Cable terminal structure and connection method

Abstract

The present invention relates to a cable terminal structure comprising a cable holding member and a cable fixed to the cable holding member. The cable includes a first core wire and a second core wire that each include a conductor and an insulator formed around the conductor. Each of the first core wire and the second core wire has a covered region covered with the insulator and an exposed region in which the insulator is partially removed, exposing the conductor. The cable holding member has a first cable holding part including a first through hole formed to extend from a first surface to a second surface and a second cable holding part including a second through hole formed to extend from the first surface to the second surface. The exposed region of the first core wire is formed so as to pass through the first cable holding part, and the exposed region of the second core wire is formed so as to pass through the second cable holding part. The present invention also relates to a novel cable connection method using the cable holding member.

Description

Cable Terminal Structure and Connection Method

[0001] The present invention relates to an electronic component, a cable terminal structure connected to the electronic component, a holding member for holding a cable, and a cable connection method.

[0002] Measuring devices, communication devices, medical probe cables, micromachines, etc. are required to be miniaturized and highly accurate, and the diameter of cables used as signal transmission paths between electronic components is becoming smaller. For example, in medical endoscopes, the diameter of the device body is being reduced to reduce the burden on patients, and the electronic components mounted are also becoming more refined. Therefore, a high mounting density is required for the assembly of cables and fine components.

[0003] In the connection between an image sensor or the like of a solid-state imaging device used in a medical endoscope or the like and a cable, in order to achieve high-density mounting, a three-dimensional connection such as in the vertical direction is essential instead of the conventional planar cable connection method. In addition, for extremely small electronic components such as image sensors, it is necessary to reduce the size of the connection board according to the size of the sensor, and the connection work is difficult. Also, the space around the connection part between such a sensor and the core wire of the cable is often limited, and further miniaturization of the connection part is required.

[0004] Here, as a technique for connecting a substrate such as a sensor and the core wire of a cable, in a connection structure between a cable in which a plurality of electric wires with exposed core wires at the ends of the electric wires are assembled and a sensor, a spacer for holding the ends of each electric wire in a separated state is provided. A technique has been disclosed that enables easy connection work between the sensor and the core wire of the cable by interposing it in the space surrounded by the covering portion of each electric wire (see Patent Document 1).

[0005] Japanese Patent Application Laid-Open No. 2020-102315

[0006] Here, in the configuration of Patent Document 1, the spacer is arranged in the space surrounded by the covering portion of each electric wire. Although the spacer is connected to the substrate while keeping each electric wire separated, a certain length is required for the connection part between the sensor and the core wire of the cable, and there is room for further improvement in the miniaturization of the connection part.

[0007] To solve the above problems, the configuration described in the claims can be adopted. For example, in a cable terminal structure comprising a cable holding member having a first surface and a second surface which is the surface opposite to the first surface, and a cable fixed to the cable holding member, the cable each has a first core wire and a second core wire, each including a conductor and an insulator formed around the conductor, the first core wire and the second core wire each have a covered area covered with the insulator and an exposed area where the insulator is partially removed so that the conductor is exposed, the cable holding member has a first cable holding portion consisting of a first through hole formed from the first surface to the second surface, and a second cable holding portion consisting of a second through hole formed from the first surface to the second surface, the exposed area of ​​the first core wire is formed to penetrate the first cable holding portion, and the exposed area of ​​the second core wire is formed to penetrate the second cable holding portion.

[0008] Another example is a connection method for forming a cable terminal structure by fixing a cable to a cable holding member, in which a cable is connected to an electronic component, a thin plate-like member having a first surface and a second surface which is the surface opposite to the first surface is prepared, a first cable holding part consisting of a first through hole formed from the first surface to the second surface, and a second cable holding part consisting of a second through hole formed from the first surface to the second surface are formed to prepare the cable holding member, and a first core wire and a second core wire each including a conductor and an insulator formed around the conductor The connection method includes preparing the cable having the first core wire and the second core wire, forming a covered area covered with the insulator and an exposed area where the insulator is partially removed so that the conductor is exposed on the first core wire and the second core wire, fixing the exposed area of ​​the first core wire to the cable holding member so that it passes through the first cable holding part, fixing the exposed area of ​​the second core wire so that it passes through the second cable holding part to form the cable terminal structure, and electrically and physically joining the first core wire and the second core wire of the cable terminal structure to the electronic component.

