JP2004031141A

JP2004031141A - Manufacturing method of flexible flat cable covered with shielding material

Info

Publication number: JP2004031141A
Application number: JP2002186211A
Authority: JP
Inventors: Hiroshi Yamanobe; 山野辺　寛; Tsutomu Komori; 小森　勉
Original assignee: Hitachi Cable Ltd
Current assignee: Hitachi Cable Ltd
Priority date: 2002-06-26
Filing date: 2002-06-26
Publication date: 2004-01-29
Anticipated expiration: 2022-06-26
Also published as: JP4066725B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a flexible flat cable covered with a shielding material with high bending reliability from which the shielding material hardly comes off. <P>SOLUTION: The flexible flat cable covered 2 with a shielding material 20 is manufactured by forming a conductor group 52 by arranging a plurality of flat conductors 51 in parallel with each other, and forming the flexible flat cable 10 by adhering and integrating insulation films 54, having an insulation adhesive layer 53, on upper and lower surfaces of the conductor group 52 while making the insulation adhesive layer 53 face inside, and adhering a shielding material 61 having conductive adhesive layers 64 at the upper and lower surfaces of the flat cable 10. A through-hole 15 is formed beforehand in a part immediately near the end of the conductor group 52 located at least at one side of the insulation film 54, immediately above at least one flat conductor 51, and the insulation films 54 are adhered to the upper and lower surfaces of the conductor group 52 to form the through-hole 15 at a grounding conductor part 25. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、シールド材被覆フレキシブルフラットケーブルの製造方法に係り、特に、シールド材被覆フレキシブルフラットケーブルの製造方法に関するものである。
【０００２】
【従来の技術】
図５，図６に示すように、フレキシブルフラットケーブル（以下、ＦＦＣと表す）５０は、厚みが約０．３ｍｍ以下の薄いテープ状のケーブルであり、１本〜数十本の導体５１を平行に配列してなる導体群５２の両面に、接着層５３を有する絶縁膜５４を貼り合わせると共に熱圧着してなるものである。
【０００３】
ここで、ＶＴＲ、ＣＤ又はＤＶＤプレーヤーなどのＡＶ機器、コピー機、スキャナ、プリンタなどのＯＡ・パソコン周辺機器、及びその他の電子・電気機器などにおいては、ノイズ防止の観点から、ＦＦＣ５０の両面にシールド材６１，６１を貼り合わせたシールド材被覆ＦＦＣ６０が用いられることが多い。
【０００４】
シールド材６１は、一般的に、最外層（基材（層厚：数μｍ〜数十μｍ））６２がＰＥＴなどの絶縁性プラスチックで、中層（層厚：数μｍ以下）６３がＣｕやＡｌなどの導電性金属で、最内層（層厚：数十μｍ）６４が導電性の接着剤で構成される。このシールド材６１と、導体５１の内、ＦＦＣ５０の表面に露出させた少なくとも１本の導体（図５，図６中では幅方向両端の導体５１ｇ，５１ｇ）の部分（接地導体部６５）とを電気的に接続することで、シールド効果が得られる。
【０００５】
ＦＦＣ５０は、耐屈曲性に優れていることから、電気・電子機器回路の可動部（屈曲部）配線に用いられることが多い。同様の理由で、シールド材被覆ＦＦＣ６０についても、同様の理由で可動部（屈曲部）配線に用いられる。
【０００６】
【発明が解決しようとする課題】
ところが、シールド材被覆ＦＦＣ６０は、接地導体部６５が片面側（図６中では上面側）だけに形成されていることから、層厚方向（図６中では上下方向）において非対称であり、ＦＦＣ５０と比較して屈曲信頼性が劣るという問題があった。また、接地導体部６５が長手方向全長に亘って、すなわちケーブル屈曲部にも形成されていることから、屈曲時に、接地導体部６５において接地導体部６５側のシールド材６１が剥離し易いという問題があった。
【０００７】
このため、シールド材被覆ＦＦＣ６０は、屈曲信頼性が低く、シールド材６１が剥離し易いという点を考慮して、ＡＶ機器、ＯＡ・パソコン周辺機器、及びその他の電子・電気機器の固定配線部や、曲げ半径が大きく、かつ、要求屈曲回数が数万回程度のスキャナ又はコピー機などにしか適用していないのが現状である。
【０００８】
以上の事情を考慮して創案された本発明の目的は、シールド材が剥がれにくく、屈曲信頼性が高いシールド材被覆フレキシブルフラットケーブルの製造方法を提供することにある。
【０００９】
【課題を解決するための手段】
上記目的を達成すべく本発明に係るシールド材被覆フレキシブルフラットケーブルの製造方法は、複数本の平角導体を平行に配列して導体群を形成し、その導体群の上下面それぞれに、絶縁性接着剤層を有する絶縁膜を接着剤層を内側にして貼り合わせると共に一体化してフレキシブルフラットケーブルを形成し、そのフラットケーブルの上下面に、導電性接着剤層を有するシールド材を貼り合わせてシールド材被覆フレキシブルフラットケーブルを製造する方法において、上記絶縁膜の少なくとも一方の導体群端部直近で、かつ、少なくとも１本の平角導体の直上部分に、予め貫通穴を形成しておき、その絶縁膜を、上記導体群の上下面それぞれに貼り合わせ、上記貫通穴を接地導体部に形成するものである。
【００１０】
