JP2011101213A - Vibration device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration device in which the planar size can be miniaturized. <P>SOLUTION: The vibration device includes a crystal vibrator 10, an IC chip 20, and a wiring board 30. The crystal vibrator 10 holds a crystal vibration piece 12 in the interior of a package 11 having an external terminal 14 at its outside surface. The IC chip 20 drives the crystal vibration piece 12. The IC chip 20 is arranged at one surface 31 of the wiring board 30, while the crystal vibrator 10 is arranged at another surface 32 of the wiring board 30. The wiring board 30 has a through hole 33, from which at least a part of the external terminal 14 of the crystal vibrator 10 is exposed in plan view. An internal connection terminal 34 formed at the one surface 31 is connected to the external terminal 14 of the crystal vibrator 10 via a metal wire 40 through the through hole 33, while the internal connection terminal 34 is connected to an IC chip connection terminal 35 formed at the one surface 31. While the IC chip 20 is arranged to cover the internal connection terminal 34 and the metal wire 40 in plan view, a terminal 21 of the IC chip 20 and the IC chip connection terminal 35 are connected being faced each other. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vibration device represented by a piezoelectric device such as a crystal oscillator and a MEMS device such as a MEMS oscillator.

  Conventionally, a piezoelectric vibrator, a wiring board in which an external connection terminal is formed on one surface and the other face is fixed to the bottom surface of the piezoelectric vibrator, and an IC chip (hereinafter referred to as an IC chip) disposed on one face of the wiring board And having an IC connection terminal connected to the circuit element (hereinafter referred to as a circuit element connection terminal) and an internal connection terminal connected to the circuit element connection terminal on one surface of the wiring board. A vibration having a configuration in which a vibrator connection terminal (hereinafter referred to as an external terminal) of a piezoelectric vibrator and an internal connection terminal of a wiring board are connected by a metal wire, and a resin portion is formed so as to cover the metal wire and the circuit element. A device is known (see, for example, Patent Document 1).

JP 2008-35026 A

In the embodiment, the vibration device is arranged so that the connection portion that connects the external terminal of the piezoelectric vibrator and the internal connection terminal of the wiring board with the metal wire and the circuit element do not overlap in a plane. For this reason, there is a concern that the plane size is increased accordingly.
Further, in the embodiment, when the connection between the circuit element and the circuit element connection terminal is flip-chip mounting in the embodiment, from the viewpoint of securing connection reliability and protecting the active surface of the circuit element, Underfill made of resin or the like is required between the wiring board and the wiring board.
And since the resin part is formed so that the said vibration device may further cover a metal wire and a circuit element after that, there exists a possibility that a manufacturing man-hour may increase by that.

  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 vibrating device according to this application example includes a vibrator that houses a vibrating piece in a package having an external terminal on the outer surface, a circuit element that drives the vibrating piece, and the circuit element on one surface. And a wiring board on which the vibrator is arranged on the other surface, and the wiring board has at least a part of the external terminals of the vibrator in a plan view from the direction of the one surface. An internal connection terminal formed on the one surface and the external terminal of the vibrator is connected by a connecting member through the through-hole or the notch, and has an exposed through-hole or notch. The internal connection terminal is connected to a circuit element connection terminal formed on the one surface, and the circuit element is disposed so as to cover the internal connection terminal and the connection member in plan view, and the circuit And the terminal of the child the circuit element connection terminal, characterized in that it is connected to face.

According to this, in the vibration device, the internal connection terminal and the external terminal of the vibrator are connected by the connection member through the through hole or the notch, and the circuit element covers the internal connection terminal and the connection member in plan view. The circuit element terminals and the circuit element connection terminals are connected to face each other.
Therefore, the vibration device is arranged so that the circuit element covers the internal connection terminal and the connection member in a plan view, so that the internal connection terminal and the connection member are within the plane size of the circuit element. .
As a result, when the vibration device is arranged so that the connection part that connects the external terminal of the vibrator and the internal connection terminal of the wiring board with the metal wire and the circuit element do not overlap in a plane as in the past. Compared with, the plane size can be reduced.

  Application Example 2 In the vibration device according to the application example, it is preferable that the connection member is a metal wire.

  According to this, since the connecting member is a metal wire, the vibrating device can be mounted with a proven track record, and the connection reliability can be improved.

  Application Example 3 In the vibration device according to Application Example 1, it is preferable that the connection member is a metal lead plate.

  According to this, since the connection member is a metal lead plate, the vibration device can suppress variations in the height direction of the connection member at the time of connection as compared with the case of a metal wire.

