JP3423788B2 - Ultrasonic probe - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe having at least a film on which an electrode pattern is formed and a piezoelectric vibrator, and these films and the piezoelectric vibrator are laminated and pressure-welded.

[0002]

2. Description of the Related Art Next, a conventional example will be described with reference to the drawings.
FIG. 2 is a block diagram of a conventional ultrasonic probe. In the figure, the first piezoelectric element (PZT) 1 has a first
The ground electrode layer 2 is formed in advance as the electrode layer, and the positive electrode layer 3 is formed in advance on the other surface side as the second electrode layer. In the conventional example, the electrode layers 2 and 3 are gold sputtered electrode layers having a thickness of about 1000 Å effective for increasing the frequency, but the material is not limited.

On the positive electrode layer 3 side of the piezoelectric vibrator 1, a conductor acoustic matching layer 5 is laminated via a pressure-hardened insulating adhesive layer 4. Further, on the acoustic matching layer 5, a polymer film 7 is laminated via an insulating adhesive layer 6 that is pressure-cured. The polymer film 7 is composed of two layers, a film body 8 as an acoustic matching layer and a copper layer 9 formed on the adhesive layer 4 side of the film body 8 by vapor deposition. The end of the polymer film 7 extends from the portion laminated with the piezoelectric vibrator 1, and the tip of the extended portion is provided with an electrode lead-out portion 7a.

An FPC 11 is laminated on the ground electrode layer 2 side of the piezoelectric vibrator 11 with a pressure-hardened insulating adhesive layer 10 interposed therebetween. This FPC 11 has a polyimide base portion 12 and a piezoelectric vibrator 1 side on the base portion 12,
A conductive pattern 13 corresponding to the piezoelectric vibrator 1 is formed by vapor deposition of copper having a thickness of about 3 μm. Further, both sides of the FPC 11 extend from the laminated portion with the piezoelectric vibrator 1, and electrode lead-out portions 11a are formed at both ends of the extended portion.

Reference numeral 14 is attached to the base portion 12 side of the FPC 11 via an adhesive layer 15 to mechanically support the piezoelectric vibrator 11 and acoustically brake the piezoelectric vibrator 11 to generate an ultrasonic pulse waveform. It is a back load material that is shortened.

Further, an acoustic lens 17 is laminated on the polymer film 7 with an adhesive layer 16 interposed therebetween. next,
A method of manufacturing the ultrasonic probe having the above structure will be described. The ground electrode layer 2 and the positive electrode layer 3 are formed on both surfaces of the piezoelectric vibrator 1 by gold sputtering (step 1).

The acoustic matching layer 5 and the polymer film 7 are laminated on the ground electrode layer 2 of the piezoelectric vibrator 1 with an adhesive, and the FPC 11 is laminated on the positive electrode layer 3 with an adhesive, and a high pressure is applied. Then, these are pressed and fixed (step 2).

Attaching the back load material 14 using an adhesive
(Step 3). Dicing is performed from the FPC 1 side to divide the piezoelectric vibrator 1 into a plurality of electrically independent arrays (step 4). The width t of the cut groove at this time is about 40 μm to 5 μm.
It is 0 μm.

Next, the acoustic lens 17 is attached using an adhesive (step 5). Finally, both sides of FPC11,
One side of the polymer film 7 is bent to have a shape as shown in FIG. 2 (step 6).

Next, the operation of the above configuration will be described. The piezoelectric vibrator 1 excites (transmits) an ultrasonic wave (mechanical vibration) in response to an electric signal applied to the piezoelectric vibrator 1 via the FPC 11. The excited ultrasonic waves are acoustically matched with the living body by the acoustic matching layer 5, the film body 8 and the acoustic lens 17, are converged by the acoustic lens 17 and are transmitted into the living body.

Further, the piezoelectric vibrator 1 generates (receives) an electric signal in response to an ultrasonic wave returned from a living body by the piezoelectric effect.

