JP3319532B2 - Two-dimensional array type ultrasonic probe and manufacturing method thereof, two-dimensional array type ultrasonic convex probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-dimensional array type ultrasonic probe and a method of manufacturing the same.

[0002]

2. Description of the Related Art A two-dimensional array type ultrasonic probe has a plurality of transducer pieces arranged in a matrix.
According to the two-dimensional array ultrasonic probe, the drive aperture and the focus distance can be freely adjusted, and the three-dimensional region can be freely scanned with the ultrasonic beam while the probe is fixed to the subject. Therefore, it is suitable for contributing to the improvement of image quality and creating a three-dimensional image. However, since the two-dimensional array type ultrasonic probe has a complicated structure in which many transducer pieces are arranged at a fine pitch,
Requires very complex manufacturing processes. In particular, the operation of drawing out the signal line from the driving electrode of the vibrator piece tends to be complicated, and development of a process of drawing out the signal line more simply and reliably is one of the important tasks in the future.

Conventional signal line drawing methods include a method of embedding a laminated FPC (flexible printed circuit board) in a backing material and electrically connecting an end face of the FPC to a drive electrode, and a method of extracting a signal line in the backing material. A method of electrically connecting a buried needle-like signal line and a drive electrode has been used. However, at present, the processing accuracy of the lamination pitch of the FPC and the embedded pitch of the needle-like signal lines cannot follow the desired fine vibrator piece pitch, and the vibrator piece pitch is adjusted to the above-mentioned processing accuracy limit. There is a problem that it has to be large.

Further, since the above-described method is a method developed on the assumption that both the driving electrode and the signal line are coupled in a plane, vibrator pieces such as a convex type probe are arranged on a curved surface. Not applicable in such cases.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a two-dimensional array type ultrasonic probe in which a signal line can be easily pulled out from a drive electrode of each transducer piece, and a method of manufacturing the same.

[0006]

Means for Solving the Problems The book described in claim 1
The invention of the present application states that “a plurality of transducer pieces are two-dimensionally arranged,
Connection of the signal line to the vibrator piece is made on the backing material side.
And the signal line passes through the inside of the backing material.
In the two-dimensional array type ultrasonic probe having
A connection between the element piece and the signal line is formed on the back side of each transducer.
Of a conductor layer having improved acoustic matching characteristics
A two-dimensional array type ultrasonic probe characterized by the above-mentioned. "
You.

[0007] The present invention described in claim 2 is based on "multiple
Vibrator pieces are arranged two-dimensionally, and each vibrator piece
The connection of the signal line is made on the backing material side, and the signal line is
Two-dimensional array having a structure passing through the inside of the backing material
In the ultrasonic probe, the signal line is the vibrator piece.
Connected by wire bonding
Two-dimensional array type ultrasonic probe characterized by the following features:
Bu. ". The present invention described in claim 4 relates to “2.
Individual connection to multiple transducer pieces arranged in a dimension
Multiple printed wiring boards with signal lines
And filling a gap between the printed wiring boards with a backing material.
And the signal lines arranged on one surface of the backing material
Two-dimensional connection of the tip of the vibrator piece to the drive electrode side of each vibrator piece
In the array type ultrasonic probe, the printed wiring board
Of the signal line is an integral multiple of the arrangement pitch of the vibrator pieces.
The printed wiring board is formed to have a pitch.
Secondary, characterized in that they are stacked offset from each other
Original array type ultrasonic probe. ".

[0008] The present invention described in claim 6 is based on the
On the conductive layer provided as a wiring pattern on the printed circuit board
Is provided with an electrical insulating layer, and the
Holes are provided in the electrical insulation layer as exposed conductors, and
A plurality of transducers two-dimensionally arranged with the conductive layer of the body exposed part
The electrodes on each back of the piece are electrically connected
A two-dimensional array type ultrasonic probe characterized by the above-mentioned. "
You. The present invention described in claim 9 relates to “printed wiring”.
Two-dimensionally exposed multiple conductor exposed parts distributed on the board
The electrodes provided on the back of each of a plurality of vibrator pieces
Two-dimensional array type ultrasonic probe that electrically connects the poles
In the manufacturing method, after connecting the electrode to the conductor exposed portion
And cutting the piezoelectric plate along the first direction.
After that, a common electrode and an acoustic matching layer are formed on the piezoelectric body,
Moving the piezoelectric body together with the acoustic matching layer in a second direction
Cutting and cutting along the second direction
Characterized by connecting a ground wire to the common electrode
A method for manufacturing a two-dimensional array type ultrasonic probe. ".

[0009] The invention of claim 10 is based on
Multiple exposed conductors distributed on the printed wiring board
Are installed on the back of each of the two-dimensionally arranged transducer pieces.
Two-dimensional array ultrasonic that electrically connects the electrodes
In the method of manufacturing a probe, the electric conductor is exposed to the conductor.
After connecting the poles, the piezoelectric plate is divided into the plurality of vibrator pieces.
And the same acoustic impedance as the printed wiring board.
Backing material with dance in front of the printed wiring board
Make sure that it is mounted on the back side where the exposed conductor is not provided.
Manufacturing method of two-dimensional array type ultrasonic probe
Law. ".

