Cable assembly, method for manufacturing electronic apparatus using same, and electronic apparatus

Abstract

The present invention addresses the problem of providing a cable assembly having exceptional connection reliability by a simple method when connecting conductors of a plurality of core wires and electrodes of a member being connected. The present invention solves the aforementioned problem by means of a cable assembly comprising a plate and a cable having a plurality of core wires, the plurality of core wires being connectable to a plurality of electrodes provided to the surface of a member being connected, wherein: the core wires each have a conductor and an insulator that is formed on the outer periphery of the conductor, and each include a conductor exposed region in which the conductor is exposed and a conductor coating region having the insulator on the outer periphery of the conductor; the plate has a first surface and a second surface having an obverse / reverse relationship with each other; the first surface is provided with a plurality of grooves to which the core wires are connected and which extend linearly; the grooves each have a first region sandwiched by at least some of the conductor exposed regions of the core wires, and a second region with which an electroconducutive connection material is held; as pertains to effective length in a direction orthogonal to the extension direction of the grooves, an effective length W2 in the second region is greater than an effective length W1 in the first region; and the conductors in the conductor exposed regions of the core wires are sandwiched between the first regions of the grooves in the plate and are fixed by the electroconductive connection material held in the second region.

Description

Cable assembly, manufacturing method for electronic device using same, and electronic device

[0001] The present invention relates to a cable assembly including a plate and a cable having a plurality of core wires, a method for manufacturing an electronic device using the cable assembly, and an electronic device.

[0002] Recently, insulated cables and coaxial cables used in electronic devices such as measuring devices, communication devices, medical probe cables, and micromachines have been required to have extremely thin outer diameters in order to accommodate the increasing wiring density associated with the miniaturization and high precision of these devices. To meet these demands, for example, coaxial cables with extremely thin outer diameters, such as 0.16 mm or 0.10 mm, are being manufactured. Multicore cables with these ultra-thin cables as cores are used in the above-mentioned electronic devices.

[0003] When connecting the core wires of such multi-core cables to electrodes densely arranged on a circuit board, the conductors of the core wires are extremely thin and the pitch of the electrodes on the circuit board is narrow, so the process of connecting the core conductors to the electrodes is extremely difficult and requires skilled techniques.In addition, the electrical connection between the core conductors and the electrodes is prone to connection defects such as short circuits and open circuits, which creates problems with the stability of the connection quality.

[0004] Japanese Patent Application Laid-Open No. 2002-95129 discloses a method for electrically connecting the central conductor of a micro-coaxial cable to a connection part provided on a substrate or the like, in which the central conductor is aligned using a heat ray-transmitting member having an alignment groove, and is pressed and fixed to an electrode part of the substrate, and heat rays are supplied through the grooved heat ray-transmitting member.

[0005] Japanese Patent Application Laid-Open No. 2010-118318 discloses a technique for electrically connecting the central conductors of coaxial cables arranged on a flexible insulating sheet to electrodes on a printed circuit board. The technique describes aligning the central conductors in grooves in a flexible insulating sheet coated with adhesive, and then connecting the central conductors to the electrodes on the printed circuit board with solder or the like.

[0006] JP 2002-95129 A JP 2010-118318 A

[0007] However, with the techniques described in Patent Documents 1 and 2, it is difficult to uniformize the strength and contact area of ​​the connection when simultaneously connecting the conductors of multiple core wires to a substrate. Furthermore, these methods require that a connecting member be formed in advance on the surface of the connection portion of the substrate using a conductive connecting material such as solder. When the structure of the connection portion of the substrate becomes finer, it becomes difficult to form the amount of connecting member required for connection on the surface of the substrate, which makes it more likely that poor connection will occur in the electrical connection with the conductors of the core wires.

[0008] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a cable assembly that can be connected to a connection target component using a simple method and that has excellent connection reliability.

[0009] In order to solve the above problems, the configurations described in the claims can be adopted. For example, a cable assembly of the present invention includes a plate and a cable having a plurality of core wires, the plurality of core wires being connectable to a plurality of electrodes provided on the surface of a connection target component, the core wires having a conductor and an insulator formed around the conductor, and including an exposed conductor region where the conductor is exposed and a conductor coated region where the insulator is around the conductor, the plate having a first surface and a second surface that are reverse to each other, the first surface of the plate having a plurality of linearly extending grooves to which the core wires are connected, the grooves having a first region in which at least a portion of the exposed conductor region of the core wire is clamped, and a second region in which a conductive connecting material is held inside, with respect to the effective lengths of the grooves in a direction perpendicular to the extension direction, the effective length W2 in the second region being greater than the effective length W1 in the first region, and the conductor of the exposed conductor region of the core wire is clamped in the first region of the grooves of the plate and fixed by the conductive connecting material held in the second region.

[0010] The second region of the groove may be formed so that the groove penetrates from the first surface to the second surface of the plate.

[0011] The plate may be provided with a recess or a protrusion on at least one of the first surface and the second surface, the recess or protrusion corresponding to the connection target component.

[0012] The recessed portion of the plate may be formed by forming a groove in a direction in which the electrode of the connection target member extends at a position corresponding to the electrode.

[0013] In the cable assembly according to the present invention, the conductor of the core wire preferably has an outer diameter of 0.01 mm to 0.15 mm.

[0014] A method for manufacturing an electronic device according to the present invention includes preparing the cable assembly described above, and electrically connecting the plurality of core wires to electrodes of the connection target member.

[0015] The method for manufacturing an electronic device may further include removing the plate after electrically connecting the plurality of core wires to the electrodes of the connection target member.

[0016] Furthermore, it is preferable that the above-mentioned method for manufacturing an electronic device includes connecting the multiple core wires and the electrodes of the connection target member so that a part or the entirety of the electrodes is positioned between the first surface and the second surface of the plate in the second region of the groove of the plate when the multiple core wires and the electrodes of the connection target member are connected.