[0012]

However, in step 2 of the manufacturing process of the ultrasonic probe having the above-described structure, that is, by using an adhesive agent for the ground electrode layer 2 of the piezoelectric vibrator 1, the acoustic matching layer 5 and the acoustic matching layer 5 are formed. The molecular film 7 is attached to the positive electrode layer 3 using an adhesive.
In the process of laminating the FPCs 11 respectively, applying a high pressure, and pressing and fixing these, the shape of the acoustic matching layer 5 changes abruptly along the ridge line, so that the portion of the polymer film 7 that is pressed by the ridge line of the acoustic matching layer 5 is pressed. Stress concentrates on the polymer film 7
There is a problem that the copper layer 9 and the conductive pattern 13 of the FPC 11 are damaged.

The present invention has been made in view of the above problems, and an object thereof is to provide an ultrasonic probe which prevents damage to an electrode pattern (electrode).

[0014]

[Means for Solving the Problems] First to solve the above problems
The invention of, at least, a film having an electrode pattern formed thereon, and a piezoelectric vibrator, in these films, in an ultrasonic probe in which piezoelectric vibrators are laminated and pressure contact, the film of a member adjacent to the film The corners of the surface facing the and are made into a gently curved surface.

According to a second aspect of the present invention, a piezoelectric vibrator, a first electrode layer formed on one surface side of the piezoelectric vibrator, and a first or second electrode layer laminated on the first electrode layer via an adhesive layer, or Two or more conductive acoustic matching layers, a first film laminated on the acoustic matching layers via an adhesive layer and having an electrode pattern formed on the adhesive layer side, and the other of the piezoelectric vibrators. A second electrode layer formed on the surface side, a second film laminated on the second electrode layer via an adhesive layer, and having an electrode pattern formed on the adhesive layer side, and the second film. A back load member laminated via an adhesive layer, a corner portion of a surface of the acoustic matching layer facing the first film, and a surface of the piezoelectric vibrator facing the second film. The corners of the curved surface are gently curved.

A polymer film is an example of the substrate of the first film of the second invention.

[0017]

In the ultrasonic probe according to the first aspect of the invention, the film and the member adjacent to the film are laminated by forming the curved surface at the corner of the surface of the member adjacent to the film facing the film. In the process of applying high pressure, pressing and fixing these, stress concentration on the film disappears,
No damage to the conductive pattern.

In the ultrasonic probe of the second invention, a corner portion between the surface of the acoustic matching layer facing the first film and a corner portion between the surface of the piezoelectric vibrator facing the second film. By forming a gentle curved surface, these are laminated, high pressure is applied, and the first film,
The stress concentration on the second film is eliminated, and the conductive patterns of the first and second films are not damaged.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of the first embodiment of the present invention.

In the figure, a plurality of piezoelectric vibrators (PZT) 31
The ground electrode layer 32 is provided as a first electrode layer on one surface of the
However, on the other surface side, the positive electrode layer 33 is formed as the second electrode layer.
However, they are formed in advance. In this embodiment, the electrode layers 32 and 33 have a thickness of 1000Å effective for high frequency.
Although the gold sputtered electrode layer is formed to some extent, the material is not limited.

On the positive electrode layer 33 side of the piezoelectric vibrator 31, a conductor acoustic matching layer 35 is laminated via a pressure-hardened insulating adhesive layer 4. Further, on the acoustic matching layer 35, via a pressure-cured insulating adhesive layer 36,
A polymer film 37 as a first film is laminated. The polymer film 37 includes a film body 38 as an acoustic matching layer, and the adhesive layer 3 of the film body 38.
It is composed of two layers, a copper layer 39 formed on the fourth side by vapor deposition. The end portion of the polymer film 37 extends from the laminated portion with the piezoelectric vibrator 31, and the electrode take-out portion 37a is formed at the tip of the extended portion.

