JP2002141659A - Method for connecting flexible printed board to each other - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for mutual connection between flexible printed boards which can reduce the manufacture cost by securely connecting terminals of the flexible printed boards to each other. SOLUTION: Wires 16 and 26 are formed on insulating films 15 and 25 as the bases of FPC's 10 and 20, and a cover lay is formed on the insulating films 15 and 25 and wires 156 and 26 except parts which become the terminals 11 and 21 to manufacture the FPC's 10 and 20. After the terminal parts 11 and 21 of the FPC's 10 and 20 thus prepared are folded to the reverse surface sides of the insulating films 15 and 26, the wires 16 and 26 are brought into contact with each other. Further, temporary crimp contact processing is performed by pressing them from the sides of the insulating films 15 and 25. In this state, electrodes 9a and 9b of a series welding device (not illustrated) are made to abut from above the wires 16 and 26 of the respective terminal parts 11 and 21, and a specific voltage is applied to join the wires 16 and 26 together.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of connecting flexible printed circuit boards, and more particularly, to a method of connecting terminals of flexible printed circuit boards inexpensively and reliably. Connection method.

[0002]

2. Description of the Related Art In recent years, wire harnesses used in automobiles and the like have been used as much as
There is a growing movement to substitute rinted circuits (FPC). According to such a movement, for example, as shown in FIG.
In order to electrically connect the electronic control unit 301, the fuse box 302, and the like mounted inside the FPC 4 in place of the conventional circuit connection wire harness 500,
00 will be used more.

When the FPC is used for such a purpose,
Generally, for example, an FPC that is much larger in size than an FPC used in home electric appliances will be used. Normally, the FPC is manufactured by punching out an outer shape by using a die, and its size is restricted to a predetermined size. However, the FPC is used instead of the conventional circuit connection wire harness 500 as shown in FIG. In such a case, an FPC having a size larger than the current production limit FPC is required.

In this case, for example, as shown in FIG.
Several FPCs 401 to 40 each manufactured separately
4 and the FPC harnesses 405, 406, etc., are jointed to form one FPC 400 for use. Thus, the FPCs 401 to 40
In order to connect the FPC harnesses 405, 406 and the like to each other and to the FPCs 401 to 404, a method of connecting the FPCs 401 to 404 and the FPC harnesses 405, 406 using a dedicated connector (not shown) is generally used. It has been done. Note that the FP can be used without using a dedicated connector.
In order to connect C, for example, a method of caulking or removing FPC terminals is also being studied, but there are problems such as electrical connection reliability and durability, and there is still a full practical use. It seems to take time. Therefore, at this stage, it is necessary to rely on connection using a dedicated connection connector.

[0005]

However, in connection between FPCs by such a dedicated connector,
Since a dedicated connector (not shown) is required for each joint portion as shown in FIG. 10, the cost of connecting FPCs alone becomes enormous, and the manufacturing cost of an in-vehicle FPC or FPC harness There is a problem that there is a risk of causing an increase. Even if such a connection method that does not use a dedicated connection connector is adopted, there is a problem that connection reliability or the like may be lacking because connection technology has not yet been established, and it is difficult to adopt the connection method.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and inexpensively and securely connects terminals of a flexible printed circuit board, thereby increasing the cost of connecting the flexible printed circuit boards. It is an object of the present invention to provide a method for connecting flexible printed circuit boards, which can reduce the manufacturing cost.

[0007]

A method for connecting flexible printed circuit boards according to the present invention is a method for connecting flexible printed circuit boards each having a conductor wiring formed on an insulating film. The two flexible prints are arranged such that the conductor wiring at the terminal of the flexible printed circuit board and the conductor wiring at the terminal of the other flexible printed circuit board face each other, and the end faces of the respective terminal parts face in the same direction. The terminal portion of the substrate is bent so that the conductor wires facing each other are brought into close contact with each other, pressure is applied to the two terminal portions in a direction in which both are brought into close contact, and one electrode is brought into contact with the conductor wires of the one flexible printed circuit board. At the same time, the other electrode is brought into contact with the conductor wiring of the other flexible printed circuit board, and a predetermined voltage is applied between the contacted electrodes to make the respective conductor wirings adhered to each other a resistance. Joined by welding And wherein the Rukoto.

