JPH0779498A - Z-axis conductive laminar backing layer for acoustic transducer - Google Patents

Abstract

PURPOSE: To provide a Z-axis conductive backing layer for an acoustic transducer for attenuating output acoustic energy from the rear surface of a transducer element and hardly generating the reflection of output acoustic energy to the transducer element. CONSTITUTION: The pattern of a conductor 24 separated for a pitch equal to the pitch of piezoelectric elements is formed on plural layers 10 (101 , 102 and 103 ) by an acoustic attenuation material, a laminated structure 30 is formed by joining the layers 10 and a conductive pad in a matrix shape conducted to the conductor 24 is provided on the lower surface of the laminated structure 30. The piezoelectric element 52 in the matrix shape corresponding to the conductive pad for which a conductive coating 36, a piezoelectric material 48 and a matching layer 68 are laminated is formed on the upper surface of the laminated structure 30, and when electric signals are supplied to the respective conductive pads, conversion to sound wave energy is performed in the piezoelectric element 52 through the conductor 24, the sound wave energy from the rear surface of the piezoelectric element 52 is absorbed by the acoustic attenuation material and the reflection is suppressed.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to acoustic transducer arrays, and more particularly to such arrays for electrically connecting such arrays to circuit elements and for eliminating spurious acoustic reflections caused by the array. Z-axis conductive laminated backing layer for acoustic transducers.

[0002]

Ultrasonic imaging systems are widely used to produce images of the internal structure of specimens or other objects. Medical diagnostic ultrasound imaging systems image an internal tissue of the human body by electrically energizing an acoustic transducer element or an array of acoustic transducer elements to produce short ultrasonic pulses that are delivered into the human body. Form. Echoes from the tissue are received by the acoustic transducer elements and converted into electrical signals. Circuit elements such as printed circuit boards, flexible cables or semiconductors receive this electrical signal. Such electrical signal is amplified and used to form a cross-sectional image of the tissue. Such imaging techniques provide a safe, non-invasive method for obtaining diagnostic images of the human body.

An acoustic transducer that emits ultrasonic pulses is provided with a plurality of piezoelectric elements arranged in an array having a predetermined pitch. This array is generally one-dimensional or two-dimensional. Reduce the pitch of the piezoelectric elements in the array,
The image resolution can be increased by increasing the number of elements. The operator of the imaging system can control the phase of the electronic pulse applied to the piezoelectric element to change the direction of the output ultrasonic beam or its focus. In this way, the operator can "steal" the direction of the ultrasonic waves to illuminate the desired portion of the human body without physically manipulating the position of the transducer.

[0004]

When one of the piezoelectric elements is energized, sound waves are emitted from both the front surface facing the imaging target and the rear surface of the element. The acoustic energy from the rear surface is considerably attenuated so that the image resolution is not adversely affected. If not attenuated, the backward acoustic signal may be reflected from the circuit elements back to the surface of the transducer, causing the desired electrical signal degradation.

To avoid such situations, a backing layer of acoustically dampening material is disposed between the piezoelectric element and the circuit element to damp unwanted acoustic energy from the back surface of the piezoelectric element. Ideally, the backing layer has an acoustic impedance that matches the impedance of the piezoelectric element so that a significant portion of the acoustic energy of the back surface of the piezoelectric element is coupled to the backing layer.

A problem with using a backing layer between a piezoelectric element and a circuit element is the problem of electrical connection between the particular piezoelectric element and its corresponding circuit element. This connection problem becomes more difficult in the case of a two-dimensional array consisting of 4 columns x 4 rows or more of piezoelectric elements. This is because the inner elements do not have exposed edges to make electrical connections. In such a two-dimensional array, the electrical connections between the individual piezoelectric elements and the electrical circuits that receive and process the electrical signals are generally made in the direction of the Z-axis, which is perpendicular to the array. However, this interconnection becomes more difficult as the number of elements in the array increases and the pitch between the elements decreases.

