JPH11205074A - Piezoelectric thin film vibrator - Google Patents

Abstract

(57) [Problem] To prevent deterioration of frequency characteristics of a piezoelectric thin film vibrator. SOLUTION: An insulating member, a lower electrode portion, a piezoelectric thin film member, and an upper electrode portion are sequentially laminated on a diaphragm of a substrate to form a vibration element, and lead electrode portions 7, 8 are respectively provided on the lower electrode portion and the upper electrode portion. Are connected to each other, and
Are connected to separate electrode pads 10, respectively. The extension conductor 16 extending from the lead-out electrode portion 7 (8) into the electrode pad formation region D, and the extension conductor 16 which is scattered and arranged with a gap therebetween in the electrode pad formation region D excluding the portion where the extension conductor 16 is formed. The electrode pad 10 is constituted by the plurality of minute conductor lands 17. When a current of any frequency is applied, most of the current flows from the electrode pad 10 through the main path passing through the extraction electrode portion and the vibrating element, and hardly flows to other portions. Deterioration can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric thin film vibrator such as a resonator or a filter using a piezoelectric member.

[0002]

2. Description of the Related Art FIG. 11 is a plan view showing an example of a piezoelectric thin film vibrator used as a resonator, a filter or the like, and FIG. 12 is a cross-sectional view taken along a line AA shown in FIG. I have. As shown in FIGS. 11 and 12, this piezoelectric thin-film vibrator has a diaphragm 2 formed on a substrate (eg, a silicon substrate) 1 and an insulating member (eg, a silicon oxide film) 3 on the substrate 1. The lower electrode part 4, the piezoelectric thin film member (for example, a ZnO film) 5 and the upper electrode part 6 are sequentially laminated to form a vibration element P, and the lower extraction electrode part 7 from the lower electrode part 4 of the vibration element P An upper extraction electrode portion 8 is formed by being drawn out from the upper electrode portion 6, respectively, and the lower extraction electrode portion 7 and the upper extraction electrode portion 8 are formed.
Has a configuration in which the electrode pads 10a and 10b are electrically connected.

FIG. 1 shows the above-mentioned electrode pads 10a and 10b.
As shown by the dotted line 1, a connection member 11 such as a solder bump or a wire bond is formed by joining, and the piezoelectric thin film vibrator can be electrically connected to an external circuit or the like using the connection member 11.

[0004]

By the way, one side of the electrode pads 10a and 10b, for example, the electrode pad 10
The current (voltage signal) externally applied to the electrode pad 10b on the other side passes through the lower extraction electrode section 7, the lower electrode section 4, the piezoelectric thin film member 5, the upper electrode section 6, and the upper extraction electrode section 8 in this order. 7 and a sub-path to the electrode pad 10b on the other side through the insulating member 3, the substrate 1, the insulating member 3, and the piezoelectric thin film member 5 as shown in FIG. Taken out.

FIG. 8 shows an equivalent circuit of a conduction path of the current (signal). As shown in FIG. 8, this equivalent circuit includes an equivalent circuit 12 corresponding to the main path constituted by a series connection of a capacitor C1, an inductor L, a resistor R1, and a capacitor C0, and a capacitor Cza. , Resistor Rs, capacitor Czb, and capacitor C
p and an equivalent circuit 13 corresponding to the above-described sub-path constituted by a series connection with p.

The impedance Zp of the equivalent circuit 12 corresponding to the main path varies greatly depending on the frequency of the current (voltage).
When a current having a resonance frequency Fk of the vibrating element P composed of a laminate of the lower electrode portion 4, the piezoelectric thin film member 5, and the upper electrode portion 6 is flowing, the impedance Zp is very small at several Ω. Thus, when a current having the anti-resonance frequency Fh of the vibrating element P is flowing, the impedance Zp greatly increases to several tens kΩ or more.

Further, an equivalent circuit 1 corresponding to the sub-path
The capacitance Cza of the capacitor Cza constituting the electrode member 3 is determined by the electrode area Sa of the electrode pad 10a and the dielectric constant ε of the insulating member 3.
And the film thickness d of the insulating member 3, the resistor Rs is determined by the resistivity r of the substrate 1, and the capacitor Cs
The capacitance Czb of the electrode pad 10b is determined by the electrode area Sb of the electrode pad 10b, the dielectric constant ε of the insulating member 3 and the thickness d of the insulating member 3, and the capacitance Cp of the capacitor Cp is determined by the electrode pad 10b.
b, which is determined by the electrode area Sb of b, the dielectric constant ε ′ of the piezoelectric thin film member 5 and the film thickness d ′ of the piezoelectric thin film member 5, the impedance Zs of the equivalent circuit 13 is determined, for example, to about several tens kΩ. .

