JP4776371B2 - FPC connection terminal and FPC and board connection structure - Google Patents

Description

The present invention relates to an FPC connection terminal for connecting an FPC (flexible printed wiring board) and a mother board such as a mounting board or a printed wiring board, and in particular, a press-fit connection method is applied to the connection with the board. The FPC connection terminal and the connection structure between the FPC and the substrate are related.

Conventionally, an FPC and a mother board (motherboard) are connected via an FPC connector. An example of connecting an FPC and a mother board using a conventional FPC connector is shown in FIG. This figure shows an example of a conventional general connection method, a through-hole connection method (FIG. 4A) and an SMT (surface mount) connection method (FIG. 4B).

The FPC connection connector 31 used in the through-hole connection method shown in FIG. 4A is connected by inserting a terminal into a through-hole 33 formed in the mother board 32 and soldering the tip. Further, the FPC connection connector 35 used in the SMT connection method shown in FIG. 4B is connected to the mother board 32 by soldering 36 on the surface of the mother board 32.

On the other hand, as shown in FIG. 5, the FPC 37 and the FPC connection connector 31 (35) are connected to the FPC 37 inserted in the FPC connection connector 31 (35) by a fixed portion provided in a housing (hereinafter referred to as HSG) 38. The circuit conductor (not shown) in the FPC and the terminal accommodated in the housing are connected and fixed by pressing at 39.

Patent Document 1 discloses a technique related to an FPC conversion adapter that connects a relay board and an FPC at a lead portion of a connector. A press fit is formed in the lead portion of the connector, and the lead portion is fixed to the through hole by the press fit. The FPC and the lead part are connected by soldering.

Moreover, in patent document 2, the technique which concerns on the connection terminal for flat cables which bent and integrated the terminal board part which provided the several crimp piece in the width direction, and the press-fit protrusion provided with the press-fit part at right angle. Is disclosed.

In the flat cable connection terminal, the press-fit protrusion is inserted into the through hole of the wiring circuit body, and the press-fit portion is brought into pressure contact with the conductive layer on the inner surface of the through hole. Further, the crimp piece is pierced into the conductor portion of the flat cable, and the tip portion of each crimp piece penetrating the flat cable is bent and secured to be connected to the flat conductor without using soldering.

Further, Patent Document 3 discloses a technique related to a press-fit connector that can prevent the jack terminal from coming off from the housing without using a jig or special parts when mounted on a circuit board.

Here, when the external connection terminal of the jack terminal protrudes downward from the bottom plate portion of the housing, when the external connection terminal is press-fitted into the press-fitting hole of the circuit board, the jack terminal is caused by the press-fitting repulsive force. The jack terminal is provided with a protrusion for preventing it from coming out upward.
JP 2004-192836 A JP 2003-187891 A JP 2002-110279

However, the above conventional techniques have the following problems.
The FPC connector currently in use requires fixing the HSG of the connector to the mother board by a method such as pressing or screwing to maintain the strength of the contact. There was also a problem that the height would increase.

In addition, since soldering is used for the connection portion between the FPC connector and the mother board, it is required to improve the heat resistance of the components, which increases the cost, and lead contained in the solder has an adverse effect on the environment. There was a problem of affecting.

In Patent Document 1, the relay substrate and the FPC are connected by the lead portion of the connector, and the connection portion of the lead portion and the FPC is soldered. The connection strength between the connector, the relay board, and the FPC is maintained by soldering, but there is the above problem because solder is used.

In Patent Document 2, as a method of connecting the terminal and the flat cable, a plurality of crimp pieces provided in the width direction of the terminal plate portion are pierced into the conductor portion of the flat cable, and the tip portion of each crimp piece penetrating the flat cable is bent. To prevent it from being removed. When this method is applied to an FPC instead of a flat cable, it is not necessary to perform soldering. However, the connection between the FPC and the crimp piece may be loosened due to vibration or temperature change, resulting in poor contact. It was.

Further, the technique disclosed in Patent Document 3 prevents the jack terminal from coming out of the housing, and is provided with a retaining protrusion so as to sandwich the bottom plate portion of the housing. Therefore, it cannot be applied to a technique that enables direct connection between the FPC and the board without using a conventional connector having a housing. Therefore, there is a problem that an installation space for the HSG is necessary and the height is increased.

Accordingly, the present invention has been made to solve these problems, and an object thereof is to provide an FPC connection terminal capable of directly connecting an FPC and a substrate and a connection structure between the FPC and the substrate.

