JP4011425B2 - Antenna coil structure for IC card, method for manufacturing the same, and IC card having the same - Google Patents

Description

【００３５】
上記の式においてＬは温度１５０℃で３０分間保持した後の樹脂フィルムの長さ、Ｌ₀は樹脂フィルムの元の長さである。
【００３６】
なお、通常のＰＥＮフィルムを予め加熱処理することにより、熱収縮率を０．３％以下にすることもでき、加熱処理したＰＥＮフィルムも低熱収縮性ＰＥＮに含まれるものである。
【００３７】
ポリカーボネート（ＰＣ）、低熱収縮性ポリエチレンナフタレート（ＰＥＮ）、低熱収縮性ポリエチレンテレフタレート（ＰＥＴ）のいずれからなるフィルムの両面の上にアモルファスポリエチレンテレフタレート（ＡＰＥＴ）のフィルムを積層する方法としては、公知の手段を採用することができ、接着剤による接着、押出し法、キャスト（注型）法等が挙げられるが、これらの中でキャスト（注型）法を採用するのが好ましい。
【００３８】
回路パターン層１３を構成する金属箔の上にアモルファスポリエチレンテレフタレートから構成される樹脂フィルム基材１１を積層する方法は、熱接着（ヒートラミネートまたはサーマルラミネートともいう）または溶融押出し接着（イクストルージョンラミネート）によって行なわれるのが好ましい。これらの方法を採用することにより、ドライラミネート用接着剤等を用いないで樹脂フィルム基材と金属箔とを固着することができる。したがって、基材と回路パターン層との間で強固な接着力を発揮し維持することができるので、従来技術の問題点を克服することが可能となる。
【００３９】
熱接着工程は、通常、加熱ロールを用いて金属箔を加熱した状態で樹脂フィルム基材を貼り合わせることによって行なわれる。熱接着の温度は１００〜１６０℃程度が好ましい。溶融押出し接着工程は、樹脂を加熱溶融させ、この樹脂を金属箔の上にダイにより押出すことによって行なわれる。
【００４０】
なお、金属箔は基材樹脂フィルムの片面または両面に積層することができ、用途、設計、使用目的等に応じて適宜使い分けることができる。
【００４１】
次に、この発明のＩＣカード用アンテナコイル構成体の製造方法の１つの実施の形態について説明する。図４〜図７はこの発明に従ったＩＣカード用アンテナコイル構成体の製造工程を示す部分断面図である。なお、図４〜図７は、図１のＩＩ−ＩＩ線の方向から見た部分断面を示している。
【００４２】
図４に示すように、金属箔１３０のそれぞれの一方面に熱接着（または溶融押出し接着）によって樹脂フィルム基材１１を固着する。このようにして、金属箔１３０と樹脂フィルム基材１１との積層体を準備する。
【００４３】
図５に示すように、アンテナコイルの仕様に従った所定の渦巻状パターンを有するようにレジストインク層１４を金属箔１３０の表面上に印刷する。印刷後、レジストインク層１４の硬化処理を行なう。
【００４４】
図６に示すように、レジストインク層１４をマスクとして用いて金属箔１３０をエッチングすることにより、回路パターン層１３を形成する。
【００４５】
その後、図７に示すように、レジストインク層１４を剥離する。
最後に、回路パターン層１３の所定領域に凹凸のある金属板と金属突起を用いてクリンピング加工を施すことにより、図２に示すように回路パターン層の接触部または圧着部１３ａを形成する。このようにして本発明のＩＣカード用アンテナコイル構成体１０が完成する。
【００４６】
この発明の製造方法において用いられるレジストインクは特に限定されないが、分子中に少なくとも１個のカルボキシル基を有するアクリルモノマーとアルカリ可溶性樹脂とを主成分とする紫外線硬化型レジストインクを用いるのが好ましい。このレジストインクは、グラビア印刷が可能であり、耐酸性を有し、かつアルカリによって容易に剥離除去することが可能であるので、連続大量生産に適している。このレジストインクを用いて金属箔に所定の回路パターンでグラビア印刷を施し、紫外線を照射して硬化させた後、通常の方法に従って、たとえば塩化第２鉄水溶液等による金属箔の酸エッチング、水酸化ナトリウム水溶液等のアルカリによるレジストインク層の剥離除去を行なうことによって、回路パターン層を形成することができる。
【００４７】
分子中に少なくとも１個のカルボキシル基を有するアクリルモノマーとしては、たとえば、２−アクリロイルオキシエチルフタル酸、２−アクリロイルオキシエチルコハク酸、２−アクリロイルオキシエチルヘキサヒドロフタル酸、２−アクリロイルオキシプロピルフタル酸、２−アクリロイルオキシプロピルテトラヒドロフタル酸、２−アクリロイルオキシプロピルヘキサヒドロフタル酸等が挙げられ、これらのうち、単独のアクリルモノマー、またはいくつかのアクリルモノマーを混合したものを使用することができる。上記のアルカリ可溶性樹脂としては、たとえば、スチレン−マレイン酸樹脂、スチレン−アクリル樹脂、ロジン−マレイン酸樹脂等が挙げられる。
【００４８】
レジストインクには、上記の成分の他に、アルカリ剥離性を阻害しない程度に通常の単官能アクリルモノマー、多官能アクリルモノマー、プレポリマーを添加することができ、光重合開始剤、顔料、添加剤、溶剤等を適宜添加して作製することができる。光重合開始剤としては、ベンゾフェノンおよびその誘導体、ベンジル、ベンゾイン、およびそのアルキルエーテル、チオキサントンおよびその誘導体、ルシリンＰＴＯ、チバスペシャリティケミカルズ製イルガキュア、フラッテリ・ランベルティ製エサキュア等が挙げられる。顔料としては、パターンが見やすいように着色顔料を添加する他、シリカ、タルク、クレー、硫酸バリウム、炭酸カルシウム等の体質顔料を併用することができる。特にシリカは、紫外線硬化型レジストインクを付けたまま、金属箔を巻き取る場合には、ブロッキング防止に効果がある。添加剤としては、２−ターシャリーブチルハイドロキノン等の重合禁止剤、シリコン、フッ素化合物、アクリル重合物等の消泡剤、レベリング剤があり、必要に応じて適宜添加する。溶剤としては酢酸エチル、エタノール、変性アルコール、イソプロピルアルコール、トルエン、ＭＥＫ等が挙げられ、これらの溶剤を単独、または混合して用いることができる。溶剤は、グラビア印刷の後、熱風乾燥等でレジストインク層から蒸発させることが好ましい。
