JP3594645B2

JP3594645B2 - Resistance / temperature fuse

Info

Publication number: JP3594645B2
Application number: JP4527494A
Authority: JP
Inventors: 敏彦川元; 充明植村; 和男有山
Original assignee: Uchihashi Estec Co Ltd
Current assignee: Uchihashi Estec Co Ltd
Priority date: 1994-02-17
Filing date: 1994-02-17
Publication date: 2004-12-02
Anticipated expiration: 2019-12-02
Also published as: JPH07230748A

Description

【０００１】
【産業上の利用分野】
本発明は、基板タイプの合金型温度ヒュ−ズに抵抗体を内蔵させた抵抗・温度ヒュ−ズに関するものである。
【０００２】
【従来の技術】
抵抗・温度ヒュ−ズにおいては、合金型の温度ヒュ−ズエレメントと抵抗体とを近接配置で一体化し、抵抗体における過電流に基づく発生熱で温度ヒュ−ズエレメントを溶断させてその過電流を遮断している。
【０００３】
従来、基板型抵抗・温度ヒュ−ズとして、図６の（イ）乃至図６の（ニ）に示す両面タイプが公知である。
図６の（イ）はこの両面タイプの基板型抵抗・温度ヒュ−ズの平面説明図を、図６の（ロ）は同じく底面説明図を、図６の（ハ）は図６の（イ）におけるハ−ハ断面図を、図６の（ニ）は図６の（ロ）におけるニ−ニ断面図をそれぞれ示し、熱伝導性絶縁基板１１’の片面に、縦中心線ａ−ａに一致させて一対の温度ヒュ−ズ用膜電極１２’，１２’を印刷し、この電極間に温度ヒュ−ズエレメントとしての低融点金属片１４’を橋設し、この低融点金属片１４’にフラックス１５’を塗布し、また、同絶縁基板１１’の他面に、縦中心線ａ−ａを基準として左右対称に２対の抵抗用膜電極１６’−１６’，１６’−１６’を印刷し、これらの各対電極間に膜抵抗体１７’を絶縁基板１１’への焼き付けにより橋設し（１８’は膜抵抗体の保護層）、各電極１２’（１６’）にリ−ド線１３’（１９’）を接続し、上記絶縁基板１１’の全面にエポキシ樹脂のような硬化性樹脂層３’を浸漬塗装法により被覆してある。
【０００４】
この抵抗・温度ヒュ−ズにおいては、保護すべき電気回路に対し、一方の膜抵抗体を回路のある部分に、他方の膜抵抗体を回路の他部分にそれぞれ挿入接続し、温度ヒュ−ズエレメントを回路の入力端に挿入接続することによって使用され、何れか一方の膜抵抗体に過電流が流れて当該膜抵抗体が発熱すると、その発生熱で温度ヒュ−ズエレメントが溶断されて回路への通電が遮断される。
【０００５】
【発明が解決しようとする課題】
上記抵抗・温度ヒュ−ズにおいては、各膜抵抗体が挿入接続される各回路部分の回路インピ−ダンスの制約上、膜抵抗体の抵抗値が異なることがある。
而るに、各膜抵抗体から温度ヒュ−ズエレメントに至る媒質の熱伝達経路が全く対称であれば、各抵抗に同一値の過電流が流れても、抵抗値の小なる膜抵抗体の発熱に基づく温度ヒュ−ズエレメントの作動時間が、抵抗値の大なる膜抵抗体の発熱に基づく温度ヒュ−ズエレメントの作動時間よりも長くなり、作動時間のアンバランスが避けられない。
【０００６】
かかるアンバランスは、抵抗値の小なる膜抵抗体と温度ヒュ−ズエレメントとの間の熱伝達性を抵抗値の大なる膜抵抗体と温度ヒュ−ズエレメントとの間の熱伝達性に較べ高くするように調整することにより排除できる。而るに、その熱伝達性は膜抵抗体と温度ヒュ−ズエレメントとの間に存在する熱伝達媒質の容積により変わり、このアンバランスの解消手段としては、抵抗値の小なる膜抵抗体と温度ヒュ−ズエレメントとの間の熱伝達媒質の容積を抵抗値の大なる膜抵抗体と温度ヒュ−ズエレメントとの間の熱伝達媒質の容積より小にして、熱伝達性を調整することが考えられるが、絶縁被覆に定形の被覆が困難な浸漬塗装法を使用している上記抵抗・温度ヒュ−ズにおいては、実施は困難である。
【０００７】
本発明の目的は、絶縁基板の中央に温度ヒュ−ズエレメントを、該温度ヒュ−ズエレメントを挾む左右に異なる抵抗値の膜抵抗体をそれぞれ設けてなる抵抗・温度ヒュ−ズにおいて、各膜抵抗体の発熱に基づく温度ヒュ−ズエレメントの作動を、実質上の差異なく行わせることにある。
【０００８】
【課題を解決するための手段】
請求項１に係る抵抗・温度ヒュ−ズは、熱伝導性絶縁基板の片面の中央に温度ヒュ−ズエレメントが、同基板の他面に前記温度ヒュ−ズエレメントを中心として左右対称に異なる抵抗値の膜抵抗体が設けられてなる抵抗・温度ヒュ−ズ本体に、プレ−ト部の周囲に枠縁を有する熱伝達調整用ケ−スがそのプレ−ト部を温度ヒュ−ズエレメント側に配され、しかもケ−スのプレ−ト部の左右部分が抵抗・温度ヒュ−ズ本体の絶縁基板の片面に近接され、残部の中間膨出部内に温度ヒュ−ズエレメントが収容されて被施され、該ケ−ス内に絶縁材が注入固化され、同一過電流のもとでの各膜抵抗体の発熱に基づく温度ヒュ−ズエレメントの作動時間をほぼ等しくするように前記ケースプレート部の膨出部分の中央位置をずらすことによりそのプレ−ト部が左右非対称とされていることを特徴とする。
請求項２に係る抵抗・温度ヒュ−ズは、熱伝導性絶縁基板の片面の中央に温度ヒュ−ズエレメントが、同片面に前記温度ヒュ−ズエレメントを中心として左右対称に異なる抵抗値の膜抵抗体が設けられてなる抵抗・温度ヒュ−ズ本体に、プレ−ト部の周囲に枠縁を有する熱伝達調整用ケ−スがそのプレ−ト部を温度ヒュ−ズエレメント側に配され、しかもケ−スのプレ−ト部の左右部分が抵抗・温度ヒュ−ズ本体の絶縁基板の片面に近接され、残部の中間膨出部内に温度ヒュ−ズエレメントが収容されて被施され、該ケ−ス内に絶縁材が注入固化され、同一過電流のもとでの各膜抵抗体の発熱に基づく温度ヒュ−ズエレメントの作動時間をほぼ等しくするように前記ケースプレート部の膨出部分の中央位置をずらすことによりそのプレ−ト部が左右非対称とされていることを特徴とする。
