JP3853566B2

JP3853566B2 - Connection method of printed wiring board and metal terminal

Info

Publication number: JP3853566B2
Application number: JP2000129986A
Authority: JP
Inventors: 一郎照沼
Original assignee: Fujikura Ltd
Current assignee: Fujikura Ltd
Priority date: 2000-04-28
Filing date: 2000-04-28
Publication date: 2006-12-06
Anticipated expiration: 2020-04-28
Also published as: JP2001313457A

Description

【０００１】
【発明の属する技術分野】
この発明は、可撓性樹脂フィルムを用いたプリント配線基板（以下単にＦＰＣという）と金属端子とを接続する方法に関する。
【０００２】
【従来の技術】
近年、自動車のパネルに装備された電装部品の接続部に、ＦＰＣを用いることが行われている。この場合、ワイヤハーネスの電線先端に取り付けられた金属端子をＦＰＣに接続するためには通常、ＦＰＣコネクタによる圧接接続が利用される（例えば特開平１０−１２３２８号公報参照）。或いはＦＰＣと金属端子の他の接続方法として、ピアッシング、半田付け等も用いられている。
【０００３】
【発明が解決しようとする課題】
しかし、ＦＰＣと金属端子を単にコネクタ等による圧接により接続する方法では、接触面積が小さく、且つ接触抵抗が大きいため、微小な電流回路にしか適用できない。例えば、１０Ａ程度以上の大電流回路では、十分な抵抗接続ができない。また、ピアッシングも信頼性が低く、やはり大電流回路には適用できない。半田を利用する方法は、ＰＥＴをベースとするＦＰＣに対してはフロー半田等による自動半田が適用できないため、量産に適しない。
【０００４】
これに対し、ＦＰＣと金属端子を超音波溶接機を用いて直接接合する方法もある。図５に示すように、ＦＰＣ１の端末の保護層１２で覆われていない導体配線１１を金属端子２に重ねて、超音波溶接機のアンビル５１とホーン（チップ）５２の間に挟み、ホーン５２に超音波振動を与える。これにより、金属端子２とＦＰＣ１を融着させることができる。
【０００５】
しかし、図５に示した従来の接続法では、ホーン５２とＦＰＣ１の樹脂フィルム１０が直接接触するため、樹脂フィルム１０に振動エネルギーの多くが吸収され、良好な接合が得られないという問題があった。また、樹脂フィルム１０が振動に伴う摩擦熱で溶融してホーン５２に付着するため、これを除去する保全作業が頻繁に必要になる。
【０００６】
この発明は、上記事情を考慮してなされたもので、大きな接合強度を得ることができるプリント配線基板と金属端子の接続方法を提供することを目的としている。
【０００７】
【課題を解決するための手段】
この発明は、可撓性樹脂フィルムを用いたプリント配線基板の導体配線に超音波溶接機を用いて金属端子を接続する方法であって、プリント配線基板を導体配線を外側にして折り畳んだ第１の折り畳み部を金属端子の先端部の第１の面に接触させ、前記第１の折り畳み部に続くプリント配線基板の部分について導体配線を外側にして折り畳んだ第２の折り畳み部を前記金属端子の第２の面に接触させ、これら第１の折り畳み部と第２の折り畳み部で前記金属端子を挟み込んだ部分を超音波溶接機のアンビルとホーンの間に挟んで超音波融着させることを特徴とする。
この発明においてより好ましくは、超音波融着に際して、第２の折り畳み部に連続する第３の折り畳み部を前記金属端子の先端面に接触させた状態とする。
【０００８】
この発明によると、プリント配線基板に導体配線が外側になるような二つの折り畳み部を作って、これらを金属端子の先端部の二つの面に接触させた状態で超音波溶接することにより、プリント配線基板と金属端子の間の引き剥がし強度が大きいものとなる。またこの発明の方法では、樹脂フィルムが直接ホーンやアンビルに接触することがなく、超音波溶接機の保守も容易になる。
【０００９】
【発明の実施の形態】
以下、図面を参照して、この発明の実施例を説明する。
図１は、この発明の実施例によるＦＰＣ１と電線３との間の接続構造を示している。この接続構造は、図６に示す通常の電線３，５の間の接続構造の一方の電線５の部分にＦＰＣ１を適用したものである。図１では、電線５に代わってＦＰＣ１が用いられているため、図６に示すような、電線５側の金属端子（端子金具）２のカシメ部２３及び導線を圧着する圧着部２４はなく、対応する部分は単なる平板部（舌片）２１となっている。しかし、端子金具２の先端部、即ち相手方の端子金具４が嵌合される嵌合部（筒状部）２２は、図１と図６とで同じである。これにより、図１においても、端子金具同士を嵌合を利用して接続する基本構造は、図６と同様としている。電線３側の端子金具４は、電線３の先端部に取り付けられるカシメ部４１と、電線３の先端導線を圧着する圧着部４２を有し、また他方の端子金具２の先端嵌合部２２に圧入される圧入部４３と先端接触部４４を有する。
【００１０】
図２は、ＦＰＣ１と端子金具２の接合構造を示している。ＦＰＣ１は、ＰＥＴ等のフレキシブル樹脂フィルム１０の上に、銅箔等による導体配線１１がパターン形成されている。配線１１の端子接続部以外は保護膜１２で覆われる。このＦＰＣ１の配線１１と端子金具２の平板部２１との間の接続には、超音波融着が用いられる。
【００１１】
図３は、その超音波融着による端子金具２の平板部２１とＦＰＣ１との接合法を具体的に示している。ＦＰＣ１の先端部を導体配線１１が外側になるように折り畳んだ第１の折り畳み部Ａを平板部２１の一方の面に接触させる。折り畳み部Ａに続くＦＰＣ１の部分は平板部２１の先端を回り込んで他方の面側に接触させ、この面でも導体配線１１が外側になるような第２の折り畳み部Ｂを作る。この様にして、二つの折り畳み部Ａ，Ｂにより平板部２１を挟み込んだ状態で、超音波溶接機のアンビル５１とホーン５２の間に配置し、超音波振動を与える。
【００１２】
このような手法で超音波融着を行うと、ＦＰＣ１は、端子金具２の平板部２１の両面に接合され、大きな引き剥がし強度、引張強度が得られる。しかもアンビルとホーンは直接ＦＰＣ１の樹脂フィルム１０には接触しないから、溶融した樹脂がアンビルやホーンに付着することがなく、付着するとしてもその量は少なく、従って超音波溶接機の保守は楽になる。
【００１３】
図４は、図３に比べてより好ましい融着の態様を示している。この場合、ＦＰＣ１の二つの折り畳み部Ａ，Ｂを平板部２１の両面に接触させると共に、更に折り畳み部Ｂに続く部分を平板部２１の先端面に接触させる。言い換えれば、第２の折り畳み部Ｂに連続する第３の折り畳み部Ｃが、平板部２１の先端面に重なった状態とする。
【００１４】
このような状態で超音波溶接を行うと、超音波振動は間接的に第３の折り畳み部Ｃにも伝わる。この結果、ＦＰＣ１は、平板部２１の上下面の他、先端面にも融着し、従ってより引き剥がし強度が大きい接合が得られる。
【００１５】
【発明の効果】
以上述べたようにこの発明によれば、超音波溶接によってプリント配線基板を金属端子の先端部に強固に接合することができ、プリント配線基板と金属端子の間の優れた電気的接続及び機械的接続が可能となる。
【図面の簡単な説明】
【図１】この発明の実施例によるＦＰＣと電線の接続構造を示す図である。
【図２】同実施例のＦＰＣと端子金具の接続法及び接続構造を示す図である。
【図３】同実施例によるＦＰＣと端子金具の接続法を示す図である。
【図４】他の実施例によるＦＰＣと端子金具の接続法を示す図である。
【図５】従来のＦＰＣと金属端子の接続法を示す図である。
【図６】従来の電線接続構造を示す図である。
【符号の説明】
