JP6348792B2

JP6348792B2 - Wiring board

Info

Publication number: JP6348792B2
Application number: JP2014149638A
Authority: JP
Inventors: 平野　聡; 聡平野; 宗之岩田; 奈緒子森
Original assignee: NGK Spark Plug Co Ltd
Current assignee: NGK Spark Plug Co Ltd
Priority date: 2014-07-23
Filing date: 2014-07-23
Publication date: 2018-06-27
Anticipated expiration: 2034-07-23
Also published as: JP2016025269A

Description

本発明は、絶縁材からなる基板本体の表面に形成した表面パッドの上方に比較的高い発熱性を有する発光素子などの素子を実装するための配線基板に関する。 The present invention relates to a wiring board for mounting an element such as a light emitting element having a relatively high heat generation property on a surface pad formed on the surface of a substrate body made of an insulating material.

例えば、平板状のセラミックからなる絶縁基体の表面の中央部に露出する搭載部を有し、且つ該搭載部と前記絶縁基体の裏面の中央部との間を該絶縁基体の垂直方向に沿って貫通して設けた貫通金属体を備え、該貫通金属体の上記絶縁基体のセラミックに接する側面に傾斜部または段差部を設けることによって、上記搭載部の上方に搭載される発光素子から発生する熱の熱放散性および実装信頼性に優れた発光素子用配線基板が提案されている（例えば、特許文献１参照）。 For example, it has a mounting portion exposed at the center portion of the surface of the insulating base made of flat ceramic, and a space between the mounting portion and the center portion of the back surface of the insulating base along the vertical direction of the insulating base. Heat is generated from a light emitting element mounted above the mounting portion by providing a penetrating metal body penetrating and providing an inclined portion or a step portion on a side surface of the penetrating metal body that contacts the ceramic of the insulating base. A wiring board for a light emitting element excellent in heat dissipation and mounting reliability has been proposed (see, for example, Patent Document 1).

しかし、前記発光素子用配線基板では、前記絶縁基体の表面に露出する貫通金属体の搭載部（上面）の面積が比較的大きいので、該貫通金属体の搭載部付近とこれに隣接する上記絶縁基体を構成しているセラミックあるいは樹脂との熱膨張係数の差に起因して作用する応力が大きくなる。その結果、上記貫通金属体の搭載部の上方に、比較的発熱量が多い発光素子などの素子を搭載した場合、上記熱膨張係数の差に起因する応力によって、貫通金属体の搭載部を囲む上記絶縁基体の表面側にクラックが生じ易くなる、という問題点があった。
しかも、前記貫通金属体の搭載部（上面）の面積が比較的大きいので、前記絶縁基体の表面にパッドや表面配線などを配置するためのスペースが制限されてしまう、という問題点もあった。 However, since the area of the through metal body mounting portion (upper surface) exposed on the surface of the insulating base is relatively large in the light emitting element wiring substrate, the vicinity of the through metal body mounting portion and the insulating material adjacent thereto are adjacent to each other. The stress acting due to the difference in thermal expansion coefficient from the ceramic or resin constituting the substrate becomes large. As a result, when an element such as a light emitting element having a relatively large calorific value is mounted above the through metal body mounting portion, the through metal body mounting portion is surrounded by the stress caused by the difference in thermal expansion coefficient. There was a problem that cracks were likely to occur on the surface side of the insulating substrate.
In addition, since the area of the mounting portion (upper surface) of the penetrating metal body is relatively large, there is a problem that a space for arranging pads, surface wirings, and the like on the surface of the insulating base is limited.

特開２００６−９３５６５号公報（第１〜２１頁、図１〜４）JP 2006-93565 A (pages 1-21 and FIGS. 1-4)

本発明は、背景技術で説明した問題点を解決し、絶縁材からなる基板本体の表面上に形成した表面パッドに比較的高い発熱性を有する発光素子などの素子を実装しても、上記表面パッドの周囲に隣接する絶縁材にクラックが生じにくく、且つ基板本体の表面に別のパッドや表面配線などを容易に配置し得る配線基板を提供する、ことを課題とする。 The present invention solves the problems described in the background art, and even if an element such as a light emitting element having a relatively high exothermic property is mounted on a surface pad formed on the surface of a substrate body made of an insulating material, the above surface It is an object of the present invention to provide a wiring board in which an insulating material adjacent to the periphery of a pad is unlikely to crack, and another pad or surface wiring can be easily arranged on the surface of the substrate body.

課題を解決するための手段および発明の効果Means for Solving the Problems and Effects of the Invention

本発明は、前記課題を解決するため、基板本体の表面上に形成する表面パッドの面積に対し、該表面パッドに一端が接続され且つ他端が前記基板本体の内部に埋設される放熱部に接続される第１接続部の断面積を小さくする、ことに着想して成されたものである。
即ち、本発明の配線基板（請求項１）は、絶縁材からなり、互いに平行な表面および裏面と、該表面と裏面との間に位置する側面を有する基板本体と、該基板本体の表面上に形成された表面パッドと、上記基板本体の内部に埋設された放熱部と、上記表面パッドと上記放熱部とを接続する第１接続部とを備えた配線基板であって、上記放熱部は、上記基板本体の表面側から裏面側に向かうに連れて平面視の断面積が大きくなる錐体形状を呈するか、あるいは、上記基板本体の裏面側から表面側に向かうに連れて平面視の断面積が大きくなる錐体形状を呈すると共に、上記放熱部における角部には、曲面部あるいは平面からなる面取り部が形成されており、平面視において、上記基板本体の表面に露出する上記第１接続部の面積は、上記表面パッドの面積よりも小さい、ことを特徴とする。 In order to solve the above-described problem, the present invention provides a heat radiating portion in which one end is connected to the surface pad and the other end is embedded in the substrate body with respect to the area of the surface pad formed on the surface of the substrate body. The idea is to reduce the cross-sectional area of the first connecting portion to be connected.
That is, the wiring board according to the present invention (Claim 1) is made of an insulating material, and has a substrate body having a front surface and a back surface parallel to each other, a side surface positioned between the front surface and the back surface, and a surface of the substrate body. A wiring board comprising a surface pad formed on the substrate body, a heat radiating part embedded in the substrate body, and a first connection part for connecting the surface pad and the heat radiating part. Exhibiting a pyramid shape in which the cross-sectional area in plan view increases from the front surface side to the back surface side of the substrate body, or breaks in plan view from the back surface side of the substrate body to the front surface side. The first connection exposed to the surface of the substrate body in plan view has a cone shape with a large area, and a corner portion of the heat radiating portion is formed with a curved surface portion or a chamfered portion. The area of the Smaller than the area of de, characterized in that.

これによれば、錐体形状を呈する前記放熱部は、基板本体の表面上に形成された表面パッドに対し、平面視で該表面パッドの面積よりも小さい面積の第１接続部を介して、接続されている。即ち、平面視において、基板本体の表面に露出する第１接続部の面積は、表面パッドの面積よりも小さくなっている。そのため、追って、上記表面パッドの上方に比較的発熱量の高い発光素子などの素子が実装された場合、該素子から発せられる熱は、第１接続部を介して上記放熱部に伝達され、該放熱部の表面から基板本体を構成している前記絶縁材中に順次放散された後、外部に放出される。その結果、前記表面パッドとこれに接する基板本体の絶縁材との間における熱膨張係数の差に起因して、該基板本体の表面側の絶縁材にクラックが生じる事態を皆無にするか、確実に抑制することが可能となる。
しかも、上記放熱部が、上記基板本体の表面側から裏面側に向かうに連れて平面視の断面積が大きくなる錐体形状を呈する形態の場合、前記発光素子などの素子から発生する熱を該放熱部の底面側に向かうに連れて、該熱の伝達速度を次第に速めつつ拡散させることができる。
更に、前記表面パッドは、平面視で前記素子が実装できる大きさの面積であれば良く、基板本体の表面を過度に占有しないので、該基板本体の表面における別のパッドや表面電極や表面配線などの配置に支障を来すことも少なくできる。
加えて、錐体形状を呈する前記放熱部の円錐面または複数の側面と、該放熱部の底面との間に位置する角部に、曲面部（アール）あるいは平面からなる面取り部が形成されているため、製造時において、追って上記放熱部となる導電性ペーストが上記角部にも確実に充填されるので、前記基板本体の内部に無用な空隙（ボイド）が生じる事態を確実に防ぐことも可能となる。
従って、追って、発熱量の高い素子が表面パッドの上方に実装されても、該素子の発熱によって、上記表面パッドに接する基板本体の表層側の絶縁材にクラックが生じにくく、上記熱の放熱性に優れると共に、上記基板本体の表面における設計の自由度が比較的高い配線基板を提供することが可能となる。 According to this, the heat radiating portion having a cone shape is connected to the surface pad formed on the surface of the substrate body through the first connection portion having an area smaller than the area of the surface pad in plan view. It is connected. That is, in plan view, the area of the first connection portion exposed on the surface of the substrate body is smaller than the area of the surface pad. Therefore, when an element such as a light emitting element having a relatively high calorific value is mounted above the surface pad, heat generated from the element is transmitted to the heat radiating part via the first connection part, and After being sequentially diffused from the surface of the heat dissipating part into the insulating material constituting the substrate body, it is discharged to the outside. As a result, it is ensured that there is no occurrence of cracks in the insulating material on the surface side of the substrate body due to the difference in thermal expansion coefficient between the surface pad and the insulating material of the substrate body in contact therewith. Can be suppressed.
In addition, in the case where the heat dissipating part has a conical shape in which the cross-sectional area in plan view increases from the front surface side to the back surface side of the substrate body, the heat generated from the element such as the light emitting element is reduced. As it goes to the bottom surface side of the heat radiating portion, it can be diffused while gradually increasing the heat transfer rate.
Further, the surface pad may have an area large enough to mount the element in plan view, and does not occupy the surface of the substrate body excessively. Therefore, another pad, surface electrode, or surface wiring on the surface of the substrate body is used. It is possible to reduce the trouble of the arrangement.
In addition, a chamfered portion made of a curved surface (R) or a flat surface is formed at a corner portion located between the conical surface or a plurality of side surfaces of the heat radiating portion having a cone shape and the bottom surface of the heat radiating portion. Therefore, during manufacturing, the conductive paste that becomes the heat radiating portion will be filled in the corners with certainty, so that it is possible to reliably prevent the occurrence of unnecessary voids in the substrate body. It becomes possible .
Therefore, even if an element with a high calorific value is mounted above the surface pad, the insulating material on the surface layer side of the substrate body in contact with the surface pad is less likely to crack due to the heat generated by the element, and the heat dissipation property In addition, it is possible to provide a wiring board having a high degree of design freedom on the surface of the substrate body.

