JPH028388Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an end connector for a flat cable.

(Prior Art) A flat cable is one in which a plurality of pairs of conductors (signal conductor and ground conductor) are arranged on both sides of an intermediate dielectric, and these conductors are covered with an outer jacket.
There is a so-called stripline type. In this type of flat cable, high frequency signals are transmitted between the pair of conductors.

A connector is connected to the end of the flat cable. Various methods of connecting this connector and flat cable have been developed in the past. The first method is to connect a conductor led out from a flat cable to a terminal of a connector by soldering, welding, or the like. The second type is one in which the conductor led out from the flat cable is inserted into the two-pronged terminal of the connector (press contact type). The third method uses a printed wiring board as a card edge connector, and connects a conductor led out from a flat cable to this wiring board. The fourth is to further connect a connector to the third wiring board.

(Problems to be solved by the invention) When the flat cable and the terminal of the connector are connected as described above, the reliability is low, the mechanical strength at the connection part is low, and the insulation resistance at the connection part is low. is likely to decrease. Furthermore, except in the second case, the connection work takes time.

Since the characteristic impedance at the connection portion and the connector changes significantly compared to the inside of the cable, matching cannot be achieved and problems such as signal reflection occur. Crosstalk tends to occur when conductors of different sets come close to each other near the connection part.

In the third and fourth connection methods using printed wiring boards, the signal propagation delay becomes large.

(Means for solving the problem) The present invention was made to solve the above problem, and its gist is that a plurality of pairs of conductors are arranged on both sides of a flat intermediate dielectric, and In the end connector of a flat cable constructed by covering the cable with a jacket, the intermediate dielectric of the flat cable and the conductors on both sides are led out from the end of the jacket, and the intermediate dielectric and the conductors on both sides are connected to each other. The end connector of the flat cable is characterized in that a flat shape-retaining member made of resin is interposed between the connectors, and the intermediate dielectric, the conductor, and the shape-retaining plate are integrated.

(Function) The conductor of the flat cable directly serves as the contact terminal of the end connector, eliminating the need for a connecting part.
Reliability and mechanical strength are improved. The time required to connect the ends of this flat cable is relatively short.

A shape-maintaining plate is interposed between a pair of conductor groups, and each conductor is embedded in the shape-maintaining plate, so it is possible to secure the spacing between the conductors of different groups, and as a result, it is possible to prevent a decrease in insulation resistance and reduce crosstalk. can be reduced.

By placing the intermediate dielectric derived from the flat cable directly in the middle of the conductor group as part of the configuration of the end connector, large changes in electrical characteristics can be alleviated. Moreover, by adjusting the dielectric constant, thickness, etc. of the shape maintaining plate, it is possible to match the characteristic impedance of the end connector with the characteristic impedance of the cable, and problems such as signal reflection can be eliminated.

(Example) Hereinafter, an example of the present invention will be described based on the drawings from FIG. 1 to FIG. 5. Reference numeral 1 in FIG. 5 indicates a flat cable, and this flat cable 1 has the configuration shown in FIG. 3. That is, a plurality of pairs of signal conductors 3 and a plurality of ground conductors 4 are arranged in parallel on both sides of a flat intermediate dielectric 2 and covered with an outer cover 5. The signal conductor 3 is narrower than the ground conductor 4 and has the same thickness. The signal conductors 3 and the ground conductors 4 are arranged alternately on both sides of the intermediate dielectric 2, forming a pair of conductor groups. The intermediate dielectric 2 is made of porous tetrafluoroethylene resin (PTFE), and the outer cover 5 is made of non-porous tetrafluoroethylene resin.