At the corner of the surface of the acoustic matching layer 35 facing the polymer film 37, a rounded portion 35a is formed as a gently curved surface. On the ground electrode layer 32 side of the piezoelectric vibrator 31, a pressure-hardened insulating adhesive layer 40 is formed.
The FPC 41 as the second film is laminated via the. The FPC 41 includes a polyimide base portion 42,
On the side of the piezoelectric vibrator 31 on the base portion 42, a conductive pattern 43 formed corresponding to the piezoelectric vibrator 31 by vapor deposition of copper having a thickness of about 3 μm is formed. Also, FP
Both sides of C41 extend from the laminated portion with the piezoelectric vibrator 31, and electrode lead-out portions 41a are formed at both ends of the extended portion.

At the corner of the surface of the piezoelectric vibrator 31 facing the FPC 41, a rounded processing portion 31a is formed as a gently curved surface.
Are formed. A back surface 44 is attached to the base portion 42 side of the FPC 41 via an adhesive layer 45 to mechanically support the piezoelectric vibrator 41 and acoustically dampen the piezoelectric vibrator 41 to shorten the ultrasonic pulse waveform. It is a load material.

Further, an acoustic lens 47 is laminated on the polymer film 7 via an adhesive layer 46. next,
A method of manufacturing the ultrasonic probe having the above structure will be described. A ground electrode layer 32 and a positive electrode layer 33 are formed on both surfaces of the piezoelectric vibrator 31 by gold sputtering (step 1).

An acoustic matching layer 35 and a polymer film 37 are laminated on the ground electrode layer 32 of the piezoelectric vibrator 31 with an adhesive, and an FPC 41 is laminated on the positive electrode layer 33 with an adhesive.
A high pressure is applied and these are pressed and fixed (step 2).

Back load material 44 is laminated using an adhesive.
(Step 3). Dicing is performed from the FPC 41 side to divide the piezoelectric vibrator 31 into a plurality of electrically independent arrays.
(Step 4). The width t of the cut groove at this time is about 40 μm.
~ 50 μm.

Next, the acoustic lens 47 is attached using an adhesive (step 5). Finally, both sides of FPC41,
One side of the polymer film 37 is bent to form the shape shown in the figure (step 6).

Next, the operation of the above configuration will be described. The piezoelectric vibrator 31 excites (transmits) an ultrasonic wave (mechanical vibration) in response to an electric signal applied to the piezoelectric vibrator 31 via the FPC 41. The excited ultrasonic waves are acoustically matched with the living body by the acoustic matching layer 35, the film body 38, and the acoustic lens 47, are converged by the acoustic lens 47, and are transmitted into the living body.

Further, the piezoelectric vibrator 31 has a piezoelectric effect.
Generates electrical signals in response to ultrasonic waves returned from the living body
(Receive) By the way, the ground electrode layer 3 of the piezoelectric vibrator 31
2 between the acoustic matching layer 35 and the acoustic matching layer 35, an insulating adhesive layer 36 between the acoustic matching layer 35 and the copper layer 39 of the polymer film 37, and a piezoelectric layer. An insulating adhesive layer 40 is interposed between the positive electrode layer 33 of the vibrator 31 and the conductive pattern 43 of the FPC 41. On the other hand, the polymer film 37, the acoustic matching layer 35, the piezoelectric vibrator 3
1 and the FPC 41 are integrated with each other using an insulating epoxy resin adhesive under a high pressure.

Therefore, these insulating adhesive layers 34,
The thicknesses of 36 and 40 are small, and the conductor members are sufficiently close to each other. Even with such a thin insulating layer, due to the tunnel effect, Schottky conductivity, impurity conductivity, etc.
Charge transfer occurs. Insulating adhesive layers 34, 36
The thicknesses of 40 and 40 are not constant, and they exist at some probability due to the surface roughness of the conductor members facing each other, and the thickness is extremely close to 0 in some places, that is,
The ground electrode layer 32 of the piezoelectric vibrator 31 and the conductive pattern 43 of the FPC 41, the positive electrode layer 33 of the piezoelectric vibrator 31 and the acoustic matching layer 35, and the acoustic matching layer 35 and the copper of the polymer film 37. There is also a portion in contact with the layer 39, and at this contact portion, charge transfer occurs.

According to the above configuration, the acoustic matching layer 35 has the R-processing section 35a, and the piezoelectric vibrator 31 has the R-processing section 3a.
1a is formed respectively, and the shape change is made into a gentle curve, so that the acoustic matching layer 35 and the polymer film 37 are attached to the ground electrode layer 32 of the piezoelectric vibrator 31 by the adhesive and the positive electrode layer 33 is attached with the adhesive. In the process of stacking the FPC 41 respectively by using, applying a high pressure and pressing and fixing them,
Stress concentration on the polymer film 37 and FPC 41 is eliminated, and damage to the copper layer 39 of the polymer film 37 and the conductive pattern 43 of the FPC 41 can be prevented.

The present invention is not limited to the above embodiment. For example, in the case of an ultrasonic probe without the acoustic matching layer 35, a rounded portion is formed on the surface of the piezoelectric vibrator 31 on the side of the positive electrode layer 33 to prevent damage to the copper layer 39 of the polymer film 37. be able to.

Further, the shapes of the radius processing parts 31a and 35a are not limited. It may be a cylindrical surface with a constant radius,
Alternatively, it may be an elliptic cylindrical surface. Although 36, 34 and 40 are insulating adhesive layers, conductive adhesives can be used if a sufficiently thin adhesive layer can be formed using conductive adhesives. .

In the above embodiment, the linear type ultrasonic probe has been described. However, in addition, a curved linear array type, matrix array type, or annular array type ultrasonic probe may be used. Applicable.

Furthermore, the conduction of the insulating adhesive layer is
It does not necessarily have to be in a direct current conducting state. When the probe itself is operated, the insulating adhesive layer functions as a capacitor, and there is no practical problem.

[0036]

As described above, according to the ultrasonic probe of the first aspect of the invention, since the corners of the facing surface of the film and the adjacent member to the film are formed into a gentle curved surface, In the process of laminating the film and the adjacent member, applying a high pressure, and pressing and fixing these, stress concentration on the film is eliminated and the conductive pattern is not damaged.

According to the ultrasonic probe of the second invention, the corner portion between the surface of the acoustic matching layer facing the first film and the surface of the piezoelectric vibrator facing the second film is gentle. Due to the curved surface, stress concentration is eliminated in the first film and the second film in the process of laminating these and applying a high pressure to press and fix them, and the conductive pattern of the first and second films No damage.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a configuration diagram of a conventional ultrasonic probe.

[Explanation of symbols]

31 Piezoelectric vibrator 32 Ground electrode layer 33 Positive electrode layer 35 Acoustic matching layer 37 Polymer film 38 Film body 39 Copper layer 41 FPC 42 Base 43 Conductive pattern 44 Back load material 47 acoustic lens

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01N 29/00-29/28 A61B 8/00-8/15 H04R 17/00 330-332

Claims (2)

(57) [Claims] 1. A piezoelectric vibrator, a first electrode layer formed on one surface side of the piezoelectric vibrator, and one or more conductive layers laminated on the first electrode layer via an adhesive layer. Acoustic matching layer, a first film laminated on the acoustic matching layer via an adhesive layer and having an electrode pattern formed on the adhesive layer side, and formed on the other surface side of the piezoelectric vibrator And a second film laminated on the second electrode layer via an adhesive layer and having an electrode pattern formed on the adhesive layer side, and an adhesive layer on the second film. And a corner portion of a surface of the acoustic matching layer facing the first film, and a corner portion of a surface of the piezoelectric vibrator facing the second film. An ultrasonic probe characterized by having a gentle curved surface. 2. The ultrasonic probe according to claim 1, wherein the base material of the first film is a polymer film.