JPH10340762A - Connecting device for flexible printed wiring and connecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible printed wiring and a connecting device, wherein thinning of form can be realized and effects of external noise and fluctuation of a reference potential can be suppressed. SOLUTION: In this connecting device for a flexible printed wiring, a flexible printed wiring F made up such that a wiring layer 11 is provided on one surface of an insulation support layer 12 having flexibility, that a conductor layer 14 is provided on the other surface thereof, and further that insulation layers 14, 14 are coveringly provided thereon, is freely detachable from a connector C fixed on a substrate K, so that electrical connection and mechanical fixation thereto can be conducted. In this event, either the wiring layer 11 or the conductor layer 14 is shortened, so as to run along the longitudinal direction and exposed such that conductor surfaces are positioned to be flush with in fore and behind relation, and a total height H of the connector from a surface of the substrate made low, when the flexible printed wiring F is inserted into the connector C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for connecting a flexible printed wiring, and more particularly to an electric circuit which is required to be as thin as possible, such as a flat panel display, an ink jet recording head and a thermal head. Flexible printed wiring (hereinafter, referred to as a flat cable F) in a device and a connection device used for the same (hereinafter, referred to as a flat cable connector C)
It is about.

[0002]

2. Description of the Related Art Conventional flat cables and flat cable connectors include, for example, Japanese Patent Publication No. 7-5260.
7 publication.

Referring to the drawings, the structure of a conventional single-sided contact cable will be described with reference to FIGS. 5 (a), 5 (b), 5 (e) and 5 (e).
(F) shows the configuration of the flat cable F, and FIGS. 5 (c), (g), (d), and (h) show the structure of the connector C, respectively.

In FIG. 5, reference numeral 51 denotes a signal contact portion;
Is a reinforcing material, 53 is an insulating material, 54 is a shield surface, and 55 is a shield contact portion. 56 is a groove, 57 is a signal contact part, 58 is a signal solder part, 59 is a shield contact part, and 510 is a shield solder part.

[0005] The thus constructed flat cable F
In order to actually connect using the flat cable connector C, the flacket cable F is inserted into the groove 56 of the connector C and connected to a printed circuit board (not shown), Signals flow through the cable conductors through 57. At the same time, the shield surface 54 is connected to the ground via the shield contact portions 55 and 59, and the shield surface is configured to be connected to the ground via the shortest distance by surface contact.

As a double-sided contact type, a configuration shown in a cross-sectional view of a main part of a flat cable F and a flat cable connector C shown in FIG. 6 is known.

That is, in this figure, 61 is a signal contact portion, 62 is a reinforcing material, 63 is an insulating material, 64 is a shield surface,
65 is a shield contact part. 66 is a groove, 67 is a signal contact part, 68 is a signal solder part, 69 is a shield contact part, and 610 is a shield solder part.

This double-sided contact type is different from the single-sided contact type in that the shield contact portion 6 is provided on the back surface of the reinforcing member 62 of the flacket cable F where the signal contact portion is provided.
5 is provided, and the shield contact portion 6 of the connector C is provided.
9 and the shield soldering portion 610 are provided on the surface facing the signal contact portion 67 and the signal soldering portion 68.

The thus constructed flat cable F
To actually connect the flat cable connector C, the blanket cable F is inserted into the groove 66 of the connector C and connected to the printed board K. As a result, a state is established in which a signal flows through the signal connection portions 61 and 67 to the conductor of the blanket cable F. At the same time, the shield surface 64 is connected to the ground by the shield contact portions 65 and 69, and the signal passing through the flacket cable F is shielded by the shield surface 64, and the shield surface is connected to the ground by the surface contact at the shortest distance. It is configured to be.

[0010]

However, in the case of a thin substrate on which a circuit for a recent liquid crystal driver is mounted, a sufficient ground installation surface for stabilizing transmission characteristics with an increase in operating frequency. Is required.
The flat cable F and the flat cable connector C are also required to be as thin as other surface mount components.

The flat cable F described with reference to FIG.
According to the configuration of the flat cable connector C, a thickness (height from the substrate K) of about 1.5 to 2.5 mm is possible, but one wiring 52 for the shield wiring is used as another signal wiring. In some cases, a ground called a guard is arranged between the signal lines.
There was a problem that the width dimension of the flat cable F became large.

In addition, since the electrical connection between the shield wiring and the ground potential is made through a small through hole or a point-like pressing contact surface, there is a possibility that the potential fluctuates and noise is generated. there were.