Since the main path and the sub path of the current have the impedances Zp and Zs as described above, when the current having the resonance frequency Fk is supplied, the impedance Zp of the main path is changed to the impedance Zs of the sub path as described above. By this, much of the current flows through the main path and hardly flows through the sub-path, and the frequency characteristic of the vibrating element P is improved as shown by the solid curve A in FIG. .

On the other hand, when a current having the anti-resonance frequency Fh is supplied, the impedance Zs of the sub path becomes very large as described above. For example, the impedance Zp of the main path is substantially equal to the impedance Zs of the sub path. It will be of the order of magnitude. In such a case, the current is split into the main path and the sub path in approximately two minutes and energized. Due to this, the frequency characteristic of the vibrating element P changes when current is applied at the anti-resonance frequency Fh. As shown by the dotted curve B in FIG.

Therefore, the impedance Z of the sub-path is
Various methods have been proposed for increasing s to improve the frequency characteristics of the anti-resonance frequency Fh when current is supplied. For example, in Japanese Patent Publication No. 1-61253, as shown in FIG. 10, an insulating member 14 is interposed between the piezoelectric thin film member 5 and the electrode pad 10b to reduce the capacitance of the sub-path to reduce the impedance Zs. A method has been proposed in which the frequency characteristics of the anti-resonance frequency Fh at the time of current supply are improved by increasing the frequency.

However, according to the proposed method, the insulating member 14 must be formed as described above, so that the number of manufacturing steps of the insulating member 14 increases, and the manufacturing process of the piezoelectric thin film vibrator becomes complicated, and the manufacturing cost is reduced. The problem of increase arises.

In addition to the method described in Japanese Patent Publication No. 1-61253, Japanese Patent Laid-Open Publication No.
In Japanese Unexamined Patent Publication (Kokai) No. 60-177711, the impedance Zs of the sub-path is increased to increase the anti-resonance frequency Fh.
There have been proposed techniques for improving the frequency characteristics at the time of current flow, but these techniques are not satisfactory because of problems such as complicating the process and deteriorating the yield.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to prevent the deterioration of frequency characteristics when a current having an anti-resonance frequency is applied, and to complicate the manufacturing process. It is an object of the present invention to provide a piezoelectric thin-film vibrator capable of preventing the formation of the piezoelectric thin film and deterioration of the yield.

[0014]

Means for Solving the Problems In order to achieve the above object, the present invention has the following structure to solve the above problems. That is, in the first invention, a laminate in which an insulating member, a lower electrode portion, a piezoelectric thin film member, and an upper electrode portion are sequentially laminated is formed on a substrate by holding the insulating member toward the substrate side, and forming the lower electrode on the substrate. In the piezoelectric thin-film vibrator, a lower extraction electrode portion is electrically connected to the upper electrode portion, an upper extraction electrode portion is electrically connected to the upper electrode portion, and the lower extraction electrode portion and the upper extraction electrode portion are electrically connected to the electrode pad. At least one of the electrode pads has a configuration in which a plurality of minute conductor lands are interspersed with each other via a gap in the electrode pad formation region to solve the above problem.

According to a second aspect of the present invention, a laminated body in which an insulating member, a lower electrode portion, a piezoelectric thin film member, and an upper electrode portion are sequentially laminated is formed on a substrate by holding the insulating member toward the substrate.
A lower extraction electrode portion is electrically connected to the lower electrode portion, and an upper extraction electrode portion is electrically connected to the upper electrode portion.
In the piezoelectric thin-film vibrator in which the lower extraction electrode portion and the upper extraction electrode portion are each electrically connected to an electrode pad, at least one of the electrode pads has a plurality of minute openings in a conductor portion thereof with a gap therebetween. It is a means for solving the above-mentioned problem with a configuration formed in a dotted manner.

