JPS5941894A - Device for soldering flexible printed board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for soldering a flexible printed circuit board, which is suitable for soldering a flexible printed circuit board that is used after soldering and then folded.

BACKGROUND ART AND PROBLEMS Conventionally, when connecting a flexible printed circuit board (1) (hereinafter simply referred to as a flexible board) to a rigid printed circuit board (21 (hereinafter simply referred to as a rigid board)), as shown in FIG. ) (3) (4) is partially removed from the conductive pattern (51 ), and both conductive patterns (
I was soldering 5 bars and 6). However, when the flexible board (1) is bent and used as shown in Fig. 1B, the direction of arrow B in Fig. 1A is an angle, and when it is bent in the direction of the arrow, the soldering part of the flexible board (1) is bent. try Therefore, a large bending stress in the direction of peeling off the soldering is concentrated at point 0, which is the starting point of soldering.
I'l1l(7) may be removed from this 0 point. In order to prevent this, the areas of the soldered joints have been particularly widened or the angles of bending have been restricted, but these have been problematic due to restrictions on use.

Purpose of the Invention The present invention has been made in view of the above-mentioned circumstances, and its purpose is to prevent the soldering from bending in the direction in which the solder is to be peeled off, even if the soldering is used after the soldering is done. An object of the present invention is to provide a device for soldering a flexible printed circuit board that is strong, strong, and reliable, regardless of the cost.

SUMMARY OF THE INVENTION In order to achieve the above-mentioned objects, the present invention provides a flexible printed circuit board in which a conductive pattern of a desired shape is coated on an insulating sheet, and an insulating coating layer is further coated on top of the conductive pattern. At the same time, a portion of the insulating coating layer is removed so that the predetermined conductive pattern is exposed, and the exposed conductive pattern is soldered.

By having the above configuration, the soldered parts are connected by soldering, and even after being bent and used, the soldered parts are not bent in the direction of peeling off the solder, making them strong and reliable. This makes it possible to solder flexible printed circuit boards with high heat resistance.

EXAMPLE A first example of the present invention will be described below with reference to FIGS. 2A and 2B. In the description, the same reference numerals are used for the same functions as in FIGS. 1A and 1B described above.

The flexible substrate (1) includes an insulating sheet (9), an electrically conductive pattern (5) in the shape of an Fli-shaped material deposited on the insulating sheet (9), and an insulating coating layer (5) deposited thereon. The ends of the conductive patterns (5) are each bent into an L-shape and formed into a conductive pattern αQ having a required width. The insulating coating layer (:() on the pattern aω is
A circular recess a1) with a width of about 100 mm is formed, and a part of the conductive pattern (10) is exposed at the bottom of each of the recesses. In addition, a through hole ([4] having approximately the same diameter as the circular recess aυ is formed at a position adjacent to the four parts ([1)] of the octopus, a part of which is connected to the recess (l)).

The substrate (I3) of the partially rigid substrate (2) has conductive patterns (6) with the same pitch as the flexible substrate (1).
) is deposited on it, and an insulating coating layer (regis l-) (41) is deposited on it.The end of the conductive pattern (6) is connected to a wide conductive layer on the flexible substrate (1). It is bent on the same side as the pattern (10), and is formed into a wide conductive pattern A4 with a width slightly larger than the diameter of the through hole (121).An insulating coating layer of the required length is also formed at the end on the connection side. A recess (15) is formed where (4) has been completely removed, and a wide conductive pattern (
assets) are exposed.

In order to connect the two boards configured as described above, the flexible board (1) is placed on the rigid board (2), and both boards (1) (2+ conductive pattern + 51 (61) are polymerized and the flexible board The through hole (1) is positioned above the wide conductive back cover ([4]) of the rigid substrate (2).

In this way, the wide conductive pattern (101) of the flexible substrate (1) and the wide conductive pattern θLa- of the rigid substrate (2) are connected via the recess (1υ) and the through hole (121), so the recess (11) Both conductive patterns (10
) (1, 4) can be soldered with solder +16).

When the flexible substrate (1) connected in this way is bent in the inward direction, the flexible substrate (1) is a
It can be bent very softly around the axis. In other words, since the flexible substrate (1) is bent softly at the X-X line where the film layer is the smallest, the bending line X of the flexible substrate (1)
No force is applied to the other portions other than the vicinity of -X to force the bending.

Therefore, since the soldering part is not bent in the direction of peeling off the solder, the stress in the direction of peeling off the solder +161 is not concentrated at points D and E, which are the starting points of soldering, and is extremely strong and strong. It is. For example, it has been confirmed that if the width of each of the wide conductive patterns QOI (14) is 1.5 mm, there is no problem even if the conductive patterns are bent almost at right angles to the entrance direction.

