JP2001298795A - Ultrasonic wave probe and manufacturing method for the ultrasonic wave probe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear and two-dimensional array ultrasonic wave probe that employs a composite piezoelectric body consisting of a solid solution group piezoelectric single crystal and a resin where no defective processing is caused at cutting and to provide a manufacturing method for the ultrasonic wave probe. SOLUTION: The ultrasonic wave probe is characterized in that inserting the piezoelectric body 111 made of a solid solution group single crystal containing at least lead titanate between resin layers 113, 115 whose acoustic impedance is smaller than that of the piezoelectric body and having conductivity can prevent occurrence of defective processing at cutting and the resin layers are used for an acoustic matching layer or electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe used for an ultrasonic diagnostic apparatus, an ultrasonic treatment apparatus, and the like, and a method for manufacturing the ultrasonic probe.

[0002]

2. Description of the Related Art An ultrasonic probe is mainly composed of a piezoelectric material, irradiates an ultrasonic wave toward an object, and receives a reflected wave from an interface having a different acoustic impedance from the object. Is used to image the internal state of. As an ultrasonic imaging apparatus employing such an ultrasonic probe, for example, there are a medical diagnostic apparatus for inspecting the inside of a human body, an inspection apparatus for detecting a flaw in metal welding, and the like.

[0003] In this ultrasonic diagnostic apparatus, which is a medical ultrasonic imaging apparatus, the velocity of the blood flow is two-dimensionally displayed in color using the Doppler shift of the ultrasonic blood flow in addition to the tomographic image (B-mode image) of the human body. Color Flow Mapping (CFM)
Imaging techniques, such as a tissue harmonic imaging (THI) method that images the second harmonic, have been developed. The ultrasonic probe has a form corresponding to these various imaging methods, and enables transmission and reception of ultrasonic waves for all organs of the human body.

In general, an ultrasonic probe used for an ultrasonic diagnostic apparatus is required to obtain a high-resolution image with high sensitivity. This is to make it possible to find small lesions and voids using an image that can be clearly displayed up to the deep part of the diagnosis target. In recent years, as one of the methods, it has been considered to further increase the sensitivity and the bandwidth of an ultrasonic probe as a sensor part.

In order to achieve the above-mentioned high sensitivity and wide band, a composite piezoelectric body having a structure in which a piezoelectric body column or a piezoelectric body powder is embedded in a resin has been studied. For example,
19151, JP-A-60-97800, JP-A-61-5
3562, JP-A-61-109400, JP-A-57-45290 and JP-A-58-2188.
3, JP-A-60-54600, JP-A-60-8569
9, JP-A-62-122499, JP-A-62-1317
00, etc., the structure has been proposed.

[0006] The ultrasonic probe using the composite piezoelectric body disclosed in these publications has a problem that the acoustic impedance decreases and approaches the impedance of a living body, and the type 1-3 and 2-2.
A configuration such as a mold has advantages such as an increase in electromechanical coupling coefficient as compared with a thin plate. This is the composite piezoelectric body, since the dielectric constant is large electromechanical coupling coefficient k ₃₃ is large PZT based piezoelectric ceramic is mainly used.

On the other hand, an ultrasonic probe using a composite piezoelectric body has a problem that the improvement in the electromechanical coupling coefficient is small compared to the decrease in the dielectric constant caused by including a resin. Therefore, in reality, the composite piezoelectric body is only used for a single-type mechanical probe or an annular array having a large element area. Therefore, k ₃₃ compared with kt have been made attempts to solve this problem by using a dramatically higher solid-solution piezoelectric single crystal. (Japanese Patent Laid-Open No. 09-841
94) In order to realize a high-sensitivity, wide-band ultrasonic probe, a composite piezoelectric body 30 composed of a solid-solution type piezoelectric single crystal 32 and resins 34, 36 as shown in an array probe 28 shown in FIG. Is formed. However, in the formation of the composite piezoelectric body 30, a defect at the time of cutting is a problem. That is, since the solid solution-based piezoelectric single crystal 32 generally has low fracture toughness and is brittle, the solid solution-based piezoelectric single crystal 32 shown in FIG.
There is a problem that chipping as shown in FIG. This chipping causes defects due to deterioration of characteristics and cracks in the element.

Therefore, we proposed a structure as shown in FIG. 14A as an ultrasonic probe using these single crystals (see Japanese Patent Application Laid-Open No. 2000-14672), and tried to improve the yield of probe production. FIG. 14A shows a cross-sectional structure of an array probe using a single crystal vibrating element. Electrodes 4 and 5 are formed on both surfaces of the single crystal vibrating element 1, and a backing material 2 is provided on the lower surface of the vibrating element 1. The acoustic matching layers 3a and 3b are formed on the upper surface of the single crystal vibrating element, and the single crystal vibrating element 1 and the acoustic matching layers 3a and 3b are arrayed. The array pitch of the array probes is as narrow as about 0.1 mm. Further, ultrasonic waves are transmitted and received through the acoustic lens 8 provided on the acoustic matching layer 3b. The electrodes 4 and 5 formed on both surfaces of the single crystal vibrating element 1 are FPC
Connected to the cable via 6, 7 and connected to the diagnostic device
(Figure omitted). In the structure of FIG. 14A, the FPC 6 is formed by expanding the conductive layer of the FPC to the area of the vibrating element and bonding the entire surface of the FPC 6 with an epoxy adhesive. Generally, metal Cu is used for the conductive layer. FIG. 14B shows the signal F shown in FIG.
FIG. 2 shows a conductive layer below the PC as viewed from the single crystal vibrating element 1. The conductive layer 6a 'of the signal FPC shown in FIG. 14A is staggered from the conductive layer 6a as shown in FIG. 14B. These array structures are prepared as described below. The electrodes 4 and 5 are formed on the single crystal vibrating element 1 having an integral shape. Backing material 2 with vibrating element with FPC bonded
After the acoustic matching layers 3a and 3b are formed, they are cut from the matching layer side using a dicing saw. Thereafter, the acoustic lens 8 is formed on the acoustic matching layer 3b to complete the process.

