JP2010263003A

JP2010263003A - Heat-conducting structure of printed board

Info

Publication number: JP2010263003A
Application number: JP2009111108A
Authority: JP
Inventors: Toshiaki Hagino; 俊昭萩野
Original assignee: NIPPON DOUROOINGU KK
Current assignee: NIPPON DOUROOINGU KK
Priority date: 2009-04-30
Filing date: 2009-04-30
Publication date: 2010-11-18

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-conducting structure of a printed board capable of securing sufficient heat conduction capacity between both surfaces of the board by a simple method, and securing a uniform metal plated layer on the front surface of the board. <P>SOLUTION: This heat-conducting structure of a printed board includes conductor layers 2 formed of metal foil and formed on both surfaces of an insulation board material 1, and a heat-conducting member 3 filled in a through-hole H formed on the insulation board material 1 along with the conductor layers 2 on both the surfaces, and is composed by forming metal plated layers 4 on the surfaces of the heat-conducting member 3 and the conductor layers 2, wherein the heat-conducting member 3 is composed by fitting and arranging, in the through-hole H, a columnar member formed at a length L projecting from the through-hole H, and plastic deformation parts 3a extending to the inside surfaces of the conductor layers 2 in openings at both the ends of the through-hole H are formed by a press working in its axial direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、絶縁基板の両面の導体層間を熱伝導部材によって接続したプリント基板の熱伝導構造に関するものである。 The present invention relates to a heat conductive structure of a printed board in which conductor layers on both sides of an insulating substrate are connected by a heat conductive member.

特許文献１に記載の如く、絶縁基板の両面に銅箔による導体層を設け、絶縁基板の貫通孔に熱伝導部材を圧入することによって両面の導体層の間を一体化することにより、発熱部品の放熱手段を構成したプリント基板の熱伝導構造が知られている。 As described in Patent Document 1, a conductive layer made of copper foil is provided on both surfaces of an insulating substrate, and a heat conductive member is pressed into a through hole of the insulating substrate to integrate the conductive layers on both surfaces, thereby generating a heat generating component. There is known a heat conduction structure of a printed circuit board that constitutes the heat dissipation means.

このプリント基板は、両面銅張りの絶縁基板に貫通孔を形成し、この貫通孔に対応する形状の放熱部材を圧入固定し、それぞれの面に金属メッキ層を形成し、エッチングによって回路パターンを形成するとともに、放熱部材の周囲を含む金属メッキ層を残存させて電子部品搭載用のダイパターンを形成する一連の工程によって製造する。 In this printed circuit board, through holes are formed in a double-sided copper-clad insulating substrate, and a heat dissipation member having a shape corresponding to the through holes is press-fitted and fixed, a metal plating layer is formed on each surface, and a circuit pattern is formed by etching. At the same time, the metal plating layer including the periphery of the heat radiating member is left to produce a die pattern for mounting electronic components.

上記製造工程により、形状精度を要しない簡易な丸棒状の放熱部材を圧入する簡易な加工により、発熱デバイスを実装したプリント基板の背面側に及んで熱拡散可能な放熱手段を形成することができる。 By the above manufacturing process, a simple heat treatment of pressing a simple round bar-like heat radiating member that does not require shape accuracy can form a heat radiating means capable of diffusing heat over the back side of the printed circuit board on which the heat generating device is mounted. .

特許第３１７４３９３号公報Japanese Patent No. 3174393

しかしながら、上記製造方法によるプリント基板の貫通孔に圧入された放熱部材は、貫通孔の内周面との間に数μｍから数十μｍの隙間が残留し、この隙間により導体層との間の熱伝導抵抗が避けられないことから、基板両面間の十分な熱伝導を確保することができないという問題があり、また、導体層との間の電気抵抗により放熱部材の端面部に十分な金属メッキ層が得られないという問題があった。このような問題により、圧入による上記熱伝導構造は、特段の放熱板を要しないことによる構成の小型化・薄型化のための有力手段であるにも拘わらず、適用範囲が限られたものとなっていた。 However, the heat radiation member press-fitted into the through hole of the printed circuit board by the above manufacturing method has a gap of several μm to several tens of μm between the inner peripheral surface of the through hole, and this gap causes a gap between the conductor layer. Since heat conduction resistance is unavoidable, there is a problem that sufficient heat conduction between the both surfaces of the substrate cannot be secured, and sufficient metal plating is applied to the end face portion of the heat dissipation member due to the electric resistance between the conductor layers. There was a problem that a layer was not obtained. Due to such problems, the heat conduction structure by press-fitting is limited in scope although it is a powerful means for downsizing and thinning the structure by not requiring a special heat sink. It was.