The method for making a connection through the backing layer is "ULTRASONIC TRANSDUCER AND METHOD FOR FABRICATI
NG THEREOF "(" Ultrasonic transducer and its manufacturing method ")
US Pat. No. 4,82, entitled Kawabe et al.
No. 5,115. According to Kawabe, a printed wiring board is used that is directly bonded to the piezoelectric array transducer element. A backing layer is then molded over the array around the wiring board, and the wiring board extends outward from the molded backing layer. According to this, although a reliable connection method is provided, the wiring board becomes a surface that reflects sound wave energy in the backing layer, which deteriorates the acoustic attenuation characteristics of the backing layer.

The problems of the prior art can be solved by forming the entire backing layer with adjacent blocks of material. In this way, the overall acoustic damping capacity of the backing layer is improved. However, the use of a solid backing layer causes manufacturing problems, ie it is difficult to provide the conductor on the solid backing layer.

A second problem that complicates the formation of electrical connections is crosstalk. Crosstalk is an interference generated between adjacent signal conductors, which is generated by capacitive coupling or inductive coupling. In typical applications, crosstalk can be minimized or eliminated by shielding the conductive elements. Shields placed around the connecting conductors in the backing layer alleviate the crosstalk problem, but this makes it more difficult to place conductors in the solid backing layer.

Accordingly, there is a need for improvements in methods and apparatus for making electrical connections between elements of an acoustic transducer array and corresponding contacts of electrical circuit elements. Such techniques must be such that the output acoustic energy from the rear surface of the pressure line element is sufficiently attenuated so that there is little reflection of such energy on the transducer element.
Also, such technology should be relatively easy to manufacture and should be able to accommodate large transducer arrays with a large number of piezoelectric elements and a relatively small pitch.

[0011]

SUMMARY OF THE INVENTION In light of the above, the present invention provides an acoustic transducer for delivering sonic energy in response to an electrical signal and converting the received sonic energy into an electrical signal. The acoustic transducer comprises an array of piezoelectric elements, a backing layer attached to the back surface of the piezoelectric elements, circuit elements separated from the piezoelectric elements by the backing layer, and each piezoelectric element for connecting each element to the circuit element. Of at least one conductor. The backing layer comprises a plurality of layers of acoustically attenuating material integrally formed in a generally laminated structure. The conductors extend along the surface of each layer and have a predetermined pitch. The thickness of each layer is approximately equal to the conductor pitch.

In one embodiment of the invention, the electrical signal conductors are each separated by a ground conductor that is not in electrical contact with the electrical signal conductors. These ground conductors significantly reduce unwanted crosstalk between adjacent conductors on a particular layer. Similarly, selected layers can be separated by ground layers to significantly reduce unwanted crosstalk between adjacent layers.

The present invention further provides a method of constructing a laminated structure from multiple layers of acoustically attenuating material. Each layer is provided with a plurality of conductor patterns having a predetermined pitch equal to the layer thickness. Next, the layers provided with this pattern are combined to form a laminated structure.
The conductor extends between the top and bottom surfaces of this structure. After combining the individual layers to form a laminated structure, electrical contacts are disposed on the lower surface of the laminated structure for making electrical connections to corresponding electrical contacts of the circuit elements. The individual piezoelectric elements of the transducer matrix are arranged on the upper surface of this laminated structure such that each piezoelectric element is electrically connected to a corresponding conductor.

[0014]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, an improved method and apparatus for electrically contacting each element of an acoustic transducer array with its corresponding electrical circuit element contacts is disclosed. The present invention sufficiently attenuates the output acoustic energy from the rear surface of the pressure line element so that there is little reflection of such energy on the transducer element. Moreover, the present invention is relatively easy to manufacture and can easily accommodate large transducer arrays with a large number of piezoelectric elements and a relatively small pitch.