As shown in FIG. 5, the flat cable 1
End connectors 10, which are a feature of the present invention, are provided at both ends of the connector. This end connector 10
is constructed as shown in FIGS. 1, 2, and 4. More specifically, an intermediate dielectric 2 and a pair of conductor groups arranged on both sides thereof are led out from the end of the outer jacket 5. A shape maintaining plate 11 made of tetrafluoroethylene-ethylene copolymer resin (ETFE) is disposed between the derived intermediate dielectric 2 and each conductor group. This ETFE has the highest mechanical strength among fluororesins, has high adhesion strength to the conductors 3 and 4, and has a relatively low melting point and is suitable for hot pressing, so it was selected as the material for the shape maintaining plate 11. In addition, the intermediate dielectric 2 and the shape maintaining plate 11 are thermally fused together by hot pressing, and the signal conductor 3 and the ground conductor 4 are embedded in the shape maintaining plate 11, and one side 3a, 4a of the signal conductor 3 and the ground conductor 4 are embedded in the shape maintaining plate 11. is exposed flush with the shape maintaining plate 11. 1μ for this surface 3a and 4a
Gold plating of m or more is applied.

The end connector 10 having the above configuration is a so-called card edge connector.

A reinforcing member 15 is provided around the boundary between the end connector 10 and the cable 2. This reinforcing member 15 is a glass fiber base material impregnated with epoxy resin.

In the end connector 10 configured as described above, the ends of each signal conductor 3 and the ground conductor 4 directly serve as contact terminals of the end connector 10, so that the conductors of the flat cable and the terminals of the end connector are different from each other as in the conventional flat cable. There is no need to connect to

In other words, since there are no connecting parts, reliability is high. Furthermore, since there is no connecting part and the shape maintaining plate 11 is used as the core material, mechanical strength is high.

Note that the mechanical strength is further increased by the reinforcing member 15. When the flat cable 1 is bent, the conductor 3 located inside the curved part and the conductors 3 and 4 located outside the flat cable 1
There may be a difference in the length within the cable, and depending on this difference, a load may be applied to the boundary between the end of the flat cable 1 and the end connector 10. However, by being held by the reinforcing member 15, , can sufficiently withstand this load.

The pair of conductor groups are separated by the intermediate dielectric 2 and the shape maintaining plate 11, and since the conductors 3 and 4 in each conductor group are embedded and fixed in the shape maintaining plate 11, a decrease in insulation resistance can be prevented. Furthermore, crosstalk between different sets of signal conductors 3 can be prevented.

Since the end connector 10 has the intermediate dielectric 2 derived from the flat cable 1, large changes in characteristic impedance etc. can be alleviated.
Moreover, by adjusting the relative permittivity and thickness of the shape-maintaining plate 11, matching can be achieved by making the characteristic impedance at the end connector 10 almost equal to that of the flat cable 1, thereby causing problems such as signal reflection. can be prevented. In fact, the intermediate dielectric 2 is 0.1
mm thickness, signal conductor 3 is 0.1 mm x 0.5 mm flat annealed copper wire,
0.8 where the ground conductor 4 is a flat annealed copper wire of 0.1 mm x 0.8 mm.
The characteristic impedance of the end connector 10 formed using the 0.8 mm thick shape maintaining plate 11 on the mm thick flat cable 1 was measured (10 to 90 mm thick).
(using a pulse with a rising edge of 35 psec), the characteristic impedance was 54 Ω, which was not much different from the characteristic impedance of 50 Ω in flat cable 1, and matching was obtained. By the way, the characteristic impedance of conventional end connectors is 69Ω to 85Ω, and matching cannot be achieved.

Further, the signal propagation delay at the end connector 10 can also be reduced.

When the end connector 10 is inserted into the receiving connector 20, the signal conductor 3 and the ground conductor 4 come into contact with a large number of terminals 21 of the receiving connector 20, respectively. Note that by grasping the reinforcing member 15, the end connector 10
can be easily inserted and removed.

In fact, even if you perform the above insertion and removal 100 times in a row,
There were no abnormalities such as peeling off of the conductors 3 and 4 from the shape maintaining plate 11 or change in shape.