本発明の目的は、簡易な方法により、基板両面間の十分な熱伝導容量を確保するとともに、基板表面の均一な金属メッキ層を確保することができるプリント基板の熱伝導構造を提供することにある。 An object of the present invention is to provide a heat conduction structure of a printed circuit board that can secure a sufficient heat conduction capacity between both surfaces of the board and a uniform metal plating layer on the board surface by a simple method. is there.

請求項１に係る発明は、絶縁基板材の両面に設けた金属箔による導体層と、これら両面の導体層と共に絶縁基板材に形成した貫通孔に充填した熱伝導部材とからなり、この熱伝導部材と共に導体層の表面に金属メッキ層を形成したプリント基板の熱伝導構造において、上記熱伝導部材は、貫通孔から突出する長さに形成した柱状部材を同貫通孔に嵌合配置して構成するとともに、その軸線方向のプレス加工処理により、貫通孔の両端開口の導体層の内周面に及ぶ塑性変形部を形成してなることを特徴とする。 The invention according to claim 1 comprises a conductor layer made of metal foil provided on both surfaces of an insulating substrate material, and a heat conducting member filled in a through hole formed in the insulating substrate material together with the conductor layers on both surfaces. In the heat conduction structure of a printed circuit board in which a metal plating layer is formed on the surface of the conductor layer together with the member, the heat conduction member is configured by fitting and arranging a columnar member formed in a length protruding from the through hole in the through hole. In addition, a plastic deformation portion that extends to the inner peripheral surface of the conductor layer at both ends of the through hole is formed by pressing in the axial direction.

上記プリント基板の貫通孔から突出する長さの熱伝導部材を貫通孔に嵌合配置した上で、貫通孔のそれぞれの開口内周面に塑性変形部が密接する程度にプレス加工することにより、導体層と塑性変形部とが一体化されて両者間の電気抵抗および熱伝導抵抗が小さく抑えられることから、熱伝導部材を介して両面の導体層の間の熱と電気の伝導性が確保されるとともに、塑性加工による耐久性が確保される。 After the heat conductive member protruding from the through hole of the printed circuit board is fitted and arranged in the through hole, by pressing the plastic deformation portion in close contact with the inner peripheral surface of each opening of the through hole, Since the conductor layer and the plastically deformed portion are integrated and the electrical resistance and heat conduction resistance between them are kept small, the heat and electrical conductivity between the conductor layers on both sides is secured via the heat conducting member. In addition, durability by plastic working is ensured.

請求項２に係る発明は、請求項１の構成において、前記熱伝導部材は、貫通孔の形状寸法および嵌合条件とによって得られる関係条件を満たす長さの金属ピンによって構成したことを特徴とする。
上記熱伝導部材は、所定の関係条件を満たす長さの金属ピンを用いることにより、適正なプレス加工によって基板の保護とともにほぼ平坦な熱伝導部が確保される。 The invention according to claim 2 is characterized in that, in the configuration of claim 1, the heat conducting member is constituted by a metal pin having a length that satisfies a relational condition obtained by the shape dimension of the through hole and the fitting condition. To do.
By using a metal pin having a length that satisfies a predetermined relational condition, the heat conducting member secures a substantially flat heat conducting portion together with protecting the substrate by appropriate pressing.

請求項１に係る発明プリント基板は、プリント基板の貫通孔から突出する長さの熱伝導部材を貫通孔に嵌合配置した上で、貫通孔のそれぞれの開口内周面に塑性変形部が密接する程度にプレス加工することにより、導体層と塑性変形部とが一体化されて両者間の熱伝導抵抗および電気抵抗が小さく抑えられることから、熱伝導部材を介して両面の導体層の間の熱と電気の伝導性が確保される。 In the printed circuit board according to the first aspect of the present invention, the heat conductive member having a length protruding from the through hole of the printed circuit board is fitted and disposed in the through hole, and the plastic deformation portion is in close contact with each inner peripheral surface of the through hole. By pressing to such an extent that the conductor layer and the plastically deformed portion are integrated, the heat conduction resistance and electrical resistance between them can be kept small, so that between the conductor layers on both sides via the heat conduction member Heat and electricity conductivity is ensured.