  Application Example 4 In the vibration device according to Application Example 1, it is preferable that the connection member is a metal brazing material.

  According to this, since the connection member is a metal brazing material, the connection area can be increased and the connection strength can be improved.

  Application Example 5 In the vibration device according to Application Example 1, it is preferable that the connection member is a conductive adhesive.

  According to this, since the connecting member is a conductive adhesive, the vibrating device can be easily connected by applying it using, for example, a dispenser.

  Application Example 6 In the vibration device according to Application Example 3, it is preferable that the metal lead plate is a wiring pattern drawn from the wiring board.

  According to this, since the vibration device is a wiring pattern in which the metal lead plate is drawn from the wiring substrate, the metal lead plate can be integrated with the wiring pattern, and the number of manufacturing steps of the metal lead plate can be reduced.

  Application Example 7 In the vibration device according to the application example described above, it is preferable that a resin is filled between the circuit element and the wiring board and in the through hole or the notch.

According to this, since the vibration device is filled with the resin between the circuit element and the wiring board and in the through hole or the notch, the resin has both an underfill function and a protective function of the connecting member. .
Therefore, the vibration device does not need to form a resin portion so as to cover the metal wire and the circuit element after filling the underfill as in the conventional case. As a result, the vibration device can reduce the number of manufacturing steps.

In addition, the vibration device has the above-described configuration. For example, when a manufacturing method in which a plurality of wiring boards are formed and cut into pieces after filling with the resin is used, the resin is supplied to the cutting position of the pieces. It can be prevented from spreading.
Accordingly, since the vibration device does not need to cut the resin, the wiring board can be easily cut by a simple press device or the like instead of the dicing device.

The schematic diagram which shows schematic structure of the crystal oscillator of this embodiment. FIG. 6 is a schematic cross-sectional view illustrating a schematic configuration of a crystal oscillator according to a first modification. FIG. 6 is a schematic cross-sectional view showing a schematic configuration of a crystal oscillator according to a second modification. FIG. 10 is a schematic cross-sectional view illustrating a schematic configuration of a crystal oscillator according to a third modification.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings.
(Embodiment)
Here, a crystal oscillator will be described as an example of a vibrating device.
FIG. 1 is a schematic diagram showing a schematic configuration of the crystal oscillator of the present embodiment. FIG. 1A is a developed perspective view as seen from the circuit element side, and FIG. 1B is a cross-sectional view taken along the line AA in FIG. In the developed perspective view, some components are omitted for convenience.

As shown in FIG. 1, the crystal oscillator 1 includes a crystal resonator 10 as a resonator, an IC (Integrated Circuit) chip 20 as a circuit element, and a wiring board 30.
The crystal oscillator 1 has a configuration in which a crystal resonator 10 and an IC chip 20 are stacked with a wiring board 30 interposed therebetween.

The crystal unit 10 includes a substantially rectangular parallelepiped package 11 and a crystal resonator element 12 as a resonator element accommodated in the package 11.
The package 11 includes a package base 11a having a recess, a lid 11b that covers the recess, and the like.
As the package base 11a, an aluminum oxide sintered body formed by firing a ceramic green sheet is used. The lid 11b is made of a metal such as Kovar, glass or the like.

Internal electrodes 13 are formed on the inner surface 11c of the package base 11a, and a plurality of external terminals 14 are formed on the outer surface 11d of the package base 11a. A predetermined terminal of the plurality of external terminals 14 is connected to the internal electrode 13 by an internal wiring (not shown).
The internal electrode 13 and the external terminal 14 are made of a metal film in which a film made of nickel, gold or the like is laminated on a metallized layer such as tungsten by plating.

As the crystal vibrating piece 12, for example, a tuning fork type crystal vibrating piece, an AT cut type crystal vibrating piece, or the like is used. The quartz crystal vibrating piece 12 is joined to the internal electrode 13 of the package base 11a through a conductive adhesive 15 such as epoxy, silicon, or polyimide that is mixed with a conductive material such as a metal filler.
Thereby, in the crystal vibrating piece 12, an excitation electrode (not shown) is electrically connected to the external terminal 14 via the internal electrode 13.

In the crystal unit 10, after the crystal vibrating piece 12 is bonded to the internal electrode 13 of the package base 11 a, the lid 11 b is bonded to the package base 11 a, so that the inside of the package 11 is hermetically sealed.
The lid 11b and the package base 11a are joined by low melting glass, seam welding using a seam ring, or the like.

