit terminal 22 is made of a metal coating such as aluminum or aluminum alloy.

The IC chip 20 is mounted on the base portion 11 of the package 10 with one main surface 21 facing the joining terminal 15 by flip chip mounting, and the circuit terminal 22 is a bump made of gold, solder, or the like on the joining terminal 15. They are joined by thermocompression bonding (bump adhesion) using 41. The circuit terminals 22a and 22b are joined to the joining terminals 15a and 15b, respectively.
The crystal oscillator 1 is configured such that a resin (underfill material) such as an epoxy resin is filled between the one main surface 21 side of the IC chip 20 and the base portion 11 so that the joint portion is reinforced or protected. May be.

  As a result, the circuit terminals 22 a and 22 b of the IC chip 20, which are terminals for connection to the crystal vibrating piece 30, pass through the bonding terminals 15 a and 15 b of the base portion 11, the mount electrodes 14 a and 14 b, and the conductive adhesive 40. Are electrically connected to the extraction electrodes 38a and 38b (excitation electrodes 35 and 37) of the quartz crystal vibrating piece 30, respectively.

As described above, in the crystal oscillator 1 of the first embodiment, the crystal resonator element 30 has the through hole 31 that penetrates in the thickness direction, and the IC chip 20 is in the package 10 in the through hole 31 in plan view. It is mounted on the base part 11.
From this, the crystal oscillator 1 has a conventional configuration in which only the thicker one of the thickness T1 of the IC chip 20 and the thickness T2 of the crystal vibrating piece 30 is reflected in the total thickness of the crystal oscillator 1. In the plan view as described above, it is possible to further reduce the thickness as compared with the case where the quartz crystal vibrating piece 30 and the IC chip 20 are arranged to overlap each other.
In recent years, as the frequency of the crystal oscillator 1 is increased, the thickness T1 of the IC chip 20 is generally thicker between the thickness T1 of the IC chip 20 and the thickness T2 of the crystal vibrating piece 30.

In the crystal oscillator 1, since the IC chip 20 is mounted on the base portion 11 by flip chip mounting, electrical connection and mechanical connection between the IC chip 20 and the base portion 11 are the main components of the IC chip 20. The process is performed collectively on the surface 21 side (base part 11 side).
From this, the crystal oscillator 1 can secure the loop height of the wire as compared with the case where the electrical connection between the IC chip 20 and the base portion 11 is performed using a wire such as wire bonding, for example. The gap between the other main surface 23 of the IC chip 20 and the lid portion 12 can be reduced by an unnecessary amount.
Accordingly, the crystal oscillator 1 can be further reduced in thickness as compared with the case where the electrical connection between the IC chip 20 and the base portion 11 is performed using a wire such as wire bonding.

In addition, since the base portion 11 of the package 10 is formed in a flat plate shape, the crystal oscillator 1 has a base portion having a step between the mounting surface of the IC chip and the mounting surface of the crystal vibrating piece as in the prior art. Compared to the above, since the formation of the step is unnecessary, the package 10 can be easily manufactured.
As a result, the crystal oscillator 1 improves the productivity of manufacturing the package 10.

In addition, since the base portion 11 is formed in a flat plate shape, the crystal oscillator 1 has a step between the mounting surface of the IC chip and the mounting surface of the crystal vibrating piece as in the prior art. Compared with a base portion having a different wall thickness, the difference in heat conduction conducted between the crystal resonator element 30 and the IC chip 20 from the outer surface 11b of the base portion 11 through the mount surface (inner surface) 11a Less.
From this, the crystal oscillator 1 has less temperature shift timing difference between the crystal resonator element 30 and the IC chip 20 due to an external temperature change.
Thereby, when the IC chip 20 has the temperature characteristic compensation circuit, the crystal oscillator 1 can more accurately compensate the temperature characteristic by the IC chip 20 with respect to the oscillation frequency of the crystal vibrating piece 30.

In addition, since the vibrating portion 33 and the base portion 32 are separated from each other because the through-hole 31 is formed in the crystal oscillator 1, vibration of the vibrating portion 33 is difficult to leak into the base portion 32, and at the time of mounting or externally. The stress generated in the base portion 32 when the temperature changes or the like is not easily transmitted to the vibration portion 33.
Thereby, the crystal oscillator 1 can obtain a stable frequency characteristic.

