JP2010199039A - Connection of multi-core extra fine-coaxial cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide connections of a multi-core extra-fine coaxial cable that facilitates forming electrically stable connections, without causing defective continuity due to a gap generated between a shield conductor and a grounding bar, or without short circuit caused such that the shield conductor is pressurized and transformed by the grounding bar to break through an internal insulator. <P>SOLUTION: In the connections of the multi-core extra-fine coaxial cable, a plurality of extra-fine coaxial cables 5 having an internal insulator 2, shield conductor 3, and an external insulator 4 sequentially formed on the periphery of a center conductor 1 are arranged in line. Each of the center conductors 1 of the extra-fine coaxial cables 5 is electrically connected to respective conductive patterns 9 formed on a circuit board 8, and each of the shield conductors 3 of the extra-fine coaxial cables 5 is electrically connected to the common grounding bar having alignment grooves for the shield conductors with soldering or a conductive adhesive, further the grounding bar is electrically connected to an earth 12 formed on the circuit board 8. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a connecting portion of a multi-core ultrafine coaxial cable used as a probe cable of a medical ultrasonic diagnostic apparatus, for example.

  In general, as a probe cable for connecting a main body of a medical ultrasonic diagnostic apparatus and a probe, as shown in FIG. 3, an inner insulator 2 and a shield are provided on the circumference of a central conductor 1 in which a plurality of fine wires are twisted. A multi-core micro coaxial cable is used in which a large number of micro coaxial cables 5 in which a conductor 3 and an external insulator (jacket) 4 are sequentially formed are assembled and integrated.

  The ultra-fine coaxial cables that make up this multi-core ultra-fine coaxial cable are required to be further reduced in diameter and used in line with the downsizing and higher performance of medical ultrasonic diagnostic equipment and other products. As the diameter of coaxial cables is reduced and the number of cables used is increased, the difficulty of connecting multicore ultrafine coaxial cables is increasing.

  When connecting a multi-core micro-coaxial cable that integrates a large number of ultra-thin micro-coaxial cables to a circuit board, for example, the center conductor of the micro-coaxial cable is formed on the circuit board by stripping the terminals. It is necessary to perform a connection operation for electrically connecting to the conductor pattern portion thus formed and for electrically connecting the shield conductor to the ground portion formed on the circuit board.

  Conventionally, soldering has been frequently used for such connection work. For example, Patent Document 1 that simplifies connection work of a multi-core micro-coaxial cable in which a large number of micro-coaxial cables are arranged in parallel is disclosed in FIG. As shown in FIG. 2, the external insulator 4 is peeled off to expose the shield conductors 3 of the micro coaxial cable 5, and the shield conductors 3 are sandwiched from above and below by two ground bars 6 and 7 made of metal foil. A method is described in which these are connected together by soldering.

  Patent Document 2 discloses a ground pattern in which a central conductor of an ultrafine coaxial cable exposed by stripping a terminal is connected to a strip line formed on a printed board by soldering and a shield conductor is formed on the printed board. Describes a method of connecting by soldering.

Japanese Patent No. 3371797 JP 2003-168499 A

  However, according to the connection method described in Patent Document 1 above, as shown in FIG. 4, the shield conductor 3 of each micro coaxial cable 5 is collectively sandwiched between the two ground bars 6 and 7 from above and below. Since this is a method of connection, there is a problem that a problem occurs due to a variation in the diameter of the shield conductor 3 of each micro coaxial cable 5 and a shift in the parallel interval between the two ground bars 6 and 7 arranged above and below. That is, for example, when each shield conductor 3 has a diameter smaller than a predetermined size, or when the parallel distance between the two ground bars 6 and 7 becomes wider due to the deviation, a part of the shield conductor 3 and the ground A gap is formed between the bars 6 and 7, and a conduction failure is likely to occur. On the contrary, when each shield conductor 3 has a diameter larger than a predetermined size or when the parallel interval between the two ground bars 6 and 7 is narrowed due to a shift, a part of the shield conductor 3 is grounded. There is a problem that the pressure is deformed by the bars 6 and 7 to break through the internal insulator 2 and cause a short circuit.

  On the other hand, the connection method by soldering in the above-mentioned Patent Document 2 is not intended for multi-core micro-coaxial cables in which a large number of micro-coaxial cables are assembled and integrated, and the shield conductor of each coaxial cable is connected to the ground bar. Since it is not used for efficient and collective connection, this is not a solution to the above problem.

