JP4390950B2

JP4390950B2 - Heat dissipation structure

Info

Publication number: JP4390950B2
Application number: JP2000052782A
Authority: JP
Inventors: 誠福田; 康則家城; 直樹和田; 攻石川
Original assignee: Mitsubishi Electric Corp; Mitsubishi Electric Lighting Corp
Current assignee: Mitsubishi Electric Corp; Mitsubishi Electric Lighting Corp
Priority date: 2000-02-29
Filing date: 2000-02-29
Publication date: 2009-12-24
Anticipated expiration: 2020-02-29
Also published as: JP2001244665A

Description

【０００１】
【発明の属する技術分野】
本発明は、回路基板に実装される回路部品に含まれる発熱部品の放熱構造に関するものである。
【０００２】
【従来の技術】
図５は従来の発熱部品の回路基板への実装状態を示す分解斜視図である。図において、２１は裏面側に回路パターンが形成された例えば平面形状がほぼ長方形状の回路基板、２２，２３は回路部品に含まれる発熱部品の例えばトランジスターおよびダイオードブリッジで、回路基板２１の表面側に実装されている。なお、発熱部品であるトランジスター２２およびダイオードブリッジ２３を含む回路部品の端子は、回路基板２１に設けられた孔（図示せず）を介して裏側に挿通され、回路パターンに半田付けされている。２４は熱伝導性のよい金属材料によって構成された放熱フィンで、発熱部品であるトランジスター２２およびダイオードブリッジ２３にそれぞれねじ２５によって取り付けられている。
【０００３】
２６は回路基板２１とほぼ等しい長方形状に形成された絶縁ケースで、プラスチック樹脂によって構成されており、上面縁部に設けられた複数の係止部２７によって回路基板２１の裏面側に着脱自在に取り付けられ、回路基板２１の幅方向の動きを規制するとともに、上方への抜けを防止している。また、絶縁ケース２６の上面縁部には複数の保持ピン２８が設けられており、この保持ピン２８を回路基板２１に設けられた保持穴２１ａに挿通させることによって、回路基板２１を取り付ける際の位置決めになるとともに、回路基板２１の長さ方向の動きを規制する。また、保持ピン２８の台部２８ａによって、回路基板２１と絶縁ケース２６の間に台部２８ａの高さ（厚さ）の間隙を形成し、この間隙によって回路基板２１の裏面側に形成された回路パターンおよび半田付けされた端子などを保護し、取り扱い性をよくするとともに、空気層を形成して回路基板２１の裏面側からの放熱を行えるようにしている。
【０００４】
そして、回路基板２１に実装された他の回路部品とともに、発熱部品であるトランジスター２２およびダイオードブリッジ２３が駆動して熱が発せられると、その熱はトランジスター２２およびダイオードブリッジ２３にそれぞれ取り付けられた各放熱フィン２４に伝わり、各放熱フィン２４から空気中に放熱される。また、トランジスター２２およびダイオードブリッジ２３からの熱は、それぞれの端子（リード部）を伝わり、回路基板２１の裏面側より間隙の空気層に放熱される。
【０００５】
【発明が解決しようとする課題】
上記のような従来の回路基板２１に実装された発熱部品であるトランジスター２２およびダイオードブリッジ２３は、それぞれに放熱フィン２４を取り付け、主にその放熱フィン２４から熱を放熱させている。このため、取り付けた放熱フィン２４による放熱には限度があり、それ以上の効果を上げるには放熱フィン２４を大型化するなど、放熱フィン２４の構造を変更しなければならなかった。しかしながら、回路基板２１が取り付けられる装置などによっても異なるが、回路基板２１上に取り付けられる放熱フィン２４の大きさおよび高さなどの構造には制限があり、放熱フィン２４の大型化は難しく放熱効果に限界があった。
【０００６】
そこで、このような問題を解決するために、例えば特開平１−７８０９０号公報には、絶縁層の表面に回路パターンを形成し、発熱部品を含む回路部品を、その回路部品の端子を回路パターンに電気的に接続して固定し、金属筐体の表面に直接積層される回路基板を有し、この回路基板に発熱部品に一部が金属筐体の表面に直接接触する孔を設けた回路部品の実装装置が開示されており、回路基板に設けた孔を介して金属筐体に発熱部品の一部を直接接触させ放熱させることによって、発熱部品の放熱効果を高めるとしている。
【０００７】
しかしながら、回路基板に各発熱部品がそれぞれ嵌入され金属筐体に直接接触させるための孔を多数設けなければならないため、その作業が面倒であるとともに、多数設けられた孔によって回路基板に形成される回路パターンの自由度が制約されてしまうなどの問題があった。
【０００８】
本発明は、上記のような課題を解決するためになされたもので、回路基板における回路パターンの形成が制約されず、簡単な構造で発熱部品の放熱効果をより向上させることのできる発熱部品の放熱構造を提供することを目的としたものである。
【０００９】
【課題を解決するための手段】
