JP5458767B2 - Electromechanical conversion mechanism, inkjet head and ultrasonic probe - Google Patents

Description

  The present invention relates to an electromechanical conversion mechanism, an inkjet head, and an ultrasonic probe, and particularly to an electromechanical conversion mechanism, an inkjet head, and an ultrasonic probe that function as a high-speed, high-resolution actuator or sensor.

  2. Description of the Related Art Conventionally, an element having a cantilever structure (single cantilever) in which a piezoelectric element, a shape memory alloy, a bimetal, and the like are formed on a substrate in a thin film shape is known. Since expansion / contraction deformation along the surface of the thin film can be efficiently converted into displacement in a direction perpendicular to the surface, a highly sensitive pressure sensor or actuator can be configured. On the other hand, the cantilever structure has a problem in that the rigidity of the cantilever structure is low because the end of the beam is not constrained, and deformation or twist due to an external force is likely to occur.

  In order to solve this problem, there has been proposed a device for increasing the rigidity of the displacement film by using a double beam structure in which both ends of the displacement film are fixed or a diaphragm (diaphragm) structure in which the periphery is fixed. Using this structure increases the rigidity of the displacement film, so the generated pressure can be increased, it can be stably deformed against external forces, and the center of the displacement film can be moved parallel to the substrate. It can be used for pumps that transport gas and liquid.

  Taking advantage of these advantages, an element having a diaphragm structure is used for an actuator of an ink jet head of an ink jet printer, for example.

  On the other hand, in order to draw an image at a high speed with an ink jet printer, a line head system in which channels are arranged in the entire width of the recording medium and scanned in one direction is desirable. In order to reduce the cost and the resolution of the head with this line head system, it is desirable to make individual channels as small as possible and arrange small channels on the head in a two-dimensional and high-density manner.

  As a method for reducing the size of the channel and increasing the density as described above, for example, Patent Document 1 proposes a method of arranging channels having an isotropic shape such as a circle or a square in a staggered arrangement.

On the other hand, the actuator for ejecting ink includes
(1) Large displacement amount (displacement volume) for achieving the ink ejection amount required from the resolution of the apparatus
(2) Large generated force for ejecting ink having a necessary viscosity (3) Requirements such as high rigidity to cope with a high-speed ejection operation are required.

  Further, as an application to a sensor having a double beam structure or a diaphragm structure, for example, it can be applied as a two-dimensional ultrasonic sensor of an ultrasonic probe used in an ultrasonic diagnostic apparatus. For example, Patent Document 2 proposes a method for manufacturing a two-dimensional ultrasonic probe for medical diagnosis.

Japanese Patent No. 3168474 JP 2002-262397

  However, for example, in the case of the circular actuator disclosed in Patent Document 1, in order to increase the displacement amount of (1), it is necessary to increase the area and the thickness, and to increase the generated force of (2). In order to achieve this, it is necessary to increase the area and the thickness, and in order to increase the rigidity of (3), it is necessary to reduce the area and increase the thickness. There are conflicting relationships.

  In the case of a circular actuator using a piezoelectric element, when the applied electric field is constant, the generated force is proportional to the square of the area and thickness, and the rigidity is proportional to the cube of the thickness and inversely proportional to the area. It is proportional to the square of the area and inversely proportional to the square of the thickness. As described above, it is difficult to satisfy the above-described three requirements at the same time with an actuator having an isotropic shape such as a circle or a square shown in Patent Document 1.

  In Patent Document 2, an ultrasonic probe, that is, an ultrasonic sensor, is manufactured by cutting an inorganic piezoelectric material such as lead zirconate titanate (hereinafter referred to as PZT) fired in bulk vertically and horizontally. ing. Although it is a bulk material, rigidity and generated force are large, but there is a problem that a displacement amount, that is, sensor sensitivity is small. Further, in order to increase the density of the sensor, the wiring is laminated and taken out with the piezoelectric material, but there is also a problem that the ultrasonic vibration is attenuated and modulated by laminating the wiring layer.

  The present invention has been made in view of the above circumstances, and provides an electromechanical conversion mechanism capable of realizing a large displacement, a large generated force, and a high rigidity, and further, at high speed and high resolution using the same. An object of the present invention is to provide a low-cost inkjet head, and a high-sensitivity, high-resolution, low-cost ultrasonic probe.

  The object of the present invention can be achieved by the following constitution.

1. A flat substrate;
A plurality of grooves formed in a two-dimensional matrix through both sides of the substrate;
A displacement layer formed on a plurality of the groove portions on one surface of the substrate;
In an electromechanical conversion mechanism comprising a plurality of electromechanical conversion elements formed on the displacement layer, corresponding to each of the plurality of grooves.
The groove and the electromechanical conversion element have a shape in which an elongated shape having a short side having a predetermined width and a long side longer than the short side is bent into a shape in which a curve or a curve and a straight line are joined. An electromechanical conversion mechanism.