However, an FPC in which the conductive layer is extended to the area of the single-crystal vibrating element by employing the above-described manufacturing method is bonded to the vibrating element and the entire surface of the vibrating element with an epoxy-based adhesive. When an acoustic matching layer is formed on the vibrating element and the array processing is performed using a dicing saw, cracks and chipping may occur at the dicing edge of the surface of the single crystal vibrating element to which the FPC is bonded. There was a problem that there is. This is considered to be caused by simultaneous cutting of the piezoelectric single crystal having low mechanical strength and the conductive layer of FPC having poor machinability during array processing. In addition, burrs from the conductive layer generated during processing roughen the cut surface of the single crystal vibrating element, and the cuttings caught in the blade cause the cutting quality to decrease. It is difficult to suppress such cracking and chipping of the single crystal vibrating element even by adjusting the processing conditions. Large cracks can lead to poor disconnection and reduce manufacturing yield, and small cracks can develop during use and cause market accidents. In addition, since chipping reduces the electrode area of the vibrating element processed into a strip shape, it causes not only deterioration of characteristics but also large variations in characteristics between array elements. Since the number of array elements ranges from tens to hundreds, variations in characteristics between array elements affect the image quality of a tomographic image displayed on a diagnostic device.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and the use of a composite piezoelectric body of a solid solution type piezoelectric single crystal and a resin reduces processing defects during cutting. It is an object of the present invention to provide a one-dimensional and two-dimensional array ultrasonic probe which does not cause any problem and a method for manufacturing the ultrasonic probe.

[0011]

The present invention employs the following means to achieve the above object.

According to a first aspect of the present invention, there is provided a single crystal piezoelectric material cut into an array, an upper surface resin layer formed on an upper surface of the piezoelectric material and having a smaller acoustic impedance than the piezoelectric material;
Alternatively, an ultrasonic vibration element including at least one of a lower surface resin layer formed on the lower surface of the piezoelectric body and having a smaller acoustic impedance than the piezoelectric body, wherein at least one of the upper surface resin layer or the lower surface resin layer is provided. Is an ultrasonic probe having good cutting properties and conductivity and functioning as an electrode.

A second aspect of the present invention relates to a piezoelectric body formed of a solid solution single crystal containing at least lead titanate, and an upper surface resin layer formed on the upper surface of the piezoelectric body and having a smaller acoustic impedance than the piezoelectric body. Or at least one of a lower surface resin layer formed on the lower surface of the piezoelectric body and having a lower acoustic impedance than the piezoelectric body.
An ultrasonic vibration element formed of a mold or a 2-2 type composite piezoelectric body, and at least one of the upper surface resin layer and the lower surface resin layer has excellent cutting properties and conductivity, and functions as an electrode. An ultrasonic probe including an ultrasonic vibration element.

Further, in the ultrasonic probe according to the second aspect, at least one of the upper resin layer and the lower resin layer has a thickness of 2 × 10 ⁶ g / m ² s to 10 × 10 ^6.
It has an acoustic impedance of g / m ² s and functions as an acoustic matching layer.

According to a third aspect of the present invention, there is provided a first step of forming a solid-solution-based piezoelectric single crystal containing at least lead titanate; A second step of forming a resin layer having a small acoustic impedance, a third step of cutting a piezoelectric single crystal and the resin layer to form a plurality of grooves, and a fourth step of filling the plurality of grooves with resin. And a step of manufacturing the ultrasonic probe.

In the ultrasonic probe manufacturing method according to a third aspect, in the second step, the plurality of grooves may be formed in a lattice shape. Also,
A configuration including a fifth step of polishing and removing the resin layer may be employed.

A fourth aspect of the present invention is a first step of forming a resin layer having a smaller acoustic impedance than the single-crystal piezoelectric body on at least one of the upper and lower surfaces of the single-crystal piezoelectric body; An ultrasonic probe manufacturing method, comprising: a second step of forming a plurality of grooves by cutting the resin layer and the resin layer; and a third step of filling the plurality of grooves with a resin.

According to a fifth aspect of the present invention, there are provided a plurality of piezoelectric bodies formed of a solid solution single crystal containing at least lead titanate and arranged in an array, and a first piezoelectric body formed on the lower surface of each of the piezoelectric bodies. And a plurality of pattern wirings each having a width smaller than the width of each of the piezoelectric bodies in the array direction and drawing out electric wiring from each of the first electrodes and connecting to the ultrasonic diagnostic apparatus main body. An ultrasonic probe comprising: a flexible printed circuit board according to claim 1;

In the method for manufacturing an ultrasonic probe according to a fifth aspect, the second probe formed on the upper surface of each of the piezoelectric bodies is formed.
A second flexible printed wiring having a plurality of electrodes and a plurality of pattern wirings each having a width smaller than the width of each of the piezoelectric bodies in the array direction and leading out an electric wiring from each of the second electrodes and making a GND connection therewith And a substrate.

According to the present invention having the configuration described above,
It is possible to manufacture an ultrasonic probe that does not cause processing defects during cutting. As a result, an ultrasonic probe having high sensitivity and wide band characteristics can be realized.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, first to seventh embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 shows a schematic configuration of an ultrasonic probe 10 according to a first embodiment.

In FIG. 1, an ultrasonic probe 10 includes a composite piezoelectric body (type 1-3), an acoustic matching layer 17, an acoustic lens 19, a common electrode plate 21, a flexible wiring board 23,
The structure includes a backing material 25.