  Therefore, the object of the present invention is that there is no possibility that a gap is formed between the shield conductor and the ground bar, causing a conduction failure, or the shield conductor is pressure-deformed by the ground bar to break through the internal insulator and cause a short circuit. An object of the present invention is to provide a connection part of a multi-core extra fine coaxial cable that can easily form an electrically stable connection part.

  In order to achieve the above object, the invention of claim 1 is a multi-core micro coaxial cable in which a plurality of micro coaxial cables in which an inner insulator, a shield conductor, and an outer insulator are sequentially formed on the circumference of a central conductor are arranged in parallel. In the connecting portion, the central conductor of the micro coaxial cable is electrically connected to a conductor pattern portion formed on the circuit board, and the shield conductor of the micro coaxial cable is provided with a common shield conductor array groove. A multi-core micro coaxial cable comprising: a ground bar electrically connected by soldering or a conductive adhesive; and the ground bar is electrically connected to an earth portion formed on the circuit board. Provide a connection.

  According to the connection portion of this multi-core micro-coaxial cable, by adopting the above configuration, the shield conductor of the micro-coaxial cable is particularly soldered to a common ground bar having a shield conductor array groove, or electrically connected by a conductive adhesive. By connecting the shield conductors to each other, the position of the shield conductor in the groove for arranging the shield conductors is surely connected to the ground bar without pressing between the two ground bars from above and below as in Patent Document 1. Therefore, due to the variation in the diameter of the shield conductor and the deviation of the parallel spacing between the two ground bars arranged above and below, a gap is formed between the shield conductor and the ground bar, resulting in poor conduction, There is no risk of the shield conductor being pressed and deformed by the ground bar, breaking through the internal insulator and causing a short circuit. It can also be formed to ease.

  According to a second aspect of the present invention, there is provided the connecting portion of the multi-core extra fine coaxial cable according to the first aspect, wherein each of the shield conductor array grooves has a curved cross section.

  According to the connecting portion of the multi-core micro coaxial cable, in addition to the above-described effect, the shield conductor array groove has a curved cross section, so that it is easy to position a shield conductor having a generally circular cross section. In addition, the connection solder or the conductive adhesive can be easily supplied to the shield conductors exposed from the grooves, thereby facilitating the connection work. In this regard, in the connection structure in which the shield conductor is sandwiched from above and below by two ground bars as in Patent Document 1, it is not easy to supply the connection solder or conductive adhesive to the shield conductor. It is necessary to devise such as applying solder (tin) plating 14 to the whole.

  According to a third aspect of the present invention, there is provided the connecting portion of the multi-core micro-coaxial cable according to the first or second aspect, wherein the cross-sectional shape of the shield conductor array groove is a concave shape or a U shape, respectively.

  According to the connecting portion of the multi-core micro coaxial cable, the cross-sectional shape of the shield conductor array groove is a concave shape or a U shape, which is a kind of curved shape, so that the same effect as described above can be obtained.

  According to the connecting portion of the multi-core micro-coaxial cable of the present invention, a gap is formed between the shield conductor and the ground bar, resulting in poor conduction, or the shield conductor is pressurized and deformed by the ground bar to break through the internal insulator. There is no possibility of causing a short circuit, and an electrically stable connection portion can be easily formed.

It is a top view which shows the connection part of the multi-core extra fine coaxial cable which concerns on one embodiment of this invention. It is sectional drawing which shows the connection state of the shield conductor and ground bar of each micro coaxial cable in the connection part of FIG. It is sectional drawing of the micro coaxial cable which comprises the multicore micro coaxial cable of FIG.1 and FIG.2. It is sectional drawing which shows the malfunctioning state of the connection of the shield conductor and ground bar of each micro coaxial cable in the conventional connection part.

  A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 relates to an embodiment of the present invention. FIG. 2 is a plan view showing a connection portion of a multi-core micro coaxial cable in which a plurality of micro coaxial cables shown in FIG. 3 are arranged in parallel. FIG. FIG. 3 is a cross-sectional view showing the connection state between the shield conductor and the ground bar of each of the micro coaxial cables in FIG. 3, and FIG. 3 is a cross-sectional view of the micro coaxial cable constituting the multicore micro coaxial cable of FIGS.