2. The electromechanical transducer has at least two electrodes,
The electrical connection according to 1 above, wherein a wiring connection portion connected to at least one electrode of the electromechanical transducer is formed in a region surrounded by the groove portion on one surface of the substrate. Mechanical conversion mechanism.

  3. 3. The electromechanical conversion mechanism according to 1 or 2, wherein the groove has one of a C shape, a U shape, an O shape, and a spiral shape.

  4). The electromechanical conversion mechanism according to any one of 1 to 3, wherein the plurality of grooves are arranged in a staggered manner.

  5. 5. The electromechanical conversion mechanism according to any one of 1 to 4, wherein the displacement layer is formed so as to cover the groove portion.

  6). 6. The electromechanical conversion mechanism according to 5, wherein the electromechanical conversion element has substantially the same width, length, and shape as the groove.

  7). The displacement layer is narrower than a predetermined width of the short side and longer than a length of the long side, and is formed on the groove portion along the groove portion. The electromechanical conversion mechanism according to any one of the above.

  8). 8. The electromechanical conversion mechanism according to 7, wherein the electromechanical conversion element has substantially the same width, length, and shape as the displacement layer.

9. The electromechanical conversion mechanism according to any one of 1 to 6,
An ink supply section for supplying ink to the groove section;
An ink jet head comprising: a nozzle that discharges ink stored in the groove.

10. An ultrasonic transmission unit that transmits ultrasonic waves toward the subject;
9. An ultrasonic probe comprising the electromechanical conversion mechanism according to any one of 1 to 8 for receiving an ultrasonic wave reflected or transmitted by the subject.

  According to the present invention, a flat substrate, grooves formed in a two-dimensional matrix on the substrate, a displacement layer formed on the groove, and a one-to-one correspondence with the groove, The groove portion and the electromechanical conversion element are joined to an elongated shape having a short side having a predetermined width and a long side longer than the short side, and a curve or a curve and a straight line are joined to each other. An electromechanical conversion mechanism capable of realizing a large displacement amount, a large generated force, and a high rigidity can be provided by forming the shape bent into the above-described shape. Furthermore, a high-speed, high-resolution, low-cost inkjet head and a high-sensitivity, high-resolution, low-cost ultrasonic probe can be provided.

It is a schematic diagram which shows an example of a structure of one channel of the inkjet head which is the 1st Embodiment of this invention. It is a top view which shows an example of the arrangement | sequence of the channel of 1st Embodiment. It is process drawing which shows the manufacturing process of the inkjet head which is the 1st Embodiment of this invention. FIG. 4 is a cross-sectional view (1/3) taken along the line A-C-A ′ of FIG. FIG. 4 is a cross-sectional view (2/3) taken along the line A-C-A ′ of FIG. FIG. 4 is a cross-sectional view (3/3) taken along the line A-C-A ′ of FIG. It is a top view which shows the 2nd to 4th embodiment of this invention. It is a schematic diagram which shows one example of a structure of one channel of the two-dimensional ultrasonic sensor of the ultrasonic probe which is the 5th Embodiment of this invention. It is a schematic diagram which shows one example of a structure of one channel of the two-dimensional ultrasonic sensor of the ultrasonic probe which is the 6th Embodiment of this invention. It is a schematic diagram which shows an example of the structure of the channel of the inkjet head using the circular actuator of the conventional diaphragm structure. It is a schematic diagram showing an example of the configuration of a channel of an ink jet head using an elongated rectangular actuator having a conventional diaphragm structure.

  Hereinafter, the present invention will be described based on the illustrated embodiment, but the present invention is not limited to the embodiment. In the drawings, the same or equivalent parts are denoted by the same reference numerals, and redundant description is omitted.

  First, an ink jet head using the above-described conventional diaphragm structure actuator will be described with reference to FIG. FIG. 10 is a schematic diagram illustrating an example of a channel configuration of an inkjet head using a conventional circular actuator having a diaphragm structure, and FIG. 10A is a schematic diagram illustrating a schematic configuration of one channel 90. FIG. 10B is a schematic diagram showing a schematic configuration of the inkjet head 9 in which a plurality of channels 90 are arranged in a staggered manner.

  10A, the channel 90 includes a nozzle 91, an ink chamber 93, a piezoelectric element 95, a wiring connection portion 97, a vibration film 99, and the like. The piezoelectric element 95 and the vibration film 99 constitute an actuator. The piezoelectric element 95 is laminated on a circular ink chamber 93 with a vibration film 99 interposed therebetween, and an upper surface electrode 955 and a lower surface electrode 953 are provided on both surfaces of the circular piezoelectric body 951. The lower surface electrode 953 is connected to the lower surface electrode 953 of another channel and serves as a common electrode. The wiring connection portion 97 has the same configuration as that of the piezoelectric element 95, and the uppermost layer is connected to the upper surface electrode 955 of the piezoelectric element 95.