On the other hand, according to the configuration of the double-side contact type flat cable F and the flat cable connector C described with reference to FIG. 6, a sufficient ground installation area can be ensured. The thickness in the vertical direction (the height H from the substrate K) is 3 to 3.5 mm. For this reason, for example, there has been a problem that it is difficult to employ a liquid crystal substrate in a notebook personal computer or the like where it is important to reduce the thickness by a few millimeters.

Accordingly, the present invention has been made in view of the above-mentioned problems, and in a flat cable and a connector for a flat cable, it is possible to reduce the thickness and to reduce the influence of external noise and fluctuation of a reference potential. It is an object of the present invention to provide a flexible printed wiring and connection device that can be suppressed.

[0015]

Means for Solving the Problems The above-mentioned problems are solved,
In order to achieve the object, according to the present invention, a wiring group is provided on one surface of a flexible insulating support layer, and a conductor layer is provided on the other surface of the insulating support layer. A flexible printed wiring connection device in which a flexible printed wiring formed by providing an insulating layer on a conductor layer is detachably attached to perform electrical connection and mechanical fixing to a connector fixed on a substrate, Either the wiring layer or the conductor layer is shortened along the longitudinal direction of the flexible printed wiring, and the conductor surface of the wiring layer or the conductor layer is placed in the same plane along the longitudinal direction. And when the flexible printed wiring is inserted into the connector, the wiring layer or the conductor surface of the conductor layer is electrically connected and mechanically fixed. With the configuration as is, it is characterized in that to reduce the overall height of the connector from the substrate surface.

Further, a wiring group is provided on one surface of the flexible insulating support layer, and a conductor layer is provided on the other surface of the insulating support layer, and an insulating layer is formed on the wiring group and the conductor layer. A flexible printed wiring connection method in which a flexible printed wiring provided is detachably attached so as to perform electrical connection and mechanical fixing to a connector fixed on a substrate, and wherein the flexible printed wiring is provided on the wiring layer or the conductor layer. Either one is shortened along the longitudinal direction of the flexible printed wiring, and the conductive surface of the wiring layer or the conductive layer is exposed so as to be in the front-back relationship of the same plane along the longitudinal direction, When the flexible printed wiring is inserted into the connector, the conductive surface of the wiring layer or the conductive layer is electrically connected and mechanically fixed. , As well as reduce the overall height of the connector from the substrate surface, it is characterized by improving the noise immunity.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

First, FIG. 1 shows a configuration of a flat cable F and a flat cable connector C of a first embodiment. FIG. 1A is a plan view of the flat cable F viewed from the contact side. FIG. 1B is a fragmentary cutaway view of the flat cable connector C. FIG. 1A is also a cross-sectional view taken along the line AA in FIG.

In FIG. 1, the blanket cable F is
A connector contact portion 11a of the signal wiring layer 11 is formed on an insulating support layer 12, which usually uses a polyimide resin film. The signal wiring layer 11
Is protected by an insulating layer 13.

On the other hand, a conductive layer 14 is formed on one side surface of the support layer 12, and the conductive layer 14 is protected by an insulating layer 13.

With the above configuration, the conductive layer 14 is
1 shield layer.

In FIG. 1 (b), the connection for connecting electrically and mechanically to the connection portion 14a of the conductor layer 14 and the connection portion 11a of the wiring layer 11 is connected to the connector C for the blanket cable. Parts 17, 19 are provided as shown.

The connecting portion 17 is a lead pin 18 having elasticity.
And has a solder surface that can be surface-mounted at a portion protruding outward from the connector C, and is configured to be connected to the substrate K with solder.

The connection portion 19 of the conductor layer of the connector is formed into a curved surface, and is configured to obtain a contact pressure by providing elasticity.

Since the connecting portion 19 is for connecting the conductor layer 14 to the ground plane of the substrate, the pad 11 is used for surface mounting.
This is a structure processed to zero.

The retainer 111 is a fixing pressurizing member for the flaket cable F, and is formed of a nylon resin. The housing portion 112 of the connector is formed from a solder reflow heat-resistant resin.

In the above configuration, the actual signal path is
The signal on the substrate K is transferred to the signal line 1 via the lead pin 18.
7 and is sent to the wiring layer 11 of the blanket cable F. In the ground system, the ground of the conductor layer 14 is connected to the connector contact portion 19 from the blanket cable contact portion 14a.
And flows through the board joint surface 110 of the connector to the board ground.