請求項３に係る抵抗・温度ヒュ−ズは、熱伝導性絶縁基板の片面に温度ヒュ−ズエレメントが、同基板の他面に同温度ヒュ−ズエレメントを挾んで抵抗値の異なる２箇の膜抵抗体が設けられてなる抵抗・温度ヒュ−ズ本体に左右対称の熱伝達調整用ケ−スがケ−スのプレ−ト部の左右部分が抵抗・温度ヒュ−ズ本体の絶縁基板の片面に近接され、残部の中間膨出部内に温度ヒュ−ズエレメントが収容されて被施され、該ケ−ス内に絶縁材が注入固化され、同一過電流のもとでの各膜抵抗体の発熱に基づく温度ヒュ−ズエレメントの作動時間をほぼ等しくするように各膜抵抗体と温度ヒュ−ズエレメントとの間隔が設定されていることを特徴とする。
請求項４に係る抵抗・温度ヒュ−ズは、熱伝導性絶縁基板の片面に温度ヒュ−ズエレメントが、同片面に同温度ヒュ−ズエレメントを挾んで抵抗値の異なる２箇の膜抵抗体が設けられてなる抵抗・温度ヒュ−ズ本体に左右対称の熱伝達調整用ケ−スがケ−スのプレ−ト部の左右部分が抵抗・温度ヒュ−ズ本体の絶縁基板の片面に近接され、残部の中間膨出部内に温度ヒュ−ズエレメントが収容されて被施され、該ケ−ス内に絶縁材が注入固化され、同一過電流のもとでの各膜抵抗体の発熱に基づく温度ヒュ−ズエレメントの作動時間をほぼ等しくするように各膜抵抗体と温度ヒュ−ズエレメントとの間隔が設定されていることを特徴とする。
【０００９】
以下、図面を参照しつつ本発明の構成について説明する。
図１の（イ）は本発明において使用する抵抗・温度ヒュ−ズ本体の平面図を、図１の（ロ）は同じく底面図を、図１の（ハ）は図１の（イ）におけるハ−ハ断面図を、図１の（ニ）は図１の（ロ）におけるニ−ニ断面図をそれぞれ示している。
【００１０】
図１の（イ）乃至図１の（ニ）において、１１は熱伝導性の絶縁基板であり、セラミックス基板が好適である。１２，１２は絶縁基板１１の片面の中央位置に設けられた一対の膜電極であり、リ−ド線取付部１２１と温度ヒュ−ズエレメント取付部１２２とを備え、縦方向中心線ａ−ａに対し左右対称の膜電極が横方向中心線ｂ−ｂに対し上下対称に配設されている。この膜電極１２は、印刷法、例えば、導電塗料をスクリ−ン印刷し、これを焼き付けたものを使用できる。１３は各膜電極１２に溶接またはろう接されたリ−ド線である。１４は膜電極間に溶接により縦方向中央線ａ−ａに沿い橋設された温度ヒュ−ズエレメントであり、丸線または角線（例えば、丸線を扁平化したもの）の低融点可溶合金線材が使用されている。１５は温度ヒュ−ズエレメント１４上に塗布されたフラツクスであり、ロジンを主成分とするものが使用されている。
【００１１】
１６，１６、１６，１６は絶縁基板１１の他面の左右部に、縦方向中心線ａ−ａに対し左右対称に設けられた２対の膜電極であり、一端にリ−ド線取付部１６１を有する帯状膜１６２が横方向中心線に対し上下対称に配設され、そのリ−ド線取付部１６１が絶縁基板１１の左右両端側に位置されている。この膜電極１６も上記の印刷法により形成されている。１７は各一対の膜電極１６，１６間に跨り、絶縁基板１１の他面に焼成された膜抵抗体であり、抵抗塗料（抵抗粒子とバインダ−との混合物であり、抵抗粒子には酸化金属物の粉末、ニッケルや鉄等の高抵抗金属の粉末を使用でき、バインダ−にはガラスフリツトを使用できる）の印刷・焼き付けにより形成されている。この膜抵抗体は温度ヒュ−ズエレメントを中心として左右対称であり、抵抗値は、異なる切り込み距離のトリミングにより異にされている。１８は両膜抵抗体１７，１７を覆って設けられた保護膜であり、前記ガラスフリツトよりも低融点のガラスフリツトが使用され、膜抵抗体の抵抗値をトリミングにより調整する際での膜抵抗体のクラック等の発生防止に有効である。１９は膜電極１６に溶接またはろう接により接続されたリ−ド線である。
【００１２】
図２の（イ）は本発明に係る抵抗・温度ヒュ−ズの一例を示す断面図、図２の（ロ）は図２の（イ）におけるロ−ロ断面図である。
図２の（イ）並びに図２の（ロ）において、１は上記した抵抗・温度ヒュ−ズ本体である。２はケ−ス（図３にも示されている）であり、中間部が膨出された左右非対称（ロ−ロは中央線）のプレ−ト部２１の周囲に枠縁２２を有し、抵抗・温度ヒュ−ズ本体１に被施され、抵抗・温度ヒュ−ズ本体１の温度ヒュ−ズエレメント１４側がケ−ス２のプレ−ト部２１に臨まされ、当該温度ヒュ−ズエレメント１４が膨出部２０内に収容され、プレ−ト部２１の左右部分２１１，２１２が絶縁基板１１の片面に近接されている。また、枠縁２２に設けられた各Ｖノッチ２２１から各リ−ド線１３，１９が引出されている。
【００１３】
このケ−ス２の枠縁２２の内郭は抵抗・温度ヒュ−ズ本体１の絶縁基板１１の外郭を実質上ギャップを残すことなく密嵌させ得るように設定されており、当該内郭の縦寸法並びに横寸法を絶縁基板の縦寸法並びに横寸法のそれぞれに対し、１．１倍以下、好ましくは１．０７倍以下とされている。３はケ−ス２内に注入固化された絶縁材であり、ケ−ス開放側を上に向け、粘度が２万〜２０万ｃｐｓ程度のエポキシ樹脂液を該ケ−ス２内に計量滴下し、硬化させてある。
【００１４】
図２の（イ）において、例えば、左側の膜抵抗体１７の抵抗値（Ｒ_１）が右側の膜抵抗体１７の抵抗値（Ｒ_２）よりも大であるとすると、左側の膜抵抗体から温度ヒュ−ズエレメント１４に至る熱伝達性Ｚ_１（膜抵抗体から温度ヒュ−ズエレメントに至る熱伝達媒質路の熱抵抗をｒ、熱容量をｃとすると、ｒが低いほど、ｃが小さいほど速く熱が伝達され、熱伝達性はｒｃで評価される）を右側の膜抵抗体から温度ヒュ−ズエレメント１４に至る熱伝達性Ｚ_２よりも低くするように（Ｒ_１Ｚ_１＝Ｚ_２Ｒ_２とするように）、ケ−スプレ−ト部２１の膨出部分２０の中央位置ｐが高抵抗値の膜抵抗体側にずらされてプレ−ト部１が中央線ロ−ロ線に対し左右非対称とされている。
【００１５】
上記の構成例では、膨出部をケ−スの左右中央点に対しずらせて形成してケ−スを左右非対称化としているが、左右非対称化の構成は、これに限定されるものではない。
上記の構成例において、保護層１８を含めた膜抵抗体１７の厚みはリ−ド線１９の直径ｄよりも小であり、フラックス塗布温度ヒュ−ズエレメント１４の高さｈはリ−ド線１３の直径ｄよりも大であり、膜抵抗体１７のリ−ド線１９上の必要絶縁厚みをｔ、絶縁基板１１の厚みをｅ、膜電極の厚みをｅ’とすれば、ケ−ス２の膨出部２０内上面に至るまでの高さＴ_１（図３）は、次式のＴよりやや大とされ、