尚、前記基板本体を構成する絶縁材は、セラミックあるいは樹脂であり、前記セラミックには、例えば、アルミナなどの高温焼成セラミックやガラス−アルミナなどの低温焼成セラミックが含まれ、上記樹脂には、熱硬化性であり且つ耐熱性を有する合成樹脂（例えば、エポキシ、ポリエステル、シリコン、ポリイミド樹脂など）が含まれる。上記絶縁材は、複数の絶縁層を積層した形態のほか、一体物（塊状）の絶縁体であっても良い。
また、前記表面上とは、前記表面パッドの底面が前記基板本体の表面に接し、該表面パッドの厚み分だけ前記基板本体の表面から突出していることを意味する。
更に、前記放熱部は、主に熱伝導性に優れた金属からなり、該金属には、Ｗ、Ｍｏ、Ａｇ、Ｃｕなどやこれらの何れかを主成分とする合金が含まれ、これらの金属を構成するための金属粉末は、製造時における流動性を確保するため、平均粒径で１μｍ以下が望ましい。但し、該放熱部は、一部に製造時に用いた導電性ペースト中に含まれていたバインダ樹脂などの非導電性成分を含んでいても良い。 The insulating material constituting the substrate body is ceramic or resin. Examples of the ceramic include high-temperature fired ceramics such as alumina and low-temperature fired ceramics such as glass-alumina. A synthetic resin (for example, epoxy, polyester, silicon, polyimide resin, etc.) that is curable and heat resistant is included. The insulating material may be a monolithic (lumped) insulator in addition to a form in which a plurality of insulating layers are stacked.
The term “on the surface” means that the bottom surface of the surface pad is in contact with the surface of the substrate body and protrudes from the surface of the substrate body by the thickness of the surface pad.
Furthermore, the heat radiation part is mainly made of a metal having excellent thermal conductivity, and the metal includes W, Mo, Ag, Cu, or an alloy mainly containing any of these metals. In order to secure fluidity at the time of manufacture, the average particle size of the metal powder for constituting is desirably 1 μm or less. However, the heat radiating portion may partially include a nonconductive component such as a binder resin included in the conductive paste used at the time of manufacture.

更に、前記基板本体の表面は、該表面に開口するキャビティの底面も含む。
また、前記表面パッド上には、追って、発光ダイオード（ＬＥＤ）などの発光素子やパワーモジュールに用いられる半導体素子などのような発熱量が比較的大きな素子が追って搭載される。
更に、前記第１接続部は、前記同様の金属からなり、断面が円形状のほか、楕円形、長円形、矩形状、または五角形以上の多角形状などを呈していても良い。
加えて、前記基板本体には、１つの前記表面パッドに対し、複数の第１接続部と、単数または複数の放熱部とが電気的に接続された形態とされていても良い。 Furthermore, the surface of the substrate body also includes a bottom surface of a cavity that opens to the surface.
Further, on the surface pad, a light emitting element such as a light emitting diode (LED) or a semiconductor element used for a power module is mounted later.
Further, the first connection portion may be made of the same metal as described above, and may have an elliptical shape, an oval shape, a rectangular shape, or a polygonal shape of pentagon or more in addition to a circular shape in cross section.
In addition, the substrate main body may be configured such that a plurality of first connection portions and a single or a plurality of heat dissipation portions are electrically connected to one surface pad.

また、本発明には、錐体形状を呈する前記放熱部の頂部側が、前記第１接続部に接続されている、配線基板（請求項２）も含まれる。
これによれば、上記放熱部は、前記基板本体の表面側から裏面側に向かうに連れて平面視の断面積が大きくなり、且つ該断面積が最少となる頂部が上記基板本体の表面側に位置する錐体形状として、該基板本体の内部に埋設されている。そのため、放熱部の該頂部と前記表面パッドとの間を、断面積が比較的小さい前記第１接続部であっても、容易に接続することが可能となる。 The present invention also includes a wiring board (Claim 2) in which the top side of the heat dissipating part having a cone shape is connected to the first connecting part.
According to this, as for the said heat radiating part, the cross-sectional area of planar view becomes large as it goes to the back surface side from the surface side of the said board | substrate body, and the top part where this cross-sectional area becomes the minimum is on the surface side of the said board | substrate body. It is embedded in the inside of the substrate body as a conical shape. Therefore, even if it is the 1st connection part with a comparatively small cross-sectional area, it becomes possible to connect between this top part of a thermal radiation part, and the said surface pad.

尚、前記面取り部の平面を区画する該平面の両側には、それぞれ鈍角（９０度超）の角部が位置している。また、上記平面は、複数であっても良い。 Note that both sides of said plane defining the plane of the front Symbol chamfer the corners of obtuse (greater than 90 degrees) each is located. The plane may be plural.

また、本発明には、錐体形状を呈する前記放熱部の円錐面または複数の側面には、該放熱部の頂部側から底面側に向かって延びる複数組の凹溝および凸条が形成されている、配線基板（請求項３）も含まれる。
これによれば、上記放熱部の円錐面または複数の側面に、該放熱部の頂部側から底面側に向かって延びる複数組の凹溝および凸条が形成されていることにより、当該放熱部の表面積が拡大されている。そのため、前記発光素子などから第１接続部を介して伝達された熱を、前記基板本体の絶縁材中に効率良く放散できると共に、該絶縁材と上記放熱部との密着強度も高められる。 Further, in the present invention, a plurality of sets of concave grooves and ridges extending from the top side to the bottom side of the heat radiating portion are formed on the conical surface or the plurality of side surfaces of the heat radiating portion having a cone shape. A wiring board (Claim 3 ) is also included.
According to this, a plurality of sets of concave grooves and ridges extending from the top side to the bottom side of the heat radiating part are formed on the conical surface or the plurality of side surfaces of the heat radiating part. The surface area is enlarged. Therefore, the heat transferred from the light emitting element or the like through the first connection portion can be efficiently dissipated into the insulating material of the substrate body, and the adhesion strength between the insulating material and the heat radiating portion is also increased.

更に、本発明には、錐体形状を呈する前記放熱部の円錐面または複数の側面は、該放熱部の内側に凹む湾曲面を有している、配線基板（請求項４）も含まれる。
これによれば、上記放熱部の円錐面または複数の側面が、該放熱部の内側に凹む湾曲面を有することにより、当該放熱部の表面積が拡大されている。そのため、前記同様に、前記素子からの熱を前記基板本体の絶縁材中に効率良く放散できると共に、該絶縁材と上記放熱部との密着強度も高められる。
尚、前記湾曲面は、例えば、ドーム形状あるいは断面Ｕ字形状の凹溝である。
また、多角錘体形状を呈する放熱部において、三角形状を呈する複数の前記側面には、該側面の一部に単数または複数の前記湾曲面を形成している形態のほか、上記側面全体を単一の湾曲面とした形態も含まれる。 Furthermore, the present invention includes a wiring board (Claim 4 ) in which a conical surface or a plurality of side surfaces of the heat dissipating part having a cone shape has a curved surface recessed inside the heat dissipating part.
According to this, since the conical surface or the plurality of side surfaces of the heat radiating part has a curved surface that is recessed inside the heat radiating part, the surface area of the heat radiating part is enlarged. Therefore, similarly to the above, the heat from the element can be efficiently dissipated into the insulating material of the substrate body, and the adhesion strength between the insulating material and the heat radiating portion is also increased.
The curved surface is, for example, a concave groove having a dome shape or a U-shaped cross section.
In addition, in the heat dissipating part having a polygonal pyramid shape, in addition to a form in which one or a plurality of curved surfaces are formed on a part of the side surfaces, a plurality of the side surfaces having a triangular shape are formed as a whole. A form with a single curved surface is also included.