[0010] The invention of claim 11 is based on
Multiple exposed conductors distributed on the printed wiring board
Are installed on the back of each of the two-dimensionally arranged transducer pieces.
Two-dimensional array ultrasonic that electrically connects the electrodes
In the probe, almost the same sound as the printed wiring board
Backing material having impedance
Attached to the back of the wire plate where the conductor exposed part is not provided
A two-dimensional array type ultrasonic probe, characterized in that: "
It is.

[0011] The invention of claim 12 is based on
Multiple exposed conductors distributed on the printed wiring board
Are installed on the back of each of the two-dimensionally arranged transducer pieces.
Two-dimensional array ultrasonic that electrically connects the electrodes
In the method of manufacturing a probe, the electric conductor is exposed to the conductor.
After connecting the poles, split the piezoelectric plate into the plurality of vibrator pieces
After the division, the printed wiring board is shared with the piezoelectric plate.
Two-dimensional, characterized by being curved into a convex shape
Manufacturing method of array type ultrasonic probe. ".

[0013] The invention of claim 13 is based on
Multiple exposed conductors distributed on the printed wiring board
Are installed on the back of each of the two-dimensionally arranged transducer pieces.
Secondary electrode characterized by electrically connecting the electrodes
Original array type ultrasonic convex probe. ".

[0013]

The two-dimensional array type ultrasonic probe according to claim 1 is provided.
According to the above, since the conductive layer has the function of the acoustic matching layer,
The characteristics can be adjusted.
Drive electrode of each vibrator element
The signal line can be easily pulled out of the device. Contract
According to the two-dimensional array type ultrasonic probe according to claim 2,
Transducer piece and signal line are wire-bonded
Because they are connected, the electrodes can be separated and pulled out.
To pull out the signal line from the drive electrode of each transducer piece.
It can be done easily.

A two-dimensional array type ultrasonic probe according to claim 4
According to the lab, the printed wiring boards are alternately shifted and laminated.
Therefore, the signal lines can be separated from each other,
Signal lines can be easily pulled out from the moving electrodes.
You. The two-dimensional array type ultrasonic probe according to claim 6.
The exposed conductor on the wiring pattern of the printed wiring board.
Having an electrically insulating layer having
Since the electrodes of the moving piece are electrically connected, lead out the signal line
Can be easily performed.

A two-dimensional array type ultrasonic probe according to claim 9
According to the method of manufacturing the probe, the piezoelectric body is shared with the acoustic matching layer.
Acoustic cutting because cutting along the second direction
Reduces talktalk and cuts along the second direction
The ground wire is connected to the grounded common electrode.
Withdrawal can be easily performed. Claim 10 and contract
A two-dimensional array-type ultrasonic probe according to claim 11 and the same
According to the manufacturing method, by using a printed wiring board
Signal lines can be easily pulled out and printed
Backing with almost the same acoustic impedance as the wire plate
By installing the material on the back of the printed wiring board,
Radiation can be reduced.

A two-dimensional array type ultrasonic probe according to claim 12.
According to the lobe manufacturing method, the electrode is connected to the exposed conductor.
After continuing, the piezoelectric plate is divided into the plurality of vibrator pieces, and divided.
Later, the printed wiring board is formed into a convex shape together with the piezoelectric plate
Easy to draw out signal lines by bending
Can be. A two-dimensional array type ultrasonic wave converter according to claim 13.
According to the Vex probe, the dispersed
Two-dimensionally arranged on a plurality of exposed conductors provided
The electrodes on the back of each of the
Easy connection of signal lines by connecting
Can be.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment FIGS. 1A to 1E are cross-sectional views sequentially showing a manufacturing process of a two-dimensional array type ultrasonic probe according to a first embodiment.
The structure of the two-dimensional array type ultrasonic probe will be described along the manufacturing procedure. As shown in FIG. 1A, the signal lines 6 for the number of the vibrator pieces at the time of completion are discretely arranged at the same pitch as the pitch of the vibrator pieces at the time of completion, and are held in a state in which both ends are projected. The piezoelectric plate 3 coated with the conductive adhesive 4 is bonded to one surface of the backing layer 5 from which the signal lines 6 protrude. As a result, the signal lines 6 protruding from the backing layer 5 are buried in the conductive adhesive 4 at the tip portions, and all the signal lines 6 are electrically connected to the piezoelectric plate 3 via the conductive adhesive 4. This state is maintained until the conductive adhesive 4 is cured.

In order to hold the signal lines 6 with the backing layer 5, the plurality of signal lines 6 arranged as described above may be filled with a curable filler and then cured. The signal line 6 may be passed through each through hole of the solid backing material in which a plurality of through holes are discretely formed at the same pitch as the pitch of the vibrator pieces when both ends are protruded. The backing layer 5 is preferably formed in a structure in which a plurality of layers having different acoustic characteristics are stacked in order to optimize the braking action of the ultrasonic wave. One surface of the backing layer 5 facing the piezoelectric plate 3 is required to have a certain degree of planar accuracy.
This can be easily achieved by performing polishing after hardening .

