JP2008003011A - Piezo-electric device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezo-electric device having excellent vibration characteristics by improving joining strength of wire bonding to a piezo-electric vibration piece while effectively preventing vibration leakage, and to provide its manufacturing method. <P>SOLUTION: The piezo-electric device provided with the wire-bonded piezo-electric vibration piece 32 and an object to be joined 45 joining the piezo-electric vibration piece 32 by using an adhesive 44 interposes a hard member 70 harder than at least the adhesive 44 between the joined face of the piezo-electric vibration piece 32 and the joined face of the object to be joined 45 by corresponding to a position 61a wire-bonding the piezo-electric vibration piece 32. The hard member 70 does not join any one or both of the piezo-electric vibration piece 32 or the object to be joined 45. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a piezoelectric device in which a wire-bonded piezoelectric vibrating piece is bonded to an object to be bonded with an adhesive.

Piezoelectric devices are widely used in small information devices such as HDDs (hard disk drives), mobile computers or IC cards, mobile communication devices such as mobile phones and paging systems, or sensors such as acceleration sensors and angular velocity sensors. in use.
FIG. 10 shows a schematic cross-sectional view of a gyro apparatus 1 which is an example of a conventional piezoelectric device (see Patent Document 1).

In the figure, the gyro device 1 includes a substrate 2, a substrate 3, a semiconductor chip 4, and a piezoelectric vibrating piece 4 that are stacked in a vertical direction.
That is, the semiconductor chip 4 is mounted face-down on the substrate 3 on which a wiring pattern (not shown) is formed, and the piezoelectric vibrating reed 5 is attached to the support base 7 on the semiconductor chip 4 using the adhesive 6. It is joined.

  The piezoelectric vibrating piece 5 and the substrate 3 are electrically connected by wire bonding using an ultrasonic method or a thermocompression bonding method. For example, the piezoelectric vibrating piece 5 and the bonding wire 8 are connected by pressing one end of the bonding wire 8 led out from the capillary onto the upper surface of the piezoelectric vibrating piece 5 to connect the piezoelectric vibrating piece 5 and bonding. The other end of the line 8 is also connected to the substrate 3.

  Here, as the adhesive 6 for joining the piezoelectric vibrating piece 5 to the support base 7 on the semiconductor chip 4, a flexible adhesive, for example, a silicone-based adhesive is often used. That is, by using the flexible adhesive 6, for example, extra vibration is generated in the piezoelectric vibrating piece 5 due to an impact from the outside, and the vibration component is transmitted to the outside through the package 2. The vibration component is absorbed by a flexible adhesive to prevent vibration leakage, and a good vibration mode can be obtained.

JP 2002-181550 A

However, since the gyro apparatus 1 having such a configuration uses the flexible adhesive 6, the bonding wire 8 may not be successfully bonded to the upper surface of the piezoelectric vibrating piece 5 during wire bonding. That is, as described above, when ultrasonic wave application or thermocompression bonding is performed for wire bonding, ultrasonic vibration and pressing force are absorbed by the flexible adhesive 6, and for example, the ultrasonic wave is not transmitted well, There may be a problem of insufficient bonding strength.
Further, when the piezoelectric vibrating piece 5 is pressed toward the support base 7 during wire bonding, the adhesive 6 spreads in the horizontal direction, and the adhesion area of the adhesive 6 with respect to the piezoelectric vibrating piece 5 varies, and Q There is also a problem that the values vary.

  The present invention has been made in order to solve the above-described problems. A piezoelectric device having excellent vibration characteristics and improved bonding strength of wire bonding to a piezoelectric vibrating piece while effectively preventing vibration leakage, and It aims at providing the manufacturing method.

  In the first invention, the above object is a piezoelectric device comprising a piezoelectric vibrating piece bonded by wire bonding and an object to be joined to which the piezoelectric vibrating piece is bonded using an adhesive. Between the bonding surface of the piezoelectric vibrating piece and the bonding surface of the object to be joined, a hard member harder than at least the adhesive is interposed, corresponding to the position of the piezoelectric vibrating piece that is wire-bonded, The hard member is achieved by a piezoelectric device that is not joined to either or both of the piezoelectric vibrating piece and the joined body.