本発明に係る発熱部品の放熱構造は、発熱部品を含む回路部品が表裏面に実装される回路基板と、回路基板の裏面側にこの裏面側を覆うように所定の間隔を隔てて取り付けられる金属ケースとを備え、回路基板と金属ケースとの間に、上面が回路基板の裏面側に実装された発熱部品に当接され、下面が金属ケースの上面に当接される放熱部材と、金属ケースを上方に切り起こして形成され、回路基板の表面側に実装された発熱部品に対応して設けられた開口部を介して発熱部品の下面にその上面が当接される放熱部とを設け、回路基板は、一対の対向するそれぞれの端部より外方側に延出した係止片を有し、金属ケースは、一対の対向するそれぞれの辺から上方に立設され、係止片を載置する上端部と、その上端部よりさらに上方に突出し、端部及び係止片の側部に接触して回路基板の動きを規制する係止部とからなる壁部を有し、金属ケースにおける壁部を有さない他の一対のそれぞれの辺、壁部の両側端部、及び、回路基板における係止片を有さない他の一対のそれぞれの端部によって形成される開口部分を有するものである。
本発明に係る発熱部品の放熱構造は、係止部は、内面側に突起部を有し、この突起部は、回路基板の端部を上方から係止するものである。
【００１０】
本発明に係る発熱部品の放熱構造は、放熱部材を、弾力性を有する熱伝導性材料からなるシート部材によって構成し、このシート部材は、その下面側に粘着剤が塗布され、金属ケースの上面に粘着剤を介して着脱自在に取り付けられたものである。
【００１１】
本発明に係る発熱部品の放熱構造は、放熱部材を、弾力性および絶縁性を有する熱伝導性材料からなり、回路基板の裏面側に実装された発熱部品が嵌合する凹部を有するシート部材によって構成したものである。
【００１２】
本発明に係る発熱部品の放熱構造は、放熱部を、金属ケースを上方に切り起こして側面形状が逆Ｌ字状に形成された突出部によって構成し、回路基板の表面側に実装された発熱部品と、回路基板に設けられた開口部を介して発熱部品の下面に当接される突出部の上面とをねじ固定したものである。
【００１３】
本発明に係る発熱部品の放熱構造は、回路基板の開口部に対向する位置に挿通穴を有し、表面側に放熱部材の下面が当接する絶縁紙を、回路基板の裏面側を覆うように回路基板と金属ケースの間に配設したものである。
【００１４】
【発明の実施の形態】
実施の形態１．
図１は本発明の実施の形態１の分解斜視図、図２はそのＡ−Ａ断面図である。図において、１は裏面側に回路パターンが形成された例えば平面形状がほぼ長方形状の回路基板で、後述する発熱部品であるダイオードブリッジ３が実装される位置に、そのダイオードブリッジ３の平面形状より若干小さい大きさの開口部１ａが設けられており、回路基板１の長辺には端部より外方側に延出した複数の係止片１ｂがそれぞれ設けられている。２，３は回路基板１に実装される回路部品に含まれる発熱部品の例えばトランジスターおよびダイオードブリッジで、トランジスター２は回路基板１の裏面側に実装され、ダイオードブリッジ３は回路基板１の開口部１ａに対向するように表面側に実装されていて、そのほぼ中心部にはねじ穴３ａが設けられている。なお、ダイオードブリッジ３を含む表面側に実装された回路部品の端子は、回路基板１に設けられた孔（図示せず）を介して裏面側に挿通され、回路パターンに半田付けされている。
【００１５】
４は例えばアルミニウムの如き熱伝導性のよい金属材料からなり、回路基板１の平面形状とほぼ等しい長方形状に形成された回路基板１の裏面側に取り付けられる金属ケースで、その長辺側には互いに対向しかつ回路基板１と金属ケース４との間に間隙Ｇ１を有するように上方に立設された壁部４ａが設けられており、その壁部４ａの上端部には上方に突出し、回路基板１の係止片１ｂの側部に係止して回路基板１の長さ方向の動きを規制するとともに、回路基板１の長辺に係止して回路基板１の幅方向の動きを規制する複数の係止部５がそれぞれ設けられている。そして、回路基板１の係止片１ｂが壁部４ａの上端部に載置されることによって、間隙Ｇ１を形成しつつ金属ケース４が回路基板１に取り付けられる。なお、壁部４ａによって間隙Ｇ１を形成するための位置決めが容易となる。また、係止部５の内面には内側に突起した突起部５ａが設けられており、金属ケース４に取り付けられた回路基板１の上方への抜けを防止する。
【００１６】
６は金属ケース４を上方に切り起こして側面形状が逆Ｌ字状に形成された放熱部である突出部で、その上面６ａは回路基板１の開口部１ａの開口形状より小さく形成されており、回路基板１を金属ケース４に取り付けたときに、突出部６の上面６ａが回路基板１の開口部１ａを介してダイオードブリッジ３の下面に当接する位置に設けられている。また、上面６ａのほぼ中心部にはねじ穴６ｂが設けられており、突出部６をダイオードブリッジ３の下面に当接させて、ねじ７によりダイオードブリッジ３の上面側からダイオードブリッジ３のねじ穴３ａおよび突出部６のねじ穴６ｂに螺合させることによって、両者３，６を接触させるとともに、金属ケース４を回路基板１に固定させる。なお、６ｃは突出部６に弾性を付与するために設けられたスリットである。
【００１７】
８は例えばポリエステルの如き絶縁性を有する材料からなり、回路基板１の平面形状とほぼ等しい長方形状に形成された絶縁紙で、回路基板１と金属ケース４の間に配設され、回路基板１の開口部１ａに対向する位置には開口部１ａとほぼ等しい大きさの挿通穴８ａが設けられている。９は例えばシリコンの如き弾力性を有する熱伝導性材料からなり、回路基板１の裏面側に実装された複数のトランジスター２の上面（実装された面とは反対の側の面）を覆う大きさに形成された例えば平面形状がほぼ長方形状の放熱部材であるシート部材で、例えばその下面側に塗布された粘着剤によって、絶縁紙８の表面側の複数のトランジスター２に対向する位置に着脱自在に取り付けられ、回路基板１を金属ケース４に取り付けたときにシート部材９の上面が複数のトランジスター２の上面に当接し、トランジスター２を保護する。なお、絶縁紙８は省略してもよく、この場合はシート部材９が金属ケース４の上面に直接取り付けられる。
