Sensor with Interconnections and Interventional Medical Device Using the Same

Abstract

To provide the further transducer design which has improved performance and integration of a sensor in a medical device having restrictions on a dimension.SOLUTION: A sensor has a sensor element with two opposite sides and an interconnect with first and second terminal segments interconnected by an intermediate segment. The first terminal segment is positioned against a first side of the sensor element and comprises a first contact terminal. The second terminal segment is positioned against the second side of the two opposite sides of the sensor element and comprises a second contact terminal on a surface facing the second side. There are third and fourth external contact terminals. The interconnect provides electrical connections between the first and fourth contact terminals and between the second and third contact terminals.SELECTED DRAWING: Figure 4J

Description

Technical Field

[0001] The present invention relates to a sensor, a medical device having the sensor, and a method of manufacturing the sensor.

Background Art

[0002] Measuring blood flow in arteries helps physicians make correct diagnoses for appropriate treatment. The measurement principle can be based on spectral Doppler. An actuator / receiver for such a device can be based on a circular disk of piezoelectric material having electrodes on the front and back sides. Electrical interconnection to the actuator / receiver is created by soldering wires to both the front and back surfaces of the piezoelectric disk. This is the current state of the art for intravascular flow sensing. Another use of piezoelectric material is for the positioning of sensors on a device in an ultrasonic field where again a circular disk transducer can be used.

[0003] Piezoelectric disks having electrical connections made by soldering wires often have reduced or limited sensitivity and strain due to the presence of the wires and soldering material. The amount of soldering material applied to the electrical connection can limit the transducer resonance performance at the expense of the acoustic pressure output.

[0004] A state-of-the-art piezoelectric disk 2 is shown in FIGS. 1A through 1C. In FIG. 1A, the back surface 4 of the disk 2 is shown. In FIG. 1B, the front surface 6 of the same piezoelectric disk 2 is shown. Electrical connections to the front and back sides are created by soldering copper wires, namely, a front-side wire 8 and a back-side wire 10 attached to the front surface 6 and the back surface 4 of the disk 2, respectively. The piezoelectric disk 2 has a hole for the front-side wire 8 to pass through. The amount of soldering material 3 required to fix the front-side wire 8 can cover a substantial portion of the front surface 6. In that case, a loss of acoustic pressure can exist due to the reduced active surface 6 of the piezoelectric disk. An exemplary top view of the front surface 6 is shown in FIG. 1C, where the soldering covers about 1 / 4 of the front surface 6.

[0005] The ceramic disk also has a very small size, such as a diameter of about 300 μm. Therefore, the wire is extremely small, and a typical wire diameter ranges from 20 to 40 μm. Due to the extremely small dimensions of both the transducer and the electrical wire, a highly reliable and reproducible connection is also very difficult to achieve using this soldering method, leading to relatively high yield losses. In particular, the amount of solder 3 applied on the front surface 6 of the transducer is difficult to control and can affect the transducer resonance performance and acoustic pressure output.

[0006] The applicant has proposed a sensor having a sensor element, an interconnecting portion, and a metal layer in European Patent Application No. 19155417.9, which has not yet been published. The interconnecting portion is configured to be disposed on the sensor element and extends around the outer peripheral edge from one side of the sensor element to the other side of the sensor element. The electrical connection to the sensor element can be made on the same side of the sensor element.

[0007] The interconnecting portion is coupled around the sensor element and has a thin single-sided metallized film wound thereon. It avoids the need for soldering and passing a thin wire through the opening of the sensor element. Summary of the Invention Problems to be Solved by the Invention

[0008] This design has to consider the conductive outer surface of the interconnecting portion. Therefore, there are some design constraints. There remains a need to provide a further transducer design with improved performance and integration of sensors in medical devices having dimensional constraints. Means for Solving the Problems

[0009] The present invention is defined by the claims.

[0010] According to the present invention, a sensor is provided, the sensor comprising: a sensor element having first and second opposite sides; an interconnect having an electrically insulating flexible carrier, the interconnect having first and second terminal segments interconnected by an intermediate segment; and the first terminal segment is disposed opposite the first side of the sensor element and has a first contact terminal on a surface facing the first side; the second terminal segment is disposed opposite the second side of the sensor element and has a second contact terminal on a surface facing the second side; the interconnect further has third and fourth external contact terminals; the interconnect further has a first internal electrical connection within the flexible carrier connecting the first contact terminal and the fourth contact terminal, and a second internal electrical connection within the flexible carrier connecting the second and third contact terminals.