According to the configuration of the first invention, since the piezoelectric vibrating piece and the object to be joined are bonded by the adhesive, the vibration component can be absorbed by the flexibility of the adhesive to prevent vibration leakage. For example, ultrasonic waves when wire bonding is performed may be absorbed by the adhesive.
However, a hard member harder than the adhesive is interposed between the bonding surface of the piezoelectric vibrating piece of the present invention and the bonding surface of the object to be bonded, corresponding to the wire-bonded position of the piezoelectric vibrating piece. Yes. For this reason, for example, the ultrasonic wave applied at the time of wire bonding is efficiently transmitted using this hard member as a base.
Further, even when the piezoelectric vibrating piece is pressed to the bonded body side during wire bonding, the hard member can withstand the pressing, and the adhesion area of the adhesive to the piezoelectric vibrating piece can be controlled.
Even if such a hard member is interposed between the joining surface of the piezoelectric vibrating piece and the joining surface of the joined body, the hard member is joined to either or both of the piezoelectric vibrating piece and the joined body. Not. For this reason, it can prevent effectively inhibiting the function of preventing the vibration leak of a flexible adhesive agent.
Therefore, it is possible to provide a piezoelectric device having improved vibration characteristics while effectively preventing vibration leakage and improving the bonding strength of wire bonding to the piezoelectric vibrating piece.

According to a second invention, in the configuration of the first invention, the hard member is a bump bonded to only one of the piezoelectric vibrating piece and the bonded body.
According to the configuration of the second invention, the hard member is a bump bonded to only one of the piezoelectric vibrating piece and the joined body. For this reason, for example, if a bump is formed on the bonding surface of the piezoelectric vibrating piece and placed on the bonded body to which the adhesive is applied, the bonding surface of the piezoelectric vibrating piece and the bonding surface of the bonded body can be easily obtained. The piezoelectric vibrating piece and the object to be joined can be joined with an adhesive while a bump is interposed therebetween.

According to a third invention, in the configuration of the first or second invention, the member to be joined is a semiconductor chip, and the piezoelectric vibrating piece is joined to a region other than a region in which the terminal of the semiconductor chip is provided. It is characterized by.
According to the configuration of the third aspect of the invention, the piezoelectric vibrating piece is bonded to a region other than the region where the terminal of the semiconductor chip that is the bonded body is provided. Therefore, for example, even when a hard member such as a bump is pressed to the semiconductor chip side during wire bonding, the hard member can be prevented from damaging the terminal of the semiconductor chip.

In a fourth aspect based on any one of the first to third aspects, the bonded body is a semiconductor chip, and the piezoelectric vibrating piece is bonded to a surface of the semiconductor chip having a terminal. The terminal is directly wire-bonded.
According to the configuration of the fourth aspect of the invention, the piezoelectric vibrating piece is bonded to the surface having the terminal of the semiconductor chip, which is the bonded body, and is directly wire bonded to the terminal. Therefore, the electrical connection between the piezoelectric vibrating piece and the semiconductor chip does not require a conductive part for routing the package, and a single bonding line can be shortened. Noise can be achieved.

According to a fifth aspect of the invention, in the configuration of the first or second aspect of the invention, the object to be joined is a wiring board in which the piezoelectric vibrating pieces are electrically connected by wire bonding, and the wiring board has the piezoelectric vibration. The semiconductor chip is electrically and mechanically connected to the surface opposite to the surface where the pieces are joined.
According to the configuration of the fifth invention, the object to be bonded is a wiring board in which the piezoelectric vibrating reeds are electrically connected by wire bonding. However, since the object to be bonded is bonded to the piezoelectric vibrating reed, The piezoelectric vibrating piece is electrically and mechanically connected. In the wiring board, a semiconductor chip is electrically and mechanically connected to a surface opposite to the surface to which the piezoelectric vibrating piece is bonded. Therefore, if the piezoelectric vibrating piece and the semiconductor chip are electrically and mechanically connected to each other with a wiring board interposed therebetween to form a module, and then this modularized product is connected to a package, the manufacturing is facilitated. In particular, if the wiring board is dimensioned so that a plurality of piezoelectric vibrating pieces and a plurality of semiconductor chips can be connected, a plurality of piezoelectric vibrating pieces and a plurality of semiconductor chips are connected to the wiring board and then separated into a plurality of modules. Can be produced at once, making mass production easier.
Further, since the wiring board is interposed between the piezoelectric vibrating piece and the semiconductor chip, the hard member does not damage the terminal of the semiconductor chip. Further, since wire bonding is performed between the piezoelectric vibrating piece and the substrate, it is not necessary to connect one end of a bonding line connected to the piezoelectric vibrating piece to the package, and the size of the package can be reduced accordingly.

