JP2002134861A - Flexible wiring substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible wiring substrate which can have a narrow width by narrowing an array width of multipole lead patterns (4 and 5). SOLUTION: Front side lands (4a) and rear side lands (5a) of lead patterns (4 and 5) are arranged along the longitudinal direction of an insulating film base (11), so that the respective lands have the same number along the widthwise direction of the film base (11). Since the front and rear side lands (4a) and (5a) are arranged not in a zigzag form, any one of the lands (4a and 5a) will be arranged as not extruded in the widthwise direction, whereby an array width can be further narrowed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible wiring board used for electrical connection between a pair of connectors and having a multi-pole lead pattern.

[0002]

2. Description of the Related Art In an electric device, when a multi-pole connector mounted on a printed wiring board is electrically connected to each other and a plurality of circuit patterns on the printed wiring board are individually electrically connected, a strip-shaped and flexible strip is required. Flexible wiring boards (hereinafter, referred to as FPCs) are used.

As shown in FIG. 6, a conventional FPC 100 of this type has a plurality of lead patterns 102 printed on one surface of a flexible insulating film base 101 such as PET (polyethylene terephthalate). The plurality of lead patterns 102 are arranged at predetermined intervals in the width direction of the film base 101, and each is formed to extend along the longitudinal direction of the film base 101.

[0004] One lead pattern 102 includes a land portion 102a and a lead wire 102b drawn from the land portion 102a. On this lead pattern 102, a resist (not shown) is laminated except for the land portion 102a, and the adjacent lead patterns 102 are arranged on the film base 101 at a predetermined interval as described above. Insulated from each other.

The FPC 100 has an FPC as shown in FIG.
Connector for PC connection (hereinafter referred to as FPC connector) 1
02, and is electrically connected to a circuit pattern (not shown) of the printed wiring board 3 via the contact 122 of the FPC connector 102.

By the way, one FPC 100 has 20
A multi-pole lead pattern 102 such as poles (20 rows) or 30 poles (30 rows) is printed. However, in a multi-pole configuration, the width of the FPC 100 is correspondingly increased and the FPC 100 is connected. The lateral width of the FPC connector 102 (the width in the direction perpendicular to the paper surface in FIG. 7) also increases. As a result, the size of the FPC 102 connector increases, and the mounting area on the printed wiring board also increases.

[0007] To cope with this, the pitch between the lead patterns 102 has been narrowed and the width of the FPC 100 has been narrowed. However, at present, the pitch between the adjacent lead patterns is limited to 0.5 mm pitch. To further increase the pitch, an FPC 110 as shown in FIG. 8 has been developed.

This is because the land portions 112 of the lead patterns 112 and 113 formed on the film base 111
By arranging the FPCs 110a and 113a in a staggered manner in two rows before and after the FPC 110 in this manner, the pitch between the lead patterns can be reduced to substantially 0.3 mm pitch. If it is a pattern, it can be arranged with a width D that is approximately 1/2 of the conventional width.

[0009]

However, in the FPC 110 as shown in FIG. 8, the lead 112a of the land 112a on the front row is connected to the land 113 on the rear row.
In order to insulate them from each other between the land portions 113a on the rear row side, the land portions 112a on the front row side and the land portions 113a on the rear row side are arranged in a staggered manner in two rows before and after.

For this reason, even if the lands are arranged in two rows before and after, one land 112a (or 113a) protrudes to form a staggered shape, and is smaller than 1/2 of the arrangement width required for the same number of poles. , In FIG.
And the FPC connector 102 connecting the same to the FPC connector 102 is limited in the width and size.

In view of the above problems, an object of the present invention is to provide a flexible wiring board in which the arrangement width of a multi-pole lead pattern is reduced to make it narrower.

[0012]

In order to achieve the above object, a flexible wiring board according to the first aspect of the present invention comprises:
In a flexible wiring board in which a plurality of lands and a plurality of lead patterns each formed of a lead wire conducting to the lands are arranged at predetermined intervals in the width direction of the flexible insulating film base, the lead pattern extends along the longitudinal direction of the insulating film base. The same number of front lands and rear lands aligned on the front side and the rear side are arranged along the width direction of the insulating film base, respectively. It is characterized by being arranged insulated from the part.