１…ＦＰＣ、１０…フレキシブル樹脂フィルム、１１…導体配線、１２…保護層、２…端子金具、２１…平板部、２２…嵌合部。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of connecting a printed wiring board (hereinafter simply referred to as FPC) using a flexible resin film and a metal terminal.
[0002]
[Prior art]
In recent years, FPC is used for the connection part of the electrical component with which the panel of the motor vehicle was equipped. In this case, in order to connect the metal terminal attached to the wire tip of the wire harness to the FPC, a pressure connection by an FPC connector is usually used (see, for example, Japanese Patent Laid-Open No. 10-12328). Alternatively, piercing, soldering, or the like is used as another method for connecting the FPC and the metal terminal.
[0003]
[Problems to be solved by the invention]
However, the method in which the FPC and the metal terminal are simply connected by pressure contact using a connector or the like is applicable only to a minute current circuit because the contact area is small and the contact resistance is large. For example, in a large current circuit of about 10 A or more, sufficient resistance connection cannot be made. Piercing is also unreliable and cannot be applied to large current circuits. The method using solder is not suitable for mass production because automatic soldering such as flow soldering cannot be applied to an FPC based on PET.
[0004]
On the other hand, there is also a method of directly joining the FPC and the metal terminal using an ultrasonic welding machine. As shown in FIG. 5, the conductor wiring 11 that is not covered with the protective layer 12 of the terminal of the FPC 1 is overlapped with the metal terminal 2 and sandwiched between the anvil 51 and the horn (chip) 52 of the ultrasonic welding machine. Gives ultrasonic vibration. Thereby, the metal terminal 2 and the FPC 1 can be fused.
[0005]
However, in the conventional connection method shown in FIG. 5, since the horn 52 and the resin film 10 of the FPC 1 are in direct contact with each other, a lot of vibration energy is absorbed by the resin film 10 and a good bonding cannot be obtained. It was. Further, since the resin film 10 is melted by the frictional heat accompanying the vibration and adheres to the horn 52, maintenance work for removing the resin film 10 is frequently required.
[0006]
The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for connecting a printed wiring board and a metal terminal capable of obtaining a large bonding strength.
[0007]
[Means for Solving the Problems]
The present invention is a method of connecting a metal terminal to a conductor wiring of a printed wiring board using a flexible resin film by using an ultrasonic welding machine, wherein the printed wiring board is folded with the conductor wiring outside. A second folded portion of the metal terminal that is folded with the conductor wiring on the portion of the printed wiring board that follows the first folded portion is brought into contact with the first surface of the tip portion of the metal terminal. It is brought into contact with the second surface, and a portion in which the metal terminal is sandwiched between the first folded portion and the second folded portion is sandwiched between an anvil and a horn of an ultrasonic welder and is ultrasonically fused. And
More preferably, in the present invention, in ultrasonic welding, a third folded portion continuous with the second folded portion is brought into contact with the tip surface of the metal terminal.