  According to a sixth aspect of the present invention, there is provided a method for manufacturing a piezoelectric device, comprising: bonding a piezoelectric vibrating piece to an object to be bonded using an adhesive; and wire bonding the piezoelectric vibrating piece. A bump is formed on the bonding surface of the piezoelectric vibrating piece with respect to the bonded body, corresponding to the wire bonding position, and then the piezoelectric vibrating piece on which the bump is formed is bonded to the bonded body with the adhesive, Thereafter, this is achieved by a method of manufacturing a piezoelectric device in which the wire bonding is performed on the piezoelectric vibrating piece.

According to the structure of 6th invention, before joining a piezoelectric vibrating piece to a to-be-joined body, a bump is formed in the joining surface of a piezoelectric vibrating piece corresponding to the position to wire-bond. Therefore, as in the first invention, for example, ultrasonic waves during wire bonding are efficiently transmitted using the bumps as a base, and the adhesion area of the adhesive to the piezoelectric vibrating piece can also be controlled. The bump is formed on the bonding surface of the piezoelectric vibrating piece and is not bonded to the bonding surface of the object to be bonded. For this reason, it can prevent effectively inhibiting the vibration leak prevention function of an adhesive agent similarly to 1st invention. In addition, since the bump is formed on the piezoelectric vibrating piece rather than the object to be joined, it is easy to match with the position for wire bonding.
Thus, it is possible to provide a method of manufacturing a piezoelectric device having improved vibration characteristics while effectively preventing vibration leakage and improving the bonding strength of wire bonding to the piezoelectric vibrating piece.

1 to 3 show a piezoelectric device according to an embodiment of the present invention, in which FIG. 1 is a schematic perspective view thereof, FIG. 2 is a schematic sectional view taken along line AA of FIG. 1, and FIG. It is the schematic plan view which expanded the vicinity of the base part of the piezoelectric vibrating piece which is a component of a device. In addition, the part shown by the parallel oblique line of FIG.2 and FIG.3 is shown for understanding, and does not represent a cross section.
In FIG. 1, the piezoelectric device 10 exemplifies a gyro device, wherein the X direction indicates an electric axis of the crystal, the Y direction indicates a mechanical axis of the crystal, and the Z direction indicates an optical axis (growth axis) of the crystal. Fig. 9 shows the state in which the angular velocity ω acts.

In the piezoelectric device 10, a piezoelectric vibrating piece 32 and a semiconductor chip 45 as an example of an object to be bonded to which the piezoelectric vibrating piece 32 is bonded are accommodated in a package 36. Since the package 36 shows the internal piezoelectric vibrating piece 32, the lid is omitted in FIG.
As shown in FIG. 2, the package 36 is formed by, for example, laminating a plurality of substrates formed by molding an aluminum oxide ceramic green sheet as an insulating material, and then sintering. Each of the plurality of substrates is formed with a predetermined hole on the inner side thereof so that a predetermined inner space S is formed on the inner side when stacked. This internal space S is a housing space for housing the piezoelectric vibrating piece 32 and the like.
That is, in this embodiment, the package 36 is formed by, for example, overlapping the first substrate 61, the second substrate 62, the third substrate 63, and the seam ring 64 from the bottom. The seam ring 64 is, for example, a Kovar ring for joining the metal lid 33 and the lid 33 is joined to the package 36 by seam welding or the like.

  The second substrate 62 and the third substrate 63 are obtained by sequentially stacking the inner material from which the inner material is removed, and the upper substrate removes the inner material from the lower substrate. By increasing the amount, the corresponding internal space is made larger. Accordingly, the space S2 inside the third substrate 63 is wider than the space S1 inside the second substrate 62, and accordingly, the upward step portion 22 is formed at the upper end of the second substrate 62. Is formed.

As shown in FIG. 3, the upward step portion 22 is provided with electrode pads 41 and 42 formed by nickel plating and gold plating on, for example, tungsten metallization.
The electrode pad 42 supplies a driving voltage to the piezoelectric vibrating piece 32 through a bonding wire 61 described later, and the electrode pad 41 transmits a signal corresponding to the rotational angular velocity sent through the bonding wire 61 described later. It has become.

  Specifically, the electrode pads 41 and 42 are routed through the package 36 and are electrically connected to electrode pads (not shown) formed on the inner bottom 23 of the package 36 as shown in FIG. . A semiconductor chip 45 having at least a circuit that oscillates the piezoelectric vibrating piece 32 is flip-chip connected to the electrode pad of the inner bottom portion 23. Further, the semiconductor chip 45 is electrically connected to the mounting terminal 25 at the bottom by a conductive through hole (not shown) passing through the package 36.

