JP2004185861A

JP2004185861A - Circuit board and battery pack

Info

Publication number: JP2004185861A
Application number: JP2002348519A
Authority: JP
Inventors: Toshio Matsuda; 俊夫松田
Original assignee: Sony Corp
Current assignee: Sony Corp
Priority date: 2002-11-29
Filing date: 2002-11-29
Publication date: 2004-07-02

Abstract

<P>PROBLEM TO BE SOLVED: To have an electromagnetic wave shield function, as well as to allow connecting an electrode terminal connecting portion with a connector connecting portion. <P>SOLUTION: A circuit board to be attached to a polymer battery with a roughly rectangular shape comprises a 1st substrate portion having a terminal connecting portion to which a positive electrode terminal and a negative electrode terminal of the polymer battery are electrically connected; a 2nd substrate portion having a circuit portion with an external connecting terminal and a battery control element mounted thereon; and a 3rd substrate portion having a wiring portion to which the electrode terminal connecting portion, the external connecting terminal portion and the battery control element are electrically connected. The 1st to the 3rd substrate portions are disposed on three mutually adjacent surfaces of the polymer battery. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、ポリマー電池の異なる面に配される端子接続部と回路部とを一体にし、さらに電磁波シールド機能を持たせた回路基板および電池パックに関する。
【０００２】
【従来の技術】
近年、ノート型パーソナルコンピュータ、ＰＤＡ（ＰｅｒｓｏｎａｌＤｉｇｉｔａｌＡｓｓｉｓｔａｎｔ）、携帯電話、カメラ一体型ＶＴＲ（ＶｉｄｅｏＴａｐｅＲｅｃｏｒｄｅｒ）等の携帯可能な小型電子機器が多く登場しており、その電源として、軽量且つ高エネルギー密度を有する非水電解質二次電池、特にリチウムイオン二次電池の開発が活発に進められている。
【０００３】
このリチウムイオン二次電池では、更なる小型軽量化を図るために、ゲル状電解質や高分子固体電解質等の固体電解質を用いると共に、外装材として熱融着が可能なラミネートフィルムを用いて発電要素である電池素子を封入することが行われている。このようなリチウムイオン二次電池は、一般的にポリマー電池と呼ばれており、電解質が固体又はゲル状であることから液漏れの心配がなく、金属製容器の代わりにラミネートフィルムからなる外装材を用いることで、更なる薄型化が可能となっている。
【０００４】
また、ポリマー電池は、充放電を制御する制御回路や、外部と電気的に接続するためのコネクタが搭載された回路基板と電気的に接続されており、過充放電等からの保護が図られている。そして、これらポリマー電池及び回路基板は、例えば特許文献１や特許文献２に示されるように、プラスチックケース等からなる外筐に収納されることによって、いわゆる電池パックとして構成されている。
【０００５】
【特許文献１】
特開２００１−２６６８２０号公報
【特許文献２】
特開２０００−１５６２０８号公報
【０００６】
【発明が解決しようとする課題】
ポリマー電池の電極端子が接続される部分と、コネクタを搭載する部分とをポリマー電池の異なる面に配した形態の電池パックも採用されている。
【０００７】
しかしながら、従来の回路基板においては、電池端子を接続する基板部と、コネクタとを搭載する基板部とは一体化されておらず、両者を電気的に接続するための手段が必要であった。
【０００８】
また、近年、電子機器では、取扱う情報量の増大に対応するために、機器内の各電子部品間でやりとりされる信号がより高周波化される傾向にあるが、これに伴い、機器自身や他の電子機器等から放射される電磁波によって機器の信号電流が乱れたりする、いわゆる電磁波障害が起りやすくなっている。特に、屋外で用いられる携帯電話等の携帯機器の場合には、小型化に伴って回路が高集積度とされた結果、筐体内の回路基板上の各電子回路相互間でも電磁波障害が発生しやすくなっていた。
【０００９】
従来、こうした機器を正常に使用可能とするために、銅板等の導電性材料で対象となる電子回路等を覆い、電磁波を内外に透過させないいわゆる電磁波シールドを行って各回路間を隔て、所定の回路から出た電磁波の別回路への到達を防ぐ構造が採用されていた。しかしながら、取り付ける部品点数が多くなり、また、取り付けの作業性が複雑で工数も多く必要であった。
【００１０】
本発明は、このような従来の実情に鑑みて提案されたものであり、電極端子接続部とコネクタ接続部とを接続できるとともに、電磁波シールド機能をも持たせた回路基板を提供することを目的とする。
【００１１】
【課題を解決するための手段】
本発明の回路基板は、略直方体形状のポリマー電池に取り付けられる回路基板であって、ポリマー電池の正極端子及び負極端子が電気的に接続される端子接続部を有する長方形状の第１の基板部と、外部接続端子及び電池制御素子が搭載された回路部を有する長方形状の第２の基板部と、上記第１の基板部と第２の基板部との間に、当該第１の基板部の長辺部及び第２の基板部の長辺部と接続して配され、端子接続部と外部接続端子及び電池制御素子とを電気的に接続する配線部を有する第３の基板部とを有する。
【００１２】
そしてこの回路基板は、上記第３の基板部は、第１の基板部と第２の基板部とが互いに直角となるように同一面内において電気的に接続し、上記第１の基板部は、ポリマー電池の一側面に配され、上記第２の基板部は、ポリマー電池の一側面にと隣り合う他側面に配され、上記第３の基板部は、ポリマー電池の一側面と他側面と隣り合う主面に配されることを特徴とする。
【００１３】
上述したような本発明に係る回路基板では、端子接続部を有する第１の基板部と、回路部を有する第２の基板部とを、配線部を有する第３の基板部で接続しているので、端子部と回路部とが電気的に一体に接続されるとともに、略直方体形状のポリマー電池の他面に配することが可能になる。
【００１４】
また、本発明の電池パックでは、ポリマー電池と、当該ポリマー電池に接続された回路基板とを備え、上記回路基板は、ポリマー電池の正極端子及び負極端子が電気的に接続される端子接続部を有する長方形状の第１の基板部と、外部接続端子及び電池制御素子が搭載された回路部を有する長方形状の第２の基板部と、上記第１の基板部と第２の基板部との間に、当該第１の基板部の長辺部及び第２の基板部の長辺部と接続して配され、端子接続部と外部接続端子及び電池制御素子とを電気的に接続する配線部を有する第３の基板部とを有する。
【００１５】
そして、本発明の電池パックは、上記第３の基板部は、第１の基板部と第２の基板部とが互いに直角となるように電気的に接続し、上記第１の基板部は、ポリマー電池の一側面に配され、上記第２の基板部は、ポリマー電池の一側面と隣り合う他側面に配され、上記第３の基板部は、ポリマー電池の一側面と他側面と隣り合う主面に配されていることを特徴とする。
【００１６】
上述したような本発明に係る電池パックでは、回路基板が、端子接続部を有する第１の基板部と、回路部を有する第２の基板部とを、配線部を有する第３の基板部で接続しているので、端子部と回路部とが電気的に一体に接続されるとともに、略直方体形状のポリマー電池の他面に配することが可能になる。
【００１７】
【発明の実施の形態】
以下、本発明を適用した回路基板及び電池パックについて、図面を参照しながら説明する。
【００１８】
この電池パック１は、例えば携帯型電話機等の電子機器等に設けられた装着部に装着され、電子機器等に対して所定の電圧の電力を安定して供給することが可能なものである。図１及び図２に示すように、この電池パック１は、収納ケースとなる外筐２に、発電要素となるポリマー電池３と、ポリマー電池３が電気的に接続された回路基板４とが収納された構造となっている。この電池パック１は、図１中矢印Ａ方向に挿入することにより、携帯電話等の電子機器に取り付けられる。
【００１９】
外筐２は、いわゆるプラスチックケースからなり、略扁平箱状の上ハーフ２ａの周壁と下ハーフ２ｂの周壁とを互いに突き合わすことで、内部にポリマー電池３、回路基板４が収納される収納空間を形成すると共に、その外形形状は略矩形平板状である。また、この外筐２には、短手方向の一側端部に、回路基板４に取り付けられたコネクタ２２を外部に臨ませる開口部５が形成されており、外筐２を構成する上ハーフ２ａ及び下ハーフ２ｂには、この開口部５を構成する切欠部５ａ，５ｂがそれぞれ形成されている。
【００２０】
ポリマー電池３は、図３に示すように、例えばリチウムイオン二次電池等の非水電解質電池であり、充放電といった電池反応が行われる電池素子６と、この電池素子６を封入するフィルム状の外装材７とを有している。
【００２１】
ポリマー電池３において電池素子６は、帯状の正極８と、帯状の負極９との間に有機高分子や電解質塩を含有させた固体電解質１０とセパレータ１１とを介在させた状態で、電極の長手方向に捲回することで発電素子として機能する。
【００２２】
正極８は、正極活物質と結着剤とを含有する正極合剤塗液を正極集電体１２上に塗布、乾燥、加圧することにより、正極集電体１２上に正極合剤層１３が圧縮形成された構造となっている。正極８には、正極端子１４が正極集電体１２の所定の位置に、正極集電体１２の幅方向に突出するように接続されている。この正極端子１４には、例えばアルミニウム等の導電性金属からなる短冊状金属片等を用いる。
【００２３】
負極９は、負極活物質と結着剤とを含有する負極合剤塗液を負極集電体１５上に塗布、乾燥、加圧することにより、負極集電体１５上に負極合剤層１６が圧縮形成された構造となっている。負極９には、負極端子１７が負極集電体１５の所定の位置に、負極集電体１５の幅方向に突出するように接続されている。この負極端子１７には、例えばニッケルや銅等の導電性金属からなる短冊状金属片等を用いる。
【００２４】
固体電解質１０は、正極８と負極９との間で例えばリチウムイオン等の授受を行うものである。このため、この固体電解質１０には、リチウムイオン導電性を有する有機固体電解質を用いる。この有機固体電解質としては、電解質塩とそれを含有させる有機高分子とによって構成される高分子固体電解質や、非水電解液を高分子マトリックスに含有させたゲル状電解質等を用いることができる。そして、固体電解質１０は、正極８及び負極９の表面に、有機固体電解質を含有する電解質溶液を塗布し、固化することで電解質層として形成される。
【００２５】
セパレータ１１は、正極８と負極９とを離間させるものであり、この種の非水電解質電池の絶縁性多孔質膜として通常用いられている公知の材料を用いることができる。
【００２６】
以上のような構成の電池素子６を封入する外装材７は、例えば樹脂層と金属層とがラミネート加工等で貼り合わされて二層以上に複合化されたラミネートフィルムであり、電池素子６と対向する面が樹脂層になるようにされている。樹脂層としては、正極端子１４及び負極端子１７に対して接着性を示すものであれば材料は特に限定されない。金属層としては、例えば箔状、板状等に成形されているアルミニウム、ステンレス、ニッケル、鉄等が用いられる。また、外装材７においては、電池１の外周層となる層に例えばナイロン等からなる樹脂層を備えることにより、破れや突き刺し等に対する強度を向上させることができる。
【００２７】
外装材７の内部に、電池素子６を収納し、外装材７の周縁部を例えばヒートシール等で樹脂層同士を張り合わせることにより、電池素子７を構成する正極９及び負極１０と導通された正極端子１４及び負極端子１７が外装材７の貼合せ面７ａの間から樹脂片１８を介して外部へと引き出された状態で電池素子７が外装材７に封入されて、ポリマー電池３となる。
【００２８】
次に、このようなポリマー電池３に接続される回路基板４について説明する。
【００２９】
回路基板４の一構成例を図４及び図５に示す。なお、図４は、回路基板４の一方の面（以下、この面を表面と称する。）を示す平面図であり、図５は、回路基板４の他方の面（以下、この面を裏面と称する。）を示す平面図である。回路基板４は、裏面をポリマー電池３に当接させ、表面を外側にしてポリマー電池３に取り付けられる。
【００３０】
なお、後述するように、回路基板４は、実際にはその一部を折り曲げた状態で電池パックに取り付けられるが、図４及び図５では、折り曲げていない状態を示している。
【００３１】
この回路基板４は、ポリマー電池３の正極端子１４及び負極端子１７が電気的に接続される端子接続部２０とサーミスタ２１とを有する第１の基板部４ａと、コネクタ２２及び電池制御回路部２３が搭載された回路部２４を有する第２の基板部４ｂと、端子接続部２０と回路部２４とを電気的に接続する配線部２５と、当該配線部２５を電磁波からシールドするシールド部２６とを有する第３の基板部４ｃとから構成される。
【００３２】
第１の基板部４ａ及び第２の基板部４ｂは、ポリマー電池３の厚みに対応した幅を有する略長方形状とされ、第３の基板部４ｃは略Ｌ字形状とされている。そして、第１の基板部４ａは、短手方向の一端部において、略Ｌ字形状をした第３の基板部４ｃの一方の端部に接続し、第２の基板部４ｂは、短手方向の一端部において、第３の基板部４ｃの他方の端部に接続している。このとき、第１の基板部４ａと第３の基板部４ｃとの間の第１の折り曲げ線２７と、第２の基板部４ｂと第３の基板部４ｃとの間の第２折り曲げ線２８とは直交する。
【００３３】
なお、ここでは、第３の基板部の形状を、途中で湾曲する略Ｌ字形状としているが、本発明はこれに限定されるものではなく、湾曲部をもたない形状とすることもできる。
【００３４】
なお、この回路基板４は、可撓性を有すると共に、パターン配線と誘電絶縁層とが交互に積層されてなる、いわゆる多層フレキシブルプリント配線基板である。そして、この回路基板４は、可撓性を有することから、第１の基板部４ａと第２の基板部４ｂとの間、及び第２の基板部４ｂと第３の基板部４ｃとの間で折り曲げ可能となっている。なお、ここでは、回路基板４としてフレキシブル基板を用いて説明しているが、このことに限定されることはなく、例えばリジッド基板等にも適用可能である。
【００３５】
そして、この回路基板４は、裏面を内側にして、第１の折り曲げ線において、第３の基板部４ｃに対して略垂直になるように第１の基板部４ａを折り曲げ、さらに第２の折り曲げ線において、第３の基板部４ｃに対して略垂直になるように第２の基板部４ｂを折り曲げることにより、第１の基板部４ａないし第３の基板部４ｃが互いに略垂直になる。
【００３６】
そして、回路基板４をポリマー電池３に取り付ける際、この第１の基板部４ａないし第３の基板部４ｃは、裏面をポリマー電池３に当接させるとともに、略直方体形状のポリマー電池３の互いに略垂直な３つの面に沿って配される。すなわち、後掲する図８に示すように、接続部２５を備えた第１の基板部４ａは、ポリマー電池３の正極端子及び負極端子が引き出される主面３ａに当接して配される。また、回路部２４を備えた第３の基板部４ｃは、上記主面３ａに隣接し略垂直な、ポリマー電池３の側面３ｂに当接して配される。また、接続部２５及びシールド部２６を備えた第３の基板部４ｃは、上記主面３ａ及び側面３ｂに隣接し略垂直な上面３ｃに当接して配される。
【００３７】
そして、この電池パック１では、コネクタ２２を、ポリマー電池３の主面３ａ側からではなく、側面３ｂ側から外部に臨ませている。
【００３８】
なお、上記第１の折り曲げ線２７及び第２の折り曲げ線２８には、基板を折り曲げ易くさせるための折り曲げパターン２７ａ，２８ａが、表面に設けられている。この折り曲げパターン２７ａ，２８ａは、第１の基板部４ａ及び第２の基板部４ｂの短手方向と略平行な線状のパターン配線となるように一つ以上形成されている。
