JP7167657B2 - Piezoelectric device manufacturing method - Google Patents

Description

The present invention relates to a piezoelectric device manufacturing method.

2. Description of the Related Art Piezoelectric devices, such as ultrasonic devices, are conventionally known that include a plurality of piezoelectric elements each having a first electrode, a piezoelectric layer, and a second electrode laminated in order on a diaphragm (see, for example, Patent Document 1).
In the ultrasonic device disclosed in Patent Literature 1, a common bypass wiring (wiring portion) is electrically connected to each of the plurality of grouped piezoelectric elements. The bypass wiring is arranged so as to bypass the vibration region in which the piezoelectric elements are arranged on the diaphragm, and is electrically connected to each piezoelectric element via a connection wiring (connection portion). The bypass wiring is formed wide to reduce its own electrical resistance, while the connection wiring is formed narrow so as not to impair the flexibility of the vibration region. That is, the width of the bypass wiring is wider than the width of the connection wiring.

JP 2018-107571 A

When manufacturing the piezoelectric device described in Patent Document 1, it is common to form a piezoelectric layer by a so-called sol-gel method and remove unnecessary portions of the piezoelectric layer (portions outside the piezoelectric element formation region) by an etching method. is.
However, when the piezoelectric layer is formed by the sol-gel method, the thickness of the piezoelectric layer formed thereon becomes uneven due to the difference in width between the bypass wiring and the connection wiring. Specifically, the piezoelectric material solution used in the sol-gel method drips from the convex portion toward the concave portion on the vibrating membrane due to liquid properties. When the width of the convex portion formed by the connection wiring is smaller than the width of the convex portion formed by the bypass wiring, the ratio of dripping from the connection wiring is higher than that from the bypass wiring. greater than the ratio. Therefore, the thickness of the piezoelectric layer formed on the bypass wiring is thicker than the thickness of the piezoelectric layer formed on the connection wiring. Therefore, when etching the piezoelectric layer, if an attempt is made to completely remove the portion formed on the bypass wiring, the portion formed on the connection wiring will be overetched and the connection wiring will be damaged. As a result, cracks or the like are likely to occur in the connection wiring, and the reliability of the piezoelectric device is lowered.

In the piezoelectric device manufacturing method of the present invention, a first vibrating plate is arranged in a first region overlapping with the opening in plan view as seen from the thickness direction of the substrate, of the diaphragm provided so as to overlap with the substrate having the opening. an electrode, a first bypass wiring arranged in a second region of the diaphragm different from the first region and having a first slit, and the first electrode arranged over the first region and the second region and a first electrode forming step of forming a first connection wiring for connecting the first bypass wiring and a piezoelectric layer so as to cover the first electrode, the first bypass wiring and the first connection wiring; and a piezoelectric layer forming step of forming a piezoelectric body by removing a part of the piezoelectric layer so that a portion of the piezoelectric layer that overlaps the first electrode in the plan view remains. and a second electrode forming step of forming a second electrode on the piezoelectric body.

In the piezoelectric device manufacturing method of the present invention, it is preferable that the first slit has a shape extending along the wiring direction of the first bypass wiring.

In the piezoelectric device manufacturing method of the present invention, the length from each end of the first bypass wiring to the first slit in the width direction of the first bypass wiring is the difference from the width of the first connection wiring. is preferably within a predetermined range.

In the piezoelectric device manufacturing method of the present invention, it is preferable that the first bypass wiring formed in the first electrode forming step has a plurality of first slits intermittently arranged along the wiring direction.

In the piezoelectric device manufacturing method of the present invention, the length of the portion of the first bypass wiring that is sandwiched between the two first slits in the wiring direction is such that the difference from the width of the first connection wiring is within a predetermined range. Preferably.

In the piezoelectric device manufacturing method of the present invention, the step of forming the first electrode further includes forming a second bypass wiring disposed in the second region of the diaphragm and having a second slit, and the step of forming the second electrode. preferably further forms a second connection wiring arranged over the first region and the second region and connecting the second electrode and the second bypass wiring.

In the piezoelectric device manufacturing method of the present invention, it is preferable that the second slit has a shape extending along the wiring direction of the second bypass wiring.

In the piezoelectric device manufacturing method of the present invention, the length from each end of the second bypass wiring to the second slit in the width direction of the second bypass wiring is different from the width of the first connection wiring. is preferably within a predetermined range.

In the piezoelectric device manufacturing method of the present invention, it is preferable that the second bypass wiring formed in the first electrode forming step has a plurality of second slits intermittently arranged along the wiring direction.