したがって、上記構成のプリント基板の熱伝導構造は、基板両面間の十分な熱伝導容量を簡易なプレス加工によって確保することができる上に、熱伝導部材の両端の塑性変形部を導体層の表面と共通レベルに研磨加工することにより、一様なメッキ電流による一様厚さの金属メッキ層を形成することができる。 Therefore, the heat conduction structure of the printed circuit board having the above configuration can secure a sufficient heat conduction capacity between both surfaces of the board by simple pressing, and the plastic deformation portions at both ends of the heat conduction member are provided on the surface of the conductor layer. By polishing to a common level, a metal plating layer having a uniform thickness can be formed with a uniform plating current.

請求項２に係る発明のプリント基板は、請求項１の効果に加え、熱伝導部材として所定の関係条件を満たす長さの金属ピンを用いることにより、適正なプレス加工によって基板の保護とともにほぼ平坦に熱伝導部が確保されるので、その両端面の研磨処理によって平坦なメッキ層による回路パターンの形成が可能となるので、最小限度の加工コストで所定の放熱特性と電導特性を確保することができる。 In addition to the effect of the first aspect, the printed circuit board according to the second aspect of the invention is substantially flat together with protection of the board by appropriate press working by using a metal pin having a length satisfying a predetermined relation condition as a heat conducting member. Since the heat conduction part is secured, it is possible to form a circuit pattern with a flat plating layer by polishing the both end faces thereof, so that it is possible to ensure predetermined heat dissipation characteristics and conductive characteristics with a minimum processing cost. it can.

各製造工程における基板断面図（ａ）〜（ｈ）Substrate cross-sectional views (a) to (h) in each manufacturing process 拡大断面による作用説明図Explanatory diagram of action with enlarged cross section

上記技術思想に基づいて具体的に構成された実施の形態について以下に図面を参照しつつ説明する。
図１は、プリント基板の熱伝導構造の各製造工程における基板断面図（ａ）〜（ｈ）である。
先ず、図１（ａ）に示すように、エポキシガラス板等の絶縁基板材１の両面に銅板による導体層２，２を接着した上で、ドリル等により全板厚Ｔに及ぶ貫通孔Ｈを形成する（図ｂ）。 Embodiments specifically configured based on the above technical idea will be described below with reference to the drawings.
1A to 1H are substrate cross-sectional views (a) to (h) in respective manufacturing steps of a heat conductive structure of a printed circuit board.
First, as shown in FIG. 1 (a), the conductor layers 2 and 2 made of copper plates are bonded to both surfaces of an insulating substrate material 1 such as an epoxy glass plate, and then a through hole H extending over the entire plate thickness T is formed by a drill or the like. Form (FIG. B).

この貫通孔Ｈにその板厚Ｔを越える長さＬの軟質銅ピン等による柱状の熱伝導部材３を挿入した上で（図ｃ）、プレス治具Ｐ等を介して熱伝導部材３を塑性域まで加圧する（図ｄ）ことにより、熱伝導部材３を拡径変形し、その両端部を導体層２，２にそれぞれ圧接する（図ｅ）。 After inserting a columnar heat conduction member 3 made of a soft copper pin or the like having a length L exceeding the plate thickness T into the through hole H (FIG. C), the heat conduction member 3 is made plastic via a pressing jig P or the like. By applying pressure to the region (Fig. D), the heat conducting member 3 is expanded in diameter and both ends thereof are pressed against the conductor layers 2 and 2 (Fig. E).

次いで、熱伝導部材３の両端面Ｓ、Ｓを導体層２，２の表面レベルに合わせてそれぞれ研磨加工した上で（図ｆ）、メッキ加工によりそれぞれの面に電気銅等による金属メッキ層４，４を形成する（図ｇ）。この金属メッキ層４，４および導体層２，２をエッチング処理によって所要の回路パターンを形成した上で（図ｈ）、所要の発熱デバイスを実装する。 Next, both end faces S, S of the heat conducting member 3 are polished according to the surface level of the conductor layers 2, 2 (FIG. F), and a metal plating layer 4 made of electrolytic copper or the like is applied to each face by plating. , 4 (FIG. G). The metal plating layers 4 and 4 and the conductor layers 2 and 2 are subjected to an etching process to form a required circuit pattern (FIG. H), and then a required heat generating device is mounted.