[0017] In addition, in the above-mentioned method for manufacturing an electronic device, a recess can be provided in the plate at a position corresponding to the electrode of the connection target component in the extension direction of the electrode, thereby controlling the relative position between the plate and the connection target component.

[0018] The electronic device according to the present invention is also an electronic device comprising a cable assembly including a plate and a cable having a plurality of core wires, the plurality of core wires being connectable to a plurality of electrodes provided on a surface of a connection target member, the core wires having a conductor and an insulator formed on the outer periphery of the conductor, including a conductor exposed region where the conductor is exposed and a conductor covered region having the insulator on the outer periphery of the conductor, the plate having a first surface and a second surface which are opposite surfaces to each other, the first surface of the plate being provided with a plurality of linearly extending grooves to which the core wires are connected, the grooves being The cable assembly has a first region in which at least a portion of the conductor exposed region of the core wire is clamped, and a second region in which a conductive connecting material is held inside, and the effective length in a direction perpendicular to the extension direction of the groove is such that the effective length W2 in the second region is greater than the effective length W1 in the first region, and the conductors of the conductor exposed region of the core wire are each clamped in the first region of the groove of the plate and fixed by the conductive connecting material held in the second region, and a connection target member having a plurality of electrodes to which the plurality of core wires are connected.

[0019] The electronic device according to the present invention is preferably a medical endoscope or an ultrasonic diagnostic device.

[0020] The cable assembly according to the present invention makes it possible to easily connect the conductors of multiple core wires to the connection target components of an electronic device, thereby achieving a highly reliable connection. Furthermore, the cable assembly according to the present invention also simplifies connection to high-density electrodes, allowing the manufacture of electronic devices with highly reliable electrical connections.

[0021] FIG. 1 is a diagram illustrating an example of a cable assembly according to the present invention. FIG. 1 is a schematic cross-sectional view of an end portion of an example of an insulated cable which is a core wire. FIG. 1 is a schematic cross-sectional view of an end portion of an example of a coaxial cable which is a core wire. FIG. 2 is a diagram illustrating the vicinity of an end portion of a core wire of an example of a cable assembly. FIG. 3 is a schematic view of an example of a plate of a cable assembly according to the present invention. FIG. 4 is a diagram illustrating an example of a cross-section of the plate. FIG. 5 is a diagram illustrating another example of a cross-section of the plate. FIG. 6 is a diagram illustrating another example of a cross-section of the plate. FIG. 7 is a diagram illustrating another example of a cross-section of the plate. FIG. 8 is a diagram illustrating a state in which conductors are arranged on the plate. FIG. 9 is a diagram illustrating a state in which conductors are fixed on the plate. FIG. 10 is a diagram illustrating a state in which the cable assembly according to the present invention is arranged on an electrode of a substrate. FIG. 11 is a diagram illustrating a state in which the cable assembly according to the present invention is connected to an electrode of a substrate. FIG. 12 is a diagram illustrating a reinforcing structure of the cable assembly according to the present invention.

[0022] The structure of a cable assembly according to one embodiment of the present invention will be described below with reference to the drawings. Note that the embodiments described below are not intended to limit the technical scope of the present invention, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0023] (Explanation of Cable Assembly) Fig. 1 is a diagram illustrating the structure of a cable assembly according to one embodiment of the present invention. The cable assembly 1 includes a cable having a plurality of core wires 10 and a plate 20, with some of the core wires 10 fixed to the plate 20. A plurality of linearly extending grooves 210 are formed on a first surface S1 of the plate 20. When each length of the plate is explained using an orthogonal coordinate system of x, y, and z axes shown in Fig. 1, the extension direction of the grooves 210, which are formed in accordance with the extension direction of the core wires 10, is the x-axis direction, and the direction perpendicular to the extension direction of the grooves is the y-axis direction.

[0024] In the example shown in FIG. 1 , the multiple core wires 10 are arranged in a flat shape near the cable end, matching the arrangement of the core wires on the plate. While other parts of the cable are not shown, the cable may be a multi-core cable with a circular cross section in which multiple core wires 10 are twisted together, or a multi-core cable with a flat cross section in which multiple core wires are arranged in parallel. The end of the core wire 10 includes a conductor-coated region in which an insulator is formed around the periphery of the conductor 100, and a conductor-exposed region in which the conductor 100 is exposed. In the conductor-exposed region of the core wire, for example, a predetermined length of insulation is removed to expose the conductor, and the conductor 100 is fixed to the plate 20. In the example shown in FIG. 1 , eight core wires 10 are arranged in parallel on the plate 20, but the number of core wires 10 fixed to one plate 20 is not limited. The number of grooves formed in one plate 20 may be determined according to the number of core wires to be fixed, and the number of core wires 10 to be fixed may be, for example, approximately 1 to 100. The cable assembly 1 of the present invention is not limited to one having one plate 20 for one cable, but may have multiple plates 20 for one cable. Also, the cable assembly 1 may have one plate 20 for multiple cables. The number of cables and the number of plates constituting the cable assembly 1 can be set according to the required form of the components to be connected.