加えて、本発明には、錐体形状を呈する前記放熱部の底面側には、前記基板本体の裏面あるいは側面に他端が露出する第２接続部の一端が接続されている、配線基板（請求項５）も含まれる。
これによれば、前記第１接続部、放熱部、および第２接続部を介して、前記基板本体の表面と裏面との間、あるいは該表面と側面との間を電気的に導通可能となる。そのため、例えば、追って、前記表面パッドの上方に実装される発光素子などの素子における一方の電極と、上記基板本体の裏面または側面に形成される裏面パッドあるいは側面導体との間が電気的に接続可能となる。しかも、上記放熱部および裏面パッドあるいは側面導体を介して、上記素子の電極と、追って本配線基板自体が搭載されるマザーボードなどの表面パッドとを電気的に接続することもできる。更に、前記素子が発する熱を裏面パッドあるいは側面導体を介して、基板本体の外部に放出することも可能となる。
尚、上記第２接続部も、前記第１接続部と同様の金属からなると共に、該第１接続部と同様の断面形状を有している。
また、上記第２接続部の他端が露出する基板本体の裏面または側面には、これらと個別に接続する裏面パッドあるいは側面導体が形成されている。
更に、前記第２接続部は、錐体形状を呈する前記放熱部の底面側から基板本体の裏面および側面の双方に延びた形態であっても良い。
In addition, in the present invention, a wiring substrate (one end of a second connection portion having the other end exposed at the back surface or side surface of the substrate body is connected to the bottom surface side of the heat radiating portion having a cone shape. Claim 5 ) is also included.
According to this, it becomes possible to electrically connect between the front surface and the back surface of the substrate body or between the front surface and the side surface through the first connection portion, the heat dissipation portion, and the second connection portion. . Therefore, for example, one electrode in a light emitting element or the like mounted above the front surface pad is electrically connected to a back surface pad or a side conductor formed on the back surface or side surface of the substrate body. It becomes possible. In addition, the electrode of the element and a surface pad such as a mother board on which the wiring board itself is mounted can be electrically connected through the heat radiating portion and the back surface pad or the side conductor. Furthermore, the heat generated by the element can be released to the outside of the substrate body through the back pad or the side conductor.
The second connection part is also made of the same metal as the first connection part and has the same cross-sectional shape as the first connection part.
Further, on the back surface or side surface of the substrate body where the other end of the second connection portion is exposed, a back surface pad or a side conductor connected individually to these is formed.
Further, the second connection portion may extend from the bottom surface side of the heat radiating portion having a cone shape to both the back surface and the side surface of the substrate body.

本発明による一形態の配線基板を示す垂直断面図。1 is a vertical sectional view showing a wiring board according to an embodiment of the present invention. （Ａ），（Ｂ）は上記配線基板に用いる放熱部などを示す斜視図。(A), (B) is a perspective view which shows the thermal radiation part etc. which are used for the said wiring board. （Ａ），（Ｂ）はそれぞれ上記配線基板の製造工程を示す概略図。(A), (B) is the schematic which shows the manufacturing process of the said wiring board, respectively. （Ａ），（Ｂ）は図３（Ｂ）に続く製造工程を示す概略図。(A), (B) is the schematic which shows the manufacturing process following FIG. 3 (B). （Ａ），（Ｂ）は図４（Ｂ）に続く製造工程を示す概略図。(A), (B) is the schematic which shows the manufacturing process following FIG. 4 (B). （Ａ），（Ｂ）はそれぞれ前記配線基板の応用形態を示す垂直断面図。(A), (B) is a vertical sectional view which respectively shows the application form of the said wiring board. （Ａ）は前記配線基板の応用形態を、（Ｂ）は異なる形態の配線基板を示す垂直断面図。(A) is a vertical cross-sectional view showing an application form of the wiring board, and (B) is a wiring board of a different form. （Ａ），（Ｂ）はそれぞれ異なる形態の配線基板を示す垂直断面図。(A), (B) is a vertical sectional view which shows the wiring board of a different form, respectively. （Ａ），（Ｂ）は更に異なる形態の配線基板を示す垂直断面図。(A), (B) is the vertical sectional view which shows the wiring board of a further different form. （Ａ），（Ｂ）はそれぞれ応用形態の放熱部などを示す斜視図。(A), (B) is a perspective view which shows the thermal radiation part etc. of an application form, respectively. （Ａ），（Ｂ）は異なる応用形態の放熱部などを示す斜視図。(A), (B) is a perspective view which shows the thermal radiation part etc. of a different application form.

以下において、本発明を実施するための形態について説明する。
図１は、本発明による一形態の配線基板１ａを示す垂直断面図、図２（Ａ），（Ｂ）は、該配線基板１ａに用いる放熱部１０ａ，１０ｂを示す斜視図である。
上記配線基板１ａは、図１に示すように、例えば、ガラス−セラミック（絶縁材）からなり、互いに平行な表面３および裏面４と、該表面３と裏面４との周辺間に位置する四辺の側面５とを有する基板本体２と、該基板本体２の表面３上に形成された表面パッド６と、該基板本体２の内部に埋設された放熱部１０ａあるいは放熱部１０ｂと、を含んでいる。
上記放熱部１０ａは、図２（Ａ）に示すように、頂部１３を有する円錐面１１と、底面視が円形の底面１２とからなる円錐体形状を呈し、前記円錐面１１と底面１２との角部の全周に沿って曲面部（アール）１４が形成されている。
一方、上記放熱部１０ｂは、図２（Ｂ）に示すように、頂部１３を有する四角錐体形状を呈し、四つの細長い三角形状の側面１５と、底面視が正方形状の底面１２とを有すると共に、該四つの側面１５と底面１２との全周に沿って曲面部１４が形成されている。 Hereinafter, modes for carrying out the present invention will be described.
FIG. 1 is a vertical sectional view showing a wiring board 1a according to an embodiment of the present invention, and FIGS. 2A and 2B are perspective views showing heat radiation portions 10a and 10b used in the wiring board 1a.
As shown in FIG. 1, the wiring board 1 a is made of, for example, glass-ceramic (insulating material), and has four sides positioned between the front surface 3 and the back surface 4 parallel to each other and the periphery of the front surface 3 and the back surface 4. A substrate body 2 having a side surface 5, a surface pad 6 formed on the surface 3 of the substrate body 2, and a heat radiating portion 10 a or a heat radiating portion 10 b embedded in the substrate body 2 are included. .
2A, the heat radiating portion 10a has a conical shape including a conical surface 11 having a top portion 13 and a bottom surface 12 that is circular in bottom view. A curved surface portion (R) 14 is formed along the entire circumference of the corner portion.
On the other hand, as shown in FIG. 2B, the heat radiating portion 10b has a quadrangular pyramid shape having a top portion 13, and includes four elongated triangular side surfaces 15 and a bottom surface 12 having a square shape in a bottom view. In addition, a curved surface portion 14 is formed along the entire circumference of the four side surfaces 15 and the bottom surface 12.

図２（Ａ），（Ｂ）に示すように、前記放熱部１０ａ，１０ｂには、それぞれの頂部１３から円柱形状の第１接続部８が同軸状に立設されており、且つそれぞれの底面１２の中心部から円柱形状の第２接続部９が同軸状に垂下している。
図１に示すように、第１接続部８は、前記基板本体２の表面３における中心部に上端部が露出し且つ前記表面パッド６の底面に接続されている。該第１接続部８に頂部１３側が接続された放熱部１０ａ，１０ｂは、基板本体２の表面３側から裏面４側に向かうに連れて平面視の断面積が大きくなるように、上記基板本体２を構成している前記セラミックの内部に埋設されている。該放熱部１０ａ，１０ｂの底面１２ごとの中心部と、上記基板本体２の裏面４における中心部に形成された裏面パッド７との間には、第２接続部９が接続されている。
尚、図１おいては、第１接続部８、第２接続部９、および放熱部１０ａ（１０ｂ）の中心軸は、それぞれ基板本体２の表面３および裏面４と直交しているが、必ずしも当該形態に限定されるものではない。 As shown in FIGS. 2 (A) and 2 (B), the heat radiation portions 10a and 10b are provided with cylindrical first connection portions 8 extending from the top portion 13 in a coaxial manner, and the bottom surfaces thereof. A cylindrical second connection portion 9 hangs coaxially from the center of 12.
As shown in FIG. 1, the first connection portion 8 has an upper end exposed at the center of the surface 3 of the substrate body 2 and is connected to the bottom surface of the surface pad 6. The heat sinks 10a and 10b connected to the first connecting part 8 on the top 13 side have the above-mentioned substrate body so that the sectional area in plan view increases from the front surface 3 side to the back surface 4 side of the substrate body 2. Embedded in the ceramic constituting 2. A second connection portion 9 is connected between the center portion of each of the bottom surfaces 12 of the heat radiating portions 10 a and 10 b and the back surface pad 7 formed at the center portion of the back surface 4 of the substrate body 2.
In FIG. 1, the central axes of the first connecting portion 8, the second connecting portion 9, and the heat radiating portion 10a (10b) are orthogonal to the front surface 3 and the back surface 4 of the substrate body 2, respectively. It is not limited to the said form.

