JPS58118739A - Ultasonic probe and production thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] ■1 Background of the invention A. Technical field The present invention relates to an ultrasonic probe and a method for manufacturing the same.

(5) B. Prior art and its problems Ultrasonic medical electronic equipment such as ultrasound diagnostic equipment that can observe tomographic images of living bodies in real time has no mechanically moving parts and uses electronic ultrasound. Electronic scanning type ultrasound probes that can scan a sound beam are often used. Such an ultrasonic probe uses a vibrator in which flat plate electrodes are formed by vapor depositing, screen printing, or coating silver on both main surfaces of a flat piezoelectric material made of a ceramic piezoelectric material. A one-dimensional array structure is adopted in which a large number of electrodes are arranged linearly and each flat plate electrode is connected to each external connection terminal by a lead.

Such an ultrasonic probe scans an ultrasonic beam by selectively and sequentially driving a large number of ultrasonic transducers arranged one-dimensionally, and also selectively drives each transducer sequentially during wave reception. Electronic scanning is performed by activating the

Conventionally, an ultrasonic probe consisting of a one-dimensional array of a large number of ultrasonic transducers like this has been designed to conduct electrical connections between each electrode (6) on both principal surfaces of a flat piezoelectric material, that is, the front and back surfaces, and the connecting lead. Each connection was made in a separate process. For example, in the first step, a flat piezoelectric material is divided into many parts, and leads are connected to the electrodes on the back of each vibrator to form individual electrodes for each vibrator. There is an example in which a common electrode such as a metal foil such as copper is commonly connected to the electrodes of the
(See No. 833). In this way, conventional manufacturing methods always require two steps to connect both electrodes of the vibrator and the access part to the external circuit, and in many cases, a large number of vibrators are temporarily connected only during the manufacturing process. I needed an auxiliary board to hold it.

Manufacturing an ultrasonic probe involves many steps, including not only connecting these electrodes and lead parts, but also bonding the backing material, acoustic matching layer, and piezoelectric material, and cutting the transducer into multiple transducers. It is required to reduce the number of steps as much as possible to reduce the price, and to eliminate the accumulation of variations in processing accuracy in each step to obtain highly reliable confectionery.

■0 Purpose of the Invention Therefore, the present invention aims to provide a method of manufacturing a highly reliable ultrasonic probe with as few steps as possible, and such an ultrasonic probe. .

According to the present invention, this object is achieved by the following method of manufacturing an ultrasound probe. That is, according to this method, the first flat conductive material is adhered to one main surface of a rectangular flat piezoelectric material in a manner that substantially covers it, and the first flat conductive material is applied to the other main surface of the rectangular flat piezoelectric material.
A second flat conductive material independent of the flat conductive material is attached, and a part of the first flat conductive material extends to the other main surface and covers a part of the other main surface in the longitudinal direction. forming a first conductive pattern extending along one long side of the opening on the surface of the flexible flat insulating material having a rectangular opening having a width smaller than the width of the rectangular flat piezoelectric material; A second conductive pattern is formed along the other long side of the opening and is independent of the first conductive turn. part of the other main surface of the flat piezoelectric material by placing the flat piezoelectric material on the surface of the flat conductive material so that its long side is substantially parallel to the long side of the opening. A part of one of the first and second flat conductive materials covering the plate is connected to the first conductive pattern of the flat insulating material, and a part of the other flat piezoelectric material is connected to the second conductive P-turn. The long side of the flat piezoelectric material is substantially connected to the long side of the backing material on the main surface of the backing material which has an acoustic impedance different from that of the flat piezoelectric material and has a shape close to the rectangular outer shape of the flat piezoelectric material. Attach the flat insulating material with its back side down so that it is parallel to and a notch is made in the backing material, and this notch extends in the rectangular width direction of the flat piezoelectric material, is located between the plurality of conductor parts, and reaches at least the main surface of the backing material. A plurality of ultrasonic transducers are formed in which the flat conductive material serves as a common electrode and the other flat conductive material serves as individual electrodes (9) According to the present invention, the following ultrasonic probe is provided.