Further, a method for connecting flexible printed boards according to the present invention is a method for connecting flexible printed boards formed by forming conductor wiring on an insulating film,
The conductor wiring of the terminal part of one flexible printed board and the conductor wiring of the terminal part of the other flexible printed board face each other,
In addition, the terminal portions of the flexible printed circuit boards are bent so that the end surfaces of the terminal portions face in the same direction, and the facing conductor wirings are brought into close contact with each other, and both the horn and the anvil are sandwiched so as to sandwich the terminal portions. An ultrasonic wave of a predetermined frequency is output between the horn and the anvil while being in contact with the flexible printed circuit board, and the closely adhered conductor wirings are joined by ultrasonic welding.

According to the present invention, the terminals of the flexible printed circuit boards to be connected (hereinafter, referred to as "FPC" only in this paragraph) face the conductor wiring formed on each terminal, In addition, the conductor wires are bent so that the end surfaces of the respective terminal portions face in the same direction, and the facing conductor wires are brought into close contact with each other. The electrodes are brought into contact with each other, and a voltage is applied between the contacted electrodes, resistance welding is performed, and the closely adhered conductor wirings are joined together to form an FPC.
They are electrically connected to each other. Further, according to the present invention, the terminal portions of the respective FPCs to be connected face each other with the conductor wirings formed on the respective terminal portions facing each other, and are bent so that the end faces of the respective terminal portions face the same direction. The conductor wiring is brought into close contact with the horn and the anvil by contacting the horn and the anvil with both the FPCs so as to sandwich both ends, and ultrasonic waves are output between the contacted horn and the anvil to perform ultrasonic welding. The FPCs are joined together to electrically connect the FPCs. For this reason, components such as a dedicated connection connector, which are necessary for the conventional electrical connection between FPCs, become unnecessary, and the cost for connection can be greatly reduced. Further, since the respective conductor wirings of the FPC are joined by, for example, resistance welding or ultrasonic welding, it is possible to obtain extremely high connection reliability as compared with joining by a dedicated connection connector or the like.

[0010] If the terminal portions of the respective FPCs to be connected are bent at 90 ° or 180 ° so that the opposing conductor wires are joined to each other by, for example, resistance welding or ultrasonic welding, the FPCs can be connected more preferably. It is possible to do.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an upper perspective view of a terminal portion for explaining a method of connecting flexible printed circuit boards according to one embodiment of the present invention, FIG. 2 is a schematic side view showing a part of the terminal section, and FIG. 5 is a flowchart showing a connection process between flexible printed circuit boards.

As shown in FIG. 1, FPCs 10 and 20 to be connected to each other are made of, for example, polyethylene terephthalate (PET) or polyethylene naphthalate (PEN).
Wirings 16 and 26 made of a conductive pattern made of copper foil are formed on resin films 15 and 25 having insulating properties (hereinafter referred to as “insulating films”) made of the same. Cover lays 17 and 2 made of synthetic resin or the like having electrical insulation properties on the tops 16 and 26
7 is formed. In addition, FPC10,
20 on the insulating films 15, 25 of the terminal portions 11, 21;
The cover lays 17 and 27 are not formed on the wirings 16 and 26, and the wirings 16 and 26, which should be originally covered by the cover lays 17 and 27, are exposed at the respective terminal portions 11 and 21. It is in a state of being exposed, and is formed so that the wirings 16 and 26 of the FPCs 10 and 20 can be easily brought into direct contact with each other.