First of all, FIGS. 1 to 5 show a method of manufacturing an acoustic transducer from a laminated structure 30 made of an acoustic damping material. Laminated structure 30 comprises a plurality of layers 10 (layer 101) formed from sheets of acoustically attenuating material cut into suitable shapes.
~ 106). In this example, this material is an epoxy with a sound absorbing agent and acoustic scattering agent such as tungsten, silica, chloroprene particles or bubbles. The material is not limited to epoxy but must be electrically insulating and sound absorbing.

Each of the layers 10 has a front surface 12, a rear surface 14,
It has an upper surface 16 and a lower surface 18. The front surface 12 is provided with an electrode coating 22. Electrode coating 2
The exact thickness of 2 can be selected to obtain the desired acoustic and structural quality. Electrode coating 22
If the is too thick, the acoustic properties of the material can be adversely affected by the increased reflectance of backward sound waves. On the other hand, if the electrode coating 22 is too thin, the conductivity will be low or the conductivity will be easily interrupted. In the preferred embodiment,
The electrode coating 22 comprises a bimetallic coating having a first chrome coating having a thickness of about 300 Angstroms and a second gold coating having a thickness of about 3000 Angstroms. Chromium promotes adhesion to layer 10, and gold provides good quality conductors that are resistant to oxidation. However, it is clear that alternative materials can be used for the electrode coating 22 provided the desired conductivity and material strength conditions are met. Metal coating is sputtering,
It can be added using plating or other conventional techniques.

The electrode coating 22 has a respective layer 10
After being added to the coated layer, the coated layer is provided with a pattern of a plurality of conductors 24 as shown in FIGS. Each conductor 24 includes an upper surface 16 and a lower surface 18 of layer 10.
Conductors 24 extending between and adjacent by a gap 26
Is separated from. This pattern can be produced by a diamond saw, the notches of which form the gap 26 between the conductors. This saw is layer 10
A very shallow cut is made to further promote insulation of the individual conductors 24. Alternatively, this pattern can be generated by conventional photolithographic techniques.

The individual conductors 24 are separated by a desired pitch which is equal to the desired pitch of the piezoelectric elements of the acoustic transducer, as will be explained below. In the preferred embodiment, the conductors 24 have a pitch of 300 microns and the gaps 26 provide a spacing of 50 microns between the conductors. The specific intervals and pitches shown are merely examples, and the enlargement ratio is not constant.

After the patterned layers 10 have been created, the layers are combined to obtain the laminated structure 30 shown in FIG. Layers 10 are bonded by an insulating epoxy or other adhesive that fills the gaps between the individual conductors under some temperature and pressure. Each of the patterned layers 10 is oriented such that the conductor 24 extends between the upper surface 32 and the lower surface 34 of the laminated structure 30. After the laminated structure 30 is formed, its outer surface is lapped by conventional cutting processes to form a generally flat and / or orthogonal surface. The edge portion 28 of each conductor 24 is exposed at the top and bottom lapped surfaces.

Referring now to FIG. 4, the lower surface 34 of the laminated structure 30 is provided with a pattern of electrical contacts. Bottom surface 34
The electrode coating 22 on the individual layers 10 described above.
The electrode coating 38 is applied in the same manner as the application of. The lower conductor or electrode coating 38 is then provided with a pattern of conductive pads 46.
Each conductive pad 46 has a conductor 24 as indicated by a dotted line.
Electrically connected to one corresponding end of the and patterned to match the corresponding element of the circuit element.

This pattern can be formed using a conventional diamond saw as described above. The saw first cuts a plurality of vertical score lines 42 having the same pitch as the gaps 26 between adjacent conductors 24 of the individual layers 10. The saw then has a plurality of horizontal scoring lines 44 spaced at the midpoints of the individual layer 10 thicknesses.
Turn off. However, other patterning techniques such as photolithography can also be applied.

In FIG. 5, a conductive coating 36 is applied to the upper surface 32 of the laminated structure 30 in the same manner as described above. However, before patterning the conductive coating 36, a layer of piezoelectric material 48 is adhered to the conductive coating. The piezoelectric material 48 may include any material that produces a sound wave in response to an electric field applied to the material, including but not limited to lead zirconium titanate.