【００４９】
回路パターン層を形成した後に、所定の位置に常温でクリンピング加工を施し、表側と裏側の金属箔の一部を電気的に接触させてアンテナコイルを形成することができる。ここで、クリンピング加工とは、たとえば、ドリル、ヤスリ、超音波等により樹脂フィルム基材を破壊し、回路パターン層を形成する金属箔の一部同士を物理的に接触させることをいう。具体的には、凹凸のある金属板上に樹脂フィルム基材と金属箔とからなる積層体を接触させ、金属突起を押し当てることにより、樹脂フィルム基材が部分的に破壊し、金属箔の表面同士が接触可能となり、電気的導通を得ることができる。
【００５０】
本発明に従ったＩＣカード用アンテナコイル構成体の構成と製造方法について説明したが、ＩＣカードとして製品化するには次のような工程がさらに行なわれる。図１に示されるＩＣカード用アンテナコイル構成体１０において、図３に示すようにＩＣチップ２０を回路パターン層１３の領域１３ｃに実装し、ＩＣチップ２０と回路パターン層１３の端部とに配線２１を接続する。さらに、回路パターン層１３と樹脂フィルム基材１１との積層体の表面と裏面に白色ＡＰＥＴ、白色ＰＶＣまたは白色ＰＥＴ等の外装層（隠蔽層）３０を被覆積層させる。積層は、前述の熱接着によって行なわれてもよく、ＥＶＡまたはポリエステル系のホットメルト剤を介在した熱接着によって行なわれてもよい。この外装層（隠蔽層）３０は、白色に制限されることはなく、公知の色顔料や体質顔料、アルミニウムフレーク等の金属顔料および公知の樹脂、ワニス、ビヒクル等を使用することができる。また、印刷層、磁気記録層、磁気遮蔽層、オーバーコート層、蒸着層等の公知のＩＣカードに採用されている構成要素を必要に応じて積層させることもできる。なお、上記のＩＣチップ以外にも必要に応じて、コンデンサ、コイル、抵抗体、配線、各種メモリー、ダイオード等を設けてもよいことは言うまでもない。
【００５１】
【実施例】
以下に本発明の実施例と比較例について説明する。
【００５２】
（実施例１）
基材として厚みが３８μｍのアモルファスポリエチレンテレフタレート樹脂（ＡＰＥＴ）フィルムの一方表面には厚み３０μm、他方表面には厚み２０μｍのアルミニウム箔（ＪＩＳ（ＡＡ） １Ｎ３０−Ｏ）を、熱接着温度１６０℃にて連続的にヒートラミネート法により接着して積層体を作製した。この積層体の両面にレジストインクとして大日本インキ化学工業（株）製のダイキュア−ＲＥ−９７（商品名）を５ｇ／ｍ²の厚みで塗布することによって、図１に示すようなパターンのレジストインク層を連続的に印刷した。このレジストインク層をマスクとして用いて余分なアルミニウム箔を塩化第２鉄水溶液でエッチングすることによって回路パターン層を形成した。その後、水酸化ナトリウム水溶液でレジストインク層を剥離した。形成された回路パターン層の所定の位置で積層体の一部に表裏の電気的導通を得るためのクリンピング加工を施すことにより、図２に示されるようなＩＣカード用アンテナコイル構成体を作製した。ＩＣカード用アンテナコイル構成体は、０．２ｋｇ／ｃｍの張力でコイル状に巻き取った。
【００５３】
得られたＩＣカード用アンテナコイル構成体のブロッキング現象を次のようにして評価した。温度４０℃または６０℃の大気中で４８時間、ＩＣカード用アンテナコイル構成体をコイル状に巻き取った状態で保管した後、巻き取りコイルの端部を手で巻き戻して評価した。評価基準は以下のとおりであった。
【００５４】
評価５：巻取りコイルを巻き戻す際に引っ張らなくてもさらりと端部が離れる。
【００５５】
評価４：巻取りコイルを巻き戻す際にちりちりと音を立てるが、特に強い力をかけなくても端部が離れる。
【００５６】
評価３：巻取りコイルを巻き戻す際に力をかけないと端部は離れないが、ある程度の力で引っ張ると端部は離れる。
【００５７】
評価２：巻取りコイルを巻き戻す際に力をかけると端部は離れるが、部分的に材料が損傷する。
【００５８】
評価１：巻取りコイルを巻き戻そうとすると完全にくっつき、力をかけても端部は離れない。
【００５９】
また、得られたＩＣカード用アンテナコイル構成体においてクリンピング加工された部分の表裏の導通抵抗値を測定した。
【００６０】
さらに、得られたＩＣカード用アンテナコイル構成体においてエッチングによって形成された回路パターン層の外観を評価した。エッチングによる回路パターンの断線、細りおよび剥離等のエッチング不良を目視で観察し、いずれのエッチング不良も存在しないものを良好とし、製品として特性上問題が生じる可能性があるものを不良とした。
【００６１】
得られたＩＣカード用アンテナコイル構成体の両面上に、ホットメルト接着剤を介在させずに厚みが１００μｍの白色ＰＥＴフィルム（帝人（株）製、商品名帝人Ｕ２）を温度１２０℃、圧力３ｋｇ／ｃｍ²で５分間、ホットプレスすることにより、外装フィルムとの接着性を評価した。この評価は、外装フィルムとＩＣカード用アンテナコイル構成体とのラミネート強度をＴ型剥離試験（ＪＩＳ Ｋ６８５４ Ｔ型剥離に準拠、ただし幅は１５ｍｍとする）にしたがって測定することにより行なった。
【００６２】
（実施例２）
基材としてＡＰＥＴの単体フィルムに代えて順に積層されたＡＰＥＴフィルム（厚み１０μｍ）／ＰＣフィルム（厚み３０μｍ）／ＡＰＥＴフィルム（厚み１０μｍ）の複層フィルムを用いたこと以外は、実施例１と同様の工程でＩＣカード用アンテナコイル構成体を作製した。
【００６３】
得られたＩＣカード用アンテナコイル構成体について、実施例１と同様にして、ブロッキング現象、クリンピング加工された部分の表裏の導通抵抗値、エッチングによって形成された回路パターン層の外観を評価した。
【００６４】
また、得られたＩＣカード用アンテナコイル構成体の両面上に、ホットメルト接着剤を介在させずに厚みが１００μｍの白色ＡＰＥＴフィルム（三菱樹脂（株）製、商品名ＰＧ−Ｗ）を温度１２０℃、圧力３ｋｇ／ｃｍ²で５分間、ホットプレスすることにより、外装フィルムとの接着性を評価した。この評価は、実施例１と同様にして行なった。