That is, in this ultrasonic probe, a first flat conductive material is adhered to one main surface of a rectangular flat piezoelectric material so as to substantially cover it, and a first flat conductive material is attached to the other main surface of the rectangular flat piezoelectric material. A second flat conductive material independent of the first flat conductive material is applied, and a part of the first flat conductive material extends to the other main surface and covers a part of the other main surface in the longitudinal direction, and a rectangular shape is formed. A first conductive pattern extending along one long side of the opening is formed on the surface of a flexible flat insulating material having a rectangular opening having a width smaller than the width of the flat piezoelectric material. forming a second conductive pattern extending along the other long side and independent of the first conductive pattern;
The second conductive pattern has a plurality of conductor parts extending away from the opening, and the flat piezoelectric material is placed on the surface of the flat conductive material so that its long side is substantially parallel to the long side of the opening. A part of one of the first and second flat conductive materials covering a part of the other main surface of the flat piezoelectric material is placed on the first conductive pattern of the flat insulating material, and a part of the other plate flat r1n) A main surface of a backing material that connects a part of the plate piezoelectric material to the second conductive/mother turn, and has an acoustic impedance different from that of the flat piezoelectric material and has a shape close to the rectangular outer shape of the flat piezoelectric material. A flat insulating material is mounted on top of the rectangular long sides of the backing material, with the flat insulating material placed on its back side so that the long sides of the flat piezoelectric material are substantially parallel to the long sides of the backing material. The flat piezoelectric material, the flat insulating material, and the backing material are bent along the sides thereof, and cuts are made in the flat piezoelectric material, the flat insulation material, and the backing material, and the cuts extend in the width direction of the rectangular shape of the flat piezoelectric material and are located between the plurality of conductor parts. , which reaches at least the main surface of the backing material, thereby including a plurality of ultrasonic transducers in which one flat conductive material serves as a common electrode and the other flat conductive material serves as individual electrodes.

According to one aspect of the present invention, the ultrasonic probe uses the first flat conductive material as a common electrode and the second flat conductive material as individual electrodes.

According to another aspect of the invention, the cut in the ultrasonic probe is between each of the plurality of conductor portions. forms a completely closed rectangle.

According to another aspect of the invention, the second
In the conductive nozzle, a plurality of conductor portions are each independently formed on the surface of a flat insulating material.

(1) Detailed Description of the Invention Next, the ultrasonic probe and method of manufacturing the ultrasonic probe of the present invention will be described in detail with reference to the accompanying drawings.

As in the embodiment shown in FIGS. 81 (4) and (2), a generally rectangular flat piezoelectric material 10 made of, for example, a ceramic piezoelectric material is provided with a side surface 12 corresponding to one long side of the rectangle, and the other side is The side surfaces and both main surfaces of the flat plate are coated in a U-shape with an ultra-thin flat conductive material formed by vapor deposition, screen printing, or coating and fixation of a conductive material such as silver, and a part of one of the main surfaces is coated with A slit 14 is made parallel to the long side of this rectangle to remove a portion of the flat conductive material and divide it into a first flat conductive material 16 and a second flat conductive material 18 . Both are completely independent of each other. In order to understand the actual dimensions of this example, the long side i of the flat piezoelectric material is
oom, the short side is 13*m + the width of the flat conductive material 16 on the main surface on the slit side is 1 mu + the width of the slit 14 is 1 mu, and the thickness is 0.4 mm at 3.5 MHz.

Next, as shown in FIG. 1 (0), a flat substrate 22 made of a flexible insulating material such as polyimide has an opening 20 having a widthwise dimension slightly smaller than the rectangular shape of the flat piezoelectric material 10. , as shown) J? A first conductive pattern 24 and a second conductive pattern 26 having a turn shape are formed. Both patterns are formed by depositing a foil of a conductive material, such as copper, on the main surface of the substrate 22. The first conductive pattern 24 consists of an electrode part 28 along one long side of the opening 20 and a lead part 30 connected to an external circuit, and the second conductive A' turn 26 consists of an electrode part 28 along one long side of the opening 20 and a lead part 30 connected to an external circuit.
The other (13) of 0 consists of an electrode part 32 along the long side and a large number of conductor parts 34 connected to an external circuit. The first conductive pattern 26 forms part of the common electrode of a large number of ultrasonic transducers 60 (FIG. 1 (2) or CF'), and the second conductive pattern 26 forms a part of the common electrode of a large number of ultrasonic transducers 60 (FIG. 1 (2) or CF'). It will form a part. Therefore, in this example, the conductor portions 34 of the second conductive pattern 26 are provided in correspondence with the number of transducers included in the completed ultrasound probe. Furthermore, a cover film made of polyimide or the like is applied so as to cover the lead portion except for the electrode portion.