[0009] The cable terminal structure according to the embodiment of the present invention, by having the above configuration, can improve the quality and accuracy of the connection between the cable and the electronic component. Furthermore, the connection method of the present invention allows for connection work to be performed in a simple manner and is advantageous for miniaturizing the connection portion between the cable and the electronic component.

[0010] [Correction based on Rule 91 07.01.2026] This is a schematic diagram illustrating a cable terminal structure according to an embodiment of the present invention. This is a diagram illustrating an example of a cable relating to the cable terminal structure according to an embodiment of the present invention. This is a diagram illustrating another example of a cable relating to the cable terminal structure according to an embodiment of the present invention. This is a diagram illustrating the tip region of the core wire of the cable terminal structure according to an embodiment of the present invention. This is a diagram illustrating an example of a cable holding member relating to the cable terminal structure according to an embodiment of the present invention. This is a diagram illustrating another example of a cable holding member relating to the cable terminal structure according to an embodiment of the present invention. This is a schematic cross-sectional view of an example of a cable holding member relating to the cable terminal structure according to an embodiment of the present invention. This is a diagram illustrating a state in which cables are arranged on a cable holding member according to an embodiment of the present invention. This is a flowchart showing an example of the process of forming a cable terminal structure according to an embodiment of the present invention and connecting a cable to an electronic component. This is a flowchart showing another example of the process of forming a cable terminal structure according to an embodiment of the present invention and connecting a cable to an electronic component. This is a diagram illustrating one of the cable connection methods according to this embodiment. This is a diagram illustrating one of the cable connection methods according to this embodiment. This is a diagram illustrating one of the cable connection methods according to this embodiment.

[0011] Embodiments of the present invention will be described below with reference to the attached drawings. However, it should be noted that the embodiments described below are not intended to limit the invention as defined in the claims, but rather are equivalent to the invention described in the claims. The components and features shown in the embodiments of the present invention can be appropriately combined with the configurations of other embodiments, unless otherwise noted and without technical inconsistency. Furthermore, not all combinations of features described in the embodiments are essential for the present invention to be established. In addition, it should be noted that the attached drawings are schematic, and the dimensional ratios of each component may differ from reality. Throughout the description of the embodiments, the same elements will be denoted by the same reference numerals.

[0012] Figure 1 is a schematic diagram illustrating an example of a cable connection structure according to an embodiment of the present invention, showing a cable holding member and a cable fixed to the cable holding member. The cable terminal structure of the present invention can be deformed to suit the electronic component to be connected. In the following description, the case in which the number of electrodes (connection points) of the electronic component to be connected is four will be used as an example, but the number of connection points of the electronic component to which the present invention can be applied is not limited to four, but can be freely deformed to six, nine, or other numbers according to the design of the electronic component. The cable terminal structure 1 in Figure 1 comprises a cable 10 and a cable holding member 20. The cable 10 comprises a plurality of core wires 110. The cable holding member 20 comprises a first surface and a second surface which is the surface opposite to the first surface, and has a cable holding portion 210 consisting of a through hole formed from the first surface to the second surface. In the cable holding member 20 of this embodiment, the surface facing the electronic component to be connected is designated as the first surface, and the surface on the opposite side, which is the cable body side, is designated as the second surface. The first core wire 110a of the cable 10 has an insulator formed on the outer circumference of the conductor 111a. The conductor 111a is exposed in the tip region of the first core wire 110a and is formed to pass through the first cable holding portion 210a formed in the cable holding member 20. The second core wire 110b has an insulator formed on the outer circumference of the conductor 111b. The conductor 111b is exposed in the tip region of the second core wire 110b and is formed to pass through the second cable holding portion 210b formed in the cable holding member 20. By having the above configuration in the cable terminal structure, the quality and accuracy of connection with electronic components can be improved in a simple manner.