[0025] The core wire 10 includes a conductor 100 and an insulator formed around the conductor. The core wire 10 may be an insulated cable consisting of only a conductor and an insulator, or a coaxial cable with a shield further formed around the insulator. The core wire 10 constituting the cable assembly 1 of the present invention may be composed of only an insulated cable or only a coaxial cable, or may be composed of a combination of an insulated cable and a coaxial cable. The cable assembly 1 of the present invention may also include a wire other than the insulated cable or coaxial cable, such as an uncoated conductor, and the wire may be fixed to the plate 20 together with the core wire. The cable constituting the cable assembly 1 may be a composite cable in which a long body such as a tube is disposed together with the core wire, and the core wire 10 fixed to the plate 20 may be a part of the composite cable. Figures 2 and 3 are schematic diagrams showing a longitudinal cross section of the end of the core wire 10, showing an example of a core wire constituting the cable assembly of the present invention. FIG. 2 shows an example of an insulated cable, insulated cable 11, in which insulator 111 is formed around conductor 101 having an outer diameter of 0.01 mm to 0.15 mm. FIG. 3 shows an example of a coaxial cable, insulated cable 12, in which insulator 112 is formed around conductor 102 having an outer diameter of 0.01 mm to 0.15 mm, shielding wires are wound transversely around insulator 112 to form shield 122, and jacket 132 is further formed around the shield 122. Conductors 101, 102, and shield 122 can be made of wire materials commonly used as conductors, such as copper, silver, aluminum, steel, and various alloys. Such wire materials are generally coated on the surface with plating such as silver or tin, and silver-plated copper alloy wires are used, for example. Conductors 101, 102 can be solid wires or stranded wires, or they can be parallel wires without being twisted.

[0026] The following describes in detail the structure of the vicinity of the cable end where the core wires of the cable assembly of the present invention are fixed to the plate, using the drawings as examples. In the cable of the cable assembly of the present invention, the core wires are preferably arranged to match the shape of the plate near the cable end where the core wires are fixed to the plate. FIG. 4 shows the vicinity of the end of an example cable, in which the core wires 10 are arranged in a flat shape and the conductors at their tips are exposed. This shows the state of the core wires 10 of the cable before they are placed on the plate. The arranged core wires 10 include conductors 100 in a conductor exposed region where the conductors are exposed, and a conductor covered region having an insulator around the conductor. At least a portion of the conductors 100 in this conductor exposed region is placed in the groove of the plate.

[0027] FIG. 5 shows an example of a plate 20 of a cable assembly according to the present invention, illustrating an example in which the conductors of the core wires are arranged in parallel. The structure of the plate will be described based on the example of FIG. A first surface S1 of the plate 20 is formed with multiple grooves 210 for fixing the conductors of the exposed conductor regions of the core wires. Here, the first surface S1 refers to the upper surface of the plate. The grooves 210 extend linearly in the direction of extension of the core wires, and each groove 210 has a first region 211 that sandwiches the conductor 100 of the exposed conductor region of the core wire and a second region 212 that holds a conductive connecting material therein. The effective length W1 of the first region 211 in the direction perpendicular to the extension direction of the groove (y-axis direction) of the groove (x-axis direction) is approximately the same as or shorter than the outer diameter of the conductor of the exposed conductor region of the core wire. When the conductor of the core wire is placed in the groove 210 of the plate, the conductor is clamped in the first region 211 of the groove 210, preventing the core wire from detaching from the plate. Furthermore, the effective length of the groove in the y-axis direction is such that the effective length W2 in the second region 212 of the groove 210 is greater than the effective length W1 in the first region 211. In other words, the effective length W2 in the y-axis direction in the second region 212 of the groove is greater than the outer diameter of the conductor in the exposed conductor region of the core wire. The conductor of the core wire easily fits into the conductive connecting material held within the second region 212 of the groove 210 and can be fixed by the conductive connecting material. When more than half of the outer circumference of the conductor is covered by the conductive connecting material in the second region 212 of the groove 210, the effect of preventing the core wire from detaching from the plate is easily achieved.

[0028] The plate 20 of the cable assembly according to the present invention is formed of an insulating material, and can be, for example, a thin plate-shaped material with a thickness of approximately 0.02 mm to 0.4 mm. Depending on the hardness of the material, the thickness can be appropriately adjusted to approximately 0.03 mm to 0.25 mm. Heat-resistant insulating materials are suitable. Examples of insulating materials that can be used include, but are not limited to, polyimide resin (PI), polyamide-imide resin (PAI), polyether ether ketone resin (PEEK), polyphenylene sulfide resin (PPS), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and polytetrafluoroethylene (PTFE). Furthermore, a material with appropriate hardness is preferred for the plate 20. Furthermore, a material with appropriate elasticity is also preferred. When the conductor of the core wire arranged in the groove 210 of the plate 20 is pressed from above the plate 20, the conductor fits into the first region 212 of the groove 210 and tends to maintain this state until the cable assembly is connected to an electrode of the connection target component. Furthermore, if the material of the plate 20 has a suitable degree of elasticity, the plate can be bent and connected even if the surface of the connection target component is curved.

[0029] FIG. 6 is a cross-sectional schematic diagram of an example of the first region 211 of the groove 210 of the plate 20, showing the cross section 6 (cross section along the y-axis direction) in FIG. 5 . While FIG. 6 shows an example in which the cross-sectional shape of the first region 211 of the groove 210 of the plate is trapezoidal, the cross-sectional shape of the groove is not limited thereto. The relationship between the cross-sectional area of ​​the conductor in the exposed conductor region of the core wire and the cross-sectional area of ​​the first region 211 of the groove 210 in a direction perpendicular to the extension direction of the groove is preferably such that the cross-sectional area of ​​the first region 211 of the groove 210 is approximately the same as or slightly larger than the cross-sectional area of ​​the conductor in the exposed conductor region of the core wire. Furthermore, if it is necessary to more firmly fix the conductor in the first region of the groove, an adhesive layer can be provided in the groove. Examples of adhesives that can be used include thermosetting resins such as epoxy resins and ultraviolet-curable resins.

[0030] FIG. 7 is a cross-sectional schematic diagram of another example of the first region 211 of the groove 210 of the plate 20. The cross-sectional shape of the first region 211 of the groove 210 is not particularly limited as long as it is a shape that allows for easy placement of conductors. For example, the cross-sectional shape may be a V-shaped groove 211a as shown in FIG. 7a), a semicircular groove 211b as shown in FIG. 7b), or a rectangular groove 211c as shown in FIG. 7c). When multiple electrodes of the connection target components are densely arranged, the cross-sectional shape of the first region 211 of the groove 210 is such that the ratio (y-axis length / z-axis length) of the groove depth (z-axis length) to the length in the direction perpendicular to the extension direction of the groove (y-axis length) is preferably less than 2, and more preferably less than 1.5. In addition, if the length of the first region of the groove in the y-axis direction changes between the first surface S1 and the second surface S2 of the plate (z-axis direction), as shown in Figure 7d), the length of the groove in the y-axis direction at its maximum within the range where the effect of clamping the conductor is obtained between the first surface S1 and the second surface S2 of the plate (the portion where the conductor and the inner surface of the groove contact each other) is defined as the ``effective length in the first region'' W1 of the groove.

