JP6197342B2 - Cable connection structure - Google Patents

Description

  The present invention relates to a cable connection structure when a cable is connected to a base material by soldering.

  For example, a cable such as an FPC (Flexible Printed Circuits) cable having flexibility that can be bent is used to connect substrates such as a printed circuit board. It has been proposed that such a cable secures the strength of the cable itself by providing a reinforcing material as in Patent Document 1, for example.

JP-A-4-48677

  By the way, a cable may be connected to a base material by soldering. In that case, for example, an end portion of the cable is firmly fixed to the base material by soldering. However, it is also known that the soldered connection part is a relatively fragile part, such as having a mechanical strength, but being susceptible to cracking when stress is applied. For this reason, it is desirable to avoid concentrating all the stress generated between the cable and the board on the connection site.

However, the configuration in which the cable itself is reinforced as in Patent Document 1 described above has a problem that stress generated between the cable and the base material cannot be relaxed. In addition, in the case of Patent Document 1, there is a problem that the flexibility is lost by reinforcing the cable, and the stress is directly transmitted to the connection site. In other words, even if the strength against temporary work such as reinforcing and soldering the cable is secured, after that, it is necessary to connect to the connection site during the operation of the device containing the cable or during the work of incorporating the cable into the device. There is a possibility that stress is applied, and there is a possibility that the mechanical strength of the connection site is lowered.
The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent all of the stress generated between the cable and the base material from being directly transmitted to the connection part, and to connect the machine of the connection part. An object of the present invention is to provide a cable connection structure that reduces the risk of lowering the mechanical strength.

In invention of Claim 1, it has the elasticity for elastically deforming itself so that the connection site | part which solders a cable to the said base material may be enclosed , and the stress which arises between a cable and a base material is elastically deformed. A stress dispersing member for dispersing around the connection site was provided.
The stress generated between the cable and the base material may be caused by dynamic factors such as a change in the positional relationship with the base material due to the cable being placed on the movable part, or the cable is bent. It may be caused by static factors such as In this case, since the cable is fixed to the connection site by soldering, the amount of change is expected to increase as the distance from the stress distribution member increases, that is, from the connection site.
Therefore, by providing an elastic stress distribution member so as to surround the connection part , the stress generated between the cable and the base material is first consumed to elastically deform the stress distribution member around the connection part. The That is, since the stress generated between the cable and the base material is first dispersed around the connection site by the stress dispersion member, it is prevented from being directly transmitted to the connection site.

  In addition, as described above, the amount of change in the cable is expected to increase toward the outer edge side of the stress dispersion member. Get smaller. That is, the stress generated between the cable and the base material is dispersed around the connection site in order to elastically deform the stress dispersion member, and gradually decreases from the outside of the stress dispersion member. Therefore, the stress is finally transmitted to the connection site in a state where the absolute amount is reduced. In other words, the stress in the vicinity of the connection site (that is, the stress transmitted directly to the connection site) is smaller than that on the outer edge side of the stress dispersion member. Thereby, the possibility that the occurrence of cracks can be suppressed and the mechanical strength of the connection site can be reduced can be reduced.

According to the second aspect of the present invention, the stress dispersing member has adhesiveness for adhering the cable and the base material to each other, and elastically deforms while maintaining the adhesive state.
Generally, it is considered that the base material to which the cable is connected is often fixed in the apparatus. Therefore, when stress is applied to the connection site, it is expected that the stress is often generated by the movement of the cable relative to the base material. In that case, if the device is fixed and used, it is considered that the direction in which stress is applied is unlikely to change, but for example when the usage state changes like a portable device or a portable device. There is a possibility that the direction in which the stress is applied varies depending on the state of use. Therefore, by adhering the cable and the base material to each other, the stress can be consumed for elastic deformation regardless of the direction in which the stress is generated.

The invention according to claim 3 is characterized in that the stress dispersion member has lower rigidity than the base material. When the stress generated between the cable and the base material is distributed around the connection site, if the stress distribution member has higher rigidity than the base material, the stress is transmitted to the connection site without being distributed. End up. Therefore, by adopting a stress dispersion member having a lower rigidity than the base material, the stress generated between the cable and the base material can be dispersed around the connection site as described above.
In addition, by adopting a material having lower rigidity than the base material, the present invention can be applied to a base material other than a material that is relatively difficult to deform, such as a printed circuit board.

  In the invention according to claim 4, the stress distribution member is arranged in the play allowance located between the connection site and the end portion of the substrate. The connection part for soldering is generally provided at a certain distance from the end, not just at the end of the substrate, for reasons of manufacturing. Therefore, by disposing the stress dispersion member at the allowance between the connection site and the end portion of the base material, it is possible to prevent the base material from becoming unnecessarily large.

