JPH0536871U - Flexible board for circuit connection - Google Patents

Abstract

(57) [Summary] [Purpose] It is possible to prevent short circuit between patterns by filling the space between adjacent patterns with molten solder, and to prevent leakage current due to decrease in insulation resistance between patterns due to flux. [Configuration] A plurality of connection patterns 2 on the flexible substrate 1
To provide. Grooves 4 are formed on both sides of the connection pattern 2 over the entire length of the connection portion 3 at the tip portion of the flexible substrate 1.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a flexible board for electrically connecting circuit boards by soldering.

[0002]

[Prior art]

 Conventionally, as a method of preventing a short circuit of a pattern adjacent to a flexible board and another wiring board, the following invention has been disclosed in which a connection path of a flexible board is provided with a conduction path of molten solder for escaping excess solder. There is.

For example, in the invention disclosed in Japanese Patent Laid-Open No. 61-263192, a hole is formed in a conductive connection terminal portion integrally formed with a wiring pattern of a flexible board, and the conductive connection terminal and another wiring board are provided. When soldering, due to the action of the holes provided in the conductive connection terminals, excess solder that is larger than the amount required to connect the conductive connection terminals to another wiring board is passed through the holes to the flexible board. An invention has been proposed in which a short circuit due to a solder bridge between adjacent patterns of a flexible wiring board is prevented by short-circuiting by accumulating it on the contact surface of another wiring board to be connected to the wiring board.

Further, in the invention described in Japanese Patent Laid-Open No. 63-260196, a cut is provided in the connection pattern of the flexible board, and by this action, the connection pattern of the flexible board and a hard metal preliminarily soldered. An invention has been proposed in which, when the circuit board is heated and solder-bonded, excess solder is allowed to escape to the surface side of the flexible board through the notch so as to prevent a short circuit between adjacent patterns of the flexible board and the hard circuit board.

[0005]

[Problems to be solved by the device]

 However, in each of the above conventional techniques, it is expected that the excess molten solder will be removed from the joint surface through the conduction path provided in the connection pattern of the flexible substrate, but since both substrates are in contact with each other. There is a gap formed by the base materials of both substrates between the patterns adjacent to each other, and there is a sufficient possibility that the molten solder fills the gap by a capillary phenomenon and short-circuits between the adjacent patterns. Especially when the space between adjacent patterns is narrow, there is a concern that the above-mentioned short circuit between patterns frequently occurs.

Further, in solder joining, a flux is usually used to remove the surface oxide film of the connecting metal and maintain the fluidity of the solder. The flux has a lower viscosity than the molten solder at the solder melting temperature, and easily moves or fills the gap between the two substrate materials. If the flux remains for a long period of time, the insulation resistance between the adjacent patterns may be reduced, or the pattern metal may be transferred to cause a decrease in reliability such as a short circuit.

Therefore, the present invention was developed in view of the drawbacks in each of the above-described embodiments, and an object thereof is to provide a flexible substrate for circuit connection, which can prevent a short circuit due to molten solder and a decrease in insulation resistance due to flux. To do.

[0008]

[Means for Solving the Problems]

 The present invention is a flexible board for soldering a connection pattern to another circuit board, wherein grooves are provided on both sides of the connection pattern on the flexible board.

That is, grooves are provided on both sides of the connection pattern on the flexible substrate, and the base material of the flexible substrate is removed over the entire length of the connection portion.

[0010]

[Action]

 The grooves provided on both sides of the connection pattern do not form a gap for accumulating or flowing molten solder or flux between the substrate of the circuit board and the substrate of the flexible board. It is possible to prevent a short circuit between the connecting patterns adjacent to each other and between the conductive patterns, or between the adjacent connecting patterns and the conductive patterns, and a decrease in insulation resistance.

[0011]

【Example】

 Hereinafter, a flexible circuit connecting board according to the present invention will be described in detail with reference to the drawings.

[0012]

First Embodiment FIG. 1 is a perspective view showing a first embodiment of the present invention.