  When a voltage is applied between the wiring connection portion 97 and the common electrode, that is, the upper electrode 955 and the lower electrode 953 of the piezoelectric element 95, the piezoelectric element 95 applies pressure to the ink chamber 93 through the vibration film 99, With this pressure, ink droplets are ejected from the nozzle 91 provided on the surface of the ink chamber 93 opposite to the piezoelectric element 95.

In FIG. 10B, the radius of the ink chamber 93 and the piezoelectric element 95 is r, the distance between the channels 90 necessary for preventing crosstalk is r, the diameter of the wiring connecting portion 97, and the wiring connecting portion 97 and the piezoelectric body 95. When the insulation interval is 0.5r, the area Sa of the ink chamber 93 and the piezoelectric element 95 is Sa = πr ² , and the area S necessary for arranging one channel 90 is indicated by a broken parallelogram in the drawing. As you can see,

It becomes. Therefore, the occupation ratio (= Sa / S) of the channel 90 is about 40%.

  On the other hand, in order to increase rigidity in a large-area channel having a diaphragm structure, a method in which the actuator has an elongated shape is conceivable. Since the short side (short diameter) of the actuator is small, the rigidity can be increased, and since the long side (long diameter) is large, there is an advantage that the displacement amount and the generated force can be increased.

  FIG. 11 is a schematic diagram showing an example of the configuration of a channel of an inkjet head using an elongated rectangular channel having a diaphragm structure.

In FIG. 11, the ink chamber 93 and the piezoelectric element 95 of the channel 90 have an elongated rectangular shape having a short side with a predetermined width and a long side longer than the short side. However, the rectangle is not essential, and for example, both ends may be rounded. In order to align the area Sa of the ink chamber 93 and the piezoelectric element 95 with the example of FIG. 10 (Sa = πr ² ), the width is set to 0.5r, the length is set to 6.3r, and other intervals are also equal to the example of FIG. To do. As a result, the interval between the nozzles 91 in the left-right direction in the figure is reduced by half to 1.5r compared to 3r in the example of FIG. In this case, the area S required to arrange one channel 90 is roughly as shown by the broken parallelogram in the figure,

Thus, the occupation ratio (= Sa / S) of the channel 90 is reduced to about 27%.

  As described above, when the elongated actuators are two-dimensionally arranged, the pitch in the short side direction can be narrowed, but the pitch in the long side direction is widened and the occupation ratio of the channel 90 is also low. Further, since the actuator portion is thin and has a difference in thickness with other substrate portions, the head strength can be distributed and the head is distorted. Furthermore, the actuator portion has residual stress due to thermal expansion during processing, shrinkage of the adhesive, and the like, which also causes head distortion. Such distortion of the head causes a shift in distance and tilt with respect to the recording medium, and causes unevenness in the image.

  In an inkjet head in which channels are two-dimensionally arranged at high density, it is desirable to arrange highly isotropic actuators so that the vertical and horizontal pitches are uniform as shown in the example of FIG. Such an elongated actuator cannot satisfy such a requirement.

  As described above, the circular channel 90 in FIG. 10 has a high occupation ratio, but cannot satisfy the displacement (displacement volume), the generated force, and the rigidity at the same time. In contrast, the elongated rectangular channel of FIG. 11 can simultaneously satisfy the displacement (displacement volume), the generated force, and the rigidity, but is less isotropic in the occupation ratio and the spacing between the channels than in the circular shape.

  Next, a first embodiment of the present invention will be described with reference to FIG. 1 and FIG. FIG. 1 is a schematic diagram showing an example of the configuration of one channel of the ink jet head according to the first embodiment of the present invention, and FIG. 1A is a plan view showing the schematic configuration of one channel. FIG. 1B is a cross-sectional view taken along the line A-C-A ′ of FIG.

  In FIG. 1A, one channel 10 of the ink jet head 1 includes a nozzle 11, an ink chamber 13, a piezoelectric element 15, a wiring connection portion 17, a vibration film 19, an inlet 23, an ink supply path 21 (not shown), and the like. ing. The piezoelectric element 15 and the vibration film 19 constitute an actuator. A nozzle 11 for ejecting ink is formed on the side opposite to the piezoelectric element 15 at one end of the ink chamber 13, and an inlet 23 for supplying ink to the ink chamber is formed on the other end. In the inkjet head 1, as will be described later with reference to FIG. 2, the channels 10 are staggered in a two-dimensional matrix.

  The ink chamber 13 and the piezoelectric element 15 are formed by bending the ink chamber 93 and the piezoelectric element 95 having a short side with a predetermined width and a long side longer than the short side as shown in FIG. This is a C-shape with a part of an annular shape lacking. By this, the characteristics satisfying the displacement amount (displacement volume), generated force and rigidity of the elongated channel at the same time, and the high occupation ratio of the circular channel Make both. However, the rectangle is not essential, and for example, both ends may be rounded.

  The piezoelectric element 15 is a drive source for ejecting ink. The piezoelectric element 15 is stacked on the ink chamber 13 via the vibration film 19, and the upper surface electrode 155 and the lower surface electrode 153 are provided on both surfaces of the piezoelectric body 151. It is a configuration. The lower surface electrode 153 is connected to the lower surface electrode 153 of another channel and serves as a common electrode.