To adhere the piezoelectric material 48 to the conductive coating 36, an insulating adhesive having a low viscosity such as epoxy is used. This adhesive is applied to a thickness of about 1 micron. The RMS roughness of the piezoelectric material 48 exceeds the bond thickness so that when heat and pressure are applied, the peak of the piezoelectric material penetrates the epoxy and the piezoelectric material and conductive coating 36.
To form an electrical connection between.

After the piezoelectric material 48 is adhered to the conductive coating 36, a graphite or polymer matching layer 68 is applied to the exposed surface of the piezoelectric material 48. This matching layer 68 enhances the forward sonic energy generated by the piezoelectric material 48, as is well known in the art. Then, for this combination of piezoelectric material 48, conductive coating 36 and matching layer 68, a pattern of vertical score lines 42 and horizontal score lines 44 in a manner similar to that described above for lower surface 34. Is provided. This technology has a laminated structure 3
It can be seen that 0 allows automatic alignment of the upper conductive coating 36 with respect to the vertical score lines 42 and horizontal score lines 44.

By this patterning technique, a plurality of layers arranged in a matrix having conductors 24 each extending in the acoustic damping material of the laminated structure 30 to a conductive pad 46 arranged on the lower surface 34 of the laminated structure. It can be seen that the piezoelectric element 52 is obtained. The conductive pads 46 on the lower surface 34 are substantially aligned with the piezoelectric elements 52 on the upper surface 32. In this way, a matrix of piezoelectric elements 52 having any desired dimensions can be obtained by simply increasing the size and number of layers 10.

FIG. 6 shows an alternative embodiment of the laminated structure 30. The pattern of the individual layers 10 has alternating electrical signal conductors 62 and ground conductors 64. Electrical signal conductor 62
The pitch of the pair of the ground conductor 64 and the ground conductor 64 is the same as the single conductor 24 described above.
Equal to the pitch of. This is intended to reduce crosstalk of electric signals between adjacent electric signal conductors 62 by providing the grounding conductor 64 therebetween. The patterning of each layer 10 is performed using a diamond saw or a photolithography process as described above. However, the upper end of layer 10 is provided with a ground pass gap 66 to prevent electrical connection between the ground conductor 64 formed in the manner described above and the piezoelectric element 52. Ground conductor 64
On the lower surface of the laminated structure 30 having a pattern, the pattern is formed on each of the individual layers 10 such that conductive pads 46 are formed for making electrical connections between the circuit elements and the ground conductor 64 and between the circuit elements and the electrical signal conductors 62. Match the spacing of. The ground conductor 64 is adapted to be electrically connected to ground potential, thus shunting any crosstalk signal induced in the ground conductor to ground.

A second alternative embodiment for controlling crosstalk between conductors 24 of adjacent layers 10 is shown in FIG.
In this embodiment, each layer 10 is divided into a first layer portion 72 and a second layer portion 74. A ground plane 76 is disposed between the first layer portion 72 and the second layer portion 74. This ground plane is also the lower surface 3 of the laminated structure 30 assembled in the same manner.
4 is electrically connected to the ground pad 46 provided in
It is designed to shunt the crosstalk signal to ground. Similarly, a heat conductor may be used in place of ground plane 76 to remove excess heat from laminated structure 30.
Such a heat conductor guides excess heat in the laminated structure 30 to an external heat sink (not shown).

Experiments with acoustic transducers formed in accordance with the present invention have demonstrated that levels of crosstalk attenuation can be obtained to direct and focus a two-dimensional array. In particular, the interlayer crosstalk level measured between adjacent conductors 24 showed a crosstalk signal of -45 dB. Similarly, the measured inter-layer crosstalk value between the conductors 24 of the adjacent layers 10 showed a crosstalk signal of -45 dB. It is believed that crosstalk attenuation can be further improved by using the ground conductors placed between the conductors described above.