[0013] Cable 10 comprises multiple core wires 110. Each core wire 110 has an insulator formed around a small-diameter conductor 111. For example, the cable shown in Figure 1 includes two coaxial cables. Figure 2 is a schematic cross-sectional view of the cable portion of the example in Figure 1. Cable 10 consists of two coaxial cables. Insulators 112a and 112b are formed around conductors 111a and 111b, and an outer conductor (ground conductor) 113 is further formed around them in a horizontal winding. In this case, core wire 110 refers to conductor 111a and the insulator 112a portion formed around the conductor, or conductor 111b and the insulator 112b portion formed around the conductor. A coaxial cable sheath 114 is provided on the outer circumference of the outer conductor 113, and the two coaxial cables are covered with a jacket layer 120.

[0014] Figure 3 illustrates another example of a cable relating to an embodiment of the present invention. Figure 3A is an example of a pseudo-coaxial cable containing four core wires 110. It has three ground conductors 113, and the four core wires 110 can function as signal lines. A shield layer 130 is formed around the twisted four core wires 110 and three ground conductors 113, and a jacket layer 140 is formed on the outer periphery of the shield layer. Figure 3B is another example of a cable containing four core wires, for example, two of which can function as signal lines and the other two can function as power lines, control lines, etc. A shield layer 130 is formed around the twisted four core wires 110, and a jacket layer 140 is formed on the outer periphery of the shield layer. The cable of the cable terminal structure according to the present invention is not limited to these examples in terms of the number of core wires, structure, and function of the core wires. Furthermore, the cable may contain long bodies other than conductors. Examples of long bodies other than conductors include tubes, resin monofilaments, resin fibers, cotton yarn, etc.

[0015] For the conductor 111 of the core wire 110, a small-diameter conductor of AWG (American Wire Gauge) 36 or less is suitable. For example, when using a silver-plated copper alloy wire of AWG 40 for the conductor 111, an example is formed by twisting together seven silver-plated copper alloy wires with an outer diameter of 0.03 mm to form an outer diameter of 0.09 mm. A single wire can also be used. The effects of the present invention are better obtained in cables using small-diameter conductors. For the cable insulator 112, fluororesins such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), and polychlorotrifluoroethylene (PCTFE), or polyolefins such as polyethylene (PE), polypropylene (PP), and polymethylpentene (PMP) can be used, and the material of the insulator is not particularly limited.

[0016] Figure 4 is a diagram illustrating the tip region of a core wire in a cable terminal structure according to an embodiment of the present invention. The core wire 110 drawn out from the cable 10 has a covered region C in which the conductor 111 is covered by an insulator 112, and an exposed region E in which the insulator 112 is partially removed so that the conductor is exposed at the tip side of the core wire 110. Here, only the core wire 110 and the outermost layer of the cable 10 are shown, but there may also be a ground conductor, interlayer, shield layer, jacket layer, etc. Furthermore, the cable 10 may have some of the core wires fixed to a cable holding member, and also include core wires that are not fixed to the cable holding member. Here, "fixing" is defined not only as bonding, but also as limiting the range of motion to a certain range.