In the piezoelectric device manufacturing method of the present invention, the length of the portion of the second bypass wiring sandwiched between the two second slits in the wiring direction is such that the difference from the width of the first connection wiring is within a predetermined range. Preferably.

1 is a plan view showing a schematic configuration of a piezoelectric device according to a first embodiment; FIG. FIG. 2 is an enlarged view showing a part of FIG. 1; FIG. 3 is a cross-sectional view of the piezoelectric device corresponding to line AA of FIG. 2; FIG. 3 is a cross-sectional view of the piezoelectric device corresponding to line BB of FIG. 2; 4 is a flowchart for explaining a method for manufacturing the piezoelectric device of the first embodiment; 4A and 4B are schematic diagrams for explaining manufacturing stages of the piezoelectric device of the first embodiment; FIG. 4A and 4B are schematic diagrams for explaining manufacturing stages of the piezoelectric device of the first embodiment; FIG. FIG. 2 is a block diagram showing a schematic configuration of an ultrasonic sensor according to a second embodiment; FIG. The figure which shows the modification of the piezoelectric device which concerns on 1st Embodiment. The figure which shows the modification of the piezoelectric device which concerns on 1st Embodiment.

[First embodiment]
A piezoelectric device 10 according to one embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG.
FIG. 1 is a plan view of a portion of the piezoelectric device 10 viewed from the thickness direction, and FIG. 2 is an enlarged view showing a portion of FIG. 3 is a cross-sectional view of the piezoelectric device 10 corresponding to line AA of FIG. 2, and FIG. 4 is a cross-sectional view of the piezoelectric device 10 corresponding to line BB of FIG.

(Overall configuration of piezoelectric device)
The piezoelectric device 10 includes a substrate 1, a diaphragm 2 provided on one side of the substrate 1, a plurality of piezoelectric elements 3 provided on the diaphragm 2, and a diaphragm covering the piezoelectric elements 3. a sealing plate 4 connected to the 2. 1 and 2, illustration of the sealing plate 4 is omitted.
In the following description, the thickness direction of the substrate 1 is defined as the Z direction, and two axial directions orthogonal to the Z direction are defined as the Y direction and the X direction, respectively.

The substrate 1 is a semiconductor substrate such as silicon. The substrate 1 is provided with a plurality of openings 11 penetrating the substrate 1 in the Z direction. A plurality of openings 11 are arranged along the X direction, and the length dimension of the openings 11 along the Y direction is set larger than the length dimension of the openings 11 along the X direction. .

A portion of the substrate 1 surrounding the opening 11 is called a wall portion 12 . The walls 12 partition the openings 11 adjacent in the X direction.
The opening 11 of the substrate 1, that is, the space surrounded by the wall 12 is filled with a damping layer 13 made of silicone resin or the like. The damping layer 13 has the function of shortening the time until the vibration of the diaphragm 2 (described later) converges and suppressing the vibration propagation (crosstalk) between the vibration regions Ar (described later).
The filling amount of the damping layer 13 with respect to the opening 11 can be arbitrarily set, and the damping layer 13 does not have to fill the entire opening 11 . Alternatively, the opening 11 may not be filled with the damping layer 13 .

The diaphragm 2 is, for example, a laminate of silicon oxide and zirconium oxide. Diaphragm 2 is provided on one side surface of substrate 1 so as to block opening 11 of substrate 1 . In other words, diaphragm 2 is supported by walls 12 of substrate 1 . The thickness dimension of the diaphragm 2 in the Z direction is sufficiently smaller than the thickness dimension of the substrate 1 .

Hereinafter, the surface of the diaphragm 2 on one side in the Z direction will be referred to as a first surface 2A, and the surface on the other side in the Z direction will be referred to as a second surface 2B. The first surface 2A of the diaphragm 2 is in contact with the substrate 1, and the second surface 2B of the diaphragm 2 is provided with a plurality of piezoelectric elements 3 arranged in an array.

The sealing plate 4 has a plurality of grooves 41 provided to accommodate the plurality of piezoelectric elements 3 on the vibration plate 2, and seals the surrounding space for each of the plurality of piezoelectric elements 3. .
Further, the sealing plate 4 is provided with through holes (not shown) for inserting wires (FPC, etc.) connected to the first electrode terminals 31P and the second electrode terminals 33P, which will be described later.

The sealing plate 4 has a plurality of partition walls 42 projecting from the bottom side of the groove 41 toward the diaphragm 2 . The plurality of partition walls 42 each extend along the X direction and are arranged at predetermined intervals along the Y direction. Each partition wall 42 is connected to the second surface 2B of the diaphragm 2 between the piezoelectric elements 3 adjacent in the Y direction via other members (bypass wiring 51 to be described later, etc.).