The level of power dissipation of the individual conductors 24 is low and therefore thermal problems are believed to be minimal.
The measured resistance value of the individual conductors 24 is less than 1 ohm. Since the resistance value of the piezoelectric element 52 as an individual acoustic transducer element is about 10,000 ohms, and about 100 volts is required for the output pulse, it is considered that each conductor 24 carries about 10 milliamps of current. be able to. Therefore, the power dissipation in each conductor 24 is about 1
It is considered to be 00 microwatts, which is relatively low.

However, depending on the application, it may be desirable to further reduce the resistance value and improve the reliability of each conductor 24. Therefore, FIGS. 8 and 9 show a third embodiment of the present invention. Instead of the single planar conductor 24 having the pattern as described above, the individual layers 10 are patterned prior to the application of the conductive coating 22 to form the generally rectangular groove 82. Then, the conductive rear wall 8 is inserted into these rectangular grooves 82.
4 and a conductive coating including conductive sidewalls 86 is added. The three-sided conductor 80 is then filled with an insulative epoxy 88 and the individual layers are bonded as described above to provide a single laminated structure. As described above, the lower conductive pad 46 is formed on the lower surface of the laminated structure 30 and the individual piezoelectric elements 52 are disposed on the upper surface of the laminated structure. The resistance value of the three-sided conductor 80 is about one third of the resistance value of the conductor 24 described above.

FIG. 10 is an exploded perspective view of an acoustic transducer 50 constructed according to the present invention. Acoustic transducer 50 is electrically attached to circuit elements shown as printed circuit board 54. This circuit element can be a semiconductor, a flexible cable or other device. The printed circuit board 54 has a plurality of electrical contacts 56 that correspond to the locations of the individual conductive pads 46 on the lower surface 34 of the acoustic transducer 50.
In addition, a ground sheet 58 overlays the exposed tops of the individual piezoelectric elements 52 to electrically connect the individual elements.

In operation, printed circuit board 54 provides electrical signals to individual conductive pads 46 of acoustic transducer 50. Such electrical signals are conducted to the back surface of individual piezoelectric elements 52 by conductors 24 passing through layers 10 of laminated structure 30. An acoustically transparent grounding sheet 58 is disposed on the exposed surface of the acoustic transducer 50 and brought into contact with an object of interest, such as the patient's skin. By providing the ground sheet 58 on the exposed surface of the piezoelectric element 52 rather than the rear surface, inadvertent electrical shock to the patient is avoided.

The electrical signal input to the piezoelectric element 52 is converted into sonic energy which is delivered to the patient via the ground sheet 58. The acoustic energy delivered by the acoustic transducer 50 is used for echographic examination. The delivery of acoustic energy from the back surface of the piezoelectric element 52 is absorbed by the laminated structure 30 formed of acoustically attenuating material. The reflected acoustic energy received by piezoelectric element 52 is converted into an electrical signal which is returned to printed circuit board 54 via conductor 24. This received signal is then conditioned by known electrical circuits on the circuit board.

Using the present invention, an array having any desired dimensions can be obtained by varying the number and size of layers 10 and varying the pitch of conductors 24 disposed in each layer.

Although the respective embodiments of the present invention have been described in detail above, in order to facilitate understanding of the respective embodiments, the respective embodiments are summarized and listed below.

(1). A backing layer for connecting an acoustic transducer having a plurality of transducer elements each having a first acoustic impedance and a back surface to an electrical circuit element having contacts to each transducer element, the backing layer comprising: Face and second
A plurality of layers of acoustically attenuating material integrally formed with the block having a surface of
A plurality of layers having an acoustic impedance of a value relative to said first acoustic impedance such that a selected portion of the acoustic energy of the rear surface transducer element is coupled to this block, at least one for each transducer element. Two conductors extending between said first and second faces and having a predetermined pitch, the conductors of adjacent transducer elements being electrically insulated from each other, A first surface on the first surface for making electrical contact between the rear surface and at least one corresponding conductor
For acoustic transducers, and second contact means provided on said second surface for making electrical contact between circuit element contacts for the transducer element and corresponding at least one conductor. Is a Z-axis conductive laminated backing layer.