According to a third aspect of the present invention, a laminate in which an insulating member, a lower electrode portion, a piezoelectric thin film member, and an upper electrode portion are sequentially laminated is formed on a substrate by holding the insulating member toward the substrate.
A lower extraction electrode portion is electrically connected to the lower electrode portion, and an upper extraction electrode portion is electrically connected to the upper electrode portion.
In the piezoelectric thin-film vibrator in which the lower extraction electrode portion and the upper extraction electrode portion are each electrically connected to an electrode pad, at least one of the electrode pads is formed to extend from the extraction electrode portion into an electrode pad formation region. The present invention is a means for solving the above-mentioned problem with a configuration having an extended conductor portion and at least one branch conductor portion branched from the conductor portion.

According to a fourth aspect of the present invention, a laminate in which an insulating member, a lower electrode portion, a piezoelectric thin film member, and an upper electrode portion are sequentially formed is formed on a substrate by holding the insulating member toward the substrate.
A lower extraction electrode portion is electrically connected to the lower electrode portion, and an upper extraction electrode portion is electrically connected to the upper electrode portion.
In the piezoelectric thin-film vibrator in which the lower extraction electrode portion and the upper extraction electrode portion are each electrically connected to an electrode pad, at least one of the electrode pads is formed to extend from the extraction electrode portion into an electrode pad formation region. The extension conductor, one or more branch conductors branched from the conductor, and the electrode pad formation region other than the extension conductor and the branch conductor formation are interspersed with each other with a gap therebetween. With a configuration formed with a plurality of small conductor lands, the above-mentioned problem is solved.

According to a fifth aspect of the present invention, a laminate in which an insulating member, a lower electrode portion, a piezoelectric thin film member, and an upper electrode portion are sequentially laminated is formed on a substrate by holding the insulating member toward the substrate.
A lower extraction electrode portion is electrically connected to the lower electrode portion, and an upper extraction electrode portion is electrically connected to the upper electrode portion.
In the piezoelectric thin-film vibrator in which the lower extraction electrode portion and the upper extraction electrode portion are each electrically connected to an electrode pad, at least one of the electrode pads is formed to extend from the extraction electrode portion into an electrode pad formation region. The above object is achieved by a configuration in which an extended conductor portion and a plurality of minute conductor lands are arranged in an electrode pad forming region excluding a portion where the extended conductor portion is formed and are interspersed with a gap therebetween. It is a means to solve.

In the invention having the above structure, the electrode pad is
A land structure, a net-like structure, a structure consisting of an extension conductor and a branch conductor, or a structure consisting of an extension conductor, a branch conductor, and a minute conductor land, or a structure consisting of an extension conductor and a minute conductor land Formed into a structure.

Compared with a conventional electrode pad in which a conductor is formed over the entire area of the electrode pad formation region, the characteristic electrode pad of the present invention can significantly reduce the electrode area. As a result, even when current flows at the anti-resonance frequency of the piezoelectric thin-film vibrator, the impedance of one electrode is larger than the impedance of the main current path from one electrode pad to the other electrode pad through the laminate. The impedance of the sub-current path from the pad to the electrode pad on the other side through the substrate can be increased, and most of the current flows through the main path. Deterioration of frequency characteristics is avoided.

Further, the piezoelectric thin-film vibrator can be manufactured by the same manufacturing process as that of the related art simply by changing the conductive pattern of the electrode pad to a conductive pattern characteristic of the present invention.
The number of manufacturing steps is prevented from increasing compared to the conventional manufacturing steps, so that the manufacturing steps are not complicated, and the yield is also prevented from deteriorating.

[0022]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a configuration of a characteristic electrode pad in the first embodiment. The feature of the first embodiment that is different from the piezoelectric thin film vibrator shown in FIG. 11 is that the electrode pad 10 has an extended conductor portion 16 and a plurality of minute conductor lands 17 as shown in FIG. The other configuration is the same as the configuration of the piezoelectric thin-film vibrator shown in FIG. 11 described above, and the overlapping description of the common parts will be omitted.

As described above, in order to prevent the frequency characteristic of the vibrating element P from deteriorating when the current having the anti-resonance frequency Fh is supplied, the main path of the current when the current having the anti-resonance frequency Fh is supplied ( It is conceivable to configure the piezoelectric thin-film vibrator such that the impedance Zs of the sub-path (equivalent circuit 13) is larger than the impedance Zp of the equivalent circuit 12) shown in FIG.