According to a first aspect of the present invention, a terminal portion that is inserted into an FPC (flexible printed wiring board) and is electrically connected to a circuit conductor formed in the FPC, and a through hole formed in the substrate are press-fitted. An FPC connection terminal for electrically connecting the FPC and the substrate with a press-fit portion electrically connected to the through-hole, wherein the press-fit portion is in contact with the through-hole side wall. It has a substantially U-shape formed from two press-fit contact portions and a press-fit connection portion that connects one end of each of the two press-fit contact portions, and the terminal portion is formed of the two press-fit contact portions. It is formed extending from each of the other end, wherein the each of the two terminal portions, contacts for contacting with the upper and lower surfaces of the circuit conductors formed on the FPC, respectively A FPC connecting terminals, characterized in that provided in countercurrent.

According to a second aspect of the present invention, there is provided the FPC connection terminal, wherein the two press-fit contact portions are respectively formed with protrusions for making contact with the through holes.

According to a third aspect of the present invention, there is provided a connection structure between an FPC and a substrate, which includes an FPC and a substrate that is electrically connected to the FPC via an FPC connection terminal, and the FPC connection terminal includes the FPC. A terminal portion that is inserted into the FPC and electrically connected to a circuit conductor formed in the FPC; and a press-fit portion that is press-fitted into a through hole formed in the substrate and electrically connected to the through hole. The FPC and the substrate are electrically connected to each other, and the press-fit portion connects two press-fit contact portions that are in contact with the through-hole side walls and one end of each of the two press-fit contact portions. to a substantially U-shape formed of a press-fit connecting portion, the terminal portion being formed by extending from the other end of each of the two press-fit contact portion, each of said two terminal portions , It said are contacts for contacting with the upper and lower surfaces of the circuit conductors formed on the FPC is provided opposite each other across the two circuit conductors terminal portions formed in the FPC The FPC and the substrate are electrically connected by press-fitting the press-fit portion into the through-hole of the substrate, and the two terminal portions are mutually connected by press-fitting the press-fit portion. This is a connection structure between an FPC and a substrate, characterized in that a force is applied in the approaching direction.

In a fourth aspect of the present invention, plating is laid on the side wall of the through hole, and the two protrusions are formed so that the distance between the tips is longer than the inner diameter of the plating, and bite into the plating. This is a connection structure between the FPC and the substrate.

According to a fifth aspect of the present invention, the two terminal portions are inserted into two or more FPCs, and the contact is provided only at an insertion position in the FPC to be electrically connected. This is a connection structure between an FPC and a substrate.

As described above, according to the present invention, it is possible to provide an FPC connection terminal capable of directly connecting an FPC and a substrate and a connection structure between the FPC and the substrate. In particular, since the terminal part to be inserted into the FPC and the press-fit part to be press-fitted into the through hole of the board are formed in a straight line, a connector housing is not required, and the connection structure between the FPC and the board is reduced. It becomes possible.

In addition, since the press-fit part is press-fitted into the through hole after the terminal part is inserted with the FPC circuit conductor interposed therebetween, it is possible to prevent a decrease in contact load due to springback between the terminal part and the circuit conductor. There is an effect that the contact strength can be maintained.

Furthermore, it becomes possible to connect to FPCs arranged in a plurality of layers by appropriately selecting the length of the terminal portion and the position of the contact provided on the terminal portion.

In the FPC connection terminal of the present invention, since it is not necessary to use solder for connecting the FPC and the board, there is no problem of cost increase due to improvement in heat resistance of the components, and the problem of adverse environmental effects due to lead is solved. Can do.

The FPC connection terminal and the connection structure between the FPC and the substrate in a preferred embodiment of the present invention will be described in detail with reference to the drawings. In addition, about each structural part which has the same function, the same code | symbol is attached | subjected and shown for simplification of illustration and description.

FIG. 1 is a cross-sectional view showing a schematic configuration of the FPC connection terminal according to the first embodiment of the present invention. The FPC connection terminal 1 is composed of two terminal portions 2 and a press-fit portion 3, and can electrically connect the FPC 11 and the substrate 12 directly.

A circuit pattern is formed of a conductor on the FPC 11, and FIG. 1 shows a cross section of the circuit conductor 13. The two terminal portions 2 of the FPC connection terminal 1 are in contact with and sandwiching the circuit conductor 13 from the left and right, whereby the circuit conductor 13 and the terminal portion 2 are electrically connected. At that time, even if the insulating material covered in the circuit conductor in the FPC is contacted in a state where it has been removed in advance, the circuit conductor is broken while the material is broken by the pointed portion of the terminal portion 2. It doesn't matter if you put them in contact with each other.