[0017] Figure 5 illustrates an example of a cable holding member relating to a cable terminal structure according to an embodiment of the invention. The cable holding member 20 is preferably in the shape of a thin plate. It is formed so that the electrode (connection point) of the connected electronic component and the tip position of the conductor 111 align. The cable holding member 20 has a cable holding portion 210 that matches the number of core conductors 111 and ground conductors 113 to be fixed, or the number of connection points of the electronic component connected to the cable terminal structure. The "through hole" of the cable holding portion refers to one that penetrates from the first surface to the second surface, and its shape is not limited as long as it can hold a conductor. For example, examples of the shape of the through hole 210 include circular, square, notched, grooved, rectangular, or elliptical shapes that have a longitudinal direction. Notched, grooved, and longitudinally oriented shapes are suitable for fixing conductors having multiple strands, such as the ground conductor of a coaxial cable. Furthermore, the shape of the through-hole may differ between the first and second surfaces, and the size of the through-hole may differ between the first and second surfaces (tapered). If the through-hole is tapered, forming it so that the size on the first surface is smaller than the size on the second surface can be expected to further improve the positional accuracy between the position of the connection electrode (connection point) of the electronic component and the tip position of the conductor 111. In the example in Figure 5, the cable holding portion 210 has two circular through-holes 211, two notched through-holes 212, and two grooved through-holes 213. However, the through-holes 210 may be formed only in the same shape, or they may be formed in multiple shapes and sizes. The shape of the cable holding member 20, and the shape, number, and arrangement of the cable holding portion 210 should be designed in accordance with the shape of the electronic component to be connected, the electrode arrangement, the space of the connection part, the type of conductor to be fixed to the cable holding member, etc. However, the aspect ratio of the first surface of the cable holding member 20 is preferably less than 3:1, preferably less than 2:1, and more preferably less than 1.5:1. At the same time, by reducing the aspect ratio of the electrode-forming surface of the electronic component, electrodes and core wires can be efficiently arranged even in the small diameter required for devices inserted into the body.Here, the aspect ratio is defined as the ratio of the length to the width if the cable holding member is a rectangle in a plan view, the ratio of the major axis to the minor axis if it is an ellipse, and the ratio of the maximum diameter to the minimum diameter if it is any other shape.

[0018] Figure 6 illustrates another example of a cable holding member relating to the cable terminal structure of the embodiment. The cable holding member 20 in Figure 6 has a protrusion 220 formed on its first surface. The protrusion 220 can be advantageously used to precisely align the electrode position of the connected electronic component with the tip position of the core conductor or the tip position of the ground conductor. The shape of the protrusion 220 can be formed to match the shape of the connected electronic component, so that the angle, front-to-back and left-to-right positions of the arrangement of the core conductor or ground conductor match. Figure 7 illustrates yet another example of a cable holding member, and is a plan view of the first surface. Figure 8 is a schematic cross-sectional view of Figure 7. In the example of Figure 7, the protrusion 220 is formed on the surface S1 of the first surface, and a part of the protrusion 220 is formed to follow the edge of the cable holding member 20. This protrusion can also function as a spacer to adjust the distance between the cable holding member 20 and the connection point of the electronic component. Furthermore, a portion of the protrusion 220 in the example of Figure 7 is formed between the cable holding portions 210 and the cable holding portions 210, and its position can be adjusted to match the gaps of electrodes, solder bumps, etc., formed on the connected electronic components. In the example of Figure 7, the protrusion 220 is provided around the entire circumference of the cable holding member, but the same effect can be obtained by forming protrusions at the four corners of the cable holding member, for example. Figure 8(A) is a schematic diagram of the A-A' cross section of Figure 7, Figure 8(B) is a schematic diagram of the B-B' cross section of Figure 7, and Figure 8(C) is a schematic diagram of the C-C' cross section of Figure 7. In the example of Figure 7, the cross-sectional shape of the protrusion is rectangular, but the cross-sectional shape may be trapezoidal or triangular, and the shape of the upper surface of the protrusion may differ from the shape of the first surface, and the area of ​​the upper surface of the protrusion may differ from the area of ​​the first surface (tapered). Here, the surface S1 of the first surface refers to the main surface that has the largest area excluding the protrusions and recesses when the first surface of the cable holding member is viewed in plan view.

[0019] The cable holding member 20 can be made of a thin plate-shaped material with a thickness of, for example, 0.02 mm to 0.50 mm. A material with moderate hardness is preferred, and depending on the hardness of the material, the thickness can be appropriately set to 0.03 mm to 0.40 mm. As an insulating material for the cable holding member, a heat-resistant material is suitable. For example, polyimide resin (PI), polyamide-imide resin (PAI), polyetheretherketone resin (PEEK), polyphenylene sulfide resin (PPS), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), etc., can be used, but are not limited to these. Furthermore, if the cable holding member 20 is removed before connecting the cable terminal structure to the electronic component, a material with low heat resistance may be used. Also, in the cable terminal structure and cable connection method of this embodiment, it is possible to remove the cable holding member before connecting the cable terminal structure to the electronic component. In this case, the material of the cable holding member is not limited to an insulating material, but may be a conductive material such as a metal plate made of SUS or aluminum.