Here, a manufacturing method of the crystal oscillator 1 of the first embodiment will be described with reference to the drawings.
FIG. 2 is a schematic cross-sectional view illustrating the manufacturing method of the crystal oscillator according to the first embodiment in the order of steps.
Here, in manufacturing the crystal oscillator 1, a description will be given focusing on a through hole forming process, a crystal vibrating piece mounting process as a piezoelectric vibrating piece mounting process, and an IC chip mounting process, which are main processes.

[Through hole forming step]
First, as shown in FIG. 2A, from the quartz wafer polished to a predetermined thickness according to the oscillation frequency, the outer shape 39 and the through-hole 31 of the quartz vibrating piece 30 are used by using a photolithography technique and an etching technique. Are formed almost simultaneously.
Next, excitation electrodes 35 and 37 and extraction electrodes 38a and 38b are formed by vapor deposition, sputtering, or the like.
Note that the outer shape 39 and the through hole 31 of the crystal vibrating piece 30 may be formed in separate steps.

[Crystal resonator element mounting process]
Next, as shown in FIG. 2B, the crystal vibrating piece 30 is mounted on the base portion 11 of the package 10.
More specifically, after applying a silicon-based conductive adhesive 40 to the mount electrodes 14a and 14b of the base portion 11 using a dispenser or the like, the lead electrodes 38a and 38b of the crystal vibrating piece 30 are mounted on the mount electrodes 14a and 14b. The quartz crystal vibrating piece 30 is mounted in alignment with Thereafter, the conductive adhesive 40 is cured by heating.
After that, annealing treatment is performed to relieve stress (strain) generated when the crystal vibrating piece 30 is mounted.
Next, the mounted quartz crystal vibrating piece 30 is inspected alone, and the non-defective product is flowed to the next process.

[IC chip mounting process]
Next, as shown in FIG. 2C, the IC chip 20 is mounted on the base portion 11 of the package 10 in the through hole 31 of the crystal vibrating piece 30 in plan view.
More specifically, the circuit terminals 22 on one main surface 21 of the IC chip 20 are joined to the joining terminals 15 of the base portion 11 by thermocompression using bumps 41 made of gold, solder or the like using flip chip mounting. To do.
At this time, an underfill material such as an epoxy resin may be filled between the one main surface 21 side of the IC chip 20 and the base portion 11 to reinforce or protect the connection portion.

Next, as shown in FIG. 2D, the lid portion 12 of the package 10 is seam welded to the joint portion 13 of the package 10.
A crystal oscillator 1 as shown in FIG. 1 is obtained through the manufacturing steps such as the above steps.

  As described above, in the method for manufacturing the crystal oscillator 1 according to the first embodiment, the crystal vibrating piece 30 is formed with the through hole forming step for forming the through hole 31 penetrating in the thickness direction, and the crystal with the through hole 31 formed therein. A quartz crystal resonator element mounting step for mounting the resonator element 30 on the base portion 11, and an IC chip mounting step for mounting the IC chip 20 on the base portion 11 in the through hole 31 in plan view after the crystal resonator element mounting step. Have.

Therefore, in the method for manufacturing the crystal oscillator 1, the crystal resonator element 30 mounted on the base portion 11 can be inspected alone by performing the crystal resonator element mounting process before the IC chip mounting process. Thereby, the manufacturing method of the crystal oscillator 1 can be made to flow to an IC chip mounting process only when the crystal vibrating piece 30 is a good product.
Therefore, the manufacturing method of the crystal oscillator 1 is higher than the conventional manufacturing method in which the IC chip is mounted before the crystal vibrating piece, so that the non-defective IC chip can be discarded. Can be improved.

  In addition, the crystal oscillator 1 is manufactured by performing an IC chip mounting process after the crystal vibrating piece mounting process, thereby causing a conventional thermal stress such as an annealing process to be applied when the crystal vibrating piece 30 is mounted. Thus, it is possible to avoid the deterioration of the characteristics of the IC chip 20 and the decrease in the reliability of the connection part between the IC chip 20 and the base part 11.

In the manufacturing method of the crystal oscillator 1, the IC chip 20 is mounted on the base portion 11 by flip chip mounting in an IC chip mounting process.
Thereby, the manufacturing method of the crystal oscillator 1 ensures the wire loop height and the like as compared with the case where the electrical connection between the IC chip 20 and the base portion 11 is performed using a wire such as wire bonding. Therefore, it is possible to manufacture the crystal oscillator 1 with a further reduced thickness.