In the FPC connection terminal 1 of the present embodiment, the contact 4 for contacting the upper surface and the lower surface of the circuit conductor 13 is provided facing each of the two terminal portions 2. By providing the contact 4, the contact area with the circuit conductor 13 can be increased, and the electrical contact between the terminal portion 2 and the circuit conductor 13 can be made good. Furthermore, this structure also exhibits the effect of increasing the fixing strength.

On the other hand, a through-hole 14 is formed in the substrate 12, and the press-fit portion 3 of the FPC connection terminal 1 is press-fitted into the through-hole 14, and the plating 15 formed on the side wall of the through-hole 14 and the press-fit portion. 3 is electrically connected.

A detailed cross-sectional view of the FPC connection terminal 1 of the present embodiment is shown in FIG. The press-fit portion 3 is formed of two press-fit contact portions 3a that are in contact with the side wall of the through hole 14 and a press-fit connection portion 3b that connects one end of each of the two press-fit contact portions 3a. It is substantially U-shaped. The two terminal portions 2 are formed to extend linearly from the other ends of the two press-fit contact portions 3a.

The FPC connection terminal 1 formed as described above is configured so that the two terminal portions 2 are pressed into contact with the circuit conductor 13 formed in the FPC 11 by press-fitting the press-fit portion 3 into the through hole 14. .

In this embodiment shown in FIG.1 and FIG.2, the protrusion part 5 is formed in the two press fit contact parts 3a, respectively. The protrusion 5 is in contact with the plating 15 formed on the side wall of the through hole 14 so as to be in contact therewith, thereby realizing a good electrical connection.

That is, the distance between the tips of the protrusions 5 provided on the two press-fit contact portions 3 a is formed to be longer than the inner diameter of the plating 15, and the press-fit portion 3 is press-fitted into the through hole 14. At this time, the tip portion of the protrusion 5 bites into the plating 15 (FIG. 1). The contact area between the protrusion 5 and the plating 15 is increased by causing the protrusion 5 to bite into the plating 15, thereby realizing a good electrical connection.

The FPC connection terminal 1 of this embodiment can be manufactured by press-molding one metal plate. That is, the terminal portion 2 formed at both ends of the linear press-fit portion 3 is formed by press-molding a single metal plate, and is substantially perpendicular at positions corresponding to both ends of the press-fit connecting portion 3b. The FPC connection terminal 1 can be formed by bending. The FPC connection terminal 1 of the present embodiment can be easily manufactured as described above, and the manufacturing cost can be reduced.

A connection structure between the FPC of the present invention in which the FPC 11 and the substrate 12 are connected using the FPC connection terminal 1 of the present embodiment and the substrate will be described below. First, the terminal portion 2 of the FPC connection terminal 1 is inserted into the FPC 11 so as to sandwich the circuit conductor 13 formed on the FPC 11. The press-fit portion 3 is press-fitted into a through hole 14 formed in the substrate 12. When the press-fit portion 3 is press-fitted into the through-hole 14, a force that causes the two terminal portions 2 to approach each other is generated, and the circuit conductor 13 is press-contacted by this force.

As described above, in the FPC connection terminal 1 of the present embodiment, since the terminal portion 2 is provided on the extension of the press-fit contact portion 3a, the press-fit portion 3 is press-fitted into the through-hole 14, whereby the terminal portion 2 is provided. Can be brought into pressure contact with the circuit conductor 13. As a result, the contact strength between the terminal portion 2 and the circuit conductor 13 can be maintained, and in particular, the structure in which the interval between the two terminal portions 2 can be prevented from being widened by the spring back.

In order for the two terminal portions 2 to press the circuit conductor 13 with an appropriate strength, the distance between the two terminal portions 2 is preferably wider than the length of the press-fit connecting portion 3b and inserted into the FPC 11. By doing in this way, when the press fit part 3 is press-fitted into the through hole 14, it is pushed in the direction in which the interval between the two terminal parts 2 is narrowed. As a result, the two terminal portions 2 can press the circuit conductor 13 with appropriate strength.

FIG. 3 shows a schematic configuration of the FPC connection terminal according to the second embodiment of the present invention. The FPC connection terminal 21 of this embodiment is used to connect the FPC 23 in the second layer and the substrate 26. FIG. 3 shows an embodiment in which two FPCs 22 and 23 are connected to one substrate 26 using the FPC connection terminals 1 and 21, but three or more FPCs are similarly connected to the substrate. It is also easy to do so.