Ｔ＝ｔ＋ｈ＋ｄ＋ｅ ▲１▼
ケ−ス内の左右部分の高さＴ_２（図３）は、次式のＴ’よりもやや大に設定されている。
Ｔ’＝ｔ＋ｄ＋ｅ＋ｅ’ ▲２▼
【００１６】
図４及び図５は本発明の別実施例に係る抵抗・温度ヒュ−ズの構成例を示し、特に図４はその別実施例の寸法関係を示している。
この構成例では、例えば、左側の膜抵抗体１７の抵抗値（Ｒ_１）が右側の膜抵抗体１７の抵抗値（Ｒ_２）よりも大とされている。そこで、図５に示すように、プレート部２０１の中間部２０を膨出させた左右対称のケ−ス２の使用のもとで、左右の各膜抵抗体の発熱に対し、温度ヒュ−ズエレメント１４をアンバランスなく作動させるために、左側の膜抵抗体１７から温度ヒュ−ズエレメント１４に至る距離Ｌ_１を右側の膜抵抗体１７から温度ヒュ−ズエレメント１４に至る距離Ｌ_２よりも大にして、左側の膜抵抗体から温度ヒュ−ズエレメントに至る熱伝達性Ｚ_１と右側の膜抵抗体から温度ヒュ−ズエレメントに至る熱伝達性Ｚ_２とを、Ｚ_１／Ｚ_２＝Ｒ_２／Ｒ_１の関係を可及的に充足させるように調整してある。
【００１７】
図４及び図５において、図２の（イ）並びに（ロ）に対し同一の符号は、同一の構成要素を示している。而して、１１は熱伝導性の絶縁基板を、１４は温度ヒュ−ズエレメントを、１５はフラックスを、１７は膜抵抗体を、１８は保護層を、１９は膜抵抗体のリ−ド線を、３はケ−ス２内に注入固化された絶縁材、例えば、エポキシ樹脂をそれぞれ示し、温度ヒュ−ズエレメントのリ−ド線は図には現れていない。
【００１８】
この構成例においても、保護層１８を含めた膜抵抗体１７の厚みはリ−ド線１９の直径ｄよりも小であり、フラックス塗布温度ヒュ−ズエレメント１４の高さｈは温度ヒュ−ズエレメントのリ−ド線の直径ｄよりも大であり、膜抵抗体１７のリ−ド線１９上の必要絶縁厚みをｔ、絶縁基板１１の厚みをｅ、膜電極の厚みをｅ’とすれば、ケ−ス２の中間膨出部２０の内面高さＴ _１は、
Ｔ_１≧ｔ＋ｈ＋ｄ＋ｅ＋ｅ’ （３）
に設定されている。
【００１９】
前記実施例では、図４及び図５に示すようにプレ−ト部２１の左右部分を本体１の絶縁基板１１に近接させ、中間部２０を膨出させた左右対称のケ−ス２（ｃ−ｃ線は中央線）を使用し、フラックス１５を塗布した温度ヒュ−ズエレメント１４をこの中間膨出部２０内に収容してある。
【００２０】
上記何れの構成例においても、ケ−スには電気絶縁物の他、アルミニウム、ステンレス等の金属のプレス成形品の使用も可能であるが、ケ−ス枠縁のＶノッチとリ−ド線との間の絶縁保証の面から、電気絶縁物、特にプラスチック、例えば、エポキシ樹脂、不飽和ポリエステル、ビニルエステル樹脂、フェノ−ル樹脂等の熱硬化性樹脂、ポリ塩化ビニル、塩素化ポリ塩化ビニル、ポリエチレン、ポリプロピレン、アクリロニトリル−ブタジエン−スチレン共重合体、ポリスチレン、ポリカ−ボネ−ト、ポリアミド、ポリフッ化ビニリデン、ポリフェニレンサルファイド、ポリスルホン、ポリエ−テル・エ−テルケトン等の熱可塑性樹脂等の射出成形品を使用することが好ましい。
【００２１】
上記抵抗・温度ヒュ−ズの各部の寸法は通常、次ぎのように設定される。
すなわち、絶縁基板の縦（温度ヒュ−ズエレメントの方向）寸法：５〜１２ｍｍ、同横寸法：６〜１８ｍｍ、厚み０．５〜１．５ｍｍ、膜電極の厚み：１０〜８０μｍ、膜抵抗体の厚み：１０〜３５μｍ、保護層の厚み：２０〜２００μｍ、温度ヒュ−ズエレメントの直径：０．３〜１．０ｍｍ、温度ヒュ−ズエレメント上の基板からのフラックスの塗布厚み：０．４〜２ｍｍ、リ−ド線の直径：０．３〜１．３ｍｍ、膜抵抗体リ−ド線の絶縁材厚み（図２や図５におけるｔ）：０．１〜２ｍｍ、ケ−スの内郭：基板の外郭寸法の１．００５〜１．１倍、ケ−スの厚み：０．１〜１．６ｍｍとされ、ケ−ス内の高さは上記▲１▼、▲２▼、▲３▼式により設定される。
本発明においては、熱伝導性絶縁基板の同一面に、温度ヒュ−ズエレメント及び該エレメントを挾んで抵抗値の異なる２箇の膜抵抗体を設けることもできる。また、ケ−スは、プレ−ト部を上下何れに向けて被せてもよい。
【００２２】
而して、（１）熱伝導性絶縁基板の片面の中央に温度ヒュ−ズエレメントを、同片面に前記温度ヒュ−ズエレメントを中心として左右対称に異なる抵抗値の膜抵抗体を設けなる抵抗・温度ヒュ−ズ本体に、プレ−ト部の周囲に枠縁を有する熱伝達調整用ケ−スを被施し、該ケ−ス内に絶縁材を注入固化し、ケ−スのプレ−ト部を同一過電流のもとでの各膜抵抗体の発熱に基づく温度ヒュ−ズエレメントの作動時間をほぼ等しくするように左右非対称の形状とすること、（２）熱伝導性絶縁基板の片面に温度ヒュ−ズエレメントを、同片面に同温度ヒュ−ズエレメントを挾んで抵抗値の異なる２箇の膜抵抗体を設けてなる抵抗・温度ヒュ−ズ本体に熱伝達調整用ケ−スを被施し、該ケ−ス内に絶縁材を注入固化し、同一過電流のもとでの各膜抵抗体の発熱に基づく温度ヒュ−ズエレメントの作動時間をほぼ等しくするように各膜抵抗体と温度ヒュ−ズエレメントとの間隔を異ならしめることも可能である。
【００２３】
本発明において、ケ−スのプレ−ト部と抵抗・温度ヒュ−ズ本体の絶縁基板との間は、通常上記の絶縁材で充填されるが、空隙の状態とすることも可能である。
【作用】
本発明に係る抵抗・温度ヒュ−ズにおいては、保護すべき電気回路に対し、一方の膜抵抗体を回路のある部分に、他方の膜抵抗体を回路の他部分にそれぞれ挿入接続し、温度ヒュ−ズエレメントを回路の入力端に挿入接続することによって使用される。
【００２４】
各膜抵抗体の抵抗値をＲ_１、Ｒ_２とすると、同一過電流ｉによる各膜抵抗体の発生熱はＲ_１ｉ^２、Ｒ_２ｉ^２であり、各膜抵抗体から温度ヒュ−ズエレメントに至る熱伝達経路の熱伝達性をＺ_１、Ｚ_２とすれば、Ｒ_１ｉ^２・Ｚ_１＝Ｒ_２ｉ^２・Ｚ_２を満たすとき、各膜抵抗体の発生熱量の差にもかかわらず、温度ヒュ−ズエレメントをほぼ同一に温度上昇させ得、抵抗値の相違にもかかわらず、同一過電流のもとでの各膜抵抗体の発熱に基づく温度ヒュ−ズエレメントの作動時間がほぼ等しくできる。
【００２５】