In order to increase the impedance Zs of the sub-path, it is conceivable to reduce the capacitances of the capacitors Cza, Czb and Cp of the sub-path. In order to reduce the above-mentioned respective capacitances, it is considered that the dielectric constant ε of the insulating member 3 is reduced, the thickness d of the insulating member 3 is reduced, or the electrode area S of the electrode pad 10 is reduced. Can be However, since the dielectric constant ε and the thickness d of the insulating member 3 are almost determined in order to obtain a predetermined frequency characteristic predetermined for the vibration element P, the impedance Zs of the sub path is increased as described above. Therefore, it cannot be freely set.

Therefore, in this embodiment, the capacitance of the capacitor Cza, the capacitor Czb, and the capacitor Cp is reduced by reducing the electrode area S of the electrode pad 10, and the impedance Zs of the sub-path is increased. And a configuration capable of preventing deterioration of the frequency characteristics of the vibrating element P when current is supplied at the anti-resonance frequency Fh.

The electrode pad 10 (1) shown in this embodiment
0a, 10b) have the extended conductor portion 16 and the plurality of minute conductor lands 17 as described above, and the extended conductor portion 16 is formed in the electrode pad formation region D surrounded by a predetermined dotted line in FIG. A plurality of minute conductor lands 17 are formed in the electrode pad formation region D except for the portion where the extension conductor portion 16 is formed, with a point therebetween with a gap therebetween. Is formed.

In this embodiment, the electrode pad formation region D is shown in FIG. 1 in consideration of the displacement of the connection position of the connection member 11 in the assembly step of forming the connection member 11 on the electrode pad 10. A region having an area larger than the area M of the joint between the electrode pad 10 and the connection member 11 surrounded by the chain line is set. Also, the connection member 11
Considering the formation position shift and the poor connection between the connection member 11 and the electrode pad 10, the extension conductor 16 and the minute conductor land 1
7, the distance between the extended conductor 16 and the minute conductor land 17, and the distance between the minute conductor lands 17 are set.

A more specific example will be described below. The substrate 1 is a silicon substrate having a plane orientation of {100}, the insulating member 3 is made of a silicon oxide film, and the piezoelectric thin film member 5 is made of ZnO.
The diameter of the solder bump, which is a connection member 11 formed by bonding to the electrode pad 10, is approximately 100 μm.
In this case, the electrode pad formation region D is set to have an area approximately twice as large as the area M of the joint portion between the electrode pad 10 and the connection member 11. For example, as shown by a dotted line in FIG. A square area having a length of about 125 μm is set.

The extension conductor 16 extending from the extraction electrode 8 (7) into the electrode pad formation region D passes through the center of the electrode pad formation region D and has a width of about 25 μm.
The electrode pad formation region D is formed in a form having a length of about 125 μm and excluding a portion where the extension conductor portion 16 is formed.
Inside, 20 square minute conductor lands 17 each having a side length of about 15 μm are interspersed and formed with a gap therebetween to form the electrode pad 10. In this electrode pad 10, the above-mentioned solder bump having a diameter of about 100 μm is connected to the extended conductor portions 16 and 1.
It will be joined to 0 to 12 minute conductor lands 17.

According to this embodiment, the extension conductor 16
11 and a plurality of minute conductor lands 17 are formed with a gap therebetween to form the electrode pad 10.
As shown in FIG. 2, the conductor portion of the electrode pad 10 can be reduced as compared with the case where the conductor portion is formed over the entire region of the electrode pad formation region D.
Electrode area S can be reduced.

By reducing the electrode area S of the electrode pad 10, the capacitances of the capacitors Cza, Czb and Cp in the current sub-path can be reduced.

For example, in the example described in the above specific example, the capacitance of the series connection of the capacitor Cza, the resistor Rs, the capacitor Czb, and the capacitor Cp in the sub path is the same as that of the electrode pad 10 shown in FIG. About 40% or more.

As described above, the sub path capacitor Cza
, The capacitance of the capacitor Czb and the capacitance of the capacitor Cp can be reduced, and the impedance Zs of the sub-path can be greatly increased.
Since the impedance Zs of the sub-path can be made larger than p, and most of the current flows through the main path and hardly flows through the sub-path even when current flows at an anti-resonance frequency, Deterioration of the frequency characteristics can be prevented, and good frequency characteristics as shown by the solid line in FIG. 9 can be obtained.

