JPH0223000Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to the structure of a flexible wiring board.

(Prior art) The lens of a camera, etc. has the function of expanding and contracting depending on the distance of the subject, but it is possible to respond to this change by electrically connecting the front and rear parts of the lens, where the distance constantly changes. A coiled flexible wiring board is used.

FIG. 1 is a perspective view showing an example of such a coiled flexible wiring board, in which 1 is a flexible insulating sheet, 2 is an overlay film, 3 is a conductor, and 4 is a terminal.

In order to manufacture such a coiled flexible wiring board, as shown in FIG. 2, a plurality of substantially circular planar flexible wiring boards are connected at one end of the circle. That is, in Fig. 2, a is a substantially circular flexible wiring board, 1 is a flexible insulating sheet, 2 is an overlay film, 3 is a conductor, 4 is a terminal, and 5 is an end to be connected.This flexible wiring board 2 The sheets were placed facing each other as shown in b, and the end portions 5 of each were overlapped and connected by solder so that the conductors thereon corresponded to each other, thereby forming a coiled flexible wiring board as shown in c.

(Problem that the invention aims to solve) This conventional structure is not 100% reliable because it relies on connections such as soldering, and if the pattern of the connection part is minute, the molten solder may In some cases, the current flowed between adjacent conductors, causing short circuits and making manufacturing impossible.

The present invention has been devised in view of these points, and provides a flexible wiring board structure with higher connection reliability.

(Means for Solving the Problems) The present invention is characterized in that a flexible wiring board having a conductor pattern on a zigzag flexible sheet in which two or more of the same shape are connected is bent at the connecting part to form a coil shape with one or more turns. This is a coiled flexible wiring board.

As an example is shown in FIGS. 3a, b, and c, a flexible wiring board equipped with terminals 4 for connecting two or more circuit parts is removed by removing a part of the annular shape and connecting the ends. 6 to form a circular coil having one or more turns, and fixed with adhesive tape or adhesive so that the connecting portion 6 maintains its bent shape. In this case, the shape of the coil may be a polygon such as a quadrangle. The number of turns of the coil may be one turn or more depending on the length, and is appropriately selected depending on the purpose. Further, in order to obtain a three-turn coiled flexible wiring board, it is sufficient to bend a flat flexible wiring board having a pattern as shown schematically in FIG. 4 at point A. In order to obtain a coiled flexible wiring board having a larger number of turns due to a larger distance between two or more circuit parts, the pattern shown in FIG. 4 may be made into a more continuous pattern. The pattern of the planar flexible wiring board to be bent may be a sine curve as shown schematically in FIG. 5, and in this case, point B is bent.

(Function) Unlike the conventional method, since solder connection is not performed to form a coil having one turn or more, there is no reduction in connection reliability due to solder connection.

Example Flexible insulation sheet 1 and overlay film 2 are polyimide films
Using KAPTON100H (DuPont, product name),
The circuit part was made of copper foil with a thickness of approximately 35 μm, and a flexible wiring board having the shape shown in Figure 3a was created.

An epoxy resin adhesive was applied to the portion of the flexible wiring board that overlapped when folded, and the board was bent as shown in FIG. 3b to form a coiled flexible wiring board with one or more turns as shown in FIG. 3c.

As an effect of this embodiment, in the case of the conventional connection method,
If the conductor pitch at the connection part was 0.6 mm or more, it would be difficult to manufacture due to poor reliability (conductor short circuit during connection), but with this invention, it is easy to manufacture even fine patterns with a conductor pitch of 0.6 mm or less. Summer. Also,
Since the bent connecting portion 6 is fixed with adhesive tape or adhesive so as to maintain its bent shape, the bent connecting portion 6 can be used between two or more circuit sections whose distance changes frequently. 6
This reduces the stress placed on the connection and improves connection reliability.

(Effects of the invention) As explained above, the structure of the invention does not require soldering to form a coil with more than one turn, unlike conventional structures, so there is no reduction in connection reliability due to soldering. .

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a coiled flexible wiring board showing an embodiment of the present invention, FIGS. 2 a to c are perspective views showing the manufacturing process for explaining a conventional example, and FIGS. A perspective view for explaining the structure of one embodiment of the invention, and FIGS. 4 and 5 are schematic diagrams of wiring patterns showing other embodiments of the invention. DESCRIPTION OF SYMBOLS 1... Flexible insulation sheet, 2... Overlay film, 3... Conductor, 6... Connecting part.

Claims (1)

[Scope of utility model registration request] A coiled flexible wiring board characterized in that a flexible wiring board having a conductor pattern on a zigzag flexible sheet in which two or more of the same shape are connected is bent at the connecting part to form a coil shape having one or more turns.