また、複数本の平角導体を平行に配列して導体群を形成し、その導体群の上下面それぞれに、絶縁性接着剤層を有する絶縁膜を接着剤層を内側にして貼り合わせると共に一体化してフレキシブルフラットケーブルを形成し、そのフラットケーブルの上下面に、導電性接着剤層を有するシールド材を貼り合わせてシールド材被覆フレキシブルフラットケーブルを製造する方法において、上記フレキシブルフラットケーブルの少なくとも一方の導体群端部直近で、かつ、少なくとも１本の平角導体の直上部分に、レーザ加工を施して上記絶縁膜を除去すると共に平角導体を露出させ、その絶縁膜除去部分を接地導体部に形成するものである。
【００１１】
また、複数本の平角導体を平行に配列して導体群を形成し、その導体群の上下面それぞれに、絶縁性接着剤層を有する絶縁膜を接着剤層を内側にして貼り合わせると共に一体化してフレキシブルフラットケーブルを形成し、そのフラットケーブルの上下面に、導電性接着剤層を有するシールド材を貼り合わせてシールド材被覆フレキシブルフラットケーブルを製造する方法において、少なくとも一方の上記導体群端部を露出させて上記フレキシブルフラットケーブルを形成し、その後、その導体群露出部を覆うように、絶縁性接着剤層を有する第２絶縁膜を接着剤層を内側にして貼り合わせる際、第２絶縁膜の導体群端部直近で、かつ、少なくとも１本の平角導体の直上部分に、予め貫通穴を形成しておき、その貫通穴を接地導体部に形成するものである。
【００１２】
また、複数本の平角導体を平行に配列して導体群を形成し、その導体群の上下面それぞれに、絶縁性接着剤層を有する絶縁膜を接着剤層を内側にして貼り合わせると共に一体化してフレキシブルフラットケーブルを形成し、そのフラットケーブルの上下面に、導電性接着剤層を有するシールド材を貼り合わせてシールド材被覆フレキシブルフラットケーブルを製造する方法において、少なくとも一方の上記導体群端部を露出させて上記フレキシブルフラットケーブルを形成し、その後、その導体群露出部を覆うように、絶縁性接着剤層を有する第２絶縁膜を接着剤層を内側にして貼り合わせ、その第２絶縁膜の導体群端部直近で、かつ、少なくとも１本の平角導体の直上部分に、レーザ加工を施して上記絶縁膜を除去すると共に平角導体を露出させ、その絶縁膜除去部分を接地導体部に形成するものである。
【００１３】
具体的には、請求項５に示すように、上記接地導体部を、上記フレキシブルフラットケーブルの非屈曲部分に形成することが好ましい。
【００１４】
これによって、シールド材被覆フレキシブルフラットケーブルの、シールド材と平角導体との接地導体部が、ケーブルの長手方向における少なくとも一方の導体群端部直近、すなわち非可動部に形成されるため、屈曲時にシールド材が剥がれにくくなる。その結果、シールド材被覆フレキシブルフラットケーブルの可動部（屈曲部）においては、接地導体部がなくなり、シールド材とフレキシブルフラットケーブルとが完全な面接着となるため、屈曲信頼性が高くなる。
【００１５】
一方、本発明に係るシールド材被覆フレキシブルフラットケーブルは、上述した製造方法を用いて形成したものである。
【００１６】
これによって、シールド材が剥がれにくく、屈曲信頼性が高いシールド材被覆フレキシブルフラットケーブルが得られる。
【００１７】
【発明の実施の形態】
以下、本発明の好適一実施の形態を添付図面に基いて説明する。
【００１８】
（第１実施の形態）
第１〜第４の実施の形態に係るシールド材被覆フレキシブルフラットケーブルの製造方法を用いて形成したシールド材被覆ＦＦＣの平面図を図１に、図１の２ａ−２ａ線断面図を図２（ａ）に、図１の２ｂ−２ｂ線断面図を図２（ｂ）に、第１及び第２の実施の形態に係るシールド材被覆フレキシブルフラットケーブルの製造方法を用いて形成したＦＦＣの平面図を図３に示す。尚、図５及び図６と同様の部材には同じ符号を付しており、これらの部材については詳細な説明を省略する。
【００１９】
図１〜図３に示すように、第１の実施の形態に係るシールド材被覆フレキシブルフラットケーブルの製造方法は、先ず、複数本の平角導体５１を平行に配列して導体群５２を形成し、その導体群５２の上下面それぞれに、絶縁性接着剤層５３を有する絶縁膜５４を接着剤層５３を内側にして貼り合わせる。
【００２０】
この時、絶縁膜５４の長手方向における少なくとも一方（図３中では上下方向両方）の導体群端部（図３中では上下の両端部）直近で、かつ、少なくとも１本（図３中では２本）の平角導体５１の直上部分に、パンチ加工機などを用いた打ち抜き加工により予め貫通穴１５を形成しておく。この貫通穴１５を有する絶縁膜５４を、導体群５２の上下面それぞれに貼り合わせることで、各貫通穴１５が接地導体部２５となる。また、接地導体部２５、すなわち各貫通穴１５は、ＦＦＣ１０の非屈曲部分に形成することが好ましい。
【００２１】
次に、導体群５２及び絶縁膜５４，５４を熱圧着により一体化し、ＦＦＣ１０を形成する。
【００２２】
次に、そのＦＦＣ１０の上下面それぞれに、導電性接着剤層６４を有するシールド材６１を貼り合わせると共に、ＦＦＣ１０及びシールド材６１，６１を熱圧着により一体化することで、シールド材被覆ＦＦＣ２０が得られる。この一体化の際、シールド材６１の導電性接着剤層６４が各貫通穴１５内に入り込み、導電性接着剤層６４と、導体５１の内、ＦＦＣ１０の表面に露出させた少なくとも１本の導体（図１，図２中では幅方向両端の導体５１ｇ，５１ｇ）とが電気的に接続され、各貫通穴１５の部分において、シールド材６１と導体５１ｇ，５１ｇとが接地され、シールド効果が得られる。
【００２３】
貫通穴１５の形状は特に限定するものではなく、接地導体部２５として機能できる形状であればよい。
【００２４】
シールド材６１の最外層６２を構成する絶縁性プラスチックとしては、製造コストを考慮するとＰＥＴが好ましいが、シールド材６１に難燃性や耐熱性が要求される場合は、ＰＰＳ（ポリフェニレンサルファイド）が好ましい。
【００２５】
また、シールド材６１の中層６３を構成する導電性金属としては、箔状のもので中層６３を形成するのであればＣｕ、Ａｌを、蒸着又はペースト状のものを塗布することで中層６３を形成するのであればＡｇ、Ｎｉ、Ａｌが挙げられ、高い耐屈曲性が要求される場合には蒸着により中層６３を形成することが好ましい。
【００２６】
また、シールド材６１の最内層６４を構成する導電性接着剤は、樹脂だけで構成されるものではなく、ＮｉやＣなどの導電性のフィラー及び難燃剤を含んでいる。樹脂としては、例えば、熱可塑性ポリエステル系樹脂などが挙げられる。
【００２７】
本実施の形態に係る製造方法を用いて形成したシールド材被覆ＦＦＣ２０の、接地導体部２５は、導体群５２の片面側（図２（ｂ）中では上面側）だけに形成されており、接地導体部２５の配置構造は層厚方向（図２（ｂ）中では上下方向）において非対称である。しかし、この接地導体部２５は、シールド材被覆ＦＦＣ２０の長手方向における両端部直近、すなわち非可動部のみに形成しており、シールド材被覆ＦＦＣ２０の可動部（屈曲部）には形成していないことから、シールド材被覆ＦＦＣ２０の可動部（屈曲部）においては、シールド材６１，６１とＦＦＣ１０とが完全な面接着となり、高い屈曲信頼性が得られる。
【００２８】
また、接地導体部２５は、シールド材被覆ＦＦＣ２０の長手方向両端部の直近、つまりＦＦＣ１０の可動部ではない部分（非可動部）に形成されており、長手方向全長に亘って形成されるものではないため、シールド材被覆ＦＦＣ２０を屈曲させる時に、接地導体部２５において接地導体部２５側のシールド材６１が剥離するということは殆どない。