Further, the piezoelectric thin-film vibrator can be manufactured by the same manufacturing process as the conventional one just by changing the conductive pattern of the electrode pad 10 to the conductive pattern as shown in FIG. Thus, the number of steps is not increased as compared with the manufacturing steps of the above, and the complication of the manufacturing steps can be prevented.

Further, even if the electrode area S of the electrode pad 10 is reduced as described above, a plurality of minute conductor lands 17 are formed in the electrode pad formation region D having an area larger than the area M required for bonding with the connection member 11. Are scattered, the connecting member 11 can be almost certainly joined to the electrode pad 10 even if the joining position of the connecting member 11 is shifted, and the joining failure between the electrode pad 10 and the connecting member 11 is prevented. Can be. In addition, since the extension conductor 16 extending from the extraction electrode 7 (8) is provided, even if the joining position of the connection member 11 is shifted, the connection member 11 is connected to the extraction electrode 7 (8).
Conductive connection can be almost surely made to (8).

Further, by forming the electrode pad 10 from the extended conductor portion 16 and the plurality of minute conductor lands 17 as described above, the effect of increasing the bonding strength between the electrode pad 10 and the connecting member 11 can be obtained. be able to. That is, as shown in FIG. 2, the connection member 11 is formed on the upper surface J of the extension conductor 16 or the minute conductor land 17.
Insulation members exposed to the side surfaces H of the extension conductors 16 and the minute conductor lands 17, the gaps between the extension conductors 16 and the minute conductor lands 17, and the gaps between the extension conductors 16, instead of the joints. 3 and the upper surface T of the piezoelectric thin film member 5, the bonding area between the electrode pad 10 and the connecting member 11 is significantly larger than the bonding area between the electrode pad 10 and the connecting member 11 in the form shown in FIG. In the electrode pad 10 according to the first embodiment, the bonding strength of the connection member 11 can be significantly increased as compared with the conventional electrode pad 10 shown in FIG.

Hereinafter, a second embodiment will be described. The feature of this embodiment is that the electrode pad 10 is formed in a net-like structure as shown in FIG. The other configuration is the same as that of the first embodiment, and the description of the common parts will not be repeated.

As shown in FIG. 3, in the electrode pad 10 shown in this embodiment, a plurality of minute openings 20 are formed in a conductor portion 18 formed in an electrode pad formation region D with a gap therebetween. The conductor portion 18 has a net-like structure.

In this embodiment, the conductor portion 18 is connected to the connecting member 11 in the process of assembling the connecting member 11.
Is formed in the electrode pad formation region D which is set in the same manner as in the first embodiment in consideration of the displacement of the bonding position, that is, is larger than the area M required for bonding the electrode pad 10 and the connection member 11. It is formed in a region having an area. The shape and opening area of each minute opening 20 and the interval between each minute opening 20 are set in consideration of the displacement of the joining position of the connecting member 11 and the poor conduction between the connecting member 11 and the conductor portion 18. .

According to the second embodiment, since the conductor portion 18 of the electrode pad 10 is formed as a mesh-shaped electrode pad, the conductor is formed over the entire area of the electrode pad formation region D as in the conventional case. As compared with the case where the minute opening 20 is formed, the electrode area S of the electrode pad 10 is small and the electrode area S can be largely reduced by the amount corresponding to the formation of the minute opening 20. The capacitance of each of the capacitors Cza, Czb, and Cp in the sub-path can be reduced, thereby significantly increasing the impedance Zs in the sub-path. For this reason, even when the current having the anti-resonance frequency Fh is supplied, most of the current is supplied through the main path passing through the vibrating element P, and the deterioration of the frequency characteristics of the vibrating element P can be avoided.

Further, as described above, the conductor portion 18 is formed in the electrode pad formation region D having a larger area than the area M required for joining with the connection member 11, so that the first embodiment differs from the first embodiment. Similarly, poor joining with the connection member 11 can be prevented. Further, by providing a plurality of minute openings 20 in the conductor portion 18 of the electrode pad 10, the bonding area between the electrode pad 10 and the connecting member 11 increases, and the bonding strength between the electrode pad 10 and the connecting member 11 is enhanced. Can be.