而るに、膜抵抗体から温度ヒュ−ズエレメントに至る熱伝達経路の熱伝達性はその間の距離、熱伝達媒質の量等により調整できるが、抵抗・温度ヒュ−ズ本体を浸漬塗装法で覆うときは、その被覆層の体積を一定にすることが困難であり、各膜抵抗体から温度ヒュ−ズエレメントに至る熱伝達経路の熱伝達性の満足せる精度のもとでの調整は至難である。
【００２６】
しかし、本発明の抵抗・温度ヒュ−ズにおいては、射出成形等により定形性をよく保証できるケ−スを抵抗・温度ヒュ−ズ本体に被せ、ケ−ス内に絶縁材を計量滴下して注入固化することを可能にしているから、上記の熱伝達性の調整を高精度で行い得、同一過電流のもとでの各膜抵抗体の発熱に基づく温度ヒュ−ズエレメントの作動時間を充分に等しくできる。
【００２７】
また、請求項３記載並びに請求項５記載の発明においては、絶縁基板の片面側の厚みの大なるフラックス塗布ヒュ−ズエレメントをケ−スの膨出部内に収容し、基板片面側の残部をケ−ス内面に近接させているから、その間の媒質の量を著しく小にでき、熱容量ｃを小さくして全体として作動迅速性を向上できる。
【００２８】
【実施例】
実施例１
図２の（イ）並びに図２の（ロ）に示す構成を用い、抵抗・温度ヒュ−ズ本体には図１の（イ）乃至図１の（ニ）に示す構成を使用した。熱伝導性絶縁基板には、厚さ０．６ｍｍ、縦９ｍｍ、横１４ｍｍのセラミックス基板を使用し、全ての膜電極を銀ペ−ストの印刷・焼き付けにより形成し、電極厚みを２５μｍとした。温度ヒュ−ズエレメントには直径０．５ｍｍ、液相温度９６℃の低融点可溶合金線を使用し、フラックス（ヒュ−ズエレメントの融点よりも低い軟化点のもの）の塗布厚みを１．２ｍｍとした。膜抵抗体は、酸化金属系抵抗塗料（酸化金属粉末とガラスフリットとの混合物）の厚み２０μｍの印刷・焼き付けにより、保護膜は低融点ガラスフリットの厚み８０μｍの焼き付けによりそれぞれ膜成し、温度ヒュ−ズエレメントからの各膜抵抗体までの距離を共に０．５ｍｍとし、両膜抵抗体の抵抗値をトリミングにより１ｋΩと９５０Ωに設定した。リ−ド線には全て、直径０．６ｍｍの銅線を使用した。
【００２９】
ケ−スには、フェノ−ル樹脂の射出成形品で、図３において、膨出部までの内部高さＴ_１が２．７ｍｍ、左右部の各内部高さＴ_２が１．５ｍｍ、膨出部の巾ｗ_０が６．３ｍｍ、左右部の各巾ｗ_１，ｗ_２が３．５ｍｍと５．１ｍｍ、内郭縦長さが９．７ｍｍ，厚みが０．６ｍｍのものを使用し、硬化性絶縁材には、浸漬塗装用のエポキシ樹脂液を使用した。
【００３０】
これらの実施例品４０個の内、２０個について抵抗値が１ＫΩの膜抵抗体と温度ヒュ−ズエレメントとを直列に接続し、定格電力（１Ｗ）の９倍に相当する電流９４．４ｍＡを流し、作動時間（通電開始の後、通電が遮断されるまでの時間）を測定したところ、２０秒〜２３秒であった。更に、残りの２０個について、抵抗値が９５０Ωの膜抵抗体と温度ヒュ−ズエレメントとを直列に接続し、上記と同一電流のもとで、同じようにして作動時間を測定したところ、２１秒〜２３秒であり、同一過電流のもとでの各膜抵抗体の発熱に基づく温度ヒュ−ズエレメントの作動時間を実質上、等しくできた。
【００３１】
比較例１
実施例１と同じ抵抗・温度ヒュ−ズ本体を使用し、実施例１で使用したエポキシ樹脂を絶縁基板に浸漬塗装した。
実施例１と同様にして、各膜抵抗体に対する温度ヒュ−ズエレメントの作動時間を測定したところ、作動時間は１９秒〜２９秒と２２秒〜３２秒であり、作動時間に約３秒の差があった。
【００３２】
実施例２
図５に示す構成を用い、実施例１で用いた抵抗・温度ヒュ−ズ本体に対し、抵抗値が１ｋΩの膜抵抗体と温度ヒュ−ズエレメントとの距離を１ｍｍだけ隔離する方向にずらし、その分だけ絶縁基板の巾を増大し、他は実施例１とものと同じとした抵抗・温度ヒュ−ズ本体を使用した。ケ−スには、中央部を膨出させた左右対称のフェノ−ル製で、膨出部内面までの高さＴ_３が２．７ｍｍ、左右内部の高さＴ_２が１．５ｍｍ、膨出部内の巾ｗ_０が６．３ｍｍ、左右部の内巾ｗ_３が４．３ｍｍ、内郭の縦長さが９ｍｍ、厚みが０．６ｍｍのものを使用し、実施例１と同様、エポキシ樹脂液を滴下法により注入固化した。
【００３３】
この実施例品４０個ににつき、実施例１と同様に、一の各膜抵抗体と温度ヒュ−ズエレメントとをそれぞれ直列に接続し、通電電流９４．４ｍＡのもとでの作動時間を測定したところ、何れの膜抵抗体についても２０秒〜２４秒であり、作動時間のバラツキは実施例１と同様、無視できた。
【００３４】
【発明の効果】
本発明の抵抗・温度ヒュ−ズは上述した通りの構成であり、絶縁基板の中央に温度ヒュ−ズエレメントを、該温度ヒュ−ズエレメントを挾む左右に異なる抵抗値の膜抵抗体をそれぞれ設けてなる抵抗・温度ヒュ−ズにおいて、各膜抵抗体の発熱に基づく温度ヒュ−ズエレメントの作動を、実質上の時間差なく行わせることを保証でき、何れの膜抵抗体に過電流が流れても回路を確実に保護できる。
【図面の簡単な説明】
【図１】図１の（イ）は本発明において使用する抵抗・温度ヒュ−ズ本体の一例を示す平面図、図１の（ロ）は同じく底面図、図１の（ハ）は図１の（イ）におけるハ−ハ断面図、図１の（ニ）は図１の（ロ）におけるニ−ニ断面図である。
【図２】図２の（イ）は本発明の実施例を示す断面図、図２の（ロ）は図２の（イ）におけるロ−ロ断面図である。
【図３】図２の実施例におけるケ−スを示す説明図である。
【図４】本発明の別実施例の寸法関係を示す断面図である。
【図５】本発明の別実施例を示す断面図である。
【図６】図６の（イ）は従来例を示す平面説明図、図６の（ロ）は同じく底面説明図、図６の（ハ）は図６の（イ）におけるハ−ハ断面図、図６の（ニ）は図６の（ロ）におけるニ−ニ断面図である。
【符号の説明】
１１絶縁基板
１２膜電極
１３リ−ド線
１４温度ヒュ−ズエレメント
１５フラックス
１６膜電極
１７膜抵抗体
１９リ−ド線
１抵抗・温度ヒュ−ズ本体
２ケ−ス
２０膨出部
２１プレ−ト部
２２枠縁
３硬化性絶縁材[0001]
[Industrial applications]
The present invention relates to a resistance / temperature fuse in which a resistor is incorporated in a substrate type alloy type temperature fuse.