前記基板本体２の表面３と裏面４との周辺部の何れかには、該表面３と裏面４との間を貫通する細長い円柱形状のビア導体２０が配設され、その上端部には、上記表面３上に形成された表面電極２１が接続され、上記ビア導体２０の下端部には、上記裏面４上に形成された裏面電極２２が接続されている。
上記表面電極２１は、図１に示すように、追って表面パッド６の上方に実装される発光素子２４における片方の電極とボンディングワイヤ２３を介して、電気的に接続される。一方、前記裏面パッド７および裏面電極２２は、追って本配線基板１ａが搭載される図示しないマザーボード側の外部端子と導通可能とされる。
尚、前記放熱部１０ａ，１０ｂ、表面・裏面パッド６，７、第１・第２接続部８，９、ビア導体２０、および表面・裏面電極２１，２２は、基板本体２を構成するセラミックが前記ガラス−セラミックのような低温焼成セラミックの場合には、主にＡｇまたはＣｕからなり、上記セラミックがアルミナなどの高温焼成セラミックの場合には、主にＷまたはＭｏからなる。 An elongated cylindrical via conductor 20 penetrating between the front surface 3 and the back surface 4 is disposed in any of the peripheral portions of the front surface 3 and the back surface 4 of the substrate body 2, A front surface electrode 21 formed on the front surface 3 is connected, and a back surface electrode 22 formed on the back surface 4 is connected to a lower end portion of the via conductor 20.
As shown in FIG. 1, the surface electrode 21 is electrically connected to one electrode of a light emitting element 24 mounted on the surface pad 6 later via a bonding wire 23. On the other hand, the back pad 7 and the back electrode 22 can be electrically connected to an external terminal on the mother board (not shown) on which the wiring board 1a is mounted.
The heat radiating portions 10a and 10b, the front and back pads 6 and 7, the first and second connecting portions 8 and 9, the via conductor 20, and the front and back electrodes 21 and 22 are made of ceramic constituting the substrate body 2. In the case of a low-temperature fired ceramic such as the glass-ceramic, it is mainly composed of Ag or Cu, and in the case where the ceramic is a high-temperature fired ceramic such as alumina, it is mainly composed of W or Mo.

以下において、前記配線基板１ａの製造方法について説明する。
予め、図３（Ａ）の垂直断面図で示すように、前記第１・第２接続部８，９を上下に有する放熱部１０ａを形成するため、これらと相似形状である模型部８ｍ，９ｍ，１０ｍからなる立体模型３０Ｍと、ビア導体２０と相似形の立体模型２０ｍとを製作した。
即ち、平均粒径が１〜５０μｍであるアクリル樹脂の粉末および接着剤などからなる液状の原料を、図示しない３次元プリンタに用いることで、図３（Ａ）に示すように、第１・第２接続部８，９の模型部８ｍ，９ｍと、これらの間を接続する円錐体形状の放熱部１０の模型部１０ｍとからなる立体模型３０Ｍを成形した。該模型部１０ｍの角部には、前記放熱部１０ａと相似形の曲面部１４が位置している。
また、上記原料および３次元プリンタを用いることで、図３（Ａ）の右側に示すように、前記ビア導体２０と相似形の立体模型２０ｍを成形した。 Below, the manufacturing method of the said wiring board 1a is demonstrated.
As shown in the vertical sectional view of FIG. 3 (A), in order to form the heat radiating portion 10a having the first and second connecting portions 8 and 9 above and below, the model portions 8m and 9m having similar shapes to these are formed. , 10 m and a three-dimensional model 20 m similar to the via conductor 20.
That is, by using a liquid raw material consisting of an acrylic resin powder having an average particle diameter of 1 to 50 μm and an adhesive for a three-dimensional printer (not shown), as shown in FIG. The three-dimensional model 30M including the model portions 8m and 9m of the two connecting portions 8 and 9 and the model portion 10m of the cone-shaped heat radiating portion 10 that connects between them was formed. A curved surface portion 14 similar to the heat radiating portion 10a is located at a corner portion of the model portion 10m.
Further, by using the raw material and the three-dimensional printer, a three-dimensional model 20m similar to the via conductor 20 was formed as shown on the right side of FIG.

次に、図示しない型内に配設された直方体状のキャビティ内に、前記立体模型３０Ｍ，２０ｍをそれぞれの上・下端面のみを該キャビティの天井面および床面に接触させ且つ拘束した状態として、上記キャビティ内にガラス−セラミック（絶縁材）のスラリをゲルキャスト法によって充填した。
その結果、図３（Ｂ）に示すように、前記ガラス−セラミックのスラリが乾燥した生（未焼成）のセラミック体からなり、表面３、裏面４、およびこれらの四辺間に位置する側面５を有し、上記立体模型３０Ｍ，２０ｍの上下の両端面が表面３と裏面４とに個別に露出している未焼成の素基板本体３１が得られた。
次いで、上記素基板本体３１を所定の温度帯に加熱して、該素基板本体３１を構成している前記ガラス−セラミックを焼成した。かかる加熱過程において、前記立体模型３０Ｍ，２０ｍを構成していた前記アクリル樹脂の粉末や接着剤などは、当該立体模型３０Ｍ，２０ｍごとの上端部側から順次外部に蒸発して行った。 Next, the three-dimensional models 30M and 20m are brought into contact with the ceiling surface and floor surface of the cavity and restrained in a rectangular parallelepiped cavity disposed in a mold (not shown). The above-mentioned cavity was filled with a glass-ceramic (insulating material) slurry by a gel casting method.
As a result, as shown in FIG. 3B, the glass-ceramic slurry is made of a dried (unfired) ceramic body, and the front surface 3, the back surface 4, and the side surface 5 located between these four sides are formed. Thus, an unfired base substrate body 31 was obtained in which the upper and lower end faces of the three-dimensional models 30M and 20m were individually exposed on the front surface 3 and the back surface 4.
Next, the base substrate body 31 was heated to a predetermined temperature range, and the glass-ceramic constituting the base substrate body 31 was fired. In this heating process, the acrylic resin powder, adhesive, etc. constituting the three-dimensional models 30M, 20m were sequentially evaporated from the upper end side of the three-dimensional models 30M, 20m to the outside.

その結果、図４（Ａ）に示すように、上記ガラス−セラミックからなり、表面３、裏面４、およびこれらの四辺間に位置する側面５を有し、上記立体模型３０Ｍ，２０ｍが蒸発して除去された跡には、該立体模型３０Ｍ，２０ｍとそれぞれ相似形の空洞部８ｓ〜１０ｓ，２０ｓが内部に形成されている焼成済みのセラミックからなる基板本体３２が得られた。
更に、前記空洞部８ｓ〜１０ｓ，２０ｓ内にＡｇ粉末あるいはＣｕ粉末（金属粉末）を含む導電性ペーストを前記表面３側の上端部（開口部）から充填した。
その結果、図４（Ｂ）に示すように、空洞部８ｓ〜１０ｓ内に上記導電性ペーストからなる未硬化の第１・第２接続部８ｐ，９ｐと、これらの間を接続する未硬化の放熱部１０ｐとが形成され、空洞部２０ｓ内に上記導電性ペーストからなる未硬化のビア導体２０ｐとが個別に形成された基板本体２が得られた。尚、上記放熱部１０ｐの角部には、前記模型部１０ｍの角部に形成された曲面部１４と相似形の空洞部に上記導電性ペーストが充填されたので、空隙を生じなかった。 As a result, as shown in FIG. 4 (A), it is made of the glass-ceramic, has the front surface 3, the back surface 4, and the side surface 5 positioned between these four sides, and the three-dimensional models 30M and 20m are evaporated. As a result of the removal, a substrate main body 32 made of fired ceramic in which hollow portions 8s to 10s and 20s similar to the three-dimensional models 30M and 20m, respectively, are formed is obtained.
Further, a conductive paste containing Ag powder or Cu powder (metal powder) was filled in the hollow portions 8 s to 10 s and 20 s from the upper end portion (opening portion) on the surface 3 side.
As a result, as shown in FIG. 4B, uncured first and second connection portions 8p and 9p made of the conductive paste in the hollow portions 8s to 10s and the uncured connecting between them. A substrate body 2 was obtained in which the heat radiating portion 10p was formed and the uncured via conductor 20p made of the conductive paste was individually formed in the hollow portion 20s. In addition, since the said conductive paste was filled into the cavity part similar to the curved-surface part 14 formed in the corner | angular part of the said model part 10m, the space | gap was not produced in the corner | angular part of the said thermal radiation part 10p.

次に、未硬化の第１・第２接続部８ｐ，９ｐおよび放熱部１０ｐと、ビア導体２０ｐとを内設する上記基板本体２を、所定の温度帯に加熱することで、上記放熱部１０ｐなどとビア導体２０ｐとを硬化（キュア）させた。その結果、図５（Ａ）に示すように、硬化した第１・第２接続部８，９および放熱部１０ａとビア導体２０とを内部に埋設している基板本体２が得られた。
そして、前記基板本体２の表面３と裏面４とを研磨した後、該表面３および裏面４に露出する第１・第２接続部８，９の端面ごと、およびビア導体２０の両端面に対し、Ｔｉ合金をスパッタリングして、それぞれ平面視が矩形状あるいは円形状を呈する下地金属層を形成し、該下地金属層ごとの表面にＣｕをスパッタリングして表層金属層を積層してパッド本体を形成した後、それらの表面に対して電解Ｎｉメッキおよび電解Ａｕメッキを順次施した。 Next, the substrate body 2 in which the uncured first and second connection portions 8p and 9p and the heat radiating portion 10p and the via conductor 20p are provided is heated to a predetermined temperature zone, thereby the heat radiating portion 10p. And the via conductor 20p were cured. As a result, as shown in FIG. 5A, the substrate main body 2 in which the hardened first and second connecting portions 8 and 9, the heat radiating portion 10a, and the via conductors 20 are embedded is obtained.
And after grind | polishing the surface 3 and the back surface 4 of the said board | substrate main body 2, with respect to the both end surfaces of the 1st and 2nd connection parts 8 and 9 exposed to this surface 3 and the back surface 4, and the both ends of the via conductor 20 , Sputtering a Ti alloy to form a base metal layer having a rectangular or circular shape in plan view, and sputtering Cu on the surface of each base metal layer to form a surface metal layer to form a pad body After that, electrolytic Ni plating and electrolytic Au plating were sequentially applied to the surfaces.