[0020] In this embodiment, it is preferable that the longitudinal axis of the cable core is fixed to the first and / or second surface of the cable holding member so as to be substantially perpendicular. Here, perpendicular means that the direction along the surface S1 of the first surface of the cable holding member 20 and the longitudinal axis of the cable intersect at an angle of 90 degrees ± 10 degrees. The cable holding portion 210 of the cable holding member should be formed to be the same as or slightly larger than the outer diameter of the conductor 111 or the ground conductor 113. The exposed region E of the tip region of the core 110 is placed in the cable holding portion 210 of the cable holding member (see Figure 9). The conductors 111 and 113 are fixed by the cable holding portion 210 so that they are held spaced apart from each other. If a common ground conductor is to be used, multiple ground conductors can be fixed to one cable holding portion, or multiple ground conductors can be mixed and then divided and fixed according to the number of cable holding portions. It is preferable that the cable holding member 20 be positioned as close as possible to the covering region C covered by the insulator 112. This has the effect of miniaturizing the connection points between cables and electronic components.

[0021] The exposed area E of the core wire 110 between the covered area C of the core wire 110 and the cable holding member 20 may be covered with an insulating material having a different composition from the insulating material of the core wire. By covering and integrating with the insulating material, the arrangement of the conductors is fixed, and the cable terminal structure can be maintained even if the cable holding member 20 is removed before connecting the cable terminal structure to the electronic components. In addition, in the tip region of the core wire 110, a part of the covered area C, along with the exposed area E, may also be covered with resin. Examples of insulating materials for covering the exposed area of ​​the core wire 110 include thermosetting resins such as epoxy resin and silicone resin, or ultraviolet curing resins such as acrylic or epoxy resins.

[0022] The exposed area of ​​the cable's core wire is formed to penetrate the cable holding portion 210 of the cable holding member 20, and the tip of the conductor protrudes from the surface S1 of the first face. This tip of the conductor is connected to the electrode of the electronic component to be connected via a conductive connector. The conductor 111 and the ground conductor 113 may be cut to a certain length along the surface S1 of the first face of the cable holding member 20. In this case, if the cable holding member 20 has a protrusion as shown in the example in Figure 7, it can be cut along this protrusion. The cable holding member 20 after the conductor 111 has been cut can also be removed from the cable end. If the exposed area is covered with an insulating material, the arrangement of the conductor will not be disrupted even if the cable holding member is removed, which is effective in miniaturizing the connection part. When the cable holding member 20 is removed, the tip of the conductor protrudes from the portion covered with the insulating material by a length equal to the thickness of the cable holding member 20, which is advantageous when connecting to an electronic component. The same effect can be obtained by making the cable holding member 20 from, for example, two plates and removing only one.

[0023] Furthermore, the cable holding member 20 can be connected to the electronic component without being removed. The cable holding member 20 is very small, for example, 0.6 mm in length, 0.6 mm in width, and 0.2 mm in thickness, and even when connected to the electronic component with the cable holding member 20 in place, a sufficient effect is obtained in miniaturizing the connection part. Also, when connecting with the cable holding member 20 in place, a protrusion can be formed on the first surface of the cable holding member 20 to precisely position the electrode position of the electronic component and the tip position of the conductor 111. In addition, by making the shape of the cable holding member such that its orientation can be determined, it is possible to easily determine the orientation that matches the position of pin 1 of the electronic component. Examples of shapes that allow for orientation determination of the cable holding member include making a notch from the first surface to the second surface (on the side) or chamfering a specific corner.

[0024] The cable terminal structure of the present invention makes it possible to easily connect multiple conductors at once simply by bringing the solder bumps of the electrodes of the electronic components to be connected close to the structure while heating them, and is also advantageous for automating the connection work.