【００３９】
折り曲げパターン２７ａ，２８ａは、例えば誘電絶縁層の主面全面にめっき法等で成膜された導電性金属等からなる金属層に、フォトリソグラフ処理等で所望のパターンとなるようにパターニング加工が施されることで設けられる。
【００４０】
以下、回路基板４を構成する第１の基板部４ａないし第３の基板部４ｃについて説明する。
【００４１】
第１の基板部４ａは、図５に示すように、その裏面に接続部２０が設けられている。そして、この第１の基板部４ａは、ポリマー電池３の正極端子１４及び負極端子１７が導出される主面３ａに当接して配される。
【００４２】
接続部２０には、上述したポリマー電池３の正極端子１４及び負極端子１７が電気的に接続される一対の接続ランド２０ａ，２０ｂが設けられている。これら一対の接続ランド２０ａ，２０ｂは、第１の基板部４ａの裏面上に長手方向に所定の間隔で並んでパターン配線の一部としてパターン形成されている。
【００４３】
これらの接続ランド２０ａ，２０ｂは、例えば誘電絶縁層の主面全面にめっき法等で成膜された銅箔層に、フォトリソグラフ処理等で所望の配線となるようにパターニング加工が施されることで設けられる。
【００４４】
そして、正極端子１４及び負極端子１７は、この第１の基板部４ａの長手方向に対して直交して配置されると共に、その先端部が一対の接続ランド２０ａ，２０ｂと接合される。
【００４５】
また、接続ランド２０ａと接続ランド２０ａとの間にはサーミスタ２１が配されている。このサーミスタ２１は、１チップ化された電池部品として実装されている。
【００４６】
サーミスタ２１は、周囲の温度が所定値になったときに回路内のリレーが作動して電気抵抗を変化させる、いわゆる温度センサ回路であり、電子部品として接続ランド２０ａ，２０ｂが実装された主面と同一主面上に実装されている。このサーミスタ２１は、ポリマー電池３の側面に当接又は側面を臨むように配置され、ポリマー電池３の表面温度又は周囲温度を検出している。また、サーミスタ２１は、コネクタ２２に電気的に接続され、検出した温度情報を電子機器側に電気信号として伝達している。これにより、電子機器では、サーミスタ２１が所定の温度を検出して電気抵抗が変化した電気信号がコネクタを介して伝達されると、この電気信号に基づいて電源を切ったり、電池パック１に命令信号を発信したりする。
【００４７】
第１の基板部４ａの表面には、図４に示すように、銅箔層２９が全面に形成されている。負極が接続される接続ランド２０ｂと銅箔層２９とはスルーホールにて接続され、負極と同一電位を有する。この銅箔層２９は、シールド部２６と電気的に接続され、シールド部２６の一部を構成している。
【００４８】
第２の基板部４ｂは、図５に示すように、その表面に回路部２４が設けられている。そして、この第２の基板部４ｂは、ポリマー電池３の側面３ｂに当接して配される。
【００４９】
回路部２４は、電池パック１が装填される電子機器と電気的に接続される外部接続用のコネクタ２２と、接続部２４に接続されたポリマー電池３を制御する電池制御回路部２３とを有している。
【００５０】
そして、第２の基板部４ｂでは、これらのコネクタ２２、電池制御回路部２３は、第２の基板部４ｂの表面に、それぞれ１チップ化された電池部品として実装され、パターン配線等で互いに接続されている。
【００５１】
コネクタ２２は、電子機器側の外部端子にそれぞれ接続される接続端子２２ａ〜２２ｃを備えている。
【００５２】
接続端子２２ａは、ポリマー電池３の正極端子１４が接続された接続ランド２０ａと配線パターン２５ａ等で繋がれており、電子機器の正極側端子となる外部端子に接続される。これにより、電子機器では、回路基板４に接続されたポリマー電池３から接続端子２５ａを介して電力の供給が行われる。
【００５３】
接続端子２２ｂは、ポリマー電池３の負極端子１７が接続された接続ランド２０ｂと配線パターン２５ｂ等で繋がれており、電子機器の負極側端子、いわゆるグランド端子に接続される。
【００５４】
接続端子２２ｃは、接続部２０のサーミスタ２１と配線パターン２５ｃ等で繋がれており、サーミスタ２１と電子機器の外部端子とを電気的に接続させ、サーミスタ２１が検出したポリマー電池３の温度やポリマー電池３の周囲の温度等の情報信号を電子機器側に電気信号として伝達させる。これにより、電子機器では、例えばポリマー電池３が異常な高温状態に陥った場合に、サーミスタ２１が検出したポリマー電池３の温度の情報信号に基づいて電源を切ってポリマー電池３に負荷が掛からないようにする。
【００５５】
電池制御回路部２３は、例えばポリマー電池３を過充電や過放電から保護する保護回路や、ポリマー電池３の電力残量等を演算する演算回路、電池パック１が装填される電子機器との間で通信を行う通信回路等で構成されている。電池制御回路部２３は、ポリマー電池３が繋がる接続ランド２０ａ，２０ｂ等に電気的に接続されることでポリマー電池３から電力が絶えず供給され、ポリマー電池３の充放電や、電子機器との間の通信等を制御する。そして、電池制御回路部２３は、第２の基板部４ｂの表面に、例えばＩＣ（ｉｎｔｅｇｒａｔｅｄｃｉｒｃｕｉｔ）チップ、ＬＳＩ（Ｌａｒｇｅ−ｓｃａｌｅＩｎｔｅｇｒａｔｅｄＣｉｒｃｕｉｔ）チップ等のような集積回路にされた状態で電子部品として実装される。
【００５６】
第２の基板部４ｂの裏面は、図６に示すように、第３の基板部４ｃから配線部２５が延びて形成されている。配線部２５における配線パターン２５ａ，２５ｂ，２５ｃと、コネクタ２２及び電池制御回路部２３とは、例えばスルーホールにて電気的に接続されている。
【００５７】
第３の基板部４ｃは、図４に示すように、その表面にシールド部２６が設けられており、図５に示すように、その裏面に配線部２５が設けられている。そして、この第２の基板部４ｂは、ポリマー電池３の上面３ｃに当接して配される。
【００５８】
配線部２５は、配線パターン２５ａ，２５ｂ，２５ｃを備えている。これら配線パターン２５ａ，２５ｂ，２５ｃのパターン間はそれぞれ絶縁処理されている。
【００５９】
配線パターン２５ａは、ポリマー電池３の正極が接続される接続ランド２０ａと、コネクタ２２における接続端子２２ａ及び電池制御回路部２３とを電気的に接続する配線である。
【００６０】
配線パターン２５ｂは、ポリマー電池３の負極が接続される接続ランド２０ｂと、コネクタ２２における接続端子２２ｂ及び電池制御回路部２３とを電気的に接続する配線である。
【００６１】
配線パターン２５ｃは、サーミスタ２１とコネクタ２２における接続端子２２ｃ及び電池制御回路部２３とを電気的に接続する配線である。
【００６２】
また、第３の基板部４ｃを、ポリマー電池３の主面のうち面積の広い上面３ｃに配することで、配線部２５の面積を広く確保することができる。これにより配線パターン２５ａ，２５ｂ，２５ｃを幅広く確保することができるので、導通抵抗を低く抑えることができる。また、配線パターン２５ａ，２５ｂ，２５ｃを幅広く確保することで、電磁波に対する影響も抑えることができる。
【００６３】
配線部２５の反対側である、第３の基板部４ｃの表面には、図４に示すように、銅箔層から構成されるシールド部２６が全面に形成されている。上述したように、電池パック１が例えば携帯電話機に搭載されて用いられる場合に、携帯電話機側の電池接続端子から漏れ電波の輻射が生じ、電気信号の通信障害、いわゆる電磁波障害が生じてしまうおそれがある。
【００６４】
そこで、この回路基板４では、配線部２５の裏側、すなわち第３の基板部４ｃの表面に、第３の基板部４ｃの全面に亘ってシールド部２６を形成している。この回路基板４をポリマー電池３に取り付けると、配線部２５はシールド部２６によって覆われることになり、電磁波からシールドされる。
【００６５】
シールド部２６は、ポリマー電池３の負極と電気的に接続されており、さらに、ポリマー電池３が搭載される電子機器（携帯電話等）の負極側端子、いわゆるグランド端子となる外部端子に接続される。これにより、電磁波をシールドすることができ、電磁波障害が防止され信頼性に優れた回路基板４となる。
【００６６】
また、配線部２５とシールド部２６とは電気的に一体に形成されているので、配線部２５とシールド部２６との電気的接触をより確実なものとして電磁波シールド性能をより高めることができる。
【００６７】
シールド機能を十分に発揮するためには、シールド部２６によって配線パターン２５ａ，２５ｂ，２５ｃがほぼ完全に覆われている必要がある。そのために、第３の基板部４ｃにおいて、裏面の配線部２５は、表面のシールド部２６の外線よりも内側に形成されていることが好ましい。
【００６８】
このように、回路基板４の一面にシールド部２６を形成することで、別個にシールド部材を取り付ける場合に比べて部品点数や組み立て工程を削減することができ、コストダウンにも繋がる。
【００６９】
以上のような外筐２、ポリマー電池３及び回路基板４によって構成される電池パック１の組立方法について説明する。具体的には、ポリマー電池３が取り付けられた回路基板４を外筐２に収容する方法について説明する。
【００７０】
ポリマー電池３が取り付けられた回路基板４を外筐２に収納する際は、先ず、図６に示すように、回路基板４の長手方向に対して直交して配置されたポリマー電池３の正極端子１４及び負極端子１７の先端部が接続部２０側の一対の接続ランド２０ａ，２０ｂと接続された状態から、正極端子１４及び負極端子１７の先端部を第１の回路基板４と共に外装材７の貼合せ面７ａ上に折り返す。さらに、第１の折り曲げ線２７において、第３の基板部４ｃが第１の基板部４ａと略垂直になるように、裏面を内側にして第３の基板部４ｃを第１の基板部４ａに対して折り曲げる。
【００７１】
これにより、図７に示すように、第１の基板部４ａが、ポリマー電池３の正極端子１４及び負極端子１７が引き出された主面３ａに沿って配されるとともに、第３の基板部４ｃの裏面が、ポリマー電池３の上面３ｃに当接された状態で配される。このとき、第１の基板部４ａは、上記主面３ａと外装材７の貼合せ面７ａと折り返し部７ｂとで形成された隙間に配される。
【００７２】
そして、両面テープや接着剤を用いて第３の基板部４ｃをポリマー電池３の上面３ｃに固定する。
【００７３】
次に、第２の折り曲げ線２８において、第２の基板部４ｂが第３の基板部４ｃと略垂直になるように、裏面を内側にして第２の基板を第３の基板に対して折り曲げる。
【００７４】
これにより、図８に示すように、第３の基板部４ｃは、ポリマー電池３の側面３ｂに当接した状態で配される。
【００７５】
以上のようにして、第１の基板部４ａないし第３の基板部４ｃが、略直方体形状のポリマー電池３の、互いに略垂直な主面３ａ、側面３ｂ、上面３ｃに沿って配されて、回路基板４がポリマー電池３に取り付けられる。
【００７６】
このとき、ポリマー電池３の外装材７の折り曲げ部７ｂの端部は、第１の基板部４ａと第２の基板部４ｂとの間に存在しており、回路基板４に上記端部は直接には当たらない。また、回路基板４は第３の基板部４ｃによってポリマー電池に固定されているので、これにより、外装材７の弾性により折り曲げ部７ｂが戻ってきても、折り曲げ端部７ｂに当接している第２の基板部４ｂが、電池パック３から外れてしまうことはない。
【００７７】
そして、これらポリマー電池３及び回路基板４を、外筐２の上ハーフ２ａと下ハーフ２ｂとの間に収納した後、これら上ハーフ２ａと下ハーフ２ｂとを接合する。以上のようにして、図１に示すような電池パック１が組み立てられる。
【００７８】
そして、この電池パック１は、図１中矢印Ａ方向に挿入することにより、携帯電話等の電子機器に取り付けられる。
【００７９】
なお、回路基板４が取り付けられたポリマー電池３は略直方体形状ではなく、側面部において第２の基板部４ｂの分だけ凸になっている。この平面長方形状の外筐２に収納すると、外筐２とポリマー電池３との間に空間が出来てしまう。そこで、外筐２の上ハーフ２ａと下ハーフ２ｂには、回路基板４が取り付けられたポリマー電池３の形状に合わせて、切り欠き部２ｃ，２ｄが形成されている。これにより筐体内での無駄なスペースを削減することができる。
【００８０】
以上説明したような本発明の電池パック１が有する回路基板４では、略直方体形状のポリマー電池３の別個の側面にそれぞれ配された接続部２５と回路部２４とを電気的に接続する配線部２５を有する第３の基板部４ｃを、ポリマー電池３の主面のうち面積の広い上面３ａに配することで、ポリマー電池３の３面に亘る基板が一体化されるとともに、配線部２５の面積を広く確保することができる。これにより配線パターン２５ａ，２５ｂ，２５ｃを幅広く確保することができるので、導通抵抗を低く抑えることができる。また、配線パターンを幅広く確保することで、電磁波に対する影響も抑えることができる。
【００８１】
さらに、本発明の回路基板４では、第３の基板部４ｃにおいて、配線部２５の裏側に、ポリマー電池３の負極と電気的に接続されたシールド部２６を形成している。これにより配線部２５は電磁波からシールドされて、電磁波障害が防止され信頼性に優れた回路基板となる。
【００８２】
また、回路基板４の一面にシールド部２６を形成することで、別個にシールド部材を取り付ける場合に比べて部品点数や組み立て工程を削減することができ、コストダウンにも繋がる。
【００８３】
【発明の効果】
本発明では、略直方体形状のポリマー電池の別個の側面にそれぞれ配された接続部と回路部とを電気的に接続する配線部を、ポリマー電池の主面のうち面積の広い上面部に配して広く確保することで、配線パターンを幅広く確保して、導通抵抗を低く抑えることができる。
【００８４】
さらに本発明では、配線部の裏側に、ポリマー電池の負極と電気的に接続されたシールド層を形成することで配線部は電磁波からシールドされて、電磁波障害が防止され信頼性に優れたものとなる。
【００８５】
また、回路基板の一面にシールド層を形成することで、別個にシールド部材を取り付ける場合に比べて部品点数や組み立て工程を削減することができ、コストダウンにも繋がる。
【図面の簡単な説明】
【図１】本発明を適用した電池パックを示す斜視図である。
【図２】同電池パックの内部構造を示す分解斜視図である。
【図３】
同電池パックに備わるポリマー電池の内部構造を示す分解斜視図である。
【図４】回路基板の表面側を示す平面図である。
【図５】回路基板の裏面側を示す平面図である。
【図６】ポリマー電池及び回路基板を外筐に収納する方法を説明する図であり、回路基板にポリマー電池が取り付けられた状態を示す斜視図である。
【図７】ポリマー電池及び回路基板を外筐に収納する方法を説明する図であり、回路基板を第１の折り曲げ線で折り曲げて、第１の基板部及び第２の基板部をポリマー電池の主面に配した状態を示す斜視図である。
【図８】ポリマー電池、発熱素子及び回路基板を外筐に収納する方法を説明する図であり、回路基板を第２の折り曲げ線で折り曲げて、第２の基板部をポリマー電池の側面に配した状態を示す斜視図である。
【符号の説明】
１電池パック、２外筐、２ａ上ハーフ、２ｂ下ハーフ、３ポリマー電池、４回路基板、４ａ第１の基板部、４ｂ第２の基板部、４ｃ第３の基板部、５開口部、６電池素子、７外装材、７ａ，７ｂ，７ｃ貼合せ面、１４正極端子、１７負極端子、２０端子接続部、２１サーミスタ、２２コネクタ、２３電池制御回路部、２４回路部、２５配線部、２６シールド部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a circuit board and a battery pack in which a terminal connection portion and a circuit portion arranged on different surfaces of a polymer battery are integrated and further provided with an electromagnetic wave shielding function.
[0002]
[Prior art]
2. Description of the Related Art In recent years, many portable small electronic devices such as notebook personal computers, PDAs (Personal Digital Assistants), mobile phones, and camera-integrated VTRs (Video Tape Recorders) have emerged. The development of nonaqueous electrolyte secondary batteries having the above, particularly lithium ion secondary batteries, has been actively promoted.
[0003]