[0011] This sensor has an interconnect that provides an internal connection extending between both sides of the sensor element from one sensor terminal on one side of the sensor element to the first external terminal. Since this is shielded within the insulating carrier, this means that it can pass along any desired path, such as through an opening in the sensor element or around the outside. Another internal connection extends from the other side of the sensor element to the second external terminal. Thus, the interconnect provides two external contact terminals for the sensor and contacts both sides of the sensor element. Direct wire connections to the sensor element are avoided. Instead, the connection to the sensor element is by way of the first and second contact terminals. These connections may be made by physical pressure, or by contact pad soldering (rather than wire soldering), by adhesion, or by any other suitable connection method.

[0012] In the example of the first set, the third and fourth contact terminals are on the second terminal segment, on the side opposite to the second contact terminal of the carrier. In this design, only the first and second terminal segments are required. The second terminal segment is double-sided, with one side facing the sensor element and the other side facing outwards, forming an external contact surface for the sensor. The second internal electrical connection between the second and third contact terminals may be, for example, a via extending through the carrier.

[0013] In the example of the second set, the third and fourth contact terminals are on the third terminal segment of the interconnect, and the third terminal segment is interconnected to the second terminal segment by a second intermediate segment.

[0014] In the example of this set, there are three linearly arranged terminal segments with two intermediate segments. In this case, the interconnect may have a folded configuration with a space between the sensor element and the third terminal segment. This space may be used, for example, for acoustic attenuation.

[0015] Then, the third and fourth contact terminals may be on the same side as the second contact terminal of the carrier. The second contact terminal faces the second side of the sensor element, and the third and fourth contact terminals face outwards. They may face in opposite directions after a 180-degree bend in the second intermediate segment.

[0016] Alternatively, there may be a 90-degree bend or a Z-bend in the second intermediate segment such that the third and fourth contact terminals are located in a plane perpendicular to the second side of the sensor element. This may enable the wire connection to be made without bends. The (first) intermediate segment is folded through or around the sensor element so as to extend between opposite sides.

[0017] The second terminal segment may be connected to the first base unit. The first base unit may be a matching or damping backing layer for the sensor element.

[0018] Alternatively or similarly, the third terminal segment may be connected to the second base unit. This provides, for example, additional rigidity and aids handling and processing.

[0019] The first or second base unit has active electronic components such as components of an ASIC.

[0020] The second intermediate segment extends, for example, around the outer edge of the first and / or second base unit.

[0021] In an example having both the first and second base units, the second intermediate segment may extend around the outer edge of the first base unit, and the second base unit may extend at 90 degrees to the first base unit. This provides the external third and fourth contact terminals in a plane parallel to the direction in which the external connection wires typically extend, thereby avoiding the need for bending at the ends of the wires that connect them to the third and fourth contact terminals.

[0022] The sensor further has, for example, a first wire connected to the third contact terminal and a second wire connected to the fourth contact terminal. These wires provide sensor connection to an external circuit. The first and second wires each have an end connected to the third and fourth contact terminals, respectively.

[0023] These connections may be parallel to the plane in which the third and fourth contact terminals extend. Thus, the ends of the wires are connected flat to the contact terminals. Alternatively, the connections may be perpendicular to the plane in which the third and fourth contact terminals extend. Thus, the connections may be made using wires connected to the contact terminals at their tips, for example by solder bumps.

[0024] In all of the above examples, the (first) intermediate segment of the carrier may be arranged adjacent to the laterally outer side of the sensor element, and the first and second terminal segments are bent over the first and second sides of the sensor element. This is suitable, for example, for sensors having a block shape. The intermediate segment extends around the outer edge.

[0025] Alternatively, the sensor element may have a central opening, the intermediate segment is bent with respect to the second terminal segment, the intermediate segment of the carrier passes through the central opening, and the first terminal segment is bent over the first side of the sensor element. The intermediate segment, for example, has no external conductive part, so it can be safely arranged through the central opening of the sensor element.

[0026] The sensor element is, for example, an ultrasonic sensor element.

[0027] The first side of the ultrasonic sensor is configured, for example, for acoustic matching for the emission of ultrasonic waves into the anatomical medium and the reception of ultrasonic waves from the anatomical medium.

[0028] The second side of the ultrasonic transducer may be provided with, for example, a conductive ultrasonic attenuation material.

[0029] The present invention also provides an interventional medical device, the interventional medical device comprising the sensor defined above, and an elongated body, the sensor is attached to the distal end of the elongated body.

[0030] The elongated body may be a catheter or a guide wire for intravascular body sensing, for example ultrasonic flow sensing.

[0031] The present invention provides a method for manufacturing a sensor, the method comprising providing a sensor element having two opposite sides, Providing an interconnect having an electrically insulating flexible carrier having first and second terminal segments interconnected by an intermediate segment; The first terminal segment is in contact with the first sides of two opposite sides of a sensor element having a first contact terminal facing the first side; The second terminal segment is in contact with the second sides of two opposite sides of a sensor element having a second contact terminal facing the second side; Bending the interconnect as such; Using the interconnect to provide a first internal electrical connection in the flexible carrier connecting the first contact terminal to a fourth external contact terminal and a second internal electrical connection in the flexible carrier connecting the second contact terminal to a third external contact terminal; having.