[0025] Next, a method for manufacturing a cable terminal structure according to an embodiment of the present invention will be described. The steps described below are not limited to the order in which they are described. Figure 10 is a flowchart showing an example of the process of forming a cable terminal structure according to an embodiment of the present invention and connecting the cable to an electronic component. Figure 11 is a flowchart showing another example of the process of forming a cable terminal structure according to an embodiment of the present invention and connecting the cable to an electronic component.

[0026] The example shown in Figure 10 includes the steps described below. <Material Preparation Step> This step involves preparing the cable and retaining member to be used in the cable terminal structure of the present invention. Preparation of Cable Retaining Member A thin sheet of material is prepared. For example, a polyimide film with a thickness of 0.2 mm, a length of 0.6 mm, and a width of 0.6 mm is prepared, and a cable retaining member is created with the surface facing the electronic component to be connected as the first surface. Through holes are formed at 0.2 mm intervals from the first surface to the second surface as cable retaining parts to hold the conductor. The number and arrangement of cable retaining parts are designed to correspond to the positions of the electrodes of the electronic component to be connected. The size of the through holes in the cable retaining parts can be adjusted according to the thickness of the conductor. If necessary, protrusions for positioning the electrodes of the electronic component to be connected and the conductor terminal may be provided. A laser or the like can be used to process the thin sheet of material into the shape of the cable retaining member. Preparation of Cable Prepare the cable. Here, as an example, a cable made by twisting together two coaxial cables with a conductor with an outer diameter of 0.030 mm as the central conductor will be used for explanation. The cable jacket is removed to pull out the coaxial cable, and the sheath of the coaxial cable is removed. The outer conductor, which is formed by winding horizontally inside the sheath, is bundled together, and the core wires are taken out and prepared. <Arrangement process> This is the process of removing the insulator from the tip region of the core wires and arranging the conductors in the cable holding member. The tip of the core wire is stripped by about 0.5 to 3 mm to expose the terminal portion of the conductor (formation of exposed region). The exposed conductors are arranged in the cable holding member and fixed so that they pass through the cable holding part. As shown in Figure 7, the conductors in the exposed region are fixed in a state where they are spaced apart by the cable holding member. Here, in the example of Figure 7, the cable holding member is arranged so that the longitudinal axis of the core wire is approximately perpendicular to the first and / or second surface of the cable holding member, but if an angle other than perpendicular is required for the connection angle with the electronic component to be connected, the arrangement angle of the cable holding member can be determined to correspond to the electronic component to be connected. The cable holding member according to the present invention has a thin plate shape, and the arrangement angle can be easily adjusted.