Next, as shown in Fig. 1), the flexible substrate 2 of Fig.
A backing material 40 is prepared which is slightly larger than the opening 20 of No. 2 and has a shape at least as large as the rectangular shape of the piezoelectric material 10 shown in FIG. After this backing material is completed as an ultrasonic probe, it reflects the ultrasonic waves (14) emitted in the opposite direction to the ultrasonic output direction of the probe, that is, to the back side, thereby transmitting ultrasonic waves to the front load. It can be used as a reflective material to increase the output and improve the sensitivity of the probe, or as an absorbing material to sharpen the ultrasonic pulse by absorbing the ultrasonic waves emitted to the back surface, improving the responsiveness of the probe. fulfill the role of To give an example of a suitable reflective material for improving sensitivity, the acoustic impedance of the piezoelectric material 10, for example, 30
An epoxy resin having an acoustic impedance significantly different from XIOf/-/crls, such as about 3xlO55'zZ, is preferred.

According to the method of manufacturing an ultrasonic probe according to the present invention, the piezoelectric material 10 including the first and second flat conductive materials 16 and 18 is oriented as shown in FIG.
The opening 20 or the piezoelectric material 10 is placed on the flexible substrate 22 shown in C).
Place it so that it overlaps the rectangle. In this state, the electrode parts 28 and 32 of the first and second conductive patterns 24 and 26, and parts of the first and second flat conductive materials 16 and 18 that are in contact with these, are connected by soldering or other means. Join. In this case, it is advantageous in terms of process to heat the back surface of the substrate 22. As a result, the first and second flat conductive members 16 and 18 are electrically connected to the terminal portions 30 and 34 of the first and second conductive i4 turns 24 and 26, respectively.

Next, the piezoelectric material 10 mounted on the flexible substrate 22 is placed on the backing material 40 shown in FIG. 1(C) in the state shown in FIG. The flexible substrate 22 is placed with the patterned side facing up and the opening 20 aligned with the substrate 22. The substrate 22, parts of the first and second conductive materials 16 and 18 exposed from the 2° opening thereof, and the piezoelectric material 10 at the slit 14 are bonded to the backing material 40 using adhesive such as epoxy resin. Do it with a drug. Backing material 40
It is preferable to use an adhesive containing the same material as the backing material 40, so that when the backing material 40 is an epoxy resin, the adhesive is also an epoxy resin. By doing so, an interface is not formed between the adhesive and the backing material 40, and reflection of ultrasonic waves at an undesirable interface can be prevented.

Next, as shown in FIG. 1(G), the flexible substrate 22 is bent along both sides of the backing material 40, and the two are similarly bonded with adhesive.

? Make a cut 50 in the width direction of the piezoelectric material 1o using a thin grinding wheel such as a scribing dicer.
The piezoelectric material 10 is divided into equal parts in the longitudinal direction. As shown in FIGS.
8 and a part of the first conductive material 16 to the flexible substrate 2
The tips 52 of the first and second conductive patterns 24 and 26 on the same figure (
As shown in (g), the electrode portion 3 of the second conductive turn 26
The cutting edge is slightly cut into the backing material 40 at the position where it completely separates the backing material 40 (the position of the tip of the arrow A in FIG. 3). Also, the distance between two adjacent notches 50, that is, (
17) The pitch is the plurality of lead parts 34 of the second conductive pattern 26
One notch 5G is located approximately at the center of two adjacent conductor portions 34 and is equal to the arrangement pitch of 1♀, so as to electrically disconnect the lead portions 34 that are in contact with each other.

The tip 52 of the notch 50 must not reach the end 36 of the first conductive pattern 24 (which is also the end of the flexible substrate 22 in this example), and must not reach the end 36 of the first conductive pattern 24 (which is also the end of the flexible substrate 22 in this example), as shown in FIG. The first conductive pattern 24 is not divided by the notches 50 and is continuous. As a result, an ultrasonic probe 62 including a large number of ultrasonic transducers 60 is completed. This electrical connection is shown in Figure 2. In this figure, elements shown in FIG. 1 are conceptually indicated by the same reference numerals. As you will see, the first flat conductive material 16 is connected to the individual vibrators 60.
The second flat conductive plate #18 is connected to the conductor portion 34 as an individual electrode unique to each vibrator 60.