上記の一連の工程において、基板の貫通孔Ｈにその板厚Ｔを越える長さＬの柱状の熱伝導部材３を挿入配置した上で、熱伝導部材３を塑性域まで加圧（図ｄ）することにより、熱伝導部材３の両端部を導体層２，２にそれぞれ圧接する（図ｅ）ことにより、各導体層２，２と熱伝導部材３との間の隙間が解消されて、熱伝導部材３の伝導性が生かされるとともに、耐久性が確保される。 In the above series of steps, the columnar heat conductive member 3 having a length L exceeding the plate thickness T is inserted and disposed in the through hole H of the substrate, and then the heat conductive member 3 is pressurized to the plastic region (FIG. D). By doing so, both ends of the heat conducting member 3 are pressed into contact with the conductor layers 2 and 2 (FIG. E), so that the gaps between the conductor layers 2 and 2 and the heat conducting member 3 are eliminated, The conductivity of the conductive member 3 is utilized and durability is ensured.

すなわち、導体層２，２を両面に設けたプリント基板の貫通孔Ｈから突出する長さＬの熱伝導部材３を貫通孔Ｈに嵌合配置した上で、図２の拡大断面による作用説明図に示すように、少なくとも、それぞれの導体層２，２の厚さと対応する部分の塑性変形部３ａ、３ａが貫通孔Ｈの開口内周面に密接するようにプレス加工することにより、導体層２，２と塑性変形部３ａ、３ａとが一体化されて両者間の熱伝導抵抗および電気抵抗が小さく抑えられることから、熱伝導部材３を介して両面の導体層２，２の間の熱と電気の伝導性が確保される。 That is, after the heat conduction member 3 having a length L protruding from the through hole H of the printed circuit board provided with the conductor layers 2 and 2 on both sides is fitted and arranged in the through hole H, the operation explanatory view by the enlarged cross section of FIG. As shown in FIG. 4, at least the portions corresponding to the thicknesses of the respective conductor layers 2 and 2 are pressed so that the plastic deformation portions 3a and 3a are in close contact with the inner peripheral surface of the through hole H, whereby the conductor layer 2 , 2 and the plastic deformation portions 3a, 3a are integrated so that the heat conduction resistance and the electric resistance between them can be kept small, so that the heat between the conductor layers 2, 2 on both sides via the heat conduction member 3 can be reduced. Electrical conductivity is ensured.

したがって、上記構成のプリント基板の熱伝導構造は、基板両面間の十分な熱伝導容量を簡易なプレス加工によって確保することができる上に、熱伝導部材３の両端面を導体層２，２の表面と共通レベルに研磨加工することにより、その導電性によって熱伝導部材３の両端面にもメッキ電流が確保されて段差なく一様厚さの金属メッキ層４，４を形成することができる。 Therefore, the heat conduction structure of the printed circuit board having the above-described configuration can secure a sufficient heat conduction capacity between both surfaces of the board by a simple pressing process, and both end surfaces of the heat conduction member 3 are formed on the conductor layers 2 and 2. By polishing to the same level as the surface, the plating current is ensured on both end faces of the heat conducting member 3 due to its conductivity, and the metal plating layers 4 and 4 having a uniform thickness can be formed without any step.

また、熱伝導部材３は、貫通孔Ｈの形状寸法と嵌合条件とによって定まる関係条件に沿ってその長さＬを規定することにより、適正なプレス加工によって基板の保護とともに十分な熱伝導性が確保され、さらに、僅かな研磨処理によって表面の平坦化が可能となるので、最小限度の加工コストで所定の放熱作用を確保することができる上に、温度変化受けても機械的な一体化により耐久性が確保される。 In addition, the heat conducting member 3 is provided with a length L in accordance with a relational condition determined by the shape dimension of the through-hole H and the fitting condition, so that sufficient heat conductivity can be achieved together with protection of the substrate by appropriate pressing. In addition, since the surface can be flattened by a slight polishing process, a predetermined heat dissipation action can be secured at a minimum processing cost, and mechanical integration can be achieved even under temperature changes. This ensures durability.

このように、上述の構成による熱伝導構造は、放熱板等の特段の構成部材を要することなく、基板の背面に及ぶ熱伝導性を確保することができるので、構成の小型化・薄型化のための有力手段としての広汎な適用が可能となる。また、プリント基板の部品実装面と半田面との間で大電流が流れるスルーホールに適用することにより、熱伝導部材による大きな電流容量によって温度上昇を抑えることができる。 As described above, the heat conduction structure having the above-described configuration can ensure thermal conductivity extending to the back surface of the substrate without requiring a special component such as a heat radiating plate. Therefore, it can be widely applied as a powerful means for this purpose. Further, by applying to a through hole in which a large current flows between the component mounting surface and the solder surface of the printed circuit board, a temperature increase can be suppressed by a large current capacity due to the heat conducting member.