Here, the wall portion 12 of the substrate 1 is connected to the first surface 2A side of the diaphragm 2 , and the partition wall 42 of the sealing plate 4 is connected to the second surface 2B side of the diaphragm 2 . As a result, each region of the diaphragm 2, which overlaps with the opening 11 in plan view in the Z direction and is surrounded by the wall 12 and the partition wall 42 in plan view, can vibrate. Vibration region Ar. In other words, in the diaphragm 2, the wall portion 12 is in contact between the vibration regions Ar adjacent in the Y direction, while the partition wall 42 is in contact between the vibration regions Ar adjacent in the X direction.
The vibration area Ar of the diaphragm 2 corresponds to the first area of the invention, and the area of the diaphragm 2 other than the vibration area Ar corresponds to the second area of the invention.

The piezoelectric element 3 has a first electrode 31 , a piezoelectric body 32 and a second electrode 33 , which are laminated in order on the second surface 2B of the vibration area Ar of the diaphragm 2 . The first electrode 31 and the second electrode 33 are composed of, for example, a conductive layer (single layer or multiple layers) such as iridium or titanium, and the piezoelectric body 32 is composed of, for example, PZT (lead zirconate titanate).

The piezoelectric element 3 is provided for each vibration region Ar of the diaphragm 2, and the combination of the vibration region Ar and the piezoelectric element 3 constitutes one ultrasonic transducer Tr. In the piezoelectric device 10 of this embodiment, a plurality of ultrasonic transducers Tr are arranged in a matrix along the Y direction and the X direction.

In the ultrasonic transducer Tr, when a pulse wave voltage of a predetermined frequency is applied between the first electrode 31 and the second electrode 33, the piezoelectric body 32 bends and the vibration region Ar vibrates, thereby generating ultrasonic waves. sent.
Further, when the ultrasonic wave propagated toward the piezoelectric device 10 vibrates the vibration region Ar of the diaphragm 2, a potential difference is generated between the upper and lower portions of the piezoelectric body 32 in the vibration region Ar. Therefore, by detecting the potential difference generated between the first electrode 31 and the second electrode 33, it is possible to detect the received ultrasonic waves.
In addition, in FIG. 1, for the sake of convenience, the number of ultrasonic transducers Tr is reduced from the actual number.

(Wiring configuration)
The piezoelectric device 10 has first wirings 5 connected to the plurality of first electrodes 31 and second wirings 6 connected to the plurality of second electrodes 33 .
The first wiring 5 and the second wiring 6 will be described below. In the following description, the row of piezoelectric elements 3 arranged in the Y direction is called an element group 3A.

The first wiring 5 is provided on the second surface 2B of the diaphragm 2, and includes a first bypass wiring 51 electrically connected to an external drive circuit or the like, and a first electrode 31 of each piezoelectric element 3. and a first connection wiring 52 that connects with the first bypass wiring 51 . In this embodiment, one first wiring 5 is arranged for each two element groups 3A, and in each first wiring 5, a plurality of first connection wirings 52 are arranged for one first bypass wiring 51. is connected.

The first bypass wiring 51 is arranged outside the vibration region Ar on the second surface 2B of the diaphragm 2 and extends along the Y direction or the X direction. Specifically, the first bypass wiring 51 includes a Y-direction bypass wiring 511 formed along the Y direction between the adjacent element groups 3A and a Y-direction bypass wiring 511 formed between the adjacent piezoelectric elements 3 along the X direction. and a plurality of X-direction bypass wirings 512 .
The Y-direction bypass wiring 511 has both ends in the Y direction drawn out to the peripheral edge of the substrate 1, and the first electrode terminals 31P are provided at the both ends.
A plurality of X-direction bypass wirings 512 are arranged with the piezoelectric element 3 interposed therebetween in the Y-direction, and are connected to the Y-direction bypass wirings 511 at portions intersecting the Y-direction bypass wirings 511 .

The first connection wiring 52 connects the first electrode 31 of the piezoelectric element 3 and an X-direction bypass wiring 512 arranged on one side of the piezoelectric element 3 in the Y direction. First connection wirings 52 are connected to the first electrodes 31 of the piezoelectric element 3 on both sides in the Y direction. In this embodiment, the width Wc of the first connection wiring 52 is smaller than the overall width Wb1 of the first bypass wiring 51, and more specifically, is less than half the overall width Wb1 of the first bypass wiring 51. is also formed small (see FIG. 2).