[0002]
[Prior art]
In the resistance / temperature fuse, an alloy type temperature fuse element and a resistor are integrated in a close arrangement, and the temperature fuse element is blown by generated heat based on an overcurrent in the resistor, and the overcurrent is generated. Is shut off.
[0003]
Conventionally, a double-sided type shown in FIGS. 6 (a) to 6 (d) has been known as a substrate type resistance / temperature fuse.
FIG. 6 (a) is a plan view of the double-sided substrate type resistor / temperature fuse, FIG. 6 (b) is a bottom view, and FIG. 6 (c) is FIG. 6) shows a cross-sectional view of FIG. 6 (d), and FIG. 6 (d) shows a cross-sectional view of FIG. 6 (b), taken along a vertical center line aa on one surface of the heat conductive insulating substrate 11 '. A pair of temperature fuse membrane electrodes 12 ', 12' are printed in agreement with each other, and a low melting point metal piece 14 'as a temperature fuse element is bridged between the electrodes. And a pair of resistive membrane electrodes 16'-16 'and 16'-16' on the other surface of the insulating substrate 11 'symmetrically with respect to the vertical center line aa. Is printed, and a film resistor 17 'is bridged between these counter electrodes by baking on the insulating substrate 11' (18 'is a protective layer of the film resistor), and each electrode 12' is formed. 16 ') to re - word line 13''connecting the), the insulating substrate 11' (19 are coated by dip coating method of the curable resin layer 3 ', such as entire epoxy resin.
[0004]
In this resistance / temperature fuse, one of the film resistors is inserted and connected to a certain portion of the circuit and the other is inserted and connected to the other portion of the circuit for the electric circuit to be protected. This element is used by inserting and connecting an element to the input end of a circuit. When an overcurrent flows to one of the membrane resistors and the corresponding membrane resistor generates heat, the generated heat causes the temperature fuse element to be blown and cut off. Is turned off.
[0005]
[Problems to be solved by the invention]
In the above-mentioned resistance / temperature fuse, the resistance value of the film resistor may be different due to the restriction of the circuit impedance of each circuit portion to which each film resistor is inserted and connected.
If the heat transfer path of the medium from each film resistor to the temperature fuse element is completely symmetric, even if an overcurrent of the same value flows through each resistor, the resistance of the film resistor having a small resistance value is reduced. The operation time of the temperature fuse element based on heat generation is longer than the operation time of the temperature fuse element based on heat generation of the membrane resistor having a large resistance value, and an imbalance in operation time is inevitable.
[0006]
This imbalance is caused by comparing the heat transfer between the film resistor having a small resistance value and the temperature fuse element with the heat transfer between the film resistor having a large resistance value and the temperature fuse element. It can be eliminated by adjusting it to be higher. However, the heat transfer property varies depending on the volume of the heat transfer medium existing between the film resistor and the temperature fuse element. As a means for eliminating the imbalance, a film resistor having a small resistance value is used. Adjusting the heat transfer by reducing the volume of the heat transfer medium between the temperature fuse element and the volume of the heat transfer medium between the membrane resistor having a large resistance value and the temperature fuse element. However, it is difficult to carry out the above-mentioned resistance / temperature fuse which uses a dip coating method in which a fixed coating is difficult for the insulating coating.
[0007]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a resistance / temperature fuse having a temperature fuse element at the center of an insulating substrate and film resistors having different resistance values on the left and right sides of the temperature fuse element. An object of the present invention is to make the operation of the temperature fuse element based on heat generation of the membrane resistor be performed without a substantial difference.
[0008]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a resistance / temperature fuse, wherein a temperature fuse element is provided at the center of one surface of the thermally conductive insulating substrate, and the other surface of the substrate has different resistances symmetrically with respect to the temperature fuse element. A heat transfer adjusting case having a frame edge around a plate portion is provided on a resistance / temperature fuse body provided with a film resistor having a predetermined value, and the plate portion is connected to the temperature fuse element side. In addition, the left and right portions of the plate portion of the case are close to one surface of the insulating substrate of the resistance / temperature fuse body, and the temperature fuse element is accommodated in the remaining intermediate bulge portion and is covered. Insulating material is injected and solidified in the case, and the case plate portion is set so that the operating time of the temperature fuse element based on heat generation of each film resistor under the same overcurrent is made substantially equal. By shifting the center of the bulge Wherein the isolation portion is asymmetrical.
3. A resistance / temperature fuse according to claim 2, wherein a temperature fuse element is provided at the center of one surface of the thermally conductive insulating substrate, and the other surface of the heat conductive insulation substrate has a resistance value which differs symmetrically with respect to the temperature fuse element. A heat transfer adjusting case having a frame edge around a plate portion is arranged on a resistance / temperature fuse body provided with a resistor, and the plate portion is arranged on the temperature fuse element side. In addition, the left and right portions of the case plate portion are close to one surface of the insulating substrate of the resistance / temperature fuse body, and the temperature fuse element is accommodated and covered in the remaining intermediate bulging portion. An insulating material is injected and solidified in the case, and the case plate portion swells so as to make the operating time of the temperature fuse element based on the heat generation of each film resistor under the same overcurrent substantially equal. By shifting the center position of the part, the plate part Characterized in that it is asymmetrical.
According to a third aspect of the present invention, there is provided a resistance / temperature fuse having a temperature fuse element on one surface of a thermally conductive insulating substrate, and two resistances having different resistance values sandwiching the same temperature fuse element on the other surface of the substrate. A left-right symmetrical heat transfer adjusting case is provided on the resistance / temperature fuse body provided with the membrane resistor, and the left and right portions of the case plate are formed on the insulating substrate of the resistance / temperature fuse body. A temperature fuse element is accommodated and accommodated in the remaining intermediate bulging portion which is close to one side, and an insulating material is injected and solidified in the case, and each film resistor under the same overcurrent is applied. The distance between each film resistor and the temperature fuse element is set so that the operation time of the temperature fuse element based on the heat generation of the temperature fuse element is substantially equal.
According to a fourth aspect of the present invention, there is provided a resistance / temperature fuse comprising two film resistors having different resistance values with a temperature fuse element on one side of the thermally conductive insulating substrate and the same temperature fuse element on the same side. The right and left symmetrical heat transfer adjustment cases are provided on the resistance / temperature fuse body provided with the heat sink body, and the left and right portions of the plate portion of the case are close to one surface of the insulating substrate of the resistance / temperature fuse body. The temperature fuse element is housed and covered in the remaining intermediate bulging portion, and an insulating material is injected and solidified in the case, and the heat generated by each of the film resistors under the same overcurrent is reduced. The interval between each of the film resistors and the temperature fuse element is set so that the operating time of the temperature fuse element is substantially equal.