In the embodiment shown in FIG. 3, the two terminal portions 2 provided on the FPC connection terminal 21 are inserted into the two FPCs 22 and 23 and are electrically connected to the FPC 23 in the second layer. The contact 4 is provided only at the insertion position.

Since the FPC connection terminal of the present invention does not require a housing and the terminal portion 2 and the press-fit portion 3 are linearly coupled, it is easy to reduce the height of the connection structure including the FPC connection terminal. . For this reason, the FPC and the substrate can be connected in close proximity. As a result, as shown in FIG. 3, it becomes easy to stack two or more layers of FPC and connect them to the substrate, and it is possible to reduce the installation space of the FPC and the substrate and reduce the cost.

Note that the description in this embodiment shows an example of the FPC connection terminal and the connection method thereof according to the present invention, and the present invention is not limited to this. The detailed configuration and detailed operation of the FPC connection terminal and the connection method thereof in the present embodiment can be changed as appropriate without departing from the spirit of the present invention.

FIG. 1 is a cross-sectional view showing a schematic configuration of the FPC connection terminal according to the first embodiment of the present invention. FIG. 2 is a detailed cross-sectional view of the FPC connection terminal according to the first embodiment. FIG. 3 is a cross-sectional view showing a schematic configuration of the FPC connection terminal according to the second embodiment of the present invention. FIG. 4 is a cross-sectional view showing an example of a conventional FPC connector. 4A is a diagram for explaining a through-hole connection method, and FIG. 4B is a diagram for explaining an SMT (surface mounting) connection method. FIG. 5 is a diagram for explaining a conventional FPC connection example in which an FPC is inserted into an FPC connection connector and fixed.

Explanation of symbols

1, 21, 31, 35 ... FPC connection terminal 2 ... terminal part 3 ... press fit part 3a ... press fit contact part 3b ... press fit connecting part 4 ... contact 5 ..Protrusions 11, 22, 23, 37 ... FPC
12, 26 ... Substrate 13, 24, 25 ... Circuit conductors 14, 27, 33 ... Through hole 15 ... Plating 32 ... / Matrix substrate 34, 36 ... Soldering 38 ... Housing 39 ... fixed part

Claims (5)

A terminal portion that is inserted into an FPC (flexible printed wiring board) and is electrically connected to a circuit conductor formed in the FPC, and is press-fitted into a through-hole formed in the substrate to be electrically connected to the through-hole. An FPC connection terminal that electrically connects the FPC and the substrate with a press-fit portion that
The press-fit portion has a substantially U-shape formed by two press-fit contact portions that come into contact with the through-hole side walls, and a press-fit connection portion that connects one end of each of the two press-fit contact portions. ,
The terminal portion is formed extending from the other end of each of the two press-fit contact portions ,
Each of the two terminal portions is provided with contacts for making contact with the upper and lower surfaces of the circuit conductor formed on the FPC, respectively, so as to face each other . 2. The FPC connection terminal according to claim 1, wherein the two press-fit contact portions are each formed with a protrusion for making contact with the through hole. A connection structure between an FPC and a board that is electrically connected to the FPC via an FPC connection terminal. The FPC connection terminal is inserted into the FPC and formed in the FPC. A terminal portion that is electrically connected to the circuit conductor, and a press-fit portion that is press-fitted into a through hole formed in the substrate and electrically connected to the through hole, and the FPC and the substrate Electrically connect
The press-fit portion has a substantially U-shape formed by two press-fit contact portions that come into contact with the through-hole side walls, and a press-fit connection portion that connects one end of each of the two press-fit contact portions. ,
The terminal portion is formed extending from the other end of each of the two press-fit contact portions, and each of the two terminal portions is brought into contact with an upper surface and a lower surface of a circuit conductor formed on the FPC. Contactors are provided opposite to each other,
The two terminal portions are inserted across a circuit conductor formed on the FPC, and the FPC and the substrate are electrically connected by press-fitting the press-fit portion into a through hole of the substrate,
A connection structure between an FPC and a substrate, wherein force is applied in a direction in which the two terminal portions are close to each other by press-fitting the press-fit portion. Plating is laid on the side wall of the through hole,
4. The FPC-substrate connection structure according to claim 3 , wherein the two protrusions are formed so that a distance between tips thereof is longer than an inner diameter of the plating and bite into the plating. 5. The said 2 terminal part is inserted in 2 or more FPC, The said contactor is provided only in the insertion position in FPC electrically connected, The Claim 3 or Claim 4 characterized by the above-mentioned. Connection structure of FPC and board.

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