その結果、図５（Ｂ）に示すように、第１・第２接続部８，９、放熱部１０ａ、およびビア導体２０を基板本体２の内部に埋設していると共に、該第１・第２接続部８，９の端面ごとに個別に接続した表面・裏面パッド６，７と、ビア導体２０の両端面に個別に接続した表面・裏面電極２１，２２とを、前記表面３あるいは裏面４に形成した前記配線基板１ａを得ることができた。
尚、前記模型部１０ｍの形状を変更することで、前記放熱部１０ｂを基板本体２の内部に対し前記同様に埋設した配線基板１ａを製造することもできる。
以上のような製造方法によれば、前記配線基板１ａを、一個でも多数個取り方式でも、比較的少ない工程によって、精緻で且つ確実に製造することができる。 As a result, as shown in FIG. 5B, the first and second connection portions 8 and 9, the heat radiating portion 10a, and the via conductor 20 are embedded in the substrate body 2, and the first and second connection portions are embedded. 2 The front and back pads 6 and 7 individually connected for each end face of the connecting portions 8 and 9 and the front and back electrodes 21 and 22 individually connected to both end faces of the via conductor 20 are connected to the front face 3 or the back face 4. The wiring board 1a formed in (1) was obtained.
In addition, the wiring board 1a which embed | buried the said thermal radiation part 10b with respect to the inside of the board | substrate body 2 similarly to the above can also be manufactured by changing the shape of the said model part 10m.
According to the manufacturing method as described above, it is possible to manufacture the wiring substrate 1a precisely and reliably with relatively few steps, whether it is a single piece or a multi-piece method.

前記のような配線基板１ａによれば、円錐体形状または四角錐体形状を呈する放熱部１０ａ，１０ｂは、基板本体２の表面３上に形成された表面パッド６に対し、平面視で該表面パッド６の面積よりも小さい面積の第１接続部８を介して接続されている。即ち、平面視において、基板本体２の表面３に露出する第１接続部８の面積は、表面パッド６の面積よりも小さい。そのため、追って、表面パッド６の上方に比較的発熱量の高い発光素子２４が実装された場合、該発光素子２４から発せられる熱は、第１接続部８を介して放熱部１０ａ，１０ｂに伝達され、該放熱部１０ａ，１０ｂの表面から基板本体２を構成しているセラミック中に順次放散された後、外部に放出される。その結果、上記表面パッド６とこれに接する基板本体２のセラミックとの間における熱膨張係数の差に起因して、該セラミックの表面３側にクラックが生じる事態を皆無にできるか、確実に抑制することが可能となる。 According to the wiring substrate 1a as described above, the heat radiating portions 10a and 10b having a cone shape or a quadrangular pyramid shape are formed on the surface pad 6 formed on the surface 3 of the substrate body 2 in a plan view. The connection is made through the first connection portion 8 having an area smaller than the area of the pad 6. That is, in plan view, the area of the first connection portion 8 exposed on the surface 3 of the substrate body 2 is smaller than the area of the surface pad 6. Therefore, when the light emitting element 24 having a relatively high calorific value is mounted above the surface pad 6 later, the heat generated from the light emitting element 24 is transmitted to the heat radiating parts 10a and 10b via the first connection part 8. Then, after being sequentially dissipated into the ceramic constituting the substrate body 2 from the surfaces of the heat dissipating parts 10a, 10b, it is emitted to the outside. As a result, the occurrence of cracks on the surface 3 side of the ceramic due to the difference in thermal expansion coefficient between the surface pad 6 and the ceramic of the substrate body 2 in contact with the surface pad 6 can be reliably suppressed. It becomes possible to do.

しかも、前記放熱部１０ａ，１０ｂは、基板本体２の表面３側から裏面４側に向かうに連れて平面視の断面積が大きくなる錐体形状を呈するので、前記発光素子２４からの熱を該放熱部１０ａ，１０ｂの頂部１３側から底面１２側に向かうに連れて、該熱の伝達速度を次第に速めつつ迅速に拡散させることができる。
更に、前記表面パッド６は、平面視で前記発光素子２４が実装できる面積であれば良く、基板本体２の表面３を過度に占有しないので、該基板本体２の表面３における表面電極２１や表面配線などの配置に支障を来す事態を少なくできる。
従って、追って、発熱量の高い発光素子２４が表面パッド６の上方に実装されても、該素子２４から発せられる熱によっても、上記表面パッド６に接する基板本体２の表面３側のセラミックにクラックが生じにくく、上記熱の放熱性に優れていると共に、上記基板本体２の表面における設計の自由度が比較的高い配線基板１ａを提供することができる。 In addition, the heat radiating portions 10a and 10b have a conical shape in which the cross-sectional area in plan view increases from the front surface 3 side to the back surface 4 side of the substrate body 2, and thus the heat from the light emitting element 24 is transferred to the heat radiating portions 10a and 10b. As it goes from the top 13 side to the bottom surface 12 side of the heat radiating portions 10a, 10b, the heat transfer rate can be gradually diffused while gradually increasing.
Further, the surface pad 6 may have an area where the light emitting element 24 can be mounted in a plan view and does not occupy the surface 3 of the substrate body 2 excessively. Situations that hinder the layout of wiring can be reduced.
Accordingly, the ceramics on the surface 3 side of the substrate main body 2 in contact with the surface pad 6 are cracked by the light emitting element 24 having a high calorific value mounted on the surface pad 6 or by heat generated from the element 24. Thus, it is possible to provide a wiring board 1a that is excellent in heat dissipation and has a relatively high degree of design freedom on the surface of the board body 2.

図６（Ａ）は、前記配線基板１ａの応用形態を示す垂直断面図である。
応用形態の配線基板１ａは、図６（Ａ）に示すように、前記同様の基板本体２、表面パッド６、第１接続部８、および放熱部１０ａ（１０ｂ）を備えている。該配線基板１ａは、放熱部１０ａ（１０ｂ）の底面１２と基板本体２の裏面４との間に前記第２接続部９を有していない反面、基板本体２における周辺部に一対のビア導体２０を左右対称にして貫通させ、且つこれらの両端ごとに表面電極２１および裏面電極２２を個別に接続している。
上記表面パッド６の上方には、図６（Ａ）に示すように、追って、発熱量が比較的多い半導体素子２５が実装され、該半導体素子２５における一対の外部電極（図示せず）と、左右一対の表面電極２１との間は、ボンディングワイヤ２３を介して電気的に接続される。 FIG. 6A is a vertical cross-sectional view showing an applied form of the wiring board 1a.
As shown in FIG. 6A, the wiring board 1a according to the application form includes the same substrate body 2, surface pad 6, first connection portion 8, and heat radiation portion 10a (10b) as those described above. The wiring board 1a does not have the second connection portion 9 between the bottom surface 12 of the heat radiating portion 10a (10b) and the back surface 4 of the substrate body 2, but a pair of via conductors in the peripheral portion of the substrate body 2. 20 is symmetrically penetrated, and the front surface electrode 21 and the back surface electrode 22 are individually connected to both ends thereof.
As shown in FIG. 6A, a semiconductor element 25 having a relatively large amount of heat generation is mounted above the surface pad 6, and a pair of external electrodes (not shown) in the semiconductor element 25; The pair of left and right surface electrodes 21 are electrically connected via bonding wires 23.

以上のような応用形態の配線基板１ａによれば、前記半導体素子２５から発生する熱は、表面パッド６および第１接続部８を介して放熱部１０ａ（１０ｂ）に放散され、基板本体２を構成する前記セラミックに拡散された後に、外部に放出される。しかも、上記半導体素子２５は、前記ボンディングワイヤ２３、基板本体２を貫通する一対のビア導体２０、および前記裏面電極２２を介して、外部のプリント基板などのマザーボード（図示せず）と導通可能とされるので、所要の動作を確実に奏することができる。更に、基板本体２の裏面４には、一対の裏面電極２２だけを形成すれば良いので、それらの配置すべき位置を比較的自由に設計することもできる。
尚、前記放熱部１０ａ（１０ｂ）の底面１２と、基板本体２の裏面４との間に、更に前記第２接続部９を配置した形態としても良い。 According to the wiring board 1a of the application form as described above, the heat generated from the semiconductor element 25 is dissipated to the heat radiating part 10a (10b) through the surface pad 6 and the first connecting part 8, and the board body 2 After being diffused into the ceramic to be formed, it is discharged to the outside. In addition, the semiconductor element 25 can be electrically connected to a mother board (not shown) such as an external printed circuit board through the bonding wire 23, the pair of via conductors 20 penetrating the substrate body 2, and the back electrode 22. Therefore, the required operation can be reliably performed. Furthermore, since only the pair of back surface electrodes 22 need be formed on the back surface 4 of the substrate body 2, the positions where they should be arranged can be designed relatively freely.
In addition, it is good also as a form which has arrange | positioned the said 2nd connection part 9 further between the bottom face 12 of the said thermal radiation part 10a (10b), and the back surface 4 of the board | substrate body 2. FIG.