This lithium-ion secondary battery uses a solid electrolyte such as a gel electrolyte or a polymer solid electrolyte to further reduce the size and weight, and uses a heat-sealable laminate film as an exterior material to generate power. Is being sealed. Such a lithium ion secondary battery is generally called a polymer battery, and since the electrolyte is in a solid or gel state, there is no risk of liquid leakage, and a packaging material made of a laminated film instead of a metal container. By using, it is possible to further reduce the thickness.
[0004]
In addition, the polymer battery is electrically connected to a control circuit that controls charging and discharging and a circuit board on which a connector for electrically connecting to the outside is mounted, and protection from overcharging and discharging is achieved. ing. The polymer battery and the circuit board are configured as a so-called battery pack by being housed in an outer casing made of a plastic case or the like, for example, as shown in Patent Literature 1 and Patent Literature 2.
[0005]
[Patent Document 1]
JP 2001-266820 A
[Patent Document 2]
JP 2000-156208 A
[0006]
[Problems to be solved by the invention]
A battery pack in which a portion to which an electrode terminal of a polymer battery is connected and a portion for mounting a connector are arranged on different surfaces of the polymer battery is also employed.
[0007]
However, in a conventional circuit board, a board portion for connecting a battery terminal and a board portion for mounting a connector are not integrated, and a means for electrically connecting both is required.
[0008]
In recent years, in electronic devices, in order to cope with an increase in the amount of information to be handled, signals exchanged between electronic components in the device have tended to have higher frequencies. Electromagnetic waves radiated from electronic devices and the like disturb the signal current of the devices, that is, so-called electromagnetic interference is likely to occur. In particular, in the case of mobile devices such as mobile phones used outdoors, as circuits become more highly integrated with miniaturization, electromagnetic interference also occurs between electronic circuits on a circuit board in a housing. It was easier.
[0009]
Conventionally, in order to allow such devices to be used normally, a target material such as a copper plate is covered with a conductive material such as an electronic circuit, and a so-called electromagnetic wave shield that does not allow electromagnetic waves to pass through the inside and outside of the device is used. A structure was adopted to prevent the electromagnetic waves from the circuit from reaching another circuit. However, the number of parts to be mounted has increased, and the workability of mounting has been complicated, and many man-hours have been required.
[0010]
The present invention has been proposed in view of such a conventional situation, and an object of the present invention is to provide a circuit board that can connect an electrode terminal connection portion and a connector connection portion and also has an electromagnetic wave shielding function. And
[0011]
[Means for Solving the Problems]
The circuit board of the present invention is a circuit board attached to a polymer battery having a substantially rectangular parallelepiped shape, and has a rectangular first board portion having a terminal connection portion to which a positive terminal and a negative terminal of the polymer battery are electrically connected. A first substrate portion between the first substrate portion and the second substrate portion, and a rectangular second substrate portion having a circuit portion on which an external connection terminal and a battery control element are mounted. And a third substrate portion having a wiring portion that is connected to the long side portion of the second substrate portion and the long side portion of the second substrate portion, and has a wiring portion that electrically connects the terminal connection portion to the external connection terminal and the battery control element. Have.
[0012]
In this circuit board, the third board section is electrically connected in the same plane so that the first board section and the second board section are at right angles to each other, and the first board section is , Disposed on one side of the polymer battery, the second substrate portion is disposed on the other side adjacent to one side of the polymer battery, and the third substrate portion is disposed on one side and the other side of the polymer battery. It is characterized by being arranged on adjacent main surfaces.
[0013]
In the circuit board according to the present invention as described above, the first substrate portion having the terminal connection portion and the second substrate portion having the circuit portion are connected by the third substrate portion having the wiring portion. Thus, the terminal portion and the circuit portion are electrically connected integrally, and can be arranged on the other surface of the substantially rectangular polymer battery.
[0014]
Further, the battery pack of the present invention includes a polymer battery, and a circuit board connected to the polymer battery, wherein the circuit board has a terminal connection portion to which a positive terminal and a negative terminal of the polymer battery are electrically connected. A first substrate portion having a rectangular shape, a second substrate portion having a rectangular shape having a circuit portion on which an external connection terminal and a battery control element are mounted, and the first substrate portion and the second substrate portion. A wiring portion disposed between the first connection portion and the long side portion of the second substrate portion to electrically connect the terminal connection portion to the external connection terminal and the battery control element; And a third substrate portion having:
[0015]
In the battery pack of the present invention, the third substrate portion is electrically connected so that the first substrate portion and the second substrate portion are at right angles to each other, and the first substrate portion is The second substrate portion is disposed on one side surface of the polymer battery, the second substrate portion is disposed on another side surface adjacent to one side surface of the polymer battery, and the third substrate portion is adjacent to one side surface and the other side surface of the polymer battery. It is characterized by being arranged on the main surface.
[0016]
In the battery pack according to the present invention as described above, the circuit board includes the first board part having the terminal connection part and the second board part having the circuit part in the third board part having the wiring part. Since the terminals are connected, the terminal portion and the circuit portion are electrically connected integrally, and can be arranged on the other surface of the substantially rectangular polymer battery.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a circuit board and a battery pack to which the present invention is applied will be described with reference to the drawings.
[0018]