The figure which shows the cable connection structure by one Embodiment typically The figure which shows the conventional cable connection structure as a comparative example typically The figure which shows an example of the FPC cable to which the cable connection structure is applied The figure which shows the cable connection structure by other embodiment typically.

Hereinafter, a cable connection structure according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. In the following drawings, the size of each part is clearly shown for explanation, and the actual size is not necessarily shown.
FIG. 1A schematically shows the cable connection structure of the present embodiment, and is provided between the cable 1, the base material 2 for attaching the cable 1, and the cable 1 and the base material 2. A stress distribution member 3 is shown. In the present embodiment, a so-called FPC cable is adopted as the cable 1, and a so-called printed board made of glass epoxy is assumed as the base material 2.
The cable 1 is formed in such a manner that a plurality of wiring patterns are sandwiched between insulating coatings such as a polyimide film, and penetrates for inserting pins 4 provided on the base material 2 corresponding to each wiring pattern. A hole is provided. The cable 1 is soldered to the pins 4 with solder 5. This soldered portion corresponds to the connection portion 6. Further, the cable 1 is bonded to the base material 2 by a stress dispersing member 3.

The stress dispersion member 3 has elasticity for elastically deforming itself. Further, the stress distribution member 3 has adhesiveness for bonding the cable 1 and the base material 2. For this reason, the stress distribution member 3 of the present embodiment adheres the cable 1 and the substrate 2 to each other and elastically deforms while maintaining the adhesion state.
This stress distribution member is disposed between the connection portion 6 and the end portion of the base material 2 by utilizing a structural allowance 7 provided between the connection portion 6 and the end portion of the base material 2. ing. Further, the stress dispersion member 3 is formed of, for example, a resin material having lower rigidity than the base material 2 and functions as a double-sided tape. For this reason, the cable 1 and the base material 2 are bonded in a state of surface contact with each other. That is, the stress distribution member 3 of the present embodiment adheres almost the entire width of the cable 1 (FPC cable). In addition, you may employ | adopt the thing of the layer structure which pinched | interposed the elastic member with the adhesive tape as the stress distribution member 3. FIG.

Here, a conventional cable 1 connection structure will be described as a comparative example. As shown in FIG. 2, the conventional cable 1 connection structure does not include the stress distribution member 3. For this reason, when the cable 1 moves in the vertical direction as shown by the arrow A (that is, when the positional relationship between the cable 1 and the base material 2 changes), the cable 1 and the base material 2 are not connected. Stress (hereinafter simply referred to as “stress”) is generated, and the stress is concentrated on the neck portion 8 serving as an end portion (solder end) of the connection portion 6. Then, when the stress is concentrated, there is a risk that the mechanical strength of the connection portion 6 is lowered, such as a crack is generated in the neck portion 8.
On the other hand, in the case of the cable 1 connection structure of the present embodiment, the stress distribution member 3 is provided between the cable 1 and the substrate 2 as shown in FIG. And since this stress distribution member 3 has adhesiveness and elasticity, as shown in Drawing 1 (B), cable 1 is relative to base material 2 as shown by arrow B, for example. Even if the positional relationship is changed, the cable 1 and the base material 2 are elastically deformed while maintaining the adhesive state. That is, the generated stress is consumed for elastically deforming the stress dispersion member 3. Thereby, it can suppress that stress is transmitted to the connection part 6 directly.

Further, since the cable 1 is fixed to the connection portion 6 by soldering and is adhered to the base material 2 by the stress distribution member 3 in the periphery thereof, the cable 1 is outside the stress distribution member 3, that is, the connection portion 6. The amount of change with respect to the description increases as the distance from the position increases. In this case, the stress dispersion member 3 is greatly deformed on the outer edge side, while the deformation gradually decreases as the connection portion 6 is approached. That is, the force F1 consumed for elastic deformation at the outer edge of the stress dispersion member 3 is larger than the force F2 consumed on the connection site 6 side. In the present embodiment, the force F2 corresponds to a stress that is directly transmitted to the connection site 6.
As described above, the stress is greatly consumed on the outer edge side of the stress dispersion member 3, but the consumption gradually decreases as it approaches the connection part 6, so that the absolute amount of stress finally transmitted to the connection part 6 Decreases. Thereby, the possibility that the occurrence of cracks in the neck portion 8 and the like can be suppressed and the mechanical strength of the connection portion 6 can be reduced. At this time, since the rigidity of the stress distribution member 3 is lower than that of the base material 2, the stress is first consumed to deform the stress distribution member 6 having low rigidity and is distributed around the connection portion 6. become.