The composite piezoelectric body (1-3 type) 11 has a single-crystal piezoelectric body 111, an upper PVC resin layer 113, and a lower PVC resin layer 115. That is, the composite piezoelectric body (1-
Type 3) 11 is a piezoelectric body in which a one-dimensional thin rod of a single crystal piezoelectric ceramic is embedded in a PVC resin matrix which is a three-dimensional polymer, and has a high electromechanical coupling coefficient and a low acoustic impedance. Have. Composite piezoelectric body 11
On both upper and lower surfaces, electrodes (not shown) for transmitting and receiving electric signals by piezoelectric direct effect and piezoelectric reverse effect,
It is formed by a method described later.

The single crystal piezoelectric body 111 is a solid solution single crystal piezoelectric ceramic containing lead zinc niobate (PZN), lead titanate (PT), and the like, and is prepared by a method described later.

The upper PVC resin layer 113 is made of a piezoelectric material 111
This layer is formed by applying a PVC resin containing silver on the ultrasonic irradiation side (hereinafter, upper side) of the substrate, and has conductivity, good cutting properties, and a small acoustic impedance (for example, 2 × 10 ⁶ g / m ² s to 10 × 10 ⁶ g
/ M ² s).

The lower PVC resin layer 115 is a layer formed by applying a PVC resin containing silver on the side opposite to the upper side of the single-crystal piezoelectric body 111 (hereinafter, lower side), and has a conductive property.
It has good machinability and low acoustic impedance as compared with a single crystal piezoelectric material. The lower PVC resin layer 115 and the upper PVC resin layer 113 play a role in preventing the single crystal piezoelectric body 111 from chipping or cracking. The method of forming the lower PVC resin layer 115 and the upper PVC resin layer 113 will be described later in detail.

The acoustic matching layer 17 is provided so as to be located between the subject (not shown) and the composite piezoelectric body 11, and is composed of a single layer or a multilayer. By adjusting parameters such as sound speed, thickness, and acoustic impedance in the matching layer 17, acoustic impedance matching between the subject and the composite piezoelectric body 11 can be achieved.

The acoustic lens 19 is a lens made of silicone rubber or the like whose acoustic impedance is close to that of a living body. The acoustic lens 19 focuses an ultrasonic beam using refraction of a sound wave to improve the resolution.

The common electrode plate 21 is formed of the upper PVC resin layer 11
3 is provided at one end. The common electrode plate 21 is an electrode for applying electric power to an electrode (not shown) formed on the upper surface of the composite piezoelectric body 11, and is connected to the ground.

The flexible wiring board 23 is made of a lower PVC.
Each composite piezoelectric element 1 is provided at one end of the resin layer 115.
1 is an electrode substrate having flexibility for applying electric power to the electrode substrate.

The backing material 25 is provided on the back surface of the flexible wiring board 23, and mechanically supports the composite piezoelectric body 11. Further, the backing material 25 brakes the composite piezoelectric body 11 in order to shorten the ultrasonic pulse.
The thickness of the backing material 25 is maintained at a sufficient thickness (thickness that is sufficiently attenuated) with respect to the wavelength of the ultrasonic frequency to be used in order to maintain good acoustic characteristics of the transducer.

Next, a method of manufacturing the 1-3 type composite piezoelectric body 11 used in the ultrasonic probe 10 according to the first embodiment will be described. This manufacturing method includes forming a single-crystal piezoelectric body 111 (first step) and forming upper and lower PVC resin layers (second step).
Step), dicing of the PVC resin layers 113 and 15 (third step), resin filling (fourth step), PVC
Polishing of the resin layers 113 and 15 (fifth step) can be divided into five large steps.

First, the formation of the composite piezoelectric body 11 in the first step will be described.

[0035] Lead zinc niobate (PZN) and lead titanate (PT) were dissolved in a platinum container at a molar ratio of 91: 9 together with Pb flux by heating and then cooled to room temperature to form a solid solution single crystal. Cultivate. Thereafter, the orientation of the <001> axis of the single crystal is determined using a Laue camera, and the single crystal is cut by a cutter perpendicular to the axis. After polishing to a thickness of 300 μm, Ti / Au electrodes are formed on both surfaces by a sputtering method, whereby the single crystal piezoelectric body 111 can be formed.

Next, the upper and lower PVC resin layers 1 in the second step
The formation of 13 and 15 will be described.

The piezoelectric body 1 formed in the first step
11 is temporarily fixed to a glass plate, and the surroundings are masked with a Kapton tape. Then, a conductive silver-containing PVC resin is applied and polished to a thickness of 300 μm with a plane polisher to form an upper PVC resin layer 113 having good machinability. I do. Similarly, the lower side of the piezoelectric body 11 also has a lower PVC resin layer 1 having good cutability of 300 μm.
15 are formed. Note that the order of forming the upper PVC resin layer 113 and the lower PVC resin layer 115 may be reversed.

Next, the upper PVC resin layer 1 in the third step
13 and the resin filling in the fourth step will be described.

The silver-containing P formed in the second step
The piezoelectric body 111 sandwiched by the VC resin layers 113 and 115 is cut by a dicing saw with a 50 μm thick blade at a pitch of 200 μm and a depth of 800 μm (100
The grooves of (μm uncut) are arranged in an array, and the epoxy resin 12 is filled in the cut grooves and cured. Similarly, a similar cut groove is formed at right angles to the previous cut groove, and the epoxy resin 12 is filled and cured.

Next, the upper and lower PVC resin layers 1 in the fifth step
The polishing of Nos. 13 and 115 will be described.

Thereafter, the uncut side is temporarily fixed to the glass plate with the lower side as the lower surface, and the layer on the opposite side is polished to 150 μm by a plane polishing machine. Further, 150 μm is similarly set with the uncut side as the upper surface.
Polish to m. Then, on both sides by sputtering, T
By forming the i / Au electrode, it is possible to form the 1-3 type composite piezoelectric body 11 with little chipping or cracking due to cutting or the like.