The battery pack 1 is mounted on a mounting portion provided in an electronic device such as a mobile phone, for example, and can stably supply a predetermined voltage power to the electronic device and the like. As shown in FIGS. 1 and 2, this battery pack 1 houses a polymer battery 3 as a power generation element and a circuit board 4 to which the polymer battery 3 is electrically connected in an outer case 2 as a storage case. The structure has been. The battery pack 1 is attached to an electronic device such as a mobile phone by inserting it in the direction of arrow A in FIG.
[0019]
The outer casing 2 is formed of a so-called plastic case, and a storage space in which the polymer battery 3 and the circuit board 4 are stored inside by abutting the peripheral wall of the upper half 2a and the peripheral wall of the lower half 2b with each other. And its outer shape is a substantially rectangular flat plate. The outer casing 2 has an opening 5 formed at one end in the short direction to expose the connector 22 attached to the circuit board 4 to the outside. Notches 5a and 5b forming the opening 5 are formed in the lower half 2a and the lower half 2b, respectively.
[0020]
As shown in FIG. 3, the polymer battery 3 is a nonaqueous electrolyte battery such as a lithium ion secondary battery, for example. And an exterior material 7.
[0021]
In the polymer battery 3, the battery element 6 has a band-shaped positive electrode 8, a band-shaped negative electrode 9, a solid electrolyte 10 containing an organic polymer or an electrolyte salt, and a separator 11 interposed between the electrodes. By winding in the direction, it functions as a power generating element.
[0022]
The positive electrode 8 is formed by applying a positive electrode mixture coating liquid containing a positive electrode active material and a binder on the positive electrode current collector 12, drying, and pressing, so that the positive electrode mixture layer 13 is formed on the positive electrode current collector 12. It has a structure formed by compression. A positive electrode terminal 14 is connected to the positive electrode 8 at a predetermined position on the positive electrode current collector 12 so as to protrude in the width direction of the positive electrode current collector 12. For the positive electrode terminal 14, for example, a strip-shaped metal piece made of a conductive metal such as aluminum is used.
[0023]
The negative electrode 9 forms a negative electrode mixture layer 16 on the negative electrode current collector 15 by applying a negative electrode mixture coating liquid containing a negative electrode active material and a binder on the negative electrode current collector 15, drying, and pressing. It has a structure formed by compression. A negative electrode terminal 17 is connected to the negative electrode 9 at a predetermined position on the negative electrode current collector 15 so as to protrude in the width direction of the negative electrode current collector 15. For the negative electrode terminal 17, for example, a strip-shaped metal piece made of a conductive metal such as nickel or copper is used.
[0024]
The solid electrolyte 10 exchanges, for example, lithium ions between the positive electrode 8 and the negative electrode 9. Therefore, an organic solid electrolyte having lithium ion conductivity is used as the solid electrolyte 10. As the organic solid electrolyte, a polymer solid electrolyte composed of an electrolyte salt and an organic polymer containing the same, a gel electrolyte in which a non-aqueous electrolyte is contained in a polymer matrix, and the like can be used. The solid electrolyte 10 is formed as an electrolyte layer by applying and solidifying an electrolyte solution containing an organic solid electrolyte on the surfaces of the positive electrode 8 and the negative electrode 9.
[0025]
The separator 11 separates the positive electrode 8 and the negative electrode 9 from each other, and may use a known material that is generally used as an insulating porous film of this type of nonaqueous electrolyte battery.
[0026]
The packaging material 7 for enclosing the battery element 6 having the above-described configuration is a laminated film in which a resin layer and a metal layer are bonded to each other by lamination or the like to be composited into two or more layers. The surface to be formed is a resin layer. The material of the resin layer is not particularly limited as long as it has adhesiveness to the positive electrode terminal 14 and the negative electrode terminal 17. As the metal layer, for example, aluminum, stainless steel, nickel, iron, or the like formed into a foil shape, a plate shape, or the like is used. In the case 7, the outer layer of the battery 1 is provided with a resin layer made of, for example, nylon or the like, so that the outer layer 7 can be improved in strength against breakage or piercing.
[0027]
The battery element 6 was housed inside the exterior material 7, and the outer edge of the exterior material 7 was electrically connected to the positive electrode 9 and the negative electrode 10 constituting the battery element 7 by bonding resin layers together by, for example, heat sealing. The battery element 7 is sealed in the exterior material 7 in a state where the positive electrode terminal 14 and the negative electrode terminal 17 are drawn out from between the bonding surfaces 7a of the exterior material 7 via the resin pieces 18 to form the polymer battery 3. .
[0028]
Next, the circuit board 4 connected to such a polymer battery 3 will be described.
[0029]
One configuration example of the circuit board 4 is shown in FIGS. FIG. 4 is a plan view showing one surface of the circuit board 4 (hereinafter, this surface is referred to as a front surface), and FIG. 5 is a plan view showing the other surface of the circuit board 4 (hereinafter, this surface is referred to as a back surface). FIG. The circuit board 4 is attached to the polymer battery 3 with the back surface in contact with the polymer battery 3 and the front surface facing outward.
[0030]
As will be described later, the circuit board 4 is actually attached to the battery pack in a state where a part thereof is bent, but FIGS. 4 and 5 show a state where the circuit board 4 is not bent.
[0031]
The circuit board 4 includes a first board portion 4 a having a terminal connection portion 20 to which the positive electrode terminal 14 and the negative electrode terminal 17 of the polymer battery 3 are electrically connected, and a thermistor 21, a connector 22 and a battery control circuit portion 23. A wiring portion 25 for electrically connecting the terminal connecting portion 20 and the circuit portion 24, a shielding portion 26 for shielding the wiring portion 25 from electromagnetic waves, And a third substrate portion 4c having the following.
[0032]
The first substrate portion 4a and the second substrate portion 4b have a substantially rectangular shape having a width corresponding to the thickness of the polymer battery 3, and the third substrate portion 4c has a substantially L shape. The first substrate portion 4a is connected at one end in the short direction to one end of a substantially L-shaped third substrate portion 4c, and the second substrate portion 4b is connected to the short direction. Is connected to the other end of the third substrate portion 4c. At this time, a first bending line 27 between the first substrate part 4a and the third substrate part 4c and a second bending line 28 between the second substrate part 4b and the third substrate part 4c Is orthogonal to.