[0009]
Hereinafter, the configuration of the present invention will be described with reference to the drawings.
FIG. 1A is a plan view of the resistance / temperature fuse body used in the present invention, FIG. 1B is a bottom view thereof, and FIG. 1C is FIG. FIG. 1D shows a cross-sectional view taken along line II-II of FIG. 1B.
[0010]
In FIGS. 1A to 1D, reference numeral 11 denotes a thermally conductive insulating substrate, preferably a ceramic substrate. Reference numerals 12 and 12 denote a pair of membrane electrodes provided at a central position on one surface of the insulating substrate 11, which are provided with a lead wire attaching portion 121 and a temperature fuse element attaching portion 122, and have a longitudinal center line aa. Are symmetrically arranged with respect to the horizontal center line bb. This membrane electrode 12 can be used by a printing method, for example, screen printing of a conductive paint and baking it. 13 is a lead wire welded or brazed to each membrane electrode 12. Reference numeral 14 denotes a temperature fuse element bridged along the longitudinal center line aa between the membrane electrodes by welding, and has a low melting point melting property of a round wire or a square wire (for example, a flat round wire). Alloy wire is used. Reference numeral 15 denotes a flux applied on the temperature fuse element 14, which is mainly composed of rosin.
[0011]
Reference numerals 16, 16, 16 and 16 denote two pairs of membrane electrodes provided on the left and right portions of the other surface of the insulating substrate 11 symmetrically with respect to the longitudinal center line aa. A strip-shaped film 162 having a 161 is disposed vertically symmetrically with respect to the center line in the horizontal direction, and its lead wire attachment portions 161 are located on both left and right sides of the insulating substrate 11. This membrane electrode 16 is also formed by the printing method described above. Reference numeral 17 denotes a film resistor straddling between the pair of film electrodes 16 and 16 and fired on the other surface of the insulating substrate 11, and is a resistive paint (a mixture of resistive particles and a binder; Powder, powder of a high-resistance metal such as nickel or iron, and glass frit can be used as a binder). This film resistor is symmetrical about the temperature fuse element, and its resistance value is made different by trimming different cutting distances. Reference numeral 18 denotes a protective film provided to cover both the film resistors 17 and 17, which is made of glass frit having a lower melting point than the glass frit, and is used to adjust the resistance of the film resistor by trimming. It is effective in preventing the occurrence of cracks and the like. Reference numeral 19 denotes a lead wire connected to the membrane electrode 16 by welding or brazing.
[0012]
FIG. 2A is a cross-sectional view showing an example of the resistance / temperature fuse according to the present invention, and FIG. 2B is a cross-sectional view of FIG.
In FIGS. 2A and 2B, reference numeral 1 denotes the above-described resistance / temperature fuse body. Reference numeral 2 denotes a case (also shown in FIG. 3), which has a frame edge 22 around an asymmetrical plate (roller is a center line) 21 in which an intermediate portion is bulged. , Is applied to the resistance / temperature fuse body 1, and the temperature fuse element 14 side of the resistance / temperature fuse body 1 faces the plate portion 21 of the case 2. 14 is accommodated in the bulging portion 20, and the left and right portions 211 and 212 of the plate portion 21 are close to one surface of the insulating substrate 11. Lead wires 13 and 19 are drawn from V notches 221 provided on the frame edge 22.
[0013]
The inner edge of the frame edge 22 of the case 2 is set so that the outer edge of the insulating substrate 11 of the resistance / temperature fuse body 1 can be closely fitted without substantially leaving a gap. The vertical and horizontal dimensions are 1.1 times or less, preferably 1.07 times or less with respect to the vertical and horizontal dimensions of the insulating substrate, respectively. Reference numeral 3 denotes an insulating material injected into the case 2 and solidified, and an epoxy resin liquid having a viscosity of about 20,000 to 200,000 cps is measured and dropped into the case 2 with the open side of the case facing upward. And cured.
[0014]
In FIG. 2A, for example, assuming that the resistance value (R ₁ ) of the left film resistor 17 is larger than the resistance value (R ₂ ) of the right film resistor 17, for example, a temperature fuse - thermal conductivity Z ₁ leading to's element 14 _(temperature fuse from film resistor - the thermal resistance of the heat transfer medium path leading to's elements r, the thermal capacity is is c, as r is low, c is small As soon as heat is transferred, the heat transfer is evaluated by rc) is lower than the heat transfer Z ₂ from the right-side membrane resistor to the temperature fuse element 14 (R ₁ Z ₁ = Z). as the ₂ R _2), Ke - spray - in Russia line - center p of the bulging portion 20 of the isolation portion 21 is shifted to the membrane resistor side of the high resistance value pre - isolation portion 1 is the center line b On the other hand, it is left-right asymmetric.
[0015]
In the above configuration example, the bulging portion is formed so as to be shifted from the left and right center points of the case to make the case left-right asymmetric, but the configuration of the left-right asymmetry is not limited to this. .
In the above configuration example, the thickness of the film resistor 17 including the protective layer 18 is smaller than the diameter d of the lead wire 19, and the height h of the flux application temperature fuse element 14 is equal to the lead wire. 13 is larger than the diameter d of the film resistor 13, and if the required insulating thickness on the lead wire 19 of the film resistor 17 is t, the thickness of the insulating substrate 11 is e, and the thickness of the film electrode is e ', the case The height T ₁ (FIG. 3) up to the inner upper surface of the bulging portion 20 of FIG. 2 is slightly larger than T in the following equation.
T = t + h + d + e (1)
The height T ₂ (FIG. 3) of the left and right portions in the case is set slightly larger than T ′ in the following equation.
T '= t + d + e + e' (2)
[0016]
4 and 5 show an example of the configuration of a resistance / temperature fuse according to another embodiment of the present invention. In particular, FIG. 4 shows the dimensional relationship of the other embodiment .
In this configuration example, for example, the resistance value (R ₁ ) of the left film resistor 17 is set to be larger than the resistance value (R ₂ ) of the right film resistor 17. Therefore, as shown in FIG. 5, the temperature fuse is used for the heat generation of the left and right film resistors under the use of the symmetrical case 2 in which the intermediate portion 20 of the plate portion 201 is bulged. to operate the element 14 imbalance without temperature from the left side of the film resistor 17 fuse - temperature fuse the distance L ₁ leading to's element 14 from the right side of the film resistor 17 - than the distance L ₂ leading to's element 14 in the large, temperature fuse from the left side of the film resistor - temperature from the heat transfer resistance Z ₁ and the right side of the film resistor leading to's elements fuse - the thermal conductivity Z ₂ leading to's element, Z 1 _/ Z ₂ = It has been adjusted to satisfy the R ₂ / R ₁ relationship as much as possible.
[0017]
4 and 5, the same reference numerals as those in FIGS . 2A and 2B denote the same components. Thus, 11 is a thermally conductive insulating substrate, 14 is a temperature fuse element, 15 is a flux, 17 is a film resistor, 18 is a protective layer, and 19 is a lead of the film resistor. The line 3 indicates an insulating material, for example, an epoxy resin injected and solidified in the case 2, and the lead wire of the temperature fuse element is not shown in the figure.