In order to improve the reliability of the connection, it is effective to form the tip of each signal line 6 to be exposed in a convex shape from the viewpoint of increasing the contact area and ensuring the electrical connection. It is considered that the tip of the signal line 6 is exposed in a convex shape, and can be easily realized by plating the tip or by removing only the resin layer at the tip by etching using plasma or the like. . Next, FIG.
As shown in (b), a groove 7 is formed by cutting at a depth from the surface side of the piezoelectric body 3 to the backing layer 5 according to the arrangement of the vibrator pieces at the time of completion. As a result, the piezoelectric body 3 is separated into a plurality of vibrator pieces 3 ', and the electrical connection between the vibrator pieces is cut.

It is sufficient that the cutting is performed to at least the lower surface of the conductive adhesive 4. However, in order to reduce crosstalk of acoustic signals between adjacent vibrator pieces, the backing layer 5 is formed at an arbitrary depth. It is preferable to perform cutting beforehand . Then, as shown in FIG.
Is filled with a curable resin 9. After the resin 9 is cured, FIG.
As shown in (d), the common electrode 2 is mounted on the vibrator piece 3 '. As this mounting method, any method such as a method of attaching a thin copper foil or the like, a method of applying a metal film by vacuum evaporation, a method of applying a conductive curable adhesive, and the like may be adopted. However, here, in particular, a method of mounting a film-shaped conductive resin is adopted. In this method, the common electrode 2 has an effect as an acoustic matching layer by selecting an optimal film thickness and an acoustic impedance. It is possible to make it.

Finally, as shown in FIG. 1E, an acoustic matching layer 1 is laminated on the common electrode 2, and the acoustic matching layer 1 is cut to improve the directional characteristics of the vibrator element. br /> As a material of the acoustic matching layer 1, a mixed material of a plurality of types of materials having different acoustic characteristics whose acoustic characteristics can be adjusted is employed. It is preferable to fill the groove 8 by cutting with a resin or the like from the viewpoint of structural strength. According to the present embodiment, the alignment of the connection between the signal line 6 and the vibrator piece 3 'and the operation thereof are simplified, so that the operation efficiency is improved. In addition, since the cutting of the piezoelectric plate 3 is performed after the backing layer 5 is bonded to the piezoelectric plate 3, the cutting can be performed up to the backing layer 5 as necessary, and therefore, high-precision cutting is not required.

Incidentally, by appropriately selecting the thickness and the acoustic impedance of the conductive adhesive 4, the effective acoustic impedance in consideration of the braking effect of the adhesive 4 can be adjusted. It is possible to adjust the overall characteristics of the ultrasonic probe. Also,
The acoustic matching layer 1 may be laminated on the common electrode 2 before attaching the common electrode 2 to the vibrator piece 3 ′. Furthermore, by fixing the signal line 6 to the backing layer 5 only at the tip portion, the arrangement of the vibrator pieces 3 ′ can be given a curvature after cutting the piezoelectric plate 3, for example, to form a convex probe or concave probe. It is.

(Second Embodiment) FIG. 2 (a) is a side view of a state of drawing out signal lines according to a second embodiment, and FIG. 2 (b) is a view of this from above. . In this embodiment, the vibrator piece 3 ′ and the substrate 1
The arrangement of the substrates 11 and 12 when electrically connecting the first and second electrodes 13 to each other by a wire bonding method is characteristic. A substrate 11 on which a plurality of electrodes 13 are formed,
Numeral 12 is for electrically relaying the two-dimensional array type ultrasonic probe to a device main body for performing transmission / reception control processing and image generation processing of the two-dimensional array type ultrasonic probe.
Each vibrator piece 3 ′ is individually connected to the electrodes 13 of the substrates 11 and 12. At this time, the substrate 11 is arranged with an inclination so as to surround the vibrator piece 3 ′ on a mortar.
The substrate 12 has the same inclination as the substrate 11 and is arranged in a platform shape so as not to overlap the substrate 11 when viewed from above.

By arranging the substrates 11 and 12 in this manner, the signal lines 6 can be routed without overlapping, so that the occurrence of electric crosstalk due to the contact between the signal lines can be suppressed, and the vibrator element 3 can be formed. 'And the electrode 13 can be linearly connected by the signal line 6, so that the working efficiency can be improved. Further, since the electrodes 13 for the number of the vibrator pieces can be dispersed on a plurality of, here eight, substrates 11, 12, the electrodes can be separated from each other with a sufficient distance, and the signal lines 6 can be separated. Can be tolerated to some extent when coupling to the electrode 13.

After the connection between all the electrodes 13 and all the transducer pieces 3 'by the signal line 6 is completed, the backing layer 5 is formed by casting. Other processing, that is, formation of the common electrode 2, lamination and cutting of the acoustic matching layer 1, are the same as in the first embodiment. Third Embodiment FIG. 3 shows a spacer 30 and a flexible printed circuit board (hereinafter abbreviated as “FPC”) 31, which are one component of a two-dimensional array type ultrasonic probe according to a third embodiment. The spacer 30 is formed of a nonconductive acrylic resin, for example, with a thickness of the vibrator piece pitch in the row direction at the time of completion. Two through holes 32 for positioning are penetrated in the spacer 30 at predetermined intervals. Spacer 3
0 is not limited to an acrylic resin, but may be a non-conductive material such as a metal, a resin, a rubber material, and glass.

A plurality of signal lines 33 are arranged on the FPC 31 at intervals of a transducer piece pitch in the column direction at the time of completion.
Also in this FPC 31, two through holes 34 having the same diameter as the through hole 32 of the spacer 30 are provided.
And at intervals. The structure of the two-dimensional array type ultrasonic probe according to the present embodiment using the spacer 30 and the FPC 31 will be described below along the manufacturing procedure. 4 to 8 are perspective views sequentially showing the manufacturing procedure.