  A wiring connection portion 17 is provided at the center inside the C-shaped piezoelectric element 15. The wiring connection portion 17 has the same configuration as that of the piezoelectric element 15, and the uppermost layer is connected to the upper surface electrode 155 of the piezoelectric element 15. Since the substrate 101 is located below the wiring connection portion 17, the wiring connection portion 17 is not affected even if the piezoelectric element 15 is driven to vibrate.

  The ink chamber 13 and the piezoelectric element 15 have a width of 0.5r, a C-shaped outer diameter of 2.5r, and an inner diameter of 1.5r. The diameter of the wiring connection portion 17 is 0.5r. The distance between the piezoelectric element 15 and the wiring connection portion 17 is 0.5r.

  In FIG. 1B, the channel 10 is composed of an upper body 100 and a lower body 200.

  The upper body 100 includes a substrate 101, a displacement layer 111, a piezoelectric element 15, a wiring connection portion 17, and the like. The substrate 101 is made of, for example, crystalline silicon, and an ink chamber 13 is formed in the substrate 101 through both surfaces of the substrate 101. The displacement layer 111 is an oxide film obtained, for example, by oxidizing the surface of the substrate 101, and the portion of the displacement layer 111 that contacts the ink chamber 13 is the vibration film 19. Here, the ink chamber 13 functions as a groove in the present invention, the piezoelectric element 15 functions as an electromechanical conversion element in the present invention, and the upper body 100 functions as an electromechanical conversion mechanism in the present invention.

  The lower body 200 is formed of, for example, photosensitive resin, and is configured by stacking three layers of a nozzle plate 231, an ink supply plate 251 and an inlet plate 271 in this order. The nozzle plate 231 has nozzles 11 for discharging ink. The ink supply plate 251 is formed with an ink supply path 21 that communicates with an external ink tank and supplies ink to the ink chamber 13, and an ink chamber 13 that communicates with the ink chamber 13 of the upper body 100. The manufacturing process of the upper body 100 and the lower body 200 will be described in detail with reference to FIG.

  The inlet plate 271 communicates with the ink supply path 21 of the ink supply plate 251 and the ink chamber 13 of the upper body 100, the inlet 23 that supplies ink to the ink chamber 13, and the ink chamber 13 of the upper body 100 and the ink supply An ink chamber 13 for communicating with the ink chamber 13 formed on the plate 251 is formed.

  A circuit board 401 is provided on the upper body 100, and a conductive adhesive or solder ball is provided between the wiring pattern 403 on the circuit board 401 and the wiring connection portion 17, that is, the upper surface electrode 155 of the piezoelectric element 15. The connection members 405 such as are connected. The wiring pattern on the circuit board 401 and the common electrode in which the lower surface electrodes 153 of the piezoelectric elements 15 are bundled are connected at a portion that does not affect the channel 10, for example, the end of the inkjet head 1.

  When a voltage is applied between the wiring connection portion 17 and the common electrode, that is, between the upper surface electrode 155 and the lower surface electrode 153 of the piezoelectric element 15, the piezoelectric element 15 pressurizes the ink chamber 13 via the vibration film 19. The ink droplet is ejected from the nozzle 11 provided on the surface of the ink chamber 13 opposite to the piezoelectric element 15 by this pressure.

  In the first embodiment, the piezoelectric element 15 is a drive source for ejecting ink. However, the present invention is not limited to this, and for example, a shape memory alloy film or bimetal may be used as the drive source. In this case, the electrode shape and the method of taking out the electrode may be those suitable for the driving source to be used.

  FIG. 2 is a plan view illustrating an example of the arrangement of the channels 10 according to the first embodiment.

In FIG. 2, the channels 10 are staggered in a two-dimensional matrix. The area Sa of the ink chamber 13 and the piezoelectric element 15 in the channel 10 is Sa = πr ² ignoring the portion lacking the annular shape. Assuming that the spacing between the channels 10 necessary for preventing crosstalk is r as in FIG. 10, the area S required for arranging one actuator is:

Thus, the occupation ratio (= Sa / S) of the channel 10 is about 30%.

Since the width of the ink chamber 13 and the piezoelectric element 15 is 0.5 r and the area Sa = πr ² , the three requirements of displacement, force, and rigidity are the same as those of the elongated rectangular channel shown in FIG. , Intermediate between the circular channel of FIG. 10 and the elongated rectangular channel of FIG.

  Next, the manufacturing process of the first embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a process diagram showing a manufacturing process of the ink jet head according to the first embodiment of the present invention. 4 to 6 are cross-sectional views taken along the line A-C-A 'of FIG. 4 to 6 show only the manufacturing process of one channel 10, the channels 10 are actually manufactured in a staggered arrangement in a two-dimensional matrix. In FIGS. 4 to 6, description of A, C, and A ′ is omitted as appropriate in order to make the drawings easy to see.