【００２９】
すなわち、シールド材被覆ＦＦＣ２０の屈曲時に、シールド材６１，６１が、具体的には接地導体部２５側のシールド材６１がＦＦＣ１０から剥離しにくくなり、シールド材被覆ＦＦＣ２０の屈曲信頼性が高まり、具体的には、屈曲寿命が約２倍以上に向上する。よって、ＡＶ機器、ＯＡ・パソコン周辺機器、及びその他の電子・電気機器の固定配線部や、曲げ半径が大きく、かつ、要求屈曲回数が数万回程度のスキャナ又はコピー機などだけではなく、高い耐屈曲性が要求される可動配線部にも、シールド材被覆ＦＦＣ２０を適用することが可能となる。
【００３０】
次に、本発明の他の実施の形態を添付図面に基いて説明する。
【００３１】
（第２実施の形態）
図１〜図３に示すように、第２の実施の形態に係るシールド材被覆フレキシブルフラットケーブルの製造方法は、先ず、複数本の平角導体５１を平行に配列して導体群５２を形成し、その導体群５２の上下面それぞれに、絶縁性接着剤層５３を有する絶縁膜５４を接着剤層５３を内側にして貼り合わせると共に、導体群５２及び絶縁膜５４，５４を熱圧着により一体化し、ＦＦＣ１０を形成する。
【００３２】
次に、ＦＦＣ１０における絶縁膜５４の長手方向の少なくとも一方（図３中では上下方向両方）の導体群端部（図３中では上下の両端部）直近で、かつ、少なくとも１本（図３中では２本）の平角導体５１の直上部分に、エキシマレーザやＹＡＧレーザによるレーザ加工を施して絶縁膜５４の一部を除去すると共に平角導体５１を露出させ、その絶縁膜除去部分（貫通穴１５）を接地導体部２５に形成する。接地導体部２５、すなわち各絶縁膜除去部分は、ＦＦＣ１０の非屈曲部分に形成することが好ましい。
【００３３】
次に、接地導体部２５を形成したＦＦＣ１０の上下面それぞれに、導電性接着剤層６４を有するシールド材６１を貼り合わせると共に、ＦＦＣ１０及びシールド材６１，６１を熱圧着により一体化することで、シールド材被覆ＦＦＣ２０が得られる。
【００３４】
以上、本実施の形態においても、第１の実施の形態と同様の作用効果が得られることは言うまでもない。
【００３５】
また、第１の実施の形態においては、絶縁膜５４の貼り合わせ前に、打ち抜き加工により貫通穴１５を形成しているため、貼り合わせ方によっては貫通穴１５と平角導体５１の位置がずれるおそれがあった。これに対して、本実施の形態においては、絶縁膜５４を貼り合わせた後に、レーザ加工によって平角導体５１の直上の位置に絶縁膜除去部分（貫通穴１５）を形成しているため、絶縁膜除去部分と平角導体５１の位置がずれるおそれがない。
【００３６】
（第３実施の形態）
第３及び第４の実施の形態に係るシールド材被覆フレキシブルフラットケーブルの製造方法を用いて形成したＦＦＣの平面図を図４に示す。尚、図３と同様の部材には同じ符号を付しており、これらの部材については詳細な説明を省略する。
【００３７】
図１、図２、図４に示すように、第３の実施の形態に係るシールド材被覆フレキシブルフラットケーブルの製造方法は、先ず、複数本の平角導体５１を平行に配列して導体群５２を形成し、その導体群５２の上下面それぞれに、絶縁性接着剤層５３を有する絶縁膜５４を接着剤層５３を内側にして貼り合わせると共に、導体群５２及び絶縁膜５４，５４を熱圧着により一体化し、第１ＦＦＣ４０ａを形成する。
【００３８】
次に、第１ＦＦＣ４０ａの長手方向の少なくとも一方（図４中では上下方向両方）の導体群端部近傍の、領域４１ａ，４１ｂに相当する部分の絶縁膜５４を除去し、導体群５２を露出させる。
【００３９】
次に、第１ＦＦＣ４０ａの導体群露出部、すなわち絶縁膜５４の一部を除去した部分である領域４１ａ，４１ｂを覆うように、絶縁性接着剤層を有する第２絶縁膜４４ａ，４４ｂを接着剤層を内側にして貼り合わせると共に、第１ＦＦＣ４０ａ及び第２絶縁膜４４ａ，４４ｂを熱圧着により一体化し、第２ＦＦＣ４０ｂを形成する。
【００４０】
この時、第２絶縁膜４４ａ，４４ｂの導体群端部直近で、かつ、少なくとも１本（図４中では２本）の平角導体５１の直上部分に、パンチ加工などにより予め貫通穴１５を形成しておく。この貫通穴１５を有する第２絶縁膜４４ａ，４４ｂを、領域４１ａ，４１ｂに貼り合わせることで、各貫通穴１５が接地導体部２５となる。接地導体部２５、すなわち各貫通穴１５は、第２ＦＦＣ４０ｂの非屈曲部分に形成することが好ましい。また、第２絶縁膜４４ａ，４４ｂを、領域４１ａ，４１ｂに貼り合わせる際は、第２絶縁膜４４ａ，４４ｂの一部が絶縁膜５４に重なるように貼り合わせる。また、第２絶縁膜４４ａ，４４ｂは、絶縁膜５４と同じものを適用することができる。
【００４１】
次に、その第２ＦＦＣ４０ｂの上下面それぞれに、導電性接着剤層６４を有するシールド材６１を貼り合わせると共に、第２ＦＦＣ４０ｂ及びシールド材６１，６１を熱圧着により一体化することで、シールド材被覆ＦＦＣ２０が得られる。
【００４２】
ここで、本実施の形態においては、予め貫通穴１５を形成しておいた第２絶縁膜４４ａ，４４ｂを、領域４１ａ，４１ｂに貼り合わせる場合について説明を行ったが、これに限定するものではなく、第２の実施の形態において説明したように、第２絶縁膜４４ａ，４４ｂを領域４１ａ，４１ｂに貼り合わせた後に、レーザ加工によって平角導体５１の直上の位置に絶縁膜除去部分（貫通穴１５）を形成するようにしてもよい。
【００４３】
以上、本実施の形態においても、第１及び第２の実施の形態と同様の作用効果が得られることは言うまでもない。
【００４４】
また、第１及び第２の実施の形態においては、可動部及び非可動部を、すなわち絶縁膜５４を長手方向に一体に形成していたため、シールド材被覆ＦＦＣ２０を屈曲させた時に、可動部の絶縁膜５４の屈曲が、非可動部の絶縁膜５４に波及するおそれがあった。これに対して、本実施の形態においては、第２ＦＦＣ４０ｂの接地導体部２５側の絶縁膜を、絶縁膜５４及び第２絶縁膜４４ａ，４４ｂで構成しており、長手方向に別体に形成しているため、接地導体部２５における接地導体部２５側のシールド材６１の接着信頼性がより高まる。その結果、シールド材被覆ＦＦＣ２０の屈曲信頼性がより高まり、シールド材６，６１がより剥離しにくくなる。
【００４５】
（第４実施の形態）
前実施の形態においては、導体群５２と絶縁膜５４，５４とを熱圧着により一体化した後、絶縁膜５４の一部を除去していた。
【００４６】
これに対して、第４の実施の形態に係るシールド材被覆フレキシブルフラットケーブルの製造方法は、導体群５２の上下面に、絶縁膜５４と、絶縁膜５４よりも長手方向長さが短い絶縁膜４５とを貼り合わせるものである。
【００４７】
具体的には、図１、図２、図４に示すように、先ず、複数本の平角導体５１を平行に配列して導体群５２を形成し、その導体群５２の上下面それぞれに、絶縁性接着剤層５３を有する絶縁膜４５，５４を接着剤層５３を内側にして貼り合わせる。この時、絶縁膜４５は、絶縁膜５４と比較して長手方向長さを短く形成しており、この貼り合わせによって、絶縁膜４５側において、長手方向の少なくとも一方（図４中では上下方向両方）の導体群５２の領域４１ａ，４１ｂに相当する部分が露出する。
【００４８】
その後、導体群５２及び絶縁膜４５，５４を熱圧着により一体化し、第１ＦＦＣ４０ｃを形成する。