[0033]
Note that, here, the shape of the third substrate portion is a substantially L-shape curved midway, but the present invention is not limited to this, and may be a shape without a curved portion. .
[0034]
The circuit board 4 is a so-called multilayer flexible printed circuit board having flexibility and having pattern wirings and dielectric insulating layers alternately laminated. Since the circuit board 4 has flexibility, the circuit board 4 is provided between the first board section 4a and the second board section 4b and between the second board section 4b and the third board section 4c. Can be bent. Here, the description is made using a flexible substrate as the circuit board 4, but the present invention is not limited to this, and can be applied to, for example, a rigid substrate.
[0035]
Then, the circuit board 4 is formed by bending the first substrate portion 4a so that the back surface is on the inside and substantially perpendicular to the third substrate portion 4c at the first bending line, and furthermore, the second bending is performed. By bending the second substrate portion 4b so as to be substantially perpendicular to the third substrate portion 4c in the line, the first substrate portion 4a to the third substrate portion 4c become substantially perpendicular to each other.
[0036]
When the circuit board 4 is attached to the polymer battery 3, the first substrate portion 4 a to the third substrate portion 4 c have the back surfaces thereof in contact with the polymer battery 3 and the substantially rectangular parallelepiped polymer batteries 3 are substantially mutually separated. It is arranged along three vertical planes. That is, as shown in FIG. 8 described later, the first substrate portion 4a including the connection portion 25 is disposed in contact with the main surface 3a from which the positive electrode terminal and the negative electrode terminal of the polymer battery 3 are drawn out. Further, the third substrate portion 4c provided with the circuit portion 24 is disposed in contact with the side surface 3b of the polymer battery 3 which is substantially perpendicular to and adjacent to the main surface 3a. The third substrate portion 4c including the connection portion 25 and the shield portion 26 is disposed in contact with the substantially vertical upper surface 3c adjacent to the main surface 3a and the side surface 3b.
[0037]
In the battery pack 1, the connector 22 faces outside from the side surface 3 b, not from the main surface 3 a side of the polymer battery 3.
[0038]
The first bending line 27 and the second bending line 28 are provided with bending patterns 27a and 28a for facilitating the bending of the substrate. One or more of the bent patterns 27a and 28a are formed so as to be linear pattern wirings substantially parallel to the short direction of the first substrate portion 4a and the second substrate portion 4b.
[0039]
The bending patterns 27a and 28a are formed, for example, by patterning a metal layer made of a conductive metal or the like formed over the entire main surface of the dielectric insulating layer by a plating method or the like into a desired pattern by photolithographic processing or the like. It is provided by being done.
[0040]
Hereinafter, the first to third substrate portions 4a to 4c of the circuit substrate 4 will be described.
[0041]
As shown in FIG. 5, the first substrate portion 4a is provided with a connection portion 20 on the back surface. The first substrate portion 4a is disposed in contact with the main surface 3a from which the positive terminal 14 and the negative terminal 17 of the polymer battery 3 are led out.
[0042]
The connection portion 20 is provided with a pair of connection lands 20a and 20b to which the positive electrode terminal 14 and the negative electrode terminal 17 of the polymer battery 3 are electrically connected. The pair of connection lands 20a and 20b are pattern-formed on the back surface of the first substrate portion 4a as a part of the pattern wiring at a predetermined interval in the longitudinal direction.
[0043]
The connection lands 20a and 20b are formed by patterning a copper foil layer formed on the entire main surface of the dielectric insulating layer by a plating method or the like so that desired wiring is formed by photolithography or the like. Provided.
[0044]
The positive electrode terminal 14 and the negative electrode terminal 17 are arranged orthogonally to the longitudinal direction of the first substrate portion 4a, and the tips are joined to the pair of connection lands 20a and 20b.
[0045]
A thermistor 21 is arranged between the connection lands 20a. The thermistor 21 is mounted as a one-chip battery component.
[0046]
The thermistor 21 is a so-called temperature sensor circuit that activates a relay in the circuit when the ambient temperature reaches a predetermined value to change the electrical resistance. The main surface on which the connection lands 20a and 20b are mounted as electronic components is provided. Are mounted on the same main surface. The thermistor 21 is disposed so as to contact or face the side surface of the polymer battery 3 and detects the surface temperature or the ambient temperature of the polymer battery 3. The thermistor 21 is electrically connected to the connector 22 and transmits detected temperature information to the electronic device as an electric signal. Thereby, in the electronic device, when the thermistor 21 detects a predetermined temperature and transmits an electric signal whose electric resistance has changed through the connector, the electronic device turns off the power based on the electric signal or issues an instruction to the battery pack 1. Or send out a signal.
[0047]
As shown in FIG. 4, a copper foil layer 29 is formed on the entire surface of the first substrate portion 4a. The connection land 20b to which the negative electrode is connected and the copper foil layer 29 are connected by a through hole and have the same potential as the negative electrode. The copper foil layer 29 is electrically connected to the shield part 26 and forms a part of the shield part 26.
[0048]
The circuit portion 24 is provided on the surface of the second substrate portion 4b as shown in FIG. The second substrate portion 4b is disposed in contact with the side surface 3b of the polymer battery 3.
[0049]
The circuit section 24 has an external connection connector 22 electrically connected to the electronic device in which the battery pack 1 is mounted, and a battery control circuit section 23 for controlling the polymer battery 3 connected to the connection section 24. are doing.
[0050]
In the second board part 4b, the connector 22 and the battery control circuit part 23 are mounted on the surface of the second board part 4b as battery parts formed as one chip, respectively, and are connected to each other by pattern wiring or the like. Have been.
[0051]
The connector 22 includes connection terminals 22a to 22c connected to external terminals on the electronic device side, respectively.
[0052]
The connection terminal 22a is connected to a connection land 20a to which the positive electrode terminal 14 of the polymer battery 3 is connected by a wiring pattern 25a or the like, and is connected to an external terminal serving as a positive electrode side terminal of the electronic device. Thus, in the electronic device, power is supplied from the polymer battery 3 connected to the circuit board 4 via the connection terminal 25a.
[0053]
The connection terminal 22b is connected to a connection land 20b to which the negative electrode terminal 17 of the polymer battery 3 is connected by a wiring pattern 25b or the like, and is connected to a negative electrode side terminal of an electronic device, a so-called ground terminal.
[0054]
The connection terminal 22c is connected to the thermistor 21 of the connection unit 20 by a wiring pattern 25c or the like, and electrically connects the thermistor 21 to an external terminal of the electronic device. An information signal such as the temperature around the battery 3 is transmitted to the electronic device as an electric signal. Thus, in the electronic device, for example, when the polymer battery 3 falls into an abnormally high temperature state, the power is turned off based on the information signal of the temperature of the polymer battery 3 detected by the thermistor 21 and no load is applied to the polymer battery 3. To do.
[0055]
The battery control circuit unit 23 includes, for example, a protection circuit that protects the polymer battery 3 from overcharge and overdischarge, an arithmetic circuit that calculates the remaining power of the polymer battery 3, and an electronic device in which the battery pack 1 is mounted. And a communication circuit or the like for performing communication. The battery control circuit section 23 is constantly connected to the connection lands 20a and 20b to which the polymer battery 3 is connected, so that the power is constantly supplied from the polymer battery 3 to charge and discharge the polymer battery 3 and to connect with the electronic device. Control communication and the like. Then, the battery control circuit unit 23 is provided as an electronic component on the surface of the second substrate unit 4b as an integrated circuit such as an integrated circuit (IC) chip, a large-scale integrated circuit (LSI) chip, or the like. Implemented.
[0056]
As shown in FIG. 6, a wiring portion 25 extends from the third substrate portion 4c on the back surface of the second substrate portion 4b. The wiring patterns 25a, 25b, and 25c in the wiring unit 25 are electrically connected to the connector 22 and the battery control circuit unit 23 by, for example, through holes.
[0057]
As shown in FIG. 4, the third substrate portion 4c is provided with a shield portion 26 on the front surface, and as shown in FIG. 5, a wiring portion 25 is provided on the back surface. The second substrate portion 4b is disposed in contact with the upper surface 3c of the polymer battery 3.
[0058]
The wiring section 25 includes wiring patterns 25a, 25b, and 25c. The wiring patterns 25a, 25b, and 25c are insulated from each other.
[0059]
The wiring pattern 25a is a wiring that electrically connects the connection land 20a to which the positive electrode of the polymer battery 3 is connected, the connection terminal 22a of the connector 22, and the battery control circuit unit 23.
[0060]
The wiring pattern 25b is a wiring that electrically connects the connection land 20b to which the negative electrode of the polymer battery 3 is connected, the connection terminal 22b of the connector 22, and the battery control circuit unit 23.
[0061]
The wiring pattern 25c is a wiring that electrically connects the thermistor 21, the connection terminal 22c of the connector 22, and the battery control circuit unit 23.
[0062]
Further, by arranging the third substrate portion 4c on the upper surface 3c having a large area among the main surfaces of the polymer battery 3, a large area of the wiring portion 25 can be secured. As a result, the wiring patterns 25a, 25b, and 25c can be widely secured, so that the conduction resistance can be reduced. Further, by securing the wiring patterns 25a, 25b, 25c widely, the influence on the electromagnetic wave can be suppressed.
[0063]
As shown in FIG. 4, a shield portion 26 made of a copper foil layer is formed on the entire surface of the third substrate portion 4c opposite to the wiring portion 25, as shown in FIG. As described above, when the battery pack 1 is used by being mounted on, for example, a mobile phone, radiation of leaked radio waves may occur from the battery connection terminal of the mobile phone, and a communication failure of an electric signal, that is, a so-called electromagnetic interference may occur. There is.
[0064]
Therefore, in the circuit board 4, the shield part 26 is formed on the back side of the wiring part 25, that is, on the surface of the third substrate part 4c, over the entire surface of the third substrate part 4c. When the circuit board 4 is attached to the polymer battery 3, the wiring section 25 is covered by the shield section 26, and is shielded from electromagnetic waves.
[0065]
The shield part 26 is electrically connected to the negative electrode of the polymer battery 3, and is further connected to a negative electrode side terminal of an electronic device (a mobile phone or the like) on which the polymer battery 3 is mounted, that is, an external terminal serving as a so-called ground terminal. You. As a result, the electromagnetic wave can be shielded, and the electromagnetic wave interference is prevented, resulting in a highly reliable circuit board 4.
[0066]
Further, since the wiring part 25 and the shield part 26 are formed electrically integrally, the electrical contact between the wiring part 25 and the shield part 26 can be made more reliable, and the electromagnetic wave shielding performance can be further improved.
[0067]
In order to sufficiently exhibit the shielding function, the wiring patterns 25a, 25b, and 25c need to be almost completely covered by the shield portion 26. Therefore, in the third substrate portion 4c, the wiring portion 25 on the back surface is preferably formed inside the outer line of the shield portion 26 on the front surface.
[0068]
By forming the shield portion 26 on one surface of the circuit board 4 as described above, the number of components and the number of assembly steps can be reduced as compared with a case where a shield member is separately attached, leading to cost reduction.
[0069]
A method of assembling the battery pack 1 including the outer casing 2, the polymer battery 3, and the circuit board 4 as described above will be described. Specifically, a method of housing the circuit board 4 to which the polymer battery 3 is attached in the outer casing 2 will be described.
[0070]
When the circuit board 4 to which the polymer battery 3 is attached is housed in the outer casing 2, first, as shown in FIG. 6, the positive electrode terminal of the polymer battery 3 is arranged orthogonal to the longitudinal direction of the circuit board 4. From the state in which the distal ends of the negative electrode terminal 14 and the negative terminal 17 are connected to the pair of connection lands 20a and 20b on the connecting portion 20 side, the distal ends of the positive terminal 14 and the negative terminal 17 together with the first circuit board 4 It is folded back on the bonding surface 7a. Further, the third substrate portion 4c is attached to the first substrate portion 4a with the back surface inside so that the third substrate portion 4c is substantially perpendicular to the first substrate portion 4a at the first bending line 27. Bend against.
[0071]
Thereby, as shown in FIG. 7, the first substrate portion 4a is arranged along the main surface 3a from which the positive electrode terminal 14 and the negative electrode terminal 17 of the polymer battery 3 are drawn out, and the third substrate portion 4c Of the polymer battery 3 is in contact with the upper surface 3c of the polymer battery 3. At this time, the first substrate portion 4a is arranged in a gap formed by the main surface 3a, the bonding surface 7a of the exterior material 7, and the folded portion 7b.
[0072]
Then, the third substrate portion 4c is fixed to the upper surface 3c of the polymer battery 3 using a double-sided tape or an adhesive.
[0073]
Next, the second substrate is bent with respect to the third substrate with the back surface inside so that the second substrate portion 4b is substantially perpendicular to the third substrate portion 4c at the second bending line 28. .
[0074]
As a result, as shown in FIG. 8, the third substrate portion 4c is disposed in a state of being in contact with the side surface 3b of the polymer battery 3.
[0075]
As described above, the first substrate portion 4a to the third substrate portion 4c are disposed along the main surfaces 3a, the side surfaces 3b, and the upper surface 3c of the substantially rectangular parallelepiped polymer battery 3 which are substantially perpendicular to each other. The circuit board 4 is attached to the polymer battery 3.
[0076]
At this time, the end of the bent portion 7b of the exterior material 7 of the polymer battery 3 exists between the first substrate 4a and the second substrate 4b, and the end is directly connected to the circuit board 4. Does not hit. Further, since the circuit board 4 is fixed to the polymer battery by the third board portion 4c, even if the bent portion 7b returns due to the elasticity of the exterior material 7, the circuit board 4 is in contact with the bent end portion 7b. The second substrate portion 4 b does not come off the battery pack 3.
[0077]
After the polymer battery 3 and the circuit board 4 are housed between the upper half 2a and the lower half 2b of the outer casing 2, the upper half 2a and the lower half 2b are joined. As described above, the battery pack 1 as shown in FIG. 1 is assembled.
[0078]
The battery pack 1 is attached to an electronic device such as a mobile phone by inserting it in the direction of arrow A in FIG.
[0079]
The polymer battery 3 to which the circuit board 4 is attached is not in a substantially rectangular parallelepiped shape, but is convex on the side surface by the amount of the second substrate portion 4b. When housed in the outer casing 2 having a flat rectangular shape, a space is created between the outer casing 2 and the polymer battery 3. Therefore, cutouts 2c and 2d are formed in the upper half 2a and the lower half 2b of the outer casing 2 according to the shape of the polymer battery 3 to which the circuit board 4 is attached. As a result, useless space in the housing can be reduced.
[0080]
In the circuit board 4 included in the battery pack 1 of the present invention as described above, the wiring section for electrically connecting the connection section 25 and the circuit section 24 respectively disposed on the separate side surfaces of the polymer battery 3 having a substantially rectangular parallelepiped shape. By arranging the third substrate portion 4c having the upper surface 25 on the upper surface 3a having a large area among the main surfaces of the polymer battery 3, the substrates over the three surfaces of the polymer battery 3 are integrated and the wiring portion 25 is formed. A large area can be secured. As a result, the wiring patterns 25a, 25b, and 25c can be widely secured, so that the conduction resistance can be reduced. Further, by securing a wide wiring pattern, the influence on the electromagnetic wave can be suppressed.
[0081]
Further, in the circuit board 4 of the present invention, the shield part 26 electrically connected to the negative electrode of the polymer battery 3 is formed behind the wiring part 25 in the third substrate part 4c. Thus, the wiring portion 25 is shielded from the electromagnetic wave, so that an electromagnetic wave interference is prevented and a highly reliable circuit board is obtained.
[0082]
Further, by forming the shield portion 26 on one surface of the circuit board 4, the number of components and the number of assembly steps can be reduced as compared with a case where a shield member is separately attached, which leads to cost reduction.
[0083]
【The invention's effect】
In the present invention, the wiring portion for electrically connecting the connection portion and the circuit portion respectively disposed on the separate side surfaces of the polymer battery having a substantially rectangular parallelepiped shape is arranged on the upper surface portion having a large area of the main surface of the polymer battery. As a result, the wiring pattern can be made wider and the conduction resistance can be kept low.
[0084]
Furthermore, in the present invention, by forming a shield layer electrically connected to the negative electrode of the polymer battery on the back side of the wiring portion, the wiring portion is shielded from electromagnetic waves, thereby preventing electromagnetic interference and having high reliability. Become.
[0085]
Further, by forming the shield layer on one surface of the circuit board, the number of components and the number of assembly steps can be reduced as compared with a case where a shield member is separately attached, which leads to cost reduction.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a battery pack to which the present invention is applied.
FIG. 2 is an exploded perspective view showing the internal structure of the battery pack.
FIG. 3
FIG. 2 is an exploded perspective view showing an internal structure of a polymer battery provided in the battery pack.
FIG. 4 is a plan view showing the front side of the circuit board.
FIG. 5 is a plan view showing the back side of the circuit board.
FIG. 6 is a diagram for explaining a method of housing the polymer battery and the circuit board in an outer casing, and is a perspective view showing a state where the polymer battery is mounted on the circuit board.
FIG. 7 is a diagram for explaining a method of housing the polymer battery and the circuit board in the outer casing, wherein the circuit board is bent at a first bending line, and the first substrate unit and the second substrate unit are connected to each other. It is a perspective view showing the state where it was arranged on the main surface.
FIG. 8 is a diagram for explaining a method of housing a polymer battery, a heating element, and a circuit board in an outer casing, wherein the circuit board is bent along a second bending line, and a second board portion is arranged on a side surface of the polymer battery. It is a perspective view showing the state where it did.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 battery pack, 2 outer casing, 2 a upper half, 2 b lower half, 3 polymer battery, 4 circuit board, 4 a first board section, 4 b second board section, 4 c third board section, 5 opening section, 6 Battery element, 7 exterior material, 7a, 7b, 7c bonding surface, 14 positive electrode terminal, 17 negative electrode terminal, 20 terminal connection portion, 21 thermistor, 22 connector, 23 battery control circuit portion, 24 circuit portion, 25 wiring portion, 26 Shield section

Claims

A circuit board attached to a substantially rectangular polymer battery,
A rectangular first substrate portion having a terminal connection portion to which a positive electrode terminal and a negative electrode terminal of the polymer battery are electrically connected;
A second rectangular substrate portion having a circuit portion on which an external connection terminal and a battery control element are mounted;
A terminal connection part and an external connection are provided between the first substrate part and the second substrate part, and connected to the long side part of the first substrate part and the long side part of the second substrate part. A third substrate portion having a wiring portion for electrically connecting the terminal and the battery control element,
The third substrate unit is electrically connected in the same plane so that the first substrate unit and the second substrate unit are perpendicular to each other,
The first substrate is disposed on one side of the polymer battery, the second substrate is disposed on another side adjacent to one side of the polymer battery, and the third substrate is disposed on the side of the polymer battery. A circuit board disposed on a main surface adjacent to one side surface and another side surface.

2. The circuit board according to claim 1, wherein the first substrate portion is disposed along a surface of the polymer battery from which a positive electrode terminal and a negative electrode terminal are led out. 3.

A shield layer electrically connected to one of the positive electrode and the negative electrode of the polymer battery and having the same potential is formed on a surface of the third substrate portion opposite to the surface on which the wiring portion is formed, and The circuit board according to claim 1, wherein the board unit is attached to the polymer battery with the side on which the shield layer is formed facing outward.

4. The circuit board according to claim 3, wherein in the third board portion, the wiring portion is formed inside an outer line of the shield layer.

The circuit board according to claim 1, wherein the shield layer is electrically connected to a wiring electrically connected to one of the positive electrode and the negative electrode in the wiring portion through a through hole.

A battery pack including a polymer battery and a circuit board connected to the polymer battery,
The circuit board has a rectangular first substrate portion having a terminal connection portion to which a positive terminal and a negative terminal of a polymer battery are electrically connected, and a circuit portion on which an external connection terminal and a battery control element are mounted. A rectangular second substrate portion, and a long side portion of the first substrate portion and a long side portion of the second substrate portion connected between the first substrate portion and the second substrate portion; And a third substrate portion having a wiring portion for electrically connecting the terminal connection portion and the external connection terminal and the battery control element,
The third substrate portion is electrically connected so that the first substrate portion and the second substrate portion are perpendicular to each other,
The first substrate is disposed on one side of the polymer battery, the second substrate is disposed on another side adjacent to one side of the polymer battery, and the third substrate is disposed on the side of the polymer battery. A battery pack characterized by being disposed on a main surface adjacent to one side surface and another side surface.

The battery pack according to claim 6, wherein the first substrate portion is arranged along a surface of the polymer battery from which the positive electrode terminal and the negative electrode terminal are led out.

A shield layer electrically connected to one of the positive electrode and the negative electrode of the polymer battery and having the same potential is formed on a surface of the third substrate portion opposite to the surface on which the wiring portion is formed, 7. The battery pack according to claim 6, wherein the substrate is attached to the polymer battery with the side on which the shield layer is formed facing outward.

9. The battery pack according to claim 8, wherein in the third substrate portion, the wiring portion is formed inside an outer line of the shield layer.

7. The battery pack according to claim 6, wherein the shield layer is electrically connected to a wiring electrically connected to one of the positive electrode and the negative electrode in the wiring section through a through hole.