(2). The conductor is a Z-axis conductive laminate backing layer for one acoustic transducer disposed on the surface of each layer.

(3). The first contact means is a Z-axis conductive laminate backing layer for one acoustic transducer that is a first pattern of electrical contacts that substantially conforms to the rear surface of the transducer array.

(4). The second contact means is a Z-axis conductive laminate backing layer for one acoustic transducer that is a second pattern of electrical contacts that substantially matches the electrical circuit contacts.

(5). Each of the layers is a Z-axis conductive laminate backing layer for an acoustic transducer having a thickness that is approximately equal to the pitch of the conductors.

(6). The conductors are each separated by a ground conductor, which is a Z-axis conductive laminate backing layer for an acoustic transducer that is electrically insulated from the ground conductor.

(7). A selected one of the layers is a Z-axis conductive laminate backing layer for one acoustic transducer that further includes shield means for insulating the conductors of adjacent ones of the layers.

(8). An acoustic transducer for converting received acoustic energy into an electrical signal, an array of piezoelectric elements each having a front surface and a rear surface, a backing cover attached to the rear surface for attenuating the acoustic energy received from the piezoelectric elements. A backing means comprising a plurality of layers of acoustically attenuating material integrally formed in the laminated structure, a circuit element separated from the piezoelectric element by the backing means, the backing means comprising: An acoustic transducer comprising circuit elements having respective corresponding contacts and conductor means for electrically connecting the contacts to the corresponding piezoelectric elements.

(9). The conductor means comprises at least one conductor for the piezoelectric element, the conductor extending along the surface of each layer and having a predetermined pitch, the conductors for adjacent transducer elements being mutually 8 acoustic transducers that are electrically isolated.

(10). Each of the layers is 9 acoustic transducers having a thickness approximately equal to the pitch of the conductors.

(11). The conductors are each 9 acoustic transducers separated by a ground conductor, the conductors being electrically isolated from the ground conductor.

(12). Selected of the layers are the acoustic transducers of 9, further including shield means for electrically insulating the conductors of adjacent ones of the layers.

(13). The conductor means is also an acoustic transducer of 8, having a first pattern of electrical contacts disposed on top of the backing means that substantially conforms to the piezoelectric element.

(14). The conductor means are also thirteen acoustic transducers having a second pattern of electrical contacts disposed below the backing means that substantially match the circuit element contacts.

(15). A method of manufacturing an acoustic transducer having a plurality of piezoelectric elements arranged in a matrix, the method comprising: providing a laminated structure comprising a plurality of layers of acoustic damping material, each layer having a plurality of conductors; A step of disposing an electrical contact electrically connected to a corresponding one of the conductors, the electric contact being capable of being connected to an external power source, and disposing the piezoelectric element on an upper surface of the laminated structure, A method of manufacturing an acoustic transducer comprising the steps of electrically connecting the piezoelectric element to a corresponding one of the conductors.

(16). Providing the layered structure further comprises providing a conductive coating on the surface of each layer, patterning each coated surface to form the conductor, and combining the layers to form the layered structure. 15 is a method of manufacturing an acoustic transducer, which comprises providing a structure and extending the conductor between the upper surface and the lower surface.

(17). The step of disposing electrical contacts on the lower surface of the laminated structure further comprises the steps of applying a conductive coating to the lower surface and patterning the conductive coating on the lower surface to provide the electrical contacts. Is a method for manufacturing the acoustic transducer.

(18). Disposing the piezoelectric element on the top surface of the laminated structure further comprises applying a conductive coating to the top surface and adhering a piezoelectric layer to the conductive coating, and the conductive coating on the top surface and the piezoelectric layer. 15 is a method of manufacturing an acoustic transducer, comprising the steps of patterning both layers to provide the piezoelectric element.