The lands of the plurality of lead patterns are divided into front lands and rear lands, and the front lands and the rear lands are aligned along the longitudinal direction of the insulating film base. Of the land portions does not protrude in the width direction, and is １ ／ of that in the case where the land portions are arranged in one row.
The same number of read patterns can be arranged with an arrangement width of.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view partially showing an embodiment of a flexible printed circuit (FPC) according to the present invention,
FIG. 2 is an enlarged sectional view taken along line AA in FIG.

In FIGS. 1 and 2, reference numeral 11 denotes PET.
(Polyethylene terephthalate) or the like, and a plurality of lead patterns 4 and 5 are printed on the film base 11. The plurality of lead patterns 4 and 5 are arranged at predetermined intervals in the width direction of the film base 11, and the respective lead lines 4b and 5b are arranged rearward along the longitudinal direction of the film base 11 (FIG. 1). At the top).

Each of the lead patterns 4 and 5 has a land 4
a, 5a and a lead wire 4 electrically connected to the land portions 4a, 5a
b, 5b. On these lead patterns 4 and 5,
A resist (not shown) is laminated except for the land portions 4a and 5a serving as connection portions with the outside.

The plurality of lead patterns 4 and 5 include a lead pattern 4 having a front land portion 4a exposed at the front end side of the insulating film base 11 and a rear land portion at the rear side (upper side in the figure) of the front land portion 4a. The front land portion 4a and the rear land portion 5a behind the front land portion 4a are formed of two types of lead patterns 5 with the exposed 5a.
Are arranged along the longitudinal direction, that is, the front-back direction.

The same number of the front land portions 4a and the rear land portions 5a are arranged at a predetermined pitch along the width direction of the insulating film base 11, so that the adjacent lead patterns can be mutually connected. Insulated.

As shown in FIG. 2, the front land portion 4a
Each is led out to the back side of the film base 11 through a through hole 4c formed at the rear end thereof, and the back side is electrically connected to a lead wire 4b extending to the rear (left side in the drawing) of the film base 11. ing. Also, the rear side land portion 5a
Film base 11 on the film base 11 surface side
It is electrically connected to the lead wire 5b extending rearward.

As a result, the lead wire 4b conducting to the front land part 4a and the lead wire 5b conducting to the rear land part 5a are disposed on the front and back of the insulating film base 11 (in the thickness direction). The lead wire 4b connected to the lead wire 4a is insulated from the rear land portion 5a regardless of the arrangement of the lead wire 5b.

Thus, even if the front land portion 4a and the rear land portion 5a are aligned in the longitudinal direction of the insulating film base 11, the insulation between the lead patterns 4 and 5 is maintained, and one land is formed in a staggered manner. Since one of the parts 4a, 5a does not protrude to the side, the conventional FPC shown in FIG.
In comparison with 100, if the number of read patterns is the same, 1 /
With the width dimension of 2, and also in comparison with the conventional FPC 110 shown in FIG. 8, all the lead patterns can be arranged on the insulating film base 11 with the width dimension D reduced by δ.

As shown in FIG. 3, the FPC 1 configured as described above is inserted into and mounted on an FPC connector 2 (connector for FPC connection), and a circuit pattern (shown in FIG. )).

As shown in FIG. 3, the FPC connector 2 includes an insulating housing 21 mounted on the printed wiring board 3, contacts 40 and 50 symmetrically positioned and fixed in the insulating housing 21, Insulating cover 2 detachably attached to insulating housing 21
3 is provided.

Contact 4 in the insulating housing 21
Numerals 0 and 50 are formed by stamping conductive metal plates, respectively. Female contact portions 40a and 50a contacting lands 4a and 5a formed on FPC 1 and printed wiring board 3 respectively.
Leg 40 that is connected by soldering to a circuit pattern (not shown) on the surface of the substrate 3 with or without penetrating
b, 50b.

The female contact portions 40a and 50a are fixed in the insulating housing 21 so as to be elastically deformed in a direction orthogonal to the punching direction, and cut surfaces of the FPC 1 are inserted into the insulating housing 21 by elastic deformation. It comes into contact with and separates from.

The FPC connector 2 configured as described above
The FPC1 is inserted into the FPC insertion port 22 of the insulating housing 21.
Into the insulating cover 23 in the inserted state.
Is mounted in the insulating housing 21. When this FPC is inserted, the ceiling surface in the insulating housing 21 and the contact 4
There is a sufficient gap between the 0 and 50 female contact portions 40a and 50a to allow the FPC 1 to pass therethrough, and the FPC 1 can be inserted without receiving contact pressure from the female contact portions 40a and 50a.