【００１８】
このように構成された実施の形態１において、回路基板１の裏面側に絶縁紙８を介して金属ケース４を取り付け、回路基板１に実装された他の回路部品（図示せず）とともに発熱部品であるトランジスター２およびダイオードブリッジ３が駆動すると、トランジスター２およびダイオードブリッジ３から熱が発生する。そして、トランジスター２からの熱は、その上面に当接されたシート部材９を介して金属ケース４に伝えられ、金属ケース４から空気中に放熱される。また、ダイオードブリッジ３からの熱は、その下面に当接された金属ケース４を上方に切り起こして形成された突出部６に伝えられ、突出部６および金属ケース４から空気中に放熱される。さらに、回路基板１と金属ケース４の間に形成された間隙Ｇ１の空気層にもトランジスター２、シート部材９および突出部６などの熱が放熱される。
【００１９】
このように、回路基板１の裏面側に実装されたトランジスター２の熱は、その上面に当接された放熱部材であるシート部材９を介して金属ケース４に伝えられ、回路基板１の表面側に実装されたダイオードブリッジ３の熱は、その下面に当接された放熱部である突出部６および突出部６を介して金属ケース４に伝えられるので、従来例の放熱フィンのように大きさ等の構造制限を受けることなく金属ケース４の全面から放熱することができ、放熱効果を高めることができる。
【００２０】
また、トランジスター２の熱を金属ケース４に伝えるためのシート部材９を、弾力性を有する熱伝導性材料によって構成したため、トランジスター２を保護しつつ高い密着性を得ることができ、金属ケース４への熱伝導性つまり金属ケース４からの放熱効果をより向上させることができる。同様にして、ダイオードブリッジ３の熱を金属ケース４に伝えるための突出部６を、金属ケース４を上方に切り起こして形成し、ダイオードブリッジ３と突出部６とをねじ固定によって接触したため、その密着性を高めることができ、突出部６への熱伝導性つまり放熱効果をより向上させることができる。また、このねじ固定は、ダイオードブリッジ３と突出部６とを接触させるだけでなく、回路基板１に金属ケース４を取り付けるためのものでもあり、簡単な構造で金属ケース４の取り付けを容易に行うことができる。そして、金属ケース４にスリット６ｃを設けて突出部６の上面６ａに弾性を付与すれば、ダイオードブリッジ３との密着性が高められ、放熱効果をさらに向上させることができる。
【００２１】
さらに、回路基板１の表面側に実装されるごく一部の発熱部品（ここではダイオードブリッジ３）に対してのみ、回路基板１に開口部１ａを設け、回路基板１の裏面側に実装される他の発熱部品（ここではトランジスター２）に対しては、回路基板１に多数の開口部１ａを設ける必要がないため、回路基板１に形成される回路パターンの自由度を極めて大きくすることができる。これにより、発熱部品を回路基板１に容易に実装することができ、その放熱効果も確実に得ることができる。
【００２２】
また、突出部６、回路基板１の裏面側に実装されるトランジスター２およびそれに対向して設けられたシート部材９によって、回路基板１と金属ケース４との間に間隙Ｇ１を確実に保持することができ、別の部品等を用いることなく間隙Ｇ１による空気層を形成することができる。これにより、回路基板１の裏面側からの放熱効果を向上させることができる。
【００２３】
実施の形態２．
図３は本発明の実施の形態２の要部の断面図で、この実施の形態２は、実施の形態１において、回路基板１の裏面側に実装された高さ（厚さ）がほぼ等しい複数のトランジスター２に代えて、高さの異なる複数のトランジスター２を実装し、シート部材９の弾力性によって、各トランジスター２を保護するとともにシート部材９との密着性を得られるようにしたものである。
【００２４】
このように構成したことにより、実施の形態１とほぼ同じ作用および効果が得られるとともに、弾力性を有する熱伝導性材料で構成されたシート部材９によって、回路基板１の裏面側に実装された高さの異なるトランジスター２に対しても保護しつつシート部材９との密着性を得ることができ、各トランジスター２から発せられた熱を金属ケース４に確実に伝え、放熱効果を高めることができる。
【００２５】
実施の形態３．
図４は本発明の実施の形態３の要部の断面図で、この実施の形態３は、実施の形態２に係る弾力性を有する熱伝導性材料によって構成されたシート部材９に代えて、弾力性および絶縁性を有する熱伝導性材料からなり、高さが間隙Ｇ１とほぼ等しいシート部材１０とし、このシート部材１０に回路基板１の裏面側に実装された発熱部品である例えば高さの異なるトランジスター２が嵌合する凹部１０ａを設け、金属ケース４を回路基板１に取り付ける際に、この凹部１０ａにトランジスター２を嵌合したものである。
【００２６】
このように構成したことにより、実施の形態１とほぼ同じ作用および効果が得られるとともに、弾力性および絶縁性を有する熱伝導性材料で構成されたシート部材１０によって、回路基板１の裏面側に実装された高さの異なるトランジスター２を確実に保護しつつシート部材１０との密着性も高めることができ、各トランジスター２から発せられた熱を金属ケース４に確実に伝えて、放熱効果をより向上させることができる。
【００２７】
なお、上述の実施の形態１乃至３において、回路基板１を長方形状に形成した場合を示したが、これに限定するものではなく、他の形状に適宜変更することができる。この場合、金属ケース４および絶縁紙８なども回路基板１に対応した形状に形成する。
【００２８】
【発明の効果】