[0032] These and other aspects of the invention will become apparent from the embodiments described below and will be described with reference thereto.

[0033] Exemplary embodiments of the invention are described below with reference to the following drawings.

Brief Description of the Drawings

[0034]

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Mode for Carrying Out the Invention

[0035] Here, specific embodiments will be described in detail with reference to the accompanying drawings. In the following description, like reference numerals are used for like elements in different drawings. Matters defined in this description, such as detailed configurations and elements, are provided to assist in an overall understanding of exemplary embodiments. Also, well-known functions or configurations are not described in detail as they would obscure the embodiments with unnecessary detail. Further, expressions such as "at least one of" when preceding a list of elements modify the entire list of elements and not individual elements of the list.

[0036] The present invention provides a sensor having a sensor element with two opposite sides and an interconnect having a first and a second terminal segment interconnected by an intermediate segment. The first terminal segment is disposed in contact with the first side of the sensor element and has a first contact terminal. The second terminal segment is disposed opposite the second side of the sensor element and has a second contact terminal on a surface facing the second side. Third and fourth external contact terminals are present. The interconnect provides electrical connection between the first and fourth contact terminals and between the second and third contact terminals.

[0037] The present invention is a modification to a sensor design previously proposed (but not yet published) by the applicant.

[0038] Figures 2A and 2B show an example of a sensor 1 proposed in European Patent Application No. 19155417.9.

[0039] Sensor 1 has a sensor element 5. Figure 2A shows the back side 9 of sensor element 5. The back side is the side where external wire connections are made, and the front side is the side where sensing is performed. Figure 2B shows the front side 11 of sensor element 5. Sensor 1 has an interconnect 7. Interconnect 7 is disposed on sensor element 5 and has a carrier film 13, a back side wire 17, and a front side wire 19, each provided with a metal layer 15. Carrier film 13 has a front portion 13F, side portions 13S, and a back portion 13B.

[0040] The front and back wires 17, 19 are provided with bent portions, and the ends of the wires 17, 19 are substantially parallel to and located on the back side 9 of the sensor element 5. The interconnecting portion 7 provides electrical connection for the sensor element 5.

[0041] The carrier film 13 (or its front part 13F and back part 13B) is bonded to the front side 11 and the back side 9 respectively using a non-conductive thin double-sided adhesive (not visible in the figure).

[0042] The metal layer 15 is provided on the side of the carrier film 13 facing the sensor element 5. Insulating layers are provided between the side part 13S and the sensor element 5, and between the back part 13B and the sensor element 5. The front part 13F of the carrier film 13 is disposed on the front side 11 of the sensor element 5.

[0043] The carrier film 13 is wound around the side surface up to the back side 9 of the sensor element 5. Accordingly, the interconnecting portion 7 attached to the front side 11 of the sensor element 5 is brought to the back side 9 of the sensor element 5.

[0044] The front wire 19 is provided with a metal layer 15 having Au, Pt, Ag or other noble metals at least in the region where the wire 19 contacts the carrier film 13. The electrical connection is provided by the front wire 19 attached to the back part 13B of the carrier film 13 and by the back wire 17 directly bonded to the back side 9 providing the metallized surface 18 of the sensor element 5. The metallized surface of the back side 9 can have Au, Pt or other noble metals as well as the metal layer 15. The electrical connection is provided on the back side 9 of the sensor element 5. The metallized carrier film 13 is provided, for example, as a thin film.

[0045] Figures 2A and 2B show a sensor element having a central opening. European Patent Application No. 19155417.9 also discloses other possible sensor designs.

[0046] Figures 3A and 3B show equivalent designs for a block-shaped transducer. The same interposer is given the same reference numbers. Also, Figure 3A shows an insulator 16 provided between the side portion 13S and the sensor element 5, and between the back portion 13B and the sensor element 5.

[0047] This approach requires a specific bending method because the metallization exists only on one side of the thin film. In addition, since the metallization is on the outside of the film, connections through the central hole of the sensor element are not feasible because it is difficult to avoid contact with the piezoelectric material inside the central hole. Therefore, even for a disk-shaped sensor element, this approach uses interconnects that are folded around the outside of the sensor element.

[0048] The present invention provides a design in which the interconnect has internal connections. There are two internal connections, one between one side of the sensor element and the first external terminal, and the other between the other side of the sensor element and the second external terminal. The external connections are made only to the interconnect (the first and second external terminals) so that the connection design can be optimized. Therefore, external wire connections to the sensor element itself are not required. As will be apparent from the following examples, these features enable various new sensor designs.