First, as shown in FIGS. 4A and 4B,
The FPC 31 and the spacer 30 are inserted into the respective through holes 32, 3
4 is aligned as a guide, and the vibrator pieces at the time of completion are alternately stacked by the number in the row direction. As shown in FIG. 5, the stack has two pillars 36 that are at least smaller in diameter than the through holes 32 (or 34) and that are provided at the same distance as the distance between the through holes 32 (or 34). Alignment jig 35
Of the spacer 30 and the through holes 32, 3 of the FPC 31
4 is inserted. After the completion of the lamination of the vibrator pieces in the row direction at the time of completion, as shown in FIG. 6A, the fixing tool 38 is inserted from the endmost FPC 31 via the opposing jig 37 to the tip of the column 36. To fix the laminated structure. In this state, one end of the FPC 31 protrudes from the spacer 30 and the positioning jig 35.

Next, as shown in FIG.
A backing layer 39 is formed on one end of the substrate by molding with a curable liquid resin or the like. The tip of the signal line 33 of the FPC 31 is exposed from the surface of the backing layer 39 by adjusting the thickness of the backing layer 39 during molding or by shaving the surface into a flat shape after curing. Backing layer 3
9 is adjusted to an optimal acoustic impedance by mixing powder (metal oxide, metal, or glass bubbles) in an appropriate ratio with, for example, epoxy resin as a main component.

Then, the piezoelectric plate 41 is mounted on the backing layer 39 by the conductive adhesive 40, and as shown in FIG. 7B, the piezoelectric plate 41 is moved in the row direction according to the row pitch of the completed vibrator piece. 41 is divided by a cutting process.
Therefore, the piezoelectric plate 41 is electrically connected to the signal line 33 of the FPC 31. Of course, this cutting process is the first
This is performed at least to a depth reaching the backing layer 39 as in the embodiment. The piezoelectric plate 41 and the backing layer 3
9 may be bonded by an anisotropic conductive film instead of the conductive adhesive 40. Further, in order to improve the connectivity between the signal line 33 of the FPC 31 and the piezoelectric plate 41, the tip of the signal line 33 is raised by plating, or a conductive layer is formed on the upper surface of the backing layer by sputtering after the formation of the backing layer. After that, it is preferable that the piezoelectric plate 41 be bonded to the conductive layer with the conductive adhesive 40.

After filling the groove formed by the cutting process with silicon resin or the like, the common electrode 42 is formed on the piezoelectric plate 41 by a sputtering process as shown in FIG. Note that the common electrode 42 may be formed of a conductive adhesive or a conductive film instead of the sputtering process. After the acoustic matching layer 43 is formed on the common electrode 42, the piezoelectric plate 41 is divided by a cutting process in the column direction according to the pitch of the completed transducer pieces in the column direction. This cutting process is also performed at least to a depth reaching the backing layer 39. The groove formed by the cutting process is filled with a silicon resin or the like.

Thereafter, as shown in FIGS. 9A, 9B, and 9C, a ground wire 44 is connected from the side, top, or bottom of the common electrode 42. Finally, a two-dimensional array type ultrasonic probe is completed by mounting an acoustic lens on the acoustic matching layer 43. According to this embodiment, the same effects as those of the first embodiment can be obtained. The PC board is not limited to the FPC 31 but may be a PC board based on a normal glass epoxy resin or the like. In the above description, the FPC 31 is provided with a plurality of signal lines 33 at intervals of the vibrator piece pitch in the column direction at the time of completion, but the tip of the FPC 31 is cut along the column direction at the stage of FIG. Therefore, as shown in FIG. 10, the signal lines 33 may be commonly connected at their ends. In this case, it becomes easy to cope with the sub die of the vibrator piece.

The cutting process in the column direction shown in FIG. 8 may be performed at the stage shown in FIG. 7A or 7B. In some cases, the acoustic lens in the row direction (slice direction) is unnecessary in the two-dimensional array type ultrasonic probe. In this case, only the living body contact layer formed of a rubber material or the like is provided instead of the acoustic lens. Good. Further, the positioning jig 35 is not limited to the above-described shape, and may be deformed to another form as long as the function as the positioning can be ensured.
Further, the fixing of the laminated structure of the spacer 30 and the FPC 31 is not performed by screwing the fixing tool 38 into the post 36 of the positioning jig 35, but by using the post 36 of the positioning jig 35.
Each time the through hole of the spacer 30 or the FPC 31 is inserted, the positioning jig 35 may be removed before the backing layer is formed.

The base of the FPC 31 may have a function as a spacer. Also, in the above description, the positioning jig 3
5 are aligned while being stacked, but when the plurality of openings 46 are provided at intervals of the transducer piece pitch in the row direction at the time of completion, the openings 46 of the rack 45 as shown in FIG.
Alternatively, the FPC 31 'in FIG. 11B may be inserted as shown in FIG. Further, FIG.
FIG. 6B is a view of the state of FIG.
In general, two signal lines 33 are connected to one vibrator piece, and the electrodes of the vibrator piece for one row are drawn out by two FPCs 31. In the example, if the FPCs 31 in which the signal lines 33 are formed at an integral multiple of the vibrator piece pitch are alternately shifted by the vibrator piece pitch and arranged in a staggered manner, adjacent signal lines can be sufficiently separated. Therefore, it is possible to follow the miniaturization of the pitch of the vibrator pieces.