As described above, by forming the joint surfaces of both the wiring layer 11 and the conductor layer 14 on the same plane side of the flacket cable F, the height of the contact parts 18 and 19 made of the elastic body on the connector side is increased. Since the thickness can be reduced to one side, a thinner structure can be achieved, and the ground conductor layer 14 can obtain a sufficient effect to realize stable transmission characteristics.

Next, FIG. 2 shows the configuration of a flat cable F and a flat cable connector C according to a second embodiment, and FIG. 2A is a plan view of the flat cable F viewed from the contact side. FIG. 2B is a fragmentary cutaway view of the flat cable connector C. FIG. 2A is also a sectional view taken along the line AA of FIG. 2B.

In this figure, the blanket cable F is
The connector contact portion 11a of the signal wiring layer 11 is formed so as to pass through the inside of the support layer 22 made of an insulator usually made of a polyimide resin film. The upper part of the signal wiring layer 11 is protected by the insulating layer 23.

On the other hand, a conductor layer 24 is formed on one side surface of the support layer 22, and the conductive layer 24 is protected by an insulating layer 23.

With the above configuration, the conductor layer 24 is formed on the wiring layer 1
1 shield layer.

In FIG. 2B, the connector C for the blanket cable has a connecting portion 25 of the conductor layer 24,
Connecting portions 27 and 29 for electrically and mechanically connecting to the ball-shaped portion of the connecting portion 11a of the wiring layer 11, respectively.
Are provided as shown.

The connecting portion 27 is a lead pin 28 having elasticity.
And has a solder surface that can be surface-mounted at a portion protruding outward from the connector C, and is configured to be connected to the substrate K with solder.

The connecting portion 29 of the conductor layer of the connector is formed into a curved surface, and is configured to obtain a contact pressure by providing elasticity.

Since the connecting portion 29 is for connecting the conductor layer 24 to the ground plane of the substrate, the pad 21 is used for surface mounting.
This is a structure processed to zero.

The above-mentioned ball-shaped portion is composed of conductive projections 21. Here, a plurality of bumps are formed. As a forming method, a through hole is formed in the support layer 22 so that the metal can be deposited by electroplating. Also, at this time, the same effect can be obtained by directly placing a solder ball and forming a bump (ball-shaped portion) by half-melting without providing the support layer 22.

In the above configuration, as shown in FIG. 2B, when the flacket cable F is connected to the connector C, the contact portion 27 is made flat, and the elasticity by the pressing members 213 and 214 instead of the retainer is used. It is configured to obtain a pressing force by deformation. According to this configuration, since a stable connection state can be obtained by elastic deformation between the layers of the blanket cable F, a further reduction in thickness can be realized because the retainer 111 in FIG. 1 can be omitted.

FIGS. 3A and 3B are cross-sectional views of the blanket cable F, in which the width of the conductor layer 34 is formed to be the same as the width of the wiring layer 31. FIG. .

FIG. 4 shows that the support layer 42 is formed by the conductor layer 44.
It is formed so as to cover the entire upper wiring layer 41 and is covered with the protective layer 43 so that the radiation noise reduction effect can be further obtained.

As described above, by employing the printed wiring board and the connection device of the present invention, the transmission characteristics are greatly improved. That is, by arranging the wiring layer and the conductor layer on the same plane at front and rear positions along the direction of insertion into the connector C, the configurations of the flat cable F and the flat cable connector C can be reduced in thickness, and the width can be reduced. An increase in size can be suppressed. Further, the shield wiring layers 14, 24, 3
4 does not need to be connected to the reference potential through a small through-hole as in the related art, and the fluctuation of the potential and the adverse effect of noise can be prevented. Furthermore, for wiring layers and conductor layers,
By providing the conductive protrusion, it is possible to achieve a reduction in thickness as compared with a metal spring material in a conventional contact.

By arranging the ground conductor layer to be wider, the fluctuation of the reference potential can be minimized.

Further, by employing a structure in which the wiring group 41 is surrounded by the conductors 44 as shown in FIG. 4, the above-described shielding effect can be further improved. Further, with the simple configuration as described above, the improvement of the reliability of the electric circuit device can be realized without causing a significant increase in cost.

According to each of the above embodiments, only the case where the conductor layer is provided below the support layer and the wiring layer is provided above the support layer has been described. However, the present invention is not limited to this. May be provided above the support layer, and the wiring layer may be provided below the support layer.