  In FIG. 3, the inkjet head 1 is manufactured by separately forming an upper body 100 and a lower body 200 and then connecting them.

(Upper body forming process)
As described above, the substrate 101 of the upper body 100 is a substrate made of crystalline silicon (Si) that is often used in a microfabrication technique such as MEMS (Micro Electro Mechanical Systems). The thickness of the substrate 101 is, for example, about 300 μm. This state is shown in FIG.

Displacement layer forming step (step S11)
The substrate 101 is put into a heating furnace and held at a temperature of about 1500 ° C. for a predetermined time to form a thermal oxide film (quartz: SiO ₂ ) that becomes the displacement layer 111 on the surface of the substrate 101. The thickness of the displacement layer 111 is, for example, about 2 μm. This state is shown in FIG.

Piezoelectric element layer forming step (step S13)
The substrate 101 with the displacement layer 111 formed on the surface is cooled to room temperature, and titanium, platinum, or the like is deposited by sputtering to form the lower electrode 153. The substrate 101 on which the lower surface electrode 153 is formed is reheated to about 600 ° C., PZT is formed, and a layer of the piezoelectric body 151 is formed. The substrate 101 on which the layer of the piezoelectric body 151 is formed is cooled to room temperature, and chromium, gold, or the like is formed by a sputtering method to form the upper surface electrode 155. The thickness of the piezoelectric body 151 is, for example, about 5 μm, and the thicknesses of the lower surface electrode 153 and the upper surface electrode 155 are, for example, about 100 nm. This state is shown in FIG.

Patterning step (step S15)
A photosensitive resin material is applied onto the substrate 101 on which each layer of the piezoelectric element 15 is formed by a spin coat method, and exposed through a mask, whereby the shape of the piezoelectric element 15, the wiring connection portion 17, and a connection portion between them is formed. And the PZT and the electrode are removed by a reactive ion etching method, thereby forming the piezoelectric element 15, the wiring connection portion 17, and the connection portion between them. This state is shown in FIG.

Ink chamber forming step (step S17)
A photosensitive resin material is applied by spin coating on the surface of the substrate 101 opposite to the surface on which the piezoelectric element 15, the wiring connection portion 17, and the connecting portion of both are formed, and is exposed through a mask, thereby exposing the ink chamber 13. Transfer the shape. Using the photosensitive resin material as a resist, Si of the substrate 101 is removed using a reactive ion etching method, and the ink chamber 13 is formed. By forming the ink chamber 13, the portion of the displacement layer 111 that contacts the ink chamber 13 becomes the vibration film 19. This state is shown in FIG. Thus, the upper body 100 is formed.

(Lower body formation process)
The lower body 200 is formed by laminating and processing a photosensitive resin film on the dummy substrate 201. As with the substrate 101 of the upper body 100, the dummy substrate 201 uses crystalline silicon (Si). The thickness of the dummy substrate 201 is, for example, about 400 to 500 μm. This state is shown in FIG.

Sacrificial layer forming step (step S21)
A sacrificial layer 211 is formed by applying a resin resist or the like on the dummy substrate 201 by a spin coating method or the like. The thickness of the sacrificial layer 211 is, for example, about 100 nm. This state is shown in FIG.

Nozzle plate forming step (step S23)
A photosensitive resin film is attached on the sacrificial layer 211 to form a nozzle plate 231. The nozzle 11 is formed by exposing and exposing the nozzle plate 231 through a mask and immersing it in an etching solution. The thickness of the nozzle plate 231 is, for example, about 20 μm. This state is shown in FIG.

Ink supply plate forming step (step S25)
A photosensitive resin film is attached on the nozzle plate 231 to form the ink supply plate 251. The ink supply plate 251 is exposed to light through a mask to be exposed and immersed in an etching solution, whereby the ink supply path 21 and the ink chamber 13 communicating with the nozzle 11 are formed. The thickness of the ink supply plate 251 is, for example, about 100 μm. This state is shown in FIG.

Inlet plate forming step (step S27)
A photosensitive resin film is attached on the ink supply plate 251 to form an inlet plate 271. The inlet plate 271 is exposed to light through a mask to be exposed and immersed in an etching solution, so that the ink chamber 13 communicates with both the inlet 15 and the ink chamber 13 of the ink supply plate 251 and the ink chamber 13 of the upper body 100. And form. The thickness of the inlet plate 271 is, for example, about 20 μm. This state is shown in FIG. Thus, the lower body 200 is formed.

  Subsequently, the upper body 100 and the lower body 200 are joined to complete the inkjet head 1.

Body coupling step (step S31)
Adhesive 121 is applied to the end surface of the upper body 100 on which the ink chamber 13 is formed, and the upper body 100 is aligned so that the ink chamber 13 of the upper body 100 and the ink chamber 13 of the lower body 200 communicate with each other. Join. This state is shown in FIGS. 6 (a) and 6 (b).