The wiring substrate 30 is formed in a flat plate shape having a substantially rectangular planar shape, and is formed so that the planar size is substantially equal to the planar size of the crystal resonator 10.
As the wiring board 30, a polyimide type or glass epoxy type substrate is used.
The IC chip 20 is disposed and bonded to one surface 31 of the wiring substrate 30, and the crystal resonator 10 is disposed and bonded to the other surface 32 of the wiring substrate 30 by an adhesive (not shown) or the like. .

The wiring board 30 has two through holes 33 through which at least a part of the external terminal 14 electrically connected to the crystal resonator element 12 of the crystal resonator 10 is exposed in a plan view from the direction of the one surface 31. have.
Internal connection terminals 34 are formed in the vicinity of each through hole 33 on one surface 31 of the wiring board 30.
Further, on one surface 31 of the wiring board 30, a plurality of IC chip connection terminals 35 as circuit element connection terminals connected to the plurality of terminals 21 of the IC chip 20 face each terminal 21 of the IC chip 20. Each is formed at a position.
In addition, on one surface 31 of the wiring board 30, mounting terminals 36 that are used when the crystal oscillator 1 is mounted on the external device 50 are formed at four corners.

Of the IC chip connection terminals 35, a terminal for connection to the crystal unit 10 is connected to the internal connection terminal 34 by a wiring pattern. Among the IC chip connection terminals 35, terminals for input / output, power supply, etc. The mounting terminal 36 is connected by a wiring pattern.
The wiring board 30 is a single-sided wiring board in which terminals and wiring patterns are not formed on the other surface 32. Thereby, the manufacturing cost of the wiring board 30 is reduced as compared with a case where terminals and a wiring pattern are formed on both surfaces.

The internal connection terminal 34, the IC chip connection terminal 35, and the mounting terminal 36 are made of, for example, a metal film obtained by laminating various films such as nickel, copper, and gold on a copper foil by plating or the like. Since the mounting terminal 36 is required to be higher than the IC chip 20 from the wiring substrate 30, a desired height is secured by thick plating of copper or the like.
Note that a metal ball such as a solder ball may be mounted on the mounting terminal 36 in place of the thick plating in order to ensure a desired height.

In the crystal oscillator 1, the internal connection terminal 34 and the external terminal 14 of the crystal resonator 10 are connected through a through hole 33 by a metal wire 40 as a connection member. This connection is performed using a wire bonding technique.
In order to suppress the height of the metal wire 40, the bonding order is preferably bonded first to the external terminal 14 of the crystal resonator 10 and then bonded to the internal connection terminal 34.

The IC chip 20 is made of a silicon substrate or the like, and an oscillation circuit for driving the crystal vibrating piece 12 is formed on the active surface 22 side, and a plurality of terminals 21 connected to the oscillation circuit or the like are formed. The IC chip 20 is disposed so as to cover the internal connection terminals 34 of the wiring substrate 30 and the metal wires 40 in plan view, and the terminals 21 of the IC chip 20 and the IC chip connection terminals 35 face each other. It is connected.
This connection is performed using a flip chip mounting technique via bumps 41 such as gold and solder. Since the active surface 22 of the IC chip 20 is covered with an insulating film (passivation film), there is no possibility of short circuit even if the metal wire 40 comes into contact.

Between the IC chip 20 and the wiring substrate 30 and in the through hole 33, an insulating resin 42 such as an epoxy resin is filled using a filling device such as a dispenser.
This resin 42 has both the protection of the active surface 22 of the IC chip 20 and the underfill function for reinforcing the bonding between the IC chip 20 and the wiring substrate 30 and the protection function for sealing and protecting the connection portion of the metal wire 40. Yes.

  The crystal oscillator 1 receives a drive signal from the external device 50 or the like through the mounting terminal 36, so that the oscillation signal (drive signal) is transmitted from the oscillation circuit of the IC chip 20 to the terminal 21, the IC chip connection terminal 35, the internal The vibration is transmitted to the excitation electrode of the crystal vibrating piece 12 via the connection terminal 34, the external terminal 14, the internal electrode 13, and the like, and the crystal vibrating piece 12 resonates (drives) at a predetermined frequency.

As described above, in the crystal oscillator 1 of the present embodiment, the internal connection terminal 34 and the external terminal 14 of the crystal resonator 10 are connected by the metal wire 40 through the through hole 33, and the IC chip 20 is viewed in plan view. The terminals 21 and the IC chip connection terminals 35 of the IC chip 20 are connected to face each other while being disposed so as to cover the internal connection terminals 34 and the metal wires 40.
Thereby, the crystal oscillator 1 can accommodate the internal connection terminal 34, the metal wire 40, and the IC chip connection terminal 35 within the planar size of the IC chip 20 in plan view.