  In the micro coaxial cable 5 of FIG. 3, as described above, the inner insulator 2, the shield conductor 3, and the outer insulator (jacket) 4 are sequentially formed on the circumference of the central conductor 1 in which a plurality of fine wires are twisted together. The cable is excellent in bending resistance. The shield conductor 3 is configured by spirally winding a plurality of thin wires on the circumference of the internal insulator 2.

  The connection portion of the multi-core micro coaxial cable of FIG. 1 is formed by arranging 32 micro coaxial cables 5 of FIG. 3 in parallel at a narrow pitch of 0.3 mm, and stripping the ends of each micro coaxial cable 5 The exposed center conductor 1 is electrically connected to the conductor pattern portion 9 formed on the circuit board 8 by soldering, and the shield conductor 3 is made of a thin conductive metal plate having the shield conductor array grooves 10 respectively. The ground bar 11 is electrically connected to the common ground bar 11 by soldering, and the ground bar 11 is electrically connected to the ground portion 12 formed on the circuit board 8 by soldering (ground connection). Configured. Incidentally, the multi-core micro coaxial cable in which such a connection part or connection assembly is formed is used as a probe cable of a medical ultrasonic diagnostic apparatus. Note that the stripping of the end of the micro coaxial cable 5 can be performed by a known method such as using a laser beam if necessary.

  In this connection portion, on the circuit board 8 connected to the flat multi-core micro coaxial cable, conductor pattern portions 9 are formed at a pitch of 0.3 mm corresponding to the center conductor 1 of each micro coaxial cable 5. In addition, an earth portion 12 is formed corresponding to the ground bar 11 in which the shield conductors 3 are collectively connected.

  As shown in FIG. 2, the ground bar 11 made of a thin conductive metal plate has a shield conductor array groove 10 formed into a U-shaped section by press working corresponding to the shield conductor 3 having a 0.3 mm. The shield conductors 3 and the ground bar 11 are formed with a narrow pitch. The shield conductors 3 are exposed after the shield conductors 3 are aligned and arranged in the shield conductor array grooves 10 formed in a U-shaped cross section. This can be done by supplying the connecting solder 13 from the surface side and soldering the shield conductor 3 to the ground bar 11. The cross-sectional shape of the shield conductor array groove 10 may be the same curved concave shape instead of the U shape.

  According to the connecting portion of the multi-core extra fine coaxial cable, the shield conductor 3 of the extra fine coaxial cable 5 is aligned and soldered to the arrangement groove 10 of the common ground bar 11 provided with the arrangement groove 10 for the shield conductor. By connecting the shield conductor 3 to the ground bar 11 without positioning and pressing the shield conductor 3 from above and below with two ground bars as in Patent Document 1, Since the connection can be made reliably, there is a gap between the shield conductor and the ground bar due to variations in the diameter of the shield conductor and the parallel gap between the two ground bars arranged above and below. There is no risk of failure or the shield conductor is deformed under pressure by the ground bar, breaking through the internal insulator and causing a short circuit. It is possible to easily form a connection part.

  In the above embodiment, the shield conductor 3 and the ground bar 11 are connected by soldering, but it is of course possible to connect using a conductive adhesive.

DESCRIPTION OF SYMBOLS 1 Center conductor 2 Internal insulator 3 Shield conductor 4 External insulator 5 Micro coaxial cable 6, 7 Ground bar 8 Circuit board 9 Conductor pattern part 10 Shield conductor arrangement groove 11 Ground bar 12 Ground part 13 Solder for connection

Claims (3)

  In the connection portion of the multi-core micro coaxial cable in which a plurality of micro coaxial cables in which an inner insulator, a shield conductor, and an outer insulator are sequentially formed on the circumference of the center conductor are arranged in parallel, the center conductor of the micro coaxial cable is respectively connected It is electrically connected to a conductor pattern portion formed on the circuit board, and the shield conductor of the micro coaxial cable is electrically soldered to a common ground bar provided with an array groove for shield conductor or electrically conductive adhesive. A connecting portion of a multi-core extra fine coaxial cable, wherein the connecting portion and the ground bar are electrically connected to an earth portion formed on the circuit board.   The connection part of the multi-core extra fine coaxial cable according to claim 1, wherein each of the shield conductor array grooves has a curved cross-sectional shape.   The connection part of the multi-core micro coaxial cable according to claim 1 or 2, wherein a cross-sectional shape of the shield conductor array groove is a concave shape or a U shape, respectively.

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