  Further, in the method of manufacturing the crystal oscillator 1, the through hole 31 is formed without increasing the number of manufacturing steps of the crystal vibrating piece 30 because the through hole forming step is performed simultaneously with the outer shape formation of the crystal vibrating piece 30. .

(Second Embodiment)
FIG. 3 is a schematic diagram illustrating a schematic configuration of the crystal oscillator according to the second embodiment. 3A is a plan view, and FIG. 3B is a cross-sectional view taken along line BB in FIG. 3A. In addition, the same code | symbol is attached | subjected to a common part with 1st Embodiment, and the description is abbreviate | omitted.

As shown in FIG. 3, in the crystal oscillator 101 of the second embodiment, the crystal resonator element 30 is electrically connected to the IC chip 20 by wire bonding as compared to the crystal oscillator 1 of the first embodiment. In addition, it is different in that it is mounted on the base portion 111 by a non-conductive adhesive 42 as an adhesive.
Hereinafter, a description will be given focusing on differences from the first embodiment.

In the crystal oscillator 101, the crystal vibrating piece 30 is mounted on the base portion 111 of the package 110 at two locations of the extraction electrodes 38a and 38b by a non-conductive adhesive 42 such as epoxy or polyimide.
In the crystal oscillator 101, after the crystal resonator element 30 is mounted, the IC chip 20 is mounted on the base portion 111 of the package 110 via the adhesive 43 with the one main surface 21 facing the lid portion 12 side. .

In the base portion 111 of the package 110, a plurality of joint terminals 115 are formed in the vicinity of the IC chip 20 around the mounted crystal vibrating piece 30. The junction terminal 115 is connected to the mounting terminal 16 and the like by internal wiring (not shown).
In the crystal oscillator 101, the lead electrodes 38a and 38b of the crystal vibrating piece 30 are electrically connected to the circuit terminals 22a and 22b of the IC chip 20 through the wire 50 by wire bonding.
In the crystal oscillator 101, the circuit terminal 22 of the IC chip 20 is electrically connected to the bonding terminal 115 of the base portion 111 through the wire 50 by wire bonding.

  In the crystal oscillator 101, the lead electrodes 38a and 38b are not shown in the bonding terminal 115 through the wire 50 by wire bonding so that the mounted crystal vibrating piece 30 alone can be inspected. It is connected to the junction terminals 115a and 115b connected to the inspection terminals.

As described above, in the crystal oscillator 101 of the second embodiment, the crystal vibrating piece 30 is electrically connected to the IC chip 20 by wire bonding, and a non-conductive adhesive such as epoxy or polyimide is used. 42 is mounted on the base 111.
From this, the crystal oscillator 101 generates outgas such as siloxane that adversely affects the aging characteristics of the crystal vibrating piece 30 compared to the case where a silicon-based conductive adhesive is used for mounting the crystal vibrating piece 30. Can be reduced.

Here, a manufacturing method of the crystal oscillator 101 of the second embodiment will be described with a focus on differences from the manufacturing method of the crystal oscillator 1 of the first embodiment with reference to the drawings.
FIG. 4 is a schematic cross-sectional view showing the method of manufacturing the crystal oscillator according to the second embodiment in the order of steps.

[Crystal resonator element mounting process]
As shown in FIG. 4A, the quartz crystal vibrating piece 30 is mounted on the base portion 111 at two locations of the extraction electrodes 38 a and 38 b by the nonconductive adhesive 42.
Next, the lead electrodes 38a and 38b of the crystal vibrating piece 30 and the joint terminals 115a and 115b of the base portion 111 connected to the inspection terminal are electrically connected via the wire 50 by wire bonding.
Next, after the annealing process or the like, the mounted quartz crystal vibrating piece 30 is inspected and the non-defective product is flowed to the next process.

[IC chip mounting process]
As shown in FIG. 4B, after mounting the crystal vibrating piece 30, the IC chip 20 is oriented in the through hole 31 of the crystal vibrating piece 30 with the one principal surface 21 side facing the lid portion 12 side in plan view. In this state, it is mounted on the base portion 111 with the adhesive 43.
Next, the lead electrodes 38a and 38b of the crystal vibrating piece 30 and the circuit terminals 22a and 22b of the IC chip 20 are electrically connected via the wire 50 by wire bonding, and the circuit terminal 22 and the bonding terminal 115 are connected to the wire. Electrical connection is made through the wire 50 by bonding.