Note that when the flexible board (1) is bent in direction B, the flexible board (1) is bent around the edge F of the rigid board (2) as an axis, and this bending direction is not the direction in which the solder is to be peeled off. In this case, there is no particular problem in terms of strength.

Next, a second embodiment of the present invention will be described based on FIGS. 3A and 3B.

As in the first embodiment, the flexible substrate (1) includes an insulating sheet (9), a conductive pattern (5) of a desired shape adhered on the insulating sheet (9), and a conductive pattern (5) adhered on this insulating sheet (9). A fourth part (I8) is formed by removing the required length of the insulating coating layer (3) at the end on the connection side. 1
8), the S-electrode pattern (5) is exposed. In the vicinity of the rectangular recess (181), through holes (1 round) are formed adjacent to the conductive pattern (5), and the centers of these through holes are aligned with straight lines that cross the flexible substrate (1) at almost right angles. It is arranged on Y-Y.

On the other hand, the rigid substrate (2) also has a conductive pattern (6) with the same pitch as the flexible substrate (1) on the substrate (13), and further has an insulating coating layer on it. (4) is adhered thereto.A recess (4) from which the insulation coating layer (4) of a required length has been removed is formed at the end on the connection side, and a guide pattern (6) is formed. is exposed.

To connect the side board (11 (2+) configured as described above, either the side board must be tilted down or one side, for example, a flexible board (
Dip the connection end of 1) in a solder bath and apply solder to the conductive pattern (51) in this part. Then, attach the side board (
1) (21 conductive pattern (51 (61) is polymerized, heated and pressure is applied, side substrate (1) (2+ is solder (
Connected by 21+.

When the flexible board (1) connected in this way is bent, the bending line connecting the centers of the through-holes (19) with the least amount of fillets and layers is formed in the flexible board (1), as in the first embodiment. Y-Y can be bent to il'llll.Therefore, as mentioned above, the flexible board (1) bent along this Y-Y line (except near the Y-Y line 11) Since no unreasonable force is applied to the soldering point Gζ, no bending stress is applied in the direction of peeling off the solder ■υ.

In the first and second embodiments described above, the through hole α
3(t!1 and the concave portion αυ are circular, but this shape is free, and may be, for example, an ellipse.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, the flexible substrate is provided with a negative through hole, and the flexible substrate can be bent softly around a straight line connecting the centers of the through holes, so that soldering is not possible. Even if the soldering part is bent at almost a right angle, the soldering part will not be bent in the direction of peeling off the solder. Therefore, in a flexible substrate connected in this way, the connection part is strong and strong regardless of the bending direction, and there is no fear that the solder will peel off, so that very high reliability can be guaranteed.

In addition, according to the present invention, the flexible substrate can be used in a nearly right-angled state without being limited to the bending corner layer as in the past, and there is no need to widen the area of the connection part as in the past. It is used to make full use of its original properties, and the space factor is improved. In addition, although it is flexible and lightweight, it is very easy to work with when processing and installing.

[Brief explanation of drawings]

The @1 person figure is a vertical cross-sectional view showing a conventional example in which a flexible board is connected to a rigid board, Figure 1B is a vertical cross-sectional view showing the state in which the flexible board shown in Figure 1A is bent and used, Figures 2A, and Fig. 2B shows the first embodiment of the present invention, Fig. 2A is a plan view of a flexible board connected to a rigid board, and Fig. 2B is a sectional view taken along the line ■-■ of Fig. 2A. , 3A, and 3B show a second embodiment of the present invention, where FIG. 3A is a plan view similar to FIG. 2A, and FIG. 3B shows a flexible substrate connected as shown in FIG. 6A. This is a vertical cross-sectional view shown folded. 4In the symbols used in the drawings, (1)...
...Flexible printed circuit board (3)...
......Insulating coating layer (5)001...
・・・・・・Conductive pattern (9)・・・・・・・・・
・・・・・・Insulation sheet (1ri0 success・・・・・・・・・
...Through hole (161 (2υ)......Solder. Agent: Masaru Ueya, Yoshio Tsune, Toshiki Sugiura, Figure 1A, Figure 2, Figure 1B, Figure 2A, So.

Claims (1)

[Claims] A conductive pattern of a desired shape is deposited on an insulating sheet, and a through hole is formed in a flexible printed circuit board formed by depositing an insulating coating layer on top of the conductive pattern, so that the predetermined conductive pattern is exposed. A device for soldering a flexible printed circuit board formed by removing a part of the above-mentioned insulating coating layer and soldering the exposed conductive pattern.