[0008]
According to the present invention, the printed wiring board is formed with two folded portions such that the conductor wiring is on the outside, and is ultrasonically welded in a state where they are in contact with the two surfaces of the tip portion of the metal terminal. The peeling strength between the wiring board and the metal terminal is large. Further, according to the method of the present invention, the resin film does not directly contact the horn or anvil, and the maintenance of the ultrasonic welding machine is facilitated.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a connection structure between an FPC 1 and an electric wire 3 according to an embodiment of the present invention. In this connection structure, the FPC 1 is applied to one electric wire 5 portion of the connection structure between the normal electric wires 3 and 5 shown in FIG. In FIG. 1, since the FPC 1 is used in place of the electric wire 5, there is no crimping portion 24 for crimping the caulking portion 23 of the metal terminal (terminal fitting) 2 on the electric wire 5 side and the conducting wire as shown in FIG. The corresponding portion is a simple flat plate portion (tongue piece) 21. However, the front end portion of the terminal fitting 2, that is, the fitting portion (tubular portion) 22 into which the counterpart terminal fitting 4 is fitted is the same in FIGS. Thereby, also in FIG. 1, the basic structure which connects terminal metal fittings using fitting is the same as that of FIG. The terminal fitting 4 on the electric wire 3 side has a caulking portion 41 attached to the tip end portion of the electric wire 3 and a crimping portion 42 for crimping the tip conducting wire of the electric wire 3, and the tip fitting portion 22 of the other terminal fitting 2 A press-fit portion 43 to be press-fitted and a tip contact portion 44 are provided.
[0010]
FIG. 2 shows a joint structure between the FPC 1 and the terminal fitting 2. In the FPC 1, a conductor wiring 11 made of copper foil or the like is patterned on a flexible resin film 10 such as PET. Except for the terminal connection portion of the wiring 11, it is covered with a protective film 12. Ultrasonic fusion is used for connection between the wiring 11 of the FPC 1 and the flat plate portion 21 of the terminal fitting 2.
[0011]
FIG. 3 specifically shows a method of joining the flat plate portion 21 of the terminal fitting 2 and the FPC 1 by the ultrasonic fusion. A first folded portion A in which the front end portion of the FPC 1 is folded so that the conductor wiring 11 faces outside is brought into contact with one surface of the flat plate portion 21. The portion of the FPC 1 that follows the folding portion A wraps around the tip of the flat plate portion 21 and makes contact with the other surface side, and a second folding portion B is formed so that the conductor wiring 11 is also outside on this surface. In this manner, with the flat plate portion 21 being sandwiched between the two folding portions A and B, the flat plate portion 21 is disposed between the anvil 51 and the horn 52 of the ultrasonic welder to apply ultrasonic vibration.
[0012]
When ultrasonic fusion is performed by such a method, the FPC 1 is bonded to both surfaces of the flat plate portion 21 of the terminal fitting 2 and a large peeling strength and tensile strength are obtained. Moreover, since the anvil and the horn do not directly contact the resin film 10 of the FPC 1, the molten resin does not adhere to the anvil or the horn, and even if it adheres, the amount is small, and therefore the maintenance of the ultrasonic welder becomes easy. .