【００４９】
次に、第１ＦＦＣ４０ｃの導体群露出部、すなわち絶縁膜４５側の領域４１ａ，４１ｂを覆うように、絶縁性接着剤層を有する第２絶縁膜４４ａ，４４ｂを接着剤層を内側にして貼り合わせると共に、第１ＦＦＣ４０ｃ及び第２絶縁膜４４ａ，４４ｂを熱圧着により一体化し、第２ＦＦＣ４０ｄを形成する。
【００５０】
この時、第２絶縁膜４４ａ，４４ｂの導体群端部直近で、かつ、少なくとも１本（図４中では２本）の平角導体５１の直上部分に、パンチ加工などにより予め貫通穴１５を形成しておく。この貫通穴１５を有する第２絶縁膜４４ａ，４４ｂを、領域４１ａ，４１ｂに貼り合わせることで、各貫通穴１５が接地導体部２５となる。また、接地導体部２５、すなわち各貫通穴１５は、第２ＦＦＣ４０ｄの非屈曲部分に形成することが好ましい。また、第２絶縁膜４４ａ，４４ｂを、領域４１ａ，４１ｂに貼り合わせる際は、第２絶縁膜４４ａ，４４ｂの一部が絶縁膜４５に重なるように貼り合わせる。また、第２絶縁膜４４ａ，４４ｂは、絶縁膜５４，４５と同じものを適用することができる。
【００５１】
次に、その第２ＦＦＣ４０ｄの上下面それぞれに、導電性接着剤層６４を有するシールド材６１を貼り合わせると共に、第２ＦＦＣ４０ｄ及びシールド材６１，６１を熱圧着により一体化することで、シールド材被覆ＦＦＣ２０が得られる。
【００５２】
以上、本実施の形態においても、第１〜第３の実施の形態と同様の作用効果が得られることは言うまでもない。
【００５３】
また、第３の実施の形態においては、第２ＦＦＣ４０ｂを形成するために、絶縁膜５４，５４を導体群５２の上下面に貼り合わる工程、領域４１ａ，４１ｂに相当する部分の絶縁膜５４を除去する工程、及び領域４１ａ，４１ｂを覆うように、絶縁性接着剤層を有する第２絶縁膜４４ａ，４４ｂを接着剤層を内側にして貼り合わせる工程の３つの工程を必要としていた。これに対して、本実施の形態においては、第２ＦＦＣ４０ｄを形成するために必要な工程は、絶縁膜５４，４５を導体群５２の上下面に貼り合わる工程、及び絶縁膜４５側の領域４１ａ，４１ｂを覆うように、絶縁性接着剤層を有する第２絶縁膜４４ａ，４４ｂを接着剤層を内側にして貼り合わせる工程の２つだけである。つまり、第２ＦＦＣ４０ｄの製造工程を少くすることができるため、その結果、シールド材被覆ＦＦＣ２０の生産性がより向上すると共に、製造コストの低減を図ることができる。
【００５４】
以上、本発明の実施の形態は、上述した実施の形態に限定されるものではなく、他にも種々のものが想定されることは言うまでもない。
【００５５】
【実施例】
次に、本発明について、実施例に基づいて説明するが、本発明はこれらの実施例に限定されるものではない。
【００５６】
（実施例１）
先ず、幅０．７ｍｍ、厚み５０μｍのＳｎめっき平角軟銅線を、ピッチ１ｍｍで１５本配列し、幅１６ｍｍの導体群を形成する。その導体群の上下面それぞれに、厚み２５μｍのＰＥＴフィルム上に、難燃性ポリエステル接着剤層（層厚：３５μｍ（アンカーコートの厚みを含む））を形成したＰＥＴ絶縁膜（膜厚５０μｍ）を、接着剤層を内側にして貼り合わせる。この時、ＰＥＴ絶縁膜における長手方向両端部直近には、幅方向両端の２本のＳｎめっき平角軟銅線の直上部分に、パンチ加工機により予め貫通穴を形成しておく。
【００５７】
その後、導体群及びＰＥＴ絶縁膜を熱圧着により一体化し、ＦＦＣを形成する。次に、そのＦＦＣの上下面それぞれに、厚み１２．５μｍのＰＥＴフィルム上に、順に厚み０．１μｍ未満のＡｌ蒸着層（導電性金属層）、厚み３０μｍで、Ｎｉフィラーを添加した難燃性ポリエステル接着剤層（層厚：３０μｍ（アンカーコートの厚みを含む））を形成したシールド材（膜厚約４２．５μｍ）を貼り合わせると共に、ＦＦＣ及びシールド材を熱圧着により一体化することで、シールド材被覆ＦＦＣを作製する。
【００５８】
（従来例１）
図５及び図６に示した構造を有している以外は、実施例１と同様にしてシールド材被覆ＦＦＣを作製する。
【００５９】
実施例１及び従来例１のシールド材被覆ＦＦＣについて、屈曲寿命の評価を行った。屈曲寿命の評価は、各シールド材被覆ＦＦＣを、１５０回／分の屈曲速度、２５０ｍｍのストローク、１６ｍｍの平行平板間距離（曲げ半径Ｒ＝８ｍｍに相当）、２３℃の試験環境で屈曲試験を行い、２本の接地導体間の導体抵抗が初期値の３倍以上になるまでの時間を屈曲寿命として測定した。
【００６０】
その結果、実施例１のシールド材被覆ＦＦＣは、従来例１のシールド材被覆ＦＦＣと比較して、屈曲寿命が約２．５倍以上に向上していた。
【００６１】
また、各シールド材被覆ＦＦＣについて、各種の信頼性試験（高温放置試験、低温放置試験、耐湿試験、ヒートサイクル試験、折り曲げ試験）を行ったが、いずれの試験においても、実施例１のシールド材被覆ＦＦＣは従来例１のシールド材被覆ＦＦＣと同等又はそれ以上の特性を有していた。特に、実施例１のシールド材被覆ＦＦＣは、従来例１のシールド材被覆ＦＦＣと比較して、耐折り曲げ性に優れていた。
【００６２】
【発明の効果】
以上要するに本発明によれば、次のような優れた効果を発揮する。
（１）　シールド材と平角導体との接地導体部は、シールド材被覆フレキシブルフラットケーブルの非可動部に形成し、可動部（屈曲部）においては、シールド材とフレキシブルフラットケーブルとが完全に面接着するようにしているため、シールド材が剥がれにくくなり、屈曲信頼性が高くなる。
（２）　（１）の製造方法を用いることにより、シールド材が剥がれにくく、屈曲信頼性が高いシールド材被覆フレキシブルフラットケーブルが得られる。
【図面の簡単な説明】
【図１】第１〜第４の実施の形態に係るシールド材被覆フレキシブルフラットケーブルの製造方法を用いて形成したシールド材被覆ＦＦＣの平面図である。
【図２】図１の２ａ−２ａ線、２ｂ−２ｂ線断面図である。
【図３】第１及び第２の実施の形態に係るシールド材被覆フレキシブルフラットケーブルの製造方法を用いて形成したＦＦＣの平面図である。
【図４】第３及び第４の実施の形態に係るシールド材被覆フレキシブルフラットケーブルの製造方法を用いて形成したＦＦＣの平面図である。
【図５】従来のシールド材被覆フレキシブルフラットケーブルの製造方法を用いて形成したシールド材被覆ＦＦＣの平面図である。
【図６】図５の６−６線断面図である。
【符号の説明】
１０　ＦＦＣ（フレキシブルフラットケーブル）
１５　貫通穴
２０　シールド材被覆ＦＦＣ（シールド材被覆フレキシブルフラットケーブル）
２５　接地導体部
４０ａ，４０ｃ　第１ＦＦＣ（フレキシブルフラットケーブル）
４０ｂ，４０ｄ　第２ＦＦＣ（フレキシブルフラットケーブル）
４１ａ，４１ｂ　領域（導体群露出部）
４４ａ，４４ｂ　第２絶縁膜
４５，５４　絶縁膜
５１　平角導体
５２　導体群
５３　絶縁性接着剤層（絶縁膜）
６１　シールド材
６４　導電性接着剤層（シールド材）[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a shielded material-covered flexible flat cable, and more particularly to a method for manufacturing a shielded material-covered flexible flat cable.