[0049] Figure 4 shows a first example according to the present invention.

[0050] Figures 4A and 4B show an electrically insulating flexible carrier 40 that itself is called an interposer and forms part of the interconnect between the sensor element and the external wire. The interconnect has an interposer between the sensor element and the external circuit, that is, the connection to the interposer and the external wire. Figure 4A shows one side from a top view, and Figure 4B shows the opposite side from a bottom view. As in the above example, the flexible carrier 40 has first and second terminal segments 13F and 13B interconnected by an intermediate segment 42.

[0051] The first terminal segment 13F is for placement against the first side (front) of the sensor element and has a first contact terminal 50 on the surface facing the first side of the sensor element.

[0052] The second terminal segment 13B is for placement against the second side (back) of the sensor element and has a second contact terminal 52 on the surface facing the second side.

[0053] The intermediate segment is for winding around the sensor element or passing through the sensor element between the two sides.

[0054] The flexible carrier 40 further has third and fourth external contact terminals 54, 56.

[0055] The first internal electrical connection is within the flexible carrier 40 and connects the first contact terminal 50 and the fourth contact terminal 56, and the second internal electrical connection within the flexible carrier connects the second and third contact terminals 52, 54. Thus, the internal connections couple one external terminal to one side of the sensor element and the other external terminal to the other side of the sensor element.

[0056] Figures 4A and 4B show the interposer in a flat state in which the interposer is manufactured.

[0057] Figures 4C (top view) and 4D (bottom view) show the interposer after the intermediate segment is bent 90 degrees with respect to the plane of the second terminal segment so that the first contact terminal can be pushed through the central opening of the sensor element.

[0058] Figures 4E (top view) and 4F (bottom view) show the interposer after the first contact terminal has been pushed through the central opening of the sensor element 5.

[0059] The second terminal segment 13B contacts the second side 9 (back side) of the sensor element 5, and the second contact terminal 52 is in electrical contact with the terminal on that side of the sensor element 5.

[0060] Here, the first terminal segment 13F protrudes through the central opening.

[0061] Figures 4G (top view) and 4H (bottom view) show the interposer after the first contact terminal 50 has been bent so that the first contact terminal is disposed with respect to the first side 11 (front) of the sensor element and the first contact terminal 50 makes electrical contact with the front-side terminal of the sensor element 5.

[0062] Figures 4I (top view) and 4J (bottom view) show the connection of the external wires 17, 19 to the third and fourth (external) contact terminals 54, 56.

[0063] The flexible carrier and wire connections define the interconnect portion 7. One of the internal connections extends from one sensor terminal on one side of the sensor element to the first external terminal between both sides of the sensor element (through the central hole in this example). This means that it can pass along any desired path, such as through the opening as shown. Another internal connection extends from the other side of the sensor element to the second external terminal. Direct wire connections to the sensor element are avoided. Instead, the connections to the sensor element itself are made using the first and second contact terminals. These connections may be created by physical pressure, soldering, adhesion, or any other suitable connection method.

[0064] The interposer presented in Figure 4 requires electrical connection pads on both the front and back sides. Electrical vias within the interposer may be used to connect the front and back electrical connection terminals (i.e., pads). The interposer may be realized using conventional double-sided flexible PCB technology, for example, with metallization (vias) from the front side to the back side. Suitable flexible substrate materials can be, for example, polyimide or LCP (liquid crystal polymer).

[0065] Alternatively, the interposer can be implemented using so-called flex-to-rigid (F2R) technology. F2R technology is an interconnect manufacturing platform developed to integrate complex electronic sensing and imaging functions at the tips of catheters and guidewires. This is based on the same microfabrication technology used in the manufacture of cMUT transducers. This enables the manufacture of silicon islands of any shape, any size, and any thickness, including (cMUT) ultrasonic transducers, sensors, ASICs, and / or passive interposers.

[0066] F2R enables the manufacture of a flexible interconnect consisting of a metal routing layer sandwiched between two layers of flexible polyimide on a silicon wafer. This is followed by a separation step, whereby the individual elements are separated by deep reactive ion etching (DRIE) and reactive ion etching (RIE). F2R manufacturing is based on standard IC manufacturing technology, which enables the device to be scaled down so that all kinds of sensing functions and electronics can be integrated at the tip of the catheter.

[0067] Therefore, the metal routing layer of F2R technology can be used to form internal electrical interconnects between the contact terminals of the interposer while maintaining an electrically insulating outer surface (other than the contact terminals themselves).