図６（Ｂ）は、配線基板１ａの異なる応用形態の概略を示す垂直断面図である。
かかる応用形態の配線基板１ａは、図６（Ｂ）に示すように、前記同様の基板本体２、表面パッド６、第１接続部８、放熱部１０ａ（１０ｂ）、第２接続部９、裏面パッド７、ビア導体２０、および表面・裏面電極２１，２２を備えている。
かかる配線基板１ａは、第２接続部９における放熱部１０ａ（１０ｂ）の底面１２側に、該底面１２に近付くに連れて平面視の断面積が大きくなる円錐形状部１６を形成している。
上記のような異なる応用形態の配線基板１ａによれば、前記図１に示した形態の配線基板１ａによる効果に加え、追って表面パッド６の上方に実装される前記発光素子２４からの熱を、放熱部１０ａ（１０ｂ）の底面１２側から第２接続部９を介して裏面パッド７側へ一層スムーズに伝達することが可能となる。 FIG. 6B is a vertical cross-sectional view showing an outline of a different application form of the wiring board 1a.
As shown in FIG. 6 (B), the wiring board 1a of this application form includes the same substrate body 2, surface pad 6, first connection part 8, heat radiation part 10a (10b), second connection part 9, and back surface. A pad 7, a via conductor 20, and front and back electrodes 21 and 22 are provided.
The wiring board 1a has a conical portion 16 whose cross-sectional area in plan view increases as it approaches the bottom surface 12 on the bottom surface 12 side of the heat radiating portion 10a (10b) in the second connection portion 9.
According to the wiring board 1a of the different application form as described above, in addition to the effect of the wiring board 1a of the form shown in FIG. 1, the heat from the light emitting element 24 that is mounted on the surface pad 6 later, It becomes possible to transmit more smoothly from the bottom surface 12 side of the heat radiating portion 10a (10b) to the back surface pad 7 side via the second connection portion 9.

図７（Ａ）は、前記配線基板１ａの更に異なる応用形態を示す垂直断面図である。該応用形態の配線基板１ａは、図７（Ａ）に示すように、前記同様の基板本体２、表面パッド６、第１接続部８、放熱部１０ａ（１０ｂ）、第２接続部９、裏面パッド７、ビア導体２０、および表面・裏面電極２１，２２を備えている。
上記配線基板１ａは、図７（Ａ）に示すように、放熱部１０ａ（１０ｂ）の曲面部１４と上記基板本体２の側面５との間に、基板本体２の表面３と平行な第２接続部３３を更に形成すると共に、該第２接続部３３の端部が露出する基板本体２の側面５には、側面導体３４が形成されている。尚、同図中の破線で示すように、上記側面導体３４の下端部を、更に、基板本体２の裏面４側まで延ばして、別の裏面パッドまたは裏面電極を形成するようにしても良い。
更に異なる応用形態の上記配線基板１ａによれば、前記図１に示した形態の配線基板１ａによる効果に加え、前記素子２４，２５からの熱を一層効果的に放散することが可能となる。尚、図７（Ａ）の上記配線基板１ａにおいて、第２接続部９および裏面パッド７を省略した形態とすることも可能である。 FIG. 7A is a vertical sectional view showing still another application form of the wiring board 1a. As shown in FIG. 7A, the circuit board 1a of the applied form includes the same substrate body 2, surface pad 6, first connection portion 8, heat radiation portion 10a (10b), second connection portion 9, and back surface as described above. A pad 7, a via conductor 20, and front and back electrodes 21 and 22 are provided.
As shown in FIG. 7A, the wiring board 1 a has a second parallel to the surface 3 of the substrate body 2 between the curved surface portion 14 of the heat radiating portion 10 a (10 b) and the side surface 5 of the substrate body 2. A side conductor 34 is formed on the side surface 5 of the substrate body 2 where the connection portion 33 is further formed and the end of the second connection portion 33 is exposed. As indicated by a broken line in the figure, the lower end portion of the side conductor 34 may be further extended to the back surface 4 side of the substrate body 2 to form another back surface pad or back surface electrode.
Furthermore, according to the wiring board 1a of a different application form, in addition to the effect of the wiring board 1a of the form shown in FIG. 1, the heat from the elements 24 and 25 can be dissipated more effectively. In addition, in the said wiring board 1a of FIG. 7 (A), it can also be set as the form which abbreviate | omitted the 2nd connection part 9 and the back surface pad 7. FIG.

図７（Ｂ）は、異なる形態の配線基板１ｂの概略を示す垂直断面図である。
かかる配線基板１ｂは、図７（Ｂ）に示すように、前記同様の基板本体２、表面パッド６、第１接続部８、第２接続部９、裏面パッド７、ビア導体２０、および表面・裏面電極２１，２２を備えている。
上記配線基板１ｂは、図７（Ｂ）に示すように、第１接続部８と第２接続部９との間に、第１接続部８側から第２接続部９側に向かうに連れて断面積が徐々に拡大し、且つ内側に凹んだ円錐面１６あるいは複数の側面１７を有する円錐体形状または四角錐体形状を呈する放熱部１０ｃあるいは放熱部１０ｄを配設している。かかる配線基板１ｂによっても、前記図１に示した形態の配線基板１ａと同様な効果を奏することが可能である。 FIG. 7B is a vertical cross-sectional view schematically showing a wiring board 1b having a different form.
As shown in FIG. 7B, the wiring substrate 1b includes the same substrate body 2, surface pad 6, first connection portion 8, second connection portion 9, back surface pad 7, via conductor 20, Back electrodes 21 and 22 are provided.
As shown in FIG. 7B, the wiring board 1b is located between the first connecting portion 8 and the second connecting portion 9 from the first connecting portion 8 side toward the second connecting portion 9 side. A heat dissipating part 10c or a heat dissipating part 10d having a conical shape or a quadrangular pyramid shape having a conical surface 16 or a plurality of side surfaces 17 that are gradually increased in cross-sectional area is disposed. Such a wiring board 1b can achieve the same effects as the wiring board 1a having the configuration shown in FIG.

図８（Ａ）は、更に異なる形態の配線基板１ｃの概略を示す垂直断面図である。
かかる配線基板１ｃは、図８（Ａ）に示すように、前記同様の基板本体２、表面パッド６、第１接続部８、第２接続部９、裏面パッド７、ビア導体２０、および表面・裏面電極２１，２２を備えている。
上記配線基板１ｃは、図８（Ａ）に示すように、第１接続部８と第２接続部９との間に、かかる第１接続部８側から第２接続部９側に向かうに連れて、断面積が第１接続部８側では急速に拡大し且つ第２接続部９側に近付くほど緩やかに拡大する円錐体（半紡錘体）形状または四角錐体形状を呈し、且つ円錐面１８または複数の側面１９を有する放熱部１０ｅあるいは放熱部１０ｆを配設している。
以上のような配線基板１ｃによっても、前記図１に示した形態の配線基板１ａと同様な効果を奏することが可能である。 FIG. 8A is a vertical cross-sectional view showing an outline of a wiring board 1c of still another form.
As shown in FIG. 8A, the wiring substrate 1c includes the same substrate body 2, surface pad 6, first connection portion 8, second connection portion 9, back surface pad 7, via conductor 20, and surface / surface as described above. Back electrodes 21 and 22 are provided.
As shown in FIG. 8A, the wiring board 1c is arranged between the first connection portion 8 and the second connection portion 9 from the first connection portion 8 side toward the second connection portion 9 side. Thus, the cross-sectional area exhibits a conical (semi-spindle) shape or a quadrangular pyramid shape that rapidly expands on the first connection portion 8 side and gradually increases as it approaches the second connection portion 9 side. Alternatively, the heat dissipating part 10e or the heat dissipating part 10f having a plurality of side surfaces 19 is provided.
Even with the wiring board 1c as described above, the same effects as those of the wiring board 1a of the embodiment shown in FIG. 1 can be obtained.

図８（Ｂ）は、別異なる形態の配線基板１ｄの概略を示す垂直断面図である。
かかる配線基板１ｄは、図８（Ｂ）に示すように、前記同様の基板本体２、表面パッド６、第１接続部８、第２接続部９、ビア導体２０、および表面・裏面電極２１，２２を備えている。上記第１接続部８と第２接続部９との間には、前記同様の錐体形状（または四角錐形状）を呈し、円錐面２６（複数の側面２７）を有する放熱部１０ｇ（１０ｈ）が、基板本体２の裏面４側から表面３側に向かうに連れて平面視の断面積が次第に大きくなるような形態、即ち、前記各形態とは上下を逆にした姿勢で配設されている。尚、上記第１接続部８と放熱部１０ｇ（１０ｈ）における上面２８との間には、前記熱の伝達をスムーズにするため、円錐面を有する円錐形状部２９が形成されている。
以上のような配線基板１ｄによっても、前記図１に示した形態の配線基板１ａと同様な効果を奏することが可能である。 FIG. 8B is a vertical cross-sectional view showing an outline of a wiring board 1d having a different form.
As shown in FIG. 8B, the wiring substrate 1d includes the same substrate body 2, surface pad 6, first connection portion 8, second connection portion 9, via conductor 20, and front / back electrodes 21, as described above. 22 is provided. Between the said 1st connection part 8 and the 2nd connection part 9, the heat dissipation part 10g (10h) which exhibits the same cone shape (or quadrangular pyramid shape) as the above, and has the conical surface 26 (several side surfaces 27). However, the cross-sectional area in plan view gradually increases from the back surface 4 side to the front surface 3 side of the substrate body 2, that is, arranged in a posture that is upside down with respect to each of the above embodiments. . A conical portion 29 having a conical surface is formed between the first connecting portion 8 and the upper surface 28 of the heat radiating portion 10g (10h) in order to smoothly transfer the heat.
Also with the wiring board 1d as described above, it is possible to achieve the same effects as those of the wiring board 1a having the configuration shown in FIG.