(Fourth Embodiment) A fourth embodiment is directed to a two-dimensional array type ultrasonic probe.
The present invention relates to a wiring pattern of a flexible printed circuit board (hereinafter abbreviated as “FPC”) for leading an electrode of a vibrator piece and an improvement in connection between the wiring pattern and the vibrator piece. Any of the wiring patterns shown in FIGS. 14 to 16 is adopted for the FPC according to the present embodiment. FIGS. 14 to 16 are plan views showing only the wiring pattern of the portion facing the eight vibrator pieces from the first column to the eighth column of the m-th row, but the other portions are the same pattern repeated. It has been omitted.

In FIG. 14, 50m1 to 50m8 are:
Each of the transducer pieces 51m1 to 51m1 in the first to eighth columns of the m-th row
A conductor exposed portion to be connected to the 51m8 electrode. The conductor exposed portions 50m1 to 50m8 are arranged at the same pitch in the column direction as the pitch of each of the transducer pieces 51m1 to 51m8 in the column direction. Also, conductor exposed portions 50m1 to 50m8
Are arranged so as to be shifted in the row direction within the range of the length of each of the transducer pieces 51m1 to 51m8 in the row direction so that the positions of the adjacent conductor exposed portions do not coincide in the column direction. Arranging the conductor exposed portions 50m1 to 50m8 in the row direction in this manner means that each of the conductor exposed portions 50m1 to 50m8 is
The signal lines 52 individually connected to the 50m8 can be distributed on both sides of the FPC and wired with a straight-line and simple wiring pattern, thereby simplifying the manufacturing process of the FPC.

Further, since the gap between the exposed conductors is large, the size of the exposed conductors 50m1 to 50m8 can be increased. Note that the plurality of signal lines 52 may be concentrated on only one side of the FPC, but in this case, a fine processing technique for reducing the width of each signal line is required. It is not preferable because the allowable current capacity is reduced. FIG. 15 shows a wiring pattern in which the number of signal lines in FIG. 14 is reduced to half. The following description is based on the assumption that the number of transducer pieces in the column direction is eight. This wiring pattern is composed of two conductor exposed portions 50m1 and 50m1, which are line-symmetric with respect to the center line C in the column direction.
m8, 50m2 and 50m7, 50m3 and 50m6, 50
m4 and 50m5, in other words, two conductor exposed portions which are in the same row and have the same distance from the center line C are commonly connected by one signal line 52, respectively.

In a two-dimensional array type ultrasonic probe, there are cases where two transducer pieces having the above-mentioned positional relationship are driven at the same phase (at the same timing). Even if the two exposed portions of the relationship are connected in common, no problem occurs. Therefore, the wiring pattern for commonly connecting the two conductor exposed portions in the above positional relationship realizes a reduction in the number of signal lines and an increase in the signal line pitch. FIG. 16 shows the most commonly used conductor exposed portion 50 at the same time.
5 shows a wiring pattern corresponding to a case where m1 to 50m8 are linearly arranged. In this wiring pattern, as in the case of FIG. 15, two conductor exposed portions having a line symmetrical positional relationship with respect to the center line C in the column direction are connected in common and bent so as to avoid adjacent conductor exposed portions. Then, the signal line 52 is wired. According to such a wiring pattern, the number of signal lines is larger than that in FIG. 15, but the signal line density is reduced and the exposed conductor portion and the signal line width can be increased.

In the wiring patterns shown in FIGS. 14 to 16, pads or through holes for electrical connection are provided at the ends of the signal lines. A necessary electric circuit may be provided on the FPC. In the wiring patterns shown in FIGS. 14 to 16, a wiring pattern non-formation area is provided between rows of the vibrator pieces, and the signal line 52 is not wired in this area. This after mounting the piezoelectric plate to FPC in the manufacturing process to be described later (piezoelectric ceramics), when separating the plurality of transducer element by cutting the piezoelectric plate, by performing cutting only in that region, cutting a signal line 52 This is to avoid doing so. Therefore, if there is no possibility of cutting the signal line 52 that simply forms a groove in the piezoelectric plate, it is, of course, not necessary to provide the above-described region.

The exposed conductor portion 50 shown in FIGS.
m1 to 50m8 are formed in any of the cross-sectional structures shown in FIGS. 17 (a), (b), (c) and FIGS. 18 (a), (b). FIG. 17A shows an adhesive 61 on a base 60.
After bonding the conductor layer (signal line) 62 with an adhesive and further bonding an insulating layer (cover lay film) 64 on the conductor layer 62 with an adhesive 63, the insulating layer 64 and the adhesive 63 are penetrated to the conductor layer 62. The structure is shown in which the insulating layer through hole 65 that reaches is provided at an appropriate position as a conductor exposed portion.