[0068] A suitable method for achieving electrical connection between the interposer contact terminals and the transducer is by applying pressure to achieve a gold-gold contact. A suitable metal surface finish on the interposer contact terminals may be obtained, for example, by known electroless nickel immersion gold (ENIG) or electroless nickel electroless palladium immersion gold (ENEPIG) plating steps. First, an appropriate amount of a suitable adhesive is applied between the electrode pads to be joined. Second, sufficient pressure is applied to squeeze out the excess of the adhesive until the gold on the opposing electrode pads comes into contact with each other, thereby forming an electrical connection.

[0069] By simultaneously applying the second step to both the front and back sides, both transducer connections can be achieved in a single operation.

[0070] Another way to achieve the electrical connection between the interposer and the transducer is by pre-applying solder on the electrical contact terminals and then reflowing the solder after the flex is bent around the transducer.

[0071] FIG. 5 shows a modification of FIG. 4, where the electrical connection is created between the interposer and the transducer by pre-applying solder on the electrical pads and then reflowing the soldering after the interposer is bent around the transducer.

[0072] FIGS. 5A and 5B show the interposer in a flat state in which the interposer is manufactured. To enable the solder to be applied to one plane, the first and second electrodes 50, 52 are on the same side of the interposer (different from the configuration of FIG. 4). The second electrode 52 is also divided into two sections 52a, 52b.

[0073] FIG. 5C (top view) and FIG. 5D (bottom view) show the interposer after solder is applied to the first and second electrode terminals, which is indicated by hatching in FIG. 5D.

[0074] FIG. 5E (top view) and FIG. 5F (bottom view) show the interposer after the intermediate segment 42 is bent at 90 degrees so that the first contact terminal 50 can be pushed through the central opening of the sensor element.

[0075] FIG. 5G (top view) and FIG. 5H (bottom view) show the interposer after the first contact terminal 50 is pushed through the central opening of the sensor element 5.

[0076] The second terminal segment 13B contacts the second side 9 (back) of the sensor element 5, and the second contact terminal 52 is in electrical contact with the terminals of the sensor element 5.

[0077] Here, the first terminal segment 13F projects through the central opening.

[0078] Figures 5I (top view) and 5J (bottom view) show an interposer after the first contact terminal 50 has been bent so that the first contact terminal is disposed in contact with the first side 11 (front) of the sensor element and the first contact terminal 50 is in electrical contact with the terminals of the sensor element 5.

[0079] Figures 5K (top view) and 5L (bottom view) show the connection of the external wires 17, 19 to the third and fourth (external) contact terminals 54, 56.

[0080] Appropriate wire connection to the interposer can be achieved by connecting the exposed wire ends to the electrode pads on the proximal side of the resulting transducer subassembly. The wire connection can be realized by any suitable means known in the art, for example, soldering or ultrasonic bonding.

[0081] The sensor element may have other shapes, such as a square or rectangular block. Figure 6 shows an example having a block-shaped transducer.

[0082] Similar to the above example, the interposer has first and second terminal segments 13F, 13B interconnected by an intermediate segment 42. The first terminal segment 13F has a first contact terminal 50 on the surface facing the first side of the sensor element. The second terminal segment has a second contact terminal 52 on the surface facing the second side. In this example, the contact terminals 50 and 52 are on the same side of the interposer that wraps around the lateral edges of the sensor element. The interposer further has third and fourth external contact terminals 54, 56.

[0083] Figures 6A (top view) and 6B (bottom view) show the interposer in a flat state in which the interposer is manufactured.

[0084] FIG. 6C (top view) and FIG. 6D (bottom view) show the interposer after being wrapped around the sensor element 5.

[0085] FIG. 6E (top view) and 6F (bottom view) show the connection of the external wires 17, 19.

[0086] As described above, the F2R process enables the formation of silicon islands on a flexible carrier. This means that the silicon segments may be incorporated under selected portions of the interposer. This provides additional support during the operation and / or assembly of the transducer and wires with respect to the interposer. An additional advantage is that all electrical contacts are made on the same side of the interposer, thereby ensuring better uniformity of the electrode surface.

[0087] FIG. 7 shows a first variant in which the interposer has silicon support segments 80, 82 that function as a base unit under both the transducer region and the wire connection region. This provides optimal support during the assembly of the transducer interposer and the connection of the wires.

[0088] FIG. 7A shows the manufactured interposer. The external wire connections are made in this initial configuration.

[0089] This example is based on a sensor element having a central opening. The first and second terminal segments 13F, 13B and the intermediate segment are the same as the design in FIG. 5, and the first and second contact terminals 50, 52 are on the same side.

[0090] The third and fourth contact terminals 54, 56 are on the third, more remote, terminal segment 13R of the interconnecting portion. The third terminal segment 13R is interconnected to the second terminal segment 13B by the second intermediate segment 44.

[0091] The third and fourth contact terminals 54, 56 are on the same side as the first and second contact terminals 50, 52 of the interposer. Thus, all four contact terminals are on the same side of the interposer.