As shown in FIG. 4, the semiconductor chip 45 is die-bonded to the inner bottom portion 23 of the package so that the surface 45a having terminals faces the upper surface (package opening side), and the substrate is laminated more than the package shown in FIG. The number is increased to form a second upward step 27, and an electrode pad (not shown) provided on the second upward step 27 and the semiconductor chip 45 are electrically connected by wire bonding. Also good.
As shown in FIG. 2, in the semiconductor chip 45 of this embodiment, a surface 45a having a terminal is mounted face-down on the inner bottom portion 23 on the opposite side to the piezoelectric vibrating piece 32 side. Then, it is easily joined to a region other than the region where the terminals (not shown) of the semiconductor chip 45 are provided, and a hard member 70 described later comes into contact with the terminals (not shown) of the semiconductor chip 45, The terminal is prevented from being damaged.

  In the case of this embodiment, the piezoelectric vibrating piece 32 is a sensor main body of a gyro device. For example, a crystal wafer having a size capable of separating a plurality of piezoelectric vibrating pieces or a large number of piezoelectric vibrating pieces is used as an etching solution. By forming the outer shape by wet etching, a large number of piezoelectric vibrating pieces having the shape shown in FIG. 1 are formed.

  That is, the substantially square base 51 of the piezoelectric vibrating piece 32 is supported with respect to the semiconductor chip 45 that is the bonded body. From the base 51, as shown in FIG. Integrally formed rod-like or shaft-like support portions 52, 52 extend. Further, as shown in FIG. 1, the end portions of the support portions 52 and 52 are formed in both directions starting from the end portions of the support portions 52 and 52 in the direction intersecting with the extending direction of the support portions 52 and 52. Exciting vibrating arms 54 and 54 are provided. That is, the excitation vibrating arms 54 and 54 extend in parallel with each other via the support portions 52 and 52 from the base 51, and excitation electrodes (not shown) are provided on the excitation vibrating arms 54 and 54. Is formed.

In FIG. 3, two detection vibrating arms 55, 55 are formed at substantially the center of the upper and lower sides of the base 51 in a direction intersecting with the extending direction of the support portions 52, 52. As shown in FIG. 1, the detection vibrating arms 55 and 55 and the excitation vibrating arms 54 and 54 provided at the ends of the support portions 52 and 52 are parallel to each other.
When a physical quantity such as a predetermined rotational angular velocity acts on the piezoelectric vibrating piece 10 in this state, the excitation vibrating arms 54 and 54 have a Coriolis force acting in the direction of the vector product of the direction of vibration of itself and the rotational angular velocity. In response, a predetermined vibration is excited. This vibration can detect the rotational angular velocity by taking out the electric charge based on the vibration of the vibrating arms 55 and 55 for detection as a signal through the support portions 52 and 52 and the base portion 51.

Also, as shown in FIG. 3, electrode pads 56, 57, 56, and 57 for detection electrodes are formed on the base end portions of the detection vibrating arms 55 and 55, respectively, on the substantially square base portion 51. Electrode pads 58, 59, 58, 59 for excitation electrodes are formed at the base ends of the support parts 52, 52.
One end 61a of the bonding wire 61 is joined to the electrode pads 56, 57, 56, 57 of the base 51, and the other end 61b of the bonding wire 61 is connected to the upward step portion 22, Wire bonding is performed by bonding to the electrode pads 41, 41, 41, and 41 shown in FIG.
One end 61a of the bonding wire 61 is bonded to the electrode pads 58, 59, 58, 59 of the base 51, and the electrode pads 42, 42, 42, 42 of the upward stepped portions 22, 22 of the package 36 are By bonding the other end 61b of the bonding wire 61, wire bonding is performed, and electrical connection is made. As shown in FIG. 2, the bonding lines 61 and 61 extend in the space S <b> 2 inside the third substrate 63 and the seam ring 64 of the package 36.

  As the bonding wire 61, gold (Au), aluminum (Al), copper (Cu), or the like, or a wire material containing these as a main component can be suitably used. The piezoelectric vibrating piece 32 and the bonding wire 61 are connected by pressing one end 61a of the bonding wire 61 and applying ultrasonic waves, and the other end 61b of the bonding wire 61 is connected to the package 36 in the same manner. I am doing so.

Then, as shown in FIG. 2, such a piezoelectric vibrating piece 32 is bonded to a semiconductor chip 45 that is a bonded body using an adhesive 44. That is, the adhesive 44 adheres to the surface of the base 51 of the piezoelectric vibrating piece 32 opposite to the upper surface provided with the electrode pads 56, 57, 58, 59 shown in FIG. 3, and the piezoelectric vibrating piece 32 is supported. Yes.
As the adhesive 44 of this embodiment, a silicone-based adhesive that is more flexible than an epoxy-based adhesive is used. That is, the relatively flexible adhesive can absorb a vibration component to be transmitted between the piezoelectric vibrating piece 32 and the semiconductor chip 45, so that so-called vibration leakage is prevented and a good vibration mode is obtained. Obtainable.