[0002]
[Prior art]
As shown in FIGS. 5 and 6, a flexible flat cable (hereinafter, referred to as FFC) 50 is a thin tape-like cable having a thickness of about 0.3 mm or less, in which one to several tens of conductors 51 are arranged in parallel. An insulating film 54 having an adhesive layer 53 is attached to both surfaces of a conductor group 52 arranged in a matrix and thermally pressed.
[0003]
Here, in the case of AV devices such as VTRs, CD or DVD players, OA / PC peripheral devices such as copiers, scanners and printers, and other electronic / electric devices, etc., shield both sides of the FFC 50 from the viewpoint of noise prevention. In many cases, a shield material-coated FFC 60 in which materials 61 are bonded together is used.
[0004]
In general, the outermost layer (base material (layer thickness: several μm to several tens μm)) 62 is an insulating plastic such as PET, and the middle layer (layer thickness: several μm or less) 63 is Cu or Al. The innermost layer (layer thickness: several tens of μm) 64 is formed of a conductive adhesive such as a conductive metal. The shielding material 61 and at least one conductor (conductors 51g, 51g at both ends in the width direction in FIGS. 5 and 6) exposed on the surface of the FFC 50 among the conductors 51 are connected to each other. By electrically connecting, a shielding effect can be obtained.
[0005]
The FFC 50 is excellent in bending resistance and is therefore often used for wiring of a movable portion (bent portion) of an electric / electronic device circuit. For the same reason, the shield material-coated FFC 60 is also used for the movable portion (bent portion) wiring for the same reason.
[0006]
[Problems to be solved by the invention]
However, the shield material-coated FFC 60 is asymmetric in the layer thickness direction (the vertical direction in FIG. 6) since the ground conductor 65 is formed only on one side (the upper side in FIG. 6). There was a problem that the bending reliability was inferior in comparison. Further, since the ground conductor 65 is formed over the entire length in the longitudinal direction, that is, also at the bent portion of the cable, the problem that the shield material 61 on the side of the ground conductor 65 in the ground conductor 65 is easily peeled off when bent. was there.
[0007]
For this reason, the shielding material-coated FFC 60 has a low bending reliability, and in consideration of the fact that the shielding material 61 is easily peeled off, the fixed wiring portion of the AV device, the OA / PC peripheral device, and other electronic / electric devices, At present, it is applied only to a scanner or a copier having a large bending radius and a required number of bending times of about tens of thousands.
[0008]
SUMMARY OF THE INVENTION An object of the present invention, which has been made in view of the above circumstances, is to provide a method of manufacturing a shielded material-covered flexible flat cable having high reliability in bending, in which a shielding material is not easily peeled off.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a method of manufacturing a shielded material-covered flexible flat cable according to the present invention comprises the steps of: forming a conductor group by arranging a plurality of rectangular conductors in parallel; A flexible flat cable is formed by laminating and integrating an insulating film having an adhesive layer with the adhesive layer inside, and a shielding material having a conductive adhesive layer on the upper and lower surfaces of the flat cable. In the method of manufacturing a coated flexible flat cable, a through hole is formed in advance immediately before at least one end of the conductor group of the insulating film and immediately above at least one rectangular conductor, and the insulating film is formed. The through holes are formed in the ground conductor portion by bonding the upper and lower surfaces of the conductor group.
[0010]
Also, a plurality of rectangular conductors are arranged in parallel to form a conductor group, and an insulating film having an insulating adhesive layer is bonded to and integrated with the upper and lower surfaces of the conductor group, with the adhesive layer inside. Forming a flexible flat cable, and bonding a shielding material having a conductive adhesive layer to the upper and lower surfaces of the flat cable to produce a shielding material-covered flexible flat cable, wherein at least one conductor of the flexible flat cable is Forming a portion of the ground conductor near the end of the group and immediately above at least one rectangular conductor by laser processing to remove the insulating film and expose the rectangular conductor; It is.
[0011]
Also, a plurality of rectangular conductors are arranged in parallel to form a conductor group, and an insulating film having an insulating adhesive layer is bonded to and integrated with the upper and lower surfaces of the conductor group, with the adhesive layer inside. Forming a flexible flat cable, and bonding the shielding material having a conductive adhesive layer to the upper and lower surfaces of the flat cable to produce a shielding material-covered flexible flat cable, wherein at least one of the conductor group ends is formed. The flexible flat cable is exposed to be exposed, and then, when the second insulating film having the insulating adhesive layer is bonded with the adhesive layer inside so as to cover the conductor group exposed portion, the second insulating film is formed. A through-hole is formed in advance immediately before the end of the conductor group and directly above at least one rectangular conductor, and the through-hole is formed in the ground conductor. It is intended.
[0012]
Also, a plurality of rectangular conductors are arranged in parallel to form a conductor group, and an insulating film having an insulating adhesive layer is bonded to and integrated with the upper and lower surfaces of the conductor group, with the adhesive layer inside. Forming a flexible flat cable, and bonding the shielding material having a conductive adhesive layer to the upper and lower surfaces of the flat cable to produce a shielding material-covered flexible flat cable, wherein at least one of the conductor group ends is formed. The flexible flat cable is formed by exposing the flexible flat cable, and then a second insulating film having an insulating adhesive layer is bonded with the adhesive layer inside so as to cover the exposed portion of the conductor group. A laser processing is performed on the portion immediately above the end of the conductor group and directly above at least one rectangular conductor to remove the insulating film and expose the rectangular conductor. It is, and forms the insulation film removing portion in the ground conductor.
[0013]
Specifically, as described in claim 5, it is preferable that the ground conductor is formed at a non-bent portion of the flexible flat cable.
[0014]
Thereby, the grounding conductor portion of the shield material and the rectangular conductor of the shielded material-covered flexible flat cable is formed near at least one end of the conductor group in the longitudinal direction of the cable, that is, at the non-movable portion. The material is less likely to come off. As a result, in the movable portion (bent portion) of the shield material-covered flexible flat cable, the ground conductor portion is eliminated, and the shield material and the flexible flat cable are completely bonded to each other, so that the bending reliability is improved.
[0015]
On the other hand, the shielded material-covered flexible flat cable according to the present invention is formed using the above-described manufacturing method.
[0016]
This makes it possible to obtain a shielded material-covered flexible flat cable that is less likely to peel off the shield material and has high bending reliability.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.