  As described above, in the method of manufacturing the crystal oscillator 101 according to the second embodiment, the crystal resonator element 30 is mounted on the base 111 by the non-conductive adhesive 42 such as epoxy or polyimide in the crystal resonator element mounting step. Then, after mounting the IC chip 20 in the IC chip mounting step, the crystal vibrating piece 30 is electrically connected to the IC chip 20 by wire bonding.

  As a result, the manufacturing method of the crystal oscillator 101 is compared with the case where a silicon-based conductive adhesive is used for mounting the crystal vibrating piece 30, and the outgas of siloxane or the like that adversely affects the aging characteristics of the crystal vibrating piece 30. The crystal oscillator 101 with reduced generation can be manufactured.

(Modification)
Here, a modification of the crystal oscillator 101 of the second embodiment will be described with reference to the drawings.
FIG. 5 is a schematic diagram showing a schematic configuration of a crystal oscillator according to a modification of the second embodiment. 5A is a plan view, and FIG. 5B is a cross-sectional view taken along the line CC in FIG. 5A. In addition, the same code | symbol is attached | subjected to a common part with 2nd Embodiment, and the description is abbreviate | omitted.

  As shown in FIG. 5, the crystal oscillator 201 of the modified example has a mount on the base 111 of the crystal vibrating piece 30 on the short side of the crystal vibrating piece 30 compared to the crystal oscillator 101 of the second embodiment. The point which is one place of the approximate center position of the base 32 in the direction along is different.

As a result, the crystal oscillator 201 and the base portion 111 can be compared with the crystal resonator element 30 when the surrounding temperature changes, as compared with the case where the crystal resonator element 30 is mounted at two places as in the second embodiment. The generation of stress due to the difference in thermal expansion coefficient with respect to can be suppressed.
From this, the crystal oscillator 201 can obtain a stable frequency characteristic with less frequency fluctuation.

Compared with the manufacturing method of the crystal oscillator 101 of the second embodiment, the manufacturing method of the crystal oscillator 201 of the modified example is configured such that the crystal vibrating piece 30 is crystallized by the non-conductive adhesive 42 in the crystal vibrating piece mounting step. The difference resides in that the base portion 111 is mounted at one location substantially at the center position of the base portion 32 in the direction along the short side of the resonator element 30.
Thereby, the manufacturing method of the crystal oscillator 201 can manufacture the crystal oscillator 201 in which the generation of stress due to the difference in thermal expansion coefficient between the crystal vibrating piece 30 and the base portion 111 is suppressed when the ambient temperature changes. .

(Third embodiment)
FIG. 6 is a schematic diagram illustrating a schematic configuration of the crystal oscillator according to the third embodiment. 6A is a plan view, and FIG. 6B is a cross-sectional view taken along line DD in FIG. 6A. In addition, the same code | symbol is attached | subjected to a common part with 1st Embodiment, and the description is abbreviate | omitted.

  As shown in FIG. 6, in the crystal oscillator 301 of the third embodiment, the shape of the through-hole 331 of the crystal vibrating piece 330 is notched compared to the crystal oscillator 1 of the first embodiment. Is different. Hereinafter, a description will be given focusing on differences from the first embodiment.

In the crystal oscillator 301, the through-hole 331 of the crystal vibrating piece 330 is formed in a “U” -shaped notch shape in which the short side on the base 332 side is notched in plan view.
In the crystal oscillator 301, the IC chip 20 is mounted on the base portion 11 in a notch-shaped through hole 331 in a plan view.

According to this, in the crystal oscillator 301, since the through-hole 331 of the crystal vibrating piece 330 is notched, the base portion 332 and the vibrating portion are not necessary for the portion that connects the two base portions 332 of the crystal vibrating piece 330 to each other. The length of the quartz crystal vibrating piece 330 along the direction (long side direction) for connecting to 33 can be shortened.
Therefore, the crystal oscillator 301 can be reduced in planar size as compared with the crystal oscillators (1 and the like) of the first and second embodiments and the modified examples.
The crystal vibrating piece 330 can also be applied to the crystal oscillator 101 of the second embodiment.