図９（Ａ）は、更に異なる応用形態の配線基板１ａを示す垂直断面図である。
かかる配線基板１ａは、図９（Ａ）に示すように、前記同様の基板本体２、表面パッド６、第１接続部８、放熱部１０ａ（１０ｂ）、ビア導体２０、および表面・裏面電極２１，２２を備えている。上記放熱部１０ａ（１０ｂ）は、その円錐面１１（または側面１５）と底面１２との角部に、前記曲線部１４に替えて側面視で平面からなる面取り部１４ｆを全周に沿って有している。更に、上記底面１２と基板本体２の裏面４との間に少なくも左右一対（複数）の第２接続部９を形成すると共に、かかる第２接続部９の下端部が露出する基板本体２の裏面４ごとに、裏面パッド７が形成されている。かかる配線基板１ａによっても、前記図１に示した形態の配線基板１ａと同様な効果を奏することが可能である。
尚、前記放熱部１０ｃ〜１０ｈについても、それらの前記曲面部１４を面取り部１４ｆに替えた形態としても良い。 FIG. 9A is a vertical sectional view showing a wiring board 1a of a further different application form.
As shown in FIG. 9A, the wiring substrate 1a includes the same substrate body 2, surface pad 6, first connection portion 8, heat radiating portion 10a (10b), via conductor 20, and front and back electrodes 21 as described above. , 22 are provided. The heat dissipating part 10a (10b) has a chamfered part 14f having a flat surface in a side view instead of the curved part 14 at the corner part between the conical surface 11 (or side surface 15) and the bottom surface 12 along the entire circumference. doing. Further, at least a pair of left and right second connection portions 9 are formed between the bottom surface 12 and the back surface 4 of the substrate body 2, and the lower end of the second connection portion 9 is exposed. A back surface pad 7 is formed for each back surface 4. Also with this wiring board 1a, it is possible to achieve the same effect as the wiring board 1a of the form shown in FIG.
In addition, about the said thermal radiation parts 10c-10h, it is good also as a form which replaced those said curved surface parts 14 with the chamfering part 14f.

図９（Ｂ）は、別個なる形態の配線基板１ｅの概略を示す垂直断面図である。
かかる配線基板１ｅは、図９（Ｂ）に示すように、前記同様の基板本体２、比較的面積の大きい表面パッド６、左右一対（複数）の第１接続部８、第２接続部９、ビア導体２０、および表面・裏面電極２１，２２を備えている。上記第２接続部９の左右（前後）には、互いに対称に傾斜した左右一対（複数）の第２接続部９ａが更に配置されている。上記第１接続部８，８と第２接続部９，９ａとの間には、平坦な円形状（または正方形状）の頂面（頂部）３８と、該頂面３８から基板本体２の裏面４側に向かうに連れて平面視の断面積が拡大する円錐面（または複数の側面）３７と、上記頂面３８と相似形の底面３９とからなり、全体が円錐体形状（四角錐体形状）を呈し且つ垂直断面が台形状である放熱部３５（３６）が配設されている。尚、該放熱部３５（３６）の曲面部１４も前記面取り部１４ｆに替えても良い。
以上のような配線基板１ｅによれば、前記図１に示した形態の配線基板１ａによる効果（放熱性および電気的接続性）を一層効果的に奏することが可能である。 FIG. 9B is a vertical cross-sectional view showing an outline of the wiring board 1e in a separate form.
As shown in FIG. 9B, the wiring substrate 1e includes a substrate body 2 similar to the above, a surface pad 6 having a relatively large area, a pair of left and right first connection portions 8, a second connection portion 9, A via conductor 20 and front and back electrodes 21 and 22 are provided. On the left and right sides (front and rear) of the second connection portion 9, a pair of left and right (a plurality of) second connection portions 9a inclined symmetrically with each other are further arranged. Between the first connecting portions 8 and 8 and the second connecting portions 9 and 9a, there is a flat (or square) top surface (top portion) 38, and the back surface of the substrate body 2 from the top surface 38. Consists of a conical surface (or a plurality of side surfaces) 37 whose cross-sectional area in plan view expands toward the side 4, and a bottom surface 39 similar to the top surface 38. ) And a heat radiating portion 35 (36) having a trapezoidal vertical cross section is disposed. The curved surface portion 14 of the heat radiating portion 35 (36) may be replaced with the chamfered portion 14f.
According to the wiring board 1e as described above, the effects (heat dissipation and electrical connectivity) of the wiring board 1a having the configuration shown in FIG. 1 can be more effectively exhibited.

図１０（Ａ）は、前記放熱部１０ａの円錐面１１に、該放熱部１０ａの頂部１３側から底面１２側に向かって延びる複数組の凹溝４１および凸条４０を円周方向に沿って連続して形成した形態を示す斜視図である。上記複数組の凹溝４１および凸条４０は、前記放熱部１０ｃ，１０ｅ，１０ｇ，３５の円錐面１６，１８，２６，３７に対しても、上記と同様に形成しても良い。
図１０（Ｂ）は、前記放熱部１０ｂにおける複数の側面１５ごとに、該放熱部１０ｂの頂部１３側から底面１２側に向かって延びる複数組の凹溝４３および凸条４２を幅方向に沿って連続して形成した形態を示す斜視図である。該複数組の凹溝４３および凸条４２は、前記放熱部１０ｄ，１０ｆ，１０ｈ，３６における複数の側面１７，１９，２７，３７に対しても、上記と同様に形成しても良い。
以上のような複数組の凹溝４１，４３および凸条４０，４２を更に形成することで、前記放熱部１０ａ〜１０ｈ，３５，３６の表面積が一層大きくなるので、前記基板本体２を構成する前記セラミックとの密着面積が増大すると共に、前記発光素子２４あるいは半導体素子２５からの熱を基板本体２のセラミック中に一層効率良く放散することが可能となる。 FIG. 10A shows a plurality of sets of concave grooves 41 and ridges 40 extending in the circumferential direction on the conical surface 11 of the heat radiating portion 10a extending from the top 13 side toward the bottom surface 12 side of the heat radiating portion 10a. It is a perspective view which shows the form formed continuously. The plurality of sets of concave grooves 41 and ridges 40 may be formed on the conical surfaces 16, 18, 26, and 37 of the heat radiating portions 10c, 10e, 10g, and 35 in the same manner as described above.
10B shows, for each of the plurality of side surfaces 15 in the heat radiating portion 10b, a plurality of sets of concave grooves 43 and ridges 42 extending from the top 13 side toward the bottom surface 12 side of the heat radiating portion 10b along the width direction. It is a perspective view which shows the form formed continuously. The plurality of sets of concave grooves 43 and ridges 42 may be formed on the plurality of side surfaces 17, 19, 27, and 37 of the heat radiating portions 10d, 10f, 10h, and 36 in the same manner as described above.
By further forming the plurality of sets of concave grooves 41 and 43 and the ridges 40 and 42 as described above, the surface areas of the heat radiating portions 10a to 10h, 35, and 36 are further increased, so that the substrate body 2 is configured. The contact area with the ceramic increases, and heat from the light emitting element 24 or the semiconductor element 25 can be dissipated more efficiently into the ceramic of the substrate body 2.

図１１（Ａ）は、前記放熱部１０ａの円錐面１１に、該放熱部１０ａの頂部１３側から底面１２側に向かって延び且つ該放熱部１０ａの内側に凹む複数の湾曲面４４を円周方向に沿って形成した形態を示す斜視図である。かかる複数の湾曲面４４は、前記放熱部１０ｃ，１０ｅ，１０ｇ，３５の円錐面１６，１８，２６，３７に対しても、上記と同様に形成しても良い。
図１１（Ｂ）は、前記放熱部１０ｂにおける複数の側面１５を、それぞれ該放熱部１０ｂの内側に凹む湾曲面４５にした形態を示す斜視図である。かかる湾曲面４５は、前記放熱部１０ｄ，１０ｆ，１０ｈ，３６における複数の側面１７，１９，２７，３７ごとに対しても、上記と同様に形成しても良い。
以上のような湾曲面４４，４５を更に形成すれば、前記放熱部１０ａ〜１０ｈ，３５，３６の表面積が更に大きくなるので、前記基板本体２を構成するセラミックとの密着面積が増大すると共に、前記発光素子２４あるいは半導体素子２５からの熱を、基板本体２のセラミック中に一層効率良く放散することが可能となる。 FIG. 11 (A) shows a plurality of curved surfaces 44 that extend from the top 13 side toward the bottom surface 12 side of the heat radiating portion 10a and are recessed on the inner side of the heat radiating portion 10a on the conical surface 11 of the heat radiating portion 10a. It is a perspective view which shows the form formed along the direction. The plurality of curved surfaces 44 may also be formed on the conical surfaces 16, 18, 26, and 37 of the heat radiating portions 10c, 10e, 10g, and 35 in the same manner as described above.
FIG. 11B is a perspective view showing a form in which a plurality of side surfaces 15 of the heat radiating portion 10b are curved surfaces 45 that are recessed inside the heat radiating portion 10b. The curved surface 45 may be formed in the same manner as described above for each of the plurality of side surfaces 17, 19, 27, and 37 in the heat radiating portions 10d, 10f, 10h, and 36.
If the curved surfaces 44 and 45 as described above are further formed, the surface areas of the heat radiating portions 10a to 10h, 35, and 36 are further increased, so that the contact area with the ceramic constituting the substrate body 2 is increased. Heat from the light emitting element 24 or the semiconductor element 25 can be dissipated more efficiently into the ceramic of the substrate body 2.