Here, the application of the cable connection structure of this embodiment will be described with illustrative of some.
FIG. 3 (A) shows an example of the application example, and the cable 1 is soldered to the base material 2 which is an auxiliary plate for attaching the connector 9 as shown in FIG. 3 (B). The cable 1 to which the connector 9 is soldered in this way is used as, for example, a wiring member for electrically connecting the rotation axes of the rotation axis of the robot. In this case, since the rotation axes of the robot rotate relative to each other, vibration is transmitted to the cable 1 due to dynamic factors such as vibration generated at that time, and the positional relationship between the cable 1 and the substrate 2 changes. Stress may occur.
Even in such a case, by providing the stress dispersion member 3, the stress applied to the connection portion 6 can be dispersed and relaxed. At this time, even if, for example, vibration is repeatedly applied and an environment in which stress is constantly generated is generated, the stress is dispersed by the stress dispersing member 3, so that the mechanical properties of the connection portion 6 are caused by so-called metal fatigue. It is also possible to reduce the risk of the strength being lowered. In addition, for example, what is accommodated in what is called a cable bear (trademark) and the cable 1 itself deform | transforms at the time of operation | movement etc. is assumed.

  In addition, during the operation of wiring such a cable 1 inside the robot, the stress applied to the connection site 6 can be dispersed and relaxed. Specifically, recent robots are required to be miniaturized, and space for wiring is also reduced. When wiring to such a robot, wiring is generally performed with the connector 9 attached. In that case, when the cable 1 with the connector 9 is inserted into a narrow space, the connector 9 may come into contact with an internal component or the like. That is, the cable 1 may not move but the positional relationship may change due to external factors such as contact on the connector 9 side. If the mechanical strength of the connection portion 6 is reduced due to an impact at the time of contact or the like, there is a risk of causing a malfunction of the robot, a reduction in life, or the like. Further, since the contact failure of the connector 9 is a failure that is relatively difficult to notice, there is a risk that man-hours may be unnecessarily taken for investigation of the cause. Such an assembly operation or an inspection operation can be dealt with by providing the stress dispersion member 3 to disperse and relax the stress applied to the connection site 6.

  Alternatively, the present invention is also applicable to devices such as a PLC (Programmable Logic Controller) and a handy POS (Point Of Sale) terminal that have a reduced wiring space for miniaturization. That is, when the cable 1 is bent and wired inside the POS terminal or the like, the stress generated by the cable 1 trying to extend straight (stress generated by the static factor described above) is applied to the connection portion 6. It will be. Even in such a case, the stress that is constantly generated by providing the stress dispersion member 3 can be dispersed around the connection portion 6. For example, even when vibration or the like is applied when the POS terminal is used, the connection part 6 can be protected from stress caused by the vibration. Furthermore, in the case of a POS terminal, the orientation may change depending on the usage state (used in a so-called “topless” state). In that case, although it is assumed that the direction of the stress changes, since the adhesive state is maintained between the cable 1 and the base material 2 by providing the stress dispersion member 3 with adhesiveness, Even if the stress is generated, the stress is consumed for elastically deforming the stress dispersion member 3. That is, the absolute amount of stress transmitted to the connection site 6 by the stress dispersing member 3 can be reduced regardless of the usage state of the device that accommodates the cable 1.

According to this embodiment described above, the following effects can be obtained.
A stress dispersion member 3 having elasticity for elastically deforming itself at least around the connection site 6 and for dispersing stress generated between the cable 1 and the base material 2 around the connection site 6 by elastic deformation. Since it is provided, the stress generated between the cable 1 and the base material 2 is first consumed for elastically deforming the stress dispersion member 3 around the connection site 6. Thereby, it can prevent that all the stress which arises between the cable 1 and the base material 2 is transmitted to the connection site | part 6 directly.
Moreover, since the stress distribution member 3 has adhesiveness, it elastically deforms while maintaining the adhesive state between the cable 1 and the base material 2. Specifically, when the cable 1 moves upward in the figure as shown in FIG. 1B, stress is consumed to extend the stress dispersing member 3, and when the cable 1 moves downward in the figure. Stress is consumed to compress the stress distribution member 3. Thus, by providing the stress dispersion member 3 with adhesiveness, the stress can be consumed for elastic deformation regardless of the direction in which the stress is generated. Therefore, the stress can be dispersed regardless of the usage state of the device that accommodates the cable 1 and the cable 1 being placed in the device (inside the housing) in any state. .