以上のように本発明に係る発熱部品の放熱構造は、発熱部品を含む回路部品が表裏面に実装される回路基板と、回路基板の裏面側にこの裏面側を覆うように所定の間隔を隔てて取り付けられる金属ケースとを備え、回路基板と金属ケースとの間に、上面が回路基板の裏面側に実装された発熱部品に当接され、下面が金属ケースの上面に当接される放熱部材と、金属ケースを上方に切り起こして形成され、回路基板の表面側に実装された発熱部品に対応して設けられた開口部を介して発熱部品の下面にその上面が当接される放熱部とを設けたので、発熱部品の熱を放熱部材および放熱部を介して金属ケースに確実に伝えることができ、金属ケースの全面から放熱することができて放熱効果を向上することができる。また、回路基板に多数の開口部を設ける必要がないため、回路基板に形成される回路パターンの自由度を極めて大きくすることができるとともに、放熱部材および放熱部によって回路基板と金属ケースとの間に間隙を確実に保持することができ、別の部品等を用いることなく間隙による空気層を形成できて回路基板の裏面側からの放熱効果を高めることができる。
【００２９】
本発明に係る発熱部品の放熱構造は、放熱部材を、弾力性を有する熱伝導性材料からなるシート部材によって構成したので、回路基板に高さの異なる複数の発熱部品が実装された場合でも、各発熱部品を保護するとともにシート部材との密着性が得られ、各発熱部品からの熱を金属ケースに確実に伝えて、放熱効果を高めることができる。
【００３０】
本発明に係る発熱部品の放熱構造は、放熱部材を、弾力性および絶縁性を有する熱伝導性材料からなり、回路基板の裏面側に実装された発熱部品が嵌合する凹部を有するシート部材によって構成したので、回路基板に高さの異なる複数の発熱部品が実装された場合でも、各発熱部品を確実に保護するとともにシート部材との密着性を高めることができ、各発熱部品からの熱を金属ケースに確実に伝えて放熱効果をより向上させることができる。
【００３１】
本発明に係る発熱部品の放熱構造は、放熱部を、金属ケースを上方に切り起こして側面形状が逆Ｌ字状に形成された突出部によって構成し、回路基板の表面側に実装された発熱部品と、回路基板に設けられた開口部を介して発熱部品の下面に当接される突出部の上面とをねじ固定したので、発熱部品と突出部との密着性を高めることができ、突出部への熱伝導性つまり放熱効果をより向上させることができる。また、このねじ固定は、回路基板と金属ケースとの取り付けも兼ねているため、簡単な構造で金属ケースの取り付けを容易に行うことができる。
【００３２】
本発明に係る発熱部品の放熱構造は、回路基板の開口部に対向する位置に挿通穴を有し、表面側に放熱部材の下面が当接する絶縁紙を、回路基板の裏面側を覆うように回路基板と金属ケースの間に配設したので、絶縁紙によって回路基板と金属ケースとの間の絶縁をより確実にすることができる。
【図面の簡単な説明】
【図１】本発明の実施の形態１の分解斜視図である。
【図２】図１のＡ−Ａ断面図である。
【図３】本発明の実施の形態２の要部の断面図である。
【図４】本発明の実施の形態３の要部の断面図である。
【図５】従来の発熱部品の回路基板への実装状態を示す分解斜視図である。
【符号の説明】
１回路基板、１ａ開口部、２トランジスター（発熱部品）、３ダイオードブリッジ（発熱部品）、３ａ，６ｂねじ穴、４金属ケース、６突出部、６ａ上面、７ねじ、８絶縁紙、８ａ挿通穴、９，１０シート部材、Ｇ１間隙。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat dissipation structure for a heat generating component included in a circuit component mounted on a circuit board.
[0002]
[Prior art]
FIG. 5 is an exploded perspective view showing a state where a conventional heat generating component is mounted on a circuit board. In the figure, 21 is a circuit board having a circuit pattern formed on the back side, for example, a substantially rectangular circuit board, and 22 and 23 are heat generating parts included in the circuit parts, such as transistors and diode bridges. Has been implemented. Note that the terminals of the circuit components including the transistor 22 and the diode bridge 23 which are heat generating components are inserted into the back side through holes (not shown) provided in the circuit board 21 and soldered to the circuit pattern. Reference numeral 24 denotes a heat radiating fin made of a metal material having good thermal conductivity, and is attached to the transistor 22 and the diode bridge 23 which are heat generating parts by screws 25.