本発明は、以上において説明した各形態に限定されるものではない。
例えば、前記基板本体を構成する絶縁材は、ガラス−セラミック以外の低温焼成セラミックや、アルミナなどの高温焼成セラミックとしても良い。後者の場合、前記放熱部やビア導体には、ＷまたはＭｏなどが適用される。更に、上記絶縁材には、熱硬化性であり且つ耐熱性を有する合成樹脂（例えば、エポキシ樹脂など）を適用しても良い。上記セラミックや樹脂は、前記ゲルキャスト法によって基板本体を成形するほか、複数のセラミック層または樹脂層を積層する方法によって、前記基板本体を形成しても良い。
また、前記基板本体は、その表面の中央部に開口するキャビティを有する形態とし、該キャビティの底面（表面）に前記第１接続部８の一端部を露出させ、その真上に表面パッド６を形成しても良い。 The present invention is not limited to the embodiments described above.
For example, the insulating material constituting the substrate body may be a low-temperature fired ceramic other than glass-ceramic or a high-temperature fired ceramic such as alumina. In the latter case, W, Mo, or the like is applied to the heat radiating portion or the via conductor. Furthermore, a synthetic resin (for example, an epoxy resin) that is thermosetting and heat resistant may be applied to the insulating material. In addition to forming the substrate body by the gel casting method, the substrate body may be formed by laminating a plurality of ceramic layers or resin layers.
The substrate body has a cavity having an opening at the center of the surface thereof, one end portion of the first connection portion 8 is exposed on the bottom surface (surface) of the cavity, and the surface pad 6 is directly above the first connection portion 8. It may be formed.

また、前記放熱部は、単一の基板本体の内部に複数個を埋設し、該複数個の放熱部ごとに前記第１接続部を接続し、更に、第２接続部を接続しても良い。
更に、前記放熱部は、前記基板本体の表面側から裏面側に向かうに連れて平面視の断面積が大きくなる錐体形状と、該基板本体の裏面側から表面側に向かうに連れて平面視の断面積が大きくなる錐体形状との双方を併有する形態としても良い。
加えて、前記放熱部の円錐面や複数の側面に形成する複数組の凹溝および凸条、あるいは凹溝状の前記湾曲面は、該放熱部の中心軸と直交する方向（上記円錐面の円周方向、上記側面の幅方向）に沿って形成しても良い。あるいは、上記円錐面や複数の側面に、複数の浅いドーム形状を呈する凹部を形成しても良い。 In addition, a plurality of the heat radiating portions may be embedded in a single substrate body, the first connecting portions may be connected to the plurality of heat radiating portions, and the second connecting portions may be further connected. .
The heat dissipating part has a conical shape in which a cross-sectional area in a plan view increases from the front surface side to the back surface side of the substrate body, and a plan view as the back surface side of the substrate body moves from the back surface side to the front surface side. It is good also as a form which has both the cone shape from which cross-sectional area becomes large.
In addition, a plurality of sets of concave grooves and ridges formed on the conical surface or a plurality of side surfaces of the heat radiating portion, or the concave groove-shaped curved surface is in a direction orthogonal to the central axis of the heat radiating portion (the conical surface of the conical surface). You may form along the circumferential direction and the width direction of the said side surface. Or you may form the recessed part which exhibits a some shallow dome shape in the said conical surface or a some side surface.

本発明によれば、絶縁材からなる基板本体の表面上に形成した表面パッドに比較的高い発熱性を有する発光素子などの素子を実装しても、前記表面パッドの周囲に隣接する絶縁材にクラックが生じにくく、且つ基板本体の表面に別のパッドや表面配線などを容易に配置し得る配線基板を提供することができる。 According to the present invention, even when an element such as a light emitting element having relatively high heat generation is mounted on the surface pad formed on the surface of the substrate body made of an insulating material, the insulating material adjacent to the periphery of the surface pad is attached. It is possible to provide a wiring board in which cracks are unlikely to occur and another pad or surface wiring can be easily arranged on the surface of the board body.

１ａ〜１ｅ…………………………配線基板
２……………………………………基板本体
３……………………………………表面
４……………………………………裏面
５……………………………………基板本体の側面
６……………………………………表面パッド
８……………………………………第１接続部
９，３３……………………………第２接続部
１０ａ〜１０ｈ，３５．３６……放熱部
１１，１６，１８，２６，３７…円錐面
１２，３９…………………………底面
１３，３８…………………………頂部
１４…………………………………曲面部
１４ｆ………………………………面取り部
１５，１７，１９，２７，３７…放熱部の側面
４０，４２…………………………凸条
４１，４３…………………………凹溝
４４，４５…………………………湾曲面 1a to 1e ………………………… Wiring board 2 …………………………………… Board body 3 …………………………………… Surface 4… ………………………………… Back side 5 …………………………………… Side side of the board body 6 …………………………………… Surface pad 8 …………………………………… 1st connection part 9, 33 ……………………………… 2nd connection part 10a-10h, 35.36 …… Heat dissipation part 11, 16, 18, 26, 37 ... Conical surface 12, 39 ………………………… Bottom surface 13, 38 ………………………… Top 14 …………………………… ...... Curved surface portion 14f ……………………………… Chamfered portion 15, 17, 19, 27, 37 ... Side surface of heat radiating portion 40, 42 ………………………… Projection 41, 43 ………………………… concave groove 44, 45 ……………… ......... curved surface

Claims

絶縁材からなり、互いに平行な表面および裏面と、該表面と裏面との間に位置する側面を有する基板本体と、
上記基板本体の表面上に形成された表面パッドと、
上記基板本体の内部に埋設された放熱部と、
上記表面パッドと上記放熱部とを接続する第１接続部とを備えた配線基板であって、
上記放熱部は、上記基板本体の表面側から裏面側に向かうに連れて平面視の断面積が大きくなる錐体形状を呈するか、あるいは、上記基板本体の裏面側から表面側に向かうに連れて平面視の断面積が大きくなる錐体形状を呈すると共に、
上記放熱部における角部には、曲面部あるいは平面からなる面取り部が形成されており、
平面視において、上記基板本体の表面に露出する上記第１接続部の面積は、上記表面パッドの面積よりも小さい、
ことを特徴とする配線基板。 A substrate body made of an insulating material and having a front surface and a back surface parallel to each other, and a side surface located between the front surface and the back surface;
A surface pad formed on the surface of the substrate body;
A heat dissipating part embedded in the substrate body;
A wiring board comprising a first connection part for connecting the surface pad and the heat dissipation part,
The heat dissipating part has a conical shape in which a cross-sectional area in a plan view increases from the front surface side to the back surface side of the substrate main body, or from the back surface side to the front surface side of the substrate main body. While presenting a cone shape with a large cross-sectional area in plan view,
A chamfered portion formed of a curved surface portion or a flat surface is formed at the corner portion of the heat dissipation portion,
In plan view, the area of the first connection portion exposed on the surface of the substrate body is smaller than the area of the surface pad.
A wiring board characterized by that.

錐体形状を呈する前記放熱部の頂部側が、前記第１接続部に接続されている、
ことを特徴とする請求項１に記載の配線基板。 The top side of the heat radiating part exhibiting a cone shape is connected to the first connection part,
The wiring board according to claim 1.

錐体形状を呈する前記放熱部の円錐面または複数の側面には、該放熱部の頂部側から底面側に向かって延びる複数組の凹溝および凸条が形成されている、
ことを特徴とする請求項１または２に記載の配線基板。 A plurality of sets of concave grooves and ridges extending from the top side to the bottom side of the heat dissipating part are formed on the conical surface or the plurality of side surfaces of the heat dissipating part exhibiting a cone shape.
The wiring board according to claim 1 or 2, wherein

錐体形状を呈する前記放熱部の円錐面または複数の側面は、該放熱部の内側に凹む湾曲面を有している、
ことを特徴とする請求項１または２に記載の配線基板。 The conical surface or the plurality of side surfaces of the heat dissipating part exhibiting a cone shape have a curved surface recessed inside the heat dissipating part.
The wiring board according to claim 1 or 2 , wherein

錐体形状を呈する前記放熱部の底面側には、前記基板本体の裏面あるいは側面に他端が露出する第２接続部の一端が接続されている、
ことを特徴とする請求項１乃至４の何れか一項に記載の配線基板。 One end of a second connection portion, the other end of which is exposed on the back surface or side surface of the substrate body, is connected to the bottom surface side of the heat radiating portion exhibiting a cone shape.
The wiring board according to any one of claims 1 to 4 , wherein the wiring board is provided.