JPH02278611A - Polytetrafluoroethylene insulating tape-coated cable and its production - Google Patents

Abstract

PURPOSE:To obtain stable connection by connecting an earthing conductor to a sealed layer by hot-dipping. CONSTITUTION:A plurality of conductors are comprised of a prescribed number of signal conductors 11 of a metal having a melting point higher than a sintering temperature of tetrafluoroethylene resin and a prescribed number of earthing conductor 12 of a metal having a melting point lower than the sintering temperature of the tetrafluoroethylene resin. At least one tape of the tetraethylene resin tape 13 is a porous tape 13 and the earthing conductor 12 is electrically connected to a sealed layer 13 through a metal layer 15 of the earthing conductor 12 diffused to the pores of the porous tape 13. As a result, with this structure, troublesome processes in cutting the porous tape 13 and press-bonding the earthing conductor 12 and the sealed layer 13 become unnecessary. Connection of the earthing conductor and the sealed layer thus becomes stable and durable owing to oxidation of the conductor and the sealed layer.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a tetrafluoroethylene resin insulating tape electric wire and a method for manufacturing the same.

(Prior Art) Tape wires with extremely small signal line spacing are often used for internal wiring in computers and the like, and shielded tape wires are used when electrical shielding is required. This type of electric wire usually has a connector attached to the terminal and connects it to the device.For this purpose, the ground wire is also placed at the same spacing as the signal wire, and the placement position of the ground wire is determined by the user's request. It will be done. In a narrow space inside a device, it is difficult to ground both the ground wire and the shield layer, and grounding the shield layer is particularly troublesome. Therefore, there is a structure in which the ground wire is electrically connected to the shield layer so that the shield layer can also be grounded by grounding only the ground wire.

Furthermore, in order to improve the transmission characteristics of signal lines, there is a tendency to use polytetrafluoroethylene resin, which itself has a low dielectric constant, as an insulator.

Examples of the structure of the shielded tape electric wire as described above are shown in cross-sectional views in FIGS. 3 and 4. In these figures, 2 is a signal conductor, and 2 is a grounding conductor, both of which are normally made of copper wire. These conductors are arranged in parallel in a horizontal row at predetermined intervals, and the tetrafluoroethylene resin tape 3 is tightly integrated by sandwiching these conductors from both sides like a sandwich. An opening 4 may be formed as appropriate to expose the grounding conductor 2, and a shield layer 5 may be wrapped to cover the entirety of the grounding conductor 2, and the grounding conductor 2 may be formed by pressure contact from both sides, or a conductive adhesive may be used to form the grounding conductor 2. is formed so as to be electrically conductive to the shield layer. Note that a porous tape may be used as the tetrafluoroethylene resin tape 3.

(Problem to be Solved by the Invention) In the shielded tape electric wire having the above structure, a method for exposing the grounding conductor is to attach the signal conductor and the grounding conductor on both sides in a sandwich-like manner using tetrafluoroethylene resin tape. The method used is to sandwich the ground conductor so that it is tightly integrated and then remove it by cutting the tetrafluoroethylene resin tape on the grounding conductor part, but if the distance between the conductors is narrow, use tetrafluoroethylene There is a risk of damaging the signal conductor part of the resin tape, and there will be a gap equal to the thickness of the polytetrafluoroethylene resin tape between the ground conductor and the shield layer, so it is necessary to conduct between them. This requires laborious work such as pressing the shield layer to make it stick tightly or adhering it with a conductive adhesive, making manufacturing difficult, especially when the distance between the conductors is narrow. Furthermore, it is difficult to maintain a stable connection for a long period of time due to the grounding conductor coming off the insulator due to long-term use, or oxidation of the conductor and shield layer.

(Means for Solving the Problems) The present invention has been made to solve the problems as described above. The conductor is plated with a metal whose melting point is lower than that of the firing temperature of the polytetrafluoroethylene resin, and the grounding conductor is a conductor plated with a metal whose melting point is lower than that of the firing temperature of the polytetrafluoroethylene resin, such as Suzumetsuki, and these conductors are spaced at specified intervals. are arranged in parallel to each other, at least one of the polytetrafluoroethylene resin tapes is sandwiched between the two sides as a porous tape in the form of a sandwich, and then tightly integrated, and further covered with a shielding layer. To provide a shielded tape electric wire having a structure in which plated metal of a grounding conductor flows into holes of a porous tape so that the grounding conductor and a shield layer are electrically connected.

The method for manufacturing the above-mentioned electric wire is to run the required number of signal conductors and grounding conductors in parallel at a predetermined interval, and to sandwich at least one of these conductors from both sides.
The sheet is supplied with a polytetrafluoroethylene resin tape made of an unsintered porous tape and a shield tape, heated to a temperature lower than the firing temperature of the polytetrafluoroethylene resin, for example, about 300°C, and then molded with a forming roll. While making the tapes stick together, the plating metal of the grounding conductor flows into the holes of the porous tape to establish continuity between the grounding conductor and the shielding tape, and then it is introduced into a firing furnace and the firing temperature of the polytetrafluoroethylene resin is adjusted to A method is provided for manufacturing a shielded tape electric wire having the above structure by heating a porous tape to, for example, about 400° C. and sintering it.

(Function) As mentioned above, when it is heated and then formed by a roll, the plating metal of the grounding conductor melts due to the heat and flows into the holes of the porous tape, and the grounding conductor and the shield layer are bonded together by the pressure of the roll. electrical conduction occurs, and the green porous tape is then sintered.