In addition, the terminal 21 of the receiving connector 20 and the conductors 3, 4
The contact resistance is 2 to 3 mΩ when the conductor width is 0.8 mm,
The resistance was 5 to 6 mΩ when the conductor width was 0.5 mm, and 8 to 9 mΩ when the conductor width was 0.2 mm, which was sufficient for practical use.

The time required to convert the end of the flat cable 1 into a connector is relatively short, about 10 minutes.

The present invention is not limited to the above embodiments and can be modified in various ways. For example, in order to reliably fix the conductor to the shape-maintaining plate, devices such as those shown in FIGS. 6 to 9 may be used. In FIG. 6, conductor 41 (signal conductor and ground conductor, the same applies to conductors 42 to 44 below)
The tip 41a is curved and is completely buried within the shape maintaining plate 11 without being exposed to the outside, and this tip 41a functions to prevent it from coming off. In the case of FIG. 7, the conductor 42 has a trapezoidal cross section, and both sides 42a of the conductor 42 function as a retainer. In the case of FIG. 8, unevenness extending in the longitudinal direction is formed on the surface 43a of the conductor 43 opposite to the exposed surface, and the resin of the shape-maintaining plate 11 enters into the unevenness and functions to prevent it from coming off. There is. In the case of FIG. 9, the resin of the shape maintaining plate 11 is raised in the vicinity of both sides of the conductor 44, and this raised portion 50 prevents the both sides of the conductor 44 from coming off.

The jacket of the flat cable may be comprised of an inner porous resin layer and an outer non-porous resin layer.

The conductor may be configured such that only a portion thereof is embedded in the shape maintaining plate and the remaining portion protrudes from the shape maintaining plate.

Discontinuities in electrical characteristics can be avoided by making the thickness of the shape-maintaining plate gradually thicker from the base end (the end on the flat cable side) to the middle part, and making it uniform from the middle part to the tip. You may try to relax it.

(Effects of the invention) As explained above, with the invention, the reliability and mechanical strength of the end connector can be improved, and the insulation resistance and
Electrical characteristics such as crosstalk and characteristic impedance matching can be improved, and furthermore, the processing time for the end connector can be shortened.

[Brief explanation of the drawing]

The drawings from Fig. 1 to Fig. 5 show one embodiment of the present invention, Fig. 1 is a plan view of the end connector and its vicinity, and Fig. 2 shows the end connector connected to the receiving connector. Figure 3 is a cross-sectional view of the flat cable taken along line - in Figure 1, Figure 4 is a cross-sectional view of the end connector along line - in Figure 1, and Figure 5 is a cross-sectional view of the end connector taken along line - in Figure 1. 6 to 9 show different ways of embedding the conductor in the shape-maintaining plate. The cross-sectional views of FIGS. 7 to 9 are cross-sectional views taken in a direction perpendicular to the longitudinal direction of the flat cable. 1...Flat cable, 2...Intermediate dielectric, 3...
Signal conductor, 4... Ground conductor, 5... Outer cover, 10... End connector, 11... Shape maintenance plate, 41-44... Conductor.

Claims (1)

[Claims for Utility Model Registration] (1) An end connector of a flat cable constructed by arranging a plurality of pairs of conductors on both sides of a flat intermediate dielectric and covering these conductors with an outer jacket. In this method, the intermediate dielectric and the conductors on both sides of the flat cable are led out from the ends of the jacket, and flat resin shape-maintaining plates are interposed between the intermediate dielectric and the conductors on both sides, and these intermediate dielectric An end connector for a flat cable, characterized in that a body, a conductor, and a shape maintaining plate are integrated. (2) The intermediate dielectric and the shape-retaining plate are heat-sealed, and the conductor is embedded in the shape-retaining plate with at least one side exposed, so that the intermediate dielectric, the conductor, and the shape-retaining plate are integrated. An end connector for a flat cable according to Claim 1 of the Utility Model Registration Claim. (3) The end of the flat cable according to claim 1, in which the intermediate dielectric is made of porous tetrafluoroethylene resin and the shape maintaining plate is made of tetrafluoroethylene-ethylene copolymer resin. section connector.