In this embodiment, the first bypass wiring 51 and the first connection wiring 52 are integrally formed, and no clear boundary is provided between them. However, in the first wiring 5, the position where the end in the wiring direction of the first connection wiring 52 is in contact with the end in the width direction of the first bypass wiring 51 is the first connection wiring 51 and the first connection wiring. It can be regarded as a boundary with the wiring 52 .
Here, the wiring direction is a direction parallel to the second surface 2B of the diaphragm 2 and corresponding to the longitudinal direction of the wiring (the wiring extending direction; the direction in which current is conducted). The width direction of the wiring is a direction parallel to the second surface 2B of the diaphragm 2 and perpendicular to the wiring direction. The width of the wiring is the dimension of the wiring in the width direction described above.

The second wiring 6 is provided on the second surface 2B of the diaphragm 2, and includes a second bypass wiring 61 electrically connected to an external drive circuit or the like, and a second electrode 33 of each piezoelectric element 3. and a second connection wiring 62 that connects with the second bypass wiring 61 . In this embodiment, the second wirings 6 are arranged alternately with the first wirings 5 in the Y direction. 62 are connected.

The second bypass wiring 61 is arranged outside the vibration region Ar on the second surface 2B of the diaphragm 2 and extends along the Y direction. Both ends of the bypass wiring 61 in the Y direction are drawn out to the peripheral edge of the substrate 1, and the second electrode terminals 33P are provided at the both ends.

The second connection wiring 62 connects the second electrode 33 of the piezoelectric element 3 and the second bypass wiring 61 arranged on one side of the piezoelectric element 3 in the X direction. A second connection wiring 62 is connected to one side in the X direction of the second electrode 33 of the piezoelectric element 3 .
In this embodiment, the overall width Wb2 of the second bypass wiring 61 is formed equal to the overall width Wb1 of the first bypass wiring 51 . Although the width of the second connection wiring 62 is not particularly limited, it is formed to be approximately the same as the width Wb2 of the second bypass wiring 61 in this embodiment (see FIG. 2).

In this embodiment, in a plan view of the piezoelectric device 10 in the Z direction, the first bypass wiring 51 is arranged on three of the four sides with respect to the piezoelectric element 3, and the second bypass wiring is arranged on the other side. 61 is placed. Thus, the piezoelectric element 3 is surrounded on all four sides by the first bypass wiring 51 and the second bypass wiring 61 .

Here, the first connection wiring 52 is arranged inside and outside the vibration area Ar, so that the first electrode 31 arranged inside the vibration area Ar and the first bypass wiring arranged outside the vibration area Ar are arranged. 51 are connected. Also, unlike the second connection wiring 62 , the first connection wiring 52 is in close contact with the diaphragm 2 integrally with the first electrode 31 . Therefore, if the flexibility of the first connection wiring 52 is reduced due to the large width of the first connection wiring 52, the vibration of the vibration region Ar may be hindered.
Therefore, in the present embodiment, the width Wc of the first connection wiring 52 is set to a sufficiently small value so that the first connection wiring 52 does not impede the vibration of the vibration area Ar.

Further, if the widths Wb1 and Wb2 of the first bypass wiring 51 and the second bypass wiring 61 are small, the electric resistance of each wiring increases, and the characteristics of the piezoelectric element 3 deteriorate.
Therefore, in the present embodiment, by setting the widths Wb1 and Wb2 of the first bypass wiring 51 and the second bypass wiring 61 to sufficiently large values, the electrical resistance of the piezoelectric element 3 is suppressed and the piezoelectric element 3 has sufficient characteristics. It is configured so that it can demonstrate

(slit)
In this embodiment, a plurality of first slits 54 are provided for the first bypass wiring 51 , and a plurality of second slits 64 are provided for the second bypass wiring 61 .
The first slit 54 and the second slit 64 have the same configuration. Below, the 1st slit 54 and the 2nd slit 64 may be described as the slits 54 and 64. FIG. Also, the first bypass wiring 51 and the second bypass wiring 61 may be referred to as bypass wirings 51 and 61 in some cases.

The slits 54 and 64 pass through the bypass wirings 51 and 61 in the Z direction at the central portions of the bypass wirings 51 and 61 in the width direction. A plurality of slits 54, 64 are intermittently provided in the bypass wirings 51, 61 along the wiring direction.

Moreover, the slits 54 and 64 have shapes extending along the wiring direction of the portions of the bypass wirings 51 and 61 where the slits 54 and 64 are provided.
Specifically, the first slit 54 provided in the Y-direction bypass wiring 511 of the first bypass wiring 51 has a rectangular shape extending along the Y direction, and the first slit 54 provided in the X-direction bypass wiring 512 has a rectangular shape. The first slit 54 has a rectangular shape extending along the X direction. A second slit 64 provided in the second bypass wiring 61 has a rectangular shape extending along the X direction. Each corner of the rectangular shape formed by the first slit 54 and the second slit 64 is formed in a curved shape when viewed from above in the Z direction.