Here, between the bonding surface of the piezoelectric vibrating piece 32 and the bonding surface of the semiconductor chip 45, which is an object to be bonded, corresponds to the wire-bonded position of the piezoelectric vibrating piece 32 and is at least harder than the adhesive 44. A hard member 70 is interposed.
In the present embodiment, the hard member 70 is formed of metal bumps made of Au (gold), Al (aluminum), Cu (copper), and the like, and is bonded to the base 51 of the piezoelectric vibrating piece 32. It is arranged immediately below one end 61a of 61, so that it can resist ultrasonic vibration and pressing force during wire bonding.

  The hard member 70 is not bonded to one or both of the piezoelectric vibrating piece 32 and the semiconductor chip 45. That is, when the hard member 70 is bonded to both the piezoelectric vibrating piece 32 and the semiconductor chip 45, vibration leakage occurs through the hard member 70. Therefore, it is only the adhesive 44 that bonds the piezoelectric vibrating piece 32 and the semiconductor chip 45, and the hard member 70 is not bonded to at least one of the piezoelectric vibrating piece 32 or the semiconductor chip 45. It has become.

In the case of the present embodiment, the hard member 70 is bonded only to the piezoelectric vibrating piece 32 side so that it can be accurately placed immediately below the one end 61a of the bonding wire 61, as will be described in the manufacturing method described later. In order to join the bump which is the hard member 70 to the piezoelectric vibrating piece 32, a metal pattern (not shown) made of, for example, Au or Cr with tungsten metallized as a base is formed on the bonding surface of the base 51 of the piezoelectric vibrating piece 32. ) Is formed.
Further, a plurality of hard members 70 are provided corresponding to one ends 61a of the plurality of bonding wires 61, and as shown in FIG. 2, leveling is performed so as to reduce the variation in the height dimension H1 of each hard member 70. Has been.
Moreover, it is preferable that the hard member 70 is provided at at least three points on the joint surface, thereby preventing the level of the piezoelectric vibrating piece 32 from being hindered by the hard member 70 serving as a fulcrum. . Further, the hard member 70 of the present embodiment is a peripheral region of the substantially square base 51 and is provided for each side.

Next, a method for manufacturing the piezoelectric device 10 according to the embodiment of the present invention will be briefly described.
5 to 7 are diagrams for explaining a method of manufacturing the piezoelectric device 10, wherein FIG. 5 is a process diagram of the piezoelectric device 10, and FIGS. 6 and 7 are conceptual diagrams of manufacturing processes corresponding to the process of FIG. It is.
As shown in FIG. 5, the piezoelectric device 10 is prepared by preparing the above-described package, semiconductor chip, and piezoelectric vibrating piece separately (ST0 in FIG. 5: preparation step). This step of connecting is performed (ST1 to ST6 in FIG. 5).

Here, in the preparatory process (ST0 in FIG. 5), the semiconductor chip is flip-chip connected as described above, so that the bump 66 such as the Au bump shown in FIG. (ST0-1 in FIG. 5), and then bump leveling is performed (ST0-2 in FIG. 5). That is, since the height of the bump has a certain degree of variation, the bump is pressed against a flat surface with a predetermined load to control the height of the bump.
Also, during the preliminary preparation process (ST0 in FIG. 5), bumps 70 such as Au bumps are formed on the bonding surface of the base 51 described with reference to FIGS. 2 and 3 for the piezoelectric vibrating piece (ST0-10 in FIG. 5). ). The bump 70 is a hard member. That is, the bump 70 is formed on the bonding surface of the piezoelectric vibrating piece 32 (the back surface of the base 51) corresponding to the wire bonding position (position 61a).

2 may be formed using a bonder for forming the bump 66 on the semiconductor chip 45. The bumper 70 shown in FIG.
In the case of this embodiment, as shown in FIG. 6A, a plating bump system is adopted so as to accurately correspond to a plurality of wire bonding positions and to form small bumps. 6A is a partially enlarged view of the base 51, and the right view of FIG. 6A is a cross-sectional end view taken along the line BB of the left view, as shown in the right view of FIG. 6A. In addition, a metal pattern 68 is formed on the joint surface of the base 51, a mask is formed with a resist 67, and electric solder plating is performed in the through hole 67a formed corresponding to a position where a bump is to be formed. 67 is excluded.
Thereafter, since the height of the completed bump varies, the bump is pressed against a plane with a predetermined load to control the height dimension H1 (see FIG. 2) of the bump 70 (ST0-20 in FIG. 5).
: Bump leveling).