[0027] The flowchart in Figure 11 shows an example of a process that, in addition to the process of forming the cable terminal structure described in Figure 10, may include the following processes: <Shaping Process> After fixing the core wire to the cable holding member, and before the subsequent coating integration process, a process (shaping process 1) may be included in which the exposed area of ​​the core wire is pushed down to a position close to the coated area of ​​the core wire to shape it. This is expected to reduce the neck portion of the cable holding member (the exposed area between the coated area of ​​the core wire and the cable holding member) and minimize the connection area with electronic components. Furthermore, a process (shaping process 2) may be included in which the conductor that penetrates the cable holding portion of the cable holding member and protrudes from the surface of the first surface is cut to a certain length along the surface of the first surface of the cable holding member. If a protrusion is formed on the cable tip side surface of the cable holding member, it can be cut along that protrusion. After performing shaping process 2, for example, it will look like Figure 1, with the conductor cut to the height of the protrusion protruding from the cable holding member 20. This protruding conductor is joined by piercing into solder bumps or other structures formed on the connection electrodes of electronic components. This is expected to improve both positional accuracy and connection quality due to the protrusion. The molding process 2 is easier to perform if it is carried out after the coating integration process described later. <Coating Integration Process> This process involves covering the lower part of the cable holding member (the exposed area between the coated area of ​​the core wire and the cable holding member) at the tip of the core wire with an insulating material of a different composition from the insulating material of the core wire. By covering and integrating with the insulating material, not only is the insulating effect of the conductor enhanced, but the fixing of the core wire is also reinforced, making it easier to handle without the arrangement of the core wire being disrupted. In addition, the coating of the lower part of the cable holding member with the insulating material may cover not only the exposed area of ​​the core wire but also a part of the coated area of ​​the core wire. Once the coating integration process is completed, the cable terminal structure will have sufficient strength. Therefore, it is possible to transport the cable assembly up to this process, in which case the final process, the cable connection process, in which the conductor tip of the core wire is electrically and physically joined to the electronic component, can be carried out at another location.<Step to remove cable holding member> After the above-described sheathing integration step, a step to remove the cable holding member may be included. The cable holding member in this embodiment can be removed before connecting to electronic components. By removing the cable holding member, further minimization of the connection portion with electronic components can be expected. When removing the cable holding member, it is easier to handle if done after the fixing of the core wire of the cable terminal structure has been reinforced in the sheathing integration step. Also, if the conductor is cut in line with the surface of the first surface of the cable holding member in the above-described shaping step 2 without providing a protrusion on the cable holding member, when the cable holding member is removed, a conductor with a length equal to the thickness of the cable holding member will protrude from the sheathing integrated insulating material. This can be expected to have an advantageous effect on connecting to electronic components. <Conductive connector material formation step> A step of impregnating or coating the conductor in the exposed area of ​​the core wire with a conductive connector material may be included. Solder is most commonly used as the conductive connector material, but other materials such as silver paste, copper paste, or pastes containing conductive substances such as gold, nickel, or carbon can also be used. Here, solder will be used as an example of the conductive connector material. By impregnating or applying solder to the conductor tip before the cable connection process, it becomes easier to connect with the solder bump on the electronic component during the cable connection process. Also, if a sufficient amount of solder is applied to the conductor tip, forming a solder reservoir in the protruding area of ​​the conductor tip, it is possible to connect even if there is no solder on the electronic component side. <Cable connection process> This is the process of electrically and physically joining the cable terminal structure and the electronic component. The conductor of the cable terminal structure and the electrode of the electronic component to be connected can be electrically and physically joined using a conductive connecting material. Here, solder is used as an example of a conductive connecting material. The position of the conductor tip of the cable terminal structure 1 is adjusted to match the position of the electronic component 30 (Figure 12). It is preferable to form the cable holding member 20 to be slightly smaller than the electronic component 30. By forming the cable holding member smaller, it becomes easier to check the positional relationship with the electronic component 30 and to align it. In the example described here, a solder bump 310 is formed on the electronic component 30 (Figure 13).With the position adjusted, the cable terminal structure is brought close and the ends of the conductor 111 and ground conductor 113 are brought into contact with the solder bump 310 of the electronic component. While in contact, the solder bump 310 is melted, joining the conductors 111 and 113 to the electrodes of the electronic component via the solder bump 310. The conductor tips of the cable terminal structure joined to the electronic component are fixed in the solder that joins the electronic component and the cable structure (Figure 14). The melting of the conductive connecting material can be appropriately selected, such as heating with a heater or ultrasound. After joining the cable terminal structure and the electrodes of the electronic component, the area around the joint may be covered with an insulating material to reinforce the joint.

[0028] As described above, the cable terminal structure of this embodiment can be formed and connected to electronic components. According to the cable terminal structure of the present invention, high-precision connection between the cable conductor and electronic components can be performed with simple connection work, and it is expected to be effective in minimizing the connection portion. In the embodiment described above, an example using two coaxial cables was explained, but the type of cable, the number of cores, and the number and configuration of conductors and ground conductors are not limited thereto. Also, in the embodiment described above, the arrangement of the cable holding member is described as being substantially perpendicular to the longitudinal direction of the cable, but the arrangement angle can be adjusted and changed according to the arrangement and space of the electronic components to be connected.

[0029] The cable terminal structure and cable connection method of the present invention stabilize the dimensional accuracy and connection quality of the connection between electronic components and the core wires of the cable, and enable connection work in a simple manner. Furthermore, the technology of the present invention is advantageous in realizing further miniaturization of the connection portion between the cable and the electronic component, and is useful in fields such as imaging devices such as catheter endoscopes introduced into the body, as well as micromachines, measuring devices, and communication devices where miniaturization and high precision are required.