In this embodiment, auxiliary wirings 57 and 67 are provided to fill the slits 54 and 64 with respect to the bypass wirings 51 and 61 . The auxiliary wirings 57 and 67 are gold wirings, for example, and are made of a material that is more flexible than the bypass wirings 51 and 61 . 1 and 2, illustration of the auxiliary wirings 57 and 67 is omitted.

(number and dimensions of slits)
In this embodiment, the numbers and dimensions of the first slits 54 and the second slits 64 are set as follows.

The width Ws1 of the first slit 54 is equal to the width Wc of the first connection wiring 52 by the length Wb11 from each end of the first bypass wiring 51 in the width direction to the first slit 54 in the first bypass wiring 51. set to be equal.
Similarly, the width Ws2 of the second slit 64 is such that the length Wb21 from each end of the second bypass wiring 61 in the width direction of the second bypass wiring 61 to the second slit 64 is It is set to be equal to the width Wc.

The length Ls1 and the number of the first slits 54 are such that the length Lb11 of the portion of the first bypass wiring 51 sandwiched between the two first slits 54 in the wiring direction is equal to the width Wc of the first connection wiring 52. set to be equal.
Similarly, the length Ls2 and the number of the second slits 64 are such that the length Lb21 of the portion sandwiched between the two second slits 64 in the wiring direction of the second bypass wiring 61 is equal to the width Wc of the first connection wiring 52. is set to be equal to

In the description of dimensions in this specification, the term "equal" is not limited to being strictly matched, but includes differences in dimensions within a predetermined range. Here, the predetermined range is a range in which the effects to be described later can be exhibited, and includes, for example, variations and errors at the time of manufacturing. Specifically, it is preferable that the difference in each dimension is within 10%. As an example, when the width Wc of the first connection wiring 52 is used as a reference, each of Wb11, Wb21, Lb11, and Lb21 having a length of “width Wc±10%” is defined as “equal to width Wc. ”.

(Piezoelectric device manufacturing method)
A method for manufacturing the piezoelectric device 10 will be described with reference to the flowchart of FIG. The following description mainly describes the method of forming the piezoelectric element 3 on the diaphragm 2, and other constituent elements can be formed using conventional methods.

First, the substrate 1 provided with the diaphragm 2 is prepared (step S1), and the first electrode 31, the first wiring 5 (the first bypass wiring 51 and the first connection wiring 51) are formed on the second surface 2B of the diaphragm 2. 52), and a second bypass wiring 61 is formed (step S2; first electrode formation configuration).
Specifically, a conductive layer (single layer or multiple layers) of iridium, titanium, or the like is formed on the second surface 2B of the diaphragm 2 by a sputtering method. Thereafter, a mask is formed on a predetermined region of the conductive layer by photolithography, and the conductive layer other than the mask region is removed by etching. Here, no mask is formed in the regions of the conductive layer corresponding to the first slits 54 and the second slits 64, and the conductive layer in these regions is removed. Thereby, a first bypass wiring 51 having a first slit 54 and a second bypass wiring 61 having a second slit 64 are formed (see the first from the top in FIG. 6).

Next, the piezoelectric layer 32A is formed by the sol-gel method (steps S3 and S4; piezoelectric layer forming step).
Specifically, a piezoelectric material such as a PZT (lead zirconate titanate) solution is applied on the second surface 2B of the diaphragm 2 so as to cover the first electrode 31, the first wiring 5 and the second bypass wiring 61. A solution is applied (step S3), and the applied piezoelectric material solution is baked (step S4). During this firing, the region (vibration region Ar) where the piezoelectric element 3 is formed is surrounded by the first bypass wiring 51 and the second bypass wiring 61, so heat conduction to the piezoelectric material solution in this region is uniform. , and it is possible to suppress poor baking (so-called half-baked).
By repeating the steps S3 and S4 described above a predetermined number of times, the piezoelectric layer 32A having a predetermined thickness is formed (see the second from the top in FIG. 6).
Here, FIG. 7 is a cross-sectional view of a portion corresponding to line CC in FIG. 2, and shows a state in which the piezoelectric layer 32A is formed by repeating steps S3 and S4.
At this time, the second bypass wiring 61 (see FIG. 6), the first bypass wiring 51 and the first connection wiring 52 (see FIG. 7) have approximately the same width of the convex portions formed thereon. The ratio of the piezoelectric material solution dripping from above is also about the same. As a result, a piezoelectric layer 32A having approximately the same thickness is formed on each wiring.

