JPH04121639A - Testing method of bending resistance of flexible wiring board - Google Patents

Abstract

PURPOSE:To enable bending life to be evaluated accurately by providing a fixed wing and a movable wing, allowing a constant current to flow to a conductor of a wiring board while repeatedly bending the flexible wiring board at an angle of 0 to 180 degrees, and detecting increase in resistance of the conductor. CONSTITUTION:A bending tester consists of a fixed wing 2 which can place and fix one half-surface side of a flexible wiring board 1 and finely adjusts it up and down and a movable wing 3 which is placed opposingly at an upper side of this fixed wing 2 at a specified gap and allows the other half side of the flexible wiring board 1 to be bent. By performing bending operation from 0 to 180 deg. while allowing current to flow to a conductor of the flexible wiring board 1 mechanically and continuously and performing automatic measurement of resistance of the conductor, increase in resistance of the conductor can be detected, thus enabling bending life of the flexible wiring board 1 to be confirmed with improved accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a bending resistance test method suitable for accurately evaluating the bending life of a flexible wiring board from 08° to 180°.

(Prior Art) Conventionally, the bending life of a flexible wiring board has been evaluated as follows.

That is, from 0° to 180° with respect to the flexible wiring board.
If the wiring board is repeatedly bent to a degree of 1°, stress will be applied to the conductor of this wiring board, causing cracks to occur, resulting in an increase in resistance by 1, and eventually breaking.

Therefore, for boat fishing, as shown in FIGS. 2(a) and 2(b), one half of the flexible wiring board 1 is placed on a flat plate 2, and the other half is placed on a radius of curvature adjusting plate 3. Fold it around and temporarily fix it in place.

Next, when the other half side of the flexible wiring board 1 is pressed from above with the presser plate 4, the central part of the flexible wiring board 1 forms a radius of curvature R corresponding to the thickness of the radius of curvature adjustment plate 3, and the center part of the flexible wiring board 1 forms a radius of curvature R corresponding to the thickness of the radius of curvature adjustment plate 3. °Can be bent.

After holding this state for a few seconds, remove the presser plate 4, hold the other temporarily fixed half side with your hand, and place the entire flexible wiring board 1 on the flat plate 2 in a horizontal state, that is, the central part of the flexible wiring board 1. Return to 0°.

In this way, while repeatedly bending the flexible wiring board 1, a constant current is applied to the conductor of the wiring board 1, and the conductor is measured with a milliohmmeter or the like every certain number of times in order to detect cracks, disconnections, etc. in the conductor. The resistance value of the flexible wiring board 1 is measured to test the bending life of the flexible wiring board 1.

(Problem to be Solved by the Invention) However, in the conventional testing method as described above, since the work is performed manually, bending points and bending loads on the flexible wiring board 1 are There is a problem in that the test results are not constant, causing variations in the life measurement up to the point of disconnection of the conductor, resulting in unreliable test results.

The present invention has been made in view of the above circumstances, and its purpose is to provide continuous energization.

It is possible to repeatedly perform bending tests, which are continuous opening and closing of flexible wiring boards under a constant load and at a constant speed, and conductor resistance can be automatically measured, reducing data variation and conducting reliable tests with high precision. The present invention provides a method for testing the bending resistance of flexible wiring boards.

(Means for Solving the Problems) In order to achieve the above objects, the present invention has one half of a flexible wiring board mounted and fixed on a fixed wing, and the other half of the flexible wiring board fixed on a fixed wing. The flexible wiring board is bonded and fixed to the movable wings which are placed opposite each other at a distance and can be opened and closed, and as the movable wings open and close, the flexible wiring board is repeatedly bent from Oo to a bending angle of 180°. The method is characterized in that a constant current is passed through the conductor of the wiring board, and an increase in resistance of the conductor of the flexible wiring board is detected.

(Function) In order to evaluate the bending life of a flexible wiring board, this invention mechanically continuously performs a bending operation from 0° to 180° without applying a constant current to the conductor of the flexible wiring board. By automatically measuring the resistance of the conductor and detecting the rise in resistance of the conductor, the bending life of the flexible wiring board can be accurately confirmed.

(Example) Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIGS. 1(a) and 1(b) are explanatory diagrams showing a bending resistance test method for a flexible wiring board according to the present invention.

In the figure, 10 is a flexible wiring board similar to the conventional one;
1 is a bending tester.

In order to bend the flexible wiring board 10 at a predetermined bending radius, this bending tester 11 includes a fixed wing 12 that can place and fix one half of the flexible wiring board 10 and finely adjust it up and down. A movable member is disposed oppositely above the wing 12 at a predetermined interval, rotates by an arbitrarily set angle range α around the rotating shaft 13a at one end thereof, and bends the other half of the flexible wiring board 10. It is composed of a wing 14 (rotary lever).

In addition, by providing a bending angle to the attachment end on the bidirectional surface side of the flexible wiring board 10, it becomes more reliable that the entire wiring board 10 is bent uniformly.

Therefore, when performing a bending resistance test on the flexible wiring board 10 using this bending tester 11, first, as shown in FIG.
One half of the blade is placed and fixed on the fixed blade 12'', and the other half is joined and fixed to the movable blade 13, and the movable blade 13 is set in a closed state, that is, parallel to the fixed blade 12. .

At this time, the flexible wiring board 10 is approximately U as shown in the figure.
The bending point 10a is
is a bending angle of θ-0° with respect to the dotted line in the figure, which is a virtual line.

Next, when the movable blade 13 is rotated from this state to the open state, that is, at an angle α with respect to the dotted line, as shown in FIG.
As shown in , the bending point 10a is set in a horizontal state at θ=180°.

In this way, the flexible wiring board 10 is bent by repeating the opening and closing operations of the movable wings 13, and while a constant current is passed through the conductor of the flexible wiring board 10 from a current supply device (not shown), its resistance is measured with a milliohmmeter or the like. .

In order to evaluate the bending life of the flexible wiring board 10 like two legs, this invention bends the flexible wiring board 10 from Oo to 180° while applying a constant current to the conductor of the flexible wiring board 10. Since the test is carried out repeatedly and mechanically, it is possible to perform this type of test automatically under a constant load and at a constant speed, and it is also possible to automatically detect a rise in the resistance of the conductor, and to analyze the data. It is possible to eliminate variations and perform reliable tests with high accuracy.

(Effects of the Invention) As explained above, according to the bending resistance test method of the present invention, it is no longer necessary to manually bend a flexible wiring board from 0° to 180° as in the past. It is configured to automatically and continuously bend the flexible wiring board instead of mechanically, allowing the repeated bending work of flexible wiring boards to be performed continuously under a constant load and at a constant speed. It is possible to perform reliable tests with high accuracy by reducing data variations.

[Brief explanation of drawings]

FIGS. 1(a) and (b) are explanatory diagrams showing a bending test method for a flexible wiring board according to the present invention, and FIGS. 2(a) and (b)
is an explanatory diagram showing a conventional bending test method. 10... Flexible wiring board 11... Bending test machine 12... Fixed wing 13... Movable wing

Claims (1)

[Claims] 1. One half of the flexible wiring board is mounted and fixed on a fixed wing, and the other half is bonded and fixed to a movable wing that is disposed facing the fixed wing at a constant distance and is attached to be openable and closable. A constant current is applied to the conductor of the flexible wiring board while repeatedly bending the flexible wiring board at a bending angle of 0° to 180° as the flexible wiring board opens and closes.
A bending resistance test method for a flexible wiring board, characterized by detecting an increase in resistance of a conductor of the flexible wiring board.