Finally, the 1 formed by the above manufacturing method is
An electric field of 1 KV / mm is applied to the −3 type composite piezoelectric body 11 to perform polarization processing.

The above-described method for manufacturing a composite piezoelectric material can be variously modified without changing its essence. For example, 1-
Although the three-type composite piezoelectric body 11 has been described as an example, the present invention
As described in the second embodiment, the present invention is also applicable to a 2-2 type composite piezoelectric body. Alternatively, the resin may be cut into a matrix form from the beginning and then filled with resin. further,
When the epoxy resin is filled in two stages as in this embodiment, the type may be changed.

Next, the 1 manufactured by the above manufacturing method was used.
An example of a method of manufacturing the one-dimensional array type ultrasonic probe 10 using the −3 type composite piezoelectric body will be described with reference to FIG.

FIG. 2 is a diagram showing a cross section of the ultrasonic probe 10 according to the present embodiment.

First, the common electrode plate 21 is connected to the upper PVC resin layer 113 of the composite piezoelectric body 11, and the flexible wiring board 23 is connected to the lower PVC resin layer 115 by using a conductive paste. The second acoustic matching layer 17 is formed. Thereafter, the backing material 25 and the flexible wiring board 23 are bonded with an epoxy resin.

Then, a 50 μm-thick
Is cut in the array direction at a pitch of 200 μm. The groove is filled with a silicone-based adhesive, and the acoustic lens 19 is bonded.

Then, a capacitance of 110 pF / m and a length of 2
By connecting the m coaxial cables to the flexible wiring board 23, the one-dimensional array type ultrasonic probe 10 can be manufactured.

Next, the operation of the ultrasonic probe manufactured by the above manufacturing method will be described.

In the ultrasonic probe 10, since the 1-3 type composite piezoelectric body 11 sandwiches the single crystal piezoelectric body 111 between the upper PVC resin layer 113 and the lower PVC resin layer 115, an array of grooves is formed. In this case, the occurrence of chipping can be prevented.

The upper PVC resin layer 113 and the lower PV
Since the C-resin layer 115 has smaller acoustic impedance, conductivity, and good cutting properties than the single-crystal piezoelectric body 111, the C-resin layer 115 transmits or receives an electric signal related to the single-crystal piezoelectric body 111, It can be a matching layer.

After the formation of the arrayed grooves and the filling of the epoxy resin 12 by the first to fourth steps, that is, the possibility of occurrence of chipping is eliminated, the upper PVC resin layer 113 and the lower PVC resin are formed in the fifth step. Layer 11
5 may be entirely polished and a new electrode or acoustic matching layer may be provided.

The upper PVC resin layer 113 and the lower PV
The C resin layer 115 has a durometer hardness of 700 to 10
00HDd is preferred.

Therefore, according to such a configuration, by providing the layer having good machinability according to the present invention on at least one of the upper and lower surfaces of the solid solution type piezoelectric single crystal, processing defects at the time of cutting can be reduced, and high sensitivity, A broadband ultrasonic probe can be easily manufactured. In addition, since the PVC resin layer has conductivity, the electrical connection with the single crystal piezoelectric body is high, and an ultrasonic vibration element having good characteristics can be formed.

(Second Embodiment) In the first embodiment, 1
The method for manufacturing the −3 type composite piezoelectric body 11 and the method for manufacturing the ultrasonic probe 10 using the piezoelectric element have been described. On the other hand, in the second embodiment, a method for manufacturing a 2-2 type composite piezoelectric body and a method for manufacturing an ultrasonic probe using the 2-2 type composite piezoelectric body will be described.

The external appearance of the ultrasonic probe using the 2-2 type composite piezoelectric body is the same as that of the ultrasonic probe 10 using the 1-3 type composite piezoelectric body shown in FIG. The description of the components already described is omitted. In addition, description of portions that are the same as the manufacturing method described in the first embodiment will be omitted, and only different portions will be described.

The method of manufacturing the 2-2 type composite piezoelectric material according to the second embodiment is the same as that of the first embodiment in the first step and the second step.

The dicing of the upper PVC resin layer 113 and the lower PVC resin layer 115 in the third step and the resin filling in the fourth step will be described.

The silver-containing P formed in the second step
The piezoelectric body 11 sandwiched by the VC resin layers 3 and 4 is cut by a dicing saw with grooves of 200 μm pitch and a depth of 800 μm (100 μm uncut portion) perpendicular to the array direction with a 50 μm blade, and then epoxy resin 12 is filled into the cut groove and cured.

Next, the upper and lower PVC resin layers 1 in the fifth step
The polishing of Nos. 13 and 115 will be described.

Thereafter, the uncut side is temporarily fixed to the glass plate with the lower surface as the lower surface, and the layer on the opposite side is polished to 150 μm by a plane polishing machine. Further, 150 μm is similarly set with the uncut side as the upper surface.
Polish to m. Then, on both sides by sputtering, T
By forming the i / Au electrode, it is possible to form the 2-2 type composite piezoelectric body 11 with little chipping or cracking due to cutting or the like.

Finally, the 2 formed by the above manufacturing method
An electric field of 1 KV / mm is applied to the -2 type composite piezoelectric body 11 to perform polarization processing.

Next, the 2 manufactured by the above manufacturing method was used.
An example of a method of manufacturing the one-dimensional array type ultrasonic probe 10 using the −2 type composite piezoelectric body will be described.

First, the common electrode plate 21 is connected to the upper PVC resin layer 113 of the composite piezoelectric body 11 and the flexible wiring board 23 is connected to the lower PVC resin layer 115 by using a conductive paste. The second acoustic matching layer 18 is formed. Then, it is bonded to the backing material 25 with an epoxy resin.

Next, the wafer was cut by a dicing saw at a pitch of 200 μm in the array direction using a blade having a thickness of 50 μm. The groove is filled with a silicone-based adhesive, and the acoustic lens 6 is bonded.