[0018]
(1st Embodiment)
FIG. 1 is a plan view of a shield material-coated FFC formed by using the method of manufacturing a shield material-coated flexible flat cable according to the first to fourth embodiments, and FIG. 2 is a cross-sectional view taken along line 2a-2a of FIG. FIG. 2A is a cross-sectional view taken along the line 2b-2b in FIG. 1, and FIG. 2B is a plan view of an FFC formed by using the method for manufacturing a shielded material-covered flexible flat cable according to the first and second embodiments. Is shown in FIG. The same members as those in FIGS. 5 and 6 are denoted by the same reference numerals, and detailed description of these members will be omitted.
[0019]
As shown in FIGS. 1 to 3, in the method for manufacturing a shielded material-covered flexible flat cable according to the first embodiment, first, a plurality of rectangular conductors 51 are arranged in parallel to form a conductor group 52, An insulating film 54 having an insulating adhesive layer 53 is attached to the upper and lower surfaces of the conductor group 52 with the adhesive layer 53 inside.
[0020]
At this time, at least one end (upper and lower ends in FIG. 3) of at least one of the conductor groups in the longitudinal direction (both in the vertical direction in FIG. 3) and at least one (two in FIG. 3) A through-hole 15 is formed in advance directly above the rectangular conductor 51 of the present embodiment by punching using a punching machine or the like. By bonding the insulating film 54 having the through holes 15 to the upper and lower surfaces of the conductor group 52, each through hole 15 becomes the ground conductor portion 25. Further, it is preferable that the ground conductor portion 25, that is, each through hole 15 is formed in a non-bent portion of the FFC 10.
[0021]
Next, the conductor group 52 and the insulating films 54 and 54 are integrated by thermocompression bonding to form the FFC 10.
[0022]
Next, a shield material 61 having a conductive adhesive layer 64 is attached to each of the upper and lower surfaces of the FFC 10, and the FFC 10 and the shield materials 61, 61 are integrated by thermocompression bonding to obtain a shield material-coated FFC 20. Can be At the time of this integration, the conductive adhesive layer 64 of the shield material 61 enters each through-hole 15, and the conductive adhesive layer 64 and at least one of the conductors 51 exposed on the surface of the FFC 10 (The conductors 51g, 51g at both ends in the width direction in FIGS. 1 and 2) are electrically connected, and the shield material 61 and the conductors 51g, 51g are grounded at the portions of the through holes 15 to obtain a shielding effect. Can be
[0023]
The shape of the through hole 15 is not particularly limited as long as it can function as the ground conductor 25.
[0024]
As the insulating plastic forming the outermost layer 62 of the shielding material 61, PET is preferable in consideration of manufacturing cost. However, when the flame resistance and heat resistance of the shielding material 61 are required, PPS (polyphenylene sulfide) is preferable. .
[0025]
In addition, as the conductive metal forming the middle layer 63 of the shield material 61, if the middle layer 63 is formed of a foil, the middle layer 63 is formed by depositing Cu or Al, or by applying a paste-like material. If so, Ag, Ni, and Al can be used. When high bending resistance is required, it is preferable to form the middle layer 63 by vapor deposition.
[0026]
Further, the conductive adhesive forming the innermost layer 64 of the shield member 61 is not only formed of a resin but includes a conductive filler such as Ni or C and a flame retardant. Examples of the resin include a thermoplastic polyester resin.
[0027]
The ground conductor portion 25 of the shield material covering FFC 20 formed using the manufacturing method according to the present embodiment is formed only on one side (the upper side in FIG. 2B) of the conductor group 52, and The arrangement structure of the conductor portion 25 is asymmetric in the layer thickness direction (the vertical direction in FIG. 2B). However, the ground conductor portion 25 is formed near both ends in the longitudinal direction of the shield material covering FFC 20, that is, only at the non-movable portion, and not at the movable portion (bent portion) of the shield material covering FFC 20. Therefore, in the movable portion (bent portion) of the shield material-coated FFC 20, the shield materials 61, 61 and the FFC 10 are completely bonded to each other, and high bending reliability is obtained.
[0028]
In addition, the ground conductor portion 25 is formed in the vicinity of both ends in the longitudinal direction of the shield material covering FFC 20, that is, in a portion (non-movable portion) that is not a movable portion of the FFC 10, and is formed over the entire length in the longitudinal direction. Therefore, when the shield material covering FFC 20 is bent, the shield material 61 on the side of the ground conductor portion 25 in the ground conductor portion 25 hardly peels off.
[0029]
That is, when the shield material-coated FFC 20 is bent, the shield materials 61, 61, specifically, the shield material 61 on the ground conductor portion 25 side are less likely to be separated from the FFC 10, and the bending reliability of the shield material-coated FFC 20 is increased. Specifically, the flex life is improved about twice or more. Therefore, not only fixed wiring portions of AV devices, OA / PC peripheral devices, and other electronic / electric devices, scanners or copiers having a large bending radius and a required number of bending times of about tens of thousands of times, but also high The shield material-coated FFC 20 can also be applied to a movable wiring portion that requires bending resistance.
[0030]
Next, another embodiment of the present invention will be described with reference to the accompanying drawings.
[0031]
(2nd Embodiment)
As shown in FIGS. 1 to 3, in the method for manufacturing a shielded material-covered flexible flat cable according to the second embodiment, first, a plurality of rectangular conductors 51 are arranged in parallel to form a conductor group 52, An insulating film 54 having an insulating adhesive layer 53 is attached to the upper and lower surfaces of the conductor group 52 with the adhesive layer 53 inside, and the conductor group 52 and the insulating films 54 and 54 are integrated by thermocompression bonding. The FFC 10 is formed.
[0032]
Next, at least one of the conductor group ends (upper and lower ends in FIG. 3) of at least one of the longitudinal directions of the insulating film 54 in the FFC 10 (both vertical directions in FIG. 3) and at least one conductor group (in FIG. 3) In this case, laser processing using an excimer laser or a YAG laser is performed on the portion directly above the two rectangular conductors 51 to remove a part of the insulating film 54 and expose the rectangular conductor 51. ) Is formed on the ground conductor portion 25. It is preferable that the ground conductor portion 25, that is, a portion where each insulating film is removed, is formed in a non-bent portion of the FFC 10.
[0033]
Next, a shield member 61 having a conductive adhesive layer 64 is attached to each of the upper and lower surfaces of the FFC 10 on which the ground conductor portion 25 is formed, and the FFC 10 and the shield members 61 are integrated by thermocompression bonding. The shield material-coated FFC 20 is obtained.
[0034]
As described above, also in the present embodiment, it is needless to say that the same operation and effect as those of the first embodiment can be obtained.
[0035]
In the first embodiment, since the through-hole 15 is formed by punching before bonding the insulating film 54, the position of the through-hole 15 and the position of the rectangular conductor 51 may be shifted depending on the bonding method. was there. On the other hand, in the present embodiment, after the insulating film 54 is attached, the insulating film removed portion (through hole 15) is formed at a position immediately above the rectangular conductor 51 by laser processing. There is no possibility that the position of the removed portion and the position of the rectangular conductor 51 are shifted.
[0036]
(Third embodiment)
FIG. 4 is a plan view of an FFC formed by using the method for manufacturing a shielded material-covered flexible flat cable according to the third and fourth embodiments. Note that the same members as those in FIG. 3 are denoted by the same reference numerals, and detailed description of these members will be omitted.