Next, a mask is formed on a predetermined region of the piezoelectric layer 32A by photolithography, and the piezoelectric layer 32A is removed by etching to form the piezoelectric layer 32 (step S5; piezoelectric layer forming step). ). Thereby, the piezoelectric body 32 is formed on the first electrode 31 (see the third from the top in FIG. 6).

Next, the second electrode 33 and the second connection wiring 62 are formed (step S6; second electrode forming step).
Specifically, a conductive layer (single layer or multiple layers) of iridium, titanium, or the like is formed on the second surface 2B of the diaphragm 2 so as to cover the first wiring 5, the second bypass wiring 61, and the piezoelectric body 32. is formed by a sputtering method. After that, a mask is formed on the necessary portion of the conductive layer by, for example, photolithography, and the unnecessary portion other than the masked region is removed by etching. Thereby, the second electrode 33 and the second connection wiring 62 are formed (see the fourth from the top in FIG. 6).

A plurality of piezoelectric elements 3 are formed on the second surface 2</b>B of the diaphragm 2 by the flow described above.
Incidentally, auxiliary wirings 57 and 67 are provided for the first bypass wiring 51 and the second bypass wiring 61 at some timing after step S5. After the wiring process for the vibration plate 2 is completed, the piezoelectric device 10 is manufactured by installing the sealing plate 4 and forming the opening 11 in the substrate 1 by the same method as in the conventional art. be done.

[Action and effect of the present embodiment]
In the method for manufacturing the piezoelectric device 10 of this embodiment, the bypass wirings 51 and 61 formed in the first electrode forming step (step S2) have slits 54 and 64. As shown in FIG. Therefore, the width of the convex shape formed on the diaphragm 2 by the bypass wirings 51 and 61 is divided by the concave slits 54 and 64 . Therefore, the width of the convex shape formed by the bypass wirings 51 and 61 is smaller than when the slits 54 and 64 are not provided. That is, the width of the protrusion formed by the bypass wirings 51 and 61 can be brought closer to the width of the protrusion formed by the first connection wiring 52 . As a result, in the piezoelectric layer forming process (steps S3 and S4), the thickness of the piezoelectric layer 32A formed above the bypass wirings 51 and 61 and the first connection wiring 52 can be made more uniform (FIG. 6 second from the top and see FIG. 7).
Therefore, in the piezoelectric layer forming step (step S5), the portion of the piezoelectric layer 32A that is arranged on the bypass wirings 51 and 61 and the portion that is arranged on the first connection wiring 52 are etched at similar etching rates. can be removed by That is, it is possible to appropriately remove the piezoelectric layer 32A other than the formation position of the piezoelectric element 3 while suppressing damage to the first connection wiring 52 .
In addition, in the present embodiment, the slits 54 and 64 have a shape extending along the wiring direction of the bypass wirings 51 and 61, so that the above-described convex shape can be preferably formed.

In particular, in the first electrode forming step (step S2) of the present embodiment, the lengths Wb11 and Wb21 of the bypass wirings 51 and 61 from the respective ends in the width direction of the bypass wirings 51 and 61 to the slits 54 and 64 are , and the width Wc of the first connection wiring 52 . Therefore, the thickness of the piezoelectric layer 32A formed above the bypass wirings 51 and 61 and the first connection wiring 52 becomes more uniform, and damage to the first connection wiring 52 due to the etching method performed in the piezoelectric formation process is prevented. can be suppressed more.

In the piezoelectric device 10 manufactured by the manufacturing method described above, in a state in which the widths of the bypass wirings 51 and 61 and the first electrode 31 are appropriately designed, the occurrence of cracks or the like in the first connection wiring 52 is suppressed, The reliability of the piezoelectric device 10 can be improved.

In the first electrode forming step (step S2) of the present embodiment, a plurality of slits 54 and 64 intermittently arranged in the wiring direction are provided for the bypass wirings 51 and 61 . In such a configuration, since the slits 54 and 64 do not completely cut off the bypass wirings 51 and 61, the auxiliary wirings 57 and 67 may not be provided for the bypass wirings 51 and 61, thereby saving labor.

In the first electrode forming step (step S2) of the present embodiment, the lengths Lb1 and Lb2 of the portions of the bypass wirings 51 and 61 sandwiched between the two slits 54 and 64 in the wiring direction are equal to the lengths of the first connection wiring 52. Equal to width Wc. Therefore, the thickness of the piezoelectric layer 32A formed above the bypass wirings 51 and 61 and the first connection wiring 52 becomes more uniform, and damage to the first connection wiring 52 due to the etching method performed in the piezoelectric formation process is prevented. can be suppressed more.