Dummy substrate peeling process (process S33)
By removing the sacrificial layer 211 with a solvent, the dummy substrate 201 is peeled from the inkjet head 1 to complete the inkjet head 1. This state is shown in FIG.

  As described above, according to the first embodiment, an upper portion in which a C-shaped ink chamber and piezoelectric elements lacking a part of an annular shape are formed in a two-dimensional matrix on a flat substrate. A high-speed, high-resolution, low-cost inkjet head can be provided by combining the lower body including the body and having the ink chamber, the nozzle, the inlet, and the ink supply path and the above-described upper body.

  Next, second to fourth embodiments of the present invention will be described with reference to FIG. FIG. 7 is a plan view showing the second to fourth embodiments of the present invention. The second to fourth embodiments are modifications of the first embodiment, and the manufacturing process is the same as that of the first embodiment. In the first embodiment, the shape of the ink chamber 13 and the piezoelectric element 15 is formed by bending a long and narrow rectangular shape having a short side having a predetermined width and a long side longer than the short side into a circular shape. Although a C-shaped shape with a part missing is used, the shape is not limited to this, and other shapes are also conceivable. However, the rectangle is not essential, and for example, both ends may be rounded.

  In FIG. 7A, the ink chamber 13 and the piezoelectric element 15 of the second embodiment are U-shaped. In the center of the U-shape, a wiring connection portion 17 that is an extension of the piezoelectric element 15 is arranged as in the first embodiment. The width (= 0.5r), length (= 6.3r) of the ink chamber 13 and the piezoelectric element 15, the diameter (= 0.5r) and the insulation distance (= 1.5r) of the wiring connection part 17 are set to the first value. If it is the same as embodiment, the length of a U-shaped linear part will be about 1.57r. The nozzle 11 and the inlet 23 are preferably disposed at both ends of the U-shape.

  In FIG. 7B, the ink chamber 13 and the piezoelectric element 15 of the third embodiment have an annular shape. In the center of the annular shape, a wiring connection portion 17 that is an extension of the piezoelectric element 15 is disposed as in the first embodiment. In the case of this example, the dimensions of each part are substantially the same as in the first embodiment. The nozzle 11 and the inlet 23 are preferably arranged at diagonal positions in an annular shape.

  In FIG. 7C, the ink chamber 13 and the piezoelectric element 15 of the fourth embodiment are spiral. As in the first embodiment, a wiring connection portion 17 that is an extension of the piezoelectric element 15 is disposed in the spiral center. In order to obtain a spiral shape, for example, the width of the ink chamber 13 and the piezoelectric element 15 is made half (= 0.25r) of the first embodiment, and the length is doubled (= 12.6r). . The nozzle 11 and the inlet 23 are preferably disposed at both ends of a spiral shape.

  As in the fourth embodiment, the width of the ink chamber 13 and the piezoelectric element 15 is narrowed to be spiral, so that the shape can be made to be longer than that in the first embodiment. In addition to the effects of the embodiment, an increase in displacement (displacement volume) can be realized.

  Next, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 8 is a schematic diagram showing an example of the configuration of one channel of the two-dimensional ultrasonic sensor of the ultrasonic probe according to the fifth embodiment of the present invention. FIG. FIG. 8B is a cross-sectional view taken along the line DD ′ of FIG. 8A.

  In the example of FIG. 8, the upper body 100 of the inkjet head 1 shown in the first embodiment is used as the two-dimensional ultrasonic sensor 5. The manufacturing process of the two-dimensional ultrasonic sensor 5 is the same as the manufacturing process of the upper body 100 of the first embodiment. Here, the two-dimensional ultrasonic sensor 5 functions as an electromechanical conversion mechanism in the present invention.

  In FIG. 8A, the channel 50 includes an ultrasonic wave introduction part 53, a piezoelectric element 15, a wiring connection part 17, a vibration film 19, and the like. In the two-dimensional ultrasonic sensor 5, as shown in FIG. 2, the channels 50 are staggered in a two-dimensional matrix.

  The ultrasonic wave introduction unit 53 and the piezoelectric element 15 are formed by bending the ink chamber 93 and the piezoelectric element 95 in the shape of an elongated rectangle having a short side with a predetermined width and a long side longer than the short side shown in FIG. Thus, the C-shaped shape with a part of the annular shape lacking is obtained. By this, the characteristics satisfying the displacement amount (sensor sensitivity), generated force and rigidity of the elongated channel at the same time, and the occupation ratio of the circular channel Balance height. However, the rectangle is not essential, and for example, both ends may be rounded.

  The piezoelectric element 15 is a sensor that converts the ultrasonic wave US into an electrical signal. The piezoelectric element 15 is laminated on the ultrasonic wave introduction unit 53 via the vibration film 19, and has an upper surface electrode 155 and a lower surface electrode 153 on both surfaces of the piezoelectric body 151. Is provided. The lower surface electrode 153 is connected to the lower surface electrode 153 of another channel and serves as a common electrode. A wiring connection portion 17 is provided at the center inside the C-shaped piezoelectric element 15. The wiring connection portion 17 has the same configuration as that of the piezoelectric element 15, and the uppermost layer is connected to the upper surface electrode 155 of the piezoelectric element 15.