In the second embodiment, the non-conductive adhesive 42 is used for mounting the crystal vibrating piece 30. However, the present invention is not limited to this, and a conductive adhesive may be used. In this case, for example, as in the first embodiment, if the mount electrodes 14a and 14b (see FIG. 1) are formed on the base 111 and the mount electrodes 14a and 14b are connected to the inspection terminal, the mounted crystal Inspection with the vibration piece 30 alone can be performed.
As a result, the crystal oscillator 101 eliminates the need for connection by wire bonding between the extraction electrodes 38a and 38b and the bonding terminals 115a and 115b and the bonding terminals 115a and 115b.

In the second embodiment and the modified example, the base portion 111 is formed in a flat plate shape. However, the present invention is not limited to this. 115 may be provided.
According to this, the crystal oscillators 101 and 201 can easily perform wire bonding since the steps of the crystal resonator element 30 and the IC chip 20 and the bonding terminal 115 are reduced.

  In each of the above embodiments and modifications, quartz is exemplified as the material of the piezoelectric vibrating piece. However, the material is not limited to this, and lithium tantalate, lithium niobate, or the like may be used.

  DESCRIPTION OF SYMBOLS 1 ... Crystal oscillator as a piezoelectric device, 10 ... Package, 11 ... Base part, 12 ... Lid part, 13 ... Joint part, 14a, 14b ... Mount electrode, 15, 15a, 15b ... Joint terminal, 16 ... Mounting terminal, 20 DESCRIPTION OF SYMBOLS IC chip, 21 ... One main surface, 22, 22a, 22b ... Circuit terminal, 23 ... Other main surface, 30 ... Crystal vibrating piece as piezoelectric vibrating piece, 31 ... Through-hole, 32 ... Base, 33 ... Vibrating part, 34 ... one main surface, 35, 37 ... excitation electrode, 36 ... other main surface, 38a, 38b ... extraction electrode, 40 ... conductive adhesive as adhesive, 41 ... bump, T1 ... thickness of IC chip, T2: Thickness of the crystal vibrating piece.

Claims (10)

A piezoelectric vibrating piece, an IC chip, and a package that mounts the piezoelectric vibrating piece and the IC chip on a base portion and accommodates them inside,
The piezoelectric device, wherein the piezoelectric vibrating piece has a through-hole penetrating in a thickness direction, and the IC chip is mounted on the base portion in the through-hole in a plan view.   2. The piezoelectric device according to claim 1, wherein the IC chip is mounted on the base portion by flip chip mounting.   2. The piezoelectric device according to claim 1, wherein the piezoelectric vibrating reed is electrically connected to the IC chip by wire bonding and is mounted on the base portion by an adhesive. .   4. The piezoelectric device according to claim 3, wherein the piezoelectric vibrating piece is mounted on the base portion at one location by the adhesive. 5.   The piezoelectric device according to claim 1, wherein the base portion is formed in a flat plate shape. A method of manufacturing a piezoelectric device comprising: a piezoelectric vibrating piece; an IC chip; and a package that mounts the piezoelectric vibrating piece and the IC chip on a base portion and stores the package inside the piezoelectric device.
A through hole forming step of forming a through hole penetrating in the thickness direction in the piezoelectric vibrating piece;
A piezoelectric vibrating piece mounting step of mounting the piezoelectric vibrating piece in which the through-hole is formed on the base portion;
An IC chip mounting step of mounting the IC chip on the base portion in the through hole in plan view after the piezoelectric vibrating piece mounting step.   7. The method of manufacturing a piezoelectric device according to claim 6, wherein, in the IC chip mounting step, the IC chip is mounted on the base portion by flip chip mounting. The method for manufacturing a piezoelectric device according to claim 6, wherein in the piezoelectric vibrating piece mounting step, the piezoelectric vibrating piece is mounted on the base portion with an adhesive,
In the IC chip mounting step, after mounting the IC chip, the piezoelectric vibrating piece is electrically connected to the IC chip by wire bonding.   9. The method of manufacturing a piezoelectric device according to claim 8, wherein, in the piezoelectric vibrating piece mounting step, the piezoelectric vibrating piece is mounted on the base portion at one location by the adhesive. .   10. The method for manufacturing a piezoelectric device according to claim 6, wherein the through-hole forming step is performed together with the outer shape formation of the piezoelectric vibrating piece. 10.

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