[0003]
Reference numeral 26 denotes an insulating case formed in a rectangular shape substantially equal to the circuit board 21 and is made of plastic resin, and is detachably attached to the back surface side of the circuit board 21 by a plurality of locking portions 27 provided on the upper edge. It is attached and restricts the movement of the circuit board 21 in the width direction and prevents upward slipping. In addition, a plurality of holding pins 28 are provided on the edge of the upper surface of the insulating case 26, and when the circuit board 21 is attached, the holding pins 28 are inserted into the holding holes 21 a provided in the circuit board 21. In addition to positioning, the movement of the circuit board 21 in the length direction is restricted. Further, the base portion 28 a of the holding pin 28 forms a gap (height) of the base portion 28 a between the circuit board 21 and the insulating case 26, and this gap is formed on the back side of the circuit board 21. The circuit pattern and the soldered terminals are protected to improve handling, and an air layer is formed so that heat can be radiated from the back side of the circuit board 21.
[0004]
When the transistor 22 and the diode bridge 23 which are heat generating components are driven together with other circuit components mounted on the circuit board 21 and heat is generated, the heat is applied to the transistor 22 and the diode bridge 23, respectively. The heat is transmitted to the heat radiating fins 24 and is radiated from the heat radiating fins 24 into the air. Further, heat from the transistor 22 and the diode bridge 23 is transmitted through the respective terminals (lead portions), and is radiated from the back side of the circuit board 21 to the air layer in the gap.
[0005]
[Problems to be solved by the invention]
The transistor 22 and the diode bridge 23, which are heat generating components mounted on the conventional circuit board 21 as described above, are each provided with a heat radiating fin 24, and heat is mainly radiated from the heat radiating fin 24. For this reason, there is a limit to the heat radiation by the attached heat radiating fins 24, and to increase the effect, the structure of the heat radiating fins 24 must be changed, for example, the size of the heat radiating fins 24 is increased. However, although it differs depending on the device to which the circuit board 21 is attached, there are limitations on the structure such as the size and height of the radiation fins 24 mounted on the circuit board 21, and it is difficult to increase the size of the radiation fins 24, and thus the heat radiation effect. There was a limit.
[0006]
In order to solve such a problem, for example, Japanese Patent Laid-Open No. 1-78090 discloses that a circuit pattern is formed on the surface of an insulating layer, a circuit component including a heat generating component, and a terminal of the circuit component as a circuit pattern. A circuit board that has a circuit board that is electrically connected to and fixed directly on the surface of the metal casing, and a hole in the heat generating component that directly contacts the surface of the metal casing. A component mounting apparatus is disclosed, and a heat radiation effect of a heat-generating component is enhanced by causing a part of the heat-generating component to directly contact and dissipate heat through a hole provided in a circuit board.
[0007]
However, since it is necessary to provide a large number of holes for inserting each heat-generating component into the circuit board and bringing it into direct contact with the metal housing, the work is troublesome and the circuit board is formed by the many holes provided. There was a problem that the degree of freedom of the circuit pattern was restricted.
[0008]
The present invention has been made in order to solve the above-described problems, and the formation of a circuit pattern on a circuit board is not restricted, and a heat generating component capable of further improving the heat dissipation effect of the heat generating component with a simple structure is provided. The object is to provide a heat dissipation structure.
[0009]
[Means for Solving the Problems]
The heat dissipating structure of the heat generating component according to the present invention includes a circuit board on which circuit parts including the heat generating component are mounted on the front and back surfaces, and a metal that is attached to the back surface side of the circuit board at a predetermined interval so as to cover the back surface side. And a metal case between the circuit board and the metal case, wherein the upper surface is in contact with the heat generating component mounted on the back side of the circuit board and the lower surface is in contact with the upper surface of the metal case, A heat dissipating part whose upper surface is in contact with the lower surface of the heat generating component through an opening provided corresponding to the heat generating component mounted on the surface side of the circuit board, The circuit board has a locking piece extending outward from a pair of opposing ends, and the metal case is erected upward from each of the pair of opposing sides to mount the locking piece. Projecting further upward from the upper end of the upper end, Parts and have a wall portion comprising a locking portion for restricting the movement of the circuit board in contact with the side portion of the lock piece, each side of the other pair with no wall portion of the metal case, the wall portion And an opening portion formed by each of a pair of other end portions having no locking piece on the circuit board .
In the heat dissipation structure for a heat generating component according to the present invention, the locking portion has a protrusion on the inner surface side, and the protrusion locks the end of the circuit board from above.
[0010]
In the heat dissipation structure for a heat generating component according to the present invention, the heat dissipating member is constituted by a sheet member made of a heat conductive material having elasticity , and this sheet member is coated with an adhesive on the lower surface side thereof, and the upper surface of the metal case. It is attached detachably through an adhesive .
[0011]
The heat dissipating structure of the heat generating component according to the present invention is a sheet member having a heat sink made of a heat conductive material having elasticity and insulation and having a recess into which the heat generating component mounted on the back side of the circuit board is fitted. It is composed.
[0012]
Radiation structure of the heat-generating component according to the present invention, the heat radiating portion, by cutting and raising the metal case upward constituted by protrusions is side shape is formed in an inverted L-shape, it is mounted on the surface side of the circuit board heating The component and the upper surface of the protruding portion that comes into contact with the lower surface of the heat-generating component through an opening provided in the circuit board are fixed by screws.