【００６５】
（比較例１）
厚みが３０μｍと２０μｍのアルミニウム箔（ＪＩＳ（ＡＡ） １Ｎ３０−Ｏ）のそれぞれの一方表面に、ドライラミネート用接着剤としてポリエステルウレタン接着剤を３ｇ／ｍ²の厚みで塗布した後、基材として厚みが３８μｍのポリエチレンナフタレート樹脂（ＰＥＮ）フィルムの一方表面には厚み３０μｍ、他方表面には厚み２０μｍのアルミニウム箔を連続的にドライラミネート法により接着して積層体を作製した。この積層体の両面にレジストインクとして大日本インキ化学工業（株）製のダイキュア−ＲＥ−９７（商品名）を５ｇ／ｍ²の厚みで塗布することによって、図１に示すようなパターンのレジストインク層を連続的に印刷した。このレジストインク層をマスクとして用いて余分なアルミニウム箔を塩化第２鉄水溶液でエッチングすることによって回路パターン層を形成した。その後、水酸化ナトリウム水溶液でレジストインク層を剥離した。形成された回路パターン層の所定の位置で積層体の一部に表裏の電気的導通を得るためのクリンピング加工を施すことにより、図２に示されるようなＩＣカード用アンテナコイル構成体を作製した。ＩＣカード用アンテナコイル構成体は、０．２ｋｇ／ｃｍの張力でコイル状に巻き取った。
【００６６】
得られたＩＣカード用アンテナコイル構成体について、実施例１と同様にして、ブロッキング現象、クリンピング加工された部分の表裏の導通抵抗値、エッチングによって形成された回路パターン層の外観を評価した。
【００６７】
また、得られたＩＣカード用アンテナコイル構成体の両面上に、ＥＶＡのホットメルト接着剤として厚みが３０μｍの東亞合成（株）製のアロンメルトＥＥＦ１１１（商品名）を介在させて、厚みが１００μｍの低熱収縮性白色ＰＥＴフィルム（帝人（株）製、商品名帝人Ｕ２）を温度１２０℃、圧力３ｋｇ／ｃｍ²で５分間、ホットプレスすることにより、外装フィルムとの接着性を評価した。この評価は、実施例１と同様にして行なった。
【００６８】
（比較例２）
基材としてＰＥＮフィルムに代えて厚みが３８μｍの低熱収縮性ＰＥＴフィルムを用いたこと、ドライラミネート用接着剤としてポリエステルウレタン接着剤に代えてエポキシ含有ポリエステルポリウレタン接着剤を用いたこと以外は、比較例１と同様の工程でＩＣカード用アンテナコイル構成体を作製した。
【００６９】
得られたＩＣカード用アンテナコイル構成体について、比較例１と同様にして、ブロッキング現象、クリンピング加工された部分の表裏の導通抵抗値、エッチングによって形成された回路パターン層の外観、外装フィルムとの接着性を評価した。
【００７０】
（比較例３）
基材としてＰＥＮフィルムに代えて厚みが１５０μｍのＡＰＥＴフィルムを用いたこと以外は、比較例１と同様の工程でＩＣカード用アンテナコイル構成体を作製した。
【００７１】
得られたＩＣカード用アンテナコイル構成体について、比較例１と同様にして、ブロッキング現象、クリンピング加工された部分の表裏の導通抵抗値、エッチングによって形成された回路パターン層の外観、外装フィルムとの接着性を評価した。
【００７２】
以上の評価結果を表１に示す。
【００７３】
【表１】

【００７４】
表１から、本発明に従った実施例１と２の試料では、ブロッキング現象を防止することができ、外装フィルムとの接着性も良好であったが、比較例１の試料ではブロッキング現象が生じ、外装フィルムとの接着強度が低く、比較例２と３の試料では外装フィルムとの接着強度が低いことがわかる。
【００７５】
以上に開示された実施の形態や実施例はすべての点で例示的に示されるものであり、制限的なものではないと考慮されるべきである。本発明の範囲は、以上の実施の形態や実施例ではなく、特許請求の範囲によって示され、特許請求の範囲と均等の意味および範囲内でのすべての修正や変更を含むものである。
【００７６】
【発明の効果】
以上のように、この発明のＩＣカード用アンテナコイル構成体によれば、ドライラミネート用接着剤を使用していないので、ブロッキング現象を防止することができるとともに、外装層との接着性を改善することができる。
【００７７】
また、この発明のＩＣカードによれば、ＩＣカードを構成する積層体において各層間の接着力を向上させることができるので、改ざん防止、エンボス加工性、長期間の使用に対する耐久性等を改善することができる。
【００７８】
さらに、この発明のＩＣカード用アンテナコイル構成体の製造方法によれば、外装層を積層する際にホットメルト接着剤を必ずしも使用する必要がないので、製造工程と製造コストを削減することができる。
【図面の簡単な説明】
【図１】 この発明の１つの実施の形態に従ったＩＣカード用アンテナコイル構成体を示す平面図である。
【図２】 図１のＩＩ−ＩＩ線の方向から見たＩＣカード用アンテナコイル構成体の部分断面図である。
【図３】 図１のＩＩ−ＩＩ線の方向から見たＩＣカードの部分断面図である。
【図４】 この発明の１つの実施の形態に従ったＩＣカード用アンテナコイル構成体の第１の製造工程を示す部分断面図である。
【図５】 この発明の１つの実施の形態に従ったＩＣカード用アンテナコイル構成体の第２の製造工程を示す部分断面図である。
【図６】 この発明の１つの実施の形態に従ったＩＣカード用アンテナコイル構成体の第３の製造工程を示す部分断面図である。
【図７】 この発明の１つの実施の形態に従ったＩＣカード用アンテナコイル構成体の第４の製造工程を示す部分断面図である。
【符号の説明】
１：ＩＣカード、１０：ＩＣカード用アンテナコイル構成体、１１：樹脂フィルム基材、１３：回路パターン層、１４：レジストインク層、２０：ＩＣチップ、３０：外装層、１３０：金属箔。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an antenna coil structure for an IC card, a manufacturing method thereof, and an IC card including the same.