Then, a capacitance of 110 pF / m and a length of 2
The one-dimensional array type ultrasonic probe 10 can be manufactured by connecting the m coaxial cables to the flexible wiring board 23.

According to the ultrasonic probe having the 2-2 type composite piezoelectric body manufactured by the above method, the same operation and effect as those of the ultrasonic probe having the 1-3 type composite piezoelectric body described in the first embodiment are obtained. The effect can be obtained.

(Third Embodiment) In the third embodiment, 1
A method of manufacturing a two-dimensional array type ultrasonic probe in which ultrasonic vibration elements are two-dimensionally arranged (for example, arranged in a matrix) using a −3 type composite piezoelectric body 11 will be described.

FIG. 3 is a cross-sectional view of a two-dimensional array type ultrasonic probe 30 according to the third embodiment.

The components already described with reference to FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. In addition, the first and second
The description of the parts overlapping with the manufacturing method described in the above embodiments will be omitted, and only different parts will be described.

The method of manufacturing the 1-3 type composite piezoelectric body 11 according to the third embodiment is the same as that of the first embodiment in the first step and the second step.

Next, in the third step, the upper PVC resin layer 1
13 and the resin filling in the fourth step will be described.

The P containing silver formed in the second step
The piezoelectric body 11 sandwiched by the VC resin layers 3 and 4 is arranged in an array with grooves of 200 μm pitch and 700 μm depth (100 μm left uncut) by a dicing saw at a pitch of 200 μm with a dicing saw, and the epoxy resin 12 is cut into grooves. Fill and cure. Similarly, a similar cut groove is formed at right angles to the previous cut groove, and the epoxy resin 12 is filled and cured.

Next, the upper and lower PVC resin layers 1 in the fifth step
The polishing of Nos. 13 and 115 will be described.

Thereafter, the uncut side is temporarily fixed to the glass plate with the lower side as the lower surface, and the layer on the opposite side is polished to 150 μm by a plane polishing machine. Further, 150 μm is similarly set with the uncut side as the upper surface.
Polish to m. That is, the lower surface PV of the uncut side after polishing
The C resin layer 113 is not cut.

Then, Ti is formed on both surfaces by sputtering.
By forming the / Au electrode, it is possible to form the 1-3 type composite piezoelectric body 11 having a two-dimensional arrangement with little chipping or cracking due to cutting or the like.

Next, the 2 manufactured by the above manufacturing method was used.
An example of a method of manufacturing the two-dimensional array type ultrasonic probe 30 using a composite piezoelectric body having a three-dimensional array will be described.

First, the uncut upper surface PVC resin layer 11
3, a common electrode plate 21 is bonded, and a flexible wiring board 8 on which two-dimensional signal wiring is provided on the opposite surface is bonded over the entire surface. After forming the second acoustic matching layer 18 on the ultrasonic wave emitting surface side, it was bonded to the backing material 25 with an epoxy resin.
The silicone-based acoustic lens 19 was bonded to this. FP
Collectively, the signal side of C is 1K between the signal side and the GND side.
A voltage of V / mm was applied to perform polarization processing.

In addition, a capacitance of 110 pF / m and a length of 2
The two-dimensional array type ultrasonic probe 30 can be manufactured by connecting the m coaxial cables to the flexible wiring board 8.

In the above description, the two-dimensional array type ultrasonic probe 30 using the 1-3 type composite piezoelectric body has been described, but the present invention is applicable to the 2-2 type composite piezoelectric body.

Accordingly, the two-dimensional array type ultrasonic probe 30 having the 1-3 type composite piezoelectric body according to the third embodiment is described.
Can obtain the same operation and effect as those of the one-dimensional array type ultrasonic probe described in the first and second embodiments.

(Fourth Embodiment) In the fourth embodiment,
Another method of manufacturing the 1-3 type or 2-2 type composite piezoelectric body 11 will be described.

First, another method of manufacturing the 1-3 type composite piezoelectric body 11 will be described.

A single-crystal piezoelectric body 111 is formed by the same method as in the first step shown in the first embodiment.

In the subsequent second step, in this embodiment, upper and lower PVC resin layers 113 and 115 are formed as described below. That is, the plurality of piezoelectric bodies 111 formed in the first step are arranged and adhered on the conductive resin sheet, and the sheet is cut to the size of the back surface of the piezoelectric body 11. As the conductive resin sheet, a sheet obtained by molding a PVC resin containing conductive silver into a sheet shape is used.

Subsequently, the 1-3 type composite piezoelectric body 11 is formed through the same steps as the third, fourth and fifth steps shown in the first embodiment. 1 formed
The −3 type composite piezoelectric body 11 is subjected to a polarization process by applying an electric field of 1 KV / mm.

The 1-3 type composite piezoelectric body 11 described in the first embodiment can also be formed by the manufacturing method described above. In addition, the present manufacturing method has a benefit in increasing the size of an ultrasonic probe using a piezoelectric single crystal. That is, in general, it is difficult to increase the size of the piezoelectric single crystal itself, and therefore, it is not easy to increase the size of the ultrasonic probe using the composite piezoelectric body of the piezoelectric single crystal. However, according to the present manufacturing method, in particular, by arranging a plurality of single-crystal piezoelectric bodies 111 on a conductive resin sheet, for example, a plurality of single-crystal piezoelectric bodies 111 are arranged in an array direction.
The type composite piezoelectric body 11 can also be easily manufactured, and the size of the ultrasonic probe can be easily increased.

Next, another method of manufacturing the 2-2 type composite piezoelectric body 11 will be described. 2-2 type composite piezoelectric body 1
Also in 1, the 2-2 type composite piezoelectric body can be formed from the single crystal piezoelectric body adhered to the conductive resin sheet by the same procedure as the above-described method of manufacturing the 1-3 type composite piezoelectric body 11. Other steps are the same as in the second embodiment.