(19). The step of providing the layered structure is a method of manufacturing fifteen acoustic transducers, further comprising spacing selected ones of the layers with a ground conductor.

(20). The step of providing the layered structure further comprises the step of spacing each of the conductors by a ground conductor, the method of manufacturing fifteen acoustic transducers wherein the ground conductor is electrically insulated from the conductor.

[0056]

As described above, according to the present invention, conductors electrically connected to the first surface and the second surface and electrically insulated from each other are formed in each of the plurality of layers made of the damping material. , Blocking the plurality of layers, providing contact means for making electrical contact on the second surface, and first acoustic so as to couple a selected portion of the acoustic energy of the acoustic conversion element to the first surface. It is configured to have an acoustic impedance of a value relative to the impedance, and the electric signal of the second surface is passed through the conductor to the first
Since the acoustic conversion element on the surface side of the converter is configured to convert to the acoustic level, the output acoustic energy from the rear surface of the transducer element is sufficiently attenuated and the reflection of this output energy to the transducer element hardly occurs. In addition, it is relatively easy to manufacture, and can easily accommodate a large-sized transducer array having a large number of piezoelectric elements and a relatively small pitch. Along with this, a high-resolution acoustic image can be obtained.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a laminated structure of an acoustic transducer backing layer of the present invention.

2 is a partial enlarged view of one layer of FIG. 1. FIG.

FIG. 3 is a perspective view of the backing layer of FIGS. 1 and 2 combined in a single laminated structure.

FIG. 4 is a partial bottom view of a laminated structure showing a pattern of electrical contacts.

FIG. 5 is a partial perspective view of a laminated structure showing individual piezoelectric elements arranged on the upper surface of the laminated structure.

FIG. 6 is a partial perspective view of one layer of a laminated structure similar to that of FIG. 2, showing an embodiment in which ground conductors are alternately arranged with electric conductors.

FIG. 7 is an exploded perspective view similar to FIG. 1, in which a ground layer is provided between conductive layers.

FIG. 8 is a partial perspective view of one layer in which a conductor having three surfaces is used.

9 is a partial plan view of the layer of FIG.

FIG. 10 is an exploded perspective view of the acoustic transducer of the present invention.

[Explanation of symbols]

 10, 101-106 layers 12 front surface 14 rear surface 16, 32 upper surface 18, 34 lower surface 22, 38 electrode coating 24 conductor 26 gap 28 edge portion 30 laminated structure 36 conductive coating 42, 44 cut groove line 46 conductive pad 48 piezoelectric material 50 Acoustic transducer 52 Piezoelectric element 54 Printed circuit board 56 Electrical contact 58 Grounding sheet 62 Electrical signal conductor 64 Grounding conductor 66 Grounding pass gap 68 Matching layer 72 First layer portion 74 Second layer portion 76 Grounding surface 80 Three-sided conductor 82 Rectangular groove 84 Rear wall 86 Side wall 88 Epoxy

Claims (1)

[Claims] 1. A backing layer for connecting an acoustic transducer having a plurality of transducer elements each having a first acoustic impedance and a back surface to an electrical circuit element having contacts to each transducer element. And a plurality of layers of acoustically attenuating material integrally formed in a block having a first surface and a second surface, said block comprising acoustic energy of a transducer element on a rear surface of said first surface. A plurality of layers having an acoustic impedance of a value relative to the first acoustic impedance such that selected portions of the are coupled to this block, at least one conductor for each transducer element, Conductors that extend between two surfaces and have a certain pitch, the conductors of adjacent transducer elements being electrically insulated from each other, the rear surface of each transducer element and its corresponding The first for electrical contact between the at least one conductor that
First contact means provided on the surface of the second surface and a second contact surface of the second surface for making electrical contact between the circuit element contact for the transducer element and the corresponding at least one conductor. Z-axis conductive laminated backing layer for acoustic transducers consisting of contact means.