[0092] The first and second contact terminals 50, 52 are wound around the sensor element in the same manner as described above. The third and fourth contact terminals can then be placed in various positions by bending the second intermediate segment 44.

[0093] FIG. 7B shows the interposer after the intermediate segment has been bent 90 degrees so that the first contact terminal can be pushed through the central opening of the sensor element. The silicon support segments 80, 82 are folded on top of each other, and the third terminal segment 13R is parallel and beneath the second terminal segment 13B.

[0094] FIG. 7C shows the sensor element 5 mounted on the protruding first contact terminal 50.

[0095] FIG. 7D shows the interposer after the first contact terminal has been bent so that the first contact terminal 50 is positioned with respect to the first side 11 (front) of the sensor element and the first contact terminal 50 is in electrical contact with the terminals of the sensor element 5.

[0096] FIG. 7E shows a wire bent to be parallel, for example, to the elongated shaft of a catheter.

[0097] The silicon segment 82 under the external wire connection region has the additional advantage of facilitating the wire connection process because wire bonding on silicon is well-known and is a more controllable process than bonding directly onto the flex adhered to the back surface of the transducer.

[0098] The silicon segment 82 under the wire connection area also allows for multiple orientations of the wire ends with respect to the transducer. For example, the wire connection area can be parallel to the transducer electrode surface. This requires, for example, a 90-degree bend of the wire as seen in FIGS. 4 and 5.

[0099] FIG. 8 shows an example of avoiding the bending of these wires.

[0100] FIG. 8A corresponds to FIG. 7A. FIG. 8B shows a wire connection area perpendicular to the transducer electrode surface. This avoids the need to bend the wire ends. The disadvantage is that this device can increase the rigid length of the transducer tip, which has an adverse effect on the flexibility of the guide wire tip.

[0101] FIGS. 7 and 8 show a parallel orientation of two wire connection pads. FIGS. 9 and 10 show variations of FIGS. 7 and 8 having a V-shaped orientation of the third and fourth connection terminals 54, 56.

[0102] FIGS. 9A to 9E show the implementation steps corresponding to FIGS. 7A to 7E, and FIGS. 10A and 10B correspond to FIGS. 8A and 8B.

[0103] This V-shaped orientation is expected to facilitate wire connection as it prevents the need for a double S-shaped buckling of the wire ends. On the other hand, in some cases, this can increase the required width of the wire connection segment, and thus, this may not be feasible in certain sealed housing configurations.

[0104] FIG. 11 shows a variation of FIG. 10 where only the support segment 82 exists under the third terminal segment 13R, i.e., under the third and fourth contact terminals.

[0105] FIG. 11A shows the manufactured configuration, and FIG. 11B shows the configuration in use.

[0106] A potential drawback of using silicon segments in the interposer region directly beneath the transducer is that it can adversely affect the vibration behavior of the transducer. Thus, FIG. 11 shows a state where there is no such silicon segment directly beneath the transducer. This example has a wire connection region oriented perpendicular to the transducer electrode plane and has a V-shaped orientation of two wire connection pads, but it can be understood that the removal of the silicon segment directly beneath the transducer can be combined with any of the other interposer deformations. Instead of simply omitting the silicon segment from the interposer region directly beneath the transducer, one or more suitable acoustic matching or damping backing layers can be added, for example, using an adhesive bond to the bottom side of the interposer.

[0107] FIG. 12 shows an example.

[0108] FIG. 12A shows insert 120, which can be a matching layer such as a high-density, high-modulus metal such as molybdenum or tungsten, or a high-density ceramic such as tungsten carbide. The insert may also be a damping backing layer such as an epoxy having aluminum oxide or glass filler. This alternative means of including a suitable matching or damping backing layer on the bottom side of the interposer can be combined with any of the other interposer deformation examples.

[0109] FIGS. 12B through 12F correspond to FIGS. 9A through 9E respectively, with the insert replacing silicon segment 80. An alternative to connecting the wire ends while they are parallel to the wire connection pads is to insert them into suitable openings created in the wire connection region. FIG. 13 shows this alternative wire connection approach applied to the general design of FIG. 9.

[0110] Figure 13A shows the manufactured interposer. External wire connections are made in this initial configuration. An opening 130 is formed within the third terminal segment 13R. Metal pads that can be used to solder wires in place are formed around these openings. The advantage is a relatively short rigid tip length, which avoids the need to bend the wire ends.

[0111] Figure 13A shows the configuration before wire soldering, and Figure 13B shows the configuration after wire soldering.

[0112] Figure 13C shows the first contact terminal 50 bent upward and the third terminal segment 13R bent around the two silicon segments 80, 82.

[0113] Figure 13D shows the introduction of the sensor element 5, and Figure 13E shows the final stage of bending the first contact terminal on the sensor element.