[0013]
The heat dissipating structure of the heat generating component according to the present invention has an insertion hole at a position facing the opening of the circuit board, and covers the insulating paper with which the lower surface of the heat radiating member abuts on the front surface side so as to cover the back surface side of the circuit board. It is disposed between the circuit board and the metal case.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is an exploded perspective view of Embodiment 1 of the present invention, and FIG. In the figure, reference numeral 1 denotes a circuit board having a circuit pattern formed on the back side, for example, a substantially rectangular circuit board. The diode bridge 3 which is a heat generating component to be described later is mounted at a position from the planar shape of the diode bridge 3. An opening 1a having a slightly smaller size is provided, and a plurality of locking pieces 1b extending outward from the end are provided on the long side of the circuit board 1, respectively. Reference numerals 2 and 3 denote, for example, a transistor and a diode bridge of heat generating components included in the circuit component mounted on the circuit board 1, the transistor 2 is mounted on the back side of the circuit board 1, and the diode bridge 3 is an opening 1 a of the circuit board 1. Are mounted on the surface side so as to face each other, and a screw hole 3a is provided at substantially the center thereof. The terminals of the circuit components mounted on the front surface side including the diode bridge 3 are inserted into the back surface side through holes (not shown) provided in the circuit board 1 and soldered to the circuit pattern.
[0015]
4 is a metal case made of a metal material with good thermal conductivity such as aluminum and attached to the back side of the circuit board 1 formed in a rectangular shape substantially equal to the planar shape of the circuit board 1, Wall portions 4a are provided so as to face each other and have a gap G1 between the circuit board 1 and the metal case 4, and project upward from the upper end of the wall portion 4a. The circuit board 1 is locked to the side of the locking piece 1b of the board 1 to restrict the movement of the circuit board 1 in the length direction, and is locked to the long side of the circuit board 1 to restrict the movement of the circuit board 1 in the width direction. A plurality of locking portions 5 are provided. Then, the locking piece 1b of the circuit board 1 is placed on the upper end of the wall 4a, so that the metal case 4 is attached to the circuit board 1 while forming the gap G1. Note that the positioning for forming the gap G1 is facilitated by the wall 4a. In addition, a protrusion 5 a protruding inward is provided on the inner surface of the locking portion 5, and prevents the circuit board 1 attached to the metal case 4 from being pulled upward.
[0016]
Reference numeral 6 denotes a projecting portion which is a heat radiating portion formed by cutting and raising the metal case 4 upward to form a side surface in an inverted L shape, and its upper surface 6a is formed smaller than the opening shape of the opening portion 1a of the circuit board 1. When the circuit board 1 is attached to the metal case 4, the upper surface 6 a of the projecting portion 6 is provided at a position where it abuts on the lower surface of the diode bridge 3 through the opening 1 a of the circuit board 1. Further, a screw hole 6b is provided at substantially the center of the upper surface 6a, the projecting portion 6 is brought into contact with the lower surface of the diode bridge 3, and the screw hole of the diode bridge 3 from the upper surface side of the diode bridge 3 by the screw 7. The metal case 4 is fixed to the circuit board 1 while being brought into contact with each other 3 and 6 by being screwed into the screw holes 6 b of 3 a and the projecting portion 6. In addition, 6c is a slit provided in order to give elasticity to the protrusion part 6. FIG.
[0017]
8 is an insulating paper made of an insulating material such as polyester and formed in a rectangular shape substantially equal to the planar shape of the circuit board 1, and is disposed between the circuit board 1 and the metal case 4. An insertion hole 8a having a size substantially equal to that of the opening 1a is provided at a position facing the opening 1a. Reference numeral 9 is made of a heat conductive material having elasticity such as silicon, and covers a top surface of the plurality of transistors 2 mounted on the back side of the circuit board 1 (a surface opposite to the mounted surface). For example, a sheet member which is a heat dissipation member having a substantially rectangular planar shape, for example, can be detachably attached to a position facing the plurality of transistors 2 on the surface side of the insulating paper 8 by an adhesive applied to the lower surface side thereof, for example. When the circuit board 1 is attached to the metal case 4, the upper surface of the sheet member 9 comes into contact with the upper surfaces of the plurality of transistors 2 to protect the transistors 2. The insulating paper 8 may be omitted. In this case, the sheet member 9 is directly attached to the upper surface of the metal case 4.
[0018]
In the first embodiment configured as described above, the metal case 4 is attached to the back side of the circuit board 1 via the insulating paper 8, and the heat generating parts are combined with other circuit parts (not shown) mounted on the circuit board 1. When the transistor 2 and the diode bridge 3 are driven, heat is generated from the transistor 2 and the diode bridge 3. Then, the heat from the transistor 2 is transmitted to the metal case 4 through the sheet member 9 in contact with the upper surface thereof, and is radiated from the metal case 4 to the air. Further, the heat from the diode bridge 3 is transmitted to the protruding portion 6 formed by cutting and raising the metal case 4 abutted on the lower surface thereof, and is radiated from the protruding portion 6 and the metal case 4 to the air. . Furthermore, heat from the transistor 2, the sheet member 9, the protruding portion 6, and the like is also radiated to the air layer in the gap G <b> 1 formed between the circuit board 1 and the metal case 4.
[0019]
Thus, the heat of the transistor 2 mounted on the back surface side of the circuit board 1 is transmitted to the metal case 4 through the sheet member 9 that is a heat radiating member in contact with the upper surface thereof, and the surface side of the circuit board 1 Since the heat of the diode bridge 3 mounted on the metal case 4 is transmitted to the metal case 4 via the protrusion 6 and the protrusion 6 which are heat dissipation portions in contact with the lower surface of the diode bridge 3, it is as large as the heat dissipation fin of the conventional example. It is possible to radiate heat from the entire surface of the metal case 4 without being subjected to a structural restriction such as, thereby enhancing the heat dissipation effect.