[0037]
As shown in FIGS. 1, 2, and 4, a method of manufacturing a shielded material-covered flexible flat cable according to a third embodiment includes first arranging a plurality of rectangular conductors 51 in parallel to form a conductor group 52. An insulating film 54 having an insulating adhesive layer 53 is bonded to the upper and lower surfaces of the conductor group 52 with the adhesive layer 53 inside, and the conductor group 52 and the insulating films 54, 54 are bonded by thermocompression bonding. Then, the first FFC 40a is formed.
[0038]
Next, the portion of the insulating film 54 corresponding to the regions 41a and 41b near the end of the conductor group in at least one of the longitudinal directions of the first FFC 40a (both vertically in FIG. 4) is removed to expose the conductor group 52. .
[0039]
Next, the second insulating films 44a and 44b having an insulating adhesive layer are coated with an adhesive so as to cover the exposed conductor group of the first FFC 40a, that is, the regions 41a and 41b which are portions where the insulating film 54 is partially removed. The first FFC 40a and the second insulating films 44a and 44b are integrated by thermocompression bonding, with the layers being bonded inside, to form the second FFC 40b.
[0040]
At this time, a through-hole 15 is formed in advance immediately before the end of the conductor group of the second insulating films 44a and 44b and directly above at least one (two in FIG. 4) rectangular conductor 51 by punching or the like. Keep it. By bonding the second insulating films 44a and 44b having the through holes 15 to the regions 41a and 41b, each through hole 15 becomes the ground conductor portion 25. It is preferable that the ground conductor portion 25, that is, each through hole 15 is formed in a non-bent portion of the second FFC 40b. When the second insulating films 44a and 44b are attached to the regions 41a and 41b, the second insulating films 44a and 44b are attached so that a part of the second insulating films 44a and 44b overlap the insulating film 54. Further, the same as the insulating film 54 can be applied to the second insulating films 44a and 44b.
[0041]
Next, a shield material 61 having a conductive adhesive layer 64 is attached to each of the upper and lower surfaces of the second FFC 40b, and the second FFC 40b and the shield materials 61, 61 are integrated by thermocompression bonding. Is obtained.
[0042]
Here, in the present embodiment, a case has been described where the second insulating films 44a and 44b in which the through holes 15 have been formed in advance are bonded to the regions 41a and 41b, but the present invention is not limited to this. Instead, as described in the second embodiment, after the second insulating films 44a, 44b are bonded to the regions 41a, 41b, the insulating film removed portion (through hole) is formed at a position immediately above the rectangular conductor 51 by laser processing. 15) may be formed.
[0043]
As described above, it is needless to say that also in the present embodiment, the same operational effects as those of the first and second embodiments can be obtained.
[0044]
In the first and second embodiments, the movable portion and the non-movable portion, that is, the insulating film 54 is formed integrally in the longitudinal direction. The bending of the insulating film 54 may spread to the insulating film 54 of the non-movable part. On the other hand, in the present embodiment, the insulating film on the ground conductor portion 25 side of the second FFC 40b is constituted by the insulating film 54 and the second insulating films 44a and 44b, and is formed separately in the longitudinal direction. Therefore, the bonding reliability of the shield member 61 on the ground conductor portion 25 side in the ground conductor portion 25 is further improved. As a result, the bending reliability of the shield material-coated FFC 20 is further increased, and the shield materials 6 and 61 are more difficult to peel.
[0045]
(Fourth embodiment)
In the previous embodiment, after the conductor group 52 and the insulating films 54 and 54 are integrated by thermocompression bonding, a part of the insulating film 54 is removed.
[0046]
On the other hand, in the method of manufacturing the shielded material-covered flexible flat cable according to the fourth embodiment, the insulating film 54 and the insulating film having a shorter longitudinal length than the insulating film 54 are formed on the upper and lower surfaces of the conductor group 52. 45.
[0047]
Specifically, as shown in FIGS. 1, 2 and 4, first, a plurality of rectangular conductors 51 are arranged in parallel to form a conductor group 52, and the upper and lower surfaces of the conductor group 52 are respectively insulated. The insulating films 45 and 54 having the conductive adhesive layer 53 are bonded with the adhesive layer 53 inside. At this time, the length of the insulating film 45 in the longitudinal direction is shorter than that of the insulating film 54, and this bonding allows at least one of the longitudinal directions (both in the vertical direction in FIG. 4) on the insulating film 45 side. The portions corresponding to the regions 41a and 41b of the conductor group 52) are exposed.
[0048]
After that, the conductor group 52 and the insulating films 45 and 54 are integrated by thermocompression bonding to form the first FFC 40c.
[0049]
Next, the second insulating films 44a and 44b having an insulating adhesive layer are bonded with the adhesive layer inside so as to cover the exposed conductor group of the first FFC 40c, that is, the regions 41a and 41b on the insulating film 45 side. At the same time, the first FFC 40c and the second insulating films 44a and 44b are integrated by thermocompression bonding to form a second FFC 40d.
[0050]
At this time, a through-hole 15 is formed in advance immediately before the end of the conductor group of the second insulating films 44a and 44b and directly above at least one (two in FIG. 4) rectangular conductor 51 by punching or the like. Keep it. By bonding the second insulating films 44a and 44b having the through holes 15 to the regions 41a and 41b, each through hole 15 becomes the ground conductor portion 25. Further, it is preferable that the ground conductor portion 25, that is, each through hole 15 is formed in a non-bent portion of the second FFC 40d. When the second insulating films 44a and 44b are attached to the regions 41a and 41b, the second insulating films 44a and 44b are attached so that a part of the second insulating films 44a and 44b overlap the insulating film 45. Further, the same as the insulating films 54 and 45 can be applied to the second insulating films 44a and 44b.
[0051]
Next, a shield material 61 having a conductive adhesive layer 64 is attached to each of the upper and lower surfaces of the second FFC 40d, and the second FFC 40d and the shield materials 61, 61 are integrated by thermocompression bonding to form a shield material-coated FFC 20. Is obtained.
[0052]
As described above, also in the present embodiment, it is needless to say that the same operation and effect as those of the first to third embodiments can be obtained.
[0053]
Further, in the third embodiment, in order to form the second FFC 40b, a step of bonding the insulating films 54, 54 to the upper and lower surfaces of the conductor group 52, and a step of bonding the insulating films 54 corresponding to the regions 41a, 41b. Three steps were required: a removing step and a step of bonding the second insulating films 44a and 44b having an insulating adhesive layer with the adhesive layer inside so as to cover the regions 41a and 41b. On the other hand, in the present embodiment, the steps required to form the second FFC 40d include a step of bonding the insulating films 54 and 45 to the upper and lower surfaces of the conductor group 52 and a step of forming the region 41a on the insulating film 45 side. , 41b so as to cover the second insulating films 44a, 44b having an insulating adhesive layer with the adhesive layer inside. That is, since the number of manufacturing steps of the second FFC 40d can be reduced, as a result, the productivity of the shield material-coated FFC 20 can be further improved, and the manufacturing cost can be reduced.
[0054]
As described above, the embodiments of the present invention are not limited to the above-described embodiments, and it is needless to say that various other embodiments are also conceivable.
[0055]
【Example】
Next, the present invention will be described based on examples, but the present invention is not limited to these examples.