Hereinafter, the FPC 1 thus formed will be described.
A connection method between 0 and 20 will be described. First, sheets and the like constituting insulating films 15 and 25 serving as bases of FPCs 10 and 20 composed of PET or PEN are prepared and processed into a desired shape or the like (S1). Next, on the processed insulating films 15 and 25, wirings 16 and 26 made of a conductive pattern made of Cu or the like constituting the circuits of the FPCs 10 and 20 are formed by patterning, for example, by etching or the like. Then, coverlays 17 and 27 are formed on the insulating films 15 and 25 and the wirings 16 and 26 except for the portions that will become the FPCs 10 and 20 (S2). At this stage, the FPCs 10 and 20 in the state shown in FIG. 1 can be prepared. next,
Terminal 1 of FPCs 10 and 20 prepared in this way
1, 21 in the direction of the arrow in FIG.
After each bending to the lower side (-90 ° direction) (S
3) When the wires 16 and 26 are brought into contact with each other, the terminal 1
1 and 21 are in a state as shown in FIG. In this state, the wirings 16 and 2 of the respective terminal units 11 and 21 are
6, the contacted wires 16, 26 are further separated using, for example, crimping heads 19, 29 of a crimping device (not shown), as shown in FIG. Preliminary pressure bonding is performed by pressing each of the insulating films 15 and 25 (S4). Then, in this state, as shown in FIG.
26, for example, a series welding device (not shown)
Of the electrodes 9a, 9b, and the contacted electrodes 9a, 9b.
A predetermined voltage is applied during 9b to supply a large current having a capacity used for series welding. Then, due to the thermal energy generated by energization and the pressing force of the electrodes 9a and 9b, the copper of the wirings 16 and 26 is mutually diffused into the other layer, so that the wirings 16 and 26 that are in contact with each other are welded and joined (S
5) Connect the FPC 10 and the FPC 20 electrically and mechanically. By connecting the FPCs 10 and 20 in this manner, high connection reliability can be obtained, and an FP that does not require components such as a dedicated connection connector.
Since the connection between the Cs is possible, the cost related to the connection can be significantly reduced, and the increase in the manufacturing cost of the FPC can be suppressed.

In the above example, the FPCs 10, 20
Although connection using resistance welding has been described when connecting each other, the connection method is not particularly limited to this,
For example, connection by ultrasonic welding as shown in FIG. 4 may be performed. Hereinafter, the connection method by the ultrasonic welding will be described. The parts already described in the connection method by resistance welding are omitted.

In the method for connecting FPCs by ultrasonic welding, the steps up to step S3 are the same, but the subsequent steps are different. That is, each terminal unit 1
After bending the wires 21 and 21 to bring the wires 16 and 26 into contact with each other,
For example, a horn 50 of an ultrasonic welding device (not shown) is brought into contact with the lower surface side of the insulating film 15 of the terminal portion 11, and
The anvil 51 is brought into contact with the lower surface side of the insulating film 25 to output ultrasonic waves having a frequency of about 60 KHz to 120 KHz between the horn 50 and the anvil 51, and the contacted wirings 16 and 26 are joined together by ultrasonic welding. FP
C10 and FPC20 are electrically and mechanically connected.
For this reason, as in the case of the connection by resistance welding, high connection reliability can be obtained, and connection between FPCs that does not require components such as a dedicated connection connector becomes possible, and the connection cost is greatly reduced. It is possible to reduce the manufacturing cost of the FPC.

FIG. 5 is an upper perspective view of a terminal portion for explaining a method of connecting flexible printed circuit boards according to another embodiment of the present invention, and FIG. 6 is a schematic side view showing a part of the terminal portion in cross section. FIG. 7 and FIG. 7 are flowcharts showing a connection process between flexible printed circuit boards.

As shown in FIG. 5, the FPCs 30 and 40 to be connected to each other form wirings 36 and 46 made of a conductive pattern of copper foil on insulating films 35 and 45 made of PET, PEN or the like. These insulating films 3
5, 45 and wirings 36 and 46 are covered with coverlays 37 and 47 made of synthetic resin or the like having electrical insulation. In addition, on the insulating films 35 and 45 of the terminal parts 31 and 41 of the FPCs 30 and 40, and the wiring 3
The coverlays 37 and 47 are not formed on the bases 6 and 46, and the wirings 36 and 46, which should be originally covered by the coverlays 37 and 47, in the respective terminal portions 31 and 41.
Are exposed, and the FPCs 30, 40 can be easily
The wires 36 and 46 are formed so as to be able to directly contact each other.

