JPS63166286A - Flexible printed wiring - 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 Application of the Invention] This invention relates to flexible printed wiring boards (Flexib
le Pr1inted C1rcuit Board,
(hereinafter referred to as FPC board).

[Background of the invention] FPC boards can be bent and twisted, are thin and lightweight, have a larger surface area than rigid printed wiring boards, and can be used as an alternative to traditional wiring harnesses. They are used as electronic circuits in many devices, and demand for them is increasing.

Conventionally, various connection lands have been formed on an FPC board. This connection land is a connection area that is an opening in the coverlay of a connection pattern that is to be connected to other electrical components (IC5 resistors, capacitors, etc.) or that is electrically conductive to other PC boards. Consists of an exposed area. In recent years, there has been an increase in the number of connections, especially with ICs and other PC boards, which have connection terminals arranged in rows, and for this reason, FPC
There are also places where a plurality of plate connection lands are formed in a row.

Connecting lands in rows of FPC board and other parts or PC
Connection with the board is generally made with solder, conductive adhesive, etc., but what is required in this connection work is the flatness of the connection land area of the FPC board. This means that FP
The characteristics of the C board, that is, its ability to bend and return to its original position, conflict with each other, so the actual connection work involves holding the land area of the FPC board flat using a jig or the like, or taking the trouble to A backing plate was attached to the back side of the area, which caused major problems in terms of workability and cost. Also, if you use a jig during connection work,
Even if the connecting land area of the PC board is kept flat during connection work, the jig will be removed after the work, and the land area of the FPC board will be removed during other work or due to impact. The curvature of the connector may cause the joint to peel off, and a solution to this problem has been desired.

In addition, when the above-mentioned connection lands for connecting electrical components such as ICs are provided near the outer periphery of the FPC board, the creepage distance to the land becomes very small, resulting in poor insulation for electronic circuits. As a result, there was a problem in that electromagnetic interference was more likely to occur.

[Object of the invention] The object of the invention is to
An object of the present invention is to provide an improved FPC board that can maintain the flatness of the board portion and/or prevent noise from entering from solder connection lands.

[Summary of the invention] The improved FPC board according to the present invention has the following basic configurations:
The present invention is characterized in that a parallel wiring group is formed near a column-shaped connection land group and arranged substantially parallel to the land group. In the FPC board according to the present invention, due to the large number of parallel wiring groups in the connection land group, the bending rigidity of the FPC board at the installation position of the land becomes extremely large, and as a result, there is a risk that the flatness of the installation surface of the land will be impaired. As a result, the solder connection to the land can be reliably performed without failure, and peeling of the connected portion after connection can also be prevented.

[Embodiments of the invention] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing a wiring connection part in an embodiment of the FPC board according to the present invention. In the wiring connection part of the FPC board of this embodiment, a large number of solder connection lands 2 are arranged in two rows and arranged collectively on the FPC board bulge part 1 formed in the shape of an island or a peninsula. A large number of parallel wiring groups 3 and 4 are arranged in an annular or pseudo annular shape surrounding the solder connection land group. The parallel wiring groups 3 and 4 are portions 3a and 3b extending parallel to the rows of solder connection lands 2 on the bulge 1.

4a, and an extension 3c of the parallel wiring groups 3 and 4,
3d, 4b, and 4c extend over the constricted connecting portions 6 and 7 that connect the bulging portion 1 and the other FPC board portion 5. In the case of this embodiment, the FPC board portion on which the solder connection runt 2 is formed has a peninsula-like or island-like bulge portion 1 that protrudes from the other FPC board portion 5 (for example, the main circuit installation portion).
The parallel wiring groups 3 and 4 on the bulge 1 are arranged along the outer periphery of the bulge 1.

The connecting portions 6 and 7 are connected to opposite sides of the bulge 1, and the respective longitudinal axes of the connecting portions 6 and 7 are oriented in different directions.

FIG. 2 is a plan view of the portion shown in FIG. 1 viewed from the rear surface, and parallel wiring groups 3° and 4° are also arranged on this surface as shown.

The features of the FPC board of this embodiment having the structure as described above are listed below.

(i) Since the solder connection land 2 is surrounded by a large number of parallel wiring groups 33 and 4 in an almost annular shape, the solder connection land 2 is electromagnetically shielded by the parallel wiring groups 3 and 4; Noise can be prevented from entering the electronic circuit from the solder connection land 2. In addition, since the distance m (i.e., creepage distance) between the solder connection land 2 and the outer edge of the FPC board (i.e., the outer edge of the bulged portion 1) becomes longer, the insulation property of the solder connection land 2 is increased. As described above, it is possible to prevent noise from entering the electronic circuit, and the reliability of the electronic circuit is improved.

