A conventional flat cable comprises a plurality of conductors covered with insulation arranged to joint each other in a side-by-side fashion to form a cable having a flat structure. The flat cable is commonly used for transmission of signal in a variety of electrical appliances, electronic facility, computer facility, and communication facility.
Recently, flexible circuit board technology has also been applied to construct flat cables. The flexible circuit-board flat cables that are commonly used currently are constructed in different configurations that are either a single-sided board, a double-sided board, or a multiple-layered board, in order to meet the needs of applications that require different numbers of conductors for signal transmission.
Adopting a flat cable that has a flat structure to serve as a signal transmission line constitutes no severe problem in practical applications where the flat cable needs to extend through an elongate space. However, lots of existing electronic or communication devices use a hinge structure that has a bore. For example, in the structure designs of various consumer electronic devices, such as notebook computers, liquid crystal displays, digital cameras, mobile phones, touch panels, or other electronic devices, a cover or a screen is coupled to a body of the electronic device with a hinge structure. To allow a signal to be transmitted from the body of the electronic device to the cover or the screen, the state-of-the-art techniques use a miniaturized flat cable or bundled extra thin leads to serve as a signal transmission line. In the applications mentioned previously, adopting the conventional flat cable constitutes problems, for example, rotation of the hinge being negatively affected by the existence of the conventional flat cable, insufficient flexibility of the conductors or leads, poor durability against flexing of the conductors or leads. Due to these problems, the present inventor provided various flexible flat circuit cables that have a bundled structure and a cluster section. The cluster section is composed of a plurality of cluster strips formed by slitting a flexible substrate in an extension direction.