The structure of FIG. 17B is a structure in which the insulating layer through hole 65 of FIG. 17A is filled with a metal 66 having good conductivity such as copper to the surface. FIG.
(A) A bump structure in which the insulating layer through hole 65 is filled with a soluble metal having good conductivity such as solder and protrudes from the surface of the insulating layer. FIG. 18A shows that the insulating layer through hole 65 of FIG. 17A is filled with a metal 68 having good conductivity such as copper to the surface, and the metal 68 is melted with good conductivity such as solder. This is a bump structure in which the conductive metal 69 is projected.

FIG. 18B shows that the insulating layer through hole 65 of FIG. 17A is filled with a metal 70 having good conductivity such as copper and protruded from the surface of the insulating layer. It has a bump structure plated with a metal 71 having good properties. Note that the protruding portions in FIGS. 17C, 18A, and 18B may slightly extend on the surface of the insulating layer 64.
Although the insulating layer 64 is a cover lay film in the above description, the insulating layer 64 may be formed by applying a non-conductive paint (ink) or the like to both surfaces of the conductive layer 62 and drying and curing the conductive layer. Further, the structure may be such that the base 60 on the side not facing the vibrator piece is removed.

Next, the manufacturing procedure of the two-dimensional array type ultrasonic image processor 9 using any one of the above-described FPCs will be described. Here, a description will be given using a piezoelectric ceramic as an example of the piezoelectric plate. FIG. 17 (c), FIG.
In the case where a bump structure is employed for the exposed conductor as shown in FIG. 8 (a) and FIG. 18 (b), a similar bump structure can be formed at the corresponding position of the piezoelectric ceramics, and both can be connected by pressure welding. In other cases, the conductive exposed portion can be connected to the corresponding position of the piezoelectric ceramic by a conductive adhesive, an anisotropic conductive film, or soldering.

First, electrodes are formed on the back surface (the surface facing the FPC) of the piezoelectric ceramic as shown in FIG. 19A or 19B. In the case of FIG. 19A, the divided electrodes 801 to 808 of the number of rows common to the vibrator pieces in the same row are used.
Are formed in parallel along the column direction. In the case of FIG. 19 (b), the divided electrodes (80m1 to 80m8) corresponding to the total number of transducer pieces
Are formed in a matrix according to the arrangement of the vibrator pieces at the time of completion. The split electrodes shown in FIG. 19A or FIG. 19B are formed by mounting a mask sheet on which the respective division patterns are printed in advance on the back surface of the piezoelectric ceramic, or by forming a conductive layer formed on the entire back surface of the piezoelectric ceramic by the division pattern. In accordance with the method described above, a method of dividing by groove processing by etching processing or cutting processing is adopted. FIG. 19 (a)
In the case of forming the electrode divided only in the row direction shown in (1), it is necessary to divide the divided electrodes 801 to 808 together with the piezoelectric ceramic when dividing the piezoelectric ceramic described later in the row direction.

Of course, when a method of connecting the exposed portion of the conductor and the divided electrode by bump pressing or anisotropic conductive film is employed, a bump structure is formed on each divided electrode on the back surface of the piezoelectric ceramic after the step. When connecting the conductor exposed portion of the FPC and the divided electrodes on the back surface of the piezoelectric ceramics with a conductive adhesive, the conductive adhesive is applied to the entire surface of each divided electrode on the back surface of the piezoelectric ceramics as shown in FIG. . In addition, as shown in FIG. 21, a conductive adhesive is applied in a circular shape to a portion of each split electrode on the back surface of the piezoelectric ceramic facing each conductor exposed portion of the FPC. In FIG. 21, the conductive adhesive is not limited to being applied in a circular shape, but may be applied in another shape such as a square.

Next, the structure of the two-dimensional array type ultrasonic probe using the piezoelectric ceramics and the FPC thus formed will be described according to the manufacturing procedure. First,
As shown in FIGS. 22A to 22C, the FPC 91 is aligned and mounted on the back surface of the piezoelectric ceramic 90 on which the divided electrodes are formed as described above.
A backing material 92 for preventing sound leakage is attached to the back of the device. As the backing material 92, it is preferable to use the same material as the conventional vibrator piece or a material having an acoustic impedance substantially equal to that of the FPC 91 so as to reduce the acoustic reflection at the FPC 91. Further, as the backing material 92, a material which has a small heat change and a high pressure resistance is preferable in order to suppress a manufacturing error in a later step. Further, a plurality of members are laminated in the thickness direction to form the backing material 92, that is, a laminated backing having a material with little heat change and high pressure resistance as a lower layer and an upper layer having a layer for adjusting acoustic performance. By forming the material, it is possible to suppress manufacturing errors and obtain good acoustic characteristics. Further, when the FPC 91 has a structure without a base as an insulating layer in which a conductor is exposed on the back side, it is preferable that the backing material 92 be formed of an electrically insulating material.

Next, as shown in FIG. 23A, the piezoelectric ceramics 90 are moved along the row direction by at least half of the thickness.
By cutting to the above depth, the piezoelectric ceramics 90 is divided into the number of vibrator pieces in the column direction at the time of completion (here, two for convenience of explanation). Of course, when the piezoelectric ceramics 90 can be divided without dividing the signal line 52, the piezoelectric ceramics 90 may be completely separated and cut to the FPC 90. Then, the non-conductive and hardening filler 94 is filled in the groove 93 formed by the cutting as shown in FIG. As a material of the filler 94, a resin having small acoustic coupling between adjacent elements and high mechanical strength is used. After filling with the filling material 94, FIG.
As shown in (c), an Au thin film as a common ground electrode 95 is formed on one surface of the front surface (ultrasonic radiation surface) of the piezoelectric ceramic 90 by, for example, a sputtering process.