[0002]
[Prior art and problems to be solved by the invention]
In recent years, IC cards have made remarkable progress and have begun to be used for telephone cards, credit cards, prepaid cards, cash cards, ID cards, card keys, various membership cards, book tickets, examination tickets, commuter passes, and the like. As a base material for these conventional IC cards, a resin film such as a general-purpose polyethylene terephthalate (PET) film has been used. For an IC card in which a circuit pattern layer is formed on the surface of a base material by attaching a metal foil to both surfaces of this resin film by a dry laminating method and then etching the metal foil. An antenna coil construction was used.
[0003]
However, the conventional IC card antenna coil structure has the following problems in the manufacturing process and product characteristics.
[0004]
(1) After the antenna coil structure for IC card is manufactured, the antenna coil structures are stacked on each other or wound up until an IC chip is mounted on the antenna coil structure. Transported and stored. At this time, a phenomenon (referred to as blocking) occurs in which the overlapping portions of the antenna coil constituents are in close contact with each other. Since the close contact portion cannot be easily separated, there is a problem that the IC card production line stops when the antenna coil structure is supplied to the next process. In addition, there is a problem that defective IC cards are generated by supplying the antenna coil structure to the next process while overlapping.
[0005]
In order to prevent this blocking phenomenon, the excess dry laminating adhesive remaining on the surface of the substrate where the metal foil is removed by etching, that is, where the circuit pattern layer is not formed, is removed. Or the countermeasure of inserting release paper in the part which an antenna coil structure overlaps can be considered. However, with respect to the former measure, it is extremely difficult to completely remove the adhesive. For the latter measure, a process for inserting and removing a release paper is required. Therefore, no matter which measure is taken, there is a problem that an extra process is required and the manufacturing cost increases.
[0006]
(2) After an IC chip is mounted on the IC coil antenna coil structure, a colored vinyl chloride resin (PVC) film or polyethylene terephthalate (PET) film, etc., is used as an exterior layer to heat polyester or ethylene vinyl acetate. Thermal bonding is performed using a molten (hot melt) adhesive. However, excess dry laminating adhesive remains on the surface of the substrate where the metal foil has been removed by etching, that is, where the circuit pattern layer is not formed, between the substrate and the exterior layer. Therefore, the thermal adhesive force of the outer layer by the hot melt adhesive is not sufficient. As a result, the conventional IC card has problems in durability against long-term use and prevention of tampering.
[0007]
In order to solve this problem, the adhesive type is changed between the dry laminate adhesive layer and the hot melt adhesive layer. It is necessary to take measures such as providing an intervening layer such as a polymer (EVA) or removing the adhesive layer for dry lamination by some method. However, each measure has a problem of deteriorating workability and increasing manufacturing costs.
[0008]
Accordingly, an object of the present invention is to provide an IC card antenna coil structure that can improve adhesion to the exterior layer without causing blocking, and that has no problem in appearance, a manufacturing method thereof, and the same. It is to provide an IC card.
[0009]
[Means for Solving the Problems]
An antenna coil structure for an IC card according to the present invention comprises: a base material whose surface includes amorphous polyethylene terephthalate; and a circuit pattern layer including a metal foil formed so as to be in contact with the surface of the base material. Prepare.
[0010]
In the antenna coil structure for an IC card according to the present invention, the circuit pattern layer is fixed so as to be in contact with the surface of the base material using a material containing amorphous polyethylene terephthalate as the base material, thereby preventing a blocking phenomenon. In addition, it is possible to increase the thermal bond strength of the exterior layer as compared with the conventional IC card.
[0011]
In the antenna coil structure for IC card of the present invention, the circuit pattern layer is preferably fixed on the surface of the substrate by thermal bonding or melt extrusion bonding.
[0012]
  In the IC coil antenna coil structure of the present invention, the base material isTheIt consists of a multilayer film in which films of amorphous polyethylene terephthalate are laminated on both sides of a film consisting of one selected from the group consisting of recarbonate, low heat shrinkable polyethylene naphthalate and low heat shrinkable polyethylene terephthalate.The
[0013]
Further preferably, in the antenna coil structure for IC card of the present invention, the circuit pattern layer is formed on the first circuit pattern layer formed on one surface of the base material and on the other surface of the base material. Second circuit pattern layer. In this case, it is preferable that at least a part of the first circuit pattern layer is in contact with at least a part of the second circuit pattern layer. Thereby, electrical conduction between the first and second circuit pattern layers can be achieved. The contact between the first and second circuit pattern layers can be easily performed by crimping.
[0014]
An IC card according to the present invention has an IC chip mounted on an IC card antenna coil structure having any one of the above-described structures, and an IC card antenna coil structure so as to cover the IC chip. A formed exterior layer.
[0015]
The manufacturing method of the IC coil antenna coil structure according to the present invention includes the following steps.
[0016]
(A) A step of fixing a base material containing a resin on the surface of the metal foil by thermal bonding or melt extrusion bonding.
[0017]
(B) A step of printing a resist ink layer having a pattern on a metal foil.
(C) A step of forming a circuit pattern layer including a metal foil by etching at least a part of the metal foil using the resist ink layer as a mask.
[0018]
(D) A step of removing the resist ink layer after forming the circuit pattern layer.
In the production method of the present invention, the resin constituting the substrate preferably contains amorphous polyethylene terephthalate.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a plan view of an IC card antenna coil structure according to one embodiment of the present invention, and FIG. 2 is a partial cross-sectional view of the IC card antenna coil structure seen from the direction of line II-II in FIG. 3 and 3 are partial cross-sectional views of the IC card as seen from the direction of the line II-II in FIG.