[0045]

As described above, according to the present invention, it is possible to provide a highly reliable flexible printed wiring and a connection structure thereof, which can realize a thin mounting and have no potential fluctuation and no adverse effect of noise.

[0046]

[Brief description of the drawings]

FIG. 1A is a plan view of a first embodiment of a flexible cable F and a connector C according to the present invention, and FIG.

2A is a plan view of a flexible cable F and a connector C according to a second embodiment of the present invention, and FIG.

FIG. 3 is a cross-sectional view of a flexible cable F according to the present invention.

FIG. 4 is a cross-sectional view of a flexible cable F according to the present invention.

FIG. 5 is a configuration diagram of a conventional flexible cable F and a connector C.

FIG. 6 is a sectional view of a main part of a conventional flexible cable F and a connector C.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Wiring layer (wiring group) 12 Support layer (insulating support layer) 13 Insulating layer 14 Conductive layer 14a Contact part 17 Contact part 19 Contact part F Flexible cable C Connector

Claims (12)

[Claims] 1. A wiring group is provided on one surface of a flexible insulating support layer, a conductor layer is provided on the other surface of the insulating support layer, and an insulating layer is coated on the wiring group and the conductor layer. A flexible printed wiring connection device in which a flexible printed wiring provided is detachably attached so as to perform electrical connection and mechanical fixing to a connector fixed on a substrate, wherein the connection layer of the wiring layer or the conductor layer is provided. Either one is shortened along the longitudinal direction of the flexible printed wiring, and the conductive surface of the wiring layer or the conductive layer is exposed so as to be in the front-back relationship of the same plane along the longitudinal direction, When the flexible printed circuit is inserted into the connector, the wiring layer or the conductor surface of the conductor layer is electrically connected and mechanically fixed. In connecting device of a flexible printed circuit, characterized in that to reduce the overall height of the connector from the substrate surface. 2. The flexible printed wiring connection device according to claim 1, wherein one or a plurality of conductive protrusions are formed from the wiring layer or the conductor layer with the insulating support layer interposed. . 3. The flexible printed wiring connection device according to claim 1, wherein the conductor layer has a width corresponding to the entire width of the wiring group. 4. The flexible printed wiring connection device according to claim 1, wherein the conductor layer is formed so as to surround the periphery of the wiring group. 5. The connector according to claim 1, wherein the connector further includes a retainer for fixing the flexible printed wiring in an immovable state after the flexible printed wiring is inserted, either integrally or as a separate part. Flexible printed wiring connection device. 6. The flexible printed wiring connection device according to claim 1, wherein the substrate is a substrate on which a liquid crystal driver circuit is surface-mounted, and a plurality of the connectors are mounted on an edge portion. 7. A wiring group is provided on one surface of a flexible insulating support layer, a conductor layer is provided on the other surface of the insulating support layer, and an insulating layer is formed on the wiring group and the conductor layer. A flexible printed wiring connection method in which a flexible printed wiring provided is detachably mounted so as to perform electrical connection and mechanical fixing to a connector fixed on a substrate, and wherein the flexible printed wiring comprises a wiring layer or a conductive layer. Either one is shortened along the longitudinal direction of the flexible printed wiring, and the conductive surface of the wiring layer or the conductive layer is exposed so as to be in the front-back relationship of the same plane along the longitudinal direction, When the flexible printed wiring is inserted into the connector, the wiring layer or the conductor surface of the conductor layer is configured so as to be electrically connected and mechanically fixed, A method of connecting a flexible printed wiring, wherein the overall height of the connector from the substrate surface is reduced and noise resistance is improved. 8. The flexible printed wiring connection method according to claim 7, wherein one or more conductive protrusions are formed from the wiring layer or the conductor layer with the insulating support layer interposed therebetween. . 9. The method according to claim 7, wherein the conductor layer has a width corresponding to the entire width of the wiring group. 10. The method according to claim 7, wherein the conductor layer is formed so as to surround the wiring group. 11. The connector according to claim 1, further comprising a retainer for fixing the flexible printed wiring in an immovable state after insertion of the flexible printed wiring, either integrally or as a separate component, and securely fixing the flexible printed wiring to the connector. The flexible printed wiring connection method according to claim 7, wherein 12. The flexible printed wiring connection method according to claim 7, wherein the substrate is a substrate on which a liquid crystal driver circuit is surface-mounted, and a plurality of the connectors are mounted on an edge portion.