[0030] 1 Cable terminal structure, 10 Cable, 110 Core wire, 111 Conductor, 112 Insulator, 113 Conductor (Ground conductor), 20 Cable holding member, 210 Cable holding part, 220 Protrusion, 30 Electronic component, 310 Solder bump, C Covered area, E Exposed area

Claims

1. A cable terminal structure comprising: a cable holding member having a first surface and a second surface which is the surface opposite to the first surface; and a cable fixed to the cable holding member, wherein the cable each has a first core wire and a second core wire, each including a conductor and an insulator formed around the conductor; the first core wire and the second core wire each have a covered area covered with the insulator and an exposed area where the insulator is partially removed so that the conductor is exposed; the cable holding member has a first cable holding portion consisting of a first through hole formed from the first surface to the second surface, and a second cable holding portion consisting of a second through hole formed from the first surface to the second surface; the exposed area of ​​the first core wire is formed to penetrate the first cable holding portion; and the exposed area of ​​the second core wire is formed to penetrate the second cable holding portion.

2. The cable terminal structure according to claim 1, wherein the first core wire is fixed such that its longitudinal axis is perpendicular to the first and / or second surface of the cable holding member, and the second core wire is fixed such that its longitudinal axis is perpendicular to the first and / or second surface of the cable holding member.

3. The cable terminal structure according to claim 1 or 2, wherein the cable holding member is in the shape of a thin plate having a thickness of 0.4 mm or less.

4. The cable terminal structure according to claim 1 or 2, wherein the cable holding member is detachably fixed.

5. The cable terminal structure according to claim 1 or 2, wherein a portion of the exposed area of ​​the core wire located between the covering area of ​​the core wire and the cable holding member is covered with an insulating material having a different composition from the insulating material of the core wire.

6. A connection method for forming a cable terminal structure by fixing a cable to a cable holding member, the method comprising: preparing a thin plate-like member having a first surface and a second surface which is the surface opposite to the first surface; preparing the cable holding member by forming a first cable holding portion consisting of a first through hole formed from the first surface to the second surface and a second cable holding portion consisting of a second through hole formed from the first surface to the second surface; preparing the cable having a first core wire and a second core wire, each including a conductor and an insulator formed around the conductor; forming a covered area covered with the insulator and an exposed area where the insulator is partially removed so that the conductor is exposed on the first core wire and the second core wire, respectively; fixing the exposed area of ​​the first core wire to the cable holding member so that it penetrates the first cable holding portion, and fixing the exposed area of ​​the second core wire so that it penetrates the second cable holding portion, thereby forming the cable terminal structure. A connection method comprising electrically and physically joining the first core wire and the second core wire of the cable terminal structure to the electronic component.

7. The connection method according to claim 6, comprising, after fixing the first core wire and the second core wire to the cable holding member, and before joining the first core wire and the second core wire of the cable structure to the electronic component, integrally covering a portion of the exposed area of ​​the core wire between the covering area of ​​the core wire and the cable holding member with an insulating material having a different composition from the insulating material of the core wire.

8. The connection method according to claim 6, comprising, after fixing the first core wire and the second core wire to the cable holding member, and before joining the first core wire and the second core wire of the cable structure to the electronic component, cutting the conductor protruding from the first surface of the cable holding member to a certain length from the surface of the first surface of the cable holding member.

9. The connection method according to claim 6, further comprising: integrally covering a portion of the exposed area of ​​the core wire between the covering area of ​​the core wire and the cable holding member with an insulating material having a different composition from the insulating material of the core wire, and removing the cable holding member before joining the first core wire and the second core wire of the cable terminal structure to the electronic component.

10. The connection method according to claim 6, characterized in that when joining the first core wire and the second core wire of the cable terminal structure to the electronic component, the first core wire and the second core wire are connected collectively to their respective corresponding positions.

11. The connection method according to claim 7, characterized in that a portion of the exposed area of ​​the core wire and a portion of the covered area between the covered area of ​​the core wire and the cable holding member are integrally covered with an insulating material having a different composition from the insulating material of the core wire.

Images