[0031] FIG. 8 is a schematic cross-sectional view of an example of the second region 212 of the groove 210 of the plate 20, showing the cross section 8 (cross-section along the y-axis direction) of FIG. 5 . While FIG. 8 illustrates an example in which the second region 212 of the groove 210 of the plate is formed penetrating from the first surface S1 to the second surface S2 of the plate, the second region of the groove is not limited to being penetrating. The conductive connecting material 300 is held in the second region 212 of the groove 210 of the plate, and the amount of conductive connecting material can be precisely controlled by the volume of the space within the second region 212. The volume of the space within the second region 212 can be adjusted by the length of the second region 212 in the x-axis direction, the length of the second region 212 in the y-axis direction, and the depth of the groove (length in the z-axis direction). Fixing the conductor of the core wire by the conductive connecting material held in the second region 212 makes the core wire less likely to detach from the plate 20.

[0032] When the second region 212 is formed penetrating from the first surface S1 to the second surface S2 as in the example of Fig. 8, either the first surface S1 or the second surface S2 of the plate 20 can be selected as the surface facing the connection target component when connecting multiple core wires fixed to the plate 20 to electrodes of the connection target component. Fig. 9 is a schematic cross-sectional view of another example of the second region 212 of the groove 210 of the plate 20, in which the second region 212 is formed without penetrating. In the example of Fig. 9, the surface facing the connection target component may be the first surface S1 of the plate 20.

[0033] FIG. 8 shows an example in which the cross-sectional shape of the second region 212 of the groove 210 is trapezoidal. The area of ​​the second region 212 of the groove 210 on the first surface S1 of the plate (the opening area as viewed from above the first surface) is smaller than the area on the second surface S2 (the opening area as viewed from below the second surface). When the conductive connecting material held in the second region 212 solidifies while covering the conductor of the core wire, the core wire is less likely to detach from the conductive connecting material. The anchor effect of the conductive connecting material is also expected to make the conductive connecting material less likely to detach from the plate 20. Conversely, the area of ​​the second region 212 of the groove 210 on the first surface S1 of the plate may be larger than the area on the second surface S2. This is expected to facilitate the removal of the plate 20 after connecting the core wire to the electrode as described below. The cross-sectional shape of the second region 212 of the groove 210 is not limited to the trapezoidal or rectangular shape described above. FIG. 10 is a diagram showing yet another example of a cross section of the second region 212 of the groove 210 of the plate 20. The shape of the second region 212 is not particularly limited as long as it allows the conductor to easily penetrate into the conductive connecting material. For example, the second region 212 may be a groove 212a having a curved inner wall as shown in FIG. 10a), a groove 212b having a stepped inner wall as shown in FIG. 10b), a groove 212c having a bottle-shaped inner wall as shown in FIG. 10c), or a groove 212d having a narrow interior as shown in FIG. 10d). As shown in FIGS. 8 and 10, if the length of the second region of the groove in the direction perpendicular to the extension direction of the groove (y-axis direction) changes between the first surface S1 and the second surface S2 of the plate (z-axis direction), the length at which the length of the second region of the groove in the y-axis direction is maximum between the first surface S1 and the second surface S2 of the plate is defined as the "effective length of the second region" W2 of the groove.

[0034] Figure 11 shows an example of the shape of the second region 212 of the groove of the plate 20, as viewed from above the first surface S1. The effective length W2 of the second region 212 of the groove 210, measured in a direction perpendicular to the groove extension direction, is greater than the outer diameter of the conductor in the exposed conductor region of the core wire. This ensures a sufficient amount of conductive connecting material for connection to the connection target component, even when the outer diameter of the core wire conductor is small. The technology of the present invention is particularly effective when connecting a thin core wire conductor to electrodes arranged at a narrow pitch. The shape of the second region 212 of the groove 210 on the first surface S1 and the cross-sectional shape of the second region 212 of the groove 210 along the y-axis direction are not particularly limited, as long as they allow the core wire conductor to be embedded in the conductive connecting material holding it within the second region. For example, as shown in Figures 11a) to 11d), the groove 210 may have a rectangular, diamond, elliptical, or other shape. Alternatively, the groove 210 may have only one first region 211, as shown in Figure 11d). 11e), one groove 210 may have two or more second regions 212. It is possible to connect different conductors of the core wires to the upper second region 212a and the lower second region 212b, respectively, resulting in a two- or three-tiered connection structure suited to the arrangement of high-density board electrodes. When the second region of the groove has a shape other than a square, such as in FIG. 11b), the boundary between the first and second regions of the groove is defined as a point where the length in the direction perpendicular to the extension direction of the groove is greater than the outer diameter of the conductor in the exposed conductor region of the core wire.

[0035] The arrangement of the second regions 212 of the grooves 210 of the plate may correspond to the arrangement of the electrodes of the connection target component. When the grooves 210 of the plate are arranged in parallel, the spacing P between the grooves 210 is the distance between the center of the length in the y-axis direction of the second region 212 on the surface of the plate facing the connection target component (first surface S1 in FIG. 9 ) and the center of the length in the y-axis direction of an adjacent groove. The spacing P between the grooves 210 may be, for example, 0.04 mm to 1.0 mm. The technology of the present invention can also be applied when multiple electrodes of the connection target component are arranged at high density, and can be applied to a process of connecting a core wire 10 to electrodes arranged on the connection target component at intervals of 0.10 mm, 0.05 mm, or the like.