[0020]
As shown in FIGS. 1 and 2, an IC card antenna coil assembly 10 includes a resin film base 11 and a metal foil formed according to a predetermined pattern so as to be in direct contact with both surfaces of the resin film base 11. And a circuit pattern layer 13 made of As shown in FIG. 1, the circuit pattern layer 13 is formed in a spiral pattern on the surface of the resin film substrate 11. A region for connecting wiring to the IC chip is formed at the end of the circuit pattern layer 13, and a region 13c for mounting the IC chip is formed in the vicinity of the end. A circuit pattern layer indicated by a dotted line in FIG. 1 indicates a circuit pattern layer formed on the back surface of the resin film substrate 11, and the circuit pattern layers on the front and back surfaces are electrically connected to each other in each of the crimping portions 13a and 13b. Are in contact. This contact is achieved by partially breaking the resin film substrate 11 by crimping.
[0021]
As shown in FIG. 3, the IC card 1 includes an IC chip 20 mounted on the IC card antenna coil structure 10 shown in FIG. 2, and an IC card antenna coil structure so as to cover the IC chip 20. 10 and an exterior layer 30 formed on the substrate 10. The IC chip 20 is connected to the end of the circuit pattern layer 13 by a wiring 21.
[0022]
In the above one embodiment, the metal foil constituting the circuit pattern layer 13 can be at least one selected from aluminum foil, copper foil, stainless steel foil, titanium foil, tin foil, and the like. Among these metal foils, it is most preferable to use an aluminum foil as a constituent material of the circuit pattern layer 13 from the viewpoint of economy and reliability. Here, the aluminum foil is not limited to pure aluminum foil, but also includes aluminum alloy foil.
[0023]
The metal foil preferably has a thickness of 7 μm to 60 μm and a purity of 97.5% by mass to 99.7% by mass, more preferably a thickness of 15 μm to 50 μm and a purity of 98.0% by mass or more. It is 99.5 mass% or less.
[0024]
When the thickness of the metal foil is less than 7 μm, many pinholes are generated and there is a risk of breaking during the manufacturing process. On the other hand, when the thickness of the metal foil exceeds 60 μm, the etching process for forming the circuit pattern layer 13 takes time and increases the material cost.
[0025]
When the purity of the metal foil is less than 97.5% by mass, the impurities contained in the metal foil are increased, the electrical resistance of the circuit pattern layer 13 is increased, the corrosion resistance is extremely deteriorated, and even a slight amount of moisture is corroded. May progress. On the other hand, when the purity of the metal foil exceeds 99.7% by mass, the corrosion resistance of the metal foil is excessively improved, so that the etching process takes time.
[0026]
Specifically, as the material of the circuit pattern layer 13, for example, a pure aluminum foil or an aluminum alloy foil such as 1030, 1N30, 1050, 1100, 8021, and 8079 can be adopted as a symbol of JIS (AA).
[0027]
In the present invention, the purity when an aluminum foil is used as the metal foil is iron (Fe), silicon (Si), copper (Cu), manganese (Mn), magnesium (Mg), zinc (Zn), gallium (Ga). The total mass% of main impurity elements such as titanium (Ti), zirconium (Zr), nickel (Ni), and chromium (Cr) is subtracted from 100 mass%. When using an aluminum foil, the iron content is 0.2 to 1.5 mass%, the silicon content is 0.05 to 1.0 mass%, and the copper content is 0.3 mass% or less. Is preferred.
[0028]
Further, from the viewpoint of the strength of the aluminum foil, the above composition range is preferable, the tensile strength is preferably 70 to 120 MPa, and the elongation is preferably 5% or more. If the tensile strength of the metal foil is less than 70 MPa or the elongation is less than 5%, bending or wrinkles may occur during the manufacturing process, and the dimensional accuracy of the circuit pattern layer may deteriorate. The metal foil is preferably a soft foil or a semi-hard foil, and is preferably annealed at a temperature of about 250 to 550 ° C. after being rolled into a foil. If a hard foil having a tensile strength exceeding 120 MPa is used, there are problems in terms of remaining rolling oil and flexibility (winding properties), which is not preferable.
[0029]
In one embodiment of the present invention, amorphous polyethylene terephthalate (APET) is used as the resin constituting the resin film substrate 11. Specifically, the amorphous polyethylene terephthalate is obtained by substituting a part of ethylene glycol with 1,4-cyclohexanedimethanol to control the crystallization rate of the base polyethylene terephthalate (PET). The form in which amorphous polyethylene terephthalate is used for the resin film base 11 is preferably a film of amorphous polyethylene terephthalate (APET) alone or a multilayer film in which amorphous polyethylene terephthalate is laminated on at least the surface. In the multilayer film, amorphous polyethylene terephthalate (APET) film is laminated on both sides of a film made of polycarbonate (PC), low heat shrinkable polyethylene naphthalate (PEN), or low heat shrinkable polyethylene terephthalate (PET). Are preferred.
[0030]
The thickness of the above-mentioned single APET film is preferably 5 μm or more and 100 μm or less, more preferably 20 μm or more and 80 μm or less. Further, the multilayer film preferably has a total thickness of 30 μm or more and 130 μm or less, more preferably an APET layer having a thickness of 5 μm or more and 50 μm or less and a total thickness of 40 μm or more and 100 μm or less.
[0031]
When the thickness of the single APET film is less than 5 μm, the adhesion with the metal foil constituting the circuit pattern layer is not sufficient, and the thin circuit pattern layer may not be formed by etching. In addition, when the total thickness of the multilayer film is less than 30 μm, there is a problem in workability in each manufacturing process because the rigidity of the laminate with the metal foil is insufficient. On the other hand, if the total thickness exceeds 130 μm, the crimping process described later may not be performed reliably.
[0032]
The heat shrinkage rate of a film made of PC, low heat-shrinkable PEN or low heat-shrinkable PET constituting the multilayer film is preferably 0.3% or less when held at a temperature of 150 ° C. for 30 minutes. When this thermal shrinkage rate exceeds 0.3%, there is a problem that the dimensional accuracy of the circuit pattern layer formed on the substrate is deteriorated.
[0033]
The heat shrinkage rate is a linear shrinkage rate and is calculated by the following equation.