[Second embodiment]
Next, a second embodiment will be described. In the second embodiment, a distance sensor 100 will be described as an example of an electronic device including the piezoelectric device 10 described in the first embodiment.

As shown in FIG. 8, the distance sensor 100 of this embodiment includes an ultrasonic module 101 including the piezoelectric device 10 and the driving circuit 7, and a control unit 8 that controls the ultrasonic module 101. As shown in FIG.

The drive circuit 7 includes a switching circuit 71 , a transmission circuit 72 and a reception circuit 73 .
The switching circuit 71 is connected to the piezoelectric device 10 (specifically, the first electrode terminal 31</b>P and the second electrode terminal 33</b>P in the first embodiment), the transmission circuit 72 and the reception circuit 73 . The switching circuit 71 is configured by a switching circuit, and switches between a transmission connection connecting the piezoelectric device 10 and the transmission circuit 72 and a reception connection connecting the piezoelectric device 10 and the reception circuit 73 .

The transmission circuit 72 is connected to the switching circuit 71 and the control unit 8 , and outputs a drive signal based on the control of the control unit 8 when the switching circuit 71 is switched to the transmission connection, thereby transmitting ultrasonic waves from the piezoelectric device 10 . send.
The receiving circuit 73 is connected to the switching circuit 71 and the control unit 8, and receives a received signal from the piezoelectric device 10 when the switching circuit 71 is switched to receive connection. The receiving circuit 73 includes a linear noise amplifier, an A/D converter, etc., and converts the input received signal into a digital signal, removes noise components, and amplifies each signal to a desired signal level. After performing the processing, the received signal after processing is output to the control unit 8 .

The control unit 8 is configured by a CPU (Central Processing Unit) and the like. The control unit 8 controls the piezoelectric device 10 via the drive circuit 7 to cause the piezoelectric device 10 to transmit and receive ultrasonic waves. Also, the control unit 8 acquires the position information of the object based on the received signal input from the piezoelectric device 10 . For example, when using the ToF (Time of Flight) method, the time from the transmission timing when the ultrasonic wave is transmitted from the piezoelectric device 10 to the reception of the received signal and the speed of sound in the air are used to determine the The distance to the object can be calculated.
In addition, the control unit 8 may also include a storage unit that stores various data, various programs, and the like for controlling the distance sensor 100 .

[Modification]
The present invention is not limited to the above-described embodiments, and any modifications or improvements within the scope of achieving the object of the present invention are included in the present invention.

In the first embodiment, the bypass wirings 51, 61 have a plurality of slits 54, 64 arranged intermittently in the wiring direction, but the number, arrangement and shape of the slits 54, 64 are not limited to this.
For example, as shown in FIG. 9, the first slit 54A and the second slit 64A (slits 54A, 64A) may be provided so as to completely divide the bypass wirings 51, 61 in the width direction. In other words, the slits 54A, 64A may penetrate the bypass wirings 51, 61 in the wiring direction of the portions of the bypass wirings 51, 61 provided with the slits 54A, 64A.
Further, as shown in FIG. 10, a plurality of first slits 54B and second slits 64B (slits 54B, 64B) that completely divide the bypass wirings 51, 61 in the width direction are arranged in the width direction of the bypass wirings 51, 61. may be placed in
In the case shown in FIG. 9 or 10, auxiliary wirings similar to the auxiliary wirings 57 and 67 of the first embodiment are provided. The auxiliary wiring electrically connects the parts separated by the slits 54A, 64A, 54B, 64B to the bypass wirings 51, 61, respectively.

As another modified example of the slits 54 and 64, a plurality of the slits 54 and 64 intermittently arranged in the wiring direction of the bypass wirings 51 and 61 may be arranged side by side in the width direction of the bypass wirings 51 and 61. . Alternatively, the slits 54 and 64 may be arranged in a staggered manner in the bypass wirings 51 and 61 .
Moreover, the shape of the slits 54 and 64 is not limited to a rectangular shape or a linear shape, and may be any other shape as long as it follows the wiring direction.
Furthermore, the slits 54 and 64 are not limited to passing through the bypass wirings 51 and 61 in the thickness direction, and may be provided as recesses for the bypass wirings 51 and 61 .