  Next, this step is entered, and as shown in FIG. 6B, bumps 66 formed on the surface 45 a having the terminals of the semiconductor chip 45 are electrode pads (not shown) formed in advance on the inner bottom 23 of the package 36. The semiconductor chip 45 is mounted face down (ST1 in FIG. 5).

Next, as shown in FIG. 7 (c), the surface 45b opposite to the mounting surface of the semiconductor chip 45 mounted face-down, on the region corresponding to the base of the piezoelectric vibrating piece, has flexibility such as silicone. The adhesive 44 having is applied.
Next, as shown in FIG. 7D, the piezoelectric vibrating reed 32 on which the bump 70 has already been formed in the preparatory step (ST0-10) is placed on the bonding surface 45b of the semiconductor chip 45 to which the adhesive 44 has been applied. (ST3 in FIG. 5) Then, the adhesive 44 is dried, and the piezoelectric vibrating piece 32 and the semiconductor chip 45 are joined with the adhesive 44 (ST4 in FIG. 5).

  Next, as shown in FIG. 7E, wire bonding is performed on the piezoelectric vibrating piece 32 (ST5 in FIG. 5). That is, one end 61a of the bonding wire 61 led out from the capillary is pressed against the piezoelectric vibrating piece 32 and an ultrasonic wave is applied to connect the piezoelectric vibrating piece 32 and the bonding wire 61. The other end 61 b is also connected to the upward step portion 22 of the package 36. Then, since the bump 70 is disposed as a hard member harder than at least the adhesive 44 immediately below the tip 61a of the bonding wire 61, this bump 70 serves as a support base, It will receive a pressing force.

  Next, a probe pin is brought into contact with a mounting terminal (not shown) that is electrically connected to a semiconductor chip adjustment or inspection terminal (not shown), and an adjustment is made based on the inspection result ( ST6) in FIG. 5 completes the piezoelectric device.

  The embodiment of the present invention is configured as described above, and the gap between the bonding surface of the piezoelectric vibrating piece 32 and the bonding surface of the semiconductor chip 45 corresponds to the wire-bonded position of the piezoelectric vibrating piece 32. Since the hard member 70 is interposed, for example, ultrasonic waves during wire bonding are efficiently transmitted using the hard member 70 as a base. Further, even when the piezoelectric vibrating piece 32 is pressed against the semiconductor chip 45 during wire bonding, the hard member 70 can withstand this pressing, and the area where the adhesive 44 adheres to the piezoelectric vibrating piece 32 can be controlled. it can. Further, the hard member 70 can also improve the level of the piezoelectric vibrating piece 32 (particularly, in the case of a gyro device, since the shake of the level of the piezoelectric vibrating piece 32 causes a large difference in detection result, this effect is large). Even if such a hard member 70 is provided, since the hard member 70 is not joined to either or both of the piezoelectric vibrating piece 32 and the semiconductor chip 45, vibration leakage of the flexible adhesive 44 is prevented. It can prevent effectively inhibiting the function of preventing.

  In the manufacturing method of the present embodiment, bumps that are the hard members 70 are formed on the piezoelectric vibrating piece 32, and then the piezoelectric vibrating piece 32 is placed on the adhesive 44. For this reason, the position of wire bonding and the position of the hard member 70 can be matched without worrying about the positional accuracy when placing the piezoelectric vibrating piece 32.

  In the present embodiment, the gyro device is exemplified as the piezoelectric device 10, but the present invention is not limited to this, and may be an acceleration sensor, a piezoelectric vibrator, a SAW filter, or the like. Further, the semiconductor chip 45 is exemplified as the bonded body to which the piezoelectric vibrating piece 32 is bonded, but the bonded body may be the package 36 or other electronic components.

FIG. 8 is a schematic cross-sectional view of the piezoelectric device 12 according to the first modification of the above-described embodiment of the present invention, and corresponds to the schematic cross-sectional view of FIG.
In FIG. 8, the same reference numerals as those used in FIGS. 1 to 7 have the same configuration, and therefore, redundant description will be omitted, and differences will be mainly described.
The piezoelectric device 12 in FIG. 8 is mainly different from the piezoelectric device 10 in FIGS. 1 to 7 in the connection structure between the semiconductor chip 45 and the piezoelectric vibrating piece 32.