[0020]
In addition, since the sheet member 9 for transmitting the heat of the transistor 2 to the metal case 4 is made of a heat conductive material having elasticity, high adhesion can be obtained while protecting the transistor 2, and the metal case 4 can be obtained. The heat conductivity, that is, the heat dissipation effect from the metal case 4 can be further improved. Similarly, the protrusion 6 for transferring the heat of the diode bridge 3 to the metal case 4 is formed by cutting and raising the metal case 4 upward, and the diode bridge 3 and the protrusion 6 are contacted by screw fixing. Adhesiveness can be improved, and the thermal conductivity to the protrusion 6, that is, the heat dissipation effect can be further improved. Further, the screw fixing is not only for contacting the diode bridge 3 and the projecting portion 6 but also for attaching the metal case 4 to the circuit board 1. The metal case 4 can be easily attached with a simple structure. be able to. If the slit 6c is provided in the metal case 4 to give elasticity to the upper surface 6a of the protruding portion 6, the adhesion to the diode bridge 3 can be enhanced and the heat dissipation effect can be further improved.
[0021]
Furthermore, the opening 1a is provided in the circuit board 1 and mounted on the back side of the circuit board 1 only for a small part of the heat generating components (here, the diode bridge 3) mounted on the front surface side of the circuit board 1. For other heat generating components (here, the transistor 2), since it is not necessary to provide a large number of openings 1a in the circuit board 1, the degree of freedom of the circuit pattern formed on the circuit board 1 can be greatly increased. . Thereby, a heat-emitting component can be easily mounted on the circuit board 1, and the heat dissipation effect can also be obtained reliably.
[0022]
In addition, the gap G1 is reliably held between the circuit board 1 and the metal case 4 by the protrusion 6, the transistor 2 mounted on the back side of the circuit board 1, and the sheet member 9 provided to face the transistor 2. And an air layer formed by the gap G1 can be formed without using another component. Thereby, the heat dissipation effect from the back surface side of the circuit board 1 can be improved.
[0023]
Embodiment 2. FIG.
FIG. 3 is a cross-sectional view of the main part of the second embodiment of the present invention. In the second embodiment, the height (thickness) mounted on the back side of the circuit board 1 in the first embodiment is substantially equal. In place of the plurality of transistors 2, a plurality of transistors 2 having different heights are mounted, and the elasticity of the sheet member 9 protects each transistor 2 and provides adhesion to the sheet member 9. is there.
[0024]
With this configuration, substantially the same operations and effects as in the first embodiment can be obtained, and the circuit board 1 is mounted on the back side of the circuit board 1 by the sheet member 9 formed of a heat conductive material having elasticity. Adhesion with the sheet member 9 can be obtained while protecting the transistors 2 having different heights, and heat generated from each transistor 2 can be reliably transmitted to the metal case 4 to enhance the heat dissipation effect. .
[0025]
Embodiment 3 FIG.
FIG. 4 is a cross-sectional view of a main part of the third embodiment of the present invention. In the third embodiment, instead of the sheet member 9 made of the heat conductive material having elasticity according to the second embodiment, The sheet member 10 is made of a heat conductive material having elasticity and insulation and has a height substantially equal to the gap G1. The sheet member 10 is a heat generating component mounted on the back surface side of the circuit board 1, for example, having a height. A recess 10 a into which a different transistor 2 is fitted is provided, and the transistor 2 is fitted into the recess 10 a when the metal case 4 is attached to the circuit board 1.
[0026]
With this configuration, substantially the same operations and effects as in the first embodiment can be obtained, and the sheet member 10 made of a heat conductive material having elasticity and insulation can be used on the back side of the circuit board 1. Adhesion with the sheet member 10 can be enhanced while reliably protecting the mounted transistors 2 with different heights, and the heat generated from each transistor 2 can be reliably transmitted to the metal case 4 to further enhance the heat dissipation effect. Can be improved.
[0027]
In the first to third embodiments described above, the case where the circuit board 1 is formed in a rectangular shape is shown, but the present invention is not limited to this, and can be appropriately changed to other shapes. In this case, the metal case 4 and the insulating paper 8 are also formed in a shape corresponding to the circuit board 1.
[0028]
【The invention's effect】
As described above, the heat dissipation structure for a heat generating component according to the present invention has a circuit board on which the circuit component including the heat generating component is mounted on the front and back surfaces, and a predetermined interval so as to cover the back surface side on the back surface side of the circuit board. A heat dissipating member between the circuit board and the metal case, the upper surface of which is in contact with a heat-generating component mounted on the back side of the circuit board, and the lower surface of which is in contact with the upper surface of the metal case And a heat dissipation part that is formed by cutting and raising the metal case upward and whose upper surface is in contact with the lower surface of the heat generating component through an opening provided corresponding to the heat generating component mounted on the surface side of the circuit board Therefore, the heat of the heat generating component can be reliably transmitted to the metal case through the heat radiating member and the heat radiating portion, and can be radiated from the entire surface of the metal case, so that the heat radiation effect can be improved. In addition, since it is not necessary to provide a large number of openings in the circuit board, the degree of freedom of the circuit pattern formed on the circuit board can be greatly increased, and the heat dissipation member and the heat dissipation part can be used between the circuit board and the metal case. Therefore, it is possible to reliably hold the gap, and to form an air layer by the gap without using another component or the like, thereby enhancing the heat radiation effect from the back side of the circuit board.