Hereinafter, the FPC 3 thus formed will be described.
A connection method between 0 and 40 will be described. First, sheets and the like constituting insulating films 35 and 45 serving as bases of the FPCs 30 and 40 composed of PET or PEN are prepared and processed into a desired shape or the like (S10). Next, on the processed insulating films 35 and 45, wirings 36 and 46 made of a conductive pattern made of Cu or the like constituting the circuits of the FPCs 30 and 40 are formed by patterning, for example, by etching or the like. Then, coverlays 37 and 47 are formed on the insulating films 35 and 45 and the wirings 36 and 46 excluding the parts to become the FPCs 30 and 40 (S20). At this stage, the FPCs 30, 40 in the state shown in FIG. 5 can be prepared. Next, the terminal portions 31 and 41 of the FPCs 30 and 40 prepared as described above are placed in the direction of the arrow in FIG.
45 (the lower surface side -180 ° direction), and processing is performed so that the lower surfaces of the insulating films 35 and 45 face each other (S30), and the wires 36 and 46 of the terminal portions 31 and 41 are brought into contact with each other. The terminal units 31 and 41
The state is as shown in FIG. That is, the terminal portions 31 and 41 are connected to the wirings 36 and 46 by the insulating film 3.
The wires 36 and 46 are bent into a U-shape so that the wires 36 and 46 come into contact with the outside of the wires 5 and 45. After the wires 36 and 46 are brought into contact with each other, as shown in FIG. 2B, for example, the electrodes 9a and 9a of a series welding device (not shown) are used.
9b is contacted with the wirings 36 and 46 and the insulating film 3
The terminals 5 and 45 are brought into contact with the wirings 36 and 46 at opposite positions, and the electrodes 9a and 9b press the terminal portions 31 and 41 (S40). Then, in this state, the electrodes 9a, 9
b, a predetermined voltage for applying a large current having a capacity used for series welding is applied, and the heat energy generated by the application of the current and the pressure applied by the electrodes 9a and 9b are applied to the wiring 3.
The wirings 36 and 46 that were in contact with each other as the coppers 6 and 46 diffused into the other layer were welded together (S50), and the FP
The C30 and the FPC 40 are electrically and mechanically connected.
By connecting the FPCs 30 and 40 in this manner, an FP that does not require components such as a dedicated connector is required.
C can be connected to each other, so that the cost of connecting FPCs can be greatly reduced, and FPs used in automobiles and the like can be used.
It is possible to suppress an increase in the manufacturing cost of C.

In this example, the connection between the FPCs is described using the connection by resistance welding. However, the connection method is not particularly limited, and therefore, for example, the ultrasonic welding as shown in FIG. Connection may be performed.
Hereinafter, the connection method by the ultrasonic welding will be briefly described.

In this method of connecting FPCs by ultrasonic welding, the steps up to step S30 are the same, but the subsequent steps are different. That is, the respective terminal portions 31 and 41 are bent by 180 ° and the wirings 36 and 46 are bent.
After the contact, for example, the wiring 3 outside the terminal unit 31
The horn 50 of the ultrasonic welding device (not shown) is brought into contact with the horn 6, and the anvil 51 is brought into contact with the wiring 46 on the outside of the opposite terminal portion 41 (at a position facing the horn 50). Ultrasonic waves of about 60 KHz to 120 KHz are output between the horn 50 and the anvil 51, and the contacted wirings 36, 46 are joined together to form the FPC 30 and the FPC 40.
Are electrically and mechanically connected to each other. As a result, as in the case of the connection by resistance welding, high connection reliability can be obtained, and connection between FPCs that does not require components such as a dedicated connection connector becomes possible. Can be greatly reduced. Further, in the connection between the FPCs by ultrasonic welding in this example, since the horn 50 and the anvil 51 do not directly contact the insulating films 35, 45, the insulating films 3
Even if 5, 45 is melted during the ultrasonic welding operation, the possibility of adhering to horn 50 or anvil 51 is small, and a good connection process can be continuously performed.

[0021]

As described above, according to the present invention,
The terminals of the respective FPCs to be connected face each other with the conductor wires formed on the respective terminal portions facing each other, and are bent so that the end faces of the respective terminal portions face in the same direction so that the facing conductor wires are brought into close contact with each other. Apply pressure in the direction in which the two parts are in close contact with each other, contact the electrodes on the conductor wiring of each FPC with the pressure applied, apply a voltage between these contacted electrodes, and perform resistance welding to make contact. The FPCs are electrically connected by joining the conductor wirings thus formed. Further, according to the present invention, the terminal unit of each FPC to be connected is
The conductor wires formed on the respective terminal portions are opposed to each other, and the conductor wires are bent so that the end faces of the respective terminal portions face in the same direction, and the opposed conductor wires are brought into close contact with each other, and both the horn and the anvil are sandwiched between both terminals. An ultrasonic wave is output between the horn and the anvil contacted with the FPC and ultrasonic welding is performed between the horn and the anvil, thereby joining the closely adhered conductor wirings to form an F.
The PCs are electrically connected. For this reason, the conventional FPC
Since components such as a dedicated connector required for electrical connection between the components are not required, the cost for connection can be greatly reduced, and each conductor wiring of the FPC can be formed by, for example, resistance welding or superconducting. Since joining is performed by sonic welding, it is possible to obtain an effect that extremely high connection reliability can be obtained as compared with joining using a dedicated connection connector or the like.