The one-dimensional or two-dimensional array type ultrasonic probe using the 1-3 type or 2-2 type composite piezoelectric material formed by each of the above manufacturing methods can be manufactured by the above-described method. .

(Fifth Embodiment) In the fifth embodiment,
Another one-dimensional or two-dimensional array type ultrasonic probe using the 1-3 type or 2-2 type composite piezoelectric body 11 will be described.

FIG. 4 shows a schematic configuration of an array type ultrasonic probe according to this embodiment. 3 is different from the probe shown in FIG. 3 in that an electrode 24 is provided on the lower PVC resin layer 115 of each single-crystal piezoelectric body 111.
Is drawn out from one end of the flexible wiring board 23. Even in such a configuration, the first to third
The same operation and effect as those of the array type ultrasonic probe described in the embodiment can be obtained.

(Sixth Embodiment) In the sixth embodiment,
Without forming the lower PVC resin layer and the upper PVC resin layer,
A one-dimensional array type ultrasonic probe that reduces chipping and cracks will be described.

First, the schematic configuration of the one-dimensional array type ultrasonic probe 35 according to the present embodiment will be described with reference to FIGS.

FIG. 5 is a sectional view of a one-dimensional array type ultrasonic probe 35 according to the present embodiment.

As shown in FIG. 5, each single crystal piezoelectric body 111
The first electrode 40 is formed on the upper surface, and the second electrode 50 is formed on the lower surface. A first flexible wiring board 42 is connected to each first electrode 40 with a conductive paste.
On the other hand, a second flexible wiring board 44 is connected to each second electrode 50 with an epoxy-based adhesive.

A predetermined electric power is applied or detected to each of the electrodes 40 and 50 via each of the flexible wiring boards 42 and 44. The first flexible wiring board 42 is a multilayer board including a conductive layer 420 made of copper or the like and an insulating layer 421 made of a polyimide film or the like, and is used for establishing a GND connection. The second flexible wiring board 44 includes conductive layers 440 and 442 made of copper or the like.
Insulating layers 441 and 443 made of a polyimide film or the like;
445 and a probe 35
And the ultrasonic diagnostic apparatus main body are electrically connected. The conductive layer 444 has a predetermined wiring pattern described later (see FIG. 6).

The one-dimensional array type ultrasonic probe 35 has a first acoustic matching layer 17 and a second acoustic matching layer 18. The arrangement pitch of the vibration elements of the probe 35 is as narrow as about 0.1 mm.

FIG. 6 shows the second flexible wiring board 44.
Of the conductive layer 440 of FIG.

As shown in FIG. 6, the second flexible wiring board 44 has a predetermined pattern of wiring 440a. The pitch width of the wiring 440a is equal to or smaller than the pitch width of the array of the single crystal piezoelectric members 111 included in the probe 35. Each wiring 440a is bonded to each second electrode corresponding to each single-crystal piezoelectric body 111 with an epoxy-based adhesive on the entire surface of the second electrode 440, and is alternately pulled out in the opposite direction as shown in FIG. The alternate extraction of the wiring is not essential. For example, all the wirings may be extracted in the same direction.

In this embodiment, the first flexible wiring board 42 is the same as the second flexible wiring board 44.

According to such a probe 35, the first flexible wiring board 42 and the second flexible wiring board 44 are set to be equal to or smaller than the pitch width of the array arrangement of the single crystal piezoelectric members 111. It is not necessary to cut the conductive layer 444 and the single crystal piezoelectric body 111 at the same time. That is, the conductive layers 4 having different machinability
Since the single crystal 44 and the single crystal piezoelectric body 111 are not cut at the same time, it is possible to suppress the occurrence of cracks and chipping in array production. Also, by cutting the single-crystal piezoelectric body 111 in a state where the first flexible wiring board 42 and the second flexible wiring board 44 are connected, the occurrence of cracks and chipping is suppressed.

According to the experiment of the present inventors, when the characteristics of the completed probe 35 were evaluated, no disconnection element was present and the sensitivity variation was as small as 2 dB.

On the other hand, in the conventional method, for example, the conductive layer 440 of the second flexible wiring board 44 is expanded to the size of the contact surface of the single-crystal piezoelectric body 111, and
When the entire surface of No. 1 was joined with an epoxy adhesive, the present inventors evaluated as follows. That is, about 30% of cracks occurred during array processing. The probe was completed and the characteristics were evaluated.
The sensitivity variation was as large as 10 dB. Examination of the cause of the disconnection revealed that the vibrating element of the channel where the disconnection occurred had cracks which were considered to have occurred during array processing. Also,
Many vibrating elements also exhibited chipping. These results are considered to have influenced the sensitivity variation.

By the way, from the viewpoint of mass production of probes, it is not necessary to use the same first flexible wiring board 42 as the second flexible wiring board 44 in some cases. Since the wiring 442 of each flexible wiring board is patterned with the same width or less as the single-crystal piezoelectric bodies 111 arranged in an array, the position between the first flexible wiring board 42 and the second flexible wiring board 44 It is not easy to match.

Therefore, the second flexible wiring board 44
Only the conductor layer shown in FIG. 6 may be used. According to such a configuration, the conductive layer that needs to be cut is the first conductive layer.
Since only the vicinity of the end of the vibrating element of the flexible wiring board 42 is affected, its influence is negligible, and cracks and chipping during processing do not occur. According to the evaluations of the present inventors, there were no disconnection elements in the probe 53 and the sensitivity variation was as small as 2 dB.

The ultrasonic probe 3 according to the present embodiment
5 is not intended to be limited to the above configuration. For example, the following modifications are possible.

FIG. 7 is a view for explaining a modification of the ultrasonic probe 35. FIG. 8 is a view showing the pattern wiring of the second flexible wiring board 44 included in the ultrasonic probe 35 according to the modification.