When the insulating cover 23 is mounted in the insulating housing 21 after the FPC 1 is inserted, the back surface of the FPC 1 is pressed by the insulating cover 23, and the female contact portions 40a, 50a
After being elastically deformed in a direction away from the FPC 1 as indicated by a broken line in FIG. 3, the female contacts 40a, 50a (contacts 40, 5a)
0), the respective land portions 4a, 5a of the FPC 1 and the circuit patterns of the printed wiring board 3 are electrically connected.

FIGS. 4 and 5 are a plan view and a front view (FPC) showing the entire structure of the FPC connector 2 partially cut away.
Here, the FPC connector 2 as a component unit before mounting on the printed wiring board 3 (before mounting the FPC 1 of the present invention) is denoted by the same reference numeral, and the same parts as those in FIG. It is shown attached.

The FPC connector 2 has a lead pattern 4
5 is used for the FPC1 of the present invention having a multi-pole configuration having 20 poles (20 rows) or more.
As shown in FIG. 4 and FIG. 5, the same number of contacts 40 and 50 as 5 are mounted in two rows at equal intervals along the longitudinal direction.

In this case, as described above, the FPC 1
As compared with the conventional FPC 110 shown in FIG. 8, if the number of lead patterns is the same, the horizontal width can be shortened by one land width δ.
Also, the width can be reduced as compared with the conventional FPC connector to which the FPC 110 is connected.

For this reason, the FPC connector 2 is less likely to warp or vary in structure in the width direction, and can apply a uniform contact pressure to each of the lead patterns 4 and 5.
Contact failure does not occur. Further, the size of the connector 2 is further reduced, and the mounting area of the printed wiring board 3 is also reduced.

In the above embodiment, the front land 4
The lead wire 4b, which is electrically connected to the rear land portion 5a, is led out to the back side of the film base 11 through the through hole 4c.
However, if the overall width of the lead patterns 4 and 5 is shorter than the horizontal width D 'in which the lands 4a and 5a are staggered, the rear lands 5a are insulated from the rear lands 5a. The lead 4b may be wired between 5a.

[0034]

As described above, according to the present invention, the arrangement width of the multi-pole lead pattern is set such that the lands are staggered by two.
It can be made even narrower than in the case of arranging in a step.

As a result, the width of the flexible printed circuit board can be reduced, the width of the FPC connector connecting the flexible printed circuit board is also reduced, and warpage and structural variation in the width direction are less likely to occur. A uniform contact pressure can be applied to the pattern, and no poor contact occurs.

Further, since the size of the FPC connector itself is reduced, the mounting area of the printed wiring board is also reduced.

[Brief description of the drawings]

FIG. 1 is a plan view partially showing an embodiment of a flexible wiring board 1 according to the present invention;

FIG. 2 is an enlarged sectional view taken along line AA in FIG.

3 is a sectional view of an FPC connection connector 2 to which the FPC 1 shown in FIG. 1 is mounted.

FIG. 4 is a plan view partially cut away showing the entire configuration of the FPC connector 2 shown in FIG. 3;

FIG. 5 is a front view of the FPC connector 2;

FIG. 6 is a plan view partially showing a conventional flexible wiring board 100.

7 is a conventional flexible wiring board 100 shown in FIG.
FIG. 3 is a cross-sectional view of the FPC connection connector 102 to which is mounted.

FIG. 8 is a plan view partially showing a conventional flexible wiring board 110 in which a narrow pitch is achieved.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexible wiring board (FPC) 2 Connector for FPC connection (FPC connector) 4, 5 Lead pattern 4a Front land part 5a Rear land part 4b, 5b Leader 11 Flexible insulating film base

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5E317 AA07 AA24 BB03 BB11 CD34 GG14 5E338 AA02 AA12 AA16 BB02 BB13 BB25 BB75 CC01 CD11 CD32 CD40 EE23

Claims (1)

[Claims] A land part (4a, 5a) and a land part (4
a, a plurality of lead patterns (4, 5) comprising lead wires (4b, 5b) conducting to the flexible insulating film base (11) are arranged at predetermined intervals in the width direction of the flexible insulating film base (11). In the wiring board, the front land portion (4a) and the rear land portion (5a) aligned with the front end side and the rear side along the longitudinal direction of the insulating film base (11) are respectively connected to the insulating film base (11). A flexible wiring board, wherein the same number of the lead wires (4b) are arranged along the width direction, and the lead wires (4b) conducting to the front land portion (4a) are insulated from the rear land portion (5a).