[0114] In all of the above embodiments, the wire connections are relatively close to the transducer. This assumes a (quasi)-rigid potting of the transducer subassembly, including wire connections in certain housings using an appropriate potting material. In this approach, a short rigid tip length is required as it is favorable for the flexibility of the best guide wire tips.

[0115] Alternatively, the length of the flexible portion of the interposer may be increased, for example, to 3 cm so that the wire connections no longer form part of the rigid tip, thus reducing the length of the rigid tip in another way.

[0116] An exemplary embodiment having a long flexible portion forming the second intermediate segment 44 is shown in Figure 14.

[0117] Figure 14A shows the interposer, and Figure 14B also shows the connected sensor element. This is shown as a modification to the example of Figure 7.

[0118] Using such an approach, the flexibility of the guidewire tip can be increased beyond what is achievable using any of the other known methods. This approach of leading the wire connection away from the transducer area may solve spatial constraint problems that may exist in the transducer area, or proximally to the transducer area in some cases, for example when multiple sensors are integrated onto the same guidewire for, e.g., flow and pressure sensing.

[0119] Figure 15 shows two further examples.

[0120] Figure 15A shows an example of a sensor having interconnects in a top image in a non-folded plan view and a side view coupled to sensor element 5 in a bottom image. Figure 15B shows an example of a sensor having non-folded interconnects in a top image in a plan view of one side (e.g., a top view), in a plan view of the opposite side (e.g., a bottom view) in a central image, and in a side view coupled to sensor element 5 in a bottom image.

[0121] In both cases, as in the above examples, the interconnect 7 has an electrically insulating flexible carrier having first and second terminal segments 13B, 13F interconnected by an intermediate segment 42.

[0122] The first terminal segment 13F has a first contact terminal 50 on a surface facing the first side 11, and the second terminal segment 13B has a second contact terminal 52 on a surface facing the second side 9. The interconnect further has third and fourth external contact terminals 54, 56 and the internal electrical connection described above.

[0123] The third and fourth contact terminals 54, 56 are on a third terminal segment 13R interconnected to the second terminal segment 13B by a second intermediate segment 44.

[0124] In Figure 15A, the contact terminals are all on the same surface and the intermediate segment bends around the sensor.

[0125] In FIG. 15B, the first and second contact terminals are on the surfaces on both sides of the interconnecting portion. One is folded under the sensor and the other is folded over the sensor. This means that all the bridge portions are on one side of the sensor.

[0126] These are just further examples of possible configurations.

[0127] It should be noted that all interposer variations having at least one of the silicon segments 80, 82 (which can be realized using Flex-to-Rigid technology) may include electronic ASIC functionality. The functionality of this electronic device can be signal amplification, multiplexed signals from multiple sensors, or any other relevant electronic function or combination of functions.

[0128] Even if emphasis has been placed on the guide wire, the present invention is applicable to other catheter-like devices such as microcatheters having similar flow sensing or position tracking capabilities. The main difference between the guide wire and the microcatheter is that the microcatheter is a hollow tube suitable for accommodating the guide wire within its main lumen. Thus, the outer diameter of the microcatheter is larger, and when a disc including a central hole is used for the piezoelectric transducer, the hole of the transducer is larger to fit the guide wire.

[0129] FIG. 16 shows the catheter in a cross-sectional view of FIG. 16A and a perspective cross-sectional view of FIG. 16B. The transducer 150 has an annular shape around the inner tube 152 of the catheter. The transducer is held by an adhesive layer 154 having backing and / or matching characteristics. The transducer may have, for example, a piezoelectric transducer for blood flow measurement.

[0130] In all of the above examples, the sensor can be used for several medical applications such as Doppler flow measurement, ultrasonic imaging, etc. Further, ultrasonic tracking of the sensor by an external ultrasonic probe is also enabled.

[0131] The sensor may have an acoustic stack of materials, including an active part and a passive part. The sensor element is the active part that generates / receives ultrasonic waves. The sensor element may have a ceramic disk or a plate in any geometric form (circular, square, hexagonal, octagonal, etc.). The passive part of the sensor serves to effectively couple the acoustic wave to a desired medium.

[0132] The passive part is provided by one or more matching layers in front of the active part and one or more dematching layers behind the active part. The dematching layer can have a backing material for attenuating the transmission of ultrasonic waves in an undesired direction (e.g., the proximal shaft of the device). The dematching layer can have a non-conductive epoxy material. The active part can have a single-crystal piezoelectric material. The matching layer efficiently couples ultrasonic waves to a medium (e.g., anatomical structures, various body fluids, etc.) in a desired direction.