In FIG. 7, the ultrasonic probe 35 has a through hole 45 in addition to the configuration shown in FIG. As shown in FIG. 8, the through holes 45 conduct electricity between the wirings 440a and 440b of the conductive layer 440.

According to the ultrasonic probe 35 according to the present embodiment described above, chipping and cracks can be reduced.

(Seventh Embodiment) In the seventh embodiment,
A description will be given of an ultrasonic probe in which the wiring drawn from the first electrode 40 and the wiring drawn from the second electrode 50 are integrated and taken out from the lower surface of the single-crystal piezoelectric body 111.

FIG. 9 is a view for explaining a schematic configuration of an ultrasonic probe 50 according to the seventh embodiment. In addition,
FIG. 2 shows a state before the first electrode 40 and the second electrode 50 are bonded to the second flexible wiring board 44. In FIG. 9, the first electrode 40 for GND is
It is a turn-in electrode that is continuous from the upper surface of the single crystal piezoelectric body 111 to the lower surface via the side surface. First electrode 40
Is connected to the conductive layer 442 of the second flexible wiring board 44, and the second electrode 50 is connected to the conductive layer 440 of the second flexible wiring board 44. Although not shown, exposed portions are formed on the conductive layers 442 and 440 in accordance with the electrodes 40 and 50 of the single-crystal piezoelectric body 111.

The thickness of each of the conductive layers 440 and 442 is 18
μm. The thickness of the insulating layer 443 made of polyimide is 12.5 to 25 μm.

Next, a modified example of the ultrasonic probe 50 will be described.

FIG. 10 is a diagram showing an ultrasonic probe 51 which is a modification of the ultrasonic probe 50. As shown in FIG. 10, the conductive layer 442 is extended to
The first electrode 40 is connected to the wraparound first electrode 40. The extended conductive layer 440 is wrapped around the extended insulating layer 443 to be connected to the second electrode 50. The turn-in structure can be formed by a method such as plating the end.

When compared with the ultrasonic probe 50 shown in FIG. 9, the probe 51 shown in FIG.
2 and the conductive layer 44 are eliminated. Therefore, with such a configuration, it is possible to prevent breakage of the single crystal piezoelectric body 111 which may be caused by pressure bonding.

FIG. 11 is a view showing an ultrasonic probe 52 which is a modification of the ultrasonic probe 51. The probe 52 shown in FIG. 11 is, for example, the probe 5 shown in FIG.
This is advantageous when it is difficult to form the conductive layer 440 in the configuration of the first embodiment. As shown in FIG.
2, the vertical relationship between the conductive layers 440 and 442 is shown in FIG.
It is opposite to the case of 0. Further, the position of the turning-in structure of the first electrode 40 is also opposite to that of the probe 51, and the first electrode 40, the conductive layers 442, 4
Power is supplied to the terminal 42a.

With such a configuration, the single-crystal piezoelectric body 11
After bonding the first and second flexible wiring boards 44,
The first electrode 40 and the conductive layer 442 by the conductive member 48;
442a may be connected. Note that the conductive member 48 is preferably a conductive paste. The connection by the conductive member 48 may be performed after the formation of the ultrasonic vibration element array.

FIG. 12 is a view showing an ultrasonic probe 53 which is a modification of the ultrasonic probe 52. As shown in FIG. 12, the ultrasonic probe 53 exposes the exposed portion 442 b from the tip of the conductive layer 442, and after bonding the single crystal piezoelectric body 111, bends the exposed portion 442 b and connects the exposed portion 442 b to the first electrode 40. With such a configuration, a more stable connection can be obtained.

Note that the first type shown in FIGS.
In the same manner as the second flexible wiring board 44, the flexible wiring board 42 has a pattern wiring 440a whose pitch width is equal to or less than the pitch width of the array arrangement of the single crystal piezoelectric members 111 included in the probe 35, thereby processing the flexible wiring board 42. Cracks and chipping inside can be suppressed. This is because the conductive layer having poor machinability and the single-crystal piezoelectric body 111 are not cut together.

Although the present invention has been described based on the embodiments, various changes and modifications may be made by those skilled in the art within the scope of the present invention. It is understood that examples also fall within the scope of the present invention. For example, as shown in (1) and (2) below, various modifications can be made without changing the gist of the invention.

(1) The single crystal piezoelectric material used in each embodiment is not particularly limited. For example, Pb ((Zn1 / 3Nb2 / 3) 0.91Ti
0.09) A composite perovskite type containing at least lead titanate, such as a single crystal composed of a solid solution of lead zinc niobate and lead titanate represented by O3, and a single crystal composed of a solid solution of lead magnesium niobate and lead titanate. Crystals, single crystals made of a solid solution of lead scandium niobate and lead titanate, and the like are included. Alternatively, a single crystal such as lithium niobate and potassium niobate may be used.

(2) The present invention is applied to the first to third embodiments.
According to the embodiment, a high-sensitivity broadband ultrasonic probe is formed by forming a PVC resin layer on the upper and lower surfaces of the single crystal piezoelectric body 111 to prevent the occurrence of chipping and having a function of an electrode or an acoustic matching layer. Was realized. However, even if the PVC resin layer is formed only on one side of the single crystal piezoelectric body 111, it is possible to prevent chipping and to play a role of an electrode or an acoustic matching layer.

[0123]

As described above, according to the present invention, it is possible to manufacture an ultrasonic probe which does not cause processing defects at the time of cutting. As a result, an ultrasonic probe having high sensitivity and wide band characteristics can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of an ultrasonic probe 10 according to first and second embodiments.

FIG. 2 is a diagram showing a cross section of the ultrasonic probe 10 according to the first and second embodiments.

FIG. 3 is a diagram showing a cross section of an ultrasonic probe 30 according to a third embodiment.

FIG. 4 is a diagram showing a schematic configuration of an array-type ultrasonic probe according to a fifth embodiment.