具体的な構成例をあげれば、板厚が１．６ｍｍのガラスエポキシ基板に、直径１ｍｍ〜１５ｍｍのアニール処理した銅ピンを適用した場合について、放熱性と電流容量において良好な結果が得られており、直径１ｍｍ未満についても上記同様の取扱いが可能であり、また、アルミニューム、鉄その他の展性延性を有する熱伝導性金属材料についても、銅に準じた取扱いが可能なことから、その説明を省略する。 As a specific configuration example, when a annealed copper pin having a diameter of 1 mm to 15 mm is applied to a glass epoxy substrate having a thickness of 1.6 mm, good results in heat dissipation and current capacity are obtained. The same handling is possible for a diameter of less than 1 mm, and aluminum, iron and other thermally conductive metal materials having malleable ductility can be handled in accordance with copper, so that explanation Is omitted.

このような放熱性と電流容量を確保しうるプリント基板の適用分野については、ＬＳＩ、ＩＣ、ＬＥＤ、ＴＲ、Ｄ、抵抗、コイル、パワー半導体モジュール、パワーＴＲ等に幅広く適用が可能となり、特に、耐用年数が放熱性能によって左右される照明用の発光ダイオード、熱による誤動作を起こしやすいＬＳＩ、ＩＣについて、放熱性と電流容量の点から大きな効果が見込まれる。 Regarding the application field of printed circuit boards that can ensure such heat dissipation and current capacity, it can be widely applied to LSI, IC, LED, TR, D, resistor, coil, power semiconductor module, power TR, etc. For light emitting diodes for lighting whose useful life depends on heat dissipation performance, LSIs and ICs that are prone to malfunction due to heat, great effects are expected in terms of heat dissipation and current capacity.

１絶縁基板材
２導体層
３熱伝導部材
３ａ塑性変形部
４金属メッキ層
Ｈ貫通孔
Ｌ長さ
Ｐプレス治具
Ｓ端面
Ｔ板厚 DESCRIPTION OF SYMBOLS 1 Insulation board | substrate material 2 Conductor layer 3 Thermal conductive member 3a Plastic deformation part 4 Metal plating layer H Through-hole L Length P Press jig S End surface T Thickness

Claims

絶縁基板材（１）の両面に設けた金属箔による導体層（２）と、これら両面の導体層（２）と共に絶縁基板材（１）に形成した貫通孔（Ｈ）に充填した熱伝導部材（３）とからなり、この熱伝導部材（３）と共に導体層（２）の表面に金属メッキ層（４）を形成したプリント基板の熱伝導構造において、
上記熱伝導部材（３）は、貫通孔（Ｈ）から突出する長さ（Ｌ）に形成した柱状部材を同貫通孔（Ｈ）に嵌合配置して構成するとともに、その軸線方向のプレス加工処理により、貫通孔（Ｈ）の両端開口の導体層（２）の内周面に及ぶ塑性変形部（３ａ）を形成してなることを特徴とするプリント基板の熱伝導構造。 Conductive layer (2) made of metal foil provided on both sides of insulating substrate material (1), and heat conduction member filled in through hole (H) formed in insulating substrate material (1) together with conductive layers (2) on both sides In the heat conduction structure of the printed circuit board, in which the metal plating layer (4) is formed on the surface of the conductor layer (2) together with the heat conduction member (3),
The heat conducting member (3) is configured by fitting and arranging a columnar member formed in a length (L) protruding from the through hole (H) in the through hole (H), and pressing in the axial direction thereof. A heat conduction structure of a printed circuit board, wherein a plastic deformation portion (3a) extending to the inner peripheral surface of the conductor layer (2) at both ends of the through hole (H) is formed by treatment.

前記熱伝導部材（３）は、貫通孔（Ｈ）の形状寸法および嵌合条件とによって得られる関係条件を満たす長さ（Ｌ）の金属ピンによって構成したことを特徴とする請求項１記載のプリント基板の熱伝導構造。 The said heat conductive member (3) was comprised with the metal pin of the length (L) which satisfy | fills the relational condition obtained by the shape dimension and fitting condition of a through-hole (H). Heat conduction structure of printed circuit board.