  Therefore, in the crystal oscillator 1, the connection portion that connects the external terminal 14 of the crystal resonator 10 and the internal connection terminal 34 of the wiring substrate 30 with the metal wire 40 and the IC chip 20 do not overlap in a planar manner as in the related art. Compared with the case where it arrange | positions in this way, planar size can be reduced more.

  In addition, since the connection member between the external terminal 14 of the crystal resonator 10 and the internal connection terminal 34 of the wiring substrate 30 is the metal wire 40, the crystal oscillator 1 can be connected using a wire bonding technique with excellent results. It becomes possible, and the reliability of connection can be improved.

In addition, since the crystal oscillator 1 is filled with an insulating epoxy resin 42 between the IC chip 20 and the wiring substrate 30 and in the through hole 33, the resin 42 has an underfill function and a metal. It also has a protection function for the wire 40.
Therefore, the crystal oscillator 1 does not need to form a resin portion so as to cover the metal wire 40 and the IC chip 20 after filling the underfill as in the prior art. As a result, the crystal oscillator 1 can reduce the number of manufacturing steps.

Further, the crystal oscillator 1 has the above-described configuration. For example, when the wiring board 30 is formed by taking a plurality of pieces and is cut into pieces after filling with the resin 42, the resin 42 spreads to the cutting position of the pieces. Can not be.
Thereby, since the crystal oscillator 1 does not need to cut | disconnect the resin 42, the wiring board 30 can be easily cut | disconnected not with a dicing apparatus but with a simple press apparatus.

In the present embodiment, the two through holes 33 are provided in accordance with the number of the internal connection terminals 34, but the two through holes 33 may be connected to be one, instead of the through holes 33. The cutout portion may be a cutout from the outer shape of the wiring board 30 to the portion corresponding to the through hole 33.
In this case, for example, when forming a plurality of wiring boards 30, the notches of the adjacent wiring boards 30 are formed as one through hole, and each notch is formed at the stage of cutting into individual pieces. It can also be formed.
Further, the planar shape of the through hole 33 is not limited to the illustrated rectangle, and may be a polygon, a circle, an ellipse, or the like.
Further, the number of through holes 33 is appropriately set according to the number of internal connection terminals 34 and the like.
In addition, when it is set as a notch instead of the through-hole 33, it is a figure when considering that the underfill flowing into the notch droops to the lid 11b side or cuts the resin 42 when the above-described pieces are cut. The configuration of one embodiment may be preferred.

Here, the modification of the said embodiment is demonstrated with reference to drawings.
(Modification 1)
FIG. 2 is a schematic cross-sectional view showing a schematic configuration of the crystal oscillator of the first modification. The cross-sectional position is the same as in FIG. In addition, about the common part with the said embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted and it demonstrates centering on a different part from the said embodiment.

As shown in FIG. 2, the crystal oscillator 101 of Modification 1 is drawn out from the wiring board 30 onto the through hole 33 by the connecting member between the external terminal 14 of the crystal resonator 10 and the internal connection terminal 34 of the wiring board 30. A wiring pattern made of copper foil or the like is used as the metal lead plate 140.
As a method for bonding the metal lead plate 140, eutectic bonding such as gold / tin alloy plating, gold plating, solder bonding, or the like can be used.

According to this, since the connection member is the metal lead plate 140 in the crystal oscillator 101, compared to the case of the metal wire 40, the height direction of the connection member at the time of connection (thickness direction of the crystal oscillator 101). Can be suppressed.
Further, since the crystal oscillator 101 is a wiring pattern in which the metal lead plate 140 is drawn from the wiring substrate 30, the metal lead plate 140 is integrated with the wiring pattern, thereby reducing the number of manufacturing steps of the metal lead plate 140. Can be reduced.
The metal lead plate 140 may be formed separately from the wiring pattern.

(Modification 2)
FIG. 3 is a schematic cross-sectional view showing a schematic configuration of the crystal oscillator of the second modification. The cross-sectional position is the same as in FIG. In addition, about the common part with the said embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted and it demonstrates centering on a different part from the said embodiment.

  As shown in FIG. 3, the crystal oscillator 201 of the second modified example has a copper brazing, silver brazing, gold brazing, platinum brazing as connecting members between the external terminals 14 of the crystal resonator 10 and the internal connection terminals 34 of the wiring board 30. Both are brazed by using a metal brazing material 240 such as nickel brazing.