  The ultrasonic introduction part 53 and the piezoelectric element 15 have a width of 0.5r, a C-shaped outer diameter of 2.5r, and an inner diameter of 1.5r. The diameter of the wiring connection portion 17 is 0.5r. The distance between the piezoelectric element 15 and the wiring connection portion 17 is 0.5r.

  In FIG. 8B, the upper body 100 includes a substrate 101, a displacement layer 111, a piezoelectric element 15, a wiring connection portion 17, and the like. The substrate 101 is made of, for example, crystalline silicon, and an ultrasonic wave introduction portion 53 is formed on the substrate 101 so as to penetrate both surfaces of the substrate 101. The displacement layer 111 is an oxide film obtained, for example, by oxidizing the surface of the substrate 101, and the portion of the displacement layer 111 that contacts the ultrasonic wave introduction portion 53 is the vibration film 19. Here, the ultrasonic wave introduction part 53 functions as a groove part in the present invention, the piezoelectric element 15 functions as an electromechanical conversion element in the present invention, and the upper body 100 functions as an electromechanical conversion mechanism in the present invention.

  A circuit board 401 is provided on the upper body 100, and a conductive adhesive or solder ball is provided between the wiring pattern 403 on the circuit board 401 and the wiring connection portion 17, that is, the upper surface electrode 155 of the piezoelectric element 15. The connection members 405 such as are connected. The wiring pattern on the circuit board 401 and the common electrode in which the lower surface electrodes 153 of the piezoelectric elements 15 are bundled are connected at a portion that does not affect the channel 10, for example, an end portion of the two-dimensional ultrasonic sensor 5.

  When the ultrasonic wave US is incident on the ultrasonic wave introduction unit 53, the piezoelectric element 15 vibrates due to the vibration of the ultrasonic wave US via the vibration film 19. When the piezoelectric element 15 vibrates, a voltage is generated between the upper surface electrode 155 and the lower surface electrode 153 of the piezoelectric element 15, and the ultrasonic wave US is converted into an electric signal. The converted electrical signal is transmitted from the wiring connection portion 17 to the wiring pattern 403 on the circuit board 401 via the connection member 405, and is detected by an ultrasonic detection circuit (not shown).

  As described above, according to the fifth embodiment, the C-shaped ultrasonic wave introduction portion and the piezoelectric elements, each lacking a ring shape, are formed in a two-dimensional matrix form on a flat substrate. By doing so, a displacement amount (sensor sensitivity), generated force, and rigidity can be satisfied at the same time, and a high-resolution and low-cost two-dimensional ultrasonic sensor can be provided. Further, by providing the wiring connection portion inside the C-shaped piezoelectric element, it is possible to provide a two-dimensional ultrasonic sensor in which channels are arranged at high density without affecting the vibration caused by reception of ultrasonic waves. .

  Next, a sixth embodiment of the present invention will be described with reference to FIG. FIG. 9 is a schematic diagram showing an example of the configuration of one channel of the two-dimensional ultrasonic sensor of the ultrasonic probe according to the sixth embodiment of the present invention, and FIG. FIG. 9B is a cross-sectional view taken along the line EE ′ of FIG. 9A.

  In the example of FIG. 8, the upper body 100 of the inkjet head 1 shown in FIG. 1 is used as it is as the channel 50 of the two-dimensional ultrasonic sensor 5, but the two-dimensional ultrasonic sensor needs to pressurize the liquid like an inkjet head. Therefore, it is not necessary to hold the periphery of the sensor, and it is only necessary to hold both ends. The manufacturing process is the same as in the fifth embodiment.

  In FIG. 9A, the channel 50 includes an ultrasonic wave introduction part 53, a piezoelectric element 15, a wiring connection part 17, a vibration film 19 and the like, as in the fifth embodiment. The piezoelectric element 15 and the vibration film 19 have an annular shape with the same width, and the ultrasonic wave introduction portion 53 has a C-shape lacking a part of an annular shape wider than the piezoelectric element 15 and the vibration film 19. It has a shape.

  That is, the piezoelectric element 15 and the vibration film 19 are supported by the portion 101a of the substrate 101 where the ultrasonic introduction portion 53 is not formed, and the portion formed on the ultrasonic introduction portion 53 is suspended in the air. Yes. Thereby, when the ultrasonic wave US is incident on the ultrasonic wave introduction section 53, a displacement amount larger than that of the fifth embodiment can be obtained, and high sensor sensitivity can be realized. Others are the same as those of the fifth embodiment, and thus description thereof is omitted.

  As described above, according to the sixth embodiment, an annular piezoelectric element and a vibration film on a flat substrate, and a C type wider than that and lacking a part of the annular shape. By forming the shaped ultrasonic wave introduction portions in a two-dimensional matrix, it is possible to provide a two-dimensional ultrasonic sensor having higher sensor sensitivity than that of the fifth embodiment. Also, by providing the wiring connection portion inside the C-shaped ultrasonic wave introduction portion, it is possible to provide a two-dimensional ultrasonic sensor in which channels are arranged at high density without affecting the vibration due to reception of ultrasonic waves. Can do.