On the common ground electrode 95, FIG.
The acoustic matching layer 96 is mounted as shown in FIG. Subsequently, as shown in FIG. 24B, grooves 97 are formed along the column direction by cutting at a depth reaching at least the FPC 91 and the backing material 92 from the acoustic matching layer 96 via the piezoelectric ceramics 90, and the acoustic matching layer 96 and the piezoelectric ceramics 90 are divided into the number of vibrator pieces in the row direction at the time of completion (three here for convenience of explanation). This division is shown in FIG.
Since the wiring pattern is formed in the wiring pattern non-forming region described with reference to FIG. 16, the wiring pattern 52 is not divided.

After this division, as shown in FIG.
FPC 98 for extracting common ground electrode 95 to the outside
Attach. The groove 97 formed by cutting has
As shown in FIG. 7, a non-conductive and hardening filler 99 is filled. As described above, according to the present embodiment, a two-dimensional array type ultrasonic probe can be completed in a simple process as in the first embodiment. The convex probe having a convex ultrasonic output surface is manufactured by the following steps.
In this case, after the above-described step of FIG.
As shown in (a), the whole is forcibly bent, and this state is maintained. Then, as shown in FIG. 26B, the curved state is fixed by attaching the holding member 99 to the back surface of the backing material 92. Thereafter, the process returns to the process of FIG. 24C, and the same process is performed.

The dimensions (thickness × times)
Depending on (width × length), unnecessary vibration modes other than the desired vibration mode may appear in close proximity. In this case, in addition to the vibrator piece dividing grooves shown in the step shown in FIG.
It is also possible to form divided grooves having a depth of two or more, and to configure the vibrator pieces to be driven simultaneously from a plurality of vibrator piece groups (here, four). In this case, in the step shown in FIG. 24B, the row direction of the vibrator piece dividing groove position and / or
A groove having a depth that does not divide the common ground electrode 95 in the row direction is formed in the acoustic matching layer. In this case, the steps shown in FIG. 23 are replaced with the steps of FIG. 27, the steps shown in FIG. 24 are replaced with the steps of FIG. 28, and the steps shown in FIG. 25 are replaced with the steps of FIG.
Thereby, the appearance of the unnecessary vibration mode can be reduced. This is the same for convex probes.

The present invention is not limited to the above-described embodiment, but can be implemented with various modifications without departing from the spirit of the invention.

[0051]

According to the present invention, it is possible to easily draw out signal lines in a two-dimensional array type ultrasonic probe.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a manufacturing process of a two-dimensional array type ultrasonic probe according to a first embodiment.

FIG. 2 is a diagram of a state of drawing out signal lines according to a second embodiment as viewed from the side and above.

FIG. 3 is a view showing a spacer and a flexible printed circuit board, which are one component of a two-dimensional array type ultrasonic probe according to a third embodiment.

FIG. 4 is a view showing a step of laminating a spacer and a flexible printed board in FIG. 3;

FIG. 5 is a view showing a positioning step following the laminating step of FIG. 4;

FIG. 6 is a view showing a step of fixing the laminated structure and a step of forming a backing layer subsequent to the step of FIG. 5;

FIG. 7 is a view showing a column-direction cutting step and a step of forming a common electrode following the step of FIG. 6;

FIG. 8 is a view showing a row-direction cutting step following the step of FIG. 7;

FIG. 9 is a view showing a ground electrode extraction step following the step of FIG. 8;

FIG. 10 is a view showing another flexible printed circuit board.

FIG. 11 is a diagram showing a rack and a flexible printed circuit board applied to another laminating step and a positioning step.

FIG. 12 is a perspective view showing a state where a flexible printed circuit board is mounted on the rack shown in FIG. 11;

FIG. 13 is a view showing a laminated structure of another flexible printed circuit board in the laminating step of FIG. 4;

FIG. 14 is a plan view of a wiring pattern of a flexible printed circuit board according to a fourth embodiment.

FIG. 15 is a plan view of another wiring pattern.

FIG. 16 is a plan view of still another wiring pattern.

FIG. 17 is a cross-sectional view of the conductor exposed portion of FIG.

FIG. 18 is a sectional view of another conductor exposed portion.

FIG. 19 is a plan view showing an electrode pattern formed on the back surface of the piezoelectric ceramic.

20 is a view showing an application pattern of a conductive adhesive applied to the electrode of FIG. 19;

FIG. 21 is a diagram showing another application pattern.

FIG. 22 is a diagram showing a first step of a manufacturing process of the two-dimensional array type ultrasonic probe according to the fourth embodiment.

FIG. 23 is a view showing a step that follows the step of FIG. 22;

FIG. 24 is a view showing a step that follows the step of FIG. 23;

FIG. 25 is a view showing a final step following the step of FIG. 24;

FIG. 26 is a diagram showing a step added when the two-dimensional array type ultrasonic probe of the fourth embodiment is manufactured as a convex type.