FIG. 4 shows an example of another shape of the flexible substrate 22. FIG. 4(4) shows an example in which the second conductive pattern is not continuous, but is independent as individual conductor portions 34 from the beginning. Therefore, piezoelectrically, the connection of the material 10 with the second electrically conductive material 32 . This is done for A. FIG. 4B shows a flexible substrate 22 having an opening 20A in which the periphery of the opening 20 shown in FIG. 1 (0) is not completely closed, but is partially open. Any substrate 22 can be satisfactorily applied to the manufacturing method according to the present invention.

FIG. 5 shows an example in which the pitch of the notches 50 is 173 times the pitch of the terminal portions 34, and the individual electrodes 18 of three vibrators 60 are commonly connected to one terminal portion 34. The electrical connection is shown in FIG. In this way, the correspondence between the terminal portions 34 and the vibrators 60 is not necessarily one-to-one, but may be one-to-multiple.

FIG. 7 shows one end 36 of the substrate 22 attached to a backing material 40.
An example is shown in which the piezoelectric material is not bent along the side surface of the piezoelectric material, but is stretched and bonded to its main surface, that is, the surface on which the piezoelectric material is mounted. In this case, in order for the first conductive material 16 to function as a common electrode, the first conductive pattern 24 must not be separated into individual vibrators 60; The cutting stroke is indicated by arrow B in Figure 7.
As shown in , it is necessary to control the conductive pattern so that it does not reach the end 36 of the first conductive pattern 24 . In the embodiment shown in FIG. 1, there is no need to control the cutting stroke as described above with reference to FIG. 3, and only the depth of cutting (arrow A) is required.

In any of the above embodiments, the ultrasonic probe #'-a
2, the first conductive material 16 serves as a common electrode for each vibrator 60. However, the manufacturing method according to the present invention is not necessarily limited to this form. First conductive material 16
The piezoelectric material 10 shown in FIG. In the same figure (Qa), it may be placed on the flexible substrate 22 and bonded.It should be noted that an ultrasonic probe with the first conductive material 16 as a common electrode is better when the common electrode is grounded. This has the advantage of excellent resistance to noise caused by induced current.

■0 Specific effects of the invention According to the ultrasonic probe and the method for manufacturing an ultrasonic probe of the present invention, the connection of the two electrodes of the ultrasonic transducer to the circuit pattern on the flexible substrate is , can be performed simultaneously in a single step. Further, this electrode connection step and the step of dividing into each ultrasonic transducer can be performed almost simultaneously. Therefore, both electrodes can be accurately connected to the circuit line before being divided into individual ultrasonic transducers. Further, in the dividing step, each ultrasonic transducer can be formed uniformly with highly accurate mechanical dimensions. Since the circuit connections to each electrode are made by printed circuits formed on the flexible substrate, highly accurate mechanical dimensions can be obtained for the circuit connections for a large number of vibrators. Moreover, the use of such a printed circuit board (21) at the access to the external circuit also results in good compatibility at the mechanical interface with the external circuit.

Therefore, not only the manufacturing process is shortened and the price is reduced, but also a highly reliable ultrasonic probe in which a large number of highly accurate ultrasonic transducers are densely integrated can be provided.

In the ultrasonic probe provided in this way, the mechanical and electrical characteristics of the individual transducers are uniform, and the transducers are mechanically independent, so vibrations between each transducer are uniform. In the case of electronic scanning, there is little interference in time, and the -dimensional array is arranged with high precision at a uniform pitch, so in the case of electronic scanning, there is no problem in electric circuit design due to non-uniformity of transducers or arrangement or mutual interference between transducers. This has the effect that inconveniences such as errors between the combined beam direction and the actual beam direction do not occur.

[Brief explanation of drawings]

Fig. 1 (4) to C) are perspective views for explaining the manufacturing process of the ultrasonic probe according to the present invention, and Fig. 2 is a circuit diagram showing an example of circuit connection of the ultrasonic probe (22). , FIG. 3 is an end view of the ultrasonic probe shown in FIG. 1 (G), and FIGS. 4 (4) and (B) are plan views showing other examples of the flexible substrate shown in FIG. 1. , Fig. 5 is a partial side view showing another embodiment of the ultrasonic probe, Fig. 6 is a circuit diagram showing the circuit connection of the embodiment shown in Fig. 5, and Fig. 7 is a partial side view showing another embodiment of the ultrasonic probe. FIG. 7 is an end view showing another embodiment. 10... Flat piezoelectric material 16... First flat conductive material 18... Second flat conductive material 20... Opening 22... Flexible substrate 24... First circuit pattern 26 ...Second circuit pattern 40...Backing material 50...Notch 60...Ultrasonic transducer 62...Ultrasonic probe. Figure 1 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Turn off at 6F r=, H