[0133] The sensor element may have a piezoelectric ultrasonic emitter / sensor array or a capacitive microfabricated ultrasonic emitter / sensor array. The sensor element may have a plurality of or a single acoustic stack of materials. The ultrasonic emitter / receiver element or transducer element provides an increased aperture for receiving ultrasonic scattering and reflection from anatomical media (structures, fluids) on the impinging ultrasonic waves.

[0134] The contact terminals of the interposer have other noble metals such as, for example, metals such as gold (Au) or platinum (Pt). Other noble metals such as Au or Pt may be preferred to prevent corrosion. Silver (Ag) can also be used if appropriately shielded. The thickness of the metal layer ranges from about 10 to 500 nanometers, preferably about 30 to 50 nanometers (including tolerances).

[0135] As in the prior art, the need for additional soldering material on the transducer surface is avoided when replacing the soldered wire with the interconnects described herein. Also, the interconnects provide less detrimental acoustic effects or even enhance the acoustic pressure output.

[0136] Wires 17, 19 are provided with a metal layer having, for example, Au, Pt, Ag, or other noble metals, at least in the region where wires 17, 19 contact the contact terminals.

[0137] The sensor element used with the interconnects described herein may have a matching layer thickness of 20 to 100 microns. Between a predetermined frequency, for example, between 6 and 45 MHz, the thickness of the carrier can be part of the matching layer or can form the matching layer entirely by itself. The thickness of the first terminal segment 13F in any of the embodiments is preferably selected to act as a quarter - wavelength (λ / 4) acoustic matching layer that bridges a large acoustic impedance mismatch between the piezoelectric material and the anatomical structure of the human body.

[0138] Although the invention has been illustrated and described in the drawings and the foregoing description, such illustrations and descriptions should be considered illustrative or exemplary and not restrictive. The invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and achieved by those skilled in the art in practicing the claimed invention, from a review of the drawings, the disclosure, and the dependent claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain means are recited in mutually different dependent claims does not indicate that a combination of these means cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Explanation of Reference Signs

[0139] 1: Sensor 5: Sensor element 7: Interconnection part 9: Back side of the sensor element 11: Front side of the sensor element 13: Carrier film 15: Metal layer 16: Insulator 17: Back side wire 18: Metal plating surface 19: Front side wire 40: Electrically insulating flexible carrier 42: Intermediate segment 44: Second intermediate segment 50: First contact terminal 52: Second contact terminal 54: Third external contact terminal 56: Fourth external contact terminal 80, 82: Silicon segment 120: Insert 130: Opening 150: Transducer

Claims

1. a sensor element having first and second opposing sides; an interconnect having an electrically insulating flexible carrier and having first and second terminal segments interconnected by an intermediate segment; In a sensor having the first terminal segment is disposed against the first side of the sensor element and has only one first contact terminal on a surface facing the first side; the second terminal segment is disposed against the second side of the sensor element and has only one second contact terminal on a surface facing the second side; the interconnection portion further includes third and fourth external contact terminals; the interconnection portion includes a first internal electrical connection portion within the flexible carrier connecting the first contact terminal and the fourth contact terminal, and a second internal electrical connection portion within the flexible carrier connecting the second and third contact terminals; the third and fourth contact terminals are on the second terminal segment opposite the carrier from the second contact terminal. Sensor.

2. The sensor of claim 1 , further comprising a first wire connected to the third contact terminal and a second wire connected to the fourth contact terminal.

3. The first and second wires each include Parallel to a plane in which the third and fourth contact terminals extend, or perpendicular to a plane in which the third and fourth contact terminals extend, The sensor of claim 2 having ends connected to the third and fourth contact terminals.

4. 4. The sensor of claim 1, wherein the intermediate segment of the carrier is positioned adjacent to a laterally outer side of the sensor element, and the first and second terminal segments are folded over the first and second sides of the sensor element.

5. The sensor according to claim 1 , wherein the sensor element is an ultrasonic sensor element.

6. A sensor according to any one of claims 1 to 5. With a long, slender body, 1. An interventional medical device comprising: the sensor is attached to a distal end of the elongate body; Interventional medical devices.

7. A method for manufacturing a sensor, comprising the steps of: Providing a sensor element having two opposite sides; providing an interconnect having an electrically insulating flexible carrier and having first and second terminal segments interconnected by an intermediate segment; the first terminal segment contacts the first of the two opposing sides of the sensor element with only one first contact terminal facing the first side; the second terminal segment contacts the second of the two opposing sides of the sensor element with only one second contact terminal facing the second side; bending the interconnect so that using the interconnect to provide a first internal electrical connection within the flexible carrier connecting the first contact terminal to a fourth external contact terminal and a second internal electrical connection within the flexible carrier connecting the second contact terminal to a third external contact terminal, the third and fourth contact terminals being on an opposite side of the second terminal segment from the second contact terminal of the carrier; The method according to claim 1,

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