[0056]
(Example 1)
First, 15 Sn-plated rectangular soft copper wires having a width of 0.7 mm and a thickness of 50 μm are arranged at a pitch of 1 mm to form a conductor group having a width of 16 mm. On each of the upper and lower surfaces of the conductor group, a PET insulating film (film thickness: 50 μm) having a flame-retardant polyester adhesive layer (layer thickness: 35 μm (including the thickness of the anchor coat)) formed on a PET film having a thickness of 25 μm. , With the adhesive layer inside. At this time, in the vicinity of both ends in the longitudinal direction of the PET insulating film, through holes are formed in advance immediately above the two Sn-plated rectangular soft copper wires at both ends in the width direction by a punching machine.
[0057]
After that, the conductor group and the PET insulating film are integrated by thermocompression bonding to form an FFC. Next, on each of the upper and lower surfaces of the FFC, on a PET film having a thickness of 12.5 μm, an Al vapor-deposited layer (conductive metal layer) having a thickness of less than 0.1 μm, a flame retardant film having a thickness of 30 μm and a Ni filler added. By bonding the shield material (film thickness of about 42.5 μm) on which the polyester adhesive layer (layer thickness: 30 μm (including the thickness of the anchor coat)) is formed, and integrating the FFC and the shield material by thermocompression bonding, A shield material-coated FFC is manufactured.
[0058]
(Conventional example 1)
Except having the structure shown in FIG. 5 and FIG. 6, a shield material-coated FFC is produced in the same manner as in Example 1.
[0059]
The flex life was evaluated for the shield material-coated FFCs of Example 1 and Conventional Example 1. The flex life was evaluated by conducting a flex test on each shield material-coated FFC at a flex speed of 150 times / min, a stroke of 250 mm, a distance between parallel plates of 16 mm (corresponding to a bending radius of R = 8 mm), and a test environment of 23 ° C. The bending life was measured as the time required for the conductor resistance between the two ground conductors to become three times or more the initial value.
[0060]
As a result, the bending life of the shield-coated FFC of Example 1 was improved to about 2.5 times or more as compared with the shield-coated FFC of Conventional Example 1.
[0061]
In addition, various reliability tests (high-temperature storage test, low-temperature storage test, moisture resistance test, heat cycle test, bending test) were performed for each shield material-coated FFC, and in each test, the shield material of Example 1 was used. The coated FFC had the same or better characteristics as the shield material-coated FFC of Conventional Example 1. In particular, the shield material-coated FFC of Example 1 was superior to the shield material-coated FFC of Conventional Example 1 in bending resistance.
[0062]
【The invention's effect】
In short, according to the present invention, the following excellent effects are exhibited.
(1) The ground conductor between the shield material and the rectangular conductor is formed on the non-movable part of the shielded material-covered flexible flat cable. Therefore, the shield material is hardly peeled off, and the bending reliability is improved.
(2) By using the manufacturing method of (1), a shield material-covered flexible flat cable having high bending reliability and a high reliability of the shield material is obtained.
[Brief description of the drawings]
FIG. 1 is a plan view of a shield material-coated FFC formed using a method of manufacturing a shield material-coated flexible flat cable according to first to fourth embodiments.
FIG. 2 is a sectional view taken along lines 2a-2a and 2b-2b of FIG.
FIG. 3 is a plan view of an FFC formed by using the method for manufacturing a shielded material-covered flexible flat cable according to the first and second embodiments.
FIG. 4 is a plan view of an FFC formed by using the method for manufacturing a shielded material-covered flexible flat cable according to the third and fourth embodiments.
FIG. 5 is a plan view of a shield material-coated FFC formed using a conventional method of manufacturing a shield material-coated flexible flat cable.
FIG. 6 is a sectional view taken along line 6-6 in FIG. 5;
[Explanation of symbols]
10 FFC (flexible flat cable)
15 Through hole 20 Shield material-coated FFC (Shield material-coated flexible flat cable)
25 ground conductors 40a, 40c first FFC (flexible flat cable)
40b, 40d 2nd FFC (flexible flat cable)
41a, 41b area (conductor group exposed part)
44a, 44b Second insulating films 45, 54 Insulating film 51 Rectangular conductor 52 Conductor group 53 Insulating adhesive layer (insulating film)
61 Shielding material 64 Conductive adhesive layer (shielding material)

Claims

A conductor group is formed by arranging a plurality of rectangular conductors in parallel, and an insulating film having an insulating adhesive layer is bonded to the upper and lower surfaces of the conductor group with the adhesive layer inside and integrated and flexible. In a method of forming a flat cable and bonding a shield material having a conductive adhesive layer to upper and lower surfaces of the flat cable to manufacture a shield material-covered flexible flat cable, an end portion of at least one conductor group of the insulating film A through hole is formed in the immediate vicinity and immediately above at least one rectangular conductor, and the insulating film is bonded to the upper and lower surfaces of the conductor group, and the through hole is formed in the ground conductor portion. A method of manufacturing a shielded material-covered flexible flat cable, comprising:

A conductor group is formed by arranging a plurality of rectangular conductors in parallel, and an insulating film having an insulating adhesive layer is bonded to the upper and lower surfaces of the conductor group with the adhesive layer inside and integrated and flexible. In a method of forming a flat cable and bonding a shield material having a conductive adhesive layer to upper and lower surfaces of the flat cable to produce a shield material-covered flexible flat cable, at least one conductor group end of the flexible flat cable A laser processing is performed on the portion immediately adjacent to the portion and directly above at least one rectangular conductor to remove the insulating film and expose the rectangular conductor, and the insulating film removed portion is formed in the ground conductor portion. Of manufacturing a flexible flat cable covered with a shielding material.

A conductor group is formed by arranging a plurality of rectangular conductors in parallel, and an insulating film having an insulating adhesive layer is attached to the upper and lower surfaces of the conductor group with the adhesive layer inside and integrated and flexible. Forming a flat cable, a method of manufacturing a shield material-coated flexible flat cable by bonding a shield material having a conductive adhesive layer to the upper and lower surfaces of the flat cable, exposing at least one end of the conductor group. When the above-mentioned flexible flat cable is formed and then the second insulating film having the insulating adhesive layer is bonded with the adhesive layer inside so as to cover the exposed portion of the conductor group, the conductor of the second insulating film is A through hole is formed in advance immediately before the end of the group and immediately above at least one rectangular conductor, and the through hole is formed in the ground conductor. Shielding material coating method of manufacturing a flexible flat cable, wherein.

A conductor group is formed by arranging a plurality of rectangular conductors in parallel, and an insulating film having an insulating adhesive layer is attached to the upper and lower surfaces of the conductor group with the adhesive layer inside and integrated and flexible. Forming a flat cable, a method of manufacturing a shield material-coated flexible flat cable by bonding a shield material having a conductive adhesive layer to the upper and lower surfaces of the flat cable, exposing at least one end of the conductor group. To form a flexible flat cable, and then bond a second insulating film having an insulating adhesive layer with the adhesive layer inside so as to cover the exposed portion of the conductor group. A laser process is performed on the portion immediately near the end of the group and immediately above at least one rectangular conductor to remove the insulating film and expose the rectangular conductor. Shielding material covering the flexible manufacturing method of the flat cable, characterized by forming the insulating film removing portion in the ground conductor.

The method for manufacturing a shielded material-covered flexible flat cable according to any one of claims 1 to 4, wherein the ground conductor portion is formed at a non-bent portion of the flexible flat cable.

A shielded material-covered flexible flat cable formed using the manufacturing method according to claim 1.