Claims (1)

[Claims] 1. A first flat conductive material is adhered to one main surface of a rectangular flat piezoelectric material in a manner that substantially covers the main surface, and a first flat conductive material is attached to the other main surface of the rectangular flat piezoelectric material. A second flat conductive material independent of the conductive material is applied, and a portion of the first flat conductive material extends to the other main surface and covers a portion of the other main surface in the longitudinal direction. C. On the surface of the flexible flat insulating material having a rectangular opening having a width smaller than the width of the rectangular flat piezoelectric material, a first conductive hole extending along one long side of the opening? a second conductive pattern extending along the other long side of the opening and independent of the first conductive pattern, the second conductive pattern being a plurality of conductors extending in a direction away from the opening; the flat piezoelectric material is placed on the surface of the flat insulating material so that its long side is substantially parallel to the long side of the opening; A part of one of the first and second flat conductive materials covering a part of the other main surface is connected to the first conductive 1,000 turns of the flat insulating material, and a part of the other flat piezoelectric material are respectively connected to the second conductive patterns, and have an acoustic impedance different from that of the flat piezoelectric material, and a backing material having a shape close to the rectangular outer shape of the flat piezoelectric material. Long side force (the flat PM material is installed with the back side of the flat marine edge material facing down so that it is substantially parallel to the long side of the backing material, and the flat plate insulating material is attached to the rectangular length of the backing material. bending the backing material toward the side surface along the sides, making cuts in the flat piezoelectric material, the flat insulating material, and the backing material, and the cuts extending in the width direction of the rectangular shape of the flat piezoelectric material to (2) located between the conductor portions of the backing material and reaching at least the main surface of the backing material, thereby making one of the flat conductive materials a common chamber (r) and the other flat conductive material serving as individual electrodes. An ultrasonic probe comprising an ultrasonic transducer. 2. The ultrasonic probe according to claim 1, wherein the first flat conductive material is a common electrode, and the second flat conductive material is an individual electrode. 3. The ultrasonic probe according to claim 2, wherein the cut is located between each of the plurality of conductor parts. 4. The ultrasonic probe according to claim Mz or claim 3, wherein the opening of the flat insulating material has a rectangular shape with a closed periphery. 5. The second conductive/mother turn has a plurality of conductor parts independently formed on the surface of the flat insulating material 6. A second conductive/mother turn is formed on one main surface of the rectangular flat piezoelectric material so as to substantially cover the main surface. A first flat conductive material is deposited on the other main surface, a second flat conductive material independent of the first flat conductive material is deposited on the other main surface, and a part of the first flat conductive material is attached to the other main surface. a flexible flat plate insulating material having a shape extending to the main surface of the other main surface and covering a part of the other main surface in the longitudinal direction, and having a rectangular opening having a width smaller than the width of the rectangular flat piezoelectric material; A first conductive pattern extending along one long side of the opening is formed on the surface, and a second conductive pattern independent of the first conductive pattern is formed along the other long side of the opening. The second conductive i+ turn has a plurality of conductor parts extending in a direction away from the opening, and the flat piezoelectric material is placed on the surface of the flat insulating material so that its long side is substantially the same as the long side of the opening. A part of one of the first and second flat conductive materials covering a part of the other main surface of the flat piezoelectric material is placed parallel to the flat piezoelectric material. A part of the other flat piezoelectric material is connected to the first conductive pattern, and a part of the other flat piezoelectric material is connected to a second conductive pattern, and has an acoustic impedance different from that of the flat piezoelectric material, and has a shape close to the rectangular outline of the flat piezoelectric material. Mounting the flat insulating material on the main surface of the backing material so that the long side of the flat piezoelectric material is substantially parallel to the long side of the backing material, with the back surface of the flat insulating material facing down; The flat insulating material is bent along the long sides of the rectangle of the backing material toward the side surface of the backing material, and cuts are made in the flat piezoelectric material, the flat insulating material, and the backing material, and the cuts are formed in the flat piezoelectric material, the flat insulating material, and the backing material. The piezoelectric material extends in the width direction of the rectangular shape and is located between the plurality of conductor parts, and reaches at least the main surface of the backing material. 1. A method of manufacturing an ultrasonic probe, comprising forming a plurality of ultrasonic transducers each using a conductive material as an individual electrode.