[0034]
[Expression 1]

[0035]
In the above formula, L is the length of the resin film after being held at a temperature of 150 ° C. for 30 minutes, L₀Is the original length of the resin film.
[0036]
In addition, by heat-processing a normal PEN film previously, a heat shrinkage rate can also be 0.3% or less, and the heat-treated PEN film is also contained in the low heat-shrinkable PEN.
[0037]
As a method of laminating an amorphous polyethylene terephthalate (APET) film on both surfaces of a film made of any one of polycarbonate (PC), low heat shrinkable polyethylene naphthalate (PEN), and low heat shrinkable polyethylene terephthalate (PET), a known method Means can be employed, and examples thereof include adhesion by an adhesive, extrusion method, and cast (casting) method. Among these, the cast (casting) method is preferably employed.
[0038]
The method of laminating the resin film substrate 11 composed of amorphous polyethylene terephthalate on the metal foil composing the circuit pattern layer 13 includes thermal bonding (also called heat lamination or thermal lamination) or melt extrusion bonding (extrusion lamination). ). By adopting these methods, the resin film substrate and the metal foil can be fixed without using an adhesive for dry lamination or the like. Therefore, since it is possible to exert and maintain a strong adhesive force between the base material and the circuit pattern layer, it is possible to overcome the problems of the prior art.
[0039]
A heat bonding process is normally performed by bonding a resin film base material in the state which heated metal foil using the heating roll. The temperature for thermal bonding is preferably about 100 to 160 ° C. The melt-extrusion adhesion process is performed by heating and melting a resin and extruding the resin on a metal foil with a die.
[0040]
In addition, metal foil can be laminated | stacked on the single side | surface or both surfaces of a base resin film, and can be properly used suitably according to a use, a design, a use purpose, etc.
[0041]
Next, an embodiment of a method for manufacturing an IC coil antenna coil assembly according to the present invention will be described. 4 to 7 are partial cross-sectional views showing the manufacturing process of the IC card antenna coil structure according to the present invention. 4-7 has shown the partial cross section seen from the direction of the II-II line | wire of FIG.
[0042]
As shown in FIG. 4, the resin film base material 11 is fixed to one surface of each metal foil 130 by thermal bonding (or melt extrusion bonding). Thus, the laminated body of the metal foil 130 and the resin film base material 11 is prepared.
[0043]
As shown in FIG. 5, the resist ink layer 14 is printed on the surface of the metal foil 130 so as to have a predetermined spiral pattern according to the specifications of the antenna coil. After printing, the resist ink layer 14 is cured.
[0044]
As shown in FIG. 6, the circuit pattern layer 13 is formed by etching the metal foil 130 using the resist ink layer 14 as a mask.
[0045]
Thereafter, as shown in FIG. 7, the resist ink layer 14 is peeled off.
Finally, crimping is performed on a predetermined region of the circuit pattern layer 13 using a metal plate having protrusions and depressions and metal protrusions, thereby forming a contact portion or a crimping portion 13a of the circuit pattern layer as shown in FIG. In this way, the IC card antenna coil structure 10 of the present invention is completed.
[0046]
The resist ink used in the production method of the present invention is not particularly limited, but it is preferable to use an ultraviolet curable resist ink mainly composed of an acrylic monomer having at least one carboxyl group in the molecule and an alkali-soluble resin. This resist ink is suitable for continuous mass production because it can be gravure printed, has acid resistance, and can be easily removed by alkali. After applying gravure printing to the metal foil with a predetermined circuit pattern using this resist ink and curing it by irradiating with ultraviolet rays, the metal foil is acid-etched, for example, with ferric chloride aqueous solution, hydroxylated, etc. according to a normal method. The circuit pattern layer can be formed by peeling and removing the resist ink layer with an alkali such as an aqueous sodium solution.
[0047]
Examples of acrylic monomers having at least one carboxyl group in the molecule include 2-acryloyloxyethyl phthalic acid, 2-acryloyloxyethyl succinic acid, 2-acryloyloxyethyl hexahydrophthalic acid, 2-acryloyloxypropyl phthalate. Acid, 2-acryloyloxypropyltetrahydrophthalic acid, 2-acryloyloxypropylhexahydrophthalic acid, and the like. Among these, a single acrylic monomer or a mixture of several acrylic monomers can be used. . Examples of the alkali-soluble resin include styrene-maleic acid resin, styrene-acrylic resin, and rosin-maleic acid resin.
[0048]
In addition to the above components, normal monofunctional acrylic monomers, polyfunctional acrylic monomers, and prepolymers can be added to the resist ink to such an extent that alkali peelability is not hindered. Photopolymerization initiators, pigments, additives It can be prepared by appropriately adding a solvent or the like. Examples of the photopolymerization initiator include benzophenone and derivatives thereof, benzyl, benzoin and alkyl ethers thereof, thioxanthone and derivatives thereof, lucillin PTO, Irgacure manufactured by Ciba Specialty Chemicals, Esacure manufactured by Fratelli Lamberti, and the like. As the pigment, a coloring pigment is added so that the pattern is easy to see, and extender pigments such as silica, talc, clay, barium sulfate, calcium carbonate and the like can be used in combination. In particular, silica is effective in preventing blocking when a metal foil is wound with an ultraviolet curable resist ink attached. Additives include polymerization inhibitors such as 2-tertiary butyl hydroquinone, antifoaming agents such as silicon, fluorine compounds, and acrylic polymers, and leveling agents, which are added as necessary. Examples of the solvent include ethyl acetate, ethanol, denatured alcohol, isopropyl alcohol, toluene, MEK and the like, and these solvents can be used alone or in combination. The solvent is preferably evaporated from the resist ink layer by hot air drying after gravure printing.
[0049]
After forming the circuit pattern layer, the antenna coil can be formed by performing crimping processing at a predetermined position at room temperature, and electrically contacting part of the front and back metal foils. Here, the term “crimping” refers to, for example, destroying a resin film substrate with a drill, a file, an ultrasonic wave, or the like, and physically contacting parts of the metal foil forming the circuit pattern layer. Specifically, a resin film base material is partially broken by bringing a laminate comprising a resin film base material and a metal foil into contact with an uneven metal plate and pressing metal protrusions. The surfaces can be brought into contact with each other, and electrical conduction can be obtained.