The third embodiment will be described below. The feature of the third embodiment is that, as shown in FIG. 4, the electrode pad 10 is constituted by an extended conductor 16, a plurality of minute conductor lands 17, and a branch conductor 21. . The other configuration is the same as that of each of the above embodiments, and the overlapping description of the common parts will be omitted.

As shown in FIG. 4, the electrode pad 10 according to this embodiment is provided with an extended conductor portion 16 extending from the extraction electrode 7 (8) into the electrode pad formation region D. A branch conductor 21 is formed to branch off from the extension conductor 16 in a direction orthogonal to the direction in which the extension conductor 16 extends. Further, in the electrode pad formation region D excluding the portions where the extension conductor portion 16 and the branch conductor portion 21 are formed, a plurality of minute conductor lands 17 are scattered and formed with a gap therebetween.

Also in the third embodiment, the electrode area S of the electrode pad 10 can be reduced in the same manner as in each of the above embodiments, and as a result, the impedance Zs of the current sub-path increases. The anti-resonance frequency Fh
It is possible to prevent the frequency characteristics of the vibrating element P from deteriorating when the current is supplied. In addition, it is possible to prevent the bonding failure between the electrode pad 10 and the connecting member 11, and further to obtain the effect that the bonding strength between the electrode pad 10 and the connecting member 11 can be enhanced.

It should be noted that the present invention is not limited to the above embodiments, and various embodiments can be adopted. For example, in each of the above embodiments, both the electrode pad 10a connected to the lower extraction electrode section 7 and the electrode pad 10b connected to the upper extraction electrode section 8 are formed in the forms shown in the above embodiments. However, these electrode pads 1
Only one side of Oa and 10b may be formed in the electrode pad of the form shown in each of the above embodiments, and the other side may be formed of the electrode pad 10 in a form as shown in FIG.

For example, when only the electrode pad 10a is formed in the form shown in each of the above embodiments, the capacitor C of the current sub-path is smaller than that of the conventional example shown in FIG.
Since the capacitance of za decreases in accordance with the decrease in the electrode area S of the electrode pad 10a, the same effect as in the above embodiments can be obtained in this case as well. When only the electrode pad 10b is formed in the form shown in each of the above embodiments, the respective capacitances of the capacitor Czb and the capacitor Cp of the current sub-path are reduced by the decrease of the electrode area S of the electrode pad 10b. In this case, the same effects as in the above embodiments can be obtained.

One of the electrode pads 10a and 10b is formed in the form shown in the first embodiment, and the other electrode pad 10 is formed in the form shown in the second embodiment. That is, the form of the electrode pad 10a and the form of the electrode pad 10b do not have to be equal.

Further, in each of the above embodiments, the electrode pad formation region D is square, but this electrode pad formation region D may be circular as shown in FIG. Or may be set to a polygon with five or more corners,
The shape and area of the electrode pad formation region D are determined by the connection member 1
1 may be appropriately set in consideration of the prevention of bonding failure of No. 1. Since the shape of the conductor portion 18 of the electrode pad 10 shown in the second embodiment is based on the shape of the electrode pad formation region D, the shape and size of the conductor portion 18 may be poor connection of the connection member 11. It is appropriately set in consideration of prevention and the like.

Further, in each of the above embodiments, the substrate 1 is constituted by a silicon substrate having a plane orientation of {100}. However, the substrate 1 may be formed of, for example, a silicon substrate having a plane orientation of {110} or a plane orientation of {111}. Or a substrate made of a material other than silicon, such as GaAs, metal, ceramics, or glass.

Further, in each of the above embodiments, the insulating member 3 is made of a silicon oxide film. However, the insulating member 3 may be made of an insulating material other than the silicon oxide film. Further, in each of the above embodiments, the piezoelectric thin film member 5 is made of ZnO.
The piezoelectric thin film member 5 may be made of a piezoelectric material other than ZnO such as (lead zirconate titanate).

Further, in the third embodiment, two branch conductors 21 are formed by branching from the extension conductor 16, but only one branch conductor 21 may be formed.
As shown in FIGS. 5A and 5B, three or more lines may be formed.

Further, in the third embodiment, FIG.
As shown in FIG. 5, the electrode pad 10 is provided with a plurality of minute conductor lands 17 in addition to the extension conductor 16 and the branch conductor 21, but as shown in FIGS. 5 (a) and 5 (b), The electrode pad 10 may be configured by the extension conductor 16 and the branch conductor 21 without providing the minute conductor land 17.

