JPH03295112A - Sandwich type flexible cable - Google Patents

Abstract

PURPOSE:To prevent damage to a sandwich type flexible cable by providing a reinforcement member on the stress concentration part of the thin plastic film that covers both a wiring part and a terminal part for connection, so as to prevent exterior shearing force and bending stress from concentrating on the stress concentration part. CONSTITUTION:A reinforcement member 8 made of flexible plastic film or of hard rubber and the like, is adhered to the part correspondent to a stress concentration part 3 in a thin plastic film 4 of a sandwich type flexible cable. Since the reinforcement member 8 is thus provided on the stress concentration part 3 of the thin plastic film, shearing and bending stress from the outside will not be concentrated on the stress concentration part, and the cable will not be broken even when handling for soldering connection work to an apparatus and so on.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sandwich type flexible cable used in optical disk drives or general electrical equipment.

[Prior Art] Conventionally, a sandwich-type flexible cable for electrical wiring is a wiring in which metal wiring having a desired pattern shape is arranged on a flexible plastic thin film, as shown in FIGS. 3 and 4, for example. As shown in FIG. 4, which is a cross-sectional view taken along line A-A in FIG. The metal wiring 5 is buried in the plastic thin film 4, and the connection terminal part 2 is exposed in the recess 4a formed when the plastic thin film 4 is peeled off. It has a structure in which solder 7 is laminated by soldering. and metal wiring 5
and the metal thin film 6 are electrically connected.

[Problem to be solved by the invention] However, such a sandwich-type flexible cable,
The metal wiring 5 and its leads 5a are integrally formed with copper foil, and when soldering is performed on the copper foil, a phenomenon occurs in which the copper and solder become alloyed and harden.
When shear stress or bending stress is applied to one end of the copper foil, the stress concentrates particularly around the boundary between the wiring section 1 and the connection terminal section 2, making it difficult to solder the equipment from the pre-soldering state. There was a problem in that a wire breakage occurred in the stress concentration part 3 during the handling process until the process was completed.

FIG. 5 shows the state of wire breakage when shear forces from the directions of arrows B and C are applied to the stress concentration portion 3.

[Means for Solving the Problems] In order to solve the above problems, the sandwich type flexible cable of the present invention has a wiring part in which metal wiring having a desired pattern shape is arranged in a flexible plastic thin film, and an external connection. In the sandwich-type flexible cable, the sandwich-type flexible cable has a connecting terminal portion which is pre-soldered on the lead of the metal wiring in order to make an electrical connection, and the connecting terminal portion is coated over the wiring portion and the connecting terminal portion. It is characterized in that a reinforcing member is provided in the application concentrated area of the plastic thin film. Also, a wiring part in which metal wiring having a desired pattern shape is arranged in a flexible plastic thin film, and a connection terminal part in which preliminary solder is applied to the lead of the metal wiring for electrical connection with the outside. In the sandwich type flexible cable, the thickness of the plastic thin film covering the wiring portion and the connection terminal portion is set to be thicker at the portion corresponding to the stress concentration portion than the periphery of the stress concentration portion (formation). It is characterized by:

[Function] Such a sandwich type flexible cable is provided with a reinforcing member at the stress concentration part of the plastic thin film covering the wiring part and the connection terminal part.
External shearing force and bending stress do not concentrate on the stress concentration area.

Further, since the stress concentration portion of the plastic thin film covering the wiring portion and the connection terminal portion is made thicker than the periphery of the stress concentration portion, the same effect as described above is obtained.

[Example] Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a sectional view of essential parts of a sandwich-type flexible cable according to an embodiment of the present invention.

When a reinforcing member 8 made of a flexible plastic film or hard rubber was adhered to the stress concentration area 3 of the plastic thin film 4 of the conventional sandwich-type flexible cable explained with reference to FIG. No breakage occurred even when applying shearing force or bending.

FIG. 2 is a sectional view of a main part showing a sandwich type flexible cable according to another embodiment of the present invention. A portion 4a corresponding to the stress concentration portion 3 in the plastic thin film 4 of the conventional sandwich type flexible cable shown in FIG.
When the thickness of Y was made thicker than that of the periphery of Y, the same effect as described above was obtained.

[Effects of the Invention] As explained above, the present invention provides a reinforcing member in the stress concentration part of the plastic thin film that covers the wiring part and the connection terminal part, so that it is not affected by external shearing force or Bending stress is no longer concentrated on the stress concentration portion, and high reliability is achieved in that wire breakage does not occur even when handling by soldering to equipment or the like.

Further, in the present invention, the thickness of the plastic thin film covering the wiring part and the connection terminal part corresponding to the stress concentration part is made thicker than the periphery of the stress concentration part. The same effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the main parts of a sandwich-type flexible cable according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of main parts showing another embodiment of the invention, and FIG. 3 is a conventional sandwich-type flexible cable A partial plan view showing a flexible cable, FIG. 4 is a sectional view taken along line A-A in FIG. 3, and FIG. 5 shows a conventional sandwich-type flexible cable broken due to external shearing force FIG.

Claims (2)

[Claims] (1) A wiring part in which metal wiring having a desired pattern shape is arranged in a flexible plastic thin film, and a connection terminal in which preliminary solder is applied to the lead of the metal wiring to establish an electrical connection with the outside. What is claimed is: 1. A sandwich type flexible cable having a reinforcing member provided in a concentrated area of the plastic thin film covering the wiring part and the connection terminal part. (2) A wiring section in which metal wiring having a desired pattern shape is arranged in a flexible plastic thin film, and a connection terminal in which preliminary solder is applied to the lead of the metal wiring for electrical connection with the outside. In the sandwich type flexible cable having a part, the thickness of the part corresponding to the stress concentration part of the plastic thin film covering the wiring part and the connection terminal part is made thicker than the periphery of the stress concentration part. A sandwich-type flexible cable that is characterized by: