JP3806696B2

JP3806696B2 - Pack battery

Info

Publication number: JP3806696B2
Application number: JP2003036464A
Authority: JP
Inventors: 秀世森田; 久岩隈
Original assignee: Sanyo Electric Co Ltd
Current assignee: Sanyo Electric Co Ltd
Priority date: 2003-02-14
Filing date: 2003-02-14
Publication date: 2006-08-09
Anticipated expiration: 2023-02-14
Also published as: JP2004247198A

Description

【０００１】
【発明の属する技術分野】
本発明は、２個の薄型電池を内蔵するパック電池に関する。
【０００２】
【従来の技術】
ケースに薄型電池を内蔵するパック電池は、たとえば特許文献１の公報に記載される。このパック電池は、薄型電池の電極端面に回路基板を配置して、回路基板と薄型電池を一対のリードで連結している。この構造のパック電池は、ケースにひとつの薄型電池を収納しているので、２本のリードで薄型電池を回路基板に接続できる。このように、電極端面に回路基板を配置する構造で、ふたつの薄型電池を積層してケースに収納することができる。ふたつの電池は、並列あるいは直列に接続される。電池を並列に接続してケースに収納するパック電池は、薄型電池を同じ方向に向けて、すなわち薄型電池の凸部電極端面が同一面となるように積層し、積層している薄型電池の凸部電極と底側端面の電極をそれぞれリードで接続できる。電池を直列に接続するパック電池は、ふたつの薄型電池を同じ方向に向けて積層すると、直列に接続するリードが長くなる。この欠点は、ふたつの薄型電池を逆向きに向けて積層して解消できる。逆向きの薄型電池は、ひとつの薄型電池の凸部電極端面と他方の薄型電池の底側端面を同一面に位置させるので、短いリードで直列接続できる。さらに、電池を直列に接続するリードとは反対側の電極端面に回路基板を配置し、電池の凸部電極と底側端面の電極とをリードで接続して、短いリードで回路基板と電池を接続できる。したがって、直列に接続するこの構造のパック電池は、もっとも短いリードで電池を直列に接続し、さらに薄型電池を回路基板に接続できる。
【０００３】
【特許文献１】
特開２００２−８６０８号公報
【０００４】
【発明が解決しようとする課題】
しかしながら、以上の構造では、回路基板を薄型電池にしっかりと連結するのが難しく、また、各々の薄型電池の電圧を独立して検出するためには、薄型電池を直列に連結している反対側のリードを回路基板に接続する必要があり、電圧検出用のリードが長くなる欠点がある。本発明は、さらにこの欠点を解決することを目的に開発されたもので、本発明は、回路基板と薄型電池とを理想的な配置で連結して、回路基板をしっかりと薄型電池に連結でき、さらに直列に接続している薄型電池の正負の電極に接続している一対の端部リードの短絡を確実に阻止しながら回路基板に連結できるパック電池を提供することにある。
【０００５】
【課題を解決するための手段】
本発明のパック電池は、ふたつの薄型電池１を積層している。薄型電池１は、凸部電極端面３に凸部電極２を設けており、凸部電極端面３と反対側の電極端面である底側端面４を凸部電極２と異なる極性の電極としている。ふたつの薄型電池１は、一方の薄型電池１の凸部電極端面３と他方の薄型電池１の底側端面４とが同一端面に位置するように積層している。さらに、パック電池は、ひとつの薄型電池１の凸部電極端面３と他方の薄型電池１の底側端面４とが位置する第１の端面５に対向して回路基板７を配置している。回路基板７と対向する第１の端面５に位置する凸部電極端面３と底側端面４に中間リード８を接続し、この中間リード８でふたつの薄型電池１を互いに直列に電気接続し、さらにこの中間リード８を回路基板７の中間部分に接続している。また、回路基板７の両端部分には一対の端部リード９を接続して、中間リード８と端部リード９は回路基板７の片方の側縁で折曲している。一対の端部リード９は、一方をひとつの薄型電池１の凸部電極２に、他方を他方の薄型電池１の凸部電極２と反対側の電極に接続しており、中間リード８と端部リード９とでふたつの薄型電池１に回路基板７を連結している。
【０００６】
パック電池は、一対の端部リード９を、保護素子１０を介して薄型電池１の電極に接続することができる。
【０００７】
さらに、パック電池は、一対の端部リード９の端部を、第１の端面５の反対側にある第２の端面６に位置している薄型電池１の凸部電極２と底側端面４とに接続できる。さらに、パック電池は、薄型電池１の間に絶縁材１１を配設し、この絶縁材１１を、第２の端面６から突出させて、第２の端面６の凸部電極端面３と底側端面４とに接続している一対の端部リード９の間に配置して、絶縁材１１で端部リード９を確実に絶縁できる。
【０００８】
パック電池は、薄型電池１をケース１２に収納し、ケース１２の内面であって絶縁材１１と対向する位置に凹部１３を設けて、絶縁材１１でより確実に一対の端部リード９を絶縁できる。さらに、ケース１２の内面に設けている凹部１３の両側に、薄型電池１の凸部電極端面３と底側端面４に向かって突出する突出部１４を設け、この突出部１４と電極端面との間に端部リード９を配設して、さらに確実に一対の端部リード９を絶縁できる。
【０００９】
【発明の実施の形態】
以下、本発明の実施例を図面に基づいて説明する。ただし、以下に示す実施例は、本発明の技術思想を具体化するためのパック電池を例示するものであって、本発明はパック電池を以下のものに特定しない。
【００１０】
さらに、この明細書は、特許請求の範囲を理解しやすいように、実施例に示される部材に対応する番号を、「特許請求の範囲の欄」、および「課題を解決するための手段の欄」に示される部材に付記している。ただ、特許請求の範囲に示される部材を、実施例の部材に特定するものでは決してない。
【００１１】
図１ないし図６に示すパック電池は、ふたつの薄型電池１を積層して、これに回路基板７を連結している電池コア１５をケース１２に収納している。電池コア１５を、図６ないし図１２に示している。電池コア１５は、凸部電極端面３に凸部電極２を設けており、この凸部電極端面３と反対側の電極端面である底側端面４を凸部電極２と異なる極性の電極とする薄型電池１を積層している。薄型電池１は、正負の電極と電解液を外装缶に入れ、この外装缶の開口部を、凸部電極２のある封口板で閉塞して製作される。外装缶は、金属板をプレス加工して製作される。封口板はレーザー溶接して、あるいはカシメられて外装缶に気密に固定される。この薄型電池１は、凸部電極２と外装缶とを正負の異なる電極としている。凸部電極を負極とする薄型電池は、外装缶を正極とし、凸部電極を正極とする薄型電池は、外装缶を負極とする。薄型電池１はリチウムイオン電池である。ただし、薄型電池は、ニッケル−水素電池やニッケル−カドミウム電池、ポリマー電池等のように、充電できるすべての二次電池とすることができる。
【００１２】
ふたつの薄型電池１は、図７の斜視図と図８の断面図に示すように、一方の薄型電池１の凸部電極端面３と他方の薄型電池１の底側端面４とが同一平面に位置する姿勢で積層される。積層されたふたつの薄型電池１は、図８の断面図に示すように、凸部電極２と底側端面４とに中間リード８を連結するので、凸部電極２の先端面と底側端面４とをほぼ同一面とするようにして積層される。ただ、凸部電極端面の平面部と底側端面とを同一平面とするように積層して、中間リードを連結することもできる。金属板である中間リードを曲げて凸部電極と底側端面とに連結できるからである。
【００１３】
電池コア１５は、ひとつの薄型電池１の凸部電極端面３と、他方の薄型電池１の底側端面４とが位置する第１の端面５（図８において薄型電池１の左側の端面）に対向して回路基板７を配置している。回路基板７は、第１の端面５の外形にほぼ等しい外形としている。この回路基板７は、第１の端面５に対向して、第１の端面５と平行な姿勢で配設されて、薄型電池１から外部に突出しない。回路基板は、第１の端面の外形よりも小さくすることもできる。小さい回路基板も薄型電池の外側に突出しないからである。ただし、回路基板を第１の端面よりもわずかに大きくすることもできる。
【００１４】
回路基板７は、電池の保護回路を実現する電子部品２５と、出力端子１６とを固定している。図の電池コア１５は、出力端子１６を端子ホルダー１７に固定して、回路基板７に連結している。回路基板７に実装される保護回路は、図１３の回路図に示すように、パック電池の出力端子１６と薄型電池１との間に接続される。この回路図のパック電池は、保護回路１８と保護素子１０の両方を備えており、保護素子１０を各々の薄型電池１と直列に接続している。パック電池は、保護素子１０を介して薄型電池１を回路基板７に接続している。保護素子１０は電池に過電流が流れ、あるいは電池温度が設定温度よりも高くなると電流を遮断する素子である。図の回路図のパック電池は、保護素子１０をＰＴＣとしている。ただし、保護素子には、ＰＴＣに代わって、ブレーカやヒューズ等も使用できる。このパック電池は、保護素子１０と保護回路１８の両方で二重に電池を保護する。パック電池は、必ずしも保護回路と保護素子の両方を備える必要はない。保護回路と保護素子のいずれかひとつの保護回路を設けることもできる。さらに、薄型電池をニッケル−水素電池やニッケル−カドミウム電池とするパック電池は、保護回路と保護素子の両方を省略することもできる。
【００１５】
回路基板７は、中間リード８と一対の端部リード９を介して薄型電池１に連結される。中間リード８は、回路基板７の中間、好ましくはほぼ中央部分に連結される。一対の端部リード９は、回路基板７の両端部分に連結される。中間リード８と端部リード９は金属板で製作される。中間リード８と端部リード９の金属板は、ニッケル板、あるいは表面をニッケルメッキした金属板である。金属板である中間リード８と端部リード９は、スポット溶接して確実に薄型電池１の電極と回路基板７に連結される。中間リード８と端部リード９をスポット溶接して連結する回路基板７は、スポット溶接する部分に、金属プレートを半田付け等の方法で固定している。中間リード８と端部リード９は半田付けして回路基板７に連結することもできる。この回路基板７は、金属プレートを固定することなく、回路基板７の表面に設けている導電部に、中間リード８と端部リード９を直接に半田付けして固定できる。中間リード８と端部リード９は、薄型電池１の電極にはスポット溶接のみでなく、レーザー溶接あるいは超音波溶接して連結することもできる。
【００１６】
中間リード８は、図７と図８に示すように、回路基板７と対向する第１の端面５に位置する凸部電極２と底側端面４とに接続されて、ふたつの薄型電池１を互いに直列に電気接続する。中間リード８は、第１の端面５の中央部分を横方向に横断して、凸部電極２と底側端面４とに連結され、さらに、第１の端面５と対向して配置している回路基板７の中間部分に接続される。回路基板７は第１の端面５と平行に配設されるので、中間リード８は、図８の断面図に示すように、回路基板７の片方の側縁でＵ曲されて、その先端部分を回路基板７に連結している。中間リード８は、第１の端面５においてふたつの薄型電池１に連結され、さらに第１の端面５に対向して配設している回路基板７の中間部分に連結するので、最短距離で薄型電池１を回路基板７に連結する。この中間リード８は、ふたつの薄型電池１を互いに直列に電気接続すると共に、回路基板７を薄型電池１に連結する部材にも併用される。さらに、中間リード８は、各々の薄型電池１の電圧を測定する電圧検出用のリードとしても使用される。回路基板７に連結された中間リード８は保護回路に接続されており、中間リード８を介して各々の薄型電池１の電圧が検出される。このように、各々の薄型電池１の電圧を独立して検出できるパック電池は、各々の薄型電池１を理想的に制御できる。
【００１７】
一対の端部リード９は、回路基板７の両端部分に接続される。一対の端部リード９と中間リード８は、回路基板７の片方の側縁で折曲されている。この電池コア１５は、図７に示すように、回路基板７を第１の端面５と直角な姿勢として、中間リード８と端部リード９を回路基板７と薄型電池１に連結した後、中間リード８と端部リード９を折曲して、回路基板７を第１の端面５と平行な姿勢とする。この電池コア１５は、中間リード８と端部リード９の一端を回路基板７に接続した後、中間リード８と端部リード９を薄型電池１に連結できる。また、中間リード８と端部リード９を薄型電池１に連結した後、回路基板７に連結することもできる。
【００１８】
図の電池コア１５は、一対の端部リード９の端部を、第１の端面５の反対側にある第２の端面６に位置している薄型電池１の凸部電極２と底側端面４とに接続している。端部リード９は、保護素子１０を介して薄型電池１の電極に接続している。図の電池コア１５は、一方の端部リード９に接続している保護素子１０をひとつの薄型電池１の凸部電極端面３の平面部に配置して、他方の端部リード９に接続している保護素子１０を薄型電池１の側面に配置している。このように、凸部電極端面３の平面部に保護素子１０を配置する構造は、図９に示すように、凸部電極２の側部のスペースを有効に利用して保護素子１０を省スペースに配設できるので、パック電池の外形を小さくできる特長がある。この構造のパック電池は、保護素子１０に、電池温度を検出して電流を遮断する素子を使用する。このパック電池は、各々の保護素子１０で、各々の薄型電池１の温度を検出して電流を遮断するので、いずれの薄型電池１の温度が異常に高くなっても、保護素子１０で電池の電流を遮断できる。ただし、本発明のパック電池は、両方の保護素子を薄型電池の底側端面に配置し、あるいは薄型電池の側面に配置することもできる。
【００１９】
第２の端面６に一対の端部リード９を連結しているパック電池は、図８と図１４の断面図に示すように、第２の端面６で端部リード９が互いに接近する。そして、互いに接近する一対の端部リード９を確実に絶縁するために、図のパック電池は、積層している薄型電池１の間に絶縁材１１を配設している。絶縁材１１は、第２の端面６から突出して、第２の端面６の凸部電極２と底側端面４とに接続している一対の端部リード９の間に配置している。さらに、図１４のパック電池は、ケース１２の内面であって絶縁材１１と対向する位置に凹部１３を設けて、凹部１３の両側に、薄型電池１の凸部電極端面３と底側端面４に向かって突出する突出部１４を設けて、ケース１２の突出部１４と電極端面との間に端部リード９を配設している。この構造のパック電池は、仮に端部リード９が薄型電池１の底側端面４から外れても、他の端部リード９や底側端面４に接触してショートすることがない。外れた端部リード９が絶縁材１１を越えて隣に移動するのを阻止できるからである。図５と図１４のケース１２は、内面の突出部１４と対向する外側に、パック電池を装着している機器から取り出すための取出凹部１９と、パック電池を機器に装着するために機器に設けている嵌合用爪（図示せず）を案内する嵌合用凹部２０とを設けている。このケース１２は、外側に設けている取出凹部１９と嵌合用凹部２０を利用して、内側に突出部１４を設けることができる。
【００２０】
以上のパック電池は、以下のようにして製造される。
(1) 第１の端面５に凸部電極２を配置している薄型電池１の凸部電極端面３に絶縁材２１を接着する。絶縁材２１は、凸部電極２を外部に表出させる貫通孔を設けている。したがって、凸部電極端面３に絶縁材２１を接着する状態で、凸部電極２は外部に表出している。
(2) 薄型電池１の電極にクラッド材をスポット溶接して固定する。クラッド材は、中間リード８と端部リード９をスポット溶接するための金属板であるから、中間リード８と端部リード９をスポット溶接して連結する部分に固定される。中間リードと端部リードを電極に直接にスポット溶接できる薄型電池は、クラッド材を固定する必要はない。
(3) ふたつの薄型電池１を、絶縁材１１を介在して接着して積層する。絶縁材１１は、第２の端面６から突出するように薄型電池１の間に配設される。薄型電池１は、絶縁材１１の表面に設けている粘着層を介して接着される。さらに、絶縁材１１の表面に両面接着テープを付着して薄型電池１を接着することもできる。互いに接着して連結している薄型電池１は、その後の工程を簡単にできる。
(3) 図７に示すように、積層している薄型電池１の両側に絶縁材２２を接着する。この絶縁材２２は、図に示すように、第１の端面５の両端部分を被覆する長さを有し、第１の端面５の両端部分を被覆する。
(4) 図１５に示すように、回路基板７に中間リード８と一対の端部リード９をスポット溶接して連結する。中間リード８と端部リード９は、半田付けして回路基板７に連結することもできる。中間リード８と端部リード９は、回路基板７の片側で折曲されるので、片側から外側に突出する姿勢で、回路基板７に連結される。図の回路基板７は下方に突出するように、中間リード８と端部リード９を連結している。端部リード９は、あらかじめ端部に保護素子１０を連結している。各部にストレスがかからないように注意して、中間リード８と端部リード９を、回路基板７の片側で直角に折曲する。
(5) 中間リード８の端部を第１の端面５の凸部電極２と底側端面４とにスポット溶接してふたつの薄型電池１を直列に連結する。さらに、一対の端部リード９を、第１の端面５の両端で薄型電池１の隅部に沿うように折曲し、さらに第２の端面６の両側で薄型電池１の隅部に沿うように折曲して、各々の端部を第２の端面６の凸部電極２と底側端面４に連結する。
(6) 第１の端面５と回路基板７との間に絶縁材２３を配設し、この絶縁材２３を挟むように、中間リード８と端部リード９を折曲して、回路基板７を第１の端面５と平行な姿勢とする。
(7) 図１０と図１１のハッチングで示すように、電池コア１５の側面に、端部リード９の一部あるいは全部を被覆するように絶縁材２４を接着する。
(8) 以上にようにして製作された電池コア１５を、ケース１２に収納してケース１２を閉塞する。ケース１２は第１ケース１２Ａと第２ケース１２Ｂからなり、第１ケース１２Ａと第２ケース１２Ｂの周壁を超音波溶着し、あるいは接着し、あるいは嵌着して連結する。
【００２１】
【発明の効果】
本発明のパック電池は、回路基板と薄型電池とを理想的な配置で連結して、回路基板をしっかりと薄型電池に連結できる特長がある。それは、本発明のパック電池が、一方の薄型電池の凸部電極端面と他方の薄型電池の底側端面とを同一平面に位置するようにふたつの薄型電池を積層して、凸部電極端面と底側端面とが位置している第１の端面に対向して回路基板を配置し、この回路基板の中間に接続している中間リードを、回路基板と対向する第１の端面の凸部電極と底側端面に接続してふたつの薄型電池を直列に電気接続して回路基板に連結し、さらに、回路基板の両端部分に一対の端部リードを接続して、中間リードと端部リードを回路基板の片方の側縁で折曲して、一対の端部リードをひとつの薄型電池の凸部電極と他方の薄型電池の凸部電極と反対側の電極に接続しているからである。この構造のパック電池は、短い中間リードでふたつの薄型電池を直列に電気接続して、しかも薄型電池を回路基板に最短距離で連結できる。このため、中間リードでもって、ふたつの薄型電池を極めて低抵抗な状態で直列に電気接続しながらしっかりと回路基板に連結できる。
【００２２】
また、本発明のパック電池は、中間リードで薄型電池に連結している回路基板の両端に一対の端部リードを接続しており、端部リードを薄型電池に連結しているので、薄型電池の正負の電極に接続している一対の端部リードの短絡を確実に阻止して回路基板に連結できる特長もある。
【図面の簡単な説明】
【図１】本発明の一実施例にかかるパック電池の正面図
【図２】図１に示すパック電池の右側面図
【図３】図１に示すパック電池の左側面図
【図４】図１に示すパック電池の平面図
【図５】図１に示すパック電池の底面図
【図６】図１に示すパック電池の分解斜視図
【図７】図６に示す電池コアを反転して回路基板を展開した状態を示す斜視図
【図８】電池コアの断面図であって図１２のＡ−Ａ線断面に相当する図
【図９】電池コアの正面図
【図１０】図９に示す電池コアの右側面図
【図１１】図９に示す電池コアの左側面図
【図１２】図９に示す電池コアの平面図
【図１３】本発明の一実施例にかかるパック電池の回路図
【図１４】図１に示すパック電池のＡ−Ａ線断面図及び一部拡大断面図
【図１５】中間リードと端部リードを回路基板に連結した状態を示す平面図
【符号の説明】
１…薄型電池
２…凸部電極
３…凸部電極端面
４…底側端面
５…第１の端面
６…第２の端面
７…回路基板
８…中間リード
９…端部リード
１０…保護素子
１１…絶縁材
１２…ケース１２Ａ…第１ケース１２Ｂ…第２ケース
１３…凹部
１４…突出部
１５…電池コア
１６…出力端子
１７…端子ホルダー
１８…保護回路
１９…取出凹部
２０…嵌合用凹部
２１…絶縁材
２２…絶縁材
２３…絶縁材
２４…絶縁材
２５…電子部品[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a battery pack incorporating two thin batteries.
[0002]
[Prior art]
A battery pack in which a thin battery is incorporated in a case is described in, for example, Japanese Patent Application Laid-Open No. 2004-26883. In this battery pack, a circuit board is disposed on an electrode end face of a thin battery, and the circuit board and the thin battery are connected by a pair of leads. Since the battery pack with this structure houses one thin battery in the case, the thin battery can be connected to the circuit board with two leads. Thus, with the structure in which the circuit board is arranged on the electrode end face, two thin batteries can be stacked and stored in the case. The two batteries are connected in parallel or in series. A battery pack in which batteries are connected in parallel and housed in a case is laminated with the thin batteries facing in the same direction, that is, with the convex electrode end faces of the thin batteries on the same surface, and the convexity of the laminated thin batteries The partial electrodes and the electrodes on the bottom end face can be connected by leads. In a battery pack in which batteries are connected in series, when two thin batteries are stacked in the same direction, leads connected in series become long. This drawback can be solved by stacking two thin batteries facing in the opposite direction. The thin battery in the opposite direction can be connected in series with a short lead because the end surface of the convex electrode of one thin battery and the bottom end face of the other thin battery are located on the same plane. Furthermore, the circuit board is arranged on the electrode end surface opposite to the lead connecting the batteries in series, the convex electrode of the battery and the electrode on the bottom end face are connected with the lead, and the circuit board and the battery are connected with the short lead. Can connect. Therefore, the battery pack of this structure connected in series can be connected in series with the shortest lead, and a thin battery can be connected to the circuit board.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-8608
[Problems to be solved by the invention]
However, with the above structure, it is difficult to securely connect the circuit board to the thin battery, and in order to detect the voltage of each thin battery independently, the opposite side of connecting the thin batteries in series There is a disadvantage that the lead for voltage detection becomes long because it is necessary to connect the lead to the circuit board. The present invention has been developed with the aim of solving this drawback. The present invention can connect a circuit board and a thin battery in an ideal arrangement, and can firmly connect the circuit board to the thin battery. Another object of the present invention is to provide a battery pack that can be connected to a circuit board while reliably preventing a short circuit between a pair of end leads connected to the positive and negative electrodes of a thin battery connected in series.
[0005]
[Means for Solving the Problems]
In the battery pack of the present invention, two thin batteries 1 are stacked. In the thin battery 1, the convex electrode 2 is provided on the convex electrode end surface 3, and the bottom end surface 4, which is the electrode end surface opposite to the convex electrode end surface 3, is an electrode having a polarity different from that of the convex electrode 2. The two thin batteries 1 are stacked such that the convex electrode end face 3 of one thin battery 1 and the bottom end face 4 of the other thin battery 1 are located on the same end face. Further, in the battery pack, the circuit board 7 is disposed so as to face the first end face 5 where the convex electrode end face 3 of one thin battery 1 and the bottom end face 4 of the other thin battery 1 are located. An intermediate lead 8 is connected to the convex electrode end face 3 and the bottom side end face 4 located on the first end face 5 facing the circuit board 7, and the two thin batteries 1 are electrically connected in series with each other by the intermediate lead 8. Further, the intermediate lead 8 is connected to the intermediate portion of the circuit board 7. A pair of end leads 9 are connected to both ends of the circuit board 7, and the intermediate leads 8 and the end leads 9 are bent at one side edge of the circuit board 7. One pair of end leads 9 is connected to the convex electrode 2 of one thin battery 1, and the other is connected to the electrode opposite to the convex electrode 2 of the other thin battery 1. The circuit board 7 is connected to the two thin batteries 1 by the part lead 9.
[0006]
In the battery pack, the pair of end leads 9 can be connected to the electrode of the thin battery 1 via the protective element 10.
[0007]
Further, in the battery pack, the end portions of the pair of end leads 9 are located on the second end surface 6 on the opposite side of the first end surface 5, and the convex electrode 2 and the bottom end surface 4 of the thin battery 1. Can be connected to. Further, in the battery pack, an insulating material 11 is disposed between the thin batteries 1, and the insulating material 11 is protruded from the second end surface 6, so that the convex electrode end surface 3 and the bottom side of the second end surface 6 are disposed. It is arranged between the pair of end leads 9 connected to the end face 4, and the end leads 9 can be reliably insulated by the insulating material 11.
[0008]
In the battery pack, the thin battery 1 is housed in a case 12, and a recess 13 is provided on the inner surface of the case 12 at a position facing the insulating material 11, so that the pair of end leads 9 are more reliably insulated by the insulating material 11. it can. Further, on both sides of the concave portion 13 provided on the inner surface of the case 12, there are provided projecting portions 14 projecting toward the convex electrode end surface 3 and the bottom end surface 4 of the thin battery 1, and the projecting portion 14 and the electrode end surface The end leads 9 are disposed between them, and the pair of end leads 9 can be further reliably insulated.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. However, the example shown below illustrates the battery pack for embodying the technical idea of the present invention, and the present invention does not specify the battery pack as follows.
[0010]
Further, in this specification, in order to facilitate understanding of the scope of claims, the numbers corresponding to the members shown in the examples are referred to as “the scope of claims” and “the means for solving the problems”. It is added to the member shown by. However, the members shown in the claims are not limited to the members in the embodiments.
[0011]
In the battery pack shown in FIGS. 1 to 6, two thin batteries 1 are stacked, and a battery core 15 connecting a circuit board 7 to the thin battery 1 is housed in a case 12. The battery core 15 is shown in FIGS. In the battery core 15, the convex electrode 2 is provided on the convex electrode end surface 3, and the bottom side end surface 4, which is the electrode end surface opposite to the convex electrode end surface 3, is an electrode having a polarity different from that of the convex electrode 2. Thin batteries 1 are stacked. The thin battery 1 is manufactured by putting positive and negative electrodes and an electrolytic solution in an outer can and closing the opening of the outer can with a sealing plate having the convex electrode 2. The outer can is manufactured by pressing a metal plate. The sealing plate is hermetically fixed to the outer can by laser welding or crimping. This thin battery 1 uses the convex electrode 2 and the outer can as different positive and negative electrodes. A thin battery having a convex electrode as a negative electrode has an outer can as a positive electrode, and a thin battery having a convex electrode as a positive electrode has an outer can as a negative electrode. The thin battery 1 is a lithium ion battery. However, the thin battery can be any rechargeable secondary battery such as a nickel-hydrogen battery, a nickel-cadmium battery, or a polymer battery.
[0012]
As shown in the perspective view of FIG. 7 and the cross-sectional view of FIG. 8, the two thin batteries 1 have the convex electrode end face 3 of one thin battery 1 and the bottom end face 4 of the other thin battery 1 in the same plane. Laminated in position. As shown in the sectional view of FIG. 8, the two laminated thin batteries 1 connect the intermediate lead 8 to the convex electrode 2 and the bottom side end surface 4, so that the leading end surface and the bottom side end surface of the convex electrode 2 are connected. 4 are laminated so that they are substantially flush with each other. However, it is also possible to connect the intermediate leads by laminating the flat part of the convex electrode end face and the bottom end face so as to be in the same plane. This is because the intermediate lead, which is a metal plate, can be bent and connected to the convex electrode and the bottom end face.
[0013]
The battery core 15 is formed on a first end face 5 (an end face on the left side of the thin battery 1 in FIG. 8) where the convex electrode end face 3 of one thin battery 1 and the bottom end face 4 of the other thin battery 1 are located. The circuit board 7 is arranged so as to oppose. The circuit board 7 has an outer shape substantially equal to the outer shape of the first end surface 5. The circuit board 7 is disposed in a posture parallel to the first end surface 5 so as to face the first end surface 5 and does not protrude from the thin battery 1 to the outside. The circuit board can be smaller than the outer shape of the first end face. This is because even a small circuit board does not protrude outside the thin battery. However, the circuit board can be slightly larger than the first end face.
[0014]
The circuit board 7 fixes an electronic component 25 that realizes a battery protection circuit and an output terminal 16. In the illustrated battery core 15, the output terminal 16 is fixed to the terminal holder 17 and connected to the circuit board 7. The protection circuit mounted on the circuit board 7 is connected between the output terminal 16 of the battery pack and the thin battery 1 as shown in the circuit diagram of FIG. The battery pack of this circuit diagram includes both a protection circuit 18 and a protection element 10, and the protection element 10 is connected in series with each thin battery 1. In the battery pack, the thin battery 1 is connected to the circuit board 7 via the protective element 10. The protection element 10 is an element that cuts off the current when an overcurrent flows through the battery or when the battery temperature becomes higher than a set temperature. In the battery pack shown in the circuit diagram of FIG. However, a breaker, a fuse, or the like can be used as the protective element instead of the PTC. This battery pack double protects the battery by both the protection element 10 and the protection circuit 18. The battery pack does not necessarily include both a protection circuit and a protection element. Any one of the protection circuit and the protection element can be provided. Furthermore, in a battery pack in which a thin battery is a nickel-hydrogen battery or a nickel-cadmium battery, both the protective circuit and the protective element can be omitted.
[0015]
The circuit board 7 is connected to the thin battery 1 through an intermediate lead 8 and a pair of end leads 9. The intermediate lead 8 is connected to the middle of the circuit board 7, preferably approximately at the center. The pair of end leads 9 are connected to both end portions of the circuit board 7. The intermediate lead 8 and the end lead 9 are made of a metal plate. The metal plate of the intermediate lead 8 and the end lead 9 is a nickel plate or a metal plate whose surface is nickel-plated. The intermediate lead 8 and the end lead 9, which are metal plates, are spot-welded and reliably connected to the electrode of the thin battery 1 and the circuit board 7. The circuit board 7 for connecting the intermediate lead 8 and the end lead 9 by spot welding has a metal plate fixed to the spot welded portion by a method such as soldering. The intermediate lead 8 and the end lead 9 can be connected to the circuit board 7 by soldering. The circuit board 7 can be fixed by directly soldering the intermediate lead 8 and the end lead 9 to the conductive portion provided on the surface of the circuit board 7 without fixing the metal plate. The intermediate lead 8 and the end lead 9 can be connected to the electrode of the thin battery 1 not only by spot welding but also by laser welding or ultrasonic welding.
[0016]
As shown in FIGS. 7 and 8, the intermediate lead 8 is connected to the convex electrode 2 located on the first end face 5 facing the circuit board 7 and the bottom end face 4 to connect the two thin batteries 1. Make electrical connections in series with each other. The intermediate lead 8 traverses the central portion of the first end surface 5 in the lateral direction, is connected to the convex electrode 2 and the bottom side end surface 4, and is disposed opposite to the first end surface 5. It is connected to an intermediate part of the circuit board 7. Since the circuit board 7 is disposed in parallel with the first end face 5, the intermediate lead 8 is U-curved at one side edge of the circuit board 7 as shown in the sectional view of FIG. Are connected to the circuit board 7. The intermediate lead 8 is connected to the two thin batteries 1 at the first end face 5 and further connected to the intermediate portion of the circuit board 7 disposed facing the first end face 5, so that the intermediate lead 8 is thin at the shortest distance. The battery 1 is connected to the circuit board 7. The intermediate lead 8 is used for a member for electrically connecting the two thin batteries 1 in series with each other and for connecting the circuit board 7 to the thin battery 1. Further, the intermediate lead 8 is also used as a voltage detection lead for measuring the voltage of each thin battery 1. The intermediate lead 8 connected to the circuit board 7 is connected to a protection circuit, and the voltage of each thin battery 1 is detected via the intermediate lead 8. Thus, the battery pack capable of independently detecting the voltage of each thin battery 1 can ideally control each thin battery 1.
[0017]
The pair of end leads 9 are connected to both end portions of the circuit board 7. The pair of end leads 9 and the intermediate leads 8 are bent at one side edge of the circuit board 7. As shown in FIG. 7, the battery core 15 is configured such that the circuit board 7 is placed at a right angle to the first end surface 5, and the intermediate leads 8 and end leads 9 are connected to the circuit board 7 and the thin battery 1. The lead 8 and the end lead 9 are bent so that the circuit board 7 is in a posture parallel to the first end surface 5. The battery core 15 can connect the intermediate lead 8 and the end lead 9 to the thin battery 1 after connecting one end of the intermediate lead 8 and the end lead 9 to the circuit board 7. Further, the intermediate lead 8 and the end lead 9 can be connected to the circuit board 7 after being connected to the thin battery 1.
[0018]
In the illustrated battery core 15, the end portions of the pair of end leads 9 are located on the second end surface 6 on the opposite side of the first end surface 5, and the convex electrode 2 and the bottom side end surface of the thin battery 1. 4 and connected. The end lead 9 is connected to the electrode of the thin battery 1 through the protective element 10. In the illustrated battery core 15, the protective element 10 connected to one end lead 9 is arranged on the flat surface of the convex electrode end surface 3 of one thin battery 1 and connected to the other end lead 9. The protective element 10 is disposed on the side surface of the thin battery 1. As described above, the structure in which the protective element 10 is arranged on the flat surface of the convex electrode end surface 3 saves the protective element 10 by effectively using the space on the side of the convex electrode 2 as shown in FIG. The battery pack has the advantage of reducing the outer shape of the battery pack. In the battery pack having this structure, an element that detects the battery temperature and interrupts the current is used as the protection element 10. In this battery pack, each protection element 10 detects the temperature of each thin battery 1 and cuts off the current. Therefore, even if the temperature of any thin battery 1 becomes abnormally high, the protection element 10 The current can be cut off. However, in the battery pack of the present invention, both protective elements can be arranged on the bottom end face of the thin battery, or can be arranged on the side surface of the thin battery.
[0019]
In the battery pack in which the pair of end leads 9 are connected to the second end face 6, the end leads 9 approach each other at the second end face 6 as shown in the cross-sectional views of FIGS. 8 and 14. In order to reliably insulate the pair of end leads 9 that are close to each other, the battery pack in the figure has an insulating material 11 disposed between the laminated thin batteries 1. The insulating material 11 protrudes from the second end face 6 and is disposed between the pair of end leads 9 connected to the convex electrode 2 and the bottom end face 4 of the second end face 6. Further, the battery pack of FIG. 14 is provided with a concave portion 13 at a position facing the insulating material 11 on the inner surface of the case 12, and the convex electrode end surface 3 and the bottom side end surface 4 of the thin battery 1 on both sides of the concave portion 13. A projecting portion 14 projecting toward the end is provided, and an end lead 9 is disposed between the projecting portion 14 of the case 12 and the electrode end surface. In the battery pack having this structure, even if the end lead 9 is detached from the bottom side end surface 4 of the thin battery 1, it does not contact with the other end lead 9 or the bottom side end surface 4 to cause a short circuit. This is because it is possible to prevent the detached end lead 9 from moving next to the insulating material 11. The case 12 of FIGS. 5 and 14 is provided on the outside facing the protruding portion 14 on the inner surface, an extraction recess 19 for removing the battery pack from the equipment, and the equipment for attaching the battery pack to the equipment. And a fitting recess 20 for guiding a fitting claw (not shown). The case 12 can be provided with a protruding portion 14 on the inner side by using an extraction concave portion 19 and a fitting concave portion 20 provided on the outer side.
[0020]
The above battery pack is manufactured as follows.
(1) An insulating material 21 is bonded to the convex electrode end surface 3 of the thin battery 1 in which the convex electrode 2 is disposed on the first end surface 5. The insulating material 21 is provided with a through hole that exposes the convex electrode 2 to the outside. Therefore, the convex electrode 2 is exposed to the outside in a state where the insulating material 21 is bonded to the convex electrode end face 3.
(2) The clad material is spot welded to the electrode of the thin battery 1 and fixed. Since the clad material is a metal plate for spot welding the intermediate lead 8 and the end lead 9, the clad material is fixed to a portion where the intermediate lead 8 and the end lead 9 are connected by spot welding. A thin battery in which the intermediate lead and the end lead can be directly spot welded to the electrode does not need to fix the clad material.
(3) Two thin batteries 1 are bonded and laminated with an insulating material 11 interposed therebetween. The insulating material 11 is disposed between the thin batteries 1 so as to protrude from the second end face 6. The thin battery 1 is bonded via an adhesive layer provided on the surface of the insulating material 11. Furthermore, the thin battery 1 can be adhered by attaching a double-sided adhesive tape to the surface of the insulating material 11. The thin battery 1 bonded and connected to each other can simplify subsequent processes.
(3) As shown in FIG. 7, the insulating material 22 is bonded to both sides of the laminated thin batteries 1. As shown in the drawing, the insulating material 22 has a length that covers both end portions of the first end surface 5, and covers both end portions of the first end surface 5.
(4) As shown in FIG. 15, the intermediate lead 8 and the pair of end leads 9 are connected to the circuit board 7 by spot welding. The intermediate lead 8 and the end lead 9 can be connected to the circuit board 7 by soldering. Since the intermediate lead 8 and the end lead 9 are bent on one side of the circuit board 7, the intermediate lead 8 and the end lead 9 are coupled to the circuit board 7 in a posture protruding outward from the one side. The circuit board 7 shown in the figure connects the intermediate lead 8 and the end lead 9 so as to protrude downward. The end lead 9 has a protective element 10 connected to the end in advance. The intermediate leads 8 and the end leads 9 are bent at a right angle on one side of the circuit board 7 so that no stress is applied to each part.
(5) The end portions of the intermediate lead 8 are spot welded to the convex electrode 2 and the bottom end surface 4 of the first end face 5 to connect the two thin batteries 1 in series. Further, the pair of end leads 9 are bent along the corners of the thin battery 1 at both ends of the first end surface 5, and further along the corners of the thin battery 1 at both sides of the second end surface 6. Each end is connected to the convex electrode 2 and the bottom-side end surface 4 of the second end surface 6.
(6) An insulating material 23 is disposed between the first end surface 5 and the circuit board 7, and the intermediate lead 8 and the end lead 9 are bent so as to sandwich the insulating material 23, so that the circuit board 7 Is a posture parallel to the first end face 5.
(7) As shown by hatching in FIGS. 10 and 11, an insulating material 24 is bonded to the side surface of the battery core 15 so as to cover a part or all of the end lead 9.
(8) The battery core 15 manufactured as described above is housed in the case 12 and the case 12 is closed. The case 12 includes a first case 12A and a second case 12B, and the peripheral walls of the first case 12A and the second case 12B are ultrasonically welded, bonded, or fitted and connected.
[0021]
【The invention's effect】
The battery pack of the present invention has an advantage that the circuit board and the thin battery are connected in an ideal arrangement, and the circuit board can be firmly connected to the thin battery. In the battery pack of the present invention, two thin batteries are laminated so that the convex electrode end face of one thin battery and the bottom side end face of the other thin battery are located on the same plane, A circuit board is arranged opposite to the first end face where the bottom end face is located, and an intermediate lead connected to the middle of the circuit board is connected to the convex electrode on the first end face facing the circuit board. And two bottom batteries are connected in series and connected to the circuit board, and a pair of end leads are connected to both ends of the circuit board to connect the intermediate leads and end leads. This is because it is bent at one side edge of the circuit board and the pair of end leads are connected to the convex electrode of one thin battery and the electrode opposite to the convex electrode of the other thin battery. The battery pack having this structure can electrically connect two thin batteries in series with a short intermediate lead and connect the thin batteries to the circuit board in the shortest distance. For this reason, with the intermediate lead, the two thin batteries can be firmly connected to the circuit board while being electrically connected in series in an extremely low resistance state.
[0022]
In the battery pack of the present invention, the pair of end leads are connected to both ends of the circuit board connected to the thin battery by the intermediate leads, and the end leads are connected to the thin battery. Another advantage is that a short circuit between the pair of end leads connected to the positive and negative electrodes can be reliably prevented and connected to the circuit board.
[Brief description of the drawings]
1 is a front view of a battery pack according to an embodiment of the present invention. FIG. 2 is a right side view of the battery pack shown in FIG. 1. FIG. 3 is a left side view of the battery pack shown in FIG. 1 is a plan view of the battery pack shown in FIG. 1. FIG. 5 is a bottom view of the battery pack shown in FIG. 1. FIG. 6 is an exploded perspective view of the battery pack shown in FIG. FIG. 8 is a cross-sectional view of the battery core corresponding to the cross section taken along the line AA of FIG. 12. FIG. 9 is a front view of the battery core. Fig. 11 is a right side view of the battery core. Fig. 11 is a left side view of the battery core shown in Fig. 9. Fig. 12 is a plan view of the battery core shown in Fig. 9. Fig. 13 is a circuit diagram of a battery pack according to an embodiment of the present invention. 14 is a cross-sectional view taken along line AA and a partially enlarged cross-sectional view of the battery pack shown in FIG. 1. FIG. 15 is a circuit board with intermediate leads and end leads. Plan view showing the connecting state [EXPLANATION OF SYMBOLS]
DESCRIPTION OF SYMBOLS 1 ... Thin battery 2 ... Convex electrode 3 ... Convex electrode end surface 4 ... Bottom side end surface 5 ... 1st end surface 6 ... 2nd end surface 7 ... Circuit board 8 ... Intermediate lead 9 ... End part lead 10 ... Protection element 11 ... Insulating material 12 ... Case 12A ... First case 12B ... Second case 13 ... Recess 14 ... Protrusion 15 ... Battery core 16 ... Output terminal 17 ... Terminal holder 18 ... Protection circuit 19 ... Removal recess 20 ... Fitting recess 21 ... Insulating material 22 ... Insulating material 23 ... Insulating material 24 ... Insulating material 25 ... Electronic components

Claims

The convex electrode end surface (3) is provided with a convex electrode (2), and the bottom end surface (4), which is the electrode end surface opposite to the convex electrode end surface (3), has a polarity different from that of the convex electrode (2). The two thin batteries (1) used as the electrodes of the thin battery (1) are located on the same end face of the projecting electrode end face (3) of the one thin battery (1) and the bottom end face (4) of the other thin battery (1). Are stacked like
The circuit board (7) faces the first end face (5) where the convex electrode end face (3) of one thin battery (1) and the bottom end face (4) of the other thin battery (1) are located. The intermediate lead (8) is connected to the convex electrode end face (3) and the bottom end face (4) located on the first end face (5) facing the circuit board (7), Two thin batteries (1) are electrically connected in series with each other at the intermediate lead (8),
Connect this intermediate lead (8) to the intermediate part of the circuit board (7), connect a pair of end leads (9) to both ends of the circuit board (7), and connect the intermediate lead (8) and the end part The lead (9) is bent at one side edge of the circuit board (7),
One end lead (9) is connected to the convex electrode (2) of one thin battery (1) and the other is connected to the electrode opposite to the convex electrode (2) of the other thin battery (1) And
A battery pack in which a circuit board (7) is connected to two thin batteries (1) by an intermediate lead (8) and an end lead (9).

The battery pack according to claim 1, wherein the pair of end leads (9) are connected to the electrodes of the thin battery (1) through the protective element (10).

The projecting electrodes (2) of the thin battery (1) positioned on the second end surface (6) opposite to the first end surface (5) are connected to the ends of the pair of end leads (9). The battery pack according to claim 1, wherein the battery pack is connected to the bottom end face (4).

An insulating material (11) is disposed between the thin batteries (1). The insulating material (11) is projected from the second end surface (6), and the convex portion of the second end surface (6). The battery pack according to claim 3, wherein the battery pack is disposed between a pair of end leads (9) connected to the electrode end face (3) and the bottom end face (4).

The thin battery (1) is housed in a case (12), and a recess (13) is provided on the inner surface of the case (12) at a position facing the insulating material (11). Pack battery.

Protruding portions (14) projecting toward the projecting electrode end surface (3) and the bottom end surface (4) of the thin battery (1) are provided on both sides of the recess (13) provided on the inner surface of the case (12). 6. The battery pack according to claim 5, wherein an end lead (9) is disposed between the protruding portion (14) and the electrode end face.