(if) Since the parallel wiring groups 3 and 4 are arranged in the vicinity of the solder connection land 2, the bending rigidity of the FPC board portion (that is, the bulged portion 1) where the solder connection land 2 is installed and The torsional rigidity is significantly increased, and therefore the flatness of the FPC board portion (especially important, no curvature in the land row direction)
The risk of damage to the FPC board is significantly reduced compared to conventional FPC boards. As a result, in the FPC board of this embodiment, the group of solder connection lands can be kept flat, so that each land can be soldered uniformly, preventing soldering failures and providing reliable soldering. It is possible to form a solder joint with high properties.

In addition, since the parallel wiring groups 3 and 4 are provided with portions 3a, 3b, and 4a that are parallel to the row of solder connection lands 2, the bending moment centered on the line x-X perpendicular to the row of solder connection lands 2 is On the other hand, the bulge 1 has extremely high rigidity, so even if some bending moment is applied to the bulge 1 during the soldering process, there is no risk that the bulge 1 will bend. As a result, uniform soldering can be performed on each solder connection land during the soldering process.

(fit) Since two connecting parts 6 and 7 whose longitudinal axes have different O's are connected to the bulging part 1, even if bending moments act on both connecting parts at the same time, the directions of both bending moments will be different. Since the angles are different, there is no risk that the bulged portion 1 will bend. That is, the connecting portion 6 is
and 7 are designed.

(iv) By arranging the parallel wiring group in the region directly behind the land portion on the back surface, the effects of (if) and (iii) above are further promoted.

In the illustrated embodiment, solder connection lands and parallel wiring groups 3 and 4 are provided on the bulge 1 that protrudes from other parts of the FPC board.
However, the solder connection land 2 and the parallel wiring groups 3 and 4 may be installed together with the main circuit on the main circuit mounting part of the FPC board without being provided on the bulge 1, or ,
Another circuit may be formed outside the parallel wiring groups 3 and 4.

[Effects of the Invention] As explained above, according to the present invention, the flatness of the solder connection land formation surface can be maintained, and the risk of noise intrusion from the solder connection land into the electronic circuit can be reduced. It is possible to provide an improved flexible printed wiring board.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a part of a flexible printed wiring board according to an embodiment of the present invention as seen from the front surface, and FIG. 2 is a plan view of the portion shown in FIG. 1 seen from the back surface. 1... Swelling part 2... Land for solder connection 3
．． 4...Parallel wiring group 5...Other parts of FPC board 6
．． 7...Connection part 212 trees Ta Ko Taira 1゛1 j-,,,J

Claims (1)

[Scope of Claims] 1. A group of connecting lands in which a plurality of connecting lands are aligned and arranged in at least one row, and a plurality of parallel connecting lands near the connecting land group and substantially parallel to the land group. A flexible printed wiring board characterized by having a group of wiring arranged thereon. 2. The flexible printed wiring board according to claim 1, wherein the parallel wiring group is arranged on both sides of the connection land group. 3. A group of connecting lands in which a plurality of connecting lands are aligned and arranged in at least one row on one side (front surface), and a plurality of connecting lands arranged approximately parallel to the group of connecting lands near the group of connecting lands. A first parallel wiring group of
1. A flexible printed wiring board, characterized in that a plurality of second parallel wiring groups are disposed on the rear side thereof, substantially directly behind the connection land group and substantially parallel to the connection land group. 4. The flexible printed wiring board according to claim 3, wherein the parallel wiring group is arranged on both sides of the connection land group. 5. A solder connection land group in which a plurality of connection lands are arranged in at least one row or more, and a large number of parallel solder connection lands arranged in an annular shape or a pseudo-annular shape surrounding the connection land group. A flexible printed wiring board comprising a wiring group, wherein the parallel wiring group has a portion extending parallel to the row of connection lands. 6. A connection land group in which a plurality of connection lands are aligned and arranged in at least one row, and a large number of parallel wiring groups arranged in a pseudo-annular shape surrounding the connection land group; The board portion on which the connection portion is provided is formed as an island-like or peninsula-like bulge that bulges out from the other board portion in plan, and the parallel wiring group is arranged along the periphery of the bulge, and the parallel wiring group has a portion extending parallel to the row of connection lands. 7. A connection land group in which a plurality of connection lands are arranged in at least one row or more, and a large number of parallel wiring groups arranged in a pseudo-annular shape surrounding the connection land group; The board portion on which the connection portion is provided is formed as an island-like or peninsula-like bulge that bulges out from the other board portion in plan, and the parallel wiring group is arranged along the periphery of the bulge and has a portion extending parallel to the row of connection lands, in which the bulge and other board portions are connected to each other. Connecting constricted joints project from opposite sides of the bulge, an extension of the parallel wiring group is formed on the joints, and the longitudinal axis of each joint is A flexible printed wiring board characterized by not being parallel to each other.