[0050]
The configuration and the manufacturing method of the antenna coil structure for an IC card according to the present invention have been described, but the following steps are further performed for commercialization as an IC card. In the IC card antenna coil structure 10 shown in FIG. 1, the IC chip 20 is mounted in the region 13 c of the circuit pattern layer 13 as shown in FIG. 3, and wiring is provided between the IC chip 20 and the end of the circuit pattern layer 13. 21 is connected. Further, an exterior layer (hiding layer) 30 such as white APET, white PVC, or white PET is laminated on the front and back surfaces of the laminate of the circuit pattern layer 13 and the resin film substrate 11. Lamination may be performed by the above-described thermal bonding, or may be performed by thermal bonding through an EVA or polyester hot melt agent. The exterior layer (hiding layer) 30 is not limited to white, and known color pigments, extender pigments, metal pigments such as aluminum flakes, and known resins, varnishes, vehicles, and the like can be used. In addition, components used in known IC cards such as a printing layer, a magnetic recording layer, a magnetic shielding layer, an overcoat layer, and a vapor deposition layer can be laminated as necessary. Needless to say, a capacitor, a coil, a resistor, wiring, various memories, a diode, and the like may be provided in addition to the above IC chip.
[0051]
【Example】
Examples of the present invention and comparative examples will be described below.
[0052]
Example 1
As a base material, an amorphous polyethylene terephthalate resin (APET) film having a thickness of 38 μm has an aluminum foil (JIS (AA) 1N30-O) having a thickness of 30 μm on one surface and a thickness of 20 μm on the other surface at a heat bonding temperature of 160 ° C. A laminate was prepared by continuously bonding by a heat laminating method. Daigoku Ink Chemical Co., Ltd. Daicure-RE-97 (trade name) 5 g / m as a resist ink on both sides of the laminate.²The resist ink layer having a pattern as shown in FIG. 1 was continuously printed. Using this resist ink layer as a mask, an excess aluminum foil was etched with a ferric chloride aqueous solution to form a circuit pattern layer. Thereafter, the resist ink layer was peeled off with an aqueous sodium hydroxide solution. The IC coil antenna coil structure as shown in FIG. 2 was produced by subjecting a part of the laminated body to crimping processing to obtain front and back electrical continuity at a predetermined position of the formed circuit pattern layer. . The IC coil antenna coil structure was wound into a coil with a tension of 0.2 kg / cm.
[0053]
The blocking phenomenon of the obtained IC card antenna coil structure was evaluated as follows. The IC card antenna coil structure was stored in a coiled state in the atmosphere at a temperature of 40 ° C. or 60 ° C. for 48 hours, and then the end of the winding coil was manually rewound and evaluated. The evaluation criteria were as follows.
[0054]
Evaluation 5: Even when the winding coil is unwound, the end portion is separated even if it is not pulled.
[0055]
Evaluation 4: A noise is made when the winding coil is rewound, but the end part is separated without applying a particularly strong force.
[0056]
Evaluation 3: The end is not separated unless a force is applied when the winding coil is rewound, but the end is separated when pulled by a certain amount of force.
[0057]
Evaluation 2: When a force is applied when the winding coil is rewound, the end portion is separated, but the material is partially damaged.
[0058]
Evaluation 1: When the winding coil is rewound, it sticks completely, and the end does not leave even when force is applied.
[0059]
Further, the conduction resistance values of the front and back of the crimped portion of the obtained IC card antenna coil structure were measured.
[0060]
Furthermore, the external appearance of the circuit pattern layer formed by etching in the obtained antenna coil structure for IC card was evaluated. Etching defects such as disconnection, thinning, and peeling of the circuit pattern due to etching were visually observed, and those that did not have any etching defects were evaluated as good, and those that might cause problems as a product were determined as defective.
[0061]
A white PET film (product name: Teijin U2 manufactured by Teijin Ltd.) having a thickness of 100 μm without interposing a hot melt adhesive on both surfaces of the obtained IC coil antenna coil structure was heated to 120 ° C. and 3 kg pressure. / Cm²The adhesiveness with the exterior film was evaluated by hot pressing for 5 minutes. This evaluation was performed by measuring the laminate strength between the exterior film and the IC coil antenna coil structure according to a T-type peel test (compliant with JIS K6854 T-type peel, but with a width of 15 mm).
[0062]
(Example 2)
As in Example 1, except that a multilayer film of APET film (thickness 10 μm) / PC film (thickness 30 μm) / APET film (thickness 10 μm) laminated in order instead of the single film of APET was used as the base material. In this process, an IC card antenna coil structure was produced.
[0063]
The obtained IC card antenna coil structure was evaluated in the same manner as in Example 1 for the blocking phenomenon, the conduction resistance values of the front and back surfaces of the crimped portion, and the appearance of the circuit pattern layer formed by etching.
[0064]
Further, a white APET film (product name: PG-W, manufactured by Mitsubishi Plastics Co., Ltd.) having a thickness of 100 μm with no hot melt adhesive interposed on both surfaces of the obtained IC coil antenna coil structure at a temperature of 120 ℃, pressure 3kg / cm²The adhesiveness with the exterior film was evaluated by hot pressing for 5 minutes. This evaluation was performed in the same manner as in Example 1.
[0065]
(Comparative Example 1)
3 g / m of polyester urethane adhesive as an adhesive for dry lamination on one surface of aluminum foil (JIS (AA) 1N30-O) having thicknesses of 30 μm and 20 μm²After coating with a thickness of 30 μm, a polyethylene naphthalate resin (PEN) film having a thickness of 38 μm as a base material is continuously bonded by dry laminating with an aluminum foil having a thickness of 30 μm on the one surface and a thickness of 20 μm on the other surface. A laminate was produced. Daigoku Ink Chemical Co., Ltd. Daicure-RE-97 (trade name) 5 g / m as a resist ink on both sides of the laminate.²The resist ink layer having a pattern as shown in FIG. 1 was continuously printed. Using this resist ink layer as a mask, an excess aluminum foil was etched with a ferric chloride aqueous solution to form a circuit pattern layer. Thereafter, the resist ink layer was peeled off with an aqueous sodium hydroxide solution. The IC coil antenna coil structure as shown in FIG. 2 was produced by subjecting a part of the laminated body to crimping processing to obtain front and back electrical continuity at a predetermined position of the formed circuit pattern layer. . The IC coil antenna coil structure was wound into a coil with a tension of 0.2 kg / cm.