[0018]
Also in this configuration example, the thickness of the film resistor 17 including the protective layer 18 is smaller than the diameter d of the lead wire 19, and the height h of the flux application temperature fuse element 14 is the temperature fuse. It is larger than the diameter d of the lead wire of the element, t is the required insulation thickness on the lead wire 19 of the film resistor 17, e is the thickness of the insulating substrate 11, and e 'is the thickness of the membrane electrode. if, Ke - inner surface height _{T 1} of the middle bulged portion 20 of scan 2,
T ₁ ≧ t + h + d + e + e ′ (3)
Is set to
[0019]
In the above-described embodiment, as shown in FIGS. 4 and 5 , the left and right portions of the plate portion 21 are brought close to the insulating substrate 11 of the main body 1 and the middle portion 20 is bulged. The temperature fuse element 14 to which the flux 15 is applied is accommodated in the intermediate bulging portion 20 using the -c line as the center line.
[0020]
In any of the above configuration examples, in addition to the electric insulator, a press-formed product of a metal such as aluminum or stainless steel can be used for the case. However, the V notch at the edge of the case frame and the lead wire can be used. From the standpoint of ensuring insulation between them, electrical insulators, especially plastics, for example, thermosetting resins such as epoxy resin, unsaturated polyester, vinyl ester resin, phenol resin, polyvinyl chloride, and chlorinated polyvinyl chloride Injection molded products such as thermoplastic resins such as polyethylene, polypropylene, acrylonitrile-butadiene-styrene copolymer, polystyrene, polycarbonate, polyamide, polyvinylidene fluoride, polyphenylene sulfide, polysulfone, and polyetheretherketone. It is preferred to use
[0021]
The dimensions of each part of the resistance / temperature fuse are usually set as follows.
That is, the vertical dimension of the insulating substrate (direction of the temperature fuse element): 5 to 12 mm, the horizontal dimension: 6 to 18 mm, the thickness of 0.5 to 1.5 mm, the thickness of the membrane electrode: 10 to 80 μm, the membrane resistor Thickness: 10 to 35 μm, thickness of protective layer: 20 to 200 μm, diameter of temperature fuse element: 0.3 to 1.0 mm, thickness of applied flux from substrate on temperature fuse element: 0.4 2 to 2 mm, lead wire diameter: 0.3 to 1.3 mm, insulation thickness of the film resistor lead wire (t in FIGS. 2 and 5): 0.1 to 2 mm, out of the case Section: 1.05 to 1.1 times the outer dimension of the substrate, thickness of the case: 0.1 to 1.6 mm, and the height in the case is the above (1), (2), and (1) Set by equation (3).
In the present invention, a temperature fuse element and two film resistors having different resistance values may be provided on the same surface of the heat conductive insulating substrate with the element interposed therebetween. Further, the case may be covered with the plate portion facing up or down.
[0022]
(1) A resistor having a temperature fuse element provided at the center of one surface of a thermally conductive insulating substrate and a film resistor having a different resistance value provided on the same surface symmetrically with respect to the temperature fuse element. .A heat transfer adjusting case having a frame edge around a plate portion is applied to the temperature fuse body, and an insulating material is injected and solidified in the case to form a case plate. (2) one side of the heat conductive insulating substrate, wherein the portion has a left-right asymmetric shape so that the operation time of the temperature fuse element based on heat generation of each film resistor under the same overcurrent is substantially equal. In addition, a case for adjusting heat transfer is provided on the body of the resistance and temperature fuse, which is provided with a temperature fuse element and two membrane resistors having different resistance values with the same temperature fuse element interposed on the same surface. Insulating material is injected into the case and solidified, and each film resistor under the same overcurrent is applied. Body temperature fuse based on the heat generation - the film resistor to substantially equalize the operation time's elements and the temperature fuse - can be made different spacing between's elements.
[0023]
In the present invention, the space between the plate portion of the case and the insulating substrate of the resistance / temperature fuse body is usually filled with the above-mentioned insulating material, but it is also possible to form a gap.
[Action]
In the resistance / temperature fuse according to the present invention, for the electric circuit to be protected, one film resistor is inserted and connected to a part of the circuit, and the other film resistor is inserted and connected to the other part of the circuit. It is used by inserting a fuse element at the input of the circuit.
[0024]
Assuming that the resistance values of the respective film resistors are R ₁ and R ₂ , the heat generated by the respective film resistors due to the same overcurrent i is R ₁ i ² and R ₂ i ^2. Assuming that the heat transfer properties of the heat transfer path leading to the element are Z ₁ and Z ₂ , when R ₁ i ² · Z ₁ = R ₂ i ² · Z ₂ is satisfied, the difference in the amount of heat generated by each film resistor is also satisfied. Regardless, the temperature fuse element can be raised in temperature substantially the same, and the operating time of the temperature fuse element based on heat generation of each film resistor under the same overcurrent despite the difference in resistance value. Can be almost equal.
[0025]
The heat transfer property of the heat transfer path from the film resistor to the temperature fuse element can be adjusted by the distance between them, the amount of the heat transfer medium, and the like. When covering, it is difficult to make the volume of the covering layer constant, and it is very difficult to adjust the heat transfer path from each film resistor to the temperature fuse element with satisfactory accuracy of heat transfer. It is.
[0026]
However, in the case of the resistance / temperature fuse of the present invention, a case capable of ensuring good formability by injection molding or the like is placed on the resistance / temperature fuse body, and the insulating material is dropped into the case. Since it is possible to inject and solidify, the above-mentioned heat transfer can be adjusted with high accuracy, and the operating time of the temperature fuse element based on the heat generation of each membrane resistor under the same overcurrent is reduced. Can be sufficiently equal.
[0027]
According to the third and fifth aspects of the present invention, the flux-coated fuse element having a large thickness on one side of the insulating substrate is accommodated in the bulging portion of the case, and the remaining portion on the one side of the substrate is removed. Since it is close to the inner surface of the case, the amount of medium therebetween can be significantly reduced, the heat capacity c can be reduced, and the operation speed can be improved as a whole.
[0028]
【Example】
Example 1
The configuration shown in FIGS. 2A and 2B was used, and the configuration shown in FIGS. 1A to 1D was used for the resistance / temperature fuse body. A ceramic substrate having a thickness of 0.6 mm, a length of 9 mm, and a width of 14 mm was used as the heat conductive insulating substrate, and all the membrane electrodes were formed by printing and baking silver paste to make the electrode thickness 25 μm. For the temperature fuse element, a low melting point fusible alloy wire having a diameter of 0.5 mm and a liquidus temperature of 96 ° C. was used, and the applied thickness of the flux (softening point lower than the melting point of the fuse element) was 1. It was 2 mm. The film resistor is formed by printing and baking a metal oxide-based resistance paint (mixture of metal oxide powder and glass frit) with a thickness of 20 μm, and the protective film is formed by baking a low melting glass frit with a thickness of 80 μm. The distance from each of the film resistors to each film resistor was 0.5 mm, and the resistance values of both film resistors were set to 1 kΩ and 950 Ω by trimming. A copper wire having a diameter of 0.6 mm was used for all the lead wires.