In the tape electric wire manufactured in this way, the grounding conductor and the shielding layer are electrically connected, so the process requires further cutting of the porous tape and pressure contact between the grounding conductor and the shielding layer. becomes unnecessary.

(Example) FIG. 1 is a cross-sectional view of an example of a tetrafluoroethylene resin insulation tape electric wire according to the present invention. In the figure, the signal conductor 11 is plated with a metal whose melting point is higher than the firing temperature of the polytetrafluoroethylene resin, for example, silver plated to a thickness of about 1 mm.
．． The grounding conductor 12 is plated with a metal having a melting point lower than the firing temperature of the polytetrafluoroethylene resin, such as tin plating, to a thickness of about 10 μm.

The required number of signal conductors 11 and grounding conductors 12 are arranged horizontally in parallel at predetermined intervals, and are insulated with polytetrafluoroethylene resin porous tape 13 so as to sandwich these conductors from both sides. , the shield tape 14 is arranged and wrapped so as to cover the whole. 15 is the plated metal of the grounding conductor 12 that has flowed out into the holes in the porous tape 13, thereby providing electrical continuity between the grounding conductor and the shield tape. Note that although the grounding conductor is placed at the outermost position in the figure, it can be placed at any position according to the user's request.

FIG. 2 is a schematic diagram illustrating an embodiment of the method for manufacturing a shielded tape electric wire according to the present invention. A required number of signal conductors 11 and grounding conductors 12 arranged in parallel at predetermined intervals are sent out from the reel group 21, and are advanced through guide rolls 22 for maintaining these conductors at predetermined intervals. On the other hand, unfired polytetrafluoroethylene resin porous tapes 23 each having a thickness of 0.1 mm are sent out from the reels 24 and heated to about 300°C in the preheating furnace 25, and at the same time shield tapes are respectively fed from the outside from the reels 26. It is sent out and heated and pressurized with a forming roll 27 to form it. Further, a hot air generator 28 blows hot air at about 300° C. onto the bonding surface between the tape and the conductor. The plated metal (for example, tin) of the grounding conductor 12 is melted and flows out into the holes of the porous tape 23 by the pressure of the forming roll 27, thereby establishing electrical continuity between the grounding conductor 12 and the shield tape 14. At this temperature, the plating metal of the signal conductor 11 (
For example, silver) does not melt.

Next, it is led to a firing furnace 29 and heated at about 400° in an inert gas.
The porous tape 23 is fired by heating to C and then cooled by a cooling roll 30 to obtain a product. Note that an external sheath may be applied if necessary.

(Effects of the Invention) In the tetrafluoroethylene resin insulating tape electric wire of the present invention, the grounding conductor and the shield layer are not in mechanical contact as in the conventional example.
Alternatively, since the connection is made through hot-dip plating, unlike the connection through a conductive adhesive, a stable connection can be obtained without causing poor contact.

Of course, since the ground conductor and the shield layer are electrically connected, the shield layer is also grounded by simply grounding the ground conductor, making the grounding work easy. The grounding conductor can be placed in any position or in plurality according to the user's request.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an embodiment of a tetrafluoroethylene resin insulation tape electric wire according to the present invention, and FIG. 2 is a schematic diagram showing an embodiment of a method for manufacturing a tetrafluoroethylene resin insulation tape electric wire according to the present invention. 3 and 4 are cross-sectional views of conventional tetrafluoroethylene resin insulating tape electric wires. 1, 11: Signal conductor, 2.12: Grounding conductor, 3, 1
3: Tetrafluoroethylene resin tape, 14: Shield layer (shield tape), 27: Forming roll, 29: Firing furnace.

Claims (3)

[Claims] (1) In a tetrafluoroethylene resin insulation tape electric wire, in which multiple conductors arranged in parallel are insulated by sandwiching them with tetrafluoroethylene resin tape, and a shield layer is provided to cover the entire conductor, the multiple conductors However, the required number of signal conductors are plated with a metal whose melting point is higher than the firing temperature of the tetrafluoroethylene resin, and the grounding conductor is plated with a metal whose melting point is lower than the firing temperature of the tetrafluoroethylene resin. At least one of the tetrafluoroethylene resin tapes is made of a porous tape, and the grounding conductor is electrically connected to the shield layer through the plated metal of the grounding conductor that has flowed into the holes of the porous tape. A tetrafluoroethylene resin insulation tape electric wire. (2) Claim 1 in which the plurality of conductors comprises a required number of silver-plated signal conductors and a tin-plated grounding conductor.
The described tetrafluoroethylene resin insulation tape electric wire. (3) A required number of signal conductors plated with a metal whose melting point is higher than the firing temperature of the tetrafluoroethylene resin and a grounding conductor plated with a metal whose melting point is lower than the firing temperature of the tetrafluoroethylene resin. While running the conductors in parallel at a predetermined interval, attach at least one unsintered polytetrafluoroethylene resin tape to sandwich these conductors from both sides.
The sheet is a porous tape, and a shielding tape is supplied together with the porous tape. After heating to a temperature lower than the firing temperature of the tetrafluoroethylene resin, the tapes are brought into close contact with a forming roll, and the plated metal of the grounding conductor is attached to the porous tape. A method for manufacturing a tetrafluoroethylene resin insulating tape electric wire, which comprises letting the electrical wire flow out into the holes of the shielding tape, and then introducing the wire into a firing furnace and heating it to the firing temperature of the polytetrafluoroethylene resin to sinter it. .