[0066]
The obtained IC card antenna coil structure was evaluated in the same manner as in Example 1 for the blocking phenomenon, the conduction resistance values of the front and back surfaces of the crimped portion, and the appearance of the circuit pattern layer formed by etching.
[0067]
Also, Aronmelt EEF111 (trade name) manufactured by Toagosei Co., Ltd. having a thickness of 30 μm as an EVA hot melt adhesive is interposed on both surfaces of the obtained IC coil antenna coil structure, and the thickness is 100 μm. Low heat-shrinkable white PET film (manufactured by Teijin Limited, trade name Teijin U2) at a temperature of 120 ° C. and a pressure of 3 kg / cm²The adhesiveness with the exterior film was evaluated by hot pressing for 5 minutes. This evaluation was performed in the same manner as in Example 1.
[0068]
(Comparative Example 2)
Comparative example, except that a low heat-shrinkable PET film having a thickness of 38 μm was used instead of a PEN film as a substrate, and an epoxy-containing polyester polyurethane adhesive was used instead of a polyester urethane adhesive as an adhesive for dry lamination In the same process as in No. 1, an IC card antenna coil structure was produced.
[0069]
About the obtained IC coil antenna coil structure, in the same manner as in Comparative Example 1, the blocking phenomenon, the conduction resistance value of the front and back of the crimped portion, the appearance of the circuit pattern layer formed by etching, and the exterior film Adhesion was evaluated.
[0070]
(Comparative Example 3)
An IC card antenna coil structure was fabricated in the same process as Comparative Example 1 except that an APET film having a thickness of 150 μm was used instead of the PEN film as the substrate.
[0071]
About the obtained IC coil antenna coil structure, in the same manner as in Comparative Example 1, the blocking phenomenon, the conduction resistance value of the front and back of the crimped portion, the appearance of the circuit pattern layer formed by etching, and the exterior film Adhesion was evaluated.
[0072]
The above evaluation results are shown in Table 1.
[0073]
[Table 1]

[0074]
From Table 1, in the samples of Examples 1 and 2 according to the present invention, the blocking phenomenon could be prevented and the adhesion with the exterior film was good, but the blocking phenomenon occurred in the sample of Comparative Example 1. It can be seen that the adhesive strength with the exterior film is low, and the samples of Comparative Examples 2 and 3 have low adhesive strength with the exterior film.
[0075]
The embodiments and examples disclosed above are exemplarily shown in all respects and should be considered as not restrictive. The scope of the present invention is shown not by the above embodiments or examples but by the scope of claims, and includes all modifications and changes within the meaning and scope equivalent to the scope of claims.
[0076]
【The invention's effect】
As described above, according to the antenna coil structure for IC card of the present invention, since the adhesive for dry lamination is not used, the blocking phenomenon can be prevented and the adhesion to the exterior layer can be improved. be able to.
[0077]
In addition, according to the IC card of the present invention, the adhesion between the layers can be improved in the laminate constituting the IC card, so that tamper prevention, embossability, durability against long-term use, etc. are improved. be able to.
[0078]
Furthermore, according to the method for manufacturing an IC coil antenna coil structure of the present invention, it is not always necessary to use a hot melt adhesive when laminating the exterior layers, and therefore the manufacturing process and manufacturing cost can be reduced. .
[Brief description of the drawings]
FIG. 1 is a plan view showing an antenna coil structure for an IC card according to one embodiment of the present invention.
2 is a partial cross-sectional view of the IC card antenna coil structure as viewed from the direction of line II-II in FIG. 1;
3 is a partial cross-sectional view of the IC card as seen from the direction of line II-II in FIG.
FIG. 4 is a partial cross sectional view showing a first manufacturing process of the IC coil antenna coil structure according to one embodiment of the present invention;
FIG. 5 is a partial cross sectional view showing a second manufacturing step of the IC coil antenna coil structure according to the embodiment of the present invention.
FIG. 6 is a partial cross sectional view showing a third manufacturing step of the IC card antenna coil structure according to one embodiment of the present invention.
FIG. 7 is a partial cross-sectional view showing a fourth manufacturing step of the IC card antenna coil structure according to one embodiment of the present invention;
[Explanation of symbols]
1: IC card, 10: antenna coil structure for IC card, 11: resin film substrate, 13: circuit pattern layer, 14: resist ink layer, 20: IC chip, 30: exterior layer, 130: metal foil.

Claims (6)

A substrate whose surface contains amorphous polyethylene terephthalate;
A circuit pattern layer including a metal foil formed on and in contact with the surface of the substrate ;
The base material is composed of a multilayer film in which films of amorphous polyethylene terephthalate are laminated on both surfaces of a film selected from the group consisting of polycarbonate, low heat-shrinkable polyethylene naphthalate and low heat-shrinkable polyethylene terephthalate. IC card antenna coil structure.   2. The IC coil antenna coil structure according to claim 1, wherein the circuit pattern layer is fixed on the surface of the base material by thermal bonding or melt extrusion bonding. 3. The circuit pattern layer includes a first circuit pattern layer formed on one surface of the base material, and a second circuit pattern layer formed on the other surface of the base material. The antenna coil structure for IC card according to 1 or 2 . 4. The IC coil antenna coil structure according to claim 3 , wherein at least a part of the first circuit pattern layer is in contact with at least a part of the second circuit pattern layer. An IC chip mounted on the IC coil antenna coil structure according to any one of claims 1 to 4 ,
An IC card comprising: an exterior layer formed on the IC coil antenna coil structure so as to cover the IC chip. It is a manufacturing method of the antenna coil structure for IC cards according to any one of claims 1 to 4,
Fixing a base material containing a resin on the surface of the metal foil by thermal bonding or melt extrusion bonding;
Printing a resist ink layer having a pattern on the metal foil;
Forming a circuit pattern layer including the metal foil by etching at least a part of the metal foil using the resist ink layer as a mask;
And a step of removing the resist ink layer after forming the circuit pattern layer.

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