According to this, since the connecting member is the metal brazing material 240, the crystal oscillator 201 has a large connection area and can improve the connection strength.
Thus, the crystal oscillator 201 can improve connection reliability.
In addition to the brazing using the metal brazing material 240, the crystal oscillator 201 forms bumps such as gold and solder so as to straddle the external terminals 14 of the crystal resonator 10 and the internal connection terminals 34 of the wiring board 30. Then, both may be connected.
According to this, the crystal oscillator 201 can obtain the same effect as described above.

(Modification 3)
FIG. 4 is a schematic cross-sectional view showing a schematic configuration of the crystal oscillator of the third modification. The cross-sectional position is the same as in FIG. In addition, about the common part with the said embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted and it demonstrates centering on a different part from the said embodiment.

As shown in FIG. 4, in the crystal oscillator 301 of the third modification, a conductive material such as a metal filler is mixed in the connection member between the external terminal 14 of the crystal resonator 10 and the internal connection terminal 34 of the wiring board 30. The conductive adhesive 340 such as epoxy, silicon or polyimide is used.
According to this, since the connection member is the conductive adhesive 340, the crystal oscillator 301 can perform the connection work easily by applying using, for example, a dispenser.

  In the above-described embodiment and each modification, the crystal oscillator has been described as an example of the piezoelectric device. However, the present invention is not limited to this. For example, a pressure sensor or a gyro provided with a detection circuit or the like on the IC chip 20 is used. A sensor may be used.

The material of the piezoelectric vibrating piece is not limited to quartz, but lithium tantalate (LiTaO ₃ ), lithium tetraborate (Li ₂ B ₄ O ₇ ), lithium niobate (LiNbO ₃ ), zirconate titanate A piezoelectric body such as lead acid (PZT), zinc oxide (ZnO), and aluminum nitride (AlN), or a semiconductor such as silicon may be used.
In addition, various vibrating pieces other than the piezoelectric vibrating piece can be used instead of the quartz vibrating piece 12. For example, a MEMS (Micro Electro Mechanical Systems) vibrating piece formed by processing a silicon substrate may be used. .

  DESCRIPTION OF SYMBOLS 1 ... Crystal oscillator as a vibration device, 10 ... Crystal resonator as a vibrator, 11 ... Package, 11a ... Package base, 11b ... Lid, 11c ... Inner surface, 11d ... Outer surface, 12 ... Quartz crystal vibration piece as a vibration piece, DESCRIPTION OF SYMBOLS 13 ... Internal electrode, 14 ... External terminal, 15 ... Conductive adhesive, 20 ... IC chip as a circuit element, 21 ... Terminal, 22 ... Active surface, 30 ... Wiring board, 31 ... One surface, 32 ... Other Surface, 33 ... Through hole, 34 ... Internal connection terminal, 35 ... IC chip connection terminal as circuit element connection terminal, 36 ... Mounting terminal, 40 ... Metal wire as connection member, 41 ... Bump, 42 ... Resin, 50 ... External equipment, 101 ... crystal oscillator, 140 ... metal lead plate, 201 ... crystal oscillator, 240 ... metal brazing material, 301 ... crystal oscillator, 340 ... conductive adhesive.

Claims (7)

A vibrator that houses a resonator element inside a package having external terminals on the outer surface;
A circuit element for driving the resonator element;
A circuit board in which the circuit element is disposed on one surface and the vibrator is disposed on the other surface;
The wiring board has a through-hole or a notch in which at least a part of the external terminal of the vibrator is exposed in a plan view from the direction of the one surface,
The internal connection terminal formed on the one surface and the external terminal of the vibrator are connected by a connection member through the through hole or the notch,
The internal connection terminal is connected to a circuit element connection terminal formed on the one surface,
The circuit element is disposed so as to cover the internal connection terminal and the connection member in a plan view, and the terminal of the circuit element and the circuit element connection terminal are connected to face each other. And vibration device.   The vibration device according to claim 1, wherein the connection member is a metal wire.   2. The vibration device according to claim 1, wherein the connection member is a metal lead plate.   The vibration device according to claim 1, wherein the connection member is a metal brazing material.   The vibrating device according to claim 1, wherein the connection member is a conductive adhesive.   4. The vibration device according to claim 3, wherein the metal lead plate is a wiring pattern drawn from the wiring board.   The vibration device according to claim 1, wherein a resin is filled between the circuit element and the wiring board and in the through hole or the notch. .

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