[0029]
The heat dissipating structure of the heat generating component according to the present invention is constituted by a sheet member made of a heat conductive material having elasticity, even when a plurality of heat generating components having different heights are mounted on the circuit board, While protecting each heat-emitting component, adhesiveness with a sheet | seat member is obtained, the heat from each heat-emitting component can be reliably transmitted to a metal case, and the heat dissipation effect can be improved.
[0030]
The heat dissipating structure of the heat generating component according to the present invention is a sheet member having a heat sink made of a heat conductive material having elasticity and insulation and having a recess into which the heat generating component mounted on the back side of the circuit board is fitted. As a result, even when multiple heat-generating components with different heights are mounted on the circuit board, each heat-generating component can be reliably protected and the adhesion to the sheet member can be improved, and the heat from each heat-generating component can be reduced. The heat dissipation effect can be further improved by reliably transmitting to the metal case.
[0031]
Radiation structure of the heat-generating component according to the present invention, the heat radiation portion, by cutting and raising a metal casing upwards constituted by protrusions is side shape is formed in an inverted L-shape, it is mounted on the surface side of the circuit board heating Since the component and the upper surface of the projecting portion that comes into contact with the lower surface of the heat generating component through the opening provided in the circuit board are screwed, the adhesion between the heat generating component and the projecting portion can be improved. The thermal conductivity to the part, that is, the heat dissipation effect can be further improved. Moreover, since this screw fixing also serves as the attachment of the circuit board and the metal case, the metal case can be easily attached with a simple structure.
[0032]
The heat dissipating structure of the heat generating component according to the present invention has an insertion hole at a position facing the opening of the circuit board, and covers the insulating paper with which the lower surface of the heat radiating member abuts on the front side so as to cover the back side of the circuit board. Since it is disposed between the circuit board and the metal case, the insulation between the circuit board and the metal case can be further ensured by the insulating paper.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a first embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA of FIG.
FIG. 3 is a cross-sectional view of a main part of a second embodiment of the present invention.
FIG. 4 is a cross-sectional view of a main part of a third embodiment of the present invention.
FIG. 5 is an exploded perspective view showing a mounting state of a conventional heat generating component on a circuit board.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Circuit board, 1a Opening part, 2 Transistor (heat-generating component), 3 Diode bridge (heat-generating component), 3a, 6b Screw hole, 4 Metal case, 6 Protruding part, 6a Top surface, 7 Screw, 8 Insulating paper, 8a Insertion hole , 9,10 Sheet member, G1 gap.

Claims

A circuit board on which circuit parts including heat generating parts are mounted on the front and back surfaces, and a metal case attached to the back surface side of the circuit board at a predetermined interval so as to cover the back surface side,
Between the circuit board and the metal case, a heat dissipating member whose upper surface is in contact with a heat generating component mounted on the back side of the circuit board and whose lower surface is in contact with the upper surface of the metal case, and the metal case A heat dissipating part that is formed by cutting and raising upward and whose upper surface is in contact with the lower surface of the heat generating component is provided through an opening provided corresponding to the heat generating component mounted on the surface side of the circuit board. ,
The circuit board has a locking piece extending outward from a pair of opposing ends,
The metal case is erected upward from each of a pair of opposing sides , and protrudes further upward from the upper end portion on which the locking piece is placed, and the end portion and the locking piece side in contact with the part we have a wall portion comprising a locking portion for restricting the movement of the circuit board,
By the other pair of sides that do not have the wall portion in the metal case, the both side end portions of the wall portion, and the other pair of end portions that do not have the locking piece in the circuit board A heat-dissipating structure for a heat-generating component, comprising an opening formed .

2. The heat dissipation structure for a heat-generating component according to claim 1, wherein the locking portion has a protruding portion on an inner surface side, and the protruding portion locks an end portion of the circuit board from above.

The heat dissipating member is constituted by a sheet member made of a heat conductive material having elasticity,
The heat generating component according to claim 1 or 2, wherein the sheet member is coated with an adhesive on a lower surface side thereof and is detachably attached to the upper surface of the metal case via the adhesive. Heat dissipation structure.

The heat dissipating member is made of a heat conductive material having elasticity and insulation, and is constituted by a sheet member having a recess into which a heat generating component mounted on the back side of the circuit board is fitted. The heat-radiating structure for a heat-generating component according to claim 2.

The heat dissipating part is constituted by a protruding part whose side shape is formed in an inverted L shape by cutting and raising the metal case upward, and a heat generating component mounted on the surface side of the circuit board, and an opening provided in the circuit board The heat-radiating structure for a heat-generating component according to any one of claims 1 to 4, wherein an upper surface of the protruding portion that is in contact with the lower surface of the heat-generating component via a portion is screwed.

An insulating paper that has an insertion hole at a position facing the opening of the circuit board and is in contact with the lower surface of the heat dissipation member on the front surface side is disposed between the circuit board and the metal case so as to cover the back surface side of the circuit board. The heat dissipating structure for a heat generating component according to any one of claims 1 to 5, wherein the heat dissipating structure is provided.