[Brief description of the drawings]

FIG. 1 is a top perspective view of a terminal unit for explaining a method of connecting flexible printed circuit boards according to an embodiment of the present invention.

FIG. 2 is a schematic side view showing a part of a terminal section in a cross section for explaining the connection method.

FIG. 3 is a flowchart showing a connection process between the flexible printed circuit boards.

FIG. 4 is a schematic side view showing a cross section of a part of a terminal portion for explaining a method of connecting flexible printed circuit boards according to another embodiment of the present invention.

FIG. 5 is a top perspective view of a terminal unit for explaining a method of connecting flexible printed circuit boards according to still another embodiment of the present invention.

FIG. 6 is a schematic side view showing a part of a terminal section in a cross section for explaining the connection method.

FIG. 7 is a flowchart showing a connection process between the flexible printed circuit boards.

FIG. 8 is a schematic side view showing a part of a terminal section in cross section for explaining a method of connecting flexible printed circuit boards according to still another embodiment of the present invention.

FIG. 9 is an FP used for a dashboard of an automobile or the like.
It is an upper perspective view which shows C and a wire harness.

FIG. 10 is a diagram for explaining a joint structure of the FPC harness.

[Explanation of symbols]

10, 20, 30, 40 ... FPC, 11, 21, 31,
41 ... terminal part, 15, 25, 35, 45 ... insulating film, 16, 26, 36, 46 ... wiring, 17, 27, 3
7, 47 ... coverlay.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H01R 43/02 H01R 43/02 B // B23K 101: 38 B23K 101: 38 101: 42 101: 42 F term (reference) 4E067 AA07 BF00 DA13 DA17 EA04 EB00 5E051 LA02 LA04 LB05 5E085 BB09 CC03 DD03 DD04 HH11 HH13 JJ50 5E344 AA02 AA10 AA12 AA22 BB02 BB05 CC07 DD10 DD14 EE16 EE21

Claims (4)

[Claims] 1. A method for connecting flexible printed circuit boards, each having a conductive wiring formed on an insulating film, comprising: a conductive wiring at a terminal portion of one of the flexible printed boards; Face the conductor wiring of the terminal part of
In addition, the terminal portions of the two flexible printed circuit boards are bent so that the end surfaces of the respective terminal portions face in the same direction, and the opposed conductor wirings are brought into close contact with each other. An electrode in which one electrode is brought into contact with the conductor wiring of the one flexible printed board and the other electrode is brought into contact with the conductor wiring of the other flexible printed board. A method for connecting flexible printed circuit boards, wherein a predetermined voltage is applied between the conductive wirings and the conductor wirings that are brought into close contact with each other are joined by resistance welding. 2. A method of connecting flexible printed circuit boards each having a conductive wiring formed on an insulating film, wherein the conductive wiring at a terminal portion of one flexible printed circuit board and the other flexible printed circuit board are connected. Face the conductor wiring of the terminal part of
In addition, the terminal portions of the flexible printed circuit boards are bent so that the end surfaces of the terminal portions face in the same direction, and the facing conductor wirings are brought into close contact with each other, and the horn and the anvil are sandwiched so as to sandwich the terminal portions. A flexible printed circuit is produced by outputting ultrasonic waves of a predetermined frequency between the horn and the anvil and joining the closely adhered conductor wirings by ultrasonic welding. How to connect printed circuit boards. 3. The terminal portion of each of the flexible printed circuit boards is 9
The method for connecting flexible printed circuit boards according to claim 1 or 2, wherein the opposed conductor wirings are joined by being bent by 0 °. 4. The terminal portions of the two flexible printed circuit boards are
3. The method for connecting flexible printed circuit boards according to claim 1 or 2, wherein the opposed conductor wirings are joined by being bent by 80 [deg.].