In the first embodiment, both the bypass wirings 51 and 61 are formed and each of the bypass wirings 51 and 61 has the slits 54 and 64, but the present invention is not limited to this.
For example, either the bypass wiring 51 or the bypass wiring 61 may not have the slits 54 and 64 . Alternatively, either the bypass wiring 51 or the bypass wiring 61 is not formed on the diaphragm 2, and instead, a linear electrode layer forming the plurality of first electrodes 31 or the plurality of second electrodes 33 is formed. may be

In the second embodiment, the distance sensor 100 is exemplified as an example of an electronic device that includes the piezoelectric device 10, but the present invention is not limited to this. For example, the piezoelectric device of the present invention can be used for an inkjet head that drives a piezoelectric element to eject ink droplets, a pressure sensor that measures the pressure of a pressure medium from the amount of displacement of the piezoelectric element, and the like.

DESCRIPTION OF SYMBOLS 1... Substrate 11... Opening 12... Wall part 13... Damping layer 2... Diaphragm 2A... First surface 2B... Second surface 3... Piezoelectric element 31... First electrode 31P... Second 1 electrode terminal 32 piezoelectric body 32A piezoelectric layer 33 second electrode 33P second electrode terminal 3A element group 4 sealing plate 41 groove 42 partition 5 second 1 wiring, 51... first bypass wiring, 511... Y-direction bypass wiring, 512... X-direction bypass wiring, 52... first connection wiring, 54, 54A, 54B... first slit, 6... second wiring, 61... second wiring 2 Bypass wiring 62 Second connection wiring 64, 64A, 64B Second slit 57, 67 Auxiliary wiring 7 Driving circuit 71 Switching circuit 72 Transmitting circuit 73 Receiving circuit 8 Control unit 10 Piezoelectric device 100 Distance sensor 101 Ultrasonic module Ar Vibration region Tr Ultrasonic transducer.

Claims (9)

a first electrode arranged in a first region overlapping with the opening in a plan view seen from the thickness direction of the substrate in a diaphragm provided so as to overlap a substrate having an opening; a first bypass wiring arranged in a second region different from the first region and having a first slit; and a first bypass wiring arranged over the first region and the second region and connecting the first electrode and the first bypass wiring. a first electrode forming step of forming a first connection wiring to
a piezoelectric layer forming step of forming a piezoelectric layer so as to cover the first electrode, the first bypass wiring and the first connection wiring;
a piezoelectric body forming step of forming a piezoelectric body by removing part of the piezoelectric layer so that a portion of the piezoelectric layer that overlaps the first electrode in plan view remains;
a second electrode forming step of forming a second electrode on the piezoelectric body ;
The piezoelectric device manufacturing method , wherein the first bypass wiring formed in the first electrode forming step has a plurality of the first slits intermittently arranged along the wiring direction . In the piezoelectric device manufacturing method according to claim 1,
The piezoelectric device manufacturing method, wherein the first slit has a shape extending along the wiring direction of the first bypass wiring. In the piezoelectric device manufacturing method according to claim 1 or 2,
In the first bypass wiring, the length from each end in the width direction of the first bypass wiring to the first slit has a difference from the width of the first connection wiring within a predetermined range. A method for manufacturing a piezoelectric device. 2. The piezoelectric device manufacturing method according to claim 1 , wherein the length of a portion of the first bypass wiring sandwiched between the two first slits in the wiring direction has a difference from the width of the first connection wiring within a predetermined range. A method for manufacturing a piezoelectric device, characterized by: In the piezoelectric device manufacturing method according to any one of claims 1 to 4 ,
The step of forming the first electrode further forms a second bypass wiring disposed in the second region of the diaphragm and having a second slit,
The step of forming the second electrode further comprises forming a second connection wiring arranged to overlap the first region and the second region and connecting the second electrode and the second bypass wiring. A method for manufacturing a piezoelectric device. In the piezoelectric device manufacturing method according to claim 5 ,
The piezoelectric device manufacturing method, wherein the second slit has a shape extending along the wiring direction of the second bypass wiring. In the piezoelectric device manufacturing method according to claim 5 or 6 ,
In the second bypass wiring, the length from each end of the second bypass wiring to the second slit in the width direction has a difference from the width of the first connection wiring within a predetermined range. A method for manufacturing a piezoelectric device. In the piezoelectric device manufacturing method according to any one of claims 5 to 7 ,
The piezoelectric device manufacturing method, wherein the second bypass wiring formed in the first electrode forming step has a plurality of the second slits intermittently arranged along the wiring direction. 9. The piezoelectric device manufacturing method according to claim 8 , wherein the length of a portion of the second bypass wiring sandwiched between the two second slits in the wiring direction has a difference from the width of the first connection wiring within a predetermined range. A method for manufacturing a piezoelectric device, characterized by:

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