[0013]
FIG. 4 shows a more preferable fusion mode as compared with FIG. In this case, the two folded portions A and B of the FPC 1 are brought into contact with both surfaces of the flat plate portion 21, and further, the portion following the folded portion B is brought into contact with the front end surface of the flat plate portion 21. In other words, the third folding part C that is continuous with the second folding part B is in a state where it overlaps the front end surface of the flat plate part 21.
[0014]
When ultrasonic welding is performed in such a state, the ultrasonic vibration is also indirectly transmitted to the third folded portion C. As a result, the FPC 1 is fused not only to the upper and lower surfaces of the flat plate portion 21 but also to the distal end surface, and thus a bond with higher peeling strength can be obtained.
[0015]
【The invention's effect】
As described above, according to the present invention, the printed wiring board can be firmly joined to the tip of the metal terminal by ultrasonic welding, and the excellent electrical connection and mechanical between the printed wiring board and the metal terminal can be achieved. Connection is possible.
[Brief description of the drawings]
FIG. 1 is a diagram showing a connection structure between an FPC and an electric wire according to an embodiment of the present invention.
FIG. 2 is a view showing a connection method and a connection structure between the FPC and the terminal fitting of the same embodiment.
FIG. 3 is a view showing a method of connecting the FPC and the terminal fitting according to the embodiment.
FIG. 4 is a diagram showing a method of connecting an FPC and a terminal fitting according to another embodiment.
FIG. 5 is a diagram showing a conventional method of connecting an FPC and a metal terminal.
FIG. 6 is a diagram showing a conventional wire connection structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... FPC, 10 ... Flexible resin film, 11 ... Conductor wiring, 12 ... Protective layer, 2 ... Terminal metal fitting, 21 ... Flat plate part, 22 ... Fitting part.

Claims

A method of connecting a metal terminal to a conductor wiring of a printed wiring board using a flexible resin film using an ultrasonic welding machine,
A first folded portion obtained by folding the printed wiring board with the conductor wiring on the outside is brought into contact with the first surface of the tip portion of the metal terminal, and the conductor wiring is placed on the outer side of the printed wiring board following the first folded portion. The second folded portion folded in contact with the second surface of the metal terminal, and the portion where the metal terminal is sandwiched between the first folded portion and the second folded portion is an anvil of an ultrasonic welder. A method for connecting a printed wiring board and a metal terminal, characterized in that ultrasonic welding is performed between horns.

2. A printed wiring board and a metal terminal according to claim 1, wherein a third fold portion continuous with the second fold portion is brought into contact with a front end surface of the metal terminal at the time of ultrasonic fusion. Connection method.