[0036] At least one of the first and second surfaces of the plate of the cable assembly of the present invention can be provided with a recess or protrusion corresponding to the protrusion or recess formed on the surface on which the electrode of the connection target component is provided. This can be used to align the conductor of the core wire with the corresponding electrode when connecting the conductor to the connection target component, thereby preventing misalignment. If the electrode of the connection target component has a linear shape, a recess can be provided in the plate at a position corresponding to the electrode of the connection target component in the extension direction of the electrode.

[0037] The conductive connecting material held inside the second region 212 of the groove 210 of the plate 20 can be a material that hardens when heated or exposed to ultraviolet light. In the present invention, if a material that is in a liquid or paste state before heating is used, it is easy to fill the inside of the second region of the groove and adjust the amount held. Examples of conductive connecting materials include solder paste, silver paste, and copper paste. Other examples include pastes containing conductive substances such as gold, nickel, lead, and carbon.

[0038] (Embodiment of Cable Assembly) The conductor 100 of the core wire 10 of the cable is arranged in the groove 210 formed in the plate 20 described above. Fig. 12 shows the state in which the conductor 100 of the core wire 10 is aligned according to the arrangement of the groove 210 of the plate 20. Fig. 12a) is a schematic cross-sectional view of a first region 211 of the groove 210 of the plate 20 taken along the y-axis direction, in which the conductor 100 is arranged on the first region 211 of the groove 210 of the plate 20. Fig. 12b) is a schematic cross-sectional view of a second region 212 of the groove 210 of the plate 20 taken along the y-axis direction, in which the conductor 100 is arranged on the conductive connecting material 300 held in the second region 212 of the groove 210 of the plate 20.

[0039] FIG. 13A) shows an example of a method for clamping the conductor 100 of the core wire 10 between the plate 20. This is a schematic cross-sectional view of the first region 211 of the groove 210 along the y-axis direction when the conductor 100 placed in the groove 210 is pressed from above the plate 20 to fit into the first region 211 of the groove in the plate 20. FIG. 13A) shows a cross-section at the same position as the cross-section in FIG. 12A). If the length of the first region 211 of the groove in the plate 20 in the direction perpendicular to the extension direction of the groove is formed to be smaller than the outer diameter of the conductor 100 in the conductor-exposed region of the core wire, the conductor 100 can be easily fitted into the first region 211 of the groove in the plate 20 when the conductor 100 is pressed toward the plate. After the conductor 100 is fitted into the groove in the plate, the plate is less likely to detach from the core wire. At this time, the conductor 100 in the second region 212 of the groove of the plate 20 is indented by the conductive connecting material 300 held in the second region 212 ( FIG. 13 b). In this state, the plate 20 can be heated, for example, to harden the conductive connecting material. When the conductive connecting material 300 hardens while covering at least a portion of the conductor 100, the conductor 100 is fixed to the plate 20. A structure in which multiple core conductors are fixed to the plate and integrated can be connected all at once simply by heating the plate in correspondence with the electrodes of the connection target component.

[0040] FIG. 16 shows an example in which the end of a cable's core wire is fixed to a plate to strengthen the integrated portion. In addition to the first and second groove regions 211 and 212, the plate 20 may also have a third region 213 for maintaining the cable arrangement. Furthermore, a copper foil pad or other material may be placed on the top surface of the plate with the conductor 100 of the core wire 10 fixed therein, covering the groove and the conductor. This not only strengthens the fixation between the plate and the conductor, but also strengthens the connection surface between the conductor and the electrode. Further strengthening of the connection surface can be expected by coating the surface of the copper foil pad with gold or silver plating. Furthermore, if a connector or probe pin contact is required, the board can be treated like a regular circuit board. Similarly, an anisotropic conductive sheet can be used instead of the copper foil pad. In this case, the conductor and electrode can be connected together by applying heat and pressure.

[0041] (Method of Connecting a Cable Assembly) FIG. 13 shows the state in which the conductor 100 of the core wire 10 is fixed to the plate 20. When the second region 212 of the groove of the plate has a penetrating structure as in the example of FIG. 13 , the surface facing the connection target component when connecting the core wire to the electrode of the connection target component may be either the first surface S1 or the second surface S2 of the plate. Selecting an insulating material with appropriate hardness as the material of the plate 20 facilitates uniform contact between multiple conductors and electrodes, which is advantageous for achieving stable connections. In this specification, "connection" refers to connecting the conductor of the core wire to the electrode of the connection target component via a conductive connecting material held within the second region of the groove of the plate, and refers to both electrical and physical connection. As in the example of Figure 9, when the second region 212 of the groove of the plate 20 has a structure that does not penetrate from the first surface S1 to the second surface S2 of the plate 20, the surface that faces the connection target component when connecting the core wire and the electrode of the connection target component becomes the first surface S1 of the plate, and the conductor 100 and the electrode can be connected by directly facing each other.

[0042] FIG. 14 shows an example of a state in which a plate of a cable assembly is positioned opposite a target component. FIG. 14a) is a cross-sectional view of the first region 211 of the groove of the plate 20 along the y-axis direction. A linear electrode 400 is provided on the surface of the target component 40, and the plate 20 is positioned to correspond to this electrode. A linear recess 220 corresponding to this electrode is provided on the second surface S2 of the plate 20 facing the target component. The linear electrode portion 410 (400) and the recess 220 of the plate can be used, for example, for position adjustment purposes. Furthermore, a protrusion or recess can be provided at any position on the surface of the target component on which the electrode is provided, and a corresponding recess or protrusion can be provided on the surface of the plate facing the target component. FIG. 14b) is a cross-sectional view of the second region 212 of the groove of the plate 20 along the y-axis direction. The second region 212 of the groove of the plate 20 is located at a position corresponding to the electrode 400 of the target component 40.