FIG. 27 is a view showing a process replaced by FIG. 23;

FIG. 28 is a view showing a step replaced by FIG. 24;

FIG. 29 is a view showing a process replaced by FIG. 25;

[Explanation of symbols]

1 ... Acoustic matching layer, 2 ... Common electrode, 3 ... Piezoelectric plate, 4 ...
Conductive adhesive 4, 5 ... backing layer, 6 ... signal line,
7, 8 ... groove, 9 ... filler.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Haruyasu Rokuroda 1385-1 Shimoishigami, Otawara-shi, Tochigi Pref. 63-146699 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04R 17/00 332 A61B 8/00 G01N 29/24 502

Claims (13)

(57) [Claims] 1. A plurality of transducer pieces are two-dimensionally arranged,
In a two-dimensional array type ultrasonic probe having a structure in which a signal line is connected to each vibrator piece on the backing material side and the signal line passes through the inside of the backing material, the connection between the vibrator piece and the signal line Connection is on the back of each transducer
A two-dimensional array type ultrasonic probe characterized by being formed by a conductor layer having acoustic matching characteristics formed on a substrate. 2. A plurality of transducer pieces are two-dimensionally arranged,
In the two-dimensional array type ultrasonic probe in which the connection of the signal line to each transducer piece is made on the backing material side and the signal line passes through the inside of the backing material, the signal line is connected to the transducer piece. Characterized by being connected by a wire bonding process.
Dimensional array type ultrasonic probe. 3. The two-dimensional array type ultrasonic probe according to claim 1, wherein the backing material is formed by laminating a plurality of acoustic materials having different acoustic characteristics. 4. A plurality of printed wiring boards in which signal lines individually connected to a plurality of vibrator pieces arranged two-dimensionally are stacked, and a gap between the printed wiring boards is filled with a backing material. In the two-dimensional array type ultrasonic probe, the tip of the signal line arranged on one surface of the backing material is connected to the drive electrode side of each of the vibrator pieces, the tip of the signal line of the printed wiring board is A two-dimensional array type ultrasonic probe which is formed so as to have a pitch which is an integral multiple of the arrangement pitch of the vibrator pieces, and which is formed by alternately displacing the printed wiring boards. 5. The printed wiring board according to claim 4, wherein the plurality of printed wiring boards are held by racks.
Dimensional array type ultrasonic probe. 6. A wiring pattern provided on a printed wiring board.
Above the conductive layer An electric insulating layer is provided on the conductive layer.
Holes in the electrical insulation layer to reach the conductor so as to reach
And a two-dimensional array with the conductive layer of the plurality of conductor exposed portions
The electrodes provided on the back of each of the
Two-dimensional array type ultrasonic wave characterized by being connected together
probe. 7. The conductor-exposed portion is filled with copper, and the copper
It is characterized in that the solder is provided in a protruding state on the top
The two-dimensional array type ultrasonic probe according to claim 6. 8. Positions in the same row and symmetric with respect to the center of the row
The two exposed conductors connected to the two transducer pieces
7. A common connection in the same conductive layer.
The two-dimensional array type ultrasonic probe according to claim 1. 9. Dispersedly provided on a printed wiring board
Multiple vibrations arranged two-dimensionally on multiple conductor exposed parts
Secondary to electrically connect the electrodes provided on each back of the child piece
In the manufacturing method of the original array type ultrasonic probe, After connecting the electrode to the exposed conductor, the piezoelectric plate is
Along the direction, and then share on the piezoelectric body.
Forming a conductive electrode and an acoustic matching layer, and
Cutting along the second direction with the matching layer,
The common electrode cut along the second direction is grounded.
Two-dimensional array type ultrasonic wave, characterized by connecting
Probe manufacturing method. 10. Dispersedly provided on a printed wiring board
A plurality of two-dimensionally arranged vibrations
2 for electrically connecting the electrodes provided on each back surface of the moving piece
In a method for manufacturing a two-dimensional array type ultrasonic probe, After connecting the electrode to the conductor exposed portion, the piezoelectric plate
The printed wiring board is divided into a plurality of vibrator pieces.
Backing material with almost the same acoustic impedance as
The conductor exposed portion of the printed wiring board is not provided.
Two-dimensional array type super sound characterized by being attached to the back
Wave probe manufacturing method. 11. Dispersedly provided on a printed wiring board
A plurality of two-dimensionally arranged vibrations
2 for electrically connecting the electrodes provided on each back surface of the moving piece
A three-dimensional array type ultrasonic probe having substantially the same acoustic impedance as the printed wiring board.
The conductor exposed before Symbol printed wiring board backing material to
It is characterized by being attached to the back where no part is provided
Two-dimensional array type ultrasonic probe . 12. An electrode provided on each back surface of a plurality of vibrator pieces arranged two-dimensionally is electrically connected to a plurality of conductor exposed portions dispersedly provided on a printed wiring board.
In the method for manufacturing a two-dimensional array type ultrasonic probe, the piezoelectric plate is divided into the plurality of vibrator pieces after the electrodes are connected to the conductor exposed portions, and the printed wiring board is formed into a convex shape together with the piezoelectric plate after the division. A method for manufacturing a two-dimensional array type ultrasonic probe, characterized by being curved. 13. An electrode provided on each back surface of a plurality of vibrator pieces arranged two-dimensionally is electrically connected to a plurality of conductor exposed portions dispersedly provided on a printed wiring board. A two-dimensional array type ultrasonic convex probe characterized by the following.