That is, in the first modification, the piezoelectric vibrating piece 32 is bonded to the surface 45 a having the terminals of the semiconductor chip 45 and is directly wire bonded to the terminals (not shown).
Specifically, the semiconductor chip 45 is not flip-chip connected to the package 36, and is die-bonded to the inner bottom 23, and the surface 45 a having terminals faces the bonding surface of the piezoelectric vibrating piece 32.
Further, by reducing the height dimension of the second substrate 62 in the package 36, the upward stepped portion 22 is formed so as to be substantially flush with the surface 45 a having the terminals of the semiconductor chip 45. 45 and an electrode pattern (not shown) formed on the upward step portion 22 are wire-bonded by a bonding wire 69.
The piezoelectric vibrating piece 32 is joined to a region (in the case of FIG. 8, a central region) other than the region where the terminals (not shown) of the semiconductor chip 45 are provided, and the terminals (not shown) of the semiconductor chip 45. And the bonding wire 61 is directly wire-bonded.

  The first modification of the embodiment of the present invention is configured as described above, and the piezoelectric vibrating piece 32 is bonded to the surface 45a having the terminals of the semiconductor chip 45, and directly bonded to the terminals. . Therefore, the electrical connection between the piezoelectric vibrating piece 32 and the semiconductor chip 45 is not required to provide a conductive portion for routing the package 36, and one bonding line can be shortened. Signal noise can be reduced.

FIG. 9 is a schematic cross-sectional view of the piezoelectric device 14 according to the second modification of the above-described embodiment of the present invention, and corresponds to the schematic cross-sectional view of FIG.
In FIG. 9, the same reference numerals as those used in FIG. 1 to FIG. 8 have the same configuration, and therefore, redundant description will be omitted, and differences will be mainly described.
The piezoelectric device 14 in FIG. 9 is mainly different from the piezoelectric devices 10 and 12 in FIGS. 1 to 8 in the connection structure between the semiconductor chip 45 and the piezoelectric vibrating piece 32.

That is, the bonded body of this modification is not the semiconductor chip 45 but the wiring board 80. The wiring board 80 has a pad (not shown) to which the piezoelectric vibrating piece 32 is electrically connected by wire bonding.
On the other hand, the semiconductor chip 45 is electrically and mechanically connected to a surface 80a on the opposite side of the surface of the wiring substrate 80 to which the piezoelectric vibrating piece 32 is bonded. Specifically, a pad (not shown) to which the bonding wire 61 of the wiring board 80 is connected is provided on the surface 80a opposite to the surface to which the piezoelectric vibrating piece 32 is bonded by a through hole or a wiring pattern. A conductive pad (not shown). The pads provided on the opposite surface 80 a of the wiring substrate 80 and the terminals of the semiconductor chip 45 are connected via the bumps 66 so that the semiconductor chip 45 is flip-chip connected to the wiring substrate 80. .
As described above, the piezoelectric vibrating piece 32 and the semiconductor chip 45 are electrically and mechanically connected with the wiring board 80 interposed therebetween.

In addition, the piezoelectric vibrating piece 32, the semiconductor chip 45, and the wiring board 80 according to the present embodiment are not sequentially mounted on the package 36. Before mounting on the package 36, the components 32, 45, and 80 are not separated. It is modularized by electrical and mechanical connection. That is, before mounting on the package 36, the semiconductor chip 45 is flip-chip connected to one surface of the wiring substrate 80, and then the adhesive 44 is applied to the other surface of the wiring substrate 80, and the bump 70 is formed thereon. The piezoelectric vibrating piece 32 formed with is mounted and fixed, and then wire-bonded to form a module.
A wiring board having a size corresponding to the plurality of piezoelectric vibrating pieces 32 and the semiconductor chip 45 is prepared, and the plurality of piezoelectric vibrating pieces 32 and the semiconductor chip 45 are attached to the large wiring board by the same method as described above. Mass production is possible by electrically and mechanically connecting to a predetermined position and then cutting the wiring board into a size corresponding to one piezoelectric device 14 and dividing it into a module.

Then, the assembly of the piezoelectric vibrating piece 32, the semiconductor chip 45, and the wiring board 80 that are modularized in this way is connected to the package 36 side. That is, in the horizontal direction, the peripheral edge 80 b of the wiring board 80 having an area larger than that of the semiconductor chip 45 is electrically and mechanically connected to the upward stepped portion 22 of the package 36.
Specifically, the pads (not shown) provided on the surface 80a of the wiring board 80 connected to the semiconductor chip 45 via the bumps 66 are provided on the peripheral surface 80b on the same surface 80a of the wiring board 80. Is electrically connected to a pad (not shown). The pad (not shown) on the peripheral edge 80b is joined to the electrode pattern (not shown) formed on the upward step 22 by solder, conductive adhesive 82, or the like.