[0043] FIG. 15 shows an example of a state in which a plate of a cable assembly and an electrode of a connection target component are connected. After arranging the conductors of the plate and the multiple electrodes of the connection target component so that they correspond to each other as described above, the conductors of the core wires are connected to the electrodes by applying heat, pressure, etc. FIG. 15a) is a cross-sectional view of the first region 211 of the groove of the plate 20 along the y-axis direction. A portion 410 of the line-shaped electrode of the connection target component 40 fits into a recess 220 provided on the second surface S2 of the plate, preventing the plate from shifting. FIG. 15b) is a cross-sectional view of the second region 212 of the groove of the plate 20 along the y-axis direction. When solder paste is used as the conductive connecting material, heating the second region 212 melts the solder components, allowing for easy connection. Applying pressure simultaneously with heating can further improve the reliability of the connection. In the example shown in FIG. 15b, in the second region 212 of the grooves of the plate 20, the wall formed between adjacent grooves extends between adjacent electrodes 400 of the connection target component 40. This positions at least a portion of the electrode 400 within the second region 212 of the grooves of the plate 20, in the region between the first surface S1 and the second surface S2 of the plate 20. The wall formed between adjacent grooves in this second region 212 can function as a partition wall that separates the conductor 100 and the electrode into a single cell. This structure is expected to be effective in suppressing short circuits caused by solder leakage. Furthermore, if a recess 220 is provided on the surface of the plate 20 facing the connection target component as a recess in the direction of extension of the electrode, excess solder components held in the second region of the plate can escape into this recess 220, which is expected to be effective in preventing solder leakage between the electrodes.

[0044] Furthermore, the connection method including the cable assembly of the present invention is effective in preventing connection defects due to insufficient supply of conductive connecting material between the electrode surface and the conductor. As wiring density and pitch become higher, electrodes become smaller, making it difficult to detect the supply status of conductive connecting material in the connection between the electrode and the conductor through visual inspection. In particular, when the outer diameter of the conductor is large compared to the size of the electrode, not only is the electrode portion hidden by the conductor, making it impossible to confirm the fillet shape, but it is also difficult to supply conductive connecting material to the area hidden by the conductor. As a result, open defects are more likely to occur. The connection method including the cable assembly of the present invention makes it possible to supply a sufficient amount of conductive connecting material between the electrode surface and the conductor, and stable connection quality can be expected even in such cases.

[0045] After connecting the core wires and the electrodes of the connection target component, the plate 20 can be removed. The plate can be removed by heating or deforming it to an extent that does not affect the connection. When removing the plate after connecting the core wires of the cable assembly and the electrodes of the connection target component, the surface of the plate facing the connection target component should be the first surface S1 of the plate.

[0046] In the cable assembly of the present invention, when connecting a plate in which the conductive connecting material containing the conductor has hardened to an electrode of a connection target component, an anisotropic conductive film can also be used between the conductor and the electrode. When using an anisotropic conductive film, the anisotropic conductive film is laminated on the surface of the cable assembly plate facing the connection target component, and the plate is positioned corresponding to the electrode of the connection target component. The anisotropic conductive film is formed into a film-like shape by dispersing conductive particles such as fine metal particles in a thermosetting resin base. When this sheet is sandwiched between the conductor and the electrode and heat and pressure are applied, the conductive particles dispersed in the film approach each other and only the areas where pressure is applied are electrically connected. When the surface facing the connection target component is the second surface S2 of the plate, the conductor and the electrode of the connection target component are electrically connected via the conductive connecting material and the anisotropic conductive film. When the surface facing the connection target component is the first surface S1 of the plate, the conductor and the electrode of the connection target component are connected via the anisotropic conductive film alone, or via the conductive connecting material and the anisotropic conductive film.

[0047] The structure of the cable assembly and its connection method of the present invention have been described above. However, the cable assembly of the present invention can be manufactured, for example, by the following steps. The steps described below are not limited to the order described. <Cable Preparation Step> A cable is prepared, with multiple insulated cables and / or coaxial cables as the core wire. Cables are often cables with a circular cross section in which multiple core wires are twisted together, or cables with a flat cross section in which multiple cables are arranged in parallel. <Conductor Exposure Step> The core wires at the end of the prepared cable are arranged to match the shape of the plate. The insulation at the end of the multiple core wires is removed to expose the conductors. When using coaxial cables as the core wires, the jacket, shield conductor, and insulation are removed from the outer periphery of the core wire in this order to expose the conductor. <Plate Preparation Step> A plate material is prepared. Multiple grooves are formed, each having a first region that holds the core wire conductor and a second region that holds the conductive connecting material. Grooves can be formed in the film that will serve as the plate material by processing using a laser or the like. The second region of the groove of the processed plate is filled with a conductive connecting material, and excess material is removed. <Step of placing the conductor on the plate> The conductor, exposed by removing the insulation from the core wire, is placed in a groove formed in the prepared plate. <Step of fixing the conductor to the plate> The conductor placed in the groove of the prepared plate is pressed from above the plate to engage the conductor with the groove in the first region of the plate groove. Furthermore, the conductor is forced into the conductive connecting material in the second region of the plate groove to create a cable assembly. For the cable assembly, the plate with the conductor fixed thereto may be preheated as necessary to harden the conductive connecting material. <Step of connecting the cable assembly to the electrodes of the connection target component> The conductors of the prepared cable assembly are connected to the electrodes of the connection target component. When solder paste is used as the conductive connecting material, the plate is placed in a position corresponding to the electrodes of the connection target component, with the second surface of the plate facing the connection target component. Heating is performed to prevent misalignment between the plate and the electrodes, melting the solder paste, thereby electrically and physically fixing the conductors and electrodes via the solder paste.It is also possible to connect the first surface of the plate as the surface facing the component to be connected. When connecting using an anisotropic conductive film, the anisotropic conductive film is laminated on either the first surface or the second surface of the plate, which is the surface facing the component to be connected. The plate with the anisotropic conductive film laminated thereon is placed in a position corresponding to the electrode of the component to be connected. By applying heat and pressure from above the plate, pressure is applied to the anisotropic conductive film sandwiched between the conductor of the core wire fixed to the plate and the electrode on the component to be connected, causing conductivity, and the conductor and electrode are electrically and physically connected via the solder paste and the anisotropic conductive film.