Further, by providing the stress distribution member 3, the stress generated between the cable 1 and the base material 2 is distributed around the connection portion 6 in order to elastically deform the stress distribution member 3, and the stress distribution is performed. The absolute amount that is gradually reduced from the outside of the member 3 and is finally transmitted to the connection portion 6 is reduced. In other words, the stress transmitted to the vicinity of the connection site 6 (that is, the stress transmitted directly to the connection site 6) is smaller than that on the outer edge side of the stress dispersion member 6. Therefore, it is possible to reduce the possibility that the mechanical strength of the connection site 6 is lowered, such as the generation of cracks can be suppressed.
Since the stress distribution member 3 is formed of a member having lower rigidity than the base material 2, when stress is generated, the stress is first consumed to deform the stress distribution member 6 having low rigidity. Therefore, the stress generated between the cable 1 and the base material 2 can be dispersed around the connection site 6. That is, the stress transmitted to the connection site 6 can be reduced.

Since the stress dispersion member 3 is disposed in the play allowance 7 provided between the connection portion 6 and the end portion of the base material 2, it is possible to prevent the base material 2 from being unnecessarily enlarged. An increase in manufacturing cost can be suppressed. As a result, an increase in the size of the device that accommodates the cable 1 can be prevented.
Since both the stress caused by the dynamic factor and the stress caused by the static factor can be dispersed and relaxed by the stress dispersing member 3, for example, the cable 1 is inserted in a narrow space with the connector 9 attached as shown in FIG. The stress can be relaxed even during assembly, and the quality of the product can be improved.
Of course, it is possible to relieve stress on the connection portion 6 during operation. In this case, even when the cable 1 is in a movable state during the operation of the apparatus and the stress is repeatedly generated and lost, the stress is distributed by the stress distribution member 3 so that the soldered connection portion 6 is obtained. It is possible to suppress the occurrence of metal fatigue. Therefore, the so-called life of the connection portion 6 can be extended, and as a result, the life of the product can be extended.

(Other embodiments)
The present invention is not limited to those exemplified in each embodiment, and can be modified or expanded as follows, for example.
In one embodiment, the stress distribution member 3 including the connection site 6 is provided. However, as shown in FIG. 4A, the stress distribution member 3 may be provided at a position not including the connection site 6. In FIG. 4A, for the sake of explanation, the stress distribution member 3 is given a certain thickness, but a thin one may be adopted to reduce the deformation of the cable 1.
In one embodiment, the mode of connecting the end portions of the cable 1 has been illustrated. However, as shown in FIG. 4B, the stress distribution member 3 may be provided when connecting the intermediate portion of the cable 1. Moreover, you may solder the edge part of the cable 1 extended in the inner side (illustration left) of the base material 2 instead of the edge part side (illustration right side) of the base material 2. FIG.

In the embodiment, the mode of soldering to the pins 4 is illustrated, but the present invention may be applied to the mode of soldering directly to the base material 2 as shown in FIG. Moreover, although FPC cable was illustrated in one Embodiment, you may apply to what is called an electric wire which coat | covered conducting wire with resin, enamel, etc., for example.
In one embodiment, a glass epoxy substrate is exemplified as the base material 2, but other materials may be used. Moreover, the base material 2 may have a deformable elasticity. In that case, the effect similar to one Embodiment can be acquired by making the stress dispersion | distribution member 3 into a thing lower in rigidity (a thing with a large elasticity) than the base material 2. FIG.
What is necessary is just to set the magnitude | size of the stress dispersion | distribution member according to the kind of cable, assumed stress, etc. FIG. For example, if the adhesion area of the stress dispersion member is increased, it is possible to cope with a larger stress. In addition, since the magnitude | size of the base material 2 will also become large if an adhesion area becomes large, you may set also considering manufacturing cost.
In the embodiment, the connection structure of the cable 1 is exemplified, but the cable 1 may be a target, for example, a surface mount type connector.

  In the drawings, 1 is a cable, 2 is a base material, 3 is a stress dispersion member, 6 is a connection site, and 7 is a play allowance.

Claims (4)

A cable connection structure for connecting a cable to a substrate by soldering,
It has elasticity for elastically deforming itself so as to surround a connection part for soldering the cable to the base material, and stress generated between the cable and the base material is elastically deformed to surround the connection part. A cable connection structure characterized in that a stress distribution member is provided for dispersion in the cable.   The cable connection structure according to claim 1, wherein the stress distribution member has adhesiveness for adhering the cable and the base material to each other, and elastically deforms while maintaining the adhesive state.   The cable connection structure according to claim 1, wherein the stress distribution member is formed of a material having lower rigidity than the base material.   The cable connection structure according to any one of claims 1 to 3, wherein the stress distribution member is disposed at a play allowance located between the connection site and an end of the base material.

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