Reference numeral 1 is a flexible substrate, and the flexible substrate 1 is provided with a plurality of connection patterns 2. The tip portion of the flexible substrate 1 is a connecting portion 3, and grooves 4 are formed on both sides of the connecting pattern 2 over the entire length of the connecting portion 3.

The connection pattern 2 of the flexible board 1 having the above-described structure or the conductor pattern 6 of the circuit board 5 to be connected by the flexible board 1 is soldered in advance, or cream solder is applied to both the patterns 2. , 6 are applied, and then the connection pattern 2 and the conductor pattern 6 are brought into contact with each other so as to overlap each other, and the two patterns 2 and 6 are thermocompression bonded to realize soldering.

At this time, the grooves 4 provided on both sides of the connection pattern 2 do not form a gap for accumulating or flowing molten solder or flux between the circuit board 5 and the flexible board 1, so that the connection can be made. The surplus solder used and the flux work so as not to short-circuit the adjacent connection patterns 2 or the conductor patterns 6 or to reduce the insulation resistance.

According to the present invention, by simple means of providing the grooves 4 on both sides of the connection pattern 2 on the flexible substrate 1, short circuit between patterns due to excess solder and reduction in insulation resistance do not occur, and high reliability is achieved. Board-to-board connection can be realized.

[0017]

Second Embodiment FIG. 2 is a partially enlarged plan view showing a second embodiment of the present invention.

The flexible substrate 7 of the present embodiment is different in that an R portion 8 is formed at the main body side end portion (end portion opposite to the tip end side) of the groove 4 of the connection portion 3 in the first embodiment, and other The configuration is composed of the same configuration, and the same components are given the same numbers and their explanations are omitted.

The R portion 8 formed in the groove 4 of the flexible substrate 7 having the above structure relieves the mechanical concentrated stress applied to the groove 4. Other operations are the same as those in the first embodiment, and the description of the operation is omitted.

According to the present embodiment, since the R portion 8 is formed at the end portion of the groove 4 on the main body side, the end portion of the groove 4 on the main body side of the groove 4 on the flexible substrate 7 which is thin and weak in strength easily concentrates. It is possible to prevent destruction.

[0021]

Third Embodiment FIG. 3 is a partially enlarged plan view showing a third embodiment of the present invention.

Reference numeral 11 denotes a flexible substrate, and the flexible substrate 11 is provided with a plurality of connection patterns 12 which are retracted from the tip base material 11 a of the flexible substrate 11 by an appropriate length. The tip portion of the connection pattern 12 is a connection portion 13, and elongated hole groove portions 14 are formed on both sides of the connection pattern 12 over the entire length of the connection portion 13.

The tip substrate 11 a of the flexible substrate 11 having the above-mentioned configuration binds the tip portion of the flexible substrate 11 without disturbing the pattern arrangement of the connection pattern 12. Other functions are the same as those in the first embodiment, and the description of the functions is omitted.

According to the present embodiment, unlike the groove 4 in the first embodiment, the slotted groove portion 14 does not reach the tip of the flexible substrate 11, and the tip base material 11a binds the tip. When connecting the flexible substrate 11 to another wiring board, the tip of the connection pattern 12 is not disturbed, which facilitates the work.

[0025]

[Effect of the device]

 As described above, according to the flexible board for circuit connection of the present invention, the space between the adjacent patterns is filled with the molten solder to prevent the patterns from being short-circuited, and the flux reduces the insulation resistance between the patterns. As a result, it is possible to realize a highly reliable wiring board connection in which leakage current does not occur.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a partially enlarged plan view showing the second embodiment.

FIG. 3 is a partially enlarged plan view showing the third embodiment.

[Explanation of symbols]

 1 flexible board 2 connection pattern 3 connection part 4 groove 5 circuit board 6 conductor pattern 7 flexible board 8 R part 11 flexible board 12 connection pattern 13 connection part 14 slotted groove part

Claims (1)

[Scope of utility model registration request] 1. A flexible board for soldering a connection pattern to another circuit board, wherein the flexible board is provided with grooves on both sides of the connection pattern of the flexible board.