[0048] In a manufacturing method for an electronic device using a connection method using a cable assembly according to an embodiment of the present invention, it is possible to collectively connect the conductors of multiple core wires to multiple electrodes of a connection target component, enabling wiring with excellent connection reliability in a simple manner. Furthermore, there is no need to provide a connector on the wiring board of the electronic device, which is expected to reduce the wiring space within the electronic device. The manufacturing method for an electronic device using a connection method including a cable assembly according to the present invention can be applied to electronic devices that require miniaturization, such as medical imaging devices, micromachines, measuring devices, and communication devices, and is particularly useful for medical endoscopy and ultrasound diagnostic devices.

[0049] (Measurement of the Conductor Cross-Sectional Shape of a Cable Assembly) When measuring the cross-sectional shape of the conductor in the groove of the plate of a cable assembly and the exposed conductor region of the core wire, a cross section is created by cutting along the direction perpendicular to the extension direction of the conductor and groove (y-axis direction) so that the shape of the measurement point is maintained, and this cross section is used as the measurement cross section. For example, the area near the measurement point can be embedded in a curable resin or the like, and then cut along the direction perpendicular to the extension direction of the conductor to create a cross section while maintaining the shape. The measurement cross section is measured using a digital microscope or the like. Measurements are performed at locations where the conductor is presumed to be stably fixed to the plate, such as near the center of the first region of the groove in the x-axis direction and near the center of the second region of the groove in the x-axis direction. Measurements are performed on all of the multiple conductors fixed to the plate, or on 20 or more randomly selected conductors. <Effective Length W1 of the First Region of the Groove in the Direction Perpendicular to the Extension Direction of the Groove (y-axis direction)> The effective length W1 of the first region of the groove in the y-axis direction is measured at a portion where the groove can effectively clamp the conductor when the conductor is fitted into the groove. In the measurement cross section of the cable assembly, the length of the groove in the y-axis direction, between the first and second surfaces of the plate, at the portion where the inner surface of the groove and the conductor contact is at its maximum, is measured and defined as the "effective length W1 of the first region." If the shape of the first region of the groove is such that the length in the y-axis direction varies depending on the cutting position, cross sections are prepared at different positions and measurements are taken at multiple locations (e.g., five or more randomly selected locations). The arithmetic mean value of the measurements is defined as W1. <Effective length W2 of the second region of the groove in the direction perpendicular to the extension direction of the groove (y-axis direction)> The length of the second region of the groove in the y-axis direction, between the first and second surfaces of the plate, at the measurement cross section of the cable assembly, is measured and defined as the "effective length W2 of the second region." If the shape of the second region of the groove is such that the length in the y-axis direction varies depending on the cutting position, cross sections are prepared at different positions and measurements are taken at multiple locations (e.g., five or more randomly selected locations). The arithmetic mean value of the measurements is defined as W2.Regarding the above-mentioned relationship that the effective length W2 of the second groove region in the y-axis direction is greater than the effective length W1 of the first groove region in the y-axis direction, if this relationship holds for 50% or more of the grooves whose lengths have been measured, the cable assembly is treated as having the effective length W2 of the second groove region in the y-axis direction greater than the effective length W1 of the first groove region in the y-axis direction. (Measurement of the Area of ​​the Second Groove Region) The area of ​​the second groove region of the plate of the cable assembly is measured on the surface of the plate using a digital microscope or the like. On the plate surface, an area whose length in the direction perpendicular to the extension direction of the groove is greater than the outer diameter of the conductor of the exposed conductor region of the core wire is measured as the second groove region. The opening area of ​​the second groove region is measured on each of the first and second surfaces of the plate. The area of ​​the second region is measured for all grooves formed on the plate or for at least 20 randomly selected grooves. Regarding the relationship that the area of ​​the second groove region on the first surface of the plate is smaller or larger than the area on the second surface of the plate, if this relationship holds for 50% or more of the grooves whose areas have been measured, the second groove region is considered to have an area on the first surface of the plate smaller or larger than the area on the second surface of the plate. <Cross-sectional area of ​​the plate groove> The cross-sectional area of ​​the plate groove can be measured simultaneously when measuring the conductor cross-sectional shape of the cable assembly. In measuring the cross-section created above, the area enclosed by a straight line along the plate surface near the groove and the outline of the inner surface of the plate groove is the cross-sectional area of ​​the groove. If the groove contains an insulating material, such as an adhesive, different from the material of the plate body, the outline of that material is treated as the outline of the groove, and the area occupied by that material is excluded from the cross-sectional area of ​​the groove. <Plate Groove Spacing P> The plate groove spacing P can be measured simultaneously when measuring the conductor cross-sectional shape of the cable assembly. In measuring the cross section created above, the distance between the center of the y-axis length of a groove on a line along the plate surface near the groove and the center of the y-axis length of an adjacent groove is the spacing P of the grooves on the plate.If 50% or more of the measured groove spacing P is within the predetermined range, the groove spacing P of the plate of that cable assembly is treated as being within the predetermined range.