In the third embodiment, the branch conductor 21 is formed in a direction perpendicular to the direction in which the extension conductor 16 extends, but as shown in FIG. The conductor portion 21 may be branched from the extension conductor portion 16 in any direction.

Further, in each of the first and third embodiments, the shape of the minute conductor land 17 is a square shape.
As shown in FIG. 5C, the shape may be a circle, a triangle, a polygon having five or more angles, or the like. Further, the shape of each minute conductor land 17 may not be all equal, for example, the square minute conductor land 17 and the circular minute conductor land 17 are mixed.

Further, in each of the first and third embodiments, the plurality of minute conductor lands 17 have substantially the same area. However, as shown in FIG. The areas of the minute conductor lands 17 need not all be equal.

Further, in the above-described second embodiment, the shape of the minute opening 20 is a square, but may be a circle, a triangle, a polygon having five or more corners, or the like. In addition, the shapes of the minute openings 20 do not have to be equal, for example, the square minute openings 20 and the circular minute openings 20 are mixed. Further, the opening areas of the respective minute openings 20 do not need to be all equal.

Further, in each of the above embodiments, the insulating member 3 is provided above the portion of the substrate 1 on which the diaphragm 2 is formed.
The diaphragm type piezoelectric thin film vibrator in which the vibrating element P is formed by sequentially laminating the lower electrode portion 4, the piezoelectric thin film member 5, and the upper electrode portion 6 has been described.
As shown in FIG. 7, the vibration element P can also be applied to a bridge type piezoelectric thin film vibrator which is formed by holding the insulating member 3 toward the substrate 1 and holding the substrate 1 through the gap 22 with the substrate 1. In this case, the same effects as those of the above embodiments can be obtained.

[0059]

The electrode pad is constituted by an electrode pad having a land structure, the electrode pad is constituted by an electrode pad having a net-like conductor portion, or the electrode pad is constituted by an extended conductor portion and at least one branch conductor portion. And an electrode pad composed of an extended conductor, one or more branch conductors, and a plurality of minute conductor lands, and an electrode pad composed of an extension conductor and a plurality of minute conductor lands. Can significantly reduce the electrode area of the electrode pad as compared with the electrode pad formed by forming a conductor over the entire area of the electrode pad formation region.

As described above, since the electrode area of the electrode pad can be reduced, the impedance in the sub-path of the current from one electrode pad to the other electrode pad through the substrate can be significantly increased.
When current flows at the anti-resonance frequency of the piezoelectric thin-film vibrator, the current flowing from one electrode pad to the other electrode pad through the laminate of the insulating member, the lower electrode portion, the piezoelectric thin-film member, and the upper electrode portion is reduced. The impedance of the sub-path of the current can be made larger than the impedance of the main path.

From this, most of the current does not flow through the main path to the sub-path irrespective of the frequency of the current flow. Deterioration of characteristics can be prevented.

An electrode pad formation region is set in consideration of a displacement of a connection member such as a solder bump or a wire bond formed on the electrode pad. Since the conductors such as the mesh-shaped conductor, the extended conductor portion, and the branch conductor portion are formed, the connection member can be almost reliably joined to the conductor, and the problem of poor conduction between the connection member and the electrode pad can be prevented. it can.

Furthermore, the characteristic bonding area of the electrode pad and the connecting member in the present invention can be greatly increased as compared with the conventional bonding area of the electrode pad and the connecting member. Can be.

Further, the piezoelectric thin-film vibrator of the present invention can be manufactured in the same manufacturing process as the conventional one only by changing the formation pattern of the electrode pads, so that the manufacturing process of the piezoelectric thin-film vibrator is not complicated. It is also possible to avoid a decrease in yield.

[Brief description of the drawings]

FIG. 1 is a model diagram showing a characteristic form of an electrode pad in the first embodiment.

FIG. 2 is an explanatory view showing the effect of improving the bonding strength between the electrode pad of the embodiment shown in FIG. 1 and a connecting member.

FIG. 3 is a model diagram showing a characteristic form of an electrode pad in the second embodiment.

FIG. 4 is a model diagram showing a characteristic form of an electrode pad in a third embodiment.

FIG. 5 is an explanatory diagram showing another embodiment.

FIG. 6 is an explanatory view showing still another embodiment.