FIG. 5 is a sectional view of an array-type ultrasonic probe 35 according to a sixth embodiment.

FIG. 6 is a top view of a conductive layer 440 of the second flexible wiring board 44.

FIG. 7 is a view for explaining a modified example of the ultrasonic probe 35;

FIG. 8 is a view showing pattern wiring of a second flexible wiring board 44 included in an ultrasonic probe 35 according to a modification.

FIG. 9 is a view for explaining a schematic configuration of an ultrasonic probe 50 according to a seventh embodiment.

FIG. 10 is a view showing a modification of the ultrasonic probe according to the seventh embodiment.

FIG. 11 is a view showing a modified example of the ultrasonic probe according to the seventh embodiment;

FIG. 12 is a view showing a modified example of the ultrasonic probe according to the seventh embodiment.

FIG. 13A is a diagram showing a cross section of a conventional composite piezoelectric body 30. FIGS. 13B and 13C are diagrams for explaining chipping and cracks that occur during the manufacturing process of the conventional composite piezoelectric body 30.

FIG. 14A is a diagram showing a cross section of a conventional ultrasonic probe. FIG. 14B is a diagram illustrating pattern wiring of a flexible wiring board 6 included in a conventional ultrasonic probe.

[Explanation of symbols]

 10, 35, 50, 51, 52, 53 ultrasonic probe 11 composite piezoelectric body 12 epoxy resin 17 first acoustic matching layer 18 second acoustic matching layer 19 acoustic lens 21 common electrode plate 23 ... Flexible wiring board 24 ... Electrode 25 ... Backing material 38 ... Groove 40 ... First electrode 50 ... Second electrode 42 ... First flexible wiring board 44 ... Second flexible wiring board 45 ... Through hole 50 ... Second Electrode 111: single crystal piezoelectric body 113: upper PVC resin layer 115: lower PVC resin layer 420, 440, 442 ... conductive layer 421, 443, 445 ... insulating layer 440a ... pattern wiring 442b ... exposed part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) A61F 7/00 322 G01N 29/24 502 G01N 29/24 502 A61B 17/36 330 H01L 41/09 H01L 41 / 08 U 41/08 H 41/22 41/22 Z (72) Inventor Mamoru Izumi 1st place, Komukai Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Pref. 1, Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi Toshiba R & D Center

Claims (10)

[Claims] 1. A single-crystal piezoelectric body cut in an array, an upper surface resin layer formed on the upper surface of the piezoelectric body and having a lower acoustic impedance than the piezoelectric body, or the lower surface of the piezoelectric body formed on the lower surface of the piezoelectric body At least one of a lower resin layer having an acoustic impedance smaller than the body, and at least one of the upper resin layer or the lower resin layer has good cutting properties and conductivity, An ultrasonic probe, which functions as an electrode. 2. A piezoelectric body formed of a solid solution single crystal containing at least lead titanate, and an upper surface resin layer formed on the upper surface of the piezoelectric body and having an acoustic impedance smaller than that of the piezoelectric body, or a piezoelectric material of the piezoelectric body. An ultrasonic vibrating element formed of a 1-3 type or 2-2 type composite piezoelectric body comprising at least one of a lower surface resin layer formed on a lower surface and having a lower acoustic impedance than the piezoelectric body; An ultrasonic probe, wherein at least one of the layer and the lower resin layer has good cutting properties and conductivity, and functions as an electrode. 3. The method according to claim 1, wherein at least one of the upper resin layer and the lower resin layer has a thickness of 2 × 10 ⁶ g / m ² s to 10 × 1.
0 6 ^{g /} m 2 ^s ultrasonic probe according to claim 2, characterized in that the function of the acoustic matching layer has an acoustic impedance of. 4. A first step of forming a resin layer having an acoustic impedance smaller than that of the single-crystal piezoelectric body on at least one of the upper and lower surfaces of the single-crystal piezoelectric body; and forming the single-crystal piezoelectric body and the resin layer. An ultrasonic probe manufacturing method, comprising: a second step of forming a plurality of cut grooves; and a third step of filling the plurality of grooves with a resin. 5. The method according to claim 4, wherein in the second step, the plurality of grooves are formed in a lattice shape.
The method for manufacturing an ultrasonic probe according to the above. 6. The method of manufacturing an ultrasonic probe according to claim 4, wherein said method of manufacturing an ultrasonic probe includes a fourth step of polishing and removing said resin layer. 7. A first step of bonding a plurality of single-crystal piezoelectric bodies to a resin sheet on a resin sheet, and a second step of cutting a single-crystal piezoelectric body and the resin layer to form a plurality of grooves. And a third step of filling the plurality of grooves with a resin. 8. A plurality of piezoelectric bodies formed of a solid solution single crystal containing at least lead titanate and arranged in an array, a first electrode formed on a lower surface of each of the piezoelectric bodies, and a width of each of the piezoelectric bodies. A first flexible printed circuit board having a plurality of pattern wirings for extracting electric wiring from each of the first electrodes and connecting the extracted wiring to the ultrasonic diagnostic apparatus main body, the width being smaller than the width of each of the piezoelectric bodies in the array direction; An ultrasonic probe, comprising: 9. A second electrode formed on an upper surface of each of said piezoelectric bodies, and a width of each of said second electrodes is smaller than a width of each of said piezoelectric bodies in an array direction. GN
The ultrasonic probe according to claim 8, further comprising: a second flexible printed wiring board having a plurality of pattern wirings for D connection. 10. A flexible printed wiring board in which a conductive layer of a predetermined width is patterned in parallel on a resin member, a first step of bonding a single-crystal piezoelectric body, and a step between the conductive layers. A second step of cutting both the flexible printed substrate and the single crystal piezoelectric body to form a piezoelectric vibrating element array having a pitch width equal to or greater than the width of the conductive layer. Probe manufacturing method.