The second modification of the embodiment of the present invention is configured as described above, and the piezoelectric vibrating piece 32 and the semiconductor chip 45 are electrically and mechanically connected to each other with the wiring board 80 interposed therebetween, and are modularized. Thereafter, since the wiring board 80 is connected to the upward stepped portion 22 of the package 36, the manufacture is easy. Further, if such a structure that can be modularized is adopted, in the manufacturing method, after connecting the plurality of piezoelectric vibrating pieces 32 and the plurality of semiconductor chips 45 to the wiring board having a large size, the plurality of piezoelectric vibrating pieces 32 and the plurality of semiconductor chips 45 are separated into pieces. Modularized products can be produced at once. Therefore, mass production becomes easy.
In addition, since the wiring substrate 80 is interposed between the piezoelectric vibrating piece 32 and the semiconductor chip 45, the hard member 70 such as a bump does not damage the terminal of the semiconductor chip 45.

  The present invention is not limited to the above-described embodiments and modifications. Each configuration of each embodiment and modification can be combined or omitted as appropriate, and can be combined with other configurations not shown.

1 is a schematic perspective view of a piezoelectric device according to an embodiment of the present invention. FIG. 2 is a schematic sectional view taken along line AA in FIG. 1. FIG. 2 is a schematic plan view in which a base portion of a piezoelectric vibrating piece that is a component of the piezoelectric device in FIG. 1 is enlarged. FIG. 3 is a schematic cross-sectional view corresponding to FIG. 2, showing another embodiment of the piezoelectric device of the present invention. Process drawing for demonstrating the manufacturing method of the piezoelectric device which concerns on embodiment of this invention. The conceptual diagram of the manufacturing process corresponding to the process of FIG. The conceptual diagram of the manufacturing process corresponding to the process of FIG. It is a schematic sectional drawing of the piezoelectric device which concerns on the 1st modification of embodiment of this invention, and is a figure corresponding to the schematic sectional drawing of FIG. It is a schematic sectional drawing of the piezoelectric device which concerns on the 2nd modification of embodiment of this invention, and is a figure corresponding to the schematic sectional drawing of FIG. FIG. 6 is a schematic cross-sectional view of a gyro apparatus that is an example of a conventional piezoelectric device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10, 12, 14 ... Piezoelectric device, 32 ... Piezoelectric vibrating piece, 36 ... Package, 44 ... Adhesive, 45 ... Bonded body (semiconductor chip), 61 ... Bonding wire , 70 ... Hard member (bump)

Claims (6)

A piezoelectric device comprising a wire-bonded piezoelectric vibrating piece and a bonded body to which the piezoelectric vibrating piece is bonded using an adhesive,
A hard member harder than at least the adhesive is interposed between the bonding surface of the piezoelectric vibrating piece and the bonding surface of the object to be joined, corresponding to the wire-bonded position of the piezoelectric vibrating piece. ,
The said hard member is not joined to either one or both of the said piezoelectric vibrating piece and the said to-be-joined body. The piezoelectric device characterized by the above-mentioned.   2. The piezoelectric device according to claim 1, wherein the hard member is a bump bonded to only one of the piezoelectric vibrating piece and the member to be bonded. The joined body is a semiconductor chip;
The piezoelectric device according to claim 1, wherein the piezoelectric vibrating piece is bonded to a region other than a region where the terminals of the semiconductor chip are provided. The joined body is a semiconductor chip;
4. The piezoelectric device according to claim 1, wherein the piezoelectric vibrating piece is bonded to a surface of the semiconductor chip having a terminal and is directly wire-bonded to the terminal. The bonded body is a wiring board in which the piezoelectric vibrating pieces are electrically connected by wire bonding,
3. The piezoelectric device according to claim 1, wherein a semiconductor chip is electrically and mechanically connected to a surface of the wiring board opposite to a surface to which the piezoelectric vibrating piece is bonded. A method for manufacturing a piezoelectric device in which a piezoelectric vibrating piece is bonded to an object to be bonded using an adhesive, and then the piezoelectric vibrating piece is wire bonded.
A bump is formed on the bonding surface of the piezoelectric vibrating piece to the object to be bonded corresponding to the position where the wire bonding is performed,
Thereafter, the piezoelectric vibrating piece on which the bump is formed is bonded to the bonded body by the adhesive,
Thereafter, the wire bonding is performed on the piezoelectric vibrating piece. A method for manufacturing a piezoelectric device.

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