[0029]
Ke - The scan, phenol - Le a resin injection molded article, in FIG. 3, the internal height _{T 1} is 2.7 mm, the inner height _{T 2} is 1.5mm right and left portions to the bulging portion, Rise The width w ₀ of the protruding part is 6.3 mm, the widths w ₁ and w _{2 of} the left and right parts are 3.5 mm and 5.1 mm, the inner vertical length is 9.7 mm, and the thickness is 0.6 mm. An epoxy resin liquid for dip coating was used for the curable insulating material.
[0030]
Out of the 40 products of these embodiments, a film resistor having a resistance value of 1 KΩ and a temperature fuse element are connected in series for 20 of them, and a current of 94.4 mA corresponding to 9 times the rated power (1 W) is applied. When the operation time (time from the start of energization to the interruption of energization) was measured, it was 20 seconds to 23 seconds. Further, with respect to the remaining 20 pieces, a membrane resistor having a resistance value of 950Ω and a temperature fuse element were connected in series, and the operating time was measured in the same manner under the same current as above, and the result was 21. Second to 23 seconds, the operating time of the temperature fuse element based on the heat generation of each film resistor under the same overcurrent was substantially equalized.
[0031]
Comparative Example 1
Using the same resistance / temperature fuse body as in Example 1, the epoxy resin used in Example 1 was dip-coated on an insulating substrate.
When the operation time of the temperature fuse element for each membrane resistor was measured in the same manner as in Example 1, the operation times were 19 seconds to 29 seconds and 22 seconds to 32 seconds, and the operation time was about 3 seconds. There was a difference.
[0032]
Example 2
Using the structure shown in FIG. 5, the distance between the film resistor having a resistance value of 1 kΩ and the temperature fuse element is shifted by 1 mm with respect to the resistance / temperature fuse body used in the first embodiment, The width of the insulating substrate was increased by that amount, and a resistance / temperature fuse body which was the same as that of the first embodiment was used. Ke - The scan, phenol symmetrical obtained by bulging a central portion - made le, height T ₃ is 2.7mm to bulging portion inner surface, the left and right internal height T ₂ is 1.5 mm, Rise width _{w 0} of the output portion is 6.3 mm, the inner width _{w 3} of the right and left portions using 4.3 mm, those vertical length of the inner contour is 9 mm, a thickness of 0.6 mm, as in example 1, an epoxy resin The liquid was injected and solidified by a dropping method.
[0033]
For each of the forty samples of this embodiment, one membrane resistor and a temperature fuse element were connected in series in the same manner as in the first embodiment, and the operation time was measured under an energizing current of 94.4 mA. As a result, it was 20 seconds to 24 seconds for each of the membrane resistors, and the variation in the operation time was negligible as in Example 1.
[0034]
【The invention's effect】
The resistance / temperature fuse of the present invention has the same configuration as described above. A temperature fuse element is provided at the center of the insulating substrate, and film resistors having different resistance values are sandwiched between the temperature fuse element. In the resistance / temperature fuse provided, it is possible to guarantee that the operation of the temperature fuse element based on the heat generation of each film resistor is performed without a substantial time difference, and that an overcurrent flows through any of the film resistors. Circuit can be reliably protected.
[Brief description of the drawings]
1 (a) is a plan view showing an example of a resistance / temperature fuse body used in the present invention, FIG. 1 (b) is a bottom view thereof, and FIG. 1 (c) is FIG. 1A is a cross-sectional view taken along line c-c of FIG. 1, and FIG. 1D is a cross-sectional view taken along line d-i of FIG.
2A is a cross-sectional view showing an embodiment of the present invention, and FIG. 2B is a cross-sectional view of FIG.
FIG. 3 is an explanatory view showing a case in the embodiment of FIG. 2;
FIG. 4 is a sectional view showing a dimensional relationship of another embodiment of the present invention .
FIG. 5 is a sectional view showing another embodiment of the present invention .
6 (a) is a plan view showing a conventional example, FIG. 6 (b) is a bottom view, and FIG. 6 (c) is a sectional view taken along the line c-a of FIG. 6 (a). FIG. 6 (d) is a cross-sectional view taken along the line ni-ii in FIG. 6 (b).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Insulating substrate 12 Membrane electrode 13 Lead wire 14 Temperature fuse element 15 Flux 16 Membrane electrode 17 Membrane resistor 19 Lead wire 1 Resistance / temperature fuse body 2 Case 20 Swelling part 21 G22 Frame edge 3 Curable insulating material

Claims

A resistance / temperature in which a temperature fuse element is provided at the center of one surface of a thermally conductive insulating substrate, and a film resistor having a different resistance value is provided on the other surface of the substrate symmetrically with respect to the temperature fuse element. In the fuse body, a heat transfer adjusting case having a frame edge around the plate portion is arranged on the side of the temperature fuse element, and the plate portion of the case is further provided. The right and left portions are close to one surface of the insulating substrate of the resistance / temperature fuse body, the temperature fuse element is accommodated in the remaining intermediate bulging portion, and the insulating material is injected into the case. The preheated portion of the case plate portion is shifted by shifting the center position of the swelled portion so that the operating time of the temperature fuse element based on heat generation of each film resistor under the same overcurrent is substantially equalized. -Make sure that the Resistance and temperature fuse and symptoms -'s.

A resistance / temperature fuse in which a temperature fuse element is provided at the center of one surface of the heat conductive insulating substrate, and a film resistor having a different resistance value is provided on the same surface symmetrically with respect to the temperature fuse element. A heat transfer adjusting case having a frame edge around the plate portion is arranged on the body, and the plate portion is arranged on the side of the temperature fuse element, and the left and right portions of the plate portion of the case are arranged. Is placed close to one side of the insulating substrate of the resistance / temperature fuse body, the temperature fuse element is accommodated in the remaining intermediate bulging portion, and the insulating material is injected and solidified in the case. The plate portion is shifted by shifting the center position of the bulging portion of the case plate portion so that the operating time of the temperature fuse element based on heat generation of each film resistor under the same overcurrent is made substantially equal. Is characterized by being left-right asymmetric That resistance-temperature fuse -'s.

A resistance / temperature fuse in which a temperature fuse element is provided on one side of a thermally conductive insulating substrate and two film resistors having different resistance values are provided on the other side of the substrate with the same temperature fuse element interposed therebetween. A heat transfer adjusting case symmetrical to the fuse body is provided. The left and right portions of the plate portion of the case are close to one surface of the insulating substrate of the resistance / temperature fuse body, and the temperature in the remaining intermediate bulge is The fuse element is accommodated and applied, and the insulating material is injected and solidified in the case, and the operating time of the temperature fuse element based on the heat generated by each of the membrane resistors under the same overcurrent is reduced. A resistance / temperature fuse, wherein the distance between each film resistor and the temperature fuse element is set to be substantially equal.

A temperature / heat fuse element is provided on one side of a thermally conductive insulating substrate, and a resistance / temperature fuse body comprising two film resistors having different resistance values sandwiching the same temperature fuse element on the same side. A left-right symmetrical heat transfer adjusting case is provided so that the right and left portions of the plate portion of the case are close to one surface of the insulating substrate of the resistance / temperature fuse body, and the temperature fuse is located in the remaining intermediate bulge portion. The element is accommodated and applied, and an insulating material is injected and solidified in the case to make the operating time of the temperature fuse element based on heat generation of each membrane resistor under the same overcurrent substantially equal. The distance between each film resistor and the temperature fuse element is set as described above.