FIG. 7 is a model diagram showing an example of a current flow path in a piezoelectric thin-film vibrator.

FIG. 8 is a circuit diagram showing an equivalent circuit of a current flow path in the piezoelectric thin-film vibrator.

FIG. 9 is a graph showing an example of a frequency characteristic of a piezoelectric thin film vibrator.

FIG. 10 is an explanatory diagram showing a proposal example.

FIG. 11 is a model diagram showing an example of a conventional piezoelectric thin film vibrator.

FIG. 12 is a sectional view showing a section taken along the line AA shown in FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 3 Insulating member 4 Lower electrode part 5 Piezoelectric thin film member 6 Upper electrode part 7 Lower extraction electrode part 8 Upper extraction electrode part 10 Electrode pad 16 Extension conductor part 17 Micro conductor land 18 Conductor part 20 Micro opening 21 Branch conductor part

Claims (5)

[Claims] A laminated body in which an insulating member, a lower electrode portion, a piezoelectric thin film member, and an upper electrode portion are sequentially laminated is formed on a substrate by holding the insulating member toward the substrate, and the lower electrode portion has In a piezoelectric thin-film vibrator in which a lower extraction electrode portion is electrically connected to an upper extraction electrode portion on the upper electrode portion, and the lower extraction electrode portion and the upper extraction electrode portion are electrically connected to an electrode pad, respectively. A piezoelectric thin-film vibrator characterized in that at least one of the electrode pads has a plurality of minute conductor lands interspersed with each other with a gap in the electrode pad formation region. 2. A laminated body in which an insulating member, a lower electrode portion, a piezoelectric thin film member, and an upper electrode portion are sequentially laminated and formed on a substrate while holding the insulating member toward the substrate side. In a piezoelectric thin-film vibrator in which a lower extraction electrode portion is electrically connected to an upper extraction electrode portion on the upper electrode portion, and the lower extraction electrode portion and the upper extraction electrode portion are electrically connected to an electrode pad, respectively. A piezoelectric thin-film vibrator characterized in that at least one of the electrode pads has a plurality of minute openings formed in a conductor portion thereof interspersed with a gap therebetween. 3. A laminated body in which an insulating member, a lower electrode portion, a piezoelectric thin film member, and an upper electrode portion are sequentially laminated is formed on a substrate by holding the insulating member toward the substrate side. In a piezoelectric thin-film vibrator in which a lower extraction electrode portion is electrically connected to an upper extraction electrode portion on the upper electrode portion, and the lower extraction electrode portion and the upper extraction electrode portion are electrically connected to an electrode pad, respectively. At least one of the electrode pads is configured to have an extended conductor portion extending from the extraction electrode portion into the electrode pad formation region and one or more branch conductor portions branched from the conductor portion. A piezoelectric thin-film vibrator. 4. A laminate in which an insulating member, a lower electrode portion, a piezoelectric thin film member, and an upper electrode portion are sequentially laminated is formed on a substrate by holding the insulating member toward the substrate, and the lower electrode portion has In a piezoelectric thin-film vibrator in which a lower extraction electrode portion is electrically connected to an upper extraction electrode portion on the upper electrode portion, and the lower extraction electrode portion and the upper extraction electrode portion are electrically connected to an electrode pad, respectively. At least one of the electrode pads includes an extended conductor portion extending from the lead electrode portion into the electrode pad formation region, one or more branch conductor portions branched from the conductor portion, and a branch portion extending from the extension conductor portion. A piezoelectric thin film comprising a plurality of minute conductor lands interspersed with a gap therebetween in an electrode pad formation region excluding a conductor formation portion. Vibrator. 5. A laminate in which an insulating member, a lower electrode portion, a piezoelectric thin film member, and an upper electrode portion are sequentially laminated is formed on a substrate by holding the insulating member toward the substrate side, and the lower electrode portion has In a piezoelectric thin-film vibrator in which a lower extraction electrode portion is electrically connected to an upper extraction electrode portion on the upper electrode portion, and the lower extraction electrode portion and the upper extraction electrode portion are electrically connected to an electrode pad, respectively. At least one of the electrode pads is interspersed with a gap between the extension conductor portion extending from the extraction electrode portion into the electrode pad formation region and the electrode pad formation region excluding the portion where the extension conductor portion is formed. A piezoelectric thin film vibrator comprising: a plurality of minute conductor lands to be arranged.