[0050] Example: Four insulated cables were prepared as core wires, each consisting of a conductor with an outer diameter of 0.030 mm coated with an insulator made of PFA. Three uninsulated conductors with an outer diameter similar to the insulated cables were also prepared. A cable was created by placing the insulated cable at the center and twisting the insulated cable and uninsulated conductors alternately around it. Three of these cables were used to arrange 12 core wires (insulated cables) in parallel. The ends were stripped 3.0 mm to expose the conductors. A 125 μm thick polyimide film was prepared as the plate material, and a groove having a first region and a second region was formed on the first surface of the polyimide film by laser processing. The groove spacing P was 0.1 mm. A recess was formed on the second surface of the plate by laser processing at a position corresponding to the electrode of the connection target component. A solder paste with a solder particle size of 10 μm was filled into the second region of the groove to prepare a cable assembly plate. The core conductor was placed in the groove of the prepared plate, and a small press was used to press the plate and conductor from above, fitting the conductor into the first region of the groove. At the same time, the conductor was pressed into the solder paste held within the second region. When the small press pressed the plate and conductor from above, heating was simultaneously applied, pre-hardening the solder paste and fixing the conductor to the plate, thereby preparing a cable assembly. The conductor of the prepared cable assembly was connected to the electrodes of the connection target component. The plate of the cable assembly had a second surface as the connection surface facing the connection target component, and was placed on the connection target component using a recess formed on the second surface so that the core conductor corresponded to the electrode. A welder was used to heat the second region of the plate and its surrounding area, melting the solder and connecting the conductor of the cable assembly to the electrodes of the connection target component. The cable assembly of the example enabled all of the multiple conductors fixed to the plate to be connected accurately at once, and the appropriate amount of solder was supplied for the connection, resulting in no open or short circuit defects.

[0051] The cable assembly of the present invention enables a simple and highly reliable connection between the conductors of multiple core wires and the electrodes of a connection target component. Therefore, a method for manufacturing an electronic device using the cable assembly of the present invention allows for a simple wiring method for the electronic device, which is advantageous for manufacturing electronic devices with highly reliable electrical connections. Furthermore, there is no need to provide a connector on the wiring board, which is expected to reduce the wiring space within the electronic device. Electronic devices using a connection method including the cable assembly of the present invention are particularly expected to be highly effective in medical endoscopes, ultrasound diagnostic devices, and the like. The cable assembly of the present invention is also useful for other electronic devices requiring miniaturization, such as imaging devices, micromachines, measuring devices, and communication devices.

[0052] REFERENCE SIGNS LIST 1 Cable assembly, 10 Core wire, 100 Conductor, 20 Plate, 210 Groove, 211 First region of groove, 212 Second region of groove, 220 Recess 300 Conductive connecting material, 40 Connection target member, 400 Electrode S1 First surface, S2 Second surface, W1 Effective length in first region, W2 Effective length in second region x Groove extension direction, y Direction perpendicular to groove extension direction

Claims

1. A cable assembly comprising: a plate; and a cable having a plurality of core wires, the plurality of core wires being connectable to a plurality of electrodes provided on a surface of a target component, the core wires having a conductor and an insulator formed on the outer periphery of the conductor, including a conductor exposed region where the conductor is exposed, and a conductor covered region having the insulator on the outer periphery of the conductor, the plate having a first surface and a second surface which are reverse to each other, the first surface being provided with a plurality of linearly extending grooves to which the core wires are connected, the grooves having a first region in which at least a portion of the conductor exposed region of the core wire is clamped, and a second region in which a conductive connecting material is held within, the grooves having an effective length in a direction perpendicular to the extension direction of the grooves, an effective length W2 in the second region is greater than an effective length W1 in the first region, and the conductor of the conductor exposed region of the core wire is clamped in the first region of the groove of the plate and fixed by the conductive connecting material held in the second region.

2. The cable assembly according to claim 1, wherein said second region of said groove is formed through said plate from said first surface to said second surface.

3. A cable assembly as described in claim 1, characterized in that the plate has a recess or protrusion corresponding to the connection target component on at least one of the first surface and the second surface.

4. A cable assembly as described in claim 3, characterized in that the recess of the plate is a groove formed in a position corresponding to the electrode of the connection target component and extending in the direction of the electrode.

5. The cable assembly according to claim 1, wherein the outer diameter of the conductor of the core wire is 0.01 mm to 0.15 mm.

6. A method for manufacturing an electronic device, comprising: preparing a cable assembly as described in claim 1; and electrically connecting the plurality of core wires to the electrodes of the connection target component.

7. A method for manufacturing an electronic device as described in claim 6, further comprising removing the plate after electrically connecting the plurality of core wires to the electrodes of the connection target component.

8. A method for manufacturing an electronic device as described in claim 6, comprising connecting the multiple core wires and the electrodes of the connection target component so that a portion or the entirety of the electrodes is positioned between the first surface and the second surface of the plate in the second region of the groove of the plate when the multiple core wires and the electrodes of the connection target component are connected.

9. A method for manufacturing an electronic device as described in claim 6, comprising providing a recess in the extension direction of the electrode of the connection target component at a position on the plate corresponding to the electrode of the connection target component, and controlling the relative position between the plate and the connection target component.

10. An electronic device comprising a cable assembly including a plate and a cable having a plurality of core wires, the plurality of core wires being connectable to a plurality of electrodes provided on a surface of a connection target component, the core wires having a conductor and an insulator formed on the outer periphery of the conductor, including a conductor exposed region where the conductor is exposed, and a conductor covered region having the insulator on the outer periphery of the conductor, the plate having a first surface and a second surface which are in a front-back relationship, the first surface being provided with a plurality of linearly extending grooves to which the core wires are connected, the grooves having a first region in which at least a portion of the conductor exposed region of the core wire is clamped, and a second region in which a conductive connecting material is held therein, the effective length in a direction perpendicular to the extension direction of the grooves being such that an effective length W2 in the second region is greater than an effective length W1 in the first region, and the conductor of the conductor exposed region of the core wire is clamped in the first region of the grooves of the plate and fixed by the conductive connecting material held in the second region; and a connection target member having a plurality of electrodes to which the plurality of core wires are connected.

11. The electronic device according to claim 11, wherein the electronic device is a medical endoscope or an ultrasonic diagnostic device.

Images