  By providing an ultrasonic transmission unit that transmits ultrasonic waves toward the subject and the two-dimensional ultrasonic sensor described in the fifth and sixth embodiments, high sensitivity, high resolution, and low cost can be achieved. An acoustic probe can be provided.

  As described above, according to the present invention, a flat substrate, grooves formed in a two-dimensional matrix on the substrate, a displacement layer formed on the grooves, and a one-to-one correspondence with the grooves are provided. And an electromechanical conversion element formed on the displacement layer, and the groove portion and the electromechanical conversion element have a long and narrow shape having a short side having a predetermined width and a long side longer than the short side. Alternatively, it is possible to provide an electromechanical conversion mechanism that can realize a large displacement, a large generated force, and a high rigidity by bending the curved and straight lines into a shape that is joined. Furthermore, a high-speed, high-resolution, low-cost inkjet head and a high-sensitivity, high-resolution, low-cost ultrasonic probe can be provided.

  It should be noted that the detailed configuration and detailed operation of each component constituting the electromechanical conversion mechanism, the inkjet head, and the ultrasonic probe according to the present invention can be changed as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Inkjet head 10 Channel (of inkjet head) 11 Nozzle 13 Ink chamber 15 Piezoelectric element 151 Piezoelectric body 153 Lower surface electrode 155 Upper surface electrode 17 Wiring connection part 19 Vibration film 21 Ink supply path 23 Inlet 100 Upper body 101 Substrate 111 Displacement layer 200 Lower part Body 201 Dummy substrate 211 Sacrificial layer 231 Nozzle plate 251 Ink supply plate 271 Inlet plate 401 Circuit board 403 Wiring pattern (on circuit board) 405 Connection member 5 Two-dimensional ultrasonic sensor 50 Channel of two-dimensional ultrasonic sensor 53 Super Sound wave introduction unit US Ultrasound

Claims (10)

A flat substrate;
A plurality of grooves formed in a two-dimensional matrix through both sides of the substrate;
A displacement layer formed on a plurality of the groove portions on one surface of the substrate;
In an electromechanical conversion mechanism comprising a plurality of electromechanical conversion elements formed on the displacement layer, corresponding to each of the plurality of grooves.
The groove and the electromechanical conversion element, the short sides of the predetermined width, said elongated shape with a longer long side than the short side, Ri shape der by bending into a shape joining the lines and curves or curves ,
The electromechanical transducer has at least two electrodes,
Each of the groove portions has a shape surrounding a predetermined region,
Wherein the one surface of the substrate, in the predetermined region, the electro-mechanical conversion electromechanical conversion mechanism, wherein Rukoto wiring connected connecting section to at least one of the electrodes is formed of elements. A flat substrate;
A plurality of grooves formed in a two-dimensional matrix through both sides of the substrate;
A displacement layer formed on a plurality of the groove portions on one surface of the substrate;
In an electromechanical conversion mechanism comprising a plurality of electromechanical conversion elements formed on the displacement layer, corresponding to each of the plurality of grooves.
The groove and the electromechanical conversion element, the short sides of the predetermined width, said elongated shape with a longer long side than the short side, Ri shape der by bending into a shape joining the lines and curves or curves ,
The groove, C-shaped, U-shaped, O-shaped or spiral any one electromechanical conversion mechanism, wherein the shape der Rukoto. The electromechanical transducer has at least two electrodes,
Each of the groove portions has a shape surrounding a predetermined region,
The electromechanical conversion mechanism according to claim 2, wherein a wiring connection portion connected to at least one electrode of the electromechanical conversion element is formed in the predetermined region on one surface of the substrate. .   The electromechanical conversion mechanism according to any one of claims 1 to 3, wherein the plurality of grooves are arranged in a staggered manner.   The electromechanical conversion mechanism according to claim 1, wherein the displacement layer is formed so as to cover the groove portion.   The electromechanical conversion mechanism according to claim 5, wherein the electromechanical conversion element has substantially the same width, length, and shape as the groove.   The displacement layer is narrower than a predetermined width of the short side and longer than a length of the long side, and is formed on the groove along the groove. The electromechanical conversion mechanism according to any one of the above.   The electromechanical conversion mechanism according to claim 7, wherein the electromechanical conversion element has substantially the same width, length, and shape as the displacement layer. The electromechanical conversion mechanism according to any one of claims 1 to 6,
An ink supply section for supplying ink to the groove section;
An ink jet head comprising: a nozzle that discharges ink stored in the groove. An ultrasonic transmission unit that transmits ultrasonic waves toward the subject;
An ultrasonic probe comprising: the electromechanical conversion mechanism according to any one of claims 1 to 8 for receiving ultrasonic waves reflected or transmitted by the subject.

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